JPH0254381B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyolefin composition having excellent chlorine water resistance. Conventionally, metal pipes such as galvanized steel pipes, copper pipes, and lead pipes have 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, and copper pipes suffer from electrolytic corrosion. There are disadvantages such as the occurrence of pinholes or blue water due to
New piping materials are needed. In some areas, piping made of synthetic resins such as polyvinyl chloride, polyethylene, and poly-1-butene, which do not generate pinholes due to rust or electrolytic corrosion, is already being used. In particular, polyolefins such as polyethylene and poly-1-butene are chemically stable, easy to mold, and inexpensive among synthetic resins, so it is expected that they will rapidly replace conventional metal pipes in the future. ing. In other words, polyethylene has high strength, excellent creep properties, stress crack resistance, and flexibility, so it can be used as water supply pipes for waterworks, etc.
On the other hand, if it comes into contact with water that contains a lot of chlorine, it can cause blisters and, in extreme cases, it can cause peeling, which can block the water supply valve, for example. In addition, poly-1-butene has excellent compressive strength, internal pressure creep durability at high temperatures, high and low temperature characteristics, abrasion resistance, flexibility, etc., so it is used for hot water supply pipes in addition to water supply pipes like polyethylene. It can also be used, but like polyethylene, it may be chemically degraded by water containing a lot of chlorine. Such deterioration of polyrefin due to chlorine-containing water causes not only the above-mentioned problem of peeling and occlusion but also a decrease in mechanical strength and flexibility. In general, water supply pipes and hot water supply pipes are installed in narrow, inconspicuous places, such as inside walls or under floors, so that re-construction after installation is difficult and economically disadvantageous. Therefore, once installed, it is preferable that it can be used for as long as possible, preferably semi-permanently, without failure. Particularly in recent years, with the deterioration of water quality in urban areas, large amounts of chlorine have come to be used for sterilization, so improving the chlorine water resistance of polyolefins will lead to expanded uses for instant water supply and hot water supply. In view of the above-mentioned current situation, the present inventors conducted intensive research to find a way to somehow improve the chlorine water resistance of polyolefins, and as a result, discovered a new compound that imparts chlorine water resistance to polyolefins, and arrived at the present invention. That is, the present invention provides a chlorine-resistant water-resistant polyolefin composition characterized in that 0.01 to 3 parts by weight of a compound of the following general formula is blended with 100 parts by weight of a polyolefin, provided that the compound of the general formula (Here, R ₁ to _{R 4} are hydrogen or a hydrocarbon group with or without a substituent, and m+n, l, z are 1
or 2, r+t, x is an integer from 1 to 4, and q is an integer from 0 to 6). The polyolefin of the present invention includes ethylene,
Propylene, 1-butene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene,
Homopolymers of α-olefin such as 4-methyl-1-pentene or copolymers of two or more of these monomers, and other monomers copolymerizable with α-olefin, such as styrene, acrylonitrile, and vinyl chloride. , copolymers with vinyl acetate, acrylic esters, methacrylic esters, etc., blends of these or other thermoplastic resins, block copolymers,
Any polyolefin such as a graft copolymer or a modified product of maleic acid, maleic anhydride, acrylic acid, or methacrylic acid may be used. Among these, polyethylene and poly-1-butene are preferred. Examples of polyethylene include ethylene homopolymers produced by high-pressure, medium-pressure, and low-pressure methods, ethylene and other α-olefins, such as propylene, 1-butene, etc. Copolymers of butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, etc., ethylene and alkadienes having 8 or less carbon atoms, such as propadiene, 1,2-butadiene, 1,3-butadiene, piperylene,
Copolymers with 1,4-pentadiene, etc., ethylene and vinyl acetate, vinyl alcohol, acrylic acid,
Copolymers with methacrylic acid, maleic acid, maleic anhydride, acrylic acid, and methacrylic acid modified products of the above-mentioned ethylene homopolymers or ethylene copolymers, which include polymers mainly composed of ethylene. . Poly-1-butene may be a homopolymer of 1-butene or 1-butene and up to 10 mol% of other α-olefins, such as ethylene and/or propylene, 4-methyl-
Copolymers with 1-pentene, 1-hexene, 1-octene, etc. and/or up to 50% by weight of other α
- It is a mixture with olefin polymer, and the melt flow rate (hereinafter referred to as MFR) is usually 0.1 to 50g/
10 min (ASTM D 1238N). The compound which is another component to be blended into the above-mentioned polyolefin is a compound represented by the following general formula. Here, R ₁ to _{R 4} are hydrogen or a hydrocarbon group with or without a substituent. Examples of the hydrocarbon group include a chain hydrocarbon group having 1 to 8 carbon atoms;
That is, straight or branched chain hydrocarbon groups such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl, cyclopentyl,
Examples include alicyclic hydrocarbon groups such as cyclohexyl and cyclobutyl, aromatic hydrocarbon groups such as phenyl, and examples of hydrocarbon groups having substituents include alkyl groups, phenyl groups, etc. Substituted with alkylidene group, hydroxyl group, carbonyl group, etc., such as tolyl group, xylyl group, mesityl group, cumenyl group, benzyl group, phenethyl group, α-methylbenzyl group,
Examples include methylbenzyl group, cyclohexylcarbonyl group, benzoyl group, and tooyl group. Further, m+n, l and z are 1 or 2, r+t and x are 1 to 4, and q is an integer of 0 to 6. Specific examples of the compound represented by the above general formula include 3,5-di-t-butyl-4-hydroxybenzoic acid 4'-hydroxyphenyl ester, 3,5-di-t-butyl-4-hydroxy Benzoic acid-3'-t-butyl-4'-hydroxyphenyl ester, 3,5-di-t-butyl-4-hydroxybenzoic acid 3',5'-dimethyl-4'-hydroxyphenyl ester, 3 ,5-di-t-butyl-
4-hydroxybenzoic acid 3'-methyl-5'-t-butyl-4'-hydroxyphenyl ester, 3,5
-di-t-butyl-4-hydroxybenzoic acid 3',
5'-di-t-butyl-4'-hydroxyphenyl ester, 3,5-di-t-butyl-4-hydroxybenzoic acid 3',,5'-di-t-octyl-4'-hydroxyphenyl ester enyl ester, 3,5-di-t-butyl-4-hydroxybenzoic acid 2',5'-di-t-butyl-4'-hydroxyphenyl ester, 3,5
-Di-t-butyl-4-hydroxybenzoic acid 4'-
t-butyl-3'-hydroxyphenyl ester,
3,5-di-t-butyl-4-hydroxybenzoic acid 4',6'-di-t-butyl-3'-hydroxyphenyl ester, 3-methyl-5-t-butyl-4
-3',5'-di-t-butyl hydroxybenzoate-
4'-Hydroxyphenyl ester, 4-(3',
5'-di-t-butyl-4'-hydroxybenzoyloxymethyl)-2,6-di-t-butylphenol, 3,5-bis(3',5'-di-t-butyl-
4′-hydroxybenzoyloxymethyl)-2,
4,6-trimethylphenol, 3-(3′,5′-
di-t-butyl-4'-hydroxybenzoyloxymethyl)-2,4,6-trimethylphenol, 3-(3',5'-di-t-butyl-4'-hydroxybenzoyloxymethyl)-2, 4-dimethyl-6-t-butylphenol, 2-(3',5'-
di-t-butyl-4'-hydroxybenzoyloxymethyl)-4,6-di-t-butylphenol, 2,6-bis(3',5'-di-t-butyl-
4'-Hydroxybenzoyloxymethyl)-4-
t-butylphenol, 2-(3″,5″-d-t-
Butyl-4″-hydroxybenzoyloxy)-
3,3'-di-t-butyl-5,5'-dimethyl-
2′-hydroxydiphenylmethane, 4-(3″,
An example is 5''-di-t-butyl-4''-hydroxybenzoyloxy)-2,2',6,6'-tetra-t-butyl-4'-hydroxydiphenylmethane. The compound of the above general formula can be easily produced by the well-known synthetic method shown below. That is, for polyhydroxybenzenes or hydroxyphenyl alkanols in which R ₃ and R ₄ of the above general formula are substituents, (1) benzoin whose substituents are R ₁ , R ₂ , and OH in the above general formula; How to perform an esterification reaction with an acid (2) A method of carrying out an esterification reaction with a benzoic acid anhydride in which R ₁ , R ₂ , and OH of the above general formula are substituents. (3) A method of carrying out an esterification reaction with a benzoic acid chloride having R ₁ , R ₂ , and OH of the general formula described above as substituents. can be mentioned. In these syntheses, when using benzoic acids (reaction (1) above), in the presence of a catalyst such as para-toluenesulfonic acid,
When benzoic acid anhydride and benzoic acid chloride are used (reactions (2) and (3) above), the reaction is carried out in the presence of an electron acceptor such as pyridine. In addition to the synthesis methods (1) to (3) above, the compound of the general formula can also be obtained by synthesis using a halomethylated compound as a raw material. That is, (4) the benzoic acids used in the above (1) to (3) and the hydroxyphenylbenzyl halides in which R ₃ , R ₄ , and OH of the above general formula are substituents (in the following formula, x is chlorine). , representing bromine) in the presence of an electron acceptor such as pyridine. The compound of the above general formula may be used alone or in combination of two or more in an amount of 0.01 parts by weight per 100 parts by weight of polyolefin.
It is blended in an amount of 3 to 3 parts by weight, preferably 0.05 to 1 part by weight, particularly preferably 0.1 to 0.6 parts by weight.
If the amount is less than 0.01 parts by weight, the effect of chlorine water resistance will be insufficient, and if it exceeds 3 parts by weight, bleed-out may occur or the tensile yield stress may decrease, which is not preferable. The chlorine-resistant, water-resistant polyolefin of the present invention also contains various known compounding agents that can be added to the polyolefin, such as heat-resistant stabilizers, weather-resistant stabilizers, lubricants, antistatic agents, antifogging agents, and inorganic or organic fillers. , dyes, pigments, etc. may be added. Specific examples of such compounding agents include 2,6-di-t-butyl-p-cresol, 4,4'-methylene-bis(2,6-di-t-butylphenol),
1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 1,3,5-tris(4-t-
Butyl-3-hydroxy-2,6-dimethylphenyl)isocyanate, n-octadecyl-3
(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 4,4'-thiobis(3-
methyl-6-t-butylphenol), 1,1,
3-tris(2-methyl-4-hydroxy-5-
t-butylphenyl)butane, tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propiate]titanium, (2',
4'-di-t-butylphenyl)-3,5-di-t
-Butyl-4-hydroxybutylbenzoate,
n-hexadecyl-3,5-di-t-butyl-4
-Hydroxybenzoate, dilaurylthiodipropionate, distearylthiodipropionate, laurylstearylthiodipropionate,
Dibutylthiodipropionate, diamylthiodipropionate, dihexylthiodipropionate, diheptylthiodipropionate, dioctylthiodipropionate, dinonylthiodipropionate, didecylthiodipropionate, dimyristylthiodipropionate pionate, distearyl thiodibutyrate, distearyl β, β'-thiodibutyrate, pentaerythritutetetra (β-lauryl thiopropionate), bis(3,5
-di-t-butyl-4-hydroxybenzoylsulfonic acid) nickel salt of monoethyl ester, 2,
2'-dihydroxy-3,3'-di(α-methylcyclohexyl)-5,5'-dimethyl-diphenylmethane, tris(2,4-di-t-butylphenyl) phosphite, stabilizers such as vitamin E, silicic acid Fillers such as salt, alumina, barium carbonate, carbon black, etc., and 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), such as Mg ₆ Al ₂ (OH) ₁₆ CO ₃ 4H ₂ O, Mg ₈ Al ₂ (OH) ₂₀ CO ₃・5H ₂ O, Mg ₅ Al ₂ (OH) ₁₄ CO ₃・4H ₂ O, Mg ₁₀ Al ₂ (OH) ₂₂ (CO ₃ ) ₂・4H ₂ O, Mg ₆ Al ₂ ( OH) ₁₆ HPO ₄・4H ₂ O, Ca ₆ Al ₂ (OH) ₁₆ CO ₃・4H ₂ O, Zn ₆ Al ₂ (OH) ₁₆ CO ₃・4H ₂ O, Zn ₆ Al ₂ (OH) ₁₆ SO ₄ Examples include 4H ₂ O, Mg ₆ Al ₂ (OH) ₁₆ SO ₄ 4H ₂ O, Mg ₆ Al ₂ (OH) ₁₂ CO ₃ 3H ₂ O, etc. A specific method for obtaining the composition of the present invention is as follows:
The above-mentioned polyolefin and the compound of the general formula () are mixed in the above-mentioned proportions by various known methods, such as a method of mixing in a blender, a ribbon blender, a benziel mixer, a tumbler blender, or after mixing in the above-mentioned blender, an extruder is used. Examples include a method of granulating with a single-screw extruder, a multi-screw extruder kneader, a Banbury mixer, etc., followed by granulation or pulverization. Furthermore, a method for forming water supply pipes and hot water supply pipes using the chlorine-resistant water-based polyolefin of the present invention includes melting the polyolefin of the present invention, extruding it through a die, sizing it, and then cooling it in a cooling water tank. An example is a method of cutting or winding the material through a take-up machine. As the extruder used at this time, a single-screw metering type screw can generally be used, and the die can be exemplified by a straight head type, crosshead type or offset type. The sizing method may be a sizing plate method, an outside mandrel method, a sizing box method, or an inside mandrel method. As mentioned above, the chlorine-resistant water-resistant polyolefin of the present invention does not cause chemical deterioration or peeling even if it comes into contact with chlorine-containing water for a long period of time, so it can be used for various types of piping for water supply and hot water supply, and the piping can be It is more flexible than conventional steel pipes, can be easily formed into pipes of various diameters, and is lightweight, making it easy to handle. Hereinafter, the content of the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples as long as the purpose thereof is not impaired. Examples 1 to 7 and Comparative Examples 1 to 5 Poly-1 with MFR 0.8 g/10 min (ASTM D 1238N) and density 0.915 g/cm ³ (ASTM D 1505)
- 0.15 parts by weight of calcium stearate and the compounds shown in Table 1 per 100 parts by weight of butene.
After blending 0.4 parts by weight and mixing with a Henschel mixer,
It was granulated using a 20 mmφ extruder. After melting the granulated pellets in a heated press at 200℃ for 10 minutes,
A press sheet having a thickness of 1 mm was produced by applying pressure for 3 minutes using a cooling press at .degree. 10mm from the press sheet
Cut out a 150mm test piece, attach it to the holder,
A chlorine degradation acceleration test was conducted by immersing the sample in a container in which chlorine-containing water at 90°C with an effective chlorine concentration of 100 ppm was passed once per hour. The specimen was economically removed and cut at a length of approximately 10 mm from the tip. After the cut piece was bent at an angle of 90 degrees, the bent portion was observed under a microscope (×30 magnification) to determine the time until crazing occurred. The results are shown in Table 1.

【table】

【table】

[Table] Example 8 MFR1.5g/10min (ASTM D 1238E), density
0.92 g/cm ³ (ASTM D 1505) low-density polyethylene was mixed with 0.05 parts by weight of hydrotalcite and 0.4 parts by weight of the same benzoic acid ester compound as in Example 1. A press sheet was prepared and a chlorine deterioration acceleration test was conducted.
When external defects were observed under a microscope, no changes were observed even after 7 weeks. Comparative Example 6 Except for not adding a benzoic acid ester compound,
The same procedure as in Example 8 was carried out. As a result, after 4 weeks, a film-like peeling phenomenon appeared on the sheet surface.

Claims (1)

[Scope of Claims] 1. A chlorine-resistant aqueous polyolefin composition comprising 0.01 to 3 parts by weight of a compound of the following general formula in 100 parts by weight of a polyolefin, provided that the compound of the general formula (Here, R ₁ to _{R 4} are hydrogen or a hydrocarbon group with or without a substituent, and m+n, l, z are 1
or 2, r+t, x is an integer from 1 to 4, and q is an integer from 0 to 6). 2. The chlorine water-resistant polyolefin composition according to claim 1, wherein q is 0 or 1.