JPS6099119A - Preparation of particles of amino resin - Google Patents

Abstract

PURPOSE:To obtain transparent and globular particles of amino resin, by blending a precondensate of a specific amino compound and formalin with an acidic curing agent, mixing the blend with a non-solvent of the precondensate, curing it under heating. CONSTITUTION:An amino compound (preferably melamine and/or urea) is precondensed with formalin in the presence of an alkali catalyst until the burbidity point becomes >=40 deg.C. An aqueous solution of the precondensate is blended with an acidic curing agent (e.g., phosphoric acid, etc.) to give a resin solution, which is mixed with a non-solvent of the precondensate (e.g., silicone oil, etc., preferably 100-900pts.wt. non-solvent based on 100pts.wt. precondensate), and preferably dye, and the mixture is heated with stirring at 40-90 deg.C, so that the precondensate is cured, to give globular amino resin particles having preferably 30mu- 3mm. particle diameter. USE:The prepared amino resin particles are useful a filler for polyamide or epoxy resin, a colorant, filter aid, or thickening agent for coating compound.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing small spherical amino resin particles having a particle size of 30 microns to 30 microns. The particles obtained by the practice of this invention are useful as fillers in polyamides and epoxy resins, and as colorants, filter aids, and thickening agents for paints.

It is known to use melamine resin particles as an organic filler for polyamide and epoxy resins.

Usually, such resin is a mechanically crushed product of cured melamine resin, which is irregular in shape and rough in appearance.
It is opaque. Such pulverized products tend to have a lower filling rate than spherical fillers. Furthermore, when the objective is to produce a transparent resin molded product, there is a drawback that such an opaque filler cannot be used.

On the other hand, a water-soluble compound obtained by reacting a polyisocyanate compound and an alkylene oxide adduct of alcohol is mixed with urea and formalin [7, then a curing agent - such as an aqueous phosphoric acid solution is added, and from 60 to 63℃
A condensation reaction is carried out to obtain a white dispersion, a brightener, urea and water are added to this dispersion, and the reaction is carried out at 58 to 60°C.
Furthermore, a caustic soda aqueous solution was added to adjust the pH to 8.4,
It is known to produce a urea resin dispersion with good storage stability that is useful as a coating agent for paper (Japanese Patent Laid-Open No. 57-1
No. 70916).

The resin particles in such a dispersion are fine, about 1 to 3 microns, and are more difficult to separate than water.

The present inventor conducted various studies in order to obtain large particles with a particle size of 300 microfron to cocoon in a method in which resin particles are precipitated by reacting an amine compound and formaldehyde in a solvent. It has been found that resin particles having the desired particle size can be obtained by performing precondensation in an aqueous solvent and curing the precondensate in a mixed solution of water and a non-solvent of the condensate. , we have arrived at the present invention. Moreover, the resin particles obtained by practicing the present invention are transparent and dusty.

That is, in the present invention, a resin solution prepared by blending an acidic curing agent into an aqueous solution of a precondensate of an amino compound with a white turbidity point of 40° C. or higher and formalin is mixed with a nonsolvent of the precondensate,
An amino-based resin characterized in that a precondensed metal is cured by heating a mixed solution of the resin solution and a non-solvent to 40 to 90° C. while stirring to precipitate a transparent, small spherical amino resin. A method for producing particles is provided.

In the practice of the present invention, examples of amino-based compounds include amino groups (-NH
Examples include compounds having 2).

゛ As acidic curing agents, mineral acids such as phosphoric acid, sulfuric acid, and hydrochloric acid,
Examples include organic acids such as halatoluenesulfone tel, ant-e, and xylene sulfonic acid.

Examples of the non-solvent for the amino resin precondensate include silicone oil, liquid paraffin, linear paraffins such as hexane and octane, aromatic paraffins such as benzene, toluene and xylene, and carbon tetrachloride.

However, in order to produce an amino resin precondensate, an amino compound and an aqueous solution of formaldehyde (formalin) are mixed in the presence of an alkaline catalyst such as caustic soda or caustic potash for 60 to 60 minutes.
The cloudy point at a temperature of 90°C is 40°C or higher, preferably 60°C or higher
Precondensation is carried out until the temperature reaches 70°C. The pH of the solution containing the alkali catalyst is 8 to 12.

The clouding point here refers to the temperature at which cloudiness is observed in the liquid when a 3% aqueous solution of the amino resin precondensate is gradually cooled from 90°C [Industrial Chemistry Magazine, Embo Volume, No. 1, 56
7 pages (1957)].

If the precondensate has a cloudy point of less than 40° C., the curing reaction time during particle production will be undesirably long.

The amount of formaldehyde charged per equivalent of the amino group of the amino compound is preferably 1/12 to 1.

If necessary, the resin liquid may be dehydrated under reduced pressure to prepare a solid resin component.

The acidic curing agent is added to the aqueous solution of the precondensate thus produced, and the pH of the system is adjusted to 1-6.

This resin solution is mixed with the non-solvent of the precondensate, and reacted with stirring at a temperature of 40 to 90° C. for 30 to 60 minutes to precipitate amino resin particles.

At this time, it is also possible to incorporate a protective colloid agent such as polyvinyl alcohol, polyvinylpyrrolidone, or CMC into the mixed solution.

In addition, a dye such as Spiron Red z W (
(Product name: Hoyagami Chemical Co., Ltd.), Solvent Yellow 56 (Product name: Oil Yellow GG-8. Orient Chemical Co., Ltd.),
If Solvent Orange 72 (trade name: Diamond Resin Brown A1, manufactured by Mitsubishi Chemical Industries, Ltd.) or Solvent Blue 3S (trade name, Oil Blue IIN, manufactured by Orient Chemical Industries, Ltd.) is blended, the dye will be absorbed by the hardening resin particles, making the dyed transparent. Amino resin spherical particles are obtained. The dye is used in an amount of 0.001 to 1 part by weight per 100 parts by weight of the precondensate.

A non-solvent such as silicone oil is also incompatible with water, and is used in a proportion of 100 to 900 parts by weight per 100 parts by weight of the precondensate.

The spherical resin particles produced by heating and curing are
After washing with water and drying, it becomes a product. The particle size of the resin particles is 30 μm to 3 μm, and they are clear and transparent. The particle size depends on the dispersion strength of the resin liquid in a non-solvent, so that resin particles having a desired spherical diameter can be obtained.

These resin particles are useful as fillers for polyamides, epoxy resins, phenolic resins, unsaturated polyester resins, etc., and the dyed resin particles are useful as colorants.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Melamine 63 was placed in a stainless steel reactor equipped with a cooler.
0t and 37% formalin 1215F were added, and then caustic soda was added to adjust the pH of the liquid to 8.5.

Then, a condensation reaction was carried out at 80°C until the cloudy point reached 62°C (water miscibility: 110).

400f of this precondensed resin aqueous solution was added to 935% hydrochloric acid (262ml) in another reactor, mixed well, and silicone oil (Toshiba Silicon YF-33) was added to 1200ml of this aqueous solution. Under stirring conditions such that the resin liquid is dispersed into fine particles in silicone oil, the curing reaction is continued at 60°C for 1 hour to produce resin particles. After filtration and washing, the resin particles are dried and the average particle size is determined. 38 of transparent spherical fine particles with a diameter of about 100 microns were obtained.

Example 2 Melamine 518? was placed in a reaction vessel equipped with a cooler. , urea 124f and Nippon Gosei Polyvinyl Alcohol 1
Add 16 tons of Gohsenol 'l'-330' (trade name), then add 48% caustic soda aqueous solution to adjust the pH of the liquid.
was set to 11.5 and heated to 80°C to perform a precondensation reaction to obtain an aqueous solution with a cloudy point of 60°C.

Transfer 400f of this precondensed resin aqueous solution into another reaction vessel, add 262g of 35% hydrochloric acid, mix well, add 1200g of liquid paraffin, and react at 60°C for 1 hour with stirring to precipitate resin particles. I let it happen.

The resin particles were separated by filtration and washing with water, and then dried. The resin particles obtained were spherical and transparent with an average particle size of about 90 microns.

Example 3 A 48% aqueous sodium hydroxide solution was added to a mixed solution of 300 y of urea and 810 t of 37% formalin, and the pH was adjusted to 9. Then, a 30 molecule precondensation reaction was carried out at 80° C. while stirring.

Then, formic acid was added so that the pH of the aqueous solution became 4.2, to obtain an aqueous resin solution with a cloudy point of 60°C.

- Take 400f of this aqueous solution and add 26f of 35% hydrochloric acid to it.
After thorough mixing, 120 Of liquid paraffin was added and reacted at 60° C. for 1 hour with stirring to precipitate resin particles.

The resin particles were separated by filtration and washing with water, and then dried. The obtained resin particles were spherical with an average particle size of about 60 microns and were transparent.

Example 4 Melamine 518t1 Urea 1241 and Nippon Gosei Polyvinyl Alcohol 1 were placed in a reaction vessel equipped with a cooler.
Pour in Gohsenol T-330# (trade name) 162, then add 48% caustic soda aqueous solution to bring the pH of the liquid to 1.
1.5 and heated to 80°C to perform a precondensation reaction to obtain an aqueous solution with a cloudy point of 60°C.

400f of this precondensed resin aqueous solution was placed in another reaction vessel, 26f of 35% hydrochloric acid was added, and after mixing well, 1200f of a 2=1 mixture of silicone oil and carbon tetrachloride was added, and the mixture was heated for 60 ml with gentle stirring. Resin particles were produced by reacting at ℃ for 1 hour.

The resin particles were separated by filtration and washing with water, and then dried. The obtained resin particles were spherical with an average particle size of about 2.5 mm and were transparent.

Example 5 In a reaction vessel equipped with a cooler, melamine 518f1 urea 124t and Nippon Gosei Kagaku polyvinyl alcohol 1
Gohsenol T-330' (trade name) 161 was added, and then 48% caustic soda aqueous solution was added to adjust the pH of the liquid to 1.
1.5 and heated to 80°C to perform a precondensation reaction to obtain an aqueous solution with a cloudy point of 60°C.

400 g of this precondensation resin aqueous solution was placed in another reaction container, and 400 g of this precondensation resin aqueous solution was added to the Hodogaya Chemical dye "Spiron Red 0.22".
After adding 262 ml of 35% hydrochloric acid and mixing well, 120 ml of silicone oil was added, and the mixture was reacted at 60° C. for 1 hour with stirring to precipitate resin particles.

The resin particles were separated by filtration and washing with water, and then dried. The obtained resin particles were spherical with an average particle diameter of about 85 microns, and were transparent and red.

Patent applicant Yuka Melamine Co., Ltd. Agent: Patent Attorney Hidetoshi Furukawa Agent: Patent Attorney Masahisa Nagatani

Claims (1)

[Claims] 1) A resin solution prepared by blending an acidic curing agent with an aqueous solution of an amino compound with a white turbidity point of 40°C or higher and formalin for preliminary wire hardware. The precondensate is mixed with the non-solvent of the pre-wire hardware and heated to 40-90° C. while stirring to cure the pre-condensate to form a transparent, small spherical amine resin. A method for producing amino resin particles, the method comprising: producing amino resin particles. 2) The manufacturing method according to claim 1, wherein the amine compound is melamine, urea, or a mixture of both. 3) The manufacturing method according to claim 1, wherein the resin particles have a particle size of 30 to 3 microns. 4) The manufacturing method according to claim 1, wherein the curing of the preliminary wire hardware is carried out in the presence of a dye.