JPS61278341A - Emulsifier for emulsion polymerization - Google Patents

Abstract

PURPOSE:To obtain the titled emulsifier capable of producing a high molecular emulsion which has a fine particle size and forms a film excellent in water resistance, the transparency and the smoothness by combining higher aliphatic alcohol or alkylphenol and respective betaine esters in the specified weight ratio and using the mixing. CONSTITUTION:An aimed emulsifier is obtained by combining (a) betaine ester of higher aliphatic alcohol or alkylphenol and (b) higher aliphatic alcohol or alkylphenol in the proportion of a/b=99/1-6/4 and using the mixture. Wherein the component (a) is acted as a dispersant and the component (b) is acted as a coactivator. As a result, a high molecular emulsion which is small in the particle size and forms an excellent film is obtained. The high molecular emulsion obtained by such a way is preferable for the formation of an electrically- conductive film besides paint and an adhesive and exhibits the excellent effect when using it as an antistatic agent or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an emulsifier for emulsion polymerization, and particularly to an emulsifier suitable for producing a fine particle polymer emulsion that forms a film with excellent water resistance, transparency, and smoothness. This invention relates to emulsifiers for polymerization.

Conventionally, various surfactants have been used as emulsifiers for emulsion polymerization used when producing polymer emulsions by emulsion polymerization of unsaturated monomers. Among them, as cationic surfactants, alkyltrimethylammonium salts, dialkyldimethylammonium salts, polyoxyethylenealkylamines, polyoxyethylenealkyltrimethylenediamines, polyoxyethylenealkylmethylammonium salts, polyoxyethylenealkyldimethyltrimethyleneammonium salts. , 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolium betaine, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolium betaine, N-alkyldimethylamine oxide, and the like.

However, when these are used as emulsifiers, a large amount of aggregates are produced in the polymer, and the particle size of the resulting polymer emulsion becomes large. Moreover, the mechanical stability, chemical stability,
Storage stability is also adversely affected, and furthermore, when the polymer emulsion is used as a paint or adhesive.

It was customary to have an influence on its performance.

On the other hand, a degradable glycine betaine alkyl ester has been proposed as a cationic surfactant to solve these problems (Angew, Chew, et al.).

71.604 (1959)). However, even when this glycine betaine alkyl ester is used as an emulsifier, there is a problem in that the film formed using the resulting polymer emulsion is poor in water resistance, transparency, and smoothness.

SUMMARY OF THE INVENTION An object of the present invention is to provide an emulsifier for emulsion polymerization that can produce a polymer emulsion that has a fine particle size and forms an excellent film.

The emulsifier for emulsion polymerization of the present invention contains (a) a betaine ester of a higher aliphatic alcohol and/or a betaine ester of an alkylphenol, and (b) a higher aliphatic alcohol and/or an alkylphenol in a weight ratio. They are characterized in that they are used in combination at a ratio of (a)/(b) = 99/1 to 6/4, and these may be used alone or in combination.

Specific examples of betaine esters of higher aliphatic alcohols as component (a) include those represented by the following general formula (1):
Further, examples of betaine esters of alkylphenols include those represented by the general formula (■).

R1 ■ R10-OCR,N・-R4-X”
(1) ■ R1 (In the formula, Rx-Rx-R3, R4, Ray R, and X each represent the following.

R□: Alkyl group or alkenyl group having 8 to 20 carbon atoms R2: Alkylene group having 1 to 5 carbon atoms R,,R4,R,: Alkyl group having 1 to 3 carbon atoms or 10, H, OH, They may be the same or different.

RG: alkyl group or alkenyl group having 6 to 20 carbon atoms X: inorganic anion or organic anion It is something. Moreover, the general formula (I
R6 in I) may be linear or branched, and preferably has 8 to 18 carbon atoms.

Inorganic anions of X include halides such as CQ- and Br-, and organic anions include CHaCOO-,0
Representative examples include 8OaCHa--08OaCzHs-.

These betaine esters of higher aliphatic alcohols or alkylphenols can be obtained by various preparation methods, for example, those of the general formula (III) or (I
V) Using a higher aliphatic alcohol or long-chain alkylphenol represented by R10H(m) (wherein R1 and R6 are as described above) as a starting material, converting it into an ester with a lower haloalkylcarboxylic acid, and further trimethylamine, It can be obtained by reacting with a lower trialkylamine such as triethylamine. Further, if necessary, Xo in the above general formulas (I) and (II) can be converted into an organic anion by an ion exchange method or the like.

Specific examples of the higher aliphatic alcohol and/or alkylphenol as component (b) include the following general formula (II
Examples include those shown in I) and (IV).

R10H(III) (In the formula, Ryu and Rs each represent the following.

R1: Alkyl group or alkenyl group having 8 to 20 carbon atoms R6: Alkyl group or alkenyl group having 6 to 20 carbon atoms The preferred ranges of R and R1 are as described above.

In the present invention, (a) higher aliphatic alcohol or alkylphenol, betaine, acts as a dispersing agent, and (b) higher aliphatic alcohol or alkylphenol acts in concert as a causer factant (co-activator). As a result, the unsaturated monomer and water are quickly emulsified in the emulsification process to form a microemulsion, and furthermore,
Because of its excellent polymerization stability, the polymerization and aging steps proceed quickly, resulting in a polymer emulsion with small particle diameters that forms a good film.

The weight ratio of component (a) and component (b) is (a)/(b).
=99/1 to 6/4, preferably 98/2 to 65/35
Used within the range of If this ratio is larger than 9971, the film formed using the resulting polymer emulsion will be inferior in water resistance, transparency and smoothness, and if it is smaller than 6/4, the emulsifying power of the unsaturated monomer and water will be poor. Because of the lack of
Polymerization stability is poor, the amount of aggregates produced in the polymer increases, and furthermore, the properties of the film formed by the polymer emulsion deteriorate.

Components (a) and (b) may be separately prepared and blended, and since component (b) is the raw material for producing the betaine ester of component (a), The emulsifier of the present invention can also be obtained by setting conditions during the production of betaine ester so that component (b) remains as an unreacted component.

The higher aliphatic alcohol or alkylphenol (b) is preferably one that is structurally similar to the alcohol moiety or phenol moiety of component (a). When a betaine ester of a higher aliphatic alcohol is used as the component (a), a higher aliphatic alcohol can be used as the component (b), and when a betaine ester of an alkylphenol is used as the component (a), the betaine ester of an alkylphenol can be used as the component (b). Preference is given to using alkylphenols.

If necessary, the emulsifier of the present invention can also be used in combination with a nonionic surfactant or a polymer substance that acts as a protective colloid for the polymer emulsion.

As nonionic surfactants, polyoxyethylene alkyl ether, polyoxyethylene, alkyl phenyl ether, polyoxyethylene fatty acid ester, polyoxypropylene-polyoxyethylene glycol (Pluronic type surfactant), etc. can be used. Yes, especially.

A polyoxyethylene nonionic surfactant having an average number of added moles of ethylene oxide of 5 to 80, preferably 8 to 60 per active hydrogen is suitable.

Further, as the water-soluble polymer substance, polyvinyl alcohol, hydroxyethyl cellulose, etc. can be used. When using a nonionic surfactant and/or a water-soluble polymer substance in combination, the appropriate amount is 0.05 to 10 parts by weight for each part by weight of the total amount of components (a) and (b). It is.

The emulsifier of the present invention can be used for emulsion polymerization of one or more types of various unsaturated monomers. Butadiene, isoprene, 1,3-pentadiene, chloroprene as unsaturated monomers.

Aliphatic polyunsaturated hydrocarbons such as cyclopentadiene and hexadiene; aromatic polyunsaturated hydrocarbons such as halogen-substituted hydrocarbons such as nidivinylbenzene and diisopropylbenzene; ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, A diester compound of a dihydric alcohol such as propylene glycol, polypropylene glycol, polyethylene glycol-polypropylene glycol Brotta copolymer, 1,3-butylene glycol, hydrogenated bisphenol A, etc., and (meth)acrylic acid or crotonic acid;
Diether compounds and divinyl ether compounds of alcohols and (meth)allylic alcohols or croton alcohols; glycerol, trimethylolpropane,
Polyester compounds of polyhydric alcohols such as pentaerythritol and (meth)acrylic acid or crotonic acid; polyether compounds and polyvinyl ether compounds of the polyhydric alcohol and (meth)allyl alcohol or crotonic alcohol; magnesium, calcium, etc. Metal salt compounds of metals and (meth)acrylic acid or crotonic acid; Ester compounds and vinyl ester compounds of (meth)acrylic acid or crotonic acid and (meth)allyl alcohol or crotonic alcohol; Phthalic acid, isophthalic acid, terephthalic acid , diester compounds and divinyl ester compounds of dibasic acids such as oxalic acid, succinic acid, adipic acid, maleic acid, fumaric acid, itaconic acid, etc., and (meth)allylic alcohol or croton alcohol; trimellitic acid, pyromellitic acid, etc. Polyester compounds and polyvinyl ester compounds of polybasic acids such as (meth)allyl alcohol or croton alcohol; metal salt compounds of metals such as magnesium, calcium, etc. and vinyl oligosulfonic acid or styrene-p-sulfonic acid; ) unsaturated-basic acids such as acrylic acid, crotonic acid, etc.; maleic acid, fumaric acid,
Unsaturated dibasic acids such as itaconic acid; monohydric alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, 2-ethylhexyl alcohol, dodecyl alcohol, stearyl alcohol, phenyl alcohol, benzyl alcohol, etc.; Monoester compounds with basic acids; monoester compounds with dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol and lower monohydric alcohols such as methyl alcohol, ethyl alcohol, and butyl alcohol. Monoester compounds of ethers and unsaturated dibasic acids; unsaturated alcohols such as (meth)allyl alcohol, croton alcohol, etc.;
Ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-butylene glycol, bisphenol A hydroxide.

Vinyl ether compounds of polyhydric alcohols such as glycerol, trimethylolpropane, pentaerythritol, etc.; ether compounds of polyhydric alcohols and (meth)allylic alcohol or crotonic alcohol; monomers of polyhydric alcohols and (meth)acrylic acid or crotonic acid. Ester compounds; methyl alcohol, ethyl alcohol,
Ester compounds of monohydric alcohols such as isopropyl alcohol, butyl alcohol, 2-ethylhexyl alcohol, dodecyl alcohol, stearyl alcohol, phenyl alcohol, benzyl alcohol, etc. and (meth)acrylic acid or crotonic acid; monohydric alcohols and maleic acid, fumaric acid acid, diester compounds with unsaturated dibasic acids such as itaconic acid and citraconic acid; combinations of dihydric alcohols such as ethylene glycol, diethylene glycol and triethylene glycol and monohydric alcohols such as methyl alcohol, ethyl alcohol and butyl alcohol. Ester compounds of monoether compounds and (meth)acrylic acid or crotonic acid; diester compounds of monoether compounds and unsaturated dibasic acids; ethylene, propylene, butylene, isobutylene, octene, isooctene, decene.

Olefinic hydrocarbons such as dodecene; styrene,
Aromatic vinyl hydrocarbons such as chlorostyrene, 2-methylstyrene, vinyltoluene, vinylxylene, vinylnaphthalene; vinyl halides such as vinyl fluoride, vinyl chloride, vinyl bromide, etc.; vinylidene fluoride, vinylidene chloride, bromide Vinylidene halides such as vinylidene; (meth)acrylonitrile, crotonitrile, 2
- Unsaturated cyanogen compounds such as cyanoethyl acrylate, 2-chloroacrylonitrile, vinylidene cyanide, etc.; acetic acid, propionic acid, butyric acid, lauric acid, stearic acid, benzoic acid, p-tert-butylbenzoic acid, versatastic acid (VER5ATICACID), etc. Like 1
Vinyl ester compounds of monovalent carboxylic acids; ester compounds of monovalent carboxylic acids and (meth)allyl alcohol or croton alcohol; methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, 2-ethylhexyl alcohol.

Vinyl ether compounds of monohydric alcohols such as dodecyl alcohol, stearyl alcohol, phenyl alcohol, and benzyl alcohol; ether compounds of monohydric alcohols and (meth)allyl alcohol or croton alcohol; ethylene glycol, diethylene glycol,
Triethylene glycol S A vinyl ether compound of a monoether compound of a dihydric alcohol such as propylene glycol, dipropylene glycol, tripropylene glycol, etc. and an aliphatic monohydric alcohol having 1 to 4 carbon atoms; a monoether compound and (meth)allyl Ether compounds with alcohol or croton alcohol; (meth)
Unsaturated aldehydes such as acrolein and crotonaldehyde; amino group-containing (meth)acrylates such as diethylaminomethyl (meth)acrylate and dimethylaminoethyl (meth)acrylate; and quaternary salts of these cationized with methyl chloride; glycidyl ( Meta)
Unsaturated glycidyl esters such as acrylates;
Glycidyl ethers such as (meth)allyl glycidyl ether; (meth)acrylamide, dimethyl (meth)acrylamide, dimethylaminopropyl (meth)
Unsaturated amides such as acrylamide and quaternary salts of these cationized with methyl chloride; methylolated (meth)acrylamides, these acrylamides with 1 carbon number
Unsaturated amide derivatives such as ~4 alkyl ether compounds and the like can be mentioned.

When the unsaturated monomers are polymerized or copolymerized using the emulsifier of the present invention, any compound that generates cationic or nonionic free radicals can be used as the polymerization initiator. . For example, 2,2
'-azobis(2-amidinopropane) hydrochloride, hydrogen peroxide or a combination thereof with a reducing agent, cumene hydroperoxide, tert-butyl hydroperoxide or a combination thereof with a reducing agent,
Other known substances such as potassium persulfate and ammonium persulfate can also be used.

In emulsion polymerization of the above unsaturated monomer,
The emulsifier of the present invention can be used in exactly the same manner as conventionally known emulsifiers for emulsion polymerization. For example, the monomers are emulsified to a concentration of 20 to 70% by weight, typically in water, in the presence of an emulsifier representing 0.1 to 10% by weight of the unsaturated monomer, and 0.1-2% by weight of monomer
Emulsion polymerization can be carried out by adding a polymerization initiator corresponding to . In this case, it is also possible to use a pH adjuster, a degree of polymerization adjuster, and other auxiliary additives as required.

The emulsifier for emulsion polymerization of the present invention not only improves the drawbacks of conventional cationic emulsifiers, but also improves the polymer emulsion obtained by emulsion polymerization compared to conventional anionic and nonionic emulsifiers. It is possible to form a film with significantly superior water resistance, transparency, and smoothness compared to the polymer emulsion obtained by emulsion polymerization. .

Furthermore, since the particle size of the emulsion is small, it also has good freezing stability and storage stability.

Therefore, the polymer emulsion obtained using the emulsifier of the present invention is suitable for paints (particularly baking paints).

In addition to regular uses such as adhesives/adhesives, textile/paper processing, etc.
It is also suitable for forming a conductive film. This characteristic can be used to prevent static electricity in fibers, woven fabrics, non-woven fabrics, synthetic resin molded products, etc., conductive treatment for electronic copying paper, electrostatic recording paper, etc., and to provide unprecedented advantages when applied to magnetic materials. It has a great effect.

Example 1 3 parts by weight of the emulsifier shown in Table 1 and 1 part of water were placed in a glass reaction vessel equipped with a thermometer, stirrer, reflux condenser, and dropping funnel.
10 parts by weight were charged and dissolved, and the inside of the system was purged with nitrogen gas.

Here, the above emulsifier uses component (b) as a raw material and (a)
During the synthesis of component betaine ester, the component (b) was produced in such a manner that component (b) remained as an unreacted component in the ratio shown in Table 1. Separately, an unsaturated monomer mixture of 70 parts by weight of ethyl acrylate and 30 parts by weight of methyl methacrylate was prepared, and 10 parts by weight of these and 5 parts by weight of a 5% aqueous solution of 2,2'-azobis(amidinopropane) hydrochloride. was added to the reaction vessel, and polymerization was started at 60°C.゛Then,
The remaining 90 parts by weight of the unsaturated monomer was continuously dropped into the container over 90 minutes, and when half of the unsaturated monomer had been dropped, 2,2'-azobis(amidinopropane) was added. 5 parts by weight of a 5% aqueous solution of hydrochloride was added.

After dropping the unsaturated monomer, the mixture was aged at 60° C. for 90 minutes.

The particle size of the obtained polymer emulsion was determined by coal tar and
It was measured with a counter (manufactured by Coal Tar Electronics, USA) and the results are shown in Table 1.

Further, the polymer emulsion was cast on a 6×8 cm+ glass plate and air-dried at room temperature to form a film with a thickness of 0.2 mm, and the film properties were measured. Film properties were evaluated based on the following criteria.

Water resistance: The air-dried film was further heat-treated at 160°C for 4 hours, then immersed in a Petri dish filled with 20°C water until the 8-point newspaper type placed under the Petri dish became illegible. The time was measured (unit: 2 hours).

Transparency: The haze value of the film was measured using a haze meter.

Smoothness: The surface condition of the film was visually observed and evaluated according to the following criteria.

O: Smooth and glossy film Δ: Film with some wrinkles and cracks So (a)/(
b) Emulsion copolymerization of ethyl acrylate and methyl methacrylate was carried out in the same manner as in Example 1 using the emulsifiers shown in Table 2 containing = 10010 to 56/44.

Here, the emulsifier was produced by setting conditions such that component (b) remained as an unreacted component in the above ratio when synthesizing betaine ester, component (a), using component (b) as a raw material.

The particle diameter of the obtained polymer emulsion and the properties of the film formed in the same manner as in Example 1 were measured, and the results are shown in Table 2.

Samples Nα9, 10 and 11 are examples of the present invention,
Samples Na 8 and 12 are comparative examples. From Table 2 (
It can be seen that the appropriate ratio of component a) to component (b) is 9971 to 6/4.

Example 3 Into the same reaction vessel as in Example 1, 3 parts by weight of the emulsifier shown in Table 3 and 110 parts by weight of water were added and dissolved.

Separately, an unsaturated monomer mixture of 50 parts by weight of butyl acrylate and 50 parts by weight of styrene was prepared, of which 10 parts by weight and 5 parts by weight of a 5% aqueous solution of 2,2'-azobis(amidinopropane) hydrochloride were added. In addition, the temperature was raised to 60°C to start polymerization.

90 parts by weight of the remaining monomer mixture was continuously dropped into the reaction vessel over 90 minutes, and when half of the monomers had been dropped, 5% of the 2,2'-azobis(amidinopropane) hydrochloride was added dropwise. 5 parts by weight of an aqueous solution was added. After the monomer was added dropwise, the mixture was aged at 60° C. for 90 minutes.

The particle size of the polymer emulsion obtained by polymerization was measured, and a film was formed in the same manner as in Example 1, and its properties were evaluated. The results are shown in Table 3.

(Margin below)

Claims (1)

[Claims] 1. (a) a betaine ester of a higher aliphatic alcohol and/or a betaine ester of an alkylphenol; (b) a higher aliphatic alcohol and/or an alkylphenol in a weight ratio of (a)/(b); ) = 99/1 to 6/4.