JPS5863706A - Stabilizer for emulsion polymerization of styrene - Google Patents

Abstract

PURPOSE:To provide the titled stabilizer composed of a polyvinyl alcohol containing >=4C hydrocarbon group and sulfonic acid group or sulfate group at the side chain, and giving an emulsion suitable as an adhesive, pressure-sensitive adhesive, textile or paper processing agent, etc. CONSTITUTION:Vinyl acetate is copolymerized with an ethylenic unsaturated monomer having >=4C hydrocarbon group at the side chain (e.g. lauryl vinyl ether, isoamyl vinyl ether, etc.) to obtain a copolymer having a polymerization degree of 200-3,000, which is saponified in methanol containing NaOH. The resultant modified PVA containing 0.01-15mol% hydrocarbon group is made to react with chlorosulfonic acid in pyridine, and neutralized to obtain the objective stabilizer. In place of the reaction with chlorosulfonic acid, the PVA may be copolymerized with a sulfonic acid group-containing monomer (e.g. sodium allylsulfonate).

Description

DETAILED DESCRIPTION OF THE INVENTION A specific modified polyvinyl alcohol (hereinafter referred to as polyvinyl alcohol'k) having a hydrophobic group and a hydrophilic group according to the present invention
The present invention relates to a styrene O emulsion polymerization stabilizer consisting of tP (abbreviated as Pvm).

In emulsion polymerization of styrene, conventionally low molecular weight surfactants such as yoshyalkyl bene sulfonates, alkyl f phthalene sulfonates, higher fatty acid salts, and disproportionated logi/# salts are used singly or in combination. It is used as an emulsion polymerization stabilizer. However, it is difficult to use emulsions produced by methods using such low-molecular-weight surfactants as paints, adhesives, paper processing agents, etc., and to store them for a long period of time.
If R is added too little, coarse particles will be generated, and for mechanical safety, the emulsion will be easily curdled or destroyed when transferred by a pump or applied with a spreader roll, so handle the bottle accordingly. has the disadvantage that it requires careful attention. When used as an adhesive, the low-molecular-weight surfactant migrates to the surface of the film and tends to cause poor adhesion.

In order to overcome these difficulties, it has been proposed to use a polymeric surfactant such as PVA.

PVA is useful as an emulsion polymerization stabilizer of vinyl acetate ester, and emulsion carbonate is useful for mechanical stability, freezing! i! It has excellent melting stability and other types of stability, and is often used as adhesives and paints. However, even if emulsion polymerization of styrene is attempted using PVA (PVA) as a stabilizer, the polymerization progresses extremely unevenly, and smooth polymerization cannot be achieved as many coarse particles are produced during polymerization or the entire product gels.

Emulsion polymerization is possible if a low-molecular-weight surfactant and PVA are used in combination, but it is difficult to solve various problems such as poor adhesion due to the transfer of the low-molecular-weight surfactant to the am film.

An attempt to emulsion polymerize styrene using (meth)allylsulfone iron alkali salt, acetic acid vinyl ester, and O modified PVA as a stabilizer by copolymerization is known in 轡 Official Introduction 51-1, $871. However, even if (meta)emulsion polymerization is attempted, 1
In addition to the drawbacks such as extremely slow synthesis rate and large number of i9-group grains, the fact is that the above-mentioned point s when attempting emulsion polymerization using unmodified PVA has hardly been resolved. be.

In view of the above-mentioned situation, the inventors of the present invention have conducted extensive research and have developed a Pv-based polymeric surfactant that can smoothly polymerize p-styrene and has an extremely stabilizing effect. Found KljN) Original WAKIAJ Reached O In other words, it is good if styrene is emulsified using modified PVA containing hydrocarbon lA& with 4 or more carbon atoms in the side chain and a sulfonic acid group or sulfuric acid ester group as an emulsion polymerization stabilizer. This book allows the polymerization-bX to proceed quickly at a moderate polymerization rate, and allows smooth emulsification to be carried out without problems such as generation of coarse particles or gelation. This 4II effect can only be obtained by modified PVA having both a hydrocarbon group with a prime number of 4 or more and a sulfonic acid group or a sulfur ester group. It is surprising that remarkable performance is obtained that cannot be obtained from modified PVA having only a few ester groups.

It is necessary that the hydrocarbon group of the present invention has 4 or more carbon atoms. When the number of carbon atoms is 3 or less, the emulsion polymerization rate is slow and the modification effect is not reliable.

The amount of hydrocarbon group introduced is preferably in the range of 0.01 to 15 moles. If it is less than 0.0.1 mol, the effects of the present invention may be difficult to achieve, such as slow emulsion polymerization rate or insufficient emulsion stability. 15 mol-
When more than 1 bottle of V40 is used, the potency becomes saturated (t5c), but it also depends on the number of sulfone groups or the amount of sulfone group O conduction. ), and PVA's original properties such as strong film-forming properties are lost, which is good! ! There are times when you may not be able to come. The amount of sulfonic acid group or sulfuric acid group introduced is 0.01 mol-
It is preferable that the range is from 1 mol IGc) to 1 mol IGc).

If the amount is less than 0.01 mol, depending on the amount of hydrocarbon groups introduced, the modified PVA may not dissolve in water), or the stability of the emulsion polymerization emulsion may not be sufficient. I'm worried. Even if the amount exceeds 15 mol, the effect will no longer be saturated, but rather the performance of the emulsion will deteriorate, probably because the good performance such as the strong propagation properties that PVA originally has will be lost. There is a tendency to

Further, it is preferable that the northernmost hydrogen group is a monobranched hydrocarbon group rather than a &chain hydrocarbon group because it provides superior emulsion stability and film performance.

The reasons for this are not clear, but include the fact that the ratio of methyl groups, methylene groups, and methine groups in the hydrocarbon group differs between branched and straight-chain hydrocarbon groups, and crystallinity.

Orientation, association, etc! Since it is caused by lK, it is thought that there is a line.

Method for introducing hydrocarbon groups into modified PVAo@ chains of the present invention - Ethylenically unsaturated monomers having hydrocarbon groups 5 For example, alkyl vinyl ethers such as butyl vinyl ether, lauryl vinyl ether, stearyl vinyl ether, hepteno-1 , octene-11 dodecene-1
1-olefins such as luffric acid vinyl ester,
Vinyl esters, such as stearin vinyl ester,
A method of copolymerizing N-alkyl-substituted acrylic ides such as N-tert-butylacrylamide and vinyl acetate and saponifying the copolymerized vinyl ether, Va ova-10 (Shell Co., Ltd.; average carbon (branched aliphatic vinyl ester with number 10)
22: Which monomer having a branched hydrocarbon group is preferably used. Furthermore, a method of acetalization with aliphatic monoaldehydes is proposed.

Examples of methods for introducing a sulfonic acid ester group into a sulfonic acid group include a sulfone-imported polymer such as vinyl sulfone Wb'ylylsulfone iron, methallyl sulfone family, N-7 crylamide propane sulfone family, etc. Methods such as copolymerizing it with vinyl acetate and saponifying it, and reacting PV with sulfuric acid, chlorsulfone, etc. to esterify it have been unsuccessful.

Regarding the degree of saponification, there is no limit as long as it is within the range of water solubility, but a degree of saponification of 60 mol is usually better in terms of water resistance of FjLllI obtained from the emulsion. . The degree of polymerization is acceptable.
etc., you should choose as appropriate, but usually! 00～5ooo
A range of is appropriate.

A good emulsion polymerization emulsion can be obtained by emulsion polymerizing styrene by a known method in an aqueous phase in the presence of a radical polymerization initiator using the above-mentioned modified PV film alone as a stabilizer. In emulsion polymerization, it is also possible to use dienes, acrylic iron esters, methacrylic iron esters, vinyl chloride, and acrylic esters as ingredients.

Although emulsion polymerization can be carried out stably when the modified PVA of this invention is used alone, it is not a problem to use a low-molecular external active agent in combination as an auxiliary means, for example, to adjust the particle size. In addition, other protective colloids such as Pvum may be used as the case may be.

Polyacrylic plates, polymethacrylic ribbons, and their salts,
Polyvinyl alkyl ether, copolymerization of vinyl acetate and acrylic acid or methacrylic acid, or vinyl acetate-maleic anhydride copolymerization, and its saponified product, lower alkyl vinyl ether-maleic anhydride group X compound, alkyl cellulose, Cellulose derivatives such as hydroxyalkyl cellulose, alkyl starch, carboxymethyl starch,
Tltized starch, gum arabic, gum tragacanth, polyalkylene glycol, etc. can be used during polymerization or can be added after polymerization. In addition, liquid regulators used in ordinary emulsion polymerization, monohydric or polyhydric alcohols, lubricants, inorganic salts such as sodium chloride, sodium chloride, sodium phosphate, sodium chloride, and ammonia. , sodium hydroxide, hydrochloric acid, etc. OPH
I have rarely seen the use of auxiliary agents such as regulators and antifoaming agents during or after polymerization.

The modified PVA used in the present invention can be used in an amount of 12 to 26% by weight of O, S to styrene until the emulsion polymerization is completed. It gets cloudy.

The superposition initiators used are those used in conventional emulsion polymerizations, such as water-soluble initiator systems 1, such as hydrogen peroxide alone or hydrogen peroxide and oxycarboxylic acids; Aldehydes, water soluble+! 1# Combination with salt attack, supersulfurized salt-1 supercharcoal salt #A, supersulfated salts,
The emulsion polymerized emulsion obtained using this Il exhibits excellent stability and has a viscosity of turbidity.
Cohesive agent, fiber processing agent 5 paper processing agent, and even cement) II
It is also effective in Japanese preparations and has extremely high industrial utility value Fi.

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

In the examples, "part" and "chi" are defined based on the amount of @shi, without exception.

Example 1 770 parts of vinyl acetate, 970 s of methanol, and 25.1 ml of fluorinated vinyl ether were charged into a polymerization reactor and polymerized in a conventional manner, unreacted vinyl acetate was expelled, and the mixture was cured in methanol containing caustic soda.

The obtained modified PVA contained 0.9 mol of lauryl ether groups and had a saponification degree of 99.07 Ru.

Next, this modified PVA was reacted with chlorosulfone in a pyridine medium, and then neutralized. The resulting modified PVA contained 0.9 mol of lauryl ether groups and t-2.4 mol of sulfone ester groups. Containing silicenization [99,x
The viscosity of the 4-inch aqueous solution at mol-120°C decreased to 16 centivoise.

0 parts of Kono-modified PVAl is dissolved in 260 s of water, 3 s of S ammonia water is added, and the temperature is maintained at 60°C. After 150 parts of styrene was added in a nitrogen gas atmosphere and stirred for 5 minutes, 5 parts of a 2g6 aqueous solution of ammonium persulfate was added to start polymerization. After 2 hours, it was cooled and the contents were taken out to give a clean emulsion with no coarse particles of average size &0.15μ. The polymerization rate of styrene was 8.4%, and this product remained stable for 4 hours after being left for three months. Also B[
Using a viscosity needle, temperature [30℃, 1 turn 1! The viscosity measured at l[lOrpm failed at 940 ep.

Comparative Example 1 Contains 0.9 mol of the lacryl ether group obtained as an intermediate product in Example 1, and has a saponification degree of 99.0.
Attempts were made to emulsion polymerize styrene using modified PVA, but the modified PVA did not dissolve in either cold or hot water, and it was not possible to obtain an emulsion of styrene that was highly tractable. Example 2 Too many parts of pyroacetate, 50 parts of OV-1O (Vel Co., Ltd.), which is a branched fatty vinyl ester with an average molecular weight of 1O, and 82 parts of methanol 2000Is allylsulfonate sodium were polymerized in a can. The polymer solution was saponified by a conventional method using caustic soda as a catalyst. The obtained modified PVA contains hydrocarbon S<Vernatic ester part) tl, 1 mol, and several sulfone groups at 29 mol.
Meeting, saponification [97.8 mol - 4s aqueous solution viscous mouse at 120°C was heated with modified PVA of 12 centivoise.

Emulsion polymerization of styrene was carried out in the same manner as in Example 1 except that this modified PVA was used. The 1 ratio after 2 hours was 99.
8%, type B viscosity 1340c at 30°C and 10 rpm
A clean emulsion free of coarse particles with a particle size of 0.1 μm was obtained. This emulsion remained completely stable even after being left for six months.

Comparative Example 2 0.8 mol of propyl vinyl ether and 2.0 mol of allyl sulfone sodium trichloride formed by a layered hydrogen group having 3 carbon atoms.
Emulsion polymerization of styrene was attempted in the same manner as in Example 1, except that modified PVAI was used, which was obtained by molar copolymerization and had a viscosity of 1 mol % and a 4-water S liquid viscosity of 9 cm at 20°C. The polymerization rate of styrene after 2 hours was 3.7-471! The polymerization rate was extremely slow, so it was a failure.

Comparative Example 3 9 was prepared by copolymerizing 2.0 mol of sodium allyl sulfonyl by a conventional method, and the 9 parts were O-saponified [98.7 mol,
Emulsion polymerization of styrene was attempted in the same manner as in Example 1, except that a modified Pvm with a 4-aqueous solution viscosity of 10 Sendebois at 20°C was used.The polymerization rate of styrene after 2 hours was 3.9, which was extremely high. The polymerization rate was slow.0 Comparative Example 4 Polymerization degree was 1700. Styrene was prepared in the same manner as in Example 1, except that 9 g of saponified II, 57 l of unmodified PVA (/Tre-PVA11, 4-water at 20°C, liquid viscosity of 28 centiboise) was used. I tried to emulsion polymerize it. The polymerization rate of styrene after a certain amount of time was 4.0-, indicating that the polymerization rate was extremely slow.Example 3 The polymerization rate of styrene obtained in Example 1 was 9.
A modified pv film containing 11 moles of sulfonic acid ester group and 2.4 moles of sulfonic acid ester groups was heated and dissolved in 20 g of water and then cooled. Add and dissolve 0.1 part. After adding 9ONS of O6 styrene and 60 parts of butadiene, the mixture was kept at 60° C. for 12 hours with stirring, then cooled and the contents were taken out. The reaction rate is 98.5- and the round average particle size is 0.2.
It was covered with clean texture without μ aggregation (
Even if it was left at iOrim temperature for 4 months, it remained stable without agglomeration or thickening. Also, the B type accuracy at 30°C and lOrpm is 870 centipoise Ton, and this latex is 0.
The film prepared to a thickness of 5 fi was slightly cloudy.

Example 4 Versatic ester '11 which is a branched hydrocarbon group
．． The modified P wrinkled in Example 2 contains 1 mole, contains several sulfone groups, tz and emo, and is saponified [97,87 lu], and has a viscosity of 12 centiboise at 20°C. Emulsion polymerization was carried out in the same manner as in Example 3, except that the emulsion polymer was used. The reaction rate was 99.1-6cm, and a clean latex with no agglomeration and an average particle size of 0.2μ was obtained. This product remains stable without agglomeration or thickening even if left at 0 Fi-temperature for six months. Also 30″C,
This latex was made to flow to a thickness of 0.5 MO using a viscosity manufactured by B (till 0 centipoise) at 10 rpm, and the latex was found to have good transparency.

Licensed seller: Kinsha Co., Ltd. Yoshioiri Patent Attorney Rin Honda

Claims (1)

[Claims] (1) A styrene emulsion polymerization stabilizer consisting of polyvinyl alcohol containing a hydrocarbon bulk group having 4 or more carbon atoms and a sulfonic acid group or a sulfonic ester group in its side chain. (To) The emulsion polymerization stabilizer according to Section 11 (1) K, wherein the hydrocarbon bulk group is a branched hydrocarbon bulk group.