IE903948A1

IE903948A1 - Fluorinated acrylic telomers and their application in the¹waterproofing and oil-proofing treatment of various¹substrates

Info

Publication number: IE903948A1
Application number: IE394890A
Authority: IE
Original assignee: Atochem
Priority date: 1989-11-02
Filing date: 1990-11-01
Publication date: 1991-05-08
Also published as: ATE107668T1; DE69010145D1; NO904780D0; ES2055885T3; EP0426530B1; CA2028975A1; FR2653772A1; NO904780L; JPH0678299B2; EP0426530A1; AU6579590A; FR2653772B1; DE69010145T2; JPH03218349A; KR910009755A; KR930007500B1; FI905431A0

Abstract

Fluorine-containing acrylic products obtained by telomerisation of: (a) 2 to 40 % of one or more thiols RF-B-SH where RF denotes a perfluoroalkyl radical and B an alkylene radical; (b) 20 to 70 % of one or more polyfluorinated monomers of general formula: <IMAGE> where Rf denotes a perfluoroalkyl radical, Q denotes an oxygen or sulphur atom, D is a divalent chain sequence linked to Q by a carbon, one of the symbols R denotes a hydrogen atom and the other a hydrogen atom or an alkyl radical; and (c) 0 to 65 % of one or more monomers of any kind, other than those defined under (b). These telomers, which are soluble in solvents which may be unhalogenated, are particularly well suited for making leathers water-repellent and oil-repellent. They can also be applied to other substrates.

Description

The present invention relates to the field of fluorinated products intended for waterproofing and oilproofing treatment of substrates such as textiles, pile carpets, wall coverings, wood, construction materials, metals and plastic materials, and in particular, relates to new products which are soluble in solvents, which may be non-halogenated, and can be used more particularly for the protection of leather, the finish and care of which must have the following characteristics: suppleness, a pleasant appearance and pleasant to the touch.

Products which have been proposed as products more particularly suited for leather are those soluble or dispersible in water, such as: * chromium complexes of fluorinated carboxylic 15 acids (US patents 2,934,450, 3,651,105, 3,907,576 and 3,574,518 which effectively confer good properties but have the disadvantage of having a strong green colour and of imparting this colour to the substrates to which they are applied, thus limiting their use; * fluorinated carboxylic acids (US patent 3,382,097) and polyfluoroalkylthiodicarboxylic acids (US patent 3,471,518); * acrylic copolymers such as those described in French patent 2,579,211, but the use of these products in an aqueous medium necessitates a very long drying time; moreover, water could be harmful for some leathers and some supports. - 3 Fluorinated acrylate polymers or copolymers have also been proposed (US patent 3,524,760). However, these products as synthesized or when diluted for use in chlorinated solvents present a hazard to the environment.

Compositions containing perfluoro groups and urethane chains are also known: see, for example, US 3,468,924, 3,503,915, 3,528,849, 3,896,035, 3,896,251 and 4,024,178, FR 2,062,244, DE 1,620,965, CA 1,071,225, EP 103,752, CH 520,813 and 512,624. Unfortunately, these products have the disadvantage: - either of containing chlorinated solvents - or of requiring for their synthesis intermediates which are difficult to prepare, - or of imparting stain-resistant properties 15 which remain relatively poor, - or, again, of being supplied as an aqueous emulsion because of their poor solubility in organic solvents.

Fluorinated telomers obtained from a 20 fluorinated thiol and ethylenic compounds have been proposed as surfactants in the patents US 4,460,480, US 4,577,036 and FR 2,416,222. These products, which are generally soluble in water, do not confer any water-resistant and oil-resistant properties.

We have now found, according to the present invention, telomers which are soluble in alkanes and are particularly well suited for the treatment of leathers, to - 4 which they impart remarkable water-resistant and oilresistant properties without affecting the colouring, the appearance, the touch or the handle and without an adverse effect on the gloss and do not present any major hazard for the environment.

The products according to the invention are telomers which contain, by weight, in telomerized form: (a) 2 to 40 %, preferably 10 to 30 %, of one or more fluorinated thiols of general formula: Rp-B-SH (I) in which RF represents a straight-chain or branched perfluoroalkyl radical containing from 2 to 20 carbon atoms and B represents an alkylene radical containing 1 to 4 carbon atoms; (b) 20 to 70 %, and preferably 30 to 50 %, of one or more polyfluorinated monomers of general formula: O II Rf-D-Q-C-C = CH-R (II) | R in which Rf represents a straight-chain or branched perfluoroalkyl radical containing 2 to 20 carbon atoms, Q represents an oxygen or sulphur atom, D represents a divalent chain bonded to Q by a carbon and able to carry one - 5 or more oxygen, sulphur and/or nitrogen atoms, and one of the symbols R represents a hydrogen atom and the other a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms; and (c) 0 to 65 %, and preferably 25 to 50 %, of one or more monomers of any type other than those defined under (b).

The perfluoroalkyl radicals Rp and Rf can be identical or different and preferably contain 4 to 16 carbon atoms.

Amongst the fluorinated thiols of formula (I), those in which B is a straight-chain alkylene radical and, more particularly, an ethylene or tetramethylene radical are preferred. These thiols can be prepared by known processes, for example that described in French patent 2,609,463.

Preferred polyfluorinated monomers of formula (II) are those corresponding to the formula: O II Rf-(CH2 ) p-O-C-C = CH-R (HI) R in which Rf and R have the same meanings as above and 25 p represents an integer from 1 to 20 and preferably 2 or 4.

These monomers can be prepared by known processes, for example by esterification of the corresponding alcohols of formula: Rf-(CH2)p-OH (IV) by means of an alkene-monocarboxylic acid of formula: HOOC-C = CH-R (V) such as acrylic acid, methacrylic acid or crotonic acid, in the presence of an acid catalyst such as sulphuric acid or p-toluenesulphonic acid. In place of the alkenemonocarboxylic acids of formula (V) it is also possible to 10 use their esters, anhydrides or halides. For economic and practical reasons, it has proved particularly worthwhile to use a mixture of monomers of formula (III) having different radicals Rf.

Other examples of polyfluorinated monomers of 15 formula (II) which may be mentioned are the esters of acids of formula (V) with the alcohols and the thiols of formulae Rf-(CH2)p~S02_N~(cxx')q-C-0H (VI) Rf-(CH2)p-SH (VII) Rf-(CH2)p-O-(CH2)r-OH (VIII) - Ί - Rf-(CH2)p-s-(CH2)r-OH (ix) Rf-(CH2)p-(OCH2CH2)r-OH (X) Rf-(ch2)p-so2-(CH2)r-0H (Xi) Rf-CH = CH-(CH2)p-OH (XU) Rf-SO2-N-(CH2)p-OH R (xiii) Rf-COO-(CH2)p-OH (xiv) Rf-CO-N-(CH2)p-OH (XV) R in which Rf and p have the same meanings as above, R* represents a hydrogen atom or an alkyl radical containing 1 to 10 carbon atoms (preferably methyl), R represents a hydrogen atom or an alkyl radical containing l to 4 carbon atoms, g is an integer from 1 to 4 (preferably 1 or 2), r is an integer from 1 to 20 (preferably 1 to 4) and X, X', Y and Y' are identical or different and each represent a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms.

Preferred monomers (c) which can be used in the present invention are the straight-chain, branched or cyclic alkyl acrylates and methacrylates containing from 1 to 18, and preferably at least 6, carbon atoms. - 8 The following may be mentioned as other monomers (c) which may also be used: - lower olefinic hydrocarbons, which may or may not be halogenated, such as ethylene, propylene, isobutene, 3-chloro-l-isobutene, butadiene, isoprene, chlorobutadienes and dichlorobutadienes, fluorobutadienes and difluorobutadienes, 2,5-dimethylhexa-l,5-diene and diisobutylene; - vinyl, allyl or vinylidene halides, such as 10 vinyl chloride or vinylidene chloride, vinyl fluoride or vinylidene fluoride, allyl bromide or methallyl chloride; - styrene and its derivatives, such as vinyl toluene, α-methylstyrene, a-cyanomethylstyrene, divinylbenzene or N-vinyl-carbazole; - vinyl esters, such as vinyl acetate, vinyl propionate, vinyl esters of acids known commercially as versatic acids, vinyl isobutyrate, vinyl senecionate, vinyl succinate, vinyl isodecanoate, vinyl stearate or divinyl carbonate; - allyl esters, such as allyl acetate and allyl heptanoate; - alkyl vinyl ethers or alkyl allyl ethers, which may or may not be halogenated, such as cetyl vinyl ether, dodecyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, ethyl vinyl ether, 2-ethylhexyl vinyl ether, 2-chloroethyl vinyl ether or tetraallyloxyethane; - vinyl alkyl ketones, such as vinyl methyl - 9 ketone; - unsaturated acids, such as acrylic, methacrylic, α-chloroacrylic, crotonic, maleic, fumaric, itaconic, citraconic and senecioic acids, their anhydrides and their esters, such as vinyl acrylates and methacrylates, allyl acrylates and methacrylates and 2-isocyanatoethyl acrylates and methacrylates, dimethyl maleate, ethyl crotonate, methyl hydrogen maleate, butyl hydrogen itaconate, glycol diacrylates and dimethacrylates or polyalkylene glycol diacrylates and dimethacrylates, such as ethylene glycol dimethacrylate or triethylene glycol dimethacrylate, dichlorophosphatoalkyl acrylates and methacrylates, such as dichlorophosphatoethyl methacrylate, and also bis-(methacryloyloxyethyl) hydrogen phosphate, methacryloyloxypropyltrimethoxysilane, and 2-hydroxy-3chloropropyl acrylate or methacrylate; and - acrylonitrile, methacrylonitrile, 2-chloroacrylonitrile, 2-cyanoethyl acrylate or methacrylate, methylene glutaronitrile, vinylidene cyanide, alkyl cyanoacrylates such as isopropyl cyanoacrylate, triacryloyl hexahydro-s-triazine, vinyl trichlorosilane, vinyl trimethoxysilane, vinyl triethoxysilane and N-vinyl-2pyrrolidone.

Compounds possessing at least one ethylenic bond and at least one reactive group, that is to say a group capable of reacting with another monomer, another compound or the substrate itself to establish a cross- linking, can - 10 also be used as monomers (c). These reactive groups are well known and can be polar groups or functional groups such as the groups OH, NH2, NH-alkyl, COOMe (Me = alkaline or alkaline earth metal), SO3H, CH CH2, CHO, —CH Cl, -C Br, -NH-CO-CH = CH2. Monomers of this type which may be mentioned are hydroxyalkyl acrylates and methacrylates, such as ethylene glycol monoacrylate, propylene glycol monomethacrylate, the acrylates and methacrylates of polyalkylene glycols, allyl alcohol, allyl glycolate, isobutenediol, allyloxy ethanol, o-allylphenol, divinyl carbinol, glycerol α-allyl ether, acrylamide, methacrylamide, maleamide and maleimide, N-(cyanoethyl)acrylamide, N-isopropylacrylamide, diacetone-acrylamide, N-(hydroxymethyl)-acrylamide and -methacrylamide, N-(alkoxymethyl)-acrylamides and -methacrylamides, methyl 2- acrylamido-2-methoxy acetate, glyoxal bisacrylamide, sodium acrylate or sodium methacrylate, vinylsulphonic and styrene-p-sulphonic acids and their alkali metal salts, 3- amino-crotononitrile, monoallylamine, vinylpyridines, glycidyl acrylate or glycidyl methacrylate, allyl glycidyl ether, acrolein, N,N-dimethylaminoethyl methacrylate or N-tert.-butylaminoethyl methacrylate.

Amongst the abovementioned comonomers (c), the following are preferred: vinyl acetate, vinyl esters of - 11 versatic acids, isobutyl vinyl ether, acrylic acid or methacrylic acid, maleic anhydride, ethylene glycol diacrylate or dimethacrylate or triethylene glycol diacrylate or dimethacrylate, acrylonitrile, methacrylonitrile, 2-cyanoethyl acrylate, N-vinyl-2pyrrolidone, ethylene glycol monoacrylate or methacrylate or propylene glycol monoacrylate or methacrylate, acrylamide, methacrylamide, diacetone-acrylamide, N-methylol-acrylamide or -methacrylamide, isobutoxymethyl-acrylamide or 10 methacrylamide, methyl 2-acrylamidamido-2-methoxy acetate, glycidyl acrylate or glycidyl methacrylate, Ν,Ν-dimethylaminoethyl methacrylate or N-tert.butylaminoethyl methacrylate.

The products according to the invention can be prepared in a manner known per se by telomerization in the presence or absence of solvent. The thiol (a) plays the role of the telogen and the ethylenic compounds (b) and (c) play the role of taxogens.

In a general manner, telomerization reactions are known and described, for example, in the following references: - Monomeric Acrylic Esters by H. RIDDLE, Reinhold Publishing Corp. (1965), pages 149 to 151; - G. NAGY L'Industrie chimique - No. 570 25 January 1965 - pages l to 6; - R.B. FOX and DE FIELD, U.S. Naval Research Laboratory Washington, NRL Report 5190 - 19 Nov. 1958; - 12 -M.S. KARASCH and C.F. FOCUS - Jour. Org. Chem. 13 , 1948, pages 97 to 100; - C.M. STARKS, Free Radical Telomerization, Academic Press 1974; - B. BOUTEVIN and Y. PIETRASANTA Les acrylates et polyacrylates fluor^s, deriv6s et applications (Fluorinated acrylates and polyacrylates, derivatives and applications) - EREC. 1988.

The reaction can be carried out continuously, 10 discontinuously or gradually, at a temperature from ambient temperature to the boiling point of the reaction mixture.

The reaction is preferably carried out at 50 to 90°C. The total concentration of the reagents is generally from 5 to 100 % by weight.

The telomerization can be carried out in the following, for example, as solvents: ketone (for example acetone, methyl ethyl ketone or methyl isobutyl ketone), alcohols (for example isopropanol), esters (for example ethyl acetate or butyl acetate), ethers (for example diisopropyl ether, ethylene glycol ethyl ether or ethylene glycol methyl ether, tetrahydrofuran or dioxane), aliphatic or aromatic hydrocarbons, halogenated hydrocarbons (for example perchloroethylene, 1,1,1-trichloroethane or trichlorotrifluoroethane), dimethylformamide or N-methyl-225 pyrrolidone. It is possible to use a single solvent or a mixture.

The telomerization is usually carried out in - 13 the presence of one or more initiator which are used in an amount of, say, 1 to 4 % relative to the total weight of the telogens and taxogens employed. Initiators which may be used are peroxides such as benzoyl peroxide, lauroyl peroxide, succinyl peroxide and tert.-butyl perpivalate, or azo compounds such as 2,2'-azo-bis-isobutyronitrile, 4,4'-azobis-(4-cyanopentanoic) acid and azodicarbonamide. It is also possible to carry out the reaction in the presence of UV radiation and photoinitiators such as benzophenone, 2-methylanthraquinone or 2-chlorothioxanthone.

The telomer solution obtained may, if appropriate, be diluted with the telomerization solvent or, provided there is reciprocal miscibility, with another solvent or a mixture of solvents. If desired, it is also possible to isolate the telomer by removing the solvent or solvents.

Substrates which may be mentioned as being capable of being rendered oleophobic and hydrophobic with the products according to the invention are, in the main, leathers. Other very diverse materials such as papers, woven or non-woven articles based on cellulose or regenerated cellulose, natural, artificial or synthetic fibres, such as cotton, cellulose acetate, wool, silk, polyamide fibres, polyester, polyolefin, polyurethane or polyacrylonitrile, plastic materials, glass, wood, metals, porcelain, masonry and painted surfaces may also be mentioned.

In the case of leathers, solutions of telomers - 14 according to the invention are applied in the main in an alcoholic medium, in an aliphatic hydrocarbon medium or in a mixture of an aliphatic hydrocarbon and an alcohol, in accordance with well known techniques, for example by spraying or by coating using a brush.

The supports treated with the telomers according to the invention have good oleophobic and hydrophobic properties after simple drying at ambient temperature or at a higher temperature, which varies with the type of support but can be up to 250°C. The leathers are preferentially dried at ambient temperature or at a moderate temperature up to about 60°C.

In order to obtain a particular effect or better fixation, it can sometimes be advantageous on certain supports to combine the telomers according to the invention with certain adjuvants such as polymers, thermocondensable products, catalysts, anti-UV agents, fungicides or antistatic agents.

The amount of telomer to be used varies with the nature of the support to be treated and with the fluorine content of the telomer. On leather, this amount is generally from 0.2 to 5 g per m2 and preferably from 0.5 to 2.5 g/m2. When treated in this way, all types of leathers, tanned with chromium salts or vegetable tannins, can have good hydrophobic and oleophobic properties.

To evaluate the performance of the substrates treated in accordance with the invention, we have used the - 15 following tests: Test to determine the resistance to water (RW) The test consists in measuring the time taken for a drop of water deposited on the substrate to penetrate. 5 If the penetration time is longer than two hours, this resistance is judged to be excellent.

Test to determine the resistance to oil (RO) The test consists in measuring the time taken for a drop of vaseline oil deposited on the substrate to penetrate. If the penetration time is longer than two hours, this resistance is judged to be excellent. The test is deliberately stopped after 9 hours; it is considered that this lapse of time offers the maximum oil-resistance values. Test to determine the hydrophobic properties (H) On some supports the hydrophobic effect was measured using test solutions numbered from 1 to 10 and consisting of water/isopropanol mixtures in the following proportions by weight: Test solution Water Isopropanol 1 90 10 2 80 20 3 70 30 4 60 40 5 50 50 6 40 60 7 30 70 8 20 80 9 10 90 10 0 100 The test consists in depositing drops of these mixtures on the treated substrates and then observing the effect produced. The assessment is made by giving, as the value, the number corresponding to the solution which contains the highest percentage of isopropanol and has not penetrated or wetted the substrate after 30 seconds in contact.

The repellency of the treated supports with respect to oils (OR) and water (ST) was measured in accordance with the standards AATCC 118-1975 (Oil repellency: hydrocarbon resistance test) and AATCC 22-1975 (Water repellency: spray test). On leather, the water repellency (spray test) was determined in the following way: after all of the water has been poured onto the surface of the leather, the latter is - 17 laid flat and covered with a sheet of blotting paper; pressure is then exerted on the whole by moving a inetal roller weighing 2 kg backwards and forwards. An assessment is then made as a function of the spots formed by water which wets the leather and according to the values indicated in the evaluation table of the standard AATCC 22-1975. On textiles, on the other hand, the measurements were made strictly in accordance with the standard.

The following Examples, in which, unless indicated 10 to the contrary, the parts and percentages are by weight, further illustrate the invention.

EXAMPLE 1 a) Preparation: 41.25 parts of n-heptane, 13.9 parts of ethyl 15 acetate, 2.5 parts of thiol C8F17C2H4SH and 5.6 parts of a mixture of polyfluorinated monomers of general formula: CF3-(CF2)n-C2H4-O-C-C = II 1 0 ch3 ch2 (xvi) 20 having the following composition: n : 5 7 9 11 13 15 : 1 58 24 12 3 2 and then 10.5 parts of technical grade stearyl methacrylate (mixture containing approximately 70 % of C^S ester and 30 % - 18 of C^6 ester), 1.37 parts of ethylene glycol monomethacrylate and 0.75 part of glycidyl methacrylate are charged into a reactor having a capacity of 500 parts by volume and fitted with a stirrer, a thermometer, a reflux condenser, a dropping funnel, a nitrogen inlet and a heating device.

The air is driven from the reactor by a stream of anhydrous nitrogen, the solution is brought to reflux (that is 77°C), 0.2 part of lauroyl peroxide and 0.06 part of tert.-butyl perpivalate are added and a solution of 13.75 parts of n-heptane, 4.6 parts of ethyl acetate, 7.5 parts of thiol CgF^7C2H4SH, 16.75 parts of the mixture of polyfluorinated monomers described above, 3.36 parts of technical grade stearyl methacrylate, 4.1 parts of ethylene glycol methacrylate and 2.25 parts of glycidyl methacrylate is then run in dropwise in the course of one hour.

The mixture is then kept under reflux for 6 hours, adding 0.06 part of tert.-butyl perpivalate every 30 minutes and 0.1 part of lauroyl peroxide every 150 minutes. At the end of this time, chromatographic analysis (VPC) shows that all of the thiol and the monomers have disappeared.

After cooling to ambient temperature, a clear yellow solution of a telomer according to the invention is obtained. By drying this solution for 2 hours at 120°C, its proportion of non-volatile matter is determined and is then adjusted to 25 % by adding a 75/25 mixture of n-heptane and ethyl acetate. A pale yellow clear solution (SI) in which - 19 the proportion of fluorine is 9.5 % is then obtained, b) Applications: parts of this solution SI are diluted to 100 parts with an 85/15 mixture of n-heptane and isopropanol. The new solution thus obtained is then applied by spraying to a chrome-tanned calf leather in an amount of 200 g/m2 and left to dry for 8 hours at ambient temperature before examining the performance obtained. The results are indicated in the following table, in comparison with the same leather untreated.

Characteristics Chrome-tanned calf Treated Untreated Resistance to water 2 hours 30 min less than 5 seconds (RW) Resistance to oil more than 8 h less than 5 seconds (RO) A new solution of the telomer according to the invention is prepared by diluting 4 parts of solution SI to 100 parts with n-heptane. This new solution is applied by spraying to vegetable-tanned calf skin leather in an amount of 100 g/m2 and left to dry for 8 hours at ambient temperature before examining the performance obtained. The results are indicated in the following table, in comparison with the same leather untreated.

Characteristics Vegetable-tanned calf skin leather Treated Untreated Water repellency (ST) 100 0 Oil repellency (OR) 4 0 Test to determine hydrophobic properties (H) 4 0 EXAMPLE 2 a) Preparation: The procedure is as in Example 1 but in the absence of ethylene glycol monomethacrylate. After diluting to 25 %, a solution (S2) of a telomer according to the invention is obtained. This solution contains 10.5 % of fluorine. b) Application: 4 parts of this solution S2 are diluted to 100 parts with n-heptane and the dilute solution (S2d) is then applied by sizing to a polyester fabric (PE) and a polyamide fabric (PA) with degrees of expression of 70 % and 65 % respectively. The fabrics are then left to dry at ambient temperature and the treated fabrics are then tested in comparison with untreated fabrics, before and after one and three washings in accordance with the standard - 21 NF 607-136 6A. The results obtained are indicated in the following table.

Water repellency (ST) Fabric 0 washings PE PA 1 washing PE PA 3 washings PE PA Untreated 0 0 0 0 0 0 Treated 100 100 100 90 90 90 The same dilute solution S2d is applied to chrometanned calf skin by spraying in an amount of 200 g/m^ and then left to dry for 8 hours at ambient temperature before comparing the performance obtained with that of an untreated leather. The results are indicated in the following table.

Characteristics Chrome-tanned calf skin Treated Untreated Resistance to water (RW) more than 9 h less than 5 sec Resistance to oil (RO) more than 9 h less than 5 sec Hydrophobic properties (H) 10 0 Oil repellency (OR) 4 0 - 22 EXAMPLE 3 a) Preparation: 41.3 parts of n-heptane, 13.9 parts of butyl acetate, 6 parts of a mixture of thiols of general formula: CF3-(CF2)m-C2H4-SH (XVII) having the following composition: m : 5 7 9 11 13 15 % : 58 24 12 3 2 1 .6 parts of the same mixture of polyfluorinated monomers as in Example 1, 10.5 parts of technical grade stearyl methacrylate, 1.5 parts of N-vinyl-2-pyrrolidone and 0.75 part of glycidyl methacrylate are charged successively into a reactor identical to that of Example 1.

The air is driven from the reactor by a stream of anhydrous nitrogen, the solution is brought to a temperature of 85°C and 0.2 part of lauroyl peroxide and 0.06 part of tert.-butyl perpivalate are added and a solution of 13.8 parts of n-heptane, 4.6 parts of butyl acetate, 17.6 parts of the same mixture of thiols CF3-(CF2)m-C2H4-SH, 16.75 parts of the same mixture of polyfluorinated monomers as in Example 1, 3.36 parts of technical grade stearyl methacrylate, 0.5 part of N-vinyl-2-pyrrolidone and 2.25 parts of glycidyl methacrylate is then run in dropwise in - 23 the course of one hour.

The mixture is then kept at 85°C for 6 hours, adding 0.06 part of tert.-butyl perpivalate every 30 minutes and 0.1 part of lauroyl peroxide every 150 minutes. At the end of this time, chromatographic analysis (VPC) shows that all of the thiols and the monomers have disappeared. After cooling to ambient temperature, a yellow solution of a telomer according to the invention is obtained. By drying for 2 hours at 130°C, its proportion of non-volatile matter is determined and it is then adjusted to 25 % by adding a 75/25 mixture of n-heptane and butyl acetate. A pale yellow clear solution (S3) in which the proportion of fluorine is 11.5 % is then obtained. b) Application: parts of this solution S3 are diluted to 100 parts with an 70/15/15 mixture of n-heptane/butyl acetate/isopropanol. The new solution obtained is then applied by spraying to a chrome-tanned calf leather in an amount of 200 g/m2 and then left to dry for 8 hours at ambient temperature before examining the performance. The results obtained are indicated in the following table, in comparison with the same leather untreated.

Characteristics Chrome-tanned calf skin Treated Untreated Resistance to water (RW) 7 hours 30 min less than 5 sec Resistance to oil (RO) 30 minutes less than 5 sec Oil repellency (OR) 1 0 Hydrophobic properties (H) 3 0 EXAMPLE 4 a) Preparation: 13.3 parts of n-heptane, 40 parts of ethyl acetate, 2 parts of acetone, 1.6 parts of the thiol CgF13-C2H4-SH, 8 parts of a mixture of polyfluorinated monomers of general formula: CF3-(CF2)m-C2H4-SO2-N-C2H4-O-C-CH = CH2 (XVIII) CH3 0 having the following composition: 21 : 5 7 9 11 13 % : 58 24 12 3 2 and then 6.5 parts of nonyl methacrylate and 0.5 part of 25 glycidyl methacrylate are charged into a reactor identical to that of Example 1.

The air is driven from the reactor by a stream of anhydrous nitrogen, the solution is brought to reflux, (that - 25 is to 65°C) and 0.2 part of 2,2'-azo-isobutyronitrile (AIBN) and 0.06 part of tert.-butyl perpivalate are added and a solution of 3 parts of n-heptane, 9.3 parts of ethyl acetate, 6 parts of acetone, 4.8 parts of thiol C5F13C2H4SH, 24 parts of the same mixture of polyfluorinated monomers as above, 2.4 parts of nonyl methacrylate and 1.4 parts of glycidyl methacrylate is then run in dropwise in the course of one hour.

The mixture is then kept under reflux for 6 hours, 10 adding 0.06 part of tert.-butyl perpivalate every 30 minutes and 0.1 part of AIBN every 150 minutes. At the end of this time, chromatographic analysis (VPC) shows that all of the thiol and the monomers has disappeared. After cooling to ambient temperature, a brownish solution of a telomer according to the invention is obtained. By drying for 2 hours at 12O°C, its proportion of non-volatile matter is determined and it is then adjusted to 25 % by adding a 25/75 mixture of n-heptane and ethyl acetate. A pale ochre clear solution (S4) in which the proportion of fluorine is 10 % is then obtained, b) Application: parts of this solution S4 are diluted to 100 parts with an 85/15 mixture of n-heptane and isopropanol. The new solution thus obtained is then applied by spraying to a chrome-tanned calf leather in an amount of 200 g/m2 and left to dry for 8 hours at ambient temperature before examining the performance. The results obtained are - 26 indicated in the following table, in comparison with the same leather untreated.

Characteristics Chrome-tanned calf skin Treated Untreated Resistance to water (RW) more than 9 h less than 5 sec Resistance to oil (RO) more than 9 h less than 5 sec Oil repellency (OR) 4 0 Hydrophobic properties (H) 6 0 EXAMPLE 5 a) Preparation: 18.4 parts of n-heptane, 18.4 parts of ethyl acetate, 18.4 parts of methyl isobutyl ketone, 2 parts of thiol CgFp7-C2H4-SH, 3.1 parts of a mixture of polyfluorinated monomers of general formula: CH3-(CF2)m-C2H4-O-C-CH = CH2 (XIX) II having the following composition: m : 5 7 9 11 13 15 : 58 24 12 3 2 1 and then 12.5 parts of technical grade lauryl methacrylate - 27 (mixture containing approximately 65 % of C32 ester and 35 % of C34 ester), 0.75 part of glycidyl methacrylate and 3 parts of vinyl acetate are charged into a reactor identical to that of Example 1.

The air is driven from the reactor by a stream of anhydrous nitrogen, the solution is brought to reflux (that is to 77°C) and 0.2 part of lauroyl peroxide and 0.06 part of tert.-butyl perpivalate are added and a solution of 6.1 parts of n-heptane, 6.1 parts of ethyl acetate, 6.1 parts of methyl isobutyl ketone, 4 parts of thiol C6FJ7C2H4SH, 9.2 parts of the same mixture of polyfluorinated monomers as above, 12.5 parts of technical grade lauryl methacrylate, 1 part of vinyl acetate and 2.25 parts of glycidyl methacrylate is then run in dropwise in the course of one hour.

The mixture is then kept under reflux for 6 hours, adding 0.06 part of tert.-butyl perpivalate every 30 minutes and 0.1 part of lauroyl peroxide every 150 minutes. At the end of this time, chromatographic analysis (VPC) shows that all of the thiol and the monomers have disappeared. After cooling to ambient temperature, a clear white solution of a telomer according to the invention is obtained. By drying for 2 hours at 12 0°C, its proportion of non-volatile matter is determined and it is then adjusted to 25 % by adding a mixture of equal proportions of n-heptane, ethyl acetate and methyl isobutyl ketone. A clear solution (S5) in which the proportion of fluorine is 5.5 % is obtained. - 28 b) Application: parts of this solution S5 are diluted to 100 parts with a 75/25 mixture of n-heptane and isopropanol. The dilute solution thus obtained is then applied by spraying to chrome-tanned calf leather in an amount of 200 g/m2 and then left to dry for 8 hours at ambient temperature before examining the performance. The results obtained are indicated in the following table in comparison with the same leather untreated.

Characteristics Chrome-tanned calf Treated Untreated Resistance to water 60 minutes less than 5 seconds (RW) Resistance to oil 10 minutes less than 5 seconds (RO) EXAMPLE 6 a) Preparation: 58.1 parts of n-heptane, 19.4 parts of ethyl acetate, 0.3 part of thiol C6F13-C2H4-SH, 6 parts of the same mixture of polyfluorinated monomers as in Example 1 and then 11.1 parts of technical grade stearyl methacrylate, 0.5 part of 2-hydroxy-3-chloropropyl methacrylate and 0.9 part of glycidyl methacrylate are charged into a reactor identical to that of Example 1. - 29 The air is driven from the reactor by a stream of anhydrous nitrogen, the solution is brought to reflux (that is to 77°C) and 0.3 part of 2,2'-azo-isobutyronitrile (AIBN) is added and a solution of 19.3 parts of n-heptane, 6.5 parts of ethyl acetate, 0.8 part of thiol 17.8 parts of the same mixture of polyfluorinated monomers as in Example 1, 3.7 parts of a technical grade stearyl methacrylate, 1.5 parts of 2-hydroxy-3-chloropropyl methacrylate and 2.3 parts of glycidyl methacrylate is then run in dropwise in the course of one hour.

The mixture is then kept under reflux for 6 hours, adding 0.15 part of AIBN every 60 minutes. At the end of this time, chromatographic analysis (VPC) shows that all of the thiol and the monomers have disappeared. After cooling to ambient temperature, a clear yellow solution of a telomer according to the invention is obtained. By drying for 2 hours at 12 0°C, its proportion of non-volatile matter is determined and it is then adjusted to 25 % by adding a 75/25 mixture of n-heptane and ethyl acetate. A pale yellow clear solution (S6) in which the proportion of fluorine is 8.5 % is obtained. b) Application: parts of this solution S6 are diluted to 100 parts with an 50/50 mixture of n-heptane and isopropanol. The dilute solution is then applied by spraying to chrome-tanned calf leather in an amount of 200 g/m2 and then left to dry for 8 hours at ambient temperature before - 30 examining the performance. The results obtained are indicated in the following table in comparison with the same leather untreated.

Characteristics Chrome-tanned calf skin Treated Untreated Resistance to water (RW) more than 9 h less than 5 sec Resistance to oil (RO) more than 9 h less than 5 sec Oil repellency (OR) 4 0 Hydrophobic properties (H) 9 0 EXAMPLE 7 a) Preparation: 41.25 parts of n-heptane, 13.9 parts of ethyl acetate, 2.5 parts of thiol CQFJ7-C2H4-SH, 5.6 parts of the same mixture of polyfluorinated monomers as in Example 1 and then 1.64 parts of styrene are charged into a reactor identical to that of Example 1.

The air is driven from the reactor by a stream of anhydrous nitrogen, the solution is brought to reflux (that is to 77°C) and 0.2 part of lauroyl peroxide and 0.06 part of tert.-butyl perpivalate are added and a solution of 13.75 parts of n-heptane, 4.6 parts of ethyl acetate, 7.5 parts of thiol CgFj7-C2H4-SH, 16.75 parts of the same mixture of polyfluorinated monomers as in Example 1 and 4.9 parts of - 31 styrene is then run in dropwise in the course of one hour.

The mixture is then kept under reflux for 6 hours, adding 0.06 part of tert.-butyl perpivalate every 30 minutes and 0.1 part of lauroyl peroxide every 150 minutes. At the end of this time, chromatographic analysis (VPC) shows that all of the thiol and the monomers has disappeared.

After cooling to ambient temperature, a clear white solution of a telomer according to the invention is obtained. By drying for 2 hours at 12 0°C, its proportion of non-volatile matter is determined and it is then adjusted to 25 % by adding a 75/25 mixture of n-heptane and ethyl acetate. A clear solution (S7) in which the proportion of fluorine is 13.3 % is obtained, b) Application: 3 parts of this solution S7 are diluted to 100 parts with a 60/20/15 mixture of n-heptane/butyl acetate/isopropanol. The dilute solution thus obtained is then applied by spraying to a chrome-tanned calf leather in an amount of 200 g/m2 and then left to dry for 8 hours at ambient temperature before examining the performance. The results obtained are indicated in the following table in comparison with the same leather untreated.

Characteristics Chrome-tanned calf skin Treated Untreated Resistance to water (RW) 3 hours less than 5 sec Resistance to oil (RO) 1 hour 30 min less than 5 sec Oil repellency (OR) 1 0 Hydrophobic properties (H) 3 0 EXAMPLE 8 a) Preparation: 41.25 parts of n-heptane, 13.9 parts of ethyl acetate, 2.5 parts of thiol CgF17-C2H4-SH and 5.6 parts of the same mixture of polyfluorinated monomers as in Example 1 are charged into a reactor identical to that of Example 1.

The air is driven from the reactor by a stream of anhydrous nitrogen, the solution is brought to reflux (that is to 77°C) and 0.1 part of AIBN, 0.1 part of lauroyl peroxide and 0.06 part of tert.-butyl perpivalate are added and a solution of 13.75 parts of n-heptane, 4.6 parts of ethyl acetate, 7.5 parts of thiol CgF^-^H^j-SH and 16.75 parts of the same mixture of polyfluorinated monomers as in Example 1 is then run in dropwise in the course of one hour.

The mixture is then kept under reflux for 6 hours, adding 0.06 part of tert.-butyl perpivalate every 30 minutes and 0.05 part of lauroyl peroxide and 0.05 part of AIBN every 150 minutes. At the end of this time, chromatographic - 33 analysis (VPC) shows that all of the thiol and the monomers have disappeared. After cooling to ambient temperature, a clear white solution of a telomer according to the invention is obtained. By drying for 2 hours at 120°C, its proportion of non-volatile matter is determined and it is then adjusted to 19 % by adding a 75/25 mixture of n-heptane and ethyl acetate. A clear solution (S8) in which the proportion of fluorine is 12.1 % is then obtained. b) Application: 3.5 parts of this solution S8 are diluted to 100 parts with a 65/20/15 mixture of n-heptane/butyl acetate/isopropanol. The dilute solution is then applied by spraying to a chrome-tanned calf leather in an amount of 200 g/m2 and then left to dry for 8 hours at ambient temperature before examining the performance. The results obtained are indicated in the following table in comparison with the same leather untreated.

Characteristics Chrome-tanned calf skin Treated Untreated Resistance to water (RW) 2 hours less than 5 sec Resistance to oil (RO) 1 hour less than 5 sec Oil repellency (OR) 1 0 Hydrophobic properties (H) 2 0

Claims

1. A fluorinated acrylic telomer which contains, by weight, in telomerized form: (a)

2. To 40 % of one or more fluorinated 5 thiols of general formula: Rp-B-SH (I) in which Rp represents a straight-chain or branched perfluoroalkyl radical containing from 2 to 20 carbon atoms and B represents an alkylene radical containing 1 to 4 10 carbon atoms; (b) 2 0 to 70 % of one or more polyfluorinated monomers of general formula: II 15 Rf-D-Q-C-C = CH-R (II) I R in which Rf represents a straight-chain or branched 20 perfluoroalkyl radical containing 2 to 20 carbon atoms, Q represents an oxygen or sulphur atom, D represents a divalent chain bonded to Q by carbon which can contain one or more oxygen, sulphur and/or nitrogen atoms, and one of the symbols R represents a hydrogen atom and the other a 25 hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms; and (c) 0 to 65 % of one or more co-monomers. - 35 2. A telomer according to Claim 1, in which the content of fluorinated thiol(s) of formula (I) is from 10 to 30 % by weight.

3. A telomer according to Claim 1 or 2, in which 5 the content of polyfluorinated monomer(s) of formula (II) is from 30 to 50 % by weight.

4. A telomer according to any one of Claims 1 to 3, in which the content of monomer(s) other than those of formula (II) is from 25 to 50 % by weight. 10

5. A telomer according to any one of Claims 1 to 4, in which the perfluoroalkyl radicals Rp and Rf, which may be identical or different, contain from 4 to 16 carbon atoms.

6. A telomer according to any one of Claims 1 to 15 5, in which B is a straight-chain alkylene radical.

7. A telomer according to claim 6 in which B is an ethylene or tetramethylene radical.

8. A telomer according to any one of Claims 1 to 7, in which Q is an oxygen atom and D a straight-chain 20 alkylene radical containing from 1 to 20 carbon atoms.

9. A telomer according to claim 8 in which Q is an ethylene or tetramethylene radical.

10. A telomer according to any one of Claims 1 to 9, in which at least a part of monomer (c) is a straight25 chain, branched or cyclic alkyl acrylate or methacrylate containing from 1 to 18 carbon atoms.

11. A telomer according to claim 10 in which said acrylate or methacrylate contains at least 6 carbon atoms.

12. A telomer according to claim 1 specifically identified in any one of the Examples.

13. A process for preparing a telomer as claimed 5 in any one of the preceding claims which comprises telomerising the thiol and other monomer or monomers in the specified proportions.

14. A telomer as defined in claim 1 whenever prepared by a process as claimed in claim 13. 10 15. The use of a telomer as claimed in any one of Claims 1 to 12 and 14 for oilproofing and/or waterproofing a substrate. 16. The use according to claim 15 for leather. 17. A substrate oil-proofed and/or waterproofed by

15. Means of a telomer as claimed in any one of Claims 1 to 12 and 14.