PT94915B - PROCESS FOR HYDROPHOBIZATION OF LEATHER AND HAIR SKINS FOR THE APPLICATION OF COPOLYMERS BASED ON COMPRESSED CHAIN OLEFINS AND ETHYLENICALLY INSATURATED DICARBOXYLIC ANIDRIDES - Google Patents

Abstract

Use of copolymers obtainable by free-radical copolymerisation of (a) C8-C40-monoolefins with (b) ethylenically unsaturated C4-C8-dicarboxylic anhydrides in the manner of a mass polymerisation at from 80 to 300 DEG C to form copolymers having molecular weights of from 500 to 20,000 g/mol, subsequent solvolysis of the anhydride groups of the copolymers and at least partial neutralisation in an aqueous medium with bases of the carboxyl groups formed in the course of the solvolysis and which are present in the form of aqueous dispersions or solutions, as agents for waterproofing leathers and pelt furs.

Description

Since the German patent DE-OS 3 730 885 fuels for Otto engines are known which contain, among others, small amounts of copolymers, which have olefins with 2 to 40 carbon atoms and maleic acid anhydride, polymerized, have a molar mass between 500 and 20000 g / mole ^ and in which the anhydride groups of the copolymers are reacted, totally or partially, with aqueous bases of alkali metals or alkaline earth metals, and the

the rest of the carboxyl groups are reacted with alcohols and / or amines to give the corresponding ester and / or starch groups and / or ammonium salts.

Since the German patent DE-PS 2 629 748, the use of saponified copolymers with alkali metal bases or with amines is known, obtained from olefins with 10 to 30 carbon atoms and maleic acid anhydride, for filling and greasy leather and fur. Hydrolyzed copolymers can still be reacted with alkali compound disulfide. Since the copolymers are prepared in organic solvents and the solvents are not removed, the dispersions of aqueous copolymers thus prepared contain considerable amounts of organic solvents, for example xylene or dodecyl benzene. Dispersions of this type are, in fact, suitable for greasing leather and fur; however, due to their content of organic solvents, they are practically not applicable for hydrophobizing leather and fur.

The invention aims to provide an improved composition for the hydrophobization of leather and fur.

objective is achieved according to the present invention, through the application of copolymers, which can be obtained by copolymerization by free radicals of

a) monoolefins with 8 to 40 carbon atoms, with

b) anhydrides of dicarboxylic acid with 4 to 8 ethylenically unsaturated carbon atoms, at temperatures between 80 and 3O02C, according to the type of polymerization of the substance, in order to obtain copolymers with molecular masses between 500 and 500 20000 g / mole, subsequent solvolysis of the anhydride groups of the copolymers and at least partial neutralization of the carboxyl groups resulting from the solvolysis, in aqueous medium, with bases, and said copolymers are in the form of aqueous dispersions at 0.5 to 50% by weight, as compositions for the hydrophobization of leather and fur.

The copolymers mentioned are already known, for example since the German patent DE-OS 3 730 885. They are obtained according to a type of substance copolymerization, through the operation of copolymerizing the monomers of the group (a) with the monomers of the group ( b), at temperatures between 80 and 300 ² C. Suitable monoolefins, with 8 to 40 carbon atoms are, for example, n-octene-1; 2,4,4-trimethylpentene-1; 2,4,4-trimethyl-pentene-2; dusobutene which technically occurs as an isomeric mixture of about 80% by weight of 2,4,4-trimethyl-pentene-1 and about 20% by weight of 2,4,4-trimethyl-pentene-2; 4,4-dimethylhexene-1; decene-1; dodecene-1; tetradecene-1; hexadecene-1; octadecene-1; olefin-1 in ^C 20 ' ^{olefin_1 in C} 22' ^{olef, ina-1 C} 24 'oiophine ^{-1 in c} 2 “ ^C 24 ^; olefin-1 in C - C; olefin-1 in C; olefin-1 in C _oc and 34 donated 35 olefin-1 in Ο ^ θ. Olefins, respectively mixtures of olefins, are products already on the market. In addition to straight chain olefins, cyclic olefins such as cyclooctene are also of interest. Since their preparation, olefins can contain small amounts of inert organic hydrocarbons, for example up to about 5% by weight. Generally, olefins with the quality that can be obtained in commerce are used. It is not necessary to subject these marketed olefins to any special purification operation.

Preferred olefins are olefins having 16 to 30 carbon atoms.

As component (b) of the copolymers, anhydrides of unsaturated dicarboxylic acids with 4 to 8 carbon atoms are concerned, for example maleic acid anhydride, itaconic acid anhydride, mesaconic acid anhydride, citraconic acid anhydride, methylene malonic acid anhydride and their mixtures with each other. Of the aforementioned anhydride, maleic acid anhydride is preferably used. The copolymers contain, polymerized, 40 to 60 mole% of monoolefins and 60 to 40 mole% of said anhydrides of dicarboxylic acids and have a molecular mass between 500 and 20000, preferably between 800 and 10000 g / mole. They are obtained when the monomers (a) and (b) are polymerized in the molar ratio between 1.1: 1 and 1: 1. Preferably the monomers (a) and (b) are polymerized in a molar ratio of 1: 1 or simply an excess of 1% by weight of monomers of component (a) is employed. The monomers of groups (a) and (b) form, in a known manner, alternating copolymers which, at high molecular weights, contain the monomers (a) and (b) polymerized in, respectively, 50% by weight. In case the copolymers have very low molecular weights, depending on the type of the end groups, a shift in the molar ratio may occur in the above range, when, for example, the oopolymer chain starts with monomer (a) and also ends with monomer (a).

The polymerization of the substance is carried out at a temperature in the range between 80 and 300 ² , preferably in the range between 120 and 200 ² C, so that the lowest temperature to be chosen for the polymerization is preferably at least 20 ² C, approximately above the melting temperature of the glass of the polymer formed. The polymerization conditions are chosen according to the molecular weight that the copolymers must have. Polymerization at high temperatures produces copolymers with reduced molecular weights, while polymerization at lower temperatures produces copolymers with higher molecular weights. The amount of the polymerization initiator compound also has an influence on the molecular weight. In general, a percentage comprised between 0.01 and 5% by weight, in relation to the monomers used in the polymerization operation, of substances that initiate polymerization, forming radicals. In this case, larger amounts of starting substances produce copolymers with lower molecular weights. Monomers (a) and (b) can be polymerized at temperatures above 200 ^and C, also in the absence of polymerization initiating substances. This means that it is not mandatory to use polymerization initiating substances, because monomers (a) and (b), at temperatures above 2002C, are already polymerized with radicals even in the absence of initiators. Appropriate polymerization initiators are, for example, tertiary di-butyl peroxide; acetyl-cyclohexane-sulfonyl peroxide; diacetyl peroxide dicarbonate; dicyclohexyl peroxide dicarbonate; di-2-ethylhexyl peroxide dicarbonate; tertiary butyl per-neo-decanoate; 2,2-azo-bio (4-methoxy-2,4-dimethyl-valero-nitrile); tertiary butyl perpivalate; per-2-ethylhexanoate, tert butyl _k ficiary; tertiary butyl permaleinate; 2,2 -azo-bis (isobutyronitrile); bis- (terc.-butylperoxy) -cyclohexane; carbonate; tert-butyl-peroxy-isopropyl carbonate; tert-butyl-peracetate; di-tert-butyl-peroxide; di-tert-amyl-peroxide; decumene hydroperoxide and tertiary butyl hydroperoxide. The polymerization initiator compounds can be applied individually or in mixtures with each other. They are applied

Q // in the polymerization operation in substance, preferably separately or as a solution or dispersion in the monoolefin, inside the polymerization reactor. Of course, during copolymerization, redox co-initiators, such as benzoin, dimethylaniline, ascorbic acid, as well as organic soluble complexes of heavy metals, such as copper, cobalt, iron, manganese, nickel, can also be used simultaneously. and chrome. The simultaneous use of redox co-initiators to polymerization at a lower temperature. The amounts generally employed of redox coinitiators are in the range between 0.1 and 2000, preferably in the range between 0.1 and 1000 ppm in relation to the applied amounts of monomers. If the monomer mixture is polymerized at a temperature that is at the lower limit of the temperature range to be considered for the polymerization and then is depolymerized at a higher temperature, it is convenient to use at least two different starting substances , which decompose at different temperatures, so that a sufficient concentration of radicals is available in each temperature range.

In order to prepare copolymers with low molecular weight, it is often advantageous to carry out copolymerization in the presence of regulatory substances. For this case, conventional regulatory substances can be used, such as aldehydes with 1 to 4 carbon atoms, formic acid and compounds containing organic SH groups, such as, for example, 2-mercapto-ethanol; 2-mercapto-propanol; mercaptoacetic acid; mercapto-propionic acid; tertiary butyl mercaptan; n-dodecycle-mercaptan and tertiary-mercaptan dodecycle. The polymerization regulating substances are applied, in general, in quantities between 0.1 and 10%

by weight, relative to monomers.

Copolymerization is carried out in the usual polymerization devices, for example in a pressure-sealed boiler, which is equipped with an agitator device, in boiler cascades with a pressure-sealed agitator or in a tubular reactor. In the substance polymerization process, the copolymerization of olefins and anhydrides takes place in a molar ratio, in the absence of solvents. Copolymerization can be carried out continuously or intermittently. For example, the olefin or a mixture of several olefins can be placed inside the reactor and heated with stirring to the desired polymerization temperature. Once the olefin has reached the polymerization temperature, the ethylenically unsaturated dicarboxylic acid anhydride is added to the doses.

If an initiating agent is used, it is added, dosed, to the reaction mixture, preferably separately, or else dissolved in an olefin that is suitable for polymerization. The polymerization regulating agent, if applied, is added to the mixture to be polymerized, either separately or also dissolved in an olefin. The acid anhydrides, in particular maleic acid anhydrides, are preferably added as a melt composition to the reaction mixture. The temperature of the molten mass composition is between 70 ² and 90 C, approximately. If, during copolymerization, an excess of olefin, for example, an excess of 10%, can be removed without difficulty, the aforementioned excess after the copolymerization is finished, being removed from the reaction mixture through distillation. , preferably under reduced pressure, being extracted from the copolymerization melt. Then proceed directly, coriently, with the processing of the copolymerization melt.

The copolymers thus produced are solvolized after cooling to room temperature or, preferably, in the form of melt, which has a temperature in the range between 80 and 180 ^to C, preferably between 90 and 150 ^to C. The solvolysis of the anhydride groups of the copolymers consists, in the simplest case, of hydrolysis and subsequent neutralization. It is particularly advantageous to work in pressure-sealed devices, and directly there, by adding water to a melt of the copolymers obtained by substance polymerization, to transform the anhydride groups into carboxyl groups and, by means of a further addition of bases, neutralize at least 10% of the carboxyl groups of the hydrolyzed copolymers. However, hydrolysis and neutralization can also be carried out practically simultaneously by adding diluted aqueous bases to the copolymer melt. The quantities of water and neutralizing agent are, in this case, chosen so that dispersions or solutions containing between 10 and 60% are obtained, preferably between 20 and 55% by weight of solid substances, which are marketed. From the latter, the preparation solutions are then prepared by means of dilution until they reach levels of solid substances ranging from 0.5 to 50% by weight.

Copolymers obtained through substance polymerization can also be solvolized by the addition of primary and / or secondary amines. In this case, the solvolysis is effected with such amounts of amines that 10 to 50% of the carboxyl groups resulting from the monomers (b) polymerized together are amidated by complete hydrolysis. After the formation of semiamide groups in the copolymer, neu10 follows

j tralization. This neutralization is continued to the extent that p 'I

I minus 10% of the carboxyl groups of the copolymer formed by i

polymerization of substance are neutralized. In addition, the copolymer can also be solvolized with aminocarboxylic acids, as well as salts of aminocarboxylic acids, preferably alkali metal salts. Alkali metal salts of alpha-aminocarboxylic acids are especially preferred, where the alkali metal salts of sarcosine are particularly very advantageous. Solvolysis is most conveniently carried out by means of salts of aminocarbon acids

Ixylates in aqueous medium. In this case, solvolysis is carried out

| with such amounts of aminocarboxylates that are amidated! 10 to 50% of the carboxyl groups formed from monomers I (b) polymerized together by means of complete hydrolysis. After the formation of semiamide groups in the copolymer,

I

I i _x neutralization follows. This neutralization continues until at least 10% of the carboxyl groups of the copolymer that are formed during the polymerization of the substance are neutralized.

Solvolysis can also be carried out by adding alcohols to obtain a melt of the copolymers obtained by substance polymerization. In this case, such quantities of alcohol are added that 10 to 50% of the carboxyl groups are esterified resulting, together, from the polymerized dicarboxylic acid units. A neutralization operation follows, whereby at least 10% of the total carboxyl groups formed from the copolymer containing anhydride groups are neutralized.

Preferably, 25 to 50% of the acarboxyl groups formed together are esterified or esterified respectively from the polymerized dicarboxylic acid anhydrides. Suitable neutralizing agents, for example, ammonia, amine, alkali metal bases and alkaline earth metal bases, for example sodium liquor, potassium liquor, magnesium hydroxide, calcium hydroxide, barium hydroxide, as well as all amines that are also used for the amidation of eopolymers. Preferably, neutralization is achieved by adding aqueous sodium chloride to the copolymer. The neutralization of eopolymers containing anhydride groups is carried out at least to a degree in which water-dispersible copolymers are obtained. This degree of neutralization is at least 10% of the total carboxyl groups resulting from the anhydride groups. In addition, the degree of neutralization depends on the chain length of the respective applied set of component (a). In order to obtain eopolymers that are well dispersible in water or colloidally soluble, at least 75% of a copolymer is neutralized from an olefin with 30 carbon atoms and a maleic acid anhydride, while, for example, a copolymer from an olefin with 20 to 24 carbon atoms and a maleic acid anhydride, with a degree of neutralization of 50% of the carboxyl groups resulting from said copolymer, is already well dispersible in water. In the case of a copolymer from an olefin with 12 carbon atoms and maleic acid anhydride, a 20% degree of neutralization of the carboxyl groups resulting from the polymerized maleic acid anhydride is sufficient to obtain the dispersion of the copolymer in the Water.

For the formation of amide, ammonia and a primary and secondary amine can be used. The formation of amide occurs preferably in the absence of water, by reacting the anhydride groups of the copolymer with ammonia or with amines. The primary and secondary amines in question may have 1 to 40, preferably 3 to 30, carbon atoms. Suitable amines are, for example, methylamine, ethylamine, n-propylamine, isopropylamine,? ο /// η 'J n-butylamine, isobutylamine, hexylamine, cyclohexylamine, methylcyclohexylamine, 2-ethylhexylamine, n-octylamine, isotridecylamine, tallow fat amine, stearylamine, oleylamine, dimethylamine, diethylamine, di-n-propylamine , diisopropylamine, di-n-butylamine, diisobutylamine, dihexylamine, di-cyclohexylamine, di-methylcyclohexylamine, di-2-ethylhexyl- * mine, di-n-octylamine, di-iso-tridecylamine, tallow fat diamine, di-stearylamine, di-oleylamine, ethanolamine, di-ethanolamine, n-propanolamine, di-n-propanolamine and morpholine. Preferably, morpholine is used.

In order to partially esterify the copolymers that have anhydride groups and are obtained by polymerization of the substance, the aforementioned copolymers are reacted with alcohols. Also the esterification takes place under the exclusion of water. Suitable alcohols can contain 1 to 40 carbon atoms, preferably 3 to 30 carbon atoms. Primary, secondary or tertiary alcohols can be used. Not only can saturated aliphatic alcohols be used, but also unsaturated alcohols, such as oleyl alcohol. Preferably, monofunctional alcohols, primary or secondary, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol and isomers, n-hexanol and isomers, n-octanol and isomers, such as , for example, 2-ethylhexanol; nonanols, decanols, dodecanols, tridecanols; cyclohexanol, tallow fat alcohol; stearyl alcohol, as well as alcohols easily obtained technically by oxosynthesis, or mixtures of alcohols with 9 to 19 carbon atoms, such as oxoalcohol with 9 to 11 carbon atoms, oxoalcohol with 13 to 15 carbon atoms, as well like Ziegler alcohols, which are known by the name of alfol, with 12 to 24 carbon atoms.

Preferably, alcohols with 4 to 24 carbon atoms are used, for example n-butanol, isobutanol, alcohol ’ι

amyl, 2-ethylhexanol, tridecanol, tallow fat alcohol, · stearyl alcohol, oxoalcohol with 9 to 11 carbon atoms, oxoalcohol with 13 to 15 carbon atoms, alcohols with 12 to 14 carbon atoms and alcohols with 16 to 18 carbon atoms.

After the partial transformation of the anhydride groups into semi-amide groups or semi-ester groups, hydrolysis of the remaining copolymer anhydride groups follows. The hydrolysis of the remaining anhydride groups of the copolymer can also be carried out simultaneously with the partial neutralization that is still necessary, when a base is added | aqueous to the partially amidated copolymer, respectively esterified and also containing anhydride groups. The amount of j

I water and base is chosen so that the concentration of; The copolymer or solution dispersion is preferably in the range of 20 to 55% by weight. The pH value of the compositions ready for use in hydrophobization is equal; between 4 and 10, approximately. ¹

The dispersions of aqueous copolymers thus obtained are persistent and stable in storage. They are adequate, t

an excellent shape, for finishing leather and skins with!

I fur because they ppossuem particularmen- a hydrophobic action and you marked ^1, furthermore also develop an action gorduramento en-j and subsequent tanning. 0 leather material or; of fur with fur treated with the aforementioned co-dispersions ^! polymer according to this invention still have only a minimal tendency for water absorption and water permeability. The dispersions act simultaneously as softening agents, so that, in most cases, no greasy compositions based on natural or synthetic oils are needed. The dispersions give the goods a high volume and great resistance to traction and tearing, so that no further treatment is necessary with the subsequent tanning compositions {usual in the trade, for example vegetable tanning substances or synthetic organic tanning substances; (sintanas) based on phenol- acid condensation products | ssulfonic Jfenolj formaldehyde in most cases. jf

I

A further advantage of the aqueous dispersions to be employed according to the invention is that they do not contain any additional emulsifiers. Hides and fur that have been treated with products containing emulsifiers, need, as is known, after treatment with the said compositions, to be subjected to expensive processes, such as porj i

example a further treatment with polyfunctional metal salts

In order to make emulsifiers inactive in leather or!

i on fur with fur. i

I i

The copolymer dispersions described above are suitable for the treatment of all usual tanned skins, especially with mineral tanning substances, such as, for example, tanned skins with chromium salts III. Tanned skins are generally de-acidified before treatment, j They can already be dyed before treatment. However, dyeing can also be carried out only after the hydrophobization carried out in accordance with the present invention. j

Tanned hides are treated with aqueous dispersions, conveniently in aqueous baths, which can be obtained by diluting the copolymer dispersions with water, at pH values between 4 and 10, preferably between 5 and 8, and at temperatures in the interval between

I i

and 602, preferably in the range between 30 and 50 ^ 0, during

a period of time from 0.1 to 5 hours, in particular from half an hour to 2 hours. This treatment is carried out, for example, by I

I floor a barrel. The required amount of dispersion | of copolymer in relation to the weight of the shaved leather, or the weight of the skin with wet hair, is comprised between 0.1 and 30% preferably between 1 and 20% by weight. The length of the bath, that is, the percentage proportion of the weight of the treatment bath in relation to the material, and in relation to the weight of the shaved leather, or the weight of the skin with wet hair, is generally comprised between 10 and 1000 , preferably between 30 and 150% in the case of leather, and between 50 and 500% in the case of fur. I i

After treatment with the bath described above, the value | the pH of the treatment bath is adjusted by adding acids, * preferably using acids such as formic acid, up to a pH value between 3 and 5, preferably between 3.5 and 4 i

I

In the event that the conventional tanning substances ί are used simultaneously during the process of finishing leather and fur, the treatment with the aqueous dispersions to be applied according to the present invention can take place before or after the later tanning, or also at various operational stages, so that the aqueous dispersions are applied to the portions, before, during or after the subsequent tanning operation.

Aqueous dispersions to be applied as hydrophobizing agents can also be used in conjunction with the usual finishing compositions of p leather or fur, such as paraffin-based hydrophobizing oils. In this way, in some cases, the hydrophobization action is improved.

X.

greasing and subsequent tanning.

The percentage data in the Examples are percentages by weight, unless otherwise stated. The molar masses of the copolymers were determined by gel permeation chromatography, in which tetrahydrofuran was used as the elution agent, and highly distributed fractions of polystyrene for graduation. The test with treated leather regarding the tendency for water absorption and water permeability was carried out with a Bally penetrometer, depending on the process of

I measurement IUP 10 of the International Union of Leather Chemical Associations, Commission for Physical Testing on Leather, in ί í

Das Leder, volume 12, pages 36 to 40 (1961). !

Preparation of aqueous copolymer dispersions: Dispersion

In a steel reactor equipped for polymerisations, which was equipped with a stirring device and dosing devices

1195 g of a mixture of olefin with 20 to 24) carbon atoms (Gulftene 20-24, a product sold by the Gulf Oil Chemical Company, USA) are placed and heated with stirring up to 190 ^s C in a weak current of nitrogen. As soon as that temperature is reached, 329 g of maleic acid anhydride heated to 70 ° C and 16 g of di-tert-butyl peroxide are uniformly added over 4 hours. Then the reaction mixture is stirred for 2 hours at 190 C ^and cooled to 90 ^s and C with stirring. Inside of

J. '

HF half an hour then 320 g of 50% aqueous sodium chloride and 3909 g of water are added separately, heating to 90 ⁵ C. The reaction mixture is stirred for 4 hours at a temperature between 90 and 95 ^ 0 and in se-!

The cooled is then cooled to room temperature. You get des- | !

a slightly viscous aqueous dispersion, with a j!

solid substance content of 30.2%. The molar mass of the copolymer! mere, non-hydrolyzed, from olefin and maleic acid anhydride was 8900 g / mole; 50 mole% of all the resulting carboxyl groups were neutralized.

i ί

Dispersion__II;

I

In the reactor, in which dispersion I was prepared, 1500 g of octadecene-1 are placed and heated with stirring, in an atmosphere. nitrogen beaker, up to 190 ² C. as soon as this temperature has been reached, 588 g of an acid anhydride melt are added separately and within 2 hours respectively!

maleic and a solution of 27 g of di-tert-butyl peroxide i}

in 42.8 g of octadecene-1. After adding the acid anhydride

maleic acid and peroxide, the reaction mixture is further stirred for 2 hours J 190 ⁵ C, then is cooled to 110 C. ^and addi-!

t 522 g of morpholine are dosed within 1 hour .; The reaction temperature is maintained at 110 ^e . After the addition of morpholine, the reaction mixture is stirred for an additional 2 hours at 110 ° C in order to transform the anhydride groups of the copolymer (

ro in the corresponding semiamide groups. Arefece I was then the reaction mixture under stirring to 90 C and ² are added, separately j, 480 g of an aqueous 50% solution of sodium} , and

8680 g of water, which has a temperature of 90 ^and C, within half an hour and is heated for 2 hours, up to 90 ² C. A viscous dispersion is obtained at room temperature, with a solids content of 25 , 4%. The molecular weight of the unsolvated copolymer was 4800 g / mole; 50 mole% of the total carboxyl groups resulting from the anhydride groups were as an amide group and 50 mole% were neutralized.

Example 1

Cow leather, chrome-tanned with a ras-jy thickness

pagem 1.8 mm, which had been deacidified to a value I PDE pH of 5.0 was pisoado in the tanning vessel with 15%: dispersion I in relation to the shaved weight for 2 hours' to 40 ² C. The total amount of the bath was 150%. í i

I

The leather was then dyed with 1% by weight of a usual anionic aniline dye. Then, the pH value was _; adjusted with formic acid to 3.8. Finally, it was washed, mechanically stretched and dried. !

ί j

leather obtained was very soft, supple, full ^bodied! i

uniformly dyed and had excellent dynamic water resistance. The Bally penetrometer test revealed, with! 15% repression for the water absorption aspect, after 24 hours, a value of 20.9% by weight and it was not possible to verify, during the referred period of time, no passage of water.

Example__2

Chrome-tanned cowhide, with a scraping thickness of 1.8 mm, which had been de-acidified to a pH value of 5.0 and 0.7% by weight of a conventional anionic dye was layered with 20 % of dispersion II in relation to the scraped weight, for 1 hour and 30 minutes, at 40 ² C, inside the tanning container. Following this treatment, the pH value of the leather was adjusted with formic acid to one!

I pH value of 3.6 and finished as usual. ;

The leather thus obtained was very soft and pleasant to the touch and had a high dynamic resistance to water. The Bally penetrometer test revealed, with 15% repression, for the water absorption after 24 hours a value of 23.7% by weight and, during this period of time, it was not possible! note no water permeation. :

Claims (5)

H_E_I_V_I_N_D_I_C_A_Ç_Õ_E_S ia _ Process for hydrophobizing leather and skins with! hair by applying chain olefin-based copolymers; I long and anhydrides of ethylenically unsaturated dacarboxylic acids, characterized by the fact that hydrophobization is done with copolymers obtained by copolymerization by free radicals of * ¹ . Λ ¹ (a) monoolefins in C - C with 40 (b) anhydrides of dicarboxylic acids in C. - C _o ethylenically unsaturated at temperatures between 80 and 3002C according to the type of polymerization of the substance in order to obtain copolymers with masses molecules ranging from 500 to 20000 g / mole, subsequent solvolysis of the copolymer anhydride groups and at least partial neutralization of the carboxyl groups, resulting from solvolysis, in aqueous medium, with bases, and the aforementioned copolymers being under! i in the form of aqueous solutions or dispersions. ) I i 2. A process according to claim 1, characterized in that solvolysis is carried out by adding water to the | i composition consisting of the melt of the copolymers activated by polymerization of the substance, and neutralizing at least 10% of the carboxyl groups of the hydrolyzed copolymers i i with ammonia, amines, alkali metal or alkaline earth metal bases. . i i 3 - Process according to claim 1, characterized in that to carry out the solvolysis by the addition of primary amines and / or secondary composition comprises the melt of the copolymers obtained by polymerizing substance is amidate 10 to 50% of the total of the resulting carboxyl groups Lants of the monomers (b) polymerized and neutralized by; least 10% of the total resulting carboxyl groups. j i 4 ^A - Process according to claim 1, characterized in carrying out the solvolysis of the copolymers obtained by polymerizing the substance in aqueous medium by adding salts of aminocarboxylic acids, if amidate 10 to 50% of total carboxyl groups resulting from the polymerized monomers (b) and neutralize at least 10% of the total resulting carboxyl groups. 5 - Process according to claim 1, characterized in carrying out the solvolysis by the addition of alcohol to a composition consisting of a melt of the copolymers obtained by polymerizing substance esterifying 10 to 50% of total carboxyl groups resulting from the polymerized monomers (b), and neutralize at least 10% of the carboxyl groups obtained.