JPS5815511A - Production of crosslinked copolymer - Google Patents

Abstract

PURPOSE:To obtain a crosslinked copolymer useful in the production of poultice compositions, by introducing a water-soluble portion into a copolymer, pH<=8, prepared by polymerizing a monomer mixture consisting of an alpha,beta-unsaturated carboxylic acid and its alkali metal salt in the presence of a polyfunctional crosslinking agent. CONSTITUTION:In the presence of a 10<-4>-10<-2>mol% polyfunctional crosslinking agent is polymerized a monomer mixture consisting of an alpha,beta-unsaturated carboxylic acid of formulaI, wherein R is H, COOH or COOX, R1 is H, CH3, CH2COOH or CH2COOX1, X and X1 are each an alkali metal, or its derivative and an alkali metal salt of an alpha,beta-unsaturated carboxylic acid (in a blending ratio such that the produced copolymer has a pH<=8). The polymerization reaction is carried out under conditions including a starting reaction temperature of -5-+4 deg.C and an amount of a polymerization catalyst of 10<-3>-3X10<-1>wt%, based on the monomer. The titled composition is prepared by introducing 10- 27wt% water-soluble portion into the produced copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a crosslinked polycarboxylic acid copolymer having a water-soluble portion of 10 to 70% by weight. Conventionally, polycarboxylic acid polymers have been used for various purposes, but
The present manufacturing method is particularly intended for application to cloth agent compositions.

The so-called tomoe agent is a slurry consisting of a powder base material such as kaolin, bentonite, and zinc oxide, a wetting agent such as glycerin, propylene glycol, and turpitol, and a volatile medicinal agent such as menthol, camphor, methyl salicylate, etc. The drug composition is prepared by spreading and coating a cloth such as flannel or lint cloth, and then laminating a removable protective film such as a polyethylene film on the drug surface.

This tofu agent is effective in eliminating inflammation and pain relief for fractures, bruises, sprains, stiff shoulders, etc. When using this patch, the protective film can be peeled off from the drug side and immediately applied to the affected area. It is expected to have therapeutic effects such as anti-inflammatory and analgesic effects.

The quality of the tomoe agent composition is that it has good miscibility with pure gold, is flexible and adheres well to the skin, has good water retention and remains moist on the skin for a long time, and has a firm overall appearance. In addition, conventionally, in order to give the above-mentioned performance to the dressing composition, sodium polyacrylate, combined addition of sodium polyacrylate and carboxymethyl cellulose, gelatin, sodium alginate, xanthan gum, etc., and a PH adjuster have been added as active ingredients. Attempts have been made to mix them together, but nothing satisfactory has yet been achieved.

The present inventors have focused on the effectiveness of active polymers that improve the miscibility and water retention of the tomoe composition and provide stability to medicinal ingredients over time, and have developed polymers that have all of these properties. As a result of various research on the manufacturing method of P
The present invention was completed after learning that a crosslinked polycarboxylic acid copolymer having H8 or less and a water-soluble portion of 10 to 70% by weight exhibits high performance as a drape composition. That is, the present invention has the general formula % ((wherein, R is I), 000 H spanning coox,
R1 is I], OH3,0T (2000H'! or 0H2
000Xj is shown. In addition, X and Xl are alkali,
α/β-unsaturated carboxylic acid or its derivative and its general formula represented by 0 representing a metal.

coox2 (wherein R2 is H,000H or a o o x5
R3 is ■], OH5, Cll2COOI (or an2o.

Indicates OX4. Incidentally, X2, X3 and X4 represent alkali metals, and a mixed monomer consisting of an alkali metal salt of an α/β-unsaturated carboxylic acid as shown below is used at a ratio of 10-4 to 10-4 to the monomer.
In the presence of a polyfunctional crosslinking agent with a molar ratio of 10-2, the reaction initiation temperature is 15 to +40°C, and the amount of polymerization catalyst is 1O-3 to 3X10.
PI-18 or less obtained by polymerization under conditions of -1% by weight (based on the monomer mixture) and 10 to 70% by weight
The present invention relates to a method for producing a crosslinked polycarboxylic acid copolymer having a water-soluble portion.

The α/β-unsaturated carboxylic acid represented by the general formula (1) or its derivative used in the present invention (5) is, for example, acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, etc. The alkali metal salts of the α/β-unsaturated carboxylic acid represented by the general formula (2) include, for example, sodium acrylate, potassium acrylate, lithium acrylate, sodium methacrylate, and methacrylic acid. Examples include potassium, lithium methacrylate, sodium maleate, sodium itaconate, and other substances contained in general formula (2). These alkali metal salts of α/β-unsaturated carboxylic acids may be used alone or in combination of two or more.

α/β-unsaturated carboxylic acid or its derivative and α/β-
The mixing ratio of the unsaturated carboxylic acid with the alkali metal salt is such that the pH of the crosslinked copolymer obtained by copolymerizing the monomer mixture in the presence of a polyfunctional crosslinking agent is 8 or less. . More preferably, they are mixed so that the pH is in the range of 6 to 8.

Examples of the polyfunctional crosslinking agent include compounds having at least two polymerizable double bonds (non-conjugated) in the molecule, such as (1) di- or polyvinyl compounds (di- or trivinylbenzene, divinyltoluene, , divinylxylene, divinyl ether, divinyl ketone, etc.), (li
) Di- or poly-esters of unsaturated 1,000-fold d polycarboxylic acids and polyols [di- or tri(meth)acrylic acids of polyols (ethylene glycol, l-IJ methylolpropane, glycerin, polyethylene glycol, polypropylene glycol, etc.) ester,
(iii) bis(meth)acrylamide (N,N'-methylenebisacrylamide, etc.), OV) polyisocyanate 1- (T D
Carlenocumyl ester [hydroxyethyl (meth)] obtained by the reaction of NCl0 group-containing pubipolymer obtained by reacting I, HDT, MDI, etc. and an active hydrogen-containing compound with an active hydrogen-containing compound and a hydroxyl group-containing monomer di(meth)acrylic acid carbamyl ester of acrylate and the above diisocyanate, etc.], (v) di- or poly-(meth)allyl ether of polyol (alkylene glycol, glycerin, polyalkylene glycol, carbohydrate, etc.) (polyethylene glycol diallyl) ether, a, mono-nord starch, allylated cellulose, etc.), (di- or poly(meth)allyl ester of VD polycarboxylic acid (diallyl phthalate, diallyl adipate, etc.). &il polyol mono(meth)allyl ether and unsaturation Examples include esters with carboxylic acids [polyethylene glycol monoallyl ether (meth)acrylate, etc.].

These polyfunctional crosslinkers have a 10-4
~10-2 molti, preferably 10-3~5 X 10
The method may be any conventionally known method, for example, using water, tetrahydrofuran, acetone, or a mixture thereof as a polymerization solvent, and using, for example, ceric salt, hydrogen peroxide, benzoyl peroxide, azobisisobutyronitrile, Polymerization method using radical polymerization catalysts such as ammonium persulfate, persulfates such as potassium persulfate and ammonium persulfate, and aniline, monoethanolamine, hexamethylenediamine, jetanolamine, diethylaniline, triethanolamine, tetramethylethylenediamine Examples include polymerization methods using so-called redox polymerization catalysts in combination with organic amines such as It is also possible to adopt a method.

It is usually produced by water bath liquid polymerization and contains 10-3 to 3 x 101% by weight, preferably 10
-2 to 10-1% by weight.

The reaction starting temperature is -5 to 40°C, preferably 0 to 20°C, and the reaction time is preferably 1 to 9 hours.
It is made into a powder by precipitation or evaporation using a water-soluble solvent such as methanol or acetone, and then used for various purposes.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 500-122 equipped with nitrogen introduction pipe and thermometer,
01 thymethylene bisacrylamide aqueous solution 1 part 2.63
Added F. The reactor was cooled to bring the temperature inside the system to 5°C. After replacing with N2 for 1 hour, 409 g of 1% ammonium persulfate aqueous solution, 409 v of 2-thiosulfite aqueous solution
was added and reacted for 6 hours.

After the reaction was completed, the product was washed with a water/methanol mixed solution, dried with hot air at 120° C. all day and night, and then powdered.

0 1)H of the obtained 1H aqueous solution of the polymer powder was 62. The strained aqueous solution 4007 was distributed door to door using 200 m² wire mesh, and the total volume was 2,000 m1! The remaining gel was dried, and the amount of water-soluble portion was calculated from its weight to be 43% of the total weight.

Example 2 7.0.1 timethylene pis acrylamide aqueous solution 065
7 was added and cooled to bring the temperature inside the system to 10°C. After purging with N2 for 1 hour, 1% ammonium persulfate water bath solution 24
2.43 ii' of an aqueous solution of 37.2 thorium sulfite was added and reacted for 8 hours. Polymer powder was obtained in the same manner as in Example 1.

1]I (of 1% aqueous solution of the obtained polymer powder is 7°3
Met. Further, the amount of water-soluble portion was 33% by weight. Example 3 1.9.8 f of fumaric acid and 1697 of a 0.1% aqueous solution of ethylene glycol dimethacrylate were added. After setting the humidity in the system to 20° C. and purging with N2 for 1 hour, 4.09 f of a monofunctional ammonium persulfate aqueous solution and 4097 f of a dibasic sodium persulfite aqueous solution were added and reacted for 6 hours.

Polymer powder was obtained in the same manner as in Example 1.

The P I of the 1% water bath solution of the obtained polymer powder is 6.8
Met. Further, the amount of water-soluble portion was 13% by weight.

Comparative Example 1 In Example 1, the amount of methylene bisacrylamide charged was 1%, % aqueous solution, +2.6%. If we set it as ``3'' and 17'', and all other conditions are the same, we get this, 1'ro, gain-
The amount of water-soluble portion of the obtained polymer was 53% by weight.

Comparative Example 2 The same conditions as in Example 2 were carried out except that methylene pickle and acrylamide were not added, and the amount of water-soluble portion of the obtained polymer was 99% by weight.

Claims (1)

[Claims] General formula % formula % (wherein, 几 represents +1.0OOH or coox,
R1 is H, OH5, OH2000T-1 or 0r(2
ao, ox, are shown. Note that X and Xl represent an alkali metal. ) and the general formula % formula % (wherein R2 is H,0OOH or co o' x
3, R= indicates H, OH,,0r (2000H or oH2a o o X4. In addition, x2,
X3 and X4 represent alkali metals.
In the presence of 10-2 molar polyfunctional crosslinking agent, the reaction initiation temperature was 15 to +40°C, and the amount of polymerization catalyst was 10-3 to aX10.
- Production of a polycarboxylic acid-based crosslinked copolymer having a pH of 8 or less and having a water-soluble portion of 10 to 70% by weight, obtained by polymerization under conditions of 1i weight ratio (relative to the monomer mixture) Method.