CA1134986A

CA1134986A - Organosilicon polymers

Info

Publication number: CA1134986A
Application number: CA000337498A
Authority: CA
Inventors: Peter M. Burrill; Charles Smith
Original assignee: Dow Corning Ltd
Current assignee: Dow Silicones UK Ltd
Priority date: 1978-11-08
Filing date: 1979-10-12
Publication date: 1982-11-02
Also published as: FR2440961B1; GB2036052A; ZA795749B; AU528039B2; FR2440961A1; GB2036052B; JPS5566928A; DE2942786C2; AU5252779A; IT7927102A0; JPS586731B2; IT1165361B; DE2942786A1

Abstract

Abstract of the Disclosure Process for preparing a polydiorganosiloxane contai-ning amino-substituted organic groups by reacting (A) a silanol-terminated polydiorganosiloxane, in which at least 50 per cent of the total silicon-bonded organic substituents are methyl groups, with (B) a silane CH3(XO)2SiZ in which X represents alkyl or alkoxyalkyl and Z represents a mono-valent group composed Or carbon, hydrogen, nitrogen and optionally oxygen and which contains at least two amine groups, (A) and (B) being reacted in a proportion of from 1.75 to 3.5 moles of (B) per mole of (A). The polydiorgano-siloxanes are mixed with alkylhydrogen-polysiloxanes and the compositions employed for the treatment of textiles.

Description

~3~ 6 This invention relates to organosilicon polymers, to com-positions prepared from said polymers and to the use of the said compositions for the treatment of textiles.
In German OLS 2 621 460 of November 25, 1976 there are disclosed compositions for the treatment of wool to render itshrink 5 resistant, the said compositions comprising (A) a polydiorganosil-oxane having terminal OX radicals, in which X represents hydrogen, alkyl or alkoxyalkyl, and also having silicon-bonded substituents which contain at least two amino groups, and (B) an organosiloxane having at least three silicon-bonded hydrogen atoms in the molecule.
10 The preferred polydiorganosiloxanes (A) are those which are prepared by reacting a silanol-terminated polydiorganosiloxane which is free of the specified amino-containing substituents with a silane CH3(X0)2SiZ, in which Z represents a monovalent radical containing at least two amino groups. A polydiorganosiloxane of this type 15 which is specifically described in the German OLS is that obtained by reacting the silanol terminated polymer with 0.75% by weight of the silane. However, although such a polydiorganosiloxane functions satisfactorily as a component of the shrinkproofing compositions it has been found that the viscosity of such polymers tends to increase 20 during storage. This viscosity change constitutes a significant manufacturing inconvenience especially when it is desired to store or ship the polydi.organosi.loxane prior to subjecting it to emulsi-fication.
Acccrding to this invention we have now found that amino-~5 substituted polydiorganosiloxanes having improved stability of vis-cosity during storage can be obtained if the silane and polydiorgan-osiloxane reactants are brought together in certain molar proportions.
Accordingly this invention provides a process for the preparation of a polydiorganosiloxane which comprises reacting to-30 gether (a) a silanol-terminated polydiorganosiloxane having a mole-cular weight of at least 10,000 and wherein at least 50 per cent of the total silicon-bonded organic substituents are methyl groups, any remaining organic substituents being monovalent hydrocarbon groups having from 2 to 2Q carbon atoms, and (B) a silane of the general 35 formula C~3(X0)2SiZ wherein X represents an alkyl or alkoxyalkyl group having up to 5 carbon atoms and Z represents a monovalent group composed of carbon, hydrogen, nitrogen andt optionally, ~ ' .

'~

.. . . .

oxygen, the said group containing at least two amine groups and being attached to silicon through a silicon to carhon linkage, (A) and (B) being reacted in a proportion from 1.75 to 3.5 moles of (B) per mole of (A).
The polydiorganosiloxanes (A) employed in the preparation 5 of the copolymers of this invention are those having a hydroxylgroup attached to each terminal silicon atom and a molecular weight of at least 10,000. At least 50 per cent of the total silicon-bonded sub-stituents in the polydiorganosiloxane should be methyl groups, any remaining substituents being monovalent hydrocarbon radicals having l0from 2 to 20 carbon atoms, for example, ethyl, propyl, 2,4,4-tri-methylpentyl, cyclohexyl, vinyl and phenyl. Preferably the poly-diorganosiloxanes are polydimethylsiloxanes, those having molecular weights in the range from 20,000 to 60,000 (that is, having visco-sities from about 1000 to 10,000 cS at 25C) being most preferred.
In the general formula of the silanes (B) X may represent an alkyl group having from 1 to 5 carbon atoms or an alkoxyalkyl group having up to 5 carbon atoms, each X preferably representing methyl or ethyl. The group Z may be for example -( 2)3NH CH2CH2NH CH2CH2NH
2Q ~H2CH2NH2-(CH2)3~lH CH2CH2CH(CH2)3NH2 -(CH2~3NH(CH2)2NH CH2COOCH3, but is preferably selected from - (CH2)3NH CH2CH2NH2, -(CH2)4NH CH2C 2 2 2CH(CH3)CH2NH CH2CH2N~2 Reaction between (A) and (s) can be brought about by mixing the two at room temperature. It is preferred, however, to expedite the reaction by heating a mixture of (A) and (B) at a tem-perature of from 60 to 160C for a period of from 30 minutes to 3 hours. A catalyst for the reaction between -Si OX groups may be 30 employed if desired but the reaction usually proceeds at a satis-factory rate in the absence of a catalyst. At least 1.75 moles of the silane (B) are employed per mole of (A), the preferred range being from 1.95 to 2.5 moles of (B) per mole of (A).
The polymers prepared according to the process of this 35 invention can be emplo~ed in the manner described in German OLS

2 621 46~ to provide compositions for the treatment of keratinous fibres, e.g. ~ool, to render such fibres shrink resistant. They ~ . ~ .

. . - . .

_4_ ~3f~6 may also be employed as described in German OLS 2 728 597 in the preparation of compositions which can be applied to cellulosic and synthetic fibres, e.g. nylon, polyester and polyester-cotton blends, to impart thereto resilience and/or crease resistance. According to a further aspect of this invention, therefore, there are provided compositions comprising (i) a polydiorganosiloxane prepared by the process of this invention and (ii) an organosiloxane having at least three silicon-bonded hydrogen atoms in the molecule and in which the organic substituents are alkyl groups having less than 19 carbon atoms. Such compositions, in the form o~ solutions in organic sol-vents, or, more preferably, as aqueous emulsions, may be applied toa variety of textiles to impart thereto certain desirable properties.
For example they may be applied to keratinous fibres, particularly woollen garments, to impart thereto a significant resistance to shrinkage during launderi~g. When there is added to the composi-tions comprising (i) and (ii) a siloxane curing catalyst (iii) theresulting compositions are particularly suitable for the treatment of celluslosic and/or synthetic fibres to impart resilience and/or resistance to creasing. A wide variety of siloxane curing catalysts are known including acids, bases and organic metal compounds. The preferred catalysts are metal carboxylates e.g. lead 2-ethylhexoate, zinc naphthenate, stannous octoate, dibutyltin dioctoate, di-n-octyltin diacetate, dibutyltin di(iso-octylthioglycollate), dior-ganotin alkoxides e.g. dibutyltin diethoxide and dioctyltin dimeth-oxide, and titanium alkoxides e.g. butyl titanate, octylene glycol t;tanate and triethanolamine titanate. The most preferred catalysts are the organic tin compounds.
The organosiloxanes which comprise component (ii) of the compositions of this invention are, in general, well-known materials.
They may comprise any one or more organosiloxanes having at least three silicon-bonded hydrogen atoms in the molecule. They are pre-ferably linear siloxane polymers but may if desired be cyclic or ~ranched. The organic substituents present in the organosiloxane are preferably methyl groups but other alkyl radicals having less than 19 carbon atoms e.g. ethyl or 2 r 4,~-trimethylpentyl may also be present. The organosiloxane may be, for example, a copalymer of di-methylsiloxane units, methylhydrogensiloxane units and trimethyl-siloxane units or more preferably a trimethylsiloxy-terminated poly .~

~3~

(methylhydrogen siloxane).
The relative proportions of (i) and (ii) employed to pre-pare the treating compositions according to this invention are not critical. Up to about 20 per cent or more of (ii) based on the weight of (i) may be used. However, it is generally preferred that 5 the siloxane (il) be employed in a proportion of from 0.5 to 10 per cent by weight based on the weight of polydiorganosiloxane (i).
When the catalyst (iii) is incorporatecl in the treating compositions it is preferably employed in a proportion of from 0.25 to 10 per cent by weight based on the total weight of (i) and (ii).
When the compositions are applied as an organic solvent solution any appropriate volatile solvent may be employed as the carrier, for example toluene, xylene, white spirit or perchloro-ethylene. Any suitable emulsifying agent may be employed to prepare the aqueous emulsion treating compositions. The preferred emulsi-15 fying agents are those of the non-ionic or cationic types, for ex-ample the polyethoxy ethers of nonyl phenol and octyl phenol, the trimethylnonyl ethers of polyethylene glycols, monoesters of alco-hols and fatty acids, e.g. glyceryl monostearate, and ethoxylated amines.
Application of the compositions to textiles can be carried out using conventional techniques such as padding, dipping and spraying. Drying of the treated fibres and cure of the siloxane composition can be allowed to occur by exposure to normal ambient termperatures, that is from about 15 to 25C, for periods of up to 25 4 days or more. In general, however, it is preferred to expedite the drying and/or curing steps by exposure of the treated fibres to elevated temperatures, preferably from 50 to 17QC.
The following examples, in which the parts are expressed by weight, illustrate the invention.
30 Example 1 The silane CH3(CH3O)2Si(CH2)3NHCH2CH2NH2 (14 parts) (2 mol) and a polydimethylsiloxane (1000 parts) (1 moI? having a hy-droxyl group attached to each terminal silicon atom and a viscosity of approximately 4500 cS at 25C (mol.w~. approximately 46000) were 35 mixed together in a reaction vessel fitted with a stirrer and nitrogen purge. The reaction mixture was then heated to 135C with stirring and under nitrogen for 1.5 hours. The product was a siloxane polymer -6- ~3~ 6 (Polymer A) having a viscosity of approximately 6,500 cS at 25 C.
A portion of this polymer was stored at 22 C and its vis-cosity measured periodically during 6 months~ For comparison, similar viscosity measurements were also performed on a siloxane polymer (Polymer B) which had been prepared by an identical procedure except 5 that the silane was employed in a proportion of 1.25 moles per mole of the polydimethylsiloxane. This polymer had an initial viscosity of approximately 7,000 cS at 25C. The results obtained were as follows:

10 Siloxane ~iscosity (cS at 25C) . . __ .
Initial2 months 4 months 6 months Polymer A 6,5009~000 13,000 20,000 15 Polymer B 7,00013,000 29,000 52,000 Polymer A (33.3 parts), as prepared prior to storage was added gradually to a mixture of 3.33 parts of a non-ionic emulsifier (Tergitol ~ TMN-6) and water (7.30 parts). This mixture was 20 stirred for one hour, passed through a colloid mill and then diluted with water (56.0 parts) to yield an aqueous emulsion (Emulsion X).
Employing a similar procedure an aqueous emulsion (Emul-sion Y) of a trimethylsiloxy-terminated polymethylhydrogen siloxane (viscosity 30 cS at 25C) was prepared from 33.3 parts of the sil-25 oxane, 0.86 parts of an ethoxylated fatty amine emulsifying agent,1.65 parts of Tergitol TMN and 63.5 parts of water.
Emulsion X (4.6 parts) and Emulsion Y (0.06 parts) were mixed with 2040 parts of water in which had been dissolved 10.2 parts of sodium sulphate and 1.0 part of 50% aqueous acetic acid. A
30 piece of botany wool fabric (60g.) was immersed in the resulting liquor, the temperature of the liquor raised to 40C and the wool agitated therein. After about 30 minutes the liquor had become clear, indicating deposition of the siloxane on the fabric. The fabric was then removed, dried at 80C for about 6 minutes and ex-35 posed to the ambient atmosphere (60% RH, 20C) for 3 days.
The resistance of the treated sample to shrinkage wasmeasured according to the method of the International Wool Secre-,~1 :, . :. . ..
, . - , , : .

.L L3'~

tariat, Specification WSS 128, Test Method 185 employing a launder-ing period of one hour. The sample exhibited a shrinkage of only 0.3%
Example 2 Emulsion X and Emulsion Y, both as described in Example 5 1, were employed to treat nylon fabric according to the following procedure. Emulsion X (3 parts), Emulsion Y (0.5 part), a 20~ by weight aqueous emulsion of dibutyltin di(iso-octylthioglycollate) (0.1 part) and an aqueous solution (0.1 part) containing triethanol-amine titanate (50% by weight) and zinc acetate (11~ by weight), 10 were added separately with stirring to 2000 parts of water.
A piece of nylon fabric (lOOg.) was immersed in the aqueous liquor prepared as described above, the mixture being main-tained at 25C. After about 30 minutes the treating liquor had be-come clear indicating deposition of the siloxane on to the fabric.
15 The fabric was then removed from the treating bath, dried at 100C
and placed in an oven at 150C for 3 minutes to cure the siloxane.
When the crease recovery angle of the fabric was measured according to British Standard Specification 3086 a value of 156 was obtained.
The value for the untreated fabric was 110.
Example 3 Employing the pxocedure of Example 1 the silane ~CH3CH30)2Si(CH2)3NH CH2CH2NH2 (15.4 parts) (2.2 mol.) was reacted with a silanol terminated polydimethylsiloxane having a viscosity of approximately 4,000 cS at 25C. The product was a siloxane polymer (Polymer C) having a viscosity of 6,450 cS at 25C.
The polymer was stored at normal ambient temperature in a sealed container and its viscosity measured at intervals over a period of several months. For comparison, similar viscosity measurements were performed on a siloxane polymer (Polymer D) which had been prepared by an identical procedure but using 1.25 moles of silane per mole of polydimethylsiloxane. The results oktained were as follows:
Siloxane~ Viscosity (cS. at 25C) - - ~
Initial I After 2 months After 5 months Polymer C 6,450 8,200 11,500 Polymer D 7,600 19,800 41,400 ;~

.. .. .. - - . , ., . , . -, .~ , . . ... ... . ..

-8- ~ ~3 Example 4 A siloxane polymer was prepared as described in Example 1 except that the quantity of the silane employed was increased from 14 to 21 parts.
8.7 parts of this sïloxane polymer and 0.11 parts of a trimethylsiloxy end-stopped methylhydrogen polysiloxane were dis-solved in 750 ~arts of perchloroethylene and the resulting solution employed to treat pieces of knitted Shetland wool fabric (cover factor 0.85) by padding, the add-on of siloxane being 3% by weight based on the weight of the wool. The wool pieces were dried at 80C, subjected to further heating at 80C for 15 minutes to cure the siloxane and stored for 3 days prior to testing.
When the shrinkage of the fabric during laundering was measured as described in Example 1 a value of -1.2% was obtained after a one hour wash and -0.5 after a 3 hour wash.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for the preparation of a polydiorgano-siloxane which consists essentially of reacting together (A) a silanol-terminated polydiorganosiloxane having a molecular weight of at least 10,000 and wherein at least 50 per cent of the total silicon-bonded organic sub-stituents are methyl groups, any remaining organic sub-stituents being monovalent hydrocarbon groups having from 2 to 20 carbon atoms, and (B) a silane of the general formula CH3(XO)2SiZ, wherein X represents a group selec-ted from alkyl and alkoxyalkyl groups having up to 5 carbon atoms, and Z represents a monovalent group com-posed of carbon, hydrogen, nitrogen and, optionally oxy-gen, the said group having therein at least two amine groups and being attached to silicon through a silicon to carbon linkage, (A) and (B) being reacted in a propor-tion of from 1.75 to 3.5 moles of (B) per mole of (A).

2. A process as claimed in Claim 1 wherein the poly diorganosiloxane (A) has a molecular weight in the range from 20,000 to 60,000.

3. A process as claimed in Claim 1 wherein X is selec-ted from methyl groups and ethyl groups.

4. A process as claimed in Claim 1 wherein Z repre-sents a group selected from -(CH2)3NH CH2CH2NH2, -(CH2)4NH CH2CH2NH2 and -CH2CH(CH3)CH2NH CH2CH2NH2.

5. A composition consisting essentially of (i) a polydiorganosiloxane which has been prepared by the pro-cess claimed in Claim 1 hereof and (ii) an organosiloxane having at least three silicon-bonded hydrogen atoms in the molecule and in which the organic substituents are alkyl groups having less than 19 carbon atoms.

6. A composition as claimed in Claim 5 when in the form of an aqueous emulsion.

7. A composition as claimed in Claim 5 wherein (ii) is prcsent in a proportion of from 0.5 to 10 per cent by weight based on the weight of (i).

8. A composition as claimed in Claim 5 wherein there is also present a siloxane curing catalyst.

9. A process for treating textiles which consists essentially of applying to a textile a composition as claimed in Claim 5 and thereafter curing the applied com-position.

10. A process as claimed in Claim 9 in which the ap-plied composition contains a siloxane curing catalyst.