JPH05214243A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which can desirably be blow-molded without oxidative deterioration into a molding excellent in mechanical strengths, heat resistance and heat stability by adding an antioxidant to a specified polyamide resin composition. CONSTITUTION:The title composition is obtained by adding 0.1-2.0 pts.wt. antioxidant to 100 pts.wt. resin composition comprising 90-55wt.% polyamide resin having a relative viscosity of 2.5 or above when measured in 98% sulfuric acid in a concentration of 1g/dl at 25 deg.C and 10-45wt.% MBS elastomer having a composition of 2.0-5.0wt.% methyl methacrylate, 70.0-80.0wt.% butadiene-1,3 and 15.0-25.0wt.% styrene. This composition can desirably be blow-molded into a molding excellent in mechanical strengths, impact strength, etc., and high in heat resistance and heat stability and therefore it can extensively be used as the material of blow moldings for uses requiring heat stability, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide resin composition, and more specifically, it can be suitably blow molded without causing oxidative deterioration, and the resulting molded article has excellent mechanical strength,
The present invention relates to a polyamide resin composition having heat resistance and heat stability.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
Examples of synthetic resins used for blow molding include high density polyethylene (HDPE) and polyethylene (PP).
Although these resins have excellent hollow moldability, they have low heat resistance, heat stability, etc. and are not sufficiently satisfactory when they are used in applications where heat resistance, heat stability, etc. are required for the obtained molded product. It was In particular, in the engine room of automobiles or ducts in the engine room, which are hollow molded products such as HDPE, PP, etc., the amount of heat generated in the engine part increases and the temperature of the engine room tends to rise due to the exhaust gas regulations of automobiles in recent years. Therefore, there is a demand for a molded product made of a material having more excellent heat resistance and thermal stability.

On the other hand, polyamide resins are known to have excellent heat resistance, thermal stability, etc., but when the above-mentioned blow molding is carried out, the viscosity at the time of melting becomes low, so that the resulting molded product machine It was not suitable for blow molding because of problems with its mechanical strength. As described above, the obtained molded product has mechanical strength, heat resistance, thermal stability, etc., and a material suitable for blow molding has not yet been developed.

[0004]

Therefore, the present inventors have
We have conducted intensive research to solve the above problems and to develop a raw material that has excellent mechanical strength, heat resistance, and thermal stability and high hollow moldability. As a result, they have found that a resin composition obtained by blending a polyamide resin with an elastomer having a specific composition and an antioxidant can serve as a material suitable for the above purpose. The present invention has been completed based on such findings.

That is, the present invention relates to (A) (a) 90 to 55% by weight of a polyamide resin having a relative viscosity of 2.5 or more at a concentration of 1 g / dl in 98% sulfuric acid at 25 ° C., and (b)
Methyl methacrylate 2.0-5.0 wt%, butadiene-1,3 70.0-80.0 wt% and styrene 1
Resin composition consisting of 10 to 45% by weight of MBS elastomer having a composition of 5.0 to 25.0% by weight (hereinafter referred to as (A))
The present invention provides a polyamide resin composition obtained by adding 0.1 to 2.0 parts by weight of (B) an antioxidant (hereinafter referred to as "component (B)") to 100 parts by weight of the component). ..

In the present invention, the component (A) is (a) 25.
The relative viscosity at a concentration of 1 g / dl in 98% sulfuric acid at 2.degree. C. is 2.
5 or more polyamide resin and (b) methyl methacrylate 2.0 to 5.0% by weight, butadiene-1,37
An MBS (methyl methacrylate-butadiene-styrene) elastomer having a composition of 0.0 to 80.0% by weight and styrene 15.0 to 25.0% by weight is blended. In the component (A), the polyamide resin (a) may have various relative viscosity at 25 ° C. in 98% sulfuric acid at a concentration of 1 g / dl of 2.5 or more, preferably 3.0 or more, without any particular limitation. Things can be used. Here, if the relative viscosity is less than 2.5, the impact strength of the molded product decreases, which is not preferable.

Specific examples of the (a) polyamide resin as the component (A) include polyamides obtained by polycondensation of an aliphatic diamine and an aliphatic dicarboxylic acid or an aromatic dicarboxylic acid, such as nylon 6.6, nylon 6. 1
0, nylon 6/12, MXD-nylon 6 and the like, polyamides obtained by ring-opening polymerization of aliphatic lactams such as nylon 6, nylon 12 and the like, polyamides obtained by polycondensation of amino acids, such as nylon 11 and the like,
Examples thereof include copolymers of the repeating units of polyamides described above. Of these, nylon 6.6 is most suitable.

Further, (b) the MBS-based elastomer is 2.0 to 5.0% by weight of methyl methacrylate, preferably 3.0.
~ 4.0% by weight, butadiene-1,3 70.0 to 80.0
% By weight, preferably 17.0 to 23.0% by weight and styrene 15.0 to 25.0% by weight, preferably 73 to 78% by weight. When the composition ratio is less than or exceeds the composition ratio, that is, methyl methacrylate 2.
Less than 0 wt% or more than 5.0 wt%; butadiene-1,3 less than 70.0 wt% or more than 80.0 wt%; styrene less than 15.0 wt% or 25.0 wt% If it exceeds, the heat resistance and impact strength of the obtained resin composition are deteriorated, which is not preferable.

The resin composition of component (A) of the present invention comprises 90 to 55% by weight, preferably 80 to 60% by weight of the above-mentioned (a) polyamide resin and (b) MBS elastomer.
10 to 45% by weight, preferably 20 to 40% by weight is blended. In the resin composition of the component (A), the polyamide resin (a) is mainly a sea component (matrix phase or continuous phase) in the molded article, and (b) the MBS elastomer is mainly an island by adjusting the blending ratio. It can be a sea-island structure that forms a component. By using such a polymer alloy composition, while maintaining the excellent heat resistance of conventional polyamide resins, excellent hollow moldability is exhibited, and high mechanical strength can be imparted to the obtained molded product. Of.

The blending ratio of the resin composition of component (A) is
(A) Polyamide resin If it exceeds 90% by weight, that is, if (b) the MBS elastomer is less than 10% by weight, the rigidity and dimensional change of the obtained molded product are remarkably impractical due to moisture absorption. Further, (a) polyamide resin
If it is less than 55% by weight, that is, if the amount of the (b) MBS elastomer exceeds 45% by weight, there is a problem in that the mechanical strength, particularly the durability of rigidity and heat resistance of the molded product deteriorates.

Next, various antioxidants can be used as the component (B) of the present invention without particular limitation. By adding the antioxidant as the component (B), it is possible to prevent the fusion failure of pinch-off due to the oxidative deterioration caused by the parison being exposed to the air during the hollow molding, and the moldability is improved.

Examples of the antioxidants include phosphorus-based antioxidants such as hindered phenol-based antioxidants, phosphite ester-based and phosphoric ester-based antioxidants, and amine-based antioxidants, and particularly hindered phenol-based antioxidants. The above-mentioned antioxidant is preferable because it does not cause discoloration of the molded product. Examples of the hindered phenolic antioxidant include Irganox 1098.
(Ciba-Geigy product name), Irganox 106
7 (Ciba Geigy, trade name), Irganox 10
10 (trade name, manufactured by Ciba Geigy), 2,6-di-t-
p-cresol (BHT), Ethyl 330 (manufactured by Ethyl Co., trade name), Sumilizer CM (manufactured by Sumitomo Chemical Co., Ltd.,
Trade names) are preferably used. The addition amount of the component (B) antioxidant is 0. 0 with respect to 100 parts by weight of the component (A).
It is 1 to 2.0 parts by weight, preferably 0.2 to 1.0 parts by weight.
If the amount added is less than 0.1 part by weight, a sufficient effect cannot be obtained, and if it exceeds 2.0 parts by weight, impact strength is lowered, which is not preferable.

The present invention mainly comprises the components (A) and (B), but if necessary, dyes, pigments, nucleating agents, plasticizers, lubricants, release agents may be used within the range not impairing the object of the present invention. It is also possible to add an appropriate amount of a foaming agent or a weathering agent (carbon black, ultraviolet absorber) or the like.

The resin composition of the present invention can be produced by melt-kneading the above-mentioned components by various methods. Specifically, in the production of polyamide resin, the above-mentioned MBS elastomer, the antioxidant, and other additives to be added as necessary are added to the polyamide resin which is still in a molten state after the completion of the polymerization reaction, and the mixture is melt-kneaded. The method includes a method in which a polyamide resin, an MBS elastomer, an antioxidant, and other additives that are added as necessary are mixed at the same time and melt-kneaded.

The blending and melt-kneading of these respective components may be carried out using a single-screw extruder, a twin-screw extruder, a multi-screw extruder, a co-kneader, a ribbon blender, a Henschel mixer, a Banbury mixer, a drum tumbler or the like. The temperature in the melt-kneading is not particularly limited and may be appropriately selected depending on the type of resin, blending ratio, etc., but it is usually 270 to 3
It is in the range of 50 ° C, preferably 280 to 310 ° C.

[0016]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. Examples 1 to 5 and Comparative Examples 1 to 6 A resin composition was produced by blending the components shown in Table 1 at a predetermined ratio and kneading the mixture at 280 ° C. in a same-direction twin-screw extruder (diameter 30 mm). .. The physical properties of the obtained resin composition are shown in Table 1. The types of each component in Table 1 and the evaluation of physical properties are shown below.

1. Type of each component [Polyamide resin] PA-1 Nylon 6.6, Relative viscosity 3.10, Amino group terminal concentration 4.9 × 10 ^-5 equivalent / g PA-2 Nylon 6.6, Relative viscosity 2.60, Amino group terminal concentration 5.2 × 10 ^-5 equivalent / g PA-3 Nylon 6.6, relative viscosity 2.3, Amino group terminal concentration 5.2 × 10 ^-5 equivalent / g

[MBS Elastomer] M-1 Composition Ratio Methyl Methacrylate 3.8 wt% Butadiene-1,3 75.0 wt% Styrene 21.2 wt% M-2 Composition Ratio Methyl Methacrylate 10.0 wt% Butadiene-1,3 6.0% by weight Styrene 30.0% by weight M-3 Composition ratio Methyl methacrylate 1.0% by weight Butadiene-1,3 76.0% by weight Styrene 23.0% by weight

[Antioxidant] Trade name Irganox-
1098, phenolic, made by Ciba Geigy

2. Evaluation of physical properties 1) Heat resistance (HDT) 5 ″ × 1/2 ″ × 1/6 ″ test pieces were manufactured by injection molding and measured in accordance with the standard of ASTM D648. 2) Moldability (drawdown property) ) 50 using an S-50ND hollow forming machine (manufactured by Placo)
The presence or absence of molding was confirmed by molding a 0 cc cylindrical bottle. No drawdown ···, with drawdown · × 3) Bending elastic modulus A 5 ″ × 1/2 ″ × 1/6 ″ test piece was manufactured by injection molding and measured according to the standard of ASTM D790. 4) Izod impact strength A 5/2 "x 1/2" x 1/6 "test piece was manufactured by injection molding and measured according to ASTM D256A. 5) Pinch off strength Using an S-50ND hollow forming machine (made by Placo), 50
The strength of the pinch-off part was confirmed by molding a 0 cc cylindrical bottle. ○: No problem. ×: The pinch-off part peels off.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

As described above, the resin composition of the present invention is
It is possible to suitably perform molding by blow molding, the obtained molded product is excellent in mechanical strength, impact strength, etc., and further has high heat resistance and thermal stability. Therefore, it can be widely used as a material for a hollow molded product, particularly as a material for a hollow molded product for which heat resistance, thermal stability and the like are required, such as a duct for an engine room of an automobile.

Claims (3)

[Claims] 1. (A) 90 to 55% by weight of (a) a polyamide resin having a relative viscosity of 2.5 or more at a concentration of 1 g / dl in 98% sulfuric acid at 25 ° C. and (b) methyl methacrylate 2.0. ~ 5.0% by weight, butadiene-1,3 7.0
~ 80.0% by weight and styrene 15.0 ~ 25.0% by weight
10-45% by weight of MBS elastomer having the composition
A polyamide resin composition obtained by adding 0.1 to 2.0 parts by weight of the antioxidant (B) to 100 parts by weight of the resin composition comprising. 2. The polyamide resin composition according to claim 1, wherein the polyamide resin (A) (a) is nylon 6.6. 3. The polyamide resin composition according to claim 1, wherein the antioxidant (B) is a phenolic antioxidant.