JPH04366162A - Polyester composition - Google Patents

Abstract

PURPOSE:To obtain a polyester composition having a high crystallization rate and improved moldability, mechanical properties, electrical properties and weather resistance by mixing a specified polyester resin with a reinforcing or filling substance and an aliphatic polyether ester. CONSTITUTION:A polyester resin is obtained by polycondensing (a lower alkyl ester of) an 8-20C aromatic dicarboxylic acid with a 2-20C diol in the presence of 0.01-20 pts. wt., per 100 pts.wt. obtained thermoplastic polyester, organic phenolic sulfonate of the formula [wherein Ar is a 6-30 C aromatic ring; M is an alkali (alkaline earth) metal; m is 1 or 2; and n is 1-5]. 100 pts.wt. said resin is mixed with 5-140 pts.wt. reinforcing or filling substance and 0.1-10 pts.wt. aliphatic polyether ester comprising a polyalkylene glycol comprising repeating units derived from a 4-46C aliphatic dibasic acid, repeating units derived from a 2-8C aliphatic glycol and repeating units derived from a 2-4C glycol.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic polyester resin composition which has a fast crystallization rate, excellent moldability when using a mold at low temperatures, and has good mechanical properties, electrical properties and weather resistance.

0002

[Prior Art] Thermoplastic polyesters are being used in a wide range of fields because of their excellent mechanical, physical, and chemical properties. Among them, some thermoplastic polyesters such as polyethylene terephthalate,
Although it has particularly excellent properties, it is currently not widely used in injection molding applications. This is especially true in the case of polyethylene terephthalate, which has a slower crystallization rate than other crystalline polymers.
This is due to the fact that there was a problem with moldability in that a mold at a low temperature of 0 to 95° C. did not sufficiently crystallize, making it impossible to obtain a satisfactory molded product.

[0003] Therefore, in order to improve the moldability, various methods have been studied to improve the crystallization rate of thermoplastic polyester.

For example, JP-A-56-57825 discloses that an alkali metal chlorinated sulfonic acid group and an alkali metal chlorinated phenolic hydroxyl group are bonded to an aromatic ring selected from a benzene ring, a naphthalene ring, and an anthracene ring. A crystallization accelerator for polyester is disclosed.

[0005] Furthermore, JP-A-58-198558 discloses a polyester resin composition in which a polyester consisting of an aliphatic dibasic acid and glycol is blended with the nucleating agent and reinforcing filler to improve the crystallization rate. .

Furthermore, JP-A-56-92918 discloses a high-speed crystallization polyester characterized in that the polyester is polymerized in the presence of a copolymer component that converts the terminal end of the polyester into a metal salt or an alkali metal. Furthermore, an example is disclosed in which a fatty acid ester of polyalkylene glycol is added to this rapidly crystallized polyester.

[0007]

[Problems to be Solved by the Invention] However, even if the above-mentioned method is applied, there is a problem that not only the crystallization rate of polyester is not improved significantly, but also the mechanical properties of the molded article are deteriorated.

[0008] The inventors of the present invention have conducted extensive studies to significantly improve the crystallization rate of thermoplastic polyester, improve moldability, and at the same time obtain a polyester resin composition that has good mechanical properties. By adding a metal salt of an aromatic sulfonic acid containing a phenolic hydroxyl group, and further adding reinforcing or fillers, and a specific aliphatic polyether ester before the completion of polyester polymerization, the original purpose can be effectively achieved. The present invention was achieved by discovering that this can be achieved.

[0009]

[Means for Solving the Problems] That is, the present invention provides (A
) Based on 100 parts by weight of a thermoplastic polyester starting from an aromatic dicarboxylic acid having 8 to 20 carbon atoms or a lower alkyl ester thereof and a diol having 2 to 20 carbon atoms,
A polyester resin obtained by adding 0.01 to 20 parts by weight of a phenolic hydroxyl group-containing organic sulfonate represented by the lower general formula (1) before the completion of polycondensation of the thermoplastic polyester 100 parts by weight HO-Ar- (SO3-(M)1/m)n
Formula (1) (wherein, Ar represents an aromatic ring having 6 to 30 carbon atoms,
M represents an alkali or alkaline earth metal, m represents 1 or 2, and n represents an integer of 1 to 5. ), and (B) 5 to 140 parts by weight of reinforcing or filler material, and (
C) An aliphatic compound having a molecular weight of 500 or more, consisting of an aliphatic dibasic acid having 4 to 46 carbon atoms, an aliphatic glycol having 2 to 8 carbon atoms, and a polyalkylene glycol having repeating units of glycol having 2 to 4 carbon atoms. A polyester composition containing 0.1 to 10 parts by weight of polyether ester.

The thermoplastic polyester used in the present invention is a dicarboxylic acid (or its ester-forming derivative)
It is a polymer or copolymer obtained by a polycondensation reaction containing as main components a diol (or an ester-forming derivative thereof) and a diol (or an ester-forming derivative thereof).

The dicarboxylic acids mentioned here include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2,2'-biphenyl Dicarboxylic acid, 3,3'-biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-diphenyl etherdicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, 4 , 4'-diphenylisopropylidene dicarboxylic acid, 1,2-bis(phenoxy)ethane-4,
4'-dicarboxylic acid, 2,5-anthracenedicarboxylic acid, 2,6-anthracenedicarboxylic acid, 4,4'-p
- Aromatic dicarboxylic acids such as terphenylene dicarboxylic acid and 2,5-pyridine dicarboxylic acid, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, dodecanedioic acid, and sebacic acid, alicyclic dicarboxylic acids such as cyclohexane dicarboxylic acid, etc. and terephthalic acid can be preferably used. Note that two or more of these dicarboxylic acids may be used in combination.

[0012] In addition, as diol components, ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 2
Examples include aliphatic diols such as -methyl-1,3-propanediol, diethylene glycol and triethylene glycol, alicyclic diols such as 1,4-cyclohexanedimethanol, and mixtures thereof. In addition, if it is a small amount, a long chain diol with a molecular weight of 400 to 6000, such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc.
More than one species may be copolymerized.

Specific examples of thermoplastic polyesters include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polycyclohexane dimethylene terephthalate, and polyethylene 1,2-bis(phenoxy)ethane- In addition to 4,4'-dicarboxylate, examples include copolymerized polyesters such as polyethylene isophthalate/terephthalate, polybutylene terephthalate/isophthalate, polybutylene terephthalate/decanedicarboxylate, and polycyclohexane dimethylene terephthalate/isophthalate. . Among these, polybutylene terephthalate, polycyclohexane dimethylene terephthalate, polyethylene naphthalate, and polyethylene terephthalate, which have well-balanced mechanical properties and moldability, can be preferably used.

The thermoplastic polyester used in the present invention has an intrinsic viscosity of 0.25 to 3.0 dl/g, particularly 0.4 to 2.0 dl/g, as measured in o-chlorophenol solution at 25°C.
．． 25 dl/g is preferred.

In the present invention, the compound added before the completion of polymerization of polyester in order to improve the crystallization rate has the following general formula (
It has the structural formula 1).

HO-Ar-(SO3-(M)1/m)n
Formula (1) (wherein, Ar represents an aromatic ring having 6 to 30 carbon atoms,
M represents an alkali or alkaline earth metal, m represents 1 or 2, and n represents an integer of 1 to 5. ) The above general formula (1)
Examples of aromatic rings that form the basic skeleton include hydrocarbon aromatic rings such as benzene, naphthalene, phenanthrene, anthracene, and pyrene, as well as pyridine, triazine,
Cyclic systems containing heteroaromatic rings such as furan, quinoline, isoquinoline, and 1,10-phenantholene, and general aromatic rings such as indene, indole, benzofuran, fluorene, and dibenzofuran can also be used, and are not particularly limited.

[0017] Here, it is essential that the aromatic ring has one hydroxyl group bonded to it, and if it does not have a hydroxyl group, it will hardly exhibit any effect of improving the crystallization rate. Furthermore, the hydroxyl group must not be metal chlorinated with a metal such as an alkali metal. This is because when the hydroxyl group is converted into a metal salt, the salt often becomes a foreign substance due to its strong concentrating force, which not only makes the effect of improving the crystallization rate insufficient, but also makes the obtained thermoplastic polyester composition This is because it deteriorates the mechanical properties of the molded product.

[0018]Although one or more metal chlorinated sulfonic acid groups must be bonded to the aromatic ring, it is desirable that the number of these groups be small. This is for the same reason as mentioned above. That is, if there is too much of this group, it will not be uniformly dispersed in the polymerization system and will become foreign matter, reducing the effect of improving the crystallization rate and deteriorating the mechanical properties of the molded article. Therefore, the number of metal chlorinated sulfonic acid groups is preferably two or less, most preferably one.

The above-mentioned hydroxyl group and metal chlorinated sulfonic acid group can be bonded to any bondable position of the aromatic ring. However, the degree of improvement in crystallization rate obtained differs depending on the position of the substituent. For example, in the case of sodium phenolsulfonate, the substituent can be placed in three positions: ortho, meta, and para, but it is the para position that significantly improves the crystallization rate;
Those in the meta position tend to have a small effect on improving the crystallization rate. In addition, in the case of phenol disulfonic acid disodium salt, the bonding positions of the sulfonic acid are 2, 3; 2, 4;
There are six types: 2,5; 2,6; 3,4; 3,5; among these, the ones that have the greatest effect on improving the crystallization rate are 2,6; 3,
5, with 3rd and 5th positions being particularly preferred.

As described above in the examples, those in which a substituent is bonded to the aromatic ring so as not to break the symmetry are particularly preferred because they have a large effect of improving the crystallization rate.

Furthermore, the additive of the present invention may contain other substituents other than the hydroxyl group and the metal-chlorinated sulfonic acid group as long as they do not impede the effects of the present invention. Such substituents include methyl groups, aliphatic groups such as ethyl groups, halogen groups such as chromium and bromine, cyano groups, nitro groups, aral groups such as acetyl, propionyl, and beyzoyl, methylsulfonyl, ethylsulfonyl, and phenyl. Sulfonyl groups such as sulfonyl and tolylsulfonyl,
N-phenylcarboxamide, N-ethylcarboxamide,
Examples include carboxamide groups such as N-propylcarboxamide, alkoxy groups such as methoxy and ethoxy, and aromatic groups such as phenyl, among which aliphatic groups, halogen groups and alkoxy groups are preferred.

Specific examples of the compound represented by the above formula (1) include compounds obtained by converting the sulfonic acid group of the following compound into a metal salt with an alkali metal or an alkaline earth metal.

That is, the base compound is o-
Phenolsulfonic acid, m-phenolsulfonic acid, p
-phenolsulfonic acid, 1-hydroxy-3,5-benzenedisulfonic acid, 1-hydroxy-2,6-benzenedisulfonic acid, 1-hydroxy-2,4-benzenedisulfonic acid, 1-hydroxy-3,4-benzene Disulfonic acid, 2-naphthol-6-sulfonic acid, 1-naphthol-5-sulfonic acid and 1-naphthol-4-sulfonic acid, 9-hydroxy-10-anthracenesulfonic acid, etc., among which phenolsulfonic acid, In particular, p-phenolsulfonic acid is most preferred in terms of performance and economy.

The metal of the metal salt of the sulfonic acid compound used in the present invention is preferably an alkali metal such as lithium, sodium, potassium, rubidium, or cesium, or an alkaline earth metal such as calcium or barium. Among the alkali metals, lithium is particularly preferred. and sodium are preferred.

[0025] The amount of the sulfonic acid metal salt compound added in the present invention is 0.01 to 20 parts by weight, preferably 0.05 to 10 parts by weight, more preferably 0.1 parts by weight, based on 100 parts by weight of the thermoplastic polyester. ~5 parts by weight. If the amount added is less than 0.01 part by weight, the effect of improving the crystallinity of the thermoplastic polyester will not be sufficient, and if it exceeds 20 parts by weight, the melt viscosity will increase, the fluidity of the resin will deteriorate, and the mechanical properties will deteriorate. This is not desirable because it tends to decrease.

The sulfonic acid metal salt compound of the present invention must be added before the completion of polymerization in order to obtain an excellent crystallization rate improving effect. In addition, by devising the polymerization conditions, the obtained polyester resin has a molecular weight of 2,000 or less in terms of polystyrene equivalent molecular weight, and a sulfur concentration of 0.
It is preferable that the polyester is polymerized to contain 1 to 20% by weight of a polyester component of 0.005% by weight or more because a polyester having particularly excellent crystallization speed and mechanical properties can be obtained. In addition, in order to further increase the effect of improving the crystallization rate, the sulfur concentration of the polyester component with a molecular weight of 2000 or less should be 0.005% or more, particularly 0.01% or more, and more preferably 0.05% or more. desirable.

[0027] Polyesters with particularly excellent crystallization rates often exhibit a molecular weight distribution with a peak or shoulder in the molecular weight region of about 1,000.

The reason why the presence of this low molecular weight greatly improves the crystallization rate of polyester remains to be investigated in the future. However, when this low molecular weight component was separated by gel permeation chromatography and subjected to elemental analysis, it was found that the content of sulfur was high. It is thought that the crystallization rate is greatly improved by taking a structure added to the polyester oligomer and finely dispersing it in the polyester. When ordinary sulfur-free polyester oligomers are added to polyester, or when polymerization is carried out under conditions that generate such oligomers, there is almost no effect of improving the crystallization rate, and sulfur-containing polyester oligomers are added to polyester. Oligomers that do this are particularly effective in improving the crystallization rate.

The content of oligomers having a molecular weight of 2000 or less can be determined by a conventional gel permeation chromatography method. As a solvent, o-chlorophenol/
Chloroform = 1/4 (vol/vol), and a differential refractometer can be used as a detector. In other words, calibrate the column using commercially available polystyrene with a narrow molecular weight distribution, and calculate the ratio of the area after the retention time corresponding to the molecular weight of polystyrene of 2000 to the entire area narrowed by the polyester output curve and the baseline. , calculate the oligomer content.

[0030] The amount of sulfur contained in the oligomer can be determined by separating the polyester component with a molecular weight of 2000 or less,
It can be determined by quantifying it by elemental analysis.

The amount of this oligomer varies depending on the time of addition of the sulfonate compound having a phenolic hydroxyl group and the method of addition (powder, solution, suspension), and also depends on the esterification reaction, esterification, reaction, and transesterification reaction. Or the polymerization reaction (it is greatly influenced by the type of catalyst, amount of catalyst, temperature, speed of temperature rise, etc.).The optimal conditions differ depending on the sulfonate compound with a phenolic hydroxyl group to be added, so it cannot be generalized. However, in general, desirable results are often obtained when the sulfonate compound having a phenolic hydroxyl group is added at the early stage of the transesterification reaction or esterification reaction, or even before the reaction.

The reinforcing or filling material (B) used in the composition of the present invention includes glass fibers, carbon fibers, metal fibers, aramid fibers, asbestos, potassium titanate whiskers, wollastenite, glass flakes, glass beads, and talc. , mica, clay, calcium carbonate, barium sulfate, titanium oxide and aluminum oxide, among which chopped strand type glass fiber is preferably used. The amount of these added is 5 to 140 parts by weight, particularly preferably 5 to 100 parts by weight, per 100 parts by weight of the thermoplastic polyester.

The aliphatic polyether ester (C) used in the present invention is a polyalkylene consisting of an aliphatic dibasic acid having 4 to 46 carbon atoms, an aliphatic glycol having 2 to 8 carbon atoms, or a glycol having 2 to 4 carbon atoms. It is an aliphatic polyether ester having a molecular weight of 500 or more and consisting of glycol.

Here, the aliphatic dibasic acids having 4 to 46 carbon atoms constituting the polyether ester include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid,
Examples include azelaic acid, sebacic acid, dodecanedioic acid, and dimer acid, among which adipic acid and sebacic acid are preferred. Furthermore, examples of aliphatic glycols having 2 to 8 carbon atoms include ethylene glycol, propylene glycol, 1,4-butanediol, hexylene glycol,
Examples include neopentyl glycol, 2-methyl-1,3-propanediol, and among these, ethylene glycol, 1,4-butanediol, and neopentyl glycol are preferred. Preferred examples of polyalkylene glycols consisting of glycols having 2 to 4 carbon atoms include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and copolymers of ethylene oxide and propylene oxide, among which polyethylene glycol, polypropylene Glycols are preferred. The molecular weight of the polyalkylene glycol is preferably from 200 to 5,000, particularly from 200 to 1,000, since this has a large effect of improving the crystallization rate.

It should be noted that (C) the aliphatic polyether ester should have fewer free carboxylic acids and hydroxyl groups, not only to avoid lowering the molecular weight of the polyester when producing the composition, but also to improve retention stability and crystallization rate. preferable. The acid value is 1 mg-KOH/g or less, especially 0.5 mg-KOH/g.
g or less, preferably 0.3 mg-KOH/g or less. The hydroxyl value is preferably 50 mg-KOH/g or less, more preferably 10 mg-KOH/g or less, even more preferably 1 mg-KOH/g or less. Reducing the terminal acid value can generally be easily achieved by using an excess diol component in the polyether ester polymerization process and performing the polymerization while removing the excess diol from the system under reduced pressure. . It is possible to lower the hydroxyl value by adding an excess of monobasic acid to the terminal end of the polyether ester obtained in this manner and blocking the end, and then removing unreacted acid. The acid used for terminal blocking is not particularly limited, but benzoic acid and acetic anhydride are commonly used and preferred compounds.

(C) The molecular weight of the aliphatic polyether ester is 500 or more. If the molecular weight is less than this, it often volatilizes during the production of the composition and a sufficient effect of improving the crystallization rate cannot be obtained. Further, in order to sufficiently obtain the effect of improving the crystallization rate, the molecular weight is preferably 500 or more and 30,000 or less, particularly 500 or more and 10,000 or less, and more preferably 500 or more and 5,000 or less.

(C) The amount of aliphatic polyether ester added is 0.1 to 10 parts by weight per 100 parts by weight of polyester.
Parts by weight. If it is less than 0.1 parts by weight, the effect of improving crystallization rate is not sufficient, and if it exceeds 10 parts by weight, mechanical properties,
This is not preferred because heat resistance and electrical properties deteriorate.

(C) It is essential that polyalkylene glycol is copolymerized with the aliphatic polyether ester. When an aliphatic polyester consisting of an aliphatic dibasic acid and an aliphatic glycol in which no polyalkylene glycol is copolymerized is used in combination with component (A) of the present invention, the effect of improving the crystallization rate is insufficient. The crystallization rate of a polymer can be estimated by the difference (ΔT) between the crystallization temperature (Tcc) when the temperature is raised and the crystallization temperature (Tc) when the temperature is lowered, as measured by a differential scanning thermal analyzer. Generally, the addition of a crystal nucleating agent has the function of increasing Tc, and the crystallization promoter such as aliphatic polyester or polyether ester has the function of decreasing Tcc and improving the crystallization rate. (A) of the present invention
The phenolic group-containing sulfonate added to the ingredients has a high nucleating effect and significantly increases Tc, but when an aliphatic polyester that does not contain polyalkylene glycol is added to it, Tcc decreases, but Tc also decreases, making it an excellent product. It does not show any accelerating effect on crystallization rate. When an aliphatic polyether ester copolymerized with polyalkylene glycol, which is component (C) of the present invention, is used, there is no decrease in Tc but only Tcc, resulting in a significantly excellent crystallization promoting effect. I understand. Although the reason for this is not clear, it is believed that it is due to the synergistic effect of the polyalkylene glycol unit and aliphatic polyester unit contained in the aliphatic polyether ester, and the nucleating agent component. (C) The content of polyalkylene glycol in the aliphatic polyether ester is 3% by weight.
It is preferably 95% by weight or less, more preferably 10% by weight or more and 80% by weight or less. If the amount added is less than 3% by weight or more than 95% by weight, the effect will be similar to that of simply adding aliphatic polyester or polyalkylene glycol, and the synergistic effect of the three mentioned above will result in an excellent crystallization rate improvement effect. This is not preferable because it does not provide

From the viewpoint of improving moldability, it is also possible to use various organic acid salts and inorganic compounds known as moldability improvers for thermoplastic polyesters, such as polyethylene terephthalate, in combination with the polyester composition of the present invention. preferred. Specific examples of these compounds include stearates such as sodium stearate and barium stearate, sodium salts of partially saponified montanic acid esters, barium salts, ionomers, sodium salts of β-diketones, talc, and salicylanilide. Examples include sodium salts, sodium salts of substituted phenols such as sodium salts of salicylaldehyde, and sodium salts of nitrophenol.

Furthermore, the polyester composition of the present invention may be added with antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, mold release agents, colorants including dyes and pigments, etc., to the extent that the purpose of the present invention is not impaired. One or more of the usual additives can be added.

A small amount of thermoplastic resin, such as polycarbonate, polyamide, polyphenylene oxide,
Polypropylene, polyethylene, ethylene/propylene copolymer, ethylene/butene-1 copolymer, ethylene/
Propylene/nonconjugated diene copolymer, ethylene/ethyl acrylate copolymer, ethylene/glycidyl methacrylate copolymer, ethylene/vinyl acetate/glycidyl methacrylate copolymer, and ethylene/propylene-g-maleic anhydride copolymer It is also possible to add combinations and the like.

The method for producing the polyester composition of the present invention and the method for adding the above-mentioned additives thereto are not particularly limited, and may be added at the final stage of polyester polymerization or melt-kneaded using an extruder. However, it is necessary to add the phenolic hydroxyl group-containing organic sulfonate represented by formula (1) in component (A) before the completion of polymerization, and other additives must be added before the extruder is It is preferable to melt and knead the mixture.

The polyester composition of the present invention can be easily molded by conventional methods such as injection molding and extrusion molding, and the molded products obtained exhibit excellent performance. Particularly in injection molding, it is characterized by good moldability even when a low temperature mold of 50 to 95°C is used.

Furthermore, the molded product has particularly good mechanical properties, electrical properties such as arc resistance, and weather resistance.

[0045]

[Examples] The effects of the present invention will be explained in more detail below with reference to Examples.

Reference Example 1 100 parts by weight of dimethyl terephthalate, 62 parts by weight of ethylene glycol, 0.16 parts by weight of lithium acetate, 0.04 parts by weight of antimony trioxide and 0.02 parts by weight of manganese acetate.
To each part by weight of the mixture, 3 parts by weight of sodium p-phenolsulfonate was added. This was heated to 140℃,
After the dimethyl terephthalate has melted, start stirring;
The temperature was raised from 140°C to 245°C over 3.5 hours to carry out the transesterification reaction, and most of the methanol was distilled off. Next, while raising the temperature from 245° C. to 280° C. over 3 hours, the mixture was gradually evacuated and polymerization was carried out under a vacuum of 0.6 mmHg.

The intrinsic viscosity of the o-chlorophenol solution at 25° C. was measured to be 0.61 dl/g.

The obtained polyethylene terephthalate composition was subjected to differential thermal analysis using a differential scanning calorimeter manufactured by PerkinElmer, Inc., and the crystallinity was evaluated by measuring the heating crystallization temperature and cooling crystallization temperature. As is generally well known, the higher the cooling crystallization temperature rises and the lower the heating crystallization temperature, the better the crystallinity. Therefore, △T = (cooling crystallization temperature) - ( ΔT when the temperature was increased (temperature-raising crystallization temperature) was used as a measure of crystallinity. ΔT was 93°C.

Reference Example 2 Polymerization was carried out in the same manner as in Reference Example 1 except that p-phenolsulfonic acid sodium salt was not added. Intrinsic viscosity 0
．． Polyethylene terephthalate of 61 dl/g and ΔT of 22°C was obtained.

Reference Example 3 Polymerization was carried out in the same manner as in Reference Example 1 except that 2 parts of p-phenolsulfonic acid disodium salt was added instead of p-phenolsulfonic acid sodium salt. Intrinsic viscosity 0
．． Polyethylene terephthalate of 62 dl/g and ΔT of 71°C was obtained.

Examples 1 to 3, Comparative Examples 1 to 5 Chopped strand type glass fiber (3 mm length, 13 μm diameter) was added to 100 parts by weight of the obtained polyethylene terephthalate.
) 40 parts by weight and the crystallization accelerator shown in Table 1 were added by dry blending, and the temperature was set at 285°C.
The mixture was melt-kneaded and pelletized using a twin-screw extruder.

[0052]

[Table 1]

Further, the above pellets were dehumidified and dried at 145°C for 5 hours, and then injection time/cooling time/intermediate time 15 seconds/20 seconds/ 5 seconds, mold temperature 75℃
, length 40mm, width 60mm, depth 20mm, wall thickness 1
．． A 5 mm box-shaped molded product was molded, and the force (mold release force) required to separate the box-shaped molded product from the mold was determined.

Also, under similar injection conditions, ASTM-1
A dumbbell was molded and its tensile properties were measured according to ASTM D-638.

Further, a 1/16 inch bending test piece was molded under the same injection conditions and the deflection temperature under high load was measured using a method similar to ASTM D-648.

The above results are also shown in Table 1.

From the results in Table 1, the polyester composition of the present invention has a significantly improved crystallization rate, exhibits good mold releasability even in low-temperature molds, and has good mechanical properties, and can be used even in thin-walled molded products. It can be seen that it exhibits high heat resistance due to its fast crystallization rate.

[0058]

[Effects of the Invention] The polyester composition of the present invention has a fast crystallization rate, so it has excellent moldability in a low-temperature mold, and the molded products obtained have good mechanical properties, electrical properties, and weather resistance. Therefore, it is particularly useful for electrical and electronic parts, automobile parts, mechanical mechanism parts, etc.

Claims (1)

[Claims] Claim 1: (A) 100 thermoplastic polyesters starting from an aromatic dicarboxylic acid having 8 to 20 carbon atoms or a lower alkyl ester thereof and a diol having 2 to 20 carbon atoms;
A polyester resin obtained by adding 0.01 to 20 parts by weight of a phenolic hydroxyl group-containing organic sulfonate represented by the lower general formula (1) to parts by weight before completion of polycondensation of the thermoplastic polyester 100 Weight part HO-A
r-(SO3-(M)1/m)n Formula (1
) (wherein, Ar is an aromatic ring having 6 to 30 carbon atoms, M is an alkali or alkaline earth metal, m is 1 or 2,
n represents an integer of 1 to 5. ), and (B) 5 to 140 parts by weight of reinforcing or filler material, and (C)
Aliphatic polyether with a molecular weight of 500 or more, consisting of an aliphatic dibasic acid having 4 to 46 carbon atoms, an aliphatic glycol having 2 to 8 carbon atoms, and a polyalkylene glycol having repeating units of glycol having 2 to 4 carbon atoms. A polyester composition containing 0.1 to 10 parts by weight of an ester.