JPH0629315B2 - Microspherical resin composition and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention is characterized by rapid curing by heating and good adhesion strength,
The present invention relates to a fine spherical resin composition composed of a resole resin and an epoxy resin capable of forming a cured coating film having impact resistance and excellent chemical resistance, and a method for producing the same.

<Prior art><Problems to be solved by the present invention> Fine powder of a curable resin is widely used as a powder coating material for a cured coating film. It has been desired to improve the mechanical properties such as adhesion strength, impact strength, and bending strength of the film and the chemical resistance to strong acids and strong alkalis.

It is known that the properties of the cured coating film of this epoxy resin can be greatly improved by mixing the resole resin, but in particular, uniform and intimate mixing of the epoxy resin and the phenol resin results in good curing. It is also known to be an important factor in the production of a coating film.

As a method for producing a resin composition composed of an epoxy resin and a resole resin, a solution method or a melting method has been conventionally known, but it is difficult to obtain a solid powder suitable for a powder coating by the solution method or the melting method, or Not only is it difficult to obtain a cured coating film with excellent physical properties, but there are various problems in the manufacturing process of powder and coating film, and improvements have been desired. For example, a solution method that can obtain a relatively good cured coating film is to obtain a cured coating film by dissolving and mixing a resole resin and an epoxy resin in a solvent, and then baking it while evaporating the solvent at high temperature. However, it is not suitable for the production of powder because it does not take out the mixed composition of resol resin and epoxy resin in the form of solid powder before curing. Moreover, this method has economic problems due to environmental pollution due to volatilization of a large amount of solvent and unrecovered solvent. On the other hand, in the melting method, as in Japanese Patent Publication No. 59-52657, the resol resin and the epoxy resin are melt-mixed and then pulverized into a solid powder and then a cured coating film. Since it was not good, the properties of the cured coating were not always satisfactory. Further, this method has a problem that not only a crushing step is required after the melting step, but also the powder shape is indefinite, the fluidity of the powder is poor, and it is difficult to handle.

The present invention has solved the conventional problems as described above, and a first object of the present invention is to provide a fine spherical resin composition comprising a resole resin and an epoxy resin, and a simple and economical production method thereof. To do.

A second object of the present invention is a fine spherical resin composed of a resole resin and an epoxy resin, which is excellent not only in heat reactivity and fluidity as a powder but also in physical properties of a cured coating film after heat curing. It is to provide a composition and a manufacturing method thereof.

<Means for Solving Problems> As a result of earnest research to solve such problems, the inventors of the present invention can achieve the object by emulsion-polymerizing a resole resin in the presence of an epoxy resin. And arrived at the present invention.

That is, the present invention comprises a fine spherical resin composition comprising a resole resin and an epoxy resin and having a spherical shape with a particle size of 500 μm or less, obtained by emulsion polymerization, and phenols and aldehydes in water. It is a method for producing a fine spherical resin composition having a spherical shape with a particle size of 500 μm or less, which is characterized by reacting in the presence of an epoxy resin and a basic catalyst in an amount of 40 to 200 wt% with respect to the class.

The present invention will be described in more detail below.

The fine spherical resin composition of the present invention composed of a resole resin and an epoxy resin has a substantially spherical shape with a particle size of 500 μm or less. The term "spherical shape" as used herein means a spherical ball shape obtained by emulsion polymerization, in which the surface of the particle is a closed curved surface having a convex surface, and is composed of a smooth mirror surface. The particle size and shape can be easily measured and observed by a magnified photograph with a vernier scale, but the fine spherical resin composition of the present invention is substantially spherical, unlike conventional molten and ground powders. It has a shape and a particle size of 5
Since it has a fine spherical shape of 00 μm or less, particularly 100 μm or less, it has good fluidity as a powder and is easy to handle. The ratio of the epoxy resin in the resin composition of the present invention is
40 to 20 with respect to phenols constituting the resole resin
It is 0 wt%, and particularly preferably 80 to 150 wt%.

Next, a method for producing a fine spherical resin composition of the present invention, which comprises a resole resin and an epoxy resin, will be described.

According to the method of the present invention, phenols and aldehydes are added in water in an amount of 40 to 20 with respect to emulsion stabilizer and phenols.
The reaction is carried out in the presence of 0 wt% epoxy resin and a basic catalyst.

The phenols used in the present invention are phenols and phenol derivatives. Examples of the phenol derivative include m-alkylphenols, o-alkylphenols and p-alkylphenols substituted with an alkyl group having 1 to 9 carbon atoms, specifically, Is m-cresol, p-ter-
Butylphenol, o-propylphenol, resorcinol, bisphenol A, and halogenated phenol derivatives in which some or all of the hydrogen atoms of these benzene nuclei or alkyl groups are substituted with chlorine or bromine,
These 1 type (s) or 2 or more types are used. The phenols are not limited to these, and any other compound containing a phenolic hydroxyl group can be used. Examples of aldehydes used in the present invention include formaldehyde and furfural in any form of formalin or paraformaldehyde, and the molar ratio of aldehydes to phenols is preferably 1 to 2 and particularly preferably 1.1 to 1.4.

As the emulsion stabilizer used in the present invention, a substantially water-insoluble inorganic salt having a solubility in water at 25 ° C. of not more than 0.2 g / or an organic protective colloid is used. Examples of the substantially water-insoluble inorganic salts include calcium fluoride, magnesium fluoride, strontium fluoride, calcium phosphate, magnesium phosphate, barium phosphate, aluminum phosphate, barium sulfate, calcium sulfate, zinc hydroxide, Aluminum hydroxide, iron hydroxide, etc. are mentioned, especially calcium fluoride,
Magnesium fluoride and strontium fluoride are preferred. The amount used is 0.2-10 wt.
%, Particularly 0.5 to 3.5 wt% is preferable. As a method for adding such substantially water-insoluble inorganic salts, these inorganic salts may be directly added to the reaction system before or during the reaction, but even if such inorganic salts are produced by a chemical reaction during the reaction. Well, for example, sodium fluoride, potassium fluoride,
It is also possible to add at least one selected from ammonium fluoride and at least one selected from chlorides, sulfates and nitrates of calcium, magnesium and strontium in a solid form or an aqueous solution thereof. When such an inorganic salt is used, the surface of the fine spherical resin composition obtained by the method of the present invention is coated with the ultrafine inorganic salt, so that coalescence during the resin production is prevented and the fine spherical resin composition is substantially spherical. Not only is it easy to obtain fine particles, but also the storage stability of the obtained fine spherical resin composition is significantly improved.

Examples of the organic protective colloid include gum arabic, gatch gum, hydroxylalkyl guar gum, and partially hydrolyzed polyvinyl alcohol. Further, the amount of the organic protective colloid used is preferably 0.2 to 10% by weight, particularly 0.5 to 3.5% by weight based on the phenols.

The present invention is carried out in an aqueous medium. In this case, the amount of water charged is 30 to 70 wt% as the solid content of the resin, especially 5
It is preferably in the range of 0 to 60 wt%.

The epoxy resin used in the present invention is a compound having two or more epoxy groups in one molecule, and a typical example thereof is a condensate of epichlorohydrin and a bisphenol compound, such as 2,2- Bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3,5
-Dichlorophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, bis (4
A condensate of a bisphenol compound represented by -hydroxyphenyl) methane and epichlorohydrin is preferable. The epoxy resin used in the present invention has a softening point of 50 to 1
It is preferably 40 ° C, particularly 65 to 130 ° C. If a softening temperature is too low or too high, it tends to be difficult to obtain a fine spherical resin composition. The amount used is 40 to 200 wt% with respect to phenols, and particularly preferably 8
It is 0 to 150 wt%.

Further, as the basic catalyst used in the present invention, a basic catalyst used in the production of ordinary resol resin can be used,
For example, there can be mentioned armonia water, hexamethylenetetramine and alkylamines such as dimethylamine, diethyltriamine and polyethyleneimine. The molar ratio of these basic catalysts to phenols is preferably 0.02 to 0.2.

In the production method of the present invention, for example, an epoxy resin is dissolved in phenols with stirring, and then aldehydes, a basic catalyst, an emulsion stabilizer and water are added, and the mixture is stirred at 0.
5 to 1.5 ℃ / min, preferably 75 to 9 at 0.8 to 1.2 ℃ / min
After gradually raising the temperature to 5 ° C., preferably 85 to 95 ° C., heating reaction is carried out at this temperature for 60 to 150 minutes, preferably 80 to 120 minutes. Then, when cooled to 40 ° C. or lower, an aqueous emulsion of the resin composition solidified into microspheres is produced.
The target microspherical resin composition is taken out by solid-liquid separation, washing and drying.

The method of the present invention can be carried out by either a continuous method or a batch method, but is usually carried out by the batch method.

In the method of the present invention, when reacting phenols and aldehydes in water in the presence of an emulsion stabilizer, an epoxy resin, and a basic catalyst, a flame retardant such as phosphorus, an inorganic filler such as talc, or a foaming agent is used as necessary. Various additives such as agents can be made to coexist.

The microspherical resin composition comprising the resole resin and the epoxy resin of the present invention includes a thermoplastic resin, a thermosetting resin, a flame retardant, a foaming agent, a reinforcing agent, a filler, an extender, a leveling agent, if necessary. Additives such as flow regulators, stabilizers, antistatic agents, electrical conductors or dyes and pigments can be added.

Examples of thermoplastic resins include polyethylene, polypropylene, polystyrene, rubber-modified polystyrene, A
Polyolefin such as S, ABS, polyvinyl chloride, polymethylmethacrylate, ethylene-vinyl acetate copolymer, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyester such as polyarylate, polycaprolactam, polyhexamethylene adipamide, etc. Examples thereof include polyamide, polysulfone, polyphenylene sulfide and the like.

Examples of the thermosetting resin include melamine resin, urea resin, furan resin, alkyd resin, unsaturated polyester resin and the like.

Examples of flame retardants include halogen compounds such as decabromodiphenyl ether, antimony trioxide,
Examples thereof include inorganic and organic phosphorus compounds.

Examples of the reinforcing agent, filler, extender and the like include glass fiber, asbestos fiber, carbon fiber, metal fiber, quartz, mica, asbestos, kaolin, aluminum oxide, silica, aluminum hydroxide, antimony trioxide and the like. Examples of other additives include titanium oxide, iron oxide, aluminum powder, iron powder, metal soap, carbon black, wood powder, paper and the like.

<Examples> Hereinafter, the present invention will be specifically described with reference to Examples.

Example 1 In a three-necked flask of 1, 100 g of phenol and an epoxy resin (Yukaka Shell Co., Ltd. Epicoat 1001 softening point 68) were used.
100 ° C), and the mixture was heated and stirred at 80 ° C for 60 minutes to dissolve the epoxy resin in phenol and then cooled to 50 ° C.

Next, 100 g of 37 wt% formalin, 140 g of water, 9.0 g of hexamethylenetetracin, 8.4 g of calcium chloride and 5.8 g of potassium fluoride were added, the temperature was raised to 90 ° C over 40 minutes, and then the mixture was stirred at the same temperature for 90 minutes. The reaction was carried out separately to obtain an emulsion of the resin composition. Next, the contents of the flask were cooled to 40 ° C., the supernatant was removed, and the microsphered resin particles in the lower layer were washed with water and air dried. Then, it is dried under reduced pressure (5 mmHg or less) at 60 ° C, and the average particle size is 50μ.
m spherical resin particles having a spherical shape (resin A
Called).

Example 2 The reaction was performed in the same manner as in Example 1 except that the epoxy resin of Example 1 was replaced with Epicoat 1007 (softening point 128 ° C.) manufactured by Yuka Shell Epoxy Co., Ltd. Post-treatment, average particle size 5
0 μm-shaped spherical microscopic resin composition particles were obtained (referred to as resin B).

Example 3 140 g of phenol, 60 g of epoxy resin (Epicoat 1001 of Yuka Shell Epoxy Co., softening point 68 ° C.), 3
7wt% formalin 140g, hexamethylenetetramine
12.6g, calcium chloride 8.4g and potassium fluoride 5.8g
After the reaction was carried out in the same manner as in Example 1 except that the composition was changed to, post-treatment was performed to obtain fine spherical resin composition particles having a spherical shape with an average particle diameter of 50 μm (referred to as resin C).

Comparative Example 1 100 g phenol, 37 wt% formalin 100 g, and 20 wt% caustic soda aqueous solution 30 g were placed in the three-necked flask of 1.
Was added under stirring, the temperature was raised to 70 ° C., and stirring was continued for 30 minutes at this temperature. Subsequently, the mixture was cooled to 40 ° C., 10 g of 25 wt% aqueous ammonia was added, the mixture was again heated to 70 ° C., and stirring was continued for 2 hours. The obtained product was cooled to 40 ° C., the solid was separated by filtration, washed with water, and subsequently dried at 60 ° C. under reduced pressure (50 mmHg) to obtain a solid resol resin.

Next, 50 parts by weight of this solid resol resin and 50 parts by weight of epoxy resin (Epicoat 1001) were melt extruded at 70 ° C. using an extruder, cut and pelletized, and further crushed by a crusher, A powder with a particle size that passed through a mesh screen was obtained (designated Resin D).

Comparative Example 2 Phenol 200 g, 37 wt% formalin 200 g, water 140 g, hexamethylenetetramine 18 g, and calcium chloride 8.4 g were charged into a three-necked flask of 3 with stirring to make a uniform solution, and 5.8 g of potassium fluoride was added thereto. After the addition, the temperature was raised to 85 ° C. over 60 minutes, and stirring was continued at the same temperature for 80 minutes. After the completion of the reaction, the contents were cooled to 40 ° C. to produce solid fine spherical resol resin. This was separated by filtration, washed with water, and dried to obtain a fine spherical resole resin having an average particle size of about 50 μm. 100 g of this resol resin and 100 g of epoxy resin (Epicoat 1001) were mixed and then pulverized with a ball mill to obtain a powder mixture that passed through a 140-mesh sieve (referred to as resin E).

Reference Examples 1 to 5 Resins A to E obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were baked and coated on mild steel plates, and the physical properties of the obtained cured coating films were determined according to JIS-5.
The results of measurement based on 400 are shown in Table 1.

It should be noted that the coating film was formed on a mild steel plate degreased using an electrostatic coating machine so as to have a dry thickness of 50 μm.
Baking for 10 minutes at 0 ° C.

As is clear from Table 1, good cured coating films were obtained from the resins A to C of the present invention, but the cured coating films made from the resins D and E had poor physical properties, and particularly those of the resin E were remarkable. It was inferior. The resin D tended to be clogged at the supply port to the electrostatic coating machine and was difficult to handle.

<Effects of the Present Invention> The fine spherical resin composition of the present invention composed of the resole resin and the epoxy resin has a composition in which the phenol resin and the epoxy resin are extremely uniformly dispersed. Therefore, the cured coating film obtained therefrom is excellent. It has excellent strength, adhesion, hardness and chemical resistance. Further, the microspherical resin composition of the present invention rapidly cures at a temperature of 150 ° C. or higher and has excellent curability. Furthermore, the microspherical resin composition of the present invention not only has a substantially spherical shape, but also has a particle size of 5
It has a diameter of less than 00 μm and is therefore excellent in fluidity as a powder and easy to handle.

The production method of the present invention is applied to the use of a resin composition composed of a resol resin and an epoxy resin in the form of powder, for example,
It provides a fine spherical powder suitable for applications such as electrostatic powder coating by a simple and economical method, which is extremely industrially significant.

The microspherical resin composition of the present invention is used in various applications by taking advantage of its features. For example, protective coatings for can inner surfaces such as drum cans and pipe inner surfaces, electrical insulating coatings, adhesives,
It can be widely applied to high-temperature curing applications such as binders and molding materials.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication location C09D 163/00 PKH 8830-4J (72) Inventor Tadashi Ishikura 23 Uji Kozakura Uji-shi, Kyoto Unitika stock Inside the Central Research Laboratories of the ceremony company (72) Ritsuko Yotei 23 Uji Kozakura, Uji-shi, Kyoto Unitika Co., Ltd. Yoshihiro Fuji (56) Kai 59-204614 (JP, A) JP 60-99119 (JP, A) JP 58-183730 (JP, A) JP 59-52657 (JP, B2) JP 56-8845 ( JP, B2) JP 54-6080 (JP, B2)

Claims (5)

[Claims] 1. A fine spherical resin composition comprising a resole resin and an epoxy resin, obtained by emulsion polymerization and having a spherical shape with a particle size of 500 μm or less. 2. The proportion of epoxy resin in the resin composition is
40 to 2 with respect to phenols constituting the resole resin
The fine spherical resin composition according to claim 1, wherein the composition is 00 wt%. 3. The microspherical resin composition according to claim 1 or 2, wherein the epoxy resin is an epoxy resin having a softening point of 50 to 140 ° C. 4. Phenols and aldehydes in water are emulsion stabilizers, and 40 to 200 relative to phenols.
A method for producing a fine spherical resin composition having a true spherical shape with a particle size of 500 μm or less, which is characterized by reacting in the presence of wt% of an epoxy resin and a basic catalyst. 5. The production method according to claim 4, wherein the epoxy resin is an epoxy resin having a softening point of 50 to 140 ° C.