JPH0834881A - Polyamide/polypropylene resin composition - Google Patents

Abstract

PURPOSE:To improve the moldability by compounding a polyamide with a modified polyolefin and an unmodified polyolefin to disperse the polyolefins as core/shell particles into the polyamide as a matrix. CONSTITUTION:A polyamide (A), e.g. nylon 66, is mixed with a polyolefin (B) modified with an alpha,beta-unsaturated carboxylic acid, e.g. maleic acid, or a derivative thereof and having a modulus in flexure (at 23 deg.C) of 1GPa or higher, e.g. a modified crystalline polypropylene resin, and an unmodified polyolefin (C) having a modulus in tension (at 23 deg.C) of 200MPa or lower, e.g., an ethylene/alpha- olefin copolymer, the amounts of the ingredients (A), (B), and (C) being 30-80wt.%, 5-50wt.%, and 5-65wt.%, respectively, based on the total amount thereof. The mixture is melt-kneaded with, e.g. a kneader at about 220 deg.C or higher to obtain the objective composition with excellent moldability in which the ingredient (A) serves as a matrix phase and the ingredients (B) and (C) serve as a dispersed phase having a core/shell particle structure.

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 comprising a polyamide and a polyolefin, which is excellent in low water absorption, dimensional stability, rigidity, toughness and moldability, and more particularly to a polyamide-polypropylene resin composition. The thermoplastic resin composition of the present invention can be used in a wide range of fields such as machine parts, automobile parts, and electric / electronic parts.

[0002]

2. Description of the Related Art Polyamide resins are widely used for electric / electronic parts, automobile parts, etc. because they have a good balance of mechanical properties, heat resistance, chemical resistance and moldability. However, since polyamide resin is hygroscopic, it causes a dimensional change due to moisture absorption and a significant decrease in mechanical properties such as bending strength and elastic modulus, and its range of use is wide for parts that require dimensional accuracy. There are many restrictions, and improvements are desired.

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 price. However, its use range is restricted because heat resistance, strength, and rigidity are insufficient, and the shrinkage rate at the time of molding due to crystallinity is large and the dimensional accuracy of the molded product is poor.

Conventionally, in order to improve the dimensional change due to water absorption of polyamide, 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, or low water absorption. Disclosed is a method of blending the above polymers.
In this case, as a low water-absorbing polymer used for blending, a crystalline resin or rubber made of polypropylene, polyethylene modified by unsaturated carboxylic acid and its derivative, and a copolymer thereof is known.

For example, JP-B-42-12546 discloses a thermoplastic resin having an improved compatibility, which comprises 50 to 99% by weight of polyamide and 50 to 1% by weight of a copolymer of unsaturated carboxylic acid and olefin. Compositions are disclosed.
Although these resin compositions have excellent mechanical properties, in particular, rupture properties, the disclosed resin compositions are insufficient in combination of low water absorption, rigidity and heat resistance.

JP-B-45-30945 discloses a dispersibility comprising an olefin polymer, a polyamide and / or a polyester, and a polyolefin modified with at least one of an acid, an ester, an amide, an acid anhydride and an epoxy group. A method for producing a resin composition suitable for good fibers is disclosed. However, the resin composition obtained is
When applied to injection molded products and extrusion molded products, the shrinkage rate at the time of molding is large, and the dimensional accuracy of the molded products is inferior.
There are problems such as insufficient impact resistance.

JP-A-60-262853 discloses a low water absorption 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 low water absorption is insufficient.

In JP-A-62-223250, a modified polyolefin obtained by kneading a crystalline polyolefin with a polyamide and an unsaturated carboxylic acid derivative is further kneaded with the polyamide and the polyolefin to obtain a low water absorption property. , A resin composition excellent in tensile strength and surface gloss is disclosed. However, this resin composition is in a situation where compatibility of rigidity and impact resistance is insufficient.

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

Japanese Unexamined Patent Publication (Kokai) No. 1-51458 discloses a polyamide resin, an unsaturated carboxylic acid-modified crystalline polypropylene, and an unsaturated carboxylic acid-modified ethylene-α-olefin copolymer, which have a small water absorption dimensional change, rigidity and resistance. A polyamide resin composition having excellent impact properties is disclosed. However, in a composition having many polyamide components, although the mechanical properties are excellent, the improvement of water absorption is insufficient,
It cannot be said that compatibility between low water absorption and mechanical properties has been sufficiently achieved.

Japanese Unexamined Patent Publication (Kokai) No. 64-86652 discloses a polypropylene having a high impact resistance which comprises a partially modified crystalline propylene-ethylene block copolymer, a polyamide and a modified ethylene-α-olefin copolymer rubber. Resin compositions are disclosed. However, these are
Polypropylene is used as a matrix and polyamide is used as the dispersed phase, and although it has improved heat resistance and mechanical properties compared to polypropylene, it has significantly higher rigidity and heat resistance than polyamide. It remains low.

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. MF
It is disclosed that a resin composition having excellent rigidity, water resistance and weld strength can be obtained by using a modified polyolefin having a relatively high molecular weight of R of 2.0 g / 10 minutes or less. However, this resin composition does not show the effect of improving impact resistance, has a high molding shrinkage ratio, is poor in dimensional stability in molding, and has a problem that melt flowability is insufficient.

JP-A-3-91560 discloses that modified polyolefins 1 to 10 are added to 100 parts by weight of polyamide.
Organic heat-resistant stabilizer 0.01 to 0.01 parts by weight based on a mixture of 0 parts by weight and polypropylene resin 5 to 250 parts by weight of polyamide, modified polyolefin and polypropylene resin.
3.0 parts by weight and specific carbon black 0.1 to
A polyamide resin composition containing 5.0 parts by weight and excellent in heat aging resistance is disclosed. However, this resin composition still has a problem that impact resistance and dimensional stability during molding are not sufficient.

Japanese Unexamined Patent Publication (Kokai) No. 3-109452 discloses a molding material composed of polypropylene and polyamide, wherein a polypropylene resin 10 is added to 100 parts by weight of the molding material.
~ 89.9 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 thermal deformation stability. Is disclosed. However, even in this resin composition, melt fluidity at the time of molding,
Lightness is not enough, leaving a problem.

Japanese Unexamined Patent Publication (Kokai) No. 3-115342 discloses that polypropylene 94 to 50% by weight, modified polyolefin 1 to
40% by weight and 5-40% by weight polyamide,
A polypropylene resin composition is disclosed in which the melt viscosity ratio of polypropylene to the polyamide used is 1 or more. However, although this resin composition has improved heat resistance as compared with polypropylene, the level of improvement in dimensional stability during molding and toughness is not sufficient.

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

Japanese Unexamined Patent Publication (Kokai) No. 3-207735 discloses that poly
From amides, polyolefins and modified polyolefins
In the resin composition, the tensile yield strength is 300 kg /
cm ²By using the above modified polyolefin,
A resin molded product with excellent mechanical properties, especially weld strength, is obtained.
Is disclosed. However, this resin
The composition has a large shrinkage rate due to solidification during molding.
In addition, the dimensional stability and toughness of the molded product are insufficient.

Japanese Patent Publication No. 55-44108 has ethylene, carbonyl compounds, α, β-unsaturated carboxylic acids and their derivatives, unsaturated epoxides, carboxylic acids and their derivatives, acrylic acid esters, and aromatic side chains. At least one of a monomer and an unsaturated carbon-carbon monomer
A multiphase thermoplastic resin composition is disclosed in which a polymer having one or more residues coexists in separate particles in a polyamide matrix resin. However, while this composition is excellent in impact resistance and flexural modulus, it is insufficient in low water absorption, and has not achieved both mechanical properties and water absorption dimensional stability.

JP-A-55-9661 discloses that α, β
-Unsaturated carboxylic acid or its derivative 0.05-1.
A flexible thermoplastic resin composition comprising a modified ethylene copolymer grafted with 5% by weight and a polyamide in a ratio of 2/3: 1 to 6: 1 is disclosed. However, in this thermoplastic resin composition, although the flexibility and impact resistance are improved, the rigidity and the elongation at break are reduced.

Japanese Unexamined Patent Publication (Kokai) No. 54-123158 discloses a polyolefin resin composition which comprises a polyolefin resin containing an unsaturated carboxylic acid-added polyolefin resin, a nitrogen-containing resin and a filler and which is excellent in mechanical strength, heat resistance and paintability. The thing is disclosed. However, although this resin composition is improved in bending strength, heat distortion temperature and coatability, it still has problems in combining rigidity, toughness, lightness 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 70% by weight or more and having excellent dyeability. There is. However, since this polyolefin resin composition is mainly composed of polyolefin, when it is applied to an injection-molded article, the properties such as strength, rigidity and heat resistance are improved as compared with the polyolefin, but the improvement level is However, there is still a problem that it is not enough.

Japanese Unexamined Patent Publication (Kokai) No. 60-118735 discloses a resin composition composed of a polyamide and a modified polyolefin and having both mechanical properties and low water absorption.
However, the disclosed resin composition does not always have sufficient balance between rigidity and low water absorption.

JP-A-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 as an α, β-unsaturated carvone. A resin composition comprising a polyolefin modified with an acid and its derivative is disclosed.
Although this resin composition has improved impact resistance and appearance, 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 modified propylene-α-olefin copolymer. A superior propylene polymer composition is disclosed. However, since the disclosed resin composition uses polypropylene as a matrix, the rigidity indicated by the flexural modulus is much lower than that of polyamide.

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

[0026]

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

[0027]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above object, and as a result, have found that a polyamide resin, a modified polyolefin resin having a specific flexural modulus, and a specific range It has been found that a resin composition satisfying the above-mentioned object can be obtained by blending the copolymer composition of (1) and an unmodified poly α-olefin copolymer having a specific tensile modulus at a specific ratio, and The invention was reached.

That is, the present invention relates to polyamide (A),
In a resin composition comprising a modified polyolefin (B) and an unmodified polyolefin (C), the polyamide (A) is 30 to 80% by weight and the modified polyolefin (B) is 5 to 50% by weight based on the entire resin composition. , And 5 to 65% by weight of the unmodified polyolefin (C) (however,
The total amount of (A), (B) and (C) is 100% by weight), and the modified polyolefin (B) is modified with α, β-unsaturated carboxylic acid anhydride and its derivative.
A crystalline polypropylene resin having a flexural modulus of 1 GPa or more at 0 ° C., and the unmodified polyolefin (C) is an ethylene-α-olefin copolymer having a tensile modulus of 20 MPa or less at 23 ° C. It is a thermoplastic resin composition.

As described above, the thermoplastic resin composition of the present invention has a good balance of the mechanical strength, heat resistance and moldability of polyamide, and the light weight and low water absorption of polyolefin. It is a polyamide-polypropylene resin composition having low warpage during molding, dimensional stability, and impact resistance, which are lacking in resin.

Therefore, in the present invention, as means for achieving the above object, crystals modified with a thermoplastic polyamide and an α, β-unsaturated carboxylic acid anhydride and a derivative thereof having the above-mentioned specific flexural modulus. In a resin composition obtained by blending a water-soluble polypropylene-based resin and an unmodified ethylene-α-olefin copolymer rubber in the above-mentioned specific ratio, the polyamide being a continuous phase (matrix phase), This is because the polyolefin component composed of the modified crystalline polypropylene resin and the unmodified crystalline ethylene-α-olefin copolymer rubber forms a core-shell type composite particle dispersed phase.

The present invention will be described in detail below. Examples of the polyamide (A) used in the resin composition of the present invention include hexamethylenediamine, decamethylenediamine,
Dodecamethylenediamine, 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, isophthalic acid, etc. Polyamide obtained by polycondensation with acid, ε-
Examples thereof include polyamides obtained from lactams such as caprolactam and ω-laurolactam, copolymerized polyamides containing these components, and mixtures of these polyamides and / or copolymerized polyamides.

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 6/66/612, nylon 6T (T : Terephthalic acid component), nylon 6I (I: isophthalic acid component), nylon 6 / 6T, nylon 6 / 6I, nylon 66/6
T, nylon 66 / 6I and the like. Of these, nylon 6, nylon 66, nylon 11, nylon 12, nylon 6/66, nylon 6T, nylon 6 are considered in terms of moldability, balance of mechanical properties, and cost.
The use of 6 / 6T or the like is preferable. 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 It is preferably from 0.0 to 4.0. If the relative viscosity of the polyamide is less than 2.0, the mechanical strength of the finally obtained polyamide resin composition may decrease.
If it is less than 1.0, the mechanical strength of this polyamide resin composition is significantly reduced. Further, when the relative viscosity of the polyamide exceeds 4.0, the melt viscosity of the polyamide-polypropylene resin composition becomes high, resulting in deterioration of moldability.

The modified polyolefin used as the component (B) of the resin composition of the present invention is a crystalline polyolefin modified with α, β-unsaturated carboxylic acid or its derivative, and has a flexural modulus of 1 GPa or more as described later. Is a crystalline polypropylene resin modified with α, β-unsaturated carboxylic acid or its derivative. Examples of the α, β-unsaturated carboxylic acid or its derivative used herein include monobasic carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid and isocrotonic acid, maleic acid,
Dibasic carboxylic acids such as fumaric acid, itaconic acid and citraconic acid, and acid anhydrides or salts thereof. Acrylic acid, methacrylic acid, maleic anhydride, itaconic anhydride and their zinc salts and sodium salts are preferable, and maleic anhydride and itaconic anhydride are particularly preferable.

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 preferable. When the content of the α, β-unsaturated carboxylic acid and its derivative is lower than the above range, the adhesion between the polyamide and the polyolefin phase is insufficient and the resulting resin composition has an unstable structure structure. , The mechanical strength becomes low. If it is higher than the above range,
In the obtained resin composition, the melt fluidity is deteriorated. As a method for modifying a polyolefin, the polyolefin and the above α, β-unsaturated carboxylic acid and its derivative are mixed with a radical initiator (hydroperoxide, dialkyl peroxide, peroxy ester or other organic peroxide) in a molten state or a solution state of the polyolefin. Etc., for example, benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, cyclohexanone peroxide, t-butylperoxybenzoate, etc.) and the method of stirring under heating.

The unmodified polyolefin constituting the modified polyolefin (B) of the present invention is a crystalline polyolefin, and particularly a crystalline polypropylene resin. As the crystalline polypropylene resin, a propylene homopolymer and a block or random copolymer of propylene and 20 mol% or less of α-olefin such as ethylene or 1-butene can be used. Among these, propylene homopolymer is preferable because it has a high elastic modulus. Further, as a measure of the molecular weight of the above component (B), it is measured according to ASTM D1238,
A load of 2.16 kg, a melt flow rate at 230 ° C. (hereinafter abbreviated as “MFR”) of 1 g / 10 min or more,
It is preferably 10 to 200 g / 10 min. More preferably, the amount is 10 to 100 g / 10 min. If the MFR is less than 1g / 10min,
This is not preferable because the size of the polyolefin dispersed phase in the obtained thermoplastic resin composition becomes large and the fracture properties such as impact resistance become low. In addition, MFR is 1-10
In the range of g / 10 min, this unfavorable phenomenon tends to occur. In addition, MFR is 200g / 10mi
When it exceeds n, the melt viscosity of the component (B) becomes too low as compared with the melt viscosity of the component (A), and it becomes difficult for the component (A) to form a continuous phase. Will decrease the mechanical strength, 100-200 g /
In the range of 10 min, the tendency becomes visible.

In addition, the component (B) used, AS
The flexural modulus at 23 ° C. measured according to TM D790 is preferably 1 GPa or more, particularly preferably 1.5 GPa or more. If the flexural modulus is less than 1 GPa,
The resulting resin composition has low rigidity, and the object of the present invention cannot be achieved.

Next, the unmodified polyolefin copolymer used as the component (C) of the polyamide-polypropylene resin composition of the present invention is a poly α-olefin copolymer and is selected from α-olefins described later. Obtained by copolymerizing at least two kinds of monomers,
The α-olefin copolymer has a tensile elastic modulus at 23 ° C. of 200 MPa or less measured according to 638. The α-olefin component unit constituting the unmodified polyolefin copolymer used as the component (C) is an α-olefin having 2 or more carbon atoms, particularly 2 to 18 carbon atoms, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1
-Decene and the like can be exemplified, and these are one kind or a mixture of two or more kinds. Of these olefin monomer units, ethylene is an essential unit, and propylene and 1-butene are preferably used as its copolymerization monomer unit. The copolymer composition of the unmodified polyolefin copolymer used as the component (C) has an ethylene unit content of 30 to 85 mol%, preferably 45 to 85 mol%. If the ethylene content is below this range,
The affinity between the component (B) and the above-mentioned component (C) is insufficient, the tissue structure becomes unstable, and the mechanical strength of the obtained resin composition becomes low. When the ethylene content is higher than this range, the effect of improving the impact resistance becomes small, the shrinkage at the time of molding and solidification becomes large, and the dimensional stability of the molded product of the polyamide resin composition becomes low. In addition, in order to surely suppress the occurrence of these unfavorable phenomena, it is preferable that the ethylene content be within the above-mentioned preferable range.

Further, the component (C) preferably has a probability of 0.5 or less of the presence of three consecutive α-olefin units other than ethylene in the arrangement of the monomer units along the molecular chain. If it deviates from this range, the tensile strength and impact resistance of the obtained resin composition may not be improved, which is not preferable. Further, as the component (C), one that is flexible at room temperature is suitable, and has a tensile elastic modulus of 200 M at 23 ° C. measured according to ASTM D638.
It is preferably Pa or less. If the tensile modulus is higher than this range, the resulting resin composition may have low impact resistance and the effect of improving molding shrinkage and warpage during molding may not be sufficient.

Furthermore, as a measure of the molecular weight of the above-mentioned component (C), the MFR at 230 ° C. under a load of 2.16 kg measured according to ASTM D1238 is 0.
5g / 10min or more, preferably 2-60g / 10m
in. If the MFR is less than 0.5 g / 10 min, the size of the polyolefin dispersed phase in the obtained thermoplastic resin composition will be large, and the fracture characteristics such as impact resistance will be unfavorable. In addition, when the MFR is in the range of 0.5 to 2 g / 10 min, this undesirable phenomenon tends to occur. Also, MFR is 60g /
If it exceeds 10 min, the melt viscosity of the component (C) becomes too low as compared with the melt viscosity of the component (A), and it becomes difficult for the component (A) to form a continuous phase. It will reduce the mechanical strength.

In the polyamide-polypropylene resin composition of the present invention, it is also 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 that has an affinity, in the resulting resin composition, the polyolefin phase does not form a core-shell type dispersed structure, and the polyolefin core-shell described below is formed. No advantageous properties of the structure are obtained.

In the resin composition of the present invention, it is essential that the polyamide (A) is used as the matrix phase. By forming a continuous phase with the polyamide component (A), the excellent properties of the polyamide in terms of heat resistance and mechanical properties can be largely reflected in the properties of the resin composition obtained, and the elastic modulus, heat resistance and fracture properties can be improved. A resin composition having excellent strength can be obtained. Polyamide component (A)
If a discontinuous phase is formed, the resin composition obtained has poor mechanical properties and heat resistance, 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 above-mentioned 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 (C) forms a core phase, whereby mechanical properties such as flexural modulus, tensile and flexural strength, and impact resistance are obtained. It is possible to obtain a resin composition having excellent properties, low melt viscosity, and excellent fluidity during molding, which satisfies the object of the present invention. When both polyolefin components modified with polar groups having an affinity for polyamide are used, each polyolefin is dispersed individually in the polyamide matrix phase to obtain the above-mentioned superiority of the core-shell structure. I can't.

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 5 of the modified polyolefin (component B). ˜50 wt%, and 5 to 65 wt% unmodified polyolefin (component C) (however, the total of the component (A), the component (B) and the component (C) is 100 wt%). The blending ratio of the component (B) is preferably 10 to 45% by weight. And as a preferable compounding ratio of the said component (C), it is 10-40 weight%.
Is.

When the amount 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 product due to moisture absorption becomes large, which is not preferable. On the other hand, if the mixing ratio of the component (A) is less than 30% by weight, the continuity of the polyamide phase (component A) cannot be maintained, resulting in deterioration of mechanical properties and heat resistance, which is not preferable.

Further, when the blending ratio of the component (B) in the resin composition of the present invention is less than 5% by weight, the compatibility of the polyamide component and the polyolefin component is deteriorated, and the desired level is obtained in the obtained resin composition. It is not possible to obtain low water absorption and flexural modulus. Further, if the blending ratio of the component (B) exceeds 50% by weight, a resin composition having the mechanical properties and heat resistance targeted by the present invention cannot be obtained. In order to prevent the occurrence of the above-mentioned unfavorable phenomenon when the compounding ratio of the component (B) in the resin composition is out of the range, the compounding ratio of the component (B) falls within the above-mentioned preferred range. Should.

Component (C) in the resin composition of the present invention,
That is, when the blending ratio of the unmodified polyolefin exceeds 65% by weight, the component (C) forms a continuous phase and the flexural modulus becomes low, so that the object of the present invention cannot be satisfied. On the other hand, if the blending ratio of the component (C) is less than 5% by weight, the impact resistance becomes low and the shrinkage rate at the time of molding becomes large, which is not suitable. It should be noted that the mixing ratio of the component (C) should be within the above-mentioned preferable range in order to surely suppress the occurrence of the above-mentioned unfavorable phenomenon, as in the case of the component (B).

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) in the mixing ratio of the present invention as described above at room temperature,
The temperature at which the melting of each of these components is sufficiently advanced and does not decompose is 220 ° C. or higher, preferably 240 to 300.
A method of melt-kneading can be applied at a temperature of ° C. Pre-mixing is a high speed rotary mixer and cone blender such as a Henschel mixer used for normal mixing,
It can be performed by using a low speed rotating mixer such as a tumbler. Further, the melt-kneading can be performed using a normal melt-kneading processing machine such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader.

The polyamide-polypropylene resin composition of the present invention may be added with various types of reinforcing agents and fillers in various shapes such as fibrous, powdery, flake-like or matte-like form within a range not impairing moldability and physical properties. You can 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 fiber, stainless fiber, aluminum, titanium,
Inorganic and metal fibers such as copper, brass and magnesium, and organic fibers such as polyamide, polyester, polyacrylonitrile and cellulose, metal powders such as copper, iron, nickel, zinc, tin, lead, stainless steel, aluminum, gold and silver, Examples include fumed silica, aluminum silicate, glass beads, 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, those having an average fiber diameter of 0.1 to 30 μm and a fiber length / fiber diameter ratio of 10 or more are preferably used. These reinforcing materials and fillers may be surface-treated with known silane coupling agents or titanate coupling agents.

The amount of the reinforcing material and the 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 parts by weight, the effect of adding the reinforcing material and the filler is not recognized, and if it exceeds 300 parts by weight, the moldability and mechanical properties of the polyamide-polypropylene resin composition are deteriorated. Absent. These reinforcing materials and fillers may be used alone or in combination of two or more.

Furthermore, if necessary, the polyamide-polypropylene resin composition of the present invention may contain a hindered phenol, hydroquinone, thioether, phosphite,
Antioxidants and heat stabilizers such as amines and their substitution products and copper compounds, UV absorbers such as resorcinol, salicylate, benzotriazole and 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 ester-based, melamine or cyanuric acid-based organic flame retardants, It is possible to add one or more flame retardant aids such as antimony oxide, antistatic agents such as sodium dodecylbenzene sulfonate, polyalkylene glycols, and other additives such as crystallization accelerators, dyes and pigments.

Further, the polyamide-polypropylene resin composition of the present invention is within the range not impairing the object of the present invention.
Proper amount of polyethylene, ethylene-propylene copolymer,
Ethylene / 1-butene copolymer, ethylene-4-methylene-1-pentene copolymer, ethylene / 1-octene copolymer, ethylene / vinyl acetate copolymer, ethylene / vinyl alcohol copolymer, polyvinyl acetate , Vinyl compound polymer such as polyvinyl chloride, polyolefin such as poly 1-butene, poly 4-methyl-1-pentene, polyamide, polyamide elastomer, polyester elastomer, polyethylene terephthalate, thermoplastic polyester such as polybutylene terephthalate, polycarbonate, Thermoplastic resins such as polysulfone, polyphenylene ether and polyphenylene sulfide, and thermosetting resins such as phenol resin, melamine resin, urea resin, silicone resin and epoxy resin can be added.

The polyamide-polypropylene resin composition of the present invention contains, in addition to the above-mentioned three components (A), (B) and (C), a predetermined amount of the above-mentioned additive which is optionally added. However, the order of compounding is not particularly limited, and each component may be compounded at the same time, and the components (A), (B) and (C) are first compounded. After the mixture is produced by the above process, other components such as additives may be added.

The polyamide-polypropylene 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]

EXAMPLES The present invention will be described in more detail based on the following examples and comparative examples. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded. The mechanical properties described in each of the following Examples and Comparative Examples were measured according to the following. (1) Tensile properties (tensile strength and tensile modulus): AST
M D638 (2) Flexural modulus: ASTM D790 (3) Deflection temperature under load: ASTM D648, load 4.
6kg / cm ² (4) Izod impact strength: ASTM D256

(5) Melt viscosity A nozzle having a nozzle diameter / length = 1/10 (mm / mm) is used.
Use the attached plunger-type capillary rheometer
Setting temperature 280 ° C, shear rate 240 sec ^-1smell
Measured.

(6) Molding Shrinkage ASTM No. 1 test piece (thickness 1/8 inch) 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 the shrinkage rate (%) in the flow direction.

(7) Warpage during molding A disc test piece having a thickness of 2 mm and a diameter of 100 mm was produced by injection molding, and the maximum warp amount (mm) at both ends of the diameter of the test piece was measured using a three-dimensional measuring machine. did.

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

[0059]

[Equation 1]

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

(B) Polyolefin copolymer composition From ¹³ C-NMR spectrum, ethylene, propylene,
The content of ethylene units was calculated from the chain fraction of three monomer units consisting of 1-butene, and expressed as a mole fraction.

(C) From the chain fraction ¹³ C-NMR spectrum of three olefin units other than ethylene in component C, PPP or B for the total amount of triad chains of α-olefin comonomer is obtained.
The chain fraction of BB (wherein P represents a propylene unit and B represents a 1-butene unit) was calculated and expressed as a mole fraction.

(D) Maleic anhydride modification amount It was calculated from the absorbance ratio of infrared absorption spectra at 1785 cm ^-1 and 840 cm ^-1 .

(E) X-ray crystallinity Using a press sheet having a thickness of 0.5 mm, 2θ = 5 to 35
In the X-ray diffraction intensity curve in the range of °, a smooth curve having a peak at 2θ = 16 ° is used to separate the crystalline part and the amorphous part, the ratio of the area of the crystalline part is determined, and this is X-ray crystallized. I took it.

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

Examples 1 to 5 As a polyamide (component A), nylon 66 (PA6)
6 and ηr = 2.51), and as modified polyolefin (component B), five types of modified crystalline polypropylene systems having the propylene content, MFR, modifying group species and modification amount, and flexural modulus shown in Table 1. Resin (hereinafter "PP"
Abbreviated), PP1 (maleic anhydride modified homo P
P, MFR: 30 g / 10 min, maleic anhydride modification amount: 0.2 wt%, flexural modulus: 1.9 GPa) and ethylene content shown in Table 2 as an unmodified polyolefin (component C), three propylene units Of 5 kinds of ethylene-α-olefin copolymer rubbers (hereinafter abbreviated as “EPR”) having chain fraction, X-ray crystallinity, MFR, tensile elastic modulus, modifying group species and modifying amount of EPR1 ( Ethylene content: 82 mol%, that is, propylene content: 18 mol%, MFR: 9 g / 10 min, tensile elastic modulus: 10 M
Pa) and each of the ratios shown in Table 3 were dry blended 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.

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[Table 1]

[0068]

[Table 2]

[0069]

[Table 3]

Examples 6 and 7 Instead of PP1 as the component B, PP2 (homo PP) and P shown in Table 1 were obtained in Examples 6 and 7, respectively.
P3 (block PP) was used, and the blending ratio of each component was set to 7 for component A in both Examples 6 and 7.
55% by weight for 0% by weight, 30% by weight for 20% by weight for component B, 10% by weight for C
Was changed to 15% by weight, and a resin composition having the physical properties shown in Table 4 was obtained in the same manner as in Example 1.

Comparative Examples 1 and 2 In Comparative Examples 1 and 2, PP4 (random PP) and PP5 (homo PP) shown in Table 1 were used instead of PP1 as the component B, respectively. A resin composition having the physical properties shown in Table 4 was obtained in the same manner as in 6.

[0072]

[Table 4]

Examples 8 to 10 EPR as component C in Examples 8, 9 and 10
1 instead of EPR2 and EPR3 shown in Table 2, respectively.
And using EPR4, and component A, component B
And that the composition ratio of Component C is shown in Table 5,
A resin composition having the physical properties shown in Table 5 was obtained in the same manner as in Example 1.

Comparative Example 3 A resin composition having the physical properties shown in Table 5 was obtained in the same manner as in Example 8 except that maleic anhydride-modified EPR (EPR5) shown in Table 2 was used as the component C instead of EPR2. It was

[0075]

[Table 5]

Example 11 The blending ratio of component A was changed to 70% by weight, 55% by weight, the blending ratio of component B was changed to 20% by weight, 40% by weight, and the blending ratio of component C was changed to 10% by weight. Was obtained in the same manner as in Example 1 except that the resin composition having the physical properties shown in Table 6 was obtained.

Comparative Example 4 Table 6 is the same as Example 11 except that the component B was not compounded and the compounding ratio of the component C was changed to 5% by weight to 45% by weight. A resin composition was obtained.

Comparative Example 5 Resin having the physical properties shown in Table 6 was obtained in the same manner as in Example 11 except that the blending ratio of the component B was changed to 40% by weight to 45% by weight and the component C was not blended. A composition was obtained.

Comparative Example 6 The same as Example 1 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 B was changed to 20% by weight and 65% by weight. A resin composition having the physical properties shown in Table 6 was obtained.

[0080]

[Table 6]

Examples 12 to 15 and Comparative Examples 7 and 8 As Component A, instead of nylon 66, nylon 6 (PA
6, ηr = 2.3) was used, and the mixing ratios of Component A, Component B, and Component C were changed to 70% by weight, 20% by weight, and 10% by weight, and the mixing ratios shown in Table 7 were obtained, respectively. A resin composition was obtained in the same manner as in Example 1. Table 7 shows the physical properties of the obtained resin composition.

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[Table 7]

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EFFECT OF THE INVENTION A crystalline polypropylene resin modified with polyamide, an unsaturated carboxylic acid and its derivative and an unmodified ethylene-α-olefin copolymer are blended in a specific ratio, and the polyamide is used as a matrix phase. The resin composition of the present invention is excellent in mechanical properties such as low water absorption, dimensional stability, lightness, rigidity and toughness as compared with conventionally known polyamide resin compositions, and is excellent in molding processability. A polyamide-polypropylene resin composition,
It can be used in a wide range of fields such as mechanical parts, automobile parts, and electric / electronic parts. Particularly, it is preferably used for electric parts for automobiles.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yutaka Matsutomi 3-10 Nakamiyakitamachi, Hirakata-shi, Osaka Ube Industries Ltd. Hirakata Laboratory

Claims (1)

[Claims] 1. A resin composition comprising a polyamide (A), a modified polyolefin (B) and an unmodified polyolefin (C), wherein 30 to 80% by weight of the polyamide (A) is modified with respect to the entire resin composition. The polyolefin resin (B) is 5 to 50% by weight, and the unmodified polyolefin (C) is 5 to 65% by weight (however, the total of (A), (B) and (C) is 100% by weight). (A) forms a matrix phase, while the modified polyolefin (B) and the unmodified polyolefin (C) are resin compositions exhibiting a dispersed phase having a core-shell type particle structure, and the modified polyolefin (B) is α , A crystalline polypropylene resin modified with a β-unsaturated carboxylic acid and its derivative and having a flexural modulus at 23 ° C. of 1 GPa or more, and Sex polyolefin (C) is a tensile modulus at 23 ° C. is not more than 200 MPa,
A polyamide-polypropylene resin composition, which is an ethylene-α-olefin copolymer.