JPH0713083B2 - Emulsifier for emulsion polymerization - Google Patents

Description

TECHNICAL FIELD The present invention relates to an emulsifier for emulsion polymerization, and more particularly to an emulsifier for emulsion polymerization suitable for producing a polymer emulsion which forms a film having excellent water resistance, transparency and smoothness. .

2. Description of the Related Art Conventionally, various surfactants such as an alkyltrimethylammonium salt, a dialkyldimethylammonium salt, and a polyoxyethylene are used as emulsifiers for emulsion polymerization used in the production of polymer emulsions by emulsion polymerization of unsaturated monomers. Ethylene alkyl amine, polyoxyethylene alkyl trimethylene diamine, polyoxyethylene alkyl methyl ammonium salt, polyoxy ethylene alkyl dimethyl trimethylene ammonium salt, 2-alkyl-N-
Carboxymethyl-N-hydroxyethylimidazolium betaine, 2-alkyl-N-carboxyethyl-N
-Hydroxyethyl imidazolium betaine, N-alkyldimethylamine oxide and the like are used.

However, when these are used as an emulsifier, the amount of aggregates formed in the polymer is large, and the particle size of the polymer emulsion formed is large. Moreover, the obtained polymer emulsion has mechanical stability, chemical stability,
It has a bad influence on the storage stability, and when a polymer emulsion is used as a paint or an adhesive, its performance is usually influenced.

On the other hand, a decomposition type glycine betaine alkyl ester has been proposed as a surfactant that solves these problems (Angew. Chem., 71 , 604 (1959)). However, even when this glycine betaine alkyl ester is used as an emulsifier, there is a problem that the film formed by using the produced polymer emulsion is inferior in water resistance, transparency and smoothness.

OBJECT OF THE INVENTION The present invention provides an emulsifier for emulsion polymerization capable of producing a polymer emulsion capable of forming a film excellent in water resistance, transparency and smoothness.

Structure of the Invention The emulsifier for emulsion polymerization of the present invention comprises a quaternary ammonium salt represented by the following general formula (I) (hereinafter sometimes abbreviated as AEB) and / or a quaternary ammonium salt represented by (II). It is characterized by comprising an ammonium salt (hereinafter sometimes abbreviated as APEB), and these are used alone or in combination.

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , n and X respectively represent the following.

R ₁ : an alkyl group or an alkenyl group having 8 to 20 carbon atoms R ₂ : an alkylene group having 2 to 4 carbon atoms R ₃ : an alkylene group having 1 to 5 carbon atoms R ₄ , R ₅ , R ₆ : 1 to 3 carbon atoms Or an alkyl group of -C ₂ H ₄ OH, which may be the same or different.

R ₇ : alkyl group having 6 to 20 carbon atoms n: average number of moles added, n = 1 to 20 X: inorganic anion or organic anion) In the general formula (I), R ₁ is linear or branched. It may be in the form of, and preferably has 10 to 18 carbon atoms. R ₇ in the general formula (II) may be linear or branched, and preferably has 8 to 18 carbon atoms.

Higher aliphatic alcohol residue R ₁ O- or long-chain alkylphenol residue The alkylene oxide units -R ₂ O-is to be added, ethylene oxide, propylene oxide, is introduced by the addition polymerization of one or more of butylene oxide, preferably ethylene oxide. When two or more kinds of alkylene oxides are added, the addition form may be random addition or block addition. The preferred average number of added moles of alkylene oxide is 3 to 15.

The X inorganic anions Cl ^-, Br ^- is halide, such as,
Examples of organic anions _{^{CH 3 COO -, OSO 3 CH}} 3 -, OSO 3 C 2 H 5 -
Typical examples are as follows.

Such AEB and APEB can be obtained by various preparation methods.
, For example, the general formula (A) or (B) R₁OH (A)(However, R₁And R₇Is as described above. ) Higher aliphatic alcohol or long-chain alkyl group
Starting material from the phenol, adding alkylene oxide
To make an alkoxylate, and then this alkoxylate
To an ester with a lower haloalkylcarboxylic acid,
In addition, low amounts of trimethylamine, triethylamine, etc.
Obtained by reacting with a primary trialkylamine
You can In addition, if necessary, the ion exchange method
X in the general formulas (I) and (II) To an organic anion
You can also

Generally, emulsion polymerization is divided into three steps: emulsion, polymerization and aging. The quaternary ammonium salt represented by the general formula (I) or (II) of the present invention is excellent in emulsifying property and can microemulsify an unsaturated monomer and water in the emulsification step, and further, it can be polymerized and aged. Part of the quaternary ammonium salt decomposes in the process, and the resulting decomposed product acts cooperatively as a cosurfactant (coactivator), and is excellent in polymerization stability, and also has excellent water resistance, transparency, and smoothness. A good polymer emulsion is obtained.

In addition, such cosurfactants and AEB or A
By using it as an emulsifier in combination with PEB in advance,
By further effectively utilizing the concerted effect, it is possible to further reduce the particle size of the produced polymer emulsion. As the cosurfactant, at least one of polyoxyethylene alkyl ether and polyoxyethylene alkylphenyl ether represented by the following general formulas (III) and (IV) is used.

R ₁ OR ₂ OnH (III) (R ₁ , R ₂ , R ₇ , and n are as follows: R ₁ is an alkyl or alkenyl group having 8 to 20 carbon atoms R ₂ : an alkylene group having 2 to 4 carbon atoms R ₇ : 6 to 20 carbon atoms Alkyl group n: represents the average number of moles added, and n = 1 to 20) The preferable range of R ₁ , R ₂ , R ₇ , and n are the same as those already described for AEB and APEB.

The weight ratio of (a) AEB or APEB and (b) polyoxyethylene alkyl (or alkylphenyl) ether is (a) / (b) = 99/1 to 6/4, preferably 95/2 to 65 /. 35
It is suitable to use within the range. If this ratio is larger than 99/1, the particle diameter of the polymer emulsion formed will be large, and if it is smaller than 6/4, the characteristics of the film formed by the polymer emulsion will be lacking.

The components (a) and (b) may be separately prepared and blended, and since the component (b) is a raw material for producing the quaternary ammonium salt of the component (a), ( a)
The emulsifier of the present invention can be obtained by setting the conditions such that the component (b) remains as an unreacted component during the production of the quaternary ammonium salt of the component.

(B) As the polyoxyethylene alkyl (or alkylphenyl) ether, AEB or AEPB used
It is preferably structurally similar to the alcohol part or the phenol part. When AEB is used as the emulsifier, polyoxyethylene alkyl ether is preferable, and when AEPB is used, polyoxyethylene alkylphenyl ether is preferable.

AEB and APEB of the present invention are those which sufficiently exert the function as an emulsifying agent for emulsion polymerization by themselves, but if necessary, a polymeric substance acting as a protective colloid of a nonionic surfactant or a polymeric emulsion, etc. Can also be used together.

As the nonionic surfactant, polyoxyethylene alkylamine, polyoxyethylene alkyl trimethylene diamine, polyoxyethylene fatty acid ester, polyoxypropylene-polyoxyethylene glycol (pluronic type surfactant), etc. can be used. Particularly, a polyoxyethylene-based nonionic surfactant having an average added mole number of ethylene oxide of 5 to 80, preferably 8 to 60 per 1 active hydrogen is suitable.

Further, as the water-soluble polymer substance, polyvinyl alcohol, hydroxyethyl cellulose and the like can be used. When a nonionic surfactant and / or a water-soluble polymer substance is used in combination, 0.05 to 10 parts by weight is suitable for each 1 part by weight of AEB and APEB.

The emulsifier of the present invention can be used for emulsion polymerization of one or more kinds of various unsaturated monomers. As unsaturated monomers, butadiene, isoprene, 1,3-pentadiene,
Fatty acid polyunsaturated hydrocarbons such as chloroprene, cyclopentadiene and hexadiene; halogen substitution products of the hydrocarbons; aromatic polyunsaturated hydrocarbons such as divinylbenzene, diisopropylebenzene; ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol , Dipropylene glycol, polypropylene glycol, polyethylene glycol-polypropylene glycol block copolymers, 1,3-butylene glycol, diester compounds of (meth) acrylic acid or crotonic acid with dihydric alcohols such as hydrogenated bisphenol A; Diether compounds and divinyl ether compounds of dihydric alcohols with (meth) allyl alcohol or croton alcohol; glycerol, trimethylolpropane, penta Polyester compound of a polyhydric alcohol and (meth) acrylic acid or crotonic acid, such as such as Risuritoru; polyether compound with polyhydric alcohol and (meth) allyl alcohol or crotonic alcohol and polyvinyl ether compound; magnesium,
Metal salt compounds of metals such as calcium 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, Diester compounds and divinyl ester compounds of dibasic acids such as terephthalic acid, oxalic acid, succinic acid, adipic acid, maleic acid, fumaric acid and itaconic acid with (meth) allyl alcohol or croton alcohol; trimellitic acid, pyromellitic acid Polyester compounds and polyvinyl ester compounds of polybasic acids such as acids with (meth) allyl alcohol or croton alcohol; metals such as magnesium, calcium and vinyl sulfonic acid or styrene
Metal salt compounds with p-sulfonic acid; unsaturated monobasic acids such as (meth) acrylic acid and crotonic acid; unsaturated dibasic acids such as maleic acid, fumaric acid and itaconic acid;
Monoester compounds of monohydric alcohols and unsaturated dibasic acids such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, 2-ethylhexyl alcohol, dodecyl alcohol, stearyl alcohol, phenyl alcohol, benzyl alcohol; ethylene glycol, diethylene glycol , Monoethylene compounds of dihydric alcohols such as triethylene glycol, propylene glycol, dipropylene glycol and tripropylene glycol with lower monohydric alcohols such as methyl alcohol, ethyl alcohol and butyl alcohol, and unsaturated dibasic acid monoester compounds : Unsaturated alcohols such as (meth) allyl alcohol and croton alcohol; ethylene glycol, diethylene glycol, triethylene glycol Call, propylene glycol,
Dipropylene glycol, tripropylene glycol,
1,3-butylene glycol, hydroxylated bisphenol A,
Vinyl ether compounds of polyhydric alcohols such as glycerol, trimethylolpropane and pentaerythritol; ether compounds of polyhydric alcohols with (meth) allyl alcohol or crotonic alcohol; monofunctional polyhydric alcohols with (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 and benzyl alcohol with (meth) acrylic acid or crotonic acid; monohydric alcohols and maleic acid, fumaric acid. Diester compounds with unsaturated dibasic acids such as acid, itaconic acid and citraconic acid; monohydric alcohols such as ethylene glycol, diethylene glycol and triethylene glycol and monohydric alcohols such as methyl alcohol, ethyl alcohol and butyl alcohol Ester compound of ether compound and (meth) acrylic acid or crotonic acid; Diester compound of monoether compound and unsaturated dibasic acid; Ethylene, propylene, butylene, iso Styrene, octene, isooctene, decene, such olefinic hydrocarbons, such as dodecene; styrene, chlorostyrene, 2-methylstyrene,
Aromatic vinyl hydrocarbons such as vinyltoluene, vinylxylene, vinylnaphthalene; vinyl fluoride, vinyl chloride,
Vinyl halide such as vinyl bromide; Vinylidene halide such as vinylidene fluoride, vinylidene chloride, vinylidene bromide; (meth) acrylonitrile, crotonnitrile, 2-cyanoethyl acrylate, 2-chloroacrylonitrile, vinylidene cyanide, etc. Unsaturated cyan compounds such as; vinyl ester compounds of monovalent carboxylic acids such as acetic acid, propionic acid, butyric acid, lauric acid, stearic acid, benzoic acid, p-tert-butylbenzoic acid, VERSATIC ACID; monovalent Ester compounds of carboxylic acid and (meth) allyl alcohol or croton alcohol; methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, 2-ethylhexyl alcohol, dodecyl alcohol, stearyl alcohol, phenyl alcohol Vinyl ether compounds of monohydric alcohols such as benzyl alcohol and benzyl alcohol; ether compounds of monohydric alcohols with (meth) allyl alcohol or croton alcohol; ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol Such as dihydric alcohol and 1 to 4 carbon atoms
Vinyl ether compounds of monoether compounds with aliphatic monohydric alcohols; ether compounds of monoether compounds with (meth) allyl alcohol or croton alcohol; unsaturated aldehydes such as (meth) acrolein, crotonaldehyde, etc .; diethylaminomethyl ( Amino group-containing (meth) acrylates such as (meth) acrylate and dimethylaminomethyl (meth) acrylate and quaternary salts obtained by cationizing these with methyl chloride; unsaturated glycidyl esters such as glycidyl (meth) acrylate; (meth) Glycidyl ether such as allyl glycidyl ether; (meth) acrylamide,
Unsaturated amides such as dimethyl (meth) acrylamide and dimethylaminopropyl (meth) acrylamide, and quaternary salts obtained by cationizing these with methyl chloride; methylolated (meth) acrylamides, alkyls having 1 to 4 carbon atoms Examples thereof include unsaturated amide derivatives such as ether compounds.

When the unsaturated monomer is polymerized or copolymerized by using the emulsifier of the present invention, as the polymerization initiator, any compound that generates a cationic or nonionic free radical can be used. . 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 of these with a reducing agent, and other known peroxides. Potassium sulfate, ammonium persulfate and the like can also be used.

And in emulsion-polymerizing the unsaturated monomer,
The emulsifier of the present invention can be used in the same manner as a conventionally known emulsifier for emulsion polymerization. For example, the monomer is emulsified and dispersed in a concentration of 20 to 70% by weight, typically in water, in the presence of an emulsifier corresponding to 0.1 to 10% by weight of the unsaturated monomer, and the unsaturated monomer is added. Emulsion polymerization can be carried out by adding a polymerization initiator corresponding to 0.1 to 2% by weight of the body. In this case, if necessary, a pH adjusting agent, a polymerization degree adjusting agent,
It is also conventional that other auxiliary additives can be used.

EFFECTS OF THE INVENTION The emulsifier for emulsion polymerization of the present invention is improved in the drawbacks found in conventional cationic emulsifiers, and since it is a cationic degradable activator, a polymer emulsion obtained by emulsion polymerization is Compared with the polymer emulsion obtained by emulsion polymerization using the anionic and nonionic emulsifiers, the formed film is remarkably excellent in water resistance, transparency and smoothness. Furthermore, the foamability is low,
It has good chemical, freezing and storage stability.

Therefore, the polymer emulsion obtained by using the emulsifier of the present invention is suitable not only for ordinary applications such as paints (particularly baking paints), adhesives / adhesives, fiber / paper processing, but also for forming conductive films. Is. Utilizing this property, when used for antistatic treatment of fibers, woven fabrics, non-woven fabrics, synthetic resin moldings, etc. Exert the effect.

Example 1 In a glass reaction vessel equipped with a thermometer, a stirrer, a reflux condenser and a dropping funnel, 3 parts by weight of the emulsifier shown in Table 1 and water 11
0 part by weight was charged and dissolved, and the inside of the system was replaced with nitrogen gas. Separately, an unsaturated monomer mixture of 70 parts by weight of ethyl acrylate and 30 parts by weight of methyl methacrylate was prepared.
10 parts by weight and 5 parts by weight of a 5% aqueous solution of 2,2'-azobis (amidinopropane) hydrochloride were added to the reaction vessel, and polymerization was initiated at 60 ° C. Then, the remaining 90 parts by weight of the unsaturated monomer was continuously dropped into the anti-container over 90 minutes, and halfway through the half of the unsaturated monomer was dropped at the end of the process.
5 parts by weight of a 5% aqueous solution of 2,2'-azobis (amidinopropane) hydrate chloride was added. After the addition of the unsaturated monomer was completed, the mixture was aged at 60 ° C for 90 minutes.

The polymer emulsion thus obtained is 6 × 8 cm
It was cast on a glass plate of, and air-dried at room temperature to form a film having a thickness of 0.2 mm, and the film characteristics were measured.

Table 1 shows the measurement results of the film characteristics of the polymer emulsion. When the emulsifier of the present invention is used, the water resistance, transparency and smoothness are excellent as compared with the case of using the conventional emulsifier. I understand. The film characteristics were evaluated according to the following criteria.

Water resistance: The film after air-drying is further heat-treated at 160 ° C for 4 hours and immersed in a petri dish filled with water at 20 ° C until the 8-point newspaper type laid under the dish becomes unreadable. Was measured (unit: hours).

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

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

◯: Smooth and glossy film Δ: Slightly wrinkled or cracked film ×: Extremely wrinkled or cracked film Example 2 (b) an EO adduct of alcohol (or phenol) shown in Table 2 (the following structural formula (I)) as an emulsifier,
(A) A quaternary ammonium salt having an EO adduct skeleton (residue) of this alcohol (or phenol) (the following structural formula (II) in a weight ratio of (a) / (b) = 9/1) A polymer emulsion was obtained in the same manner as in Example 1 except that the emulsifier blended in (3) was used.

R-EOEnH ...... (I) (RO: Alcohol or Phenol Residue EO: Addition Unit of Ethylene Oxide) Here, the emulsifier is prepared by synthesizing (a) a quaternary ammonium salt from (b) an EO adduct of alcohol (or phenol) as a raw material. In this case, the conditions were set so that the EO adduct of alcohol (or phenol) (b) remained as the unreacted component in the above proportion, and the reaction was performed.

The particle size of the obtained polymer emulsion was measured by Coulter
The results are shown in Table 2 as measured by a counter (manufactured by Coulter Electronics Co., USA).

Then, a film was formed in the same manner as in Example 1, and the film characteristics were measured and shown in Table 2.

Sample No. 11 is a cosurfactant (b)
Particle size of the polymer emulsion in the case of not using the EO3 molar adduct of C _{12 to 14} 2 alcohol components (corresponding to the sample No.1 of Example 1) was 0.20 [mu] m.

From Table 2, it can be seen that the combined use of the component (b) as the cosurfactant reduces the particle size obtained.

Example 3 As in Example 1, polymerization of quaternary ammonium salts of the following structural formula (III) having polyoxyethylene cetostearyl ether residues of various ethylene oxide average addition mole numbers (EO) shown in Table 3 is carried out. Emulsion copolymerization of ethyl acrylate and methyl methacrylate was performed by using as an emulsifying agent.

(RO: cetostearyl alcohol residue n: average added mole number EO of ethylene oxide) A film of the polymer emulsion thus obtained was formed and the film characteristics were measured. The results are shown in Table 3.

Sample Nos. 4, 21, 22 and 23 are examples of the present invention.
Nos. 8 and 24 are comparative examples. From Table 2, it is found that the oxyethylene group in the molecule of betaine ester is suitably 1 to 20.

Example 4 As an emulsifier, the components (a) and (b) shown in Table 4 were used.
Emulsion copolymerization of ethyl acrylate and methyl methacrylate was performed in the same manner as in Example 1 except that the components were used together in a weight ratio of (a) / (b) = 17/3. Here, the emulsifier is produced by setting the conditions such that the component (b) remains as an unreacted component when the quaternary ammonium salt of the component (a) is synthesized using the component (b) as a raw material. did.

The emulsion particle size and coating properties were evaluated and are set forth in Table 4.

Also, in sample No. 25, without using the component (b) (a)
When the components alone were used as the emulsifier, the particle size of the obtained polymer emulsion was 0.18 μm.

In Table 4, sample Nos. 28 and 32 are comparative examples, and the others are examples.

Example 5 4 parts by weight of the emulsifier shown in Table 5 and 110 parts by weight of water were added to and dissolved in the same reaction vessel as in Example 1. Separately, an unsaturated monomer mixture of 50 parts by weight of butyl acrylate and 50 parts by weight of styrene was prepared, and 10 parts by weight of this mixture 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 initiate polymerization. The remaining 90 parts by weight of the monomer mixture was continuously added dropwise into the reaction vessel over 90 minutes, and 5% of 2,2'-azobis (amidinopropane) hydrochloride was added at the time when half the amount of the monomer had been added. 5 parts by weight of the aqueous solution was added. After the dropping of the monomer was completed, the mixture was aged at 60 ° C. for 90 minutes.

Using the polymer emulsion obtained by the above-mentioned polymerization, a film was formed in the same manner as in Example 1 and its characteristics were measured. The results are shown in Table 5.

Example 6 A polymer emulsion was obtained in the same manner as in Example 5 except that 4 parts by weight of the emulsifier consisting of the components (a) and (b) shown in Table 6 were used, and the average particle size and film characteristics were evaluated. The results are shown in Table 6.

Further, in the sample No. 44, without using the component (b), 100% of the component (a) (corresponding to the sample No. 34 of Example 5) was used as an emulsifier, the particle size was 0.16 μm. Met.

Example 7 As an emulsifier, (a) a quaternary ammonium salt of the following structural formula (IV) having a polyoxyethylene nonylphenyl ether residue, (EO: Addition unit of ethylene oxide) (b) Polyoxyethylene nonylphenyl ether (EO
) Was used in the weight ratio shown in Table 7, and ethyl acrylate and methyl methacrylate emulsion copolymerization was carried out in the same manner as in Example 1.

Here, the component (b) is prepared by using the polyoxyethylene nonylphenyl ether (component b) as a starting material to produce a quaternary ammonium salt having the polyoxyethylene nonylphenyl ether residue (component a) ( The production conditions were controlled so that the component b) remained as an unreacted component in the weight ratio shown in Table 7, and this unreacted component was used as it was.

In addition, as the sample No. 53, the results when the component (a) was used alone are also shown.

Claims (1)

[Claims] 1. The following general formula (I) and / or (II)
An emulsifier for emulsion polymerization, which comprises a quaternary ammonium salt represented by: (In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , n and X respectively represent the following: R ₁ : an alkyl or alkenyl group having 8 to 20 carbon atoms R _2: alkylene group R ₃ having from 2 to 4 carbon atoms: an alkylene group R ₄ having 1 to 5 carbon atoms, R _5, R _6: an alkyl group or -C ₂ H ₄ OH of 1 to 3 carbon atoms, respectively R ₇ : alkyl group having 6 to 20 carbon atoms n: average number of moles added, n = 1 to 20 X: inorganic anion or organic anion)