JPH0788355A - Microcapsule - Google Patents

Abstract

PURPOSE:To form an org. halogen compd. into a microcapsule and to remote the reforming or curing of a resin composition by using a film consisting of a fine-grain org. polymer carrying an inorg. fine grain on the surface. CONSTITUTION:The core material of the org. halogen compd., halogenated resin having a functional group or organotin compd. is dispersed in an aq. medium, a coagulant for coagulating a fine-grain org. polymer, especially a positively charged alumina sol, is added, and then the emulsion of an org. polymer carrying an inorg. fine grain on the surface is added in small amts. under strong agitation. A deionizing agent such as an amphoteric ion exchanger is added, as required, agitation is continued, hence a composite film of the org. polymer and inorg. fine grain is formed on the core material, and a microcapsule slurry is obtained. The microcapsule is excellent in compatibility with resin and dispersibility, and the toxicity, corrosiveness or chemical reaction acceleration of the org. halogen compd., etc., as the core material are retarded.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an organic halogen compound,
The present invention relates to a microcapsule body containing a halogenated resin having a functional group or an organic tin compound (hereinafter referred to as "organic halogen compound or the like"). The microcapsule body of the present invention is suitably used as a compounding agent for the purpose of modifying or accelerating curing of a resin or a resin composition (hereinafter, simply referred to as “resin”).

[0002]

2. Description of the Related Art Blending of organic halogen compounds and the like for the purpose of modifying resins, for example, blending of di-n-butyltin dilaurate as a curing agent for brominated epoxy resins or silicone resins for increasing flame retardancy has been attempted. ing.

However, in general, organic halogen compounds and the like have remarkably poor compatibility and dispersibility with resins,
Further, since these compounds and the like have high reactivity and are difficult to control, they are disadvantageous in that they are difficult to handle in processing and cause nonuniform reaction in the resin. Furthermore, even if it could be successfully incorporated into a resin, many of these compounds were highly toxic and corrosive, and it was necessary to prevent them from being easily released from the resin under a normal environment.

On the other hand, organic halogen compounds and the like generally have high water repellency and therefore are difficult to disperse in fine powder form in water, and it has been difficult to produce microcapsules containing these compounds and the like. In addition, many of these compounds and the like have a large lipophilicity, and even if they are successfully encapsulated, they have the problem that they easily penetrate into the normal wall membrane and are released to the outside. The body was not obtained.

[0005]

The problem to be solved is that organic halogen compounds and the like have poor compatibility and dispersibility when blended with a resin, and it is difficult to control the reaction. That is, the reaction is likely to occur and the handling is difficult in the processing step, and these compounds are easily released from the resin even when incorporated into the resin.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventor has found that an organic halogen compound can be obtained by using a film composed of an aggregate of finely divided organic polymers carrying inorganic fine particles on the surface. The inventors have found that they can be microencapsulated, and have completed the present invention.

The technical elements of the microcapsule body of the present invention will be described below. (1) Organic Polymer As the organic polymer used in the present invention, conventionally known thermoplastic resins and thermosetting resins can be used, but those which are easily emulsified in water are preferred. Examples of such an organic polymer include acrylonitrile-butadiene rubber, acrylic rubber, styrene-butadiene rubber or ethylene-vinyl acetate rubber; or vinyl chloride resin, vinylidene chloride resin, fluorine resin, silicone polymer or styrene-acryl. Examples thereof include acid copolymers.

The fine-particle organic polymer having the fine inorganic particles supported on the surface thereof is obtained by, for example, emulsion-polymerizing a monomer constituting the above-mentioned organic polymer by a usual method, and the fine-particle organic polymer obtained has inorganic fine particles on the surface thereof. Can be carried to obtain.
At this time, it is necessary to have a sufficient affinity between the surface of the fine particle polymer and the inorganic fine particles. For example, in order to support colloidal silica as inorganic fine particles on the surface of the fine particle polymer, it is necessary to allow silanol groups to exist on the surface of the fine particle polymer. There are various methods for producing a finely divided organic polymer having a surface modified as described above, but those obtained by the core-shell type emulsion polymerization method have high stability in an emulsified state, and when encapsulated. The film-forming property is good, which is preferable.

In the core-shell type emulsion polymerization method, an emulsion of an organic polymer serving as a core is formed in advance, and then a monomer as a raw material of a polymer serving as a shell is added to the emulsion to carry out copolymerization. You can get it. As a surfactant used for forming an emulsion of an organic polymer serving as a core, an anionic surfactant, particularly a derivative of sodium sulfonate or sodium sulfate can be used to obtain an organic polymer having a large molecular weight. It is possible and preferable. The particle size of the core organic polymer is 0.05
˜1.0 μm is preferable. The organic polymer component serving as the core is 10 to 90 out of the resulting core-shell type polymer.
It is preferably contained by weight%, more preferably 50 to
90% by weight. If it is less than 10% by weight, the characteristics of the organic polymer itself are not sufficiently exhibited when it is formed into a microcapsule film, which is not preferable.

Monomers which are the raw materials of the shell polymer are acrylonitrile, methacrylonitrile, N
-Vinylpyrrolidone or N-vinylcaprolactam;
Used in combination with three components of an alkoxysilane having an acryloxy group, a methacryloxy group or a vinyloxy group; and another monomer having a vinyl group such as styrene, vinyltoluene, methyl (meth) acrylate or ethyl (meth) acrylate. It is preferable that a stable emulsion of polymer particles is easily formed.

Specific examples of the alkoxysilane having an acryloxy group, a methacryloxy group or a vinyloxy group include γ-acryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane and γ- (meth) acryloxypropyltris. (Trimethylsiloxy) silane, vinyltrimethoxysilane,
Examples thereof include vinyltris (methoxyethoxy) silane and vinyltrichlorosilane.

Another method for producing a surface-modified fine-particle organic polymer is to produce an emulsion of an organic polymer, and add a silane coupling agent, titanate coupling agent or aluminum silane coupling agent to the emulsion. There is a method of adding and reacting.

(2) Inorganic fine particles The inorganic fine particles used in the present invention preferably have a diameter of 50 mμ or less, and when they are in a colloidal form in which ultrafine particle powder is dispersed in water, the surface is modified. It is more preferable because it can be easily supported on the surface of the finely divided organic polymer. Examples of such inorganic fine particles include colloidal silica, alumina sol, zirconia sol, antimony oxide sol, tin oxide sol, silica or alumina powder having a diameter of 50 mμ or less.

The method of supporting the inorganic fine particles on the surface of the finely divided organic polymer whose surface has been modified is, for example, by dispersing the inorganic fine particles directly or in an aqueous medium and stirring in the organic polymer emulsion. A method of gradually adding is preferable. At this time, it is preferable to heat the system to 40 to 60 ° C. because loading is easily performed.

The combined ratio of the organic polymer emulsion and the inorganic fine particles is adjusted according to the properties required for the final microcapsule film, but it is 2 in the total amount of the organic polymer component and the inorganic component in the emulsion. It is general that about 98% by weight is the organic polymer component, preferably 2
It is 0 to 90% by weight. If it is less than 2% by weight, the performance of the organic polymer in the film does not appear, and if it exceeds 98% by weight,
The dispersibility of the fine particle organic polymer during microencapsulation is not preferable, which is not preferable.

The fact that the inorganic fine particles are supported on the surface of the fine particle organic polymer means that, for example, in the case of an organic polymer having high adhesiveness, a film is formed from an organic polymer emulsion before and after the inorganic fine particles are supported, and It can be confirmed by measuring a significant decrease in tackiness.

(3) Core Material The organic halogen compound or the like used as the core material in the present invention is a compound having fluorine, chlorine, bromine or iodine in the molecule; a fluorine resin having a functional group, a brominated epoxy resin or the like. Examples thereof include halogenated resins having a functional group or precursors thereof; alkylated tin compounds such as tetrabutyltin and esterified tin compounds such as dibutyltin dilaurate. The substance used as the core material may be liquid or powder as long as it becomes fine particles in the aqueous medium.

A liquid substance having a low solubility in water can be used by dispersing it in the form of fine particles in an aqueous medium. Powdery compounds with low solubility in water have poor dispersibility when added directly to the aqueous medium during the encapsulation process.
The compound is once added to a medium such as a basic sol or water glass, and this is kneaded or pulverized to obtain a dispersion of the compound in the form of fine particles, which is subjected to an encapsulation process. When added to the aqueous medium, the compound can be easily dispersed in the aqueous medium in the form of fine powder. Specifically, it can be made into fine particles by dispersing in an alumina sol, water glass or aluminum lactate sol and then kneading with a ball mill. At this time, the positively charged alumina sol also acts as an aggregating agent for solidifying the negatively charged fine particle organic polymers in the encapsulation step.

(4) Encapsulation method The above core material is dispersed in an aqueous medium, and an aggregating agent for aggregating the particulate organic polymer, particularly preferably a positively charged alumina sol, is added, followed by high agitation. Then, an emulsion of an organic polymer carrying inorganic fine particles on the surface is added little by little.

If necessary, a deionizing agent such as an amphoteric ion exchanger is added and stirring is continued to form a composite film of an organic polymer and inorganic fine particles on the core material to obtain a microcapsule slurry. At this time, it is better to heat when the film forming temperature of the organic polymer is high. The use of a deionizing agent, the formation of the composite film gradually progresses to facilitate encapsulation, and at the same time, the generated slurried capsule body can remove the leaching ionic compound from the vicinity of the interface between the core material and the film,
This is a preferred method because the elution of the core material from the capsule body can be further prevented.

By allowing fine particulate antimony oxide to exist in the slurry capsule body, it is possible to prevent dust explosion of the obtained fine powder capsule body, which is safe in handling.

When the slurry is filtered to remove coarse particles and then applied to a spray drier, fine powdery microcapsule bodies are obtained.

[0023]

The microcapsule body of the present invention is obtained by encapsulating a core material while agglomerating an emulsion of an organic polymer carrying inorganic fine particles on the surface with a flocculant, and by using this method, A practical capsule body having a halogen compound or the like as a core material could be obtained. Further, since the microcapsule body of the present invention covers the organic halogen compound and the like with a dense composite film composed of an inorganic substance and an organic polymer, it is easily dispersed in another resin, and permeates and elutes the core material. Are prevented.

[0024]

EXAMPLES The present invention will be described in more detail with reference to examples. Example 1 (Synthesis of core-shell type emulsion having silanol group) 1000 cc of pure water and Lebenol WZ (26 of sodium polyoxyethylene alkylphenyl ether sulfate) were placed in a stainless steel autoclave having an internal volume of 2 liters.
Wt% aqueous solution, manufactured by Kao Corporation) 19.2 g, potassium persulfate 2.5 g, tertiary dodecyl mercaptan 1.0 g,
Butyl acrylate 250 g and butadiene 250 g
Was charged with stirring with a propeller type stirring blade at 350 rpm,
The reaction is carried out at 50 ° C for 15 hours, and then Lebenol WZ
19.2 g, potassium persulfate 0.5 g, styrene 60
g, 30 g of acrylonitrile and 10 g of NUC silane monomer A-171 (vinyltrimethoxysilane, manufactured by Nippon Unicar Co., Ltd.) were added, and emulsion polymerization was continued at 70 ° C. for 5 hours.

The obtained emulsion was obtained by forming a styrene / acrylonitrile copolymer having silanol groups in the shell portion with butyl acrylate / butadiene copolymer rubber particles as the core, and the solid content was 36% by weight. .

(Preparation of fine particle dispersion of brominated epoxy resin) Brominated epoxy resin BREN-S (epoxy equivalent: 285 g / eq., Bromine content: 35.3% by weight, softening point: 83.5 ° C., Nippon Kayaku Co., Ltd.) 400 g and Alumina sol 200 (positively charged alumina sol having a particle size of 30 to 100 mμ, concentration 10% by weight, manufactured by Nissan Chemical Industries, Ltd.) 1
000 g was placed in a 5 liter magnetic ball mill and wet pulverized at 300 rpm at room temperature for 12 hours to obtain a dispersion liquid.

(Support of Inorganic Fine Particles) One 660 g of an organic polymer emulsion having a silanol group on the surface is used.
Charge into a liter beaker and use a propeller-type stirring blade for 200
With stirring at rpm, 2 g of 2,4,7,9-tetramethyl-5-decyne-4,7 diol was added as an antifoaming agent, and then Snowtex UP (solid content 20% by weight, diameter 5
An aqueous sol of elongated colloidal silica having a length of ˜20 mμ and a length of 40 to 300 μm. Nissan Chemical Industries, Ltd.) 23
0 g was gradually added, and stirring was continued at 40 to 45 ° C. for 1 hour to obtain a preparation liquid.

(Synthesis of Microcapsule Body) A 12-liter mixing tank was charged with 5.8 liters of pure water and 650 g of the fine particle dispersion of the above-mentioned brominated epoxy resin, and the mixture was stirred at room temperature with a propeller-type stirring blade at 400 rpm. 1 part of 890 g of the latex polymer having the above-mentioned inorganic fine particles supported on its surface
Added over time. Then, pure water 610 cc, diantimony trioxide powder 61.4 having an average particle size of 1.2 to 1.6 μm
g and ion exchange resin Amberlite IRN-150
(Mixed ion exchanger of cation and anion having sulfonic acid and quaternary amine group. Particle size 0.40
1.19 mm bead shape. Organo Co., Ltd.) 280g
Was added and stirring was continued at 50 ° C. for 3 hours.

The resulting slurry-like mixture was passed through a 80-mesh filter cloth to remove coarse particles, and then passed through a disc-type spray dryer to be dried, whereby a particle size of 3 to 1 was obtained.
A fine powdery microcapsule body containing 33% by weight of a 5 μm brominated epoxy resin and 67% by weight of a composite film consisting of a butadiene copolymer, silica, alumina and diantimony trioxide was obtained. Attached is a scanning electron micrograph (magnification: 500) of the particle structure of this microcapsule.

(Measurement of Bromine Eluted by Hot Water in Capsule Body) 1.0 g of the obtained capsule body and 40 cc of pure water were put into a Teflon pressure-resistant wet decomposition crucible (trade name "Uniseal", actual volume 110 cc, pressure resistance 350 kg). / cm ² , manufactured by Acom Co., Ltd.), sealed and heated at 120 ° C. for 200 hours. After heating and cooling to 25 ° C. and filtration, the content of bromine in the eluate was measured. As a result, 5 ppm of bromine was eluted with respect to the amount of brominated epoxy resin contained in the capsule body.

The above brominated epoxy resin BREN-S itself was used in place of the capsule body (0.33
g), when a similar experiment was conducted, 80 ppm of bromine was eluted.

Example 2 (Synthesis of capsule containing di-n-butyltin dilaurate) A capsule containing di-n-butyltin dilaurate was synthesized as follows. Instead of the fine particle dispersion of brominated epoxy resin used in Example 1, the following di-
A fine particle dispersion of butyltin dilaurate was prepared. 1
In a 2 liter internal volume mixing tank, 5.8 liters of pure water, 5.3 g of Metroses 90SH4000 (methoxy hydroxypropyl cellulose, manufactured by Shin-Etsu Chemical Co., Ltd.), di-n
186 g of butyltin dilaurate and alumina sol 2
00 186 g was charged, and stirring was continued at room temperature with a propeller-type stirring blade at 400 rpm for 30 minutes to prepare a dispersion liquid.

Next, 890 g of an emulsion of an organic polymer having the inorganic fine particles obtained in Example 1 supported on its surface was gradually added over 5 minutes. Subsequent operations are exactly the same as in Example 1, including 33% by weight of di-n-butyltin dilaurate having a particle size of 5 to 30 μm, and containing butadiene copolymer, silica, alumina and diantimony trioxide composite film 67. A finely powdered microcapsule body with a weight percentage was obtained. Attached is a scanning electron micrograph of 5000 times the particle structure of the microcapsules.

(Evaluation of pot life as a curing accelerator for silicone resin) Kaneka Cyril SAT200
(Silicone-acrylic resin, manufactured by Kanegafuchi Chemical Industry Co., Ltd.)
100 g, 3.03 g of the capsule obtained in Example 2 (including 1.0 g as di-n-butyltin dilaurate) and 0.5 g of pure water were charged in a stainless steel container and mixed with a disper at 2000 rpm for 10 minutes, The capsule bodies were dispersed well. This was left at room temperature for 1 week, but no increase in viscosity was observed. Meanwhile, at 120 ℃ 3
When heated for 0 minutes, it was completely cured.

On the other hand, 1.0 g of di-n-butyltin dilaurate was used instead of using the capsule body, and the same procedure as described above was performed except that it was almost cured after 1 day at room temperature.

[0036]

INDUSTRIAL APPLICABILITY The microcapsule body of the present invention is excellent in compatibility and dispersibility with respect to a resin, and has sufficient toxicity, corrosiveness or chemical reaction accelerating property of an organic halogen compound as a core material under a normal environment. It can be suppressed and, for the first time, exhibits flame retardancy or an effect as a polymerization catalyst under the conditions of use, for example, at a high temperature.

[Brief description of drawings]

FIG. 1 is a scanning electron micrograph (magnification: 500) of the particle structure of the microcapsules obtained in Example 1.

FIG. 2 is a scanning electron micrograph (magnification: 5000) of the particle structure of the microcapsules obtained in Example 2.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C08L 101/00

Claims (1)

[Claims] 1. A microcapsule body having a film made of an aggregate of fine particle organic polymers having an organic halogen compound, a halogenated resin having a functional group or an organic tin compound as a core material, and supporting inorganic fine particles on the surface.