JPH05302028A - Blow-molded article - Google Patents

Abstract

PURPOSE:To provide the title article which is made from a polyamide resin of excellent blow moldability and is excellent in heat, impact and chemical resistances. CONSTITUTION:The title article is made from a polyamide resin composition comprising 20-80wt.% polyamide resin (A), 3-30wt.% polyphenylene sulfide resin (B), 1-50wt.% modified polyolefin resin (C) prepared by copolymerizing and/or grafting an alpha,beta-unsaturated carboxylic acid or its derivative with or onto a polyolefin mainly consisting of an ethylene component and/or a propylene component and 0-45wt.% glass fibers (D) (the total of components A to D being 100wt.%), and satisfying the requirements: 0.6>B/A>0.05, and 0.4>C(A+B) (wherein A to C are the amounts of components A to C used, respectively).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow molded article, and more specifically, it is made of a polyamide resin composition and is excellent in heat resistance, mechanical properties and chemical resistance, and can be molded well. Therefore, the present invention relates to a hollow molded article which is extremely useful as a hollow duct for automobiles and machines and a transportation pipe.

[0002]

2. Description of the Related Art Hollow molded articles made of polyamide resin are widely used because of their excellent mechanical strength, heat resistance and chemical resistance. However, since polyamide resins generally have low viscosity, it is difficult to obtain a large-sized molded product or a complicated molded product by hollow molding. Further, there is a limit in use in parts that require high heat resistance and chemical resistance, such as various ducts used in underhoods of automobiles and oil transfer pipes. In particular, radiators for automobiles that come into contact with high-temperature antifreeze and parts attached thereto have extremely high requirements for heat resistance and chemical resistance. Also, in order not to be easily destroyed by impact,
High impact characteristics are also required.

Conventionally, as a method for improving the hollow moldability of a polyamide resin, a method of blending a polyolefin resin such as an acid-modified polyethylene resin or an ionomer resin with the polyamide resin, or a method of crosslinking the polyamide resin with a crosslinking agent such as an epoxy resin. Are known. However, in the method of blending the polyolefin resin and the ionomer resin, the heat resistance of the polyamide resin is significantly lowered,
In addition, there is a drawback that the chemical resistance is lowered. On the other hand, the method of cross-linking with a cross-linking agent such as an epoxy resin has the drawbacks that the deterioration of the polyamide resin is promoted, the melt viscosity is difficult to adjust, and the impact properties are also poor.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is a polyamide resin having excellent hollow moldability, heat resistance, impact resistance and chemical resistance. It is to provide a hollow molded article made of

[0005]

That is, the gist of the present invention is a hollow molded article comprising a polyamide resin composition, wherein the polyamide resin composition comprises (A) a polyamide resin of 20 to 80% by weight, (B) Polyphenylene sulfide resin (3 to 30% by weight), (C) Ethylene component and / or polyolefin having propylene component as a main constituent, α, β unsaturated carboxylic acid or its derivative was copolymerized and / or graft polymerized. Modified polyolefin resin 5 to 50% by weight and (D) glass fiber 0 to 45% by weight (however, the total amount of the components A to D is 100% by weight), and the respective proportions of the components (A) to (C). Is 0.6>
(B) / (A)> 0.05 and 0.4> (C) /
A hollow molded article characterized by being a polyamide resin composition satisfying the condition of [(A) + (B)]> 0.03.

The present invention will be described in detail below. The hollow molded article of the present invention comprises a polyamide resin composition containing a polyamide resin, a polyphenylene sulfide resin and a modified polyolefin resin as essential components, and glass fiber as an optional component.

First, the polyamide resin will be described.
In the present invention, as the polyamide resin, (1) a lactam having three or more membered rings, (2) a polymerizable ω-amino acid,
(3) A polyamide resin obtained by polycondensation of each polyamide raw material of diamine and dicarboxylic acid can be used.

Specific examples of the lactam having a three-membered ring or more include ε-caprolactam, enanthlactam, α-pyrrolidone, α-piperidone and the like.
Specific examples of the amino acid include 6-aminohexanoic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid and 9-aminononanoic acid.

Specific examples of the diamine include hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, metaxylylenediamine, and the like, and specific examples of the dicarboxylic acid include terephthalic acid. , Isophthalic acid, adipic acid, sebacic acid, dodecane dibasic acid, glutaric acid and the like.

Specific examples of the polyamide resin include nylon 4, 6, 7, 8, 11, 12, 6,6, 6,10,6.
・ 11, 6 ・ 12, 6T, 6/6 ・ 6, 6/12, 6 /
6T, 6I / 6T and the like can be mentioned. In the present invention,
Nylon 6 resin, nylon 6 · 6 resin and various copolymers containing them as a main component are preferably used. And
The melting point of the polyamide resin is 200 ° C. from the viewpoint of heat resistance.
The above is preferable.

The relative viscosity (η _rel ) of the polyamide resin is 2 or more, preferably 4 or more as a value measured in accordance with JIS K6810 in 98% sulfuric acid at a concentration of 1% and a temperature of 25 ° C. It If the relative viscosity of the polyamide resin is too low, the hollow moldability is insufficient.

Next, the polyphenylene sulfide resin will be described. The polyphenylene sulfide resin used in the present invention contains 90 mol% or more, preferably 95 mol% of repeating units represented by the following chemical formula [Chemical formula 1].
It is a polymer containing the above.

[Chemical 1]

The polyphenylene sulfide resin as described above is commercially available, for example, from Phillips Chemical Co. under the trademark "Ryton". Generally, the polyphenylene sulfide resin has a low melt viscosity, but in the present invention, the polyphenylene sulfide having a melt viscosity of 1,000 poise or more, preferably 10,000 poise or more, measured under the conditions of a temperature of 300 ° C. and an apparent shear rate of 200 sec ^−1. Resins are preferred.

Next, the modified polyolefin resin will be described. The modified polyolefin resin used in the present invention is a modified polyolefin resin obtained by copolymerizing and / or graft-polymerizing an α, β unsaturated carboxylic acid or a derivative thereof with a polyolefin having an ethylene component and / or a propylene component as main constituent components. is there.

Examples of the polyolefin resin include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-ethylacryl. Examples thereof include acid copolymers and ethylene-sodium acrylate copolymers.

As the α, β-unsaturated carboxylic acid or its derivative to be copolymerized, acrylic acid, methacrylic acid,
Methyl methacrylic acid, sodium acrylate, zinc acrylate, vinyl acetate, glycidyl methacrylate and the like can be mentioned, and they are contained within the range of 40 mol% in the molecular chain. Examples of the modified polyolefin as described above include ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-ethylacrylic acid copolymer, ethylene-sodium acrylate copolymer and the like.

The α, β-unsaturated carboxylic acid or its derivative to be grafted is, for example, acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid or their acid anhydrides, or esters of these acids. ,
For example, an ester represented by the following chemical formula [Formula 2] and the like can be mentioned.

[0018]

[Chemical 2]

In the above chemical formula, n is 0 to 4 and m is 1 to 1.
0 represents an integer, R ¹ and R ² represent a hydrogen atom or an alkyl group, and R ³ represents a hydrogen atom, an alkyl group or a carboxyl group. Among the above-mentioned modifying compounds, maleic anhydride is particularly preferable. The grafting amount is selected from the range of 0.01 to 25% by weight, preferably 0.05 to 1.5% by weight, based on the polyolefin resin.

The grafting reaction is usually carried out by melt-mixing a polyolefin resin and an α, β-unsaturated carboxylic acid or its derivative at a resin temperature of 150 to 300 ° C. according to a conventional method. In the grafting reaction, an organic peroxide such as α, α′-bis-t-butylperoxy-p-diisopropylbenzene is added in an amount of 0.001 to 0.05% by weight in order to efficiently carry out the reaction. Is good.

Next, the glass fiber will be described. Although glass fiber is an optional component, it has the effect of enhancing the heat resistance and rigidity of the hollow molded article of the present invention. The shape of the glass fiber is not limited, roving glass commercially available as resin-reinforced glass fiber, chopped strand glass,
Glass fibers of any shape up to milled glass can be selected. Further, the length of the glass fiber in the hollow molded product is preferably about 0.005 to 10 mm.

In the present invention, the above components are blended in the following proportions. That is, (A) polyamide resin is 20
-80% by weight, (B) polyphenylene sulfide resin 3 to 30% by weight, (C) modified polyolefin resin 1 to
50% by weight and (D) glass fiber 0 to 45% by weight (however, the total amount of components A to D is 100% by weight), and the respective proportions of components (A) to (C) are 0.6> (B ) / (A)
> 0.05 and 0.4> (C) / [(A) + (B)]>
The condition of 0.03 is satisfied.

If the blending ratio of the polyphenylene sulfide resin is less than the above range, the effect of improving the heat resistance and chemical resistance of the polyamide-based fat-based composition is insufficient, and if it is more than the above range, hollow molding is performed. Sex decreases. Also,
When the blending ratio of the modified polyolefin resin is more than the above range, the heat resistance of the polyamide-based fat composition is significantly reduced and the hollow moldability is also lowered, and when the blending ratio is less than the above range, the impact is decreased. And the effect of improving hollow moldability are insufficient. Glass fiber content of 45% by weight
If it exceeds, the lightness is impaired and the surface smoothness is deteriorated. The preferred blending amount of glass fiber is 10 to 3
It is 0% by weight.

The above-mentioned hollow moldability means that in hollow molding, there is little self-weight deformation called drawdown when forming a cylindrical parison before so-called hollow blow molding, and moreover, puncture occurs during blow molding. In other words, it means that a hollow molded product having less uneven thickness, uniform expansion, and less wall thickness distribution can be obtained.

In the present invention, a copper compound may be added to the above polyamide-based fat-based composition in order to increase the strength of the pinch-off portion during hollow molding. The copper compound is not particularly limited as long as it can be uniformly blended with the polyamide resin, and halogens such as copper iodide, cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, etc. Organic acids such as copper oxide, copper formate, copper acetate, copper propionate, copper stearate, copper oxalate, copper sebacate, copper lactate, copper benzoate, copper salicylate, copper sulfate, copper nitrate, copper phosphate, and copper Inorganic acid copper such as copper phosphate or a copper chelate compound may be mentioned.
Particularly, copper iodide or cuprous chloride is preferable.

It is also possible to add various inorganic fillers to the above polyamide-based fat-based composition as a filler for supplementing glass fibers. Specifically, carbon fibers, fibers such as metal whiskers, ceramic fibers, silica, silica-alumina, titania, magnesia, kaolin, talc, wollastonite, bentonite, novaculite, graphite, glass flakes and other granular inorganic fillers. Is mentioned.

Further, the above polyamide-based fat-based composition may be blended with a coloring agent such as carbon black or titanium oxide, a flame retardant, an antistatic agent, a weather resistance-imparting agent, and the like. It is also possible to mix other resins within the range that does not impair the above. The above-mentioned respective components are compounded by, for example, a well-known method using a Banbury mixer, a super mixer, an extruder, etc.
A melt mixing method utilizing an extruder is preferable.

[0028]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples unless it exceeds the gist thereof. In the following examples, measurement values and the like were measured by the following methods. (1) Melt viscosity Measured with a capillary rheometer manufactured by Orientec Co., Ltd. (2) Vicat thermal softening temperature It was measured according to ASTM D-1525. (3) Izod impact strength For test pieces of 1/2 ″ thickness, ASTM D-256
It was measured according to.

(4) Blow Moldability A blow molding machine with a die diameter of 25 mm was used, and the diameter was 6
A bottle of 0 mm and a height of 200 mm was blow-molded, and the wall thickness of the obtained bottle was measured with a micrometer at a portion 20 mm from the upper and lower end surfaces. FIG. 1 is an explanatory diagram of a bottle used for evaluation of blow moldability. Here, it is shown that the thicker the wall, the less the drawdown of the parison. Therefore, it is preferable that the wall thickness is large and the difference between the upper and lower wall thicknesses is small.

(5) Antifreeze resistance Commercially available antifreeze at 120 ° C. (“Long L” manufactured by Kyoishi Co., Ltd.)
An Izod impact test piece having a thickness of 1/2 ″ was immersed in “if Coolant”), and the impact strength after 250 hours and 500 hours was measured.

Reference Example 1 (Production of Polyphenylene Sulfide Resin) In an autoclave, 32.6 kg of sodium sulfide (2
50 mol, containing 40% by weight of water of crystallization), 100 g of sodium hydroxide, 36.1 kg of sodium benzoate (250
Mol) and 79.2 kg of N-methylpyrrolidone, the temperature is gradually raised to 205 ° C. with stirring, and water 6.9 is added.
7.01 kg of distillate containing kg was removed. To the residual mixture, 37.5 kg of 1,4-dichlorobenzene and 20.0 kg of N-methylpyrrolidone were added and heated at 265 ° C for 4 hours. The reaction product was washed 8 times with hot water, dried in a vacuum dryer at 150 ° C. for 12 hours, and further heated in a hot air circulation dryer at 150 ° C. for 24 hours. A resin powder having a melt viscosity of 1200 poise was obtained.

Reference Example 2 (Production of Modified Polyolefin Resin) 100 parts by weight of an ethylene-propylene copolymer having a melt index of 0.7 and a propylene content of 21% by weight measured at a resin temperature of 230 ° C. were added to a small amount of acetone. 0.025 parts by weight of dissolved α, α'-bis-t-butylperoxy-p-diisopropylbenzene and 0.4 parts by weight of maleic anhydride were mixed in a Henschel mixer,
The obtained blended product was melt-kneaded at a resin temperature of 230 to 240 ° C. with a single screw extruder having a cylinder diameter of 40 mm to form pellets. Press molding a part of the obtained pellets,
As a result of quantifying maleic anhydride in the infrared spectrum,
0.32% maleic anhydride was detected.

Examples 1 to 6 and Comparative Examples 1 to 5 As a polyamide resin, a commercially available nylon 6 resin having a relative viscosity of 5.5 (“Novamid 1040” manufactured by Mitsubishi Kasei Co., Ltd.)
And a commercially available nylon 66 resin (“Zytel 42” manufactured by DuPont) having a relative viscosity of 5.5 was used. In accordance with the proportions shown in Table 1, the above-mentioned nylon resins were blended with the polyphenylene sulfide resin of Reference Example 1, the modified polyolefin resin of Reference Example 2 and a commercially available glass fiber (Asahi Fiber Glass Co., Ltd. “MA486”), and a cylinder diameter 30m
m extruder with a vent, resin temperature 250-290 ℃
Were melt-kneaded in the range of 1 to obtain pellets, and then the obtained pellets were vacuum dried with a vacuum dryer at 100 ° C.

With respect to the above pellets, a test piece was molded by an injection molding machine and blow moldability was evaluated by a blow molding machine. As the injection molding machine, an injection molding machine (“IS75PNII” manufactured by Toshiba Machine Co., Ltd.) having a mold clamping force of 75 t was used.
A blow molding machine having a cylinder diameter of 50 mm (“NB3B / S50” manufactured by Nippon Steel Co., Ltd.) was used as the blow molding machine. The Izod impact strength and the Vicat heat softening point of the obtained test piece were measured, and an antifreeze resistance immersion test was performed. Table 2 shows the above measurement results and the like.

[0035]

[Table 1] ──────────────────────────────────── Nylon 6 Nylon 66 PPS modified PO glass fiber ─ ─────────────────────────────────── Example 1 50 ── 20 10 20 Example 2 ── 70 20 10 --Example 3 --45 20 15 20 20 Example 4 --55 55 20 5 20 Example 5 --65 5 5 10 20 Example 6 --50 50 10 5 35 Comparative Example 1 100 ------- Comparative Example 2 ── 60 20 20 ── 20 Comparative Example 3 ─ 70 70 ── 10 20 Comparative Example 4 ─ 35 35 15 15 20 Comparative Example 5 ── 35 10 ────────── ────────────────────────── In the table, "PPS" is polyphenalene sulfide. "Modified PPO" represents a modified polyolefin. The unit of each numerical value is% by weight.

[0036]

[Table 2] ──────────────────────────────────── Blow molding thickness Vicat Immersion in antifreeze / Izod impact Strength Upper and lower thermal softening points 0Hr 100Hr 250Hr ──────────────────────────────────── Example 1 1.85 2.10 192 21 26 23 Example 2 1.65 1.80 235 30 48 45 Example 3 1.90 2.20 245 24 31 33 Example 4 1.60 1.85 249 17 26 29 Example 5 1.75 2.00 242 20 29 30 Example 6 2.20 2.45 253 18 30 32 Comparison Example 1 Unmoldable 197 5 15 6 Comparative Example 2 Unmoldable 250 7 24 25 Comparative Example 3 1.80 2.25 246 21 35 18 Comparative Example 4 Unmoldable 255 14 21 19 Comparative Example 5 Unmoldable 218 25 18 11 ─────── ────────────────────────────── “Unmoldable” in the table is due to puncture, and
The unit of each measured value is as follows. Blow molding thickness: mm Vicat softening point: ° C Izod impact strength: Kg-cm / cm

As is clear from the results shown in Table 2, the hollow molded article of the present invention can be blow molded satisfactorily and has a large and uniform wall thickness. In addition, it has high impact resistance and heat resistance, and is also excellent in antifreeze resistance.

[0038]

EFFECTS OF THE INVENTION According to the present invention described above, a polyamide resin composition is used, which is excellent in heat resistance, mechanical properties and chemical resistance and can be molded well, and therefore, a hollow duct for automobiles and machines. Provided is a hollow molded article which is extremely useful as a pipe or a transportation pipe.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a bottle used for evaluation of blow moldability.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08K 7/14 KLC 7242-4J C08L 23/26 LDA 7107-4J 51/06 LLE 7142-4J // (C08L 77/00 81:02 51:06) B29K 77:00 B29L 22:00 4F 31:30 4F

Claims (2)

[Claims] 1. A hollow molded article comprising a polyamide resin composition, wherein the polyamide resin composition comprises (A)
Polyamide resin (20 to 80% by weight), (B) polyphenylene sulfide resin (3 to 30% by weight), and (C) an ethylene and / or propylene component as a main constituent polyolefin are mixed with α, β unsaturated carboxylic acid or its derivative. 1 to 50% by weight of a modified and / or graft-polymerized modified polyolefin resin and 0 to 45% by weight of (D) glass fiber (however, the total amount of components A to D is 100% by weight), and (A) To (C) component ratios of 0.6> (B) / (A)> 0.05 and 0.4>
A hollow molded article, which is a polyamide resin composition satisfying the condition of (C) / [(A) + (B)]> 0.03. 2. The hollow molded article according to claim 1, which is used for a radiator for an automobile and parts attached thereto.