JPS6254735A - Production of porous microparticle of resin - Google Patents

Abstract

PURPOSE:To obtain porous microparticles of a resin by making it chemically grindable in a temperature range lower than the m.p. of the resin to be ground, by dissolving the resin in a solvent comprising a specified urea derivative and spontaneously cooling the solution. CONSTITUTION:A resin is dissolved in a solvent based on a urea derivative of formula I (wherein R and R' are each H or alkyl) at 70 deg.C or above, and the solution is spontaneously cooled to 60 deg.C or below. If necessary, after this spontaneous cooling, a nonsolvent for this resin which is compatible with the urea derivative is added to the solution to produce porous microparticles of the resin. Examples of the resin which can be applied include polyester resins, polyamide resins, polycarbonate resins, methacrylic resins, polyethylene resins, guanamine resins, novolak resins and maleic resins. As the urea derivatives of formula I, compounds of formulas II, III and IV, for example are desirable.

Description

[Detailed Description of the Invention] [Industrial Application Fields] The present invention chemically converts resins into porous fine particles to be used in adsorbents, filtration agents, fillers, molding materials, paints, cosmetics, etc. The present invention relates to a method for producing porous fine particles of resin, which provides new materials for the industry.

[Conventional technology]

Powderization of resins has been attempted in the past for resins such as polystyrene, polyethylene, polyamide, polypropylene, and vinyl chloride, and these powders have been used for various purposes.

However, these resin powders do not have a porous structure because the internal structure of the powder particles is dense. Therefore, most of these resin powders are made by physical friction grinding using machines such as ball mills, sand mills, and jet mills, but in order to avoid melting of the resin due to frictional heat, generation of frictional heat is The temperature must be below the melting point of the resin to be crushed. For this reason, the pulverized material is also regulated by the melting point of the resin, and currently, the lower the melting point of the resin, the less fine it can be made.

The cryo-pulverization method was developed to solve this problem.

In this method, the resin is cooled with a gas refrigerant and pulverized by applying mechanical friction while attempting to make it embrittle at low temperatures. This cryo-pulverization method is used to crush resins with low melting points and resins with high hardness. However, since this method is a pulverization method using physical friction, the pulverized product has large variations in particle size and is not constant, and there is no porous structure inside the powder particles.

Further, as a chemical pulverization method, there is a method in which a polymerized diallyl phthalate resin is dissolved in acetone, and this solution is poured into methanol to precipitate a polymer. The polymerized diallyl phthalate resin thus obtained becomes a powder, but does not have a porous structure. In the case of polyester resins, Patent Publication 1982-1291 describes poly(tetramethylene terephthalate) polyesters and their copolymers as dichlorobenzene, trichlorobenzene, chlornaphthalene, methylnaphthalene, diphenyl ether, benzyl ether, biphenylbenzyl alcohol. 15 in a solvent whose main component is a solvent selected from the group of
Dissolve by heating at a temperature of 0 to 220°C, then increase the precipitation temperature to 'r
p (Tp means the temperature at which turbidity becomes visible for the first time when a clear solution is slowly cooled.) ~ (Tp-2
The present invention discloses a method for producing polyester porous spherical particles characterized by growing spherulites while cooling at a slow cooling rate such that the particles remain in the temperature range of 0)'C for 1 hour or more.

In this method, only poly(tetramethylene terephthalate)-based polyester, which is neither polyester typified by polyethylene terephthalate nor polybutylene terephthalate, is used as the resin. This one type of specified resin is heated and melted in a solvent in the resin melting temperature range of 150'C to 220'C, and then cooled to a temperature range of 'rp to (Tp-20)'C.
I am controlling it so that it stays for more than an hour. If you disturb the cooling time and cooling rate in this temperature range,
The precipitated resin is not spherical, and the structure within the particles is such that the occupancy rate of the porous structure decreases.

[Problems to be solved by the invention] In view of these circumstances, the present invention solves the following problems when crushing resins:
The resins are chemically processed in a temperature range below the melting point of the material to be crushed, without using physical crushing methods using machines, or without the resin identification and cooling control found in conventional chemical crushing methods. The present invention aims to provide a method for producing porous fine particles of resins by pulverization.

[Means for Solving the Problems] In order to achieve the above object, the method for producing porous fine particles of resins of the present invention provides a method for producing porous fine particles of resins according to the present invention. After dissolving the resins in a solvent of 70'C or higher that is mainly composed of a urea derivative represented by carbon number (an integer of 1 to 6), the resin is naturally cooled to 60°C or lower, or it is naturally cooled to 60°C or lower. Porous fine particles of the resin are produced by adding a non-solvent of the resin that is compatible with the urea derivative after natural cooling.

As these urea derivatives, for example, the following are desirable.

Examples of resins that can be dissolved in solvents containing these urea derivatives at temperatures of 70°C or higher include polyester resins,
There are polyamide resins, polycarbonate resins, methacrylic resins, polyethylene resins, guanamine resins, novolak resins, and maleic acid resins, but urea derivatives include 70'
Resins that are melted at a temperature of C or higher are not limited to these resins.

When these resins are thermoplastic, the resin content is 10
When dissolved to form a urea derivative solution of ~20 wL%, porous fine particles of the resin are precipitated by natural cooling to 60° C. or lower, preferably 40° C. to room temperature. Also,
When the urea derivative solution has a resin content of 10 wt % or less, porous fine particles of the resin will not precipitate even if it is naturally cooled to room temperature.

In this case, a non-solvent for the resins that is compatible with the urea derivative may be added. Nonsolvents include water, ethers, alcohols, phenols, glycol ethers, ketones, aldehydes, esters, amines, nitro compounds, aromatic hydrocarbons, or chlorinated hydrocarbons. Considering that the urea derivative and non-solvent can be recovered and reused, alcohols are preferable. Moreover, the porous fine particles of the resin obtained by precipitation by cooling are washed with a non-solvent, filtered, and dried to become porous fine particles having a size of 3 to 10 microns.

On the other hand, if a non-solvent is added to make porous fine resin particles, which are washed with the same non-solvent, filtered and dried, the resulting porous fine particles will have a size of 0.1 to 5 microns.

In the present invention, the resins that are dissolved in the urea derivative have a crystalline structure when observed under an optical microscope.

〔Effect of the invention〕

Due to the method for producing porous fine particles of resins having the above-mentioned structure, porous fine particles of resins consisting of relatively uniform particles can be produced in a short time with simple operations without reducing the degree of polymerization. be.

Example 1 100g of polyester pellets was mixed with 1,8-dimethyl-2
-Imidazolidinone is dissolved in 400 g of solvent at 95°C, then naturally cooled to 40°C to form a precipitate consisting of porous fine particles of poly,'J-stell, and this precipitate is filtered to remove the solvent and particles. It was separated into two parts.

Next, the separated particles were washed five times with methyl alcohol, and the particles and methyl alcohol were separated by filtration.

When these particles are dried, the particle size is between 3 microns and 1 micron.
Porous microparticles of polyester having a size of 0 micron were obtained. Using 1 g of this polyester porous fine particles, 5 cc of a trimethylamine aqueous solution with a concentration of 5380 ppm
It became paste-like after adsorbing it, and the odor of trimethylamine was only slightly perceptible. Crosslinked polystyrene having an average particle size of 6 microns was used in the comparative test, but it simply floated on the trimethylamine aqueous solution and did not become paste-like, nor did it absorb any odor.

Example 2 Pellets of nylon (13) were dissolved at 85°C in a solvent of 100 F and 500 F of 3-diethyl-2-imidazolidinone, and then naturally cooled to 30°C to form a precipitate consisting of porous fine particles of nylon (12+). This precipitate was then filtered to separate the solvent and particles.

Next, the particles were washed five times with methyl alcohol, and the particles and methyl alcohol were separated by filtration.

When the particles were dried, porous fine particles of nylon (121) having a size of 3 to 8 microns and a substantially spherical shape were obtained.

In addition, 50 f of pellets of nylon (121) were placed in a solvent of 500 g of 1,3-diethyl-2-imidazolidinone.
After dissolving at °C, methyl alcohol is added to the ao'c solution to obtain a dispersion of nylon 0z after natural cooling. The slurry of nylon U7J obtained by filtering this dispersion was washed five times with methyl alcohol, and the particles and methyl alcohol were separated by filtration.

When the particles were dried, porous fine particles of nylon +13 having a size of 0.1 to 3 microns and a substantially spherical shape were obtained. Autocolon (
When 5 grams of Kanebo Vulcan Fresh Cologne were added, it was absorbed and became an eau de cologne powder made of porous fine particles of nylon (121).This eau de cologne powder has a long-lasting fragrance and is easy to rub into the skin. It was also smooth.

Example 3 50f of crystalline powder of benzoguanamine resin was dissolved in a solvent of 500f of 1,8-dipropyl-2-imidazolidinone.
After dissolving at 5°C, and naturally cooling to 40°C, ethyl alcohol is added to obtain a benzoguanamine resin dispersion. The benzoguanamine slurry obtained by filtering this dispersion was washed four times with ethyl alcohol, and the particles and ethyl alcohol were separated by filtration. When these particles were dried, porous fine particles of benzoguanamine resin having a size of 1 to 3 microns were obtained.

When 40 cc of water was added to 10f of porous fine particles of benzoguanamine resin and 10f of crystalline powder of benzoguanamine resin, the porous fine particles of benzoguanamine resin absorbed water and became paste-like, but the crystalline powder of benzoguanamine resin became paste-like. It didn't turn out that way.

Applicant Shoko Kagaku Institute Co., Ltd. Procedural amendment (voluntary) July 11, 1985 Director General of the Patent Office Michibe Uga 2 Name of the invention Process for producing porous fine particles of fat 3 Person making the amendment Relationship to the case Patent applicant: 〒541 5゜Contents of amendment (1) The "Claims" of the specification will be amended as shown in the attached sheet.

(2)・Page 7 line 8 of the specification, page 8 line 9, line 11 of the specification
"Natural cooling" on page 9, line 19, page 10, line 17
Correct the statement to "cooling".

(3) In the specification, page 7, line 8, page 11, line 7, and page 12, lines 5 to 6, the words "after natural cooling" are corrected to "after cooling."

(4) From page 7, line 6 to line 7 of the specification, “70°C
In a solvent of 70℃ or higher, preferably (
(resin melting point) - (40°C)).''

(5) On page 9, line 19 of the specification, "95°C" is corrected to "200°C."

(6) "85°C" on page 10, line 17 and page 11, line 7 of the specification shall be corrected to "150°C."

(7) On page 12, line 5 of the specification, replace “95°C” with “2”
10℃”.

Claims (1) After dissolving resins in a solvent at 70°C or higher containing a urea derivative represented by the general formula (in which R and R' are hydrogen or an alkyl group), A method for producing porous fine particles of the resin, which comprises cooling to a temperature below .degree.

(2) The method for producing porous fine particles of a resin according to claim 1, wherein n and w in the general formula (1) are urea-based derivatives in which carbon numbers are integers of 1 to 6.

(3) Production of porous fine particles of resins according to claim 1, wherein the resins are polyester resins, polyamide resins, polycarbonate resins, methacrylic resins, polyethylene resins, guanamine resins, novolak resins, or maleic acid resins. Method.

(4) After dissolving resins in a solvent at 70°C or higher containing a urea derivative represented by general formula (1) as a main component,
1. A method for producing porous fine particles of a resin, which comprises adding a non-solvent of the resin which is compatible with a urea derivative after cooling to a temperature below C.

(5) The method for producing porous fine particles of a resin according to claim 4, wherein R and R' in the general formula (1) are urea derivatives having an integer of 1 to 6 carbon atoms.

(6) The method for producing porous fine particles of a resin according to claim 4, wherein the resin is a polyester resin, a polyamide resin, a polycarbonate resin, a methacrylic resin, a polyethylene resin, a guanamine resin, a novolac resin, or a maleic acid resin. .

(7) The nonsolvent is water, ethers, alcohols, buenols, glyfur ethers, ketones, aldehydes, esters, amines, nitro compounds, aromatic hydrocarbons, or chlorinated hydrocarbons. A method for producing porous fine particles of resins according to claim 4.

(Margin below)

Claims (7)

[Claims] (1) General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (R and R' in the formula are hydrogen or alkyl groups) In a solvent at 70℃ or higher containing a urea derivative as the main component A method for producing porous fine particles of resins, which comprises dissolving the resins and then naturally cooling them to 60° C. or lower. (2) The method for producing porous fine particles of a resin according to claim 1, wherein R and R' in the general formula (I) are urea-based derivatives having an integer of 1 to 6 carbon atoms. (3) The resin is polyester resin, polyamide resin,
A method for producing porous fine particles of a resin according to claim 1, which is a polycarbonate resin, a methacrylic resin, a polyethylene resin, a guanamine resin, a novolak resin, or a maleic acid resin. (4) After dissolving the resins in a solvent at 70°C or higher containing a urea derivative represented by general formula (I) as a main component,
A method for producing porous fine particles of a resin, which comprises adding a non-solvent for the resin that is compatible with a urea derivative after natural cooling to 0° C. or lower. (5) The method for producing porous fine particles of a resin according to claim 4, wherein R and R' in the general formula (I) are urea-based derivatives having an integer of 1 to 6 carbon atoms. (6) The method for producing porous fine particles of resins according to claim 4, wherein the resins are polyester resins, polyamide resins, polycarbonate resins, methacrylic resins, polyethylene resins, guanamine resins, novolak resins, or maleic acid resins. . (7) The nonsolvent is water, ethers, alcohols, phenols, glycol ethers, ketones, aldehydes, esters, amines, nitro compounds, aromatic hydrocarbons, or chlorinated hydrocarbons. A method for producing porous fine particles of resins according to claim 4.