JPH0138818B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to modified polyalkylene terephthalate compositions, and in particular to modified polyalkylene terephthalate compositions for molding. More specifically, it is a modified polyalkylene terephthalate composition obtained by copolymerizing and/or mixing a polyoxyalkylene compound having an organic carboxylic acid metal salt, which has an extremely fast crystallization rate, significantly improved moldability, and This invention relates to a novel modified polyalkylene terephthalate composition that has excellent heat resistance and mechanical strength. A high molecular weight linear polyalkylene terephthalate obtained from a dicarboxylic acid mainly consisting of terephthalic acid or its ester-forming derivative and a diol or its ester-forming derivative has a high softening point,
It is widely used in fibers, films, and molded products because of its heat resistance, chemical resistance, light resistance, as well as excellent electrical properties and physical and mechanical properties. However, when such polyalkylene terephthalate is used as an injection molded product, the crystallization rate is slow compared to the same crystalline polymers such as nylon and polyacetal. In particular, polyethylene terephthalate hardly crystallizes at temperatures below 100°C. do not. It has been strongly desired to improve the crystallization properties of polyalkylene terephthalate, particularly polyethylene terephthalate, shorten the molding cycle, and widen the mold temperature range during molding. The present inventors have surprisingly found that by copolymerizing and/or mixing a polyoxyalkylene compound having an alkali metal salt or an alkaline earth metal salt with polyalkylene terephthalate, the crystallization rate of polyalkylene terephthalate can be significantly increased. In addition to shortening the molding cycle, the crystallization rate is rapid even when the mold temperature is lowered to 100℃ or less when molding polyethylene terephthalate, and the molded product has extremely excellent heat resistance and mechanical strength. was found to be obtained. The present invention relates to (a) a polyalkylene terephthalate polymer and (b) a polyoxyalkylene compound having at least one carboxylic acid metal salt (provided that the metal is an alkali metal or alkaline earth metal) in one molecule. A modified polyalkylene terephthalate composition containing 0.001 to 2.0% by weight of the metal based on the total amount of (a) and (b). In the present invention, the polyalkylene terephthalate polymer (a) is a dicarboxylic acid component in which at least 90 mol% is terephthalic acid, and at least 90 mol% is ethylene glycol, propane-1,3-diol, Butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, cyclohexane-1,4-
It is obtained by direct esterification or transesterification with a diol component, which is dimethanol, and then polycondensation. From an industrial standpoint, polyethylene terephthalate and polybutylene terephthalate are particularly preferred. 0 to 10 mol% of the dicarboxylic acid component of polyalkylene terephthalate is other aromatic dicarboxylic acid having 6 to 14 carbon atoms, aliphatic dicarboxylic acid having 4 to 8 carbon atoms, or alicyclic dicarboxylic acid having 8 to 12 carbon atoms. It may be hot. Examples of such dicarboxylic acids include phthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, adipic acid, sebacic acid, cyclohexanedicarboxylic acid, and the like. In addition, 0 to 10 mol% of the diol component is other aliphatic diols having 3 to 10 carbon atoms, other alicyclic diols having 6 to 15 carbon atoms,
Alternatively, it may be an aromatic diol having 6 to 12 carbon atoms. Examples of such diols include 2,2-
Dimethylpropane-1,3-diol, 2,2-
Examples include bis-(4'-hydroxycyclohexyl)-propane, 2,2-bis-(4'-hydroxyphenyl)propane, and hydroquinone.
Furthermore, oxycarboxylic acids such as ε-oxycaproic acid, hydroxybenzoic acid, etc. may be copolymerized in an amount of 10 mol% or less of the dicarboxylic acid component and diol component. Of course, the polyalkylene terephthalate may also be branched with trihydric or tetrahydric alcohols or tribasic or tetrabasic acids. Examples of suitable branching agents include trimesic acid, trimellitic acid, trimethylolpropane, pentaerythritol, and the like. In the present invention, the polyoxyalkylene compound (b) has the general formula R ₁ [-(OR ₂ )- _l OR ₃ ]m (wherein R ₁ is hydrogen or an m-valent organic group, and R ₂ is C ₂ ～
_C4 aliphatic hydrocarbon group, l is 0 or a positive integer,
R ₃ is a group containing hydrogen or a carboxylic acid metal salt,
m is a positive integer from 1 to 6. ). Such a polyoxyalkylene compound can be obtained by, for example, essentially esterifying a monofunctional or polyfunctional alcohol of polyoxyalkylene with a polyhydric carboxylic acid anhydride, and then neutralizing it with a metal hydroxide or metal alcoholate. It can also be obtained by, for example, reacting a monofunctional or polyfunctional alcohol of substantially polyoxyalkylene with a monocarboxylic acid containing a carboxylic acid metal salt or an ester-forming derivative thereof. Here, "substantially" means that a portion of the molecule may contain other elements or organic groups. Specific examples of such polyoxyalkylene compounds include sodium salts of mono- and disuccinates, potassium salts of mono- and difumarates, mono- and Diphthalic acid ester sodium salt, mono and di(tetrabromo)phthalic acid ester sodium salt, mono and ditrimellitic acid ester sodium salt, mono and chlorendic acid ester sodium salt, etc., monotrimellitic acid ester sodium salt of monomethoxypolyethylene glycol, mono( Examples include tetrabromo)phthalic acid ester sodium salt. Furthermore, glycerin-alkylene oxide adduct, trimethylolpropane-alkylene oxide adduct,
Preferred compounds include pentaerythritol-alkylene oxide adduct sodium salts of mono-, di-, tri-, or tetraphthalic esters, and sodium salts of mono-, di-, tri-, or tetra(tetrabromo) phthalic esters. These alkali metal bases have the general formula (However, X is a halogenated or non-halogenated aliphatic, alicyclic, or aromatic hydrocarbon group, M is an alkali metal, and n is a positive integer of 1 to 5). When an alkaline earth metal salt is used in place of an alkali metal salt, it is natural that the carboxylic acid metal salt is represented by -COOM1/2. Of course, as a polyoxyalkylene compound,
It is not limited to those exemplified above.
These may be used alone or in combination of two or more. Further, these can be used in combination with polyoxyalkylene itself such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. By copolymerizing and/or mixing and dispersing polyoxyalkylene compounds having these organic carboxylic acid metal salts, the crystallization rate of polyalkylene terephthalate is significantly improved. This is because the polyoxyalkylene chains with a low glass transition point are copolymerized or mixed and dispersed in the polyalkylene terephthalate with good compatibility, which improves the mobility of the polyalkylene terephthalate chains and the organic carboxylic acid alkali that is the nucleating agent component. It is presumed that this is caused by a combination of uniform dispersion of the metal salt. Furthermore, polyoxyalkylene compounds having a metal salt of a halogen-containing organic carboxylic acid such as tetrabromophthalic acid ester sodium salt are particularly preferred since they have the effect of improving crystallization properties and flame retardancy. The molecular weight range of polyoxyalkylene compounds is from 200 to 20,000, especially from the viewpoint of compatibility with polyalkylene terephthalate chains.
200-6000 is preferred. The amount of the polyoxyalkylene compound is such that the amount of metal is 0.001 to 2.0% by weight, preferably 0.1 to 2.0% by weight based on the polyalkylene terephthalate.
It is used at a concentration of 0.5% by weight. If it is less than 0.001% by weight, the effect of improving crystallization properties is small;
If it exceeds % by weight, the mechanical strength and heat resistance will be significantly reduced. The amount of the polyoxyalkylene compound used varies depending on its type, molecular weight, etc., but is usually 0.1 to 30% by weight, preferably 1 to 20% by weight, based on the modified polyalkylene terephthalate composition. The alkali metal salt or alkaline earth metal salt in the present invention is preferably a metal salt of a carboxylic acid, and the use of an alkali metal salt is particularly advantageous from the viewpoint of crystallization properties. Copolymerization and/or mixing of such polyoxyalkylene compounds can be carried out by adding the polyoxyalkylene compound during production of polyalkylene terephthalate and reacting or mixing it, or by mixing polyalkylene terephthalate with a kneading device such as an extruder. This can be achieved by a method of further performing a melt polycondensation reaction after mixing. Furthermore, it is also possible to subsequently subject the copolymer or mixture to a solid-phase polycondensation reaction. In the present invention, mechanical strength, heat resistance,
Dimensional stability can be further improved. Examples of the granular or plate-like inorganic fillers used include mica, kaolin, clay, talc, asbestos, calcium silicate, calcium sulfate, and calcium carbonate, with mica and talc being particularly preferred. These may be used alone or in combination of two or more. Its blending amount is 0 to 100 parts by weight of modified polyalkylene terephthalate.
The amount is 200 parts by weight, and preferably 10 to 50 parts by weight when considering mechanical strength, heat resistance, and fluidity. In the present invention, a fibrous reinforcing agent can also be blended in order to further improve heat resistance under high loads, strength at high temperatures, and dimensional accuracy. Examples of the fibrous reinforcing agent used include glass fiber, mineral fiber,
Examples include carbon fiber, silicon carbide fiber, boron carbide fiber, potassium titanate fiber, gypsum fiber, etc.
Glass fibers and mineral fibers are particularly preferred. In order to improve affinity with modified polyalkylene terephthalate, a fibrous reinforcing agent whose surface has been treated with a silane coupling agent or the like is preferably used. The blending amount of these fibrous reinforcing agents is 0 to 200 parts by weight per 100 parts by weight of modified polyalkylene terephthalate, and preferably 5 to 150 parts by weight when considering heat resistance, strength, fluidity, etc. . Furthermore, in the present invention, flame retardancy can be further improved by incorporating a flame retardant. Examples of the flame retardant used include compounds containing elements of groups, groups, groups, and groups of the periodic table, with halogen compounds, phosphorus compounds, and antimony compounds being particularly preferred. These can be used alone or in combination of two or more. Specific examples of flame retardants include tetrabromobisphenol A or its derivatives, decabromodiphenyl ether,
Examples include tetrabromo phthalic anhydride, perchlorocyclopentadiene derivative, triphenyl phosphate, and antimony trioxide. The blending amount of the flame retardant is 0 to 30 parts by weight per 100 parts by weight of modified polyalkylene terephthalate. Granular or plate-like inorganic fillers, fibrous reinforcing agents,
Any method can be used to blend the flame retardant. Examples include a method of mixing and extruding together with modified polyalkylene terephthalate in an extruder, a method of simply mixing with modified polyalkylene terephthalate and direct injection molding, and a method of adding and blending during production of modified polyalkylene terephthalate. The thus obtained composition of the present invention is particularly suitable for injection molding, but it can also be made into a molded article by extrusion molding or other molding methods. As is clear from the examples described below, the molded product obtained by molding the composition of the present invention has significantly improved crystallization characteristics and moldability compared to molded products made from polyalkylene terephthalate alone, and can be molded in a short time. Molded products with excellent mold releasability from the mold even during cycles, good surface appearance, and excellent mechanical strength and heat resistance can be stably obtained. In particular, whereas polyethylene terephthalate alone molded products can only be obtained at a mold temperature of 140°C or higher and under a long molding cycle, the polyethylene terephthalate composition according to the present invention can be obtained at a mold temperature of 100°C or lower, and With a short molding cycle, molded products with excellent mold releasability, surface appearance, heat resistance, and mechanical strength can be obtained. In addition to other known nucleating agents, thermal oxidation stabilizers, light stabilizers, etc., additives such as plasticizers, lubricants, and colorants may be added to the composition of the present invention. Furthermore, a small proportion of other types of thermoplastic resins can be blended,
It is also possible to introduce a small proportion of rubber components to improve impact resistance. The composition of the present invention can be widely used for molding various molded parts, pipes, containers, etc., and can be particularly suitably used for automobile parts, electrical parts, etc. In some cases, it can also be used for fibers, films, and sheets. The present invention will be explained below with reference to Examples. still,
In the examples, the intrinsic viscosity of the polymer was 2.5°C in phenol/tetrachloroethane (1:1 parts by weight).
It was determined from the logarithmic viscosity measured at a concentration of 0.5 g/d1. The melting point Tm, cooling crystallization temperature Tc (C) from a molten state, and heating crystallization temperature Tc (H) from a glass state of the modified polyalkylene terephthalate were measured using a Perkin-Elmer Model DSC-1B. The tensile strength of the molded product is ASTM-D638, and the heat distortion temperature is
Measured using a method compliant with ASTM-D648. Flammability was measured in accordance with the UL94 vertical test method. Example 1, Comparative Example 1 1942 g (10 mol) of dimethyl terephthalate, 1366 g (22 mol) of ethylene glycol, and 1.2 g of zinc acetate as a transesterification catalyst were placed in a 4-liter autoclave equipped with a stirrer, and heated at 160 to 210°C under a nitrogen atmosphere. The mixture was heated and stirred for 2 hours to carry out the transesterification reaction. After the theoretical amount of methanol has been distilled out, the average molecular weight
4480 pentaerythritol-ethylene oxide adduct-ditrimellitic acid ester 4Na 448g
(0.1 mol), and 2.1 g of triphenyl phosphate as a thermal stabilizer, and antimony trioxide as a polycondensation catalyst.
0.7g was added. Subsequently, a polycondensation reaction was carried out at 270°C and <1 Torr. The properties of the obtained polymer are shown in Table 1. Ionox 330 (manufactured by Ciel Chemical Co., Ltd.) was added at a rate of 0.5% as an antioxidant to the dried chips of the above polymer.
The mixture was added and mixed in a weight percent, and then injection molded to obtain a molded product. The injection moldability and physical properties of the obtained molded product are shown below.
Shown in 1. As a comparative example, Table 1 also shows the results of polymerization and molding in the same manner except for pentaerythritol-ethylene oxide adduct-ditrimellitic acid ester 4Na.

[Table] As can be seen from Table 1, the copolymer of the present invention has a significantly lower Tc (H) of 92°C (which means
(means that it has practically sufficient crystallization ability even below 100℃), Tc (C) increases (means that nucleation is promoted), and the crystallization possible temperature range (Tc (C) )-Tc(H)) is significantly increased.
And there is almost no decrease in the crystal melting point Tm. The releasability and surface appearance of the molded product according to the present invention from the mold are good even at a mold temperature of 90°C and a short molding cycle (25 seconds), and the heat deformation temperature is higher than that of polyethylene terephthalate alone, making it practical. A molded article having sufficient mechanical strength can be obtained. In the comparative example, a long molding cycle (75 seconds) is required, and a satisfactory molded product cannot be obtained. Example 2 Instead of pentaerythritol-ethylene oxide adduct-ditrimellitic acid ester 4Na,
A polymer having an intrinsic viscosity of 0.85 was obtained in the same manner as in Example 1 using 304 g (0.1 mol) of pentaerythritol-ethylene oxide adduct-tri(tetrabromo)phthalate 3Na having an average molecular weight of 3040. Add 0.5 liters of Ionox 330 to the dried chips of the above polymer.
% by weight, and 3% by weight of antimony trioxide as a flame retardant were added and mixed, and the mixture was extruded using an extruder to form pellets, which were then subjected to injection molding. Mold temperature 90℃, molding cycle
A molded product with good releasability from the mold and good surface appearance was obtained in 25 seconds, with a tensile strength of 580 Kg/cm ² and a heat distortion temperature (4.7 Kg/cm ² load) of 150°C. When the flammability of this test piece was measured, it showed excellent self-extinguishing properties. Examples 3 to 9, Comparative Examples 2 to 3 Polyethylene terephthalate (intrinsic viscosity 0.80),
Polybutylene terephthalate (intrinsic viscosity 1.10),
Polyoxyalkylene compound, mica (Suzorite
mica 200HK (manufactured by Kuraray Co., Ltd.), glass fiber with a fiber length of 3 mm (manufactured by Asahi Fiberglass Co., Ltd.), and a flame retardant in the proportions shown in Table 2 were mixed and kneaded into pellets using an extruder and subjected to injection molding. Table 2 shows the mold releasability, surface appearance, tensile strength, and heat distortion temperature of the obtained molded product. As is clear from Table 2, by blending a polyoxyalkylene compound, even low temperature molds can be
In addition, molded products with good releasability from the mold, surface appearance, and heat resistance under shortened molding cycles.

[Table] was obtained. By blending mica as an inorganic filler and glass fiber as a fibrous reinforcing agent, a significant increase in tensile strength and heat resistance and further improvement in moldability were achieved. Furthermore, by incorporating a flame retardant, excellent self-extinguishing properties were achieved. Comparative Example 4 100 parts of polyethylene terephthalate of Comparative Example 1 was added with an ionomer resin [Mitsui Dupont Chemical Co., Ltd.
made of ethylene/methacrylic acid copolymer with partial Na
28 parts of salt (Na content: 17,500 ppm) were blended and molded in the same manner. The Na content of the blend is shown in Example 1.
(0.385% by weight). As a result, the same values as in Example 1 were obtained for mold releasability and molding cycle, but the surface appearance was poor, the melting point was significantly lowered to 212°C, and the heat distortion temperature was 75°C. ℃, tensile strength is 360Kg/cm ²
It was unsuitable for practical use. Example 10 Pentaerythritol-ethylene oxide adduct-ditrimellitic acid ester 4Na of Example 1
22.20g (0.06 mol) of polyethylene glycol phthalate Na with an average molecular weight of 370,
A polymer having an intrinsic viscosity of 0.60 was obtained in the same manner as in Example 1. Dry chips of the above polymer
0.5% by weight of Ionox 330 was added and mixed, and then injection molded to obtain a molded product. At a mold temperature of 100℃ and a molding cycle of 30 seconds, the mold releasability from the mold and the surface appearance were both good, the tensile strength was 650Kg/cm ² , and the heat distortion temperature (4.7
kg/cm ² load) was 122°C. Example 11 Pentaerythritol-ethylene oxide adduct-ditrimellitic acid ester 4Na of Example 1
Polypropylene glycol trimellitic acid ester 2Na 19.68g (0.03
The intrinsic viscosity was determined in the same manner as in Example 1 using
A polymer of 0.65 was obtained. 0.5% by weight of Ionox 330 was added to and mixed with the dried chips of the above polymer, and then injection molded to obtain a molded article. At a mold temperature of 100℃ and a molding cycle of 30 seconds, the mold release property and surface appearance were good, the tensile strength was 630Kg/ ^cm2 , and the heat distortion temperature (4.7Kg/ ^cm2 load) was 115℃. Ta.

Claims (1)

[Scope of Claims] 1. (a) a polyalkylene terephthalate polymer and (b) a polyester having at least one carboxylic acid metal salt (provided that the metal is an alkali metal or alkaline earth metal) in one molecule. A modified polyalkylene terephthalate composition containing an oxyalkylene compound, wherein the amount of the metal is 0.001 to 2.0% by weight based on the total amount of (a) and (b). 2 90 of polyalkylene terephthalate polymer
The composition of claim 1, wherein at least % by weight is polyalkylene terephthalate. 3. The composition according to claim 1 or 2, wherein the polyalkylene terephthalate is selected from polyethylene terephthalate, polybutylene terephthalate, copolymers thereof and mixtures thereof. 4 The polyoxyalkylene compound has the general formula R ₁ [-(-OR ₂ ) _-l OR ₃ ]m (where R ₁ is hydrogen or an m-valent organic group, and R ₂ is
_C2 - _C4 aliphatic hydrocarbon group, l is 0 or a positive integer, _R3 is a group containing hydrogen or carboxylic acid metal salt, m is a positive integer of 1-6. ) The composition according to claim 1. 5 The molecular weight of the polyoxyalkylene compound is 200
20,000. 6. The composition according to claim 1, wherein a polyoxyalkylene compound is copolymerized with a polyalkylene terephthalate.