pipe

Abstract

To provide a resin pipe having high quality while contributing to environment maintenance and the formation of a sustainable society.SOLUTION: In this technology, the pipe is provided which contains biomass-derived resin as a resin component, and has a fracture time of 1000 hours or longer in a hot internal pressure creep test at 95°C conforming to JIS K6769. The biomass degree of the pipe relating to the technology can be 20% or higher to contribute to environment maintenance and the formation of sustainable society.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present technology relates to a resin pipe. [Background technology]

[0002] Resin pipes are often used for hot water supply piping, hot water piping for floor heating, etc. from the viewpoint of heat resistance, durability, corrosion resistance, and pressure resistance. For example, Patent Document 1 discloses a pipe that uses polyethylene with specific properties, which has excellent pressure resistance, long-term durability, and impact resistance, and can be molded by both injection molding and extrusion molding.

[0003] Furthermore, Patent Document 2 discloses a technology for producing a silane-crosslinked polyethylene pipe that is excellent in flexibility, pressure resistance, and creep resistance at high temperatures, particularly as a pipe for hot water, by combining two types of high-density polyethylene with specific properties and a linear low-density polyethylene.

[0004] Furthermore, Patent Document 3 discloses a technology for producing cross-linked polyethylene pipes that have excellent creep performance at high temperatures, are easy to install, have good cross-linking efficiency, and have good moldability and surface smoothness by using a polyethylene resin composition having specific properties.

[0005] Recently, in order to contribute to environmental considerations and the creation of a sustainable society, techniques for producing resins using plant resources have been proposed. For example, Patent Document 4 discloses a technique for producing one or more olefins from the residue of renewable natural raw materials. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-194060 [Patent Document 2] Japanese Patent Application Publication No. 2018-168229 [Patent Document 3] Japanese Patent Application Publication No. 2019-143035 [Patent Document 4] Special Publication No. 2010-511634 Summary of the Invention [Problem to be solved by the invention]

[0007] As mentioned above, in recent years, there has been a demand for the use of resins obtained from plant resources in various applications in order to contribute to environmental considerations and the creation of a sustainable society, but there is a concern that molded articles made from biomass-derived resins may be inferior in various performance aspects compared to molded articles made from petroleum-derived resins. As a result, progress has been slow in practical application of biomass-derived resins to pipes that require properties such as heat resistance, durability, corrosion resistance, and pressure resistance.

[0008] Therefore, the main objective of this technology is to provide high-quality resin pipes while contributing to environmental conservation and the creation of a sustainable society. [Means for solving the problem]

[0009] That is, in the present technology, a biomass-derived resin is contained as a resin component, The present invention provides a pipe that has a fracture time of 1,000 hours or more in a hot internal pressure creep test at 95°C in accordance with JIS K6769. The biomass-derived resin used in the pipe according to the present technology may contain a biomass-derived resin having a melt flow rate (MFR) measured in accordance with JIS K7210 of 0.1 to 0.5 g / 10 min. The biomass-derived resin has a density of 0.945 to 0.960 g / cm 3 The biomass-derived resin may contain a biomass-derived resin. The pipe according to the present technology may have a crystallinity of 45 to 70% as measured by X-ray diffraction. The biomass content of the pipe according to the present technology can be 20% or more. The pipe according to the present technology may have a gel fraction of 50% or more as measured in accordance with JIS K6769. The pipe according to the present technology may contain a petroleum-derived resin as a resin component, In this case, the petroleum-derived resin may have a crystallinity of 40 to 55% as measured by X-ray diffraction. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferred embodiments for implementing the present technology will be described below. The embodiments described below are examples of typical embodiments of the present technology, and any of the embodiments can be combined. Furthermore, the scope of the present technology will not be interpreted narrowly by these embodiments.

[0011] (1) Raw materials The pipes according to this technology are characterized by using biomass-derived resin as the resin component. In addition, as long as the effects and advantages of this technology are not impaired, resin pipes can be manufactured using one or more of the raw materials used in the manufacture of general resin pipes in any combination.

[0012] For example, the pipe according to the present technology can be produced by crosslinking a resin composition for producing a resin pipe (hereinafter also referred to as "the resin composition") containing a resin component, a crosslinking agent, a catalyst, and other components as necessary, and molding the resin composition into a cylindrical shape. The components of the resin composition for producing a pipe used in the present technology will be described in detail below.

[0013] (1-1) Resin component The resin component that can be used in this technology can be one or more commonly used resins for resin pipes, freely selected and used within the scope that does not impair the purpose and effects of this technology. Examples include thermoplastic resins such as polyolefin resins, polystyrene resins, polyamide resins, and polyester resins; thermoplastic elastomers such as olefin thermoplastic elastomers and styrene thermoplastic elastomers; synthetic rubbers such as ethylene propylene rubber (EPDM); and thermosetting elastomers such as natural rubber. Among these, polyolefin resins are preferred for this technology.

[0014] The polyolefin resin that can be used in the present technology is a resin whose main component is an olefin component unit. A resin whose main component is an olefin component unit is a resin containing 50% by mass or more of the olefin component unit. In the present technology, the content of the olefin component unit in the resin is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, and it is particularly preferable that the resin component is composed only of a polyolefin resin.

[0015] Examples of polyolefin resins that can be used in the present technology include polyethylene resins, polypropylene resins, polybutene, polypentene, and copolymers of olefin monomers and monomers copolymerizable with the olefin monomers, and these can be used alone or in combination of two or more.

[0016] Examples of polyethylene resins include ethylene homopolymers such as high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and very low-density polyethylene (VLDPE); ethylene-propylene random copolymers, ethylene-propylene block copolymers, ethylene-butene block copolymers, ethylene-butene random copolymers, ethylene-vinyl acetate copolymers (EVA), and ethylene-methyl methacrylate copolymers.

[0017] Examples of polypropylene-based resins include propylene homopolymers such as isotactic polypropylene, syndiotactic polypropylene, and atactic polypropylene; propylene-ethylene random copolymers, propylene-ethylene block copolymers, propylene-butene random copolymers, propylene-butene block copolymers, propylene-ethylene-butene terpolymers, propylene-acrylic acid copolymers, and propylene-maleic anhydride copolymers.

[0018] Among these, in the present technology, it is preferable to use a polyethylene-based resin, and among polyethylene-based resins, it is preferable to use high-density polyethylene (HDPE).

[0019] This technology is characterized by using biomass-derived resin as part or all of the resin component. In this technology, biomass-derived resin refers to a renewable resin made from animals and plants, excluding fossil fuels such as petroleum. The biomass-derived resin is a resin obtained by polymerizing biomass-derived monomers. The biomass-derived monomer is a polymerizable organic compound made from organic resources derived from animals and plants, excluding fossil resources. The biomass-derived monomer does not need to contain 100% biomass-derived components, but the biomass content of the biomass-derived resin used in this technology is, for example, 50% or more, preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more.

[0020] The biomass content of biomass-derived resin is determined by the amount of 14 This can be determined by measuring the concentration of C. In other words, there is a certain percentage of 14 C, while the carbon in petroleum-derived resins contains 14 Since it does not contain C, it is 14 The biomass ratio can be calculated by measuring the concentration of C. For example, if all of the carbon in a biomass-derived resin is derived from petroleum, the biomass ratio will be 0%, and if all of the carbon is derived from biomass, the biomass ratio will be 100%.

[0021] In the present technology, the biomass content (%) of the biomass-derived resin is a value calculated in accordance with ASTM D6866.

[0022] As the biomass-derived resin that can be used in the present technology, one or more general biomass-derived resins can be freely selected and used as long as the purpose and effects of the present technology are not impaired. Examples include biomass-derived polyolefin-based resins such as biomass polyethylene-based resins and biomass polypropylene-based resins; biomass-derived polyester-based resins such as biomass polyethylene terephthalate, biomass trimethylene terephthalate, polylactic acid, and biomass polybutylene succinate; and biomass-derived polyamide-based resins. Among these, it is preferable to use biomass-derived polyolefin-based resins in the present technology. Note that the details of polyolefin-based resins are the same as those described above, so a detailed description will be omitted here.

[0023] The density of the biomass-derived resin that can be used in the present technology can be freely set within a range that does not impair the purpose and effects of the present technology. The lower limit of the density of the biomass-derived resin is, for example, 0.900 g / cm. 3 or more, preferably 0.915 g / cm 3 More preferably, 0.920 g / cm 3 In this technology, in particular, the density is 0.945 g / cm 3 It is preferable to use a biomass-derived resin having a density in this range. By using a biomass-derived resin having a density in this range, the oxidation induction time of the manufactured pipe can be extended, and the heat deterioration of the pipe can be prevented, thereby improving the heat resistance of the pipe.

[0024] The density is 0.940 g / cm 3When the following biomass-derived resins are used, the content thereof in 100 parts by mass of the resin component is preferably 15 parts by mass or less, more preferably 13 parts by mass or less, even more preferably 12 parts by mass or less, even more preferably 11 parts by mass or less, and particularly preferably 10 parts by mass or less. 3 By setting the content of the following biomass-derived resin within this range, the oxidation induction time of the manufactured pipe can be extended, thermal deterioration of the pipe can be prevented, and the heat resistance of the pipe can be improved.

[0025] The upper limit of the density of the biomass-derived resin is not particularly limited, and is, for example, 0.960 g / cm 3 The following is the result.

[0026] The melt flow rate (MFR) of the biomass-derived resin usable in this technology can be freely set within a range that does not impair the purpose and effects of this technology. The lower limit of the MFR of the biomass-derived resin is, for example, 0.1 g / 10 min or more, preferably 0.2 g / 10 min or more, and more preferably 0.3 g / 10 min or more.

[0027] The upper limit of the MFR of the biomass-derived resin is, for example, 3.0 g / 10 min or less, preferably 2.0 g / 10 min or less, and more preferably 1.0 g / 10 min or less. In this technology, it is particularly preferable to use a biomass-derived resin with an MFR of 0.5 g / 10 min or less. By using a biomass-derived resin with an MFR in this range, the oxidation induction time of the manufactured pipe can be extended, thermal degradation of the pipe can be prevented, and the heat resistance of the pipe can be improved.

[0028] The melting point of the biomass-derived resin that can be used in the present technology is not particularly limited as long as it does not impair the purpose and effects of the present technology. The lower limit of the melting point of the biomass-derived resin is, for example, 90°C or higher, preferably 100°C or higher, more preferably 110°C or higher, even more preferably 120°C or higher, and even more preferably 125°C or higher. In the present technology, it is particularly preferable to use a biomass-derived resin with a melting point of 130°C or higher. By using a biomass-derived resin with a melting point within this range, the oxidation induction time of the manufactured pipe can be extended, thermal degradation of the pipe can be prevented, and the heat resistance of the pipe can be improved.

[0029] When using a biomass-derived resin with a melting point of 120°C or less, the content per 100 parts by mass of the resin component is preferably 15 parts by mass or less, more preferably 13 parts by mass or less, even more preferably 12 parts by mass or less, even more preferably 11 parts by mass or less, and particularly preferably 10 parts by mass or less. By setting the content of the biomass-derived resin with a melting point of 120°C or less within this range, the oxidation induction time of the manufactured pipe can be extended, thermal degradation of the pipe can be prevented, and the heat resistance of the pipe can be improved.

[0030] The upper limit of the melting point of the biomass-derived resin is not particularly limited, and is, for example, 145°C or lower.

[0031] The content of the biomass-derived resin used in this technology is not particularly limited as long as it does not impair the purpose and effects of this technology. The lower limit of the content of the biomass-derived resin per 100 parts by mass of the resin component is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 25 parts by mass or more, and even more preferably 30 parts by mass or more. By setting the lower limit of the content of the biomass-derived resin used in this technology within this range, the biomass content of the manufactured pipe can be improved, thereby contributing to environmental conservation and the creation of a sustainable society.

[0032] The upper limit of the amount of biomass-derived resin in 100 parts by mass of the resin component is, for example, 90 parts by mass or less, preferably 80 parts by mass or less, more preferably 70 parts by mass or less, even more preferably 60 parts by mass or less, and even more preferably 50 parts by mass or less. By setting the upper limit of the amount of biomass-derived resin used in the present technology within this range, it is possible to prevent a decrease in the physical properties of the manufactured pipe.

[0033] In this technology, biomass-derived resin is essential, but petroleum-derived resin may also be included as a resin component.

[0034] When a petroleum-derived resin is used, the crystallinity of the petroleum-derived resin measured by X-ray diffraction is preferably 40% or more. Furthermore, the upper limit of the crystallinity of the petroleum-derived resin measured by X-ray diffraction is preferably 55% or less. By using a petroleum-derived resin with a crystallinity in this range, a pipe with excellent surface smoothness can be manufactured.

[0035] When using a petroleum-derived resin, the oxidative induction time (OIT) of the petroleum-derived resin in an oxygen atmosphere at 220°C as determined by differential thermal analysis is preferably 6 minutes or longer. By using a petroleum-derived resin with an oxidative induction time in this range, a pipe with high heat resistance can be manufactured.

[0036] When a petroleum-derived resin is used, the density of the petroleum-derived resin that can be used in the present technology can be freely set within a range that does not impair the purpose and effects of the present technology. The lower limit of the density of the petroleum-derived resin is, for example, 0.900 g / cm. 3 or more, preferably 0.915 g / cm 3 More preferably, 0.920 g / cm 3 In this technology, in particular, the density is 0.945 g / cm 3 It is preferable to use a petroleum-derived resin having a density in this range. By using a petroleum-derived resin having a density in this range, the oxidation induction time of the manufactured pipe can be extended, and thermal deterioration of the pipe can be prevented.

[0037] When a petroleum-derived resin is used, the upper limit of the density of the petroleum-derived resin is not particularly limited, and may be, for example, 0.960 g / cm 3 The following is the result.

[0038] When a petroleum-derived resin is used, the melt flow rate (MFR) of the petroleum-derived resin usable in the present technology can be freely set within a range that does not impair the purpose and effects of the present technology. The lower limit of the MFR of the petroleum-derived resin is, for example, 0.1 g / 10 min or more, preferably 0.2 g / 10 min or more, and more preferably 0.3 g / 10 min or more.

[0039] When a petroleum-derived resin is used, the upper limit of the MFR of the petroleum-derived resin is, for example, 3.0 g / 10 min or less, preferably 2.0 g / 10 min or less, and more preferably 1.0 g / 10 min or less. By using a petroleum-derived resin with an MFR within this range, the oxidation induction time of the produced pipe can be extended, thermal degradation of the pipe can be prevented, and the heat resistance of the pipe can be improved.

[0040] When a petroleum-derived resin is used, the melting point of the petroleum-derived resin that can be used in the present technology is not particularly limited as long as it does not impair the purpose and effects of the present technology. The lower limit of the melting point of the petroleum-derived resin is, for example, 90°C or higher, preferably 100°C or higher, more preferably 110°C or higher, even more preferably 120°C or higher, and even more preferably 125°C or higher. In the present technology, it is particularly preferable to use a petroleum-derived resin with a melting point of 130°C or higher. By using a petroleum-derived resin with a melting point within this range, the oxidation induction time of the manufactured pipe can be extended, thermal degradation of the pipe can be prevented, and the heat resistance of the pipe can be improved.

[0041] When a petroleum-derived resin is used, the upper limit of the melting point of the petroleum-derived resin is not particularly limited, and is, for example, 145°C or lower.

[0042] The resin used in the present technology may contain recycled resins recycled from waste such as molded articles using the resins described above. In the present technology, recycled resins are resins produced from resin compositions that have been decrosslinked using a general method. That is, in the present technology, recycled resins are not resin pulverized products obtained by simply pulverizing resin molded articles, but resins that have been decrosslinked by subjecting used resin molded articles to pulverization, shearing, melt-kneading, and the like.

[0043] (1-2) Crosslinking agent The pipe according to the present technology is preferably a cross-linked body. By cross-linking the pipe according to the present technology during its production, heat resistance and durability can be improved.

[0044] The pipes according to the present invention can be crosslinked by irradiation with ionizing radiation, or chemically by using a crosslinking agent. As the crosslinking agent that can be used in the present invention, one or more crosslinking agents that can be used in the production of resin pipes can be freely selected and used, as long as they do not impair the purpose and effects of the present invention.

[0045] Examples of crosslinking agents that can be used in the present technology include crosslinking agents having a chemical structure such as a silane group, a peroxide, a hydroxyl group, an amide group, an ester group, etc. Among these, in the present technology, it is preferable to use a silane coupling agent or an organic peroxide as the crosslinking agent.

[0046] Examples of silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, etc. Among these, in the present technology, it is preferable to use vinyltrimethoxysilane as the crosslinking agent.

[0047] Examples of organic peroxides include dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, di-t-butyl peroxide, di-t-butylperoxy-3,3,5-trimethylcyclohexane, and t-dibutyl hydroperoxide. Among these, in the present technology, it is preferable to use 2,5-dimethyl-2,5-di(t-butylperoxy)hexane as a crosslinking agent.

[0048] The amount of crosslinking agent used in the production of the pipe according to the present technology can be freely set as long as it does not impair the function and effect of the present technology. In the present technology, the content of the crosslinking agent per 100 parts by mass of the resin component in the resin composition is, for example, 0.2 parts by mass or more, preferably 0.4 parts by mass or more, and more preferably 0.6 parts by mass or more. By setting the content of the crosslinking agent in the resin composition within this range, the degree of crosslinking can be improved, and the mechanical properties of the produced pipe, such as heat resistance and durability, can be improved.

[0049] In the present technology, the content of the crosslinking agent in the resin composition relative to 100 parts by mass of the resin component is, for example, 4.0 parts by mass or less, preferably 3.0 parts by mass or less, and more preferably 2.0 parts by mass or less. By setting the content of the crosslinking agent in the resin composition within this range, moldability can be improved.

[0050] (1-3) Catalyst A catalyst can be used in the production of the pipe according to the present technology. As the catalyst that can be used in the present technology, one or more catalysts that can be used in the production of resin pipes can be freely selected and used as long as the action and effect of the present technology are not impaired.

[0051] Examples of the catalyst include metal catalysts (organometallic catalysts) such as tin compounds (dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctate, dioctyltin dilaurate, tin(II) octate, stannous acetate, tin naphthenate, etc.), iron compounds (iron acetylacetonate, etc.), nickel compounds (nickel acetylacetonate, nickel octoate, nickel naphthenate, etc.), bismuth compounds (bismuth octoate, bismuth naphthenate, etc.), lead compounds (lead octoate, lead naphthenate, etc.), cobalt compounds (cobalt acetylacetonate, cobalt octoate, cobalt naphthenate, etc.), zirconium compounds (zirconium acetylacetonate, etc.), and zinc compounds. Examples of suitable amine catalysts include piperazine amines such as dimethylpiperazine, diethanolamine, bis(2-dimethylaminoethyl)ether, N,N,N',N",N"-pentamethyldiethylenetriamine, imidazole compounds, dimethylpiperazine, N-methyl-N'-(2-dimethylamino)ethylpiperazine, and N-methyl-N'-(2-hydroxyethyl)piperazine; morpholine amines such as N-methylmorpholine and N-ethylmorpholine; and amine catalysts such as amines known as DBU homologues, such as 1,8-diazabicyclo-[5,4,0]-undecene-7 (DBU), 1,5-diazabicyclo-[4,3,0]-nonene-5 (DBN), 1,8-diazabicyclo-[5,3,0]-decene-7 (DBD), and 1,4-diazabicyclo-[3,3,0]octene-4 (DBO). Among these, in the present technology, it is preferable to use a metal-based catalyst, and among the metal-based catalysts, it is more preferable to use a tin compound.

[0052] The amount of catalyst in the resin composition used to manufacture the pipe according to the present technology can be freely set as long as it does not impair the function and effect of the present technology. In the present technology, the lower limit of the catalyst content in the resin composition is, for example, 0.01 parts by mass or more, preferably 0.05 parts by mass or more, and more preferably 0.1 parts by mass or more, per 100 parts by mass of the resin component. By setting the lower limit of the catalyst content in the resin composition within this range, the crosslinking reaction during manufacturing can be promoted, improving the degree of crosslinking. As a result, the mechanical properties of the manufactured pipe, such as heat resistance and durability, can be improved.

[0053] In this technology, the upper limit of the catalyst content in the resin composition is, for example, 3.0 parts by mass or less, preferably 2.0 parts by mass or less, and more preferably 1.0 part by mass or less, per 100 parts by mass of the resin component. By setting the upper limit of the catalyst content in the resin composition within this range, it is possible to prevent instability of various reactions during production. As a result, a pipe with excellent mechanical properties and appearance can be obtained.

[0054] In this technology, the catalyst can be used as a masterbatch in which the catalyst is dispersed in the resin component. By using a catalyst masterbatch, it is possible to improve the dispersibility of the catalyst in the resin component.

[0055] (1-4) Other ingredients In manufacturing pipes according to the present technology, one or more of the various components that can be used in manufacturing plastic pipes can be freely selected and used as other components depending on the purpose, as long as the purpose and effect of the present technology are not impaired.

[0056] Examples of components that can be used in the production of pipes according to the present technology include inorganic fillers, flame retardants, stabilizers, plasticizers, colorants, antioxidants, dispersants, and ultraviolet absorbers.

[0057] (2) Manufacturing method The pipes according to the present technology are characterized by their physical properties and the resin components used, and there are no particular limitations on the manufacturing method as long as it does not impair the functions and effects of the present technology. Pipes can be manufactured by one or a combination of two or more general resin pipe manufacturing methods.

[0058] In this technology, it is preferable to perform extrusion molding. Specifically, for example, a resin raw material and, if necessary, additives such as a crosslinking agent and a catalyst are supplied to an extruder and heated and mixed to prepare a molten resin composition, which is then introduced into an annular die provided downstream of the extruder and extruded from the tip of the annular die, thereby producing a resin pipe.

[0059] (3) Hot internal pressure creep performance The pipe according to the present technology is characterized by a failure time of 1,000 hours or more in a hot internal pressure creep test at 95°C in accordance with JIS K6769. While resin molded products made from biomass-derived raw materials are generally considered to have poor physical properties, the pipe according to the present technology is characterized by having high hot internal pressure creep performance despite being made from biomass-derived resin. Therefore, the pipe according to the present technology can be suitably used for applications such as hot water supply piping and hot water piping for floor heating.

[0060] (4) Crystallinity The crystallinity of the pipe according to the present technology is not particularly limited as long as it does not impair the functions and effects of the present technology, but the crystallinity measured by X-ray diffraction is, for example, 45% or more, preferably 46% or more, more preferably 47% or more, even more preferably 48% or more, still more preferably 49% or more, and particularly preferably 50% or more. By setting the lower limit of the crystallinity of the pipe within this range, it is possible to further improve the hot internal pressure creep performance.

[0061] The upper limit of the crystallinity measured by X-ray diffraction is, for example, 70% or less, preferably 68% or less, more preferably 66% or less, and even more preferably 65% ​​or less. By setting the upper limit of the crystallinity of the pipe within this range, the surface smoothness can be further improved.

[0062] In the present technology, the crystallinity of the pipe is a value measured by the method in the examples described below.

[0063] (5) Biomass ratio The biomass ratio of the pipe according to the present technology is not particularly limited as long as it does not impair the action and effect of the present technology, but is, for example, 20% or more, preferably 23% or more, more preferably 25% or more, even more preferably 26% or more, still more preferably 27% or more, and particularly preferably 28% or more. Setting the lower limit of the biomass ratio of the pipe within this range can contribute to environmental conservation and the formation of a sustainable society.

[0064] The upper limit of the biomass degree of the pipe is, for example, 90% or less, preferably 80% or less, and more preferably 75% or less. By setting the upper limit of the biomass degree of the pipe within this range, deterioration of the physical properties of the pipe can be prevented.

[0065] In this technology, the biomass content (%) of the pipe is a value calculated using the following formula. Biomass content (%) = {(Weight of biomass material × Biomass content of biomass material / 100) / Total weight of raw materials} × 100

[0066] (6) Gel fraction In this technology, the degree of cross-linking of a pipe is estimated by measuring the gel content (gel fraction measurement) by solvent extraction (citing JIS K6769:1998), and the effect on the physical properties of the pipe is examined. The gel fraction of the pipe according to this technology is not particularly limited as long as it does not impair the function and effect of the technology, but is, for example, 50% or more, preferably 60% or more, and more preferably 65% ​​or more. A pipe with a gel fraction within this range can fully meet the durability needs in various applications. The upper limit of the gel fraction of the pipe is not particularly limited in this technology, and can be, for example, 90% or less.

[0067] In this technology, the gel fraction of the pipe is a value measured in accordance with JIS K6769:2013.

[0068] (7) Density The density of the pipe according to the present technology is not particularly limited as long as it does not impair the action and effect of the present technology, but it is, for example, 0.940 g / cm 3 or more, preferably 0.941 g / cm 3 More preferably, 0.942 g / cm 3 More preferably, 0.943 g / cm 3 More preferably, 0.944 g / cm 3 More preferably, 0.945 g / cm 3 That's all. A pipe with a density in this range can adequately meet the need for durability in a variety of applications. The upper limit of the density of the pipe is not particularly limited in the present technology, and is, for example, 0.960 g / cm 3 It can be as follows:

[0069] In the present technology, the density of the pipe is a value calculated by a method in an example described later.

[0070] (8) Oxidative Induction Time (OIT) The oxidation induction time of the pipe according to the present technology is not particularly limited as long as it does not impair the function and effect of the present technology, but the oxidation induction time of the pipe in an oxygen atmosphere at 220°C as measured by differential thermal analysis is, for example, 3 minutes or more, preferably 4 minutes or more, and more preferably 5 minutes or more. By setting the oxidation induction time of the pipe within this range, thermal degradation of the pipe can be prevented and the heat resistance of the pipe can be further improved.

[0071] In the present technology, the oxidation induction time of the pipe is a value measured by the method of the examples described later.

[0072] (9) Inner diameter The inner diameter of the pipe according to the present technology can be freely set as long as it does not impair the function and effect of the present technology. The lower limit of the inner diameter of the pipe is, for example, 10 mm or more, preferably 13 mm or more, more preferably 14 mm or more, and even more preferably 15 mm or more. By setting the lower limit of the inner diameter of the pipe within this range, it is possible to improve formability.

[0073] The upper limit of the inner diameter of the pipe is, for example, 80 mm or less, preferably 70 mm or less, and more preferably 65 mm or less. By setting the inner diameter of the pipe within this range, the pipe can have an appropriate thickness, and heat resistance and durability can be improved.

[0074] (10) Outer diameter The outer diameter of the pipe according to the present technology can be freely set as long as it does not impair the function and effect of the present technology. The lower limit of the outer diameter of the pipe according to the present technology is, for example, 30 mm or more, preferably 35 mm or more, more preferably 45 mm or more, and even more preferably 50 mm or more. By setting the lower limit of the outer diameter of the pipe according to the present technology within this range, the pipe according to the present technology can have an appropriate thickness, and heat resistance and durability can be improved.

[0075] The upper limit of the outer diameter of the pipe is, for example, 100 mm or less, preferably 90 mm or less, and more preferably 80 mm or less. By setting the outer diameter of the pipe within this range, formability can be improved.

[0076] (11) Thickness The thickness of the pipe according to the present technology can be freely set as long as it does not impair the function and effect of the present technology. In the present technology, the lower limit of the pipe thickness is, for example, 2 mm or more, preferably 3 mm or more, and more preferably 4 mm or more. By setting the lower limit of the pipe thickness within this range, it is possible to improve heat resistance and durability.

[0077] The upper limit of the pipe thickness is, for example, 20 mm or less, preferably 17 mm or less, and more preferably 15 mm or less. By keeping the pipe thickness within this range, formability can be improved. [Example]

[0078] The present technology will be described in more detail below based on examples. Note that the examples described below are examples of typical examples of the present technology, and the scope of the present technology should not be construed as being narrow.

[0079] (1) Pipe manufacturing The resins and raw materials shown in Table 1 below were fed into a compounder and heated and kneaded to prepare a molten resin composition. The prepared molten resin composition was fed into an extruder, introduced into an annular die provided downstream of the extruder, and extruded from the lip at the tip of the annular die to produce a pipe.

[0080] (2) Measurement of pipe properties [Biomass ratio] The biomass content (%) of the biomass-derived resin was calculated in accordance with ASTM D6866. The biomass content (%) of the manufactured pipe was calculated using the following formula. Biomass content (%) = {(Weight of biomass material × Biomass content of biomass material / 100) / Total weight of raw materials} × 100

[0081] [Crystallization] For the raw material resin and the manufactured pipe, an X-ray diffractometer ("Empyrean" manufactured by Malvern Panalytical) was used, and the crystallinity was calculated from the ratio of the peak area of ​​the crystalline component to the total peak area (peak area of ​​the crystalline component + halo pattern area of ​​the amorphous component).

[0082] [density] Weight (g) / volume (cm) of manufactured pipe 3 The density was calculated by the calculation of

[0083] [Oxidative Induction Time (OIT)] The raw resin and the manufactured pipe were heated at a temperature increase rate of 20°C / min. After reaching 220°C, the gas was switched to oxygen gas 5 minutes later, and the time from the time of switching to the rise of the exothermic peak due to oxidation was measured as the oxidation induction time.

[0084] [Hot internal pressure creep test] The manufactured pipes were subjected to a hot internal pressure creep test at 90°C in accordance with JIS K6769:2014. Pipes with a time to fracture of 1000 hours or more were rated as passing (○), and pipes with a time to fracture of less than 1000 hours were rated as failing (×).

[0085] [Surface smoothness] The surfaces of the manufactured pipes were visually inspected by a panel of five experts, and pipes with no defects due to surface irregularities were rated as passed (◯), and pipes with defects were rated as failed (×).

[0086] [Gel fraction] The gel fraction of the produced pipe was measured in accordance with JIS K6769:2013.

[0087] (3) Results The results are shown in Table 1 below.

[0088] [Table 1]

[0089] (4) Discussion As shown by the results of Reference Example 1 and Comparative Examples 1 to 3, the pipes using biomass-derived resins had a thermal internal pressure creep test result of less than 1000 hours. In contrast, the pipes of Examples 1 to 4 had a biomass content equal to or greater than that of Comparative Examples 1 to 3, but had a thermal internal pressure creep test result of 1000 hours or more.

[0090] Focusing on the raw materials, Example 1, which used a biomass-derived resin with an MFR in the range of 0.1 to 0.5 g / 10 min, showed better results in the thermal internal pressure creep test and a longer oxidation induction time than Comparative Examples 2 and 3, which used biomass-derived resins with an MFR exceeding 0.5 g / 10 min.

[0091] Density: 0.945~0.960g / cm 3 In Example 1, a biomass-derived resin in the range of 3 Compared to Comparative Examples 2 and 3, which used biomass-derived resins with less than 100 kJ / g, the results of the thermal internal pressure creep test were better and the oxidation induction time was also longer.

[0092] Density is 0.940g / cm 3 Compared to Comparative Example 1, in which the content of the following biomass-derived resin exceeds 15 parts by mass, the density is 0.940 g / cm 3 Example 3, in which the content of the biomass-derived resin below was 15 parts by mass or less, showed better results in the thermal internal pressure creep test and also had a longer oxidation induction time.

[0093] Focusing on the physical properties, Examples 1 and 3, which had a crystallinity of 45% or more, had better results in the thermal internal pressure creep test and also had a longer oxidation induction time than Comparative Example 2, which had a crystallinity of less than 45%.

[0094] Comparing the examples, compared to Example 4, which had a crystallinity of 68%, Examples 1 to 3, which had a lower crystallinity, had improved surface smoothness.

Claims

1. Contains biomass-derived resin as a resin component, A pipe having a fracture time of 1000 hours or more in a hot internal pressure creep test at 95°C in accordance with JIS K6769.

2. The biomass-derived resin contains a biomass-derived resin having a melt flow rate (MFR) measured in accordance with JIS K7210 of 0.1 to 0.5 g / 10 min. The pipe according to claim 1.

3. The biomass-derived resin has a density of 0.945 to 0.960 g / cm ３ 2. The pipe according to claim 1, comprising a biomass-derived resin comprising:

4. 2. The pipe of claim 1, wherein the crystallinity as measured by X-ray diffraction is 45 to 70%.

5. 2. The pipe according to claim 1, having a biomass content of 20% or more.

6. 2. The pipe according to claim 1, which has a gel fraction of 50% or more as measured in accordance with JIS K6769.

7. Contains petroleum-derived resin as a resin component, 2. The pipe of claim 1, wherein the petroleum-derived resin has a crystallinity of 40 to 55% as measured by X-ray diffraction.

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