JPH0225933B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polyetherester block copolymer fine particles. For more details,
The present invention relates to a method for producing highly crystalline polyetherester block copolymer fine particles, which comprises dissolving the polyetherester block copolymer in a lactam. Polyether ester block copolymers (hereinafter referred to as polyether esters) containing polyester hard segments such as polybutylene terephthalate and polyether soft segments such as poly(tetramethylene oxide) glycol have elastic recovery properties and flexibility. Because of its excellent mechanical properties such as elasticity and high-temperature properties, it is used in a variety of applications. However, when used as a fine powder material, it has the problem that it is difficult to finely powder it due to its excellent physical and chemical properties. In other words, if you try to mechanically pulverize it, hot pulverization is required due to the low Tg of polyether ester.
Furthermore, although it is suitable for coarse grinding, there is a limit to its ability to be finely pulverized. Therefore, the present inventors have conducted various studies on the method of producing polyetherester fine particles, and have found that highly crystalline polyetherester fine particles can be obtained by heating and dissolving polyetherester in lactam and then cooling. They discovered this and arrived at the present invention. That is, the present invention uses terephthalic acid, 1,4-butanediol, and a number average molecular weight of about 300 to 6000.
Provided is a method for producing polyetherester copolymer fine particles, which comprises dissolving a polyetherester block copolymer containing 5 to 80% by weight of polyalkylene glycol in a lactam of the following general formula and then precipitating it. It is. (R in the above formula is an alkyl group having 1 to 5 carbon atoms or an H atom, and n is an integer of 1 to 10.) The polyether ester used in the present invention contains terephthalic acid and 1,4-butanediol as essential components. It consists of a hard segment made of polyester and a soft segment made of polyoxyalkylene glycol having a number average molecular weight of about 300 to 6000. The polyester which is the hard segment of this polyether ester contains terephthalic acid and 1,4-butanediol as essential components, and may further contain other dicarboxylic acids and/or other diols. Dicarboxylic acids other than terephthalic acid include isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,
Aromatic dicarboxylic acids such as 4'-dicarboxylic acid, diphenoxyethane dicarboxylic acid, sodium 3-sulfoisophthalate, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, succinic acid, oxalic acid, adipic acid , aliphatic dicarboxylic acids such as sebacic acid, dodecanedioic acid, and dimer acid. Of course, ester-forming derivatives of dicarboxylic acids such as lower alkyl esters, aryl esters, carbonic esters, and even acid halides can be equally used. In addition, examples of diol components other than 1,4-butanediol include ethylene glycol, trimethylene glycol, pentamethylene glycol,
Aliphatic diols such as hexamethylene glycol, neopentyl glycol, decamethylene glycol, 1,1-cyclohexanedimethanol,
Alicyclic diols such as 1,4-cyclohexanedimethanol and tricyclodecane dimethanol,
Xylylene glycol, bis(p-hydroxy)
Diphenyl, bis(p-hydroxyphenyl)propane, 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane, bis[4-(2-
Examples include diols containing an aromatic group such as hydroxy)phenyl]sulfone and 1,1-bis[4-(2-hydroxyethoxy)phenyl]cyclohexane. Such diols can also be used in the form of ester-forming derivatives such as acetyl derivatives, alkali metal salts, and the like. The polyester hard segment containing terephthalic acid and 1,4-butanediol as essential components is preferably composed of 100 to 40 mol%, more preferably 100 to 50 mol% of polybutylene terephthalate units. Polybutylene terephthalate units have excellent high temperature properties, elastic recovery and flexibility in this range. Furthermore, if the polybutylene terephthalate unit content is less than 40 mol %, the melting point will become low and the high temperature properties will deteriorate, which is not preferable. The soft segment of the polyether ester of the present invention is composed of the same dicarboxylic acid as the hard segment and a polyoxyalkylene glycol having a number average molecular weight of about 300 to 6,000. The polyoxyalkylene glycols mentioned here include polyethylene glycol, poly(1,2- and 1,3-propylene oxide) glycol, poly(tetramethylene oxide) glycol, copolymers of ethylene oxide and propylene oxide, and copolymers of ethylene oxide and tetrahydrofuran. Examples include polyoxyalkylene glycols such as polymers, and among these, poly(tetramethylene oxide) glycol is particularly suitable for applications requiring high-temperature properties and elastic recovery properties. The number average molecular weight of polyoxyalkylene glycol is 300 to 6000, more preferably 500 to 4500; if the molecular weight is too large, the polyoxyalkylene glycol unit itself becomes crystalline and loses its elastic recovery function. In addition, the compatibility becomes worse.
On the other hand, if the molecular weight is less than 300, the length of the polyester block, which is a hard segment, becomes too short and elastic recovery properties are lost in this case as well. The ratio of polyether soft segment to polyester hard segment in the polyetherester must be 80/20 to 5/95. When the ratio is 80/20 or more, the hard segment properties of the polymer almost disappear, making it impossible to obtain a polyetherester having excellent elastic recovery properties and high-temperature properties. Moreover, if it is 5/95 or less, the polyoxyalkylene glycol unit, which is a low Tg component, is small, so the flexibility and elastic recovery properties decrease under normal use conditions or at low temperatures, which is not preferable. A particularly preferred soft segment content is 15 to 70% by weight. The most preferable polyetherester used in the present invention is 100 to 50 mol% of butylene terephthalate units and other ester units.
It is a copolymer with excellent high-temperature properties, elastic recovery properties, and flexibility, with a (co)polymerized polyester of 0 to 50 mol% as a hard segment and a polyoxyalkylene glycol content of 15 to 70% by weight. By pulverizing this into fine particles using the method of the present invention, it becomes possible to expand its use as a powder material while maintaining the above-mentioned physical properties. The polyether ester consisting of each of the above components can be produced by a known method. For example, lower alcohol diesters of dicarboxylic acids, excess low molecular weight glycols and polyoxyalkylene glycols are transesterified in the presence of a catalyst, and the resulting reaction products are polycondensed, or dicarboxylic acids, glycols and polyoxyalkylene glycols are used. A method in which polybutylene terephthalate is made in advance and other dicarboxylic acids, diols or polyoxyalkylene glycols are added to it, or other co-products are added. Any method may be used, such as adding polymerized polyester and randomizing it by transesterification. As a common catalyst for transesterification or esterification reactions and polycondensation reactions, titanium catalysts give good results. Particularly preferred are tetraalkyl titanates such as tetrabutyl titanate and tetramethyl titanate, and metal salts of titanium oxalate such as potassium titanium oxalate. Other catalysts include tin compounds such as dibutyltin oxide and dibutyltin laurate, and lead compounds such as lead acetate. Furthermore, a polycarboxylic acid, a polyfunctional hydroxy compound, an oxyacid, or the like may be copolymerized as part of the dicarboxylic acid or glycol. The polyfunctional component effectively acts as a viscosity increasing component, and the range in which it can be copolymerized is 3 mol% or less. Examples of compounds that can be used as such polyfunctional components include trimellitic acid, trimesic acid, pyromellitic acid, benzophenonetetracarboxylic acid, butanetetracarboxylic acid, glycerin, pentaerythritol and their esters and acid anhydrides. can. The polyetherester in the present invention has a logarithmic viscosity of at least 0.35, preferably 0.50 to 4.0. The lactam of the present invention is a compound of the following general formula. (R in the above formula is an alkyl group having 1 to 5 carbon atoms or an H atom, n is an integer of 1 to 10) Specifically, β-propiolactam, γ-butyrolactam, γ-valerolactam, δ-valerolactam Examples include lactam, ε-caprolactam, heptolactam, and the like, and one type or a mixture of two or more of these can be used. In addition, many other solvents that have heat resistance and boiling point that do not cause operational problems during heating and dissolution, and are compatible with the above-mentioned lactams can also be used in combination. The method of dissolving the polyether ester in the lactam is arbitrary and is not particularly limited.
For example, lactam may be added to a sealed container purged with nitrogen and heated to 100°C to 250°C, then polyether ester may be added while stirring, and the mixture may be heated for 5 to 30 minutes to dissolve. In addition, various additives may be added during dissolution, such as forming aids such as known crystal nucleating agents and lubricants, known antioxidants, heat-resistant and light-resistant stabilizers such as ultraviolet absorbers,
Hydrolysis resistance improvers, colorants (pigments, dyes), antistatic agents, conductive agents, flame retardants, reinforcing agents, fillers, plasticizers, mold release agents, etc. can be optionally added and incorporated into the fine particles. . In particular, if a known heat stabilizer such as a hindered phenol type or an amine type is used in combination, the heat aging resistance can be further improved. Further, by adding talc or the like as a known crystal nucleating agent, it becomes possible to produce finer particles. In this case, the amount added is preferably 0.005 to 5.0% by weight based on the total weight of the polyether ester and lactam. In the method of the present invention, the shape, crystallinity, etc. of the fine particles depend on the process of cooling the lactam solution in which the polyether ester is dissolved to precipitate the polyether ester. For example, large spherulite particles can be obtained by slowing down the cooling rate and precipitating at a high temperature, and small spherulite particles can be obtained by rapid cooling. Moreover, if the precipitation is performed while applying shear, randomly shaped and highly crystalline fine particles can be obtained. Furthermore, it is possible to produce fine particles having any degree of crystallinity, shape, and particle size distribution by precipitating under pressure, etc., and all of these are included in the technical scope of the present invention. Polyetherester fine particles can be obtained by dissolving the lactam in the polyetherester-containing slurry or solid cooled as described above in a solvent such as water, and then filtering and drying the slurry or solid. The solvent used at this time is not particularly limited to water,
Any material may be used as long as it dissolves the lactam and does not dissolve the polyether ester at around room temperature, and examples include methanol, ethanol, ether, and tetrahydrofuran. The polyether ester fine particles of the present invention can be used for various purposes, such as resin powder for powder coating, fillers, suspensions, nucleating agents for molding, etc. Furthermore, they can be used for physical or chemical treatment. Therefore, it can be applied to many uses. Also,
During the manufacturing process of the polyetherester fine particles of the present invention, ie, the particles can be precipitated by cooling, dissolved in a solvent such as water, filtered, and further dispersed in a solvent such as water to be used as a dispersion. The present invention will be explained below with reference to Examples. In the examples, all "%" and "parts" are expressed as weight ratios. Further, the logarithmic viscosity shown in the text and examples is a value measured in orthochlorophenol at 30°C and at a concentration of 0.5%. In addition, the crystallinity in the example is the wide angle X manufactured by Rigaku Denki Co., Ltd.
It was determined from the ratio of total scattering intensity and crystal scattering intensity using a line scattering device. In addition, the particle shape and particle size distribution were determined by microscopic observation. Examples 1 to 6 Comparative Example 1 136 parts of dimethyl terephthalate, 38.5 parts of poly(tetramethylene oxide) glycol with a number average molecular weight of 1000, and 94.5 parts of 1,4-butanediol were mixed with 0.10 parts of titanium tetrabutoxide catalyst using a helical ribbon type stirring blade. into a reaction vessel equipped with a
95% of methanol was distilled out of the system. After adding 0.42 parts of "Irganox" 1010 to the reaction mixture, the temperature was raised to 245°C, and then the pressure in the system was reduced to 0.2 mHg over 50 minutes, and polymerization was carried out under these conditions for 2 hours. The melting point of the obtained polyetherester (A) was 216°C and the logarithmic viscosity was 0.94. Next, ε- was placed in a three-necked flask equipped with a stirring blade.
After adding caprolactam and purging with nitrogen, the mixture was heated to 200°C. After raising the temperature, polyether ester (A) and talc were put into a three-necked flask at the ratio shown in Table 1, stirred and dissolved for about 10 minutes, and then cooled to room temperature according to the procedure shown in Table 1 to precipitate polyether ester (A). . The obtained solid was dissolved in distilled water, filtered, washed with water, and dried to obtain fine particles. The properties of the fine particles and the properties of the mechanically pulverized powder are also included for comparison. The mechanically pulverized powder used was obtained by pulverizing polyetherester (A) pellets in a pulverizer for one hour while cooling them with liquid nitrogen, and then passing them through a 100-mesh sieve.

【table】

[Table] Examples 7-8 In Example 1, dimethyl terephthalate 136
part and dimethyl terephthalate instead of 38.5 parts of poly(tetramethylene oxide) glycol
Polymerization was carried out in the same manner except that 135 parts and 86.2 parts of poly(tetramethylene oxide) glycol having a number average molecular weight of 1000 were used to obtain a polyether ester (B) containing 58% polybutylene terephthalate as a hard segment. Furthermore, 94.5 parts of dimethyl terephthalate, 41.5 parts of dimethyl isophthalate
Polymerization was carried out in the same manner using 38.5 parts of poly(tetramethylene oxide) glycol having a number average molecular weight of 1000, and 94.5 parts of 1,4-butanediol to obtain a polyether ester having a melting point of 169°C and a logarithmic viscosity of 0.95.
I got (C). Fine particles were obtained in the same manner as in Example 1 using polyether ester (B). The particle size of the obtained fine particles is approximately
The crystallinity was 15μ, the crystallinity was 45%, and the yield was 97%. For comparison, the powder was mechanically pulverized in the same manner as in Comparative Example 1, and a powder with a crystallinity of 28% and a particle size of about 100 μm was obtained. The yield was 23%. Next, polyether ester (C) was dissolved in ε-caprolactam at 180°C for about 20 minutes, and the solution was cooled to room temperature over about 1 hour. The obtained solid was dissolved in distilled water, filtered, and added to distilled water to a concentration of 40% with stirring to obtain an aqueous dispersion. For comparison, polyether ester (C) powder mechanically crushed in the same manner as in Comparative Example 1 was added to distilled water to the same concentration and stirred. Many particles floated on the surface of the distilled water and bubbles were generated at the same time, resulting in dispersion. I couldn't convert it. The particle size of each dispersion particle was about 10μ and about 100μ.

Claims (1)

[Scope of Claims] 1. A polyether containing terephthalic acid, 1,4-butanediol, and a polyoxyalkylene glycol having a number average molecular weight of about 300 to 6000 as essential components, and containing 5 to 80% by weight of polyoxyalkylene glycol. 1. A method for producing fine particles of a polyether ester block copolymer, which comprises dissolving the ester block copolymer in a lactam having the following general formula and then precipitating the ester block copolymer. (R in the above formula is an alkyl group having 1 to 5 carbon atoms or an H atom, and n is an integer of 1 to 10.)