JPH0618833B2 - Method for producing non-aqueous resin dispersion - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a non-aqueous resin dispersion liquid which is useful for paints, adhesives, toners for electrophotographic liquid developers, and the like.

Prior art A polyhydric alcohol diacrylate such as diethylene glycol dimethacrylate and a polymerizable monomer such as lauryl acrylate are polymerized in an aromatic hydrocarbon solvent such as toluene, benzene, or xylene in the presence of a polymerization initiator to carry out a copolymerization reaction. Methods for producing polymeric resins are known.
The resin thus obtained has been widely used for paints and adhesives. However, since the aromatic hydrocarbon solvent is used in the method for producing such a resin (solution), the crosslinking of the resin is likely to proceed, and the resin gels during the polymerization reaction, or the resin solidifies during storage. was there. The same applies to the case where this non-aqueous resin is used for paints and adhesives, and the adhesive strength is reduced due to solidification during storage. Therefore, in order to solve these problems, conventionally, the amount of polyfunctional acrylic acid ester such as polyhydric glycol diacrylate was set to 3
It was necessary to keep it below the weight percent. Even if the above problems are solved in this way, the resin is soluble in the aromatic solvent and therefore obtained in a dissolved state. However, it is not desirable especially when used in an electrodeposition coating because the adhesive strength is insufficient.

Furthermore, the aromatic solvent used in this method is highly toxic and flammable, and thus not only poses a problem in terms of environmental hygiene, but also has a problem of a high risk of fire.

The purpose of the present invention is to use a aliphatic solvent which has almost no toxicity and flammability, low solubility in the resin to be obtained, and which is photochemically inactive, thereby eliminating the rapid crosslinking reaction during the polymerization. It is an object of the present invention to provide a method for producing a non-aqueous resin dispersion liquid, which facilitates the control of the process, improves the preservability, does not lower the adhesive strength, has less problems in environmental hygiene, and has less risk of fire. .

Structure The method for producing a non-aqueous resin dispersion according to the present invention comprises the general formula I in the presence of a polymerization initiator in a non-aqueous solvent containing an aliphatic hydrocarbon as a main component. (Wherein R is hydrogen or a methyl group, X is hydrogen, chlorine, bromine or iodine) and a compound represented by the general formula II {However, R'is hydrogen or a methyl group, A is -COOC _n H
_{2n + 1} or —OCOC _n H _{2n + 1} (n is an integer of 6 to 20)} in the presence or absence of a polar monomer and / or other reactive monomer. It is a feature.

The polymerization reaction of the present invention generally involves heating the non-aqueous solvent,
A mixed monomer liquid containing the monomer represented by the general formula I (hereinafter referred to as the monomer A), the monomer represented by the general formula II (hereinafter referred to as the monomer B) and a polymerization initiator is dropped therein. In this polymerization reaction, the monomer A, that is, dicyclopentenyl (meth) acrylate, has a vinyl group in the molecule, which is easily polymerized with another monomer, and a double bond, which is easily reacted with an oxygen atom, a hydrogen atom, etc. The copolymer resin obtained by the difference in reactivity of the two functional groups is given a partially crosslinked structure to be water-solubilized, while the monomer B is solvated in the non-aqueous solvent even after the polymerization, so that the resin has solubility. As a result, it particularly contributes to the dispersion stability of the resin.

Here, the ratio of the monomer A and the monomer B is 1: 1 to 99
(Weight) is appropriate.

Further, polar monomers and other reactive monomers can be added and copolymerized as other polymerizable monomers (hereinafter referred to as monomers C) to these monomers A and B, if necessary.

In the above polymerization reaction, silica fine particles and softening point 60
Wax or polyolefin at about 130 ° C can be added. When silica fine particles are used, it is considered that the resin is obtained in a state where the silica fine particles are incorporated in the crosslinked structure. In this case, the silica itself, of course, is not subjected to physical changes such as dissolution during the reaction. In any case, in the case of silica, the specific gravity is similar to that of the aliphatic hydrocarbon which is the dispersion medium, and the gelation of the resin is prevented, whereby the dispersion stability can be further improved. on the other hand,
When wax or polyolefin is used, these are dissolved in the reaction system by heating during the polymerization reaction, but after the reaction, they are precipitated in the form of fine particles by cooling, and the resin is obtained in the state of being adsorbed by these fine particles. Conceivable. Here, the wax or polyethylene has a specific gravity similar to that of the dispersion medium and prevents gelation of the resin, and since the molecular structure is similar to that of the dispersion medium, it not only helps to improve dispersion stability, but also has a low softening point. It also helps improve adhesion. The amount of silica, wax or polyolefin added is appropriately 5 to 50 parts by weight per 100 parts by weight of the resin obtained.

Next, the materials used in the present invention will be described.

First, examples of the dicyclopentenyl (meth) acrylate of the monomer A include the following.

Although these compounds are easily available as commercial products, they can be easily produced according to known methods.

Monomer B has the general formula II [Wherein R 'is hydrogen or a methyl group, A is -COOC _n' H _2n '
_+1, or -OCOC _n 'H _{2n' + 1} (although n 'is 6-20 integer) are shown, respectively. ] Specific examples thereof include lauryl methacrylate, lauryl acrylate, stearyl methacrylate, stearyl acrylate, 2-ethylhexyl methacrylate, 2-ethylhexyl acrylate, dodecyl methacrylate, dodecyl acrylate, hexyl methacrylate, hexyl acrylate, octyl acrylate. , Octyl methacrylate,
Examples include cetyl methacrylate, cetyl acrylate, vinyl laurate and vinyl stearate.

Next, among the monomers C, specific examples of polar monomers include unsaturated carboxylic acids, unsaturated carboxylic acid anhydrides, unsaturated nitrogen-containing compounds, glycidyl group-containing unsaturated compounds, and alkyl acrylate (C1-5) esters. And / or alkyl methacrylate (C1-5) ester and the like. Examples of unsaturated carboxylic acids and their anhydrides include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, crotonic acid, aconitic acid, cinnamic acid and their anhydrides. Examples of unsaturated nitrogen-containing compounds include vinylpyrrolidone, 2-vinylpyridine, 4-vinylpyridine, N-vinylpyridine and N.
-Vinylimidazole, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, etc. are exemplified, and as the alkyl (C1-5) ester of acrylic acid or methacrylic acid, methyl acrylate,
Examples include methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate and the like. Further, as the glycidyl group-containing unsaturated compound, glycidyl acrylate and glycidyl methacrylate are typically exemplified.

Other reactive monomers of the monomer C include styrene, vinyltoluene, vinyl acetate, polyhydric alcohol dimethacrylate (for example, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol methacrylate, triethylene glycol triacrylate, Triethylene glycol trimethacrylate, butanediol diacrylate, butanediol dimethacrylate, 1,6-hexanediol diacrylate,
1,6-hexanediol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, tetramethylolmethane triacrylate, tetramethylolmethane trimethacrylate, tetramethylolmethane tetraacrylate, tetramethylolmethane tetramethacrylate, dipropylene glycol diacrylate , Dipropylene glycol dimethacrylate, trimethylolhexane triacrylate, trimethylolhexane trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, 1,3-butylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, tri Methylolethane triacrylate, trimethylol Ethane methacrylate) and the like.

Benzoyl peroxide, t-butyl perbenzoate, diamyl peroxide, di-t-butyl peroxide, lauryl peroxide, and azobisisobutyronitrile can be used as the polymerization initiator.

Specific examples of commercially available wax or polyolefin having a softening point of 60 to 130 ° C. are as follows.

Next, petroleum-based aliphatic hydrocarbons or halogenated aliphatic hydrocarbons are used as the non-aqueous solvent. Specifically, ligroin, n-hexane, n-pentane, n-heptane, n-
Octane, i-octane, i-dodecane, i-nonane (these commercial products are Isopar H, G, L,
K; naphtha No. 6 and shell sol manufactured by Shell Oil Co., Ltd.), carbon tetrachloride, perfluoroethylene and the like. These aliphatic hydrocarbons or halogenated aliphatic hydrocarbons have higher flash points and weaker toxicity than aromatic solvents such as benzene and toluene. Since the solubility of the resin of the present invention in the resin is lower than that of the aromatic solvent, it is also characterized in that gelation or solidification of the resin hardly occurs during the polymerization reaction or storage. Note that these petroleum-based aliphatic hydrocarbons or halogenated aliphatic hydrocarbons have a high insulating property (electrical resistance 10 ¹⁰ Ω · cm
Above), a solvent having a low dielectric constant (dielectric constant of 3 or less). Aromatic solvents such as benzene and toluene may be added to these aliphatic solvents in small amounts.

Examples will be shown below.

Example 1 300 g of isooctane was placed in a 2.0 four-necked flask equipped with a stirrer, a thermometer and a reflux condenser, and heated to 95 ° C. 190 g of dodecyl methacrylate,
A solution consisting of 10 g of the compound of No. 4 and 6 g of azobisisobutyronitrile was added dropwise over 3 hours, and then the mixture was stirred at the above temperature for 4 hours to carry out a polymerization reaction.
% To obtain a resin dispersion having a viscosity of 320 cp.

The particle size of the resin was 0.10 to 0.20 μ.

Example 2 300 g of the resin dispersion obtained in Example 1 was mixed with 10 g of colloidal silica in a flask, heated at 100 ° C. for 3 hours and then cooled to have a viscosity of 360 cp and a colloidal silica having a particle size of 0.15 to 0.26 μ. A resin dispersion containing resin was obtained.

Example 3 300 g of isododecane was placed in the same flask as in Example 1,
Heated to 90 ° C. Then, a solution containing 300 g of lauryl methacrylate, 5 g of N-vinylpyridine, 25 g of the compound of No. 5 and 3 g of benzoyl peroxide was added to 1.
After dropping for 5 hours, the mixture was stirred at the above temperature for 4 hours to carry out a polymerization reaction, and the polymerization rate was 96.0%, the viscosity was 350 cp, and the particle size was 0.07.
A resin dispersion of ˜0.18 μ was obtained.

Example 4 300 g of the resin dispersion obtained in Example 3 was mixed with 20 g of squeezed wax in a flask, stirred at 95 ° C. for 22 hours, and then cooled to a squeeze density of viscosity 430 cp and particle size of 0.10 to 0.30 μ. A wax-containing resin dispersion was obtained.

Example 5 300 g of Isopar G and 30 g of colloidal silica were placed in the same flask as in Example 1 and heated to 90 ° C. In this, 150 g of 2-ethylhexyl methacrylate, 15 g of glycidyl methacrylate and 20 g of the compound of No. 5 were added.
g, 40 g of methyl methacrylate and 6.3 g of lauroyl peroxide were added dropwise, and the mixture was further stirred at the above temperature for 4 hours to carry out a polymerization reaction, and a resin dispersion having a polymerization rate of 96.0% and a viscosity of 420 cp and a particle size of 0.25 to 0.42 μ. A liquid was obtained.

Example 6 300 g of Isopar L and 60 g of polyethylene (AC-6 manufactured by Allied Chemical Co.) were placed in the same flask as in Example 1 and heated to 95 ° C. Next, a solution of 180 g of stearyl methacrylate, 40 g of lauryl methacrylate, 3 g of fumaric acid, 20 g of the compound of No. 4 and 4 g of lauryl peroxide was added dropwise over 3 hours, and the mixture was stirred at the above temperature for 3 hours. Carry out polymerization reaction,
A resin dispersion having a polymerization rate of 97.2% and a viscosity of 260 cp and a particle size of 0.20 to 0.40 μm was obtained.

Example 7 In the same flask as in Example 1, 300 g of Isopar H, 180 g of cetyl methacrylate, 40 g of dodecyl acrylate were used.
g, 15 g of the compound of No. 5 above, 5 g of acrylic acid and 3 g of benzoyl peroxide were taken, and the mixture was stirred at 90 ° C. for 6 hours to carry out a polymerization reaction. The polymerization rate was 93.8%, the viscosity was 220 cp, and the particle size was 0.2.
A resin dispersion of 0 to 0.40 μm was obtained.

Examples 8 to 15 Resin dispersions having the properties shown in Table 2 were prepared in the same manner as in Example 7 except that the materials shown in Table 1 below and the reaction conditions shown in Table 2 below were used.

Example 16 In the same reactor as in Example 1, 300 g of isooctane, 100 g of lauryl methacrylate, and 50 g of the compound of No. 5 above.
And take 5g of benzoyl peroxide, 1 at 90 ℃
After heat-polymerizing for 0 hours, a solution of 50 g of 2-ethylhexyl methacrylate, 10 g of glycidyl methacrylate and 1 g of benzoyl peroxide was added to this polymer, and the solution was added dropwise at the above temperature for 2 hours, followed by stirring at this temperature for 3 hours. Then, the polymerization reaction is further carried out, and the polymerization rate is 9
A resin dispersion having a viscosity of 600 cp and a particle size of 0.30 to 0.50 μm was obtained at 3.0%.

Example 17 A resin dispersion having a viscosity of 520 cp and a particle size of 0.50 to 1.00 μ was obtained in the same manner as in Example 16 except that 2-ethylhexyl methacrylate was used instead of lauryl methacrylate and methacrylic acid was used instead of glycidyl methacrylate. It was
The polymerization rate was 96.0%.

Effects As described above, in the method of the present invention, since an aliphatic solvent is used as a reaction solvent, rapid cross-linking at the time of polymerization is eliminated, the control of the polymerization process is facilitated, and storage stability is improved, resulting in a decrease in adhesive strength. Moreover, the working environment is improved and the risk of fire is reduced.

Claims (1)

[Claims] 1. A compound represented by the general formula I in the presence of a polymerization initiator in a non-aqueous solvent containing an aliphatic hydrocarbon as a main component. (Wherein R is hydrogen or a methyl group, X is hydrogen, chlorine, bromine or iodine) and a compound represented by the general formula II {However, R'is hydrogen or a methyl group, A is -COOC _n H
_{2n + 1} or —OCOC _n H _{2n + 1} (n is an integer of 6 to 20)} in the presence or absence of a polar monomer and / or other reactive monomer. A method for producing a characteristic non-aqueous resin dispersion.