JPH0768158A - Producton of capsule containing isocyanate compound - Google Patents

Abstract

PURPOSE:To easily produce capsules with water resistance. CONSTITUTION:An isocyanate compd. and polyolefin wax are melted by heating at about 100-150 deg.C, mixed and solidified by cooling. The resulting formed body is mechanically crushed. The objective capsules contg. the isocyanate compd. are easily produced.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing capsules containing an isocyanate compound.

[0002]

2. Description of the Related Art Conventionally, some capsules containing an isocyanate compound are known. Among them, as a representative one, one using a polyvinyl acetal resin having a cloud point as a wall film material is known (for example, JP-A-54-139885). However, such capsules are taken out after the inorganic matter having a large coagulation value is solidified with the salts in water, and the polyvinyl acetal that forms the coating film of the capsules has not chemically reacted and is water resistant. There was a problem of being scarce.

Further, an isocyanate capsule having a wall made of a polyvinyl alcohol polymer is known (for example, Japanese Patent Publication No. 63-6258). However, although this capsule has water resistance, it has a problem as a practical manufacturing method because it has many kinds of raw materials and needs a curing step using an acid catalyst.

[0004]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method in which the obtained isocyanate compound capsules have water resistance and can be easily produced.

[0005]

In order to solve the above-mentioned object, a method for producing capsules containing an isocyanate compound using a lower polyolefin is provided. More specifically, it is a method of producing a capsule containing an isocyanate compound by heat-melting and mixing an isocyanate compound and lower polyolefins, cooling and solidifying the mixture, and then crushing.

As the lower polyolefins which can be used in the present invention, those having a melting point of 80 ° C. to 160 ° C. or less are preferable. If the melting point is less than 80 ° C., the polyolefin that has become the wall material of the capsule is affected at room temperature and tends to cause blocking or melting, which is not preferable. Further, lower polyolefins having a melting point of higher than 160 ° C. are not preferable because the isocyanate groups are activated when the isocyanate compound is mixed and tend to react with moisture in the air.

Even in the temperature range in which the isocyanate group is difficult to react, if the viscosity of the melted lower polyolefin is too high, it is difficult to sufficiently stir it with an ordinary stirrer. Therefore, the lower viscosity is preferable. For example, the viscosity at 110 ° C., that is, at working temperature is 100,000 centipoises or less, preferably 10,000 centipoises or less.

Types of lower polyolefins that can be used in the present invention include polyethylene wax, polypropylene wax, modified products thereof, and oxidized wax. The point is that the melting point is 80 ° C. to 160 ° C. good.

The isocyanate-based compound that can be used in the present invention is preferably a liquid or powdery one, for example, tolylene diisocyanate, xylylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate and the like, and aromatics consisting of isomers and nuclei thereof. Aliphatic diisocyanates such as diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, cyclohexane-1,4-diisocyanate, isophorone diisocyanate, 4,
Alicyclic diisocyanates such as 4′-dicyclohexylmethane diisocyanate, diisocyanate compounds such as ω, ω ′-(ditrimethylene thioether) diisocyanate, S-triazine triisocyanate, thiophosphoric acid tris (p-isocyanate phenyl) ester, triphenylmethane triisocyanate Isocyanates, diphenylmethane triisocyanate, butane-1,2,2-triisocyanate, trimethylolpropane tolylene diisocyanate trimer adduct, 2,4'-diphenyl ether triisocyanates, polyisocyanate compounds such as polymethylene polyphenyl isocyanate, etc. Is exemplified.

Further, an isocyanate group-terminated compound obtained by reacting these compounds with an active hydrogen-containing compound, and an isocyanate modified product obtained by an isocyanurate-forming reaction are also included. Also. Methanol, ethyl acetoacetate,
It is also possible to use polyisocyanate partially stabilized with a blocking agent having one active hydrogen in the molecule, such as ε-caprolactam, methyl ethyl ketone oxime, and phenol.

The proportion of the lower polyolefins used in the present invention is preferably 0.1 to 100 times (weight conversion value) the NCO group of the isocyanate compound, and is 0.5.
To 100 times (value in terms of weight) is more preferable.

In the present invention, various methods can be used as the cooling and solidifying method. For example, it may be extruded in the form of a film or strand into the air from a kneading extruder called kneader-ruder, or may be poured into a mold and solidified. The point is that it can be cooled and solidified.

[0013]

EXAMPLES The present invention will be described below with reference to examples, but it goes without saying that the present invention is not limited to the examples. (Example) 100 parts by weight of polyethylene wax (trade name: Polyletts 200, manufactured by Chusei Wax Polymer Co., Ltd., melting point: 114 ° C.) as lower polyolefins, melted by heating in a vat and heated to 120 ° C. with stirring. The heating was stopped. To this, 100 parts by weight (trade name: Coronate-1025, NCO content 40%, viscosity: 30 cps / 25 ° C.) as an isocyanate compound was gradually added to obtain a mixture of lower polyolefins and an isocyanate compound. It was

This mixture was poured into a stainless steel vat to obtain a flat lump having a thickness of about 5 mm. This lump was crushed by a free crusher (M2-8 type, manufactured by Nara Machinery Co., Ltd.) to obtain a powdery substance having a particle size of 10 to 1000 microns (μm). The isocyanate group content of the obtained powder was 19.8% by weight. Further, the powdery matter having a particle size of 50 microns or less was 25% by weight of the whole. After the powder was placed in water at 25 ° C. for 24 hours, the isocyanate content was measured and found to be 18.8% by weight.

[0015]

INDUSTRIAL APPLICABILITY The present invention can be used in combination with water because the isocyanate group remains stable as described above. For example, wood chips and capsules of the isocyanate compound of the present invention are mixed and heated to form a synthetic plate. There is an advantage that it can be manufactured safely. Since it can be used with water, it does not have the danger of unencapsulated raw isocyanate. Further, when heated after kneading with wood chips, the olefin wax has an advantage that it melts and exhibits a normal adhesive action, and the olefin wax contributes to water resistance and water repellency.

Claims (2)

[Claims] 1. A method for producing a capsule containing an isocyanate compound by heat-melting and mixing an isocyanate compound and lower polyolefins, cooling and solidifying the mixture, and then crushing. 2. The melting point of the lower polyolefins is 80.
The method of claim 1, wherein the temperature is between 0 ° C and 160 ° C.