DE2049665A1 - Process for the production of modified polyacrylonitrile with basic groups - Google Patents

Description

FARBWERKE HOECHST AG. formerly Master Lucius & Brüning File number: - HOE 7o / F 197

Date: October 8, 197o - Dr.v.F./Ga

"Process for the production of modified polyacrylonitrile with basic groups"

The invention relates to a method for producing modified Polyacrylonitrile with basic groups, as well as for the production of fibers and threads from these polymers, which with anionic (acidic) dyes are easy to dye.

Copolymers of acrylonitrile with basic groups are known, vinylpyridines being used as basic comonomers (U.S. Patent 2,491,471).

Furthermore, copolymers of acrylonitrile are known, the semicarbazides or hydrazides substituted as basic components (Dutch patent applications nos. 6 8öl 479 and 6 8ol 56o).

The disadvantage of these polymers is that they either have a low thermal stability, so that the whiteness of the fibers and threads produced from them is already at low thermal loads quickly deteriorated or that in their production with the aid of a suspension precipitation polymerization no good suspensions, which guarantee a clean work-up, are created.

It is also known for the production of polymer dispersions e.g. to use an unsaturated amine of the general formula I from polyvinyl acetate to improve dispersibility <DOS 1 595 634).

¹ O ²ⁿ ^ R ₃

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Where η ** means 1, 2 or 3, R ^ " alkyl, preferably with 1-4 carbon atoms, or

Phenyl, and R "and R_ = alkyl radicals, preferably with 1-4

Carbon atoms (methyl, ethyl, n- and i-propyl, isomeric butyl residues, etc.) »also under Formation of a 5- or 6-membered ring, optionally including a heteroatom, can be linked to one another.

The preparation of the compound (I) is advantageously carried out according to the procedure described in DAS 1 245 939.

The present invention is based on the object of developing polyaeryl nitride polymers with basic groups which on the one hand have good thermal stability and, on the other hand, form easily processable suspensions during their production.

The subject of the invention is thus a process for the preparation of basic groups-containing »modified polyacrylonitrile by copolymerization of acrylonitrile with the usual comonomers by suspension-precipitation polymerization in the presence of basic comonomers with the aid of catalysts, which is characterized in that the copolymerization in the presence of 0.5 to 5, preferably 1 to 3 percent by weight, based on the total amount of the monomers used, of a compound of the general formula I CH — CH ₂ B ₂

- C - M - (OIL) - H

3 ζ η \

"3

where η = · integer from 1 to 3

■ alkyl, preferably with 1-4 carbon atoms, or phenyl and and Ro = alkyl radicals, preferably again with 1-4 C-

Are atoms which can also be linked to one another to form a 5- or 6-membered ring, optionally including a heteroatom _f

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or from their salts.

Starting products for the production of the above-mentioned modified polyacrylonitrile containing basic groups are acrylonitrile, the comonomers usually used for its copolymerization, such as acrylic acid esters, vinyl compounds (vinyl acetate, etc.), and 0.5 to 5, preferably 1-3 percent by weight, based on the total amount of the monomers used, a compound of the general formula I. The polymerization is carried out by the suspension precipitation polymerization process customary for polyacrylonitrile polymerization, the known catalyst systems, such as, for example, KL ^S 2 ° Q ^y ^ ^a 2 ^S 2 ° 5 ^{being used} * ^un S come. The polymerization is carried out at a pH below 7, i.e. in the acidic range - preferably at pH 4-5, since the incorporation of the amine I is favored in this range.

The modification components I used according to the invention can be used both as free amines and as amine salts, the salts being generally preferred. Suitable salts are both the salts of inorganic acids, such as HCl, H ₃ SO ₄ , H ₃ PO _4, etc., and the salts of organic acids, in particular of toluenesulfonic acid and naphthalenesulfonic acids.

The modified polyacrylonitrile polymers produced according to the invention are obtained in their production as very good suspension particles, those in the work-up of the polymerization batch are excellent filterable.

As a result of the good thermal stability of those produced according to the invention With polymers, the whiteness of the products made from them - especially fibers and threads - does not deteriorate strong thermal loads, especially not when the amines I used according to the invention are used as salts, for example as a salt of toluenesulfonic acid or naphthalene sulf acid, have been present.

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The fibers and threads are produced from the polymers produced according to the invention in accordance with that for polyacrylonitrile known spinning processes, e.g. by wet spinning from dimethylformamide solutions in dimethylformamide-water mixtures, as well as by dry spinning.

The fibers and threads obtained show a good absorption capacity for acid dyes, with a gradation of color depth obtained when dyeing fibers and threads made from polymers containing different amounts of the according to the Invention used amine (I) contain, so that the corresponding fibers and threads have a different number contain basic groups.

The subject matter of the invention is to be explained in more detail below with the aid of specific examples.

Examples 1-2 :

The polymers listed in Table 1 are prepared as follows.

The monomer mixture of acrylonitrile and methyl acrylate is pumped into a polymerization flask into which an aqueous solution of N-vinyldimethylaminopropyl acetamide (Vidiprop), which has been _{adjusted to pH5 with H 3} SO ₄ and sodium acetate, is simultaneously metered. Furthermore, the aqueous solutions of K ₂ S ₃ Og and Na ₃ S ₂ O _{5 are} metered into the polymerization flask from separate containers. The polymer suspension that forms is discharged continuously after an average polymerization time of 90 minutes. The concentration ratios and thus the dosage amounts are chosen so that an approx. 27% suspension concentration is established in the polymerization flask and the monomers are each present in the desired ratios. After the specified polymerization time, the

ο Polymerization by cooling the suspension to O C at a Sales of 80% started.

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Table 1

Polymerization at a constant ρΉ value of 5

example Deployed
Monomer mixture
(Wt%) K value mVal bas. Groups / kg
polymer 1 93 % acrylonitrile
5 % acrylic acid
methyl ester
2 % vidiprop 89 95 2 94 % acrylonitrile
5% acrylic acid
methyl ester
1 % vidiprop 85 45

The basic groups were determined by potentiometric titration in dimethyl formamide solution with ⁿ / 3, o methanolic p-toluenesulfonic acid and the Kalorael glass electrode system.

Examples 3 ~ 4 :

The polymers listed in Table 2 were made according to the example 1, the pH value being varied only by different buffering.

Table 2
Polymerization at different pH values

example Deployed
Monomer mixture
(Wt.%) pH of the
Polymerization
solution K value mVal bas.
Groups / kg
polymer 3
^% 4 93% acrylonitrile
5 % acrylic acid
methyl ester
2% vidiprop
93% acrylonitrile
5% acrylic acid
methyl ester
2% vidiprop 3
4th 82
84 48
9o

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Example 5;

It 'A polymer was synthesized according to Example 1 at pH 5, but with the addition of 2% Vidiprop by the equivalent amount of the corresponding salt was replaced old toluenesulfonic acid "

A polymer was obtained which had a K value of 85 contains a content of 100 BVal / kg of basic groups in the polymer.

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Claims (5)

PATENT CLAIMS: 1. Process for the preparation of basic groups containing modified Polyacrylniti'il by copolymerization of Acrylonitrile with the usual comonomers by suspension precipitation polymerization in the presence of basic comonomers with the aid of catalysts, characterized in that the copolymerization in the presence of 0.5-5, preferably 1-3, percent by weight, based on the total amount of monomers used, a compound of the general formula / 2 R ₁ -CN- (CH ₂ ) _n - N, (I) \
where η = integer from 1 to 3 ■ alkyl, preferably with 1 to 4 carbon atoms, or Phenyl and R ₃ - alkyl radicals, preferably with 1 to 4 carbon atoms, which also form a 5- or 6-membered ¹ . ring ring, optionally including a heteroatom, can be connected to one another
or from the salts of this compound I is made. 2. The method according to claim 1, characterized in that the copolymerization is made at a pH of 4-5. 3. The method according to claim 1 and 2, characterized in that the salts of the compound of formula I, salts of inorganic acids such as HCl, H ₂ SO ₄ H ₃ PO ₄ , are used. 4. The method according to claim 1 and 2, characterized in that as Salts of the compound of the formula I, salts of organic acids, such as toluenesulfonic acid or naphthalenesulfonic acid, can be used. 5. Use of the copolymers obtained according to claims 1-4 for the production of threads and fibers. 209816/1262