JPS6172036A - Production of porous epoxy spherical particle - Google Patents

Abstract

PURPOSE:To produce fine porous epoxy sherical particles, by curing emulsion of an epoxy compound, having dissolved an extractable or volatilizable compound, with a water-soluble amine compound to give spherical particles, eliminating the extractable or volatilizable compound from the spherical particles. CONSTITUTION:(A) A mixture obtained by mixing an epoxy compound with 3-60wt%, preferably 5-50wt% extractable or volatilizable compound having compatibility with the epoxy compound is blended with (B) preferably 4-30wt% surface active agent (preferably polyoxyethylene, etc.) having >=10 HLB value or preferably 0.5-80wt% protective colloid substance (e.g., polyvinyl alcohol), and water to give emulsion, which is cured with (C) preferably 0.3-4 equivalents based on epoxy value of, water-soluble amine compound (e.g., piperazine, or hydrazine) to give epoxy spherical particles, from which the compound A is extracted or volatilized to give the aimed spherical particles.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a manufacturing method for obtaining porous epoxy spherical fine particles.

The porous epoxy-based spherical particles of the present invention can be used as raw materials for sustained-release drugs and cosmetics by allowing drugs, fragrances, etc. to penetrate into the pores. It is still used as a column packing material for column chromatography. It is also used as an adsorbent for oils, fats, gases, etc.

[Conventional technology]

Japanese Patent Publication No. 55-42560 discloses a technique for obtaining bispherical particles by curing a mixture of an epoxy compound and a curing agent in water. Furthermore, Japanese Patent Application Laid-Open No. 53-73249 discloses a technique for obtaining fine powder from a mixture of epoxy resin, surfactant, curing agent, and water.

[Problem that the invention seeks to solve]

Until now, little is known about the method for producing microscopic porous epoxy spherical particles. The present invention provides a manufacturing method thereof.

[Means for solving problems]

The present invention is configured as follows.

A water-soluble acine compound is added to an emulsion of an epoxy compound in which a compound that is compatible with the epoxy compound and can be extracted or volatilized is cured, and the compatible compound is extracted or volatilized and removed. A method for producing porous epoxy spherical particles.

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

The epoxy compounds used in the present invention include:

Those containing two or more epoxy groups in the molecule are preferred, and examples include bisphenol A-type glycidyl ethers at both ends, polyethylene glycol cyclidyl ethers, phenol novolac-type compounds polyglycidyl ethers, and N.

Examples include N, N', 'N'-tetraglycidyl m-xylene diamine, which can be used alone or in combination.

Furthermore, 2. If necessary, it is possible to add a small amount of a compound 2 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, a compound that is compatible with the above-mentioned epoxy compound, is soluble in at least one kind of solvent, and can be extracted and removed from particles after curing, or a compound that can be removed by volatilization is added to the above-mentioned epoxy compound. Mix. The compound that can be extracted and removed is preferably an organic compound that has a boiling point of 60°C or higher and is soluble in an organic solvent, and the compound that can be volatilized is preferably an organic compound that has a boiling point of 60 to 130°C.

Examples of compounds that are compatible with such epoxy compounds and can be extracted and removed from cured particles include the following.

Glycerin esters such as triacetin, fatty acid esters such as butyl acetate, higher carboxylic acids such as stearic acid, etc.

Examples of compounds that are compatible with the epoxy compound and can be volatilized from the cured particles include the following.

Benzene, toluene, enlene, carbon tetrachloride.

such as methylene chloride.

It is preferable that these compounds have a low affinity for water. Note that in the present invention, compatibility means mutually uniform dissolution.

In the present invention, the above compound is
60% by weight, preferably 5 to 50% by weight. If the amount is less than this, sufficient effect on porosity cannot be achieved, and if it is more than this, the epoxy compound will harden into spherical particles.
<There is a tendency to

In the present invention, it is preferable to form an emulsion with water from a mixture of the above-mentioned epoxy compound and its compatible compounds by the action of a surfactant or a protective colloid, and then harden the mixture by adding a water-soluble amine curing agent. .

The surfactant used in the present invention preferably has an HLB value of 10 or more. When the HLB value is lower than this, the stability of the emulsion is impaired when the emulsified epoxy particles are cured into particles with a curing agent, and a good particulate cured product tends not to be obtained. Types of surfactants that can be particularly suitably used in the present invention include ether-type nonionic surfactants such as polyquineethylene, fer/-substituted ethers, and polyoxyethylene/polyoquinopropitane block polyethers. , ester-type nonionic surfactants such as higher fatty acid esters of polyethylene glycol and fatty G esters of polyhydric alcohols, and alkoxylated rosins. In addition, examples include those that are self-emulsifying and act as curing agents for epoxy compounds, such as polyamide amines, which are reaction products of guimaric acid and polyether diamines or aliphatic polyamines, and when their HLB value is 10 or more, 9 Suitably used in the invention.

The amount of surfactant used is also important in the present invention.

The emulsifier is preferably added in an amount of 4 weight φ or more to the mixture of the epoxy compound and the compatible compound.

When the amount of surfactant is less than this, the stability of the uncured epoxy emulsion decreases.

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

There is no particular upper limit to the amount of surfactant used, but it is necessary to prevent deterioration of the physical properties of each particle.

Generally, it is preferable that the weight ratio is 60 or less based on the mixture of the uncured epoxy compound and the compatible compound.

Protective colloidal substances used in the present invention include polyvinyl alcohol, hydroxymethylcellulose, carboxymethylcellulose, gum arabic, sodium alginate, and sodium polyacrylate. These protective colloidal substances are preferably used in an amount of 0.5% by weight or more based on the mixture of the epoxy compound and the compatible compound.

If it is less than this, the stability of the emulsion decreases and there is a tendency that good particulate cured products cannot be obtained.

Furthermore, when the amount of the protective colloidal substance used increases, the viscosity of the emulsion dispersion medium increases, resulting in operational problems such as difficulty in handling. Therefore, the amount of the protective colloidal substance used is preferably 80% by weight or less.

In the present invention, it is also possible to use a powder emulsifier together with a surfactant or a protective colloidal substance.

Representative examples of methods for emulsifying a mixture of an epoxy compound and a compatible compound are listed below.

When a surfactant is used, water in the above temperature range is gradually added to the mixture containing the surfactant while stirring at high speed. It is generally preferable to add water intermittently rather than continuously, and a method in which addition periods and periods in which only stirring is performed is alternated is recommended.

When using a protective colloidal substance, add an aqueous solution containing the protective colloidal substance while stirring the above mixture at high speed.
Add in the same manner as when using a surfactant.

Emulsification can also be carried out under heating or cooling conditions, if necessary.

There is a close relationship between the concentration of Evokin emulsion and the emulsion particle size and stability, and if the concentration is too low, aggregation will easily occur and stability will deteriorate.

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

The emulsion particles of the present invention may contain other additives as long as they do not impair the present invention.

The most typical additives are organic and inorganic pigments and dyes used to color epoxy particles. Conductive agents, ultraviolet absorbers, etc. can also be added depending on the purpose. These additives.

The uncured epoxy compound is usually added before emulsification and blended by thorough mixing or dissolution.

In order to achieve the present invention, it is preferable to add a water-soluble amine compound to an emulsion of a mixture of an epoxy compound and a compatible compound as described above and harden the mixture into spherical particles.

The amine compound used in the present invention is obtained by mixing a stoichiometrically calculated equivalent amount of amine with an epoxy compound at room temperature,
Preferably, the amine compound is characterized in that the mixture has a Shore A hardness of 50 or more after being left at room temperature for 8 hours.

If Noyoa A hardness is smaller than this value.

There is a tendency that the curability of the emulsion decreases and it becomes impossible to obtain a good particulate cured product. 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, diethylenetosamine, and triethylenetetramine, alcohol amines such as monoethanolamine, and N(2-aminoethyl)piperazine.

In the present invention, it is preferable to achieve this by adding to the emulsion an amine compound that satisfies the above-mentioned 7 IOA hardness condition, but the amount of curing agent used is important in the present invention. In the present invention, the amine compound is preferably 0.3 equivalent or more as calculated stoichiometrically from the epoxy value of the emulsion. When the amount of the curing agent used is less than this, the curability of the emulsion tends to decrease, making it difficult to obtain a good particulate cured product. There is no particular upper limit on the use of the above-mentioned curing agent, but as the emulsion stability decreases as the amount used increases, it is generally recommended that the amount of amine 4 equivalents or less calculated stoichiometrically from the epoxy value of the emulsion is preferable.

There are two methods for curing the emulsion particles into particulate form: (1) a method in which an amine compound is added to an epoxy compound in advance and then emulsified; and (2) a method in which a water-soluble amine compound is added to the emulsion. .

For the former method, ethylenediamine, diethylenetriamine, N(2-aminoethyl)piperazine, and the like, which are liquid at room temperature, are suitable as curing agents.

Approximately 0.2 to 1.2 equivalents of these curing agents are added to the epoxy compound and emulsified. However, this method tends to result in poor emulsion stability.

In the latter method, a water-soluble amine compound is added to the emulsion obtained as described above, and the emulsion particles are hardened into particles to prepare epoxy particles.

The latter method will be explained in detail below.

To add amine compounds to emulsions.

Although it is common to mix the curing agent directly into the emulsion, there is also a method of dissolving the curing agent in advance in a water-soluble organic solvent such as water or alcohol before adding it.

It is also possible to use one or more amine compounds as a curing agent added to the emulsion. In particular, when used in combination with piperazines and hydrazines, good particulate cured products are often obtained.

After adding the above-mentioned water-soluble amine compound to the emulsion, it is heated or cooled as necessary to proceed with curing into spherical particles, but during the curing reaction, it should not be left standing or gently stirred. It is particularly preferable to carry out particulate curing.

After curing, the particles may be subjected to heat treatment to post-cure residual epoxy groups, acid treatment to eliminate unreacted epoxy groups remaining within the particles, neutralization of amino groups, or dyeing. It is also possible to

To achieve the present invention, the particles after hardening are treated with an organic solvent such as ethyl alcohol or acetone to extract and remove the above-mentioned compatible compounds. It is preferable to use a heated extractor such as a Soxhlet extractor for extraction. If the compatible compound can be removed by volatilization, it can be removed by heat treating the particles during or after curing.

The porous epoxy-based spherical particles of the present invention are produced as described above, and the average particle diameter may vary from 0.1 to 10 depending on the manufacturing conditions.
It is possible to make it approximately 00 μm.

If some agglomeration occurs during curing, it may grow into non-spherical porous particles. 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 When 10 g of a commercially available bisphenol A diglycidyl ether type epoxy resin Epicoat 828 (manufactured by Yuka Shell Epoxy) and 2 g of triacetin were placed in a 100 cc polycup and mixed, the two were mixed to become a homogeneous liquid. A stirring rod with a Teflon plate blade attached to the tip was inserted into the mixture, and the mixture was stirred at 800 rpm. Separately, polyvinyl alcohol GL05 (manufactured by Nippon Gosei Kagaku, saponification degree 88%) 1
．． 10 g of water-soluble TTI containing 5 g was prepared and added to the mixture of Epicote 828 and triacetin in 25 g portions every 3 minutes.

As a result, the Epicote 828 and triacetin mixture was emulsified in the polycup to obtain a white emulsion.

Next, 8 g of water containing 0.8 equivalents of hyherazine as a hardening agent was added to this emulsion, and the mixture was allowed to stand at 25°C for 5 minutes.
After curing for a day, fine spherical particles with an average particle diameter of about 4 μm were obtained. After filtering and washing particles, 100cc
redisperse in water.

5g of 4NH2SQ4 was added and treated at 90°C for 2 hours.

After filtering and washing again, one particle was air-dried.

The particles were placed in a Soxhlet extractor and extracted for 5 hours at the boiling point of ethyl alcohol to obtain porous epoxy spherical particles.

After extraction, the particles exhibited water retention of approximately 30% by weight. Particles made using a similar procedure without triacetin have a water retention of about 4%.

The Shore A hardness of the equivalent mixture of Epikote 828 and piperazine after being left at room temperature for 8 hours was 92. Since piperazine is a solid compound at room temperature, it was dissolved in 77 tons and then mixed with Epicote 828.

The mixture was uniformly mixed with Epicote 828 by deacetonization under reduced pressure at room temperature.

Example 2 10 g of a commercially available phenol/novolac type epoxy resin (Epicote 152. Yuka/L Epoxy) and 1.5 g of toluene were placed in a 100 cc polycup, and Emulgit 100 (Dai-Kogyo Seiyaku, HL) was added as a surfactant.
B=22.3) was added and emulsified in the same manner as in Example 1 using 10 g of water. Subsequently, 8 cc of water containing 1 equivalent of piperazine was added as a hardening liquid. 25
The mixture was left standing for 6 days at °C to obtain spherical particles with an average particle diameter of 4 μm.

After filtering and washing the particles, the particles were heated to 60° C. to volatilize the toluene over 10 hours, and the particles were dried. The particles after volatilization exhibited water retention of approximately 20% by weight.

The Shore A hardness of an equivalent mixture of Epikote 152 and piperazine after being left at room temperature for 8 hours is 94.

〔Effect of the invention〕

The present invention has made it possible to produce porous epoxy spherical particles.

Claims (1)

[Claims] A water-soluble amine compound is added to an emulsion of an epoxy compound in which a compound that is compatible with the epoxy compound and can be extracted or volatilized is cured, and the compound is extracted or volatilized and removed from the epoxy spherical particles. A method for producing porous epoxy spherical particles, characterized by: