JPS6187722A - Production of spherical epoxy particle - Google Patents

Abstract

PURPOSE:To facilitate the production of spherical particles of a specified particle diameter, by curing an epoxy compound emulsion formed in the presence of a powdered emulsifier with an amine curing agent. CONSTITUTION:An emulsion prepared by emulsifying an epoxy compound (e.g., bisphenol A diglycidyl ether) in water in the presence of a powdered emulsifier (e.g., microcrystalline cellulose of a size <=1mu) is cured with an amine curing agent (e.g., piperazine or hydrazine). Spherical epoxy particles of an average particle diameter of 10-1,000mu can be easily produced. According to a conven tional technique, particles of an average particle diameter <=50mu, particularly, <=20mu can be easily produced but particles of a larger diameter can not be easily produced. According to the present process, such particles can be easily produced. These epoxy particles can be used as a chromatography packing, a paint additive, an additive for plastic moldings or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The particles produced by the present invention are used as column fillers for chromatography, paint formulations, plastic molded product formulations, and the like.

[Conventional technology]

Japanese Patent Publication No. 53-42360 discloses a technique in which a mixture of an epoxy compound and a hardening agent is dispersed in water and hardened into spherical particles.

We have already proposed a technology for producing spherical particles by adding a water-soluble amine curing agent to an epoxy compound emulsion.

[Problem that the invention attempts to solve]

Conventional techniques for producing epoxy-based spherical particles are suitable for producing particles with an average particle diameter of 50 μm or less, particularly 20 μm or less, but are not very suitable for producing particles with an average particle diameter larger than that. . The present invention provides a method for easily producing epoxy-based spherical particles having an average particle diameter of 10 to 1000 μm.

[Means for solving problems]

The present invention is configured as follows.

A method for producing epoxy-based spherical particles having an average particle diameter of 10 to 1000 μm.

The details of the present invention will be sequentially explained below.

The epoxy compounds used in the present invention preferably contain two or more epoxy groups in the molecule. Examples include glycidyl etherified bisphenol A type compound at both ends, diglycidyl ether of polyethylene glycol, polyglycidyl ether of phenol novolak type compound, NsN, N/, N/-tetraglycidyl m-
Examples include xylene diamine, which can be used alone or in combination. Furthermore, if necessary, it is possible to add a small amount of a compound 1 having one epoxy group in the molecule, such as glycidyl methacrylate. Also used in the present invention are modified epoxy compounds in which part of the epoxy group is bonded to a compound having an amine group or the like.

In the present invention, the epoxy compound as described above is emulsified with water in the presence of a powder emulsifier to form an epoxy compound emulsion, and the emulsion is cured with a permanent amine type curing i4.2.

The powder emulsifier used in the present invention is a fine solid particle that exhibits the action of a surfactant, and the particle size is usually 1 μm.
Hereinafter, preferably particles are 0.5 μm or less. Powder emulsifiers stabilize the interface by being captured at the interface between the oil phase and the aqueous phase, using a mechanism similar to that of ordinary emulsifiers.
P60 (Engineering Library 1979)).

Powder emulsifiers that can be used in the present invention include microcrystalline cellulose, barium sulfate, clay, and talc.

Examples include titanium oxide, but the most preferred is crystalline cellulose.

Powder emulsifiers generally have different average particle diameters depending on the amount used.

The method of adding the powder particles of the present invention is generally to blend them into an epoxy compound in advance, but it is also possible to use them together with water during emulsification.

In the present invention, a surfactant can also be used in combination with the above-mentioned powder emulsifier. Types of surfactants that can be particularly preferably used in the present invention include ether-type nonionic surfactants such as polyoxyethylene/phenol-substituted ether type and polyoxyethylene/polyoxypropylene block polyether type, and polyethylene glycol-based surfactants. These include ester-type nonionic surfactants such as higher fatty acid esters and fatty acid esters of polyhydric alcohols, and alkoxylated rosins. Further, examples include those that are self-emulsifying and serve as curing agents for epoxy compounds, such as polyamide amines, which are reaction products of dimer acid and polyether diamine or aliphatic polyamine.

The uncured epoxy emulsion particles of the present invention may contain other additives within a range that does not impair the present invention. The most typical additives are organic and inorganic pigments and dyes used to color epoxy particles. A blowing agent can also be used to make the fine particles porous and hollow. Antistatic agent.

Conductive agents, ultraviolet absorbers, etc. can also be added depending on the purpose. These additives are added before emulsifying the uncured epoxy compound.

They are usually blended by thoroughly mixing or dissolving them.

Generally, the difficulty of emulsifying a compound is affected by its viscosity. When the epoxy compound has a high viscosity or is a type of epoxy compound that solidifies at room temperature.

It is difficult to emulsify sufficiently using mechanical force alone. In such cases, a diluent for the epoxy compound is used together with a surfactant.

Diluents include ketones, alcohols, selffulps,
Examples include dioxane, aromatic hydrocarbons, and esters such as ethyl acetate.

As described above, the epoxy composition prepared using the epoxy compound and the surfactant as its basic composition is then emulsified in accordance with a conventional method to form an uncured epoxy emulsion. Although the emulsification method is not particularly limited, nine representative methods are shown below.

The above-mentioned Nigeki-based composition containing a surfactant is heated to room temperature to 95°C.
Water in the above temperature range is gradually added to this while stirring at high speed. It is generally preferable to add water intermittently rather than continuously.

A method is recommended in which periods of addition and periods of only stirring are alternated. In this method, the initial addition of water causes W
/Q type emulsion is formed.

Addition of water causes a phase inversion to an O/W type emulsion.

During phase inversion and after forming an O/W type emulsion, high-speed stirring is particularly required in order to reduce particle size, homogenize, and stabilize the emulsion.

There is a close relationship between the concentration of an epoxy emulsion and the emulsion particle size and stability, and if the concentration is too low, aggregation tends to occur and stability deteriorates.

Generally, it is considered that a condition for obtaining a good emulsion is to adjust the emulsion concentration to about 10 to 80 weight s, but the present invention does not particularly limit this range.

Epoxy emulsions are given stability in water by the action of surfactants, but substances that act as protective colloids such as hydroxyethyl cellulose, carboxymethyl cellulose, gum arabic, and polyvinyl alcohol are added to the water in advance. The method is also effective in increasing emulsion stability.

Then, the emulsion particles are hardened into particles to prepare epoxy-based fine particles.

The amine curing agent used in the present invention is prepared by mixing a stoichiometrically calculated amount of amine with an uncured epoxy resin at room temperature, and the Shore A hardness of the mixture after being left at room temperature for 8 hours is 50 or more. Preferably, it is an amine compound characterized by the following.

If the Shore A hardness is less than this value, the curability of the uncured epoxy emulsion will decrease.

There is a tendency that a good particulate cured product cannot be obtained.

Note that the normal temperature here refers to 20°C.

Examples of the curing agent that can be used in the present invention include the following compounds, but are not particularly limited thereto. These include polyethylene polyamines such as piperazine, hydrazine, ethylenediamine, diethylenetriamine, and triethylenetetramine, monoethanolamine natoalcoholamines IN (2-aminoether)piperazine, and the like.

In the present invention, the Shore A hardness is achieved by adding an amine curing agent that satisfies the Shore A hardness conditions described above to the uncured epoxy resin emulsion. The amount of curing agent used is important in the present invention. In the present invention, the amount is 0.3 equivalent or more calculated stoichiometrically from the epoxy value of the uncured epoxy resin emulsion.

It is preferable to use an amine compound of

When the amount of the curing agent used is less than this, the curability of the uncured epoxy emulsion tends to decrease, making it difficult to obtain a good particulate cured product.

The upper limit of the use of the above curing agent is not particularly limited, but as the stability of the emulsion decreases as the amount used increases, it is generally calculated stoichiometrically from the epoxy value of the uncured epoxy resin emulsion. 4 equivalents or less of amine is preferred.

In order to add the amine curing agent of the present invention to an uncured epoxy resin emulsion, it is common to mix the curing agent directly into the emulsion, but it is necessary to dissolve it in a water-soluble organic solvent such as water or alcohol in advance. There is also a way to add it.

Another possible method for adding the curing agent is to add part or all of the curing agent in advance to the water used to emulsify the uncured epoxy resin, and to emulsify it using the same.

The concentration of the epoxy emulsion during curing is not particularly limited, but it is preferably 5% by weight or more from the viewpoint of stability of the emulsion. However, if the concentration of the epoxy emulsion becomes too high, the chances of contact between the nine particles will increase, making them more likely to aggregate during the curing reaction. Therefore, the emulsion concentration during curing is preferably 80% by weight or less.

In the present invention, it is also possible to use part or more of an amine curing agent as the curing agent added to the uncured epoxy resin emulsion. In particular, when used in combination with piperazines and hydrazines, good particulate cured products are often obtained.

During the curing reaction, it is preferable to stand still or to perform gentle stirring in order to perform particulate curing.

Epoxy fine particles are hardened and prepared into particles as described above. When the hardened particles are separated from water by filtration or centrifugation, they can be recovered in powder form. The epoxy fine particles have a particle size of 10 to 1000 μm, depending on the manufacturing conditions.

In some cases, they are prepared in a less or more spherical form, but they may also grow into non-spherical porous particles due to some agglomeration during curing. Such non-spherical particles are often aggregates of millet-shaped spherical particles. Further, during static curing, the particles at the bottom may be crushed and change from their original spherical shape to a flattened spherical shape, but any one or more shapes are characterized as unique to the present invention.

〔Example〕

Example 1 10 g of a commercially available bisphenol A diglycidyl ether type epoxy resin (Epicoat 828, manufactured by Yuka Shell Epoxy) was placed in a 100 cc polycup, and HL
Neugen EA-137 (No.
0.8 g of Kogyo Seiyaku Co., Ltd.) and crystalline cellulose (Avicel RC-591, Asahi Kasei Co., Ltd.) as a powder emulsifier were added.

80 Orp using a stirring rod with a Teflon plate blade attached to the tip.
m, and kneaded for 1 minute. Subsequently, 1.5 cc of 6 oc of water in a syringe was sequentially added at 1 minute intervals while stirring at 800 rpm. A milky white emulsion liquid was obtained in the polycup.

To this uncured epoxy emulsion was added 1 equivalent of N(2-
A hardening solution prepared by diluting aminoethylcopiperazine with 8 oc of water was added and gently stirred to homogenize.

A stoichiometrically calculated equivalent mixture of Epicote 828 and N(2-aminoethyl)piperazine has a Shore A hardness of 80 after being left at room temperature for 8 hours.

The mixture of the uncured epoxy emulsion and N(2-7minoethyl)piperazine was allowed to stand at 25° C. for 10 days to undergo a curing reaction to form a spherical shape.

The relationship between the amount of powder emulsifier used and the average particle diameter of epoxy particles is shown in the following table. Note that the average particle diameters shown in the table are values measured for the first slurry before drying using a centrifugal sedimentation type particle size distribution analyzer CAPA-500 manufactured by Horiba, Ltd.

Example 2 100cc of 82,810g of Epicor used in Example 1
The powder emulsifier Avicel RC-591 used in Example 1 was added to a polycup.

An uncured epoxy emulsion was prepared by emulsifying in the same manner as in Example 1 (without using a surfactant).

A hardening solution prepared by diluting 1 equivalent of piperazine with 8 cc of water was added to this uncured epoxy emulsion and homogenized by gentle stirring.

The mixture of the uncured epoxy emulsion and piperazine was left standing at 25° C. for 6 days to undergo a curing reaction and to be hardened into particles. The amount of Avicel RC591 used and the state of particle curing of the epoxy emulsion are shown in the following table. It has been found that relatively large particles of spherical shape can be obtained within the scope of the invention.

Example 3 In Example 1, fine barium sulfate treated in a 0.001M aqueous solution of sodium dodecanoate was used as a powder emulsifier instead of Avicel Re-591.

It was emulsified and hardened in the same manner as in Example 1. The amount of powder emulsifier used and the curing state are shown in the table below.

〔Effect of the invention〕

According to the present invention, it has become possible to easily produce epoxy-based spherical particles having an average particle diameter of 10 to 1000 μm.

Patent applicant Higashi Shi Co., Ltd. Company procedural amendment 1, case description 190dc2 1988 patent application No. Patent applicant address 2-2-4 Nihonbashi Muromachi, Chuo-ku, Tokyo Date of amendment order Voluntary '5 Number of inventions increased by amendment None 6 Details of the invention in the specification to be amended "Powder particles" in the 7th line of page 4 in the specification (1) in the "Explanation" column will be corrected to "powder emulsifier particles."

(2) In page 5, line 18, "In such cases, epoxy along with a surfactant" should be corrected to "In such cases, epoxy."

(3) Correct "epoxy compound and surfactant" in the third line of page 6 to "epoxy compound."

(4) Delete the entire text from lines 16 to 18 on page 6.

(5) Change “effect of surfactant” on page 7, line 6 to “
The effect of surfactants, etc. is corrected.

(6) On page 7, lines 10-11, "add to water" is corrected to "emulsify with added water."

(7) "Epoxy resin" on page 7, lines 18-19 and page 9, line 13 will be corrected to "epoxy compound."

(8) Page 8, lines 14-15, page 8, lines 17-1
"Uncured epoxy resin emulsion" in line 8, lines 5 to 6 on page 9, lines 8 to 9 on page 9, and lines 4 to 5 on page 10 are respectively "uncured epoxy emulsion". ” and correct it.

(9) Correct the "epoxy value" in lines 17-18 on page 8 and line 6 on page 9 to "epoxy equivalent".

(10) "Amine-based according to the present invention" on page 9, line 8 is corrected to "amine-based according to the present invention."

01> Correct “emulsion liquid” on page 11, line 18 to “emulsion”.

(g) "Particle hardening state" on page 13, line 14 will be corrected to "particulate hardening state."

0■ Correct "prepare." on page 7, line 16 to "can prepare."

Procedural amendment 1. Display of the case 1980 Patent Application No. 180352 2 Name of the invention Method for producing epoxy spherical particles 3 Person making the amendment Relationship to the case Patent applicant address 2-2-5 Nihonbashi Muromachi, Chuo-ku, Tokyo, Amendment Number of inventions increased by No. 6, "Detailed Description of the Invention" column of the specification subject to amendment (1) Page 7, line 6 (procedural amendment submitted on October 25, 1985) ``Actions of surfactants, etc.'' in Section (5)) will be corrected to ``Effects of powder emulsifiers, etc.''.

(2) "Emulsify with added water" in page 7, lines 10-11 (paragraph (6) of the written amendment submitted on October 25, 1985) is changed to "emulsify with added water." I will correct it.

(3) Page 8, lines 14-15, page 8, lines 17-1
Line 8, Page 9, Lines 5-6, Page 9, Lines 8-9, Page 10, Lines 4-5 (No. 8 of the written amendment submitted on October 25, 1985) ) "Uncured epoxy emulsion" will be corrected to "Uncured epoxy emulsion".

Claims (1)

[Claims] A method for producing epoxy spherical particles having an average particle diameter of 10 to 1000 μm, which comprises curing an epoxy compound emulsion emulsified in the presence of a powder emulsifier with an amine curing agent.