JP2002097282A - Method of producing polyamide resin fine powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing high quality polyamide fine powder having high solubility in a solvent, excellent workability with improved dissolving speed in the solvent and improved efficiency of washing and drying by making a polyamide resin into fine powder. SOLUTION: This method of producing polyamide resin fine powder comprises the steps of adding a poor solvent of polyamide resin to a solution of polyamide resin in a solvent to form a slurry of dispersed polyamide resin, adding the slurry to a poor solvent of polyamide resin to convert to a state of dispersed fine powder and obtaining polyamide resin in the form of fine powder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing polyamide resin fine powder, and more particularly to a method for producing polyamide resin fine powder by adding a polyamide resin dispersion slurry to a poor solvent.

[0002]

2. Description of the Related Art When taking out a polyamide resin from a polyamide solution obtained by solution polymerization or a polyamide solution obtained by varnish preparation, etc., generally, the polyamide solution is stirred and a poor solvent is added until the polyamide resin is precipitated. Is performed, but the polyamide resin tends to be in a lump,
It is easy to adhere and solidify on devices such as stirring blades, containers and kettle walls.
It is difficult to take out as a powder, the yield decreases,
Poor productivity. Further, a method of stirring a poor solvent prepared in advance and adding a polyamide solution to the poor solvent is also known, but the viscosity of the polyamide solution to be added, the dropping speed, the stirring speed of the poor solvent, etc. The form is determined and it is difficult to obtain a fine powder.

[0003]

The fineness of the polyamide resin improves the efficiency of washing and drying. Further, it is expected that the dissolution rate in the solvent at the time of processing is improved and the workability is excellent. An object of the present invention is to produce a high-quality fine polyamide resin powder having excellent solvent solubility.

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted intensive studies, and as a result, have found that a fine polyamide resin powder having good washing and drying efficiencies, extremely high quality and good solvent solubility is obtained. A manufacturing method was found. That is, the present invention relates to (1) a method of preparing a polyamide resin dispersion slurry by adding a poor solvent for a polyamide resin to a polyamide solution in which a polyamide resin is dissolved in a solvent, adding the slurry to the poor solvent for the polyamide resin, (2) A method for producing a polyamide resin fine powder characterized by obtaining a polyamide resin in a fine powder form by dispersing the polyamide resin, (2) a polyamide solution containing 10 to 50% by weight of a polyamide resin. 1) The production method according to the above. (3) The logarithmic viscosity of the polyamide resin is 3 in N, N-dimethylacetamide solvent.
The production method according to the above (1) or (2), wherein the slurry is 0.2 to 1.2 g / dl at 0 ° C., and (4) cooling the polyamide resin dispersion slurry to −10 to 25 ° C. The method according to any one of the above (1), (2) or (3), wherein the polyamide is added to a poor solvent of the polyamide resin. The method according to any one of the above (1), (2), (3) or (4), wherein the polyamide resin comprises The present invention relates to the production method according to any one of the above (1), (2), (3), (4) and (5), which is a rubber-modified polyamide containing an elastomer.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A polyamide solution in which a polyamide resin according to the present invention is dissolved in a solvent contains a dicarboxylic acid and a diamine and / or a carboxylic acid and an amine in the structure.
A solution that can contain a raw material, a condensing agent, by-products, a catalyst, additives, and the like, using a compound having one by one as a raw material, a polyamide resin produced by a polycondensation reaction, and a solvent in which the polyamide resin is soluble as essential components. The polyamide resin structure is not particularly limited, but a polyamide resin formed by a polycondensation reaction between an aromatic or aliphatic dicarboxylic acid and an aromatic or aliphatic diamine is preferable.

Specific examples of the aromatic dicarboxylic acids that can be used include phthalic acid, isophthalic acid, terephthalic acid, benzene diacetate, benzene dipropionic acid, biphenyl dicarboxylic acid, oxydibenzoic acid, thiodibenzoic acid, dithiodibenzoic acid, and dithiobis. (Nitrobenzoic acid), carbonyldibenzoic acid, sulfonyldibenzoic acid, naphthalenedicarboxylic acid, methylenedibenzoic acid, isopropylidenedibenzoic acid, hexafluoroisopropylidenedibenzoic acid, pyridinedicarboxylic acid, hydroxyisophthalic acid, hydroxyterephthalic acid, Examples thereof include dihydroxyisophthalic acid and dihydroxyterephthalic acid. Of these, isophthalic acid and hydroxyisophthalic acid are preferable.

Specific examples of the aliphatic dicarboxylic acid that can be used include oxalic acid, malonic acid, methylmalonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid,
Malic acid, tartaric acid, (meth) acryloyloxysuccinic acid, di (meth) acryloyloxysuccinic acid, (meth)
Acryloyloxymalic acid, (meth) acrylamide succinic acid, (meth) acrylamide malic acid, and the like are included.

Specific examples of the aromatic diamine that can be used include diaminobenzene, diaminotoluene, diaminodimethylbenzene, diaminomesitylene, diaminochlorobenzene, diaminonitrobenzene, diaminoazobenzene, diaminonaphthalene, diaminobiphenyl, diaminodimethoxybiphenyl, diaminodiphenylether, diaminodiphenylether, Dimethyldiphenyl ether, methylenedianiline, methylenebis (methylaniline), methylenebis (dimethylaniline), methylenebis (methoxyaniline), methylenebis (dimethoxyaniline), methylenebis (ethylaniline), methylenebis (diethylaniline), methylenebis (ethoxyaniline), methylenebis (Diethoxyaniline), methylenebis (dibromoaniline), i Pro pyridinium Denji aniline, hexafluoro isopropylidene aniline ,, diaminobenzophenone, diamino dimethyl benzophenone, diaminoanthraquinone, diaminodiphenyl thioether,
Examples thereof include diaminodimethyldiphenylthioether, diaminodiphenylsulfone, diaminodiphenylsulfoxide, and diaminofluorene. Of these, diaminodiphenylether and methylenebis (diethylaniline) are preferable.

Specific examples of the aliphatic diamine which can be used include ethylenediamine, propanediamine, hydroxypropanediamine, butanediamine, heptanediamine, hexanediamine, diaminodiethylamine, diaminodipropylamine, cyclopentanediamine, cyclohexanediamine, azapentanediamine And triazaundecanediamine.

The polyamide resin obtained by the above polycondensation reaction may be further subjected to rubber modification, (meth) acrylic modification, epoxy modification and the like. The rubber modification can be performed by further polycondensing the polyamide of the terminal amine and the elastomer of the terminal carboxylic acid, or the polyamide of the terminal carboxylic acid and the elastomer of the terminal amine. Specific examples of the elastomer include polybutadiene, butadiene-acrylonitrile copolymer, styrene-butadiene copolymer, polyurethane, and silicone rubber.In particular, a polyamide having a terminal amine is a butadiene-acrylonitrile copolymer having a terminal carboxylic acid. Modified ones are preferred.

The raw materials that can be contained in the polyamide solution represent unreacted raw materials, and the condensing agents represent those used in the polycondensation reaction.
Specific examples of the condensing agent include triphenyl phosphite, diphenyl phosphite, tri-o-tolyl phosphite, di-o-tolyl phosphite, tri-m-tolyl phosphite, and di-phosphite phosphite. -M-tolyl, tri-p-tolyl phosphite, di-p-tolyl phosphite, tri-p-chlorophenyl phosphite and the like. In addition, by-products include decomposed products of the condensing agent used, oxidation and other modified products of the decomposed products, amide compounds such as oligos, etc., and catalysts and additives are tertiary amines such as pyridine and inorganic compounds such as lithium chloride. The following shows salts, stabilizers, and the like added to the polyamide solution before performing this production method.

The solvent in which the polyamide resin is soluble is not particularly limited as long as it is a solvent that causes solvation with the polyamide resin to be used. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N -Methyl-2-
Examples thereof include pyrrolidone and dimethyl sulfoxide, a mixed solvent thereof, and a solvent containing these. The concentration of the polyamide resin in the polyamide solution is 10 to 50.
% By weight, and particularly preferably 15 to 30% by weight in consideration of the production efficiency and the solution viscosity with good operability. still,
The logarithmic viscosity of the polyamide resin used is 0.2 to 1.2 g / d at 30 ° C. in an N, N-dimethylacetamide solvent.
1 is preferable, and 0.4 to 0.8 g / dl is particularly preferable.

[0013] The polyamide resin dispersion slurry in the present invention means that when a poor solvent for the polyamide resin is gradually added to a uniform and transparent polyamide solution, the polymers coagulate and begin to scatter visible light. It refers to the state from the beginning of turbidity to the state where turbidity does not change even if a poor solvent is further added. If the poor solvent is added more than this, the viscosity of the slurry decreases, but the precipitated polyamide resin is undesirably formed as a mass. The poor solvent used for preparing the polyamide resin dispersion slurry is not particularly limited as long as it is a solvent that hardly causes solvation with the polyamide resin used,
Specific examples include water, methanol, ethanol, etc.
These include mixed solvents and solvents containing them. Also, with the amount of these poor solvents, the particle size of the polyamide resin fine powder can be controlled to some extent in the range of 1 μm to 1 mm,
The preferable amount of the poor solvent to be added is determined in the state of the finally obtained polyamide resin powder. For example, N, N-
0.4-0.1 at 30 ° C. with dimethylacetamide solvent.
Polyamide solution 1 in which a polyamide resin having a logarithmic viscosity of 6 g / dl was dissolved in N-methylpyrrolidone at 18% by weight.
To 00 g, a mixed solvent of 31 g of methanol and 24 g of water was added to prepare a polyamide resin dispersion slurry, and then the average particle diameter of the fine polyamide resin powder obtained when this slurry was added in a poor solvent was 20 to 50 μm. It is. Also, when preparing a polyamide resin dispersion slurry,
In order to prevent solidification on devices such as stirring blades, containers and kettle walls,
It is good to cool to 10 to 25 ° C, preferably to 0 to 10 ° C.

The poor solvent to which the prepared slurry of the polyamide resin dispersion is added is not particularly limited.
Examples thereof include water, methanol, ethanol, and the like, a mixed solvent thereof, and a solvent containing these, and may be the same as or different from the poor solvent used for preparing the polyamide resin dispersion slurry. The amount of the poor solvent to be precipitated is preferably equal to or more than a half volume with respect to the slurry to be added. Double amounts are particularly preferred. The poor solvent to be precipitated is prepared in advance in a container, a pot, or the like, and the slurry may be quickly added to the poor solvent with vigorous stirring. As a method of addition, use of a pump, gravity, a pressure difference or the like can be considered. In particular, a method of reducing the pressure of a vessel or a kettle for precipitation and utilizing a pressure difference is preferable.

The obtained polyamide resin fine powder dispersion is
Although the filtration may be carried out immediately, the stirring of the fine powder during filtration can be suppressed to some extent by stirring the mixture for about 1 hour. In some cases, before the filtration, the polyamide resin fine powder dispersion may be passed through a mesh of about 16 mesh.

Since the polyamide resin fine powder obtained by the above filtration has a large surface area, even if washing and drying are carried out by a usual method, a highly purified polyamide resin fine powder can be obtained in a very short time in a very efficient manner. The washing method is usually performed by repeating stirring in a poor solvent, re-dissolution and re-precipitation, or by blowing steam after preparing a polyamide resin fine powder dispersion. A combination in which steam is blown after preparing an aqueous dispersion of resin fine powder is preferable. Drying may be performed under normal pressure or reduced pressure, but the temperature is 10
The temperature may be 0 ° C or less.

The polyamide resin fine powder according to the present invention comprises:
In addition to the inherent heat resistance of the polyamide resin, the dissolution rate in a solvent that can be dissolved is high, and the solubility and compatibility with epoxies and acrylic monomers, oligomers, and other polymers are excellent, so that workability is good. Inactive organic or inorganic pigments, dyes, antifoggants, anti-fading agents, antihalation agents as necessary within a range that does not impair heat resistance, etc.
Optical brighteners, surfactants, plasticizers, flame retardants, antioxidants, fillers, antistatic agents, defoamers, flow regulators, accelerators, retarders, light stabilizers, fungicides, antibacterial Agents, magnetic substances and the like can be mixed.

Further, the polyamide resin fine powder of the present invention comprises:
Because of its high purity and high quality, it is particularly useful for electrical materials and the like. Specific applications include photoresist, liquid resist, electrophotography, direct plate materials, hologram materials,
Examples include adhesives, pressure-sensitive adhesives, adhesives, sealants, paints, coating agents, and glass fiber impregnants.

[0019]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Isophthalic acid was placed in a 500 ml reactor equipped with a thermometer, a reflux condenser, a dropping funnel, a nitrogen introducing device, and a stirring device.
0.200 g (0.0614 mol), 1.867 g (0.0103 mol) of 5-hydroxyisophthalic acid, 3,
16.205 g of 4'-diaminodiphenyl ether
(0.0809 mol) and 1.53 g of lithium chloride, 153.3 g of N-methyl-2-pyrrolidone and 18.00 g of pyridine were added while flowing dry nitrogen, and the reactor was heated to 95 ° C. while stirring. Gradually heat until
The solid was dissolved. Thereafter, the inside of the reactor was stirred at 95 ° C.
, And 39.07 g of triphenyl phosphite was added dropwise over 2 hours, and the mixture was further reacted for 1 hour. Next, 9
Keeping at 5 ° C., 25.505 g (0.0071) of butadiene acrylonitrile carboxylate copolymer (CTBN)
Mol) was dissolved in 131.7 g of N-methyl-2-pyrrolidone in 1 hour, and the mixture was further reacted for 2 hours. Thereafter, the inside of the reactor was cooled to 50 ° C. or lower to prepare a polyamide solution.

The above polyamide solution was transferred to a 1000 ml container, and 126 g of methanol was added with stirring at room temperature. After cooling to 10 ° C. or lower, 50 g of ion-exchanged water was added dropwise over 30 minutes. Thereafter, the mixture was further stirred at 10 ° C. or lower for 1 hour to prepare a polyamide resin dispersion slurry.

700 g of ion-exchanged water in a 2000 ml container
And the above-mentioned polyamide resin dispersion slurry was added in about 1 minute while stirring at room temperature to obtain a polyamide resin fine powder dispersion. Thereafter, the mixture was further stirred at room temperature for 1 hour, and after filtering the polyamide resin fine powder dispersion, 500 g of ion-exchanged water was charged into a 1000 ml container, and while stirring, the polyamide resin fine powder obtained by the filtration was gradually added.
It was redispersed, washed with stirring at room temperature for 30 minutes, and then filtered.

Into a 1000 ml reactor equipped with a thermometer, a fractionator, a steam inlet and a stirrer, the water-washed polyamide resin fine powder obtained by filtration and ion-exchanged water
The reactor was gradually heated to 95 ° C. while stirring. Thereafter, the heating was stopped, and steam was blown at a rate of about 150 g / hour for about 24 hours while stirring the inside of the reactor to perform washing. The amount of liquid distilled from the fractionator is
It was 3,600 g. Thereafter, the inside of the reactor was cooled to 50 ° C. or lower, and then filtered.

The steam-washed polyamide resin fine powder obtained by filtration was dried with hot air at 75 ° C. for 72 hours to obtain the desired polyamide resin fine powder (yield: 96%). The average particle size of the polyamide resin fine powder was 38 μm. Further, 0.100 g of this polyamide resin fine powder was added to N, N-
Dissolved in 20.0 ml of dimethylacetamide, 30 ° C
Was 0.47 dl / g.

Example 2 Isophthalic acid 1 was placed in a 500 ml reactor equipped with a thermometer, a reflux condenser, a dropping funnel, a nitrogen introducing device, and a stirring device.
6.61 g (0.0614 mol), 20.62 g (0.0809 mol) of 3,4'-diaminodiphenyl ether
And 1.96 g of lithium chloride, and 196.0 g of N-methyl-2-pyrrolidone while flowing dry nitrogen.
23.04 g of pyridine was added, and the reactor was gradually heated to 95 ° C. with stirring to dissolve solids.
Thereafter, the inside of the reactor was stirred and maintained at 95 ° C., and 50.00 g of triphenyl phosphite was added dropwise over 2 hours, and the reaction was further performed for 1 hour. Next, while keeping the inside of the reactor at 95 ° C., 7.00 g (0.0071 mol) of acrylic acid was added dropwise over 1 hour.
The reaction was further performed for 2 hours. Thereafter, the inside of the reactor was cooled to 50 ° C. or lower to prepare a polyamide solution.

The above polyamide solution was transferred to a 1000 ml container, and 126 g of methanol was added with stirring at room temperature. After cooling to 10 ° C. or lower, 50 g of ion-exchanged water was added dropwise over 30 minutes. Thereafter, the mixture was further stirred at 10 ° C. or lower for 1 hour to prepare a polyamide resin dispersion slurry.

700 g of ion-exchanged water in a 2000 ml container
And the above-mentioned polyamide resin dispersion slurry was added in about 1 minute while stirring at room temperature to obtain a polyamide resin fine powder dispersion. Thereafter, the mixture was further stirred at room temperature for 1 hour, and after filtering the polyamide resin fine powder dispersion, 500 g of ion-exchanged water was charged into a 1000 ml container, and while stirring, the polyamide resin fine powder obtained by the filtration was gradually added.
It was redispersed, washed with stirring at room temperature for 30 minutes, and then filtered.

Into a 1000 ml reactor equipped with a thermometer, a fractionator, a steam inlet, and a stirrer, the water-washed polyamide resin fine powder obtained by filtration and ion-exchanged water
The reactor was gradually heated to 95 ° C. while stirring. Thereafter, the heating was stopped, and steam was blown at a rate of about 150 g / hour for about 24 hours while stirring the inside of the reactor to perform washing. The amount of liquid distilled from the fractionator is
It was 3,600 g. Thereafter, the inside of the reactor was cooled to 50 ° C. or lower, and then filtered.

The polyamide resin fine powder after the water vapor washing obtained by filtration was dried with hot air at 75 ° C. for 72 hours to obtain the desired polyamide resin fine powder (96% yield). The average particle size of the polyamide resin fine powder was 38 μm. Further, 0.100 g of this polyamide resin fine powder was added to N, N-
Dissolved in 20.0 ml of dimethylacetamide, 30 ° C
Was 0.47 dl / g.

[0030]

According to the present invention, fine powder of polyamide resin, which has been difficult in the past, can be easily prepared, and the workability of festivals for industrially producing polyamide resin can be greatly improved.

Claims (6)

[Claims] A polyamide resin-dispersed slurry is prepared by adding a polyamide resin poor solvent to a polyamide solution in which a polyamide resin is dissolved in a solvent, and then the slurry is added to the polyamide resin poor solvent to obtain a fine powder dispersion state. A method for producing a fine polyamide resin powder, comprising: obtaining a polyamide resin in the form of fine powder. 2. The method according to claim 1, wherein the polyamide solution contains 10 to 50% by weight of a polyamide resin. 3. A polyamide resin having an logarithmic viscosity of 0.2 to 1.2 g at 30 ° C. in an N, N-dimethylacetamide solvent.
3. The method according to claim 1, wherein the ratio is / dl. 4. A polyamide resin dispersed slurry of -10 to 2
The method according to any one of claims 1, 2, or 3, wherein the method is cooled to 5 ° C and added to a poor solvent for the polyamide resin. 5. The method according to claim 1, wherein the polyamide resin is an aromatic-containing polyamide resin having an aromatic group in the main chain. 6. The method according to claim 1, wherein the polyamide resin is a rubber-modified polyamide resin containing an elastomer in the structure.