JPH0860137A - Cationic polyvinyl alcohol-based thickening agent - Google Patents

Abstract

PURPOSE: To obtain the inexpensive thickening agent, comprising plural specific copolymer units, having a specified viscosity of an aqueous solution, excellent in quality stability and adsorptivity for anionically charged substances and useful for adhesives, coatings, cosmetics, etc. CONSTITUTION: This thickening agent contains (A) 80-99.85mol% copolymer unit of formula I, (B) 0.05-10mol% copolymer unit of formula II (Y-R1 is a 4-18C alkyl ether group or an ester of a 4-18C saturated fatty acid and (C) 0.1-10mol% copolymer unit of formula III (R2 is a 1-5C alkylene; R3 , R4 and R5 are each a 1-3C alkyl; X is Cl or Br). The thickening agent has >=100cP viscosity of a 4wt.% aqueous solution at 20 deg.C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a cationized polyvinyl alcohol thickener.

[0002]

2. Description of the Related Art Inorganic or organic aqueous solutions or dispersions are widely used in the fields of adhesives, paints, detergents, agricultural chemicals, cosmetics, foods, etc. both industrially and at home. These aqueous solutions or aqueous dispersions are generally adjusted to have an appropriate viscosity in order to facilitate their handling. Examples of thickeners used at this time include polyvinyl alcohol (hereinafter abbreviated as PVA), polyacrylic acid salts, starch and its derivatives, cellulose derivatives such as carboxymethyl cellulose and methyl cellulose, and natural polysaccharides such as guar gum and xanthan gum. in use. Most of these are nonionic or anionic. In recent years, with the diversification of fields of use of inorganic or organic aqueous solutions or emulsions / dispersions, there has been an increasing demand for cationic thickeners. It is generally known that substances contained in the adhesives and paints are anionically charged, and cationic substances are easily adsorbed. A cationic thickening agent is effective as a material having both viscosity control and adsorptivity. As a cationic thickener, at present, only partly found in starch derivatives, but at present the cost is high and the quality is highly variable and used only in some fields.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cationized PVA thickener which is inexpensive and has stable quality.

[0004]

The present invention provides the following formula (A):
The mol% of the copolymerized units represented by 80.0 to 99.8.
5, the mol% of the copolymerized units represented by the following formula (B) is 0.05 to 10, the mol% of the copolymerized units represented by the following formula (C) is 0.1 to 10, and 20 4 at ℃
It is a cationized polyvinyl alcohol-based thickener characterized in that the viscosity of a wt% aqueous solution is 100 centipoise or more.

[0005]

Embedded image

(However, Y-R ₁ is at least one of an alkyl ether group having 4 to 18 carbon atoms and an ester group of a saturated branched fatty acid having 4 to 18 carbon atoms, and R ₂ is 1 to 5 carbon atoms.
Alkylene group, R ₃ , R ₄ and R ₅ each have 1 to 3 carbon atoms.
X is a chlorine atom or a bromine atom. )

Hereinafter, the present invention will be described in detail. Formula (A)
A copolymer unit represented by [hereinafter, referred to as a copolymer unit (A)
Is abbreviated. ] Is a copolymerization unit which is the main component (mol%: 80.0 to 99.85) of the cationized PVA-based resin of the present invention, and is obtained by saponification of vinyl ester of fatty acid.

A copolymer unit represented by the formula (B) [hereinafter, this is abbreviated as a copolymer unit (B). ] Has 4 to 1 carbon atoms
8 alkyl vinyl ether units and 4 to 18 carbon atoms
At least one of the vinyl ester units of saturated branched fatty acids of
More than a seed. The content of the copolymerization unit (B) is 0.05
It is -10 mol%, preferably 0.1-8 mol%. When the copolymerized unit (B) is less than 0.05 mol%, the viscosity of the cationized PVA-based aqueous solution obtained is small, and when the copolymerized unit (B) exceeds 10 mol%, it becomes difficult to dissolve in water, and thus the present invention It becomes difficult to achieve the effect of.

As a method for producing a modified PVA having a copolymerized unit (A) and a copolymerized unit (B), a fatty acid vinyl ester, an alkyl vinyl ether having 4 to 18 carbon atoms and a saturated branched chain having 4 to 18 carbon atoms are used. A method of saponifying a copolymer with at least one vinyl ester of fatty acid can be mentioned. The modified PVA can also be obtained by saponifying a copolymer of a fatty acid vinyl ester and an α-olefin having 4 to 18 carbon atoms. Examples of the fatty acid vinyl ester include vinyl formate, vinyl acetate, vinyl propionate and the like, and vinyl acetate is industrially preferable. Carbon number 4-18
Examples of the alkyl vinyl ether include butyl vinyl ether, octyl vinyl ether, lauryl vinyl ether, stearyl vinyl ether,
Examples of the vinyl ester of a saturated branched fatty acid having 4 to 18 carbon atoms include vinyl pivalate, vinyl versatate, etc., but are not limited thereto.

The method of copolymerizing the fatty acid vinyl ester with at least one of alkyl vinyl ester and vinyl ester of saturated fatty acid having 4 to 18 carbon atoms is a solution using a known radical catalyst of azo type or peroxide. It can be obtained by a polymerization method, a suspension polymerization method, an emulsion polymerization method or a bulk polymerization method. During this copolymerization, monomers copolymerizable with them, such as ethylene, propylene, vinyl chloride,
Vinylpyrrolidone, acrylic acid, acrylic acid ester,
Maleic acid, itaconic acid and their derivatives may be copolymerized within the range not impairing the effects of the present invention.

The copolymer thus obtained is saponified to obtain modified PVA.
In order to obtain the above, it can be obtained by a method of saponification by adding an alkali or acid catalyst to an alcohol solution of the copolymer. At this time, the saponification reaction of the vinyl ester unit of the saturated branched fatty acid does not substantially proceed and the modified PVA is obtained.

A copolymer unit represented by the formula (C) [hereinafter, this is abbreviated as a copolymer unit (C). ] Is the above-mentioned modified P
It can be industrially obtained by adding a quaternary ammonium salt having an epoxy group to the hydroxyl group of VA under an alkaline catalyst. Glycidyl trimethyl ammonium chloride is industrially advantageous as the quaternary ammonium salt having an epoxy group. Copolymer unit (C)
The content of is 0.1 to 10 mol%, preferably 0.5 to 8 mol%. When the copolymerization unit (C) is less than 0.1 mol%, the resulting cationic property-imparting effect is small, and when the copolymerization unit (C) exceeds 10 mol%, the hygroscopicity becomes too large and the handling becomes difficult.

The addition reaction of the modified PVA with the quaternary ammonium salt having an epoxy group is carried out in a known solvent-free system, an organic solvent such as acetone or dioxane, or a water system using a strong alkali such as sodium hydroxide as a reaction catalyst. Done. It is desirable to use a water-dispersed system or a water-wet system because of the work environment and the simplicity of manufacturing equipment. When the addition reaction is carried out in a water-dispersed system or a water-wet system, it is advantageous that the modified PVA used has a small particle size, preferably a particle size of 200 microns or less. The amount of the quaternary ammonium salt having an epoxy group added to the addition reaction system is appropriately 1.5 to 3.0 times the required addition amount in view of reaction efficiency. The reaction temperature is particularly preferably 10 to 60 ° C.

20 of the cationized PVA thickeners of the present invention
The viscosity of a 4% by weight aqueous solution at 0 ° C is at least 100.
Must be centipoise. If it is less than 100 centipoise, the amount of the cationized PVA-based resin used is large and the performance as a thickener is poor.

[0015]

The thickener of the present invention is more stable in quality than conventional natural products, and can easily adjust the viscosity of an inorganic or organic aqueous solution or emulsion / dispersion. . Further, it is cationic and has excellent adsorptivity to anionically charged substances. Further, the thickener of the present invention can be added as an aqueous solution like a normal PVA resin, or resin powder can be directly added and dissolved.

[0016]

EXAMPLES The present invention will be described in detail below with reference to examples. Example 1 A reflux condenser, a stirrer and a polymerization machine equipped with a jacket were charged with 900 parts by weight of vinyl acetate, 4 parts by weight of stearyl vinyl ether, and 300 parts by weight of methanol, and the temperature was raised to 64 ° C. with stirring. 0.2 parts by weight of butyronitrile was added to carry out a copolymerization reaction for 5 hours. The polymerization yield was 70%. In the calculation method based on the amount of residual monomers, the molar ratio of vinyl acetate units to stearyl vinyl ether units of the obtained copolymer was 9
It was 9.9: 0.1. To 100 parts by weight of a 40% methanol solution of this copolymer, 25 parts by weight of a 2% sodium hydroxide solution in methanol was added and mixed to carry out a saponification reaction at 40 ° C., neutralized and dried, and then ground to 100 mesh. A modified PVA powder having a saponification degree of 99.5 mol% and passing through a 100-mesh sieve was obtained by sieving with a sieve.

After 20 parts by weight of this modified PVA powder was immersed in an 8% aqueous sodium hydroxide solution at room temperature for 1 hour, the excess aqueous sodium hydroxide solution was filtered off, and 3 parts by weight of glycidyltrimethylammonium chloride was added to the solid product. The mixture was added and reacted at 40 ° C. for 6 hours with sufficient stirring.
Then, it was neutralized with acetic acid, thoroughly washed with methanol, and dried to obtain a cationized PVA-based resin powder. The molar fractions of the copolymerized units (A), (B) and (C) of the obtained cationized PVA-based resin powder were as shown in Table 1. In addition, the obtained cationized PV
The degree of cationization modification (addition amount of glycidyltrimethylammonium chloride) of the A-based resin powder was determined by a colloid titration method in which a toluidine blue solution was used as an indicator and titration was performed with a polyvinyl potassium sulfate solution. The viscosity of a 4% aqueous solution of this product at 20 ° C. was measured by a B-type viscometer and found to be 650 centipoise.

The performance evaluation of the obtained cationized PVA-based resin was tested by the following method.

Viscosity increase test Viscosity at 30 ° C. is 30 centipoise (B type viscometer,
10 rotations of polyvinyl acetate emulsion (solids 4
0%) 100 parts by weight was added with 10 parts by weight of a 6% by weight aqueous solution of the cationized PVA-based resin and uniformly mixed to obtain an emulsion of 70 centipoise (B-type viscometer, 10 revolutions). Also, this product was stable without separation even when left at room temperature for 1 week.

Adsorption test 100 g of kaolin clay was added to 100 g of a 0.5% by weight aqueous solution of cationized PVA-based resin, filtered, and the adsorption rate of the cationized PVA-based resin was calculated from the concentration of the filtrate to be 85%. It was

Example 2 Example 1 was repeated except that 6 parts by weight of stearyl vinyl ether and 2 parts by weight of glycidyl trimethyl ammonium chloride were used. Obtained cationized PVA
As shown in Table 1, the analysis results of the system resins showed good thickening (200 cps) and adsorptivity (75%).

Example 3 The procedure of Example 1 was repeated except that 25 parts by weight of stearyl vinyl ether and 0.5 parts by weight of glycidyl trimethyl ammonium chloride were used. As shown in Table 1, the analysis results of the obtained cationized PVA-based resin showed good thickening (800 cps) and adsorptivity (70%).

Example 4 150 parts by weight of vinyl versatate was used in place of 4 parts by weight of stearyl vinyl ether, and methanol was added at 350 parts.
Example 1 was repeated except that 10 parts by weight of glycidyl trimethyl ammonium chloride was used.
As shown in Table 1, the analysis results of the obtained cationized PVA-based resin show good viscosity increase (300 cps) and adsorptivity (9
0%).

Comparative Example 1 The procedure of Example 1 was repeated except that 0.3 part by weight of lauryl vinyl ether was used instead of 4 parts by weight of stearyl vinyl ether and 2 parts by weight of glycidyl trimethyl ammonium chloride was used. As shown in Table 1, the analysis results of the obtained cationized PVA-based resin show copolymerized units.
The mole fraction of (B) was 0.01, showing an unfavorable thickening property (27 cps).

Comparative Example 2 280 parts by weight of vinyl versatate were used in place of 4 parts by weight of stearyl vinyl ether, and methanol was added to 400 parts by weight.
Example 1 was repeated except that 5 parts by weight of glycidyl trimethyl ammonium chloride was used. As shown in Table 1, the analysis results of the obtained cationized PVA-based resin showed that the molar fraction of the copolymerization unit (B) was 12,
It was insoluble in water.

Comparative Example 3 The procedure of Example 1 was repeated except that the cationization reaction was not performed. As a result of analysis of the PVA-based resin thus obtained, as shown in Table 1, the molar fraction of the copolymerization unit (C) was 0, and the adsorbability (10%) was not good. Since no cationization reaction was carried out, residual acetic acid groups [units] were present in addition to the copolymerized units (A) and (B), and the content was 0.5 mol%.

Comparative Example 4 Commercially available PV having a polymerization degree of 1700 and a saponification degree of 99.5 mol%
For A, a cationization reaction was carried out in the same manner as in Example 1.
As shown in Table 1, the analysis results of the obtained cationized PVA-based resin showed that the molar fraction of the copolymerization unit (B) was 0,
It showed a poor thickening (27 cps).

[0028]

[Table 1]

[0029]

As is clear from the above description, according to the present invention, since it is more stable in quality as compared with the conventional natural products, an inorganic or organic aqueous solution or emulsion.
The viscosity of the dispersion liquid can be easily adjusted, and since it is cationic, it is possible to provide a thickener having excellent adsorptivity to an anionically charged substance.

Claims (1)

[Claims] 1. The mol% of the copolymerized unit represented by the following formula (A) is 80.0 to 99.85, and the mol% of the copolymerized unit represented by the following formula (B) is 0.05 to 10: , The following formula
(C) the copolymerized unit has a mol% of 0.1 to 10 and a 4% by weight aqueous solution at 20 ° C. has a viscosity of 10
A cationized polyvinyl alcohol-based thickener characterized by having a viscosity of 0 centipoise or more. Embedded image (However, Y-R ₁ is at least one of an alkyl ether group having 4 to 18 carbon atoms and an ester group of a saturated branched fatty acid having 4 to 18 carbon atoms, R ₂ is an alkylene group having 1 to 5 carbon atoms, R ₃ , R ₄ and R ₅ are each an alkyl group having 1 to 3 carbon atoms, and X is a chlorine atom or a bromine atom.)