Resin pipe composition and resin pipe

Abstract

To provide a composition for resin pipes that contains silicone oil and allows for reduced whitening of a site subjected to secondary processing.SOLUTION: A composition for resin pipes according to one aspect of the present invention includes polyvinyl chloride resin and silicone oil with a solubility parameter of 7.7(cal / cm3)1 / 2 or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a composition for a resin pipe and a resin pipe. [Background technology]

[0002] BACKGROUND ART Conventionally, compositions in which silicone oil is added to vinyl chloride resins have been known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 51-031738 Summary of the Invention [Problem to be solved by the invention]

[0004] In the manufacture of resin pipes, silicone oil is sometimes added to vinyl chloride resins to impart gloss and improve mold releasability. However, the inventors have discovered that resin pipes made from vinyl chloride resins containing silicone oil suffer from the problem of whitening during secondary processing.

[0005] An object of one aspect of the present invention is to provide a composition for a resin pipe, which contains silicone oil and can reduce whitening of a secondary processed portion, and a resin pipe. [Means for solving the problem]

[0006] The present invention includes the following aspects. <1> vinyl chloride resin, Solubility parameter is 7.7 (cal / cm 3 ) 1 / 2 The silicone oil described above, A composition for a resin pipe comprising: <2> The silicone oil is an organically modified silicone oil. <1> The composition for a resin pipe according to claim 1. <3> The organic modified silicone oil is at least one selected from the group consisting of phenyl modified dimethyl silicone oil and polyether modified dimethyl silicone oil. <2> The composition for a resin pipe according to claim 1. <4> The degree of polymerization of the vinyl chloride resin is 600 to 1500. <1> ~ <3> The composition for a resin pipe according to any one of the above. <5> As a result of the rapid cooling whitening test according to the following procedure, ΔL * The value of is less than 1, <1> ~ <4> 1. A composition for a resin pipe according to any one of the preceding claims: 1. The resin pipe composition is pressed at 15 MPa for 5 minutes to prepare a sheet-like test piece. 2. The brightness (L * ) is measured using the SCI method, and the measured value is L * Let's say it's 1. 3. Heat the test piece at 150°C for 15 minutes. 4. The test piece is cooled at -10°C for 50 minutes. 5. The brightness (L * ) is measured using the SCI method, and the measured value is L * Let's say it's 2. 6. L * 2-L * 1 value of ΔL * Let's say. <6> <1> ~ <5> A resin pipe comprising the composition for a resin pipe according to any one of the above. <7> The nozzle has one or more structures selected from the group consisting of a receiving structure, a bend structure, and a constriction structure. <6> The resin pipe according to claim 1. [Effects of the Invention]

[0007] According to one aspect of the present invention, there are provided a composition for a resin pipe, which contains a silicone oil and can reduce whitening of a secondary processed portion, and a resin pipe. DETAILED DESCRIPTION OF THE INVENTION

[0008] The following describes in detail the embodiments of the present invention. However, the present invention is not limited to these, and various modifications are possible within the scope of the description. For example, embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0009] Unless otherwise specified in this specification, "A to B" representing a numerical range means "not less than A and not more than B." In this specification, the solubility parameter is also referred to as the "SP value."

[0010] [1. Composition for Resin Pipe] The composition for resin pipes according to one aspect of the present invention contains a vinyl chloride resin and a silicone oil. Each component will be described below.

[0011] [1.1. Vinyl chloride resin] Vinyl chloride resins are commonly used as materials for pipes and are highly versatile and economical. In this specification, vinyl chloride resin refers to a resin whose main component is a unit derived from vinyl chloride. In one embodiment, the proportion of vinyl chloride-derived units in the vinyl chloride resin molecules is 50% by weight or more, 70% by weight or more, or 90% by weight or more. Only one type of vinyl chloride resin may be used, or two or more types may be used.

[0012] Specific examples of vinyl chloride resins include homopolymers of vinyl chloride, copolymers of vinyl chloride with other monomers, and graft copolymers in which vinyl chloride monomers are graft-copolymerized onto polymers. Polymers in which the vinyl chloride units contained in these polymers have been chlorinated are also included in the vinyl chloride resins (e.g., chlorinated polyvinyl chloride).

[0013] Examples of monomers copolymerized with vinyl chloride include α-olefins (ethylene, propylene, butylene, etc.); vinyl esters (vinyl acetate, vinyl propionate, etc.); vinyl ethers (butyl vinyl ether, cetyl vinyl ether, etc.); methacrylic acid esters (methyl methacrylate, ethyl methacrylate, butyl acrylate, etc.); aromatic vinyls (styrene, α-methylstyrene, etc.); and N-substituted maleimides (N-phenylmaleimide, N-cyclohexylmaleimide, etc.). The monomers copolymerized with vinyl chloride may be one type only, or two or more types.

[0014] Examples of polymers to be graft-copolymerized with vinyl chloride monomer include ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-carbon monoxide copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate-carbon monoxide copolymer, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer, acrylonitrile-butadiene copolymer, polyurethane, chlorinated polyethylene, and chlorinated polypropylene. Only one type of polymer may be graft-copolymerized with vinyl chloride monomer, or two or more types of polymers may be graft-copolymerized with vinyl chloride monomer.

[0015] The degree of polymerization of the vinyl chloride resin is not particularly limited. The degree of polymerization of the vinyl chloride resin is preferably 1500 or less, more preferably 1400 or less, and even more preferably 1300 or less. The lower limit of the degree of polymerization is preferably 600 or more, more preferably 1000 or more, and even more preferably 1200 or more. If the degree of polymerization is within the above range, the moldability of the composition for resin pipes is improved. Therefore, the occurrence of poor appearance of the product (yellowing of the molded body, inclusion of air bubbles, etc.) can be easily prevented.

[0016] The polymerization method for the vinyl chloride resin is not particularly limited. For example, vinyl chloride resins obtained by emulsion polymerization, suspension polymerization, or bulk polymerization can be used.

[0017] [1.2. Silicone oil] The resin pipe composition according to one embodiment of the present invention contains silicone oil. Silicone oil is generally blended for the purpose of imparting gloss and improving mold releasability. Only one type of silicone oil may be used, or two or more types may be used.

[0018] The solubility parameter (SP value) of silicone oil is 7.7 (cal / cm 3 ) 1 / 2 or more, 7.8 (cal / cm 3 ) 1 / 2 More than 8.0 (cal / cm 3 ) 1 / 2 More preferably, 8.2 (cal / cm 3 ) 1 / 2 More preferably, 8.5 (cal / cm 3 ) 1 / 2 The upper limit of the solubility parameter is, for example, 9.6 (cal / cm 3 ) 1 / 2 Below, 9.5(cal / cm 3 ) 1 / 2 Below, 9.4(cal / cm 3 ) 1 / 2 or less than 9.3 (cal / cm 3 ) 1 / 2 It may be the following:

[0019] The method for calculating the solubility parameter is based on the method described in Robert F. Fedors (1974) "A Method for Estimating Both the Solubility Parameters and Molar Volumes of Liquids" Polymer Engineering and Science, Vol. 14 (No. 2), pp. 147-154.

[0020] In one embodiment, the silicone oil is an organically modified silicone oil. The organically modified silicone oil is a silicone oil in which some of the methyl groups contained in dimethylsilicone oil are substituted with other organic functional groups. Examples of organically modified silicone oils include alkyl-modified silicone oils, polyether-modified silicone oils, phenyl-modified silicone oils, methylstyryl-modified silicone oils, fluorine-modified silicone oils, amino-modified silicone oils, epoxy-modified silicone oils, carboxyl-modified silicone oils, carbinol-modified silicone oils, and mercapto-modified silicone oils. In one embodiment, the organically modified silicone oil is one or more selected from the group consisting of phenyl-modified dimethylsilicone oils and polyether-modified dimethylsilicone oils. In one embodiment, the organically modified silicone oil is a phenyl-modified dimethylsilicone oil. In one embodiment, the organically modified silicone oil is a polyether-modified dimethylsilicone oil.

[0021] The lower limit of the silicone oil content in the resin pipe composition is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, based on 100 parts by weight of the vinyl chloride resin. The upper limit of the silicone oil content in the resin pipe composition is preferably 1 part by weight or less, more preferably 0.5 parts by weight or less, based on 100 parts by weight of the vinyl chloride resin.

[0022] [1.3. Other additives] The resin pipe composition according to one embodiment of the present invention may contain other additives. Examples of the other additives include stabilizers, stabilizer aids, fillers, reinforcing agents, pigments, lubricants, processing aids, light stabilizers, ultraviolet absorbers, and flame retardants. Only one type of each additive may be used, or two or more types may be used.

[0023] Examples of stabilizers include tin-based stabilizers (such as mercaptides, maleates, and laurates of organic tins (monomethyltin, dimethyltin, dibutyltin, monooctyltin, and dioctyltin)); lead-based stabilizers (such as acid-basic lead sulfate, dibasic lead phthalate, dibasic lead stearate, and lead metal soaps); barium-zinc-based stabilizers (such as barium and zinc metal soaps); and calcium-zinc-based stabilizers (such as calcium and zinc metal soaps).

[0024] Examples of the stabilizing aid include polyhydric alcohols, phenolic antioxidants, β-keto acid esters, and β-diketones.Specific examples of the polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, glycerin, diglycerin, dipentaerythritol, mannitol, sorbitol, trimethylolpropane, ditrimethylolpropane, trisisocyanurate, monopentaerythritol, and dipentaerythritol adipate. Examples of phenolic antioxidants include bisphenol A, bisphenol B, bisphenol F, 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, distearyl (3,5-di-tert-butyl-4-hydroxybenzyl) phosphonate, 1,6-hexamethylenebis[(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,6-hexamethylenebis[(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], and 1,6-hexamethylenebis[(3,5-di-tert-butyl-4-hydroxyphenyl) propionate]. acid amide], bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butyric acid] glycol ester, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl)isocyanurate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, triethylene glycol bis[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate].Examples of β-keto acid esters and β-diketones include 1,3-cyclohexadione, methylenebis-1,3-cyclohexadione, 2-benzyl-1,3-cyclohexadione, acetyltetralone, palmitoyltetralone, stearoyltetralone, benzoyltetralone, 2-acetylcyclohexanone, 2-benzoylcyclohexanone, 2-acetyl-1,3-cyclohexanedione, bis(benzoyl)methane, benzoyl-p-chlorobenzoylmethane, bis(4-methylbenzoyl)methane, and bis(2-hydroxybenzoyl)methane. , benzoylacetone, tribenzoylmethane, diacetylbenzoylmethane, stearoylbenzoylmethane, palmitoylbenzoylmethane, lauroylbenzoylmethane, dibenzoylmethane, bis(4-chlorobenzoyl)methane, bis(methylene-3,4-dioxybenzoyl)methane, benzoylacetylphenylmethane, stearoyl(4-methoxybenzoyl)methane, butanoylacetone, distearoylmethane, acetylacetone, stearoylacetone, bis(cyclohexanoyl)methane, and dipivaloylmethane.

[0025] Examples of fillers include inorganic fillers, such as calcium carbonate, talc, clay, and silica.

[0026] Examples of toughening agents include resins with rubber properties, such as acrylonitrile-butadiene-styrene copolymer (ABS resin), methyl methacrylate-butadiene-styrene copolymer (MBS resin), ethylene-vinyl alcohol copolymer (EVA resin), acrylic rubber, and chlorinated polyethylene.

[0027] Examples of pigments include organic pigments (azo pigments, phthalocyanine pigments, threne pigments, dye lake pigments, etc.); and inorganic pigments (molybdenum chromate pigments, ferrocyanide pigments, etc.).

[0028] Examples of lubricants include fatty acids (such as stearic acid); fatty acid esters (such as butyl stearate); olefin waxes (such as polyethylene and polyethylene oxide); and hydrocarbon waxes (such as paraffin).

[0029] Examples of processing aids include homopolymers or copolymers of (meth)acrylate monomers (methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, etc.); and copolymers of (meth)acrylate monomers and vinyl monomers (styrene, vinyltoluene, acrylonitrile, etc.).

[0030] Examples of the light stabilizer include hindered amine light stabilizers.

[0031] Examples of the ultraviolet absorber include salicylic acid ester-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and cyanoacrylate-based ultraviolet absorbers.

[0032] Examples of the flame retardant include halogen-based flame retardants; and oxide or hydroxide-based flame retardants (oxides or hydroxides of antimony, zirconium, molybdenum, aluminum, magnesium, silica, titanium, etc.).

[0033] The content of other additives is not particularly limited. In one embodiment, the content of lubricant in the composition for resin pipes is 0.1 to 2.5% by weight. In one embodiment, the content of filler or pigment in the composition for resin pipes is 5.0% by weight or less.

[0034] The composition for a resin pipe may contain known additives (such as plasticizers) in addition to the additives described above. The content of these additives can be determined appropriately by those skilled in the art.

[0035] [1.4. Physical properties of resin pipe composition] The resin pipe composition according to one embodiment of the present invention has a lightness increase width (ΔL* ) is small. ΔL * The value of ΔL is preferably less than 1, more preferably less than 0.6, and even more preferably less than 0.4. Since the brightness may be reduced after the quench whitening test, * The value of may be negative.

[0036] The procedure for the quench whitening test is as follows. For more specific details, see the examples of the present application. 1. The resin pipe composition is pressed at 15 MPa for 5 minutes to prepare a sheet-like test piece. 2. Lightness of the test piece (L * ) is measured using the SCI method, and the measured value is L * Let's say it's 1. 3. Heat the test piece at 150°C for 15 minutes. 4. Cool the test piece at -10°C for 50 minutes. 5. Lightness (L) of the test piece after cooling * ) is measured using the SCI method, and the measured value is L * Let's say it's 2. 6. L * 2-L * 1 value of ΔL * Let's say.

[0037] According to the research of the present inventors, the results of the quench whitening test are highly correlated with the occurrence of whitening at the secondary processing portion of the resin pipe. Therefore, the quench whitening test can be used as a simple test to predict the properties of a resin pipe when processed from a composition for resin pipe.

[0038] In the steps 2 and 5 of the rapid cooling whitening test described above, the brightness (L * 1 and L * 2) and measure ΔL * Similarly, by calculating ΔL when measured by the SCE method, it is possible to predict the properties of the resin pipe composition when it is processed into a resin pipe. * is preferably less than 2, more preferably less than 0.5, and even more preferably less than 0.

[0039] [1.4. Manufacturing method and molding method of composition for resin pipe] The resin pipe composition according to one embodiment of the present invention can be produced by a method known in the art. For example, the resin pipe composition can be produced by melt-kneading the above-described components in a melt-kneader (such as a single-screw extruder or a twin-screw extruder). Liquid components may be added during the melt-kneading process using a liquid supply pump or the like.

[0040] The method for molding the resin pipe composition is not particularly limited. A general method for molding a thermoplastic resin can be used. Examples of such molding methods include injection molding, extrusion molding, vacuum molding, press molding, calendar molding, and blow molding. After pelletizing the resin pipe composition, the obtained pellets may be used as a material for molding.

[0041] In one embodiment, the resin pipe composition is extruded. Extrusion is a commonly used method for producing resin pipes. A commercially available extruder can be used for extrusion.

[0042] [2. Resin pipe] A resin pipe according to one aspect of the present invention includes the composition for a resin pipe described above. Since the resin pipe includes the composition for a resin pipe described above, the occurrence of whitening in a secondary processed portion can be prevented.

[0043] The proportion of the composition for a resin pipe in the total weight of the resin pipe is preferably 50% by weight or more, more preferably 70% by weight or more, and even more preferably 90% by weight or more. In one embodiment, the resin pipe consists of only the composition for a resin pipe.

[0044] In one embodiment, the resin pipe has a portion that has been subjected to secondary processing. Such a pipe can effectively utilize the effect of one aspect of the present invention, namely, prevention of whitening at the secondary processed portion. In this specification, secondary processing refers to processing that is further applied to a resin pipe that has been formed into a tubular shape. In one embodiment, the resin pipe has one or more structures selected from the group consisting of a receiving structure (a portion where the diameter is enlarged), a bent structure (a portion where the diameter is bent), and a drawn structure (a portion where the diameter is reduced).

[0045] The uses of the resin pipe are not particularly limited. Examples include water pipes (waterworks pipes, sewerage pipes, etc.), water supply pipes, electric wires, and power cable protection pipes. Of these, water pipes and water supply pipes are preferred. [Example]

[0046] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples.

[0047] 〔material〕 The materials used in the examples and comparative examples are as follows. ●Vinyl chloride resin Vinyl chloride resin (TH1003, Taiyo PVC Co., Ltd., degree of polymerization: 1,300) Silicone oil Silicone oil A (KF-54, Shin-Etsu Chemical Co., Ltd., phenyl-modified dimethyl silicone oil, SP value: 8.9 (cal / cm 3 ) 1 / 2 ) Silicone oil B (KF-351A, Shin-Etsu Chemical Co., Ltd., polyether-modified dimethyl silicone oil, SP value: 8.2 (cal / cm 3 ) 1 / 2 ) Silicone oil C (KF-352A, Shin-Etsu Chemical Co., Ltd., polyether-modified dimethyl silicone oil, SP value: 7.8 (cal / cm 3 ) 1 / 2 ) Silicone oil D (KF-96-1000CS, Shin-Etsu Chemical Co., Ltd., dimethyl silicone oil, SP value: 7.0 (cal / cm 3 ) 1 / 2 ) Silicone oil E (KF-96-50CS, Shin-Etsu Chemical Co., Ltd., dimethyl silicone oil, SP value: 7.4 (cal / cm 3 ) 1 / 2 ) Silicone oil F (KF-6020, Shin-Etsu Chemical Co., Ltd., polyether-modified silicone oil, SP value: 7.6 (cal / cm 3 ) 1 / 2 ) Strengthening agent Reinforcement agent (Kane Ace B564, Kaneka Corporation, MBS polymer) Lubricant Ester lubricant (Loxiol 2899, Emery Oleochemicals Japan Co., Ltd.) Hydrocarbon lubricant (SX-105, Nippon Seiro Co., Ltd.) ●Stabilizer Organotin stabilizer (LQ2714, Sakai Chemical Industry Co., Ltd., methyltin mercapto stabilizer) Heat stabilization aid (Kisuma 5A, Kyowa Chemical Industry Co., Ltd., magnesium hydroxide) ●Pigments Deep blue organic pigment

[0048] [Evaluation test method] [1. Rapid cooling whitening test] Instead of actually subjecting the resin pipe to secondary processing, the change in the degree of whitening before and after quenching a sheet-like test piece was quantitatively evaluated. Preliminary research by the present inventors has revealed that the results of the quenching whitening test are well correlated with the occurrence of whitening during secondary processing of the resin pipe.

[0049] (1) Preparation of roll sheets The roll sheet was prepared according to the following procedure. 1. The materials having the composition shown in Table 1 below were mixed by cold blending to obtain 400 g of a compound. 2. The obtained compound was kneaded using a roll kneader (Yasuda Seiki Test Mixing Roll 191-TM). The kneading temperature was 185°C. The kneading time was 3 minutes after winding. In this way, a roll sheet with a thickness of approximately 1 mm was obtained. 3. The obtained roll sheet was placed on a flat plate and cooled at room temperature without applying any load.

[0050] [Table 1]

[0051] (2) Preparation of press sheet A press sheet was prepared in accordance with JIS K7151. The specific procedure is as follows: 1. Preheat the press to 195°C. 2. 300 g of the roll sheets prepared in (1) were prepared. The roll sheets were stacked in a 22 cm x 22 cm frame. 3. The frame was placed in a press, clamped at 0-1 MPa using a heater, and left to stand for 1 minute to preheat. 4. Pressed at 15 MPa for 5 minutes. 5. The pressed product was removed from the frame and cut into approximately 30 mm x 40 mm pieces to prepare sheet-like test pieces.

[0052] (3) Rapid cooling The degree of whitening of the test piece before and after quenching was evaluated according to the following procedure. 1. The brightness (L * ) is measured using the SCI method, and the measured value is L * I set it to 1. 2. The test piece was heated in an oven at 150°C for 15 minutes. 3. The test piece was wrapped in plastic wrap and then rapidly cooled to -10°C for 50 minutes. 4. The brightness (L * ) is measured using the SCI method, and the measured value is * I chose 2. 5. L * 2-L* 1 value of ΔL * The degree of whitening of the test piece before and after quenching was quantified. The evaluation criteria are as follows: ○:ΔL * is less than 1. No bleaching occurred. ×:ΔL * is greater than 1. Bleaching has occurred.

[0053] Using the same procedure as above, the difference in brightness ΔL of the test piece before and after quenching was measured. * was also measured by the SCE method.

[0054] [2. Bending test] We actually produced a resin pipe with secondary processing (receptacle processing and bending) and checked whether the secondary processing areas would turn white. The specific procedure is as follows. 1. Compounds were prepared in the same manner as in the quench whitening test. 2. The resulting compound was extruded to produce a resin pipe. 3. The resulting resin pipe was subjected to a receiving process. Specifically, the secondary processing area was heated at 285-300°C for 320 seconds, and then pressed into a mold with cooling water flowing through it and cooled for 100 seconds. 4. The resin pipe with the end cut was further bent. Specifically, the secondary processing area was heated for 700 to 830 seconds in a furnace heated to 300°C using a ceramic heater (the heating time was adjusted appropriately according to the ambient temperature). After that, the pipe was pressed against a mold for 3 minutes for primary cooling, and then immersed in cooling water for secondary cooling. 5. The secondary processing areas (those where the opening and bending processes were performed) were visually inspected for whitening. The evaluation criteria were as follows: ○: No whitening occurred at either the receiving end or the bending area. ×: Whitening occurred at the receiving end and / or bending area.

[0055] Example 1 Silicone oil A (phenyl-modified dimethyl silicone oil, SP value: 8.9 (cal / cm 3 ) 1 / 2 The results are shown in Table 2.

[0056] Example 2 Silicone oil B (polyether-modified dimethyl silicone oil, SP value: 8.2 (cal / cm 3 ) 1 / 2 The results are shown in Table 2.

[0057] Example 3 Silicone oil C (polyether-modified dimethyl silicone oil, SP value: 7.8 (cal / cm 3 ) 1 / 2 The results are shown in Table 2.

[0058] Comparative Example 1 Silicone oil D (dimethyl silicone oil, SP value: 7.0 (cal / cm 3 ) 1 / 2 The results are shown in Table 2.

[0059] Comparative Example 2 Silicone oil E (dimethyl silicone oil, SP value: 7.4 (cal / cm 3 ) 1 / 2 The results are shown in Table 2.

[0060] Comparative Example 3 Silicone oil F (polyether modified silicone oil, SP value: 7.6 (cal / cm 3 ) 1 / 2 The results are shown in Table 2.

[0061] [Reference example] Test pieces were prepared without silicone oil and subjected to a rapid cooling whitening test. The results are shown in Table 2.

[0062] [Table 2]

[0063] 〔result〕 As shown in Table 1, the resin pipe compositions according to the examples have a ΔL * The value of ΔL was less than 1, and no whitening occurred in the rapid cooling whitening test (ΔL by the SCE method). * The SP value of silicone oil C used in Example 3 was 7.8 (cal / cm 3 ) 1 / 2 The SP value of the silicone oil F used in Comparative Example 3 was 7.6 (cal / cm 3 ) 1 / 2 Therefore, it is estimated that there is a boundary value between these two values ​​that determines whether bleaching will occur or not (for example, when the SP value is 7.7 (cal / cm 3 ) 1 / 2 (End).

[0064] In addition, the resin pipe compositions according to Examples 1 and 2 have a lower ΔL value by the SCI method and the SCE method than the resin pipe composition according to Example 3. * The SP value of the silicone oil C used in Example 3 was 7.8 (cal / cm 3 ) 1 / 2 The SP value of the silicone oil B used in Example 2 was 8.2 (cal / cm 3 ) 1 / 2 Therefore, it is estimated that there is a boundary value for the preferable SP value between these values ​​(for example, an SP value of 8.0 (cal / cm 3 ) 1 / 2 (End).

[0065] Furthermore, the composition for a resin pipe according to Example 1 has a ΔL measured by the SCE method, which is higher than that of the composition for a resin pipe according to Example 2. *The SP value of the silicone oil B used in Example 2 was 8.2 (cal / cm 3 ) 1 / 2 The SP value of the silicone oil A used in Example 1 was 8.9 (cal / cm 3 ) 1 / 2 Therefore, it is estimated that there is a boundary value for the preferable SP value between these values ​​(for example, an SP value of 8.5 (cal / cm 3 ) 1 / 2 (End).

[0066] The resin pipe composition according to the reference example has a ΔL * The SP value was less than 1, and no whitening occurred in the quench whitening test (measurement using the SCE method also gave good results). This result suggests that the whitening phenomenon in the secondary processing area is a problem caused by the addition of silicone oil. When pipes were produced from the resin pipe composition according to the reference example, they were poor in gloss and had poor releasability. Therefore, from the viewpoint of imparting gloss and improving releasability, it is preferable to blend silicone oil into the resin pipe composition. Furthermore, in order to prevent the whitening phenomenon in the secondary processing area, it is preferable to select a silicone oil with an SP value within a specific range. [Industrial Applicability]

[0067] The resin pipe composition according to one embodiment of the present invention can be suitably used, for example, as a raw material for resin pipes.

Claims

1. vinyl chloride resin, Solubility parameter is 7.7 (cal / cm ３ ) １／２ The silicone oil described above, A composition for a resin pipe, comprising: a tin-based stabilizer.

2. The silicone oil is an organically modified silicone oil, 2. The composition for resin pipes according to claim 1, wherein the organic-modified silicone oil is at least one selected from the group consisting of alkyl-modified silicone oil, polyether-modified silicone oil, phenyl-modified silicone oil, methylstyryl-modified silicone oil, fluorine-modified silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, carboxyl-modified silicone oil, carbinol-modified silicone oil, and mercapto-modified silicone oil.

3. 3. The resin pipe composition according to claim 2, wherein the organic modified silicone oil is at least one selected from the group consisting of phenyl modified dimethyl silicone oil and polyether modified dimethyl silicone oil.

4. The composition for a resin pipe according to any one of claims 1 to 3, wherein the degree of polymerization of the vinyl chloride resin is 600 to 1500.

5. As a result of subjecting the product to a rapid cooling whitening test according to the following procedure, ΔL ＊ The composition for a resin pipe according to any one of claims 1 to 4, wherein the value of 1. The resin pipe composition is pressed at 15 MPa for 5 minutes to prepare a sheet-like test piece.

2. The brightness (L ＊ ) is measured using the SCI method, and the measured value is L ＊ Let's say it's 1.

3. Heat the test piece at 150°C for 15 minutes.

4. The test piece is cooled at -10°C for 50 minutes.

5. The brightness (L ＊ ) is measured using the SCI method, and the measured value is L ＊ Let's say it's 2.

6. L ＊ 2-L ＊ 1 value to ΔL ＊ Let's say.

6. A resin pipe comprising the composition for a resin pipe according to any one of claims 1 to 5.

7. The resin pipe according to claim 6, having one or more structures selected from the group consisting of a receiving structure, a bent structure, and a constricted structure.

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