JPH07258359A - Fine high-molecular polymer particle and production of high-molecular polymer dispersion - Google Patents

Abstract

PURPOSE:To obtain a high-molecular polymer dispersion having a uniform particle diameter distribution and a high heat resistance by forcing a specific epoxy ester or unsatd. polyester into a surfactant soln. through a microporous film to emulsify the epoxy ester or unsatd. polyester and then polymerizing it. CONSTITUTION:A high-molecular polymer dispersion having a uniform particle diameter distribution and a high heat resistance is obtd. by forcing 100 pts. mixture comprising 0-90 pts. monomer having at least one carbon-carbon double bond and a mol.wt. lower than 250 and 10-100 pts. epoxy ester obtd. from an epoxy resin having at least two carbon-carbon double bonds and a mol.wt. of 260-10,000 and an unsatd. monobasic acid or 10-100 pts. unsatd. polyester into 30-10,000 pts. aq. surfactant soln. with a concn. of 0.01-10wt.% through a microporous film having a uniform micropore size and then subjecting the resultant emulsion to polymn.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a highly cross-linked solvent resistance useful as a slipperiness improver for plastic films, a carrier for chromatography, a liquid crystal display panel spacer, a standard sample for microscopic examination, a clinical test agent and the like. The present invention relates to a polymer fine particle having excellent heat resistance and a narrow particle size distribution, and a method for producing a high molecular polymer dispersion obtained by dispersing the fine particle in an aqueous medium.

[0002]

2. Description of the Related Art Prior to describing the prior art relating to the present invention, the technical background of the present invention will be described.

In a plastic film such as a polyester film or a magnetic tape using the same as a base material, in order to reduce the coefficient of friction and obtain stable running property and wear resistance, fine irregularities are provided on the surface of the film. The slipperiness is improved. The unevenness is usually formed by internally adding an inorganic filler such as calcium carbonate, silica, talc or clay to a plastic such as polyester. Since these inorganic fillers have excellent heat resistance, they are advantageous, for example, in that they can be added during the polyester synthesis step at a high temperature of about 250 to 350 ° C. However, on the other hand, these inorganic fillers are
Due to the large difference in specific gravity from plastics such as polyester, it is difficult to disperse uniformly, and due to its poor affinity with plastics, the filler falls off from the surface during film or tape processing or high-speed winding. This may cause performance problems.

For these reasons, it is conceivable to use an organic filler having a good affinity with plastics and a small difference in specific gravity from the plastics. However, this organic filler is required to have a heat resistance of 250 to 350 ° C. as described above, as well as to have a uniform particle size, solvent resistance, and excellent transparency.

By the way, vinyl polymers have hitherto been produced by emulsion polymerization and suspension polymerization. In particular, emulsion polymerization using a seed polymerization method can produce an emulsion having an extremely uniform particle size. In seed polymerization, particles obtained by other methods such as emulsion polymerization method and dispersion polymerization method are used as seed particles, and a polymerization initiator is added to this to gradually add monomers and a surfactant so that new particles cannot be formed as the polymerization progresses. In addition, it is a method of growing particles. According to the seed polymerization method, particles having a sharp particle size distribution can be obtained by selecting appropriate seed particles, and the particle size is controlled by the swelling ratio of the seed particles and the polymerizable monomer. It is possible.

However, the molecular weights of the polymerizable monomers used in these emulsion polymerizations are all less than 250, and the polymers obtained are also inferior in heat resistance or solvent resistance. On the other hand, from the viewpoint of heat resistance, the molecular weight is 250 or more 100
It is preferable to use a polyfunctional vinyl oligomer of 00 or less, but in these oligomers, the mass transfer of the compound into the micelle is not performed smoothly, and the compound is easily separated into an aqueous phase part and an oil phase part, and is stable. An emulsion polymerization liquid cannot be obtained.

In suspension polymerization, it is technically difficult to obtain fine polymer fine particles having a uniform particle size distribution by polymerization. The reason for this is that it is difficult to produce particles that are essentially uniform, and particles also coalesce during polymerization.

Therefore, in suspension polymerization, a suspension stabilizer is used to prevent coalescence of particles and to stabilize the polymerization. Suspension stabilizers are generally calcium carbonate,
A sparingly soluble inorganic compound salt such as calcium phosphate and a water-soluble polymer such as polyvinyl alcohol and gelatin are used.

Even when these suspension stabilizers are actually used, the particle size range of the particles obtained by the suspension polymerization is about several tens of μm or more, and the particle size distribution becomes broad, so that the polymerization is carried out. Later operations such as classification are required,
Not a valid method.

It has also been studied to obtain an emulsion having a very sharp particle size distribution by emulsification using various emulsifiers having stronger shearing force.

One of them is, for example, emulsification with a homomixer. However, this method does not provide a sufficient shearing force to produce a uniform and stable emulsion, which causes a problem such as easy separation. For that purpose, machines with stronger mechanical emulsifying power than homomixer, such as colloid mill,
Emulsification using various homogenizers is being studied.

In the case of a colloid mill (Manton Gorin Co.), the slit is pressed by a strong spring, and the structure is such that the preliminary emulsified liquid injected at a high pressure passes through the gap and atomizes by a shearing force. Has become. However, in the injection of the pre-emulsion, the slit interval is not constant because it is performed while pulsating, so that the emulsion having a uniform particle size distribution cannot be obtained. It is not suitable for mass production because it is necessary to make the emulsion liquid uniform through repeated slits. In the case of a homogenizer, it is formed from a disk rotating at high speed and fine slits, and although some minute particles can be obtained, the rotation speed of the disk and the slit interval are limited, so stable and uniform fine particles are obtained. It didn't reach.

Further, attempts have been made to obtain uniform polymer fine particles by utilizing a porous film. For example, JP-A-4
Japanese Patent No. 359901 discloses a method in which a monomer suspension is obtained by injecting a monomer into a dispersion medium through a microporous body and polymerizing the suspension. According to this method, a uniform particle size is obtained. It is said that polymer particles can be obtained. In Japanese Patent Laid-Open No. 6-1854, an oil phase liquid containing an organic compound A having a molecular weight of 5000 or less and a polymerizable monomer is extruded into a water phase liquid through a porous membrane to obtain an emulsion, which is polymerized. It is said that polymer particles having a uniform particle size can be obtained. As the organic compound A, a styrene oligomer is also mentioned.

However, none of the proposals utilizing these porous membranes discloses obtaining highly heat-resistant polymer particles which can withstand a high temperature of 250 to 350 ° C., which is comparable to inorganic fine particles.

[0015]

SUMMARY OF THE INVENTION Under the above circumstances, the present invention provides a polymer fine particle having a sharp particle size distribution and excellent heat resistance, solvent resistance, and transparency, which is dispersed in an aqueous dispersion medium. It is an object of the present invention to provide a method for producing a high-molecular polymer dispersion liquid as described above.

[0016]

Therefore, as described above, the inventors of the present invention have conducted intensive studies focusing on the problems to be solved by the present invention, and as a result, have conducted a normal emulsification using a specific emulsification means. Epoxy ester resin or unsaturated polyester resin having a molecular weight of 250 or more and 10000 or less having two or more carbon-carbon double bonds, which cannot be obtained by polymerization, can be emulsified to obtain an emulsion having a very sharp particle size distribution. However, they have found that highly heat-resistant polymer fine particles (dispersion liquid) can be produced by polymerizing them, and completed the present invention.

That is, in the present invention, A) 0 to 90 parts of a monomer having a molecular weight of less than 250, which has at least one carbon-carbon double bond in one molecule, and B) two or more carbon-carbon double bonds in one molecule. Epoxy ester resin or unsaturated polyester resin 10-100 having an epoxy group-containing epoxy resin having a molecular weight of 250 or more and 10000 or less and an unsaturated group-containing monobasic acid
The total amount of A) and B) is 100 parts, and the surfactant concentration is 0.0 through a microporous membrane having a uniform pore size.
A polymer having a uniform particle size distribution and having high heat resistance, which is obtained by polymerizing an emulsion obtained by press-fitting it into an aqueous solution of 1 to 10% by weight in an amount of 30 to 10000 parts. It relates to a method for producing a polymer dispersion.

An example of an emulsifying apparatus equipped with a microporous membrane suitable for emulsifying fine particles in the present invention will be described. FIG. 1 is a conceptual diagram thereof. The emulsification device comprises a module 1 having a microporous membrane, a storage tank 3 for an oligomer (containing a monomer) as a dispersed phase, and a water storage tank 4 for dissolving a surfactant serving as a continuous phase. The emulsification takes place in module 1. That is, the water containing the surfactant, which is a continuous phase, is circulated by the pump 5, and the gas cylinder 2
Thus, emulsification is performed by press-fitting the oligomer (containing a monomer) in the dispersed phase into the module 1. In addition,
In FIG. 1, 2 is an accumulator, 6 is a pressure adjusting valve, 7 is a pressure gauge, 8 is a safety valve, 9 is a valve, 10 is a pressure gauge, and 11 is a valve.

Further, a cross section of the module 1 is shown in FIG.
This module is composed of a pipe a and a pipe b (microporous membrane), and a dispersed phase supply port c is attached to the pipe a. Reference character d denotes an O-ring attached to the pipe b to prevent liquid leakage of the dispersed phase. The pipe b is a microporous film having a thickness of 0.3 to 2 mm. This porous membrane is designed to have a large number of very uniform through holes having a pore diameter of 0.01 to 50 μm. The pipe _{material, CaO-Al 2 O 3 -B} 2 O 3 -Si
O ₂ based porous _{glass, CaO-Al 2 O 3 -B} 2 O 3 -Si
The porous film is a glass-based porous film such as O ₂ —Na ₂ O—MgO-based porous glass (shirasu porous glass: SPG) or a ceramic-based porous film such as alumina, zirconia, and magnesia.

The principle of emulsification will be described with reference to FIG. A is an oligomer (containing a monomer) which is a dispersed phase, a is a water containing a surfactant which is a continuous phase, and d is a porous film,
It is flowing in the direction of the arrow in the figure. By applying pressure to the dispersed phase, it passes through the through-holes of the porous membrane and is extruded as droplets into the continuous phase to start emulsification. In this case, the pressure required for press-fitting may be 1.0 to 10 times, preferably 1.0 to 3 times the pressure (critical pressure) at the start of emulsification.

As the monomer having at least one carbon-carbon double bond in one molecule and having a molecular weight of less than 250 used in the present invention, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, Unsaturated fatty acids such as maleic anhydride, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, Unsaturated fatty acid esters such as 2-ethylhexyl acrylate and dodecyl acrylate, (meth) acrylamide, (meth) acrylonitrile, N-methylol (meth) acrylamide, diacetone (meth) acrylamide, diethylaminoethyl (meth) acrylamide Nitrogen-containing monomers; vinyl chloride, propene, butene, and other aliphatic vinyls; styrene, vinyltoluene, divinylbenzene, pt-butylstyrene, and other aromatic vinyls; butadiene, isoprene, chloroprene, pentadiene, and other diene compounds Etc. can be mentioned. These may be used alone or in combination.

The molecular weight used in the present invention is 250 or more and 1000 having two or more carbon-carbon double bonds in one molecule.
The epoxy ester of 0 or less is an adduct of the following epoxy resin and an unsaturated group-containing monobasic acid, and can be obtained by a known production method.

As the unsaturated group-containing monobasic acid, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, sorbic acid, or hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate,
Mention may be made of various maleic acid esters such as hydroxypropyl methacrylate and dicyclopentadiene.
These may be used alone or in combination.

The epoxy resin is Epicoat 8
28, 834, 1001, 1002 (made by oiled shell epoxy), etc., Epototo YD128, YD134, YD0
Bisphenol A type such as 11 (manufactured by Toto Kasei), YDF1
70, a bisphenol F type such as YDF180 (manufactured by Toto Kasei), a phenol novolak type such as YDPN638 (manufactured by Toto Kasei), a cresol novolak type such as YDCN701, YDCN702 (manufactured by Toto Kasei) and the like. The epoxy resin is more preferably an aromatic resin as listed above.

The molecular weight used in the present invention is 250 or more and 100 or more having two or more carbon-carbon dipolymer bonds in one molecule.
The unsaturated polyester of 00 or less is a condensate of an α, β-olefinic unsaturated dicarboxylic acid shown below and a divalent glycol, and has been conventionally used widely. In the synthesis of the polyester resin, a saturated dicarboxylic acid, an aromatic dicarboxylic acid, or dicyclopentadiene that reacts with a carboxylic acid may be used in combination with these two components.

Examples of the α, β-unsaturated dicarboxylic acid include maleic acid, fumaric acid, itaconic acid, citraconic acid, and anhydrides of these dicarboxylic acids. Examples of the dicarboxylic acid used in combination with these α, β-olefin unsaturated dicarboxylic acids include adipic acid, sebacic acid,
Examples thereof include succinic acid, gluconic acid, phthalic anhydride, o-phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid and tetrachlorophthalic acid. As the divalent glycol, an alkane diol, an oxa alkane diol, a diol obtained by adding ethylene oxide or propylene oxide to bisphenol A, and the like are used. In addition to this, monool or trivalent triol may be used. As the alkane diol, ethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, cyclohexanediol, etc. Can be mentioned. Examples of the oxaalkane diol include dioxyethylene glycol and trioxyethylene glycol. Examples of monohydric or trihydric alcohols used in combination with these glycols include octyl alcohol, oleyl alcohol and trimethylolpropane.

The synthesis of the unsaturated polyester used in the present invention is generally carried out under heating, and the reaction proceeds while removing by-product water. In the present invention, the average molecular weight is usually 250.
An unsaturated polyester having an acid value of 10000 and an acid value of 0 to 250 is used.

As the surfactant used in the present invention,
Sodium laurate (potassium, etc .; the same below), fatty acid salts typified by sodium oleate, sodium alkane sulfonate, sodium dialkyl sulfosuccinate, sodium dialkyl diphenyl ether disulfonate, sodium alkyl benzene sulfonate, sodium alkyl naphthalene sulfonate, etc. Sulfonates, sodium alkyl sulfates, sodium polyoxyethylene alkyl ether sulfates, anionic surfactants such as sulfuric acid ester salts such as sodium polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether,
Nonionic surfactants such as polyoxyethylene octyl phenyl ether and polyoxyethylene nonyl phenyl ether, and cationic surfactants such as alkyltrimethylammonium chloride and dialkyldimethylammonium chloride are listed. These may be used alone or in combination. It can also be used.

The amount of these surfactants is 0.01 to 10 parts by weight with respect to 100 parts by weight of water, and a part of them can be used in the oligomer phase (containing a monomer).

The radical polymerization initiator used in the polymerization of the emulsion obtained by using the emulsifying machine of the present invention includes, for example, organic peroxides such as benzoyl peroxide and acetyl peroxide, and 2,2. ′ -Azobisisobutyronitrile, 2,
Azo compounds such as 2'-azobis (2,4-dimethylvaleronitrile), inorganic peroxides such as persulfates, hydrogen peroxide and permanganate, the inorganic peroxides and sulfites, metasulfites, Examples thereof include redox initiators of a reducing agent such as hydrosulfite and bisulfite and a metal salt such as iron salt.

The emulsion polymerization method itself in the present invention is not particularly limited, and a known method is adopted.

The high molecular polymer dispersion obtained as described above can be dried and used as a powder. As a drying method, a spray drying method typified by a spray dryer, a method of adhering to a heated rotary drum as typified by a drum dryer to dry, or a freeze drying method can be used. The powder thus obtained has a particle size (weight average) of 0.03 to 100 μm and Dw /
Dn = 1.01 to 1.50 (Dw: weight average, Dn: number average) is composed of fine polymer polymer particles having a sharp particle size distribution.

The polymer fine particles obtained by the present invention have good dispersion stability in water, very excellent heat resistance, solvent resistance, and
Fine particles with excellent transparency. Especially for heat resistance, at least 10% by thermobalance 10% weight loss temperature (TGA)
It has a temperature of 50 ° C. or higher, preferably 300 ° C. or higher, more preferably 330 ° C.

[0034]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to these examples. In the examples, “parts” means parts by weight unless otherwise specified.

Production Example 1 Bisphenol A type epoxy resin [Epototo YD12
8 <Epoxy equivalent 197> (manufactured by Tohto Kasei Co., Ltd.)] 394 parts were charged into a Kolben and dissolved at 125 ° C. Thereafter, 0.6 parts of methylhydroquinone and 1.2 parts of dimethylbenzylamine were added, and 172 parts of methacrylic acid was charged while blowing a small amount of air and reacted until the acid value became 1 or less to obtain an epoxy ester having an average molecular weight of 566. It was Thereafter, 427 parts of styrene monomer was added and well stirred to obtain a resin A having a nonvolatile content of 57% and a viscosity of 100 cps.

Production Example 2 Bisphenol A type epoxy resin [Epototo YD01
1 <Epoxy equivalent 469> (manufactured by Tohto Kasei Co., Ltd.)] 938 parts were charged into Kolben and the mixture was melted at 125 ° C. Methyl hydroquinone 1.2 parts, dimethylbenzylamine 2.2
And 172 parts of methacrylic acid were charged and reacted in the same manner as in Production Example 1 to obtain an epoxy ester having an average molecular weight of 1110. After adding 1110 parts of styrene monomer, stir well,
Resin B having a nonvolatile content of 50% and a viscosity of 200 cps was obtained.

Example 1 1 part of the above resin A was dissolved in 3 parts of Perex SS-L (manufactured by Kao) in the dispersed phase storage tank 3 of FIG.
00 parts was charged into the continuous phase storage tank 4, and the resin A was pressed into the module 1 at 3.0 kgf / cm ² while circulating the continuous phase with the pump 5 at a speed of 0.5 m / s. As the porous glass in the module 1, an SPG pipe (100 mmφ × 230 mm mini kit: manufactured by Ise Chemical Industry Co., Ltd.) having a pore diameter of 0.2 μm was used. The emulsification was completed when 100 parts of the dispersed phase had been pressed into the module 1 to obtain a fine particle emulsion. 100 parts of the emulsion was charged in a Kolben, the temperature was set to 70 ° C. under a nitrogen stream, 0.12 parts of potassium persulfate was added, and the mixture was polymerized for 2 hours and then cooled to obtain a polymer dispersion having a solid content of 50%. It was

Example 2 Using the above resin B, the same operation as in Example 1 was carried out to obtain a high molecular polymer dispersion liquid having a solid content of 50%.

Example 3 Prominate 350 (manufactured by Takeda Pharmaceutical Co., Ltd.) in which 100 parts of styrene was added to 100 parts of unsaturated polyester synthesized by a known production method using a diol obtained by adding propylene oxide to maleic acid and bisphenol A. (As Resin C) <Average molecular weight 6400, viscosity 450 cps
The same operation as in Example 1 was performed using SPG having a pore size of 0.5 μm to obtain a high molecular polymer dispersion having a solid content of 50%.

Example 4 The polymer dispersions obtained in Examples 1 to 3 were dried using a spray dryer L8 type (manufactured by Okawara Kakoki Co., Ltd.) to obtain fine powder particles. Further, the fine powder particles of Example 1 were dispersed in an organic solvent (ethyl acetate, toluene, THF),
The results of measuring the particle size after 24 hours are shown in Table 1.

[0041]

[Table 1]

Comparative Example 1 100 parts of the above resin A, 100 parts of deionized water, and 3 parts of Perex SS-L were mixed with a TK homomixer (made by Tokushu Kiki) 6
It was emulsified by stirring at 000 rpm for 10 minutes. In this case, the emulsification was inadequate, so that the particle size varied. Polymerization of the obtained emulsion was tried in the same manner as in Example 1, but aggregation of particles was considerably observed, and a uniform polymer dispersion was not obtained.

Comparative Example 2 (Seed Polymerization Method) 100 parts of deionized water, 0.03 part of Perex SS-L,
3 parts of methyl methacrylate was charged into Kolben and the temperature was raised to 70 ° C. with stirring. 0.05 part of potassium persulfate was added and stirred for 10 minutes. Next, 100 parts of the above resin A, 1 part of Perex SS-L, and 0.5 part of potassium persulfate were previously added to T
The emulsion was pre-emulsified using a K homomixer, and this emulsion was gradually dropped into Kolben. Agglomerates were generated in Kolben with the lapse of time from the initiation of polymerization, and a uniform polymer dispersion was not obtained.

Table 2 shows the results of Examples and Comparative Examples.

[0045]

[Table 2]

[0046]

Industrial Applicability As described above, according to the present invention, it is possible to obtain polymer fine particles having a sharp particle size distribution and excellent dispersion resistance, heat resistance and transparency, and a dispersion thereof can be used. By doing so, for example, to a plastic film such as a polyester film or a film such as a magnetic tape having the base material as a base material, it can be added in the same polymerization step at a high temperature as an inorganic filler, and the difference in specific gravity between the plastic film and Since it is small and has excellent affinity, particles do not fall off during film handling and no trouble occurs.

[Brief description of drawings]

FIG. 1 is a conceptual explanatory view of an emulsification device used in the present invention.

FIG. 2 is a conceptual cross-sectional view of a module of the emulsification device.

FIG. 3 is an explanatory diagram of the principle of the emulsification method.

[Explanation of symbols]

 1 Porous Membrane Module 3 Storage Tank for Oligomer (Dispersed Phase) 4 Storage Tank for Water (Continuous Phase) with Surfactant Dissolved

Claims (5)

[Claims] 1. A) At least one carbon atom in one molecule
A monomer having a carbon double bond and a molecular weight of less than 250 0 to
90 parts, B) Epoxy ester resin or unsaturated polyester resin 10 to 100 of an epoxy resin having a molecular weight of 250 to 10,000 and having two or more carbon-carbon double bonds in one molecule and an unsaturated group-containing monobasic acid Part A) + B)
The total amount is 100 parts, and the surfactant concentration is 0.01 to 10% by weight through a microporous membrane having a uniform pore size.
Of an aqueous polymer solution having a uniform particle size distribution and a high heat resistance, which is obtained by polymerizing an emulsion obtained by press-fitting it into an aqueous solution of 30 to 10,000 parts. Manufacturing method. 2. The method for producing a high molecular polymer dispersion according to claim 1, wherein the unsaturated group-containing monobasic acid of the epoxy ester resin-forming component B) is (meth) acrylic acid. 3. The pressure at the time of press-fitting into the microporous membrane is 1.0 to 10 times the pressure at the start of emulsification (critical pressure). The method for producing a high-molecular-weight polymer dispersion. 4. The particle size (weight average) is 0.03 to 100 μm.
The method for producing a polymer dispersion according to any one of claims 1 to 3, wherein m is m. 5. A method for producing fine polymer particles, which comprises further drying the polymer dispersion obtained by the production method according to any one of claims 1 to 4.