JPH0198652A - Acrylic resin emulsion and its production - Google Patents

Abstract

PURPOSE:To produce the title emulsion which is excellent in long-term stability and can give a paint film excellent in water resistance, by emulsion-polymerizing an alpha,beta-unsaturated monomer in the presence of a polymerization initiator in an aqueous medium containing a specified emulsifier. CONSTITUTION:100pts.wt. alpha,beta-unsaturated monomer (e.g., acrylic acid) is mixed with 0.1-200pts.wt. poly(H-acylethyleneimine)-grafted polysiloxane, as an emulsifier, of the formula (wherein R1 is a 1-18C alkyl or an aryl, R2 is a 1-100C alkylene chain which may contain an ether bond and/or an ester bond in the chain, R3-5 are each a monovalent organic group selected from among a hydroxyl, an allyloxy, a 1-20C alkyl, a 1-20C alkoxy and a 1-100C hydroxyl- terminated alkyl which may contain an ether bond and/or an ester bond in the chain, R6 is a 1-40C alkyl, an aralkyl or an aryl each of which may contain a hydroxyl group, k, l and n are the numbers of repeating siloxane units, k>0, l>=1, n>=0 and 2>=k+l+n<=2,000, and p is the degree of polymerization of H-acylethyleneimine and 1<=p<=200), and the mixture is emulsion-polymerized in the presence of a polymerization initiator in an aqueous medium.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an acrylic resin emulsion that has excellent stability over time and is useful in the paint field, and a method for producing the same.

Among conventional emulsifiers, anionic and cationic emulsifiers have shells that are easily affected by pH, solvents, miscellaneous ions, and other constituent components, and when used in the production of paint resins, etc., water resistance Zwitterionic emulsifiers can alleviate these drawbacks, but they are still insufficient as they are susceptible to hydrolysis and have poor stability over time. In addition, nonionic polymer emulsifiers such as polyethylene glycol and polyethyleneimine are also known, but it has been pointed out that it is difficult to obtain stable emulsifying ability due to the need to maintain a balance between wood-philicity and hydrophobicity. There is. Recently, poly(doacylethyleneimine) grafted polysiloxane in which N-acylethyleneimine is incorporated into polysiloxane has been reported (Chemical Society of Japan No. 5).
4 Spring Annual Conference Lecture Proceedings II, 1557 ('87) Takeo Saegusa), Polysiloxane hydrophobic part and polyN-
Since it has a hydrophilic moiety of acyl ethyleneimine, it is expected to have a wide range of uses such as surfactants, smoothing agents, and resin compatibility improvers.

However, in the presence of a platinum catalyst in polysiloxane, N
- Apart from the problems of the manufacturing method itself for reacting acyl ethyleneimine compounds to obtain the above compound, the grafted polysiloxane does not contain any functional groups other than N-acyl ethyleneimine, and is capable of controlling solubility and functional sites. It is extremely difficult to derive other derivatives for purposes such as imparting. Therefore, even if it is used as a polymeric emulsifier, it is difficult to be anchored in, for example, an emulsion resin or a cured coating film, and there is a concern that it may elute from the coating film and adversely affect water resistance and the physical properties of the film.

The problem to be solved by the invention is to use a nonionic polymer emulsifier that is not affected by pH 1 solvents, miscellaneous ions, etc., and is not susceptible to chemical changes such as hydrolysis or thermal changes. This is an acrylic resin emulsion for paints that has excellent stability over time, and the emulsifier itself is anchored in the paint film by chemical bonds, so it does not dissolve from the paint film or impair the physical properties of the film such as water resistance. There is a need for emulsions, and it is an object of the present invention to provide such resin emulsions and an industrially advantageous process for their production.

Means for Solving the Problems According to the present invention, when the above-mentioned object of the invention is emulsion polymerizing an α,β-unsaturated monomer in an aqueous medium containing an emulsifier in the presence of a polymerization initiator, as the emulsifier, , formula (in the formula, R1 is the same or different carbon number 1 to 1)
8 alkyl group or aryl group; R3, R4, R5 are hydroxyl group, allyloxy group, alkyl group having 1 to 20 carbon atoms,
Alkoxy group with 1 to 20 carbon atoms, with 1 to 20 carbon atoms that may contain ether and/or ester bonds in the chain! One same or different organic group selected from the terminal hydroxyalkyl groups of 00; R2 is an alkylene chain with 1 to 10 G of carbon atoms capable of forming an ether and/or ester bond in the chain; R6 is a carbon that may contain a hydroxyl group an alkyl group, an aralkyl group, or an aryl group of numbers 1 to 40; 1 and n are each the number of repeating units of siloxane, and k>O
11≧1, n≧0.2≦ and +j+n≦2000; P represents the degree of polymerization of N-acyl ethyleneimine, and poly( This is achieved by an acrylic resin emulsion obtained by the method of the invention using N-acylethyleneimine) grafted polysiloxane.

That is, in the present invention, a conventional method for producing an acrylic resin emulsion is used in which α,β-unsaturated monomers are emulsion-polymerized using an emulsifier and a polymerization initiator in an aqueous medium. It is novel in that it uses poly(N-acylethyleneimine) grafted polysiloxane, and the resulting acrylic resin emulsion has superior stability over time compared to those using conventional emulsifiers. This invention constitutes an inventive step in that there is no elution of the emulsifier from the coating film, a coating film with excellent film properties such as water resistance is obtained, and it is extremely useful industrially. Therefore, any α,β-unsaturated monomer used in the production of acrylic resins can be used as the α,β-unsaturated monomer.
-Ethylenically unsaturated monomers are used, which can be broadly classified into the following groups:

That is, as monofunctional polymerizable monomers: (1) Carboxyl group-containing monomers, such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid.

■ Hydroxyl group-containing monomers, such as 2-hydroxyethyl acrylate, hydroxypropyl acrylate,
2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate,
Hydroxybutyl methacrylate, allyl alcohol,
Metaallyl alcohol etc.

■Nitrogen-containing alkyl acrylates or methacrylates, such as dimethylaminoethyl acrylate and dimethylaminoethyl methacrylate.

■Polymerizable amides, such as acrylic amide and methacrylic amide.

■Polymerizable nitriles, such as acrylonitrile and methacrylate trile.

■Alkyl acrylate or methacrylate.

For example, methyl acrylate, methyl methacrylate, ethyl acrylate, n-butyl acrylate.

■-Butyl methacrylate, 2-ethylhexyl acrylate, etc.

■Polymerizable glycidyl compounds, such as glycidyl (meth)acrylate.

(2) Polymerizable aromatic compounds, such as styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, etc.

■α-olefins, such as ethylene and propylene.

[Co.] Vinyl compounds, such as vinyl acetate, vinyl propionate, etc.

■Diene compounds, such as butadiene, isoprene, etc.

These monomers may be used alone or in combination.

The acrylic resin can also be made into a crosslinked resin particle emulsion, so it can also contain monomers having two or more radically polymerizable ethylenically unsaturated groups in the molecule, which can be used for polymerization of polyhydric alcohols. Examples include polyunsaturated monocarboxylic acid esters, polymerizable unsaturated alcohol esters of polybasic acids, and aromatic compounds substituted with two or more vinyl groups. Specific examples include the following compounds.

Ethylene glycol diacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,4-butanediol dimethacrylate Acrylate neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate pentaerythritol tetramethacrylate, glycerol dimethacrylate, glycerol Diacrylate, glycerol allyloxy dimethacrylate, 1,1.1-trishydroxymethylethane diacrylate, 1,1.1-trishydroxymethylethane triacrylate, 1.1.1 trishydroxymethylethane dimethacrylate, 1.1 ．．
ll-Lishydroxymethylethane trimethacrylate,! ,l.

l-trishydroxymethylpropane diacrylate,
1.1. i trishydroxymethylpropane triacrylate, 1.1.1-1-lishydroxymethylpropane dimethacrylate-1, +, t, t-trishydroxymethylpropane trimethacrylate, triallyl cyanurate, triallyl isocyanurate, Triallyl trimellitate, diallyl terephthalate, diallyl phthalate and divinylbenzene.

As a polymerization initiator, any compound usually used in the production of acrylic resin emulsions, such as organic peroxides such as benzoyl peroxide, t-butyl peroxide, and cumene hydroperoxide; azobiscyanovaleric acid, azobisisobutyronitrile; Organic azo compounds such as azobis(2,4-dimethyl)valeronitrile and azobis(2-amidinopropane) hydrochloride; inorganic water-soluble radical initiators such as potassium persulfate, ammonium persulfate, sodium persulfate, and hydrogen peroxide; A redox initiator consisting of a combination of a water-soluble radical initiator and sodium pyrosulfite, sodium bisulfite, divalent iron ion, etc. is preferably used, and if desired, a water-miscible organic solvent is used for the reaction medium water. can be contained.

The most characteristic poly(N-acylethyleneimine) graft polysiloxane of the present invention is a novel polymer emulsifier synthesized by the present inventors, and
As described in the specification of the patent application dated August 8 (title of the invention "Poly(N-acylethyleneimine) grafted polysiloxane and method for producing the same"), the formula (wherein R, each has the same or different carbon number 1 to 1)
8 alkyl group or aryl group; R3, R4, R9 are hydroxyl group, allyloxy group, alkyl group having 1 to 20 carbon atoms,
One same or different organic group selected from an alkoxy group having 1 to 20 carbon atoms, and a terminal hydroxyalkyl group having 1 to 100 carbon atoms which may contain an ether bond and/or an ester bond in the chain; R2 is an ether group in the chain. and/or an alkylene chain having 1 to 100 carbon atoms that may contain an ester bond; m and n are each the number of repeating units of siloxane, and m≧1
, ■Real number that satisfies the relationship of ≧0.2≦m+n≦2000)
A step of converting all or a part of the alcoholic hydroxyl groups of the alcoholic hydroxyl group-containing polysiloxane represented by It can be easily and industrially advantageously produced by a combination of steps of ring-opening polymerization of 2-oxazolines represented by 40 alkyl, aralkyl, or aryl groups. In addition, the formula (II) used as a starting material in the above method
For example, the polysiloxane represented by the formula % is reacted with mmole of alkeneoxytrimethylsilane in the presence of a platinum acid catalyst to form a polysiloxane represented by the formula %(3), It can be easily produced by subsequent hydrolysis.In the above addition reaction, the alkeneoxytrialkylsilane does not contain a hydroxyl group that would inhibit the reaction, and since it is not an addition reaction between polymers, it is difficult to set the reaction conditions. Raw material polysiloxane can be provided with great ease and high yield.

The sulfonic acid esterification of polysiloxanes having alcoholic hydroxyl groups can be carried out by any method known per se using sulfonic acids or reactive derivatives of sulfonic acids. A particularly preferred method proceeds very easily by reacting a sulfonic acid halide such as p-toluenesulfonic acid halide, methanesulfonic acid halide, trifluoromethanesulfonic acid halide, especially chloride, in the presence of a base such as pyridine. In this case, by controlling the proportion of sulfonic acid or its reactive derivative used, reaction conditions, etc., it is possible to convert all or any desired proportion of the alcoholic hydroxyl groups into sulfonic acid ester.

Next, using the above sulfonated polysiloxane as an initiator polymer, ring-opening polymerization of 2-oxazoline represented by the formula is carried out. The reaction is carried out using an appropriate solvent,
For example, the process can be carried out extremely easily by simply heating the two in acetonitrile or chloroform. Since sulfonic acid is produced as a by-product in this reaction, such acid groups can be removed, if desired, by ion exchange using, for example, a suitable hydroxyl group-type anion exchange resin. However, in the present invention, since the target product is used in an aqueous medium, there is no need for purification when anion residues are not a problem.

As described above, in the present invention, a polymeric emulsifier containing polysiloxane as a hydrophobic part and polyN-acylethyleneimine as a hydrophilic part is used as a polymeric emulsifier having extremely useful emulsifying ability. Because it contains a hydroxyl group, by selecting an appropriate reactive monomer, the emulsifier can be chemically bonded to the emulsion resin.
Alternatively, it is possible to incorporate the emulsifier into the coating film through a chemical bond through reaction with a solid curing agent, and unlike emulsifiers that are simply adsorbed to conventional emulsion resins, the emulsifier will not be eluted from the coating film. Therefore, it is possible to provide a coating film that is extremely excellent in terms of water resistance and the like. In addition, the emulsifier used in the present invention is a chemically stable polymeric emulsifier that is not affected by changes in the external environment such as pH and miscellaneous ions, is not susceptible to hydrolysis or thermal decomposition, and has excellent dispersion stability during heating or over time. It is possible to provide an emulsion with excellent stability over time.

The present inventors used 0.1 to 200 parts by weight of poly(N-acylethyleneimine) grafted polysiloxane per 100 parts by weight of α,β-unsaturated monomer, and the nonvolatile content was 60 parts by weight.
It has also been found that obtaining emulsions of less than % by weight is particularly preferred for coating purposes.

The present invention will be explained below with reference to Examples. In the following, unless otherwise specified, parts and percentages are by weight.

Reference Example 1 10.0 g of an alcoholic hydroxyl group-containing polysiloxane represented by the structural formula (referred to as siloxane A) was thoroughly dried in chloroform 30', Omj, and pyridine 20. After adding 3.4 g of 4-toluenesulfonyl chloride while keeping the reaction temperature below 10° C., the mixture was stirred overnight at room temperature. Chloroform and pyridine were distilled off under reduced pressure, and the mixture was extracted with ether. The obtained organic layer was distilled off to obtain a viscous sulfonic acid ester of polysiloxane. 4.0 g of this initiator polysiloxane and 4.0 g of 2-methyl-2-oxazoline.
Og to acetonitrile 8. It was dissolved in Omλ and reacted at 90°C for 5 hours under nitrogen atmosphere.

The heating residue of the reaction solution (105°C x 3 hrs) was as expected, confirming that 100% of 2-methyl-2-oxazoline was polymerized. After cooling, a poly(N-acetylethyleneimine) grafted polysiloxane was obtained as a transparent pale yellow polymer with almost no fluidity.

Reference Example 2 2-Methyl-2-oxazoline 8 was prepared in the same manner as in Reference Example 1.
．． 0g was reacted to obtain poly(N-acetylethyleneimine) grafted polysiloxane as a transparent pale yellow polymer with almost no fluidity.

Example 1 852 parts of deionized water and 4 parts of the grafted polysiloxane obtained in Reference Example 1 were charged into a 2-A reaction vessel equipped with a stirrer, a cooler, a temperature control device, and a dropping funnel, and the temperature was raised to 80°C while stirring. 108 parts of methyl methacrylate, 144 parts of n-butyl acrylate,
A mixture of 104 parts of styrene and 44 parts of 2-hydroxyethyl acrylate and V-50 (Wako Pure Chemical Industries, Ltd.)
A solution of 4 parts of 2,2[deg.]-azobis(2-amidinopropane) hydrochloride, manufactured by Manufacturer Co., Ltd., dissolved in 80 parts of deionized water, was simultaneously added dropwise over 60 minutes. 30 minutes after dropping, a solution of 1 part of V-50 dissolved in 20 parts of deionized water was added dropwise over 30 minutes, and stirring was continued for 90 minutes at 80°C, resulting in a non-volatile content of 30.6% and a pH of 6. , viscosity 4
．． An acrylic resin emulsion of 2 cps (25° C.) and a particle size of 0.155 μm was obtained.

When this emulsion was filtered through a 400-mesh wire mesh, the amount of filtered matter was 0.3% (weight ratio to the charged monomer), and the amount of 'a aggregates produced was extremely small. Furthermore, this emulsion showed no aggregation or precipitation even after being stored at room temperature for 2 months, showing good stability over time.

Example 2-5 In the method for producing the emulsion of Example 1, the grafted polysiloxane of Reference Example 1.2 was used as the emulsifier as shown in Table 1, the raw material composition shown in Table 1 was used, and the same method and conditions were used. Various emulsions were obtained according to the following.

Table 2 shows the properties of this emulsion, the amount that did not pass through the 400-mesh wire mesh, and the stability over time after two months at room temperature.

Example 6 An emulsion was obtained according to the same method and conditions as in Example 1, except that ASP (manufactured by Wako Pure Chemical Industries, Ltd., ammonium persulfate) was used as an initiator.

Table 2 shows the properties of this emulsion, the amount that did not pass through the 400-mesh wire mesh, and the stability over time after two months at room temperature.

Example 7 240 parts of deionized water was charged into a one-pronged reaction vessel equipped with a stirrer, a cooler, a temperature control device, and a dropping funnel and heated to 80°C.
heated to. 218 parts of the grafted polysiloxane obtained in Reference Example 1, 44 parts of methyl methacrylate, 58 parts of n-butyl acrylate, 42 parts of styrene, 18 parts of 2-hydroxyethyl acrylate), and 162 parts of deionized water were mixed in advance by dispersion. and ■-50 (manufactured by Wako Pure Chemical Industries ■)
A solution of 0.9 parts dissolved in 18 parts of deionized water was added dropwise simultaneously over 60 minutes.

30 minutes after dropping, a solution of 2 parts of V-500 dissolved in 4 parts of deionized water was added dropwise over 30 minutes, and the mixture was heated to 80°C.
When stirring was continued for 90 minutes, the non-volatile content was 29.6%, p
H6, viscosity 6.1 cps (25°C), particle size 0.26
An acrylic resin emulsion of μ was obtained.

When this emulsion was filtered through a 400-mesh wire mesh, the amount of filtered matter was 0.3% (weight ratio to the charged monomer), and the amount of aggregates formed was extremely small. Further, this emulsion showed no agglomeration or precipitation even after being stored at room temperature for 2 months, showing good stability over time.

(Left below) For comparison purposes, an acrylic resin emulsion was prepared using a polyester resin emulsifier as described below, and its shelf life was investigated.

[Synthesis of polyester resin emulsifier]

134 parts of bishydroxyethyl taurine, 130 parts of neopentyl glycol, 236 parts of azelaic acid, 6 parts of 1 g of phthalic anhydride, and 27 parts of xylene were added to a 21-kolben equipped with a stirrer, a nitrogen inlet tube, a temperature control device, a condenser, and a decanter. Water produced by the zero reaction of charging and heating is azeotropically refluxed with xylene and removed. The temperature was raised to 190°C over about 2 hours from the start of reflux, and stirring and dehydration were continued until the acid value equivalent to carboxylic acid reached 145.
Cool to 0°C. Next, while maintaining the reaction temperature at 140°C, 314 parts of Cardura EIOJ (persatic acid glycidyl ester manufactured by Shell) was added dropwise over 30 minutes, and stirring was continued for 2 hours to complete the reaction. Polyester resin has an acid value of 59, a hydroxyl value of 90, and M
It was τ1054.

[Manufacture of emulsion]

In a reaction vessel equipped with a stirrer, a cooler, and a temperature control device, 306 parts of deionized water and 3 parts of the polyester resin obtained above were added.
1 part of dimethylethanolamine and 1 part of dimethylethanolamine were charged and dissolved while stirring while maintaining the temperature at 80°C, and 4.5 parts of azobiscyanovaleric acid was dissolved in 45 parts of deionized water and 4.3 parts of jetanolamine. Add. Then,
A mixed solution consisting of 72 parts of methyl methacrylate, 96 parts of -butyl acrylate, 72 parts of styrene and 30 parts of 2-droxyethyl acrylate was added dropwise over 60 minutes. After dropping, add 1.5 ml of azobiscyanovaleric acid.
1 part dissolved in 15 parts of deionized water and 1.4 parts of jetanolamine was added and stirred for 60 minutes at 80°C, resulting in a nonvolatile content of 41%, pH 7, and viscosity of 34 cps.
(25°C), an acrylic resin emulsion with a particle size of 0.204μ was obtained.

When this emulsion was filtered through a 400-mesh wire mesh, the amount of aggregates that did not pass through was 3.4% (weight ratio to monomer charged). Furthermore, the emulsion is kept at room temperature for 2
After being stored for several months, it curdled to a pudding-like consistency.

patent application agent

Claims (8)

[Claims] (1) In an acrylic resin emulsion in which a polymer of α,β-unsaturated monomers is stably dispersed in an aqueous medium using an emulsifier, the emulsifier has the formula ▲ mathematical formula, chemical formula, table, etc. Middle R_1 is the same or different carbon number 1~
18 alkyl or aryl groups; R_3, R_4,
R_5 is a hydroxyl group, an allyloxy group, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and 1 to 1 carbon atoms which may contain an ether and/or ester bond in the chain.
00 is the same or different monovalent organic group selected from terminal hydroxyalkyl groups; R_2 is an alkylene chain with 1 to 100 carbon atoms that may contain an ether and/or ester bond in the chain; R_6 is a carbon number that may contain a hydroxyl group 1
~40 alkyl, aralkyl, or aryl groups; k, l, and n are each the number of repeating units of siloxane, k>0, l≧1, n≧0, 2≦k+l+n≦20
00; p represents the degree of polymerization of N-acylethyleneimine, and is a poly(N-acylethyleneimine) grafted polysiloxane expressed as a real number within the range of 1≦p≦200. Characteristic acrylic resin emulsion. (2) The emulsion according to claim 1, wherein the nonvolatile content concentration is 60% by weight or less. (3) The amount of poly(N-acylethyleneimine) grafted polysiloxane used is 0.1 to 200 parts by weight per 100 parts by weight of the α,β-unsaturated monomer (Claim 1) Emulsion as described. (4) In the method for producing an acrylic resin emulsion, which involves emulsion polymerizing α,β-unsaturated monomers in an aqueous medium in the presence of a polymerization initiator, the formula ▲mathematical formula, chemical formula, table, etc. Yes▼ (In the formula, R_1 is the same or different carbon number 1~
18 alkyl or aryl groups; R_3, R_4,
R_5 is a hydroxyl group, an allyloxy group, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and 1 to 1 carbon atoms which may contain an ether and/or ester bond in the chain.
00 is the same or different monovalent organic group selected from terminal hydroxyalkyl groups; R_2 is an alkylene chain with 1 to 100 carbon atoms that may contain an ether and/or ester bond in the chain; R_6 is a carbon number that may contain a hydroxyl group 1
~40 alkyl, aralkyl, or aryl groups; k, l, and n are each the number of repeating units of siloxane, k>0, l≧1, n≧0, 2≦k+l+n≦20
00; p represents the degree of polymerization of N-acylethyleneimine; a real number within the range of 1≦p≦200) Use poly(N-acylethyleneimine) grafted polysiloxane. A method for producing an acrylic resin emulsion characterized by: (5) The method according to claim 4, wherein the nonvolatile content of the emulsion is set to 60% by weight or less. (6) Claim 4, wherein the amount of poly(N-acylethyleneimine) graft polysiloxane used is 0.1 to 200 parts by weight per 100 parts by weight of the α,β-unsaturated monomer. Method described. (7) Claim 4, wherein the aqueous medium is one in which poly(N-acylethyleneimine) grafted polysiloxane is dissolved in water or a water-water miscible organic solvent mixture system.
The method described in section. (8) The process according to claim 4, wherein the α,β-unsaturated monomer is premixed with poly(N-acylethyleneimine) grafted polysiloxane and an aqueous medium, and this is emulsion polymerized in the aqueous medium. Method.