JPH04239559A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain a polyamide resin composition suitable for blow molding, having improved moldability while maintaining excellent performances such as heat-resistant rigidity of characteristic polyamide resin by blending a polyamide resin with a specific polyolefin resin. CONSTITUTION:(A) 90-55wt.% polyamide resin having >=2.7, preferably >=3 relative viscosity (1g/dl concentration in 98% sulfuric acid at 25 deg.C) is blended with (B) 10-45wt.% polyolefin resin comprising B1:2-98wt.% modified polyolefin (e.g. ethylene/glycidyl methacrylate copolymer) containing one or more functional groups selected from carboxyl group, carboxylic acid metallic salt group, carboxylic acid ester group, acid anhydride group and epoxy group and B2:98-2wt.% propylene homopolymer and/or copolymer having <=5g/10 minutes, preferably <=1g/10 minutes melt flow rate as essential components and optionally a heat stabilizer, pigment, a plasticizer, a weather-resistant agent, etc., to give a polyamide resin composition suitable for blow molding.

Description

Description: [0001] The present invention relates to a polyamide resin composition, and more particularly to a polyamide resin composition that has excellent heat resistance and is suitable for producing blow molded products. 2. Description of the Related Art In recent years, the temperature of the engine room of automobiles has become higher due to exhaust gas regulations, etc., and heat resistance has become required for materials for automobile parts such as ducts in the engine room. Problems to be Solved by the Invention Conventionally, HDPE, PP, and the like have been widely used as synthetic resins for blow molding, but they have problems because of their poor heat resistance. On the other hand, although polyamide resin has excellent heat resistance, it has a low viscosity (tension) when melted and is not suitable for blow molding. Therefore, the present inventors have conducted extensive research in order to develop a polyamide resin composition that maintains the excellent properties inherent to polyamide resin, such as heat resistance and rigidity, and has improved moldability. [Means for Solving the Problems] As a result, it has been found that the above problems can be solved by blending a polypropylene polymer with a polyamide resin in a specific ratio. The present invention was completed based on this knowledge. That is, the present invention comprises (1) 90 to 55% by weight of polyamide resin (A) and polyolefin resin (
B) a polyamide resin composition consisting of 10 to 45% by weight,
(2) The polyamide resin composition according to claim 1, wherein the polyamide resin (A) has a relative viscosity of 2.7 or more at a concentration of 1 g/dl in 98% sulfuric acid at 25°C;
(3) The polyolefin resin (B) contains 2 to 98% by weight of a modified polyolefin having at least one type of 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; The polyamide resin composition according to claim 1, characterized in that it consists of 98 to 2% by weight of a polypropylene resin having a melt flow rate of 5.0 g/10 minutes or less, (4) having a tension at the time of melting of 1.0 g or more. The present invention provides a polyamide resin composition according to claim 1, characterized in that: The polyamide resin composition of the present invention basically consists of polyamide resin (A
) (hereinafter referred to as component (A)) is blended with polyolefin resin (B) (hereinafter referred to as component (B)), and the heat resistance decreases due to the mixing of component (B). In order to prevent this, the mixing ratio of component (B) to component (A) is limited, and component (A) mainly has a sea structure and (B)
) components can take on an island structure. Various types of polyamide resins can be used as the component (A) used in the present invention, but specifically, polylactams such as nylon 6, nylon 11, and nylon 12; nylon 66, nylon 610, and nylon 6
12, polyamides obtained from dicarboxylic acids such as nylon 46 and diamines; nylon 6/66, nylon 6
Copolymer polyamides such as /610, nylon 6/612, nylon 6/12, nylon 6/66/610; nylon 6/6T (T: terephthalic acid component), aromatic dicarboxylic acid such as isophthalic acid and meth Semi-aromatic polyamides obtained from xylene diamine or alicyclic diamine; mention may be made of polyesteramide, polyetheramide and polyesteretheramide. In addition, as component (A), the above-mentioned various polyamides may be used alone, or two or more types of polyamides may be used in combination. [0007] Furthermore, the polyamide resin that can be used in the present invention is not limited by the type, concentration, molecular weight, etc. of the terminal groups of these polyamides, as long as they are selected from the polyamides mentioned above. However, due to the moldability during blow molding, the temperature at 25°C
The relative viscosity at a concentration of 1 g/dl in 98% sulfuric acid is 2
．． A polyamide resin with a molecular weight of 7 or more, preferably 3.0 or more is desirable. Next, the polyolefin resin of component (B) of the present invention is composed of a modified polyolefin and a polypropylene resin, and contains 2 to 98% by weight of the modified polyolefin, preferably 3 to 90% by weight, and 9% by weight of the polypropylene resin.
It is blended in a proportion of 8 to 2% by weight, preferably 97 to 10% by weight. In this polyolefin resin,
If the amount of the modified polyolefin is too small, there will be a problem that no improvement in the durability of mechanical properties will be observed, and if the amount of the modified polyolefin is too large, there will be a problem of high cost. The modified polyolefin in component (B) contains carboxylic acid groups (acetic acid groups, acrylic acid groups, methacrylic acid groups, fumaric acid groups, itaconic acid groups, etc.), carboxylic acid metal bases (sodium salts, calcium salts, magnesium salts, etc.). ,
zinc salt, etc.), carboxylic acid ester groups (methyl ester group, ethyl ester group, propyl ester group, butyl ester group, vinyl ester group, etc.), acid anhydride groups (maleic anhydride group, etc.), and epoxy groups. It is a polyolefin having at least one functional 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. Specific examples of such modified polyolefins 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,
These modified polyolefins include maleic acid grafted ethylene/propylene/norbornadiene copolymer and acrylic acid grafted ethylene/vinyl acetate copolymer, and these modified polyolefins may be used alone or two or more types may be used in combination. be. On the other hand, as the polypropylene resin constituting component (B), a propylene homopolymer and/or a propylene copolymer is used. Examples of propylene copolymers include propylene-ethylene copolymers, propylene-butene-1 copolymers, and block copolymers and random copolymers of these copolymers. In addition,
For this polypropylene resin, a propylene homopolymer or a propylene copolymer may be used alone, or two or more types may be used in combination. At this time, the large molecular weight of the propylene homopolymer and propylene copolymer contributes to improving moldability, so the melt flow rate (hereinafter referred to as M
FR) is preferably 5.0 g/10 min or less, preferably 1.0 g/10 min or less. The blending ratio of each component in the resin composition of the present invention is 55 to 90% by weight of component (A) and 10 to 45% by weight of component (B). By blending within this range, it is possible to form a sea-island structure in which component (A) is mainly a sea component and component (B) is an island component. By adopting the sea-island structure in this way, it becomes possible to better exhibit the properties such as durability and heat resistance that are characteristics of the polyamide resin of the component (A), which is the sea component. If the blending ratio of component (B) is less than 10% by weight, stiffness may decrease due to moisture absorption,
Dimensional changes are large and undesirable. Moreover, if it exceeds 45% by weight, a problem arises in that the durability of mechanical properties (particularly rigidity) and heat resistance deteriorate. As mentioned above, the resin composition of the present invention contains (A)
The main components are component (B), but depending on the purpose, heat stabilizers, dyes, pigments, nucleating agents, plasticizers, lubricants, mold release agents, foaming agents, or weathering agents (carbon black, An appropriate amount of ultraviolet absorber) etc. may be added. In manufacturing 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. The temperature at which each component is melted and kneaded is not particularly limited and may be determined as appropriate, but is usually 180 to 350°C, preferably 200 to 300°C.
Selected from a range of ℃. Further, the above-mentioned melt-kneading operation can be performed using a known melt-kneading device such as a single-screw or twin-screw extruder. The obtained resin composition can be molded into any desired shape by extrusion molding, compression molding, injection molding, etc., but the improved viscosity during melting makes it suitable for use in blow molding. Became. [Example] Next, the present invention will be explained with reference to Examples and Comparative Examples.
I will explain in more detail. Examples 1 to 9 and Comparative Example 1 to
7 By blending the polyamide resin and polyolefin resin shown in Table 1 (Example) and Table 2 (Comparative Example) in a predetermined ratio and kneading in a co-directional twin screw extruder (diameter 30 mm), a resin composition was prepared. Manufactured. The polyamide resins, polyolefin resins, etc. used in Examples and Comparative Examples are as follows. [Polyamide resin] PA-1 nylon 6, relative viscosity 3.10,
Amino end group concentration 4.9×1
0-5 equivalent/g
PA-2 Nylon 6/66 copolymerization ratio (nylon 6/nylon 66) = 1
0/90, relative viscosity 2.90,
Amino end group concentration 4.7 x 10-5 equivalents/g
PA-3 Nylon 66, relative viscosity 3.02,
Amino end group concentration 5.2×
10-5 equivalent/g
PA-4 Nylon 6, relative viscosity 2.60
, amino end group concentration 5.
5×10-5 equivalent/g [Modified polyolefin] M-1 Graft-modified polypropylene; 0.35% by weight of maleic anhydride added to isotactic polypropylene having an MFR of 1.0 g/10 min at 230°C. Added graft modified polypropylene. M-2 Glycidyl methacrylate grafted ethylene-vinyl acetate copolymer; produced with reference to the method described in Japanese Patent Publication No. 12449/1983. That is, ethylene-
Glycidyl methacrylate in which dicumyl peroxide has been dissolved in advance is mixed with vinyl acetate copolymer pellets,
Infiltrated at room temperature. Next, the glycidyl methacrylate-impregnated pellets were extruded using an extruder with an inner diameter of 30 mm and a vent in the same direction at a tip temperature of 170°C to obtain graft-polymerized epoxy group-containing copolymer pellets (glycidyl methacrylate content: 2% by weight). . [Polypropylene resin] PP-1 MFR according to JIS K 6758 is 0
．． 5g/10min propylene homopolymer (manufactured by Showa Denko K.K., Showaromer SA510) PP-2 MFR according to 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 MFR of 10 g/10 min at 758 (Showa Denko K.K., Showaromer MA510
) [Antioxidant] Phenolic antioxidant (manufactured by Ciba Geikie, Irganox-1098) The obtained resin composition was evaluated as follows. (Evaluation) 1) Heat resistance (HDT) injection molding: 5...×1/2...×
A test piece of 1/6... was manufactured and measured according to the ASTM D648 standard. 2) Moldability (Melt Tension) Pellets of the above composition were produced, and the tension of the resin during melting was measured using a Capillograph (manufactured by Toyo Seiki Seisakusho). 3) Flexural Modulus Test pieces of 5×1/2×1/6 were manufactured by injection molding and measured according to the ASTM D790 standard. 4) Test pieces of 5/2...×1/2...×1/6... were produced by Izod impact injection molding and measured according to the ASTM D256A standard. The results of these evaluations are shown in Tables 1 and 2. As is clear from Tables 1 and 2, the resin composition of the present invention maintains high levels of heat resistance and melt tension. [Table 1] [Table 2] [Effects of the Invention] The resin composition of the present invention is made by blending each component of a polyamide resin and a polyolefin resin, and has excellent heat resistance and impact resistance. , a polyamide resin composition that has improved viscosity during melting and is suitable for blow molding. Therefore, the resin composition of the present invention can be usefully used in a wide range of applications as a raw material for products that require strength and heat resistance, such as automobile parts and industrial parts.

Claims (4)

[Claims] Claim 1: 90 to 55% by weight of polyamide resin (A) and 10 to 45% by weight of polyolefin resin (B)
A polyamide resin composition consisting of: 2. The polyamide resin composition according to claim 1, wherein the polyamide resin (A) has a relative viscosity of 2.7 or more at a concentration of 1 g/dl in 98% sulfuric acid at 25°C. 3. The polyolefin resin (B) is a modified polyolefin having at least one type of functional group selected from a carboxylic acid group, a carboxylic acid metal base, a carboxylic ester group, an acid anhydride group, and an epoxy group. %
The polyamide resin composition according to claim 1, comprising 98 to 2% by weight of a polypropylene resin having a melt flow rate of 5.0 g/10 minutes or less. 4. The polyamide resin composition according to claim 1, which has a tension of 1.0 g or more when melted.