JPS64416B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a water supply/hot water supply pipe made of poly-1-butene resin having 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 steel pipes tend to produce red water or black water due to rust. In the case of copper pipes, there are drawbacks such as the formation of pinholes or blue water due to electrolytic corrosion, and new piping materials are required. 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 as a raw material for pipes for water supply and hot water supply 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 intensive research to find a water supply pipe made of poly-1-butene resin that has excellent resistance to chlorine water. As a result, when we mixed poly-1-butene with resin additives conventionally known as antioxidants and stabilizers and conducted a chlorine water resistance test, we found that certain compounds among hindered phenols were mixed with poly-1-butene. It has been discovered that a pipe formed by blending the same with chlorine water exhibits excellent chlorine water resistance, and the present invention has been achieved based on this discovery. That is, according to the present invention, poly-1-butene
0.1 of at least one compound selected from the group of hindered phenols below per 100 parts by weight
(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) 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-tertiary
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 A water supply/hot water supply pipe formed by blending and molding is provided. (Action) The hindered phenols listed above are [η]
The decrease over time is small, and the initial [η] at the time of blending is relatively high, so it is thought that poly-1-butene acts to prevent deterioration of the entire poly-1-butene due to chlorine water. (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). Further, the hindered phenols used in the present invention are known by the following trade names. (a) Irganox1330, (b) Syanox1790, (c)
Goodrite3114, (d)Irganox1076, (e)
Irgastab2002, (f) Nonox WSP, (g) Antage RC,
(h) Topanol CA, (i) Irganox 1010, these are 0.1 to 1.0 parts by weight, particularly preferably 0.2 to 1.0 parts by weight, per 100 parts by weight of poly-1-butene.
Add 0.5 parts by weight. 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 the hydraulic burst strength of the poly-1-butene pipe will decrease. The above compounds can improve the chlorine water resistance of poly-1-butene, whether used alone or in combination of two or more. The compound can be blended with poly-1-butene using various known methods, such as mixing each component with a ribbon blender or Henschel mixer and then granulating it with an extruder, or directly using a Banbury mixer.
Examples include a method of melt-mixing with a kneader, two rolls, etc., and then granulating with an extruder. Further, during molding, other ultraviolet absorbers, fungicides, rust inhibitors, lubricants, fillers, pigments, dyes, heat stabilizers, etc. may be added as necessary. 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. . A water supply system made of the poly-1-butene resin of the present invention.
As a method for forming a hot water supply pipe, for example, poly-1 mixed with the various stabilizers described above may be molded using an extruder.
- Butene is melted at a temperature of 150 to 300 °C, extruded through a die, and after sizing, the water temperature is 5
An example is a method in which the material is cooled with a layer of cooling water at a temperature of 50 to 50° C., and then cut or rolled up 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) According to the present invention, by blending a small amount of the above-mentioned specific hindered phenol of 0.1 to 1.0 parts by weight with poly-1-butene and molding it, it has excellent chlorine water resistance. You can get a pipe for water supply and hot water supply, and this pipe is made of poly-1-
Because it has the inherent pressure resistance of butene, internal pressure creep durability at high temperatures, high and low temperature characteristics, and wear resistance, it can be widely used in piping for water supply equipment and hot water supply equipment. (Examples) Examples 1 to 9 Differences in chlorine water resistance mechanism of the above compounds were tested by the following method, and the results are shown in Table 1. In this example, poly-1-butene (MFR0.8g/10min: ASTM D
1238N), 0.15 parts by weight of calcium stearate and 0.05 parts by weight of synthetic hydrotalcite (trade name DHT-4A), and further
After blending 0.4 parts by weight of the compounds shown in the table, the mixture was mixed using a Henschel mixer and granulated using a 20 mmφ extruder. The specific test method is to melt the pellets in a heated press at a temperature of 200℃ for 10 minutes, and then
Press for 3 minutes with a cooling press at 30°C to produce a press sheet with a thickness of 1 mm, cut out a 10 mm x 150 mm test piece, attach the test piece to a holder, and press it with chlorine at an effective chlorine concentration of 100 ppm and a temperature of 90°C. The sample was immersed in a container in which water was passed through once per hour, and the gloss (incident light 45°) and [η] (decalin at 135°C) were measured over time. All glosses immediately after molding were within the range of 90 to 95%.

【table】

[Table] Comparative Examples 1 to 5 The same tests as in the examples were conducted using the compounds shown in Table 2 instead of the compounds shown in Table 1. The results are shown in Table 2.

[Table] (Note)

【table】

Claims (1)

[Scope of Claims] 1. 0.1 to 1.0 parts by weight of at least one compound selected from the group of the following hindered phenols per 100 parts by weight of poly-1-butene, (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) 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-tertiary
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] A water supply/hot water supply pipe formed by mixing and molding methane.