Title:
One-part adhesive composition for adhering polymeric roofing membranes to roof deck substrates
Kind Code:
A1


Abstract:
The present invention relates to a one component adhesive for adhering polymeric membranes to roof substrates. The one component adhesives are comprised of the reaction product of an isocyanate and a mixture of a compound having an average of two isocyanate reactive functional groups and a compound having an average of three isocyanate reactive functional groups.



Inventors:
Chen, Gang-fung (Dublin, OH, US)
Chang, Chung-ying (Dublin, OH, US)
Application Number:
11/061772
Publication Date:
11/10/2005
Filing Date:
02/18/2005
Primary Class:
International Classes:
C09J4/00; E04B5/00; E04D5/14; E04G23/00; (IPC1-7): E04B5/00; E04G23/00
View Patent Images:



Primary Examiner:
NILAND, PATRICK DENNIS
Attorney, Agent or Firm:
Ashland LLC (Bridgewater, NJ, US)
Claims:
1. A one component, moisture curable, isocyanate terminated adhesive composition for adhering a polymeric sheet to a substrate, comprising the reaction product of; A. an organic isocyanate containing compound having an average isocyanate functionality of at least two. B. A mixture of a compound having an average of two isocyanate reactive functional groups and a compound having an average of three isocyanate reactive functional groups, C. optionally a tackifier, and D. optionally a solvent where the equivalent ratio of the compound having an average of two isocyanate reactive functional groups and the compound having an average of three isocyanate reactive functional groups is from about 16:1 to about 1:4.

2. The composition of claim 1 further comprising, a catalyst.

3. The composition of claim 1 further comprising, an inhibitor.

4. The composition of claim 1 further comprising, a plasticizer.

5. The composition of claim 1 further comprising, a flow control agent.

6. The composition of claim 1 further comprising, a wetting agent.

7. The composition of claim 1 further comprising, a polyisocyanate crosslinker.

8. The composition of claim 1 wherein the organic isocyanate containing compound is a polymeric diphenylmethane diisocyanate.

9. The composition of claim 1 wherein the mixture comprises a simple diol and a simple triol.

10. The composition of claim 1, wherein the mixture comprises a polyether polyol, a polyester polyol, a hydroxy terminated hydrocarbon or mixtures thereof.

11. The composition of claim 1, wherein the tackifier is one or more rosin derivatives, coumarone-indene resins, terpene oligomers, aliphatic petroleum resins or alkyd modified phenolics.

12. The composition of claim 1, wherein the solvent is one or more aromatic hydrocarbons, aliphatic hydrocarbons, ketones, esters, or halogenated hydrocarbons.

13. A composite roof structure, comprising; A. a roof deck, B. a polymeric sheet, and C. between the roof deck and the polymeric sheet the cured residue of a one component, isocyanate terminated adhesive composition, comprising the reaction product of; i. an organic isocyanate containing compound having an average isocyanate functionality of at least two. ii. A mixture of a compound having an average of two isocyanate reactive functional groups and a compound having an average of three isocyanate reactive functional groups, iii. optionally a tackifier, iv. optionally a polyisocyanate crosslinker, and v. optionally a solvent where the equivalent ratio of the compound having an average of two isocyanate reactive functional groups and the compound having an average of three isocyanate reactive functional groups is from about 16:1 to about 1:4.

14. The roof structure of claim 13, wherein the polymeric sheet is selected from the groups consisting of chlorosulfonated polyethylene, polyvinyl chloride, thermoplastic polyolefin, copolymer alloy membrane and ethylene-propylene-diene-monomer.

15. The roof structure of claim 13, where in the mixture is one or more polyether polyol, polyester polyol or hydrocarbon polyol.

16. The roof structure of claim 13, wherein A. the polymeric sheet is EPDM, B. the mixture comprises; i. a polyether polyol, ii. a hydrocarbon polyol, and iii. optionally a polyester polyol, C. a tackifier, D. a solvent, and E. optionally a polyisocyanate crosslinker.

17. The roof structure of claim 13, wherein

18. The roof structure of claim 13, wherein, A. the polymeric sheet is PVC, and B. the mixture comprises; i. a polyether polyol, and ii. a polyester polyol.

17. The roof structure of claim 13, wherein, A. the polymeric sheet is TPO, and B. the mixture comprises; i. a polyether polyol, ii. a polyester polol, and iii. a hydrocarbon polyol, and C. optionally a solvent.

18. A method of preparing a composite roof structure, comprising; adhering a polymeric sheet to a roof deck with the cured residue of the adhesive of claim 1.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part of U.S. provisional application 60/546,437; filed Feb. 20, 2004.

BACKGROUND OF THE INVENTION

The present invention relates to an adhesive composition and applications thereof, and more specifically, to a one-part (1 K), moisture curable, isocyanate terminated adhesive composition for bonding polymeric roofing membranes to the surface of roof-deck substrates.

Roofs are a basic element of shelter from inclement weather. A typical modern design includes a structure to carry load, insulation to control heat flow, a barrier to control air and vapor flow, and a roofing element to prevent water penetration. There are various types of roofing products, including asphalt, wood, tile, and membranes. Among membranes, the so-called single-ply roofing membrane is of a particular importance. The name “single-ply” roofing membrane is derived from the installation technique wherein a single-ply sheet membrane is applied over the roofing deck/substrate, giving continuous watertight coverage. These flexible membranes offer lightweight, excellent chemical and weather resistance, ease of application and repair, and multiple colors.

The flexible single-ply membranes are manufactured in three forms: reinforced, non-reinforced, and fleece-back sheet. They are made from a wide variety of polymers. These include chlorosulfonated polyethylene (CSPE, a synthetic rubber manufactured by DuPont, is marketed under the name Hypalon), ethylene-propylene-diene monomer (EPDM), copolymer alloy membranes (CPAs), poly (vinyl chloride) (PVC), and thermoplastic polyolefin (TPO). The membranes come in both reinforced and non-reinforced constructions. The membrane thickness typically runs from 0.8-1.5 mm and widths typically in the range of 1.5-4.6 meters.

The greater portion of polymeric roofing membrane is installed using mechanically fastened roofing system; a lesser portion is installed in fully adhered applications. In the fully adhered system, the substrate, i.e., insulation, cover board, etc that the polymeric roofing membrane is to be attached to is fully adhered or mechanically fastened to the deck. The membrane is then adhered to the surface of the substrate. The typical method for adhering the membrane to the substrate is by applying a contact adhesive to both the membrane and substrate, rolling the membrane into place, and applying sufficient pressure to seat the roofing membrane on the substrate. Fully adhered systems can be installed on any slope. The fully adhered application offers a smooth surface that is easy to maintain and inspect, as well as excellent resistance on account of positive attachment. There are also one-sided applications where the membrane is rolled directly into the adhesive that has been applied to the substrate only.

At present, solvent-based contact adhesives are widely used for bonding polymeric roofing membranes to various roofing substrates. However, such adhesive contains a large amount of solvents, usually 70% to 75%. These solvents are typically aromatic or aliphatic hydrocarbons, such as toluene, xylene, hexane, heptane, and others, which present both health and fire hazards. Furthermore, these solvent-based contact adhesives are thermoplastic in nature and found to have a poor water resistance, particularly under hot aging conditions. Solvent-based adhesives are environmentally undesirable and subject to increasing regulations. On the other hand, there are also commercially available 100% solids two-part system for bonding PVC membranes to roof-deck structures. Examples of such systems are described in U.S. Pat. No. 6,130,268, DE. Pat. 29,920,721, U.S. Pat. No. 5,872,203, U.S. Pat. No. 4,672,100 and U.S. Pat. No. 5,951,796. JP Pat. 08260708 and JP Pat. 11081576.

With regard to one-part polyurethane systems, most commercial adhesives are solvent based, low solids, thermoplastic resins. U.S. Pat. No. 5,421,876 disclosed a one-part adhesive composition, which uses a dispersion of asphalt in a polyurethane prepolymer. U.S. Pat. No. 6,305,143, disclosed the use of reversible blocked catalyst for one-part, moisture curable, foaming polyurethane adhesive. The adhesive compositions described in this patent are based on the use of “reversibly blocked catalyst”.

It is well known that desirable adhesive characteristics are dictated by the application requirements. Structural adhesives require the fully cured adhesive to be more rigid and more elastomeric than semi or non-structural adhesives.

Furthermore, adhesive performance depends on factors governed by application requirement. Performance is also highly dependent on the substrate and membrane to be bonded. The ideal adhesive for bonding polymeric membrane to either plywood or roof-deck substrates such as isocyanurate board should possess a low viscosity, allowing the adhesive to flow and wet the substrate. During curing, the adhesive should also possess some degree of foaming to promote the spread of the adhesive thus resulting in more extensive contact with the substrate and membrane. A structural adhesive also needs to exhibit good viscoelastic properties.

It is an object of the present invention to provide improved bond strength between polymeric membranes and substrates including plywood or isocyanurate board for roof-deck construction. Another important object of the present invention is to develop an adhesive that can be applied simply with minimal labor cost. The above concept and objectives led to the discovery of the present invention. While not wishing to be bound by any theory it is believed that a high degree of molecular entanglement with low crosslink density can be controlled by the proper selection of the equivalent ratio of isocyanate reactive functional group containing compounds used in a reaction with polyisocyanates in the adhesive formulation. By manipulating the equivalent ratio, structural adhesive formulations for a broad range of membrane-substrate combinations can be formulated.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to one component, moisture curable, isocyanate terminated adhesives for polymeric roofing membranes. The adhesives are comprised of the reaction product of an organic isocyanate having an average isocyanate functionality of at least two, and a mixture of a compound having an average of about two isocyanate reactive groups and a compound having an average of about three isocyanate reactive groups. The equivalent ratio of the compound containing an average of about two isocyanate reactive functional groups and the compound containing an average of about three isocyanate reactive functional groups is from 16:1 to 1:4. In addition the adhesive composition can contain a tackifier, a solvent and other ingredients typically used in the preparation of isocyanate based structural adhesives.

The invention also relates to composite roof structures and their preparation. The roof structures comprise a polymeric membrane, the roof deck, and an adhesive material. The roof deck may be any material that a roof deck can be made of such as metal, wood, cement, etc. or an old roof consisting of the roof deck and a covering such as built-up-roofing consisting of asphalt, fiber sheathing, such as felt and a granulated cap. The composite roof structure can also comprise a layer of insulation laid down before the polymeric sheeting is applied. The composite roof structure is prepared by applying the adhesive to the roof deck, the polymer sheet or both and setting the polymeric sheet in place on the roof deck. If multiple layers of roofing materials are used or in the case of edge overlap the polyurethane adhesive compositions can be used to adhere the multiple layers or edge overlap. The adhesive can be applied directly to insulating material such as isocyanurate board and the polymeric membrane placed directly on the insulating material.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to one component, moisture curable, isocyanate terminated adhesives for polymeric roofing membranes. The adhesives are comprised of the reaction product of an organic isocyanate having an average isocyanate functionality of at least two, and a mixture of a compound having an average of about two isocyanate reactive groups and a compound having an average of about three isocyanate reactive groups. The equivalent ratio of the compound containing an average of about two isocyanate reactive groups and the compound containing an average of about three isocyanate reactive groups is from 16:1 to 1:4. In addition the adhesive composition can contain a tackifier, a solvent, inhibitor, stabilizer, flow control agent, wetting agent, isocyanate crosslinker and other ingredients typically used in the preparation of isocyanate based structural adhesives. The invention also relates to composite roof structures comprising a roof deck or substrate, the moisture curable, isocyanate terminated adhesive of the present invention and a polymeric roofing membrane. Examples of organic isocyanate containing compounds having an average functionality of at least two include but are not limited to 2,4- and 2,6-tolylene diisocyanate; the various combinations of isomers for diphenylmethane diisocyanate (MDI) as well as the pure isomer forms; naphthathylene-1,5 diisocyanate; polyphenyl polymethylene polyisocyanate; triphenylmethane-4,4′,4′-triisocyanate; 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane; 2,4- and 2,6-hexahydrotolylene diisocyanate and mixtures of these isomers; hexahydro-1,3- and/or 1,4-phenylene diisocyanate; hexamethylene diisocyanate; 1,12-dodecane diisocyanate; cyclobutane-1,3 diisocyanate; cyclohexane-1,3 and -1,4 diisocyanate and mixtures thereof. The polyisocyanates may be reacted to form relatively high molecular weight polyisocyanates containing carbodiimide, allophanate, biuret, and uretdione groups. Preferred isocyanates include polymeric MDI (pMDI). The final content of the isocyanate in the adhesive composition can be as high as 19% by weight based on the total weight of the adhesive. Preferably the isocyanate used in the reaction with a mixture of a compound having an average of about two isocyanate reactive groups and a compound having an average of about three isocyanate reactive groups is present in the adhesive in an amount of from about 2% to about 17% by weight, more preferably from about 3% to about 15% by weight of the adhesive composition. An example of a preferred modified pMDI is Rubinate 9310 commercially available from the Huntsman Corp. Rubinate is a trademark of the Huntsman Corporation. A single isocyanate containing compound or mixture of said compounds can be used.

The organic isocyanate containing compounds used herein are reacted with a mixture of a compound having an average of two isocyanate reactive functional groups and a compound having an average of three isocyanate reactive functional groups. Examples of isocyanate reactive functional groups include hydroxyl, amine, thiol, epoxy, etc. Preferred are compounds containing hydroxyl groups (polyols). The polyols can be simple diols and triols such as ethylene glycol, 1,2-butanediol, or trimethylol propane; or polyether polyols, polyester polyols, hydroxyl terminated polymeric/elastomerics hydrocarbons known to those skilled in the art, such as hydroxyl terminated polybutadiene and hydrogenated, hydroxy terminated polybutadiene, and mixtures thereof.

In general the hydrocarbon polyols impart specific adhesion to low surface energy substrates such as EPDM and TPO. Hydrocarbon polyols suitable for the present invention include non-hydrogenated hydroxyl-terminated polybutadiene, hydrogenated hydroxyl-terminated polybutadiene, and hydrogenated dimer diol derived from dimerized fatty acid. The total addition level of the hydrocarbon polyol or their mixture is between 1 and 10% by weight based on the total weight of the adhesive; preferably, between 2 and 6%. Example of the non-hydrogenated, hydroxyl-terminated polybutadiene are Sartomer's Poly BD resins and Krasol LBH resins; and Nippon Soda's Nisso-PB G-series resins. Examples of hydrogenated hydrogenated hydroxyl-terminated polybutadiene are Sartomer's Krasol HLBH resins, Nippon Soda's Nisso-PB GI-series resins, and Mitsubishi Chemical's Polytail resins. An example of hydrogenated dimer diol is Pripol 2023 from Uniqema.

The compound containing an average of two isocyanate reactive functional groups and the compound containing an average of three isocyanate reactive funtional are used in an equivalent ratio of from 16:1 to 1:4 respectively. Preferably they are used in an equivalent ratio of from 6:1 to 1:2. The preferred isocyanate terminated adhesive compositions of the present invention are comprised of an isocyanate terminated prepolymer prepared by reacting an excess of an isocyanate with a mixture of polyols in an equivalent diol:triol ratio of from 16:1 to 1:4. A single diol, triol or a mixture of diol or triol compounds having an average functionality of about two and about three respectively can be used. Catalysts can also be useful in preparing the isocyanate terminated adhesive composition of the present invention. This is especially so when preparing isocyanate terminated polyurethanes. Particularly useful catalysts include dibutyltindilaurate and Jeffcat DM-70. DM-70 is a mixture of 70% of 2,2′-dimorpholinodiethylether (DMDEE) and 30% N,N′-dimethylpiperazine (DMP). DMDEE is a powerful catalyst used to promote isocyanate-water reaction used in blowing urethane foams, and DMP is a catalyst to promote isocyanate-isocyanate or isocyanate-urethane reaction as a gelling agent. Combinations of these factors help in promoting the green strength of the adhesive. The catalysts are typically added to aid in the formation of the prepolymer and to speed up the cure of the adhesive. When used catalysts are present in amounts of from 0.01% to 1.0% by weight, preferably about in amounts of from 0.01 to 0.5% by weight based upon the total weight of adhesive.

Tackifiers can also be used in the adhesive composition of the present invention. There are many types of commercially available tackifiers. Common tackifiers include rosin derivatives, coumarone-indene resins, terpene oligomers, aliphatic petroleum resins and alkyd modified phenolics. The preferred tackifiers for the present invention include phenol modified terpene resins and copolymers from unsaturated aromatic C-9/C-10 hydrocarbon and phenol. The addition level of total tackifiers is between 5 and 50% by weight based on the total weight of adhesive; preferably, between 10 and 30%. Examples of phenol modified terpene resins are Arizona Chemcal's Sylvares TP96, TP105, TP115, TP2019, and TP7042; they are all solids at room temperatures. Commercial copolymers from unsaturated aromatic C9/C10-hydrocarbons and phenol are available as liquids and solids. Examples of liquids include Novares LA300, LA700, and LA1200 from RUTGERS VFT AG. Examples of solids include Novares TNA120; and Sylvares 520, 525, and 600. Tackifiers can be post added after the reaction of the isocyanate and isocyanate reactive components is completed. Otherwise, tackifiers can also be added to the reaction mixture containing the isocyanate compound and the compounds containing isocyanate reactive moieties. Where these tackifiers are used in the mixture of isocyanate reactive compounds, they are included in the calculation for the equivalent of the compound having an average isocyanate functionality of two. Liquid tackifiers can be easily blended in with other liquid components. However, in order to facilitate the handling and mixing, the solid tackifiers need to be pre-dissolved in the mixture of isocyanate reactive compounds at elevated temperatures, or in a solvent at ambient temperatures.

A low level of polyisocyanate crosslinker in addition to the isocyanate reacted with the mixture of a compound having an average of about two isocyanate reactive groups and a compound having an average of about three isocyanate reactive groups, may be post added to the adhesive to increase the cohesive strength and heat resistance. These are compounds having an average isocyanate functionality of at least about 2.4. The typical amount of it used is about 5.0% or less by weight based on the total weight of adhesive; preferably, 0.5% to 3% is used. Such crosslinker may include an aromatic polyisocyanate based on methylene bis-diphenyldiisocyanate (MDI), or an aliphatic one based on hexamethylene diisocyanate (HDI). Bayer's products of Modur MR-series or Desmodur N-series are typical examples of aromatic and aliphatic polyisocyantes respectively.

A low level of solvent or solvent mixture, less than 25% by weight based on the total weight of adhesive, can be added to the composition to provide optimum adhesive viscosity for practical application. Preferably, 1 to 15% of solvent by weight based on the total weight of adhesive is used. Such solvents or solvent mixtures may include aromatic hydrocarbons, aliphatic hydrocarbons, ketones, esters, and halogenated hydrocarbons. Examples of aromatic hydrocarbons are toluene, xylene, and aromatic fluids such as Aromatic 100, 150, and 200 from Exxonmobil Chemical. Examples of aliphatic hydrocarbons are hexane, heptane, and aliphatic fluids such as Exxsol D40, D60; and Varsol 1, 18 from Exxonmobil Chemical. Examples of Ketones are methyl ethyl ketone, methyl amyl ketone, and diisobutyl ketone. Examples of esters are ethyl acetate, butyl acetates, 2-ethylhexyl acetate, Dibasic Esters (DBE from DuPont), alkyl propionates (UCAR from Dow), and ethylene glycol diacetate. An example of halogenated hydrocarbons is p-chlorobenzotrifluoride (PCBTF).

An inhibitor is used to retard the curing between isocyanate and moisture can be used in the present invention. Typical inhibitors include triphenyl phosphite (TPP), benzoyl chloride, benzene phosphorous oxydichloride, phosphorous oxychloride, phthaloyl chloride, and monophenyl dichlorophosphate (MPCP). A typical concentration used is between 0.01% to 0.5% based on the total weight of adhesive.

A flow control agent is used to enhance the flow and leveling characteristics of adhesives before they are cured. There are different types of flow control agents. The flow control agents preferred for the present invention are acrylic polymer types. The addition levels are between 0.1 and 3% by weight based on the total weight of the adhesive; preferably, between 0.1 and 0.5%. Example of flow control agents are Resiflow from Estron Chemical; and Modaflow, Multiflow from UCB Inc.

A wetting agent can be used to promote the adhesive wetting on the difficult-to-bond surfaces, such as TPO and EPDM. There are many commercial wetting agents. The preferred type of wetting agents for the present invention is silicone glycol copolymer. The addition levels are between 0.1 and 3% by weight based on the total weight of the adhesive; preferably, between 0.1 and 0.5%. Examples are Dow Corning Q2-5211, Q2-5212; and Silwet 408 of GE Silicones.

A defoamer may be used for foam control particularly when the viscosity of the reaction mixture is high during adhesive preparation. Defoamer such as Dow Corning antifoam 1400 may be added into reaction mixture for foam control. Typically, a very low concentration (0.01% or less) is sufficient to eliminate most foam.

A plasticizer with strong solvent action may be used to decrease the viscosity of the adhesive without compromising the adhesive performance. Suitable plasticizer includes diisobutyl phthalate, dibutyl phthalate, disioheptyl phthalate, or butyl benzyl phthalate (Santicizer® 160, from Ferro). Up to 30% by weight of plasticizer based on the total weight of the adhesive can be used.

The adhesive compositions may be poured, brushed, squeegied or rolled on a surface to be adhered. Preferably, bead(s) of the polyurethane adhesive composition are applied along the surface of a roof deck corresponding to the position of the overlaying roofing material; or if multiple layers of roofing materials are used adhesive is applied to each layer in the multiple layer composite roof structure. The adhesive can be applied directly to the old surface of existing composite roof structures. In this case the adhesive is applied directly to the existing surface. Pressure that is sufficient to seat the roofing material in the polyurethane adhesive is applied.

For purposes of the invention when the generic term “compound” is used in reference to the various components of the isocyanate terminated adhesive it includes oligomers, polymers, etc. The article “a” when used herein means one or more than one. Following are examples of the invention. The examples are illustrative in nature and are not to be construed as limiting.

Definitions For General Components Used In The Bonding Adhesives For Roofing
Membranes
CommercialCommercial
ComponentsNameSourceChemical Description
IsocyanateRubinate 9310HuntsmanLow functional modified liquid MDI
(Methylene bisphenyl isocyanate)
PolyetherPoly-G 20-56Arch Chemicals,Polypropylene ether diol, MW 2000
polyolAcclaim 3205BayerPolyether copolymer diol based on
propylene oxide and ethylene oxide,
MW 3000
Poly-G 20-112Arch ChemicalsPolypropylene ether diol, MW 1000
AcclaimBayerPolypropylene ether triol capped with
6320Nethylene oxide, MW 6000
Acclaim 6300BayerPolypropylene ether triol, MW 6000
Pluracol 726BASFPolypropylene ether triol, MW 3000
PluracolBASFPolypropylene ether triol, MW 2500
TP2540
PluracolBASFPolypropylene ether triol, MW 4000
TP4040
PolyesterLexorezInolex ChemicalA proprietary polyester polyol based
polyol1721-65Pon adipic acid and mixed glycols,
#OH = 65
Lexorez 1640-InnolexA proprietary polyester polyol based
150Chemicalon adipic acid and mixed glycols,
#OH = 150
Lexorez 1180-InnolexA proprietary polyester polyol based
35Chemicalon adipic acid and mixed glycols,
#OH = 35
Lexorez 1180-InnolexA proprietary polyester polyol based
120Chemicalon adipic acid and mixed glycols,
#OH = 120
HydrocarbonPoly bd R-SartomerHydroxy-terminated polybutadiene,
polyol45HTLOMW 2000
GI-1000, -2000,Nippon SodaHydrogenated hydroxy-terminated
-3000polybutadiene, MW 1000, 2000, 3000
Krasol HLBH-Sartomer.Hydrogenated hydroxy-terminated
P 3000polyolefin MW 3000
Pripol 2033UniqemaHydrogenated dimerized fatty acid
diol
TackifierSylvares TPArizonaTerpene phenolic resin, softening
96point 95° C.
Sylvares TPArizonaTerpene phenolic resin, softening
7042point 147° C.
Sylvares 520ArizonaPhenol-modified copolymer of
styrene and alpha methyl styrene,
softening point 75° C.
Novares TNARUTGERS VFTA solid resin, polymers from C9-
120AGunsaturated hydrocarbons and
phenol, softening point 120° C.
Novares LARUTGERS VFTA liquid resin, polymers from C9-
700AGunsaturated hydrocarbons and
phenol
CrossLinkerMondure MRBayerAromatic Polyisocyanates
Desmodure NBayerAliphatic Polyisocyanates
DefoamerD-1400Dow CorningA silicone foam control agent
CatalystDABCO T-12Air ProductsLiquid organotin, dibutyltin dilaurate
JEFFCAT DM-Huntsman70% 2,2′-dimorpholinodiethylether,
7030% N,N-dimethylpiperazine
JEFFCATHuntsman2,2′-dimorpholinodiethylether
DMDEE
PC CAT 1NitroilDimorpholinopolyethyleneglycol
KSC
InhibitorWeston TPPCromptonTriphenyl phosphite
MPCPAkzo NobelMonophenyl dichlorophosphate
FlowResiflow LEstron ChemicalAcrylic polymer
Control
Agent
WettingQ2-5211Dow CorningSilicone glycol copolymer
agent
PlasticizerSanticizer 160FerroButyl benzyl phthalate
SolventTolueneExxonmobil
XyleneExxonmobil
Aromatic 100ExxonmobilHeavy aromatic fluid
Aromatic 150ExxonmobilHeavy aromatic fluid
Hexane
Heptane
Exxsol D40Exxonmobil‘De-aromatized’ aliphatic hydrocarons
Exxsol D60Exxonmobil‘De-aromatized’ aliphatic hydrocarons
Methy n-amylEastman
ketone
Butyl acetaesDow, Lyondelln-Butyl or t-Butyl
UCAR AlkylDown-propyl, n-butyl, or n-pentyl
propionates
PCBTFSpecialp-Chlorobenzotrifluoride
Materials

EXAMPLE 1

Synthesis of One Component (1-K) Adhesive

Adhesives were synthesized according to the formulations shown in Table 1. In a typical reaction procedure, Rubinate 9310, polyols (Acclaim 6320, polyol 033-192, Lexorez 1721-65P), and D-1400 defoamer were charged into a 3-neck reaction flask. Initial reaction was carried out at ambient temperature under nitrogen blanket with mechanical agitation. A mild exothermic temperature to 28° C. to 32° C. was usually observed in 30 minutes. A catalyst, T-12 was added and an immediate exothermic temperature to 45° C. to 48° C. was usually observed. The reaction was allowed to proceed for additional 2 hrs at 50±2° C. MPCP was added to the reactor and additional 10 minutes agitation was provided before the product was unloaded.

The concentration of pMDI (Rubinate 9310) was calculated in such a way that the final NCO content was about 10%, 12%, and 14%. It can be seen that as the NCO content increases, the viscosity decreases. It should be noted that there was no apparent viscosity increase for all three adhesives after ambient temperature aging for 3 weeks.

TABLE 1
Formulation of 1-K Adhesive
Ingredient6788-149C6788-151A6788-151B
Rubinate 9310158.11201.2255.4
Acclaim 6320N35.1835.1835.18
Polyol 033-19270.2470.2470.24
Lexorez 1721-65P110.30110.30110.30
T-120.770.840.94
MPCP0.961.041.18
Theor. NCO %101214
Vis. (cps), 2 days22,00013,3007,200
Vis. (cps), 3 wks20,90013,5007,400

The bond strength of adhesive was evaluated in the laboratory by applying strips of adhesive on the surface of plywood (3-ply) and forming a laminate by pressing a polymeric roofing membrane in place. The laminated assemblies were then allowed to stand at ambient temperature and the bond strength was determined by 180° peel at a speed of 2′ per minute using an Insertion instrument (Model 1011).

One set of the laminated assembly was tested at ambient temperature at different time (RT/RT). The rest of the laminated assemblies were allowed to stand at ambient temperature for one week before placing under different aging conditions. The condition 15° F./RT indicates the assembly has been aged at 15° F. and tested at ambient temperature. The condition 158° F./RT indicates the assembly has been aged in an oven at 158° F. and tested at ambient temperature. The condition 158° F./158° F. indicates the assembly has been aged in an oven at 158° F. and tested hot at around 150° F. to 160° F.

The bond strength of the resulting adhesives from Table 1 was determined along with a commercial control (Plibond PB 1835, a solvent-based contact adhesive) and shown in Table 2. It can be seen that these adhesives developed an excellent good strength (10 pli to 14 pli) after aging, comparable to that of the control. The most intriguing result about these 1-K adhesives is the excellent hot peel (158° F./158° F.), relative to the commercial control.

TABLE 2
Bond strength (180° Peel, pli) of 1-K Adhesives
To John Manville PVC & Plywood
BN (Adhesive)
6788-149C6788-151A6788-151B(PB 1835)
RT/RT
24 hr000
 3 days3.5 C2.6 C0.9 C8.0 C
 1 wk6.6 C7.3 C6.8 C13.8 C 
 2 wk8.1 C4.0 C4.9 C14.0 C 
 3 wk7.4 C8.6 C8.0 C6.9 C
 4 wk7.5 C8.5 C7.1 C5.7 S
15° F./RT
 3 days6.5 C12.5 C 6.2 C12.7 C 
 1 wk6.8 C8.2 C5.2 C9.5 C
 2 wk7.8 C11.3 C 8.3 C8.6 C
 3 wk3.3 C10.5 C 7.1 C5.7 C
 4 wk7.5 C8.5 C5.5 C4.3 C
158° F. H2O/RT
 3 days2.2 C6.5 C4.7 C2.0 C
 1 wk1.9 C5.3 C5.7 C1.6 C
 2 wk1.9 C2.8 C6.1 C4.0 C
 3 wk2.0 C4.0 C5.7 C1.8 C
 4 wk4.3 C4.6 C5.4 C2.9 C
158° F./158° F.
 3 days5.6 C6.6 C4.6 C2.1 C
 1 wk4.3 M4.4 C6.2 C0.7 A
 2 wk5.5 C4.6 C4.3 C0.5 M
 3 wk5.0 M6.3 C2.4 C1.3 C
 4 wk4.5 C6.1 C2.9 C1.3 A
158° F./RT
 3 days5.3 C14.5 C 13.2 C 3.9 S
 1 wk10.3 C 11.4 C 10.6 C 13.4 S 
 2 wk6.8 C12.3 C 10.4 C 11.8 C 
 3 wk5.6 C9.9 C11.6 C 7.2 C
 4 wk5.2 C12.7 C 11.1 C 12.4 C 

Notes:

A denotes adhesive failure mode,

C denotes cohesive failure mode,

S denotes substrate (plywood) failure and

M denotes a mix of adhesive and cohesive failure mode.

EXAMPLE 2

Strength Development Using Additional Catalysts

In order to facilitate the speed of cure with the 1-K adhesive, an additional catalyst 2,2′-dimorpholinodiethylether (DMDEE) at different concentrations was incorporated into 6788-149C (from Table 1). The formulation of these 1 component adhesives and their strength development are shown in Table 3. It can be seen that as the additional catalyst concentration increased, the cure speed increased. However, if the catalyst concentration was too high (such as 1%, 6928-144D), the bond strength decreased after 6 hrs of cure. It was observed that as the catalyst concentration increased, the degree of foaming increased.

The above results demonstrate that although catalyst levels can vary significantly an ideal added catalyst concentration should not exceed about 1%.

TABLE 3
RT Strength (180° Peel, pli) Development of 6788-149C
Containing an Additional Catalyst (DMDEE)
To John Manville PVC & Plywood
BN
6788-
162A6788-162B6788-162 C6788-162D6828-144D
Additional Catalyst (%)
DMDEEDMDEEDMDEEDMDEE
(0)(0.25)(0.375)(0.50)(1.0)
 1 hr00000
 2 hr0002.5A1.6M
 3 hr000.5M4.4M3.4M
 4 hr001.8M5.5M3.8M
 6 hr004.8C6.9C3.8C
 8 hr005.3C8.5C2.9C
16 hr05.7C9.9C7.9S3.6C
20 hr02.5C8.9C6.5C3.9M
24 hr02.7C5.1C10.2C4.9C
32 hr0.5C6.2C4.6C9.8C4.8C
40 hr0.9C6.1C7.7C9.6C2.6C
48 hr3.2C4.5C3.9C8.7C5.5M
72 hr8.3C8.0C9.2C9.7C2.1C

Notes:

A denotes adhesive failure mode,

C denotes cohesive failure mode, and

M denotes a mix of adhesive and cohesive failure mode

To broaden the scope of the cure speed investigation, two additional catalysts were evaluated based on 6788-149C (Table 1) adhesive. This included T-12 and Jeffcat DM-70 at concentrations ranging from 0.25 to 0.50%. Data in Tables 4 and 5 shows the strength development of these 1-K adhesives. It can be seen that these two additional catalysts promote the strength development of an adhesive compared to the one lacking catalyst (6788-162A, Tables 4 and 5).

Among the three catalysts evaluated, the Jeffcat DM-70 is most effective in promoting the cure speed in the above formulations. It compares favorably with the commercial control, PB 1835 (a solvent base contact adhesive). With as low as 0.25% of Jeffcat DM-70, the adhesive delivered 2.1 pli after 3 hrs of aging at RT. In addition, Jeffcat DM-70 also promotes the strength at 72 hrs relative to the other catalysts.

TABLE 4
RT Strength (180° Peel, pli) Development of 6788-149C
Containing an Additional Catalyst (T-12)
To John Manville PVC & Plywood
BN
6788-
6788-162A162E6788-162F6788-162G6788-162K
Additional Catalyst (%)
T-12T-12T-12PB 1835
(0)(0.25)(0.375)(0.50)Control
 1 hr00000
 2 hr00000.3C
 3 hr000.5A00.4C
 4 hr001.1A1.6C0.3C
 6 hr02.1M2.4A3.3C0.7C
 8 hr01.3M2.6A1.7C1.6C
16 hr010.7C6.3C5.4C1.9C
20 hr04.9C5.0C6.5C1.2C
24 hr04.8C3.4C4.0C1.7C
28 hr0.1C10.7C6.4C5.7C6.4C
32 hr0.5C12.8C5.6C8.6C5.7C
40 hr0.9C1.3C7.4C7.4C5.5C
48 hr3.2C3.6C7.9C7.0C9.2C
72 hr8.3C4.1C7.3M8.1M6.7C

Notes:

A denotes adhesive failure mode,

C denotes cohesive failure mode, and

M denotes a mix of adhesive and cohesive failure mode

TABLE 5
RT Strength (180° Peel, pli) Development of 1-K Adhesives
Containing Additional catalyst (Jeffcat DM-70)
To John Manville PVC & Plywood
BN
6788-162A6788-162H6788-162I6788-162J6788-162K
Additional Catalyst (%)
DM-70DM-70DM-70PB 1835
(0)(0.25)(0.375)(0.50)Control
 1 hr00000
 2 hr000.7A0.6A0.3C
 3 hr02.1M2.0M2.3A0.4C
 4 hr05.2M2.5M3.4M0.3C
 6 hr08.1M5.3C5.1M0.7C
 8 hr08.2C5.2M3.4M1.6C
16 hr09.6C8.1C6.4C1.9C
20 hr06.1C4.0C6.8C1.2C
24 hr06.2C7.9C8.0C1.7C
28 hr0.1C8.8C4.6C6.2M6.4C
32 hr0.5C6.7C4.3C5.9M5.7C
40 hr0.9C9.0C7.1C5.6C5.5C
48 hr3.2C8.2C5.5C5.3C9.2C
72 hr8.3C8.7C12.7M11.4C6.7C

Notes:

A denotes adhesive failure mode,

C denotes cohesive failure mode, and

M denotes a mix of adhesive and cohesive failure mode

EXAMPLE 3

Performance Under Different Aging Conditions

The performance of adhesives described in Tables 3 to 5 from Example 2 was also evaluated in various aging conditions. Results shown in Tables 6 to 8 indicate that adhesive formulations containing Jeffcat DM-70 gave the best overall performance, particularly in the hot aging conditions (158° F./158° F. and 158° F./RT). The adhesive containing Jeffcat DM-70 out-performed the control (PB-1835). It is important to note that while higher concentration gave a faster cure speed, it may have an adverse effect on the shelf stability. While the adhesive without additional catalyst also gave a good performance, it did not have an adequate strength development as was described in Example 2.

TABLE 6
Performance (180° Peel, pli) of 1-K Adhesives
Containing Additional DMDEE
To John Manville PVC & Plywood
BN
6788-162A6788-162B6788-162 C6788-162D6788-162K
Additional Catalyst (%)
DMDEEDMDEEDMDEEPB 1835
(0)(0.25)(0.375)(0.50)Control
RT/RT
3 days8.3C8.0C9.2C9.7C6.7C
1 wk7.5C8.8C7.9M7.0C14.3C
2 wk9.2C4.0C5.9M7.6C8.0C
3 wk8.3C5.4C8.5M7.7C5.4C
4 wk6.1C7.3C5.5M8.0C3.1C
 15° F./RT
3 days10.8C4.0C11.6M10.2C4.9C
2 wk6.7C3.6C10.9M8.4C6.8C
3 wk7.2C4.5C12.1M8.7C6.1C
4 wk6.8C2.6C11.8C8.1C12.9C
158° F.
H2O/RT
3 days3.7C3.3C7.6C5.3C1.4C
2 wk1.3C2.1C4.0C5.4C2.0C
3 wk1.5C1.8C4.3C6.5C2.4C
4 wk1.4C2.8C6.5C4.9C2.8C
158° F./158° F.
3 days5.3A2.3C1.6A2.7C0.4C
2 wk3.2A2.6M1.4M2.1M1.1C
3 wk4.1A2.3A1.4A0.8A1.2C
4 wk4.5A4.1A1.7A1.7A0.9C
158° F./RT
3 days19.1C7.6S10.7C9.8C8.5C
2 wk19.2C8.8C9.0C6.8C7.3C
3 wk14.4C8.0C8.0C4.6M12.9C
4 wk17.4M8.3C8.0C6.1A12.2C

Notes:

A denotes adhesive failure mode,

C denotes cohesive failure mode, and

M denotes a mix of adhesive and cohesive failure mode

TABLE 7
Performance (180° Peel, pli) of 1-K Adhesives
Containing Additional T-12 To John Manville PVC & Plywood
BN
6788-162A6788-162E6788-162F6788-162G6788-162K
Additional Catalyst (%)
T-12T-12T-12PB 1835
(0)(0.25)(0.375)(0.50)Control
RT/RT
3 days8.3C4.1C7.3M8.1M6.7C
1 wk7.5C5.2M6.1M7.8M14.3C
2 wk9.2C6.3M6.1M7.5M8.0C
3 wk8.3C7.9A8.7M6.5M5.4C
4 wk6.1C7.5A6.1M9.7M3.1C
 15° F./RT
3 days10.8C6.2A10.7A7.6M4.9C
2 wk6.7C7.4A6.8M5.2M6.8C
3 wk7.2C7.4C5.3A7.0M6.1C
4 wk6.8C4.0S5.9M5.2M12.9C
158° F.
H2O/RT
3 days3.7C4.8C6.1C5.3C1.4C
2 wk1.3C3.2C6.6C3.1C2.0C
3 wk1.5C4.4C6.1C4.1C2.4C
4 wk1.4C4.9C5.3C3.0C2.8C
158° F./158° F.
3 days5.3A9.5A1.3A2.5A0.4C
2 wk3.2A1.5A1.0A1.0A1.1C
3 wk4.1A3.5A1.8A1.3A1.2C
4 wk4.5A1.5A1.7A1.6A0.9C
158° F./RT
3 days19.1C10.3M9.7C10.2M8.5C
2 wk19.2C8.9M8.4A4.2A7.3C
3 wk14.4C7.5M4.5A5.6A12.9C
4 wk17.4M4.1C4.5A4.4A12.2C

Notes:

A denotes adhesive failure mode,

C denotes cohesive failure mode, and

M denotes a mix of adhesive and cohesive failure mode

TABLE 8
Performance (180° Peel, pli) of 1-K Adhesives
Containing Additional Jeffcat DM-70 To John Manville PVC & Plywood
BN
6788-162A6788-162H6788-162I6788-162J6788-162K
Additional Catalyst (%)
DM-70DM-70DM-70PB 1835
(0)(0.25)(0.375)(0.50)Control
RT/RT
3 days8.3C8.7S, M12.7M11.4C6.7C
1 wk7.5C4.6S8.7M7.7C14.3C
2 wk9.2C11.9C11.1M8.1C8.0C
3 wk8.3C8.0C10.2M8.0C5.4C
4 wk6.1C3.9C9.4M7.0C3.1C
 15° F./RT
3 days10.8C15.2C11.9M14.7C4.9C
2 wk6.7C13.1M8.6A13.3M6.8C
3 wk7.2C14.3M9.7A11.8M6.1C
4 wk6.8C12.2C8.8M12.7M12.9C
158° F.
H2O/RT
3 days3.7C4.8C4.7C5.8C1.4C
2 wk1.3C3.0C3.2C4.1C2.0C
3 wk1.5C3.2C2.8C4.0C2.4C
4 wk1.4C3.7C2.3C4.0C2.8C
158° F./158° F.
3 days5.3A15.5S3.2C16.2PVC0.4C
2 wk3.2A6.3S3.3M2.5M1.1C
3 wk4.1A2.0A4.3C5.1C1.2C
4 wk4.5A8.1A2.6A7.5C0.9C
158° F./RT
3 days19.1C10.4C8.8C5.2C8.5C
2 wk19.2C11.5M11.0M11.7M7.3C
3 wk14.4C11.8M8.4M7.1M12.9C
4 wk17.4M13.7S/M11.8M7.5M12.2C

Notes:

A denotes adhesive failure mode,

C denotes cohesive failure mode,

S denotes substrate (plywood) failure,

PVC denotes PVC failure, and

M denotes a mix of adhesive and cohesive failure mode

EXAMPLE 4

Different Polyester Polyol & Concentrations

A series of 1-K adhesives containing different polyester polyols at different concentrations were synthesized. In a typical adhesive synthesis, ingredients shown in Tables 9 and 10 were charged in the sequence of Rubinate 9310, Acclaim 6320N, polyol 033-192, and Lexorez polyol into a three-neck reaction flask. The mixture was mixed at ambient temperature with mechanical agitation under nitrogen blanket. A mild temperature increase to 28° C. to 32° C. was usually observed in 30 minutes. A catalyst, T-12 was added and an immediate exothermic temperature to 45° C. to 48° C. was usually observed. The reaction was allowed to proceed for additional 2 hrs at 50±2° C. The inhibitor MPCP and Jeffcat DM-70 were added and mixed for 10 minutes before the product was decanted.

It should be noted that all formulations shown in Tables 9 and 10 have a theoretically calculated final NCO content of about 12%. One can see from data shown in Tables 14 & 15 that as the polyester polyol concentration in the formulation increases, the viscosity of the resulting adhesive increases, particularly for the Lexorez 1640-150.

The performance of the strength development data shown in Tables 9 and 10 demonstrate that adhesive contained polyester polyol such as Lexorez 1721-65P or Lexorez 1640-150 gave higher bond strength than the adhesive without polyester polyol.

TABLE 9
Formulation of 1-K Adhesives Containing Different Concentrations of Lexorez 1721-65P
Formulations
Ingredient7025-35A7025-35C7025-35B7025-35D7025-35E
Rubinate 9310141.41148.12201.2145.65146.06
Acclaim 6320N52.8235.1835.1820.0416.61
Polyol 033-192105.4770.2470.2440.0333.17
Lexorez 1721-055.15110.3094.28104.16
65P
D-14000.030.030.030.030.03
T-120.600.620.840.600.60
MPCP0.750.771.040.750.75
Jeffcat DM-700.750.771.040.750.75
Viscosity (cps)4,68010,44015,20016,08020,200
Calc. Lexorez017.926.331.434.7
1721-65P Conc.
Strength Development (pli) To John Manville PVC & Plywood
2 hrs0.9 A4.1 M5.8 M00
4 hrs2.2 A7.1 M8.0 M 3.5 M0
6 hrs2.6 A8.4 M7.9 C 5.4 C0
8 hrs2.6 A9.2 C8.9 C 5.4 C0
1 day7.4 M7.5 M9.6 C11.9 M15.4 C
2 days5.5 M5.7 M8.4 C11.7 M16.3 C
5 days4.5 M6.1 M6.5 C14.0 M18.0 M
7 days5.2 M5.1 M7.5 C10.0 M10.9 M

Notes:

All were based on the theoretically calculated NCO content of 12%.

A denotes adhesive failure mode,

C denotes cohesive failure mode, and

M denotes a mix of adhesive and cohesive failure mode.

TABLE 10
Formulation of 1-K Adhesives Containing Different Concentrations of Lexorez 1640-150
Formulations
Ingredient7025-35A7025-36A7025-36B7025-36C7025-36C
Rubinate 9310141.41153.3157.84161.6163.38
Acclaim 6320N52.8232.1423.0417.9714.73
Polyol 033-192105.4764.1745.9935.8829.41
Lexorez 1640-050.3872.2384.5392.38
150
D-14000.030.030.030.030.03
T-120.600.600.620.600.62
MPCP0.750.750.750.750.75
Jeffcat DM-700.750.750.750.750.75
Viscosity (cps)4,68015,04026,60030,00041,800
Calc. Lexorez016.824.128.230.8
1640-150 Conc.
Strength Development (pli) To John Manville PVC & Plywood
2 hrs0.9 A7.2 M 5.8 C1.4 A2.0 A
4 hrs2.2 A9.4 M 5.6 A2.7 A4.0 A
6 hrs2.6 A11.3 M 10.5 M6.6 A5.4 A
8 hrs2.6 A11.0 M 10.5 M7.6 M7.4 A
1 day7.4 M9.3 M11.5 M10.5 M 11.8 M 
2 days5.5 M8.6 M11.2 M7.8 M9.8 M
5 days4.5 M8.3 C 8.1 M7.0 M8.8 M
7 days5.2 M8.3 M 7.8 M7.4 M5.4 A

Notes:

All were based on the theoretically calculated NCO content of 12%.

A denotes adhesive failure mode,

C denotes cohesive failure mode, and

M denotes a mix of adhesive and cohesive failure mode.

EXAMPLE 5

Additional 1-K Adhesives

Additional adhesives were prepared using the procedure described in Example 4 with formulation shown in Tables 11 and 12. The inhibitor MPCP (0.25%) and Jeffcat DM-70 (0.25%) were added at the end of reaction and mixed for 10 minutes before the product was decanted.

It should be noted that the weight ratio of Acclaim 6320, Polyol 033-192 and Lexorez 1721-65P was kept the same (except 7025-19D, Table 12). The theoretical NCO content was calculated to be from 10% to 19.5%.

TABLE 11
Formulation of 1-K Adhesives
6788-174A7017-12A7017-12B
IngredientCharge (g)wt %Charge (g)wt %Charge (g)Wt %
Rubinate 9310553.441.98603.647.92766.253.83
Acclaim 6320N123.19.34105.58.38105.57.41
Polyol 033-192245.818.64210.716.73210.714.80
Lexorez 1721-386.129.28330.926.27330.923.25
65P
D-14000.650.050.160.010.150.01
T-122.700.202.520.202.820.20
MPCP3.360.253.120.253.540.25
Jeffcat DM-703.270.253.120.253.540.25
Approx. NCO101214
%
Initial Vis.26,80015,2007,500
(cps)

TABLE 12
Formulation of 1-K Adhesives
Ingredient7025-217025-19A7025-19B7025-19C7025-19D
Rubinate862458.0481.9510.1529.7
9310
Acclaim111.655.851.948.444.1
6320N
Polyol222.6111.3103.596.632.6
033-192
Lexorez349.8174.9162.6151.7138.2
1721-65P
D-14000.030.030.030.030.03
T-123.091.601.601.601.60
MPCP3.872.002.002.002.00
Jeffcat3.872.002.002.002.00
DM-70
Approx.14.515161719.5
NCO %
Initial Vis.7,2007,2604,2203,7001,780
(cps)

The performance of 1-K adhesive derived from the formulation shown in Tables 11 and 12 is shown in Tables 13 and 14. It can be seen that an outstanding performance is obtained. Except for the hot water soak (158° F. H2O/RT), the bond strength under other aging conditions exceeded 10 pli. A particular intriguing result is the hot peel (158° F./158° F.). It can be seen that the bond strength is high enough to cause substrate and PVC membrane failure.

With respect to the performance relationship with the NCO content, performance appears to be similar at NCO content of between 10% to 14% (Table 13). However, at 16% NCO or higher, the cure speed decreased evidenced from the strength development data shown in Table 14. At 16% NCO or higher, the strength development begins to decrease, along with performance under all aging conditions. Considering the application requirement and strength development, it appears that the ideal NCO content of 1-K adhesive is between 12% (7017-12A) to 15% (7025-19A), which produces adhesive with viscosity ranging between 15,200 cps to 7,260 cps.

TABLE 13
Bond strength (180° Peel, pli) of 1-K Adhesive
To John Manville PVC & Plywood
Adhesive
6788-174A7017-12A7017-12B
RT/RT
2 hrs000
4 hrs0 0.3 M 2.8 M
6 hrs 4.3 C 2.8 M 3.7 C
8 hrs 4.8 C 8.9 C 5.9 C
1 days 8.0 C11.6 C12.1 C
3 days13.4 C14.2 C15.2 C
1 wk 9.5 C13.2 C14.4 C
2 wk11.5 C14.8 C19.6 C
3 wk13.9 SF/C13.6 C27.7 SF/PVC
4 wk12.3 C12.8 C18.4 C
15° F./RT
1 wk20.6 C14.6 C12.9 C
2 wks17.7 C13.0 C15.0 C
3 wks18.3 C11/8 C10.6 C
4 wks 9.5 C13.7 C14.6 C
158° F. H2O/RT
1 wk 4.7 C 4.7 C 5.1 C
2 wks 4.0 C 4.5 C 3.0 C
3 wks 2.9 C 5.4 C 3.2 C
4 wks 3.4 C 5.6 C 3.0 C
158° F./RT
1 wk12.6 C8.2 C24.0 C
2 wks12.6 C14.7 SF/wood20.5 C
3 wks13.0 C15.1 C18.9 C
4 wks14.3 C14.6 C19.5 C
158° F./158° F.
1 wkPVC/SSF/PVCSF/PVC
2 wksPVC/SSF/PVCSF/PVC
3 wksPVC/SSF/PVCSF/PVC
4 wksPVC/SSF/PVCSF/PVC

Notes:

A denotes adhesive failure mode,

C denotes cohesive failure mode,

S denotes substrate (plywood) failure,

M denotes a mix of adhesive and cohesive failure mode, and

SF/PVC denotes a combinations of substrate and PVC failure mode.

TABLE 14
Performance (180° Peel, pli) of 1-K Adhesive
To John Manville PVC & Plywood
Adhesive7025-217025-19A7025-19B7025-19C7025-19D
RT Strength
 2 hrs 0 0 0 00
 4 hrs 4.1 C 2.0 C 0 00
 6 hrs 7.5 C 1.8 C 0.6 C 0.3 C0
 8 hrs 8.8 C 4.0 M 1.4 C 1.0 C0.1 C
24 hrs11.1 C10.9 M 6.3 C 4.6 M1.6 M
 2 days11.3 C 8.7 C 8.3 C 5.4 M2.4 M
 1 wk12.3 C17.2 C11.6 C14.8 C4.4 M
 2 wks19.8 C17.2 C10.0 C10.6 C3.7 C
 3 wks11.8 C16.8 C 9.7 C 9.2 C3.8 M
 4 wks17.8 C12.1 C10.4 C16.0 C5.0 C
15° F./RT
 1 wk19.7 C14.6 C11.8 SF 9.8 C2.7 M
 2 wk12.3 C12.5 C12.2 C10.3 C2.2 M
 3 wk 7.0 C11.3 C 6.6 C12.8 C2.5 C
 4 wk12.4 C 9.6 C 6.7 C10.8 C3.7 C
158° F.
H2O/RT
 1 wk 7.5 C 7.5 C 6.3 C10.6 C9.4 C
 2 wk 3.7 C 3.8 C 5.8 C10.1 C7.4 C
 3 wk 5.0 C 3.3 C 5.1 C 7.4 C4.8 C
 4 wk 5.8 C 4.9 C 7.2 C 8.9 C3.7 C
158° F./RT
 1 wk32.916.3 C29.931.57.2 C
SF/PVCSF/PVCSF/PVC
 2 wk27.815.4 C25.0 C24.5 C5.4 M
SF/PVC
 3 wk27.314.9 C22.7 C19.2 C6.9 M
SF/PVC
 4 wk27.8 C16.3 C18.3 C20.4 C6.7 C
158° F./158° F.
 1 wkSF/PVCSF/PVCSF/PVCSF/PVCSF/PVC
 2 wkSF/PVCSF/PVCSF/PVCSF/PVCSF/PVC
 3 wkSF/PVCSF/PVCSF/PVCSF/PVCSF/PVC
 4 wkSF/PVCSF/PVCSF/PVCSF/PVCSF/PVC

Notes:

A denotes adhesive failure mode,

C denotes cohesive failure mode,

S denotes substrate (plywood) failure,

M denotes a mix of adhesive and cohesive failure mode, and

SF/PVC denotes a combinations of substrate and PVC failure mode.

EXAMPLE 6

Effect of Jeffcat Concentration on Bond Strength Development

The 1-K adhesive 7017-12B shown in Table 11 contained Jeffcat DM-70 in amounts ranging from 0.25% to 1.0%. The bond strength development data shown in Table 15 appear to suggest a trend that the bond strength decreases as the Jeffcat DM-70 concentration increases.

TABLE 15
Bond Strength Development of 1-K Adhesives 7017-12B
Catalyzed by Different DM-70 Concentrations
Jeffcat DM-70%
0.250.500.751.0
2 hrs 1.8 M1.3 M1.3 M5.7 M
4 hrs 4.6 M3.8 M3.5 M5.7 M
6 hrs10.2 M9.3 M6.9 M7.3 M
8 hrs 9.3 M13.1 M 7.9 M6.5 M
1 day14.3 M11.1 M 11.1 M 6.3 A
2 days12.7 C9.4 M8.5 M8.7 A
5 days11.6 C7.8 M8.4 M7.7 M
7 days11.9 M6.4 M6.3 A5.5 M

Notes:

A denotes adhesive failure mode,

C denotes cohesive failure mode,

S denotes substrate (plywood) failure and

M denotes a mix of adhesive and cohesive failure mode.

EXAMPLE 7

Negative Pressure Uplift Resistance Test of 1-K Adhesive

Negative pressure test for wind uplift resistance: The system used for the test consisted of 2-inch thick Isoboard (isocyanurate insulation board) covered single ply 45-mil, bead-adhered membrane. The 4′×8′ Isoboard was held on steel deck using 12 fasteners.

The adhesive was applied through an extrusion gun as a continuous bead on isocyanurate insulation board. The distance between each line of bead was 12 inches. PVC membrane was then laid on top of the Isoboard and the entire assembly was allow to stand at ambient temperature for one week or longer before test. The test device consisted of a vacuum chamber with a dimension large enough to cover the entire roof deck.

In a typical testing procedure, a vacuum was drawn until the gauge reading of 30 lb/sq. ft (PSF) was reached. This vacuum pressure was then held for one minutes to see if the adhesive strength was strong enough to withstand this pressure. If it was, the vacuum pressure was increased to the next level at 15 PSF increment and held at that vacuum pressure for one minute. The test was continued until either insulation board fracture or the PVC membrane delaminated from the insulation board. A typical requirement in roofing industry is for the sample to withstand at least 90 lb/sq. ft (PSF) of uplift pressure. The results shown in Table 16 indicate that all the selected 1-K adhesives withstood 90 PSF of vacuum pressure and failed into 105 PSF. It is important to note that the failure mode for all adhesives tested is board fracture. This suggests that even higher bond strength should be expected.

TABLE 16
Negative Pressure Uplift Resistance Test Results (12″ OC)
To John Manville PVC & Insulation Board
7017-12A7017-12B7025-21
90 PSF, failed 15 sec into 10590 PSF, failed 29 sec
PSF, board fractureinto 105 PSF, board
fracture
90 PSF, failed 42 sec into 10590 PSF, failed 52 sec90 PSF, failed
PSF, board fractureinto 105 PSF, board20 sec into 105
fracturePSF, board
fracture
90 PSF, failed 7 sec into
105 PSF, board fracture

Notes:

The upper limitation of the vacuum pressure of the vacuum chamber is 255 PSF.

Generally the force to pull metal plate through insulation board requires 200-350 lb, and the force to pull screw through metal plate requires 600-900 lb.

EXAMPLE 8

Shelf Stability of 1-K Adhesive

An important consideration for 1-K adhesive is the shelf stability. The data shown in Table 17 are the results of 3-month aging stability study at both ambient temperature and at 50° C. for the three adhesives described in Table 11. Data in Table 17 indicates that there was a minimum increase in viscosity after three months aging at ambient temperature. The 50° C. aging is an accelerated aging test and it is generally accepted that one month of 50° C. aging is approximately equivalent to one year of aging at ambient temperature. It can be seen that there is minimal or no increase in viscosity after one month aging at 50° C. This result indicates that the 1-K adhesive disclosed has good shelf stability.

TABLE 17
Shelf Stability Determined by Brookfield Viscosity (cps)
6788-174A7017-12A7017-12B
Ambient Temperature Aging
Initial26,80015,2007,500
1 month24,40012,3009,600
2 months34,56015,8009,400
3 months31,04018,00010,400 
50° C. Aging
1 month22,60014,7008,400

EXAMPLE 9

Effect of Hydroxyl-Terminated Polybutadiene

Polybutadiene is known to have low glass transition temperature (Tg) as well as low surface energy. When polybutadiene is incorporated into an adhesive formulation, it presumably decreases the surface energy of adhesive, which would help adhesive wetting to other low energy surface substrates, such as thermoplastic olefin (TPO) membrane. Different concentrations of polybutadiene (BD-R45HTLO) were incorporated into a series of adhesives, which contained 23% Lexorez 1721-65P polyester polyol with theoretically calculated NCO content at about 12% were prepared according to formulation shown in Table 18. It can be seen that with incorporation of as low as 1% BD-R45HTLO in the formulation, the bond performance was increased immediately. This phenomenon is even more pronounced when Lexorez 1721-65P was replaced with a theoretically calculated NCO content of about 10-11% (Table 19). It can be seen from data shown in Table 2 that when 1% of polybutadiene (BD-R45HTLO) was incorporated in the formulation, the RT bond strength increased from <1 pli to 4-5 pli range.

It should be noted that formulation shown in Tables 18 and 19 contained about 23% of Lexorez polyester polyol.

TABLE 18
Formulation & RT Bond Strength of 1-K Adhesives
Steven's TPO Membrane/Plywood
Ingredient7025-82E7025-82F77025-1B7025-71C75025-1D
Rubinate47.9747.9747.9747.9747.97
9310
Acclaim8.588.588.588.588.58
6320N
Polyol17.1217.1217.1217.1217.12
033-192
Lexorez2323232323
1721-65P
BD-01.02.04.06.0
R45HTLO
T-120.200.200.200.200.20
MPCP0.250.250.250.250.25
Initial11,52011,60012,40014,00015,600
Vis. (cps)
Ambient Temperature Bond Strength (pli)
 1 day<0.11.4 A2.1 A2.6 A2.7 A
 4 days0.4 A2.2 A1.7 A2.9 A2.5 A
 7 days0.6 A2.8 A
10 days1.7 A2.9 A3.0 A
12 days0.9 A2.9 A1.8 A3.2 A3.0 A

Notes:

All data are average of 4 specimens.

TABLE 19
Formulation & RT Bond Strength 1-K Adhesives
Steven's TPO Membrane/Plywood
5025-
Ingredient7025-82G7025-71E7025-71F7025-71G71H
Rubinate47.9747.9747.9747.9747.97
9310
Acclaim8.588.588.588.588.58
6320N
Polyol 17.1217.1217.1217.1217.12
033-192
Lexorez2323232323
1640-150
BD-01.02.04.06.0
R45HTLO
T-120.200.200.200.200.20
MPCP0.250.250.250.250.25
Approx.10.810.710.410.1
NCO %
Initial39,80039,20042,80050,40057,200
Vis. (cps)
Ambient Temperature Bond Strength (pli)
 1 day<0.1 A
 3 days5.3 A4.6 A4.6 A3.6 A
 4 days  0.8 A
 5 days4.8 A4.2 A4.2 A3.4 A
 7 days  1.0 A
10 days5.3 A3.8 A4.4 A3.2 A
12 days  0.8 A4.4 A3.8 A3.9 A3.3 A

Notes:

All data are average of 4 specimens.

TABLE 20
Formulation & RT Bond Strength of 1-K Adhesives
Steven's TPO Membrane/Plywood
Ingredient7025-72A7025-72B7025-72C7025-72D
Rubinate 931054.6154.6154.6154.61
Acclaim 6320N1.681.681.681.68
Polyol 033-1923.363.363.363.36
Lexorez 1721-36.5636.5636.5636.56
65P
BD-R45HTLO1.02.04.06.0
T-120.200.200.200.20
MPCP0.250.250.250.25
Initial Vis. (cps)11,20014,40016,00016,800
Ambient Temperature Bond Strength (pli)
 3 day2.9 A2.5 A2.4 A2.5 A
 5 days3.2 A2.5 A1.6 A2.4 A
10 days3.4 A3.0 A2.2 A2.8 A
12 days3.5 A2.8 A2.2 A3.2 A

Notes:

All data are average of 4 specimens.

EXAMPLE 10

Adhesive NCO Content, Polyester Concentration, and Performance

Several 1-K adhesives with different theoretically calculated NCO content were prepared and shown in Table 21. Adhesives were formulated in such a way that the effect of polyester polyol concentration on performance could be explored. All formulation contained about 3% of polybutadiene. (BD-R45HTLO).

Data shown in Table 21 indicate that as the NCO content increased from 10% to 14%, the RT bond strength decreased. On the other hand, there was no advantage of replacing all the polyether polyol with polyester polyol. For example, a similar performance was obtained when one compares 7025-53A with 7025-53B, or 7025-53C with 53D, or 7025-53E with 53F. An important negative impact of replacing all the polyether polyol with polyester polyol is the substantially increased viscosity, particularly at the lower (10%) NCO content.

TABLE 21
Formulation of 1-K Adhesives at Different NCO Content
& RT Bond strength on Steven's TPO Membrane
Approx. NCO %
101214
Ingredient7025-53A7025-53B7025-53C7025-53D7025-53E7025-53F
Rubinate 9210226.1172.6287.82195.97143.91220.2
Acclaim 632051.4851.4825.74
Polyol 033-192102.72102.7251.36
Lexorez 1721-65P138.0210.9138.0189.1069.00165.97
BD-R45HTLO17.2814.6517.2813.138.6413.81
T-121.080.801.200.800.600.81
MPCP1.341.001.501.000.751.01
Lexorez 1721-65P %25.6552.7323.0047.2823.041.31
BD-R45HTLO %3.213.662.883.282.883.44
Viscosity (cps)19,20070,40013,32036,40013,64014,800
Ambient temperature Bond Strength (pli)
3 days8.8 M6.9 M5.0 M3.0 A4.3 M1.6 M
5 days7.9 M8.0 M3.4 M2.7 A3.8 M2.0 A
7 days7.8 M7.7 A4.1 M2.4 A4.3 M2.3 A

EXAMPLE 11

Adhesive Contained Lexorez 1640-150

Adhesives derived from Lexorez 1640-150 containing about 1% polybutadiene at different theoretically calculated NCO content were prepared. Their formulation and bond strength performance under different accelerated aging conditions (up to 4 weeks) are shown in Table 22. It can be seen that good performance was obtained.

Selected adhesives (7025-79A, B, and C from Table 22) were used to build a 5′×9′ roofing deck and tested their up-lift resistance using a negative pressure chamber, results shown in Table 23 indicated that these adhesive easily passed the minimum requirement of 90 lb/sq. ft.

TABLE 22
Formulation & Bond Strength Performance of 1-K Adhesives
Steven's TPO Membrane/Plywood
Ingredient7025-71E7025-79A7025-79B7025-79C
Rubinate 931047.9747.9751.2354.72
Acclaim 6320N8.588.588.588.58
Polyol 033-19217.1217.1217.1217.12
Lexorez 1640-23232323
150
BD-R45HTLO1.01.01.01.0
T-120.200.200.200.20
MPCP0.250.250.250.25
Initial Vis. (cps)39,20039,60035,20029,600
Bond Strength (pli)
RT/RT
1 day3.6 A3.4 A2.3 A2.1 A
4 days3.4 A4.3 A2.3 A2.3 A
7 days3.5 A3.7 A4.2 A2.1 A
2 wks4.7 A4.5 A3.5 A2.6 A
3 wks3.9 A3.7 A3.0 A3.2 A
4 wks3.9 A3.4 A2.6 A3.0 A
5 wks3.5 A3.1 A2.2 A3.1 A
Freezer/RT
7 days4.5 A3.2 A3.3 A2.9 A
2 wks2.7 A3.4 A2.9 A2.0 A
3 wks3.6 A3.1 A2.5 A2.1 A
4 wks3.4 A2.9 A1.7 A1.9 A
158° F. H2O/RT
7 days5.4 M9.1 M7.7 M7.0 M
2 wks4.7 M7.0 M6.0 M5.1 M
3 wks2.2 Fiber7.6 M6.2 M4.4 M
4 wks2.9 Fiber8.1 M5.6 M3.6 A
158° F./RT
7 days6.9 A6.4 A7.4 A6.7 A
2 wks4.7 M7.0 M6.0 M5.1 M
3 wks5.5 A5.9 A6.3 A5.1 A
4 wks6.2 A5.5 A4.3 A4.4 A
158° F./158° F.
7 days2.7 A2.4 A2.2 A2.6 A
2 wks1.6 A1.6 A1.0 A1.8 A
3 wks1.9 A1.6 A1.4 A1.9 A
4 wks1.6 A2.1 A2.0 A2.0 A

Note:

7025-79A was a repeat synthesis of 7025-71E.

TABLE 23
Trufast Test Results (Negative Pressure Uplift Resistance)
To TPO Membrane and Insulation Board
Bead
spacing
Adhesive(inch)Results
7025-12″12 fasteners, Passes 150 PSF, failed on its way to
79A165 PSF, adhesive failure.
7025-12″12 fasteners, passed 135 PSF, failed on its way to
79B150 PSF, board fracture, adhesive failure.
7025-12″12 fasteners, passed 120 PSF, failed on its way to
79C135 PSF, board fracture, adhesive failure.

Notes:

The upper limitation of the vacuum pressure of the vacuum chamber is 255 PSF.

Generally the force to pull metal plate through insulation board requires 200-350 lb, and the force to pull screw through metal plate requires 600-900 lb.

EXAMPLE 12

Adhesive Contained Lexorez 1180-35 and 1180-120

Adhesives (containing 1-2% of polybutadiene) derived from two different Lexorez polyester polyols were also identified to give good ambient temperature strength. The theoretically calculated NCO content of these adhesives ranges from 11.0 to 12.0%. It can be seen from data shown in Table 24 that these adhesives gave about 5 pli of bond strength at 10 days.

TABLE 24
Formulation of 1-K Adhesives used for Trufast Field Trial
Steven's TPO Membrane/Plywood
Ingredient7025-103A7025-103B7025-103C7025-103D
Rubinate 931042.2541.4444.8647.61
Acclaim 6320N8.588.588.588.58
Polyol 033-19217.1217.1217.1217.12
Lexorez14.218.798.798.79
1180-35
Lexorez8.7914.2114.2114.21
1180-120
BD-R45HTLO2.01.02.02.0
T-120.190.190.190.20
MPCP0.230.230.240.24
Initial Vis.22,80033,30030,80025,400
(cps)
Ambient Temperature Bond Strength (pli)
 1 day0.1 M1.5 M1.4 M0.3 M
 3 days3.8 A5.4 A5.0 A5.4 A
 6 days4.0 A5.5 A5.0 A5.9 A
10 days4.4 A5.5 A5.3 A5.2 A

Note:

All data are based on average of 4 specimens

EXAMPLE 13

Effect of Hydrogenated and None-Hydrogenated Polybutadiene

The adhesives were prepared as follows:

Both Lexorez 1180-35 and polybutadiene (BD-R45HTLO and Krasol HLBH P-3000) were warmed to flow and charged into a 2-liter, 3-neck, clean reaction flask equipped with mechanical agitation and nitrogen blanket. This was followed by sequentially charging the rest of raw materials, Acclaim 6320N, polyol 033-192, Lexorez 1180-120, Santicizer 160, and Rubinate 9310 under a nitrogen blanket. The components were mixed for 30 minutes & T-12 was added without any heating. The exothermic reaction drove the reaction temperature to about 40° C. to 45° C. in about 30 minutes. Heat was then applied cautiously to increase the temperature to 85° C. and the reaction temperature was held between 85-90° C. for 3 hrs until the results of NCO titration agree with the theoretically calculated value. The temperature was then reduced to about 50° C. to 55° C., then MPCP was added and stirred for 5 minutes. DM-70 was added and stirred for additional 10 minutes. The product was decanted as soon as the temperature went below 50° C. The product was stored under nitrogen.

The RT bond strength of these two series of adhesives is shown in Tables 24 & 25. It can be seen that adhesives derived from the hydrogenated polybutadiene (Krasol HLBH P-3000) gave higher bond strength than those derived from non-hydrogenated polybutadiene (BD-R45HTLO).

TABLE 24
Formulation and Performance of 1-K
Adhesives Containing BD-R45HTLO
Adhesives were Laminated in Between plywood/TPO
Ingredient7025-151A7025-151B7025-151C7025-151D
Rubinate 931044.5244.5246.6246.62
Acclaim 6320N9.279.278.928.92
Polyol 033-19218.5018.5017.7917.79
Lexorez19.6719.679.139.13
1180-35
Lexorez 5.185.1814.7714.77
1180-120
BD-R45HTLO2.162.162.082.08
T-120.200.200.200.20
MPCP0.250.250.250.25
DM-700.250.25
Santicizer 1605514.014.0
Initial vis. (cps)16,20014,10011,00011,900
RT Bond Strength (pli)
1 day0.3 A0.8 A01.4 A
5 days4.1 A2.4 A3.1 A2.9 A
1 wk3.7 A2.9 A3.2 A2.6 A
2 wks4.1 A3.4 A3.6 A3.3 A

Notes:

All bond strength data are based on an average of 4 specimens.

A denotes adhesive failure mode.

TABLE 25
Formulation and RT performance of 1-K
Adhesives Containing Krasol HLBH P-3000
Adhesives were Laminated in Between plywood/TPO
Ingredient7025-152A7025-152B7025-156A7025-156B
Rubinate 931044.5246.6244.5246.62
Acclaim 6320N9.278.929.278.92
Polyol 033-19218.5017.7918.5017.79
Lexorez19.679.1319.679.14
1180-35
Lexorez5.1814.775.1814.77
1180-120
Krasol HLBH2.162.082.162.08
P-3000
Santicizer 160514.07.017
T-120.200.200.200.20
MPCP0.250.250.250.25
DM-700.250.250.250.25
Initial vis. (cps)14,80016,90013,90010,700
RT Bond Strength (pli)
1 day4.5 A2.5 A1.3 A4.3 A
3 days3.6 A4.2 A
5 days6.2 A6.2 A
6 days4.9 A4.8 A
1 wk6.2 A6.6 A
8 days5.4 A4.8 A
2 wks6.0 A6.0 A

Notes:

All bond strength data are based on an average of 4 specimens.

A denotes the failure is adhesive failure.

EXAMPLE 14

High Temperature Reaction Procedure & Shelf Stability

Since the two polyester polyols (Lexorez 1180-35 & 1180-120) contain a secondary hindered hydroxyl group, an even higher reaction temperature (than 85-90° C., from Example 13) was used to make sure all hydroxyl groups are reacted from standpoint of shelf stability consideration.

Several adhesives with formulations shown in Table 3 were prepared as follows:

Both Lexorez 1180-35 and Krasol HLBH P-3000 were warmed to flow and charged into a 2-liter, 3-neck, clean reaction flask equipped with mechanical agitation and nitrogen blanket. This was followed by sequentially charging the rest of raw materials, Acclaim 6320N, polyol 033-192, Lexorez 1180-120, Santicizer 160, and Rubinate 9310 under a nitrogen blanket. The mixture was stirred for 30 minutes and T-12 was added without any heating. The reaction temperature rose to about 40° C. to 45° C. in about 30 minutes. Heat was then applied cautiously to increase the temperature to 90° C. and the reaction temperature held at about 90-92° C. for 3 hrs until the results of NCO titration were about 9.7% to 9.90%. The temperature was reduced to about 50° C. to 55° C., then add MPCP was and stirred for 5 minutes. DM-70 was added and stirred for additional 10 minutes. The product was decanted as soon as the temperature was below 50° C. The product was stored under nitrogen.

The resulting adhesives were monitored with their RT as well as accelerated aging stability by measuring the viscosity differences. Data shown in Table 28 indicate that room temperature as well as accelerated (50° C.) aging stability is acceptable. It should be noted that in some cases, incorporation of an additional 0.1% of MPCP appears to slightly improve the shelf stability.

TABLE 27
Formulations of Adhesive with Different Santicizer 160 Concentrations
Ingredient7025-175A7025-175B7025-175C7025-175D
Rubinate 931044.5244.5244.5244.52
Acclaim 6320N9.279.279.279.27
Polyol 033-19218.5018.5018.5018.50
Lexorez19.6719.6719.6719.67
1180-35
Lexorez5.185.185.185.18
1180-120
Krasol HLBH2.162.162.162.16
P-3000
Santicizer 1608.259.510.7512.0
D-14000.0350.0350.0350.035
defoamer
T-120.200.200.200.20
MPCP0.250.250.250.25
DM-700.250.250.250.25
Initial vis. (cps)12,16011,56011,00010,440

TABLE 28
Formulations of Adhesive Derived from 7025-152A
with Increased Santicizer 160
Adhesives were Laminated in Between Plywood/Steven's TPO
Ingredient7025-175A7025-175B7025-175C7025-175D
Accelerated aging stability (as is)
Initial vis. (cps)12,16011,56011,00010,440
RT aging, 1 wk13,56013,12012,36011,920
RT aging,14,28013,80013,44012,960
2 wks
RT aging,14,84014,72015,28013,960
4 wks
50° C. aging,19,84017,48013,80013,800
2 wks
50° C. aging,16,08016,40015,44015,000
4 wks
Accelerated aging stability (with additional 0.1% of MPCP added)
RT aging, 1 wk12,96012,52011,96011,720
RT aging,15,08014,20013,44013,400
2 wks
RT aging,14,28014,32013,96013,720
4 wks
50° C. aging,14,56017,60014,72013,680
2 wks
50° C. aging,16,40018,36014,52013,480
4 wks

EXAMPLE 15

Bond Strength Performance Under Different Aging Conditions

Data shown in Table 29 are bond strength performance of adhesives from Table 27. The most striking results shown is that when the individual adhesive was introduced with an additional 0.1% of MPCP, the bond strength was enhanced. Most importantly, the addition of an extra MPCP improves the 158° F./158° F. aging performance, evidenced by the fused TPO membrane with the plywood, which is very desirable.

TABLE 29
RT Bond Strength (pli) of Adhesive under Various Aging Conditions
(with & Without an Additional MPCP)
Adhesives were Laminated in Between Plywood/Steven's TPO
Ingredient7025-175A7025-175B7025-175C7025-175D
RT/RT
1 day3.8 A(3.6 A)2.3 A(2.7 A)4.4 A(3.7 A)3.5 A(4.9 A)
7 days4.5 A(4.8 A)5.2 A(4.4 A)4.7 A(5.2 A)4.2 A(5.9 A)
2 wks5.4 A(5.9 A)5.1 A(5.8 A)4.8 A(5.5 A)4.5 A(7.2 A)
3 wks4.6 A(5.3 A)5.4 A(5.9 A)5.6 A(5.6 A)5.1 A(7.0 A)
4 wks5.6 A(5.4 A)5.1 A(4.9 A)4.3 A(5.4 A)4.4 A(6.8 A)
5 wks5.1 A(6.4 A)5.1 A(7.3 A)5.2 A(6.6 A)5.7 A(8.4 A)
Performance under Accelerated Aging Conditions
Freezer/RT
1 wks4.4 A(5.1 A)4.3 A(6.8 A)4.8 A(7.1 A)4.8 A(12.5 A)
2 wks5.2 A(5.5 A)4.8 A(6.4 A)5.5 A(7.1 A)4.9 A(12.7 A)
3 wks5.0 A(6.2 A)5.0 A(7.6 A)5.9 A(8.4 A)5.9 A(13.4 A)
4 wks5.5 A(6.4 A)5.3 A(7.5 A)6.7 A(8.1 A)5.5 A(6.4 A)
158° F. H2O/RT
1 wks6.9 M(7.9 M)7.7 M(6.4 M)8.3 M(9.4 M)8.1 M(6.3 M)
2 wks7.7 M(7.3 M)8.1 M(6.8 M)7.8 M(9.8 M)7.6 A(7.6 M)
3 wks7.0 M(7.7 M)7.0 M(9.0 M)9.7 M(9.0 M)8.1 M(8.4 M)
4 wks10.2 M(11.1 M)9.0 M(11.8 M)10.2 M(12.0 M)9.3 M(14.1 M)
158° F./RT
1 wks7.6 A(8.9 A)7.9 A(11.7 A)7.5 A(10.9 A)7.4 A(9.1 A)
2 wks8.7 A(9.5 A)8.1 A(11.4 A)8.6 A(10.1 A)8.6 A(9.2 A)
3 wks9.2 A(10.7 A)9.4 A(13.9 A)10.0 A(12.2 A)9.1 A(10.6 A)
4 wks9.7 A(10.7 A)9.8 A(13.0 A)10.6 A(12.4 A)10.1 A(12.1 A)
158° F./158° F.
1 wks1.5 A(1.5 A)1.2 A(1.5 A, TPO)1.8 A(1.3 A)1.4 A(1.7 A)
2 wks1.5 A(1.5 A)1.2 A(1.3 A, TPO)1.9 A(1.1 A)1.9 A(1.7 A)
3 wks1.4 A(1.7 A)1.8 A(3.7 A, TPO)2.1 A(2.1 A)2.7 A(5.9 A, TPO)
4 wks1.4 A(1.5 A)1.4 A(1.7 A, TPO)1.8 A(1.4 A)2.1 A(2.6 A, TPO)

Notes:

All data are based on an average of 4 specimens.

Data in ( ) are adhesive samples with an additional 0.1% of MPCP added.

A denotes adhesive failure mode,

M denotes a mix of adhesive and cohesive failure mode, and

TPO denotes that failed within TPO membrane.

EXAMPLE 16

Adhesive Containing Extra MPCP

Results shown in Tables 28 and 29 indicate that adhesive containing an extra 0.1% MPCP helps to improve bond strength performance and potentially the shelf stability. Consequently, the 7025-175D formulation from Table 27 was modified in such a way that a higher MPCP concentration was incorporated. Consequently, adhesive 7117-180 with formulation shown in Table 30 was prepared using the same reaction procedure described in Example 14.

The formulation's, initial viscosity, RT & accelerated aging characteristics, and bond strength performance of adhesive 7117-180 are shown in Tables 30 and 31. Data shown in Table 30 indicate that the initial viscosity is in the range of 10,000 cps to 12,000 cps. The accelerated aging (50° C.) data indicate that after 8 weeks aging the viscosity increased to about 15,000 cps, which is acceptable.

Data shown in Table 31 are the bond strength performance of 7117-180 and its aged counter part, comparing to the control (Pliobond 2835, a commercial solvent-based adhesive). It can be seen that while adhesive 7117-180 did not perform as well as the control in the area of RT/RT and Freezer/RT. However, 5 pli to 7 pli of RT bond strength is considered to be strong enough to pass the uplift resistance test (90 lb/sq. ft) on 5′×9′ roof deck. Most importantly, the adhesive 7117-180 out-performed the control in the areas of hot performance, such as 158° F. H2O/RT, 158° F./RT, and 158° F./158° F. It should be noted that data shown in Table 31 indicate the aged adhesives (1 month at RT and 50° C. aging) performed comparably to the adhesive without aging. It is also important to note that some of the specimens showed substrate and TPO membrane failure, which is highly desirable.

TABLE 30
Formulation & Shelf Stability of 7117-180 Adhesive
IngredientTotal charge (g)
Rubinate 931019,219.64
Acclaim 6320N4,002.68
Polyol 033-1927,986.00
Lexorez 1180-358,494.20
Lexorez 1180-1202,236.10
Krasol HLBH P-3000934.12
Santicizer 1605,178.80
D-14001.21
T-1287.12
MPCP154.88
DM-70106.48
Aging Viscosity (in cps) Characteristics
RT aging, 1 wk10,920
RT aging, 2 wks12,960
RT aging, 3 wks14,440
RT aging, 4 wks13,080
50° C. aging, 2 wks16,880
50° C. aging, 4 wks14,520
50° C. aging, 8 wks15,360

TABLE 31
Bond Strength (pli) of Adhesive 7117-180 vs Control (Pliobond 2835)
Adhesives were Laminated in Between Plywood/Steven's TPO
7117-1807117-180Pliobond
(after aging(after aging2835
at RTat 50° C.2 sided
7117-180for 1 mo)for 1 mo)application
RT/RT
7 hrs0.5A1.5M
1 days5.1A6.2A
3 days8.4A3.8A11.9M
5 days6.9A4.1A15.8M
1 wk7.2A9.6A4.2A
2 wks7.8A5.1A5.1A9.6M
3 wks6.8A5.0A5.1A9.0M
4 wks6.8A5.9A5.4A9.0M
Performance under Accelerated Aging Conditions
Freezer/RT
1 wks5.4A4.7A5.0A12.1M
2 wks5.9A6.1A6.2A12.4A
3 wks6.0A6.1A6.3A11.0M
4 wks6.5A5.0A6.6A6.3M
158° F.
H2O/RT
1 wks7.9M7.0M7.9M4.3M
2 wks8.8C8.9M6.6M3.1M
3 wks8.0M9.3M9.3M5.0M
4 wks9.2M9.5M7.6M0
158° F./RT
1 wks11.0A8.3A7.8A8.5A
2 wks10.6A9.6A8.9A5.3A
3 wks11.4A11.7A9.8A5.3A
4 wks11.7A12.3A9.6A5.7A
158° F./
158° F.
1 wks2.5ASF/TPO1.9A2.2A
2 wks2.2ASF/TPO1.8A1.0A
3 wks2.0ASF/TPO2.2A1.7A
4 wks2.2ASF/TPO1.9A1.4A

Notes:

All data are based on an average of 4 specimens.

A denotes adhesive failure mode,

M denotes a mix of adhesive and cohesive failure mode, and

SF/TPO denotes substrate and TPO failure.

EXAMPLE 17

Negative Pressure Uplift Resistance Tests with Large Roof Deck

Two negative pressure uplift resistance test on a large roof deck (12′×16′ size) were conducted with the 7117-180 adhesive. The first test was on a roof deck with 20 fasteners per 4′×8′ board using 12′ OC. Approximately 7/8 gallon of adhesive was used, and this translated to approximately 220 ft2/gal. The test result indicates the performance met the minimum requirement of 90 lb/sq. ft rating with the failure mode of board fracture. This result indicate adhesive is strong enough to fracture the insulation board without adhesive delamination.

The second test was conducted on the same size of roof deck with an increased fastener density (24 fastener per 4′×8′ insulation board. On this test, an even wider adhesive spacing (18′ OC) was used and the purpose was to put more burdens on the adhesive. The uplift resistance test result indicated the performance also met the minimum requirement of 90 lb/sq. ft, together with the failure mode of board fracture.

The above results demonstrated adhesive exhibits a tenacious adhesion to TPO membrane and provided evidence that the product performs from a practical prospective.

EXAMPLE 18

Preparation of Adhesive for Bonding EPDM membrane

A general procedure to prepare the 1-K moisture curable EPDM bonding adhesive according to the formulation shown in Table 32 is as follows: All of the polyols including the tackifiers and additives (inhibitor, flow control agent, wetting agent) were charged into a reactor. The mixture was dehydrated at 100° C. under vacuum to remove any excessive moisture in the mixture. Then, all modified MDI was charged at once. The urethane reaction under an anhydrous atmosphere can proceed either with catalyst T-12 at 50° C. for about 1 hour, or with catalyst DMDEE at 90° C. for 1 to 3 hours. Isocyanate content titration was conducted to monitor the progress of the reaction. At the completion of the reaction, additional ingredients were added. Where a solid tackifier was post added it was pre-dissolved in a solvent that was used in the adhesive formulation. Finally, the adhesive product was discharged into a container and sealed under dry inert gas.

The NCO/OH ratio was 2.5 for Adhesive #1, #2, and #3 and was 3.0 for Adhesive #4 (Table 32). The first three adhesives used a liquid tackifier Novares LA 700 in the polyol mixture to react with polyisocyanate during the preparation of the prepolymer; and the solid tackifier Sylvares 520 or TP 96 was pre-dissolved in toluene then post added. The toluene content in the adhesive #3 was increased to 15% by weight to lower the adhesive viscosity to about 12,000 cps at 25° C. In Adhesive #4, both tackifiers were blended in with the polyol mixture. Therefore, the solid tackifier, Novares TNA 120, was dissolved in the polyol mixture during the dehydration process.

TABLE 32
Formulation of 1-K EPDM Bonding Adhesives
Adhesive #
1234Notes
PU Prepolymer #PU 6119PU 6120PU 6121PU 6196
NCO/OH2.502.502.503.00
NCO Content (calc), %3.683.683.702.15
Rubinate 9310293.41293.41273.395616.0Modified MDI
Acclaim 3205763.42763.42696.9414416.0Polyether diol
Acclaim 6320N127.24127.24116.164132.0Polyether triol
Lexorez 1721-65P1060.0Polyester polyol
GI-200042.0042.0039.00Hydrogenated OH-capped
Poly BD
Krasol HLBH P-30001060.0Hydrogenated OH-capped
Polyolefin
Poly bd R45HTLO28.0028.0039.00OH-capped Poly BD
Novares LA 700140.00140.00130.003002.0Liquid phenolic C-9 resin
Novares TNA 1205296.0Solid phenolic C-9 resin,
S.P. 120° C.
Q2-52112.802.802.6069.6Wetting agent
Resiflow L2.802.802.6069.6Flowing agent
TPP0.330.330.316.80Inhibitor, Triphenyl Phosphite
T-122.802.802.60Tin Catalyst
DMDEE80.00Amine Catalyst
Additional Ingredients
MPCP3.503.503.2540.00Inhibitor
Toluene155.56184.10272.13
Xylene2400.0
t-Butyl Acetate2400.0
Sylvares 520247.06Solid phenolic C-9 resin,
S.P. 75° C.
Sylvares TP 96247.06231.31Solid phenolic C-5 resin,
S.P. 95° C.
PC CAT 1 KSC3.503.504.55Amine Catalyst
Mondur MR Light352.0Aromatic polyisocyanate X-Linker
Total1813.411842.951816.8440000.0
Visc. at 25°, cps22,80032,08012,08014,570

EXAMPLE 19

Performance of 1-K EPDM Bonding Adhesive

Performance of adhesives described in Table 32 of Example 18 was evaluated under various accelerated aging and testing conditions shown in Table 33. It can be seen that, with an exception of hot water soak test (158° F. H2O/RT), Adhesive #2 and #3 generally showed good bond strength under various accelerated aging conditions; and Adhesive #4 showed good overall adhesion performance.

TABLE 33
Adhesion Strength (pli) in 180° Peel test
of 1-K EPDM Bonding Adhesives
(Firestone EPDM To Plywood)
Adhesive # (Of Table 32)
1234
RT/RT
1 day<0.5C<0.5C<0.5C0.5C
1 week2.0C4.6C1.9A6.9M
3 weeks2.8C5.8M1.4M3.5M
4 weeks2.2C5.5M1.9M4.5M
158° F./158° F.
1 dayNil0.1C0.1C0.4M
1 weekNil0.3M0.5C0.2M
3 weeks0.3M0.7A1.7M
4 weeks0.6A0.6A0.5M
158° F. H2O/RT
1 dayNil0.9C0.9C4.7C
1 weekNil0.3C0.4C4.8M
4 weeksNillNillNill2.2M
158° F./RT
1 day1.7C5.2C4.2C5.6C
1 week2.0C2.8A5.4C4.7C
3 weeks2.2A2.1A2.6A
4 weeks2.4A2.9A4.0M
Freezer/RT
1 day2.3C2.8A1.2A5.8M
1 week2.7C3.3A1.5A5.8M
3 weeks2.4C4.6M1.4A
4 weeks2.4C2.5A1.5C4.6M

EXAMPLE 20

Performance in Negative Pressure Uplift Resistance Test

Results of negative pressure uplift resistance test are summarized in Table 34. Adhesive #3 and #4 (Table 32) were rated 105 PSF (Pound Per Sq. Ft.) when adhesive beads were applied to only one side of the insulation board at the spacing of 12 inches on center.

TABLE 34
Summary of Negative Pressure Uplift Resistance
Test for 1-K EPDM Bonding Adhesives
Adhesive #Spacing ofUplift resistanceIsoboard
(OfRoofingadhesive beadsrating,fracture
Table 32)membrane(a)(lb/sq ft)(b)
1EPDM 6″ OC75No
(Firestone)
2EPDM 6″ OC105Yes
(Firestone)
3EPDM12″ OC105Yes
(Firestone)
4EPDM12″ OC105Yes
(Firestone)

Notes:

(a) A total of 1260 g of adhesive was applied onto 6′ × 10′ roofing deck for all four adhesives and adhesive beads were applied one side to the Isoboard

(b) 2″-thick 4′ × 8′ Isoboards and 12 fasteners per board were used

EXAMPLE 21

Shelf Stability of 1-K EPDM Bonding Adhesives

The shelf stability of the 1-K EPDM bonding adhesives illustrated in Table 32 were demonstrated by measuring their viscosity changes after aging at 50° C. over a 4 weeks period. The viscosity data are shown in Table 34 This information indicates that adhesives exhibited good shelf stability

TABLE 34
Shelf Stability of 1-K EPDM Bonding Adhesives by Viscosity (cps)
Measured at 25° C. ater 50° C. Aging
Tiem (Days) (Of Table 32)
07142128
Adhesive # 12280027240263002705027690
Adhesive # 23208039860387703910040840
Adhesive # 31208012990148701387019740
Adhesive # 414570N/A177001867018840

General Difference Among PVC, TPO, and EPDM Adhesives

Three major types of single ply membranes for commercial low slope roofing are PVC, TPO, and EPDM. Because of the difference in the base materials and manufacturing process, they have very different physical properties and bondability. Consequently, bonding adhesives developed for the three roofing membranes have different formulations. The major differences in the three bonding adhesives, which are to be referred here as PVC-ADH, TPO-ADH and EPDM-ADH, are summarized as follows.

Comparison of Different Formulations of 1-K Bonding Adhesives
for PVC, TPO, and EPDM Roofing Membranes
PVC-ADHTPO-ADHEPDM-ADHNotes
Modified MDISameSameSame
NCO content*High, 12-16%Medium,Low, <6%*NCO
10-12%wt. %
Polyether polyolsSameSameSimilar
Polyester polyolUsedUsedOptional
HydrocarbonNot UsedUsedUsed
polyol
TackifierNot UsedNot UsedUsed
PolyisocyanateNot UsedNot UsedOptional
Crosslinker
SolventNot UsedOptionalUsed