DE2308151B2 - Process for the preparation of water-soluble copolymers containing carboxyl groups of monoolefinically unsaturated carboxylic acid esters - Google Patents

Description

Acrylic ester copolymers containing carboxyl groups are produced on a large scale by emulsion polymerization of acrylic esters with α, β-mono- olefinically unsaturated mono * or dicarboxylic acids. They are widely used in technology as binders, adhesive raw materials, and paints! and for the production of coatings. It is also known to produce acrylic ester copolymers containing carboxyl groups by copolymerizing the monomers in organic solvents, the acrylic esters generally being used in large excess and the monomers being used in amounts which are usually between 10 and percent by weight, based on the total batch .

It is also known to use acrylic and methacrylic acid esters at high temperature with the addition of customary water-insoluble radical-forming polymerization catalysts, optionally together with small amounts of α, / 3-monoolefinically unsaturated Carboxylic acids to polymerize. Such products

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come, for example, as a hot melt adhesive or like that Polymetbacrylsäuremethylester, as a plastic for Mission,

Finally, it is known to use acrylic esters together relatively large quantities ^ / ^ monoolefinic to polymerize unsaturated carboxylic acids, such as acrylic acid, and optionally acrylonitrile in aqueous solution. Products made by such a process are mainly used as sizing agents in the textile industry. A disadvantage of the Copolymers prepared by the known process of solution polymerization in water is before especially the relatively high viscosity of the aqueous solution, which means that the solutions in relatively low concentration, for. B. only 10 or 20%, can be put on the market.

Acrylic ester copolymers containing water-soluble carboxyl groups are used as Sd Jichtmittel: almost all of the warp threads must be used before weaving Yarns are equipped with sizing agents, the main task of which is to glue the fibers into a self-contained fiber structure and in one The thread is smoothed so that it can cope with the high demands of the weaving process. In doing so, however, the sized threads must allow the preparations for weaving to be carried out easily and z. B. do not stick to each other during storage, and they should finally, after the sized threads are woven, out of the fabric can be removed again by washing so that they can be used in subsequent finishing processes, e.g. B. when dyeing or impregnating, do not cause interference. In addition, with sizing agents that to be used for water jet looms, still requires that they, after they have been drawn onto the fiber, at 20 to 30 ° C a good resistance against water, but that they are readily soluble in low-concentration alkali or ammonia solutions are. In addition, they should practically not swell in water of 20 to 30 ° C.

From Japanese patent specification 2048396 a Sizing agent for WasserdüsenwebstShle known, which in addition to an ammonium salt of a copolymer sates of a vinyl ester and a carboxyl group-containing monomer 1 to 6 percent by weight of a wax emulsion, through which a Adhesion of the fibers is prevented and a hydrophobizing effect of the film on the fiber should be ensured. According to the information in this Japanese patent, a film has this However, after two hours of storage in water / water at 25 ° C, the detergent swells by 10.5%.

The invention relates to a process for the preparation of copolymers containing carboxyl groups of unsaturated carboxylic acid esters by polymerizing 40 to 97% by weight of monoolefinically unsaturated carboxylic acid esters with 3 to 60% by weight 3 to 5 carbon atoms containing ο, / 3-monoolefinic unsaturated mono- and / or dicarboxylic acids and 0 to 40% by weight of other olefinically saturated monomers under the usual temperature conditions and with the addition of the usual amounts of water-insoluble radical-forming polymerization catalysts. The method is characterized in that the polymerization of the monomers in the presence of 4 to 20% by weight of water-soluble alkanols and / or alkanediols and / or water-soluble ketones and / or water-soluble carboxamides

and from 0 to 10% by weight of water.

The new process gives copolymers containing water-soluble carboxyl groups, the solutions of which have a relatively low viscosity.

Monoolefinically unsaturated carboxylic acid esters are in particular acrylic acid esters containing 1 to S carbon atoms and / or vinyl esters of lower saturated aliphatic carboxylic acids, preferably containing 2 or 3 carbon atoms, such as vinyl acetate and vinyl propionate, also in particular mixed with acrylic acid esters and / or vinyl esters ^ lower methacrylic acid esters, ALcanols preferably containing 1 to 4 carbon atoms, such as methyl methacrylate in particular. Particularly suitable acrylic acid esters for the process are lower alkanols, especially methyl acrylate, ethyl acrylate and n-butyl acrylate, tert-butyl acrylate and isobutyl acrylate, as well as isopropyl acrylate, n-hexyl acrylate and Z- ethylhexyl acrylate. Α containing 3 to 5 carbon atoms .β-olefinically unsaturated carboxylic acids are acrylic acid and methacrylic acid of particular interest. Crotonic acid, maleic acid, fumaric acid and itaconic acid are also suitable.

As further monoolefinically unsaturated monomers, for. B. amides and / or nitriles a, j3-monoolefinically unsaturated carboxylic acids of the type mentioned, especially acrylamide, methacrylamide, Maleic acid monoamide, maleic acid diamide, acrylonitrile and methacrylonitrile, as well as monovinylaromatic ones Compounds such as especially styrene and / or finally vinylsuconic acid or their alkali salts are also polymerized.

It is of particular interest to use 80 to 97 percent by weight of methyl and / or ethyl acrylate with 3 to 6 percent by weight of the α, / 3-olefinically unsaturated carboxylic acids, such as acrylic acid in particular, to (»polymerize, the Up to 25% of its weight in methyl and / or ethyl acrylate can be replaced by acrylic esters containing alkanols containing 3 to 8 carbon atoms, and in addition, 0 to 17% of other monoolefinically unsaturated monomers, such as amides α, / 3-monoolefinically Unsaturated carboxylic acids and especially acrylonitrile (»can be polymerized. In this case it is in the process of advantage, 8 to 13 percent by weight, based on the monomers, of water-soluble Alkanols and / or alkanediols and / or water-soluble ketones and / or water-soluble carboxamides, preferably of the alcohols, are also to be used. With this special and preferred one Embodiment of the new process, water is preferably also used, the amount thereof in particular 4 to 7 percent by weight, based on the monomers. Water-soluble acrylic ester copolymers (A) and their aqueous Solutions are relatively low viscosity and the z. B. be used in 30 to 50% solution can. If they are used as sizes, they result in swell-resistant and waterproof ones on the threads Films that were easily washed off with dilute alkaline solutions or dilute ammonia solution can be. Acrylic ester copolymers of this type are therefore particularly advantageous as Sizing agent for water jet looms.

If, in the new process, mixtures of 40 to 80 percent by weight of n-butyl acrylate are polymerized, Isobutyl acrylate, tert-butyl acrylate, isooctyl acrylate

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and / or 2-Äthylbexylaerylat with 20 to 60 percent by weight of the α, ρ-raonoolefiniscb unsaturated carboxylic acids, such as acrylic acid in particular, acrylic ester copolymers (B) are obtained, the aqueous solutions of which are also of low viscosity and which are therefore relatively concentrated solutions of about 30 up to 50 percent by weight can be used, but the fume surf of the fibers is not only soluble in dilute alkalis, but also in W? sser, and they also swell. In this case, which is also a preferred embodiment of the new process, the proportion of the acrylic esters mentioned can be replaced by up to 50% of its weight by methyl acrylate, methyl methacrylate and / or acrylonitrile, and preferably 10 up to 15 percent by weight, based on the monomers, of the water-soluble alkanols and / or alkanediols and / or water-soluble ketones and / or water-soluble carboxamides, the alcohols, in particular the alkanols, being preferred in this case as well.

In another very interesting embodiment of the new process, 15 bis are polymerized 35 percent by weight acrylic acid and / or crotonic acid, which accounts for up to 20% of its weight amount Methacrylic acid, which replaces up to 20% of its weight with methacrylic acid and / or maleic acid can be, with 65 to 85 percent by weight vinyl acetate, up to half of its amount by vinyl propionate and / or acrylic acid esters 1 to 8, in particular 1 to 4 alkanols containing carbon atoms can be replaced, with the addition of 4 to 15 percent by weight, based on the monomers, of water-soluble alkanols containing, in particular, 2 or 3 carbon atoms and from 0 to 10 percent by weight water. In this case, vinyl acetate copolymers are obtained whose films, insofar as the polymers contain 15 to 20 percent by weight of the unsaturated acids in polymerized form, are characterized by particularly high swelling resistance and are practically only soluble in dilute alkalis are. Such vinyl acetate copolymers can be used as sizing agents for filament yarns.

The water-soluble alkanols used in the new process are preferably lower alkanols, d. H. in the generally straight-chain or branched alkanols containing 1 to 4 carbon atoms, such as methanol, ethanol, isopropanol and / or n-butanol, are used. Instead of such alkanols or together with them, it is also possible to use water-soluble alkanediols, such as, in particular, glycol, or water-soluble ketones, such as, in particular, acetone and / or water-soluble carboxamides, such as, in particular, formamide and dimethylformamide.

The new process works at customary temperatures, ie generally at temperatures from 60 to 100 ° C., preferably from 70 to 90 ° C. The customary water-insoluble radical-forming polymerization catalysts, such as organic peroxides, e.g. benzoyl peroxide, dicumyl peroxide, Acetyl peroxide and tert-butyl peroctoate and / or easily decomposable azo compounds of the type known from US Pat. No. 2,471,959, such as azo-bisisobutyronitrile, azo-bis-isobutyric acid amide and azo-bis-valeric acid nitrile, in the usual amounts, ie generally in amounts from 0.1 to 2, in particular 0.5 to 1 percent by weight, based on the

Monomers, used, will be used in the new If water is also used, this can be done entirely or in part as a template or in whole or in part together with the monomers.

In this new process, the copolymers containing carboxyl groups are obtained as highly concentrated ones Solutions that are generally obtained with dilute alkaline solutions, e.g. B. 5 to 30% potassium or Neutralize sodium hydroxide solution or with diluted ammonia water and, if necessary, with Can dilute water to a copolymer content of 25 to 60 percent by weight. Those in the polymerization product alcohols and / or ketones still present and / or water-soluble saturated Carboxamides, such as formamide and dimethylformamide, can be completely or after the polymerization partly, z. B. be separated by distillation.

The acyl ester copolymers obtainable by the new process are in particular as Suitable for sizing agents and are characterized by the particularly low viscosity of their aqueous solutions the end. Threads or yarns sized with this are characterized by excellent running properties. In addition, the carboxyl-containing acrylic ester copolymers (A) stand out when they are as Sizing is present on the fiber, due to extensive swelling resistance and practical insolubility in water from 20 to 30 ° C, but are soluble in dilute alkaline solutions. Your K values according to H. Fikentscher (Cellulose-Chemie, Volume 13, 1932, pages 58 ff.), Measured in water, are generally 10 to 60, preferably 20 to 40, especially 25 to 35.

In the solution polymerization of lower acrylic esters with acrylic acid, which in dilute aqueous Solution is carried out, one obtains highly viscous polymers even if one uses conventional regulators, z. B. mercaptans, such as dodecyl mercaptan, are also used. Even with bulk polymerization of Acrylic esters are obtained even when using the usual amounts of regulators, such as mercaptans, highly viscous products. It is therefore surprising that copolymers are used in the process according to the invention obtained, which result in relatively low-viscosity aqueous solutions.

The parts and percentages given in the following examples are based on weight.

example 1

From a mixture of 2020 parts of ethyl acrylate, 244 parts of acrylonitrile, 122 parts of acrylic acid and 49 parts of acrylamide are added to 270 parts in a mixture of 279 parts of isopropyl alcohol and 140 parts Water and 30 parts of azo-isobutyronitrile and heated to 77 ° C. with stirring. After starting the polymerization is allowed to flow in the remainder of the monomer mixture with stirring within 3 hours, the temperature being maintained in the range of 77 to 82 ° C. You then polymerize one hour at 82 to 84 ° C, allowed to cool to 70 ° C and gives a mixture of 120 parts 25% aqueous ammonia solution and 300 parts of water and then diluted with 6500 parts Water. An approximately 25% clear to slightly cloudy solution of the carboxyl group-containing solution is obtained Acrylic ester copolymers with a pH of about 8. This solution is used as a sizing agent particularly suitable for water jet looms.

If a film is made from the solution and the dried film is stored in water at 20 to 24 ° C, so this film shows a swelling of only 3 after 2 hours and a swelling of only after 24 hours 7.5%.

in example 2

4040 parts of methyl acrylate and 483 parts are mixed Acrylonitrile, 244 parts of acrylic acid and 98 parts of acrylamide and are 540 parts of this monomer mixture to a mixture of 340 parts of dimethylformamide, 280 parts of water and 50 parts of azobisisobutyronitrile and heated to 76 to 78 ° C. with stirring. After the polymerization has started one leaves the remainder of the monomer mixture within 3 hours at a temperature of up to

flow in to 90 ° C. The mixture is allowed to post-polymerize for 1 hour at 90 ° C., cooled to> ° C. and neutralized with dilute aqueous ammonia solution. The copolymer solution can be used as a sizing agent, for example after dilution with water, as a 25% solution and produces a tough film which has properties similar to the film obtainable from the copolymer of Example 1.

j ₀ example 3

1000 parts of ethyl alcohol and 75 parts of azo-bis-isobutyronitrile are placed in a reaction vessel and heated to 75 ° C. Then a Mixture of 2430 parts of ethyl acrylate, 1415 parts

η acrylic acid, 665 parts of acrylonitrile within 3 to Added 4 hours and heated to about 78 to 82 ° C.

After the end of the polymerization, the material to be polymerized is cooled to 75 ° C. and treated with a Solution of 490 parts of sodium hydroxide in 7,600 parts of water, suitably neutralized to about pH 6.

A 50% solution is obtained, which in this pH range is excellent as a sizing agent for polyester filaments suitable.

Example 4

800 parts of isopropyl alcohol, 150 parts of water and 90 parts of azo-bis-isobutyronitrile are placed in a reaction vessel and 500 parts of the following monomer mixture heated to about 78 ° C.

A monomer mixture of 2000 parts of r-butyl acrylate, 2000 parts of tert-butyl acrylate and IvX) O parts of acrylic acid are then used within of 3 hours at 80 ° C was added. 90 minutes after the start of the reaction is allowed within a 350 parts of water are added dropwise every hour.

After the end of the polymerization, some of the alcohol used can optionally be removed under reduced pressure be distilled off azeotropically. Then with about IUOO parts of aqueous 25% ammonia solution neutralized and diluted with approx. 2900 parts of water.

An approximately 50% solution is obtained, which is

fv-, plus mainly in mixtures with known

commercial starches, such as potato starch or starch ether, as a sizing agent for polyester-cotton blends suitable.

Example 5

2000 parts of ethyl alcohol and 130 parts of azo-bisisobutyronitrile are placed in a reaction vessel and heated to 75.degree. Then a Mixture of 4860 parts of ethyl acrylate, 2830 parts of acrylic acid, 1330 parts of acrylonitrile and 400 parts Water was added over the course of 3 to 4 hours and the mixture was heated to about 78 to 82.degree.

After the end of the polymerization, the material to be polymerized is cooled to 75 ° C. and the pH is adjusted by adding 6180 parts of a 65% strength aqueous ammonia solution adjusted to about pH 6.

A crystal clear, pale yellowish 50% solution is obtained, which is excellent as a sizing agent mainly suitable for polyester filament yarns.

Example 6

240 parts of Aihyiaikohoi and 20 parts of azo-bis-isobutyronitrile are heated to 72 ° C. in a reaction vessel. A mixture of 500 parts of vinyl acetate, 300 parts of tert-butyl acrylate and 200 parts of acrylic acid is then added over the course of 3 hours. The temperature is allowed to stand at about 70 ⁰ C.

After the end of the polymerization, the mixture is neutralized with 740 parts of a 5% strength aqueous ammonia solution.

An approximately 50% solution is obtained, which works well as a sizing agent for polyester or polyester /

Cotton and other filament yarns are suitable. Example 7

120 parts of ethyl alcohol are mixed with 10 parts of azo-bis-isobutyronitrile in a reaction vessel heated to 72 ° C. A mixture of 400 parts of vinyl acetate and 100 parts of acrylic acid is then added added at a temperature of about 70 ° C within 3 to 4 hours.

i "Neutralized after the end of the polymerization one with 375 parts of 5.5% aqueous ammonia solution.

An approximately 50% neutral solution is obtained, which works well as a sizing agent for filament yarns i> suitable.

Example 8

40 parts of azo-bis-isobutyronitrile and 450 parts of isopropyl alcohol are placed in a reaction vessel heated to 72 ° C. A mixture of 1200 parts of vinyl acetate, 400 parts of vinyl propionate and 400 parts of acrylic acid is then stirred in over the course of 4 hours. The temperature is left at 70 up to 73 ° C.

After the end of the polymerization, it is neutralized with 1480 parts of a 5% strength aqueous ammonia solution.

Manuli is a neutral, about 50% product, which is particularly suitable as a sizing agent for filament yarns.

Claims (4)

Claims; 1. Process for the production of carboxyl group- containing copolymers !! Unsaturated carboxylic acid ester by polymerizing 40 to 97 percent by weight of monoolefinically unsaturated carboxylic acid esters with 3 to 60 percent by weight of 3 to S carbon atoms (^^ - monoolefinically unsaturated mono- and / or dicarboxylic acids and 0 to 40 percent by weight of other olefinically unsaturated monomers under the usual temperature conditions and with the addition of the usual amounts of water-insoluble free radical polymerization catalysts, characterized in that the polymerization of the monomers is carried out in the presence of 4 to 20 percent by weight of water-soluble alkanols and / or alkanediols and / or water-soluble ketones and / or water-soluble carboxamides and from 0 to 10 percent by weight of water . 2. The method according to claim 1, characterized in that 80 to 97 percent by weight Methyl acrylate and / or ethyl acrylate with 3 to 6 percent by weight acrylic acid and 0 to 17 percent by weight acrylonitrile (»polymerized, whereby up to 25 percent by weight of the proportion of methyl acrylate and / or ethyl acrylate due to acrylic ester 3 up to 8 carbon atoms containing alkanols can be replaced. 3. The method according to claim 1, characterized in that 65 to 85 percent by weight Vinyl acetate with 15 to 35 percent by weight acrylic acid and / or crotonic acid with the addition of 4 up to 15 percent by weight, based on the monomers, of water-soluble alkanols (»polymerized. 4. Use of the prepared according to claims 1 to 3 containing carboxyl groups Acrylic ester copolymers in the form of their aqueous solutions as sizing agents.