JPH0432097B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing epoxy resin-based spherical particles suitable for use in powder adhesives and powder coatings.

[Prior art] A method of blending an epoxy resin with an organic polymer with much lower rigidity, such as polyamide, to improve the peel strength, which is a disadvantage, without reducing the shear adhesive strength, which is an advantage of epoxy resin. Techniques for this are well known. A typical example of this method is a method in which a direct mixture or solution of the epoxy resin and the organic polymer is applied to the adherend, regardless of the compatibility between the two. Furthermore, as another typical example, there is a technique in which a lump of a mixture of an epoxy resin and an organic polymer is mechanically pulverized into a powder, and the resulting material is used as a powder adhesive or a powder coating agent.

[Problems to be Solved by the Invention] However, if there is no compatibility between the epoxy resin and the organic polymer, the larger the phase separation structure becomes, the smaller the particles are ground, the more the epoxy contained in each particle becomes. There is a problem in that the blending ratio of resin and organic polymer varies.

Another problem is that mechanical pulverization yields only amorphous particles.

The present invention aims to solve the above-mentioned problems, and provides a method for producing epoxy particles that are microspherical and have no structural variation.

[Means for Solving the Problems] In order to achieve the above object, the present invention has the following configuration.

``A method for producing epoxy-based spherical fine particles having a sea-island-like phase separation structure, which is characterized by comprising the following steps A to C.

(b) A process of making a mixture consisting of at least an epoxy resin and an organic polymer into a compatible solution.

(b) A process of emulsifying the compatible solution into an emulsifying medium.

C. A process of phase-separating the epoxy resin component and organic polymer component within the particles. ” The details of the present invention will be sequentially explained below.

The epoxy resin used in the present invention preferably contains two or more epoxy groups in its molecule.

Examples of those containing two epoxy groups include bisphenol resins such as bisphenol A, B, F, S, and H, especially those with n=0 to 30 as adducts;
Examples include dimer acid-modified bisphenols, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and alicyclic epoxy resins. Those having three or more epoxy groups include polyglycidyl ethers of phenol novolak type compounds and N,N, ^N- ,N ^- tetraglycidyl-m-xylene diamine.

In the present invention, epoxy resins containing two epoxy groups, especially bisphenol resins, are preferably used from the viewpoint of compatibility with latent curing agents, which will be described later. - Monofunctional epoxy compounds such as ethylhexyl glycidyl ether are often used as a secondary compound in the bifunctional epoxy resin. When a mixture of an epoxy resin, an organic polymer, and a latent curing agent (described below) exhibits a liquid or sticky state at room temperature, it must be solidified in advance by partially curing (B
In this case, special care should be taken to prevent cross-linking at the B stage.
It is preferable that the epoxy resin with higher functionality is used only partially. When a monofunctional epoxy compound is used in a large amount, the degree of polymerization after curing tends to decrease.

The organic polymer used in the present invention is preferably an essentially linear polymer with a glass transition temperature of 80° C. or lower. When the glass transition temperature is higher than this, there is a tendency that the effect of improving the hardness of the epoxy resin and the peel adhesion strength decreases.
In addition, in the present invention, it is necessary to temporarily form a compatible solution of the epoxy resin and the organic polymer, so the organic polymer may be directly dissolved in the epoxy resin,
It must be soluble in organic solvents.

Examples of organic polymers used in the present invention include:
Examples include polyamides, especially amorphous polyamides, polyesters, especially amorphous polyesters, polyvinyl acetate and copolymers, polyvinyl formal and butyral, polyvinyl ethers, acrylic polymers and copolymers, butadiene rubbers, and the like.

In the present invention, the compounding ratio is particularly preferably achieved when the epoxy resin is 30 to 95% and the organic polymer is 5 to 70 wt%, and the epoxy resin is 40 to 90 wt% and the organic polymer is 10 to 60 wt%. 30wt of epoxy resin
%, the particles are generally too soft;
Additionally, adhesive strength is reduced. In addition, epoxy resin
If it exceeds 95 wt%, the modification effect by the organic polymer is difficult to appear.

In the present invention, the epoxy resin and the organic polymer must be able to temporarily form a compatible solution. If a compatible solution cannot be formed, the epoxy resin and the organic polymer undergo phase separation in the form of sea islands. It is clear that when oil in this state is emulsified in water to form spherical particles as described below, particles with different composition ratios are formed depending on the size of the oil droplets. That is,
Very small oil droplets are particles of only epoxy resin or organic polymer, and as the oil droplets become larger, the variation in composition ratio between particles becomes smaller. in general,
It is common knowledge that oil droplets in emulsions have a particle size distribution, and as a result, powders with varying composition ratios are obtained.

For this reason, in the present invention, the epoxy resin and the organic polymer are temporarily made into a compatible solution as a method of obtaining particles with no variation in composition ratio between particles.
An example of this method is given below.

When at least one of the epoxy resin and the organic polymer is liquid and very easily miscible, the epoxy resin and the organic polymer may become miscible simply by mixing them. Also,
If they are not compatible near room temperature but become compatible by heating, heat to a temperature above the compatibility temperature. However, as will be described later, in the present invention, a method of emulsifying a compatible solution of an epoxy resin and an organic polymer in water is preferable, and therefore, it is preferable that heating for making the epoxy resin and organic polymer be heated to a temperature below the boiling point of water. In other words, in a normal pressure system, the temperature is 100℃ or less,
More is possible with pressurized systems.

If the epoxy resin and the organic polymer are not compatible with each other simply by heating, there is a method of making them compatible by dissolving them in a common solvent. In this case, the organic solvent used preferably has suitability for emulsifying in water and removing the solvent after emulsification, as described below. For this purpose,
The organic solvent is preferably one that has a boiling point of 100° C. or lower and exhibits low to non-water solubility. When the temperature exceeds 100℃,
Since the desolvation conditions approach the boiling point of water, the amount of entrained water increases and the efficiency of desolvation decreases. Furthermore, as the water solubility of the organic solvent increases, emulsification in the water column tends to become difficult. Examples of organic solvents that can be used in the present invention include chloroform, methylene chloride, carbon tetrachloride, ethyl ether, ethyl acetate, and benzene. Note that even if these organic solvents contain about 50 wt% of water-soluble organic solvents such as methanol, ethanol, acetone, dimethylformamide, and tetrahydrafuran, it is generally possible to achieve the present invention. .

When the powder particles produced by the method of the present invention are used as adhesives or powder coatings, it is preferable that they have the ability to be cured. For this purpose, in addition to the epoxy resin and the organic polymer, it is preferable to have a latent curing agent for the epoxy resin present in the particles. Examples include dicyandiamide, imidazoles, Lewis acid complexes, phenols, carboxylic acids, acid anhydrides,
These include acidic polyesters, carboxyl group-containing polymers such as styrene-maleic acid copolymers, polyamines, and modified polyamines/dihydrazides.

Among these, those that are compatible with the above epoxy resin are recommended. Examples of phenolic curing agents include bisphenols such as bisphenol A and F, and their condensates, phenol novolacs, and polyvinylphenols.In particular, bisphenols and their condensates have excellent compatibility with epoxy resins. ing. Phenols and condensates thereof are preferred.

Derivatives of bisphenols include those that are reaction products of diglycidyl ethers of bisphenols with diamines or dicarboxylic acids and have reactivity with epoxy groups at both ends, and derivatives derived from diglycidyl ethers of bisphenols. Examples include dihydrozide.

Examples of acid anhydrides include phthalic anhydride-based ones such as methyltetrahydrophthalic anhydride, succinic anhydride-based ones, maleated terpinene, styrenic monomers and maleic anhydride oligomers, and trialkyltetrahydrophthalic anhydride and maleic anhydride. Examples include adducts, and oligomer or adduct types that utilize the reactivity of ethylenic double bonds are particularly preferably used.

Examples of amine compounds include aromatic amines such as diaminodiphenylmethane and diaminodiphenyl sulfone, and sterically hindered amines such as 2,5-dimethyl-2,5-hexanediamine and 1,8-diamino-P-menthane. can be mentioned. Also preferably used are oligomeric or polymeric compounds formed by the reaction of amino groups and epoxy groups, whose chemical bonding points are secondary or tertiary amino groups.

In the present invention, a combination of the epoxy resin and the latent curing agent showing at least partial compatibility, or even complete compatibility, is preferably used. In order to make the epoxy resin and the latent curing agent compatible, both are heated and mixed or dissolved in a common solvent for both.

The amount of latent curing agent used is usually 0.05 to 1 equivalent per equivalent of epoxy group in the epoxy resin.

When the latent curing agent is a phenol type or acid anhydride type, a small amount of tertiary amines acts as a curing catalyst, so the amount used plays an important role in changing the curing behavior. However, the tertiary amines used for this purpose generally have relatively low molecular weights and may leach out of the particles during or after curing. For catalytic purposes, the present invention recommends the use of compatible high molecular weight tertiary amines, such as condensed oligomers of diglycidyl ethers of bisphenols and piperazine.

As described below, when partially curing B-stage particles using an amine-based curing agent, the latent curing agent may be separated into islands from the epoxy resin as the degree of polymerization increases, but the separated state is Since both are fine, they do not have much influence on the curing effect of the latent curing agent, and in the present invention, the term "compatible" includes such a state.

Next, a method for obtaining the epoxy spherical fine particles of the present invention from the above blend will be explained.

If the mixture of epoxy resin, organic polymer, and (if necessary) latent curing agent is a non-adhesive solid at around room temperature, mechanically crushed particles may be suspended in a heating cylinder or allowed to fall by gravity. There is a method of spheroidizing (this is the first method).

Another method is to suspend the above-mentioned mixture in a water-based or water-insoluble liquid (emulsion or sampendion) and form it into spheres (second method). The second method is particularly preferred in terms of particle uniformity and sphericity.

Representative examples included in the second method are listed below.

A method of cutting the mixture or its solution into droplets by continuously discharging the mixture or its solution from a nozzle that vibrates in the air or in a liquid, and collecting the droplets in the liquid.

A method in which the mixture or its solution is ejected in pulses from a nozzle in the air or in the liquid, and the mixture is collected in the liquid.

A method of emulsifying the mixture or its solution using a surfactant.

A method of emulsifying the mixture or its solution using a powder emulsifier.

A method of emulsifying the mixture or a solution thereof with an aqueous liquid containing a protective colloidal substance.

Among these methods, method is excellent in obtaining particles with uniform particle diameter, but productivity is generally low. On the other hand, although the method of . . . has the advantage of high productivity, the uniformity of the particle size is not so high. However, sufficient particles are obtained for practical purposes.

The surfactants used in the above methods are not particularly limited, but include polyoxyethylene/phenol substituted ethers, polyoxyethylene/polyoxypropylene blocks, etc.
Typical examples include ether-type nonionic surfactants such as polyethers, ester-type nonionic surfactants such as higher fatty acid esters of polyethylene glycol and fatty acid esters of polyhydric alcohols, and nonionics such as alkoxylated rosins. . These surfactants are added in an amount of about 2 to 30 wt% to the mixture or solution of the epoxy resin and the organic polymer (if necessary) and the latent curing agent.
In addition, powder emulsifiers include finely powdered crystalline cellulose and barium sulfate powder, with a weight of 2 to 20wt.
% is used. In addition, as a protective colloid substance, polyvinyl alcohol, especially saponification degree 70
~95% polyvinyl alcohol, gum arabic,
Carboxymethyl cellulose, gelatin, sodium alginate, etc., are used as aqueous emulsifying media.
It is generally used by dissolving it in a range of 0.5 to 20 wt%.

Among these, at least a portion of the surfactant and powder emulsifier are contained in the particles or powder after production, so this may be undesirable depending on the intended use. However, when a protective colloidal substance is used, it has the advantage that it can be easily removed by washing with water because it is hardly compatible with the epoxy resin or organic polymer.

Examples of the emulsifying medium include water, polyethylene glycol, wax, liquid paraffin, kerosene, castor oil, olive oil, glycerin, silicone oil, and the like. Among these, an aqueous emulsifying medium is preferred from the viewpoint of ease of implementation of the present invention, ease of handling, separability from the organic solvent used, and economical reasons.

Next, epoxy resin and organic polymer (if necessary)
A representative example of a method for emulsifying a latent curing agent mixture or solution in an aqueous liquid is described. In principle, it can be applied to emulsifying media other than aqueous liquids.

Surfactants or powder emulsifiers are generally dissolved or added to the mixture or solution. In the case of protective colloidal substances, they are generally dissolved in an aqueous medium.

As a method of emulsifying and dispersing the above mixture or solution in an aqueous liquid, the aqueous liquid is gradually added to the above strongly stirred mixture or solution, or conversely, the above mixture or solution is gradually added to the strongly stirred aqueous liquid. The method is common. Emulsification is possible using either method, especially when the viscosity of the mixture or solution is low, but when the viscosity is high, the former method is used, i.e., adding an aqueous liquid to the highly stirred mixture or solution. Gradual addition is recommended.

In the present invention, since the viscosity is generally 1 poise or more, it is preferable to use the former method. A more specific explanation is as follows. First, in a container equipped with a stirring blade with a high stirring effect, such as a plate-shaped blade,
Add the above mixture or solution. At that time, if they are not in a compatible state, the temperature is raised above the compatible temperature. The emulsifying aqueous liquid is added to it under stirring at a few hundred rpm or more. The method of adding aqueous liquid is as follows:
It may be supplied continuously or it may be added stepwise in portions, but first a water-in-oil (W/O) emulsion is formed, and then an aqueous liquid is added to form oil-in-water droplets. Preference is given to phase inversion to type (O/W) emulsions, ie normal emulsions. Good results are often not obtained when large amounts of aqueous liquid are added in a short period of time so as to form an O/W emulsion suddenly. The amount of aqueous liquid required to emulsify in the manner described above is approximately 20% of the volume of the mixture or solution of epoxy resin, organic polymer, and (if necessary) latent hardener.
~150%, and the use of more aqueous liquid tends to act as a diluent for the emulsion rather than acting as an emulsifier. In order to suitably form an O/W emulsion, the required amount of the above-mentioned aqueous liquid may be divided into 1/3 to 1/10 equal parts and added in portions every 30 seconds to 30 minutes. ,
A method of continuous addition at a rate such that the entire amount is added within about 1 minute to 5 hours is recommended. Note that the aqueous liquid is preferably heated to a temperature higher than the phase separation temperature.

Next, in order to achieve the present invention, a method of phase-separating the epoxy resin component and the organic polymer within the particles to form a sea-island structure will be described. Separation can occur during or after emulsification. Typical methods are listed below.

During or after emulsification, lower the temperature below the phase separation temperature.

After emulsification, the low to water-insoluble organic solvent is removed. There are various methods for this, but the most common method is to heat the organic solvent to around or above the boiling point of the organic solvent while stirring gently under normal pressure or reduced pressure. However, in this method, particles tend to adhere to each other during heat removal, resulting in enlargement and even destruction of the emulsion, resulting in phase separation from the aqueous liquid. In such cases, it is usually effective to dissolve about 0.5 to 20 wt% of a protective colloidal water-soluble organic polymer such as polyvinyl alcohol, gum arabic, or carboxymethyl cellulose in an aqueous liquid.

If the mixture of epoxy resin, organic polymer, and latent curing agent (if necessary) is liquid or sticky at room temperature, the epoxy resin is partially cured (B-staged) to make it non-tacky at room temperature. It is preferable to keep it. For this purpose, hardeners other than latent hardeners may be used. Typical examples of curing agents and curing methods for this purpose will be described below.

A method in which a mixture of an epoxy resin to which a curing agent has been added and an organic polymer (if necessary) and a latent curing agent is suspended (emulsion or suspension) in a water-based liquid and then partially cured as it is, and an epoxy resin. and organic polymer (if required)
There is a method of partially curing a water-soluble amine type curing agent by adding a water-soluble amine type curing agent to a water-based emulsion of a mixture of latent curing agents or a sampendyon.

Whichever method is used, curing at room temperature is preferable in order to cure the suspended particles without bonding them to each other. The amine-based curing agents shown below often give favorable results.

The amine-based curing agent is an amine-based curing agent characterized by mixing a stoichiometrically calculated equivalent amount of amine with an epoxy resin and having a Shore A hardness of 50 or more after standing at 20°C for 8 hours. Preferably, it is a compound.

If the Shore A hardness is smaller than this value, the curability of the emulsion particles tends to decrease, making it difficult to obtain a good particulate cured product.

Examples of the curing agent that can be used in the present invention include the following compounds, but are not particularly limited thereto. Polyethylene polyamines such as piperazine, hydrazine, ethylenediamine, diethylenetriamine, triethylenetetramine, alcohol amines such as monoethanolamine, N(2-
aminoethyl) piperazine, etc.

The amount of the above curing agent used varies depending on the average particle diameter of the target particles, the timing of adding the curing agent, the emulsion or suspension concentration, etc., but if it is too small, particles that are solid at room temperature may not be obtained. If the amount is too high, the melting point (softening point) tends to become high and no adhesive strength is exhibited. Generally, it is preferable to use about 0.1 to 0.6 equivalents based on the epoxy compound, but when adding it to emulsions or suspensions, the curing reaction becomes a heterogeneous reaction, resulting in poor reaction efficiency; Good results may also be obtained using .

Then, the amine curing agent is added in advance to the mixture of epoxy resin, organic polymer, and latent curing agent (if necessary) to form an emulsion or suspension. When adding an amine-based curing agent after the particles have been cured, it is preferable to allow the curing reaction to occur while the curing agent is allowed to stand or is gently stirred, in order to prevent particles from joining together.

By B-staging in this manner, amino groups are introduced into the particles. It is a well-known fact that the curing reaction of some latent curing agents is accelerated by amino groups, especially tertiary amino groups, so especially when using phenolic latent curing agents, In order to achieve low temperature curing, it is also recommended to perform B-staging as described above. As mentioned above, when removing the organic solvent by heating after emulsification, if an amine curing agent such as the one mentioned above is present, the curing reaction of the phenolic latent curing agent will be activated and the curing process will occur during desolvation. Therefore, in many cases, it is preferable to add the amine curing agent at around room temperature after the organic solvent has been removed.

B-staging using an amine curing agent inevitably increases the degree of polymerization of the epoxy resin. Therefore, during this process, the compatibility between the epoxy resin and the organic polymer decreases, and phase separation is often observed. In other words, B-staging using an amine curing agent is the third method for causing intraparticle phase separation.

The state of particles with a sea-island structure that has undergone phase separation within the particles can usually be confirmed using an optical microscope.

In the present invention, it is not clear why it is particularly preferable to have a phase-separated structure, but the epoxy resin side has an adhesive function and a high glass transition temperature (Tg).
This seems to be because the organic polymer side can effectively share the function of flexibility. If the epoxy resin component and the organic polymer component form a compatible solution, both properties will generally have intermediate values between the two, resulting in the antinomic properties of high Tg and flexibility. It is considered that this cannot be expected from particles.

In the present invention, the particles may contain other additives. The most typical additives are organic and inorganic pigments and dyes used for coloring purposes.
These are usually added before the mixture is suspended or emulsified in the aqueous liquid. Further, fine powder with a sharp particle size distribution, such as crushed glass fibers, glass beads, alumina spheres, and crosslinked polystyrene spheres, may be similarly included, and adhesive fine particles containing spacers can be obtained by this method. In addition, 0.5μm such as silica sol and alumina sol
By mixing or adsorbing the following ultrafine particles,
It is also possible to prevent blocking and charging of particles.

After solidification or B-staged suspension, particles can be separated from the aqueous liquid using an appropriate method, washed, and air-dried or dried at a low temperature to be taken out as a dry powder without losing adhesive strength.

The particles obtained according to the present invention have a substantially spherical shape, and their dimensions are preferably in the range of 0.1 to 500 μm, more preferably in the range of 0.5 to 200 μm. It is substantially difficult to prepare particles with a particle size of less than 0.1 μm, and their functionality as an adhesive deteriorates. On the other hand, if the particle size exceeds 500 μm, the particle size is too large for use as a powder adhesive or for powder coating, which poses a practical problem.

Particles within the above particle size range may be used in the form of a powder with a wide particle size distribution, or may be classified and used in a state with an extremely narrow particle size distribution.

Classification techniques used for this purpose are not particularly limited, but generally include wind screening, liquid or dry cyclone, wet or dry sieving, water sieving, and the like.
It is generally recommended that these be used in combination and that the classification be carried out in stages from coarse classification to fine classification.

[Examples] Example 1 8 g of two types of epoxy resins Epicoat 828 (oiled shell epoxy, epoxy equivalent weight 187), which are bisphenol A diglycidyl ether, and Epicoat
1011 (same as left, epoxy equivalent 470), 2 g of phenolic latent curing agent Epicure 171N (same as left, phenolic OH 235 g/eq.), and 4 g of polyester adhesive Chemit K1294 (Toray, Tg = 69°C).
The mixture was placed in a 100 c.c. polyethylene wide-mouth bottle, and 11 g of chloroform was added to obtain a transparent solution. 11 g of the solution was placed in a 100 c.c. polyethylene cup, and a stirring rod equipped with a Teflon plate blade was inserted.

While stirring at 800 rpm, add polyvinyl alcohol (Nippon Gohsei, Zosenol EG05).
4% by weight aqueous solution, 1.5cc each 4 times at 1 minute intervals,
A total of 6 c.c. was added in portions. A W/O emulsion was formed in the first divided water, and the phase was inverted to an O/W emulsion in the third divided water.

After adding 20 g of water, the polyethylene cup was placed in a glass heating jacket, and the chloroform was volatilized over about 90 minutes while heating the surroundings to 60°C. Stirring was performed at approximately 50 rpm during volatilization, and the end point of solvent removal was determined from the presence or absence of chloroform odor emitted from the container.

After cooling to room temperature, add 0.7 g of piperazine to 8 g of water.
A hardening solution in which g was dissolved was added, and the mixture was left to stand at room temperature for 5 days under gentle stirring at about 1 rpm to cause phase separation, and obtain spherical particles that were non-adhesive at room temperature. The average particle diameter measured by centrifugal sedimentation was 12 μm, and differential interference microscopy confirmed that the interior of each particle had a similarly fine sea-island structure, regardless of the particle size.

One end of a 10 mm x 80 mm piece of polyethersulfone (PES) film coated with an alignment film, 10 mm x 45
2 mg of the above-mentioned dry powder was spread as evenly as possible over an area of 2.0 mm in size, and film pieces of the same size were stacked on top of each other, and the pieces were sandwiched between two glass slides and fixed with clips. It was placed in a hot air dryer at 140°C and cured for 2 hours. tensile speed 50
T-peel strength when measured in mm/min is approximately 80
g/cm. On the other hand, a powder having an average particle diameter of 10 μm prepared in the same manner as in Example 1 except for using Chemit K1294 had a T-peel strength of approximately 70 Kg/cm when measured in the same manner.

Example 2 4 parts of Epicote 828, 4 parts of Epicote 1001,
1.2 parts of Epicure 171N and soluble nylon CM
-4000 (Toray, Tg approx. 50°C) Take 10 g of a clear mixed solution of chloroform/methanol = 7/3 (weight ratio) containing 50% by weight of solids at a ratio (weight) of 2 parts,
It was emulsified with a polyvinyl alcohol aqueous solution in the same manner as in Example 1. Polyvinyl alcohol EG05-2
Add 30g of % aqueous solution and carry out the same procedure as in Example 1 to prepare 60% aqueous solution.
The solvent was removed at °C. Thereafter, in the same manner as in Example 1, partially cured spherical particles with piperazine were obtained. The average particle diameter was 8 μm, and the interior of each particle had a similarly fine sea-island structure. The T peel strength measured in the same manner as in Example 1 was 84 g/cm.

Example 3 7 parts of Epikote 828, 1.5 parts of Epicure 171N, and Hymer SBM-100, a styrene-butyl methacrylate polymer (Sanyo Chemical, Tg approx. 50
A clear chloroform solution with a solids content of 30% by weight was prepared in a proportion (by weight) of 3 parts (°C). Emulsification and solvent removal were carried out in the same manner as in Example 1, and after cooling, a curing solution of 1 g of hydrazine hydrate and 8 g of water was added, and spherical particles with non-adhesive surfaces were formed over 10 days with gentle stirring at room temperature. Obtained. Average particle size is 19μm
All of them had a uniform sea-island structure.

The T peel strength measured in the same manner as in Example 1 was approximately 85 g/cm.

Example 4 3 parts of Epicote 828, 3 parts of Epicote 1001,
1 part Epicure 171N and Hymer ST-95, a low molecular weight polystyrene (Sanyo Chemical, Tg approx. 5°C)
A clear chloroform solution of 50% by weight solids containing 4 parts (by weight) was prepared. Emulsification, solvent removal and partial curing with piperazine were carried out in the same manner as in Example 1. A powder with an average particle diameter of 22 μm and all particles having a spherical and uniform sea-island structure was obtained.

The T peel strength measured in the same manner as in Example 1 was approximately 95 g/cm.

Example 5 6 parts of Epicure 1001, 1 part of Epicure 171N and epoxy modified liquid polybutadiene E-700
A chloroform solution containing 4 parts (by weight) of -6.5 (Nisseki Chemical, Tg below room temperature, epoxy equivalent approximately 310) with a solid content of 40% by weight was prepared. This solution is cloudy at room temperature, but becomes transparent when heated to 50°C. Moreover, when the film is applied to a slide glass and the solvent is removed, the film becomes cloudy.

50℃ to a 100c.c.
10g of the above chloroform solution pre-warmed to
I took it. 4% by weight of Gohsenol EG05 at 50℃
Emulsification was carried out in the same manner as in Example 1 using an aqueous solution. Add 20g of water and then increase the jacket temperature to 60℃
chloroform was removed. Example 1
It was partially cured with piperazine in the same manner as above. A powder was obtained in which the average particle diameter was 12 μm, and each particle was spherical and had a uniform sea-island structure.

The T peel strength measured in the same manner as in Example 1 was approximately 92 g/cm.

Example 6 Epicote 828 2.25 parts, Epicote 1001 2.25
Part, Epiquure 171N 1 part and butyl acrylate/ethyl acrylate/acrylonitrile polymer WS023 (Teikoku Kagaku Sangyo, Tg below room temperature)
A clear ethyl acetate solution of 20% by weight solids containing 5.5 parts (by weight) was prepared. This solution becomes cloudy when the solvent is removed, and the epoxy resin and WS023 phase separate.

10 g of this solution was taken and emulsified in substantially the same manner as in Example 1 under the following conditions.

A 4% by weight aqueous solution of Gokenol EG05 was added 10 times in 2 c.c. portions at 2 minute intervals, totaling 20 c.c. Third
The emulsion was a W/O emulsion up to the point where the water was divided, but the phase was changed to an O/W emulsion by adding water thereafter.

In the same manner as in Example 1, the solvent was removed at a jacket temperature of 76°C, and then partially cured with piperazine. The average particle diameter was 18 μm, and all particles were spherical and had a uniform sea-island structure.

The T peel strength measured in the same manner as in Example 1 was approximately 130 g/cm.

[Effects of the Invention] The epoxy resin-based spherical particles obtained by the present invention have a uniform phase separation structure and exhibit high T-peel strength. INDUSTRIAL APPLICATION This invention is suitable as a manufacturing method of the powder adhesive which precisely adheres a fine place. Also,
Suitable as a method for producing powder for flexible powder coating.

Claims (1)

[Scope of Claims] 1. A method for producing epoxy-based spherical fine particles having a sea-island-like phase separation structure, which is characterized by comprising the following steps (a) to (c). (b) A process of making a mixture consisting of at least an epoxy resin and an organic polymer into a compatible solution. (b) A process of emulsifying the compatible solution into an emulsifying medium. C. A process of phase-separating the epoxy resin component and organic polymer component within the particles. 2. The method for producing epoxy-based spherical fine particles according to claim 1, wherein the step of converting into a compatible solution is carried out by heating to a temperature below the boiling point of water. 3. The method for producing epoxy-based spherical fine particles according to claim 1, wherein the step of forming a compatible solution is carried out by adding a low to water-insoluble organic solvent having a boiling point of 100° C. or less. 4. The epoxy-based spherical fine particles according to claim 1, wherein the emulsifying medium is an aqueous liquid, and the emulsifying step is to form an O/W emulsion via a W/O emulsion. Production method. 5. The method for producing epoxy-based spherical fine particles according to claim 4, wherein the aqueous liquid dissolves a colloidal substance. 6. The method for producing epoxy spherical fine particles according to claim 1, wherein the step of phase separation is carried out by cooling the emulsion to a temperature below the phase separation temperature. 7. The method for producing epoxy spherical fine particles according to claim 1, wherein the phase separation step involves removing a solvent from the emulsion and causing phase separation by heating or reducing pressure. 8. The method for producing epoxy-based spherical fine particles according to claim 1, wherein the step of phase separation comprises curing the epoxy resin of the emulsion to cause phase separation.