JP3290740B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition having a low coefficient of linear expansion, excellent dimensional stability, and an excellent balance between impact resistance and rigidity.

[0002]

2. Description of the Related Art In recent years, in order to improve fuel efficiency by reducing the weight of automobiles, plastic parts of automobile parts have rapidly advanced, and instrument panels, console boxes,
Interior parts such as glove boxes, handles, trims,
Various plastic materials have been used not only for exterior parts such as moldings, lamp housings, front grilles, mudguards, and side bumpers, but also for bumpers, fascias, fenders, door panels, and some parts of bodies that were conventionally metal. .

Examples of plastics used for such automobile parts include inorganic reinforced plastics such as RIM urethane, composite polypropylene, and G / F reinforced polyamide, and polymer alloy materials such as PC / PBT and PPE / PA. Can be Among these materials, composite polypropylene is, for example, a polypropylene-based composition obtained by blending an ethylene-propione copolymer rubber partially crosslinked with polypropylene, oil and the like, as disclosed in
Nos. 145857, 54-16554 and 57-1
No. 35847, each PPE / P
The polymer alloy A is a composition obtained by adding a rubber modified with a polar group-containing compound as an impact resistance improving material to a combination of a polyphenylene ether and a polyamide.
No. 53, and in order to further improve the balance between low-temperature impact resistance and rigidity, a composition comprising a modified polyphenylene ether intermediate, a polyamide and an impact modifier is proposed in JP-A-1-19664. Have been.

[0004] In particular, the materials used for fascias, fenders and door panels have come to require even higher levels of performance than conventional plastic parts. For example, impact resistance: a property of absorbing energy at the time of collision by deformation of a part and then recovering it, or a property of ductile impact fracture at a low temperature. Dimensional stability due to low coefficient of linear expansion; When a plastic molded article is used in a high-temperature environment, the degree of thermal expansion between the paint and the base plastic is different. Often occurs, and appearance and design are often deteriorated. In addition, large molded plastic products are
For example, when used in combination with a molded product such as wood or metal, the degree of thermal expansion is different in a high-temperature use environment, and thus, at present, problems such as dimensional differences and poor meshing have occurred.
Therefore, it is desired to establish a material technology that satisfies the above conditions, that is, an improvement in impact resistance of plastic and an improvement in dimensional stability at high temperatures (a technology for controlling a thermal expansion coefficient).

[0005]

In conventional plastic materials for automobiles, dimensional accuracy at high temperatures (low linear expansion coefficient)
It was difficult to achieve both high impact strength at a high level. As a general countermeasure against this, it is well known that the impact resistance is improved by, for example, blending a high content of an elastomer, but the dimensional accuracy (low linear expansion coefficient) at high temperatures is deteriorated. . Therefore, as a method to improve the impact resistance by making the elastomer a certain amount,
There is generally a morphology improvement. This is a method of increasing the compatibilizing ability between different kinds of thermoplastic resins by using a special blending technique or a blending technique, and making the domain particle size in a micro-dispersed form (domain-matrix structure) fine. The dimensional accuracy (low linear expansion coefficient) at high temperatures is not improved. Also, dimensional accuracy (low linear expansion coefficient)
In order to improve the quality of the product, it is conceivable to mix inorganic filler.However, in this case, the molded product is likely to be brittle, and the impact resistance level is lowered. And its use is severely limited. Therefore, an object of the present invention is to provide a resin composition which improves the above-mentioned drawbacks, has excellent dimensional accuracy (low linear expansion coefficient) at high temperatures, and has an excellent balance between low-temperature impact resistance and rigidity.

[0006]

Means for Solving the Problems In order to solve this problem, the present inventors have made intensive studies on the relationship between the dispersion state of thermoplastic resins having different flexural moduli and the dimensional characteristics, particularly the linear expansion coefficient. As a result, other thermoplastic resins having a lower flexural modulus than the thermoplastic resin in the thermoplastic resin are not dispersed in the form of particles, but in the form of a mesh, in other words, a form in which the thermoplastic resin is dispersed in a network. The present inventors have found that they have high dimensional characteristics which were not expected in conventional products, and completed the present invention.

That is, according to the present invention, 30 to 97% by weight of the thermoplastic resin component (a) and the thermoplastic resin component (b) 7
A composition comprising 0 to 3% by weight, wherein the ratio (Ma / Mb) of the flexural modulus (Ma) of the component (a) to the flexural modulus (Mb) of the component (b) is 5 or more, and And (b) form a network in the component (a). In particular, one side
m is the number of regions of the component (a) closed by the network of the component (b) existing in the square of m, and R represented by the following formula (I) is 0.9 or less. It is.

[0008]

(Equation 2)

Here, a method of calculating R will be described. First, for example, a part is cut out from a molded product or a pellet obtained by kneading as a sample, stained with RuO ₄ and OsO ₄ , and then an ultra-thin section is prepared using an ultramicrotome (Ultracut N manufactured by Reichert). Then, it is observed with a transmission electron microscope (JEM100CX manufactured by JEOL Ltd.). The thermoplastic resin of the component (b) is observed to be black by dyeing, and its existing state can be observed. Further, the dispersed state of the thermoplastic resin of the component (b) was binarized by an image processing analyzer (Spica 2 manufactured by Nippon Avionics Co., Ltd.), and the thermoplastic resin (b) existing in a 1 μm square was measured. )), The number m of the thermoplastic resin regions of the component (a) closed by the network is calculated, and the formula (I)
R is calculated by This analysis is performed at 10 or more, preferably 30 or more typical locations of each molded article or pellet, and the average value is obtained as an index of the network structure.

Hereinafter, the present invention will be described in detail. The thermoplastic resin of the component (a) and the component (b) used in the present invention is generally a synthetic resin which can be molded to a degree of thermoplasticity by heating, and specific examples are shown below.

<Thermoplastic resin (a)> (1) Saturated polyester For example, dicarboxylic acid or a lower alkyl ester, an acid halide or an acid anhydride derivative thereof, glycol or a dihydric phenol according to a conventional method. And a thermoplastic polyester produced by condensing. Specific examples of aliphatic or aromatic dicarboxylic acids suitable for producing this polyester include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, terephthalic acid, and isophthalic acid. Acid, phthalic acid, p, p'-dicarboxydiphenylsulfone, p-carboxyphenoxyacetic acid, p-carboxyphenoxypropionic acid, p-carboxyphenoxybutyric acid, p-carboxyphenoxyvaleric acid, 2,6-naphthalene dicarboxylic acid or 2 , 7-naphthalene dicarboxylic acid and the like or a mixture of these carboxylic acids.

The aliphatic glycols suitable for the production of saturated polyesters include linear alkylene glycols having 2 to 12 carbon atoms, for example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexane. Diols and 1,12-dodecanediol are exemplified. Examples of the aromatic glycol include p-xylylene glycol, and examples of the dihydric phenol include:
Examples include pyrocatechol, resorcinol, hydroquinone or alkyl-substituted derivatives of these compounds. Other suitable glycols also include 1,4-cyclohexanedimethanol.

Other preferred saturated polyesters include:
A polyester obtained by ring-opening polymerization of a lactone is also included.
For example, polypivalolactone, poly (ε-caprolactone) and the like. Further, as a more preferable polyester, a polymer that forms a liquid crystal in a molten state (Thermotropic)
There is polyester as Liquid Crystal Polymer (TLCP). Polyesters in these categories include Eastman Kodak's X7G and Dartco's Xyder.
(Xydar), Sumitomo Chemical's Econole and Celanese's Vectra are representative products.

Among the above-mentioned saturated polyesters,
Polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), poly (1,4-cyclohexane dimethylene terephthalate) (PCT), liquid crystalline polyester and the like are suitable for the thermoplastic resin composition of the present invention. Is a highly saturated polyester. The viscosity of the saturated polyester used here is
Phenol / 1,1,2,2-tetrachloroethane 6
The intrinsic viscosity measured at 20 ° C. in a 0/40 wt% mixture is preferably in the range of 0.5 to 5.0 dl / g. More preferably 1.0 to 4.0 dl / g, particularly preferably 2.0 to 3.0 dl / g.
It is 5 dl / g. When the intrinsic viscosity is less than 0.5 dl / g, the impact resistance is insufficient, and when the intrinsic viscosity is 5.0 dl / g or more, the moldability is poor.

(2) Polyamide The polyamide used in the present invention has a --CONH-- bond in the polymer main chain and can be melted by heating. Typical examples are nylon 4, nylon 6, nylon 6,6, nylon 4,6, nylon 12,
Nylon 6, 10, and the like. In addition, known low-crystalline and amorphous polyamides containing monomer components such as aromatic diamines and aromatic dicarboxylic acids can also be used. Preferred polyamides are nylon 6 or nylon 6,
6, and nylon 6 is particularly preferable. The polyamide used in the present invention has a relative viscosity of 2.0 to 8.0 (2
(Measured in 98% concentrated sulfuric acid at 5 ° C.).

(3) Polyolefin The polyolefin used in the present invention is ethylene, propylene, butene-1, pentene-1, hexene-1,3-methylbutene-1,4-methylpentene.
Homopolymers of α-olefins such as 1, heptene-1, octene-1, etc., random or block copolymers of these α-olefins, and the majority of these α-olefins with other unsaturated monomers Random, graft or block copolymers, these olefinic polymers are those that have been subjected to treatments such as oxidation, halogenation, sulfonation, etc., and exhibit crystallinity derived at least in part from polyolefins. Those having a degree of conversion of 20% or more are preferred.
These may be used alone or in combination of two or more.

Examples of other unsaturated monomers include: acrylic acid, methacrylic acid, maleic acid, itaconic acid, methyl acrylate, ethyl acrylate, ethyl methacrylate, maleic anhydride, arylmaleimide, Unsaturated carboxylic acids such as alkyl maleic imides or derivatives thereof; vinyl esters such as vinyl acetate and vinyl butyrate; aromatic vinyl compounds such as styrene and methyl styrene; vinyl trimethylmethoxysilane and γ-methacryloyloxypropyl trimethoxysilane Vinyl silane; non-conjugated dienes such as dicyclopentadiene and 4-ethylidene-2-norbornene.

The polyolefin can be obtained by polymerization or modification by a known method, but it may be appropriately selected from commercially available ones. Among these, propylene, butene-
Homopolymers of 1,3-methylbutene-1 and 4-methylpentene-1 or copolymers containing a majority of these are preferred, and especially crystalline propylene-based polymers, that is, crystalline propylene homopolymers, crystalline propylene -Α-olefin block or random copolymer, a copolymer of these crystalline propylene polymers and α-olefin rubber, that is, a copolymer of a plurality of rubber-like α-olefins, or a mixture of a plurality of α-olefins and a non-conjugated diene. Mixtures are preferred in terms of balance of mechanical properties.

The melt flow rate (MFR) (230 ° C., load 2.16 kg) of these crystalline propylene-based polymers or a mixture containing these and an α-olefin-based rubber is in the range of 0.01 to 250 g / 10 minutes. Preferably, 0.05-
A range of 150 g / 10 min is more preferred, especially 0.1 to
A range of 50 g / 10 minutes is preferred. When the value of MFR is lower than this range, there is a problem in molding processability, and when the value is higher than this range, the level of balance of mechanical properties is low, which is not preferable.
Among these, those having a higher molecular weight and having a MFR within the range of MFR by changing the molecular weight by heat treatment in the presence of a radical generator such as an organic peroxide or the like are also included.

(4) Polyphenylene ether The polyphenylene ether used in the present invention has the general formula (II)

[0021]

Embedded image

Wherein Q ¹ represents a halogen atom, a primary or secondary alkyl group, an aryl group, an aminoalkyl group, a halohydrocarbon group, a hydrocarbonoxy group or a halohydrocarbonoxy group; ² represents a hydrogen atom, a halogen atom, a primary or secondary alkyl group, an aryl group, a halohydrocarbon group, a hydrocarbonoxy group or a halohydrocarbonoxy group, and n represents a number of 10 or more). It is a homopolymer or a copolymer having the structure shown. Q ¹ and Q ²
Preferred examples of the primary alkyl group are methyl, ethyl, n
-Propyl, n-butyl, n-amyl, isoamyl, 2
-Methylbutyl, n-hexyl, 2,3-dimethylbutyl, 2-, 3- or 4-methylpentyl or heptyl. Suitable examples of secondary alkyl groups are isopropyl, sec-butyl or 1-ethylpropyl. In many cases, Q ¹ is an alkyl group or a phenyl group, particularly an alkyl group having 1 to 4 carbon atoms, and Q ² is a hydrogen atom.

Suitable PPE homopolymers are, for example, those comprising 2,6-dimethyl-1,4-phenylene ether units. A preferred copolymer is a random copolymer comprising a combination of the above units and 2,3,6-trimethyl-1,4-phenylene ether units. Many suitable homo- or random copolymers are
It is described in patents and literature. Also suitable are, for example, PPEs containing molecular constituents that improve properties such as molecular weight, melt viscosity and / or impact strength. P used here
PE preferably has an intrinsic viscosity at 30 ° C. of 0.2 to 0.8 dl / g measured in chloroform. More preferably, the intrinsic viscosity is 0.2 to 0.5 dl / g, and particularly preferably, the intrinsic viscosity is 0.25 to 0.4 dl / g. If the intrinsic viscosity is less than 0.2 dl / g, the impact resistance of the composition will be insufficient, and if it exceeds 0.8 dl / g, the moldability of the composition and the appearance of the molded product will be difficult.

(5) Polycarbonate Examples of the polycarbonate used in the present invention include aromatic polycarbonate, aliphatic polycarbonate, and aliphatic-aromatic polycarbonate. Among them, 2,2-bis (4-oxyphenyl) alkane-based,
Aromatic polycarbonates composed of bisphenols such as bis (4-oxyphenyl) ether, bis (4-oxyphenyl) sulfone, sulfide and sulfoxide are preferred. If necessary, a polycarbonate resin comprising bisphenols substituted with halogen can be used. The molecular weight of the polycarbonate is not limited, but is generally 10,000 or more, preferably 2
10,000 to 40,000.

Other thermoplastic resins include polyacetal (POM), fluorine resin, polyetheretherketone, ABS resin, aromatic polysulfone, aromatic polyethersulfone, silicon resin, polyvinyl chloride, polyetherimide, and polyetherimide. (Alkyl) acrylate and the like. Among them, preferably saturated polyester, polyamide, polyolefin, polyphenylene ether,
Polycarbonates are exemplified, and more preferably, saturated polyesters, polyamides, and polyolefins. The flexural modulus of these thermoplastic resins is 1,000 kg / cm ² (J
(IS K7203) or more, more preferably 3,000 kg / cm ² or more, particularly preferably 5,000 kg / cm ² or more. As for the thermoplastic resin used in the present invention, two or more thermoplastic resins which are uniformly mixed may be used in combination.

<Thermoplastic resin (b)> The thermoplastic resin used as the component (b) in the present invention has a lower flexural modulus than the component (a), and the flexural modulus of the component (a) and the component (b). The ratio (Ma / Mb) is 5 or more, preferably Ma / Mb is 10 or more.

The thermoplastic resin (b) used in the present invention is preferably a rubbery polymer. For example, hydrogenation of a block copolymer consisting of a vinyl aromatic compound polymer block A and a conjugated diene compound polymer B is preferred. The hydrogenated product of the block copolymer is a vinyl aromatic compound-conjugated diene having a structure having at least one chain block A derived from a vinyl aromatic compound and at least one chain block B derived from a conjugated diene. It is a block copolymer in which the block B aliphatic unsaturated groups of the block copolymer have been reduced by hydrogenation. The arrangement of the blocks A and B includes those having a linear structure or those having a branched structure (radical teleblock). In addition, a part of these structures may include a random chain derived from a random copolymerization part of a vinyl aromatic compound and a conjugated diene. Of these, those having a linear structure are preferred, and those having a diblock structure are more preferred.

The vinyl aromatic compound is preferably styrene, α-methylstyrene, vinyltoluene, vinylxylene, and more preferably styrene. As the conjugated diene, preferably, 1,3-butadiene, 2-
Methyl-1,3-butadiene. The proportion of the repeating unit derived from the vinyl aromatic compound in the hydrogenation of the vinyl aromatic compound-conjugated diene block copolymer is preferably in the range of 10 to 80% by weight, and more preferably in the range of 15 to 60% by weight. Among the aliphatic chain portions in these block copolymers, the ratio of unsaturated bonds derived from conjugated dienes and remaining without hydrogenation is 20%.
% Or less, and more preferably 10% or less. Also,
About 25% or less of the aromatic unsaturated bonds derived from the vinyl aromatic compound may be hydrogenated.

These hydrogenated block copolymers have a viscosity of a toluene solution at 25 ° C. of 30,000 to 10 cP (concentration: 15% by weight) as a measure of their molecular weight.
And more preferably in the range of 10.0
It is 00-30 cP. If the value is greater than 30,000 cP, the moldability of the final composition becomes difficult,
When the value is smaller than cP, the mechanical strength level of the final composition is undesirably low.

Further, as the thermoplastic resin (b) used in the present invention, a polyolefin rubber copolymer may be mentioned, and ethylene-propylene copolymer rubber and ethylene-butene copolymer rubber are preferred. Are copolymers of an amorphous random copolymer containing ethylene and propylene and ethylene and butene as main components, particularly a non-conjugated diene. As the non-conjugated diene in this case, dicyclopentadiene, 1,4-hexadiene,
Cyclooctadiene, methyl norbornene, 5-ethylidene-2-norbornene and the like are used. These ethylene-propylene copolymer rubbers are vanadium chloride,
A typical example is one produced by performing polymerization using a vanadium-based catalyst composed of a vanadium compound such as vanadium oxychloride and an organic aluminum compound such as triethylaluminum sesquichloride. The copolymer rubber produced by such a catalyst system generally has good randomness, shows little crystallinity, and preferably has a crystallinity of less than 20%.

Further, maleic acid, maleic acid monomethyl ester, maleic anhydride,
Α, β-unsaturated dicarboxylic acids such as itaconic acid, itaconic acid monomethyl ester, itaconic anhydride and fumaric acid; endo-bicyclo [2.2.1] -5-heptene-2,3
Alicyclic carboxylic acids such as dicarboxylic acids or derivatives thereof; compounds having a glycidyl group and a (meth) acrylate group in the same molecule; compounds having a glycidyloxy group and an acrylamide group in the same molecule; an alicyclic epoxy group Or an epoxy-containing compound such as butyl glycidyl maleate obtained by graft polymerization using peroxide, ionizing radiation, ultraviolet light, or the like. The thermoplastic resin (b) preferably has a flexural modulus of 10,000 kg / cm ² (JIS K7203) or less. More preferably, 8,000 kg / cm ²
Or less, particularly preferably 6,000 kg / cm ² or less. The thermoplastic resin (b) used in the present invention may be used alone or in combination of two or more.

<Composition ratio of components> The composition ratio of component (a) and component (b) is as follows, assuming that the total weight of both components is 100% by weight. Component (a) is from 30 to 97% by weight, preferably from 35 to 85% by weight, more preferably from 45 to 60% by weight. 30% by weight of component (a)
If it is less than 70%, the dimensional stability (low linear expansion coefficient) and rigidity are unsatisfactory, and if it exceeds 97% by weight, the dimensional stability (low linear expansion coefficient) and impact resistance become unsatisfactory. Component (b) is 3 to
70% by weight, preferably 15 to 65% by weight, more preferably 25 to 50% by weight. If component (b) is less than 3% by weight, dimensional stability (low linear expansion coefficient) and impact strength are unsatisfactory, and if it exceeds 70% by weight, dimensional stability (low linear expansion coefficient) and rigidity are insufficient.

<Form of Thermoplastic Resin Composition> The form of the thermoplastic resin composition of the present invention is such that the component (b) is present in the form of a network dispersed in the component (a). By processing the observed photograph, the number m of the matrix regions closed by the network existing in a square of 1 μm on a side is measured, and the average of R calculated by the formula (I) is 0.9. It has a form that gives the following index, preferably 0.85 or less, more preferably 0.80 or less, and particularly preferably 0.1 or less.
7 or less.

<Melting Shear Viscosity Ratio of Component (a) and Component (b)> The melting shear viscosity ratio of component (a) and component (b) may be any value, but is preferably component (b). The melt shear viscosity ratio of component (a) to component (a) is 1.0
Is less than 0.9, more preferably 0.9 or less, further preferably 0.85 or less, particularly preferably 0.8 or less. In addition, the melt shear viscosity mentioned here is JIS
K7210 is a method described as a reference test, that is, a shear viscosity (shear viscosity) when a molten resin is extruded from a capillary at a constant speed. A specific measurement device is an elevated flow tester (instrument). Ron·
Capillary rheometer). Using this device, for example, cylinder temperature is 280 ° C, nozzle diameter is 1m
m, the nozzle length is set to 10 mm, and the measurement can be performed by changing the extrusion speed. The melt shear viscosity used here was a value at a shear rate of 50 to 300 sec ^-1 .

<Additional Components> Other additional components can be added to the thermoplastic resin composition of the present invention. For example, well-known antioxidants and weather resistance improvers for thermoplastic resins,
Nucleating agents, flame retardants, impact modifiers, plasticizers, flow improvers and the like can be used. In some cases, an organic peroxide may be added. The addition of organic and inorganic fillers and reinforcing agents, especially glass fiber, mica, talc, wollastonite, potassium titanate, calcium carbonate, silica, etc.
It is effective for improving heat resistance and dimensional accuracy. For practical use, various colorants and their dispersants can be used well-known ones.

<Production and Molding Method of Composition> The production method for obtaining the thermoplastic resin composition of the present invention is not particularly limited, and for example, a melt mixing method or a solution mixing method can be used. As a typical method of melt mixing, use of a melt kneader generally used for thermoplastic resins can be mentioned. For example, a single-screw or multi-screw kneading extruder, a roll, a Banbury mixer, and the like. Examples of the solution mixing method include a method in which each component is dissolved in an appropriate solvent or mixed in a suspended state. The molding method of the thermoplastic resin composition of the present invention is not particularly limited, and molding methods generally used for thermoplastic resins, namely, injection molding, hollow molding, extrusion molding, sheet molding, and thermoforming. ,
Various molding methods such as rotational molding, lamination molding, and press molding can be applied.

[0037]

EXAMPLES The present invention will be described more specifically with reference to the following examples. Examples 1 to 10 The components used are as follows. Component (a): (a-1) Saturated polyester: Polybutylene terephthalate manufactured by Kanebo Co. (trade name: PBT128, flexural modulus (JI
(S K7203): 25,000 kg / cm ² ) (a-2) Polyamide: Polyamide 6 manufactured by Kanebo Co. (trade name: MC161, relative viscosity according to JIS K6810: 6.8, flexural modulus (JIS K7203): 27,000 kg
/ cm ² )

(A-3) Polyolefin: Propylene-ethylene block copolymer manufactured by Mitsubishi Yuka (trade name: BC
8DQ, MFR according to JIS K7210: 1.2 g /
10 minutes, ethylene content by infrared spectroscopy: 5.5% by weight, flexural modulus (JIS K7203): 8,000 kg / cm ² ) (a-4) PPE: Poly (2,5) produced by Nippon Polyether Company 6-dimethyl-1,4-phenylene ether)
Intrinsic viscosity measured in chloroform at 30 ° C .:
0.30dl / g, flexural modulus (JIS K7203): 26,000
kg / cm ² (a-5) polycarbonate: manufactured by Mitsubishi Gas Chemical Company (trade name: Iupilon (E-2000), flexural modulus (JI)
(SK7203): 23,000 kg / cm ² ) (a-6) Polyacetal: manufactured by DuPont Far East (trade name: Delrin 100, flexural modulus (JIS K720)
3): 26,000 kg / cm ² )

Component (b) (b-1) Hydrogenated product of vinyl aromatic-conjugated diene block copolymer (SEBS): manufactured by Shell Chemical Company (trade name:
Clayton G1652, flexural modulus (JIS K7203): 2,
000 kg / cm ² ) (b-2) Hydrogenated product of modified vinyl aromatic-conjugated diene block copolymer (modified SEBS1): 100 parts of Clayton G1652 manufactured by Shell Chemical Co., Ltd. 5 parts of epoxidized acrylamide compound (trade name: Kaneka AXE), 1,3-bis (t-
0.1 part of butyl peroxy-isopropyl) benzene (manufactured by Kayaku Nury Co., Ltd., trade name: Percadox 14) is sufficiently mixed and stirred with a super mixer, and the mixture is mixed with a twin screw extruder (TEX44 manufactured by Nippon Steel Works, Ltd.) ) Was melt-kneaded under the conditions of a set temperature of 180 ° C. and a screw rotation speed of 200 rpm to obtain a composition, which was then pelletized. The pellet was washed with acetone and dried under reduced pressure to obtain a modified resin. By measuring the infrared absorption spectrum of this modified resin,
The graft polymerization amount of the unsaturated polar compound was 1.6% by weight. The flexural modulus (JIS K7203) is 2,000 kg / cm ²
Met.

(B-3) Hydrogenated modified maleic anhydride-modified vinyl aromatic-conjugated diene block copolymer (modified SEBS2): manufactured by Shell Chemical Company (trade name: Clayton G1901X, flexural modulus (JIS K7203)) ： 1,500kg
/ cm ² ) (b-4) Maleic anhydride-modified ethylene-propylene rubber (modified EPR): manufactured by Nippon Synthetic Rubber Co., Ltd. (trade name: T77)
11SP, maleic anhydride content: 0.5 to 1% by weight, flexural modulus (JIS K7203): 150 kg / cm ² ) (b-5) Ethylene-propylene rubber (EPR); manufactured by Nippon Synthetic Rubber Co. (trade name: EP912P, flexural modulus (JI
S K7203): 120 kg / cm ² ) (b-6) Modified PE: Linear low-density polyethylene (Mitsubishi Yuka Co., trade name: Mitsubishi Polyethylene-LL UF240) 1
00 parts, 3 parts of a commercially available maleic anhydride as an unsaturated polar compound, and 0.1 part of 1,3-bis (t-butylperoxy-isopropyl) benzene (Percadox 14) were sufficiently mixed and stirred with a super mixer. This was melt-kneaded using a twin-screw extruder (TEX44) at a set temperature of 180 ° C. and a screw rotation speed of 200 rpm to form a composition, which was then pelletized. The pellet was washed with acetone and dried under reduced pressure to obtain a modified resin. According to the infrared absorption spectrum measurement of the modified resin, the amount of the unsaturated polar compound graft-polymerized was 1.3% by weight. The flexural modulus (JIS K7203) was 4,000 kg / cm ² .

The components (a) and (b) shown in Table 1 were sufficiently mixed and stirred by a super mixer at the mixing ratio shown in the table. Next, this was melt-kneaded using a twin-screw extruder (TEX44) under the conditions of a set temperature of 230 ° C. and a screw rotation speed of 350 rpm to obtain a composition, which was then pelletized. From the pellets of the resin composition described above, an in-line screw injection molding machine (IS-90B manufactured by Toshiba Machine Works, Ltd.)
), Cylinder temperature 280 ° C, mold cooling temperature 8
Injection molding was performed at 0 ° C. to produce a test piece. In addition, at the time of injection molding, using a vacuum dryer until immediately before,
It was dried for 48 hours under the conditions of 0.1 mmHg and 80 ° C. Also,
Immediately after the injection-molded test piece was placed in a desiccator and allowed to stand at 23 ° C. for 4 to 6 days, an evaluation test was performed, and the results are shown in Table 1.

[0042]

[Table 1]

For the composition obtained in Example 2, 7
FIG. 1 shows a transmission electron micrograph at a magnification of 5,000.
The component (b) (here, denatured SEBS) was observed to be black by staining, indicating that a network structure was formed. The circles in the figure indicate the number m of the regions of the polyamide 6 which are closed with the modified SEBS, and m = 62 per 1 μm square.

The physical properties and various properties were measured by the following methods. (1) Network dispersion state (R calculation method) A sample was cut out from an injection-molded product or a pellet obtained by kneading, and after a RuO ₄ or OsO ₄ dyeing, an ultramicrotome (Ultracut N manufactured by Reichert) was used. ) To prepare an ultrathin section and observe it with a transmission electron microscope (JEM100CX manufactured by JEOL Ltd.). The component (b) is observed to be black by staining, and its existing state can be observed. Further, the dispersed photograph of the thermoplastic polymer was binarized by an image processing / analysis device (Spica 2 manufactured by Nippon Avionics Co., Ltd.), and the photograph was closed by a network of the component (b) existing within a square of 1 μm on a side. The number m of the component (a) region is measured, and R is calculated by equation (I).

(2) Three-point flexural modulus ISO R178-1974 Procedure 12 (JIS
K7203) using an Instron tester. (3) Izod impact strength ISO R180-1969 (JIS K 7110)
It was measured using an Izod impact tester (manufactured by Toyo Seiki Seisaku-sho, Ltd.) according to the notched Izod impact strength. (4) Linear expansion coefficient The linear expansion coefficient was measured according to ASTM D696. However, the measurement temperature range is 23 to 80 ° C. (5) Melt Shear Viscosity Ratio [Component (b) / Component (a)] The melt shear viscosity of each component was measured using an Instron capillary rheometer according to the method described as a reference test of JIS K7210. .

Comparative Example 1 Examples 1 to 10 were repeated except that (a-2) was used as the component (a) and the following (b-7) was used as the component (b) in the proportions shown in Table 1. Was performed in the same manner as described above. Table 1 shows the results
Shown in

(B-7) Modified polyolefin (modified P
N): 100 parts of propylene-ethylene block copolymer (manufactured by Mitsubishi Yuka Co., trade name: BC8DQ), 3 parts of maleic anhydride as unsaturated polar compound, 1,3-bis (t-butylperoxy-isopropyl) 0.1 parts of benzene (Parcadox 14) was sufficiently mixed and stirred with a super mixer, and the mixture was mixed with a twin-screw extruder (TEX44).
The composition was melt-kneaded under the conditions of a set temperature of 230 ° C. and a screw rotation speed of 200 rpm to obtain a composition, which was then pelletized. The pellet was washed with acetone and dried under reduced pressure to obtain a modified resin. As a result of measuring the infrared absorption spectrum of this modified resin, the graft polymerization amount of the unsaturated polar compound was
It was 0.6% by weight. Flexural modulus (JIS K7203)
Was 8,000 kg / cm ² .

Comparative Example 2 The same procedure as in Examples 1 to 10 was carried out except that the components shown in Table 1 were used in the proportions shown in the table. Table 1 shows the results.

Comparative Example 3 Polyamide 6 (a-2 ') as component (a) (manufactured by Kanebo Co., Ltd., trade name: MC100L, relative viscosity 2.1 according to JIS K6810, flexural modulus: 27,000 kg / c)
The m ^2), except that was used in the compounding ratio shown component (b) as (b-1) in the same table were carried out in the same manner as in Examples 1-10. Table 1 shows the results. FIG. 2 shows a 75,000-fold transmission electron micrograph of the obtained composition. Component (b) is dispersed in the form of particles and there are no areas of polyamide 6 which are closed off by the polymer. Therefore, m = 0.

[0050]

According to the results of the above evaluation tests, the thermoplastic resin composition of the present invention in which the component (b) is dispersed in the composition in the form of a network in the component (a) has a dimensional stability (low linearity). It can be seen that the coefficient of expansion and the impact resistance are excellent. As a result, the material is widely used and can be an industrially useful material.

[Brief description of the drawings]

FIG. 1 is a transmission electron micrograph (7) showing a fiber shape of a composition having a network structure obtained in Example 2.
5,000 times).

FIG. 2 is a transmission electron micrograph (75,000 ) of a composition in which the component (b) obtained in Comparative Example 3 is dispersed showing a particle structure.
0 times).

[Explanation of symbols]

 1 to 62 Number of each closed area

──────────────────────────────────────────────────続 き Continuation of the front page (72) Motohiro Seki 1st Toho-cho, Yokkaichi City, Mie Prefecture Inside of Yokkaichi Research Institute, Mitsubishi Yuka Co., Ltd. (56) References JP-A-63-92668 (JP, A) JP-A Sho 63-128076 (JP, A) JP-A-53-124559 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 1/00-101/16

Claims (1)

(57) [Claims] 1. A composition comprising 30 to 97% by weight of a thermoplastic resin component (a) and 70 to 3% by weight of a rubbery polymer (b), wherein the component (a) has a flexural modulus (Ma) The component (b) has a flexural modulus (Mb) ratio (Ma / Mb) of 5 or more, and the component (b) forms a network form in the component (a) and exists in a square of 1 μm on a side. The number of regions of the component (a) closed by the network of (b) is represented by m, and the following formula (I): R is 0.9 or less and JIS K7
210. A thermoplastic resin composition, wherein the melt shear viscosity ratio of the component (b) to the component (a) according to the method described in 210 is less than 1.0.