JPH0472351A - Polyester composition - Google Patents

Abstract

PURPOSE:To obtain a polyester composition having good moldability, and giving molded products of excellent surface gloss and mechanical properties, by adding a specific amount of an organic compound such as a carboxyl metal salt. CONSTITUTION:The composition is obtained by mixing (A) 100 pts.wt. of polyethylene terephthalate or a polyester containing not less than 80 mole % of ethylene terephthalate recurring units with (B)0.01-20 pts.wt., preferably 0.1-5 pts.wt. of at least one of an organic compound bearing a carboxyl metal salt group such as sodium or potassium salt, for example, a metal salt of higher fatty acid of 7-30 carbon atoms, or a metal salt of aromatic acid, (C)0.5 to 30 pts.wt. of a modified polyolefin or modified olefin elastomer which is prepared by adding at least one of endo-bicyclo-[2,2,1]-5-heptene-2,3-dicarboxylic acid or its derivatives to polyolefin or polyolefin elastomer, and when necessary, (D) 5-150 pts.wt. of reinforcing fibers.

Description

DETAILED DESCRIPTION OF THE INVENTION 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 mold temperatures of about 120° C. or lower during injection molding.

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, fiber,
When used as a film, it is usually stretched, but when used as an injection molded product for plastics, for example, the stretching process described above has not been done, so there are problems with the molding process. It is known that some problems occur in terms of physical properties. In other words, because the crystallization rate at low temperatures is low, the mold temperature used when injection molding ordinary plastics is approximately 120°.
Below C, the crystallization rate is insufficient, resulting in a difference in crystallinity between the surface and the interior of the resulting molded product, resulting in nonuniform mechanical properties, dimensional stability, and shape stability. It is extremely difficult to obtain a molded product that can withstand practical use. Conventionally, as a 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 using a high-temperature mold is not practical because the operation for raising the temperature is complicated, the molding cycle becomes long, and the working efficiency is significantly reduced.

On the other hand, although many methods of adding crystal nucleating agents and crystallization promoters have been studied, the crystallization speed during injection molding is still not sufficient, and the molding cycle is slower than that of other plastics. In some cases, the addition of crystal nucleating agents and crystallization accelerators may significantly reduce the surface properties such as surface gloss, mechanical properties, thermal properties, etc. of the molded product.
Various problems arise, such as additives such as crystallization promoters volatilizing during molding and emitting odor. In this way, the crystal nucleating agent,
The reality is that there are still many points to be considered regarding the method of adding crystallization promoters.

Therefore, the present inventors conducted intensive research to obtain a polyethylene terephthalate composition useful as a molding material that has excellent moldability, that is, a fast crystallization rate during molding, and has excellent surface gloss and mechanical properties. , polyethylene terephthalate or a polyester having at least 80 mol% of ethylene terephthalate repeating units,
(a) At least one organic compound having a metal salt of a carboxyl group and (0) a specific amount of a specific modified polyolefin or modified olefin elastomer are blended, and if necessary, a specific amount of a fibrous reinforcing agent. The present invention has been achieved by discovering that the above object can be achieved by blending the above.

That is, the present invention is based on 100 parts by weight of polyethylene terephthalate or a polyester having at least 80 mol% or more of ethylene terephthalate repeating units.
(a) 0.01 to 20 parts by weight of at least one organic compound having a metal salt of a carboxyl group; (b)
Endo-bicyclo(2,2,1)-5-heptene-2, polyolefin or polyolefin elastomer
A polyester composition containing 0.5 to 30 parts by weight of a modified polyolefin or a modified olefin elastomer to which 0.001 to 10 mol% of at least one compound selected from the group consisting of 3-dicarboxylic acids or functional derivatives thereof is added. The present invention relates to a polyester composition in which 5 to 150 parts by weight of a fibrous reinforcing agent is blended with 100 parts by weight of the above-mentioned polyester composition.

The present invention increases the crystallization rate of PET by blending specific amounts of components (a) and (b) into PET, improves surface properties such as surface gloss, and further improves fibrous reinforcement as necessary. By incorporating the additive, a composition useful as a molding material with improved mechanical properties is provided.

Conventionally, it has been known that adding fibrous reinforcing agents such as glass fiber to PET improves the mechanical and thermal properties of PET. The crystallization rate is low, resulting in a long molding cycle, and if the mold temperature is low, for example, below about 120'C, crystallization does not proceed sufficiently, which not only deteriorates the dimensional stability of the molded product. However, there is a fatal problem in that both thermal properties and mechanical properties cannot fully demonstrate their inherent performance. In order to solve these problems, crystal nucleating agents corresponding to component (a) and (b)
Various studies have been conducted on adding crystallization promoters equivalent to the components, but in that case, additives such as crystal nucleating agents and crystallization promoters are uniformly mixed and dispersed in PET,
Even during heating during injection molding, etc., it is necessary that they are stably compatible and do not ooze out of the molded product or volatilize and escape.

However, conventionally used additives, especially crystallization promoters, are not sufficiently compatible with PET, and may partially separate and seep out when heated, or may evaporate and escape. Yes, it is a problem. On the other hand, in the polyester composition of the present invention, since a specific modified polyolefin or modified olefin elastomer is used as the component (b), the compatibility with PET is higher than that of ordinary polyolefins and olefin elastomers. Even when heated, it does not separate from PET and ooze out or volatilize. In addition, when component (B) is blended with component (A) in PET, the crystallization rate of PET is increased compared to when component (B) or component (A) is blended alone, improving moldability. It has the effect of improving the mold temperature during injection molding.
Even at temperatures below 20°C, for example from 100°C to 70°C, molded articles with excellent surface gloss can be obtained in a short cooling time. Furthermore, the polyester composition of the present invention, in which a specific amount of component (a) and component (b) is blended with a specific amount of fibrous reinforcing agent, has excellent moldability, surface properties, and excellent mechanical properties. A balanced and useful molding material can be provided.

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 solid phase polymerization. And polyester having at least 80 mol% or more of ethylene terephthalate repeating units means a copolymer consisting of 80 mol% or more of ethylene terephthalate repeating units and other repeating units, that is, other polymeric components,
As the other copolymerization components mentioned above, various acid components and glycol components can be used. For example, acid components include isophthalic acid, naphthalene dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylmethane dicarboxylic acid, diphenylsulfone dicarboxylic acid, p-(2-hydroxyethoxy)benzoic acid, 5-sodium sulfoisophthalic acid, adipic acid, azelaic acid, and sebacin. Examples include acids. Further, examples of the glycol component include polyalkylene glycols such as propylene glycol, diethylene glycol, pentyl glycol, neopentyl glycol, hexamethylene glycol, and polyethylene glycol.

Examples of the polyolefin or olefin elastomer used as a starting material in producing the modified polyolefin or modified olefin elastomer in the present invention include homopolymers of olefins such as polyethylene, polypropylene, polybutene-1, polybentene-1, etc. Ethylene-furopylene copolymer, ethylene-
Butene-1 copolymer, propylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, propylene-vinyl acetate copolymer, ethylene-butadiene copolymer, ethylene-
Isoprene copolymer, ethylene chloroprene copolymer,
Examples include copolymers with different types of olefins or diolefins, such as propylene-butadiene copolymers and ethylene-propylene-butadiene copolymers, and the types of copolymers include random copolymers and block copolymers. It may be a polymer, a graft copolymer, or an alternating copolymer. and especially ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-propylene-butadiene copolymer, ethylene-propylene isoprene copolymer, ethylene-propylene chloroprene copolymer. etc. are preferred. Further, one or more kinds of polyolefins or olefin elastomers can be used in combination.

Endo-bicyclo-C2,2゜1)-5 in the present invention
-Heptene-2,3-dicarboxylic acid or its functional derivatives include endo-bicyclo(2,2,1)-5-heptene-2,3-dicarboxylic acid, methyl-endo-cis-bicyclo-[2゜2 .1) -5-heptene-2,3-
Dicarboxylic acid, endo-bicyclo-(2,2,1)-1
Examples include 24,7,7-hexachloro-2-heptene-56-dicarboxylic acid, or acid anhydrides, esters, acid amides, acid halides, and metal salts thereof. and particularly preferably endo-bicyclo-C2,2,1) -
5-heptene-2,3 dicarboxylic acid or its acid anhydride. Note that the functional derivative does not necessarily have to be converted into a functional derivative before being added to the polyolefin or olefin elastomer, and can be converted, for example, during the modification process of the polyolefin or olefin elastomer or after forming a polyester composition.

The modified polyolefin or modified olefin elastomer of the present invention refers to the polyolefin or olefin elastomer with endo-bicyclo-(2,2,1)-
Modified polyolefins or modified tertiary-refine elastomers obtained by adding at least one compound selected from the group consisting of 5-heptene-2,3-dicarboxylic acid or functional derivatives thereof, or unmodified polyolefins or unmodified polyolefins or It means a mixture with a modified olefin elastomer.

The modified polyolefin or modified olefin elastomer can be produced by various methods, but preferably the above polyolefin or olefin elastomer and the above endo-bicyclo-[2゜2.13-5-heptene-2
, 3-dicarboxylic acid or its functional derivative by adding a radical generator, for example, an organic peroxide such as ditertiary-butyl peroxide, dicumyl peroxide, benzoyl peroxide, etc., or melting the polyolefin or olefin elastomer described above. The above-mentioned carboxylic acid or its functional derivative is dispersed in water and heated in the presence of the above-mentioned radical generator or water-soluble peroxide.

Here, the addition ratio of the carboxylic acid or its functional derivative to be added to the polyolefin or olefin elastomer depends on the use of the resulting polyester composition, the type of polyolefin or olefin elastomer and their mixing ratio, and the carboxylic acid or its functional derivative added to the polyolefin or olefin elastomer. The carboxylic acid or its functional derivative added in an amount of 0.001 to 10 mol % to the polyolefin or olefin elastomer is usually used, although it differs depending on the type of the carboxylic acid, but preferably 0.01 to 5.0 mol %.
, more preferably 0.05 to 2.0 mol % is used.

The amount of the carboxylic acid or functional derivative added is 0°001
If the amount is less than 10 mol%, the compatibility with PET and interfacial adhesion will be poor, and the effect as a crystallization promoter will not be fully demonstrated. In this step, side reactions such as lowering of the molecular weight of the polyolefin or olefin elastomer and gelation occur, which is not preferable.

As the organic compound having a metal salt of a carboxyl group used as component (a) of the present invention, any compound having a metal salt of a carboxyl group can be used, but usually the number of carbon atoms is Metal salts of higher fatty acids and aromatic acids having a molecular weight of about 7 to 30 are used, such as heptanoic acid, pelargonic acid, lauric acid, myristic acid, valmitic acid, stearic acid, behenic acid, cerotic acid, montanic acid, melisic acid, etc. Examples include metal salts of higher fatty acids, metal salts of aromatic acids such as benzoic acid, terephthalic acid, monomethyl terephthalate, isophthalic acid, and monomethyl ester of isophthalic acid.

In addition, together with the organic compound having a metal salt of a carboxyl group used as component (a) of the present invention, an average particle size of 50
An inorganic compound of μ or less and/or a polymer compound having a metal salt of a carboxyl group can be used in combination.

Examples of inorganic compounds with an average particle size of 50μ or less include carbon black, silica, calcium carbonate, synthetic silicic acid and silicates, zinc white, hallosite clay, kaolin,
Basic magnesium carbonate, mica, talc, quartz powder, diatomaceous earth, dolomite powder, titanium oxide, zinc oxide, antimony oxide, barium sulfate, calcium sulfate, alumina,
Calcium silicate and the like can be used, and combinations of mica, kaolin, talc, and silica are particularly useful in the present invention.

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 polymer compound having a metal salt of a carboxyl group can be obtained by oxidizing polyethylene. Carboxyl group-containing polyethylene, carboxyl group-containing polypropylene obtained by oxidation of polypropylene, copolymers of olefins such as ethylene, propylene, butene-1, and (meth)acrylic acid, copolymers of olefins and maleic anhydride, styrene Specific examples include metal salts such as copolymers of olefin and (meth)acrylic acid or copolymers of styrene and maleic anhydride, and usually olefins and (meth)acrylic acid or styrene and (meth)acrylic acid.
Metal salts of copolymers of acrylic acid 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 have excellent effects as crystal nucleating agents, with sodium and potassium being particularly useful.

Specific examples of the fibrous reinforcing agent used in the present invention include glass fibers, carbon fibers, aromatic polyamide fibers, silicon carbide fibers, and titanate fibers, but glass fibers are usually used. Ru. In addition, 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 PET 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 agent will be insufficient, so it is usually 0.1~
10mm fiber length is used, especially when the fibrous reinforcing agent is glass fiber, the fiber length is 0.1 to 7mm.
is preferable, and more preferably 0.3 to 4 mm. In addition, the fibrous reinforcing agent can be treated with various compounds as necessary in order to improve the interfacial adhesion with PET and increase the reinforcing effect. When using various surface treatment agents, such as vinyltriethoxysilane, T-methacryloxypropylmethoxysilane, β-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, etc. Silane-based treatment agents such as methoxysilane, T-aminopropyltriethoxysilane, T-chloropropylmethoxysilane, and T-mercaptopropyltrimethoxysilane, and those treated with chromium-based treatments such as methacrylate chromic chloride are used.

Regarding the blending amount of each component in the polyester composition of the present invention, the blending amount of at least one of the components (a), that is, an organic compound having a metal salt of a carboxyl group is 0.0000 parts by weight per 100 parts by weight of PET resin. If the amount is less than 01 parts by weight, the effect as a crystal nucleating agent is insufficient, and conversely, even if more than 20 parts by weight is added, the effect as a crystal nucleating agent is not proportional to the amount blended, and an excess amount is added. The material only acts as a filler. Therefore, the blending amount of component (a) is 0.01 parts by weight per 100 parts by weight of PET resin.
-20 parts by weight, preferably o, oos -10 parts by weight, more preferably 0.1-5 parts by weight. Furthermore, regarding the amount of component C), that is, the modified polyolefin or modified olefin elastomer, if the amount of component (B) is less than 0.5 parts by weight per 100 parts by weight of PET, the effect as a crystallization promoter will be reduced. If the amount exceeds 30 parts by weight, other performances such as thermal properties will deteriorate, so the blending amount of component C) should be 100 parts by weight of PET. The amount is 0.5 to 30 parts by weight, preferably 0.5 to 20 parts by weight, and more preferably 1 to 10 parts by weight.

Furthermore, in the present invention, the amount of the fibrous reinforcing agent blended according to the required strength is different from that of PET (a).
Polyester composition 10 consisting of component and (b) component
If it is less than 5 parts by weight relative to 0 parts by weight, the effect of improving mechanical properties and thermal properties will be insufficient;
If the amount exceeds parts by weight, it becomes difficult to uniformly mix and disperse the fibrous reinforcing agent in the composition. Therefore, the blending amount of the fibrous reinforcing agent is 5 to 150 parts by weight, preferably 25 to 100 parts by weight, based on 100 parts by weight of the polyester composition before addition of the fibrous reinforcing side.

The composition of the present invention may further contain various inorganic or organic compounds such as antioxidants, ultraviolet absorbers, colorants, mold release agents, and fillers, if necessary.

The polyester composition of the present invention can be manufactured by mixing in various ways, and the manufacturing method is not particularly limited, but usually the entire amount of each component or additive is mixed with PET.
A method in which a part of each component or additive is added and mixed in the late stage of polymerization of P and ET to obtain pellets, and then the remainder of each component or additive is added and mixed using an extruder. It is manufactured by a method of mixing using an extruder or a kneader, or a method of adding each component or additive to PET pellets and mixing using an extruder or a kneader.

The composition of the present invention can be formed into various forms, such as various molded articles, films, sheets, fibrous objects, and tubular objects.

Next, the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Note that "1 part" shown in Examples and Comparative Examples indicates "part by weight."

Examples 1 to 7, Comparative Example 1.2 Endo-bicyclo-(2,2,1)-5-heptene-2 in various polyolefins or olefin elastomers
, 3-dicarboxylic anhydride (hereinafter abbreviated as modifier (A)) or endo-bicyclo(2,2,1)-5-heptene-2,3-dicarboxylic acid methyl ester (hereinafter abbreviated as modifier (B)) ) in various proportions, and then 1 part by weight of ditertiary-butyl peroxide per 100 parts by weight of polyolefin or olefin elastomer was added, mixed at room temperature with a Henschel mixer, and the mixture was fed to an extruder. The pellets were then extruded at about 200''C to produce pellets of modified polyolefins or modified olefin elastomers shown in Table 1.

Table 1 EPR: Ethylene-propylene copolymer E/B: Ethylene-butene-1 copolymer EVA: Ethylene-vinyl acetate copolymer PE: Polyethylene PP: Polypropylene Then intrinsic viscosity (phenol/tetrachloroethane-6
/4, concentration 0.5%, temperature 20'C) 0.68
After mixing in a tumbler, predetermined amounts of various crystal nucleating agents shown in Table 2, various modified polyolefins, and glass fibers (manufactured by Asahi Fiberglass ■, product number 419 chopped strand 3 mm length) were mixed with 100 parts of polyethylene terephthalate in a tumbler.
Pellets were produced by melt extrusion using an extruder with a diameter of 65 mm. After drying the obtained pellets, cylinder temperature 24: 270-280°C, mold temperature 98°C, injection holding time 10 seconds, injection pressure 300-600Kg/c1
A test piece measuring 174 inches x 172 inches x 5 inches was molded under fl conditions.

At that time, the minimum cooling time (minimum molding cycle) was determined from the mold releasability when the cooling time was changed, and at the same time, the surface of the molded product at that time was observed. The results are shown in Table 2.

Claims (6)

[Claims] (1) Polyethylene terephthalate or at least 8
(a) 0.01 to 20 parts by weight of at least one organic compound having a metal salt of a carboxyl group per 100 parts by weight of polyester having 0 mol % or more of ethylene terephthalate repeating units; (b) polyolefin or polyolefin-based Endo-bicyclo-[2,2,1]-5-heptene-2,3 to elastomer
- A polyester composition containing 0.5 to 30 parts by weight of a modified polyolefin or modified olefin elastomer to which 0.001 to 10 mol% of at least one compound selected from the group consisting of dicarboxylic acids or functional derivatives thereof is added. . (2) The polyester composition according to claim 1, wherein the metal salt of the carboxyl group is a sodium salt or potassium salt of the carboxyl group. (3) An organic compound having a metal salt of a carboxyl group,
The polyester composition according to claim 1, which is a compound having about 7 to 30 carbon atoms. (4) Claim 1, wherein the polyolefin or polyolefin elastomer is polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene-1 copolymer, or ethylene-vinyl acetate copolymer.
The polyester composition described in . (5) polyethylene terephthalate or at least 8
(a) 0.01 to 20 parts by weight of at least one organic compound having a metal salt of a carboxyl group per 100 parts by weight of polyester having 0 mol % or more of ethylene terephthalate repeating units; (b) polyolefin or polyolefin-based Endo-bicyclo-[2,2,1]-5-heptene-2,3 to elastomer
- A polyester composition containing 0.5 to 30 parts by weight of a modified polyolefin or modified olefin elastomer to which 0.001 to 10 mol% of at least one compound selected from the group consisting of dicarboxylic acids or functional derivatives thereof is added. 5 to 100 parts by weight of fibrous reinforcing agent
A polyester composition containing 150 parts by weight. (6) The polyester composition according to claim 5, wherein the fibrous reinforcing agent is glass fiber.