JPH0764041B2 - Method for producing multi-layer structure fine article - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a microstructure having a multilayer structure in which a hot-melt adhesive resin layer is provided on the surface of solid particles, and more specifically, a liquid crystal display cell. Gap material, electro-display cell gap material, electrode plate conductive or insulative spacer, or film, sheet, spacer for holding gap between blocks, flat surface for optical and other applications Alternatively, the present invention relates to a method for producing a fine multi-layer structure product used for forming fine protrusions on a concave surface.

(Prior Art) Fine particles having a multi-layer structure formed by coating the surface of a solid particle made of a resin or an inorganic material with a hot-melt type adhesive resin are used as a substrate by melting the adhesive resin at a predetermined temperature. Since it can be adhered to, it is used, for example, as a gap material for liquid crystal display cells.

By the way, for coating the solid particles with the hot-melt adhesive resin, for example, the following method can be considered.
That is, solid particles are added to and dispersed in a solution in which a hot-melt adhesive resin is dissolved in a solvent, and then this is heated and dried to evaporate the solvent.

(Problems to be Solved by the Invention) Generally, the wettability of the hot-melt type adhesive resin to the surface of the solid particles is not good, so that it is difficult to coat the adhesive resin in the state of a monomolecular layer. It is necessary to coat the adhesive resin of. As a result, a thick adhesive resin layer is formed on the surface of the solid particles, and there is a problem that the fine particles having a multilayer structure block each other due to the adhesiveness of the adhesive resin layer. Therefore, if this fine material having a multilayer structure is used as a gap material for a liquid crystal display cell, for example, good single-particle dispersibility cannot be obtained due to mutual adhesion of the gap materials, which results in deterioration of quality.
Further, when the amount of the adhesive resin coated on the solid particles is small, the resin cannot uniformly coat the solid particles, and the adhesiveness to the substrate is reduced.

In particular, when coating a solid particle with a hot-melt adhesive resin having very low adhesiveness such as polyolefin, even if the adhesive resin is coated on the surface of the solid particle, the adhesive resin is Peels off easily.

The present invention solves the above drawbacks, and its purpose is to:
It is an object of the present invention to provide a method for producing a fine multi-layer structure product capable of forming a thin and uniform hot melt adhesive resin on the surface of solid particles. Still another object of the present invention is to provide a method for producing a fine multi-layer structure product capable of coating a resin having poor adhesiveness such as polyolefin without peeling.

(Means for Solving the Problem) The method for producing a multilayer structure fine product of the present invention comprises a step of forming a titanium oxide layer on the surface of the solid particles by hydrolyzing an organic titanate compound into the solid particles, The solid particles provided with the titanium oxide layer are dispersed in a hot-melt adhesive resin solution or emulsion, and the hot-melt adhesive resin is deposited on the surface of the titanium oxide layer from the solution or emulsion. The above-mentioned object is achieved by including the steps.

As the material and shape of the solid particles according to the present invention, those shown below can be used.

[Material]

Polyethylene, polypropylene, polymethylpentene,
Polyvinyl chloride, polytetrafluoroethylene, polystyrene, polymethyl methacrylate, polyethylene terephthalate, polybrene terephthalate, polyamide,
Linear or cross-linked polymers such as polyimide, polysulfone, polyphenylene oxide, polyacetal; epoxy resin, phenol resin, melamine resin, unsaturated polyester resin, divinylbenzene polymer, divinylbenzene-styrene copolymer, divinylbenzene-acryl. Resins having a network structure such as acid ester copolymers, diacrylic phthalate copolymers, triallyl isocyanurate polymers, and benzoguanamine polymers.

Among the above solid particles, particularly preferable are resins having a network structure such as divinylbenzene copolymer, divinylbenzene-styrene copolymer, divinylbenzene-acrylic acid ester copolymer, and diacrylic phthalate polymer. is there.

As inorganic materials, silicate glass, borosilicate glass,
Lead glass, soda-lime glass, alumina, alumina silicate or the like can be used. Of these, silicate glass and borosilicate glass are particularly preferable.

〔shape〕

The shape of the solid particles is not limited, for example,
A spherical shape, an elliptic shape, or a cylindrical shape having the following dimensions can be used.

For solid spherical solid particles, the diameter is 0.1μm to 1000μ
It is preferably in the range of m, and a particularly preferred range is 1 μm to 100 μm.

In the case of ellipsoidal solid particles, the minor axis is 0.1 μm to 1000
The range is preferably μm, and the particularly preferred range is 1 μm.
Or 100 μm. Diameter to minor axis ratio is 1 to 10
The range of 1 to 5 is particularly preferable, and the range of 1 to 5 is particularly preferable.
Is.

For cylindrical solid particles, the diameter is 0.5μm to 1000μ
The range is preferably m, and the particularly preferred range is 3 μm to 100 μm. Cylinder length to diameter ratio is 1 to 5
A range of 0 is preferable, and a particularly preferable range is 1 to 1.
It is 0.

[Formation of titanium oxide layer]

The method of forming the titanium oxide layer on the surface of the solid particles as described above can be performed, for example, by the following method. After applying the organic titanate compound to the surface of the solid particles, the organic titanate compound is hydrolyzed to form a titanium oxide layer.

Examples of the organic titanate compound used here include tetraethoxy titanium Ti (OC ₂ H ₅ ) ₄ , tetrapropoxy titanium Ti (OC ₃ H ₇ ) ₄ , tetrabutoxy titanium T
i (OC ₄ H ₉ ) ₄ , tetrapentoxytitanium Ti (OC
₅ H ₁₁ ) ₄ , tetrahexoxy titanium Ti (OC ₆ H ₁₃ ) ₄ , tetrakis (2-ethylhexoxy) titanium Ti [OCH ₂ CH
(C ₂ H ₅ ) C ₄ H ₉ ] ₄ , Tetradodecylalkoxy titanium Ti
(OC ₁₂ H ₂₅ ) ₄ , tetrastearoxytitanium Ti (OC
₁₇ H ₃₅ ) ₄ , dipropoxy bis (acetylacetonato) titanium Ti (OC ₃ H ₇ ) ₂ [OC (CH ₃ ) CHCOCH ₃ ] ₂ , dibutoxy bis (triethanolaminato) titanium Ti
(OC ₄ H ₉ ) ₂ [OC ₂ H ₄ N (C ₂ H ₄ OH) ₂ ] ₂ , dihydroxybis (lacto) titanium Ti (OH) ₂ [OCH (CH ₃ ) COO
H] ₂ , titanium propoxyoctylene glycolate Ti [OCH ₂ CH (C ₂ H ₅ ) CH (C ₃ H ₇ ) OH ₄ ] and the like are used. Among them, tetrapropoxy titanium is particularly preferable. They are tetrabutoxy titanium, tetrakis (2-ethylhexoxy) titanium, dipropoxy bis (acetylacenato) titanium, and dibutoxy bis (triethanolaminato) titanium.

As a method of applying the above-mentioned organic titanate compound to the surface of solid particles, the organic titanate compound is dissolved in a solvent such as n-hexane, cyclohexane, benzene, toluene, trichlene, and freonon-113, and the solid is dissolved in the solvent. A preferred method is to impregnate the particles and evaporate the solvent with thorough mixing. After evaporating the solvent, 60 ℃
Heating at 100 to 100 ° C. is preferable, but this heating step may be omitted.

It is considered that the organic titanate compound formed on the surface of the solid particles by the above steps reacts with moisture in the air and is hydrolyzed to form a titanium oxide layer having the following structure, for example. Be done.

[Regarding the Amount of Titanium Oxide Layer] The amount of the titanium oxide layer formed in a thin film on the surface of the solid particles is, in terms of titanium, determined in the range of 0.01 mg to 500 mg per surface area 1 m ² of the solid particles. Is preferred.
A more preferable amount of titanium oxide layer is 0.1 mg to 100 mg.
mg. If the amount of titanium oxide layer is less than 0.01 mg per surface area 1 m ² of the solid particles in terms of titanium equivalent,
Adhesion between the solid particles and the hot melt olefin resin is not exhibited. On the contrary, the amount of the titanium oxide layer is 5 in terms of titanium equivalent weight per 1 m ² of the surface area of the solid particles.
When it is more than 00 mg, it causes unfavorable results such as reduction of electric resistance value.

[Hot melt adhesive resin]

The solid particles having the titanium oxide layer formed on the surface are coated with the hot-melt adhesive resin shown below. The hot melt type adhesive resin used in the present invention is shown below.

(1) Olefin-based adhesive resin Polyethylene wax, polyethylene wax oxide, low-density polyethylene, high-density polyethylene, polyethylene oxide, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-carbon monoxide three-dimensional copolymer, Ethylene
Acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-vinyl acetate-acrylic acid three-dimensional copolymer and other carboxyl group-containing ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-vinyl alcohol three-dimensional copolymer Polymer, ethylene-oxide ion copolymer, sulfonated polyethylene, ethylene-propyne copolymer, polypropylene, hydrogenated polybutadiene, hydrogenated polyisoprene,
Hydrogenated polybutadiene-styrene block copolymer, hydrogenated polyisoprene-styrene block copolymer and oxides thereof.

(2) Other adhesive resins Polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polybutadiene, polyisoprene, polyamide, polyurethane, polyester, polyimide, acetalized polyvinyl alcohol, butyralized polyvinyl alcohol, butadiene-styrene random copolymer , Butadiene-styrene block copolymer,
Isoprene-styrene block copolymer and the like.

Among the resins shown in (1) and (2) above, the preferred adhesive resin is the polyolefin shown in (1), and the particularly preferred adhesive resin is polyethylene wax and its oxide, ethylene-vinyl acetate Polymers and their oxides, carboxyl group-containing ethylene vinyl acetate copolymers.

The requirement that the hot-melt adhesive resin should have is that it is softened or melted by heating at a temperature lower than the softening temperature and the decomposition temperature of the solid particles.
The desirable softening or melting temperature range of the adhesive resin is 85 to 200 ° C, and the particularly preferred temperature range is 90 to 170 ° C.
Is.

[Coating method of hot melt adhesive resin]

The method for coating the surface of the titanium oxide layer with the above hot-melt adhesive resin includes the following (1) and (2)
Two methods shown in can be used.

(1) After dissolving the homelt-type adhesive resin in a solvent that is soluble in the resin and insoluble in water,
This solution is emulsified by adding it to water containing a surfactant and stirring. At this time, the emulsion particles of the emulsion are preferably 1 μm or less.

The solid particles having the titanium oxide layer formed on the surface thereof are added to this emulsion and sufficiently stirred to suspend them in the liquid.
While maintaining this suspension state, the temperature of the emulsion is gradually lowered until it reaches the melting point of the hot-melt adhesive resin solution or below, or it has solubility in the solvent and is hot-melt. A precipitant having poor solubility in the mold adhesive resin is gradually added dropwise to the system. It is also effective to drop the precipitant at the same time as the temperature is lowered.

In the above steps, the concentration of the hot melt adhesive resin solution is preferably in the range of 0.1 to 20 Wt%.

Further, it is desirable that the amount of the coated solid particles added to the emulsion 1 is 100 g or less. As the surfactant, polyoxyethylene alkyl phenyl ether,
Polyoxyethylene / polyoxypropylene block polymer, sorbitan ester, glycerin ester, alkylbenzene sulfonic acid and the like can be used.
For example, when polyoxyethylene alkylphenyl ether is used as the surfactant, it is preferable to use the surfactant in an amount of 0.01 g to 0.5 g per 100 ml of water. The liquid ratio of the aqueous surfactant solution to the hot melt adhesive resin solution is in the range of 50: 1 to 1: 5, and particularly preferably in the range of 20: 1 to 3: 1.

In the above steps, when lowering the system temperature,
The initial temperature is preferably 60 ° C. or higher and 100 ° C. or lower, and the end point of temperature decrease is preferably 0 ° C. or higher and 50 ° C. or lower. Also, the rate of temperature decrease is 0.
It is desirable to be in the range of 01 ° C / min to 10 ° C / min.
Further, in the above steps, when the precipitant is added to the system, it is desirable to add the precipitant in the range of 0.01 cc / min to 1 cc.

When the above steps are completed, the surface of the titanium oxide layer is covered with the hot melt adhesive resin. Next, in order to separate this product from the system and take it out, an operation such as filtration or centrifugation is carried out, followed by washing with a suitable cleaning agent. If necessary, further heat dry,
A desired multi-layer structure fine product can be obtained.

(2) After dissolving the hot-melt type adhesive resin in a solvent, solid particles having a titanium oxide layer formed on the surface are added to this solution, and sufficiently stirred to suspend in the liquid. . While maintaining this suspension state, the temperature of the suspension is gradually lowered to a temperature not higher than the melting point of the hot-melt adhesive resin solution, or the suspension has solubility in the solvent and is hot-melt. A precipitant having poor solubility in the mold adhesive resin is gradually added dropwise to the system. It is also effective to drop the precipitant at the same time as the temperature is lowered.

In the above steps, the concentration of the hot melt adhesive resin solution is preferably in the range of 0.1 to 20 Wt%. Moreover, it is desirable that the addition amount of the solid particles having the titanium oxide layer formed on the surface thereof to the emulsion 1 is 100 g or less. In the above steps, when the system temperature is lowered, the initial temperature is preferably room temperature or higher and 200 ° C. or lower, and the end point of the temperature drop is −
It is desirable that the temperature is 30 ° C or higher and 50 ° C or lower. Also,
The rate of temperature decrease is preferably in the range of 0.01 ° C / minute to 10 ° C / minute. In addition, in the above process, when adding a precipitant to the system, 0.01 cc / min to 1 cc
It is desirable to add in the range of / min.

When the above steps are completed, the surface of the titanium oxide layer is covered with the hot melt adhesive resin. Next, in order to separate this product from the system and take it out, an operation such as filtration or centrifugation is carried out, followed by washing with a suitable cleaning agent. If desired, the desired fine multi-layer structure product can be obtained by further heating and drying.

In the production methods (1) and (2) above, as a solvent for dissolving the hot-melt adhesive resin, benzene, toluene, xylene, ethylbenzene, cyclohexylbenzene, diethylbenzene, styrene, chlorobenzene, dichlorobenzene, and tribenzene are used. Chlorobenzene, chlorotoluene, chloronaphthalene, pentanone, hexanone, cyclohexanone, heptanone, isoborone, acetophenone and the like are used. Particularly preferred solvents are benzene, toluene and xylene.

The precipitating agent is methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl ethyl ketone, ethyl acetate, tetrahydrofuran or the like. Particularly preferred precipitants are methyl alcohol, ethyl alcohol, isopropyl alcohol.

[Aspect of Hot Melt Type Adhesive Resin Layer]

The thickness of the hot melt adhesive resin layer formed on the surface of the titanium oxide layer is preferably in the range of 0.01 μm to 100 μm. After forming the hot-melt adhesive resin, it is also effective to carry out light crosslinking by means of radiation irradiation, post-heating or the like, but this step may be omitted in particular.

(Example) Below, the Example of this invention is described in detail.

Example 1 10.10 μm average particle size composed of divinylbenzene polymer,
For 10 g of resin microspheres with a standard deviation of 0.40 μm, tetrapropoxy titanium (manufactured by Nippon Soda Co., Ltd., trade name A-1)
A solution prepared by dissolving 15 g of n-hexane in 15 ml was added and mixed well with a spatula, and then n-hexane was evaporated. Then crush this thoroughly in a mortar,
I lost the lump.

As a hot-melt adhesive resin, polyethylene wax (manufactured by Sanyo Kasei Co., Ltd., trade name Sun Wax 151-
2.6 g of P) was added to 50 ml of toluene and dissolved in a 80 ° C warm bath.

On the other hand, 0.5 g of the surface-active agent Neugen EA120 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was dissolved in 300 ml of water to prepare a surface-active agent solution.
An emulsion was prepared by stirring while maintaining the temperature of.

Resin microspheres treated with the organic titanate compound were added to this emulsion, and after sufficiently suspended and dispersed, the temperature was adjusted to 0.
It was gradually cooled to 45 ° C at a temperature decrease rate of 1 ° C. During this time, stirring was continued. This suspension was filtered through a glass filter (G-4), thoroughly washed with methanol, and then suspended in an ethanol / Freon 113 mixed solution (2: 1 by volume). In this state, the mixture was allowed to stand for 15 hours, and the supernatant was decanted to remove fine particles of polyethylene wax. This was filtered again on a glass filter and then washed with Freon 113. This was dried under reduced pressure at room temperature to obtain a multi-layer structure fine product.

Coulter counter ZB
As a result of measurement with a / C-1000 type particle size measuring device, an average particle size of 10.64 μm and a standard deviation of 0.45 μm were obtained. From this result, it was revealed that the polyethylene wax was formed on the surface of the resin microspheres with an average thickness of 0.27 μm. As a result of observing the surface with a scanning electron microscope,
It was found that the surface of the resin microspheres was uniformly coated with polyethylene wax without any gaps.

A spray solution prepared by suspending the fine particles having a multilayer structure in Freon 113 was sprayed from a nozzle onto a glass plate. On the glass plate, the fine spheres were dispersed without coalescing and showed good single particle dispersibility. After the glass plate was left in a heating furnace at 110 ° C for 10 minutes, the adhesion part of the glass plate and the multilayer structure fine substance was observed with a magnifying glass of 200 times. It was confirmed that the resin microspheres were sufficiently adhered to the glass plate by being interposed between them and the spheres.

Example 2 Made of silicate glass and having a particle size of 7.30 μm and a standard deviation of 0.32 μm.
Tetrabutoxy titanium (trade name B-1 manufactured by Nippon Soda Co., Ltd.) 0.35 per 10 g of inorganic microspheres having a particle size distribution of m.
A solution prepared by dissolving g in 15 ml of n-hexane was added, mixed well with a spatula, and then n-hexane was evaporated. Then, this product was thoroughly crushed in a mortar to eliminate lumps.

As a hot-melt adhesive resin, a carboxyl group-containing ethylene-vinyl acetate copolymer (manufactured by Takeda Pharmaceutical Co., Ltd.)
2.9 g of trade name Dumira C-2280) was added to 200 ml of toluene and dissolved in a 60 ° C warm bath. Inorganic microspheres treated with the above organic titanate compound were added to this solution, and after sufficiently suspending and dispersing, ethanol was added dropwise at a rate of 0.5 ml / min. The dropping was continued until the dropping amount of ethanol reached 120 ml. After that, the temperature was lowered to room temperature, followed by filtration with a glass filter (G-4), followed by washing with ethanol. This was suspended in 1 of an ethanol / Freon 113 mixed solution (volume ratio 2: 1). In this state
The suspension was allowed to stand for 15 hours, and the supernatant was decanted to remove the carboxyl group-containing ethylene-vinyl acetate copolymer floating pieces. This was filtered again on a glass filter and then washed with Freon 113. This was dried under reduced pressure at room temperature to obtain a multi-layer structure fine product.

The particle size of this fine multi-layer structure is measured by Coulter Counter ZB
As a result of measurement with a / C-1000 type particle size measuring device, the average particle size was 7.74 μm and the standard deviation was 0.40 μm. From this result, it was found that the hot melt adhesive resin layer was formed on the surface of the inorganic microspheres with an average thickness of 0.22 μm. Further, as a result of observing the surface of the fine multi-layer structure article with a scanning electron microscope, it was found that the carboxyl group-containing ethylene-vinyl acetate copolymer layer was uniformly formed on the surface of the fine multi-layer structure article.

A spray solution prepared by suspending the fine particles having a multilayer structure in Freon 113 was sprayed from a nozzle onto a glass plate. On the glass plate, each fine multi-layered structure is sprayed without coalescence,
It showed good single particle dispersibility. This glass plate 120
After leaving it in a heating furnace at ℃ for 10 minutes, observation with a magnifying glass of 200 times confirmed that the adhesive resin layer melted and that the glass plate and the inorganic microspheres were sufficiently bonded. .

Example 3 Tetrakis (2-ethylhexoxy) titanium (manufactured by Nippon Soda Co., Ltd.) was used for 10 g of glass short fibers composed of borosilicate glass and having an average diameter of 9.05 μm and an average length of 15.1 μm.
A solution prepared by dissolving 0.3 g of TOT) (trade name) in 15 ml of n-hexane was added, mixed well with a spatula, and then n-hexane was evaporated. Then, this product was thoroughly crushed in a mortar to eliminate lumps.

As a hot-melt type adhesive resin, 3.5 g of polyethylene wax oxide (Sun Wax E-300 manufactured by Sanyo Chemical Industry Co., Ltd.) was added to 50 ml of toluene and dissolved in a hot bath at 80 ° C. Meanwhile, the surfactant Neugen EA120 is added to 300 ml of water.
(Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 g was dissolved to prepare a surfactant solution, the above polyethylene wax oxide solution was added thereto, and the mixture was stirred while maintaining a temperature of 80 ° C. to obtain an emulsion. It was created.

Glass short fibers treated with the above organic titanate compound were added to this emulsion, and while sufficiently suspended and dispersed, the temperature was gradually cooled to 45 ° C at a temperature decreasing rate of 0.2 ° C per minute, and then ethanol 2
00 ml was added. This suspension was added to a glass filter (G-
After filtering in 4) and thoroughly washing with methanol,
Separated and purified in the same manner as in Example 1.

As a result of observing the thus obtained multi-layered structure fine material with a scanning electron microscope, the average diameter was 9.45 μm.
From this result, the average of 0.20 μm on the surface of the glass short fiber
It was found that the hot melt type adhesive resin layer was formed with the thickness of.

(Effect of the Invention) As described above, according to the present invention, the surface of the titanium oxide layer can be uniformly coated with a small amount of the hot-melt adhesive resin. Moreover, by interposing the titanium oxide layer, the adhesive resin can be coated on the surface of the solid particles with relatively good adhesiveness. Therefore, even a resin having poor adhesion to the surface of solid particles, such as polyolefin, can be coated without peeling,
Moreover, it is possible to coat the adhesive resin in an almost monomolecular layer state and prevent the multi-layered structure fine particles from blocking each other, and this multi-layered structure fine material is used, for example, as a gap material for a liquid crystal display cell. When used, good single particle dispersibility is obtained.

Further, since the adhesiveness of the hot-melt type adhesive resin to the solid particles can be enhanced, it becomes possible to use an adhesive resin having a low melting point or softening point, which can be melted at a relatively low temperature to improve the productivity. In addition to the improvement, the resin can be surely melted to secure desired adhesiveness.

Claims (1)

[Claims] 1. A step of forming a titanium oxide layer on the surface of a solid particle by hydrolyzing an organic titanate compound into the solid particle, and the solid particle provided with the titanium oxide layer is subjected to hot melt adhesiveness. And a step of dispersing the hot melt adhesive resin on the surface of the titanium oxide layer from the solution or emulsion and dispersing it in a resin solution or an emulsion.