JPH11269375A - Composition for liquid or gas barrier tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding composition for liquid or gas barrier tubes that can solves the deficiency of the conventional polyamide resin moldings to permeate liquid or gas therethrough. SOLUTION: This composition comprises (A) 100 pts.wt. of a polyamide resin with an average molecular weight of 9,000-30,000 or a resin mixture containing the same and (B) 0.05-10 pts.wt. of a laminar silicate salt 0.002-1 μm long in its sides, 6-20 Å thick, dispersed 20 Å apart from each other on the average in the component (A).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material for a molded article having a liquid or gas barrier property, and more particularly, to a fluid for transferring a fluid such as a tube, a tank, a strainer, various covers, and storing or filtering a fluid. The present invention relates to a material for molded articles having a liquid or gas barrier property used for processing.

[0002]

2. Description of the Related Art Polyamide resins are widely used as injection molding materials, especially for parts such as automobiles and electric appliances, because their molded products have excellent mechanical properties.

[0003] However, polyamide resins have the property of permeating liquids and gases such as moisture, alcohol, freon gas, and gasoline, and various problems are caused by this property. For example, when a nylon tube is used as a freon tube related to a refrigeration system, a problem arises in that the freon penetrates and the freon in the device decreases,
When a nylon tank is used as a brake tank in the automotive field, there is a problem that water enters the brake fluid, and when a nylon tank is used as a gasoline tank, there is a problem that water enters the gasoline. Occurs. Further, even when a gasoline tank composed of two or more layers of polyethylene-nylon is used, if the nylon layer is too thin, gasoline will still permeate, causing a problem that it will not comply with pollution regulations and the like.

[0004] In order to solve such problems, attempts have been made to superimpose a plurality of layers of resins having different barrier properties to satisfy the specifications. However, these methods also have a problem that the process of manufacturing a molded article is complicated and that a sufficiently satisfactory barrier property cannot be obtained.

[0005]

Conventional molded articles of polyamide resin have various problems due to the permeation of liquid or gas as described above.

Accordingly, the present invention solves the above problems,
It is an object of the present invention to provide a material for a molded article whose molded article has an excellent liquid or gas barrier property.

[0007]

Means for Solving the Problems The present inventors have found that by blending a layered silicate with a polyamide resin, while maintaining or improving the excellent mechanical and thermal properties possessed by the polyamide resin, the present inventors have further developed a conventional resin. Can improve oxygen and gasoline barrier properties (permeation prevention properties), which are superior to other resins, and improve the relatively poor water and alcohol permeation defects. To complete the present invention.

The material for molded articles having a liquid or gas barrier property of the present invention comprises (A) an average molecular weight of 9,000 to 3,
100 parts by weight of 0000 polyamide resin or a resin mixture containing the polyamide resin, and (B) one side of 0.1 part by weight.
002 μm to 1 μm, 6 to 20 ° in thickness, each comprising 0.05 to 10 parts by weight of a layered silicate uniformly dispersed in the component (A) at an average distance of 20 ° or more. And

The component (A) constituting the molded article material of the present invention is a polyamide resin or a resin mixture containing a polyamide resin.

[0010] The polyamide resin has an acid amide bond (-CONH-) in the molecule.
ε-caprolactam, 6-aminocaproic acid, ω-enantholactam, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid, α-pyrrolidone, α
-A polymer or copolymer obtained from piperidone or the like;
Polymers obtained by polycondensation of diamines such as hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, metaxylylenediamine and dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid and sebacic acid Alternatively, a copolymer or a blend thereof can be exemplified.

The polyamide resin of the component (A) preferably has an average molecular weight of 9,000 to 30,000.

As the other resin used when the component (A) is a mixture of a polyamide resin and another polymer, polypropylene, ABS resin, polyphenylene oxide, polycarbonate, polyethylene terephthalate, polybutylene terephthalate and the like can be exemplified. .

When the component (A) is used as a mixture, the content of the polyamide resin is preferably at least 40% by weight.

The component (B) is a layered silicate. The component (B) is a component that contributes to imparting an excellent liquid or gas barrier property to the material for molded articles.

The layered silicate has a side of 0.002 to 0.002.
One micrometer means one unit having a thickness of 6 to 20 mm.

When the layered silicate is dispersed in the component (A),
It is preferable that each of them maintains an interlayer distance of 20 ° or more on average and is uniformly dispersed. Here, the interlayer distance refers to the distance between the centers of gravity of the plate of the layered silicate, and to uniformly disperse, the layered silicates are one by one, or the multilayers having an average overlap of 5 layers or less are 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.

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-based clay minerals such as stevensite, vermiculite, halloysite, and the like can be exemplified. May be done.

The amounts of the components (A) and (B) are
Component (B) is 0.05 with respect to 100 parts by weight of component (A).
To 10 parts by weight. (B) The mixing ratio of the component is 0.05
If the amount is less than 10 parts by weight, the effect of improving the liquid or gas barrier properties is small, and if it exceeds 10 parts by weight, the impact strength and elongation at break of the molded product are deteriorated, and the excellent properties inherent to the polyamide resin are impaired. It is not preferable.

The material for molded articles of the present invention may be appropriately mixed with dyes, pigments, fibrous reinforcing materials, particulate reinforcing materials, plasticizers, heat resistance, foaming agents, flame retardants, and the like according to the purpose. Can be.

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

When the raw material of the layered silicate as the component (B) is a multilayer clay mineral, it is brought into contact with a swelling agent to expand the layers in advance so that the monomers can be easily taken in between the layers, and then mixed with the polyamide monomer. And a method of polymerizing
-74957). Alternatively, a method may be used in which a polymer compound is used as a swelling agent, the interlayer is previously spread to 100 ° or more, and the mixture is melt-kneaded with a polyamide resin or a resin containing the same to uniformly disperse them.

The reason why the molded article obtained from the material for molded articles of the present invention exhibits excellent liquid or gas barrier properties is not clear, but the layered silicate is microscopically dispersed in the polyamide resin. It is thought to act to obstruct the flow path of the liquid or gas.

The molding material of the present invention can be applied to various uses requiring liquid or gas barrier properties. Applicable applications include gasoline tanks, alcohol tanks, fuel tubes, fuel strainers, brake oil tanks, clutch oil tanks,
Examples include a power steering oil tank, a cooler freon tube, a freon tank, a canister, an air cleaner, and an intake system part.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Example 1 Montmorillonite 1 having a layered silicate thickness of 9.5 mm on average and an average length of one side of about 0.1 μm
Was dispersed in 10 L of water, and 51.2 g of 12
-Aminododecanoic acid and 24 mL of concentrated hydrochloric acid were added, and the mixture was stirred for 5 minutes and then filtered. After sufficiently washing this, it was vacuum-dried. By this operation, a complex of ammonium 12-aminododecanoate ion and montmorillonite was prepared. The layered silicate content in the composite was 80% by weight. The distance between the silicate layers was 18.0 ° as measured by X-ray diffraction of this composite.

Next, 10 kg of ε was added to a reaction vessel equipped with a stirrer.
-Caprolactam, 1 kg of water and 100 g of the complex were added, and stirred at 100 ° C so that the inside of the reaction system became uniform. Further raise the temperature to 260 ° C,
The mixture was stirred under a pressure of / cm ² for 1 hour. Thereafter, the pressure was released, and the reaction was carried out at normal pressure for 3 hours 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 composed of a polyamide resin (average molecular weight of 15,000) and montmorillonite. This pellet is immersed in hot water, and unreacted monomer (about 10%)
Was extracted and removed, and then dried in vacuum to obtain a material for a molded article of the present invention. The interlayer distance of this material measured by X-ray diffraction was 100 ° or more.

(Test for Confirming Barrier Property) The barrier property against freon, water and gasoline was tested by the following method. The results are shown in the table.

The barrier properties against Freon First, a molded article material obtained was extruded under the following conditions, an outer diameter of 1/2 inch and a thickness was prepared 1mm tube.

Extrusion molding conditions Extruder: Screw diameter: 30 mm, manufactured by Nippon Steel Works Cylinder set temperature: C ₁ 220 ° C .; C ₂ 255 ° C .; C ₃ 255 ° C .; Die 250 ° C. Cooling conditions: water-soluble, water temperature 15 ℃

Next, the tube was cut into a length of 300 mm and reinforced with a blade (since pressure was applied to the tube after Freon injection). Freon R-22 (manufactured by Daikin Industries, Ltd., Daiflon 22) was injected into the tube until it was filled, and the tube was sealed. Note that this injection is -4
The temperature was returned to room temperature at 0 ° C., the water adhering to the tube was wiped off, and the tube was dried once at 100 ° C. for 22 hours to remove the adhering water, and the weight was used as the initial value. The Freon injection tube was then treated at 23 ° C. for 2 hours and 10 minutes.
The drying operation for a total of 24 hours at 0 ° C. for 22 hours was repeated for 10 days or more, and the average permeation amount of freon per day was measured.

Water barrier property The same tube used in the Freon barrier property test was filled with calcium chloride (water absorbent) until it was filled and sealed. Next, this tube was left in an atmosphere at 40 ° C. and a relative humidity of 90% for 10 days or more, and the average amount of water permeated per unit area per day was measured.

Barrier property against gasoline The above molding material, high-density polyethylene (Hizex 8200; manufactured by Mitsui Petrochemical Industry Co., Ltd.) and an adhesive (Admer; manufactured by Mitsui Petrochemical Industry Co., Ltd.) are used, and Hizex 8200 (outer layer) is used. /
Admar (intermediate layer) / Molding material (inner layer) = 0.6mm thickness /
A bottle of 0.2 mm thickness / 0.1 mm thickness, 60 mm (diameter) × 200 mm, having a volume of about 500 mL was prepared by a three-layer blow molding machine. 250 cc of gasoline was injected into the bottle, and the bottle was closed and allowed to stand at 60 ° C. for 12 weeks. The average daily gasoline permeation of gasoline per unit area was measured by the weight loss of the whole bottle.
In addition, since the gasoline permeation amount of the bottle not including the inner layer is 100 times or more than that of the bottle including the inner layer, the outer layer and the intermediate layer need not be considered in the present measurement results.

(Mechanical Properties of Injection Molded Article) A molding material was injection molded under the following molding conditions to prepare a test piece for measuring mechanical properties. The following tests were performed on this test piece. The results are shown in the table.

Injection molding conditions Injection molding machine: IS-80 manufactured by Toshiba Machine Co., Ltd. Cylinder set temperature: C ₁ 240 ° C .; C ₂ 250 ° C .; C
₃ 250 ° C .; C ₄ (nozzle) 250 ° C. Injection pressure: 600 kg / cm ² Mold temperature: 88 ° C. Injection time: 10 seconds Cooling time: 20 seconds

Mechanical property measurement method Tensile yield point strength: ASTM-D-638 Elongation at break: ASTM-D-638 Flexural strength: ASTM-D-790 Flexural modulus: ASTM-D-790

All tests were carried out at 23 ° C. in a completely dry state.

Example 2 A molding material was obtained in the same manner as in Example 1 except that the amount of the composite prepared in Example 1 was changed to 200 g, and each measurement was carried out. The results are shown in the table.

Example 3 A molding material was obtained in the same manner as in Example 1 except that the amount of the composite prepared in Example 1 was changed to 500 g, and each measurement was carried out. The results are shown in the table.

Comparative Example A molding material was obtained in the same manner as in Example 1 except that montmorillonite was not used, and each measurement was performed. The results are shown in the table. The display shows that the smaller the transmittance, the better the barrier property.

[0039]

[Table 1]

[0040]

The material for molded articles of the present invention exhibits excellent barrier properties against liquids and gases while maintaining or improving the excellent mechanical and thermal properties of the polyamide resin.

Continued on front page (72) Inventor Ryuichi 1978-10 Kogushi, Ube-shi, Ube-shi, Yamaguchi Ube Industries, Ltd.Ube Chemical Plant Co., Ltd. (72) Inventor Akane Okada 41-41, Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture

Claims (1)

[Claims] (A) an average molecular weight of 9,000 to 30,0
100 parts by weight of a polyamide resin or a resin mixture containing the polyamide resin, and (B) 0.002 on one side.
A liquid or gas barrier consisting of 0.05 to 10 parts by weight of a layered silicate uniformly dispersed in the component (A), each having a thickness of 6 to 20 .mu.m and a thickness of 6 to 20.degree. Tube material.