AU661279B2 - Softening agent for natural or systhetic fibres - Google Patents

Abstract

A method for the treatment of natural or synthetic fibres, such as wool, cotton, nylon or acrylic, so as to impart a softer handle comprises treating the fibres with a polymer or prepolymer as defined. The method may be performed as either a continuous process or as a batch process.

Description

86613 91 0PI DATE 20/05/92 AOJP hATE 25/06/92 APPL.N. ID PCr PCT NUMBER PCT/GB91/01792 INTERNATIONAL AfPFLICAIlUN PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (51) International Patent Classification 5 D06M 15/53, 13/372, 15/61 (11) International Publication Number: Al (43) International Publication Date: WO 92/07132 30 April 1992 (30.04.92) ee F!? 3 (21) International Application Number: PCT/GB91/01792 (22) International Filing Date: 15 October 1991 (15.10.91) Priority data: 9022305.8 15 October 1990 (15.10.90) GB /'Pe 'RocC£SEs 7X 7/ 5s (71) Applicant (for all designated States except US): 4PEISION PR OESSES (TEXTILES) LIMITED [GB/GB]; Dylan Laboratories, Ambergate, Derby DE5 2EY (GB).

(72) Inventors; and Inventors/Applicants (for US only) CONNELL, David, Longley [GB/GB]; Ithersey, Burland Green Lane, Western Underwood, Derby DE6 4PF HUDDLES- TONE, Kenneth, Michael [GB/GB]; 195 Allestree Lane, Allestree, Derby DE3 2PF BAMFORD, Susan [GB/GB]; 53 West Avenue, Ripley, Derbyshire DE5 3JA

(GB).

(74)Agent: GAUNT, Robert, John; Stevens, Hewlett Perkins, 1 Serjeants' Inn, Fleet Street, London EC4Y ILL

(GB).

(81) Designated States: AT (European patent), AU, BE (European patent), CA, CH (European patent), DE (European patent), DK (European patent), ES (European patent), FR (European patent), GB (European patent), GR (European patent), IT (European patent), JP, LU (European patent), NL (European patent), SE (European patent), US.

Published With international search report.

1279 (54) Title: SOFTENING AGENTS (57) Abstract A method for the treatment of natural or synthetic fibres, such as wool, cotton, nylon or acrylic, so as to impart a softer handle comprises treating the fibres with a polymer or prepolymer as defined. The method may be performed as either a continuous process or as a batch process.

kA WO 92/07132 PCT/GB91/01792- -1- SOFTENING AGENTS This invention relates to the novel use of known polymers and prepolymers as softening agents to improve the handle of both natural and synthetic fibres.

Traditionally employed softening agents have as their basis either fatty acid or reactive siloxane chemistry. In both cases, the use of such agents imparts a degree of hydrophobicity to the treated fibres. While attempts have been made to overcome this effect by the incorporation of hydrophilic groups, such as amino, quaternary ammonium and polyethylene oxide groups, these generally have the effect of reducing the softness of handle that can be achieved and some hydrophobicity nevertheless remains.

In addition, particularly in the case of fatty amide based softening agents, the effects are transitory and tend to be readily removed upon subsequent wet processing of the treated fibres or during domestic washing of the finished product. Consequently, it has been necessary either to re-soften the material by re-applying a softening agent (which is inefficient and uneconomic) or to tolerate a reduction in the level of softness following washing of the product.

British Patent Nos. 1470243 and 1533343 describe compounds containing aziridine radicals and their use for reducing the shrinkage and felting of protein fibres. One of the compounds disclosed is that sold under the trade name Basolan SW, and which is marketed as a hydrophilic polymer that is said to achieve a soft hydrophilic finish when applied to synthetic fibres.

1Et Y 1~1 WO 92/07132 PC7/GB91/01792 2 The.present invention seeks to provide improved softening agents suitable for use with both natural and synthetic fibres. The polymers and prepolymers employed for this purpose are the subject of our co-pending European Patent Application No.

95o4gS' g. EP-A-o m 7 1 The present invention relates to the use as a softening agent for natural or synthetic fibres of a compound of any one of the following formulae:i) Z-([A]m-N(RI)n}r

(I)

which may be expressed more simply as: J[N(Rl)n]r

(II)

or ii) structure involving crosslinkihg or bridging of the above groups or (II): N-A3R) Z B

(III)

which may be expressed more simply as: (R1)N JT B

(IV)

j 1; ,B WO 92/07132 PCT/GB91/01792 3 or iii) a low molecular weight polymeric structure formed from the above groups or (II):

(V)

wherein Z represents a residue of a polyol, preferably a di- or trivalent polyol; A represents a polyalkylene oxide residue, that is a polyether chain produced by polymerisation of, for example, ethylene, propylene or butylene oxides or tetrahydrofuran; B is the residue created by bi- or polyfunctional reaction between any polyfunctional reactive group and the parent amine of the title compounds (formula where R1 is hydrogen in all cases), or is the residue of a reactive amino-acrylic polymer of the type described in EP-A-0129322) or a reactive polyamide polymer of the type described in EP-A-0260017A or a Hercosett polymer), and may be taken, for example, to represent a group -E-(R3)pN-[D]-N(R3)p-E-

(VI)

a group

N

NR

(VII)

WO92/07132 PCF/GB91/01792 4 a group resulting from the reaction of a bior polyfunctional species capable of reacting with amino groups, for example: epihalohydrins, alkyl diand polyhalides, di- or polycarboxylic acids or their acyl halides and anhydrides, dicyandiamide, urea and formaldehyde, a group derived from low molecular weight reactive resins such as the Bisphenol A type, or a group derived from reaction of a cationic polymeric reactive species such as R

F

6 6 -CH--CH-CH- N Y- N -CH-CH-CH-- 22 H R 7

R

7 OH q where R 6 and R 7 are selected from C 1

-C

5 alkyl and

C

2

-C

5 hydroxyalkyl radicals, Y is selected from C 2

-C

6 alkylene radicals, 2-hydroxy-1,3-propylene radicals, and the radicals:

-CH

2

CH

2

NHCONHCH

2

CH

2 and

-CH

2

CHCH

2

NHCONHCHCH

2

CH

2 and q is an integer of from 0 to 20, provided that when q is greater than 2, each of the symbols Y need not necessarily have the same significance; D represents a straight or branched chain hydrocarbon, polysiloxane or polyalkylene oxide residue, and which may also either bear functional groups or may contain functional groups, such as amino groups, which may in turn either bear one or more groups R1 or, where B is polyfunctional rather than bifunctional, may represent a further functional i 'WO 92/07132 PCT/GB91/01792 5 reaction point of the group B with the rest of the molecular structure; E represents a group resulting from the reaction of a bi- or polyfunctional species capable of reacting with amino groups, for example: epihalohydrins, alkyl di- and polyhalides, dicarboxylic acids or their acyl halides and anhydrides, dicyandiamide, urea and formaldehyde; J represents a residue derived from a polyfunctional polyether; K represents the monofunctional or polyfunctional residue derived from partial reaction of the basic prepolymers in formulae or i.e.

it represents the shaded area in formula (III) as follows: 1 i

R

1 represents a fibre reactive grouping such as the residue derived from monofunctional reaction of an epihalohydrin, an alkyl or alkyl aryl polyhalide or a methylol grouping derived from monofunctional reaction of formaldehyde, or is alkyl, hydroxyalkyl or hydrogen, with the proviso that at least one group R 1 per polyoxyalkyleneamine residue, and preferably at least one for each nitrogen, retains residual fibre reactivity;

R

2 represents a fibre reactive grouping such as the residue derived from monofunctional reaction of an epihalohydrin, an alkyl or alkyl aryl polyhalide or is a methylol grouping derived from monofunctional reaction of formaldehyde, or alkyl, hydroxyalkyl or hydrogen; rI WO 92/07132 PCT/GB91/01792 -6-

R

3 represents hydrogen or C 1

-C

4 alkyl or hydroxyalkyl;

R

4 represents halogen or a group

F

(VIII)

or one of alkylamino, hydroxyalkylamino, alkoxy, alkylarylamino or a group -(R3)pN-[D]-R or a functional reaction point of the group B with the rest of the molecular structure, where B is polyfunctional rather than bifunctional;

R

5 represents hydrogen or a group -N(R 2 )n or -N(R 3 )n; m is between 4 and n is 2 or 3, with the proviso that, where n is 3, the nitrogen atom involved also bears a formal positive charge; p is 1 or 2, with the proviso that, where p is 2, the nitrogen atom involved also bears .a formal positive charge; r equals the functionality of group Z; t is a number representing the functionality of reaction of the residue B; s is a number between 1 and r-1; iL WO 92/07132 PCT/GB91/01792 -7x is between 2 and 30; and y is from x to x, t-1 with the general proviso that, in any given instance, the significance of a particular group Z, A, B, R, J or K in any given structure shall not be dictated by the significance of any other such group in the same formula, and further, wherever a formal positive charge is present in the structure, then an appropriate counter anion is taken to be present, for example chlorida ion.

The term "fibre reactive grouping" as used herein is to be understood as meaning a group having residual chemical reactivity such that it will be capable of causing a molecule to be bound to the surface of a fibre in such a way as not to be readily removable therefrom. Examples include the fibre reactive dyes in which a variety of reactive halogen groupings are sited on the molecule and which, during dyeing, react with hydroxy or amino functionalities on the fibre surface to produce a chemical bond. It will be understood that electrical bonding forces, rather than chemical forces, could be involved and that a "reaction" as such need not occur. The terminology further includes species which will be attracted to a fibre surface and bind themselves thereto by means of cross-linking mechanisms.

The term "polyfunctional reactive group" as used herein is to be understood as meaning a group which is capable of reacting with the amino functionality of compounds of formula I or II. The reactivity of group B needs to be complimentary to that of group R 1 in those compounds.

It will be understood that the polymers and Si ,1 F- IV WO 92/07132 PCT/GB91/01792 8 prepolymers may be derived from mixtures of one or more polyoxyalkyleneamines and that these may be joined by bridging groups. The bridging groups serve to link the polyoxyalkyleneamines and some examples of suitable groups were mentioned above. The bridging groups themselves could, of course, bear reactive species capable of reacting with fibres. It will also be appreciated that the bridging group B could be incorporated into the molecular structure, whilst the prepolymer is being applied to the fibre, as a separate reactive crosslinking agent.

The present invention further provides a method for the treatment of natural or synthetic fibres so as to impart a softer handle and which comprises treating the fibres with a polymer or prepolymer compound of the aforementioned type.

The softening agents and method of this invention may be applied to all types of natural and synthetic fibres, including nylon and acrylic. Thef are particularly suited to use with wool and cottQ,, including 100% cotton terry loop towelling, and to cotton or wool blends with synthetic fibres.

The softening agents of the invention may be presented for use in solution in a non aqueous solvent, such as perchloroethylene. More preferably, however, they are in the form of an aqueous solution, optionally with the addition of suitable dispersing I agents to reduce the viscosity of the solution. The total amount of polymer solids applied to the fibres is generally from 0.005 to 10.0% by weight, most preferably from 0.05 to The method of this invention can be performed as either a batch or continuous process using conventional equipment. For example, the softening agent may be applied aqueously by exhaustion on to the goods in a traditional long bath WG 92/07132 PCT/GB91/01792 -9method using suitable machinery, or may be padded onto fabric continuously or applied in foam or by suctionslot techniques. In addition, the agent may be applied to piece goods or fabric from a solvent such as perchloroethylene in suitable machinery.

If desired, the softening agents may be applied in combination with other resins, further softening agents, emulsifiers, pigments, binders fluorescent whitening agents or other materials to confer additional properties or benefits to the material.

It has surprisingly and advantageously been found that the use of polymers and prepolymers of this type as softening agents imparts rather different, and improved, properties to the treated fibres compared with conventional softeners. Not only is a very soft handle achieved, but the finish is also extremely hydrophilic and substantially more durable to subsequent washing or wet processing. The durable softness thus imparted results also in dimensional retention and elasticity in knit cotton structures without recourse to conventional cotton resin finishes.

As will be appreciated, this results in considerable benefits for both manufacturers and users of, for example, cotton towelling, bathrobes, underwear and leisurewear.

A further advantage of the softening agents of this invention arises from their extreme water dispersibility. Conventionally employed softening agents are emulsions which create problems of shear instability in such high shear situations as jet dyeing machines, suction slot evacuators, and filtration problems when treating yarn in package dyeing machines, when filtration effects can cause difficulties. These problems are reduced, or totally avoided, with the present softening agents.

I

/2 WO 92/07132 PCT/GB91/01792 A still further surprising aspect of the invention is that these softening agents, when used in combination with one or more conventional softening agents, can result in finishes with considerably superior handle and performance than may be expected.

Wash durability, handle and fuming during fabric heat setting, for example, are much improved. In some cases the improvement may be up to or above the levels achieved with either material alone, indicating a synergistic action. Examples of suitable "conventional" fabric softening agents include: oxidised polyethylene wax emulsions; silicone emulsions, especially emulsions of reactive organofunctional silicones, and more especially amonosilicones; fatty amide emulsions; and quaternised fatty amine emulsions.

The present invention will now be illustrated by the following Examples.

\I

WO 92/07132 PCT/GB9P/01792 11 Example 1 A solution was prepared containing 881 g of a bisaminopropyl polytetrahydrofuran of structure H2N CH2.CH2.CH2-tfO(CH 2 4 -Wa 0 CH2.CH2.CH 2

NH

2 (where a is approximately 28 average) in 2418 g of a mixture of isopropanol in water. To this solution was added 155.3g of epichlorohydrin with efficient stiiring at room temperature in a reaction flask fitted with a water cooled reflux condenser. The mixture was then heated to boiling and reflux maintained for approximately 4 hours or until a clear or slightly turbid homogeneous solution is produced when 5 cm 3 of the reaction mix is mixed with 30 cm 3 water. The reaction mixture was then allowed to cool and used in subsequent experiments.

Example 2 Various textile samples were treated with the product of example 1 as follows: scoured goods were placed in a blank bath at a liquor ratio of 30:1 and the bath set to pH 6.5 to 7.0 at 25 0

C.

The required amount of softener -was added to the bath in prediluted form 1:10 with water. The bath was raised to 35 0

C

and then allowed to exhaust, as indicated by the disappearance of the slight turbidity from the bath, which usually took between 15 and 30 minutes. The goods were then removed, hydroextracted and dried in a tumble dryer at between 700 and 100 0 c.

The results of the tests are presented in Table 1.

Example 3 Formulation A formulation was produced containing 20 parts product from Example 1, 20 parts nonyl phenol 8 mole ethoxylate and 10 parts nonyl phenol 6 mole ethoxylate.

Application 1 A Bowe P421 dry cleaning machine was loaded with 30 kg of mercerised Cotton 40% nylon predyed mens socks. Then 130 litres of perchlorethylene was charged to the machine and the goods tumbled in solvent for 1 minute to wet out. 1.95 kg of the above formulation was then added to the machine via the button trap and the goods tumbled for 5 minutes, then the solvent drained to the still and centrifuged to 100% expression, then tumble dried.

Application 2 The above procedure was repeated, but using 1.43 kg of the above mixture and 1.95 kg water placed in the button trap.

WO 92/07132 WO 9207132PCr/GB91/01792 12 Results Example 3b 3c Wetting time* 8 sec 1 sec Handle very soft very soft Handle after sof t sof t in addition to the ythe changes imz lateral stretching of the sock after wasti~ng were measured sand compared with an untreated sock.

Percent change in lateral- stretch f oot Example 3c Untreated -2.8 -8.*9 ankle leg -2.2 -1.3 -8.5 -7.5 welt -1.3 -2.3 This further indicates retention of softness and springness of the knitted structure after washing.

Not

I

WO 92/07132 WO 9207132PCr/GB91/01792 13 Table 1 Article treated AiMat of Product of amhwi1e I wetting test Handle Washing Handle test **after Washing lo0t cotton terr 1ccT 1.73% instantaneouis very soft 7 washes very soft hand tcxels and~ sik toH~ Cotton 3.46% 9 seconds vry soft 10 washes very soft nylon to fl.CM intarsia i.73% 3 seconds soft soft pattern raes socks cotton nylcn 3.46% not very Soft 10 washes very soft pla In d.,,vd determined to HECM navy meo SOCKS 100% cotton terry lcp 1.73% 3 seconds very soft 10 washes very soft bathrobe to fabric 3.46% 5 seconds Very sof t HIOM very soft nil instant hursh very harsh time taken for a 0.1 m~' 3 drop of water to sin), into the fabric *in a Wascator FCM7 procedlures 1 acording to Hom laundering Consultative ouncil WO 92/07132 PCT/GB91/01792 -14 Example 4 The product of Example 1 can be prepared as an aqueous solution by distilling out the isopropanol and replacing it with water, thereby minimising fire hazard. 797 parts of the product of Example 1 is distilled at atmospheric pressure until 391 parts of an isopropanol: water distillate is collected. Then, 710 parts of water and 80 parts monoethylene glycol is added to the flask and stirred. The resulting product contains about 20% w/w active solids and only 4-5% isopropanol.

The product was applied to wool and acrylic socks by an exhaustion method as in Example 2. Excellent handle and good durability was achieved.

Example The softening agent can be mixed with conventional fatty quaternary ammonium-type softeners to give a product which has excellent handle, good durability and superior hydrophilicity to conventional softeners. Such a product is particularly useful for softening cotton/nylon socks.

a) Formulation 797 parts of the product of Example 1 were distilled at atmospheric pressure until 391 parts of an isopropanol: water distillate were collected. 391 parts of water were added to this, stirred and this product blended with 341 parts of a commercial fatty quaternary ammonium softener (PPT Ltd).

Sb) Application The performance of this softener was compared against conventional types on cotton/nylon socks. The softeners were applied as described in Example 2. The results are presented in Table 2.

MOM

WO 92/07132 PCr/GB91/01792 Table 2 Sof teners applied to cotton/nylon socks A2Rl icat ion 2% Example 5 2% Ceranine PNP 1 1.2% Permavel R 2 Permavel H 2 Scour only Wett ipri 13 sec 140 sec 35 sec 270 sec 60 sec Handle before wash 3 x MSB III Patty amide s=iftener, Sandoz Products Ltd.

Durable silicome softeners, PPT Ltd, prepared as in European Paxtent Application No. 89312306.7.

described Example 6 A stable product can be formulated by taki~ng 100 parts of the product of Examile 4 and blending this with 30 parts of a silicone emulsioi, (eg Finish VP1445E, Wacker Chemicals Ltd).

This product va--s compared for handle on knitted lambswool swatches against a silicone softener (Wacker VP144SE). The softeners were apaplied by exhaustion, as described in Example 2 using 1-2% product on weight of wool. The new softener gave*~ super-soft handlem, less slippy and more natural than with the silicone. The hydIrophilicity was also noticeably superior.

WO 92/07132 PCT/GB91/01792 16 Example 7 a) To a solution of 254g bisaminopropyl polytetrahydrofuran (of the structure in Example 1) in 700g of a mixture of isopropanol in water was added 39g DER732 (Dow Chemical Co.) and 7.8g epichlorohydrin. The mixture was refluxed for 4 hours or until a clear or slightly turbid solution was obtained when 5cm 3 of the product was added to 30cm 3 of water.

b) A solution containing 238g bisaminopropyl polytetrahydrofuran (of the structure in Example 1) in 712g isopropanol was prepared. To this was added 27g DER732 (Dow Chemical 16.6g Tego OF3010 (Th. Goldschmidt Ltd) and 7.3g epichlorohydrin. The mixture was refluxed for 4 hours or until a homogeneous, but turbid, solution was obtained when 5cm 3 of the product was added to 30cm 3 of water.

Example 8 The products of Example 4 and Examples 7a and 7b were applied to a variety of knitted cotton fabrics (double jersey, single jersey, loopback interlock and pique). The softeners were applied by a) padding: the softeners were applied wet-on-wet to the fabrics from a solution containing 25g/l product, pH7, 25 0

C

at 100% pick-up and b) exhaustion: as given in Example using o.w.g. product. The fabrics were stenter dried and commercially finished then compared for handle and durability to washing against a standard fatty amide softener. A co-applied mixture of the product of Example 4 and a polyethylene wax emulsion (Bradsyn G, Hickson Welch Ltd) was also evaluated.

The relative handle and durability assessments were as follows.

In general, the handle before and after wash was superior when softeners were applied by a padding technique compared with exhaustion. Before washing the softeners were comparable in softness to the standard silicone softener (Edunine SE, ICI Colours Fine Chemicals); after wash, (3 x HLCC4<, the standard softener could be readily distinguished by its harsher handle.

The Example 4/polyethylene wax mixture performed particularly well on all fabric types, giving a cool, soft handle and excellent drape.

I,

WO 92/07132 PCT/GB91/01792 17 Example 9 The softening agents of the invention are particularly suited to use on towels and towelling fabric as a consequence of their superior hydrophilicity. The products were applied by a wet-onwet continuous pad treatment at 80% pick-up, from solutions containing 20-40g/l softener to Egyptian combed cotton towelling. The fabrics were tumble tried and finished as towels. A warm, soft handle is achieved with excellent rewettability, as compared with silicone- and fatty amide-type softeners. The new softeners impart a fuller, more luxurious feel to towelling and a silkier handle. The durability of the softeners was assessed by subjecting the towels to seven domestic washes, without additional fabric conditioner and line dried. The towels treated with the new softeners retain their original appearance, with a full, soft handle.

Example The product of Example 4 was compared for yellowing at high temperatures against standard silicone- and fatty amide-type softeners. The products were applied to 50/50 polyester/cotton by padding from solutions containing 1 g/l wetting agent (Fullwet PPT Ltd) and 10-40 g/l softener. The fabrics were padded to 100% pick-up then dried. Yellowing of the fabrics was assessed by heating the fabrics on an electrically-heated press for up to 3 minutes.

Temperature Comments 180 0 C Little difference between products 200 0 C Example 4 showed no yellowing at 1,2,3 mins at all levels. Other products yellowed slightly.

2200C Slight yellowing of Example 4. Other products were markedly yellowed.

J

Claims (13)

1. A method for the treatment of natural or synthetic fibres so as to impart a softer handle and which comprises treating the fibres with a polymer or prepolymer having one of the following structural formulae: i) or ii) J(N(Rl)nr LRnN3N(-J{NRlfr#B I or iii) wherein J represents a residue derived from a polyfunctional polyether; K represents the monofuctional or polyfunctional residue derived from partial reaction of a prepolymer of the formula: (AlIN(Rl)n) JIN(Rl)nlr (II) hydrogen; WO 92/07132 PCr/GB91/01792 19 that is, it represents the shaded area in the following formula: B is the residue created by bi- or polyfunctional reaction between any polyfunctional reactive group and the parent amine of the titi' compound (formula where R1 is hydrogen in all cases) or is the residue of a reactive amino-acrylic polymer or a reactive polyamide polymer; Z represents a residue of a polyol; A represents a polyalkylene oxide residue; R 1 represents a fibre reactive grouping such as the residue derived from monofunctional reaction of an epihalohydrin, an alkyl or alkyl aryl polyhalide or a methylol grouping derived from monofunctional reaction of formaldehyde, or is alkyl, hydroxyalkyl or hydrogen, with the proviso that at least one group R1 per polyoxyalkyleneamine residue, and preferably at least one for each nitrogen, retains residual fibre reactivity; LsT m is between 4 and n is 2 or 3, with the proviso that, where n is 3, the nitrogen atom involved also bears a formal positive charge; 11~ ii~A- N'I I- Ii equals the functionality of group Z; is a number representing the functionality of reaction of the residue B; is a number between 1 and r-1; is between 2 and 30; and x y is from to x, t-1 with the general proviso that, in any given instance, the significance of a particular group Z, A, B, R, J or K in any given structure shall not be dictated by the significance of any other such group in the same formula, and further, wherever a formal positive charge is present in the structure, then an appropriate counter anion is taken to be present.

2. A method as claimed in claim 1, wherein the total amount of polymer solids applied to the fibres is from 0.005% to 10.0% by weight.

3. A method as claimed in claim 1, wherein the total amount of polymer solids applied to the fibres is from 0.05% to 2.0% by weight.

4. A method as claimed in any one of claims 1 to 3, wherein the polymer or prepolymer is presented for use in the form of an aqueous solution.

5. A method as claimed in any one of claims 1 to 3, wherein thie polymer or prepolymor is presented for use as a solution in a non-aqueous solvent. I i ft r r

6. A method as claimed in any one of claims 1 9<9 0A that of group R 1 in those compounds. It will be understood that the polymers and WO 92/07132 PCT/GB91/01792 21 to 5, wherein the fibres being treated comprise cotton or wool.

7. A method as claimed in any one of claims 1 to wherein the fibres being treated comprise nylon or acrylic.

8. A method as claimed in any one of claims 1 to 5, wherein the fibres being treated comprise a cotton or wool blend with synthetic fibres.

9. A method as claimed in any one of claims 1 to 8, wherein the polymer or prepolymer is applied in conjunction with one or more other softening agents.

A method as claimed in any one of claims 1 to 9, and which is carried out as a continuous process.

11. A method as claimed in any one of claims 1 to 9, and which is carried out as a batch process.

12. Use as a softening agent for natural or synthetic fibres of a polymer or prepolymer of the type defined in claim 1.

13. A formulation for the treatment of fibres comprising a polymer or prepolymer of the type defined in claim 1 together with one or more other softening agents. I INTERNATIONAL SEARCH REPORT Internutional Appliction IWo PCT/GB 91/01792 1. CIASSIFICATION OF SUBJECT MATTER (if several classdfication symabols apply, indicate 119)6 According to International Patent n-assficatlon (IPC or to both National Oassiflaon and IPC Int.C1. 5 D06M15/53; D06M13/372; D06M15/61 H. FIELDS SFARQIED Minimum Documentation Searched 7 Classification System Clasification Symbols Int.Cl. 5 D06M Documentation Searched other than Minimum Documentation to the Extent that such Documents are Included in the Fields Searchedt IIL DOCUMENTS CONSIDERD TO BE RELEVANTI Category Citation of Document, It with Indication, where apprprate, of the relevant passages 1 2 Relevant to Claim No.13 PX EP,A,O 414 377 (PRECISION PROCESSES (TEXTILES) 1-13 LTD.) 27 February 1991 cited in the application see the whole document X DE,A,1 419 042 (BbHME CHEMIE GMBH) 27 March 1969 1-13 see the whole document X FR,A,1 165 287 (ONYX OIL CHEMICAL COMPANY) 21 1 October 1958 see the whole document A US,A,3 038 820 (OTTO ALBRECHT) 12 June 1962 1-13 see the whole document A GB,A,1 171 304 STEVENS CO. INC.) 19 1-13 November 1969 see the whole document 0 Special categories of cited documents 10 'T later document published after the international filing date A docmentdefiing he gnera s~eof te hish~ ~lor prioritydt n not In conflict with the applilcation but 'A Cocnside n t he geealb e of parihea le a rtwic seo cited to =nutn the puinciple or theory undeulying the consdere tobe o paticuar elevnceinvention uaier dacr mt but published on or after the International 'V document opatclreeaceheclaimed invention fiing dute =otbe coIwdnve r ant be considered to document which may throw doubts on priority claim(s) or Involve an inwastive sep which Is cited to establish the publication date of another IV docuent of cu p arta ee c th c ad invention citation or other special reason (as specified) cannot be cosdered to involve an inventive step when the 0' document referring to an oral disclosure, use, ahdlW-)n or document is combined with one or more other such docu- other means ments, such combination beiog obvious to a person sWiled 11P document published prior to the international filing date but in the art. later than the priority date claimed WA document member of the same patent family IV. CERTIFICATION Date of the Actual Completion of the International Search Date of Mailing of this International Search Report JANUARY 1992 114302.92 Internatioal Searching Authority Signature of Authorized Officer IEUROPEAN PATENT OFMCE BLAS V. Fu- PCTIIAZIO 494- dhad) (JEO 1 L11" ANNEX TO THE INTERNATIONAL SEARCH REPORT Ir ON INTERNATIONAL PATENT APPLICATION No. GB 9101792 SA 52059 This annex fists the patent family members relating to the pr. 1 tet documents cited in the above-mentioned international search report. The members ame as contained in the European Patent Office EDP file on The European Patent Office is in no way liable for thee particulars which are merely given for the purpose of information. 30/01/92 Patent document Publication Patent family Pblication cited in search reportdaem brs)at EP-A-0414377 27-02-91 AU-A- 5979590 24-01-91 JP-A- 3081324 05-04-91 DE-A-1419042 27-03-69 AT-A- 212261 AU-B- 242198 BE-A- 585393 BE-A- 585394 CA-A- 690538 CH-A- 371083 DE-A-- 1445217 13-03-69 ES-A- 255001 FR-A- 1247042 GB-A- 880897 IT-A- 626236 NL-C- 129695 NL-A- 247433 NL-A- 261126 US-A- 3347803 BE-A- 599649 CH-A- 483469 3 1-12-69 FR-E- 79266 GB-A- 913911 FR-A-1165287 BE-A- 554506 DE-B- 1103284 GB-A- 797175 US-A-3038820 BE-A- 549558 DE-B- 1060595 FR-A- 1155193 FR-A- 1158764 GB-A- 835267 GB-A- 837950 US-A- 3006935 j 0 GB-A-1171304 19-11-69 US-A- 3351622 0 06 For more details about this annex :swe Official Journal of the European Patent Office, No. 12/82