JPH04275367A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition having a high stiffness and a high heat resistance and suitable for hollow molding by mixing a specified polyamide resin with a polyolefin resin and blending a reinforcing material such as glass fiber with the resultant polymer alloy. CONSTITUTION:With (A) 90-55wt.% polyamide resin having >=2.7 relative viscosity of 1g/dl concentration in 98wt.% sulfuric acid at 25 deg.C, (B) 10-45wt.% polyolefin resin composed of 2-98wt.% modified polyolefin having a functional group selected from carboxylic acid (metal salt), carboxylic acid ester, carboxylic anhydride and epoxy and 98-2wt.% polypropylene resin having <=5.0g/10min MFR is mixed and (C) 5-30 pts.wt. reinforcing material, e.g. glass fiber and/or mica is then blended with 100 pts.wt. above-obtained polymer blend, thus giving the objective composition having >=5.0 melt strength.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a polyamide resin suitable for blow molding, and more specifically, the present invention relates to a polyamide resin suitable for blow molding, and more specifically, a polymer alloy composition containing polyamide resin as the main component (matrix component) and polyolefin resin as the main component (matrix component) is mixed with glass fibers. The present invention relates to a polyamide resin composition containing a reinforcing material or a mica reinforcing material.

0002

[Prior Art] Currently, high-density polyethylene and polypropylene are commonly used as synthetic resins for blow molding, but these resins lack rigidity and heat resistance, so these properties cannot be improved. For improvement, methods of adding glass fiber reinforcement or mica reinforcement are being considered. However, in molded products used in parts where the environmental temperature rises considerably, such as parts in the engine room of a car, there is still a problem that the mere addition of reinforcing materials still lacks rigidity and heat resistance. On the other hand, polyamide resins such as nylon 6 and nylon 66 originally have excellent heat resistance, but even when glass fiber reinforcement or mica reinforcement is added, their viscosity (tension) during melting is low, and they cannot be formed by blow molding. was not suitable for

0003

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to obtain a resin composition that has high rigidity and heat resistance, and also has good moldability during blow molding.

0004

[Means for Solving the Problems] The problem is that the relative viscosity of a concentration of 1 g/dl in 98% sulfuric acid at 25°C is 2.
A modified polyamide resin (A) containing 90 to 55% by weight of polyamide resin (A) having a molecular weight of 7 or more and at least one functional group selected from a carboxylic acid group, a carboxylic acid metal base, a carboxylic acid ester group, an acid anhydride group, and an epoxy group. Polyolefin (B
1) 100% by weight of a blend polymer (A+B) consisting of 10 to 45% by weight of a polyolefin resin (B) consisting of 2 to 98% by weight and 98 to 2% by weight of a polypropylene resin (B2) with an MFR of 5.0 g/10 minutes or less The glass fiber reinforcement material and/or the mica reinforcement material (C) are added to the
The problem can be solved by a resin composition containing 30 parts by weight and having a tension of 5.0 g or more when melted.

The present invention will be explained in detail below. The polyamide resin composition of the present invention basically consists of polyamide resin (
It is made by adding a glass fiber reinforcing material or a mica reinforcing material (C) to a resin component that is a blend of A) and a polyolefin resin (B).

The blending ratio of the polyamide resin as component (A) is determined so as to form a sea structure (matrix phase or continuous phase) in the molded article obtained from the present polyamide resin composition. That is, in order to prevent the heat resistance of the composition from decreasing due to mixing of the polyolefin resin as the component (B), the mixing ratio of the polyamide resin (A) and the polyolefin resin (B) is limited, and the The structure mainly has an ocean structure, and the component (B) has an island structure.

Various types of polyamide resins (A) can be used, but specifically polylactams such as nylon 6, nylon 11, and nylon 12: nylon 66, nylon 610, nylon 612, and nylon 4
Polyamides obtained from dicarboxylic acids such as 6 and diamine: nylon 6/66, nylon 6/610, nylon 6/612, nylon 6/12, nylon 6/66/
Copolymer polyamides such as 610: Nylon 6/6T (
T: terephthalic acid component), semi-aromatic polyamides obtained from an aromatic dicarboxylic acid such as isophthalic acid and metaxylene diamine or alicyclic diamine: polyesteramide, polyetheramide and polyesteretheramide, The above various polyamides may be used alone, or two or more types of polyamides may be used in combination.

Furthermore, the polyamide resin (A) that can be used in the present invention is not limited by the type, concentration, molecular weight, etc. of the terminal group of these polyamides, as long as it is selected from the above polyamides. However, due to the moldability of blow molding, 2
It is necessary to select one having a relative viscosity of 2.7 or more, preferably 3.0 or more at a concentration of 1 g/dl in 98% sulfuric acid at 5°C.

Next, the polyolefin resin (B) of the present invention
consists of a modified polyolefin (B1) and a polypropylene resin (B2);
) 2 to 98% by weight, preferably 3 to 90% by weight, and polypropylene resin (B2) 98 to 2% by weight, preferably 97 to 10% by weight. In this polyolefin resin (B), if the modified polyolefin (B1) is too small, there is a problem that the durability of mechanical properties cannot be improved, and if the modified polyolefin (B1) is too large, the cost will be high. A problem arises.

The modified polyolefin (B1) in component (B) contains carboxylic acid groups (acetic acid group, acrylic acid group, methacrylic acid group, fumaric acid group, itaconic acid group, etc.),
Carboxylic acid metal bases (sodium salts, calcium salts, magnesium salts, zinc salts, etc.), carboxylic acid ester groups (
A polyolefin having at least one functional group selected from a methyl ester group, an ethyl ester group, a propyl ester group, a butyl ester group, a vinyl ester group, etc.), an acid anhydride group (such as a maleic anhydride group), and an epoxy group. . Examples of the polyolefin include polyethylene, polypropylene, polybutene, ethylene/propylene copolymer, ethylene/butene copolymer, ethylene/hexene copolymer, and copolymers containing a small amount of diene. can.

Such modified polyolefin (B1)
Specific examples include ethylene/acrylic acid copolymer, ethylene/methacrylic acid copolymer, ethylene/fumaric acid copolymer, ethylene/methacrylic acid/zinc methacrylate copolymer, ethylene/acrylic acid/sodium methacrylate. copolymer, ethylene/isobutyl acrylate/methacrylic acid/zinc methacrylate copolymer, ethylene/methyl methacrylate/magnesium methacrylate copolymer, ethylene/ethyl acrylate copolymer, ethylene/vinyl acetate copolymer, Ethylene/glycidyl methacrylate copolymer, ethylene/vinyl acetate/glycidyl methacrylate copolymer, maleic anhydride grafted polyethylene, acrylic acid grafted polyethylene, maleic anhydride grafted polypropylene, maleic anhydride grafted ethylene propylene copolymer, acrylic acid Grafted ethylene, propylene copolymer, fumaric acid grafted ethylene, /1-butene copolymer, ethylene/1-hexyne-itaconic acid copolymer, ethylene/propylene-endobicyclo [2.2
．． 1]-5-heptene-2,3-dicarboxylic anhydride copolymer, ethylene/propylene-methacrylic acid grafted glycidyl copolymer, maleic anhydride grafted ethylene/
Propylene/1,4-hexadiene copolymer, fumaric acid grafted ethylene, /propylene/dicyclopentadiene copolymer, maleic acid grafted ethylene/propylene/norbornadiene copolymer, acrylic acid grafted ethylene/vinyl acetate copolymer, etc. These modified polyolefins may be used alone or in combination of two or more.

On the other hand, as the polypropylene resin (B2) constituting component (B), a propylene homopolymer and/or a propylene copolymer is used. Here, as the propylene copolymer, propylene-butene-1
There are copolymers, and block copolymers and random copolymers of these are used. This polypropylene resin (
B2) may be a propylene homopolymer or a propylene copolymer, which may be used alone or in combination of two or more. In this case, the molecular weight of the propylene homopolymer or propylene copolymer is preferably 5.0 g/10 min or less in terms of MFR, preferably 1.0 g/10 min or less, since a large molecular weight can improve moldability.

In the present invention, modified polyolefin (B
(B) consisting of 1) and polypropylene resin (B2)
The blending ratio of polyolefin resin as a component is 10~
Polyamide resin 5 which is 45% by weight and is component (A)
It is 5 to 90% by weight. By choosing within this range (
A sea-island structure can be formed in which component A) is mainly a sea component and component (B) is an island component. When the blending ratio of component (B) is less than 10% by weight, the rigidity decrease and dimensional change due to moisture absorption are large. Moreover, if it exceeds 45% by weight, mechanical properties (
In particular, problems arise in that durability (rigidity) and heat resistance deteriorate.

Next, the reinforcing material (C) added to the polyamide resin composition of the present invention is a glass fiber reinforcing material or a mica reinforcing material.
~15 μm and a length of 2.0 to 7.0 mm, preferably a diameter of 9 to 13 μm and a length of 3.0 to 6.0 mm. Further, the mica reinforcing material has an average particle diameter of 10 to 200 μm, preferably 20 to 100 μm. Furthermore, it is desirable that the mica reinforcing material has an average aspect ratio of 15 or more, preferably 25 or more. One type of reinforcing material may be used, or a combination of both may be used.

[0015] This reinforcing material (C) may be surface-treated with a silane coupling agent, a titanate treatment agent, etc., if necessary. The addition ratio of this reinforcing material (C) is 5 parts by weight per 100 parts by weight of the resin component (A+B).
~30 parts by weight, preferably 7 to 25 parts by weight. If the amount of reinforcing material (C) added is less than 5 parts by weight, the effect as a reinforcing material will be small and the improvement in rigidity and heat resistance will be insufficient. Furthermore, if the amount of reinforcing material (C) added exceeds 30 parts by weight, the parison will not stretch during blow molding and will be punctured, making it impossible to obtain a product.

[0016] Furthermore, in the present invention, the above components (A) and (B
) and (C) must have a tension of 0.5 g or more when melted. The tension during melting can be measured by measuring pellets of the resin composition using a Capillograph (manufactured by Toyo Seiki Seisakusho) or the like. If this tension is less than 0.5 g, the moldability during blow molding will deteriorate. This tension is 0.5
g or more, each of the above components (A), (B) and (
This can be achieved by blending C) within a specified range.

In producing the resin composition of the present invention, the above-mentioned components may be melt-kneaded using various methods. For example, the above-mentioned components may be added to the polyamide resin (A) which is still in a molten state after the completion of the polymerization reaction, and then melt-kneaded. Alternatively, the above-mentioned components may be added to the polyamide resin (A) in powder or pellet form and melt-kneaded. The temperature at which each component is melted and kneaded is not particularly limited and may be determined depending on the situation, but is usually 180°C.
The temperature is selected from the range of .degree. C. to 350.degree. C., preferably 200 to 300.degree. Further, the above-mentioned melt-kneading operation may be performed using a known melt-kneading device such as a single-screw or twin-screw extruder.

As mentioned above, the polyamide composition of the present invention has the following properties:
The main components are components (A) to (C), but depending on the purpose, dyes, pigments, nucleating agents, plasticizers, lubricants, mold release agents, foaming agents, or weathering agents (carbon black, ultraviolet absorbers, ) etc. can also be added in appropriate amounts.

[0019]

[Examples] Next, the present invention will be explained by examples and comparative examples.
I will explain in more detail. Examples 1 to 12 and Comparative Examples 1 to 13 Tables 1 and 2 (Examples), Table 3 and Table 4 (Comparative Examples)
A polyamide resin composition was manufactured by blending each component shown in a predetermined ratio and kneading it in a co-directional twin-screw extruder (diameter 30 mm). The composition was evaluated as follows.

(Evaluation) 1) Heat Resistance (HDT) A 5 inch x 1/2 inch x 1/6 inch test piece was manufactured by injection molding and measured according to the ASTM D648 standard. 2) Melt tension The resin tension of the pellets of the above composition when melted was measured using a Capillograph (manufactured by Toyo Seiki Seisakusho). 3) Flexural Modulus Test pieces of 5 inches x 1/2 inches x 1/6 inches were manufactured by injection molding and measured according to the ASTM D790 standard. 4) A 5/2 inch x 1/2 inch x 1/6 inch test piece was manufactured by Izod injection molding and measured according to ASTM D256A. 5) Formability The pellets of the above composition were molded into a container (width 250 x length 150 x height 350) using a blow molding machine NB-30 (manufactured by Japan Steel Works) and confirmed. <Judgment> ○ Can be molded × Cannot be molded

Polyamide resins, polyolefin resins, etc. used in Examples and Comparative Examples are as follows, and Table 1
~The abbreviations in Table 4 are also as follows. [Polyamide resin] PA-1 nylon 6, relative viscosity 3.10, amino end group concentration 4.9 x 10-5
Equivalent weight/gPA-2 Nylon 6,66 copolymerization ratio (nylon 6/nylon 66) = 10/90, relative viscosity 2
．． 90, amino end group concentration 4.7 x 10-5 equivalent/
gPA-3 Nylon 66, relative viscosity 3.02,
Amino end group concentration 5.2 x 10-5 equivalents/gPA-
4 Nylon 6, relative viscosity 2.60, amino end group concentration 5.5 x 10-5 equivalents/g

[Modified polyolefin] M-1 Graft-modified polypropylene, graft-modified polypropylene M obtained by adding 0.35% by weight of maleic anhydride to isotactic polypropylene having an MFR of 1.0 g/10 min at 230°C.
-2 Glycidyl methacrylate grafted ethylene-vinyl acetate copolymer, produced with reference to the method described in Japanese Patent Publication No. 12449/1983. That is, glycidyl methacrylate in which dicumyl peroxide had been dissolved in advance was mixed with ethylene-vinyl acetate copolymer pellets, and the mixture was allowed to penetrate at room temperature. Next, the glycidyl methacrylate-impregnated pellets were extruded at a tip temperature of 170° C. using a co-directional twin-screw extruder with an inner diameter of 30 mm and a vent, to obtain graft-polymerized epoxy group-containing copolymer pellets (glycidyl methacrylate content: 2 wt%).

[0023]
Polypropylene resin] PP-1 JIS K 6
Propylene homopolymer with an MFR of 0.5 g/10 min at 758 (Showa Denko K.K., Showaromer SA51
0) PP-2 MFR in JIS K 6758 is 0
．． 4g/10min propylene-ethylene block copolymer (Showa Denko K.K., Showaromer SK721)
PP-3 Propylene homopolymer JIS K 6
Propylene homopolymer with an MFR of 10 g/10 min at 758 (Showa Denko K.K., Showaromer MA510
)

[Reinforcing material] GF-1 A chopped strand of glass fiber with a diameter of 10 μm and a length of 3 mm was used. (Made by Asahi Fiberglass: JAFT2) MF-1
Mica having an average particle diameter of 140 μm, an average thickness of 2.6 μm, and an average aspect ratio of 75 was used. (Manufactured by Repco: S-10
0) [Antioxidant] Product name Irganox-1098,
Phenolic, manufactured by Ciba Geigy

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

[Table 4]

As is clear from the results in Tables 1 to 4, the polyamide resin composition of the present invention has excellent rigidity and heat resistance.
Moreover, it can be seen that the moldability during blow molding is also good.

[0030]

Effects of the Invention As explained above, the polyamide resin composition of the present invention has excellent rigidity, heat resistance, and impact resistance, and has moldability suitable for blow molding. It can also be used as core material for seat backs inside automobiles.

Claims (1)

[Claims] [Claim 1] Concentration 1 in 98% sulfuric acid at 25°C
90 to 55% by weight of polyamide resin (A) having a relative viscosity of g/dl of 2.7 or more, and selected from carboxylic acid groups, carboxylic acid metal bases, carboxylic ester groups, acid anhydride groups, and epoxy groups. A modified polyolefin (B1) having at least one type of functional group 2 to 98% by weight and a polypropylene resin having an MFR of 5.0 g/10 minutes or less (
B2) Polyolefin resin consisting of 98 to 2% by weight (
B) a blend polymer consisting of 10 to 45% by weight (A
+B) A composition comprising 100 parts by weight of a glass fiber reinforcing material and/or a mica reinforcing material (C) of 5 to 30 parts by weight, the composition having a tension of 5.0 g or more when melted. A polyamide resin composition characterized by the following.