JP3413534B2 - Polyamide resin composition and molded product thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polyamide resin composition and tanks and tubes molded therefrom. More specifically, the characteristics of polyamide resin are excellent in gasoline resistance and oil resistance, and the water resistance (high water absorption), which is a drawback of polyamide resin, is greatly improved.
The present invention relates to a polyamide resin composition having low water absorption, and tanks and tubes molded from the polyamide composition.

[0002]

2. Description of the Related Art In recent years, research on polymer blends has progressed, and various multi-component resin compositions having high impact resistance have been developed. Generally, a polyamide resin mixed with an olefin-based polymer or a styrene-based polymer is known as high-impact nylon or low-water-absorption nylon, and examples thereof include nylon / polypropylene and nylon / AB.
S, nylon / polyolefin rubber, etc.

[0003]

By the way, in the polyamide resin composition, if a large amount of an olefin polymer or a styrene polymer can be dispersed in a continuous phase which is a polyamide resin, a polyamide material having low water absorption can be obtained. It seems that it will come to be. However, in reality, it is difficult to mix a large amount of olefin-based polymer or styrene-based polymer into polyamide in a dispersed phase.
When they were blended in an amount of 0% by weight or more, they often became a continuous phase instead of a dispersed phase. Such a composition results in that the good gasoline resistance and oil resistance of polyamide cannot be maintained, and the water resistance is not improved.

In order to solve the above-mentioned problems, that is, to obtain a composition in which even if a large amount of an olefin polymer or a styrene polymer is blended with a polyamide resin, the polymer always forms a dispersed phase. As a result of intensive studies, the present invention has been completed.

[0005]

That is, the present invention provides a composition containing a polyamide resin (A) and a polyolefin and / or a styrene copolymer (B) containing an unsaturated dicarboxylic acid or an anhydride thereof. A polyamide resin (A) and a polyolefin and / or a styrene copolymer (B) containing an unsaturated dicarboxylic acid or an anhydride thereof are represented by the following formula (1):

[0006]

[Equation 2]

[Wherein MFR (A) is the MFR value of the polyamide resin (A) at the processing temperature during processing,
(B) is the MFR value of the polyolefin and / or styrene copolymer (B) containing unsaturated dicarboxylic acid or its anhydride at the processing temperature during processing, and Φ _A is the polyamide resin (A) and unsaturated. Polyamide resin (A) based on the total amount of polyolefin and / or styrene copolymer (B) containing dicarboxylic acid or its anhydride
Of the polyamide resin composition). The present invention further relates to tanks and tubes formed from the above composition.

The polyamide resin (A) [hereinafter also referred to as "component (A)"] used in the composition of the present invention is
Polymers having a -CO-NH- bond in the main chain, such as 4-nylon, 4,6-nylon, 6-nylon, 6,6-nylon, 12-nylon, 11-nylon, 6,10 -Nylon, MXD-nylon and the like can be mentioned.

The above-mentioned component (A) has an average molecular weight of 2000.
A relatively low molecular weight of up to 20,000 is preferable, and when the average molecular weight is higher than 20,000, it becomes difficult to satisfy the formula (1), and it is possible to maintain the desired good gasoline resistance and improve the water resistance at the same time. Becomes difficult. 8000
More preferred is an average molecular weight in the range of -15000.

The composition of the present invention also contains a polyolefin and / or a styrene copolymer (B) containing an unsaturated dicarboxylic acid or an anhydride thereof (hereinafter, also referred to as "component (B)").

As the polyolefin, various ones can be mentioned, but preferably the carbon number of low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, polybutene-1, polymethylpentene-1 and the like. A homopolymer of 2 or more, preferably 2 to 8 ethylene hydrocarbons, a copolymer of ethylene and an α-olefin of 3 or more carbon atoms, preferably 3 to 6 (ethylene-propylene copolymer, ethylene-propylene-
Diene terpolymer, ethylene-butene-1 copolymer, etc.), copolymer of ethylene and vinyl compound (ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer) Polymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene- (meth) acrylic acid (ester) -α, β unsaturated carboxylic acid (derivative) terpolymer, ethylene-chloride Vinyl copolymers) and the like. These are used alone or as a mixture.

As an example of the styrene-based copolymer, a so-called styrene block copolymer having a known S (aromatic hydrocarbon-based polymer) -B (conjugated diene-based polymer) -S type symmetric block structure is used. An example is coalescence. S and B each represent a polymer block, and examples of the central block B include polybutadiene and polyisoprene, with butadiene being preferred. In addition, some of the double bonds in polybutadiene are saturated with hydrogen by adding saturated alkyl groups (ethylene chains).
The one (SEBS) is recommended. Both end blocks S represent a polymer block of aromatic hydrocarbon, and a polymer block made of polystyrene is preferably used.

The weight ratio of the aromatic hydrocarbon polymer to the conjugated diene polymer is preferably in the range of 10/90 to 90/10, and from the viewpoint of compatibility of flexibility and processability, it is 1
The range of 5/85 to 85/15 is more preferable.

The polyolefin and / or styrenic copolymer used in the present invention contains an unsaturated dicarboxylic acid or its anhydride. Specific examples thereof include maleic acid, itaconic acid, chloromaleic acid, citraconic acid, butenylsuccinic acid, tetrahydrophthalic acid, and the like, and acid anhydrides thereof. Among them, maleic anhydride is preferable.

One or more of the above unsaturated dicarboxylic acids or acid anhydrides thereof are mixed with a polyolefin and / or a styrene copolymer in the presence of a peroxide,
For example, 100 to 250 with an extruder, a mixer, or the like.
Knead at 1 ° C for 1 to 10 minutes to react.

The amount of unsaturated dicarboxylic acid or its anhydride is preferably 0.1 to 5% by weight based on the polyolefin and / or styrene copolymer. Further, the amount of the peroxide is preferably 0.05 to 1% by weight with respect to the polyolefin and / or the styrene copolymer.

The component (B) is not limited to a polyolefin and / or a styrene copolymer modified with an unsaturated dicarboxylic acid or an acid anhydride thereof, and may be an unsaturated dicarboxylic acid or an acid anhydride thereof and a polyolefin and / or It may be a mixture of styrene copolymers.

In the present invention, the components (A) and (B) are represented by the following formula (1):

[0019]

[Equation 3]

[Wherein MFR (A) is the MFR value of the (A) component of the processing temperature during processing, and MFR (B) is
The MFR value of the (B) component of the processing temperature during processing is Φ
_A represents the volume% of the component (A) with respect to the total volume of the component (A) and the component (B)]. Here, the MFR value is JIS K 7 under the following conditions.
It is a value measured according to the regulation of 210. Load: 2160 g Measurement temperature: processing temperature of the resin composition, that is, a temperature 10 to 15 ° C. higher than the melting point of the component (A), the volume ratio of the component (A) and the component (B), and the MFR value (melt viscosity), If it is adjusted so as to satisfy 1), it is possible to provide a flexible molded article having excellent gasoline resistance and oil resistance, low water absorption and excellent impact resistance. Further, even if the volume ratio of the component (B) in the composition is large, the molded product obtained is excellent in gasoline resistance as long as the MFR value is adjusted to satisfy the formula (1). , Oil resistance, low water absorption and flexibility.

The polyamide resin composition of the present invention contains a reinforcing agent, a crystal nucleating agent, a releasing agent, a flame retardant, a light or heat stabilizer, a plasticizer, an antistatic agent, and a coloring agent according to various uses and purposes. Etc. can be added. Examples of the reinforcing agent include fibrous reinforcing agent and filler-like reinforcing agent.The fibrous reinforcing agent includes carbon fiber and glass fiber, and the filler-like reinforcing agent includes talc, mica, wollastonite, calcium carbonate and various whiskers. , Silica, kaolin, montmorillonite, clay and the like, but are not limited thereto. The amount of the reinforcing agent added is based on the polyamide resin composition.
It can be added up to 50% by weight.

Examples of the crystal nucleating agent include, but are not limited to, talc, clay, non-calcified calcium, sodium phenylphosphinate, alumina and finely ground polytetrafluoroethylene. The crystal nucleating agent can be added up to 3% by weight with respect to the polyamide resin composition.

As the release agent, a metal salt of stearic acid,
Metal salt of montanic acid wax, stearyl alcohol,
Examples thereof include, but are not limited to, silicone oil. The release agent can be added up to 2% by weight based on the polyamide resin composition.

As the flame retardant, halogen flame retardants, non-halogen flame retardants and the like can be used without particular limitation. Above all, a mixture of a halogen-based flame retardant and antimony trioxide is preferable. As a halogen-based flame retardant, brominated polystyrene,
Examples thereof include polybromodiphenyl ether, polymeric brominated epoxy resin, and the like, and examples of the halogen-free flame retardant include melamine cyanurate, red phosphorus and the like. The amount of flame retardant added is 35% by weight based on the polyamide resin composition.
Can be added up to.

As the light or heat stabilizer, carbon black, a mixture of copper halide and potassium halide,
Examples thereof include hindered phenol-based stabilizers, phosphorus-based stabilizers, benzotriazole-based stabilizers, benzophenone-based stabilizers, and mixtures thereof, but are not limited thereto. The light or heat stabilizer can be added up to 4% by weight with respect to the polyamide resin composition.

Examples of the plasticizer include dioctyl phthalate, dibenzyl phthalate, butylbenzyl phthalate, hydrocarbon oil, Nn-butylbenzenesulfonic acid amide, o-tolueneethylsulfonamide and p-tolueneethylsulfonamide. However, the present invention is not limited to these. The plasticizer can be added up to 40% by weight with respect to the polyamide resin composition.

There is no particular limitation on the mixing equipment used to obtain the polyamide composition of the present invention. That is, a conventional mixing device such as a roller kneader, a Banbury mixer, a single-screw or multi-screw extruder can be used. It suffices to knead and process at a temperature higher than the melting point of the polyamide resin (A) by 5 ° C. or more using these mixing devices.

The polyamide resin composition of the present invention not only maintains the excellent gasoline resistance and oil resistance, which are the characteristics of the polyamide resin (A), but also has a low water resistance, which is a drawback of the polyamide resin, By adding a polyolefin and / or a styrene-based copolymer (B) containing an unsaturated dicarboxylic acid or an anhydride thereof, it is possible to provide a flexible molded article that is significantly improved and has excellent impact resistance.

The composition of the present invention having such characteristics is particularly suitable for use as tanks such as gasoline tanks and oil tanks, which are required to have gasoline resistance and oil resistance, and tubes such as gasoline tubes. . Also,
It is also suitable for use in household appliances, miscellaneous goods, automobiles, etc. where changes in water absorption are a problem. Further, it is also suitably used for ski boots, wheel caps, bumpers, emblems and the like, which require good decorative properties such as painting. There is no particular limitation on the method for producing these molded products, and they are molded by a method known per se.

[0030]

The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

Various physical properties and test results listed in the examples were measured as follows. MFR value (g / 10 minutes): According to JIS K 7210. (Measurement condition: load 2160 g) Tensile elastic modulus (Kg / cm ² ): ASTM D-638
According to. Water absorption rate (wt%): Saturated water absorption rate at 23 ° C in water

Gasoline vapor permeation resistance: (A) Method for preparing test piece (thin film) 1. Sindh type SF hydraulic press (manufactured by Shinto Metal Industry Co., Ltd.)
Is set to a temperature 15 ° C. higher than the melting point of the polyamide resin constituting the composition to be tested. 2. Pellets or molded articles of the composition to be tested are placed in a mold having a thickness of 0.2 mm, which is sandwiched with Teflon sheets and sandwiched with iron plates. 3. This is put into the above-mentioned press machine (pressure is not applied) and is held for 1 minute, and pressure is gradually applied while bleeding air to 10
It is set to 0 Kg / cm ² . 4. After maintaining the pressed state for about 10 seconds, the pressure is removed to obtain a thin film (test piece) having a thickness of 0.2 mm. (B) Gasoline vapor resistance (g · mm / m ² · day · a
tm) Put about 2/3 of the internal volume of gasoline in a brass container, seal with a test piece, and fix with a screw. This is left for 4 days in an oven controlled at 40 ± 1 ° C. Measure the reduced gasoline weight and calculate the gasoline vapor permeability,

[0033]

[Equation 4]

[Wherein D is resistance to gasoline vapor permeation (permeation coefficient), t is film thickness (mm) of test piece, Q is reduction amount of gasoline weight (g / day), S is gasoline vapor) The area (m ² ) of the test piece in contact with
Uses a caliper to measure up to two digits after the decimal point. Q is measured up to 3 digits after the decimal point.

Examples 1 to 4 and Comparative Examples 1 to 4 Polyamide resins [(A) component) shown in Table 1] and a polyolefin and / or styrene copolymer containing unsaturated dicarboxylic acid or its anhydride [( B) component)],
The ingredients were blended in the weight ratio shown in Table 1 and kneaded and processed in a 30 mm twin-screw extruder (Ikegai) at a temperature (205 ° C.) higher by 10 ° C. than the melting point (190 ° C.) of the component (A). The screw rotation speed was 80 rpm. The composition discharged from the extruder is cooled in a water tank, cut with a cutter, and heated at 80 ° C x 1
6HR vacuum dried to obtain pellets. Tensile elastic modulus, water absorption and gasoline permeation resistance were measured from the obtained pellets. The results are shown in Table 1.

[0036]

[Table 1]

As is clear from Table 1, when the compounding ratio of the components (A) and (B) and the MFR value at the processing temperature satisfy the formula 1, the low elastic modulus and the excellent gasoline permeability resistance and the water absorption rate are obtained. Was also low.

Examples 5 to 7 and Comparative Examples 5 to 11 The components (A) and (B) shown in Table 2 were mixed in a volume ratio shown in Table 2 to prepare pellets in the same manner as in Example 1, Each physical property was measured in the same manner as in Example 1. The results are shown in Table 2.
Shown in.

[0039]

[Table 2]

As is clear from Table 2, even if the blending ratio of the component (B) increases, the MFR values of the component (A) and the component (B) should be adjusted so as to satisfy the formula (1). For example, it can be seen that low water absorption, low elastic modulus and excellent gasoline permeability are obtained.

The components (A) and (B) in Tables 1 and 2 are
The component abbreviations are as follows. PA: NY6 / 66 copolymer having a melting point of 190 ° C, 205 ° C
Of various values M-EPR: Tuffmer MA-8510, Mitsui Petrochemical Co., Ltd. M-SEBS: Tufftec M-1943, Asahi Kasei Co., Ltd. M-PE: Mitsui Petrochemical Co., Ltd. Hi-Zex 1
300 J, 100 parts by weight of maleic anhydride 0.3 parts by weight, dicumyl peroxide 0.15 parts by weight were kneaded by an extruder and pelletized. Comparative Examples 8 to 11 in Table 2 were ( These are the physical property values of the raw materials used as the components A) and (B).

Example 8 The composition obtained in Example 1 was molded to produce a fuel tube (inner diameter 8 mmφ, outer diameter 10 mmφ). The obtained tube exhibits excellent flexibility equivalent to that of a conventional commercial product (for example, a two-layer molded product of chlorosulfonated polyethylene and NBR), and is 100% more than the conventional product.
It showed excellent gasoline resistance of 0 times or more.

[0043]

EFFECTS OF THE INVENTION The polyamide composition of the present invention can provide a molded article having excellent gasoline resistance and oil resistance, low water absorption, and flexibility, and therefore, gasoline resistance and oil resistance. Not only is it particularly suitable for use in tanks and tubes that require high performance,
It is widely applied to applications where water absorption dimension change is a problem.

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Claims (3)

(57) [Claims] 1. A composition containing a polyamide resin (A) and a polyolefin and / or a styrene copolymer (B) containing an unsaturated dicarboxylic acid or an anhydride thereof, wherein the following formula (1): Number 1] [Wherein MFR (A) is the MFR value of the polyamide resin (A) at the processing temperature during processing, and MFR (B) is the polyolefin containing the unsaturated dicarboxylic acid or its anhydride at the processing temperature during processing. / Or the MFR value of the styrene-based copolymer (B), Φ _A is based on the total of the polyamide resin (A) and the polyolefin and / or the styrene-based copolymer (B) containing the unsaturated dicarboxylic acid or its anhydride. The polyamide resin (A) represents the volume% of the polyamide resin (A)]. 2. Tanks molded from the polyamide resin composition according to claim 1. 3. Tubes molded from the polyamide resin composition according to claim 1.