JPS61163957A - Polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin compsn. which has excellent moldability and gives moldings having excellent surface glass and mechanical properties, by blending a specified high-molecular compd. and an ester plasticizer with a mixture of polyethylene terephthalate with polybutylene terephthalate. CONSTITUTION:A resin compsn. is obtd. by blending 0.05-10pts.wt. at least one member selected from among inorg. nucleating agents having an average particle size of 50mu or below, org. compds. contg. a carboxyl group in the form of a metal salt and high-molecular compds. contg. a carboxyl group in the form of a metal salt, 0.34-10pts.wt. ester plasticizer and 0-150pts.wt. reinforc ing fiber with 100pts.wt. polyester obtd. by blending 65-95pts.wt. polyethylene terephthalate or copolyester contg. at least 80mol% of an ethylene terephthalate repeating unit with 5-35pts.wt. polybutylene terephthalate.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a polyester composition that has good moldability and provides molded articles with excellent surface gloss and mechanical properties. More specifically, the present invention relates to a polyester composition that has a high crystallization rate and provides excellent molded products even at a mold temperature of about 60 to 100° C. during injection molding. [(Prior Art) Polyethylene terephthalate has excellent mechanical properties, electrical properties, heat resistance, chemical resistance, etc., and is used in many industrial products as fibers and films.

In this way, when used as fiber or film, 1
Normally, stretched products are used, but for example, when trying to use them as injection molded products for plastic purposes, they are not subjected to the stretching process described above.
It is known that various problems occur in molding and physical properties. In other words, since the crystallization rate at low temperatures is low, 1 the crystallization rate is insufficient at mold temperatures of about 120°C or lower, which are normally used when injection molding other plastics, and the resulting molded product has There is a difference in the degree of crystallinity inside the mold, which results in uneven mechanical properties, dimensional stability, and shape stability, making it extremely difficult to obtain a molded product that can withstand practical use.

(Problem to be solved by the invention) As a conventional method to solve such problems.

Many methods have been proposed, including a method using a high-temperature mold and a method adding a crystal nucleating agent or a crystallization accelerator.

However, the method of using a high-temperature mold is not practical because trench-making to increase the temperature is complicated, the molding cycle becomes longer, and work efficiency is significantly lowered. On the other hand, many methods of adding crystal nucleating agents and crystallization promoters have been studied.

The crystallization speed during injection molding is still not sufficient.

When the mold temperature is 100°C or less1, especially between 60 and 80°C, the surface properties of the molded product such as surface gloss are poor, and when molding thin products, there are problems such as a decrease in heat deformation temperature, which still have to be solved. The reality is that there are still things that need to be done.

(Means for Solving the Problems) Therefore, the present inventors have found that the moldability is excellent at a mold temperature of 60 to 80°C, that is, the crystallization rate during molding is fast.

As a result of intensive research in order to obtain a polyethylene terephthalate composition useful as a molding material that also has excellent surface gloss and thermal and mechanical properties, we found that polyethylene terephthalate or a copolymer having at least 80 mol% of ethylene terephthalate lff1 return units was found. We found that the above objective can be achieved by blending a specific amount of polybutylene terephthalate with polyester, and further blending specific amounts of a crystal nucleating agent, a crystallization accelerator, and, if necessary, a specific amount of fibrous reinforcing material.2 We have arrived at the present invention.

That is, the present invention relates to polyethylene terephthalate or a copolymerized polyester having ethylene terephthalate repeating units of at least 80 mol%.

(hereinafter abbreviated as PET) 65 to 95 parts by weight and polybutylene terephthalate (hereinafter abbreviated as PBT) 5
to 100 parts by weight of polyester containing 35 parts by weight, (a) an inorganic crystal nucleating agent with an average particle size of 50 μm or less;
A precipitate compound containing a metal salt of a carboxyl group.

0.05 to 10 parts by weight of at least one kind of polymer compound having a metal salt of a carboxyl group, (0) 0.3 to IO parts by weight of an ester plasticizer, and (c) 0 parts by weight of fibrous reinforcing material.
This relates to a polyester resin composition containing ~150 parts by weight.

(Function) The present invention blends PET with a specific amount of PBT, and further blends component (a) and component (b), so that mold temperature 6
The object of the present invention is to provide a composition useful as a molding material that has improved surface properties such as surface gloss of molded articles at 0 to 100°C, and further improved heat resistance and mechanical properties as required.

The polyethylene terephthalate used in the present invention is obtained from terephthalic acid or an ester of terephthalic acid and ethylene glycol by a conventional melt polymerization method, or it is obtained by subjecting it to solid phase polymerization. The polyester having at least 80 mol% or more of ethylene terephthalate repeating units means 180 mol% or more of ethylene terephthalate repeating units and other repeating units.

In other words, it means a copolymer consisting of other copolymer components,
As the other copolymerization components mentioned above, various acid components and glycol components can be used.

For example, acid components include isophthalic acid, knack dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylmethane dicarboxylic acid, diphenyl dicarboxylic acid, etc. Sea lion 2.
, 2-acid, P-(2-hydroxyl-benzoic acid), 5-sodium sulfoisophthalic acid, adipic acid, azelaic acid, sebacic acid.

Dodecane-1,12-dicarboxylic acid, tetradecane-1
゜14-dicarboxylic acid, hexadecane-1,16-dicarboxylic acid, octadecane-1,18-dicarboxylic acid, 6
-Nityl-hexadecane-1, 16-dicarboxylic acid, and the like. Glycol components include propylene glycol, diethylene glycol, butylene glycol, pentyl glycol, neopentyl glycol, and hexamethylene glycol.

Examples include polyalkylene glycols such as polyethylene glycol and polytetramethylene glycol.

The polybutylene terephthalate used in the present invention is
In addition to the homopolymer consisting of terephthalic acid and butylene glycol, a copolymer of a portion of the above acid component or glycol component, for example, about 10 mol % or less, is also included.

The inorganic compound used as component (a) of the present invention is as follows.

The effect as a crystal nucleating agent varies depending on the particle size, and if the average particle size exceeds about 50 μm, the effect decreases, so in general, inorganic compounds with an average particle size of 50 μm or less are useful.

Specific examples of inorganic compounds with an average particle size of 50μ or less used in the present invention include carbon black, silica, calcium carbonate, synthetic silicic acid and silicates, zinc white, hallosite clay, kaolin, basic carbonate, etc. Magnesium, mica.

Examples include talc, quartz powder, diatomaceous earth, dolomite powder, titanium oxide, zinc oxide, antimony Mide, barium sulfate, calcium sulfate, alumina, calcium silicate, etc., and one or more of these inorganic compounds can be used. Although it can be used.

Among them, mica, kaolin, silica, and silica are useful in the present invention.

Further, as the organic compound having a metal salt of a carboxyl group used in the present invention, any compound having a metal salt of a carboxyl group can be used, but usually has about 1 to 1 carbon atoms. 30 higher fatty acids, metal salts of aromatic acids are used, such as heptanoic acid,
pelargonic acid.

Lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, cerotic acid, montanic acid.

Metal salts of higher fatty acids such as melisic acid, benzoic acid.

Terephthalic acid, terephthalic acid monomethyl ester.

Specific examples include metal salts of aromatic acids such as isophthalic acid and monomethyl ester of isophthalic acid.

Further, the polymer compound having a metal salt of a carboxyl group is not particularly limited as long as it has a metal salt of a carboxyl group at the terminal or side chain of the polymer, but for example, a carboxyl group obtained by oxidation of polyethylene is used. Containing polyethylene, carboxyl group-containing polypropylene obtained by oxidizing polypropylene, copolymers of olefins such as ethylene, propylene, butene-1, and (meth)acrylic acid, copolymers of olefins and maleic anhydride, styrene and ( Specific examples include metal salts such as copolymers of meth)acrylic acid and copolymers of styrene and maleic anhydride.1 Usually, copolymers of olefin and (meth)acrylic acid or styrene and (meth)acrylic acid are used. Polymeric metal salts are used. As the metal that forms a salt with a carboxyl group, alkaline earth metals, alkali metals, etc. are usually used, and alkali metals are excellent in their effectiveness as crystal nucleating agents, with sodium and potassium being particularly useful.

Various compounds can be used as the ester plasticizer used as the component (b) of the present invention, among which those of the following general formulas (I) and (II) are used.

Ester compounds represented by (III) are useful.

0 0 (I) R1: Alkylene group R2+ Ih: A group selected from an alkyl group, a benzyl group, and an aromatic substituted benzyl group.

R2 and Ra are the same or different groups It is.

m, n: integer greater than or equal to i
.

<II) X: Direct bond, alkylene group + -S(h -+-5-
*-0- or -C- R4, Rs: A group selected from an alkyl group, a benzyl group, a phenyl group, or a derivative thereof, and R4 and Rs are the same or different groups.

Ri + Rt: hydrogen, an alkyl group, or a halogen, and Re and Rt are the same or different groups.

m, n: integers of 1 or more Re, Re: hydrogen, alkyl group, phenyl group.

Benzyl group or these derivatives A group selected from conductors, with 3 of R R3 is the same or different group Ru.

RIO: A group selected from a phenyl group, a benzyl group, or a derivative thereof.

RII: A group consisting of hydrogen, an alkyl group, or a group defined by Rho.

n: An integer of 4 or more.

Specific examples of the fibrous reinforcing material used in the present invention include glass fibers, carbon fibers, aromatic polyamide fibers, silicon carbide fibers, and titanate fibers; however, glass fibers are usually used. Ru. There are no particular restrictions on the diameter and length of the various fibers, but if the fiber length is too long, it will be difficult to uniformly mix and disperse the fibers with polyester and other compounding agents, that is, component (a) or component (b). On the other hand, if the fiber length is too short, the effect as a reinforcing material will be insufficient. 1 to 7III11 is preferable, and more preferably 0.3
-4III+ is desirable. In addition, the fibrous reinforcing material can be treated with various (E' compounds) as needed for the purpose of improving the interfacial adhesion with polyester and increasing the reinforcing effect. When glass fibers are used as reinforcing materials, various surface treatment agents may be used, such as vinyltriethoxysilane, T-methacryloxypropylmethoxysilane, β-(3°4-epoxycyclohexyl)-ethyltrimethoxysilane, γ - Silane-based processing agents such as glycidoxypropyltrimethoxysilane, r-aminopropyltriethoxysilane, γ-chloropropylmethoxysilane, T-mercabutopropyltrimethoxysilane, and chromium-based processing agents such as methacrylate chromic chloride. The processed one is used.

Regarding the blending ratio of PBT in the polyester component of the composition of the present invention, if the blending amount of PBT is less than 5M parts, the effect of low-temperature crystallinity (formability) of the composition will be insufficient;
35ffi! It is not preferable to mix PET and PBT in a higher amount than PII765 because the heat resistance such as solder resistance will decrease.
~95 parts by weight, P[lT5~35M parts, preferably P
I! 770 to 90 parts by weight, PBT 10 to 30 parts by weight.

Regarding the blending amount of each component in the polyester resin composition of the present invention, component (a), namely, an inorganic compound with an average particle size of 50μ or less, an organic compound having a metal salt of a carboxyl group, and a polymer having a metal salt of a carboxyl group. The blending amount of at least one of the molecular compounds is 100% of the polyester component.
If it is less than 0.05 parts by weight, the effect as a crystal nucleating agent will be insufficient, and conversely, even if it is added in more than 10 parts by weight, the effect as a crystal nucleating agent will be proportional to the amount blended. First, any excess added acts only as a filler.

Therefore, the blending amount of component (a) is 10% of the polyester component.
The amount is 0.05 to 10 parts by weight relative to 0 parts by weight, preferably 0.1 to 5 parts by weight, and more preferably 0.1 to 3 parts by weight. Furthermore, regarding the amount of component (B), that is, the ester plasticizer, if the amount of component (B) is less than 0.3 parts by weight per 100 parts by weight of the polyester component, the effect as a crystallization promoter will be insufficient. However, if the amount is more than 10 M parts, the thermal properties and other properties (1) will deteriorate, so the blending amount of component (b) should be 0.3 to 10 parts by weight per 100 parts by weight of the polyester component.

Preferably 2 to 10 M parts, more preferably 3 to 7 M parts
This is the whistle section.

Furthermore, regarding the amount of the fibrous reinforcing material blended as necessary in the present invention, the blended amount is 1/1 of the Boeester component.
If it is less than 5 parts by weight based on 00 ff parts, the effect of improving mechanical properties and thermal properties will be insufficient, and if it exceeds 150 parts by weight, it will not be uniformly distributed in the fibrous reinforcement composition. Mixing and dispersing itself becomes difficult. Therefore, the blending amount of the fibrous reinforcing material is 5 to 100 parts by weight.
The amount is 150 parts by weight, preferably 25 to 100 parts by weight.

The composition of the present invention further includes an antioxidant, if necessary.
Ultraviolet absorber 1 Various inorganic or organic compounds such as colorants, mold release agents, fillers, etc. can be blended.

The polyester composition of the present invention can be produced by mixing in various methods, and the production method is not particularly limited.2 Usually, each component or additive is added to polyester pellets. It is manufactured by mixing using an extruder or Nigu.

(Example) Next, the present invention will be specifically described with reference to Examples and Comparative Examples.

Note that "parts" shown in Examples and Comparative Examples indicate "parts by weight."

Example 1. Comparative Example 1 70 parts of polyethylene terephthalate with an intrinsic viscosity of 0.68 (measured in phenol/tetrachloroethane-6/4, concentration 0.5%, temperature 20°C), 30 parts of polybutylene terephthalate with an intrinsic viscosity of 0.85 part, 2 parts of talc.

7 parts of an ester plasticizer represented by structural formula (II/).

Mix 45 parts of glass fiber (manufactured by Asahi Fiberglass ■, 3 mm long chopped strand, product number YO 429).

Pellets were created by kneading with an extruder. In the same manner as in Example 1, pellets were prepared by blending the same amount of the above compounding agent and glass fiber with 100 parts of polyethylene terephthalate. (
Comparative Example 1) After drying this pellet, the cylinder temperature was 240-
260-270℃, mold temperature 80℃1 injection pressure 400
Kg/cd, injection time 10 seconds, cooling time 15 seconds, thickness 2
A plate measuring 40 mm in width and 90 mm in length was molded and its surface condition was observed. The composition of Example 1 showed good gloss over the entire surface, but the composition of Comparative Example 1 showed poor gloss in areas far from the gate. The bending strength measured with a 4 inch x 1/2 inch x 5 inch test piece molded at a mold temperature of 80°C was 1880 Kg/cm2, the bending elastic modulus was 82.000 Kg/cm2, and the Izod I-shaped impact strength was 8.3 Kg. - indicates the value of cm/cm, 1 part 1
The heat deformation temperature (under a load of 18,56 Kg/cm2) determined for a 6 inch x 1/2 inch x 5 inch test piece was 223°C, showing excellent performance.

C112 large 0Citls (IV)
Example 2, 3.4 Polyethylene terephthalate 70 was prepared in the same manner as in Example 1.
20 parts of polyethylene terephthalate copolymerized with 20% by weight of octadecane-1,18-dicarboxylic acid, 10 parts of polybutylene terephthalate, Surlyn 1555 (
DuPont), 6 parts of dibenzyl ester of adipic acid, and 45 parts of glass fiber (Example 2)
) and pellets containing dibenzyl ester of azelaic acid instead of dibenzyl ester of adipic acid (
Example 3) and pellets containing dibenzyl ester of dodecane-1,12-dicarboxylic acid (Example 4) were prepared and dried.

In the same manner as in Example 1, the surface gloss, mechanical properties, and heat distortion temperature (molded product thickness 1/16 inch) were examined at a mold temperature of 70°C. The results are shown in Table 1.

Table 1 60 parts of polyethylene terephthalate, 7"7"-" of polyethylene (62.000) @ 10iit 2 20 parts of polyethylene terephthalate, 20 parts of polybutylene terephthalate, 2 parts of talc, 2 parts of Surlyn 1555, structural formula ( Pellets were prepared by blending 5 parts of the ester plasticizer shown in V) and 45 parts of glass fiber.This composition provided a molded product with excellent surface gloss at a mold temperature of 75°C, and had a bending strength of 1860 Kg/9. cm
”, flexural modulus 82.000Kg/cm’!,
7 It exhibited properties such as an in situ impact strength of 7.9 Kg-cm 7 cm and a heat distortion temperature (molded product thickness 1/16 inch) of 224°C.

0 (v) (Effects of the Invention) The composition of the present invention can be molded and used in various forms, for example, various molded products, such as one-sheet fibrous material, tubular material, etc. During production, the mold temperature is kept low. It can be done. This product is extremely useful industrially, as it exhibits excellent surface gloss, mechanical properties, and thermal deformation temperature.

Claims (6)

[Claims] (1) Polyethylene terephthalate or at least 8
Based on 100 parts by weight of a polyester containing 65 to 95 parts by weight of a copolyester having 0 mol% or more of ethylene terephthalate repeating units and 5 to 35 parts by weight of polybutylene terephthalate, (a) an inorganic system with an average particle size of 50 μm or less; 0.05 to 10 parts by weight of at least one of a crystal nucleating agent, an organic compound having a metal salt of a carboxyl group, and a polymer compound having a metal salt of a carboxyl group;
(b) A polyester resin composition containing 0.3 to 10 parts by weight of an ester plasticizer and (c) 0 to 150 parts by weight of a fibrous reinforcing material. (2) The ester plasticizer has the following general formula (I) or (II)
The polyester resin composition according to claim 1, which is an ester compound of at least one of (III). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) R_1: Alkylene group R_2, R_3: Groups selected from alkyl groups, benzyl groups, and aromatic substituted benzyl groups, and R_2 and R_3 are the same or different groups. m, n: Integer greater than or equal to 1 ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (II) X: Direct bond, alkylene group, -SO_2-, -S-,
-O- or ▲ Numerical formula, chemical formula, table, etc. ▼ R_4, R_5: A group selected from an alkyl group, a benzyl group, a phenyl group, or a derivative thereof, and R_4 and R_5 are the same or different groups. R_6, R_7: hydrogen, alkyl group, or halogen, and R_6 and R_7 are the same or different groups. m, n: Integers of 1 or more ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (III) R_8, R_9: Groups selected from hydrogen, alkyl groups, phenyl groups, benzyl groups, or derivatives thereof, and R_8 and R_9 are They are the same or different groups. R_1_0: A group selected from a phenyl group, a benzyl group, or a derivative thereof. R_1_1: A group consisting of hydrogen, an alkyl group, or a group defined by R_1_0. n: An integer of 4 or more. (3) The polyester resin composition according to claim 1, characterized in that one or more inorganic substances selected from the group of talc, mica, kaolin, and silica are used as the inorganic compound having an average particle size of 50 μm or less. . (4) The polyester resin composition according to claim 1, wherein the metal salt of the carboxyl group is a sodium salt or potassium salt of the carboxyl group. (5) The polyester resin composition according to claim 1, wherein the compound having a metal salt of a carboxyl group is a compound having about 7 to 30 carbon atoms. (6) The polymer compound having a carboxyl group is a copolymer of olefin and (meth)acrylic acid or a copolymer of styrene and (
Claim 1, which is a copolymer of meth)acrylic acid
The polyester resin composition described in .