JPH0119413B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a granular thermosetting resin that uses a condensation type or polyaddition type thermosetting resin prepolymer such as a phenolic resin, an epoxy resin, or a urethane resin as a starting material. The present invention relates to a method for producing a cured resin material.

[Conventional technology]

Granular cured thermosetting resins are used for many purposes, including as substrates for ion exchange resins and adsorption resins, as compounds for rubber, plastics, and paints, and for bearings, but recently they have been used as raw materials for granular activated carbon. It is also attracting attention for its use.

As a method for producing a spherical thermosetting resin cured product, for example, after prepolymerizing the epoxy resin, the epoxy compound is slowly dropped into a solvent in which the epoxy compound is insoluble or poorly soluble to form a suspended state in one step, and the epoxy compound is left in the suspended state in one step. A method of proceeding with the curing reaction using
However, when the spherical resin cured product obtained by this method is activated carbonized by firing,
It is unsuitable as a raw material for activated carbon because it inevitably causes hexagonal cracks and peeling of the surface layer. The reason for this is presumed to be that physical distortion occurs inside the resin because the resin is prepolymerized and then suspended and spheroidized in the manufacturing process.

In order to prevent such distortion, methods such as spheroidizing the thermosetting resin in the prepolymer state and then gradually proceeding with the reaction to harden this problem cannot be solved. Emulsion-type adhesives and paints of various thermosetting resins that are manufactured in large quantities from The particles become cake-like or cylindrical lumps, egg-shaped, or even string-like hardened products, so it is difficult to increase the particle size while maintaining a shape close to a true sphere. However, even after various efforts, it has been extremely difficult to obtain a solid substance that is close to a perfect sphere and has an average particle diameter of 200 μm or more.

[Problem to be solved by the invention]

The present inventors aimed to obtain a granular thermosetting resin cured product that has a relatively large particle size and can be used as a raw material for activated carbon, etc., and further, the granular resin adheres to each other and aggregates to form a lump such as a cylindrical shape. With the aim of establishing a production method that can prevent the formation of liquid substances, we have conducted intensive studies and found that liquids or solutions of various thermosetting resin prepolymers to be used are mixed in water using an emulsifier if necessary. Stir vigorously to emulsify the resin, and while the thermosetting resin molecules retain sufficient fluidity, the emulsified resin particles fuse with each other to grow the particle size, and then maintain a suspended state. However, by carrying out the curing reaction, the average particle diameter of the thermosetting resin particles was successfully increased to about 2000 μm, and this invention was completed.

[Means to solve the problem]

That is, the present invention provides a liquid resin composition containing a prepolymer selected from a condensation type phenolic resin, a polyaddition type epoxy resin, or a urethane resin, and a diluent or a solvent as essential components. After pouring it into water while stirring and emulsifying it, the emulsified resin reacts and the particles fuse together while stirring while heating, increasing the particle size and creating a suspended state, and then stirring again. This is a method for producing a granular thermosetting resin cured product, characterized in that the reaction is continued and cured while maintaining this state.

Examples of condensation type thermosetting resin prepolymers that can be used in the present invention include novolak type phenolic resin prepolymers, resol type phenolic resin prepolymers, novolak type alkyl phenolic resin prepolymers, resol type alkyl phenolic resin prepolymers, There are modified resin prepolymers made from these xylene/formaldehyde condensates or toluene/formaldehyde condensates, and in addition to the solvent for these resins, curing agents, curing catalysts, etc. may be used depending on the type of resin and curing temperature. Mix and use.

Polyaddition type thermosetting resin prepolymers that can be used in the present invention include bisphenol A diglycidyl ether, alicyclic dialcohol diglycidyl ether, bisphenol A bis(α-methylglycidyl ether), Alicyclic dialcohol bis(α-methylglycidyl ether)
There are solid or liquid epoxy resin prepolymers, such as diglycidyl ethers of polymethylene glycol, polyglycidyl compounds of polyhydric alcohols and aromatic polycarboxylic acids, etc., which are used as reactive diluents for these prepolymers. Toluene, xylene, various alkylbenzenes such as ethylbenzene, various alkylphenols, long-chain aliphatic esters, alkylphenols and alkylbenzoic acid alkyl esters or alkyl ethers, alcohols, and amines used as non-reactive diluents. , organic acids, and other organic oils or liquids can be added and used, and these diluents also serve as a solvent for the resin. In addition, various curing agents such as various polyamide polyamine types, aliphatic, aromatic or alicyclic polyamine types, and/or various acid anhydride types, and if necessary, amine type, Curing catalysts such as those based on metal complexes can be added and mixed in the same manner, and also tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate, and their additions can be used. Various aromatic or aliphatic polyisocyanates such as condensates are combined with polyvalent active hydrogen low polymers such as various polyethers, polyesters, and polyamides, and if necessary, hydrophobic aromatic or aliphatic polyisocyanates are combined. There are urethane-based prepolymers made by adding various curing catalysts such as aliphatic solvents, amine-based and metal complex-based curing catalysts, and further carrying out a partial reaction if necessary.

In the present invention, a liquid resin prepared by mixing various prepolymers with additives such as a diluent or solvent and, if necessary, a curing agent and a curing catalyst, is poured into water at once and stirred vigorously to emulsify it. For this purpose, one or more surfactants selected from anionic, cationic and neutral surfactants may be used as an emulsifier, but polyamide There are also systems that can be emulsified by stirring without adding an emulsifier, such as systems such as epoxy resin prepolymers combined with polyamine curing agents.

In addition to the various prepolymers mentioned above, various inorganic powder fillers such as calcium carbonate, talc, glass powder, and silicon oxide, various organic powder fillers such as starch-based and cellulose-based powders, and wood flour, and diazo By adding foaming agents such as peroxide-based, low-molecular-weight paraffin-based or fluorine compound-based, antioxidants, ultraviolet absorbers, various stabilizers, etc., the prepolymer's viscosity, reactivity, specific gravity, etc. , modifying the stability, appearance, specific gravity, expansion ratio, etc. of the spherical cured product,
Of course, it can also be adjusted and used.

The present invention will be explained in more detail below using Examples.

Example 1 Bisphenol A diglycidyl ether type liquid epoxy resin prepolymer with epoxy equivalent weight 190
Mix 200 g of linoleic acid dimer liquid polyamide curing agent with active hydrogen equivalent of 120, and 10 g of 2,4,6-trisdimethylaminomethylphenol, and then add 100 ml of methanol, stir evenly, and add 1 part of deionized water. The mixture was added at 1 o'clock into flask No. 2 at 50° C. and stirred at 300 rpm to emulsify.

While stirring at the same speed, the mixture was gradually heated to 70° C. over 5 hours, and the rotation speed was lowered to 200 rpm and the reaction was continued under the same conditions for an additional 8 hours. The reaction product is collected by filtration, washed with water, and dried to form a perfect spherical, light brown,
A transparent resin composition was obtained in quantitative yield. The particle size distribution of this spherical resin had a peak around 0.8 mmφ, and particles of 0.50 to 1.68 mmφ accounted for 62% of the total product.

Example 2 To 400 g of a 50% methanol/water (equal volume) solution of a phenol/cresol (7/3) resol type resin synthesized with an ammonia catalyst, 40 g of a 20% methanol solution of naphthalenedisulfonic acid was added as a curing agent. After stirring well, it was added at 1 hour to 0.8% deionized water in which 2g of polyvinyl alcohol with a degree of polymerization of 300 was dissolved in 2 flasks at 45° C. and 350 rpm. A stable emulsified state was obtained instantaneously, but the mixture was heated to 60° C. for 1 hour, and then the stirring speed was lowered to 250 rpm, and the reaction was further continued under the same conditions for 4 hours. The product was filtered, washed with water, and air-dried to obtain brown transparent spherical resin particles in quantitative yield. These spherical resin particles showed a distribution close to a normal distribution with a peak around 0.7 mmφ, and particles of 0.42 to 1.00 mmφ accounted for 59% of the total granules.

Example 3 Molecular weight synthesized from 180 g of a 75% butyl acetate solution of 1/3 (molar ratio) trimethylolpropane/TDI adduct, phthalic acid/adipic acid (80/20 molar ratio), ethylene glycol, and a small amount of glycerin.
200 g of a 50% methyl isobutyl ketone solution of 2000 hexafunctional polyester polyol and 0.2 g of a 10% butyl acetate solution of dilauryltin dilaurate were mixed and stirred well. Deionized water was stirred at room temperature and 300 rpm with a gas outlet 2
The mixture was immediately poured into a flask, and after emulsification, the mixture was further stirred for 2 hours under the same conditions. Reduce the stirring speed to 200 rpm,
The temperature was gradually lowered to 60°C over 2 hours, and the reaction was continued at the same temperature for an additional 4 hours. The cured resin was filtered, washed with water, and air-dried to obtain pale yellow, translucent spherical resin particles in quantitative yield. The diameter of this sphere is 0.02
It showed a distribution close to normal distribution with a peak around 0.7 mmφ over the range of ~1.6 mmφ.

Comparative Example 1 Bisphenol A diglycidyl ether type liquid epoxy resin prepolymer with epoxy equivalent of 190
After stirring 200 g of aromatic liquid polyamine curing agent with an active hydrogen equivalent of 120 and 100 ml of toluene, deionized water from 1 was added in the same manner as in Example 1.
The mixture was added all at once into a flask at 50°C with stirring at 300 rpm, but the system did not emulsify at all. While stirring at the same speed, the mixture was gradually heated to 70°C over 5 hours, the rotation speed was lowered to 200 rpm, and the reaction was continued under the same conditions for an additional 3 hours. The reaction product was a clumpy cured product containing cylindrical parts formed by fusion of granules with a diameter of about 2 to 3 mm, and no spherical cured product was obtained.

Comparative Example 2 10 g of bisphenol A diglycidyl ether type epoxy resin prepolymer with an epoxy equivalent of 180
was diluted with 5 ml of dibutyl phthalate to make solution A, and 2 g each of tetraethylenepentamine and 2,4,6-tris(dimethylaminomethyl)phenol were added.
were mixed to obtain liquid B. 100℃ in 1 flask
500 ml of liquid paraffin was gently stirred using a rotary blade, and both solutions A and B were quickly mixed and added dropwise into the solution from the dropping funnel over a period of 3 minutes. The product immediately became a spherical cured product, which was further stirred under the same conditions for 1 hour to advance the reaction, allowed to cool, washed with acetone, and air-dried.The product had an approximately normal distribution with an average particle size of 2 mm. A light brown transparent spherical cured product was obtained.

After carbonizing this cured product in a nitrogen stream while raising the temperature from 600°C to 1000°C, an attempt was made to activate it with steam at 1000°C, but the activated carbon was finely crushed and spherical activated carbon could not be obtained.

[Effects of the Invention] According to the method of the present invention, the particles of the thermosetting resin prepolymer do not agglomerate together and form lumps at once, and as the curing reaction progresses, the fusion of the particles gradually progresses. It is possible to obtain a cured resin product with a regular shape, and when the obtained granular cured resin product is fired and activated carbonized, no cracking or peeling of the surface occurs, making it suitable as a raw material for activated carbon. It was hot.

Claims (1)

[Claims] 1. A liquid resin composition containing one prepolymer selected from phenolic resin, epoxy resin, or urethane resin and a diluent or solvent as essential components is poured into water with strong stirring and immediately emulsified. After that, while stirring under heating, the emulsified resin reacts and the particles fuse together to increase the particle size and become a suspension state, and the reaction continues while stirring and maintaining this state. 1. A method for producing a granular thermosetting resin cured product, which comprises curing the granular thermosetting resin.