AU630275B2

AU630275B2 - Treatment of wool

Info

Publication number: AU630275B2
Application number: AU70866/91A
Authority: AU
Inventors: Derek Wallwork Heywood
Original assignee: Bip Chemicals Ltd
Current assignee: Bip Chemicals Ltd
Priority date: 1990-02-07
Filing date: 1991-02-07
Publication date: 1992-10-22
Anticipated expiration: 2011-02-07
Also published as: NZ237014A; GB9101054D0; EP0441421A1; DE69108588T2; DE69108588D1; GB9002680D0; ZA91605B; EP0441421B1; GB2240790A; AU7086691A; GB2240790B

Description

AUSTRALIA

Form PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: 1A 4 r~er i;:C

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0 0~ 00 0 o0 06 0 g0 0 0 0I 004 Complete Specification Lodged: Accepted: Lapsed: Published: Priority: Related Art: TO BE COMPLETED BY APPLICANT

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So o 0 0 0 00 *0f 0 0 o lJame of Applicant Address of Applicant Actual Inventors: Address for Service: BIP CHEMICALS LIMITED a company organized under the laws of England of 20 St Mary's Parsonage, Manchester, M3 2NL, England Derek Wallwork HE' WOOD CALLINAN LAWRIE, Patent Trade Mark Attorney, 278 High Street, Kew, Victr .ia 3101, Australia.

Complete Specification for the invention entitled: "TREATMENT OF WOOL" The following statement is a full description of this invention, including the best method of performing it known to me:-

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ROb'rFr-ankl in Had field Signature of Declarant Authorised Signatory The Commissioner of Patents.

REATMENTO F WOOLT This invention relates to the treatment of wool, and is particularly concerned with a process for improving its resistance to shrinkage.

A process very widely used for this purpose entails subjecting the wool to an oxidation 'treatment, usaally a chlorination, as with free chlorine or a hypochlorite or dichloroisocyanurate salt; removing unreacted (and potentially very damaging) oxidising agent from the wool fibres, as by passage through a reducing medium such as sodium sulphite solution, followed by a water rinseV and then treating the with a synthetic resin to impart a resistance to shrinkage which supplements that given by the oxidation treatment. Usually thereafter, but sometimes simultaneously with the resin 'treatment, the wool is treated with a softening agent to soften the harsh handle which it would otherwise have as a result of the 2 resin treatment; and in due course the treated wool is dried evenly at a moderately raised temperature to ensure that adequate curing of the resin has taken place.

The process just outlined can be applied to the treatment of wool tops (ie wool fibre before it is spun) as well as S e0 to the treatment of yarn and of woollen piece goods and o o garments.

o .o Probably the resins most used in the process are those obtained by reaction of epichlorhydrin (a compound having a reactive epoxy group attached to the radical -CHC1l) with a polyamide whose repeating unit contains basic -NHor -NH 2 groups, as distinct from the non-basic -NH- groups of the amide linkage -CO.NH-. Such a resin is for example that obtained by the reaction of epichlorhydrin with the condensation product of a polyalkylene amine eg triethylene diamine (H2NCHxCHANHCHZCH 2 NH2) and adipic acid (HOxC.OCHCHzCHCHZCOZH). Not all such resin is exhausted onto the wool from whatever medium the epichlorhydrin resin is applied, and there is now strong evidence that the resin-containing aqueous effluent from the process is harmful because of the presence in it of chlorine covalently bound to carbon, as in the -CHC1 group.

i; i 1 3- We have now found that effluent problems can be greatly reduced, and a treated wool produce obtained with properties just as good as those that result when an epichlorhydrin resin is employed, by using a colloidal melamine resin as the resin to impart shrinkage. Colloidil melamine resins are used in the treatment of paper to o0) improve its wet strength, and are obtained by dissolving a partially condensed melamine formaldehyde resin in an acid o,0) such as hydrochloric, formic, acetic or lactic acid under 'o controlled conditions, and further diluting with water.

a a a The solution becomes infinitely miscible with water, and on aging develops a bluish haze. The solution contains positively charged colloidal particles of the melamine a resin.

a a According to the invention, there is provided a process for the treatment of wool to improve its resistance to o00 "shrinkage, by subjecting it first to an oxidation treatment and then to a resin treatment to supplement the shrink resistance imparted by the oxidation treatment, the resin treatment being accompanied or followed by treatment with a softening agent to soften the harsh handle associated with use of the resin, in which process the resin employed is a colloidal melamine resin and the softening agent employed is a silicone polymer.

4 Preferably, the silicone polymer is dispersed in the colloidal melamine resin,ie in the aqueous phase which constitutes the dispersion medium of that system.

*There is described in EP-A-80272 a process for the shrinkresist treatment of wool, by o' a chlorinating the wool with an acidified hypochlorite a 0o b removing excess chlorinating agent from the wool c applying to the acidified wool an acid colloid solution of a methylol melamine resin, which solution may contain a suitable softening agent, such as for example those of the polyethylene type.

a e EP-A-80272 is not, however, concerned to avoid effluent problems arising from the presence of -CH 2 C1 or like groups in the resin conventionally used for wool treatment; nor does it mention the use of a silicone polymer as softening agent, a use which we have found has the advantage over polyethylene softeners of producing in the wool better stabilisation against shrinkage and better non-felting properties during washing.

The silicone polymer employed as softening agent may be cationic, but is preferably non-ionic. In general the silicone polymer used shows no chemical reactivity towards the colloidal melamine resin.

The melamine resin employed is preferably one which has at least two -CHzOR groups per melamine nucleus, where R H or is an alkyl group containing from one to four carbon atoms.

of* The invention is further illustrated by the following .Examples.

Example 1 An acidic melamine resin solution was produced by mixing the following ingredients in the following proportions by weight.

Aqueous solution (80% reactive solids; pH at 1:1 HZO dilution=8.5) of partially condensed melamine formaldehyde resin available as BEETLER 336 Concentrated hydrochloric acid (specific gravity=l.16) 1kg Water at 400 C 36kg 6 The mixture was allowed to stand for 2 hours to develop colloidal properties, and was then diluted with an equal volume of water to give a colloidal melamine resin having a shelf life of more than 6 months.

The diluted composition (1 part by weight) was further diluted with water (4 parts) and to this mixture was added o 11 an aqueous emulsion of a non-ionic -olydimethylsiloxane (0.5 parts by weight; silicone content 35% by weight).(The silicone release agent sold by Basildon Chemicals under the designation BC330 is very suitable.) o 4ux The mixed melamine resin/silicone polymer composition was g then applied, from a bath adjusted with acetic acid to pH S5-6, to knitted wool garments which had been conventionally chlorinated with a dichloroisocyanurate salt, treated with antichlor, and rinsed.The bath temperature was slowly raised from ambient to 400 C during 10 minutes, and held at that temperature for a further 10 minutes to exhaust the melamine resin and silicone polymer onto the wool. Weight gain was about by dry weight of the wool.The material was then removed from the bath, hydroextracted and tumble-dried at 60-800 C.

7 Example 2 For the treatment of wool tops the procedure of Example 1 was modified as follows.

o The mixed melamine resin/silicone polymer was applied in the 4th bowl of a conventional 5-bowl unit to deposit 0 about 1.5% of solid mixture onto the tops. The treated 0 tops were then passed to the 5th bowl, in which a cationic substituted stearamide had been included as additional softener. The tops were finally dried at 70-800 C.

o 0 b *-*Sain*

Claims

9- 6 A process according to any of claims 1 to 5, in which the oxidation treatment is a chlorination. 7 A process according to claim 6, in which the chlorination utilises a dichloroisocyanurate salt. 8 A process according to any of claims 1 to 7, applied to the treatment of wool tops. S Q a4 0 S 9 A process according to any of claims 1 to 7, applied a to the treatment of knitted wool garments. o .O A process according to claim 1, substantially as herein described with reference to the Examples. t* 0 o9a DATED this 7th day of February 1991 BIP CHEMICALS LIMITED by their Patent Attorneys CALLINAN LAWRIE "00.