JPH0975707A - Capsule containing isocyanate compound and its capsulated agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-resistant and easy-to-handle capsule contg. an isocyanate compd. and its capsulating agent. SOLUTION: This capsule is obtained by infiltrating an isocyanate compd. into a grain composed of a hydrophobic and thermoplastic resin, Acrylic resin, PVC resin, norbornene resin, polyester resin, polyolefin resin, etc., are appropriately used for the grain. Since the PVC resin produced by suspension polymerization has an appropriate void and an isocyanate compd. is infiltrated into the resin by heating, this resin is especially appropriate as a capsule carrier.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capsule encapsulating an isocyanate compound and its capsule, more specifically, a capsule suitable for adding to a heat-curable aqueous adhesive or the like to improve its properties. Regarding capsules.

[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 Accordingly, the object of the present invention is to provide a water-resistant isocyanate compound capsule and a capsule thereof.

[0005]

In order to solve the above-mentioned object, an isocyanate compound is permeated into the hydrophobic and thermoplastic resin particles by a method such as heat kneading to protect the isocyanate inside the particles. The present invention provides a capsule capable of suppressing the permeation of water from the outside and a capsule agent thereof.

The hydrophobic resin which can be used in the present invention preferably has a glass transition point (Tg) in the range of 60 ° C to 150 ° C. Although an isocyanate compound is hydrophobic, it reacts with water, so it is absolutely necessary to prevent the infiltration of water. In the case of a hydrophilic resin, even if the isocyanate compound can be wrapped inside the particles, it is not suitable for the present invention because the original purpose of water resistance cannot be obtained because water can easily penetrate. . Tg is 60
If the temperature is lower than 0 ° C, it tends to cause blocking or melting even at room temperature, which is not preferable.
Further, with a resin having a Tg of more than 160 ° C., when the capsule of the present invention or the capsule agent of the present invention is mixed and used in the main ingredient such as an adhesive, the capsule tends not to be broken even when heated, which is not preferable.

The resin particles that can be used in the present invention are preferably those made of a thermoplastic and hydrophobic resin, such as an acrylic resin, a vinyl chloride resin, a norbornene resin, a polyester resin and a polyolefin resin. It may be a polymer or a copolymer. Even acrylic resins are not suitable for water-absorbing or hydrophilic ones. Further, those which are compatible with the other party to which the capsule or capsule of the present invention is added, that is, the main agent such as a water-based adhesive for woodworking, a film base material, a molding base material and the like are preferable. If they are compatible with each other, the hydrophobic resin, which is a capsule-forming agent, dissolves in the main component side during heat processing, so that adverse effects on performance, particularly physical performance, can be minimized. For example, when the capsule of the present invention is used to increase the tensile strength of a vinyl chloride film, the hydrophobic resin particles are also preferably made of vinyl chloride resin.

The range of the particle size of the resin particles that can be used in the present invention depends on the use of the capsule or capsule of the present invention. For example, if it is added to a water-based adhesive to be coated with a roll coater, suitability for coater, for example, particle size 5
It is required to be 0 micron or less, but if coating is performed with a nozzle, clogging does not occur. For example, if the nozzle diameter is 50 microns, about 20 microns or less is required. If it is added to the molding resin, it may be several 100 microns or less.

The range of the porosity of the hydrophobic resin which can be used in the present invention is preferably as large as possible from the point of the present invention, but this is a limit as a carrier. That is, it is better to increase the porosity as much as possible and minimize the carrier. Although there are various methods of measuring the porosity, it is preferable to regard it as the porosity in the present invention. The range of porosity is 0.1 to 0.
8 (cc / g) is preferable. When the porosity is less than 0.1, the proportion of the carrier becomes too large, which limits the use.
That is, the influence of the carrier on the main agent becomes large. If the porosity exceeds 0.8, the function as a carrier, such as water resistance, storage stability, and mechanical strength, will be adversely affected. Depending on the type of resin, the isocyanate compound may be permeable. In that case, no microscopic voids are required. That is, the isocyanate compound penetrates into the gaps at the molecular level. An example of this is vinyl chloride resin. The vinyl chloride resin produced by the suspension polymerization method also has voids between particles, and when heated, the isocyanate compound also penetrates into the intermolecular voids, so it is optimal as the carrier particles of the present invention.

Examples of isocyanate compounds usable in the present invention include tolylene diisocyanate, xylylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, etc., and aromatic diisocyanates consisting of isomers and nuclei thereof, 1,6-hexamethylene diisocyanate, Aliphatic diisocyanates such as 1,12-dodecane diisocyanate, cyclohexane-1,4-diisocyanate, isophorone diisocyanate, alicyclic diisocyanates such as 4,4′dicyclohexylmethane diisocyanate, ω, ω ′-(ditrimethylene thioether) diisocyanate, etc. Diisocyanate compounds, S-triazine triisocyanate, tris thiophosphate (p-isocyanate phenyl)
Ester, triphenylmethane triisocyanate, diphenylmethane triisocyanate, butane-1,2,
Examples thereof include 2-triisocyanate, trimethylolpropane tolylene diisocyanate trimer adduct, 2,4'-diphenyl ether triisocyanates, and polyisocyanate compounds such as polymethylene polyphenyl isocyanate.

As the antiblocking agent used in the present invention, those which are not aqueous are suitable. Water-based compounds are unsuitable because they may react with isocyanate compounds. Stearic acid or a metal salt thereof is suitable for the present invention,
Among them, calcium stearate and / or zinc stearate are more preferable. The addition amount is preferably 0.1 to 10% by weight, and 0.5 to 2% by weight with respect to the hydrophobic resin.
Is more preferred.

[0012]

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 1) Vinyl chloride resin particles (trade name: ZEST-1000S, manufactured by Shin-Daiichi PVC Co., Ltd., T as hydrophobic resin particles)
g: 80 ° C., porosity: 0.34 cc / g) 100 parts by weight and polymethylene polyphenyl polyisocyanate as an isocyanate compound (trade name: Millionate M
R200, manufactured by Nippon Polyurethane Co., Ltd.) 100 parts by weight,
90 with a kneader (model: KPM-8, manufactured by Kurimoto)
When kneading was carried out for 10 minutes under conditions of ° C, 0.1 atm, and 30 rpm, almost free-flowing and non-blocking capsule particles were obtained. No blocking occurred in the capsule particles even after 48 hours. The isocyanate group content of the obtained capsule particles was 98%. Also, after placing the capsule particles in water at 25 ° C. for 24 hours,
The residual isocyanate group was measured and found to be 85%.

Example 2 100 parts by weight of vinyl chloride resin particles (trade name: ZEST-PB52, manufactured by Shin-Daiichi PVC Co., Ltd., Tg: 80 ° C.) as hydrophobic resin particles and diphenylmethane-4- as an isocyanate compound. 100 parts by weight of 4'diisocyanate (trade name: Millionate MT, manufactured by Nippon Polyurethane Company) and calcium stearate as a blocking inhibitor (trade name: EFCOCHEM CS-S,
1.2 parts by weight of Adeka Fine Chemical Co., Ltd., and a kneader (model: KPM-8, manufactured by Kurimoto Iron Works Co., Ltd.) at 95 ° C.,
When kneading was carried out for 10 minutes under the conditions of 0.1 atm and 30 rpm, all the isocyanate compounds penetrated into the resin particles, and almost free-flowing and non-blocking capsule particles were obtained. Blocking did not occur in these capsule particles even after 48 hours had passed (note that in this example, an antiblocking agent is indispensable). The isocyanate group content of the obtained capsule particles was 99%. After the capsule particles were placed in water at 25 ° C. for 24 hours, the degree of residual isocyanate group was measured to be 70
%Met.

(Example 3) 100 parts by weight of vinyl chloride resin particles (trade name: ZEST-E13, manufactured by Shin-Daiichi PVC Co., Ltd., Tg: 80 ° C.) as hydrophobic resin particles and polymethylene polyphenyl as an isocyanate compound. 100 parts by weight of polyisocyanate (trade name: Millionate MR200, manufactured by Nippon Polyurethane Co., Ltd.) was stirred with an anchor type stirrer at 90 ° C., normal pressure and about 30 rpm for 30 minutes, and a substantially free, non-blocking capsule was obtained. Particles were obtained. No blocking occurred in the capsule particles even after 48 hours. The isocyanate group content of the obtained capsule particles was 99.5%.
After the capsule particles were placed in water at 25 ° C. for 24 hours, the residual isocyanate group content was measured and found to be 69%.

[0015]

INDUSTRIAL APPLICABILITY The present invention can be used in combination with water because isocyanate groups remain stable as described above. For example, wood chips and capsules of the isocyanate compound of the present invention are mixed and heated to produce plywood or particles. There is an advantage that boards and the like can be manufactured safely. Since it can be used with water, it does not have the danger of unencapsulated raw isocyanate. When the capsule or capsule of the present invention is added to a raw material resin for resin molding such as a film or a pipe and molded, a mechanically reinforced molded product is obtained.

Claims (6)

[Claims] 1. A capsule obtained by encapsulating an isocyanate compound in hydrophobic resin particles. 2. The capsule according to claim 1, wherein the hydrophobic resin particles are made of a thermoplastic resin. 3. The hydrophobic resin particles are acrylic resin,
The capsule according to claim 1, which is made of vinyl chloride resin, norbornene resin, polyester resin, or polyolefin resin. 4. The hydrophobic resin particles have a particle size of 1 to 300 μm and a porosity of 0.1 to 0.8 (c).
c / g) The capsule according to claim 1. 5. The isocyanate compound is used in an amount of 10 to 90.
% Relative to 100 parts by weight of the hydrophobic resin particles included.
An encapsulant prepared by mixing 5 to 10 parts by weight of an antiblocking agent. 6. The capsule according to claim 5, wherein the antiblocking agent is stearic acid and / or a metal salt thereof.