JPS5884819A - Preparation of crosslinked copolymer containing carboxyl group - Google Patents

Abstract

PURPOSE:To obtain a water-soluble gelatinous product, showing a high viscosity at a low concentration, and having a high yield value, by crosskinking a specific copolymer having carboxyl groups and glycidyl groups. CONSTITUTION:(A) 50wt% or more alpha,beta-unsaturated carboxylic acid monomer, e.g. acrylicacid acid, (B) 0.05-10wt% polymerizable monomer having a glycidyl group, e.g. glycidyl, methacrylate, (C) 0-40wt% polymerizable monomer copolymerizable with the monomer in the component (B), e.g. methyl acrylate, and an organic radical catalyst are dissolved in an inert solvent, e.g. hexane, capable of dissolving the respective monomers but undissolving the formed copolymer at 30-90 deg.C, and the resultant copolymer is then heat-treated at 50-160 deg.C. USE:Viscosity increasing, gelling and dispersing agents, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a novel powdery crosslinked carboxyl group-containing copolymer suitable for use as a thickener for various aqueous solutions.

Conventionally, in order to produce such a polymer, a monomer having two or more ethylenically unsaturated groups in an a/β-unsaturated carboxylic acid such as acrylic acid, such as polynaryl ether , hexaallyltrimethylene torsulfone, methylene bisacrylic V amide.

Triallylic cyanurate (U.S. Special TF No. 292369)
No. 2), Detraaryl Silicon (US Patent No. 298563)
No. 1), triaryl phosphate lv (US Pat. No. 342,600)
No. 4).

A method of copolymerizing tetraaryl V oxyethane (Japanese Patent Publication No. 56-443) and the like is known. However, these polymers could not be said to be fully satisfactory in terms of performance.

As a result of extensive research into a new method for producing a crosslinked carboxyl group-containing copolymer that has superior thickening performance compared to conventionally known crosslinked copolymers, the inventors have discovered that Copolymerizing an α/β-unsaturated carboxylic acid such as acrylic acid with a polymerizable monomer having a glycidyl group and, depending on safety, a sheep and mouse body that can be copolymerized with the 2im monomer,
Next, we discovered a method of crosslinking the carboxyl groups and glycidyl groups in the resulting subaggregates by reacting them at an appropriate temperature.

The cross-linked copolymer thus obtained is dissolved in water and oxidized to around P)17 with an appropriate base, and then further concentrated at a concentration lower than that used for conventionally known copolymers. It becomes a gel-like product that exhibits viscosity, has good stability even when left outdoors, and has plastic flow characteristics with a high yield value.

The crosslinked copolymer obtained according to the present invention is gypsum.

Water-soluble paints as solid suspension stabilizers for cement, etc.

It is useful as a thickener for emulsion paints, as a sizing agent for printing in the textile industry, as a thickener in other fields, as a gelling agent, as a dispersant, and as an adhesive.

The polymerizable monomer having a glycidyl group used in the present invention is a monomer having one or more epoxy groups and one or more ethylenically unsaturated groups, and may be dissolved in an organic solvent inert to this reaction system. If so, you can use all of them. Specifically, glycidyl acetate, glycidyl ac-late, glycidyl V methacrylate: glycidyl esters such as glycidyl clotoquito, glycididiolate, glycidyl ether, isopropenyl glycidyl ether, allyl glycidyl ether, and glycidyl V glycidyl ether. These are the glycidium ethers, etc.

Particularly good results are obtained when using glycidyl acrylate and glycidyl methacrylate, which is economical.

In order to obtain the desired thickening properties of the crosslinked copolymer to be produced, it will of course depend on the crosslinking agent and other conditions, but the concentration of these glycidyl group-containing polymerizable monomers should be - °, in the range of 0.05 to 10% by weight, preferably in the range of 0.1 to 3% by weight, based on the mixed monomers.

I & excessive addition sensitivity are determined based on various conditions, and excessive cooling may further advance three-dimensionalization and produce an insoluble gel.

Furthermore, if too few wrinkles are used, the effect will not be achieved and the liquid properties will be similar to those in the case where no crosslinking agent is added.

The α/β-unsaturated levonic acids used in the present invention include acrylic acid, methacrylic acid, and crotonic acid.

It is a mixture of one or more selected from the group consisting of maleic acid, itaconic acid, fumaric acid, sorbic acid and other olefinically unsaturated carbonic acids.

Among these, acrylic acid is particularly preferred because it is inexpensive, easy to use, and provides a polymer with excellent performance.

The copolymerization reaction uses a solvent that dissolves the a/β-unsaturated carboxylic acid, the polymerizable monomer having a glycidyl group, and the monomer that can be copolymerized with these monomers, but does not substantially dissolve the resulting polymer. Using a known organic radical catalyst,
It is preferable to carry out the test in the range of 30°C to 90°C.

Examples of solvents that can be used in the present invention include organic solvents that are inert to the copolymerization reaction itself, such as hexane, heptane, octane, cyclobenzene, hexane, toluene, silane, chloroben], ethylene dichloride, etc. Even mixtures of these solvents and other solvents, such as methyl isobutyl and other solvents, are useful as long as they dissolve the monomer and do not substantially dissolve the copolymer. It is possible. For example, benzene-dioxane mixtures, chlorobenzene-methanol mixtures, etc. can also be used advantageously. However, industrially better results are obtained when one selected from the group consisting of benzene, chlorobenzene, ethylene dichloride, etc. or a mixture thereof is used.

The above-mentioned known organic radical catalysts include a-a'-azobisisobutyronitrile (hereinafter referred to as AIBN), benzoyl peroxide, 2,2'-azobis (also 2,4-dimethylvaleronitrile), and cumenehyde p. Pero afternoon shit, third class spot! Rehydro bar, etc. The operating temperature of these organic radical catalysts varies depending on the detection and operating temperature, but usually 0.
1-10% m-, preferably 0.3-331% m-
If a large amount of catalyst is used, the polymerization reaction will proceed extremely rapidly, making it difficult to remove heat and making it impossible to maintain the desired temperature.

Examples of polymerizable monomers that can be copolymerized with α/β-unsaturated carboxylic acid jsL and polymerizable monomers having a glycidyl group include ethylene, propylene, isobutylene, styrene, acrylonitrile 14/, methyl acrylate, Examples include ethyl acrylate, propyl ester, methyl methacrylate, diethyl methacrylate, vinyl acetate, vinyl chloride, etc.
Good results may be obtained by using alkyl acrylates such as /@methyl and methyl acrylate.

The copolymer of the present invention is usually produced in the following regions. The raw material monomer, copolymerization catalyst, and organic solvent are charged into a reactor equipped with a stirrer, a temperature needle, a nitrogen blowing tube, and a cooling tube. At this time, the concentration of the common electrolyte raw material is suitably within a range of 20% by weight or less, preferably from 5 to 15% by weight, depending on various conditions. As the concentration is very high and the polymerization reaction progresses, the polymer tends to precipitate, making it difficult to remove heat from the system and making it impossible to uniformly stir the reactants. Next, in order to remove oxygen dissolved in the upper space of the reaction vessel and the raw materials, nitrogen gas is blown into the solution. The hexapolymerization reaction is started by heating to a predetermined temperature of 20 to 120 degrees Celsius in a water bath, etc. The inside of the reaction system gradually changes from an initial transparent homogeneous solution to a white slurry. In addition to the above method, it is also possible to continuously add a polymerizable monomer having a glycidyl group as a crosslinking agent to the polymerization system as the polymerization progresses.After the polymerization reaction is completed, the precipitate is filtered. , thoroughly washed with a suitable solvent and dried at a temperature of 50°C to 160°C. In this way, the crosslinked polymer is obtained in the form of a white fine powder with a low bulk specific gravity.

In addition, since the crosslinking reaction of the polymer occurs simultaneously during the drying process, an excessive temperature range is required as described above. When drying at a low temperature under reduced pressure for 1 hour, the crosslinking reaction does not proceed, resulting in a product with a low viscosity, and at temperatures above 200 to 300°, there is a risk that the polymer group may undergo a decomposition reaction.

Furthermore, if a large amount of water or a/β-unsaturated carboxylic acid as a raw material is present during drying, the resulting polymer may form lumps or become insoluble in water. Therefore, it is necessary to completely remove unreacted monomers by overworking @t:16.

- By dissolving the crosslinked polymer obtained in the procedure described in U above in a large amount of water and neutralizing the carboxyl groups in the polymer to a pH of around 7 with an appropriate base, the aqueous solution exhibits a high viscosity. The crosslinked polymer can be used at a concentration of 1% or less in water to obtain the desired viscosity, and this remarkable thickening effect is a major feature.

Any known base can be used as a neutralizing agent; in addition to inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, and ammonium hydroxide, organic bases such as triethanolamine and triethylamine are also used. It is possible.

Hereinafter, the present invention will be explained in more detail with reference to cold examples, but the present invention is not limited to these examples.

Wealth - Example 1 A three-dimensional acrylic acid polymer was prepared according to the following procedure.

Acrylic acid 30 parts Glycidyl methacrylate 0.2 parts Benzene 2
70 parts AIBN O, 3 parts The reaction was carried out at 60° C. for 3 hours under a nitrogen atmosphere.

The polymer product was obtained as a white slurry, which was cooled, filtered, and thoroughly washed with benzene, the solvent used in the polymerization reaction. The cake was then heated to about 110°C.
The polymer was dried to obtain a white fine powdery polymer. The powder was dispersed in a large amount of pure water (ion-exchanged water) and neutralized to PHy using an aqueous sodium hydroxide solution to prepare a viscous solution with a concentration of 0.3%. The solution was measured using a B-type rotational viscometer at 1° C. and 6 rpm, and the viscosity was 55,000 centivoise.

Example 2 According to the method shown in Example 1, a white main polymer was obtained using exactly the same recipe except that the following solvent was used instead of benzene as the solvent. However, the solvent used in each reaction was used to wash the resulting irises. These powders were dispersed in a large amount of pure water (ion-exchanged water), and neutralized to ・P)iy4 using an aqueous sodium hydroxide solution.
A viscous solution with a concentration of 3% by volume was prepared. The viscosity of the solution was measured using a B-type rotary viscometer at 25'C and rotational speed a rpm, and the results shown in Table 1 were obtained.

Table 1 Example 3 According to the method shown in Example 1, a sanirized acrylic acid polymer was prepared according to the following formulation.

Acrylic acid 30 parts, polymerizable glycidyl compound ethylene dichloride shown in Table 2 270 parts -AIBN
Part 03.

The reaction was carried out at 60° C. for 3 hours under a nitrogen atmosphere.

After cooling, the mixture was filtered and thoroughly washed with ethylene dichloride, which was the solvent used in the polymerization reaction.

The cake was then dried at about 110°C to obtain a white fine powdery polymer. Add the powder to a large amount of pure water (ion exchange water)
(Dispersed in PH and hydroxylated)
7 to prepare a viscous solution with a concentration of 0.3]1% by weight. The viscosity of the solution was measured using a B-type rotational viscometer at a rotation speed of 5 rpm at 25° C., and the results shown in Table 2 were obtained.

Example 4 A white polymer was obtained according to the method shown in Example 1 using the same recipe except that the type of polymerization catalyst, amount added, viscosity and polymerization temperature were changed as shown in Table 3. Obtained.

Table 3 Example 5 13 G parts of ξΣi acrylic jll and 0.3 parts of 340% IBN of ethylene dichloride were charged into a reaction vessel, and polymerized at 60° C. under a 111% atmosphere. After the main unit was started, a mixed solution consisting of 0.4 parts of glycidyl methacrylate and 100 parts of ethylene dichloride, which had been substituted with nitrogen in advance, was added dropwise to IIJ over 1 hour. Then polymerize for 3 hours! I made it control. Thereafter, the mixture was treated with Example 3 at 1 INl to obtain a fine white polymer having a viscosity of 70.500 centipoise.

Example 6 A white fine polymer was obtained using the same recipe as in Example 5 except that 625 parts of acrylic IL, 340 parts of acrylic chloride, 340 parts of ethylene dichloride, and 3 parts of AIB No. were used.

The viscosity of the resulting coalescence was 65,000 centipoise.

Comparative Example 1 A fine white electrolyte was prepared using the same recipe as in Example 1 except that glycidyl methacrylate was changed to triatalyl phosphate or tetraallyloxyethane. The viscosity of the resulting product was 45,000.

The voice was 53,000 cm. When these viscous liquids and the viscous liquid obtained in Example 1 were left outdoors for one week,
Crosslinking agent (1,000 for those using triallyl phosphoric acid)
Centihoise, the one using tetraallyloxyethane was lower than i, soo centivoise, but 1 example! What I got was a 15,000 centimeter voice.

Applicant: Steel Chemical Industry Co., Ltd. Representative Hiroshi Sasaki

Claims (1)

[Claims] (1) 50% by weight of g-β-unsaturation V-bony acid monomer
The above, and 0.05 to 0.05 to a polymerizable monomer having a glycidyl group
The monomer is dissolved, but the resulting copolymer is dissolved. 1. A method for fabricating a crosslinked carboxyl group-containing copolymer, which comprises copolymerizing the copolymer in the presence of a radical polymerization catalyst in a free inert solvent, and then subjecting the resulting polymer to heat. (2) The method according to claim m1llB (1), wherein the -.beta.-unsaturated carboxylic acid monomer is acrylic acid. (3) Claim 1ife(t) in which the polymerizable monomer having a glycidyl group is glycidyl methacrylate
The method described in section. (4) The polymerizable monomer copolymerizable with the a/β-unsaturated carboxylic acid monomer and the glycidyl group-containing polymerizable monomer is 7-acrylic acid atom( The method described in section 1). (→ Claim I6, wherein the alkyl acrylate is methyl acrylate. (4) The method of JJi Kikai. (6) The method according to claim (4), wherein the alkyl acrylate is ethyl acrylate. (7) Claims in which the radical polymerization catalyst is a-α'-azobisbutyronitrile (1) The method described in XJ. (8) Claims in which the inert solvent is benzene. [
The method described in paragraph (1). (9) The method according to claim (1), wherein the inert solvent is chlorobenzene. (lO) The method according to claim (1), wherein the inert solvent is ethylene dichloride. (11) Inert solvent is benzene, chlorobenze/jd
More widespread than the group consisting of the words yohyethylene dichloride ゛2
The method described in Claim No. (υfun), which is a mixture of two or more types. Q2) The method described in Claim No. (1), wherein the heat treatment is carried out at a temperature of 50°C to 160°C.