Molded body and high-purity chemical solution transfer tube

Abstract

To provide a molding which can be used as a tube for transferring a high-purity chemical.SOLUTION: A molded article comprising a liquid-contacting layer (A) having a liquid-contacting surface and a non-liquid-contacting layer (B) having a non-liquid-contacting surface, wherein the liquid-contacting layer (A) contains a tetrafluoroethylene / fluoroalkyl vinyl ether co-polymer (a), the total amount of Na, Mg, K, Ca and Fe eluted from the liquid-contacting layer (A) into hydrofluoric acid is 10ng / cm2 or less, and the non-liquid-contacting layer (B) contains a tetrafluoroethylene / fluoroalkyl vinyl ether co-polymer (b), A total metal content of Na, Mg, K, Ca, and Fe in the non-liquid-contacting layer (B) measured by an ashing method is larger than a total metal content of Na, Mg, K, Ca, and Fe in the liquid-contacting layer (A) measured by an ashing method.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a molded article and a tube for transporting high-purity chemical solutions. [Background technology]

[0002] Patent Document 1 describes a rubber sheet that includes a first polyolefin resin layer constituting the innermost layer and a second polyolefin resin layer disposed on the outer side of the first polyolefin resin layer, and the amount of calcium elution measured in accordance with SEMI F-57 from the material of the first polyolefin resin layer is 30 μg / m 2 The invention also describes a multi-layer pipe in which the thickness of the first polyolefin resin layer is less than 0.011 to 0.17, and the ratio of the thickness of the first polyolefin resin layer to the total thickness of the first polyolefin resin layer and the second polyolefin resin layer is 0.011 to 0.17. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 066066 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a molded article that can be used as a tube for transporting high-purity chemical solutions. [Means for solving the problem]

[0005] According to the present disclosure, there is provided a molded article comprising a liquid-contacting layer (A) having a liquid-contacting surface and a non-liquid-contacting layer (B) having a non-liquid-contacting surface, wherein the liquid-contacting layer (A) contains a tetrafluoroethylene / fluoroalkyl vinyl ether copolymer (a), and the total amount of Na, Mg, K, Ca and Fe eluted from the liquid-contacting layer (A) into hydrofluoric acid is 10 ng / cm 2 is as follows: The non-liquid-contacting layer (B) contains a tetrafluoroethylene / fluoroalkyl vinyl ether copolymer (b), and a molded article is provided in which the total metal content of Na, Mg, K, Ca, and Fe in the non-liquid-contacting layer (B), as measured by an ashing method, is greater than the total metal content of Na, Mg, K, Ca, and Fe in the liquid-contacting layer (A), as measured by the ashing method. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to provide a molded article that can be used as a tube for transporting high-purity chemical solutions. DETAILED DESCRIPTION OF THE INVENTION

[0007] Specific embodiments of the present disclosure will be described in detail below, but the present disclosure is not limited to the following embodiments.

[0008] Patent Document 1 proposes a multi-layer pipe made of polyolefin resin and having the above-described configuration, which is useful as a pipe for a semiconductor cleaning liquid.

[0009] As piping, piping made of fluororesin is also known. However, in general, molded articles made of fluororesin are more expensive than molded articles made of polyolefin-based resin. There is a demand for molded articles made of fluororesin that can utilize the excellent properties of fluororesin while minimizing cost increases.

[0010] The molded article of the present disclosure comprises a liquid-contacting layer (A) having a liquid-contacting surface and a non-liquid-contacting layer (B) having a non-liquid-contacting surface. Furthermore, in the molded article of the present disclosure, the liquid-contacting layer (A) and the non-liquid-contacting layer (B) are configured such that the total metal content of Na, Mg, K, Ca, and Fe in the non-liquid-contacting layer (B) measured by an ashing method is greater than the total metal content of Na, Mg, K, Ca, and Fe in the liquid-contacting layer (A) measured by the ashing method. This configuration makes it possible to utilize the excellent properties inherent to fluororesins while minimizing cost increases. The configuration of the molded article of the present disclosure is described below.

[0011] The molded article of the present disclosure comprises at least a liquid-contacting layer (A) and a non-liquid-contacting layer (B). The molded article of the present disclosure is a molded article used in contact with a liquid, and comprises a liquid-contacting surface provided in the liquid-contacting layer (A) and a non-liquid-contacting surface provided in the non-liquid-contacting layer (B). Both the liquid-contacting surface and the non-liquid-contacting surface form the outer surface of the molded article, and both surfaces are exposed.

[0012] The liquid-contacting layer (A) and the non-liquid-contacting layer (B) may be bonded directly or via another layer, but are preferably bonded directly. The molded article of the present disclosure may be a two-layer molded article consisting of the liquid-contacting layer (A) and the non-liquid-contacting layer (B), or a three- or more-layer molded article consisting of the liquid-contacting layer (A), the non-liquid-contacting layer (B), and another layer, but is preferably a two-layer molded article consisting of only the liquid-contacting layer (A) and the non-liquid-contacting layer (B). The molded article of the present disclosure may be a two-layer molded article or a three- or more-layer molded article, but in either case, the liquid-contacting layer (A) and the non-liquid-contacting layer (B) constitute the outermost layers, and the surfaces of these layers form the exposed surface of the molded article.

[0013] <Liquid-contacting layer (A)> The liquid-contacting layer (A) is a layer having a liquid-contacting surface. The liquid-contacting surface is the surface of the exposed surface of the molded body that comes into contact with the liquid. The liquid that comes into contact with the liquid-contacting surface is not particularly limited, but examples thereof include chemical solutions such as ammonia water, ozone water, hydrogen peroxide water, hydrochloric acid, sulfuric acid, resist solution, thinner solution, and developer solution. The liquid that comes into contact with the liquid-contacting surface is preferably at least one selected from the group consisting of ozone water, hydrogen peroxide water, hydrochloric acid, hydrofluoric acid, nitric acid, and sulfuric acid.

[0014] The liquid-contacting layer (A) is configured to reduce the amount of metal components eluted into the liquid in contact with the liquid-contacting surface. In one embodiment, the total amount of Na, Mg, K, Ca, and Fe eluted from the liquid-contacting layer (A) into hydrofluoric acid is 10 ng / cm 2 or less, preferably 9.0 ng / cm 2 or less, more preferably 8.0 ng / cm 2The lower limit is not particularly limited, but is 0.1 ng / cm 2 By configuring the liquid contact layer (A) so as to reduce the amount of metal eluted into hydrofluoric acid, it is possible to suppress the amount of metal components eluted into the liquid from the molded body.

[0015] In the present disclosure, the amount of metal components eluted from the compact into the liquid (metal elution amount) is the total amount of Na, Mg, K, Ca, and Fe eluted from the compact (layer) into hydrofluoric acid. The amount of metal components eluted from the compact (layer) can be determined by contacting the compact with 50% hydrofluoric acid for 7 days, recovering only the hydrofluoric acid, heating the hydrofluoric acid to recover the evaporation residue, mixing the recovered evaporation residue with 1N nitric acid to prepare a nitric acid solution, and measuring the Na, Mg, K, Ca, and Fe contents in the nitric acid solution by inductively coupled plasma mass spectrometry.

[0016] The total metal content of Na, Mg, K, Ca, and Fe in the liquid contact layer (A) measured by an ashing method is 40 ng / g or less, preferably 40 ng / g or less, more preferably 30 ng / g or less, and preferably 1 ng / g or more. The lower limit of the metal content measured by the ashing method may be 1 ng / g. By ensuring that the metal content in the liquid contact layer (A) is within the above range, the amount of metal components eluted from the liquid contact layer (A) into hydrofluoric acid can be adjusted to within the above range. Furthermore, by ensuring that the metal content in the liquid contact layer (A) is within the above range, the amount of metal components eluted from the molded body into the liquid can be suppressed.

[0017] The metal content in each layer constituting the molded body can be measured by preparing a test piece from each layer, washing the test piece with a 1N aqueous solution of nitric acid, and then ashing the test piece in a cuvette in the atomization section of an atomic absorption spectrophotometer, and measuring the metal content using the atomic absorption spectrophotometer; or by weighing the test piece into a platinum crucible, ashing it using a gas burner or electric furnace, dissolving the ash in acid, and then measuring the metal content using an ICP optical emission spectrometer, inductively coupled plasma mass spectrometry, or a flameless atomic absorption spectrophotometer.

[0018] The liquid-contacting layer (A) contains a tetrafluoroethylene (TFE) / fluoroalkyl vinyl ether (FAVE) copolymer (a).

[0019] The total metal content of Na, Mg, K, Ca, and Fe in copolymer (a) measured by an ashing method is preferably 40 ng / g or less, more preferably 30 ng / g or less, and preferably 1 ng / g or more. The lower limit of the metal content measured by the ashing method may be 1 ng / g. By using copolymer (a) with a reduced metal content, the amount of metal components eluted from the liquid-contacting layer (A) into hydrofluoric acid can be adjusted to within the above-mentioned range. Furthermore, by using copolymer (a) with a reduced metal content, the amount of metal components eluted from the molded body into the liquid can be suppressed.

[0020] The metal content of the copolymer can be measured by, for example, washing the copolymer with a 1N aqueous solution of nitric acid, ashing the copolymer in a cuvette in the atomization section of an atomic absorption spectrophotometer, and measuring the metal content using the atomic absorption spectrophotometer; or by weighing the copolymer into a platinum crucible, ashing it using a gas burner or an electric furnace, dissolving the ash in acid, and then measuring the metal content using an ICP optical emission analyzer, inductively coupled plasma mass spectrometry, or a flameless atomic absorption spectrophotometer.

[0021] The copolymer (a) is preferably a melt-processable fluororesin. In the present disclosure, melt-processable means that the polymer can be melted and processed using conventional processing equipment such as an extruder or an injection molding machine. Therefore, melt-processable fluororesins usually have a melt flow rate of 0.01 to 500 g / 10 min, as measured by the measurement method described below.

[0022] The melt flow rate (MFR) of the copolymer (a) is 1.0 to 3.0 g / 10 min. By setting the MFR of the copolymer (a) within this range, the resistance of the liquid-contacting layer (A) to oxidizing chemicals such as ozone water and hydrogen peroxide water can be improved. Furthermore, even when the liquid-contacting layer (A) comes into contact with an oxidizing chemical, cracks are less likely to occur in the liquid-contacting layer (A), and the chemical resistance and low chemical permeability of the molded article can be further improved.

[0023] The MFR of the copolymer is measured in accordance with ASTM D1238 using a die having a diameter of 2.1 mm and a length of 8 mm, under a load of 5 kg and at 372°C.

[0024] The melting point of the copolymer (a) is 295 to 310°C.

[0025] The melting point of the copolymer is the temperature corresponding to the maximum value on the heat of fusion curve when the temperature is increased at a rate of 10°C / min (second run) using a differential scanning calorimeter (DSC).

[0026] The TFE / FAVE copolymer (a) contains tetrafluoroethylene (TFE) units and fluoroalkyl vinyl ether (FAVE) units. By forming the liquid-contacting layer (A) from the TFE / FAVE copolymer (a), it is possible to suppress permeation of chemical solutions and further to impart chemical resistance to the liquid-contacting surface.

[0027] The FAVE contained in the copolymer (a) is a FAVE represented by the general formula (1): CF2=CFO(CF2CFY 1 O) p -(CF2CF2CF2O) q -Rf (1) (In the formula, Y 1 represents F or CF3, and Rf represents a perfluoroalkyl group having 1 to 5 carbon atoms. p represents an integer of 0 to 5, and q represents an integer of 0 to 5.) and a monomer represented by general formula (2): CFX=CXOCF2OR 1 (2) (wherein X may be the same or different and represents H, F or CF3; R1 represents a linear or branched fluoroalkyl group having 1 to 6 carbon atoms which may contain 1 to 2 atoms of at least one type selected from the group consisting of H, Cl, Br and I, or a cyclic fluoroalkyl group having 5 or 6 carbon atoms which may contain 1 to 2 atoms of at least one type selected from the group consisting of H, Cl, Br and I.

[0028] Among these, the FAVE is preferably a monomer represented by general formula (1), more preferably at least one selected from the group consisting of perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether) (PEVE), and perfluoro(propyl vinyl ether) (PPVE), even more preferably at least one selected from the group consisting of PEVE and PPVE, and even more preferably PPVE.

[0029] The content of FAVE units in copolymer (a) is preferably 3.5 to 13.0% by mass, more preferably 4.0% by mass or more, even more preferably 4.5% by mass or more, more preferably 10.0% by mass or less, and even more preferably 7.0% by mass or less, based on the total monomer units.

[0030] The content of TFE units in copolymer (a) is preferably 87.0 to 96.5% by mass, more preferably 90.0% by mass or more, even more preferably 93.0% by mass or more, more preferably 96.0% by mass or less, and even more preferably 95.5% by mass or less, based on all monomer units.

[0031] Copolymer (a) may contain monomer units derived from a monomer copolymerizable with TFE and FAVE.

[0032] Monomers that can be copolymerized with TFE and FAVE include hexafluoropropylene (HFP), CZ 3 Z 4 =CZ 5 (CF2) n Z6 (In the formula, Z 3 , Z 4 and Z 5 are the same or different and represent H or F, and Z 6 represents H, F or Cl, and n represents an integer of 2 to 10.) and a vinyl monomer represented by CF2=CF-OCH2-Rf 7 (In the formula, Rf 7 represents a perfluoroalkyl group having 1 to 5 carbon atoms. Among these, HFP is preferred.

[0033] The content of monomer units derived from monomers copolymerizable with TFE and FAVE is preferably 0 to 8.0% by mass, more preferably 3.0% by mass or less, and even more preferably 1.0% by mass or less.

[0034] The copolymer (a) is preferably at least one selected from the group consisting of copolymers consisting only of TFE units and FAVE units, and TFE / HFP / FAVE copolymers, and more preferably a copolymer consisting only of TFE units and FAVE units.

[0035] In the present disclosure, the content of each monomer unit in the copolymer is: 19 Measured by F-NMR.

[0036] The number of functional groups in copolymer (a) is 10 carbon atoms. 6 The number per molecule is preferably 30 or less, more preferably 20 or less, even more preferably 10 or less, still more preferably 5 or less, and preferably 0 or more.

[0037] The functional groups are those present at the ends of the main chain or side chains of the copolymer, and those present in the main chain or side chains. The functional groups are preferably at least one selected from the group consisting of -CF=CF, -CFH, -COF, -COOH, -COOCH, -CONH, and -CHOH.

[0038] Infrared spectroscopy can be used to identify the type of functional group and measure the number of functional groups.

[0039] The number of functional groups is specifically measured by the following method. First, the copolymer is melted at 340 to 350°C for 30 minutes and compression molded to produce a film with a thickness of 0.05 to 0.25 mm. This film is analyzed by Fourier transform infrared spectroscopy to obtain an infrared absorption spectrum of the copolymer, and a difference spectrum is obtained from the base spectrum, which is completely fluorinated and has no functional groups. From the absorption peaks of specific functional groups that appear in this difference spectrum, the number of carbon atoms in the copolymer is calculated according to the following formula (A): 6 Calculate the number of functional groups per molecule, N. N=I×K / t (A) I: Absorbance K: Correction coefficient t: film thickness (mm)

[0040] For reference, the absorption frequencies, molar absorption coefficients, and correction factors for the functional groups in this disclosure are shown in Table 1. The molar absorption coefficients were determined from FT-IR measurement data of low molecular weight model compounds.

[0041] [Table 1]

[0042] The absorption frequencies of -CH2CF2H, -CH2COF, -CH2COOH, -CH2COOCH3, and -CH2CONH2 are shown in the table, and are several tens of Kaiser (cm) from the absorption frequencies of -CF2H, -COF, -COOH free and -COOH bonded, -COOCH3, and -CONH2, respectively. -1 ) becomes lower. Therefore, for example, the number of functional groups of -COF is the absorption frequency of 1883 cm due to -CF2COF. -1 The number of functional groups determined from the absorption peak of -CH2COF and the absorption frequency of 1840 cm -1 The number of functional groups is the sum of the number of functional groups determined from the absorption peaks of the compounds.

[0043] The number of functional groups may be the total number of -CF=CF2, -CF2H, -COF, -COOH, -COOCH3, -CONH2 and -CH2OH.

[0044] Functional groups are introduced into copolymers by, for example, chain transfer agents or polymerization initiators used in producing the copolymers. For example, when an alcohol is used as a chain transfer agent or a peroxide having a -CHOH structure is used as a polymerization initiator, -CHOH is introduced at the main chain end of the copolymer. Furthermore, functional groups are introduced at the side chain end of the copolymer by polymerizing a monomer having a functional group.

[0045] By subjecting a copolymer having such functional groups to a fluorination treatment, a copolymer having the number of functional groups within the above-mentioned range can be obtained. That is, the copolymer (a) may be fluorinated. The copolymer (a) may also have a -CF3 terminal group.

[0046] The liquid-contacting layer (A) may contain various additives, such as a conductive filler, a stabilizer such as a heat stabilizer, a reinforcing agent, a bulking agent, an ultraviolet absorber, a pigment, etc., within the scope of the present disclosure. In one embodiment, the liquid-contacting layer (A) does not contain any additives and contains only the copolymer (a).

[0047] <Non-wetted layer (B)> The non-liquid-contacting layer (B) is a layer having a non-liquid-contacting surface. The non-liquid-contacting surface is the exposed surface of the molded body that does not come into contact with the liquid. It is possible that components in the liquid may permeate the liquid-contacting layer (A) and come into contact with the non-liquid-contacting layer (B). Usually, when the components in the liquid permeate the liquid-contacting layer (A) and come into contact with the non-liquid-contacting layer, the components in the liquid are in the form of a gas. The gas that comes into contact with the non-liquid-contacting layer is not particularly limited, but examples include air, ozone gas, and other oxidizing gases. For this reason, the non-liquid-contacting layer (B) contains a tetrafluoroethylene (TFE) / fluoroalkyl vinyl ether (FAVE) copolymer (b).

[0048] In one embodiment, the non-liquid-contacting layer (B) does not contain a colorant. Examples of the colorant include colorants used to color the molded article to make it easier to identify the molded article. The colorant may be a pigment, a color dye, or the like.

[0049] The non-liquid-contacting layer (B) is a layer having a non-liquid-contacting surface and not having a liquid-contacting surface, and therefore may be configured such that metals are eluted into the liquid when it comes into contact with the liquid. In one embodiment, the total amount of Na, Mg, K, Ca, and Fe eluted from the non-liquid-contacting layer (B) into hydrofluoric acid is 10 ng / cm 2 more than 20 ng / cm 2 That is all. When the liquid-contacting layer (A) is configured so as to reduce the amount of metal components eluted into the liquid in contact with the liquid-contacting surface, there is a drawback in that the copolymer (a) forming the liquid-contacting layer (A) is relatively expensive. In the molded article of the present disclosure, a relatively inexpensive copolymer can be selected as the copolymer (b), so by providing the non-liquid-contacting layer (B), the amount of copolymer (a) used can be reduced, and the manufacturing cost of the molded article can be reduced.

[0050] Furthermore, by providing the liquid-non-contacting layer (B), it is possible to maintain excellent low chemical permeability for a long period of time compared to a single-layer molded product containing a TFE / FAVE copolymer. A synergistic effect can also be achieved.

[0051] The total metal content of Na, Mg, K, Ca, and Fe in the non-liquid-contacting layer (B) measured by the ashing method is higher than the total metal content of Na, Mg, K, Ca, and Fe in the liquid-contacting layer (A) measured by the ashing method. Copolymers with reduced metal contents measured by the ashing method have the disadvantage of being relatively expensive. By configuring the liquid-contacting layer (A) and the non-liquid-contacting layer (B) in this way, the non-liquid-contacting layer (B) can be formed from copolymer (b), which is cheaper than copolymer (a). This reduces the amount of copolymer (a) used to form the liquid-contacting layer (A), thereby reducing the manufacturing cost of the molded product.

[0052] The total metal content of Na, Mg, K, Ca, and Fe in the liquid-contacting layer (A) measured by an ashing method is preferably more than 40 ng / g, preferably 60 ng / g or more, more preferably 80 ng / g or more, and although there is no particular upper limit, it may be 1000 ng / g or less. By keeping the metal content in the non-liquid-contacting layer (B) within the above range, it is possible to reduce the production cost of the molded product while suppressing the elution of metal components into the liquid.

[0053] The liquid-non-contacting layer (B) contains a TFE / FAVE copolymer (b).

[0054] In one embodiment, the metal content of copolymer (b) measured by an ashing method is higher than the metal content of copolymer (a) measured by an ashing method. Copolymers with reduced metal contents measured by an ashing method have the disadvantage of being relatively expensive. In the molded article of the present disclosure, a copolymer that is cheaper than copolymer (a) can be selected as copolymer (b). Therefore, by providing non-liquid-contacting layer (B), the amount of copolymer (a) used can be reduced, thereby reducing the manufacturing cost of the molded article.

[0055] The total metal content of Na, Mg, K, Ca, and Fe in copolymer (b), as measured by an ashing method, is preferably more than 40 ng / g, preferably 60 ng / g or more, more preferably 80 ng / g or more, and the upper limit is not particularly limited, but may be 1000 ng / g or less. By using copolymer (b) having a metal content within the above range, it is possible to reduce the production cost of the molded product while suppressing the elution of metal components into the liquid.

[0056] The copolymer (b) is preferably a fluororesin having melt processability.

[0057] The melt flow rate (MFR) of the copolymer (b) is 1.0 to 70 g / 10 min, preferably 5.0 g / 10 min or more, more preferably 9.0 g / 10 min or more, even more preferably 13.0 g / 10 min or more, and preferably 50.0 g / 10 min or less, more preferably 30.0 g / 10 min or less.

[0058] The melting point of the copolymer (b) is 280 to 315°C.

[0059] The TFE / FAVE copolymer (b) contains TFE units and FAVE units. By forming the non-liquid-contacting layer (B) from the TFE / FAVE copolymer (b), it is possible to suppress permeation of chemical solutions from the liquid-contacting surface and further to impart resistance to oxidizing gases such as ozone gas to the non-liquid-contacting layer (B).

[0060] The FAVE contained in the copolymer (b) may be a FAVE represented by the general formula (1): CF2=CFO(CF2CFY 1 O) p -(CF2CF2CF2O) q -Rf (1) (In the formula, Y 1 represents F or CF3, and Rf represents a perfluoroalkyl group having 1 to 5 carbon atoms. p represents an integer of 0 to 5, and q represents an integer of 0 to 5.) and a monomer represented by general formula (2): CFX=CXOCF2OR 1 (2) (wherein X may be the same or different and represents H, F or CF3; R 1 represents a linear or branched fluoroalkyl group having 1 to 6 carbon atoms which may contain 1 to 2 atoms of at least one type selected from the group consisting of H, Cl, Br and I, or a cyclic fluoroalkyl group having 5 or 6 carbon atoms which may contain 1 to 2 atoms of at least one type selected from the group consisting of H, Cl, Br and I.

[0061] Among these, the FAVE is preferably a monomer represented by general formula (1), more preferably at least one selected from the group consisting of perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether) (PEVE), and perfluoro(propyl vinyl ether) (PPVE), even more preferably at least one selected from the group consisting of PEVE and PPVE, and even more preferably PPVE.

[0062] The content of FAVE units in copolymer (b) is preferably 3.5 to 13.0% by mass, more preferably 4.0% by mass or more, more preferably 10.0% by mass or less, even more preferably 7.0% by mass or less, and even more preferably 5.0% by mass or less, based on the total monomer units.

[0063] The content of TFE units in copolymer (b) is preferably 87.0 to 96.5% by mass, more preferably 90.0% by mass or more, even more preferably 93.0% by mass or more, still more preferably 95.0% by mass or more, and more preferably 96.0% by mass or less, based on all monomer units.

[0064] Copolymer (b) may contain monomer units derived from a monomer copolymerizable with TFE and FAVE.

[0065] Monomers that can be copolymerized with TFE and FAVE include hexafluoropropylene (HFP), CZ 3 Z 4 =CZ 5 (CF2) n Z 6 (In the formula, Z 3 , Z 4 and Z 5 are the same or different and represent H or F, and Z 6 represents H, F or Cl, and n represents an integer of 2 to 10.) and a vinyl monomer represented by CF2=CF-OCH2-Rf 7 (In the formula, Rf 7represents a perfluoroalkyl group having 1 to 5 carbon atoms. Among these, HFP is preferred.

[0066] The content of monomer units derived from monomers copolymerizable with TFE and FAVE is preferably 0 to 8.0% by mass, more preferably 3.0% by mass or less, and even more preferably 1.0% by mass or less.

[0067] The copolymer (b) is preferably at least one selected from the group consisting of copolymers consisting only of TFE units and FAVE units, and TFE / HFP / FAVE copolymers, and more preferably a copolymer consisting only of TFE units and FAVE units.

[0068] The number of functional groups in copolymer (b) is 10 carbon atoms. 6 The number per molecule is preferably 600 or less, more preferably 500 or less, even more preferably 400 or less, still more preferably 300 or less, and preferably 0 or more.

[0069] The functional groups are those present at the ends of the main chain or side chains of the copolymer, and those present in the main chain or side chains. The functional groups are preferably at least one selected from the group consisting of -CF=CF, -CFH, -COF, -COOH, -COOCH, -CONH, and -CHOH.

[0070] The copolymer (b) may be one that has been fluorinated or one that has not been fluorinated.

[0071] The non-liquid-contacting layer (B) may contain various additives, such as a conductive filler, a stabilizer such as a heat stabilizer, a reinforcing agent, a bulking agent, and an ultraviolet absorber, as long as the object of the present disclosure is not impaired. In one embodiment, the non-liquid-contacting layer (B) does not contain a colorant. In one embodiment, the non-liquid-contacting layer (B) does not contain any additives and contains only the copolymer (b).

[0072] <Configuration of molded body> The molded article of the present disclosure includes a liquid-contacting layer (A) and a non-liquid-contacting layer (B). In one embodiment, the thickness (t a ) and the thickness of the non-wetted layer (B) (t b ) total thickness [(t a +t b )] is 0.5 to 1.6 mm, Thickness (t a ) and thickness (t b ) to the total thickness of the a ) proportion [t a / (t a +t b )] is 0.175 to 0.800.

[0073] The thickness of the wetted layer (A) (t a ) and the thickness of the non-wetted layer (B) (t b ) total thickness [(t a +t b The thickness [(t a +t b )] is equal to the thickness of the molded body when the molded body is a two-layer molded body having only two layers, a liquid-contacting layer (A) and a non-liquid-contacting layer (B).

[0074] The thickness of the compact [(t a +t b If the (D) ( ) is too large, flexibility may decrease, making bending difficult. For example, if the molded product is a tube, cold flaring or inserting a connecting jig such as a sleeve may become difficult when connecting the tube to a fitting. Furthermore, if the tube is long, the weight tends to increase. The thickness of the compact [(t a +t bIf the value (( ...

[0075] Thickness to total thickness (t a ) proportion [t a / (t a +t b )] is preferably 0.175 to 0.800, more preferably 0.200 or more, even more preferably 0.300 or more, and more preferably 0.500 or less.

[0076] The thickness of the compact [(t a +t b )], the thickness of the wetted layer (A) (t a ) is too large and the thickness of the non-wetted layer (B) (t b If the proportion of (a) is too small, the amount of the relatively expensive copolymer (a) used increases, which may increase the production cost of the molded article. The thickness of the compact [(t a +t b )], the thickness of the wetted layer (A) (t a ) is too small, and the thickness of the non-wetted layer (B) (t b If the proportion of ) is too large, it is advantageous in that the manufacturing cost of the molded body can be reduced, but there is a risk that it will not be possible to prevent the elution of metal components from the molded body into hydrofluoric acid.

[0077] The thickness of the wetted layer (A) (t a ) is preferably 200 to 600 μm, more preferably 300 μm or more, even more preferably 400 μm or more, still more preferably 500 μm or more, more preferably 550 μm or less, and even more preferably 500 μm or less. a) is within the above range, the production cost of the molded article can be reduced, and even when the non-liquid-contacting layer (B) is formed using the copolymer (b) containing a relatively large amount of metal components, the metal components in the non-liquid-contacting layer (B) can be reliably prevented from penetrating into the liquid-contacting layer (A) and eluting into the liquid.

[0078] In one embodiment, the molded article is a two-layer tube having a liquid-contacting layer (A) as an inner layer and a non-liquid-contacting layer (B) as an outer layer. This two-layer tube can be used as a tube for transporting liquid, with the liquid-contacting surface of the liquid-contacting layer (A) forming the inner surface and the non-liquid-contacting surface of the non-liquid-contacting layer (B) forming the outer surface. The liquid-contacting layer (A) is configured to reduce the amount of metal components eluted into liquid that comes into contact with the liquid-contacting surface. Therefore, even when liquid passes through the two-layer tube, the amount of metal components eluted into the liquid from the inner surface of the two-layer tube is reduced, and the liquid is hardly contaminated.

[0079] The two-layer tube preferably has a hydrochloric acid permeability [P2 / P1] calculated by the following formula of 10 or less. Increase rate of hydrochloric acid permeation [P2 / P1]=P2 / P1 P1: The amount of hydrochloric acid permeation through the two-layer tube after 30 days measured by conducting a 35% by mass hydrochloric acid permeation test at room temperature P2: The amount of hydrochloric acid permeation through the two-layer tube after 150 days measured by conducting a 35% by mass hydrochloric acid permeation test at room temperature

[0080] The rate of increase in hydrochloric acid permeation amount [P2 / P1] is preferably 10 or less, more preferably 8.0 or less, and although there is no particular lower limit, it may be 7.0 or more.

[0081] The amount of hydrochloric acid permeated through the two-layer tube can be measured by the method described in the Examples.

[0082] In one embodiment, when the liquid-contacting surface of the laminate or two-layer tube of the present disclosure is observed under an electron microscope, spherulites are confirmed. By forming spherulites on the liquid-contacting surface, the liquid-contacting surface becomes smoother, further reducing contamination of the liquid.

[0083] The spherulites can be formed by adding polytetrafluoroethylene to the liquid-contacting layer (A). The content of polytetrafluoroethylene may be 0.001 to 50% by mass, or 0.001 to 1% by mass, based on the TFE / FAVE copolymer (a).

[0084] The polytetrafluoroethylene may have a crystallization temperature of 305°C or higher as measured by a differential scanning calorimeter (DSC). The heat of crystallization of the polytetrafluoroethylene may be 50 J / g or higher. The crystallization temperature of the polytetrafluoroethylene is more preferably 310°C or higher, and even more preferably 312°C or higher.

[0085] The molded article of the present disclosure can be produced by laminating the copolymer (a) and the polymer (b) using, for example, injection molding, extrusion molding, blow molding, or the like.

[0086] The copolymer (a) and the polymer (b) can be laminated by the following method: A method in which the copolymer (a) and the polymer (b) are co-extruded to heat-seal (melt-bond) the layers together; a method in which a layer containing copolymer (a) and a layer containing polymer (b) are separately produced using an extruder, and the layers are then superimposed on each other and bonded together by heat fusion; a method of preparing a monolayer tube containing copolymer (a) and extruding polymer (b) onto the surface of the monolayer tube using an extruder; A method in which a single-layer tube containing copolymer (a) is prepared, polymer (b) is electrostatically coated on the surface of the single-layer tube, and the resulting coated product is heated either entirely or from the coated side to heat and melt polymer (b). Examples include:

[0087] Examples of the coextrusion molding include conventionally known multilayer coextrusion manufacturing methods such as a multi-manifold method and a feed block method.

[0088] The molded article or two-layer tube of the present disclosure can be suitably used as a chemical liquid transport tube for circulating chemical liquids, and can be particularly suitably used as a chemical liquid transport tube used to transport high-purity chemical liquids for semiconductor device manufacturing.

[0089] The chemical liquid may be any chemical liquid used in semiconductor manufacturing, such as ammonia water, ozone water, hydrogen peroxide water, hydrochloric acid, sulfuric acid, resist solution, thinner solution, developer, etc. The chemical liquid is preferably at least one selected from the group consisting of ozone water, hydrogen peroxide water, hydrochloric acid, hydrofluoric acid, nitric acid, and sulfuric acid.

[0090] The high-purity chemical transport tube can be suitably used in semiconductor manufacturing equipment such as chemical supply equipment for semiconductor manufacturing, semiconductor cleaning equipment, and coater developers.

[0091] Although the embodiments have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the claims.

[0092] <1> According to a first aspect of the present disclosure, A molded article comprising a liquid-contacting layer (A) having a liquid-contacting surface and a non-liquid-contacting layer (B) having a non-liquid-contacting surface, The liquid-contacting layer (A) contains a tetrafluoroethylene / fluoroalkyl vinyl ether copolymer (a), and the total amount of Na, Mg, K, Ca, and Fe eluted from the liquid-contacting layer (A) into hydrofluoric acid is 10 ng / cm 2 is as follows: The non-liquid-contacting layer (B) contains a tetrafluoroethylene / fluoroalkyl vinyl ether copolymer (b), A molded body, wherein the metal content of copolymer (b), which is a raw material of the molded body, measured by an incineration method is higher than the metal content of copolymer (a), which is measured by an incineration method; Or, the total metal content of Na, Mg, K, Ca and Fe in the non-liquid-contacting layer (B) measured by the ashing method is greater than the total metal content of Na, Mg, K, Ca and Fe in the liquid-contacting layer (A) measured by the ashing method. A compact is provided. <2> According to a second aspect of the present disclosure, A molded article according to a first aspect is provided which comprises only two layers, a liquid-contacting layer (A) and a non-liquid-contacting layer (B). <3> According to a third aspect of the present disclosure, The thickness of the wetted layer (A) (t a ) and the thickness of the non-wetted layer (B) (t b ) total thickness [(t a +t b )] is 0.5 to 1.6 mm, Thickness (t a ) and thickness (t b ) to the total thickness of the a ) proportion [t a / (t a +t b The molded article according to the first or second aspect is provided, wherein the value of (R) is 0.175 to 0.800. <4> According to a fourth aspect of the present disclosure, The thickness of the wetted layer (A) (t a ) is 200 μm or more. <5> According to a fifth aspect of the present disclosure, The molded article according to any one of the first to fourth aspects is provided as a two-layer tube having a liquid-contacting layer (A) as an inner layer and a non-liquid-contacting layer (B) as an outer layer. <6> According to a sixth aspect of the present disclosure, According to a fifth aspect, there is provided a molded article having an increase rate [P2 / P1] of hydrochloric acid permeation amount calculated by the following formula of 10 or less. Increase rate of hydrochloric acid permeation [P2 / P1]=P2 / P1 P1: The amount of hydrochloric acid permeated through the two-layer tube after 30 days, measured by conducting a 35% by mass hydrochloric acid permeation test at room temperature. P2: The amount of hydrochloric acid permeated through the two-layer tube after 150 days, measured by conducting a 35% by mass hydrochloric acid permeation test at room temperature. <7> According to a seventh aspect of the present disclosure, The melting point of the copolymer (a) is 295 to 310°C, and the melt flow rate of the copolymer (a) is 1.0 to 3.0 g / 10 min, The melting point of the copolymer (b) is 280 to 315°C, and the melt flow rate of the copolymer (b) is 1.0 to 70.0 g / 10 min. According to any one of the first to sixth aspects, there is provided a molded article. <8> According to an eighth aspect of the present disclosure, The total metal content of Na, Mg, K, Ca and Fe in the liquid-contacting layer (A) measured by an ashing method is 40 ng / g or less, The total metal content of Na, Mg, K, Ca and Fe in the non-wetted layer (B) measured by the ashing method is more than 40 ng / g. According to any one of the first to seventh aspects, there is provided a molded article. <9> According to a ninth aspect of the present disclosure, The total metal content of Na, Mg, K, Ca and Fe in the copolymer (a) measured by an ashing method is 40 ng / g or less; The total metal content of Na, Mg, K, Ca and Fe in copolymer (b), as measured by the incineration method, is more than 40 ng / g. According to any one of the first to eighth aspects, there is provided a molded article. <10> According to a tenth aspect of the present disclosure, the content of the fluoroalkyl vinyl ether units in the copolymer (a) is 3.5 to 13.0 mass% based on the total monomer units in the copolymer (a); The content of the fluoroalkyl vinyl ether unit in the copolymer (b) is 3.5 to 13.0 mass% based on the total monomer units in the copolymer (b). According to any one of the first to ninth aspects, there is provided a molded article. <11> According to an eleventh aspect of the present disclosure, The number of functional groups in copolymer (a) is 10 carbon atoms. 6 Each piece is 30 or less, The number of functional groups in copolymer (b) is 10 carbon atoms. 6Each piece is 600 or less According to any one of the first to tenth aspects, there is provided a molded article. <12> According to a twelfth aspect of the present disclosure, The molded article according to any one of the first to eleventh aspects is provided, wherein the liquid-non-contacting layer (B) does not contain a colorant. <13> According to a thirteenth aspect of the present disclosure, There is provided a molded article according to any one of the first to twelfth aspects, in which spherulites are confirmed when the liquid-contacting surface is observed under an electron microscope. <14> According to a fourteenth aspect of the present disclosure, There is provided a molded article according to any one of the first to thirteenth aspects, which is produced by using injection molding, extrusion molding or blow molding. <15> According to a fifteenth aspect of the present disclosure, According to any one of the first to fourteenth aspects, there is provided a molded article which is a tube for transporting a high-purity chemical solution. [Example]

[0093] Next, embodiments of the present disclosure will be described with reference to examples, but the present disclosure is not limited to these examples.

[0094] The values ​​in the examples were measured by the following methods.

[0095] (Polymer composition) 19 Measurement was performed by F-NMR.

[0096] (Melt flow rate (MFR)) According to ASTM D1238, the mass (g / 10 min) of the copolymer flowing out from a nozzle with an inner diameter of 2.1 mm and a length of 8 mm at 372°C under a load of 5 kg per 10 min was determined using a melt indexer (manufactured by Yasuda Seiki Seisakusho Co., Ltd.).

[0097] (Melting Point) The temperature was determined as the temperature (2nd run) corresponding to the maximum value in the heat of fusion curve when the temperature was increased at a rate of 10°C / min using a differential scanning calorimeter (DSC).

[0098] (Number of functional groups) The copolymer was melted at 330-340°C for 30 minutes and compression molded to prepare a film with a thickness of 0.20-0.25 mm. This film was scanned 40 times using a Fourier transform infrared spectrometer (FT-IR (trade name: Model 1760X, manufactured by PerkinElmer)) to obtain an infrared absorption spectrum. A difference spectrum was obtained from the base spectrum, which was completely fluorinated and had no functional groups. From the absorption peaks of specific functional groups appearing in this difference spectrum, the carbon atoms in the copolymer were determined according to the following formula (A): 6 The number of functional groups per molecule, N, was calculated.

[0099] N=I×K / t (A) I: Absorbance K: Correction coefficient t: film thickness (mm)

[0100] For reference, the absorption frequencies, molar absorption coefficients, and correction factors for the functional groups in this disclosure are shown in Table 2. The molar absorption coefficients were determined from FT-IR measurement data of low molecular weight model compounds.

[0101] [Table 2]

[0102] (metal content) The ashing method described in WO 94 / 28394 was used. Test pieces made from copolymer (a) and copolymer (b), or from the liquid-contacting layer (A) and non-liquid-contacting layer (B), were washed with a 1N aqueous solution of nitric acid, then precisely weighed in the range of 2 to 6 mg, and ashed by heating at 1100°C for 180 seconds in a graphite cuvette. The ashing was then analyzed using an atomic absorption spectrophotometer (polarized Zeeman atomic absorption spectrophotometer (Z-8100), manufactured by Hitachi, Ltd.).

[0103] (50%HF eluted metal amount (ng / cm 2 )) The two-layer tubes produced in the experimental examples and comparative examples were cut to prepare test pieces with a length of 100 cm. The test pieces were bent into a U-shape and fixed, and 20 ml of 50% by mass hydrofluoric acid was poured into the test pieces and left to stand for 7 days. The hydrofluoric acid was then transferred to a platinum dish and evaporated. The evaporation residue was mixed with 0.1 N nitric acid to prepare a nitric acid solution.

[0104] This nitric acid solution was measured using a Seiko Electronics SPQ9000 ICP-MS, and the nitric acid value (Na / Mg / K / Ca / Fe = 0.3 / 0.06 / ND / 0.05 / 0.3 ("ND" means "Not Detected")) was used as the blank, and the value subtracted was used as the amount of dissolved metal per area of ​​the liquid contact part (ng / cm 2 ) was converted.

[0105] The following copolymers were used in the experimental and comparative examples. copolymer(a) TFE / PPVE copolymer TFE / PPVE=94.5 / 5.5 (mass%) MFR (372℃, 5kg): 2.0g / 10min Melting point: 303℃ Number of functional groups: 5 / 10 carbon atoms 6 less than pcs Metal content: Na / Mg / K / Ca / Fe=ND / ND / ND / 0.8 / 5.0(ng / g)

[0106] Copolymer (b) TFE / PPVE copolymer TFE / PPVE=95.8 / 4.2 (mass%) MFR (372℃, 5kg): 14.0g / 10min Melting point: 305℃ Number of functional groups: 284 / 10 carbon atoms 6 less than pcs Metal content: Na / Mg / K / Ca / Fe=13 / 10 / 9 / 32 / 82(ng / g)

[0107] Experimental Example 1 Using a two-layer tube extruder, a 1 / 2-inch tube was produced, having an inner layer (liquid-contacting layer) formed from copolymer (a) and an outer layer (liquid-non-contacting layer) formed from copolymer (b), with an outer diameter of 12.70 mm, an inner diameter of 9.50 mm, and a thickness of 1600 μm. The screw rotation speed was adjusted so that the inner layer had a thickness of 500 μm and the outer layer had a thickness of 1100 μm. The results are shown in Table 3.

[0108] The liquid-contacting layer (A) and the non-liquid-contacting layer (B) of the prepared two-layer tube were peeled off, and test pieces were prepared from each layer. The metal content in the test pieces was measured using the ashing method described above. The results are shown below. Metal content of the wetted layer (A) Na / Mg / K / Ca / Fe=0.3 / ND / ND / 1.0 / 6.0(ng / g) Metal content of non-wetted layer (B) Na / Mg / K / Ca / Fe=15 / 11 / 9 / 35 / 85(ng / g)

[0109] These results show that the metal contents in the liquid-contacting layer (A) and the non-liquid-contacting layer (B) are equivalent to the metal contents in the copolymers (a) and (b). Therefore, when a tube is produced by molding a copolymer while avoiding contamination by metal components as much as possible, the metal contents in the layers can be predicted from the metal contents in the raw copolymer.

[0110] Experimental Examples 2 to 4, Reference Example 1, Comparative Example 1 Tubes were produced and evaluated in the same manner as in Experimental Example 1, except that the copolymers forming the inner and outer layers were changed as shown in Table 3. The results are shown in Table 3.

[0111] [Table 3]

[0112] Experimental Example 5 A single-layer tube (1600 μm thick) was prepared using copolymer (a). A double-layer tube (1600 μm thick, outer layer 1100 μm / inner layer 500 μm thick) was also prepared using copolymer (a) as the inner layer and copolymer (b) as the outer layer.

[0113] Using each tube, a hydrochloric acid permeation test was performed at room temperature using 35% by mass hydrochloric acid according to the method described in International Publication No. 2005 / 108501. The increase in the amount of hydrochloric acid permeated was calculated from the amount of permeated permeation after a predetermined time. The increase in the amount of hydrochloric acid permeated after 100 days and 150 days was compared, using the amount of hydrochloric acid permeated after 30 days as the standard.

[0114] Table 4 shows the hydrochloric acid permeability (μg cm / cm) of each tube. 2 Table 5 also shows the rate of increase in the amount of hydrochloric acid permeation after 100 days and 150 days relative to the amount of hydrochloric acid permeation after 30 days.

[0115] [Table 4]

[0116] [Table 5]

[0117] The results in Tables 4 and 5 show that the two-layer tube suppressed the increase in hydrochloric acid permeation even 150 days after the introduction of hydrochloric acid. On the other hand, the single-layer tube showed a significant increase in hydrochloric acid permeation. This is presumably due to the generation of fine cracks in the tube by the hydrochloric acid. It can be seen that the two-layer tube can suppress hydrochloric acid permeation for a longer period of time than the single-layer tube made of the same copolymer, even when the two layers are made of the same copolymer.

[0118] Experimental Example 6 A circular sheet having a thickness of 200 μm was produced by compression molding using copolymer (a). A test solution containing metal components was prepared by dissolving 500 ppm of CuCl2 and 200 ppm of FeCl3 in 35% hydrochloric acid.

[0119] The obtained sheet was sandwiched between two cups equipped with a chemical solution inlet, one of which was filled with the prepared test solution, and the other with pure water. The diameter of the contact area between the sheet and the test solution and pure water was 75 mm. In this state, it was left at room temperature for 360 days.

[0120] The pure water was collected and analyzed for copper and iron ion content by ICP-MS. As a result, neither copper nor iron ions were detected in the pure water. These results show that a 200 μm thick sheet containing a TFE / FAVE copolymer does not allow metal components in a liquid to pass through.

[0121] Therefore, it can be seen that by making the thickness of the liquid-contacting layer (A) containing copolymer (a) 200 μm or more, even if the non-liquid-contacting layer (B) is formed using copolymer (b) containing a relatively large amount of metal components, it is possible to reliably prevent the metal components in the non-liquid-contacting layer (B) from penetrating into the liquid-contacting layer (A) and dissolving into the liquid.

Claims

1. A molded article comprising a liquid-contacting layer (A) having a liquid-contacting surface and a non-liquid-contacting layer (B) having a non-liquid-contacting surface, The liquid-contacting layer (A) contains a tetrafluoroethylene / fluoroalkyl vinyl ether copolymer (a), and the total amount of Na, Mg, K, Ca, and Fe eluted from the liquid-contacting layer (A) into hydrofluoric acid is 10 ng / cm ２ is as follows: the liquid-non-contacting layer (B) contains a tetrafluoroethylene / fluoroalkyl vinyl ether copolymer (b); The total metal content of Na, Mg, K, Ca and Fe in the non-liquid-contacting layer (B) measured by an ashing method is greater than the total metal content of Na, Mg, K, Ca and Fe in the liquid-contacting layer (A) measured by an ashing method. Molded body.

2. 2. The molded article according to claim 1, which comprises only two layers: a liquid-contacting layer (A) and a liquid-non-contacting layer (B).

3. The thickness of the liquid-contacting layer (A) (t ａ ) and the thickness of the non-wetted layer (B) (t ｂ ) total thickness [(t ａ +t ｂ ) )] is 0.5 to 1.6 mm, Thickness (t ａ ) and thickness (t ｂ ) to the total thickness (t ａ ) ratio [t ａ / (t ａ +t ｂ 3. The molded article according to claim 1, wherein the value of [(Ratio of Molecular Weight ...

4. The thickness of the liquid-contacting layer (A) (t ａ 3. The molded article according to claim 1, wherein the thickness of the first and second particles is 200 μm or more.

5. 3. The molded article according to claim 1, which is a two-layer tube having a liquid-contacting layer (A) as an inner layer and a non-liquid-contacting layer (B) as an outer layer.

6. 6. The molded article according to claim 5, wherein the increase rate of hydrochloric acid permeation amount [P2 / P1] calculated by the following formula is 10 or less. Increase rate of hydrochloric acid permeation amount [P2 / P1] = P2 / P1 P1: The amount of hydrochloric acid permeated through the two-layer tube after 30 days, measured by conducting a 35% by mass hydrochloric acid permeation test at room temperature. P2: The amount of hydrochloric acid permeated through the two-layer tube after 150 days, measured by conducting a 35% by mass hydrochloric acid permeation test at room temperature.

7. The melting point of the copolymer (a) is 295 to 310°C, and the melt flow rate of the copolymer (a) is 1.0 to 3.0 g / 10 min, The melting point of the copolymer (b) is 280 to 315°C, and the melt flow rate of the copolymer (b) is 1.0 to 70.0 g / 10 min. The molded article according to claim 1 or 2.

8. The total metal content of Na, Mg, K, Ca and Fe in the liquid-contacting layer (A) measured by an ashing method is 40 ng / g or less, The total metal content of Na, Mg, K, Ca and Fe in the non-liquid-contacting layer (B) measured by an ashing method is more than 40 ng / g. The molded article according to claim 1 or 2.

9. The total metal content of Na, Mg, K, Ca and Fe in the copolymer (a) as measured by an ashing method is 40 ng / g or less; The total metal content of Na, Mg, K, Ca and Fe in the copolymer (b) measured by an ashing method is more than 40 ng / g. The molded article according to claim 1 or 2.

10. the content of the fluoroalkyl vinyl ether unit in the copolymer (a) is 3.5 to 13.0 mass% based on the total monomer units in the copolymer (a); The content of the fluoroalkyl vinyl ether unit in the copolymer (b) is 3.5 to 13.0% by mass based on the total monomer units in the copolymer (b). The molded article according to claim 1 or 2.

11. The number of functional groups of the copolymer (a) is 10 carbon atoms. ６ Each piece is 30 or less, The number of functional groups of copolymer (b) is 10 carbon atoms. ６ Each piece is 600 or less The molded article according to claim 1 or 2.

12. 3. The molded article according to claim 1, wherein the liquid-non-contacting layer (B) does not contain a colorant.

13. 3. The molded article according to claim 1, wherein spherulites are observed on the liquid-contacting surface under an electron microscope.

14. 3. The molded article according to claim 1, which is produced by injection molding, extrusion molding or blow molding.

15. 3. The molded article according to claim 1, which is a tube for transporting high-purity chemical solutions.

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