JP2669978B2 - Canister - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a canister using polybutylene naphthalenedicarboxylate (hereinafter abbreviated as PBN), and more particularly to mechanical strength, chemical resistance, oil resistance, gasoline resistance and gas resistance. Related to canisters with excellent properties such as oar properties.

[0002]

2. Description of the Related Art Many kinds of materials such as metal, glass, rubber, and plastics are used in automobiles. Among them, the use of thermoplastics has been gradually increasing in recent years due to the fact that the weight of the vehicle is reduced, the degree of freedom of design is large, and the productivity is high and the cost can be easily reduced.

[0003] Among the parts for automobiles, general-purpose plastics such as polyethylene and polypropylene have been used from a relatively early stage for parts having moderate characteristics. However, parts used in harsh environments such as engine rooms and the like, which are used in harsh environments such as high temperature and high humidity, are increasingly being replaced with plastics. Therefore, engineering plastics such as polyamide, polyacetal, and polybutylene terephthalate (hereinafter abbreviated as PBT) are often used. It is becoming used.

Each engineering plastic has excellent characteristics, but it also has drawbacks. For example, polyamide has mechanical properties, heat resistance, oil resistance, gasoline resistance,
Although excellent in moldability and the like, the water absorption is high, so that dimensional change and mechanical strength are greatly reduced by water absorption, and stress cracks are caused by metal salts. Although PBT is excellent in mechanical properties, heat resistance, heat aging resistance, electrical properties, chemical resistance, and moldability, PBT has poor hot water resistance and alkali resistance. is there. These characteristics are manifested by the primary structure of the polymer and the characteristic groups such as amide group and ester group. Can not be a practical solution.

In the case of canisters, the case that was originally metal has been gradually replaced by polyamide. However, as described above, the polyamide causes stress cracks due to the metal salt and also has low gas-all resistance, so that improvement is required.

Accordingly, the present inventors have conducted intensive studies on the materials for obtaining a canister excellent in mechanical strength, chemical resistance, oil resistance, gasoline resistance, and gas all resistance, and as a result, have reached the present invention.

[0007]

The present invention is a canister using polybutylene naphthalene dicarboxylate.

In the present invention, PBN is a polyester containing naphthalene dicarboxylic acid, preferably naphthalene-2,6-dicarboxylic acid as a main acid component and 1,4-butanediol as a main glycol component, that is, all or all of the repeating units. Most (usually 90 mol% or more, preferably 95 mol% or more) of the polyester is butylene naphthalenedicarboxylate.

Further, the following components can be copolymerized in this polyester as long as the physical properties are not impaired. That is, as the acid component, aromatic dicarboxylic acids other than naphthalenedicarboxylic acid, for example, phthalic acid, isophthalic acid, terephthalic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl methane dicarboxylic acid, diphenyl ketone dicarboxylic acid, Examples thereof include diphenyl sulfide dicarboxylic acid, diphenyl sulfone dicarboxylic acid, and aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and alicyclic dicarboxylic acids such as cyclohexane dicarboxylic acid, tetralin dicarboxylic acid, and decalin dicarboxylic acid.

As the glycol component, ethylene glycol, propylene glycol, trimethylene glycol,
Pentamethylene glycol, hexamethylene glycol, octamethylene glycol, neopentyl glycol, cyclohexanedimethanol, xylylene glycol, diethylene glycol, polyethylene glycol,
Examples include bisphenol A, catechol, resorcinol, hydroquinone, dihydroxydiphenyl, dihydroxydiphenylether, dihydroxydiphenylmethane, dihydroxydiphenylketone, dihydroxydiphenylsulfide, and dihydroxydiphenylsulfone.

Examples of the oxycarboxylic acid component include oxybenzoic acid, hydroxynaphthoic acid, hydroxydiphenylcarboxylic acid, and ω-hydroxycaproic acid.

Further, as long as the polyester does not substantially lose the molding performance, trifunctional or higher functional compounds such as glycerin, trimethylpropane, pentaerythritol, trimellitic acid and pyromellitic acid can be copolymerized.

Such a polyester is obtained by polycondensing naphthalenedicarboxylic acid and / or a functional derivative thereof with butylene glycol and / or a functional derivative thereof using a conventionally known method for producing an aromatic polyester.

The PBN polymer thus obtained may contain, if necessary, various additives, for example, reinforcing agents having various shapes such as fibrous, plate-like and powder-like, as long as their physical properties are not significantly impaired. Stabilizers, coloring agents, ultraviolet absorbers, release agents, antistatic agents, crystallization accelerators, nucleating agents, fillers, impact modifiers, flame retardants, flame retardant auxiliaries and the like can be added.

In preparing the composition from the PBN polymer and these additives, it is possible to use known equipment and methods generally used as a conventional method for preparing a resin composition.

Injection molding is most preferred as a method for obtaining a molded article from PBN alone or a PBN composition, but other known molding methods such as extrusion molding, compression molding, transfer molding and blow molding are also available. In addition to the above, it is also possible to further subject the molded product obtained by these molding methods to secondary processing such as cutting, welding, bonding, joining, bending, plating vapor deposition, printing and painting. The automobile part of the present invention can be obtained by using the molded article made of PBN thus obtained.

The automotive parts using the PBN of the present invention are:
Compared with conventional parts using polyamide, PBT, etc., they have excellent properties such as mechanical strength, chemical resistance, oil resistance, gasoline resistance, and gas all resistance.

Next, the present invention will be further described with reference to examples. In addition, the measuring method of the main characteristics is as follows. (1) Tensile strength Based on ASTM D-638. (2) Chemical resistance After dipping in a 10% hydrochloric acid and a 10% NaOH aqueous solution for 7 days at 20 ° C., the appearance was visually judged. Further, after applying a saturated aqueous solution of calcium chloride, heat treatment was performed at 100 ° C. for 24 hours, and the appearance was observed. (3) Gasoline resistance and gas all resistance A film having a thickness of 300 μm was prepared using each polymer, and a gas permeation test of gasoline and gas all was performed at 60 ° C.

[0019]

Example 1 A PBN polymer was injection molded at 270 ° C. to obtain a tensile test piece. The test piece was used for the test of the above (1).

[0020]

Comparative Example 1 A PBT polymer was injection molded at 250 ° C., and a test was conducted in the same manner as in Example 1.

[0021]

Comparative Example 2 Polyamide 66 (Asahi Kasei Leona 1402)
S) was injection-molded at 270 ° C., and a test was conducted in the same manner as in Example 1.

The above results are summarized in Table 1.

[0023]

[Table 1]

 ────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Ken Kojima 3-37-19 Oyama, Sagamihara City, Kanagawa Teijin Limited, Sagamihara Research Center (56) Reference JP-A-2-60956 (JP, A) JP Hira 4-268339 (JP, A) Jitsuko Sho 59-39164 (JP, Y2)

Claims (2)

(57) [Claims] 1. A canister using polybutylene naphthalenedicarboxylate. 2. The canister according to claim 1, wherein the polybutylene naphthalene dicarboxylate is polybutylene-2,6-naphthalene dicarboxylate.