DE1276594B - Process for the hydrophobing of porous and fibrous materials - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY GERMAN 4SSl7W $ S & PATENTAMT Int. Cl .:

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EDITORIAL

C14 c German class: 8k-3 28a-9 Number: 1276 594 File number: P 12 76 594.5-43 (M 47857) Registration date: January 31, 1961 Display day: 5th September 1968

The invention relates to a method for making porous and fibrous materials hydrophobic with mixtures containing organopolysiloxanes.

A wide variety of organosilicon compounds which can be used to make porous materials and fibrous materials, such as textiles and leather, water-repellent are already known. For example, it is known to make textiles hydrophobic by impregnating them with an organopolysiloxane which contains hydrogen atoms bonded to silicon, usually in combination with a liquid methylpolysiloxane. Although these materials are widely used, they require curing after impregnation in order to develop sufficient water-repellent properties. Curing is performed by 10 to 30 minutes long heating the treated fabric to temperatures of 120 to 150 ⁰ C. dry-cleaning operations, for example, not grout facilities for carrying out the curing process at these temperatures, so that a need for a silicone treatment consists, through the textiles without a subsequent treatment at such high temperatures can be made water-repellent.

The inventor's British patent specification 773 347 describes a product with leather are made water-repellent and in which the active substances are essentially made up of a mixture consist of the following components:

1. 15 to 50 percent by weight of a zirconium compound of the general formula Zr (OR) ₄ or a partial hydrolyzate of this compound soluble in aliphatic hydrocarbons, where R is an aliphatic hydrocarbon radical with fewer than 13 carbon atoms or a hydroxylated aliphatic hydrocarbon radical with fewer than 13 carbon atoms and less than 4 is hydroxyl radicals,

2. 5 to 70 percent by weight of a methylsiloxane copolymer which consists essentially of trimethylsiloxane _{units and SiO 2} units in such amounts that the ratio of methyl radicals to Si atoms is between 1: 1 and 2.5: 1, and

3.15 to 80 percent by weight of a polysiloxane general formula

Process for the water repellency of porous and fibrous materials

Applicant:

Midland Silicones Limited, London

Representative:

Dr.-Ing. A. v. Kreisler, Dr.-Ing. K. Schönwald
and Dr.-Ing. Th. Meyer, patent attorneys,
5000 Cologne 1, Deichmannhaus

Named as inventor:

Raymond Leslie Bass,

Thomas Richard Williams, Glamorgan, Wales

(Great Britain)

Claimed priority:

Great Britain February 1, 1960 (3535) - -

in which R 'is in each case an alkyl or alkenyl radical with fewer than 6 carbon atoms or a monocyclic aryl radical and η has an average value of 2 to 2.9, with at least one of the hydrocarbon radicals mentioned being bonded to each silicon atom of the polysiloxane 3.

The products described in the above-mentioned patent specification have extensive Found application in practice, however, they are expensive. This is due in part to the relatively high rates Attributable to the cost of the zirconate component of the mixture. Another disadvantage of these products is that considerable care is required in their manufacture and storage. This disadvantage arises from the hydrolytic instability of the zirconium compounds used in the products. The absorption of moisture by the products before use deteriorates their quality and their effectiveness.

Furthermore, elastomeric products are known which are curable at room temperature and made of one Mixture of a methylpolysiloxane with a silicic acid orthoester and an amine exist. Also the Treatment of textiles with these mixtures has been suggested. Due to the elastomeric nature of these products, they form a coating on the fibers that eliminates the porosity of the fabric. Further Due to the strong odor that amines often have, it is not always desirable to use textiles with

IMSM / M4

treat products that contain them. In addition, the application of these cold-curing mixtures associated with certain processing difficulties due to their short service life.

The invention relates to a hydrophobing process for porous and fibrous materials with mixtures containing water-repellent organosilicon compounds, optionally in the presence of curing catalysts, which are cheaper and hydrolytically more stable than the known compounds of this type, and which is characterized in that the porous and fibrous materials with a Mix of

a) 5 to 60 percent by weight of an organosilicon compound of the general formula

R; 'Si (OR' ") 4-a,

in which a is 0 or 1, R "is an alkyl radical or hydrogen and R '" is an alkyl radical, and / or a product obtained by partial hydrolysis of the organosilicon compound mentioned,

b) 5 to 70 percent by weight of a polysiloxane resin composed of units of the general formula

₄ -P

consists, where R is a monovalent or substituted • monovalent hydrocarbon radical or hydrogen and ρ is an integer from 0 to 3 and the average ratio of R groups to Si atoms in the polysiloxane resin is between 1.0 and 1.9, and

c) 15 to 80 percent by weight of a polysiloxane or a polysiloxane mixture of the general formula

Rl ₁ SiO .- ,,,,

in which R 'is a monovalent hydrocarbon radical or substituted monovalent hydrocarbon radical or hydrogen and m has an average value of 1.95 to 2.9.

impregnated and allowed to harden.

The siloxanes used according to the invention can be partially polymerized substances, the unreacted Contain hydroxyl groups.

The organosilicon compounds used as mixture component a) in the process according to the invention are for the most part well known, commercially available products. Belong to them z. B. tetramethylorthosilicate, tetraethylorthosilicate, tetraisopropylorthosilicate. Methyltriethoxysilane, Ethyl polysilicate and mixtures of these compounds.

The polysiloxane resins of the formula mentioned above under b) which are suitable for the mixtures to be used according to the invention can consist of units of the type R ₃ SiO _0-5 , R ₂ SiO, RSiO ₃₇₂ and SiO ₂ . They can be homopolymer or copolymer and may only be hardened to the extent that they are still soluble in organic solvents.

Each of the monovalent hydrocarbon radicals R, R ', R "and R'" is preferably a methyl or phenyl radical. The ratio of methyl radicals to phenyl radicals can be varied over a wide range. Appropriately, at least 50 ° _{0 of} the radicals R. R 'are. R "and R '" are methyl radicals, while the proportion of phenyl radicals can be as high as is still compatible with the compatibility of the polysiloxane resin with the organosiloxane under c).

The organopolysiloxanes used as mixture component c) in the process according to the invention are benzene-soluble compounds, the viscosity of which can vary from thin liquids to deformable solids. They include products in which R 'is a monovalent hydrocarbon radical or a substituted monovalent hydrocarbon radical or hydrogen. In addition to the organic radicals mentioned, some of the R 'radicals can also be hydroxyl radicals. Specific examples of suitable siloxanes are dimethylpolysiloxane, methylhydrogensiloxane, vinylmethylsiloxane, vinylethylsiloxane, phenylmethylsiloxane, methyltolylsiloxane and mixtures of these siloxanes. Mixed polymers of these diorganosiloxanes with triorganosiloxanes, such as trimethylsiloxane, phenyldimethylsiloxane and amyldimethylsiloxane, can also be used. Monoorganosiloxane units can be present in these siloxanes as long as the value of m remains within the specified limits.

As already stated, a mixture of organopolysiloxanes can be used. So can the organosiloxanes under c) from a mixture of said polymers and copolymers, e.g. B. off consist of a mixture of a methyl hydrogen polysiloxane and a dimethyl polysiloxane.

The production of the products that are used according to the invention can be by simple Mixing the components a), b) and c), or using a common solvent. Suitable solvents are, for. B. toluene, xylene, mineral spirits, perchlorethylene and methylene chloride.

The mixtures to be used are best made as a solution in a volatile solvent applied to the objects to be impregnated. The dilution of the products used here is not critical and can be varied within very wide limits. It depends among other things of the conditions and the type of order and of the silicone intake required per order through the material to be impregnated. For the impregnation of textiles and leather, it proves It is expedient to use a solution in an organic solvent which is 2 to 20 percent by weight the organosilicon compound contains.

The mixtures to be used according to the invention can be applied in any suitable manner be e.g. B. by clapping. Spray or paint. After impregnation you can Allow treated material to air dry or dry with moderate warming.

The hardening of the compounds takes place at room temperature or at slightly elevated temperatures instead, but the curing can optionally be accelerated by adding a catalyst. Suitable catalysts for curing siloxanes are metal salts of carboxylic acids, e.g. B. dibutyltin dilaurate and zinc octoate, and amines such as triethanolamine.

The mixtures are suitable for treating a wide variety of porous materials and fibrous materials. Specific examples are nylon. Terylene. Cellulose acetate. Wool. Called cotton and leather.

example 1

A solution is made by mixing the following ingredients:

1. 21.5 parts of a 70% solution of a resinous copolymer of (CH ₃ ) ₃ SiOo, 5- and SiO ₂ units in mineral spirits,

2. 20 parts of a dimethylpolysiloxane having terminally blocked trimethylsiloxy groups a viscosity of 1000 cSt at 25 ° C,

3. 15 parts of tetraethyl-o-silicate,

4. 43.5 parts of mineral spirits.

15th

The solution is diluted with mineral spirits to a silicone content of about 10 percent by weight and Soaked wool and nylon samples with it, changing the dilution slightly to make sure that each sample has taken up to about 2 percent by weight silicone after drying.

After the impregnation, the samples are briefly ^{heated to 70 °} C. in order to remove the solvent and left to stand for 3 days at room temperature before the test.

Using the Bundesmann method (Textile Institute Specification No. 8, 1955), the treated and untreated fabrics were tested for their ability to repel water. This exam gives water absorption values of. 12.3% for the treated wool and 12.4% for the treated Nylon compared to 52% or 90% for untreated fabrics.

2. 20 parts of a terminally blocked hydroxyl group-containing dimethylpolysiloxane Viscosity of 280OcSt at 25 ° C,

3. 15 parts of tetramethylorthosilicate,

4. 43.5 parts of mineral spirits.

The two solutions are separated in the manner described in Example 1 for the impregnation of Samples of wool, nylon, terylene and acetate fabrics used.

After impregnation, the samples are briefly heated to around 70 ° C and for 3 days at room temperature left behind. The test for the ability to repel water according to the Bundesmann method, has the following results:

Wool Water absorption, ° Terylene Cellulose
acetate 29 nylon 8th 17th Solution a 33 21 9 14th Solution b 54 16 67 71 Untreated 57

Example 2

35

Samples of cotton and nylon fabrics are impregnated in the manner described in Example 1, however, the treatment agent contains ethyl polysilicate instead of tetraethyl-o-silicate.

In the test carried out according to the Bundesmann method for the ability to repel water, a water absorption of 42.5% for the cotton fabric and 14 "/ o for the nylon fabric established. For the untreated samples, values of 110 and 90% were determined.

Example 3

Two solutions, A and B, are prepared with the following composition: '

Solution A:

1. 21.5 parts of a 70% solution of a resinous copolymer of trimethylsiloxane and SiO ₂ in mineral spirits,

2. 20 parts of a dimethylpolysiloxane having terminally blocked trimethylsiloxy groups a viscosity of 1000 cSt at 25 C,

3. 15 parts of tetramethylorthosilicate,

4. 43.5 parts of mineral spirits.

55

60

Solution B:

1. 21.5 parts of a 70% solution of a resinous copolymer of trimethylsiloxane and SiO ₂ in mineral spirits.

Claims (3)

Patent claims: 1. Process for hydrophobing porous and fibrous materials with organopolysiloxanes containing mixtures, optionally in the presence of curing catalysts, characterized in that that you can mix the materials with a mixture a) 5 to 60 percent by weight of an organosilicon compound of the general formula RO'Si (OR "') 4- _fl , in which α is 0 or 1, R" is hydrogen or an alkyl radical and R'"is an alkyl radical, and / or their partial hydrolysis product, b) 5 to 70 percent by weight of a polysiloxane resin composed of units of the general formula c) consists in which R is an optionally substituted monovalent hydrocarbon radical or hydrogen and ρ = 0, 1, 2 or 3 and in the polysiloxane resin the average ratio of R: Si is between 1.0 and 1.9, and 15 to 80 percent by weight of a polysiloxane or a polysiloxane mixture of the general formula R; sio ₄ _ _m , in which R 'is an optionally substituted monovalent hydrocarbon radical or hydrogen and m has an average value between 1.95 and 2.9, impregnated and allowed to harden. 2. The method according to claim 1, characterized in that in the components used a), b) and c) each of the radicals R, R ', R " 7 8 and R "'are methyl or phenyl and _Contemplated publications: that at least _50/0 of these radicals being methyl radicals. 3. The method according to claim 1 and 2, characterized in German Auslegeschriften No. 1031 520.1 035 358; characterized in that the mixture is described in a French patent specification No. 1 032 744, common, preferably volatile, solution 5 1212 067; medium applies. U.S. Patent Nos. 2,588,366, 2,807,601. A priority document was displayed when the registration was announced. 109 599/544 B.il β Bundesdruckerei Berlin