JPH02225557A - Resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition especially excellent in low-temperature impact resistance and suitable for an automobile outside sheet coating by mixing a copolyester of an aromatic vinyl polymer with an aromatic polyester with a polyphenylene ether resin, an epoxy styrene resin and a conjugated diene- aromatic vinyl block copolymer. CONSTITUTION:100 pts.wt. resin composition comprising 5-95wt.% copolyester (obtained by polycondensing 30-70wt.% aromatic vinyl polymer with an aromatic polyester) and 5-95wt.% polyphenylene ether resin of the formula (wherein R1-R4 are each H, a halogen atom or a hydrocarbon group, and n>=50) is mixed with 0.1-5 pts.wt. epoxy styrene resin and 1-30 pts.wt. hydrogenated or nonhydrogenated conjugated diene/aromatic vinyl block copolymer or modified block copolymer prepared by grafting 0.01-10wt.% unsaturated carboxylic acid thereonto to obtain a thermoplastic resin composition of excellent low- temperature impact resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a resin composition, and more specifically, a thermoplastic resin composition having excellent heat resistance, moldability, two-dimensional stability, and mechanical properties, especially low-temperature impact resistance. relating to things.

[Prior art] With the recent development of the automobile industry and the electrical and electronic industry, the demand for industrial resins called engineering plastics is increasing, but there are also demands for them to be able to function satisfactorily under harsh usage conditions. is increasing. For this reason, there is a need to provide functions that conventional resins cannot provide (for example, resin performance that allows online painting on the premise of integral painting with steel plates).

In response to such demands, modification using polymer alloys has recently attracted attention. By blending polyphenylene ether, which has excellent heat resistance and hydrolysis resistance but has poor moldability, with aromatic polyester, which has good moldability but poor heat resistance. Various methods for imparting new functions and physical properties have also been proposed.

For example, as shown in JP-A No. 62-131015, a vinyl polymer called ``macromapa'' having a functional group reactive with polyester at one or both ends of the styrene main chain is used. Unexamined Japanese Patent Publication 1986-15
841@ or JP-A No. 63-95256, a method of blending polyphenylene ether with a copolymer consisting of a vinyl polymer and a polyester, or a method of blending a copolymer consisting of a vinyl polymer and a polyester, polyphenylene A method of blending three parts of ether and polyester is shown. The methods described in these documents can improve the moldability of polyphenylene ether and have the effect of improving heat resistance compared to aromatic polyester. However, in applications for automobile outer panels such as fenders, this resin composition still cannot be said to have sufficient impact resistance at low temperatures.

However, by blending a styrene resin into a copolyester made by copolymerizing an aromatic vinyl copolymer with an aromatic polyester, the compatibility with polyphenylene ether has been improved, and impact resistance at low temperatures has been improved. The inventors have discovered that a composition prepared by adding a modified block copolymer to improve properties has excellent heat resistance and low-temperature impact properties, and has thus arrived at the present invention.

[Object of the invention] The present invention provides a polyphenylene ether by blending a block copolymer with a styrenic resin containing a specific epoxy group in copolymerized polyester and polyphenylene ether.
The purpose of the present invention is to provide a resin composition suitable for automobile exterior panels that has excellent dimensional stability and mechanical properties, particularly low-temperature impact resistance, without impairing the heat resistance of nylene ether and the moldability of aromatic polyester.

[Structure of the Invention] The present invention provides: (A) 5 to 95% by weight of a copolymerized polyester obtained by avoiding copolymerization of an aromatic vinyl polymer to an aromatic polyester by a polycondensation reaction of 30 to 70% by weight;
and (B) a polyphenylene ether resin generally represented by the following formula (I), where R+, R2, R3, and R4 are each independently hydrogen, based on 100 parts by weight of a resin composition comprising 5 to 95% by weight. , (C) styrene resin containing epoxy group 0.1 to 5
parts by weight and ([)) a block copolymer made of 1q of hydrogenated or unhydrogenated conjugated diene and an aromatic vinyl, or o, oi to 10% by weight of an unsaturated carboxylic acid or the like based on the block copolymer; This is a thermoplastic resin composition formed by blending 1 to 30 modified block copolymers obtained by converting derivatives in graphs 1 to 3 in a double side portion.

The copolymerized polyester (A) used in the present invention is a condensation-reactive copolymer obtained by copolymerizing 70 to 30% by weight of an aromatic polyester and 30 to 70% by weight of an aromatic vinyl polymer. be. [Aromatic polyester] as used herein refers to a polyester having an aromatic group in the main chain of the polymer, which is obtained through a condensation reaction with aromatic dicarboxylic acid or its ester-forming derivative and diol or its ester-forming derivative as main components. It is a polymer or copolymer. Examples of aromatic dicarboxylic brewing ingredients include dicarboxylic acids having a benzene nucleus such as terephthalic acid and isophthalic acid, nophthalezy 2,6-dicarboxylic acid, and nophthalezy 1,5-dicarboxylic acid.

Examples include dicarboxylic acids having a naphthalene nucleus such as nophthalene 2,7-dicarboxylic acid, or ester-forming derivatives thereof. In place of such aromatic dicarboxylic acids or their ester-forming derivatives, 20 mol% or less of the acid component is made up of other aliphatic dicarboxylic acids other than aromatic dicarboxylic acids, such as adipic acid, sebacic acid, or their ester-forming derivatives. You can also.

Examples of the diol component include aliphatic glycols such as ethylene glycol, 1-heramethylene glycol, 1-1-nameethylene glycol, diethylene glycol, and cyclohexyl dimethatetool;
Examples include diols having aromatic rings such as xybenzene and bisphenol A, and ester-forming derivatives thereof.

Examples of preferable aromatic polyesters used in the present invention include polyethylene terephthalate F, polybutylene terephthalate, polyhexylene terephthalate, polycyclohexylene dimethylene terephthalate, and polyethylene-2,6-nophthalate 1. Among them, polybutylene thirephthalate-1 is most preferred. Also, this polyester has 1. t, 2.2-Te1~35 in a 2:3 mixed solvent of lachloroethane and orthochlorophenol
It is desirable that the intrinsic viscosity determined from the solution viscosity measured at an illumination temperature at °C is in the range of 0.5 to 2.0 dl/9.

Examples of "aromatic vinyl polymers" include polymers such as styrene, vinyltoluene, α-methylstyrene, nuclear halogenated styrene, vinylnaphthalene, etc. in the case of the same *i-isomer, and in particular polymers of styrene. Combination is preferred.

Further, the "aromatic vinyl polymer" may be a block copolymer made of a combination of the above-mentioned styrene polymer or the like and an aliphatic diene polymer.

Butadiene is an example of an aliphatic diene polymer.

Examples include diene polymers such as isoprene. Those 2
The polymerization method of the block copolymer of the seed polymer is not particularly limited, but the arrangement of the aromatic vinyl polymer block and diene block is such that the aromatic vinyl polymer is on both ends and the diene polymer is in the middle. , a copolymer with a diene polymer block at both ends and an aromatic vinyl polymer block in the middle, and a copolymer with two blocks of an aromatic vinyl polymer and a diene polymer block are omitted. However, although the reason is not clear, it is preferable that the aromatic vinyl polymer be present at both ends and the diene polymer be present in the middle. Further, both ends of the block copolymer must have a functional group having a carboxyl group or a hydroxyl group that can undergo a polycondensation reaction with the aromatic polyester. In the case of a block copolymer having a diene polymer at both ends and an aromatic vinyl polymer in the middle, the polycondensation reaction tends not to proceed sufficiently and it is difficult to obtain a copolymerized polyester.

In addition, the method for producing the copolymerized polyester can be carried out by a well-known polymerization method, as in the case of producing the aromatic polyester described above. That is, at any stage of the esterification or transesterification reaction of an aromatic carboxylic acid or its dimethyl ester with a diol, an "aromatic vinyl polymer" having a terminal functional group capable of polycondensation reaction is added to carry out esterification or transesterification. This is a method in which the polycondensation reaction is completed under high vacuum after the transesterification reaction is completed.

Further, in the present invention, the copolymerization amount of the aromatic vinyl polymer to the aromatic polyester must be 30 to 70% by weight, and particularly preferably 40 to 60% by weight. If the amount of copolymerization is less than 30%, the compatibility will be insufficient and no effect will be exhibited when blended with polyphenylene ether, regardless of the proportion of the copolymerized polyester in the composition. Further, when the amount of copolymerization exceeds 70% by weight, the copolymerization reaction does not proceed well.

Polyphenylene ether resin (B) used in the present invention
) has a repeating unit represented by the above formula (1), and nl is an integer of 50 or more. R1-R1
are hydrogen atoms, halogen atoms, and methyl groups.

A substituent selected from the group consisting of hydrocarbon groups such as ethyl groups and halogenated hydrocarbon groups.

Preferred polymers are those in which R3 and R4 are alkyl groups having 1 to 4 carbon atoms, and R1 and R2 are hydrogen atoms, such as poly-2,6-dimedylene-1-4-phenylene ether, Poly-2,6-diprobyl-1,4-
Examples include phenylene ether, poly-2,6-dimethylphenylene ether, and poly-2,6-dimethylphenylene ether is most preferred.

The styrene resin (C) containing an epoxy group used in the present invention is glycidyl methacrylate.

glycidyl acrylate, vinyl glycidyl ether,
Copolymerization of epoxy group-containing copolymerizable unsaturated monomers such as allyl glycidyl ether, glycidyl ether of hydroxyalkyl (meth)acrylate, glycidyl ether of polyalkylene glycol (meth)acrylate-1, and glycidyl ether-1. Alternatively, styrene-containing polymers such as graft copolymerized polystyrene, acrylonitrile-styrene copolymer, and styrene-butadiene copolymer can be exemplified.

Furthermore, the modified block copolymer used in the present invention is composed of a block copolymer of a hydrogenated or unhydrogenated conjugated diene and an aromatic vinyl, and the modified block copolymer is composed of a block copolymer of a hydrogenated or unhydrogenated conjugated diene and an aromatic vinyl. o for the copolymer, oi~1
It can be obtained by grafting 0% by weight of an unsaturated carboxylic acid or a derivative thereof.

Conjugated dienes used as raw materials for unhydrogenated block copolymers include 1,3-butadiene, isoprene (2,3
-dimethyl-1,3-butadiene), 1°3-pentadiene, and 1,3-butadiene.

Isoprene is preferably used, and examples of aromatic vinyl hydrocarbons include styrene and α-methylstyrene.

Examples include 0-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene, vinylnophthalene, and styrene is preferably used.

Furthermore, a hydrogenated block copolymer of a conjugated diene and an aromatic vinyl hydrocarbon refers to an unhydrogenated block copolymer in which at least 80% of the unsaturated content has been reduced by hydrogenation, and the aromatic nucleus It is preferable that the ratio of double bonds reduced by hydrogenation is 10% or less.

Preferred specific examples of the hydrogenated and unhydrogenated block copolymers are hydrogenated or unhydrogenated styrene/'butadiene/
'styrene triblock copolymer, hydrogenated or unhydrogenated styrene 7, 'isoprene/'styrene triblock copolymer, etc. Among them, styrene/
A 'butadiene/'styrene triblock hydrogenated copolymer is more preferably used. The modified block copolymer can be produced, for example, by adding an unsaturated carboxylic acid or a derivative thereof to an unmodified hydrogenated or unhydrogenated block copolymer.
It can be easily produced by melt-kneading (at 150 to 300°C). As an apparatus for melt-mixing, a screw extruder, a Bambaji Milly, or the like can be used.

In the resin composition of the present invention, the aromatic polyester and the polyphenylene ether are originally extremely incompatible, and the properties of the resulting molded article, particularly the low-temperature impact resistance, are extremely poor. On the other hand, it is known that borif-1 nylene ether and polystyrene are compatible on a molecular order, and by introducing a compound having a styrene group, the compatibility has been improved and the impact resistance has been improved. . That is, by blending polyphenylene ether with a copolymerized polyester in which aromatic vinyl groups have been introduced into an aromatic polyester, and adding an aromatic vinyl-containing block copolymer, which is an impact modifier, to the homogeneous dispersion system, the impact strength is improved. As well as improving
The addition of the styrene-containing epoxy resin improves the interfacial adhesion between the copolymerized polyester and polyphenylene ether. As a result, a resin composition is obtained which is excellent in heat resistance, moldability, one-dimensional stability, and mechanical properties, particularly in low-temperature packaging properties.

The mixing ratio of such a thermoplastic resin composition is 5 to 05% by weight of component (A) and 5 to 95% by weight of component (B).

For every 100 parts by weight of components (A) + (B), component (C) is 0.1 to 5 parts by weight (preferably 0.3 to 3 parts by weight), (
D) component: 1 to 30 parts by weight (preferably 5 to 20 parts by weight)
1 part). If the content of copolymerized polyester (A) is less than 5% by weight, solvent resistance and moldability will be poor;
If it exceeds m, only resins with low heat distortion temperatures will be used), which is not preferable. Furthermore, when the content of component (C) is less than 0.1 parts by weight, the improvement in low II impact properties of the resulting composition is low;
If it exceeds 5 parts, the end groups of the copolyester and (
The epoxy group of component B) reacts too much, resulting in increased viscosity and poor fluidity.

Furthermore, if the content of component (D) is less than 1 part by weight, the effect of improving impact properties will be small, and if it exceeds 40 mm part, the heat resistance of the polyphenylene ether will decrease and the surface peeling phenomenon will occur, which is undesirable.

The composition of the present invention may contain I-type or granular fillers and reinforcing agents (for example, glass fiber, charcoal xmm, asbestos, gypsum fiber, wollastonite, mica, clay, talc, alumino,
! ! titanium chloride, calcium carbonate, barium sulfate, glass peas, glass peaks, etc.), antioxidants, heat stabilizers (including, for example, hindered phenols, hydroquinones, thioethers, phosphites, and their substituted products and combinations thereof), 1A external radiation absorbers (e.g. various resorcinols, lyricylates, benzotriazoles, benzophenones, etc.), lubricants or mold release agents (e.g. stearic acid and its salts, montanic acid and its salts, half esters, esters, etc.), dyes or pigments, Flame retardants and flame retardant aids.

One or more types of conventional additives such as can be added.

Also other thermoplastic resins (eg polyethylene, polypropylene, polystyrene, ABS resin).

One or more of acrylic resin, fluororesin, polyamide, polyacetal, polycarbonate, polysulfone, and polyester elastomer may be added.

The thermoplastic resin composition of the present invention can be prepared by any method of mixing solid substances (for example, Banbury Miki 5-,
A kneading method using heated rolls, a single-screw or twin-screw extruder) can be applied.

[Example] The effects of the present invention will be explained in further detail with reference to Examples below. In addition, all "parts" and "%" in the examples are based on weight,
Impact strength was measured by the method of ASTH-256, molding shrinkage was measured by the method of ASTH-955, surface appearance was measured by the striped pattern on the surface, and heat resistance (hereinafter referred to as heat rig) was measured by the following method.

Heat rig test method: Hold a 25 mm section at one end of a molded product with a length of 125 mm, width of 25 fl 1 m, and thickness of 3 mm, and leave it horizontally for 150 minutes.
Leave the molded product in an oven at ℃ atmosphere for 1 hour, then take it out immediately and measure the amount of sagging of the molded product.

Examples 1 to 7 and Comparative Examples 1 to 6 28 parts of dimethyl terephthalate, 18 parts of 1,4-butanediol as a copolymerized polyester, 0.02 part of tetrabutoxytitanium as a catalyst, and hydroxyl having polycondensation reactivity at both ends. At the same time, 14 parts of a block copolymer of α-methylstyrene/butadiene/'α-methylstyrene (number average molecular weight: 12,900) was charged into a transesterification tank, and after the transesterification reaction was completed and discharged, polycondensation was continued. The reaction was carried out and 1 q of polymer with intrinsic viscosity [η]=1.20 was obtained.

Next, polyphenylene ether (intrinsic viscosity 0.49.G
E-1 (manufactured by Polymer Co., Ltd.), an epoxy group-containing styrene resin, and a block copolymer were blended in the respective proportions shown in Table 1 and mixed uniformly using a V-type blender.

) The resulting mixture was melt-kneaded in a 44 mm diameter twin-screw extruder at a barrel temperature of 260° C., and the thread discharged from the die was cooled and cut to obtain a pellet for molding.

Next, the pellets were dried with hot air at 130°C for 5 hours, and then a test piece mold for measuring physical properties was attached to an injection molding machine with a capacity of 5 oz.
0℃, injection pressure 800 Kg/cm2, cooling time 20
The specimens were molded under molding conditions of 45 seconds and a total cycle of 45 seconds.

Impact strength and molding shrinkage rate of 1q test piece.

Heat Nag 2 surface appearance was evaluated.

The results are shown in Table 1.

As can be seen from Table 1, compared to when components (C) and (0) are added alone to copolymerized polyester and polyphenylene ether, the combination significantly improves impact strength and reduces mold shrinkage. It can be seen that a molded product with a small heat nug ratio and a good heat nug can be obtained.

Claims (1)

[Claims] (1) (A) 5 to 95% by weight of a copolymerized polyester obtained by copolymerizing an aromatic vinyl polymer to an aromatic polyester by a polycondensation reaction of 30 to 70%; and (B) generally expressed by the following formula: Polyphenylene ether resin represented by (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) In the formula, R_1, R_2, R_3, and R_4 each independently consist of hydrogen, halogen, hydrocarbon group, or substituted hydrocarbon group. selected from the group, and n is a positive integer of 50 or more. (C) 0.1 to 5 parts by weight of a styrene resin containing an epoxy group to 100 parts by weight of a resin composition consisting of 5 to 95% by weight.
parts by weight and (D) a block copolymer obtained from a hydrogenated or unhydrogenated conjugated diene and an aromatic vinyl, or an unsaturated carboxylic acid or its derivative in an amount of 0.01 to 10% by weight based on the block copolymer; A thermoplastic resin composition comprising 1 to 30 parts by weight of a modified block copolymer obtained by grafting.