JPS64415B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a poly-1-butene resin composition for water supply and hot water supply piping, which has excellent pressure resistance and chlorine water resistance. (Prior art and its problems) Metal pipes such as galvanized steel pipes, copper pipes, and lead pipes have traditionally been used as piping materials for water supply and hot water supply, but in the case of steel pipes, red water or black water due to rust occurs. In the case of copper pipes, there are disadvantages such as the formation of pinholes or blue water due to electrolytic corrosion.
New piping materials are needed. In some cases, synthetic resin pipes such as polyvinyl chloride, polyethylene, and poly-1-butene, which do not generate pinholes due to rust or electrolytic corrosion, are already being used. Among them poly-1
-Butene is one of the most suitable resins for water supply and hot water supply pipes because it has excellent pressure resistance, internal pressure cleave durability at high temperatures, high and low temperature characteristics, abrasion resistance, etc., and is also excellent in flexibility. However, like other synthetic resins, poly-1-butene, which has these characteristics, undergoes chemical deterioration due to the action of sterilizing chlorine added to tap water, so its original high performance is lost. This effect tends to be particularly large in piping for hot water supply equipment that is subjected to high temperature and high pressure loads. (Means for Solving the Problems) In view of the current situation, the present inventors have conducted extensive research to find a poly-1-butene resin composition for water supply and hot water supply that has excellent chlorine water resistance. The results of a chlorine water resistance test of poly-1-butene mixed with resin additives conventionally known as antioxidants and stabilizers revealed that the mechanisms of chlorine water deterioration and the effects of addition varied widely. However, it was discovered that only poly-1-butene blended with a specific compound showed sufficient chlorine water resistance, and the present invention was achieved. That is, according to the present invention, poly-1-butene
Per 100 parts by weight, (A) 0.1 to 1.0 parts by weight of at least one compound selected from the group of hindered phenols; (a) 1,3,5-trimethyl-2,4,6-tris; (3,5-di-tert-butyl-4-hydroxybenzyl)benzene (b) 1,3,5-tris(4-tert-butyl-3
-hydroxy-2,6-dimethylphenyl)
Isocyanurate (c) Tris(3,5-di-tert-butyl-4-hydroxyphenyl)isocyanurate (d) n-octadecyl-3(3,5-di-tert-butyl-4-hydroxyphenyl)
Butyl-4-hydroxyphenyl) propionate (e) Nickel salt of bis(3,5-di-tert-butyl-4-hydroxybenzoylphosphonic acid) monoethyl ester (f) 2,2'-dihydroxy-3,3 ′−di(α−
methylcyclohexyl)-5,5'-dimethyl-diphenylmethane (g) 4,4-thio-bis(3-methyl-6-tert-butyl-phenol) (h) 1,1,3-tris(2-methyl- 4-Hydroxy-5-tert-butyl-phenyl)butane (i) Tetrakis[methylene-3(3,5-di-
tert-butyl-4-hydroxyphenyl)propionate]methane, and (B) 0.01 to 1.0 parts by weight of at least one compound selected from the following group, (j) 2,6-di-tert-butyl-p -Cresol (k) 4,4'-methylene-bis(2,6-di-tert-butyl-phenol) (l) Tris(2,4-di-tert-butyl-phenyl) phosphite (m) Vitamin E Provided is a poly-1-butene resin composition for water supply/hot water supply piping, which is characterized in that it is formulated with: (Function) Compounds (A) and (B) added to poly-1-butene are:
The reason is unknown, but it is thought that the mechanism of chlorine water resistance provided by each is different. Table 1 shows test examples to see the differences in the chlorine water resistance mechanisms of (A) and (B). This test example uses poly-1-butene (MFR0.8g/10min: ASTM D 1238N) 100 manufactured by Mitsui Petrochemical Industries, Ltd.
0.15 parts by weight of calcium stearate and synthetic hydrotalcite (trade name: DHT-
4A) 0.05 part by weight was blended and further 0.4 part by weight of the compounds shown in Table 1 were blended, mixed in a Henschel mixer, and granulated in a 20 mmφ extruder. The specific test method involves testing the pellets at
After melting in a heated press at 200℃ for 10 minutes, pressurize for 3 minutes in a cooling press at a temperature of 30℃ to make a 1mm thick press sheet, and cut out a 10mm x 150mm test piece.
Attach the test piece to the holder and check the effective chlorine concentration.
Gloss (incident light 45°) and [η] (decalin at 135°C) were measured over time by immersing the sample in a container in which chlorine-containing water of 100 ppm and a temperature of 90°C was passed through once per hour. All glosses immediately after molding were within the range of 90 to 95%.

【table】

[Table] (A) As shown in Table 1, the decrease in gloss over time is significant, but the decrease in [η] over time is small, and the initial [η] at the time of blending is also relatively high. It is thought that -1-butene acts to prevent deterioration of the entire chlorine water. (A) exhibiting such an effect was selected from the above-mentioned (a) to (i), and the product names were Irganox1330, Syanox1790, and Syanox1790, respectively.
Goodrite3114, Irganox1076, Irgastab2002,
Nonox WSP, Antage RC, Topanol CA,
It is known as Irganox1010. These are blended in an amount of 0.1 to 1.0 parts by weight, particularly preferably 0.2 to 0.5 parts by weight, per 100 parts by weight of poly-1-butene. If the amount is less than 0.1 part by weight, the effect of improving chlorine aqueous resistance will be small, and if it exceeds 1.0 part by weight, the tensile yield stress will decrease, and for example, the hydraulic burst strength of poly-1-butene pipes will decrease. (B) is the gross, [η] as seen in Table 1.
Although many of them show a significant decrease over time, [η] is high at the initial stage of blending. Generally, resins partially deteriorate under the conditions during molding, that is, in the presence of oxygen and in a high-temperature atmosphere, leading to a decrease in [η]. It is thought that the initial [η] during molding is at a high level because it has the effect of preventing deterioration. exhibits this kind of effect
(B) is selected from the above-mentioned (j) to (m), and these are respectively BHT or product names.
These are known as Ionox220, Irgaphos168, and Eisai Vitamin E. These are poly-1-
0.01 to 0.1 parts by weight per 100 parts by weight of butene,
Particularly preferred is 0.05 to 0.5 parts by weight.
If the amount is less than 0.01 part by weight, the above-mentioned effect will be small, and if it exceeds 1.0 part by weight, the tensile yield stress will decrease as in the case of (A) above. Although the compound selected from (A) can improve chlorine water resistance even when used alone, it is more preferable to use at least one compound selected from each group (A) and (B) in combination. In particular, the combined use of two or more compounds selected from group (A) reduces deterioration due to molding, improves the chlorine water resistance of the surface portion, and improves the chlorine water resistance of the entire poly-1-butene. This is particularly preferable because it allows (Description of preferred embodiments) Poly-1-butene in the present invention refers to a homopolymer of 1-butene or 10 mol% of 1-butene.
Copolymers with the following other α-olefins, such as ethylene and/or propylene, 4-methyl-1-pentene, 1-hexene, 1-octene, etc. and/or up to 50% by weight of other α-olefin polymers. Melt fluorate (MFR) is usually 0.1 to 50g/10min.
(ASTM D 1238N). Various known methods can be used to blend (A) and (B) into poly-1-butene. Examples include a method in which each component is mixed in a ribbon blender or Henschel mixer and then granulated in an extruder, or a method in which the components are directly melt-mixed in a Banbury mixer, kneader, two rolls, etc. and then granulated in an extruder. The poly-1-butene composition of the present invention may also contain other ultraviolet absorbers, fungicides, rust inhibitors, lubricants, fillers, pigments, dyes, heat stabilizers, etc., as necessary. Good too. Among these, metal salts of higher fatty acids and the general formula M _x Al _y (OH) _2x+3y-2z (A) _z・aH ₂ O (where M is Mg, Ca or Zn, A is an anion other than a hydroxyl group, x, y, and z are positive numbers, and a is 0 or a positive number. . As a method for molding water supply/hot water supply piping, etc. using the poly-1-butene resin composition for water supply/hot water supply piping of the present invention, for example, poly-1-butene mixed with the above-mentioned various stabilizers is mixed with 150% by extruder. or 300℃
An example is a method in which the material is melted at a temperature of 100° C., extruded through a die, sized, cooled in a cooling water layer with a water temperature of 5 to 50° C., and cut or wound through a take-up machine. As the extruder, a single-screw metering type screw can generally be used. Examples of the die include a straight head type, a crosshead type, and an offset type. The sizing method may be a sizing plate method, an outside mandrel method, a sizing box method, or an inside mandrel method. Further, the joint pipe or the hot water storage tank is molded using a combination of an ordinary injection molding machine or a blow molding machine and a mold. (Effects of the Invention) The poly-1-butene resin composition of the present invention has improved chlorine water resistance, as well as the inherent compressive strength of poly-1-butene, internal pressure creep durability at high temperatures, high and low temperature characteristics, and Because it also has abrasive properties, it can be widely used for piping in water supply equipment and hot water supply equipment. (Example) Comparative Examples 1 to 5 Tests similar to those in the Test Examples were conducted using the compound compounds shown in Table 2 instead of the compound compounds shown in Table 1. The results are shown in Table 2.

[Table] Example Instead of the compounded compounds shown in Table 1, 1, 3, 5
-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene and 4,4'-methylene-bis(2,6-di-tert-butyl-phenol). The test was carried out in the same manner as in the test example except that 0.2 parts by weight of each were added. The gloss (%) and [η] (dl/
g) was as follows.

【table】

Claims (1)

[Claims] 1. For 100 parts by weight of poly-1-butene, (A) 0.1 to 1.0 parts by weight of at least one compound selected from the group of the following hindered phenols; (a) 1,3 parts by weight; ,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (b) 1,3,5-tris(4-tert-butyl-3
-hydroxy-2,6-dimethylphenyl)
Isocyanurate (c) Tris(3,5-di-tert-butyl-4-hydroxyphenyl)isocyanurate (d) n-octadecyl-3(3,5-di-tert-butyl-4-hydroxyphenyl)
Butyl-4-hydroxyphenyl) propionate (e) Nickel salt of bis(3,5-di-tert-butyl-4-hydroxybenzoylphosphonic acid) monoethyl ester (f) 2,2'-dihydroxy-3,3 ′−di(α−
methylcyclohexyl)-5,5'-dimethyl-diphenylmethane (g) 4,4-thio-bis(3-methyl-6-tert-butyl-phenol) (h) 1,1,3-tris(2-methyl- 4-Hydroxy-5-tert-butyl-phenyl)butane (i) Tetrakis[methylene-3(3,5-di-
tert-butyl-4-hydroxyphenyl)propionate]methane, and (B) 0.01 to 1.0 parts by weight of at least one compound selected from the following group, (j) 2,6-di-tert-butyl-p -Cresol (k) 4,4'-methylene-bis(2,6-di-tert-butyl-phenol) (l) Tris(2,4-di-tert-butyl-phenyl) phosphite (m) Vitamin E 1. A poly-1-butene resin composition for water supply/hot water supply piping, characterized in that the composition is made of a poly-1-butene resin composition.