JPS6213965B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a nonaqueous resin dispersion useful for paints, adhesives, electrostatic liquid developers, and the like. It is well known that polyfunctional acrylic esters or polyfunctional methacrylic esters are polymerized by organic peroxides, heat, ultraviolet rays, radiation, etc. to form cured products with a three-dimensional structure. Utilizing its properties, it has been used to make paints, FRP, adhesives, etc. solvent-free and to modify them, printing inks, photocurable rubbers such as plywood coating resins, and crosslinking agents for plastics. An object of the present invention is to obtain a non-aqueous resin dispersion that is low in toxicity and flammability, has improved dispersibility for pigments, and has dispersion stability. That is, the present invention is directed to polymerization of the general formula (Here, R represents hydrogen or a methyl group, and n represents an integer from 6 to 20.) Monomer represented by (hereinafter referred to as monomer A)
and polyfunctional acrylic ester and/or polyfunctional methacrylic ester (hereinafter referred to as monomer B).
The present invention provides a method for producing a non-aqueous resin dispersion, characterized by carrying out a polymerization reaction with This polymerization reaction is carried out while heating the solvent to reflux. Through this reaction, monomer A and monomer B
A copolymer resin having a three-dimensional structure in which both components are crosslinked to each other in a network-like manner is obtained. Here, the monomer B itself has the property that it is solvated with a petroleum aliphatic hydrocarbon or its halide solvent before polymerization, but is not solvated with this solvent after polymerization. On the other hand, monomer A itself has the property of being solvated with the solvent both before and after polymerization. Therefore, it is considered that the resulting resin is dispersed in a solvent in a state where the monomer B component and the monomer A component solvated with the solvent are bonded around the monomer B component. The monomer A component in the resin contributes to dispersion stability (including dispersion stability to other substances such as pigments) and adhesiveness. Further, the ratio of monomer B to monomer A is suitably about 0.01 to 1:1 (by weight). In the present invention, fine silica particles, wax or polyolefin having a softening point of about 60 to 180°C can be added to the resin dispersion manufacturing process. When fine silica particles are used, it is thought that the resin is obtained with the fine silica particles incorporated in its network structure. In this case, the silica itself, of course, does not undergo physical changes such as dissolution during the reaction. In any case, in the case of silica, the specific gravity should be similar to that of the aliphatic hydrocarbon or its halide, which is the dispersion medium;
By preventing gelation of the resin, 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 into fine particles by cooling, and the resin is obtained in a state that is adsorbed to these fine particles. it is conceivable that. Here, wax or polyolefin has a specific gravity similar to that of the dispersion medium, prevents the resin from gelling, and has a molecular structure similar to that of the dispersion medium.
It not only helps improve dispersion stability, but also helps improve adhesiveness because it has a low softening point. The amount of silica, wax, or polyolefin added depends on the resin.
Approximately 5 to 50 parts by weight per 100 parts by weight is appropriate. Next, the materials used in the present invention will be explained. The petroleum aliphatic hydrocarbons or their halides used in the present invention include ligroin, n-hexane, n-pentane, n-heptane, n-octane, i-octane, i-dodecane, i-nonane (the above). Commercially available products include Isopar H, G, L, K (Naphtha No. 6 manufactured by Exxon Corporation, Ciel Sol manufactured by Shell Oil Co., etc.), carbon tetrachloride, perfluoroethylene, and the like. These aliphatic hydrocarbons have a higher flash point than aromatic solvents such as benzene and toluene, and are also less toxic. Since the solubility of the resin of the present invention is poorer than that of aromatic solvents, it also has the advantage that the resin does not gel or solidify during the polymerization reaction or during storage. These petroleum-based aliphatic hydrocarbons have high insulating properties (electrical resistance of 10 ^{to 10}
It is a solvent with a low dielectric constant (dielectric constant of 3 or less). These aliphatic solvents also include benzene,
A small amount of an aromatic solvent such as toluene may be added. Next, specific examples of monomer A include lauryl methacrylate, lauryl acrylate, stearyl methacrylate, stearyl acrylate, 2
-Ethylhexyl methacrylate, 2-ethylhexyl acrylate, dodecyl methacrylate,
Dodecyl acrylate, hexyl methacrylate, hexyl acrylate, octyl methacrylate, octyl acrylate, cetyl methacrylate, cetyl acrylate, vinyl laurate,
Examples include vinyl stearate. Examples of monomer B include 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, tetramethylolmethanetetraacrylate, tetramethylolmethanetetramethacrylate, dipropylene glycol diacrylate , dipropylene glycol dimethacrylate, trimethylolhexane triacrylate, trimethylolhexane trimethacrylate, pentaerythritate tetraacrylate, pentaerythritate tetramethacrylate, 1,3-butylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, trimethyl Examples include methylolethane triacrylate and trimethylolethane methacrylate. As a polymerization initiator, benzoyl peroxide, t-
Butyl perbenzoate, diamyl peroxide, di-t-butyl peroxide, lauryl peroxide, azobisisobutyronitrile, etc. can be used. Further, specific examples of commercially available waxes or polyolefins are as follows.

[Table] Tsukusu

[Table] Examples are shown below. Example 1 300 g of Isopar G was placed in a second flask equipped with a stirrer, a thermometer, and a reflux condenser, and heated to 90°C. Lauryl methacrylate 170 in this
g, diethylene glycol dimethacrylate 80g
A solution consisting of 3 g of benzoyl peroxide was added dropwise over 2 hours to cause a polymerization reaction, and then to complete the reaction, the mixture was stirred at 95°C for 2 hours to achieve a polymerization rate of 96.2.
%, a resin dispersion with a viscosity of 360 cp was obtained. The particle size of this resin was 5 to 8 microns. Example 2 250 g of the resin dispersion obtained in Example 1 was mixed with 20 g of polyethylene (DYNF manufactured by Union Carbide) in a flask, heated and dissolved at 110°C for 3 hours, and then cooled to obtain a polyethylene-containing resin dispersion with a viscosity of 120 cp. I got the liquid. The particle size of this resin was 3 to 5 microns. Example 3 300 g of isooctane was placed in the same container as in Example 1 and heated to 95°C. Next, add 170 g of cetyl methacrylate, 50 g of dipropylene glycol dimethacrylate and 5 g of azobisisobutyronitrile.
A solution consisting of 10 g was added dropwise over 1 hour to cause a polymerization reaction, and the reaction was further heated at 95° C. for 3 hours to complete the reaction. In this way, a resin dispersion with a polymerization rate of 98.5% and a viscosity of 290 cp was obtained. The particle size of this resin was 3 to 5 microns. Example 4 250 g of the resin dispersion obtained in Example 3 was mixed with 18 g of bleached beeswax in a flask, heated and stirred at 100°C for 2 hours, and then cooled to form a resin dispersion containing bleached beeswax with a viscosity of 108 cp. Prepared. The particle size of this resin was 2.0 to 3.8μ. Example 5 In the same container as in Example 1, 300 g of isooctane and 10 g of silica powder with a viscosity of 0.5 to 1 μm were placed and heated to 95°C. This contains 150 g of 2-ethylhexyl methacrylate, 50 g of trimethylolpropane triacrylate, and 5 g of azobisisobutyronitrile.
A solution consisting of 1.g was added dropwise over 2 hours to cause a polymerization reaction, and the reaction was further stirred at 95° C. for 2 hours to complete the reaction. In this way, the polymerization rate is 96.5% and the viscosity is
A resin dispersion of 89 cp was obtained. The particle size of this resin was 1 to 3 microns. Example 6 Isopar L300 was added to the same flask as in Example 1.
g and polyethylene (Sunwax 131-P) 50
g and heated to 95°C. Next, a solution consisting of 150 g of stearyl methacrylate, 21 g of tetramethylolmethanetetramethacrylate, and 5 g of lauryl peroxide was added dropwise to the solution at the above temperature for 1 hour to cause a polymerization reaction, and then further heated at the same temperature for 3 hours to react. completed. In this way, a resin dispersion with a polymerization rate of 95.8% and a viscosity of 118 cp was obtained. The particle size of this resin was 3 to 4 microns.

Claims (1)

[Scope of Claims] 1. In the presence of a polymerization initiator in a solvent containing a petroleum-based aliphatic hydrocarbon as a main component, the general formula (However, R represents hydrogen or a methyl group, and n represents an integer of 6 to 20.) Monomer A represented by : A method for producing a non-aqueous resin dispersion, characterized by carrying out a polymerization reaction at a weight ratio of monomer A = 0.01 to 1:1.