JP3017233B2 - Resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is excellent in moldability, and the molded product has excellent heat resistance, rigidity, water resistance, surface properties and impact resistance (plane impact resistance). And a resin composition having:

[Prior art] Polyamide resins are generally excellent in abrasion resistance, impact resistance, moldability, chemical resistance, mechanical strength, and the like, but have a problem that rigidity is reduced when water is absorbed or dimensional changes occur. is there.

Materials containing glass fibers or inorganic fillers have been used in the past to reduce dimensional change during water absorption and to improve the reduction in rigidity during water absorption. Surface impact) and surface properties, which limits the application fields.

Therefore, recently, an attempt has been made to solve such a problem by mixing two or more polymers (polymer alloy). Then, an invention has been proposed in which the disadvantages of changes in size and rigidity due to water absorption are improved while maintaining the excellent properties of the polyamide resin.

However, when two or more polymers are mixed to impart a plurality of different excellent properties to a resin, the two or more polymers naturally have different properties such as melting point and crystallinity. Are often difficult to mix. Therefore, the point of the alloying technique of the polymer alloy is how to make two or more kinds of polymers compatible so as to obtain an ideal dispersion shape and dispersion particle size.

In general, it is considered that an immiscible polymer alloy preferably has a sea-island structure, which is composed of a matrix resin serving as a sea portion and a domain resin serving as an island portion. Greatly affects physical properties.
Regarding the dispersed shape and dispersed particle size of this island (domain), the appropriate dispersed shape
Although the dispersed particle size is different, as described in many patents, the average particle size is preferably 1-2 μm or less.

However, it is difficult to reduce the average particle size of the island portion to 1 to 2 μm or less by simply mixing the resins. Therefore, several techniques have been disclosed that can improve the compatibility between resins and further improve the mixing method to reduce the average particle diameter to 1 to 2 μm or less.

In addition, the lower limit of the average particle size of the islands theoretically has a limit that deviates from the optimum range. However, in the current technical stage, in most resin combinations, how to reduce the average particle size of the islands It can be said that the point is to improve the physical properties such as impact resistance and the formability and impact resistance. Also, as for the shape, in order to prevent deformation etc. as a molded product, it is better to make it as close to a spherical shape as possible,
Regarding the uniformity, it is important that there is little variation in the average particle size, and in particular, there is no extremely large particle with respect to the average particle size.

In some patents, a functional group having an affinity for the polymer to be alloyed is introduced, or a third component having an affinity for each of two or more polymers is used as a compatibilizer to improve the compatibility. To improve the dispersion of the island,
It describes whether to improve the physical properties.

However, with the conventional methods, the dispersion of the islands is not sufficient, and in particular, the average particle size is not sufficient in terms of shape and uniformity, even if a fine one can be produced. No technique has yet been developed to obtain a material or material having excellent performance with a good balance of heat distortion temperature and impact resistance while covering the drawbacks of polyamide due to water absorption.

[Problems to be Solved by the Invention] As described above, all the properties of moldability, heat resistance, rigidity, water resistance, surface properties, and impact resistance are satisfied by modifying a conventional polyamide (such as a polymer alloy). No material has been developed, and at present the development of a material having such characteristics at the same time is strongly desired.

The present inventors have conducted intensive studies with the aim of developing a resin having excellent moldability, heat resistance, rigidity, and water-resistant surface, and as a result, a polyamide resin and an aromatic vinyl homopolymer or copolymer have been obtained. Have been found to achieve the object, and the present invention has been completed.

[Means for Solving the Problems] The composition of the present invention is based on a morphology of a sea-island structure of two or more resins, and relates to a composition comprising a combination with an inorganic substance serving as a core of the island portion. is there. The inorganic substance serving as the core is selected from those having a size corresponding to the particle size of the desired island portion, is dispersed in a fine state in advance in the resin to be the island portion, and is melt-kneaded with the resin to be the sea portion. Pellet blend to make composition. Or
When melt-kneading the sea part and the island part, the inorganic substance is mixed well with good dispersion to prepare a composition. In some cases, an inorganic substance is dispersed in a resin to be a sea portion in advance, and is melt-kneaded or pellet-blended with a resin to be an island portion to prepare a composition. The composition of the present invention is a composition in which the dispersion of islands in the polymer alloy obtained by such a method is improved, the particle size is made uniform, the shape is made uniform, and the composition is further refined.

In the present invention, either the component (A) or the component (B) may be an island portion, and the silicate is composed of the component (A) and the component (B).
It may be contained in one or both of the components, and those present in the island part finely and uniformly improve the rigidity and heat resistance of the island part, and those existing in the sea part are the entire resin In addition to improving the rigidity and heat resistance of the resin, it has a good effect on the dispersion of the islands.

 The details will be specifically described.

The composition of the present invention comprises (A) 10 to 90% by weight of a polyamide resin.
And (B) an aromatic vinyl homopolymer or copolymer 90 to
10% by weight, and (C) 0.05 to 30 parts by weight of layered silicate in component (A) and / or component (B) based on 100 parts by weight of the total of components (A) and (B) The present invention relates to a resin composition comprising a resin composition dispersed in a resin composition.

The polyamide resin as the component (A) constituting the composition of the present invention has an acid amide bond (-CONH-) in the molecule, and specifically includes ε-caprolactam, 6-aminocaproic acid, ω- Enantholactam, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid,
Polymers or copolymers obtained from α-pyrrolidone, α-piperidone, etc .; diamines such as hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, meta-xylylenediamine and terephthalic acid, isophthalic acid, adipine Examples thereof include a polymer or copolymer obtained by polycondensing an acid, a dicarboxylic acid such as sebacic acid, or a mixture thereof. The average molecular weight of the polyamide resin (A) is 90.
Those having a value of 00 to 30,000 are preferred.

The aromatic vinyl homopolymer used in the present invention is styrene, α-methylstyrene, methylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, monobromostyrene, dibromostyrene, p-tert-butylstyrene, ethylstyrene, It is a polymer of a monomer selected from vinyl and the like, and polystyrene is particularly preferable.

The aromatic vinyl copolymer is a copolymer of an aromatic vinyl monomer and a copolymerizable vinyl monomer. Examples of the vinyl monomer include vinyl cyanide compounds such as acrylonitrile and methacrylonitrile. , Methyl acrylate,
Ethyl acrylate, butyl acrylate, alkyl acrylates such as 2-ethylhexyl acrylate, methyl methacrylate, ethylene methacrylate,
Methacrylic acid alkyl esters such as 2-ethylhexyl methacrylate, maleimide, N-phenylmaleimide, maleimide compounds such as N-cyclohexylmaleimide, acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid, unsaturated acids such as cinnamic acid, Unsaturated carboxylic acid anhydrides such as maleic anhydride, itaconic anhydride, chloromaleic anhydride, citraconic anhydride, butenylsuccinic anhydride, tetrahydrophthalic anhydride, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, 2-methylallyl glycidyl Ether, 2-methylallyl glycidyl ether, styrene
p-glycidyl ether, 3,4-epoxybutene, 3,4-
Epoxy-3-methyl-1-butene, 3,4-epoxy-
1-pentene, 3,4-epoxy-3-methylpentene,
Epoxy group-containing unsaturated compounds such as 5,6-epoxy-1-hexene, vinylcyclohexene monoxide, p-glycidylstyrene, and amino group-containing unsaturated compounds such as allylamine, aminoethyl methacrylate, aminopropyl methacrylate, and aminostyrene , 3-hydroxy-
1-propene, 4-hydroxy-1-butene, cis-4
-Hydroxy-2-butene, trans-4-hydroxy-2-butene, 3-hydroxy-2-methyl-1-propene, cis-5-hydroxy-2-pentene, trans-5-hydroxy-2-pentene, cis -1,4-hydroxy-2-butene, trans-1,4-hydroxy-2-
Butene, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2-hydroxyethyl crotonate, 2,3,4,5,6-
Pentahydroxyhexyl acrylate, 2,3,4,5,6-
Pentahydroxyhexyl methacrylate, 2,3,4,5-
Hydroxy group-containing unsaturated compounds such as tetrahydroxypentyl acrylate and 2,3,4,5-tetrahydroxypentyl methacrylate and the like, and other vinyl monomers copolymerizable with these aromatic vinyl compounds may be one or more. 2
Used in more than species. Further, a copolymer of these and a diene monomer which can be a rubber substrate may be used.

Examples of preferred aromatic vinyl copolymers include polystyrene, acrylonitrile-butadiene-styrene graft polymer, styrene / maleic anhydride copolymer, styrene / N-phenylmaleimide copolymer, styrene / maleic anhydride / N- Phenylmaleimide copolymer, styrene / methacrylic acid copolymer, styrene glycidyl methacrylate copolymer and the like. The component (B) is different from the impact resistance improving material, and has a flexural modulus of 10,000 kg / cm ² or more.

The distribution ratio of the components (A) and (B) is as follows.
And the component (B) is 90 to 10 parts by weight.
If the compounding ratio of the component (A) is less than 10 parts by weight, the moldability decreases, and if it exceeds 90 parts by weight, the rigidity at the time of absorbing water decreases.

The component (C) is a layered silicate. The component (C) is used in a molded article obtained from the resin composition, and the component (B) is contained in the polyamide of the component (A), or the component (A) is used as the component (B).
It is a substance that is finely dispersed in components and contributes to imparting excellent mechanical properties, heat resistance and surface impact resistance with excellent moldability.

Further, the layered silicate which is uniformly dispersed is characterized by imparting rigidity and finely dispersing the resin to be dispersed particles, and simultaneously satisfies rigidity and impact resistance (plane impact resistance) which are contradictory properties. This is an indispensable component for providing a method for stabilizing a multi-component polymer blend which is completely different from methods for imparting rigidity and impact resistance according to known techniques.

When the layered silicate is dispersed in the component (A), each of the layered silicates maintains an interlayer distance of 20 ° or more on average and is uniformly dispersed. In the present invention, the layered silicate refers to one unit of a substance having a side of 0.002 to 1 μm and a thickness of 6 to 20 °.

In addition, the interlayer distance refers to the distance between the centers of gravity of the plate of the layered silicate.
Or, on average, multi-layered objects with 5 layers or less overlap in parallel,
Or, a state in which 50% by weight or more, preferably 70% by weight or more is dispersed without forming a local mass at random or in a state where parallel and random are mixed.

As a raw material of such a layered silicate, a layered phyllosilicate mineral composed of a layer of magnesium silicate or aluminum silicate can be exemplified. Specifically, montmorillonite, savonite, beidellite, nontronite, hectorite, smectite-based clay minerals such as stevensite, vermiculite, paroysite, etc. can be exemplified. Montmorillonite is preferred among these.

The compounding ratio of the component (C) is 0.05 to 30 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the total amount of the components (A) and (B). When the compounding ratio of the component (C) is less than 0.05 part by weight, the effect of improving the heat resistance and impact resistance of the molded article is small, and when it exceeds 30 parts by weight, the fluidity of the resin composition is extremely reduced, Moldability decreases.

Further, in addition to the components (A), (B) and (C) described above, an impact resistance improving material can be added to the present invention as needed. The impact resistance improving material is not particularly limited as long as it is an impact resistance improving material generally used for polyamide, and examples thereof include the following. When 20% by weight is added to polyamide, its impact resistance is about twice or more, and its flexural modulus is 10,000 kg / cm ² or less.

Examples of impact modifiers include styrene-butadiene (or isoprene) copolymers (random copolymers, block copolymers, hydrogenated block copolymers, and graft copolymers) that are elastomeric at room temperature. Olefin copolymers can be exemplified. Specifically, styrene-butadiene random copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, hydrogenated styrene-butadiene-styrene block copolymer, hydrogenated styrene-isoprene- Styrene block copolymer; ethylene,
Examples thereof include copolymers of two or more olefins selected from propylene, butene-1, hexene-1, decene-1, and 4-methylbutene-4-methylpentene-1.

As the impact resistance improving material, a material modified with an unsaturated carboxylic acid or the like can be used.

Preferred amounts of the impact modifier are (A) and (B).
And 30 parts by weight or less based on 100 parts by weight of the total amount of component (C). If the amount exceeds 30 parts by weight, the moldability decreases, and the heat resistance of the molded article decreases, which is not preferable.

The compatibilizer is, for example, poly (acrylic acid) having 70 parts by weight of (C) -2 poly (ethylene / glycidyl methacrylate) copolymer (ethylene / glycidyl methacrylate = 85/15) and a peroxide bond in a side chain. Poly (ethylene / glycidyl methacrylate) obtained by melt-kneading 30 parts by weight of butyl-b-styrene) (butyl acrylate / styrene-10 / 90) at a melting temperature of 200 ± 20 ° C. using a melt extruder. -G-
For example, a grafted polyolefin modified product which is poly (butyl acrylate-b-styrene) (Nippon Oil & Fats Co., Ltd. grade name MODIPER A4100) may be used.

The composition of the present invention, if necessary, dyes, pigments, nucleating agents, fillers such as release agents, glass fibers, metal fibers, reinforcing agents such as carbon fibers, plasticizers, lubricants, heat resistance imparting agents, A foaming agent, a flame retardant and the like can be blended.

The method for producing the resin composition of the present invention is not particularly limited. For example, after the layered silicate of the component (C) is brought into contact with a swelling agent to expand the layers in advance to make it easier to take in the monomers between the layers, the monomer forming the component (A) is mixed, and the mixture is polymerized (Japanese Patent Laid-Open No. Sho 62-62). JP-A-74957), and further mixed with the thermoplastic resin of the component (B),
A method of melt-kneading at 50 ° C., preferably 250 to 320 ° C .; a material obtained by melting the thermoplastic resin of the component (B) in a polyamide in a molten state after the polymerization, and expanding the interlayer distance to 50 ° or more in advance. Further, a method of kneading and blending the layered silicate of the component (C) can be applied.

In the resin composition of the present invention, it is preferable that particles that can be dispersed particles form a dispersed phase when the number average particle diameter is 2 μm or less.

The layered silicate of the component (C) may be dispersed in both phases of the component (A) and the component (B), or may be dispersed in one of the phases.

According to the present invention, both a heat resistance and an impact resistance of a molded article can be simultaneously improved by further mixing a layered silicate with a mixture of the component (A) and the component (B). Usually, when an inorganic filler is blended in a mixture of a polyamide resin and a thermoplastic resin, rigidity and heat resistance can be improved, but impact resistance is reduced. However, in the composition of the present invention, the phyllosilicate is dispersed and present in a very fine state. It is considered that since the particles can be finely dispersed, the impact resistance as well as the rigidity and heat resistance are improved.

-The resin composition of the present invention can be used as a material for manufacturing various parts of automobiles, electronic and electrical parts, mechanical parts, and general goods.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.
Parts represent parts by weight. The test method of each characteristic shown below is as follows.

Tensile strength: ASTM D-638 Flexural strength, flexural modulus: ASTM D-790 Izod impact strength: ASTM D-256 Thermal deformation temperature: ASTM D-648 High-speed impact strength: First, the resin composition of the present invention Was formed into a disk having a thickness of 3.2 mm and a diameter of 100 mm, and the disk was used as a test piece. Next, a round missile having a tip diameter of 1/2 inch at −30 ° C. was dropped at a speed of 2.5 m / sec onto the center of the test piece,
In that case, the surface impact measurement method (UBE method) was used to calculate the fracture energy from the area of the stress-strain curve at the time of fracture.

Dispersion particle size: A small piece of each compact was prepared using a cyclotome, and the small piece was stained with rhodamine B, washed with water, and then measured for the dispersed particle size in the small piece with an optical microscope (× 1000).

Examples and Comparative Examples Resin compositions were produced with the combinations and compounding ratios of the respective components shown in the following table, and test pieces for evaluating each property were produced as molded articles.

(A) Polyamide 200 g of montmorillonite having an average thickness of one unit of 9.5 mm and an average length of about 0.1 μm on one side is dispersed in 10 pieces of water, and 51.2 g of 12-aminododecanoic acid is added thereto. 24m
l of concentrated hydrochloric acid was added, and the mixture was stirred for 5 minutes and passed. After sufficiently washing this, it was vacuum-dried. By this operation, a complex of ammonium 12-aminododecanoate and montmorillonite was prepared. The layered silicate content in the composite was 80% by weight. The distance between the silicate layers was 18.0 ° in the measurement of the composite by X-ray diffraction.

Next, 10 kg of ε-caprolactam, 1 kg of water and 200 g of the dried composite were placed in a reaction vessel equipped with a stirrer, and stirred at 100 ° C. so that the inside of the reaction system became uniform. The temperature was further raised to 260 ° C., and the mixture was stirred under a pressure of 15 kg / cm ² for 1 hour. Thereafter, the pressure was released, and the reaction was carried out at normal pressure for 3 hours while evaporating water from the reaction vessel. After completion of the reaction, the reaction product taken out in a strand form from the lower nozzle of the reaction vessel was water-cooled and cut to obtain a pellet comprising a polyamide resin (average molecular weight 15,000) and montmorillonite. Next, the pellet was immersed in hot water to extract and remove unreacted monomer (about 10%), and then dried in vacuum. The ratio between the polyamide and montmorillonite in the dried pellets was 1.6 parts by weight of montmorillonite based on 100 parts by weight of the polyamide resin.

(B) Aromatic vinyl homopolymer or copolymer Styrene / maleic anhydride copolymer (Grade name, manufactured by A Copolymer Co., Ltd., Dailark 232, hereinafter abbreviated as SMAH) Impact resistance improving material Hydrogenated styrene butadiene block copolymer Polymer (Grade name of Shell Chemical Co., Ltd., Clayton G1651, hereinafter abbreviated as SEBS) A molded article was produced by the following method. First, the components shown in the table were preliminarily mixed and then melt-kneaded at 250 ° C. to 300 ° C. using an extruder having a screw diameter of 30 mm to form pellets.
Thereafter, the pellets were vacuum-dried, and then injection-molded by an injection molding machine at a cylinder temperature of 250 to 300 ° C and a mold temperature of 80 ° C to obtain a molded body.

Using the obtained molded body as a test piece for each property evaluation,
The results of the evaluation test are shown in the table.

(Effect of the Invention) As shown in the results in the table, by further mixing a layered silicate with a mixture of a polyamide and a thermoplastic resin,
Not only rigidity but also excellent impact resistance.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akane Okada 41-1 Okucho Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture Inside Toyota Central Research Laboratory Co., Ltd. (56) References JP-A-63-230766 (JP, A) JP-A-63-61049 (JP, A) Patent 2528163 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 77/00-77/12 C08L 25/00-25/18 C08K 3/34-3/36

Claims (2)

(57) [Claims] (A) a polyamide resin; (B) an aromatic vinyl homopolymer or copolymer; and (C) a component (A) and / or (B), wherein each side of one unit is 0.002 to 1 μm. A layered silicate having a thickness of 6 to 20 mm, each of which contains layered silicate uniformly dispersed with an interlayer distance of 20 mm or more on average. A resin composition in which the islands form a dispersion layer having a number average particle diameter of 2 μm or less. 2. The resin composition according to claim 1, wherein said resin composition does not contain a compatibilizer for the components (A) and (B).