Title:
Method for customizing an aged appearance in denim garments
Kind Code:
A1


Abstract:
A method is provided for producing, within a home laundry setting, a customized, aged appearance in denim garments. The garments are selectively treated with a cellulase enzyme solution, subjected to a waiting period, then mechanically agitated in a washing machine for a sufficient time to produce localized variations in color density typically associated with a well-worn denim garment. The denim garment may be machine-washed prior to treatment with the cellulase enzyme solution.



Inventors:
Mcdevitt, Jason Patrick (Alpharetta, GA, US)
Application Number:
10/277273
Publication Date:
01/22/2004
Filing Date:
10/22/2002
Assignee:
MCDEVITT JASON PATRICK
Primary Class:
International Classes:
D06M16/00; D06M23/16; D06P5/02; (IPC1-7): D06M10/00
View Patent Images:



Primary Examiner:
HAMLIN, DERRICK G
Attorney, Agent or Firm:
JASON P. MCDEVITT (WILLIAMSBURG, VA, US)
Claims:

I claim:



1. A method for producing, within a home laundry setting, an aged appearance in previously laundered denim garments, comprising: a) adding the garments to a washing machine, b) contacting the garments with an enzyme solution comprising a cellulase, and c) mechanically agitating the garments for a period of time suitable to produce localized variations in color density.

2. A method for producing, within a home laundry setting, an aged appearance in denim garments comprising: a) contacting one or more denim garments with an enzyme solution comprising a cellulase, b) waiting for at least one minute, c) adding the garments to a washing machine, d) contacting the garments with water, and e) mechanically agitating the garments for a period of time suitable to produce localized variations in color density, wherein the enzyme solution has an activity greater than 250 CMC units per mL.

3. The method of claim 2, wherein the garments have been worn previously.

4. The method of claim 2, wherein the garments have been laundered previously.

5. The method of claim 2, wherein the garments are contacted with the enzyme solution in a non-uniform manner.

6. The method of claim 2, wherein the denim garments are indigo-dyed denim.

7. The method of claim 2, wherein at least 10,000 CMC units of cellulase are applied per kilogram of denim garments.

8. The method of claim 2, wherein at least 1,000 CMC units of cellulase are directly applied to a region of the denim garments covering less than four square inches.

9. The method of claim 2 wherein the enzyme solution additionally comprises enzymes other than cellulases.

10. The method of claim 2 wherein the enzyme solution additionally comprises one or more surfactants.

11. The method of claim 2 wherein the enzyme solution additionally comprises propylene glycol.

12. The method of claim 2 wherein the enzyme solution additionally comprises a buffer system capable of maintaining the pH near the pH of optimal activity for the cellulase.

13. The method of claim 2, wherein the enzyme solution additionally comprises a proteolytic enzyme.

14. The method of claim 2, wherein the enzyme solution further comprises a pectolytic enzyme.

15. The method of claim 2, wherein said garments are further subjected to soaking in a washing machine.

16. The method of claim 15, wherein said garments are subjected to one or more periods of mechanical agitation and soaking, wherein the total residence time in said washing machine is equal to or greater than 50 minutes.

17. The method of claim 2, wherein the cellulase is not used in commercially available laundry detergents.

18. The method of claim 2, wherein the weight ratio of said water to said denim garments is equal to or greater than 10.

19. The method of claim 2, wherein the duration of said waiting is equal to or greater than 20 minutes.

20. A denim-fading liquid composition for use within a home laundry setting comprising: a) a cellulase; b) a polyol; and c) water; wherein the pH of said composition is between 4 and 10.

21. The composition of claim 20, wherein the enzyme activity of the solution is between 250 CMC units/mL and 7,500 CMC units/mL.

22. The composition of claim 20, wherein the liquid composition is provided in a dispensing container with a volume of less than 200 mL.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from U.S. Provisional Patent Application Ser. No. 60/395,860 filed on Jul. 16, 2002.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not Applicable

BACKGROUND OF THE INVENTION

[0003] 1. Field of the Invention

[0004] The invention relates to methods and compositions for treating denim garments to impart an aged appearance. The methods include spot-treating denim garments with enzyme compositions and subjecting them to mechanical agitation within a home laundry setting.

[0005] 2. Description of Prior Art

[0006] Denim fabric is the standard material used for making blue jeans. Typically, blue denim is indigo-dyed denim. As the denim fabric ages through washing and wearing, it becomes softer and the color fades, with white areas becoming visible in the fabric. This texture and appearance is popular with consumers, and manufacturers of jeans have developed techniques to attempt to approximate that texture and appearance in new jeans. For example, manufacturers sometimes wash the jeans in a washing machine with stones, such as pumice stones, to produce a stonewashed look.

[0007] In other cases, manufacturers wash the jeans with cellulase enzymes, which also provides a stonewashed appearance. In those cases, the enzyme acts on the cellulose in the jeans, thereby releasing material and color from the jeans, producing lightened or whitened areas to provide an appearance similar to that achieved using stonewashing. The use of cellulase enzymes to stonewash jeans is disclosed in U.S. Pat. Nos. 4,832,864 and 4,912,056 to Olson, and U.S. Pat. Nos. 5,006,126 and 5,122,159 to Olson et al., the entire disclosures of which are hereby incorporated by reference. Other enzymes have also been used to impart a stonewashed look to denim, or to aid in cellulase-based enzymatic stonewashing. For example, the use of proteases to limit backstaining in a cellulase stonewashing process is described in U.S. Pat. No. 6,251,144 (Clarkson et al.). Kalum et al., U.S. Pat. No. 6,146,428, describe the use of pectolytic enzymes in conjunction with a cellulase for enzymatic stonewashing. Vollmond, U.S. Pat. No. 5,908,472, describes the use of a cellulase in conjunction with an oxidoreductase and an enhancing agent for enzymatic stonewashing of denim.

[0008] The methods described above are conventionally used to treat batches of jeans by manufacturers. Other processes, such as bleaching with chlorine bleach or repeated washings using detergent, have been used by consumers to try to further fade denim. All of these processes, while useful to varying extents in lightening the jeans and producing both micro-variations and macro-variations (e.g., the seams generally get lightened more than other macro-regions) in color, still do not resemble a well-used pair of jeans as closely as many consumers would like. Hence, manufacturers have resorted to selling jeans that have been customized to provide a more genuinely worn appearance (e.g, by imparting crease lines near the crotch, selective fraying, crumples at the knee, etc.). This customization process is normally performed by trained experts using mechanical processes such as sandblasting, rubbing with sandpaper, and cutting. Increasingly, the sandblasting process is automated. This type of customization can be attempted at home by consumers, but it is risky as one can easily damage the jeans and/or do a poor job of providing an authentically aged appearance. Several products or kits are now available to consumers who want to “distress” their own denim fabric. These systems use some type of mild bleaching action or mechanical abraders such as a pumice stone for rubbing, or emery boards.

[0009] There remains a need for a suitable, mild, effective method for customizing denim garments so as to provide an authentically aged appearance. There is a need for a method that can be used safely by a consumer in his or her own home, as it may be advantageous for the person who will wear the denim garments to be the person who customizes them, in keeping with the old adage that beauty is in the eye of the beholder. There is a need for a method that can utilize conventional washing machines, along with the compositions of this invention, in a cost-effective manner to provide customized denim garments having a desirable appearance.

BRIEF SUMMARY OF THE INVENTION

[0010] The invention described herein provides for methods and compositions for producing localized “wear” patterns using cellulases and other enzymes. Importantly, the invention can be practiced at home, and is more easily controlled than the use of harsh mechanical methods such as sandpaper or harsh chemical methods such as bleach. Importantly, the invention described herein can be used gradually to enhance an already existing aged appearance. Importantly, this invention is intended for use by individuals engaged in purchasing and wearing denim garments, not for use by a manufacturer or commercial laundry prior to retail sale.

[0011] This invention contemplates a method for producing an aged appearance in denim garments comprising: contacting one or more denim garments with an enzyme solution comprising a cellulase, waiting for at least one minute to allow the solution to be absorbed by the garments, adding the garments to a washing machine, contacting the garments with water, and agitating the garments for a period of time suitable to produce localized variations in color density.

[0012] This invention specifically contemplates performing the method described above within a home laundry setting. Further, this invention contemplates performing the method described above using denim garments that have been worn and laundered previously, allowing the user of the method to accelerate and enhance the natural denim aging process. Furthermore, by performing the method on previously worn garments with existing wear patterns, the user is provided a template for application of the enzyme. There is no need to guess or approximate the expected location of wear patterns.

[0013] Specifically, this invention contemplates selective treatment of portions of the denim garments with an enzyme solution, followed by a waiting period, followed by agitation in a washing machine with additional water. Application of the enzyme in solution enables the end-user to selectively spot the enzyme in places where increased fading is desired. In other embodiments of the invention, the enzyme is directly added to the washing machine to produce a uniform fading. The invention also contemplates methods to maximize such selective placement, including using clothespins to create folds into which enzyme can be loaded. It should be noted that this method does not restrict aging solely to the treated portions of the denim garment. Within the washing machine, some of the enzyme applied to the garment is released into solution, and thus becomes available to react elsewhere on the garment. Nevertheless, the extent of wear can be much higher on spot-treated regions of the garment relative to regions that are not directly treated. This method selectively increases the local abrasion levels, permitting one to impart a designed, customized aging appearance that can not be duplicated by simply treating the garment with a homogeneous enzyme solution.

[0014] The method of the present invention is compatible with conventional consumer washing machines. For example, the “soak” cycle on standard washing machines can be used repeatedly. Agitation of the garments within the washing machine enhances fading in the context of this invention. It is important that the jeans are agitated while within the washing machine, but continuous agitation is not necessary. The invention also contemplates soaking without agitation, oftentimes intermittently between agitation periods. It is important to avoid premature exposure to a rinse cycle in order to maximize efficient use of the enzyme (i.e., if rinsing is performed after 10 minutes of washing, the effective duration of enzyme action may be shorter than desired).

[0015] This invention also comprises a denim-fading liquid composition available for in-home use comprising:

[0016] a) a cellulase;

[0017] b) a polyol;

[0018] c) water; wherein the pH of said composition is between 4 and 10.

[0019] In preferred compositions, endoglucanase activity of the composition is greater than 500 CMC units/mL.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0020] Not Applicable

DETAILED DESCRIPTION OF THE INVENTION

[0021] Before the methods of the invention are described, it is to be understood that this invention is not limited to the particular methods described. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting since the scope of the present invention will be limited only by the appended claims.

[0022] As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. Thus, for example, references to “cellulase” or “cellulase preparation” include mixtures of such cellulase enzymes, reference to “the method” includes one or more methods, and/or steps of the type described herein and/or which will become apparent to those persons skilled in the art upon reading this disclosure and so forth.

[0023] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference for the purpose of disclosing and describing the material in connection with which the reference was cited.

[0024] Definitions

[0025] The term “stonewash” used herein means that the jeans are contacted by pumice stones or other suitable abrasive materials, cellulase enzymes, a combination of cellulases and other enzymes, or a combination of abrasive materials and enzymes, and agitating the jeans for a sufficient period of time to produce localized variations in color density.

[0026] Unless stated otherwise, the term “washing machine” used herein means a machine used for laundering clothes wherein the load capacity is less than eight cubic feet, or the advertised load capacity is less than 30 kg.

[0027] The term “home laundry setting” used herein means a washing machine within a residential dwelling or complex. It should be noted that the method of this invention can be practiced using a washing machine at a retail laundromat.

[0028] In the present context, the term “cellulase” or “cellulolytic” enzyme refers to an enzyme which catalyses the degradation of cellulose to glucose, cellobiose, triose and other cello-oligosaccharides.

[0029] In the present context, the term “cellulolytic” enzyme is understood to include a mature protein or a precursor form thereof or a functional fragment thereof which essentially has the activity of the full-length enzyme. Furthermore, the term “cellulolytic” enzyme is intended to include homologues or analogues of said enzyme.

[0030] In the present context, a “home denim-fading liquid composition” refers to a liquid solution comprising a cellulase that can be used within a home laundry setting to fade denim garments.

[0031] The term “contacted in a non-uniform manner” used herein means that all portions of the garment have not been contacted evenly (e.g., spot-treating). For example, specific areas, such as the back pockets of a pair of denim jeans, can be spot-treated by contacting the back pockets with the liquid enzyme composition.

[0032] The term “soaking in a washing machine” used herein means that garments are contacted with an aqueous solution in a washing machine without mechanical agitation.

[0033] Method of the Invention

[0034] The denim garments can be treated with cellulase enzyme before ever being worn on the body, or they can be treated after having been worn. In some embodiments, the denim garments have been laundered at least once using any laundry method typical for residential use.

[0035] In somewhat greater detail, the denim garments can be contacted with an aqueous solution comprising a cellulase enzyme for a sufficient period to allow the garments to absorb the enzyme solution and undergo some initial reaction. Normally, this requires at least one minute, and longer times may be preferable to optimize the ultimate appearance of the garment. The garments are then introduced into a washing machine, contacted with water, and agitated (and optionally soaked) for a sufficient time to produce the desired effect. The amount of enzyme solution used to treat the garments depends on the size of the garments, the activity of the enzyme, the concentration of the enzyme in solution, and the extent of abrasion desired. Typically, the garments are agitated in the washing machine in an amount of water corresponding to the amount automatically added to run the “low” cycle of the washing machine, although more water can be used. In order to maximize the cost-effectiveness of the treatment, the duration of treatment in the washing machine (i.e., the combined time of mechanical agitation and soaking, prior to rinsing) should be at least 30 minutes, frequently greater than one hour.

[0036] In some embodiments of the invention, the denim garments are laundered prior to treatment with a cellulase. The time interval between laundering and treatment with a cellulase can be short or long, and the garments may be worn during the interim. For example, new denim garments may be subjected to laundering using a residential washing machine, with or without added detergent. After washing, the garments may be dried using any available means (commercial dryer, air-drying using a clothesline, etc.). The denim garments may be worn prior to laundering, or subsequent to laundering, prior to the treatment with cellulase enzymes. It can be advantageous to wear the garment prior to performing the method of this invention, since the natural aging or fading of the garment may serve to direct the placement of the enzyme solution.

[0037] The optimum temperature of treatment depends on the particular enzyme used. Depending on the starting temperature and the ambient air temperature, the temperature of the water in the washing machine tends to drop during treatment, particularly if “hot” water (i.e., the hot water cycle) is used. Typical temperatures at which the cellulase treatment is performed range from 10° C. to 70° C., more typically between 30° C. and 60° C.

[0038] For treatment of a single denim garment (e.g., a pair of jeans), a desirable liquid to solids ratio is between 2:1 and 200:1 on a weight basis, typically between 8:1 and 100:1. For example, a 0.9 kg pair of denim blue jeans can be treated with enzyme solution, held for a period to allow the garment to absorb the enzyme, then contacted with approximately 30 liters of water, which can be added manually or automatically by utilizing one of the standard washing machine cycles. Commercial launderers typically perform an enzymatic stonewashing process at a liquids:solids ratio (w/w) of less than or equal to 10. Typically, the method of the present invention will be performed at a higher liquids:solids ratio because of the ratio between the weight of water added in a typical “small” load setting of a residential top loading washing machine to the weight of one or two pairs of denim jeans.

[0039] The quantity of cellulase that is used to treat the denim garments can vary greatly, depending on the particular enzyme, its concentration in solution, and the amount of aging or fading that is desired. Typically, the cellulase is applied as a solution, and from 0.1 to 200 mL enzyme solution is used. Preferably, between 1,000 and 200,000 CMC units of cellulase are applied per kg of denim garment, wherein CMC units are measured using the method of Ghose (1987). The concentrated enzyme solution typically has an activity between 250 and 5,000 CMC units per milliliter. The enzyme solution is typically diluted in the washing machine to activity levels between 100 and 10,000 CMC units per liter

[0040] The cellulase solution can be applied to the garment in a number of ways. The enzyme solution can be applied from a squeeze bottle, or a medicine dropper. It can be applied via pipet, or can simply be poured onto the garment. To facilitate spot-treatment, any number of methods can be used to maximize local distribution of the enzymes, including bunching the fabric, using mechanical clamping means to form a valley, etc. Alternatively, the enzyme solution can be added directly to the washing machine, analogous to laundry detergent. Obviously, addition to the machine does not constitute spot-treatment. It permits custom fading, but not patterned custom fading of the garments. When adding the enzyme to the washing machine for uniform dispersal, one can also use a cellulase in solid form (e.g., granulates, T-granulates, wafers).

[0041] After applying the enzyme solution to the garment, it is convenient to wait some time to let the solution be absorbed by the fabric and initiate enzymatic hydrolysis. It is customary to wait from 1 minute to 1 hour after application of the enzyme prior to contacting the fabric with water in the washing machine. A longer holding period is contemplated as well, and may be preferable when spot damage of the garments is desired (e.g., holes in the knees).

[0042] Any type of residential washing machine is suitable for practicing the method of this invention. Top-loading and front-loading machines are contemplated. In general, washing machines suitable for practicing the method of this invention have advertised clothing capacities of 30 kg or less, with volume capacities of less than eight cubic feet.

[0043] The method of this invention can be practiced using any cycle of the machine that provides mechanical agitation of the garments. In practice, we have found that using the soak cycle, with agitation followed by a soaking period, provides a “safety” valve. Use of a regular wash cycle entails a rinse step, and thus, in the absence of an abnormally lengthened wash cycle, it is generally desirable to interrupt the cycle prior to the rinse step in order to extend the contact time between the enzyme and the denim garment. There is no upper or lower time limit for practicing the method of this invention; however, treatment time in the washing machine of less than five minutes would likely constitute inefficient use of the enzyme, as enzymatic hydrolysis will be limited. Using a low dosage of enzyme and extending the treatment cycle provides the most cost-effective method of general fading of the garment, although it is not tremendously time-efficient. After sufficient mechanical agitation to develop the desired color or level of fading, the enzyme should be rinsed from the denim garment using the rinse cycle of the washing machine. The denim garment can be removed from the washing machine prior to the rinse cycle, and the enzyme solution could be rinsed off in alternative ways or the enzyme could be deactivated using methods known in the art (e.g., heat, bleach).

[0044] Cellulolytic Enzymes

[0045] The cellulase or endoglucanase may be an acid, a neutral or an alkaline cellulase or endoglucanase, i.e., exhibiting maximum cellulolytic activity in the acid, neutral or alkaline range, respectively.

[0046] Accordingly, a useful cellulase is an acid cellulase. Representative embodiments are fungal acid cellulases. Preferable fungal cellulases can be derived from or produced by fungi from the group of genera consisting of Trichoderma, Actinomyces, Myrothecium, Aspergillus, or Botrytis, in particular Trichoderma viride, Trichoderma reesei, Trichoderma longibrachiatum, Myrothecium verrucaria, Aspergillus niger, Aspergillus oryzae, or Botrytis cinerea.

[0047] Another useful cellulase or endoglucanase is a neutral or alkaline cellulase. Neutral cellulases can minimize backstaining of indigo. Representative embodiments are fungal neutral or alkaline cellulases, which are derived from or producible by fungi from the group of genera consisting of Aspergillus, Penicillium, Myceliophthora, Humicola, Irpex, Fusarium, Stachybotrys, Scopulariopsis, Chaetomium, Mycogone, Verticillium, Myrothecium, Papulospora, Gliocladium, Cephalosporium and Acremonium, including Humicola insolens, Fusarium oxysporum, Myceliopthora thermophila, or Cephalosporium sp., notably from the group of species consisting of Humicola insolens, DSM 1800, Fusarium oxysporum, DSM 2672, Myceliopthora thermophila, CBS 117.65, or Cephalosporium sp., RYM-202.

[0048] There are several commercially available cellulase enzyme preparations that are useful in practicing the method of this invention. An example of such a cellulase is NOVOZYM® 342, available from Novozymes, Inc., Bagsvaerd, Denmark. Other useful commercial cellulase enzyme preparations include INDIAGE®, available from Genencor International, Palo Alto, Calif., and DENABRAIDE®, available from Iogen, Ottawa, Canada.

[0049] The cellulase solution optionally includes salts, surfactants, or other enzymes. In some embodiments, the cellulase solution is buffered. In another embodiment of the invention, the cellulase solution is not buffered, or possessive of only moderate buffer capacity. This can provide a self-regulating product, whereby the activity decreases as increasing hydrolysis occurs and the pH changes.

[0050] In one embodiment of the invention, multiple cellulases are used. In another embodiment of the invention, the aqueous solution comprises a cellulase comprising one or more cellulose-binding domains.

[0051] In a preferred embodiment of the invention, the cellulase enzyme or enzymes are not used commercially in the home laundry detergent industry. This greatly minimizes the possibility of an individual, in practicing the method of the present invention, developing sensitivity to a particular cellulase, then being exposed to the same cellulase during home laundering using commercially available detergents.

[0052] In another embodiment of the invention, the cellulase solution also includes enzymes from other classes, such as proteases or pectinases, which can reduce backstaining. The invention also contemplates using cellulases in conjunction with amylases, glycosidases, lipases, esterases, and oxidoreductases.

[0053] Proteolytic Enzymes

[0054] Proteases are available from several sources including microbial, plant and animal sources and are well-documented in the literature. Some important commercial proteolytic sources include Bacillus licheniformis, Bacillus subtilis and Aspergillus oryzae. Proteases suitable for the invention include, for example, serine, metallo and acid proteases, as well as endo- and exo-proteases. Subtilisins are serine proteases which generally act to cleave internal peptide bonds of proteins and peptides. Metallo proteases are exo- or endo-proteases which require a metal cofactor for activity. One of the preferred serine proteases is subtilisin.

[0055] Proteases can be incorporated into the cellulase composition, or can be added to the garments separately, as either a liquid solution or solid concentrate.

[0056] Pectolytic Enzymes

[0057] The term “pectolytic enzyme” or “pectinase” as denoted herein, is intended to include any pectinase enzyme defined according to the art where pectinases are a group of enzymes that hydrolyse glycosidic linkages of pectic substances, mainly poly-1,4-α-D-galacturonide and its derivatives. Furthermore, the term “pectolytic” enzyme is intended to include homologues or analogues of such enzymes.

[0058] A pectolytic enzyme useful in the method of the invention is a pectinase enzyme that catalyzes the random cleavage of α-1,4-glycosidic linkages in pectic acid (also called polygalacturonic acid) by transelimination such as the enzyme class polygalacturonate lyase (EC 4.2.2.2) (PGL), also known as poly(1,4-α-D-galacturonide)lyase, also known as pectate lyase. Another useful pectincase catalyzes the random hydrolysis of α-1,4-glycosidic linkages in pectic acid such as the enzyme class polygalacturonase(EC 3.2.1.15) (PG), also known as endo-PG. Another useful pectinase is polymethylgaicturonate lyase (EC 4.2.2.10) (PMGL), also known as Endo-PMGL, also known as poly(methyoxygalacturonide)lyase, also known as pectin lyase. This enzyme catalyzes the random cleavage of α-1,4-glycosidic linkages of pectin. Other useful pectinases are galactanases (EC 3.2.1.89), arabinanases (EC 3.2.1.99), pectin esterases (EC 3.1.1.11), and mannanases (EC 3.2.1.78).

[0059] The enzyme preparation useful in the present invention is preferably derived from a microorganism, preferably from a bacterium, an archea or a fungus.

[0060] Pectolytic enzymes can be incorporated into the cellulase composition, or can be added to the garments separately, as either a liquid solution or solid concentrate.

[0061] Softeners

[0062] The enzyme composition may include a softening agent. Organic cationic softeners or silicone-based products can be used, but anionic or non-ionic softeners are also useful. Examples of useful softeners are polyethylene softeners and silicone softeners, i.e., dimethyl polysiloxanes (silicone oils), H-polysiloxanes, silicone elastomers, aminofunctional dimethyl polysiloxanes, aminofunctional silicone elastomers, and epoxyfunctional dimethyl polysiloxanes, and organic cationic softeners, e.g., alkyl quaternary ammonium derivatives.

[0063] Surfactant

[0064] A surfactant can be included in the treatment compositions of the invention. The surfactant can increase the wettability of the aqueous solution, thereby promoting the activity of the cellulase enzyme in the fabric. The surfactant increases the wettability of the enzyme and fabric. Surfactants are routinely classified into nonionic, anionic, cationic and amphoteric surfactants.

[0065] Solvents

[0066] Solvents that can be used in the liquid concentrate compositions of the invention are liquid products that can be used for dissolving or dispersing the enzyme and surfactant compositions of the invention. Because of the character of the preferred nonionic surfactants, the preferred solvents are oxygen-containing solvents such as alcohols, esters, glycol, glycol ethers, etc. Alcohols that can be used in the composition of the invention include methanol, ethanol, isopropanol, and t-butanol, among others. Esters that can be used include amyl acetate, butyl acetate, ethyl acetate, esters of glycols, and others. Glycols and glycol ethers that are useful as solvents in the invention include ethylene glycol, propylene glycol, and oligomers and higher polymers of ethylene or propylene glycol in the form of polyethylene or polypropylene glycols.

[0067] In liquid concentrates, low molecular weight oligomers are preferred. In solid organic concentrates, higher molecular weight polymers are preferred. Frequently, commercial enzymes are sold in aqueous solutions containing 25% or more propylene glycol, which enhances storage stability. Other storage enhancement methods can also be utilized, including other glycols that may be more or less viscous or hydrophobic.

[0068] Other compounds that may be included in the liquid enzyme concentrate compositions of the present invention are buffer salts, preservatives, viscosity modifiers, and fragrances. In the embodiment of the invention wherein a solid cellulase product is directly added to the washing machine, other compounds that may be included in the solid enzyme concentrate compositions include, but are not limited to, buffer salts, preservatives, builders, sequestrants, and fragrances.

EXAMPLES

Example 1

[0069] Four pair of men's indigo-dyed denim jeans, waist size 32 and 33, all stonewashed, all newly purchased from a retail store, virtually identical aside from the slight jean-to-jean variations characteristic of a stone-washing process, were used in this experiment.

[0070] A pair of new, stonewashed men's denim jeans (pair A), never worn, were spot-treated along the seams, pockets, and other areas frequently associated with high wear patterns in old jeans. A total of 60 mL of a cellulase solution (obtained from Iogen Corporation, Ottawa, Calif.) was used to treat the jeans, which were wrapped in a plastic bag following application of the enzyme. After twenty minutes, the treated jeans, along with an untreated pair of new men's jeans (pair B, used to compare the effects of direct spot-treatment with the enzyme vs. a solution approach) were placed in a top-loading washing machine that had been loaded with 30L of hot water (55° C.) using a temperature setting of “hot”, a cycle setting of “soak”, and a load size setting of “small”.

[0071] Agitation was commenced for four minutes, at which time mechanical agitation of the denim jeans terminated and the jeans were left to soak for five minutes. This agitation/soak cycle was repeated six additional times. After a total of 63 minutes, the washing machine was run on a standard cycle, including agitation for an additional nine minutes followed by a standard rinse cycle to wash away the enzyme. The jeans were tumble-dried, and visually evaluated.

[0072] Subsequently, a third pair of jeans (pair C) was placed in the washing machine and subjected to the same washing machine cycles as the previous pair of jeans, albeit without any added enzyme. After a total of 63 minutes, the washing machine was run on a standard cycle, including agitation for an additional nine minutes followed by a standard rinse cycle. The jeans were tumble-dried, and visually evaluated.

[0073] A fourth pair of jeans (pair D) was left untreated as a standard.

[0074] Machine washing and tumble drying can damage fibers, and contribute to aging of a garment. Hence, pair C (washing and drying control) was expected to exhibit greater color fading than untreated pair D. Furthermore, pair B, presumably exposed to cellulase enzyme in solution that had been released from pair A, was expected to have greater fading than pair C. Finally, pair A, directly spot-treated with enzyme, was expected to show similar fading to pair B in areas of the garment that had not been directly treated with enzyme, but was expected to show greater fading in the treated areas.

[0075] As expected, pairs A and B showed significantly more fading than pair C, which was only moderately faded relative to unwashed pair D. Furthermore, pair A had a distinctly worn look relative to pair B, with greater fading along the seams and panels.

[0076] Colorimetric measurements were obtained using a MacBeth® Color-Eye® 7000 machine (from GretagMacbeth GmbH of Regensdorf, Switzerland), using a 10° observation angle and measuring values for L, a, and b. The value for DE (difference from the standard) was calculated based on the difference between the sample and measurements taken from the leg of the unwashed garment D, which served as the standard control. Samples were taken from both the leg and back pocket areas of the jeans. The enzyme solution was directly applied to the back pocket of pair A. 1

TABLE 1
Spectrophotometric measurements of enzyme-treated jeans
GarmentLabdE
D26.507−1.117−12.531
D26.513−0.651−13.160
D25.533−0.570−12.129
B (pocket)30.297−1.974−13.9944.152
B (pocket)30.298−1.449−14.6694.163
B (pocket)29.150−1.175−13.5673.940
B (leg)31.867−2.140−13.4765.538
B (leg)31.867−1.632−14.1565.533
B (leg)30.750−1.309−13.0305.345
A (pocket)33.166−1.780−10.7906.915
A (pocket)33.165−1.375−11.3356.936
A (pocket)32.279−1.080−10.3396.998
A (leg)30.301−1.701−12.0753.866
A (leg)30.303−1.249−12.6833.866
A (leg)29.321−0.999−11.6373.844

Example 2

[0077] A pair of men's blue denim jeans, worn approximately ten times but still having a fairly new appearance (also machine washed and dried on numerous occasions), was spot-treated with a cellulase-containing enzyme solution (approximately 3,000 CMC units/mL) around the back pockets, the side seams, and along one side of the zipper fly in an attempt to recreate the “whiskers” pattern characteristic of well-worn jeans. Specifically, clamps were used to create a single small channel radiating outwards from the bottom of the fly. Five mL of the cellulase solution was loaded dropwise into the channel, and a further 25 mL was used to treat the back pockets and the seams. After spot-treatment and a waiting period of approximately one minute, the jeans were rolled into a ball and placed in a plastic bag. After 10 minutes, the jeans were placed in a residential top-loading washing machine (type) which had been loaded with warm water using the “warm” water, “small” load, and “soak” cycle settings on the washing machine. Agitation was commenced for four minutes, at which time mechanical agitation of the denim jeans terminated and the jeans were left to soak for five minutes. This agitation/soak cycle was repeated eight times over the next hour, with varying intervals of soaking between mechanical agitations. After a total of 69 minutes, the washing machine was run on a standard cycle, including agitation for an additional nine minutes followed by repeated rinsing to wash away the enzyme. The jeans were tumble-dried, and visually evaluated. Significant fading was observed over the entire garment, included areas not treated with enzyme, but a higher degree of fading was observed in the spot-treated areas. In particular, one side of the zipper fly showed a far greater extent of fading than the other side, and even developed a small hole.

Example 3

[0078] A pair of women's denim blue jeans was purchased from a store and subjected to conventional machine washing/drying using a commercial laundry detergent. The jeans were spot-treated at various time points along the legs and buttocks regions with a total of 30 mL of a cellulase preparation having CMC activity of 3400 units/mL. After waiting two hours from the earliest spot-treatment, the jeans were placed in a top-loading home washing machine that had been loaded with 30 L of 41° C. water using the “warm” water, “small” load, and “soak” cycle settings on the washing machine. Agitation was commenced for four minutes, at which time mechanical agitation of the denim jeans terminated and the jeans were left to soak for two minutes. This agitation/soak cycle was repeated ten times over the next hour, with varying intervals of soaking between mechanical agitations. After a total of 60 minutes, the washing machine was run on a standard cycle, including agitation for an additional nine minutes followed by repeated rinsing to wash away the enzyme. The jeans were tumble-dried, and visually evaluated. Significant fading was observed over the entire garment, included areas not treated with enzyme, but a higher degree of fading was observed in the spot-treated areas, including streaks.

[0079] The jeans were subsequently treated again with the same cellulase preparation. This time, a total of 15 mL was applied to the back pockets of the garment. After 15 minutes, the garment was loaded into a top-loading washing machine that had been loaded with 30 L of 45° C. water (using the “small” load, “soak” cycle, and both the “warm” and “hot” water settings on the washing machine), to which had been added an additional 15 mL of the cellulase solution. Agitation was commenced for four minutes, at which time mechanical agitation of the denim jeans terminated and the jeans were left to soak for one minute. This agitation/soak cycle was repeated eight times, with varying intervals of soaking between mechanical agitations. After a total of 50 minutes, the washing machine was run on a standard cycle, including agitation for an additional nine minutes followed by repeated rinsing to wash away the enzyme. The jeans were tumble-dried, and visually evaluated and compared with a new pair of jeans that had not been treated. Significant fading was observed over the entire garment, included areas not treated with enzyme, but a high degree of fading was observed in the spot-treated areas, including streaks in the legs and a high degree of fading in the back pockets. There were also the beginnings of two small holes at corner junctions next to the back pockets.

[0080] Colorimetric measurement of the jeans was performed using a Color-Eye® 7000 machine. Measurements were taken from the back pockets and two regions from the legs, one that had been treated directly with enzyme solution and one region that had not been treated directly. A measurement was taken from a pair of new jeans, virtually identical in appearance to that of the treated jeans prior to treatment, to serve as a standard. The difference from the standard (DE) was calculated from the color score of the leg of the unwashed garment. 2

TABLE 2
Spectrophotometric measurement of enzyme-treated jeans
SampleLABdE
Standard (unwashed jeans)18.6720.135−8.497
Standard18.6820.452−8.927
Standard18.0790.270−8.194
Treated jeans (back pocket)26.936−1.278−10.9158.726
Treated jeans (back pocket)26.939−0.869−11.4668.739
Treated jeans (back pocket)26.073−0.715−10.5218.383
Treated (leg)24.368−0.898−10.7236.202
Treated (leg)24.373−0.497−11.2656.226
Treated (leg)23.546−0.441−10.3545.920
Treated (leg, direct enzyme)30.486−1.598−10.94012.189
Treated (leg, direct enzyme)30.487−1.186−11.49612.192
Treated (leg, direct enzyme)29.605−0.936−10.52011.820

Example 4

[0081] A pair of children's denim overalls was subjected to conventional machine washing/drying using a commercial laundry detergent. The overalls were spot-treated along the pockets at seams using a total of 25 mL of a commercially available cellulase preparation (NOVOZYM®342, available from Novozymes, Inc., Bagsvaerd, Denmark). After waiting twenty minutes, the overalls were placed in a top-loading home washing machine that had been loaded with approximately 30L of hot water using “hot” water, “small” load, and “soak” cycle settings on the washing machine. Agitation was commenced for four minutes, at which time mechanical agitation of the denim jeans terminated and the overalls were left to soak for ten seconds. This agitation/soak cycle was repeated five times over the next hour, with varying intervals of soaking between mechanical agitations, including soaking times of up to ten minutes without agitation. After a total of 60 minutes, the washing machine was run on a standard cycle, including agitation for an additional nine minutes followed by repeated rinsing to wash away the enzyme. The overalls were tumble-dried, and visually evaluated. The overalls were significantly faded, and had an improved appearance.

Example 5

[0082] A canvas jacket was subjected to conventional machine washing/drying using a commercial laundry detergent. The jacket was placed in a top-loading home washing machine that had been loaded with approximately 30 L of hot water using “hot” water, “small” load, and “soak” cycle settings on the washing machine, along with approximately 25 g of a solid cellulase preparation, yielding a cellulase solution in the machine having CMC activity of approximately 1,000 units/L. Mechanical agitation was commenced for four minutes, at which time agitation of the jacket terminated and the jacket was left to soak for five minutes. This agitation/soak cycle was repeated five times over the next hour, with varying intervals of soaking between mechanical agitations, including soaking times of up to ten minutes without agitation. The jacket was then subjected to a standard wash cycle, including agitation for an additional nine minutes followed by repeated rinsing to wash away the enzyme. The jacket was tumble-dried.

Example 6

[0083] A bright red sweatshirt, deemed overly bright by the owner, was subjected to conventional machine washing/drying cycles using several different commercial laundry detergents. The sweatshirt was placed in a top-loading home washing machine that had been loaded with approximately 30L of hot water using “hot” water, “small” load, and “soak” cycle settings on the washing machine, to which was added approximately 20 mL of a liquid enzyme preparation comprising cellulases as well as commercially available exoproteases and endoproteases. The CMC activity of the liquid enzyme preparation was approximately 2000 units/mL. Mechanical agitation was commenced for four minutes, at which time agitation of the garment terminated and the sweatshirt was left to soak for thirty minutes. The washing machine was then run on a standard cycle, including agitation for an additional nine minutes followed by repeated rinsing to wash away the enzyme. The sweatshirt was tumble-dried, and visually evaluated.

[0084] References

[0085] Ghose, T. K. Measurement of Cellulase Activities. International Union of Pure and Applied Chemistry, vol. 59, No. 2, pp. 257-268 (1987).