JP3013966B2 - Polyamide 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, particularly a polyamide resin composition, comprising a polyamide and a polyolefin and having excellent water absorption, dimensional stability, rigidity, toughness and moldability. The thermoplastic resin composition of the present invention,
It can be used in a wide range of fields such as mechanical parts, automobile parts, electric and electronic parts.

[0002]

2. Description of the Related Art Polyamide resins are widely used for electric / electronic parts, automobile parts, etc. because of their well-balanced mechanical properties, heat resistance, chemical resistance and moldability. However, polyamide resin has a large hygroscopic property, which causes a dimensional change and a large decrease in mechanical properties such as a bending strength and an elastic modulus due to moisture absorption. The situation is often restricted, and improvement is desired.

[0003] On the other hand, polypropylene is widely used for automobile parts and electric parts because of its light weight, low water absorption, excellent fluidity during molding, and low cost. However, its heat resistance, strength, and rigidity are insufficient, and the shrinkage during molding due to crystallinity is large and the dimensional accuracy of the molded product is inferior.

Conventionally, in order to improve the dimensional change of polyamide due to water absorption, a method of introducing a monomer unit composed of an aromatic dicarboxylic acid or diamine or a salt thereof into the polyamide main chain by copolymerization, Are disclosed.
In this case, as the low water-absorbing polymer used in the blend, a crystalline resin or rubber made of polypropylene, polyethylene, or a copolymer thereof modified with an unsaturated carboxylic acid or a derivative thereof is known.

For example, Japanese Patent Publication No. 42-12546 discloses a thermoplastic resin having improved compatibility, comprising 50 to 99% by weight of a polyamide and 50 to 1% by weight of a copolymer of an unsaturated carboxylic acid and an olefin. A composition is disclosed.
Although these resin compositions are particularly excellent in breaking properties in mechanical properties, the disclosed resin composition is insufficient in low water absorption, rigidity and heat resistance.

Japanese Patent Publication No. 45-30945 discloses a dispersant comprising an olefin polymer, a polyamide and / or a polyester and a polyolefin modified with at least one of acid, ester, amide, acid anhydride and epoxy groups. Discloses a method for producing a resin composition suitable for a fiber having a good quality. However, the resulting resin composition is
When applied to injection molded products and extrusion molded products, the shrinkage during molding is large, and the dimensional accuracy of the molded products is inferior,
There are problems such as insufficient impact resistance.

Japanese Unexamined Patent Publication (Kokai) No. 60-262853 discloses a low water-absorbing polyamide resin composition comprising a polyamide and a modified ethylene-propylene block copolymer. Although this resin composition is intended to reduce the water absorption of the polyamide to some extent without significantly impairing the rigidity and heat resistance, the level of the water absorption reduction is insufficient.

Japanese Unexamined Patent Publication (Kokai) No. 62-223250 discloses that a modified polyolefin obtained by kneading a crystalline polyolefin with a polyamide and an unsaturated carboxylic acid derivative is further kneaded with a polyamide and a polyolefin, thereby obtaining a low water absorption. A resin composition having excellent tensile strength and surface gloss is disclosed. However, this resin composition is in a situation where both rigidity and impact resistance are insufficient.

Japanese Unexamined Patent Publication (Kokai) No. 62-223251 discloses a resin composition having excellent impact resistance obtained by further adding a low-crystalline ethylene-α-olefin copolymer to the resin composition. I have. However, in this resin composition, although the water absorption is improved, the rigidity level is low,
The balance between low water absorption and mechanical properties is inadequate.

The above-mentioned Japanese Patent Application Laid-Open No. 62-223250 discloses a resin composition comprising a crystalline polyolefin and a polyamide and partially using an unsaturated carboxylic acid-modified crystallized polyolefin. However, even with this resin composition, the combination of low water absorption, rigidity, and impact resistance is insufficient, and a problem remains.

Japanese Patent Application Laid-Open No. 1-51458 discloses that water-absorbing dimensional change of a polyamide resin, an unsaturated carboxylic acid-modified crystalline polypropylene and an unsaturated carboxylic acid-modified ethylene-α-olefin copolymer is small, rigid and resistant. A polyamide resin composition having excellent impact properties is disclosed. However, a composition containing a large amount of a polyamide component has excellent mechanical properties, but insufficient improvement in water absorption,
It cannot be said that achieving both low water absorption and mechanical properties has been sufficiently achieved.

JP-A-64-87652 discloses a polypropylene having excellent impact resistance comprising a partially modified crystalline propylene-ethylene block copolymer, a polyamide and a modified ethylene-α-olefin copolymer rubber. A resin composition is disclosed. However, these are
Polypropylene is used as matrix and polyamide is used as dispersed phase.Heat resistance and mechanical properties are improved compared to polypropylene, but rigidity and heat resistance are greatly reduced with respect to polyamide properties. It stays in what was done.

JP-A-1-146942 discloses a composition comprising 40 to 60% by weight of a modified polyolefin copolymer graft-modified with an unsaturated carboxylic acid or a derivative thereof and 60 to 40% by weight of a polyamide. At
It is disclosed that a resin composition having excellent rigidity, water resistance and weld strength can be obtained by using a relatively high molecular weight modified polyolefin having an MFR of 2.0 g / 10 minutes or less. However, these resin compositions do not exhibit the effect of improving impact resistance, have a high molding shrinkage, have poor dimensional stability in molding, and have problems of insufficient melt fluidity.

Japanese Unexamined Patent Publication No. 3-91560 discloses that 100 parts by weight of a polyamide is mixed with 1 to 10 modified polyolefins.
0 parts by weight and a mixture of a polyamide, a modified polyolefin, and a polypropylene resin comprising 5 to 250 parts by weight of a polypropylene resin, and an organic heat-resistant stabilizer of 0.01 to
3.0 parts by weight and specific carbon black 0.1 to
A polyamide resin composition excellent in heat aging resistance and containing 5.0 parts by weight is disclosed. However, this resin composition has a problem that impact resistance and dimensional stability during molding are not sufficient.

Japanese Patent Application Laid-Open No. 3-109452 discloses that in a molding material composed of polypropylene and polyamide, a polypropylene resin 10
８９89.9 parts by weight, polyamide 10-89.9 parts by weight,
A resin composition comprising 0.1 to 5 parts by weight of an unsaturated carboxylic acid-modified polyolefin, 0 to 30 parts by weight of an impact modifier and 0 to 60 parts by weight of a reinforcing material exhibits excellent toughness, rigidity and heat deformation stability. Is disclosed. However, even in this resin composition, melt fluidity during molding,
Light weight is not enough, leaving a challenge.

JP-A-3-115342 discloses that 94 to 50% by weight of polypropylene and 1 to 50% of modified polyolefin are used.
40% by weight and 5-40% by weight of polyamide,
A polypropylene resin composition having a melt viscosity ratio of polypropylene to polyamide to be used of 1 or more is disclosed. However, although this resin composition has improved heat resistance as compared with polypropylene, the level of improvement in dimensional stability and toughness during molding is not sufficient.

JP-A-3-146552 discloses that 40 to 80% by weight of a polyamide and 1 to 40% of a modified polyolefin are used.
% By weight and a resin composition consisting of 20 to 60% by weight of polypropylene, a shear rate of 350 at the molding temperature.
It is disclosed that by setting the melt viscosity ratio η _PP / η _PA of ⁰ sec ⁻¹ to 0.75 or more, excellent coatability is exhibited. However, even in this resin composition, impact resistance and dimensional stability during molding are not sufficient.

JP-A-3-207735 discloses that poly
From amides, polyolefins and modified polyolefins
Resin composition having a tensile yield strength of 300 kg /
cm ^TwoBy using the above modified polyolefin,
Obtain resin molded products with excellent mechanical properties, especially weld strength
Is disclosed. However, this resin
The composition has a large shrinkage rate due to solidification during molding.
And the dimensional stability and toughness of the molded product are insufficient.

Japanese Patent Publication No. 55-44108 discloses ethylene, carbonyl compounds, α, β-unsaturated carboxylic acids and derivatives thereof, unsaturated epoxides, carboxylic acids and derivatives thereof, acrylates, and aromatic side chains. At least one of a monomer and an unsaturated carbon-carbon monomer.
A multiphase thermoplastic resin composition in which a polymer having at least two residues coexists in particles separated in a polyamide matrix resin is disclosed. However, this composition is excellent in impact resistance and flexural modulus, but insufficient in water absorption, and has not realized both mechanical properties and water absorption dimensional stability.

Japanese Patent Application Laid-Open No. 55-9661 discloses α, β
-0.05 to 1.
A flexible thermoplastic resin composition comprising a 5% by weight grafted modified ethylene copolymer and polyamide in a ratio of 2/3: 1 to 6: 1 is disclosed. However, in this thermoplastic resin composition, although flexibility and impact resistance are improved, rigidity and elongation at break are reduced.

Japanese Patent Application Laid-Open No. 54-123158 discloses a polyolefin resin composition comprising a polyolefin resin containing an unsaturated carboxylic acid-added polyolefin resin, a nitrogen-containing resin and a filler and having excellent mechanical strength, heat resistance and paintability. Is disclosed. However, although this resin composition is improved in bending strength, heat deformation temperature and coatability, it still has problems in rigidity, toughness, light weight and dimensional stability.

Japanese Unexamined Patent Publication (Kokai) No. 59-232135 discloses a polyolefin resin composition comprising a modified polyolefin, a polyamide and a crystalline polyolefin and having an olefin unit content of at least 70% by weight and having excellent dyeability. I have. However, since this polyolefin resin composition is mainly composed of polyolefin, when applied to an injection molded article, although properties such as strength, rigidity and heat resistance are improved, the level of improvement is still sufficient. is not.

JP-A-60-118735 discloses a resin composition comprising a polyamide and a modified polyolefin and having both mechanical properties and low water absorption.
However, in the disclosed resin composition, the balance between rigidity and low water absorption is not always sufficient.

Japanese Patent Application Laid-Open No. 57-8246 discloses a polyamide, a polyolefin having a crystallinity of 40% or more, and an ethylene-α-olefin copolymer having a crystallinity of 35% or less. A resin composition comprising a polyolefin modified with an acid and a derivative thereof is disclosed.
In this resin composition, although the impact resistance and the appearance are improved, the balance between rigidity and low water absorption is not sufficient.

JP-A-59-149940 and JP-A-60-110740 disclose rigidity, impact resistance, gloss and heat resistance obtained by adding polypropylene, polyamide and a modified propylene-α-olefin copolymer. A propylene polymer composition excellent in the above is disclosed. However, since the disclosed resin composition uses polypropylene as a matrix, the rigidity represented by the flexural modulus is considerably lower than that of polyamide.

As described above, a conventionally known polyamide resin composition has a good balance between the mechanical strength, heat resistance and moldability of polyamide and the light weight and low water absorption of polyolefin. Not only that, it has both the properties of these polyamides and the properties of polyolefins, and also has the low warpage during molding, dimensional stability and impact resistance that both resins lack. There is a further need for a thermoplastic resin composition having an excellent balance of properties.

[0027]

SUMMARY OF THE INVENTION The present invention provides a good balance between the mechanical strength, heat resistance and moldability of a polyamide and the light weight and low water absorption of a polyolefin. It is an object of the present invention to provide a thermoplastic resin composition, particularly a polyamide resin composition, having low warpage during molding, dimensional stability and impact resistance.

[0028]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have found that a polyamide resin, a modified ethylene-α having a specific range of a copolymer composition and a specific tensile modulus of elasticity. -It has been found that a resin composition satisfying the above-mentioned object can be obtained by blending an olefin copolymer and an unmodified polyolefin resin in a specific ratio, and has reached the present invention.

That is, the present invention provides a polyamide (A),
In the resin composition comprising the modified polyolefin (B) and the unmodified polyolefin (C), the polyamide (A) is 30 to 80% by weight, and the modified polyolefin (B) is 1 to 30% by weight based on the whole resin composition. , And unmodified polyolefin (C) in an amount of 19 to 69% by weight (provided that
(A), (B) and (C) are 100% by weight in total), and the modified polyolefin (B) is modified with α, β-unsaturated carboxylic acid anhydride at 23 ° C. Is an ethylene-α-olefin copolymer having a pressure of 200 MPa or less, and the unmodified polyolefin (C) is a crystalline polypropylene-based resin.

As described above, the thermoplastic resin composition of the present invention has a good balance between the mechanical strength, heat resistance and moldability of polyamide and the light weight and low water absorbency of polyolefin. A polyamide resin composition, which is insufficient in resin and has both low warpage during molding, dimensional stability and impact resistance.

In the present invention, means for achieving the above object include thermoplastic polyamide and an α, β-unsaturated carboxylic anhydride-modified ethylene-propylene copolymer rubber having the specific tensile modulus. And further, in a resin composition obtained by blending an unmodified crystalline polyolefin at the specific ratio, the polyamide forms a continuous phase (matrix phase), and the modified ethylene-propylene copolymer rubber; Further, the polyolefin component composed of the unmodified crystalline polyolefin is formed by forming a core-shell type composite particle dispersed phase.

Hereinafter, the present invention will be described in detail. As the polyamide (A) used in the resin composition of the present invention, hexamethylene diamine, decamethylene diamine,
Dodecamethylene diamine, 2,2,4- or 2,4
4-trimethylhexamethylenediamine, 1,3- or 1,4-bis (aminomethyl) cyclohexane, bis (p-aminocyclohexylmethane), m- or p-
Diamines such as aliphatic, alicyclic and aromatic such as xylylenediamine and dicarboxylic acids such as adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid, and isophthalic acid Polyamide obtained by polycondensation with an acid, ε-
Examples thereof include polyamides obtained from lactams such as caprolactam and ω-laurolactam, or copolyamides comprising these components, and mixtures of these polyamides and / or copolyamides.

Specifically, nylon 6, nylon 66,
Nylon 46, Nylon 610, Nylon 612, Nylon 9, Nylon 11, Nylon 12, Nylon 6/6
6, nylon 66/610, nylon 6/9, nylon 6/11, nylon 6/12, nylon 6/610, nylon 6/612, nylon 6/66/610, nylon 6/66/12, nylon 6T (T : Terephthalic acid component), nylon 6I (I: isophthalic acid component), nylon 6 / 6T, nylon 6 / 6I, nylon 66 / 6T,
Nylon 66 / 6I and the like. Among these, nylon 6, nylon 66, nylon 11, nylon 1
2, nylon 6/66, nylon 6T, nylon 66 /
Use of 6T or the like is preferred. Particularly preferred are nylon 6, nylon 66, copolymers thereof, and mixtures thereof. The molecular weight of the polyamide used as the component (A) is not particularly limited, but the relative viscosity measured at a polymer concentration of 1 g / dl in a 98% sulfuric acid solution is 1.0 or more, preferably 2 or more. Those having a range of from 0.0 to 4.0 are preferred. If the relative viscosity of the polyamide is less than 2.0, the mechanical strength of the finally obtained polyamide resin composition may be reduced,
If it is less than 10, the mechanical strength of the polyamide resin composition is significantly reduced. On the other hand, if the relative viscosity of the polyamide exceeds 4.0, the melt viscosity of the polyamide resin composition will increase, and the moldability will decrease.

The modified polyolefin used as the component (B) of the resin composition of the present invention is a poly-α-olefin modified with an α, β-unsaturated carboxylic acid or a derivative thereof. An α-olefin copolymer having a tensile modulus of 200 MPa or less, obtained by copolymerizing at least two or more monomers selected,
Modified with an α, β-unsaturated carboxylic acid or a derivative thereof. As the α, β-unsaturated carboxylic acid or derivative thereof used herein, acrylic acid, methacrylic acid, crotonic acid, monobasic carboxylic acid such as isocrotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, etc. Dibasic carboxylic acids and their acid anhydrides or salts. Preferred are acrylic acid, methacrylic acid, maleic anhydride, itaconic anhydride and their zinc salts and sodium salts, and particularly preferred are maleic anhydride and itaconic anhydride.

The content of the α, β-unsaturated carboxylic acid and its derivative in the modified polyolefin (B) is preferably 0.05 to 5% by weight, and 0.1 to 3% by weight.
Is particularly preferred. If the content of the α, β-unsaturated carboxylic acid and its derivative is too lower than the above range, the adhesion between the polyamide and the polyolefin phase is insufficient, and the tissue structure of the obtained resin composition becomes unstable. , Mechanical strength is reduced. Also, if it is higher than the above range,
The resulting resin composition causes a decrease in melt fluidity. As a method for modifying a polyolefin, a polyolefin and the above-mentioned α, β-unsaturated carboxylic acid and a derivative thereof are reacted with a radical initiator (organic peroxide such as hydroperoxide, dialkyl peroxide, peroxyester, etc.) in a molten state or a solution state of the polyolefin. For example, benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, cyclohexanone peroxide, t-butylperoxybenzoate, etc.).

The α-olefin component unit constituting the modified polyolefin (B) of the present invention, that is, the modified ethylene-α-olefin copolymer (B), has an α-olefin having 2 or more carbon atoms, particularly about 2 to 18 carbon atoms. An olefin, ethylene, propylene, 1-butene, 1-hexene, 1-
Decene, 1-pentene and the like can be exemplified, and one or a mixture of two or more of these can be exemplified. The modified polyolefin copolymer used as the component (B) has a copolymer composition before modification of 30 to propylene units.
It is 80 mol%, preferably 40 to 75 mol%, particularly preferably 45 to 75 mol%. When the propylene content is lower than this range, the component (B) and the component (C) described below are used.
The affinity for the resin composition is insufficient, the tissue structure becomes unstable, and the mechanical strength of the obtained resin composition decreases. When the propylene content is higher than this range, the effect of improving the impact resistance is reduced, and the shrinkage at the time of molding and solidification is increased, and the dimensional stability of the molded article of the polyamide resin composition is reduced. In order to reliably suppress the occurrence of these undesired phenomena, the propylene content is preferably in the above-mentioned preferred range, and more preferably in the particularly preferred range.

Furthermore, the component (B) preferably has a probability of three consecutive propylene units of 0.1 to 0.5 in the arrangement of monomer units along the molecular chain. Outside of this range, the tensile strength and impact resistance of the obtained resin composition may not be improved, which is not preferable. The component (B) is suitably flexible at room temperature, and preferably has a tensile modulus at 23 ° C. of 200 MPa or less as measured according to ASTM D638. If the tensile modulus is higher than this, the impact resistance of the obtained resin composition will be low, and the effect of improving the molding shrinkage and the warpage during molding may not be sufficient.

Next, the unmodified polyolefin used as the component (C) of the polyamide resin composition of the present invention is:
It is a crystalline polyolefin, particularly a crystalline polypropylene resin. Furthermore, the component (C) used
Has a flexural modulus at 23 ° C. of 1 GPa or more, preferably 1.5 G, measured according to ASTM D790.
It is preferably Pa or more. Flexural modulus of 1 GPa
If it is less than 1, the rigidity of the obtained resin composition is low, and the object of the present invention cannot be achieved.

As the crystalline polypropylene resin of the component (C), propylene homopolymer is suitable.
The present invention is not limited thereto, and a block or random copolymer of propylene and 20 mol% or less of an α-olefin such as ethylene or 1-butene may be used.
Further, as a standard of the molecular weight of the component (C), AS
Load 2.16k, measured according to TM D1238
g, melt flow rate (MFR) at 230 ° C. is 1 g / 10 min or more, preferably 10 to 100 g / 1.
0 min. More preferably, 10 to 50 g / 10
min is desirable. MFR is 1g / 10mi
If it is smaller than n, the size of the polyolefin dispersed phase in the obtained thermoplastic resin composition becomes large, and the fracture characteristics such as impact resistance become unfavorably low. When the MFR is in the range of 1 to 10 g / 10 min, this undesirable phenomenon tends to occur. Also, MFR
Exceeds 100 g / 10 min, the melt viscosity of component (C) becomes too low compared to the melt viscosity of component (A),
It becomes difficult for the component (A) to form a continuous phase, and the mechanical strength of the obtained resin composition is reduced.
In the range of 50 to 100 g / 10 min, such a tendency can be seen.

In the polyamide resin composition of the present invention, it is necessary that the component (C) is not modified with a polar group or a reactive group. When the component (C) is modified with a residue that reacts with polyamide or a residue having an affinity, in the obtained resin composition, the polyolefin phase does not form a core-shell type dispersion structure, and a polyolefin core-shell described later is used. No advantageous properties of the structure are obtained.

Incidentally, in the resin composition of the present invention, it is essential that the polyamide (A) is used as a matrix phase. Since the polyamide component (A) forms a continuous phase, the properties of the polyamide having excellent heat resistance and mechanical properties can be largely reflected on the properties of the obtained resin composition, and the elastic modulus, heat resistance, and fracture A resin composition having excellent strength can be obtained. Polyamide component (A)
When the compound forms a discontinuous phase, the mechanical properties and heat resistance of the obtained resin composition become low, and the object of the present invention cannot be achieved.

On the other hand, in the resin composition of the present invention, the dispersed phase formed by the components (B) and (C) is
It is necessary to exhibit a composite particle type dispersion structure having a core shell structure. In the core-shell structure, the modified polyolefin component (B) forms a shell phase, and the unmodified polyolefin component, that is, the unmodified polypropylene component (C) forms a core phase, whereby the flexural modulus, tensile and flexural strength, and A resin composition which is excellent in mechanical properties such as impact resistance, low in melt viscosity and excellent in fluidity during molding and satisfies the object of the present invention can be obtained. When both of the polyolefin components used are those modified with a polar group having an affinity for polyamide, each polyolefin is individually dispersed in the polyamide matrix phase to obtain the superiority of the core-shell structure described above. Can not do.

In the resin composition of the present invention, the mixing ratio of the component (A), the component (B) and the component (C) is 30 to 80% by weight of the polyamide (component A) and 1% of the modified polyolefin (component B). -30% by weight, and 19-69% by weight of the unmodified polyolefin (component C) (however,
The sum of the components (A), (B) and (C) is 10
0% by weight). In addition, the compounding ratio of the component (B) is preferably 3 to 20% by weight, and more preferably 5 to 15% by weight. And, a preferable mixing ratio of the component (C) is 19 to 50% by weight.

When the content of the component (A) exceeds 80% by weight, the effect of improving the water absorption of the obtained resin composition is insufficient, and the dimensional change of the molded article due to moisture absorption is undesirably large. On the other hand, if the blending ratio of the component (A) is less than 30% by weight, the continuity of the polyamide phase (component A) is not maintained, and the mechanical properties and the heat resistance are lowered.

If the proportion of the component (B) in the resin composition of the present invention is less than 1% by weight, the compatibility between the polyamide component and the polyolefin component is deteriorated, the impact resistance is reduced, and the shrinkage during molding is reduced. The rate is high and not suitable. When the proportion of the component (B) is more than 30% by weight, the obtained resin composition has a low flexural modulus, and the object of the present invention cannot be satisfied. In order to ensure that these undesirable phenomena do not occur when the mixing ratio of the component (B) in the resin composition is out of the range, the mixing ratio of the component (B) is preferably in the above-mentioned preferable range, It should be in the aforementioned more preferred range.

Component (C) in the resin composition of the present invention,
That is, when the blending ratio of the unmodified polyolefin exceeds 69% by weight, the component (C) forms a continuous phase, and the resin composition having the mechanical properties and heat resistance aimed at by the present invention cannot be obtained. On the other hand, when the compounding ratio of the component (C) is less than 19% by weight, the desired level of low water absorption and bending elastic modulus cannot be obtained in the obtained resin composition. In addition, as in the case of the component (B), the compounding ratio of the component (C) should be within the above-described preferable range in order to surely suppress the occurrence of the above-described undesirable phenomenon.

The method for producing the resin composition of the present invention is not particularly limited, and various known methods can be used. For example, after pre-mixing the components (A), (B) and (C) at the mixing ratio of the present invention as described above at room temperature,
As a temperature at which the melting of each of these components sufficiently proceeds and does not decompose, 220 ° C. or higher, preferably 240 to 300
A method of melting and kneading at a temperature of ° C. can be applied. Pre-mixing includes high-speed rotary mixers and cone blenders such as Henschel mixers used for normal mixing,
It can be performed by using a low-speed rotation mixer such as a tumbler. The melt-kneading can be performed using a conventional melt-kneading machine such as a single-screw or twin-screw extruder, a Banbury mixer, and a kneader.

The polyamide resin composition of the present invention can contain various reinforcing materials and fillers such as fibrous, powdery, flake and matte shapes as long as moldability and physical properties are not impaired. Specific examples of these reinforcing materials and fillers include glass fiber, asbestos fiber, carbon fiber, silica fiber, silica-alumina fiber, alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, basic magnesium sulfate fiber, boron Inorganic and metallic fibers such as fibers, stainless steel fibers, aluminum, titanium, copper, brass, and magnesium; and organic fibers such as polyamide, polyester, polyacrylonitrile, and cellulose; copper, iron, nickel, zinc, tin, lead,
Metal powders such as stainless steel, aluminum, gold, silver, etc., fumed silica, aluminum silicate, glass beads,
Examples include carbon black, quartz powder, talc, titanium oxide, iron oxide, calcium carbonate, magnesium oxide, calcium oxide, magnesium sulfate, and diatomaceous earth. In the case of a fibrous substance, the average fiber diameter is 0.1-30 μm.
m, those having a fiber length / fiber diameter ratio of 10 or more are preferably used. These reinforcing materials and fillers may be surface-treated with a known silane coupling agent or titanate-based coupling agent.

The amount of the reinforcing material and filler used is 1 to 300 parts by weight, preferably 10 to 250 parts by weight, based on 100 parts by weight of the resin composition of the present invention. 1 usage
If the amount is less than part by weight, the effect of adding the reinforcing material and the filler is not recognized, and if the amount exceeds 300 parts by weight, the moldability and mechanical properties of the polyamide resin composition are deteriorated. These reinforcing materials and fillers may be used alone or in combination of two or more.

The polyamide resin composition of the present invention may further contain, if necessary, an antioxidant or a heat stabilizer such as hindered phenol, hydroquinone, thioether, phosphite, amines, their substituted products, and copper compounds.
Resorcinol, salicylate, benzotriazole,
UV absorbers such as benzophenone, stearic acid and its salts, release agents such as stearyl alcohol, inorganic flame retardants such as magnesium hydroxide, calcium hydroxide and hydrotalcite, halogen-based, phosphate-based, melamine or cyanuric acid -Based organic flame retardants, flame retardant aids such as antimony trioxide, antistatic agents such as sodium dodecylbenzenesulfonate, polyalkylene glycol, and other additives such as crystallization accelerators, dyes and pigments.
More than one kind can be added.

Further, the polyamide resin composition of the present invention comprises:
Appropriate amounts of polyethylene, ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / 4-methylene-1-pentene copolymer, ethylene / 1-octene copolymer within a range not to impair the object of the present invention. Copolymer, ethylene / vinyl acetate copolymer, ethylene / vinyl alcohol copolymer, polyvinyl acetate, vinyl compound polymer such as polyvinyl chloride, poly 1-butene, poly 4-methyl-1-
Polyolefins such as pentene, polyamides, polyamide elastomers, polyester elastomers, thermoplastic polyesters such as polyethylene terephthalate, polybutylene terephthalate, thermoplastic resins such as polycarbonate, polysulfone, polyphenylene ether, polyphenylene sulfide, phenolic resins, melamine resins, urea resins, Thermosetting resins such as silicone resins and epoxy resins can be added.

The polyamide resin composition of the present invention comprises a prescribed amount of the above-mentioned additives, which are added as necessary, in addition to the three components (A), (B) and (C). Although it is a resin composition, there is no particular limitation on the order of its blending, and each component may be blended at the same time. Alternatively, the components (A), (B) and (C) may be blended first to form a mixture. After producing the above, other components such as additives may be blended.

The polyamide resin composition of the present invention obtained as described above can be processed into molded articles for various uses by injection molding, compression molding, extrusion molding and the like.

[0054]

The present invention will be described below in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to these examples unless it exceeds the gist. In addition, the measurement of the mechanical property described in each of the following Examples and Comparative Examples was performed according to the following. (1) Tensile properties (tensile strength and tensile modulus): AST
MD638 (2) Flexural modulus: ASTM D790 (3) Load deflection temperature: ASTM D648, load 4.
6 kg / cm ² (4) Izod impact strength: ASTM D256

(5) Melt viscosity Nozzle with nozzle diameter / length = 1/10 (mm / mm)
For use with attached plunger type capillary rheometer
Set temperature 280 ° C, shear rate 240sec ^-1smell
Measured.

(6) Mold Shrinkage Ratio An ASTM No. 1 test piece (1/8 inch thick) was prepared.
The ratio of the difference between the dimension between both ends of the molded test piece in the flow direction and the dimension in the mold in the same direction to the dimension in the mold was determined as a shrinkage (%) in the flow direction.

(7) Warpage at the time of molding A disk test piece having a thickness of 2 mm and a diameter of 100 mm is prepared by injection molding, and the maximum warpage (mm) at both ends of the diameter of the test piece is measured using a three-dimensional measuring machine. did.

(8) Water Absorbency Using a test piece of ASTM No. 4 test piece (1 mm thick),
190% in a thermo-hygrostat at a relative humidity of 90% and a temperature of 40 ° C.
It was allowed to stand for a period of time, and it was determined from the weight after absolute drying (absolutely dry) after molding and the weight after water absorption as the rate of increase in water absorption by the following formula 1.

[0059]

(Equation 1)

The physical properties of the polyamide (component A), modified polyolefin (component B) and unmodified polyolefin (component C) used in each of the following Examples and Comparative Examples were measured according to the following methods. (A) Relative viscosity (ηr) Measured at 25 ° C. in a 98% sulfuric acid solution having a polymer concentration of 1 g / dl according to JIS K6810.

(B) Propylene content From the ¹³ C-NMR spectrum, PPP, PPE, EP
The content of propylene units was calculated from the chain fraction of each triad of E, PEP, EEP, and EEE (where E and P represent ethylene units and propylene units, respectively) and expressed as a molar fraction.

[0062] (c) from three chain fraction ¹³ C-NMR spectrum of the propylene unit in the component B, PPP, PPE, EP
E, PEP, EEP, EEE (E and P indicate ethylene units and propylene units, respectively) The chain fraction of PPP relative to the total amount of chains of each triad was calculated and expressed as a molar fraction.

(D) Maleic anhydride modification amount Calculated from the absorbance ratio of the infrared absorption spectrum at 1785 cm ^-1 and 840 cm ^-1 .

(E) X-ray crystallinity 2θ = 5 to 35 using a pressed sheet having a thickness of 0.5 mm.
In the X-ray diffraction intensity curve in the range of °, a crystal part and an amorphous part were separated by a smooth curve having a peak at 2θ = 16 °, and the area ratio of the crystal part was determined.

(F) Melt flow rate (MFR) Measured at 230 ° C. under a load of 2.16 kg according to ASTM D1238 using a melt indexer.

Examples 1 to 5 Nylon 66 (PA6) was used as the polyamide (component A).
6, ηr = 2.51), and as modified polyolefin (component B), the propylene content shown in Table 1, the chain fraction of three propylene units, the modifying group type and the modifying amount, the X-ray crystallinity, the MFR and Five types of ethylene-propylene copolymer rubbers having tensile modulus (hereinafter abbreviated as "EPR")
Of which, EPR1 (propylene content: 75 mol%, MF
R: 35 g / 10 min, maleic anhydride modification amount: 1.
0 wt%, X-ray crystallinity: 21%, tensile modulus: 120
MPa) and an unmodified polyolefin (component C)
Among the five types of crystalline polypropylene resins (hereinafter abbreviated as “PP”) showing the propylene content, MFR, flexural modulus and maleic anhydride modification shown in Table 2, PP1 (homo-PP, MFR: 30 g / 10 min, Flexural modulus:
1.9 GPa) at a ratio shown in Table 3 and then dry-blending using a tumbler and then melt-kneaded at 280 ° C. using a 30 mmφ twin-screw extruder to obtain a resin composition. Then, the obtained resin composition was dried and injection molded to prepare a test piece for measuring physical properties. Table 3 shows the physical properties of the obtained resin composition.

[0067]

[Table 1]

[0068]

[Table 2]

[0069]

[Table 3]

Example 6 EPR2 shown in Table 1 was used in place of EPR1 as Component B, and the mixing ratio of each component was changed to 70% by weight for Component A, 60% by weight, and for Component B, 1% by weight.
A resin composition having the physical properties shown in Table 4 was obtained in the same manner as in Example 1, except that 15% by weight was used instead of 0% by weight, and 25% by weight was used instead of 20% by weight.

Comparative Examples 1 to 3 In Comparative Examples 1, 2 and 3, EPR1
In place of EPR3, EPR4 and EPR5 shown in Table 1 in place of
Was obtained.

[0072]

[Table 4]

Examples 7 and 8 In Examples 7 and 8, instead of PP1 as the component C, PP2 (homo-PP) and P
A resin composition having the physical properties shown in Table 5 was obtained in the same manner as in Example 6, except that P3 (block PP) was used.

Comparative Examples 4 and 5 In Comparative Examples 4 and 5, except that PP4 (random PP) and PP5 (maleic anhydride-modified PP) shown in Table 2 were used instead of PP1 as the component C, respectively. In the same manner as in Example 6, a resin composition having the physical properties shown in Table 5 was obtained.

[0075]

[Table 5]

Example 9 The proportion of component A was changed to 70% by weight, 50% by weight, the proportion of component B was changed to 10% by weight, and 5% by weight, and the proportion of component C was changed to 20% by weight. A resin composition having the physical properties shown in Table 6 was obtained in the same manner as in Example 1 except that the content was 45% by weight.

Comparative Example 6 Resins having the physical properties shown in Table 6 were prepared in the same manner as in Example 9 except that the blending ratio of Component B was changed to 10% by weight to 50% by weight, and that Component C was not blended. A composition was obtained.

Comparative Example 7 Except that the component B was not blended and that the blending ratio of the component C was changed to 45% by weight to 50% by weight,
In the same manner as in Example 9, a resin composition shown in Table 6 was obtained.

Comparative Example 8 The same procedure as in Example 1 was carried out except that the mixing ratio of the component A was changed to 70% by weight and 25% by weight, and the mixing ratio of the component C was changed to 20% by weight and 65% by weight. Thus, a resin composition having the physical properties shown in Table 6 was obtained.

[0080]

[Table 6]

Examples 10 to 13 and Comparative Examples 9 and 10 As component A, nylon 6 (PA
6, ηr = 2.3), and the mixing ratios of the components A, B and C were changed to 70% by weight, 10% by weight and 20% by weight, respectively. In the same manner as in Example 1, a resin composition was obtained. Table 7 shows the physical properties of the obtained resin composition.

[0082]

[Table 7]

[0083]

According to the present invention, an ethylene-α-olefin copolymer modified with a polyamide, an unsaturated carboxylic acid or a derivative thereof and a crystalline polypropylene-based resin are blended in a specific ratio, and the polyamide-based matrix phase is used. The resin composition of the present invention is a polyamide resin having excellent mechanical properties such as low water absorption, dimensional stability, light weight, rigidity and toughness, and excellent moldability compared to conventionally known polyamide resin compositions. It is a composition and can be used in a wide range of fields such as mechanical parts, automobile parts, and electric / electronic parts. In particular, it is suitably used for electrical parts for automobiles.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-34881 (JP, A) JP-A-7-500860 (JP, A) WO 93/9183 (WO, A1) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08L 77/00 C08L 23/26 C08L 23/10 WPI (DIALOG)

Claims (1)

(57) [Claims] 1. A resin composition comprising a polyamide (A), a modified polyolefin (B) and an unmodified polyolefin (C), the polyamide (A) being 30 to 80% by weight, based on the total resin composition, modified The polyolefin resin (B) comprises 1 to 30% by weight, and the unmodified polyolefin (C) comprises 19 to 69% by weight (however, the total of (A), (B) and (C) is 100% by weight), and polyamide While (A) forms a matrix phase, the modified polyolefin (B) and the unmodified polyolefin (C) are a resin composition exhibiting a dispersed phase having a core-shell type particle structure, and the modified polyolefin (B) is composed of α. Is an ethylene-α-olefin copolymer modified with β-unsaturated carboxylic acid and a derivative thereof and having a tensile modulus at 23 ° C. of 200 MPa or less, A polyamide resin composition wherein the unmodified polyolefin (C) is a crystalline polypropylene resin.