ZA200503976B

ZA200503976B - Fabric treatment

Info

Publication number: ZA200503976B
Application number: ZA200503976A
Authority: ZA
Inventors: Shameen Bhatia; Robert J Carswell; Paul J Evans; Paul H Findlay
Original assignee: Unilever Plc
Priority date: 2002-12-05
Filing date: 2005-05-17
Publication date: 2006-08-30
Also published as: CN100338298C; CN1745207A; GB0228358D0

Description

FABRIC TREATMENT

Technical Field

The present invention relates to garment treatment compositions suitable for domestic use in a laundering process, and in particular to compositions which contain components which can cross-link with cellulose.

Background of the Invention

Cellulose is a beta 1-4 linked polysaccharide and the principal component of cotton, which is a well-known material for the production of fabrics and in very widespread use. Cellulose is capable of cross-linking by hydrogen bonds which form between the cellulose chains.

The majority of garments purchased world-wide contain at least some cellulose fibres in the form of cotton or rayon and these suffer from the well-known problem that on exposure to water, such as during domestic laundering, fibre dimensions change and cause shrinking, shape change and wrinkling of the garments. It is believed that this is due to release and reformation of hydrogen bonds.

So-called ‘durable press’ treatments of fabrics are intended to overcome these difficulties. One of the most common methods of durable pressing uses a crosslinking agent to immobilise cellulose at a molecular level. Known cross-

- 2 = linking agents for whole cloth include formaldehyde, and urea-glyoxal resins. Other proposals include epichlorohydrins, vinyl sulphones, acrylo-amide and acrylo- acrylates. None of these proposed technologies have demonstrated any commercial viability for domestic on finished garments use to date.

A range of industrial processes for use in the manufacture of finished fabrics are known.

US 4588761 discloses poly-urethane coating compositions for use with a transfer paper or other temporary support. These comprise an isocyanate which is preferably blocked. This is an industrial treatment process for fabric and is inherently unsuitable for use at home on finished garments.

JP 53035098 discloses a finishing process for treating woven or knitted cellulosic fabrics with a processing solution comprising a urethane prepolymer with blocked terminal isocyanate groups, a gloxal-amide type cross-linking agent and a bromo-fluorinated metal. The process is not suitable for domestic application to finished garments.

JP6346374 discloses finishing of fabric or a sewed product by a stepwise industrial process comprising treatment with a blocked isocyanate, heat treatment and subsequent use of a gas phase cross-linking agent. A similar process is disclosed in JP8127972.

JP 55093882 discloses a method for flocked fabric production which uses masked isocyanate. JP 9316781 discloses a finishing agent for use in the production of yarn, paper or films which comprises a blocked isocyanate. JP 11131374 discloses an industrial process for the product of water repellent fabric by treatment with a glyoxal-based resin crosslinking agent, an organo-fluorine compound and a isocyanate based cross-linking agent. Followed by heat treatment for 0.5-5min. A similar process is disclosed in JP 2000129573.

An alternative proposal is to use poly-acids such as BTCA (butyl tetra carboxylic acid) or citric acid as crosslinking agents. These can esterify with the -OH groups of the cellulose to form a covalent cross-link. The covalent cross-link is not disrupted by water and this both prevents deformation of fabrics and assists return to a flat state.

One of the difficulties with this approach is that a sodium hypophosphite catalyst is generally used to cause the esterification reaction to proceed and the treated articles require heat curing. Moreover, these poly-acid materials are highly water soluble and are difficult to deposit on fabrics.

A preferred durable press system suitable for domestic use should be a non-toxic, one component, catalyst-free system with low iron-cure times, have some affinity for the fabric surface and not cause fabric strength losses. It should also avoid the need for specialised equipment and the use of use of difficult materials such as vapour-phase formaldehyde.

Brief Description of the Invention

We have determined that excellent cross-linking benefits can be obtained by treating finished garments with a cellulose cross-linking agent that is thermally activated.

Accordingly, the present invention provides a method of treating finished garments comprising cellulosic material so as to cause cross-linking, which comprises the step of treating fabrics with an effective amount of a blocked cross-linking agent for cellulose, said cross-linking agent being thermally activated.

In the context of the present invention, the term ‘thermally activated’ is intended to mean that the cross-linking agent is ‘blocked’ to prevent reaction until the cross-linking agent is activated by the application of heat. In order to achieve cross-linking is preferable that at least two reactive sites of the cross-linking agents are blocked with a thermally labile blocking group.

Preferably the blocked cross-linking sites are selected such that, when activated, they are readily capable of reacting with hydroxy groups present in cellulose. More preferably the cross-linking reaction forms an ‘ester’ linkage, which in the context of the present invention includes linkages where the alpha carbon of the ester is replaced by a hetero- atom, preferably nitrogen. In the case of the alpha-carbon being so replaced the molecule is formally known as a carbamate.

Ideally, the reaction proceeds without the requirement for a catalyst. Catalysts can optionally be present. Suitable catalysts are selected depending on the particular blocking chemistry employed and, for example, include, pH modification agents and/or metal ions.

Preferably the cross-linking agent ig bi-functional.

In one preferred embodiment of the invention the cross- linking agent is an at least bi-functional blocked polycarboxylic acid.

In another preferred embodiment of the invention the cross linking agent is an at least bi-functional blocked isocyanate.

By ‘bi-functional’ is meant that there are at least two blocked groups which can act as cross linking sites.

Preferably, both of these are either blocked isocyanates or blocked carboxylic acids. preferably the blocked carboxylic acid is an ester with relatively weak ester bonds which can trans-esterify with cellulose. This is accomplished by forming the polyester between a poly-carboxylic acid and an alcohol (which term includes phenol) which is a good leaving group. The alcohols act as thermally labile ‘blocking agents’ for the carboxylic acid groups. Essentially the same result can be obtained by the use of carboxylic acid/imide linkages.

The present invention provides a method of treating finished garments comprising cellulosic materials so as to cause cross-linking which comprises the step of transesterifying the cellulosic material with an effective amount of an at least bi-functional blocked polycarboxylic acid.

Preferably said blocked polycarboxylic acid is blocked with an electron-withdrawing alcohol or imide.

The present invention further provides a method of treating finished garments comprising cellulosic materials so as to cause cross-linking which comprises the step of treating finished garments comprising cellulosic material with an effective amount of an at least bi-functional blocked isocyanate.

In the present invention the treatment is conducted as part of a domestic laundering operation applied to finished garments.

A further aspect of the present invention provides a composition for use in the methods described above. preferably, said composition will comprise a cross-linking agent which forms an ester linkage with the cellulose.

Preferably the cross-linking agent comprises either a blocked poly isocyanate or blocked poly carboxylic acid and which is thermally activated.

Preferably, the method of the invention comprises the step of curing the treated materials by heat treatment at a temperature of from 50 to 250C, more preferably at a temperature of from 100-200C.

More preferably, the method of the present invention further comprises the step of curing the treated materials by ironing or hot pressing. That a useful effect can be obtained by ironing after treatment is surprising.

Advantageously, the present method may be performed in the absence of vapour-phase formaldehyde and other components known from the prior art which are unsuitable for domestic use.

Detailed Description of the Invention

As noted above the cellulose cross-linking agent can be a polycarboxylic acid or a blocked isocyanate. Preferred embodiments of each of these alternatives are discussed in further detail below.

In some embodiments the backbone of the cross-linking agent is polymeric in character, by which is meant that it comprises repeating structures. Typically, the backbone comprises a sufficiently long polymeric structure (preferably 2-12 carbon-carbon bond lengths) to fulfil its function as a bridging structure between the two or more reactive groups.

A. Blocked Polycarboxylicacids:

Polyesters suitable for use in the present invention comprise a polycarboxylic acid esterified with a ‘leaving’ group which is an alcohol or an imide. The polycarboxylic acid preferably has 2-6 carboxyl groups available for esterification. Typically each of the carboxyl groups will be esterified to produce a polyester.

Most preferably, the polycarboxylic acid has two carbonyl groups available for esterification and typically these are at opposite ends of an essentially linear polycarboxylic acid. In a preferred embodiment the polyester takes the form: : R30-CO-L-CO~OR2

Where RjO- and -ORj; are the same or different alcohol residues, and -CO-L-CO- is the residue of the polycarboxylic acid. L is a linking group, which may be substituted, and generally comprises a 2-12 carbon backbone.

Polycarboxylic acids:

Preferred polycarboxylic acids include one or more of : malonic Acid, methylmalonic acid, ethylmalonic acid, butylmalonic acid, dimethylmalonic acid, diethylmalonic acid;

succinic acid, methylsuccinic acid, 2,2- dimethylsuccinic acid, 2-ethyl -2-methylsuccinic acid, 2,3- dimethylsuccinic acid, meso-2,3-dimethylsuccinic acid, glutaric acid, - 5 2-methylglutaric acid, 3-methylglutaric acid, 2,2- dimethylglutaric acid, 3,3-dimethyl-glutaric acid, adipic acid, 3-methyladipic acid, 3-tert-butyladipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,11-undecanecarboxylic acid, undecanedioic acid, 1,10- decanedicarboxylic acid, 1, 12-dodecanedicarboxylic acid, hexadecanedioic acid, docosanediocic acid, tetracosanedioic acid, tricarballylic acid, 1,2,3,4-butanetetracarboxylic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, trans-glutaconic acid, trans-beta-hydromuconic acid, trans-traumatic acid, trans, trans-muconic acid, cis-aconitic acid, trans-aconitic acid, malic acid, citramalic acid,

isopropylmalic acid, 3-hydroxy-3-methylglutaric acid, tartaric acid, mucic acid, citric acid, dihydroxyfumaric acid, diglycolic acid, 3, 6-dioxaoctanedioic acid, 3,3’ -thiodipropionic acid, 3,3’ -dithiodipropionic acid, trans-DL-1,2-cyclopentanedicarboxylic acid, 3,3-tetramethyleneglutaric acid, camphoric acid, cyclohexylsuccinic acid, 1,1-cyclohexanediacetic acid, trans-1,2-cyclohexanedicarboxylic acid, 1, 3-cyclohexanedicarboxylic aicd, 1,4- cyclohexanedicarboxylic acid, 1,3, 5-cyclohexanetricarboxylic acid,

Kemp's triacid, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4,5,6-cyclohexanehexacarboxylic acid 4-Carboxyphenoxyacetic acid, 1,4-phenylenediaectic acid, 1, 4 -phenylenedipropionic acid, 1,4-phenylenediacrylic acid, 2-Carboxybenzenepropanioc acid, 4,4’ -oxybis (benzoic acid), phthalic acid, isophthalic acid, terephthalic acid, 1,2,3-benzenetricarboxylic acid, 1,3,5- benzenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid,

mellitic acid, 2-methoxyisophthalic acid, diphenic acid, 4,4' -biphenyldicarboxylic acid, : 2,6-Napthalenedicarboxylic acid, 3-carboxy-1,4-dimethyl-2-pyroleacetic acid,

Oligomers (and co-oligomers) of unsaturated carboxylic acids can be used. Suitable materials include oligomers of acrylic acid, methacrylic acid, crotonic acid, vinylacetic acid, 4-pentencic acid, and/or maleic acid

The acid can comprise a heteroatom. Nitrogen is a preferred heteroatom. Suitable N-containing acids include: iminodiacetic acid, 3-aminophthalic acid, 2-aminoterephthalic acid, 5- aminoisophthalic acid, ethylenediamine-N,N’-diacetic acid, methyliminodiacetic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, 1, 6-diaminohexane-N,N,N’ ,N’ -tetraacetic acid, trans-1,2-diaminocyclohexane-N,N,N’,N’, -tetraacetic acid, triethylenetetraminehexaacetic acid, 1,3-diamino-2-hydroxypropane-N,N,N’ ,N’-tetraacetic acid, ethylenebis(oxyethylenenitrilo) tetraacetic acid, diethylenetriaminepentaacetic acid, aspartic acid, glutamic acid,

2-methylglutamic acid, 2-aminoadipic acid, 3-aminoadipic acid, 2,6-diaminopimelic acid, cystine

N-benzyliminodiacetic acid,

N- (2-carboxyphenyl) glycine, 2,2’ - (ethylenedioxy)dianiline-N,N,N’ N'-tetraacetic acid. porphobilinogen, 4,5-imidazoledicarboxylic acid, 2,2’ -bipyridine-4, 4’ -dicarboxylic acid, 3, 4-pyridinedicarboxylic acid, 2.,5- pyridinedicarboxylic acid, 3,5-pyridinedicarboxylic acid, 2,6-pyridinedicarboxylic acid, 6-methyl-2,3-pyridinedicarboxylic acid, 2,6-dimethyl-3,5-pyridinedicarboxylic acid

In the case where a nitrogen is present, this may be quaternerised with an appropriate quaternerising agent.

Known quaternerising agents include CH3Cl, CH3I, and (CH3) 2804 .

Alcohols:

The alcohol may have a linear, branched or ring structure. preferred alcohols comprise 5- or 6-membered rings which have electron-withdrawing groups in the ortho- and para- positions relative to the alcoholic hydrogen. Examples of such preferred alcohols include N-hydroxysuccinimide and hydroxybenzotriazole. In addition, the alcohol may be in the enol form of a ketone. As noted above, and for the avoidance of doubt, phenols are considered alcohols for the purpose of this specification.

Suitable electron withdrawing substituents on the ring include one or more of : NO, CN, CO2H, COR, CONHR, CONR2,

CHO, COR, SOR, SO20R, SO0Ar, NO, Ar, NR:Y, sR,Y, NHS, F,

Cl, Br, I, OAr, SH, SR, OH, OR, CH=CR;. The electron withdrawal can be due to either inductive or resonance effects.

Phenol derivatives with at least one electron-withdrawing substituent are preferred.

Preferred phenol derivatives include:

Vanillin,

Ethyl vanillin,

Eugenol, isoeuginol, salicylic acid, ethyl salicylate, 4 -cyanophenol, hydroxyacetophenone, trichlorophenol, 2,6-dimethoxyphenol, 4-aminophenol (and quaternerised salt), dimethylaminophenol- (and quaternerised salt), chlorophenol, bromophenol, iodophenol, fluorophenol, dichlorophenol, dibromophenol, diiodophenol, difluorophenol,

hydroxythiophenol, aminocresol, 4-amino-2,5-dimethylphenol, 6-amino-2,4-dichloro-3-methylphenol,

nitrophenol, dinitrophenol, hydroxypropiophenone, 2+ -hydroxy-5' -methylacetophenone, 5’ -chloro-2' -hydroxyacetophenone, acetovanillone,

4 -hydroxybenzaldehyde, o-vanillin,

4 -hydroxy-3-methylbenzaldehyde, 2-chloro-4-hydroxybenzaldehyde, 2 -hydroxy-5-methoxybenzaldehyde,

3-ethoxy-4-hydroxybenzaldehyde, 5-nitrovanillin, 3-methoxy-5-nitrosalicyaldehyde, 4-hydroxybenzoic acid, methylsalicylic acid,

chlorosalicylic acid, methoxysalicylic acid, aminosalicylic acid, methylsalicylic acid, formylsalicylic acid,

hydroxyisophthalic acid, methyl hydroxybenzoate, ethyl hydroxybenzoate, propyl hydroxybenzoate, methyl 5-methylsalicylate,

ethyl S-methylsalicylate, hydroxybenzamide,

Claims

1. A method of treating finished garments comprising cellulosic material so as to cause cross-linking, which comprises the step of treating fabrics with an effective amount of a blocked cross-linking agent for cellulose, said cross-linking agent being thermally activated, wherein the blocked cross- linking agent comprises a polycarboxylic acid, which is blocked by esterification with an electron withdrawing alcohol or imide to form a polyester and wherein the blocking alcohol or imide comprises one or more of: a) trichlorophenol, b) isoeuginol, c) menthol, d) 4-cyanophenol, e) ethyl salicylate, £) 2,6-dimethoxy phenol, g) 4-aminophenol, h) dimethylamino phenol, and, i) N-hydroxysuccinimide. Amended sheet: 28 August 2006

2. A method according to claim 1 wherein the polycarboxylic acid is succinic acid, butyl tetra carboxylic acid (BTCA), 3,6-dioxaoctanedioic acid, tartaric acid, mucic acid, glutamic acid, methylamino diacetic acid, or nitriloacetic acid.

3. A method according to claim 1 wherein the polyester comprises one or more of: a) trichlorophenol diester of succinic acid, b) trichlorophenol diester of BTCA, c) N-hydroxysuccinimide diester of succinic acid, d) isoeugenol diester of succinic acid, and, e) menthol diester of succinic acid.

4. A method according to claim 1 which further comprises the step of heat curing the cellulosic material.

5. A method according to claim 4 wherein heat treatment is performed at a temperature of from 50 to 250C.

6. A method according to claim 4 wherein heat treatment is performed at a temperature of from 100 to 200C.

7. A method accord to claim 1 wherein the cross-linking agent has a molecular weight below 1500 Dalton. Amended sheet: 28 August 2006

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8. A composition for use in the method of any of the preceding claims which comprises an effective amount of a blocked cross-linking agent for cellulose, said cross-linking agent being thermally activated, wherein the blocked cross-linking agent comprises a polycarboxylic acid, which is blocked by esterification with an electron withdrawing alcohol or imide to form a polyester and wherein the blocking alcohol or imide comprises one or more of: a) trichlorophenol, b) isoeuginol, Cc) menthol, d) 4-cyanophenol, e) ethyl salicylate, f) 2,6-dimethoxy phenol, g) 4-aminophenol, h) dimethylamino phenol, and, i) N-hydroxysuccinimide.

9. A composition according to claim 8 further comprising a textile compatible carrier. Amended sheet: 28 August 2006

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10. A composition according to claim 9 wherein the textile compatible carrier comprises a surfactant.

11. A composition according to claim 10, packaged in the form of a spray.

12. A method according to claim 1, substantially as herein described with reference to any one of illustrative examples.

13. A composition according to claim 8, substantially as herein described with reference to any one of the illustrative examples. Amended sheet: 28 August 2006