JPH10316749A - Production of polyester resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the occurrence of foreign matters in the reaction step, prevent the clogging of a filter in polyester production, and obtain an excellent product with a reduced content of foreign matters occurring in molding by using a product obtd. by heating a mixture of an organotin compd. and an organotitanium compd. as a polyester polymn. catalyst. SOLUTION: A product obtd. by heating a mixture of an organotitanium compd. (e.g. tetrabutyl titanate or tetraethyl titanate) and an organotin compd. (e.g. monobutyltin oxide or pentyltin hydroxide) is used as a polyester polymn. catalyst. An organotitanium compd. in an amt. of 1 pt.wt. is mixed with 0.1-10 pts.wt. organotin compd. The mixture is prepd. by directly mixing the two compds. or by mixing them into a solvent (e.g. a diol compd.). The mixture is heated at about 60-250 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a polyester resin, and particularly to a method for producing a polyester resin using an aromatic dicarboxylic acid or a derivative thereof and a diol compound as raw materials. It relates to a manufacturing method.

[0002]

BACKGROUND OF THE INVENTION Polyester resins, especially polyethylene terephthalate (hereinafter referred to as "polyethylene terephthalate")
PET), polybutylene terephthalate (hereinafter, referred to as PET)
PBT), polybutylene naphthalate (hereinafter referred to as P
Polyester resins composed of an aromatic dicarboxylic acid and a diol component, such as BN), are excellent in mechanical properties, physical and chemical properties, and have good processing properties. Widely used for automobiles, electric / electronic parts, other precision machines, building materials, sundries, etc. Many organometallic compounds have been proposed as reaction catalysts in the production process of these polyester resins, and among them, organic titanium compounds and organic tin compounds are known to have excellent catalytic activity. For example, when monobutyltin oxide (BTO) is used as an organic tin compound, effects such as shortening of the esterification reaction time are recognized. However, when the production of the polyester resin is actually performed using the organotin compound, foreign substances are generated in the reaction process, and the filter is clogged in the step of filtering the reaction product generally performed in the production process. Therefore, there are problems such as difficulty in continuous production, deterioration of physical properties due to increase of foreign matters in the produced polymer, and poor appearance. As a method for avoiding this problem, a method in which a solvent-soluble portion obtained by treating an organic tin compound with an organic solvent is used as a catalyst (Japanese Patent Publication No. 55-5536), a method in which a specific organic phosphorus compound is added (JP-A-53-141
393), a method using an organotin compound having a specific thermal decomposition temperature as a catalyst (Japanese Patent Application Laid-Open No. 53-1444).
No. 998) is considered, but there are problems such as a decrease in catalytic activity and a complicated production process.

[0003]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to solve the above-mentioned problems. As a result, when the mixture obtained by mixing and heat-treating the organotin compound and the organotitanium compound is used as a polyester polymerization catalyst. The present inventors have found that there is an effect of reducing the generation of foreign substances during the reaction step, and have completed the present invention. That is, the present invention is a method for producing a polyester resin, which comprises using a product obtained by mixing and heating an organic titanium compound and an organic tin compound as a polymerization catalyst in the production of the polyester resin.

[0004]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The polyester resin to which the present invention can be applied is not particularly limited, and any polyester resin composed of a dicarboxylic acid component and a diol component, a polyester resin composed of a hydroxycarboxylic acid component, a polyester resin composed of these three components, and the like can be used. Is preferably a polyester resin comprising an acid component mainly composed of an aromatic dicarboxylic acid and a diol component. As the raw material monomer forming the main skeleton, in addition to the dicarboxylic acid and diol components,
It is also possible to use their ester-forming derivatives. Here, specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid, stilbenedicarboxylic acid, 2,2- (biscarboxyphenyl) propane,
And the like. These ester-forming derivatives include these lower alcohol esters. One or more aromatic dicarboxylic acid components as described above can be used. Next, as the diol component, ethylene glycol, propylene glycol,
1,4-butanediol, diethylene glycol, triethylene glycol, neopentyl glycol, hydroquinone, dihydroxyphenol, cyclohexanediol, cyclohexanedimethanol, naphthalene diol, dihydroxydiphenyl ether, etc., and alkyl, alkoxy or halogen-substituted products thereof One or more of these can be used. Further, in the present invention, other dicarboxylic acid and / or diol compounds as long as the original properties are not impaired,
Oxycarboxylic acid can be used as a copolymer component. Other dicarboxylic acids include, but are not particularly limited to, known dicarboxylic acids such as cyclohexanedicarboxylic acid, adipic acid, and sebacic acid. These dicarboxylic acid compounds can also be used for copolymerization in the form of a derivative capable of forming an ester, for example, a lower alcohol ester such as dimethyl ester.
In addition, two or more of these may be used. Other diol components include ethylene glycol, propylene glycol, neopentyl glycol, hydroquinone, resorcin, dihydroxyphenyl ether, naphthalene diol, dihydroxydiphenyl ether, cyclohexanedimethanol, 2,2-bis (4-hydroxyphenyl) propane, and diethoxylation. It is a dihydroxy compound such as bisphenol A and a substituted product thereof, and one or more kinds can be used. Also,
The components of oxycarboxylic acid include oxybenzoic acid, oxynaphthoic acid, diphenyleneoxycarboxylic acid, and substituted products thereof, and one or more of these may be used. Further, in addition to these, a polyester having a branched or crosslinked structure obtained by copolymerizing a small amount of trifunctional monomers, that is, trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, trimethylolpropane, etc., within a range not impairing the original characteristics. It may be a resin. The amount of these copolymerized components to be introduced is preferably 30 mol% or less, particularly preferably 20 mol% or less, based on all the constituent repeating ester units, but is not particularly limited.

According to the present invention, an organic titanium compound and an organic tin compound are used in combination as a polymerization reaction catalyst for a polyester resin,
In addition, a product obtained by mixing and heat-treating both in advance is used. As the organotitanium compound and the organotin compound used in the present invention, any of those known as polymerization catalysts for polyester resins can be used, and preferably those represented by Formula 1 and Formula 2, respectively. Ti (OR ¹ ) ₄ (Formula 1) R ² —Sn (＝ O) OH (Formula 2) (where R ¹ and R ² represent an alkyl group, an aryl group, an allylalkyl group, and a cycloalkyl group) Examples of the organic titanium compound used in the present invention include, for example, tetrabutyl titanate, tetrapropyl titanate, tetraethyl titanate, tetramethyl titanate, and hydrolysates thereof, and examples of the organotin compound include monobutyltin oxide and pentyl. Tin hydroxy oxide, hexyl tin hydroxy oxide,
Examples include, but are not limited to, octyltin hydroxyoxide, nonyltin hydroxyoxide, phenyltin hydroxyoxide, 4-butylphenyltin hydroxyoxide, cyclohexyltin hydroxyoxide, and the like.

In the present invention, the above-mentioned organotitanium compound and organotin compound are mixed and heat-treated in advance. The mixing ratio is such that the organic tin compound is 0.1 to 10 parts by weight based on 1 part by weight of the organic titanium compound. When the ratio of the organotin compound is small, the excellent characteristics of the organotin compound as a catalyst cannot be exhibited, and when the ratio of the organotin compound is too large, the effect of suppressing the generation of foreign substances during the reaction step becomes low,
The effect of the present invention cannot be obtained. Organic titanium compounds and organotin compounds are mixed directly after mixing each other, mixing them into a solvent such as a diol compound, dissolving one or both of them in a solvent such as a diol compound, or mixing them into a slurry. The effect of the present invention can be obtained in any case. The solvent used here is preferably the same as the diol component constituting the polyester resin produced according to the present invention, but is generally known as long as there is no hindrance in the properties and production steps of the produced resin. Solvents may be used. In this case, since the heat treatment temperature is limited by the boiling point of the solvent, a solvent having a low boiling point such as acetone or ether is not preferable. The concentration of the organotitanium compound and the organotin compound in the case of using a solvent is not particularly limited. However, when the concentration is too low, the total amount added as a catalyst for polymerization is not preferable. The temperature at which the mixture of the organotitanium compound and the organotin compound is heat-treated is 60 to 250 ° C, preferably 15 to 250 ° C.
0-200 ° C. In particular, when at least one of the organotitanium compound and the organotin compound is a solid, the heat treatment results in a uniform liquid product or a liquid product mainly containing a small amount of residual solid, which is used as a catalyst. Thereby, a remarkable effect can be obtained as compared with a case where both compounds are simply used in combination or mixed. When the product contains residual solids, it is preferable to remove the residual solids by filtration, decantation or the like before use. If the heat treatment temperature is too low, the effects of the present invention may not be obtained. On the other hand, when a solvent is used in the mixing / heating treatment, the range of possible heat treatment temperatures is limited by the boiling point of the solvent. In this case, it is desirable to perform the heat treatment using a device equipped with a reflux tube or the like.

The heat-treated product of the organotitanium compound and the organotin compound can be added as a catalyst immediately before the reaction or at the beginning of the reaction step, and, if necessary, several times during the reaction step. The heat treatment product is added in an amount corresponding to the amount of catalyst added in the production of a known general polyester resin. For example, it is 10 to 1200 ppm (based on polymer), particularly preferably 30 to 1000 ppm (based on polymer). In the present invention, the ratio between the organotitanium compound and the organotin compound is limited by the mixing ratio of both at the time of the heat treatment, but a simple substance of the organotitanium compound may be additionally added for the purpose of accelerating the reaction. On the other hand, the additional addition of the simple substance of the organotin compound leads to the generation of foreign matters, and therefore should be kept to the minimum necessary.

The heat treatment product may be added at a high temperature or after cooling, or the heat treatment product may be further diluted with a solvent and added, but the method is not particularly limited. When the solid component of the heat-treated product is contained, or even when the solid is precipitated by cooling, it is possible to use the catalyst as it is, but in such a case, the solid component was removed by a method such as filtration. If added later, more favorable effects can be obtained.

The present invention is characterized by the catalyst used as described above, and the type of polyester resin produced by using the catalyst is not particularly limited. It is a polyester resin composed of an acid component mainly composed of an aromatic dicarboxylic acid and a diol component, and specific examples include polybutylene terephthalate, polyethylene terephthalate, and polybutylene naphthalate. In the present invention, the production of such a polyester resin can be carried out by a conventionally known method except that the above-mentioned catalyst is used. For example,
After a precursor is generated by an esterification reaction or transesterification reaction of a dicarboxylic acid or a derivative thereof and a diol component, such a product is subjected to melt polycondensation under reduced pressure and heating while removing excess monomers and reaction by-products. Thereby, a polyester resin is obtained. In the production of such a polyester resin, a conventionally known organometallic compound, an inorganic compound, a sterically hindered phenol, a phosphorus compound or the like may be added as a stabilizer, a polymerization catalyst, a side reaction control agent, or the like to the monomer preparation step or the polymerization step. It is possible.

The polyester resin obtained by the above melt polymerization is a solvent appropriately selected depending on the kind of the resin, for example, polybutylene terephthalate having an intrinsic viscosity at 25 ° C. of about 0.5 to 1.2 dl / g in orthochlorophenol. Yes, which is then chill set, ground or pelletized, or spun as fibers. When a high degree of polymerization is required, it is also possible to shift to solid phase polymerization depending on the application. The solid-phase polymerization is generally performed by a known method, and a desired degree of polymerization can be appropriately adjusted by a residence time, a treatment temperature, and the like.

The polyester resin produced according to the present invention may be supplemented with one or more of other thermoplastic resins, additives, organic fillers, inorganic fillers and the like as needed during or after polymerization. Can also be used. Here, examples of the thermoplastic resin include polyester elastomer, polyolefin resin, polystyrene resin, polyamide resin, polycarbonate, polyacetal, polyarylene oxide, polyarylene sulfide, and fluororesin. Further, as additives, stabilizers such as conventionally known ultraviolet absorbers and antioxidants, antistatic agents, flame retardants, flame retardant aids, coloring agents such as dyes and pigments, lubricants, plasticizers, lubricants, A release agent, a crystal nucleating agent and the like are exemplified. As fillers, glass fiber, milled glass fiber, glass beads, glass flake, silica, alumina fiber, zirconia fiber, potassium titanate fiber, carbon fiber, carbon black, graphite, calcium silicate, aluminum silicate, kaolin, talc Silicates such as clay, iron oxides, titanium oxides, zinc oxides, antimony oxides, metal oxides such as alumina, carbonates and sulfates of metals such as calcium, magnesium, and zinc; and silicon carbide, silicon nitride, and nitride. Examples of the organic filler include high-boiling aromatic polyester fibers, liquid crystalline polyester fibers, aromatic polyamide fibers, fluororesin fibers, and polyimide fibers. When used as a molded article in electrical / electronic parts or automobile parts, there are many cases where flame retardancy is required depending on the use environment, and there are many cases where the blending of a flame retardant and a flame retardant auxiliary is indispensable. It is often necessary to blend a flame retardant and a flame retardant auxiliary. As the flame retardant, known halogen-containing compound-based flame retardants such as brominated polycarbonate, brominated epoxy compound, brominated diphenyl, and brominated diphenyl ether can be used.As the flame retardant aid, antimony trioxide, antimony pentoxide, In addition to antimony compounds such as antimony halides, metal compounds containing zinc and bismuth, and viscous silicates such as magnesium hydroxide and asbestos can be used.

[0012]

The polyester resin produced according to the present invention reduces the generation of foreign substances during the production process, prevents clogging of the filter during production, and makes it possible to use the resin even when the resin is made into fibers or molded. Since the product has excellent physical properties with reduced foreign matter, it can be suitably used for fibers and industrial resin parts such as automobile parts, electric / electronic parts, and the like.

[0013]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Example 1 1 part by weight of titanium tetrabutoxide (hereinafter referred to as TBT) as a viscous liquid as an organotitanium compound catalyst, and monobutyltin oxide (hereinafter referred to as BTO) as a solid powder as an organotin compound catalyst Parts by weight were mixed and heated at 200 ° C. for 30 minutes with stirring to obtain a uniform transparent liquid product (heat-treated product 1). Next, 246 parts by weight of dimethyl terephthalate, 1,4-butanediol
145 parts by weight was charged into a reactor equipped with a stirrer and a distillation tower, and 0.3 parts by weight of the heat-treated product 1 was added to carry out a transesterification reaction. The temperature was gradually raised, and methanol as a by-product was distilled off. When the distilled methanol exceeds 90% by weight of the theoretical amount, the temperature of the reactants is increased to 210 ° C., and the reactant is heated to 0.1% in 30 minutes.
The pressure was reduced to 5 Torr, and simultaneously the reaction temperature was raised to 248 ° C. After stirring for 1 hour and 10 minutes in this state, the melt was extruded as a strand from the discharge port, and the strand was cooled with water and then pelletized. And a PBT resin. Next, 120 g of the PBT resin was weighed, placed in a 10 mm inner diameter cylinder having a 300 mesh wire mesh filter, heated and melted at 250 ° C., extruded using a piston, and the amount of polymer attached to the wire mesh filter was measured. It was measured.

Comparative Example 1 A PBT resin was obtained by polymerization in the same manner as in Example 1, except that 0.15 parts by weight of TBT and 0.15 parts by weight of BTO were used as they were as added catalysts. Next, 120 g of the polymer of Comparative Example 1
Was extruded in the same manner as in Example 1, and the amount of the attached filter was measured. Table 1 shows the results of Comparative Example 1 where the polymer adhesion amount was set to 100.

Example 2 As a catalyst added, 1 part by weight of TBT and 1 part by weight of BTO were mixed in 5 parts by weight of 1,4-butanediol, heat-treated at 200 ° C. with stirring, and then cooled to 40 ° C. Polymerization was carried out in the same manner as in Example 1 except that the product 2 was used in a proportion such that the amount of the catalyst was 0.3 parts by weight, to obtain a PBT resin. Table 1 shows the results.

Example 3 A PBT resin was obtained by polymerization in the same manner as in Example 1 except that the heat-treated product 1 was cooled to room temperature as a catalyst, and then the heat-treated product 3 was used, in which the precipitated solid was removed by filtration. Get
The measurement was performed in the same manner as in Example 1, and the effects were compared. Table 1 shows the results
Shown in

Comparative Example 2 Polymerization was carried out in the same manner as in Example 1, except that 0.15 parts by weight of TBT and 0.15 parts by weight of BTO were mixed as the added catalysts, and the mixed catalyst 1 was allowed to stand at room temperature for 1 hour. Was measured in the same manner as in Example 1, and the effects were compared. Table 1 shows the results.

Comparative Example 3 Polymerization was carried out in the same manner as in Example 1 except that 0.3 parts by weight of BTO was used as an added catalyst to obtain a PBT resin. The measurement was carried out in the same manner as in Example 1, and the effects were compared. Table 1 shows the results.

[0019]

[Table 1]

Claims (8)

[Claims] In the production of a polyester resin, an organotitanium compound and an organotin compound are mixed and used as a polymerization catalyst.
A method for producing a polyester resin, comprising using a product obtained by a heat treatment. 2. The method for producing a polyester resin according to claim 1, wherein the polymerization catalyst is mainly composed of a liquid product obtained by mixing and heating an organic titanium compound and an organic tin compound, at least one of which is solid. . 3. The method for producing a polyester resin according to claim 1, wherein the polymerization catalyst is obtained by heat-treating an organic titanium compound and an organic tin compound in the presence of a diol compound. 4. The method for producing a polyester resin according to claim 1, wherein the temperature of the mixing and heating treatment of the organotitanium compound and the organotin compound is 60 to 250 ° C. 5. The method for producing a polyester resin according to claim 1, wherein an insoluble component is removed from the heat-treated product, and the resultant is used as a polymerization catalyst. 6. The method for producing a polyester resin according to claim 1, wherein the polyester resin is mainly made of an aromatic dicarboxylic acid or a derivative thereof and a diol compound. 7. The method for producing a polyester resin according to claim 6, wherein the polyester resin is mainly made of terephthalic acid or a derivative thereof and a diol compound. 8. A polyester resin produced by the production method according to claim 1.