DE1495532B2 - PROCESS FOR PRODUCING AN ALKALINE-SOLUBLE MIXED POLYMERISATE - Google Patents

Description

can be used for a variety of purposes, be it mixed with fillers and pigments or otherwise, and such uses include surface coatings, paper coatings or impregnation and as a finish for certain textiles. The solution can be used as an ice cream for casein or as a thickening colloid in emulsion polymerization.

Copolymers of vinyl acetate with acrylic acid, which in the absence of diethyl and / or dibutyl ester the fumaric or maleic acid and / or dipropyl ester of maleic acid are produced, result in emulsions, which, on the addition of ammonia, form agglomerates which are only slowly dispersible, whereby the films formed therefrom are somewhat brittle. The addition of an external plasticizer, such as. B. dibutyl phthalate, has the consequence that the emulsions are not completely soluble in aqueous alkali. The application of a internal plasticizer (of a comonomer), e.g. B. an acrylic acid ester, causes copolymerization by itself, due to the very large differences in reactivity between the vinyl ester and an acrylic acid ester is difficult. The method according to the invention solves these problems.

The following examples illustrate the invention without restricting it. All quantities mean parts by weight.

example 1

A mixed polymer was made from the following components:

Parts

Vinyl acetate 8 130

Dibutyl maleate 1,500

Acrylic acid 370

High molecular amylopectin dextrin 270

Nonionic Emulsifier 300

Sodium dodecyl benzene sulfonate .... 10

Potassium persulfate 30

Potassium bicarbonate 15

Water 10 700

The reaction was carried out in a stainless steel reaction vessel equipped with stirrers and a condenser. The vinyl acetate, acrylic acid and dibutyl maleate were mixed together. All of the water-soluble substances (except for the potassium persulfate) were mixed with the water in the reaction vessel, which was then heated to 60 ° C., and then the potassium persulfate was added, followed immediately by 10% by weight of the mixed monomers. The mixture was then heated to 75-77 ° C under initial reflux, at which stage the remaining monomers were added continuously over 5 to 7 hours and finally the mixture was heated to 90 ° C for 30 minutes. The resulting emulsion contained 50% by weight of solid matter having a particle size of up to 2 microns, and an emulsion was gradually made into a solution by adding ammonia to raise the pH above 7. The emulsion was / ₀ diluted prior to the addition of the aqueous ammonia with water to a content of solids from 20 to 30 °. The films cast from the solution had good flexibility and were clear and resistant to attack by water.

Example 2

The aqueous emulsion of a copolymer

was prepared according to the method described in Example 1 from the following ingredients:

Parts

Vinyl acetate 162.6

Dibutyl fumarate 30

Acrylic acid 7.4

High molecular weight amylopectin dextrin 5.4

Nonionic emulsifier 6

Sodium dodecyl benzene sulfonate 0.2

Potassium persulfate 0.6

* 5 potassium bicarbonate 0.3

Water 162

The solids content of the emulsion thus obtained was 55% by weight. As in example 1 The prepared solution in aqueous ammonia gave a flexible, clear film that had good resistance against attack by water.

Example 3

An aqueous emulsion of a copolymer was made in accordance with that described in Example 1 Method made from the following components:

Parts

Water 9450

High molecular amylopectin dextrin 270

Nonionic Emulsifier 270

Sodium dodecyl benzene sulfonate .... 9

Potassium persulfate; 45

Dibutyl maleate 1,800

Acrylic acid 500

Vinyl acetate 6,700

Potassium bicarbonate 43.2

Water 172.8

The solids content of the emulsion was weight percent. The emulsion was easily soluble in aqueous ammonia and formed a clear, flexible film that has good resistance to Had water.

Example 4

An aqueous emulsion of a copolymer

was prepared according to the method described in Example 1 from the following ingredients:

Parts

Vinyl acetate 75

Diethyl maleate 30

Acrylic acid 5

Nonyl phenyl ethoxylate (20 mol) ... 2

Sodium Lauryl Ether Sulphate 1

Hydroxyethyl cellulose 2

Sodium bicarbonate 0.25

Ammonium persulfate 0.25

Water 100.7

Ammonium persulfate 0.2

Water 5

The solids content of the emulsion was

6g 49.2 percent by weight. The emulsion was soluble in aqueous ammonia and formed a clear flexible film that has good resistance compared to water.

Example 5

Comparative experiment

It is to be demonstrated the technical progress made by using an ester of an unsaturated Dicarboxylic acid can be achieved as the third monomer component.

It was made according to the method described in Example 1 using the same components worked, with the exception that the dibutyl maleate used in Example 1 was replaced by the equal number of parts by weight of additional vinyl acetate. Accordingly, it became the following monomer composition used:

Vinyl acetate 9 630

Acrylic acid 370

The solids content of the emulsion was 49.1 percent by weight. The emulsion was on a Solids content of 25% diluted and ammonia to produce a pH value above 8.5 added. The polymer went into solution, but the film cast from this solution was hard and brittle and different from the tough and flexible film obtained in Example 1.

Claims (7)

1 2 underlying invention is to produce such copolymers, which can be converted into solutions with the aid of alkali and thus for the production of coatings 1. Processes for the production of an alkali-soluble or paints and the like and as a thickener mixed polymer from polymerisable un- 5 are suitable in emulsion polymerisation,
The German Auslegeschriften 1 050 058, 1 055 239 riger than 7, characterized, and 1129 285 describe one of the German Ausleged that a vinyl ester of a low molecular weight, aliphatic 1 044 408 similar process, however, is also table saturated carboxylic acid, acrylic acid and a monomer combination according to the invention diethyl and / or dibutyl ester of the fumaric or io neither described nor suggested.
Maleic acid and / or a dipropyl ester of Ma- werleic acid are polymerized in all of the above-mentioned Auslegeschriften. thus only emulsions or dispersions 2. The method according to claim 1 , characterized in that, according to the invention, the monomer to be polymerized method surprisingly in the alkaline in proportions during the polymerization reaction 15 soluble copolymers and thus solutions are introduced into the reaction vessel. Polymers can be obtained. 3. The method according to claim 1 or 2, characterized as the vinyl ester according to the invention characterized in that the polymerization in a process for the preparation of the alkali-soluble mixed pH over 3 is carried out. polymerisate is used, one preferably uses 4. The method according to any one of claims 1, 2 20, a vinyl ester of a low molecular weight aliphatic or 3, characterized in that the amount of tables, saturated carboxylic acid, such as. B. vinyl acetate. Fumaric or maleic acid ester not less than that used as the third monomer component 7 percent by weight based on the weight of the ester of an unsaturated dicarboxylic acid is a Vinyl esters. Diethyl or dibutyl esters of the fumaric or maleic 5. The method according to claim 4, characterized in 25 acid and the dipropyl ester of maleic acid. Drawn, that the amount of fumaric or maleic can, if desired, be mixtures of more than one acid esters not less than 10 percent by weight, vinyl esters can be used and also more than one based on the weight of the vinyl ester. Esters of the unsaturated dicarboxylic acid. 6. The method according to the preceding claims. characterized in that as a vinyl 3 ° turn of an emulsion polymerization technique ester vinyl acetate is used. carried out, whereby to initiate the polymerization 7. Use of an aqueous alkali solution of one of the monomers any free radical as an initiator produced according to the preceding claims is used. Preferably, the poly-copolymers, optionally with the addition of merizing monomers, added in proportions during the polymer of fillers to produce a coating reaction. Usually Dimensions. the polymerization will take place at a pH above 3, z. B. 3.5 performed. According to the invention Process can use emulsifiers and other additives commonly found in aqueous emulsion poly-40 merization systems are used The present invention relates to a method of being. Production of an alkali-soluble copolymer. The applied amount of ester of the unsaturated The process according to the invention for the preparation of dicarboxylic acid is generally not less than an alkali-soluble copolymer of polymer than 5 and advantageously 7 percent by weight, based on soluble unsaturated compounds with a 45 to vinyl ester of the saturated carboxylic acid, and a pH value lower than 7 is characterized, preferably not less than 10 percent by weight that a vinyl ester of a low molecular weight, aliphatic The amount of acrylic acid used is usually saturated carboxylic acid, acrylic acid and diethyl from 3 to 20 percent by weight, based on the total and / or dibutyl ester of fumaric or maleic acid amount of esters present , and preferably and / or a dipropyl ester of maleic acid poly- 50 at least 3.5 percent by weight,
be merized. According to the method according to the invention, from From the German Auslegeschrift 1 044 408 is the vinyl ester, acrylic acid and the ester of Process known for the production of frost-free and unsaturated dicarboxylic acid, a copolymer electrolyte-resistant polymer dispersions are prepared from which in an aqueous alkali monomer, polymerizable, unsaturated solution with the formation of a coating mass bonds in an aqueous medium with the addition of can be, which on drying a shiny water soluble catalysts. With this process film gives and which an excellent wetting Emulsifiers such as fatty alcohols or resin acids have the capacity for pigments and fillers that are in the used, the incorporated with 5 to 40 moles of ethylene oxide per mole of aqueous solution of the copolymer implemented and then sulfated. Than 60 can be. When to dissolve the mixed poly-polymerizable Monomers are used under a merisats a volatile alkali, such as. B. A large number of possible compounds, an aqueous solution of ammonia, are also available Vinyl esters, maleic or fumaric acid esters and ten films resistant to attack by Acrylic acid, but without naming any water, and after heating, the films have Combination of these compounds, called. Des 65 increased resistance to attack others are those of alkali claimed in this patent application. Polymer dispersions only as dispersions The obtained by the process according to the invention usable, whereas the above aqueous solutions of the copolymers give up