JP2003277549A - Resin composition for water pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition capable of giving a water pipe being excellent in weathering resistance and not undergoing resin deterioration and blistering due to chlorine in city water. <P>SOLUTION: The resin composition is prepared by adding at least one member selected from among a benzotriazole ultraviolet absorber, a benzophenone ultraviolet absorber, and a salicylate ultraviolet absorber to an olefin resin. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for a water pipe, and more particularly to a blister made of chlorine-containing water.
The present invention relates to a resin composition for water pipes in which generation of water is prevented. 2. Description of the Related Art Polyolefin resins such as polyethylene are lightweight, highly flexible, have excellent impact resistance, earthquake resistance, and cold resistance, and have toughness to withstand water hammer such as a water hammer. It is used as a water pipe because it has water. In a water pipe made of a polyolefin resin, weather resistance during storage of a product pipe is required, and usually about 2 to 3% by weight of carbon black is added to the resin in order to impart weather resistance. However, due to the catalytic action of carbon black, resin degradation and water bubbles (blisters) due to chlorine contained in tap water may occur on the contact surface with tap water, and there is no resin deterioration and water bubbles due to chlorine in tap water. Is also required. [0003] Accordingly, an object of the present invention is to provide a resin composition which is excellent in weather resistance and which can be used to manufacture a water pipe without resin deterioration and water bubbles due to chlorine in tap water. It is to be. The present inventors have repeatedly studied to achieve the above object, and as a result, among various additives such as ultraviolet absorbers, light stabilizers, antioxidants, etc. which prevent deterioration of the olefin resin due to light, specific ultraviolet rays It has been found that weather resistance and water bubble resistance are improved by a resin composition in which an absorbent is blended with an olefin resin. [0004] The above object is achieved by the present invention described below. That is, the present invention is a water pipe resin composition obtained by adding at least one selected from a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, and a salicylate-based ultraviolet absorber to an olefin-based resin. Next, the present invention will be described in more detail. The olefin resin used in the present invention can be any of those conventionally used in the production of water pipes,
There is no particular limitation. For example, polyethylene (low to high density), polypropylene, ethylene and α-olefin (for example, butene-1, pentene-1, hexene-1, 4-
Copolymers with methylpentene-1, octene-1 and the like (α-olefin content is about 0.5 to 15% by weight), propylene and α-olefins (eg, ethylene, butene-1, pentene-1) , Hexene-1 and the like (α-olefin content is about 0.5 to 15% by weight). [0006] In the present invention, the ultraviolet absorber incorporated in the olefin resin is at least one selected from a benzotriazole ultraviolet absorber, a benzophenone ultraviolet absorber and a salicylate ultraviolet absorber.
Examples of benzotriazole-based ultraviolet absorbers include, for example,
2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t-
Butyl-5'-methyl-5'-methylphenyl) -5
Chlorobenzotriazole, 2- (2H-benzotriazol-2-yl-4- (1,1,3,3-tetramethylbutyl) phenol, 2- (2H-benzotriazol-2-yl) -4,6- Bis (1-methyl-1-phenylethyl) phenol, etc. [0007] Benzophenone ultraviolet absorbers include
For example, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone and the like can be mentioned. Examples of salicylate-based ultraviolet absorbers include pt-butylphenyl salicylate, 2,4
-Di-t-butylphenyl-3,5-di-t-butyl-
4-hydroxybenzoate and the like. The amount of UV absorber used varies depending on the type,
The range of 0.01 to 5.0% by weight based on the olefin resin is preferable. In the resin composition of the present invention, if necessary, additives other than the above, such as a coloring agent, may be appropriately used within a range that does not impair the object of the present invention. The water pipe resin composition of the present invention is usually added with the above-mentioned ultraviolet absorber to the olefin resin, mixed using a normal mixer such as a Henschel mixer, and kneaded using an extruder to form a pellet. Processed. In the present invention, the method for preparing the resin composition is not particularly limited. The present invention will be more specifically described below with reference to examples and comparative examples. The parts in the following text are based on weight. Blister resistance is based on JW standard JW
According to the salt water resistance test of WA K144, chlorine water concentration 200
Perform a blister generation acceleration test at 0 ppm and 60 ° C.
The blistering time was measured. In addition, weather resistance, after irradiation for 600 hours with Sunshine Weather O meter,
The oxidation induction time of the irradiated surface of the test piece was measured to evaluate the degree of deterioration. Example 1 High-density polyethylene (MFR: 0.10 g / 10 mi)
n) 0.2 part of ultraviolet absorber A [2- (2'-hydroxy-5'-methylphenyl) benzotriazole] was added to 100 parts and mixed with a Henschel mixer.
Granulation was performed with a 5 mm twin-screw extruder to produce pellets. The pellet was formed into a plate-shaped molded piece having a thickness of 5 mm using a 30 mm extruder. Using this molded piece, water resistance (blister property) and weather resistance were evaluated. Table 1 shows the results. Example 2 Ultraviolet absorber A was replaced with ultraviolet absorber B [2- (2'-hydroxy-3'-tert-butyl-5'-methyl-5'-methylphenyl) -5-chlorobenzotriazole]. Except for changing, a plate-shaped molded piece was prepared in the same manner as in Example 1, and a chlorine water resistance test and a weather resistance test were performed. Table 1 shows the results. Example 3 The procedure was carried out except that the ultraviolet absorber A was changed to the ultraviolet absorber C [2- (2H-benzotriazol-2-yl-4- (1,1,3,3-tetramethylbutyl) phenol]). Example 1
A plate-shaped molded piece was prepared in the same manner as described above and subjected to a chlorine water resistance test and a weather resistance test. Table 1 shows the results. Example 4 An ultraviolet absorber D [2- (2H-
Benzotriazol-2-yl) -4,6-bis (1-
[Methyl-1-phenylethyl) phenol], except that a plate-shaped molded piece was prepared in the same manner as in Example 1 and subjected to a chlorine water resistance test and a weather resistance test. Table 1 shows the results. Example 5 A plate-shaped molded piece was prepared in the same manner as in Example 1 except that the ultraviolet absorber E [2-hydroxy-4-methoxybenzophenone] was used instead of the ultraviolet absorber A, and a chlorine water resistance test was conducted. And a weather resistance test. Table 1 shows the results. Example 6 A plate-shaped molded piece was prepared in the same manner as in Example 1 except that ultraviolet absorber F [2,2'-dihydroxy-4-methoxybenzophenone] was used instead of ultraviolet absorber A, and chlorine-resistant. A water test and a weather resistance test were performed. Table 1 shows the results. Example 7 A plate-like molded piece was prepared in the same manner as in Example 1 except that ultraviolet absorbing G [pt-butylphenyl salicylate] was used instead of ultraviolet absorbing agent A, and a chlorine water resistance test and weather resistance were performed. A sex test was performed. Table 1 shows the results. Example 8 Ultraviolet absorber H [2,4, -di-t-butylphenyl-3,5-di-t-butyl-4-]
Except for using hydroxybenzoate], a plate-shaped molded piece was prepared in the same manner as in Example 1, and a chlorine water resistance test and a weather resistance test were performed. The results are shown in Table 1. Comparative Example 1 A plate-shaped molded piece was prepared in the same manner as in Example 1 except that no ultraviolet absorber A was added, and a chlorine water test and a weather resistance test were performed. Table 1 shows the results. Comparative Example 2 A light stabilizer H [bis (2,2,2) was used instead of the ultraviolet absorber A.
6,6-tetramethyl-4-piperidyl) sebacate]
A plate-shaped molded piece was prepared in the same manner as in Example 1 except that was used, and a chlorine water resistance test and a weather resistance test were performed. Table 1 shows the results. Comparative Example 3 The light stabilizer I [poly [(6-morpholino-s-triazine-2,4-diyl)] ((2,
2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-
A plate-shaped molded piece was prepared in the same manner as in Example 1 except that piperidyl) imino]]] was used, and a chlorine water resistance test and a weather resistance test were performed. Table 1 shows the results. Comparative Example 4 A plate-like molded piece was prepared in the same manner as in Example 1 except that the antioxidant J [butylhydroxytoluene] was used instead of the ultraviolet absorber A, and a chlorine water resistance test and a weather resistance test were performed. Was done. Table 1 shows the results. Comparative Example 5 Antioxidant K [tetrakis [methylene-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate] methane] is used in place of ultraviolet absorber A. Except for the above, a plate-shaped molded piece was prepared in the same manner as in Example 1, and a chlorine water resistance test and a weather resistance test were performed. Table 1 shows the results. Comparative Example 6 Antioxidant L [Tris (2,4)
-Di-t-butylphenyl) phosphite], a plate-shaped molded piece was prepared in the same manner as in Example 1, and a chlorine water resistance test and a weather resistance test were performed. Table 1 shows the results. Comparative Example 7 Antioxidant M [4,4'-biphenylenediphosphinic acid tetrakis (2,4-di-t) was used in place of ultraviolet absorber A.
-Butylphenyl)], except that a plate-shaped molded piece was prepared in the same manner as in Example 1, and a chlorine water resistance test and a weather resistance test were performed. Table 1 shows the results. [0025] According to the present invention described above, weather resistance is excellent,
Provided is a resin composition used for manufacturing a water pipe in which generation of water bubbles due to chlorine in tap water is prevented.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) F16L 9/12 F16L 9/12 F term (reference) 2D060 AA01 AC01 3H111 AA01 BA15 BA31 CB02 CB14 DA12 DB03 4J002 BB031 BB051 BB121 BB141 EE037 EJ048 EU176 FD056 FD057 FD058 GT00

Claims (1)

Claims: 1. A water pipe resin composition comprising an olefin resin and at least one selected from a benzotriazole-based UV absorber, a benzophenone-based UV absorber and a salicylate-based UV absorber. .