JP2834477B2 - Hollow molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a polyamide hollow molding material, and more specifically, has excellent hollow molding properties, and has rigidity, dimensional safety, and The present invention relates to a polyamide hollow molding material having surface smoothness.

(Prior Art) Polyamide resins are widely used in hollow molded products such as bottles, tanks, air ducts and hollow pipes because of their excellent mechanical and thermal properties.

However, in order to adapt the melt viscosity characteristics of the polyamide resin to hollow molding processing, it must be a high molecular weight resin, but in general, it is technically difficult to produce such a resin. An olefin resin is mixed (Japanese Patent Publication No. 55-41659) or a glass fiber is mixed (Japanese Patent Application Laid-open No. Sho 60-171133) to increase the viscosity of polyamide and to improve the hollow molding properties.

However, thickening by an olefin resin reduces heat resistance and chemical resistance, so that the field of use is restricted by itself. In addition, although thickening by glass fiber improves hollow molding properties and mechanical properties, the surface condition of the molded product is rough, and the appearance, particularly the surface smoothness of the inner surface not in contact with the mold is poor, and the air duct and Parts through which gas flows inside the intake manifold and the like have problems such as generation of noise.

(Problems to be Solved by the Invention) The present invention improves the above-mentioned problems of the polyamide hollow molding material, and has excellent hollow molding characteristics and excellent rigidity, dimensional stability, heat resistance and surface smoothness. It is an object of the present invention to provide a hollow molding material.

[Constitution of the Invention] (Means and Actions for Solving the Problems) The present invention is a polyamide hollow molding material comprising 100 parts by weight of a polyamide resin (A) and 0.05 to 30 parts by weight of a layered silicate (B). .

The polyamide resin (A) has an acid amide bond (-
CONH), specific examples include ε-caprolactam, 6-aminocaproic acid, ω-enantholactam, 7-aminoheptanoic acid, 11-aminoundecanoic acid,
Polymers or copolymers obtained from 9-aminononanoic acid, α-pyrrolidone, α-piperidone, etc .; diamines such as hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, meta-xylylenediamine and terephthalic acid And a polymer or copolymer obtained by polycondensation with a dicarboxylic acid such as isophthalic acid, adipic acid and sebacic acid, or a blend thereof.

The average molecular weight of the polyamide resin (A) is 25,000 to 35,0
00 is preferred.

If the average molecular weight is 25,000 or less, the hollow molding properties are lowered, and if it is 35,000 or more, the production of polyamide itself becomes difficult, which is not preferable.

The layered silicate (B) gives the polyamide resin (A) excellent hollow molding properties, excellent mechanical properties and heat resistance without impairing its surface properties.

After the layered silicate (B) is dispersed in the component (A),
It is preferable that the interlayer distance is maintained at an average of 20 ° or more on average and the layer is uniformly dispersed. Here, the interlayer distance refers to the distance between the centers of gravity of the plate of the layered silicate. To uniformly disperse the layered silicate one by one, or a multilayer having an average overlap of 5 layers or less in parallel, Or, a state in which 50% by weight or more, preferably 70% by weight or more is dispersed without forming a local mass at random or in a state where parallel and random are mixed. Therefore, the layered silicate refers to one unit of a substance having a thickness of 6 to 20 ° and one side of 0.002 to 1 μm.

As a raw material of such a layered silicate, a layered phyllosilicate mineral composed of a layer of magnesium silicate or aluminum silicate can be exemplified. Specifically, montmorillonite, saponite, beidellite, nontronite, hectorite, smectite clay minerals such as stevensite and vermiculite, halloysite, etc. can be exemplified. May be done. Among these, montmorillonite is preferred.

The composition of the component (A) and the component (B) is such that the component (B) is 0.05 to 30 parts by weight based on 100 parts by weight of the component (A).
If the composition of the component (B) is less than 0.05 part by weight, the hollow molding properties of the material, the mechanical properties, the heat resistance and the dimensional stability are not significantly improved. Is not preferable because it becomes difficult.

Dyes and pigments according to the purpose for the molded article material of the present invention,
An appropriate amount of a fibrous reinforcing agent, a particulate reinforcing agent, a plasticizer, a heat-resistant agent, a foaming agent, a flame retardant, an impact resistance improving agent, a cross-linking agent, and the like can be appropriately compounded.

The method for producing the material for molded articles of the present invention is not particularly limited, but for example, the following method can be applied.

When the layered silicate (B) is a multilayered clay mineral,
This method involves contacting with a swelling agent to spread the interlayer in advance to make it easier to take in the monomer between the layers, and then mixing with a polyamide monomer and polymerizing (see JP-A-62-74957). In addition, using a polymer compound as the swelling agent,
It is also possible to employ a method in which the resin is spread to 20 ° or more, melt-kneaded with a polyamide resin or a resin containing the same, and uniformly dispersed.

The polyamide hollow molding material of the present invention includes parts or products formed by hollow molding, for example, various tanks such as gasoline tanks, oil tanks, pesticide bottles, various bottles such as drinking water bottles, air ducts, intake manifolds and the like. Intake and exhaust system parts for machinery and automobiles,
Automotive outer panels such as air spoilers, fenders, bumpers, etc.
It can be used for applications such as exterior structural members.

(Example) Example 1 100 g of montmorillonite having a thickness of one unit of the layered silicate of 9.5 mm on average and an average length of one side of about 0.1 μm is dispersed in 10 water, and 51.2 g of 12-amino acid is added thereto. Dodecanoic acid and 2
4 ml of concentrated hydrochloric acid was added, and the mixture was stirred for 5 minutes and then passed.
Further, after sufficiently washing this, it was vacuum-dried. By this operation, a complex of ammonium 12-amidodecanoate and montmorillonite was prepared. The layered silicate content in the composite was 80% by weight.

Next, 10 kg of ε-caprolactam, 1 kg of water and 200 g of the complex were placed in a reaction vessel equipped with a stirrer, and stirred at 100 ° C. so that the inside of the reaction system became uniform. The temperature was further raised to 260 ° C., and the mixture was stirred under a pressure of 15 kg / cm ² for 1 hour. Thereafter, the pressure was released, and the reaction was carried out at normal pressure for 2 hours and a degree of vacuum of 250 Torr for 1 hour while evaporating water from the reaction vessel. After completion of the reaction, the reaction product taken out in a strand form from the lower nozzle of the reaction vessel was water-cooled and cut to obtain a pellet comprising a polyamide resin (average molecular weight 30,000) and montmorillonite. This pellet is immersed in hot water to extract unreacted monomer (about 10%),
After the removal, it was dried in a vacuum to obtain the material for hollow molding of the present invention.

The following evaluation tests were performed on the thus obtained materials. The results are shown in the table.

1) Evaluation of mechanical properties The following mechanical properties and thermal properties were measured for the test pieces injection molded under the following conditions.

<Injection molding conditions> Injection molding machine: Toshiba Machine Co., Ltd. IS-80 cylinder _{temperature: C 1 240 ℃; C 2} 260 ℃; C 3 270 ℃; C 4 ( nozzle) 270 ° C. Injection pressure: 600 kg / cm ⁽²⁾ Mold temperature: 88 ° C Injection time: 10 seconds Cooling time: 20 seconds Measurement item Tensile yield strength: ASTM D-638 Elongation at break: ASTM D-638 Flexural modulus: ASTM D-790 All tests are 23 The test was carried out at 0 ° C. in an absolutely dry state.

 Heat distortion temperature: ASTM D-648 Tested in a completely dry state.

2) Surface roughness 220mm x 120mm x 50mm wall thickness 1.5m from sample under the following conditions
A hollow box of m was prepared, and the smoothness of the inner surface was measured.

<Blow molding conditions> Blow molding machine: Extruder Ube Industries, Ltd. 50 mm diameter parison controller Nippon Moog Resin temperature: 240 ° C Mold temperature: 80 ° C Blow pressure: 6 kg / cm ² G Die diameter: 90 mm <Smooth Measurement of Smoothness> Smoothness was measured by the following method using a surface roughness meter.

(Apparatus) Universal surface profile measuring instrument SE-3C manufactured by Kosaka Laboratory Co., Ltd. (Method) The roughness curve was measured with the above apparatus, and the surface smoothness (roughness) was determined from the width of the curve wave. .

3) Hollow molding property evaluation test Hollow molding was performed using the following hollow molding machine and molding conditions, and the length of each parison after 10 seconds, 20 seconds, and 30 seconds of extrusion time was measured. Down property) was evaluated.

This test evaluates the draw-down property of the parison, and it is preferable that the parison length changes linearly with time.

<Blow molding conditions> Blow molding machine Extruder: screw diameter 50 mm Screw rotation speed: 80 rpm Die diameter: outer diameter 73 mm inner diameter 68 mm Molding temperature: 240 ° C. Example 2 In Example 1, a composite of ammonium 12-aminododecanoate and montmorillonite The same experiment as in Example 1 was performed except that the amount of the body added was 300 g. The results are shown in the table.

Example 3 The same experiment as in Example 1 was performed except that the addition amount of the composite was 400 g. The results are shown in the table.

Comparative Example 1 The same experiment as in Example 1 was performed on the material obtained by polymerizing without adding the composite in Example 1. The results are shown in the table.

Comparative Example 2 For a material obtained by adding and mixing 25 parts by weight of glass fiber to 100 parts by weight of the polyamide resin of Comparative Example 1,
The same experiment was performed. The results are shown in the table.

Comparative Example 3 Viscosity was increased with respect to 100 parts by weight of the polyamide resin of Comparative Example 1.
As an agent, ionomer resin (Himilan 1855) to 35
The same experiment as in Example 1 was conducted for the material mixed with parts by weight.
Was done. The results are shown in the table.

[Effects of the Invention] The polyamide hollow molding material of the present invention is a composition having excellent hollow molding characteristics as compared with conventional materials, and having rigidity, dimensional safety and surface smoothness. Therefore, the characteristics greatly contribute to the above-mentioned various uses.

Continuation of the front page (72) Inventor Akane Okada 41-41, Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture Inside Toyota Central Research Laboratory Co., Ltd. (56) References JP-A-64-11157 (JP, A) JP-A Sho 62-74957 (JP, A) JP-A-60-171133 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08L 77/00-77/12

Claims (1)

(57) [Claims] A hollow molded article obtained by blow molding a composition comprising 100 parts by weight of a polyamide resin (A) having an average molecular weight of 25,000 to 35,000 and 0.05 to 30 parts by weight of a layered silicate (B).