JPH0768442B2 - Polyethylene terephthalate resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a polyethylene terephthalate resin composition for injection molding, which is excellent in moldability, mechanical properties and thermal properties, and more specifically, a mold at 90 ° C. or lower. The present invention relates to a polyethylene terephthalate resin for injection molding, which exhibits excellent moldability at temperature and gives a molded article having excellent mechanical properties and heat distortion temperature.

<Prior Art> Polyethylene terephthalate has excellent mechanical properties, heat resistance, and electrical properties, and has been conventionally used in large amounts as fibers, films, bottles, and the like. However, when used as a material for injection molding, a satisfactorily molded product cannot be obtained because of its slow crystallization rate. To improve the moldability of polyethylene terephthalate, various methods have been proposed. For example, Japanese Patent Publication No. 45-18768 discloses that polyethylene terephthalate may contain glass fibers and a mold temperature of 120
A technique for promoting crystallization by molding at ~ 170 ° C (high temperature mold) is disclosed. As described above, by combining a reinforcing material such as glass fiber and using a so-called high temperature mold, the crystallization speed was promoted and injection molding became possible. However, it is still not sufficient for injection molding in an economical molding cycle, and molding at a mold temperature of 90 ° C or less, which is usually used in ordinary injection molding, causes insufficient crystallization and results in non-uniform molding. Not obtained. So further,
In order to improve these drawbacks, various crystallization nucleating agents and crystallization accelerators have been studied, and it has been proposed to use them in combination. For example, Japanese Patent Application Laid-Open No. 54-139654 discloses polyethylene terephthalate which comprises polyethylene terephthalate and sodium or potassium salt of an ionomer, an aliphatic carboxylic acid ester and a reinforcing material or a filler, and Japanese Patent Application Laid-Open No. 55-52339 discloses a thermoplastic polyester. A composition comprising a neutral or partially neutralized montan wax salt or montan wax ester salt and glass fiber is disclosed in JP-A-57-85846. Sodium phenol sulfonate and the like, aromatic carboxylic acid ester and a reinforcing agent are disclosed in JP-A-57-85846. A composition consisting of, in JP-A-59-159848, a glass fiber in polyethylene terephthalate, a metal salt of a carboxylic acid, an ether adduct of alkylphenol and a composition consisting of montan wax ester, etc., respectively,
It is disclosed.

<Problems to be solved by the invention> However, even in these methods, the moldability in a mold of 90 ° C or less does not reach a substantially effective level, and particularly in a thin-walled molded product having a thickness of 2 mm or less, a sufficient crystallinity occurs. It is difficult to obtain a molded product. Further, the added crystallization accelerator causes a decrease in the molecular weight of polyethylene terephthalate, and thus has a drawback that the mechanical properties of polyethylene terephthalate are deteriorated.

INDUSTRIAL APPLICABILITY The present invention is an injection molding excellent in mechanical properties and thermal properties, which is sufficiently crystallized even by injection molding using a low temperature (90 degrees or less) mold, can be molded in a shortened molding cycle. A polyethylene terephthalate resin composition for use is provided.

<Means for Solving Problems> As a result of intensive investigations by the present inventors to solve the above problems,
The present invention has been reached.

That is, the present invention provides a polyethylene terephthalate resin composition for injection molding, which is obtained by adding 0.05 to 15 parts by weight of a polyoxyalkylene group-containing metal sulfonate represented by the following general formula (I) to 100 parts by weight of polyethylene terephthalate. It is a thing.

(However, Ar in the formula is an aromatic residue having or not having a substituent, R ₁ is an aliphatic hydrocarbon group containing 2 to 20 carbon atoms, R ₂ and R ₃ are hydrogen or the following general formula ( II) the substituent shown by M represents an alkali metal or an alkaline earth metal. n is an integer of 2 to 20 and m is 1 or 2. The polyethylene terephthalate used in the present invention comprises a dicarboxylic acid component having a terephthalic acid component of 80 mol% or more
A polymer obtained by polycondensation of a diol component whose mol% is at least ethylene glycol component. The terephthalic acid component as used herein includes terephthalic acid and their ester-forming derivatives, and the ethylene glycol component includes ethylene glycol and their ester-forming derivatives. Other dicarboxylic acid components used with the terephthalic acid component include isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, bis (p-carboxyphenyl) methaneanthracene dicarboxylic acid,
4,4'-diphenyldicarboxylic acid, 1,2-bis (phenoxy) ethane-4,4'-dicarboxylic acid, aromatic dicarboxylic acid such as 5-sodium sulfoisophthalic acid, 1,3-cyclohexanedicarboxylic acid, 1, Aliphatic dicarboxylic acids such as 4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, azelaic acid, decanedioic acid, dodecanedioic acid, hexadecanedioic acid, octadodecanedioic acid, dimer acid and the like, and these Examples thereof include ester-forming derivatives.

As the diol component used together with the ethylene glycol component, an aliphatic glycol having 2 to 20 carbon atoms, that is, propylene glycol, 1,4-butanediol,
Neopentyl glycol, 1,5-pentanediol, 1,6
-Hexanediol, decamethylene glycol, cyclohexanedimethanol, cyclohexanediol, etc.,
Alternatively, a long-chain glycol having a molecular weight of 400 to 6,000, that is, polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol and the like and ester-forming derivatives thereof can be mentioned.

Specific examples of these polymers include polyethylene terephthalate, polyethylene terephthalate / isophthalate, polyethylene terephthalate / adipate,
Examples thereof include polyethylene terephthalate / sebacate, polyethylene terephthalate / decane dicarboxylate, polyethylene / butylene terephthalate, polyethylene / butylene terephthalate / decane dicarboxylate, polyethylene terephthalate copolymers such as polyethylene / polyoxyethylene terephthalate, polyethylene terephthalate, polyethylene. / Butylene terephthalate and polyethylene / polyoxyethylene terephthalate are particularly preferably used.

In addition, these polyethylene terephthalates have an intrinsic viscosity of 0.35 dl / g or more in terms of mechanical properties when measured in an o-chlorophenol solution at 25 ° C, and 1.60 dl in terms of surface gloss.
Those in the range of / g or less are preferable, and particularly 0.50 to 1.35.
Those in the range of dl / g are preferable.

The polyoxyalkylene group-containing sulfonic acid metal salt used in the present invention is a compound represented by the general formula (I).

Of these, Ar (However, R represents an aliphatic hydrocarbon group having 2 to 36 carbon atoms)
Wherein R ₁ is an aliphatic hydrocarbon group having 2 to 4 carbon atoms, R ₂ and R ₃ are hydrogen groups, and M is sodium, potassium, calcium, magnesium or barium. ,
Alternatively, a metal salt of polyoxyalkylene alkylphenyl ether succinate in which R ₂ is a hydrogen group and R ₃ is a substituent represented by the general formula (II) is particularly preferably used.

Preferred specific examples of these compounds include sodium polyoxyethylene phenyl ether sulfoacetate,
Polyoxyethylene monobutyl phenyl ether sulfoacetate sodium, Polyoxy monooctyl phenyl ether sulfoacetate sodium, Polyoxyethylene monophenyl ether sulfoacetate sodium, Polyoxyethylene monododecyl phenyl ether sulfoacetate sodium, Polyoxyethylene monooctyl phenyl ether sulfo Potassium acetate,
Polyoxyethylene monooctyl phenyl ether sulfoacetate magnesium, polyoxyethylene monooctyl phenyl ether sulfoacetate barium, polyoxypropylene phenyl ether sulfoacetate sodium, polyoxypropylene octyl phenyl ether sulfoacetate sodium, polyoxybutylene phenyl ether sulfoacetate sodium, Polyoxybutylene dodecyl phenyl ether sulfoacetate sodium, Polyoxybutylene phenyl ether sulfoacetate potassium, Sodium sulfosuccinic acid polyoxyethylene phenyl ether diester, Sodium sulfosuccinic acid polyoxyethylene octyl phenyl ether diester, Potassium sulfosuccinic acid polyoxyethyl ester Emissions phenyl ether diester, polyoxypropylene phenyl ether diester of sodium sulfosuccinic acid, such as polyoxybutylene ether diester of sodium sulfosuccinic acid. These compounds represented by the general formula (I) can be used as a mixture of two or more kinds.

The content of the compound represented by the general formula (I) is 0.05 to 1 with respect to 100 parts by weight of polyethylene terephthalate.
5 parts by weight, preferably 0.1 to 10 parts by weight, particularly preferably 0.
5-8 parts by weight is recommended. When the content is less than 0.05 parts by weight, the effect of improving the crystallization rate of polyethylene terephthalate is small, and when it exceeds 15 parts by weight, heat resistance and mechanical properties are deteriorated due to a decrease in polymerization degree, which is not preferable.

The polyethylene terephthalate resin composition of the present invention containing the polyoxyalkylene group-containing metal sulfonate can be easily crystallized and can be molded by a so-called low-temperature mold at 90 ° C. or less in a shortened molding cycle. Also,
Although various generally known crystallization nucleating agents, crystallization accelerators and the like tend to drastically reduce the degree of polymerization of polyethylene terephthalate during melt processing, the compound represented by the general formula (I) does not polymerize polyethylene terephthalate. It has a remarkable feature of not significantly lowering the degree, and does not show deterioration of mechanical properties.

The composition of the present invention includes an organic carboxylic acid metal salt known as a nucleating agent for polyethylene terephthalate, and / or
Alternatively, it is also preferable to use a crystallization accelerator such as benzoic acid ester in combination from the viewpoint of improving moldability.

Specific examples of these nucleating agents include sodium stearate,
Barium stearate, sodium montanate or barium, partial sodium salt or barium salt of montanic acid ester, ionomer and the like can be preferably used, and as the crystallization accelerator, polyethylene glycol, neopentyl glycol dibenzoate, polylactone and the like can be used. .

The compositions of the present invention include, for example, reinforcing agents and fillers, for example:
It is preferable to use glass fiber, carbon fiber, mineral fiber, silicon carbide fiber, potassium titanate fiber, gypsum fiber, mica, talc, calcium silicate (wollastenite), kaolin, clay, calcium sulfate, calcium carbonate, titanium dioxide, etc. You can

Further, in the present invention, it may be used in combination with various rubber components from the viewpoint of improving the mechanical properties (particularly impact resistance) of the composition. As such a rubber component, in particular, (i) an epoxy group-containing copolymer composed of an α-olefin and an epoxy group-containing unsaturated monomer (ii) an unmodified ethylene-containing α-olefin having 3 or more carbon atoms Modified ethylene copolymer obtained by graft-reacting 0.01 to 10% by weight of unsaturated carboxylic acid or its derivative with respect to ethylene copolymer (iii) Hydrogenated or unhydrogenated conjugated diene and aromatic vinyl Block copolymer or 0.01 to the block copolymer
A modified block copolymer obtained by grafting 10% by weight of an unsaturated carboxylic acid or its derivative can be preferably used.

As specific examples of these rubber components, preferred examples of the epoxy group-containing copolymer (i) are ethylene / glycidyl methacrylate copolymer, ethylene / vinyl acetate /
Glycidyl methacrylate copolymer, ethylene / methyl methacrylate / glycidyl methacrylate copolymer, ethylene / vinyl acetate / glycidyl methacrylate copolymer, ethylene / glycidyl ether copolymer, and the like,
Of these, an ethylene / glycidyl methacrylate copolymer is the most preferable.

Further, together with the epoxy group-containing copolymer (i), an ethylene-based copolymer comprising ethylene and an α-olefin having 3 or more carbon atoms and / or ethylene, α having 3 or more carbon atoms.
-By using a diene copolymer composed of an olefin and a non-conjugated diene in combination, impact resistance can be further improved. Specific examples of these copolymers include ethylene / propylene copolymers, ethylene / butene-1 copolymers, ethylene / pentene-1 copolymers, ethylene / propylene /
Butene-1 copolymer, ethylene / propylene / 5-ethylidene-2-norbornene copolymer, ethylene / propylene / 1,4-hexadiene copolymer, ethylene / propylene / dicyclopentadiene copolymer and the like, among which Ethylene / propylene copolymer and ethylene / butene-
One copolymer is preferred.

The modified ethylene copolymer of (ii) above includes ethylene / propylene copolymer, ethylene / butene-1 copolymer, ethylene / propylene / dicyclopentadiene copolymer, ethylene / propylene / 5-ethylidene- 2-
Unsaturated carboxylic acids or their derivatives in unmodified ethylene copolymers such as norbornene copolymers, such as maleic acid, fumaric acid, glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, diglycidyl itaconate, diglycidyl citracone. , Diglycidyl butenedicarboxylate, diglycidyl tetrahydrophthalate,
Maleic anhydride, itaconic anhydride, citraconic anhydride,
Maleic acid imides, itaconic acid imides, citraconic acid imides, and the like, glycidyl methacrylate, maleic anhydride, itaconic acid anhydride, modified ethylene copolymers obtained by graft reaction of maleic acid imide, and the like are preferably mentioned, and specific examples include , Maleic anhydride grafted ethylene / propylene copolymer, maleic anhydride grafted ethylene / butene-1 copolymer, glycidyl methacrylate grafted ethylene / propylene copolymer, glycidyl methacrylate grafted ethylene / butene-1 copolymer, etc. preferable.

Examples of the block copolymer (iii) include 1,3-butadiene, isoprene, conjugated dienes such as 1,3-pentadiene and styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, 1, Hydrogenated and unhydrogenated styrene / butadiene / styrene triblock copolymers composed of aromatic vinyl hydrocarbons such as 3-dimethylstyrene and vinylnaphthalene. Among them, styrene / butadiene / styrene triblock are heat resistant. Hydrogenated copolymers are more preferably used.

Further, the modified block copolymer is particularly preferably a product obtained by graft-reacting the same unsaturated carboxylic acid and its derivative as those mentioned in the modified ethylene copolymer of (ii) above. it can.

Further, two or more kinds of these rubber components can be used in combination.

The addition amount of these rubber components in the present invention is polyethylene terephthalate 10 or even when two or more of them are used in combination.
1 to 80 parts by weight is desirable with respect to 0 parts by weight.

In the composition of the present invention, other additives such as montanic acid wax, partial metal salt of montanic acid wax, polyethylene wax, mold release agent such as silicone oil, heat stabilizer,
UV absorbers, pigments, dyes, etc., and other thermoplastic resins such as polyester resins such as polybutylene terephthalate, polycarbonate resins, polyamide resins, polyolefin resins, polystyrene resins, ABS resins, ethylene / vinyl acetate copolymers, polysulfones, Polyphenylene sulfide, polyphenylene oxide, etc. can also be added.

The compounding method of the composition of the present invention is not particularly limited, for example, a polyethylene terephthalate, a polyoxyalkylene group-containing sulfonic acid metal salt and a raw material in which other additives are optionally compounded together in a screw type extruder. A method of supplying and melt-extruding and mixing can be adopted.

The polyethylene terephthalate resin composition for injection molding of the present invention is characterized by being able to obtain an excellent molded product having a high degree of crystallinity by taking advantage of good moldability due to its high crystallization speed.

<Examples> Hereinafter, the effects of the present invention will be further described with reference to Examples.

In addition, the part in an Example shows a weight part and an abbreviation symbol means the following.

[Η]: Intrinsic viscosity PET: Polyethylene terephthalate SSP-1: Polyoxyethylene monooctyl phenyl ether sulfoacetate sodium SSP-2: Polyoxyethylene monononyl phenyl ether sulfoacetate sodium SSP-3: Polyoxyethylene monooctyl phenyl ether sulfo Barium acetate SSP-4: Polyoxyethylene octylphenyl ether diester of sodium succinic acid PEG: Polyethylene glycol NPE: Polyoxyethylene adduct of octylphenol Examples 1 to 7 and Comparative examples 1 to 8 Polyethylene terephthalate 100 having [η] of 0.602 Parts, various polyoxyalkylene group-containing sulfonates shown in Table 1, and other additives were mixed in the proportions shown in Table 1, and melted with a vented extruder having a 30 mmφ twin screw set at 280 ° C. Knead and mix Tsu was a door.

The polyethylene terephthalate composition obtained was subjected to differential thermal analysis using a differential scanning calorimeter (DSC-2) manufactured by Perkin Elmer Co., and the temperature rising crystallization temperature and the temperature falling crystallization temperature were measured to evaluate the crystallization rate. .

ΔTc when the falling crystallization temperature−the rising crystallization temperature = ΔTc
It can be considered that the larger is, the higher the crystallization rate is. Further, the pellets were subjected to an injection molding machine set at 280 ° C. to prepare each test piece (below), and then the characteristics of each test piece were measured according to the following methods.

As for moldability, a box-shaped molded product with a size of 50 mm x 50 mm x 70 mm and a thickness of 1 to 3 mm is molded, and the appearance of the molded product is visually observed, mold releasability from the mold and molding cycle time (satisfactory molding The minimum molding time (injection / pressure-holding time + cooling time) necessary for obtaining the composition was measured to evaluate the moldability. The results are shown in Table 1.

Examples 8 to 11 and Comparative Examples 9 to 16 The same procedure as in Example 2 was carried out except that glass fiber or E / GMA and other additives were added to the proportions in Table 2 in Example 2.
The results are shown in Table 2.

From the results shown in Tables 1 and 2, the composition of the present invention has a large ΔTc, the crystallization characteristics are significantly improved, and good moldability is exhibited even at a mold temperature of 90 ° C. or lower. Further, it is recognized that the decrease in [η] due to molding is small, and the mechanical properties represented by impact resistance and the thermal properties represented by heat distortion temperature are improved.

<Effects of the Invention> The polyethylene terephthalate resin composition for injection molding of the present invention has excellent moldability in a mold at 90 ° C or lower, and has excellent mechanical properties and heat resistance.

Claims (1)

[Claims] 1. A polyethylene terephthalate resin composition for injection molding, which comprises adding 0.05 to 15 parts by weight of a polyoxyalkylene group sulfonic acid metal salt represented by the following general formula (I) to 100 parts by weight of polyethylene terephthalate. (However, Ar in the formula is an aromatic residue having or not having a substituent, R ₁ is an aliphatic hydrocarbon group containing 2 to 20 carbon atoms, R ₂ and R ₃ are hydrogen or the following general formula ( II) the substituent shown by M represents an alkali metal or an alkaline earth metal. n is an integer of 2 to 20 and m is 1 or 2. )