extrusion molding

Abstract

To provide a tubular extrusion molding body which avoids environmental problems due to an inclusion of halogen elements, has excellent physical properties such as low water vapor permeability, low chemical permeability, abrasion resistance, and mechanical properties, and is suitable as a material for chemicals used in manufacture of semiconductors, liquid crystals, etc., and for piping for ultrapure water.SOLUTION: An extrusion molding body is a tubular extrusion molding body made of a resin that does not contain halogen elements, has an ether bond or an ethylene structure, and has a melting point of 200°C or higher, and has an electrical conductivity of 0.5 mS / m or less at 25°C, an amount of ion elution into water of 7500 μg / m2 or less, and an arithmetic mean roughness (Ra) of an inner surface of 0.25 μm or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an extrusion molded article. [Background technology]

[0002] Conventionally, in the manufacture of precision devices such as semiconductor devices and liquid crystal display devices, ultra-pure chemicals that have been refined to extremely high purity in wet processes such as cleaning have been used. Also, special chemical solutions are used in the development process of semiconductor manufacturing.

[0003] Piping that constitutes a transport line for ultrapure water used in the manufacture of precision devices such as semiconductor devices or liquid crystal display devices, and in the manufacture of precision devices, etc., is required to have extremely low elution of metal ions and high inner surface smoothness in order to prevent the growth of bacteria and the formation of bubbles in the air inside.

[0004] The piping materials used for these applications are fluororesins, which are chemically inert, have gas barrier properties, are very little eluted in chemical agents or ultrapure water, and have high inner surface smoothness. For example, Patent Document 1 discloses a fluororesin double tube, in which two layers of fluororesin are laminated, as piping used in semiconductor manufacturing equipment, liquid crystal manufacturing equipment, etc., in which the inner layer tube is made of a fluororesin that is highly corrosion-resistant and chemical-resistant (e.g., tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), or tetrafluoroethylene-ethylene copolymer (ETFE)), and the outer layer tube is made of a fluororesin that can suppress gas permeation (e.g., polyvinylidene fluoride (PVDF)).

[0005] Patent Document 2 discloses a multi-layer pipe for piping ultrapure water, characterized in that it comprises a first resin layer made of fluororesin that comes into contact with the ultrapure water, and a second resin layer made of gas-impermeable resin that is provided on the outer surface of the first resin layer, and further discloses that a third resin layer that protects the second resin layer is provided on the outer surface of the second resin layer, and that polyethylene is used for the third resin layer. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-112507 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-234576 Summary of the Invention [Problem to be solved by the invention]

[0007] Recently, with the increasing integration density of semiconductor chips, circuit patterns have become increasingly finer, and the required characteristics for ultrapure water piping have become increasingly strict. However, the issue of PFAS has been raised in recent years, and restrictions are being imposed on the use of fluorine-related chemicals and fluororesins. PFAS is a general term for perfluoroalkyl and polyfluoroalkyl compounds, which are organic fluorine compounds, and there are more than 10,000 types of substances.

[0008] According to a proposal for restricting PFAS published by the European Chemicals Agency (ECHA) in March 2023, the reasons for the restrictions are (1) the potential for PFAS and PFAS breakdown products to persist in the environment longer than any other man-made chemical, and (2) concerns about bioaccumulation, mobility, long-distance transport, and ecotoxicity. The former (1) persistence is due to the chemical structure of PFAS, so it applies to all PFASs subject to the restrictions, but persistence itself is not a harmful characteristic. Regarding the latter (2), scientifically supported data exists for only a few PFASs. However, the scope of the restrictions has been broadly defined based on the precautionary principle, which states that "in cases of uncertainty, protective measures should be taken without waiting until the existence and severity of risks are fully clarified."

[0009] This means that even materials that are widely used around the world and essential to our lives will be subject to restrictions. PFASs have superior properties compared to other materials, so there are many uses for which no alternatives exist. For these uses, restrictions will be in place, although there will be an 18-month transition period followed by an additional grace period of 5 or 12 years. Furthermore, as is generally known, there are environmental issues with the treatment of waste containing halogen elements, so it is best to avoid their use.

[0010] The present invention provides a tubular extrusion molded product that avoids environmental problems caused by the inclusion of halogen elements, has excellent physical properties such as low water vapor permeability, low chemical permeability, abrasion resistance, and mechanical properties, and is suitable as a material for chemicals used in the production of semiconductors, liquid crystals, etc., and for piping for ultrapure water. [Means for solving the problem]

[0011] After extensive research, the inventors have found that the above-mentioned problems can be solved by the extrusion molding of the present invention. The inventors discovered that tubular extrusion moldings made from copolymers of halogen-free resins, which contain an ether bond or an ethylene structure and have a melting point of 200°C or higher, and which have an MFR of approximately 7-18 g / 10 min (295°C), tend to have inferior water vapor permeability and chemical solution permeability compared to tubular extrusion moldings made from copolymers with an MFR of 7 g / 10 min (295°C) or less. After extensively revising the extrusion conditions as well as the composition of the copolymer used in extrusion molding, they found that even when using a copolymer with a relatively high MFR of approximately 7-18 g / 10 min, the water vapor permeability and chemical solution permeability of the tubular extrusion molding are significantly improved as long as the amount of ion elution into water from the tubular extrusion molding, with an electrical conductivity of 0.5 mS / m or less at 25°C, is low. This led to the completion of the tubular extrusion molding of the present invention.

[0012] That is, the extrusion molded article of the present invention is a tubular extrusion molded article made of a resin that does not contain halogen elements, has an ether bond or an ethylene structure, and has a melting point of 200°C or higher, and has an electric conductivity of 0.5 mS / m or less at 25°C and an ion elution amount into water of 7500 μg / m 2 The arithmetic mean roughness (Ra) of the inner surface is 0.25 μm or less. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a tubular extrusion molded product which avoids environmental problems caused by the inclusion of halogen elements, has excellent physical properties such as low water vapor permeability, low chemical permeability, abrasion resistance, and mechanical properties, and is suitable as a material for chemicals used in the production of semiconductors, liquid crystals, etc., and for piping for ultrapure water. DETAILED DESCRIPTION OF THE INVENTION

[0014] A preferred embodiment of the extrusion molded article of the present invention will be described in detail below. In this embodiment, a tubular extrusion molded article is exemplified, which is molded from a resin that does not contain halogen elements, has an ether bond or an ethylene structure, and has a melting point of 200°C or higher. The extrusion molded article has an ion elution amount of 7500 μg / m into water with an electrical conductivity of 0.5 mS / m or less at 25°C. 2 The extrusion molded article has an inner surface with an arithmetic mean roughness (Ra) of 0.25 μm or less. The extrusion molded article of this embodiment has such a configuration and therefore has excellent physical properties such as low water vapor permeability, low chemical liquid permeability, abrasion resistance, mechanical properties, and rigidity at high temperatures.

[0015] The amount of ions eluted from the extrusion molded product into water with an electrical conductivity of 0.5 mS / m or less at 25°C is 7500 μg / m 2 or less, preferably 5500 μg / m 2 or less, and more preferably 5000 μg / m 2 or less, and particularly preferably 4500 μg / m 2 The lower limit of the amount of ion elution is not particularly limited, but the lower the amount, the more preferable.

[0016] The amount of ions eluted from the extrusion molded body into water having an electrical conductivity of 0.5 mS / m or less at 25°C was determined by immersing the tubular extrusion molded body in water having an electrical conductivity of 0.5 mS / m or less at 25°C at 95°C for 1 hour, measuring the concentration by inductively coupled plasma (ICP), and calculating the amount of ions eluted per inner surface area of the tubular extrusion molded body.

[0017] When the extrusion molded body of this embodiment is used in the semiconductor industry, the metal elution suppression performance is 14 μg / m as the total amount of elution of 16 major metals (aluminum, barium, boron, calcium, chromium, copper, iron, lead, lithium, magnesium, manganese, nickel, potassium, sodium, strontium, and zinc) measured in accordance with SEMI F57-0314. 2 or less, preferably 12 μg / m 2 Less than 10 μg / m 2 or less, more preferably 9 μg / m2 or less, more preferably 8.5 μg / m 2 However, the above concentration standard is not required in all industries that use the extrusion molded article of this embodiment.

[0018] The roughness of the inner surface of the extrusion molded article of this embodiment is preferably 0.25 μm or less as an arithmetic mean roughness (Ra) measured in accordance with SEMI F57-0301. If the inner surface is too rough, substances contained in the fluid may get caught, leaving residue that may contaminate the fluid when another fluid is passed through after cleaning. In addition, the increased friction with the fluid may wear the inner surface of the extrusion molded article, causing contamination from the extrusion molded article in the fluid. This is undesirable, particularly when used in the semiconductor or pharmaceutical industries, as it can cause contamination.

[0019] The amount of metal elution is measured in accordance with SEMI F57-0314. A more specific example of the amount of metal elution is, for example, 7 μg / m as the amount of calcium elution. 2 Less than 6 μg / m 2 or less, more preferably 5.5 μg / m 2 The amount of copper eluted is, for example, 0.5 μg / m 2 or less, preferably 0.45 μg / m 2 Less than or equal to 0.4 μg / m 2 The amount of sodium eluted is, for example, 1.5 μg / m 2 or less, preferably 1.1 μg / m 2 Less than or equal to 0.7 μg / m 2 The amount of zinc eluted is, for example, 0.5 μg / m 2 Less than or equal to 0.3 μg / m 2 Less than or equal to 0.2 μg / m 2 The following are included:

[0020] Regarding the amount of anion elution, the amount of bromide ion elution is, for example, 10 μg / m 2 The amount of fluoride ions eluted is, for example, 1000 μg / m 2Less than 800 μg / m 2 less than 700 μg / m 2 less than 600 μg / m 2 For example, the nitrite ion concentration is less than 10 μg / m 2 as sulfate ions, for example, 10 μg / m 2 Examples include:

[0021] The amount of eluted organic components is measured based on SEMI F57-0314. The amount of eluted total organic components (TOC) is, for example, 10,000 μg / m 2 or less, preferably 9000 μg / m 2 Less than or equal to 8500 μg / m 2 or less, more preferably 8000 μg / m 2 The following are included:

[0022] The resin, which does not contain halogen elements, has an ether bond or an ethylene structure, and has a melting point of 200°C or higher, has a melt flow rate (MFR) at 295°C of 7.0 to 18.0 g / 10 min, preferably 10.0-15.0 g / 10 min or higher, and more preferably 11.0-13.0 g / 10 min. The tubular extrusion molded article of this embodiment contains a resin with a relatively high MFR, and therefore can be easily produced by extrusion molding. Moreover, despite the presence of such a resin with a relatively high MFR, it has excellent low water vapor permeability and low chemical liquid permeability. If the resin MFR is too high, the extrusion molded article will have poor abrasion resistance and mechanical properties. If the resin MFR is too low, the resin will not be easily molded. Furthermore, if the resin MFR is too low, the extrusion molded article will have poor rigidity at high temperatures.

[0023] The MFR disclosed herein is a value obtained in accordance with ASTM D1238 using a melt indexer, and is expressed as the mass of resin flowing out per 10 minutes (g / 10 minutes) from a nozzle with an inner diameter of 2.1 mm and a length of 8 mm under a load of 6.6 kg at 295°C.

[0024] The resin containing no halogen element and having an ether bond or an ethylene structure has a melting point of 200° C. or higher, preferably 200 to 250° C., and more preferably 200 to 220° C. When the melting point of the resin is within the above range, the mechanical properties of the tubular extrusion molded article, rigidity at high temperatures, and other physical properties are further improved.

[0025] Examples of resins that do not contain halogen elements and have an ether bond or an ethylene structure include, but are not limited to, polyetherimide resins (such as "ULTEM (registered trademark)" manufactured by Sabic Corporation), modified polyetherimide resins (such as "SILTEM (registered trademark)" manufactured by Sabic Corporation), mixtures of polyetherimide resins or modified polyetherimide resins with other halogen-free resins, rubbers, and elastomers, long-chain alkyl resins, α-olefin resins, ethylene-α-olefin resins, cycloolefin resins, polymethylpentene resins (such as "TPX (registered trademark)" manufactured by Mitsui Chemicals, Inc.), polysulfone resins (such as "Udel (registered trademark)" manufactured by Solvay), and polyethersulfone resins (such as "Veradel (registered trademark)" manufactured by Solvay and "Ultrason (registered trademark)" manufactured by BASF).

[0026] The tubular extrusion molded article according to this embodiment may contain other components such as fillers, pigments, flame retardants, lubricants, light stabilizers, weather stabilizers, conductive agents, and antistatic agents.

[0027] In this embodiment, a known extruder can be used. Specifically, an extruder including a cylinder and a screw housed in the cylinder can be used. In the manufacturing process of the tubular extrusion molded product according to this embodiment, it is preferable that the temperature of the copolymer in the cylinder during extrusion be adjusted to 250°C to 395°C.

[0028] The tubular extrusion molded body according to the present embodiment described above has excellent physical properties such as low water vapor permeability, low chemical permeability, abrasion resistance, mechanical properties, and rigidity at high temperatures, and can therefore be suitably used, for example, as a piping component for transporting chemical solutions.

[0029] As described above, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present invention. [Example]

[0030] The present invention will be described in more detail below with reference to examples and comparative examples, but the scope of the present invention is not limited thereto. In these examples, tubular extrusions and sheet-shaped extrusions made of resin were prepared in Examples 1 to 6 and Comparative Examples 1 to 3, and various measurements were carried out on each of the prepared extrusions. Examples 1 to 6 and Comparative Examples 1 to 3 will be described below.

[0031] Table 2 below shows the resins constituting the extrusion molded articles of Examples 1 to 6 and Comparative Examples 1 to 3. Table 1 below also shows the resin properties (presence or absence of halogen elements, difference between ether structure and ethylene structure, melting point, melt flow rate) of the resins constituting the extrusion molded articles of Examples 1 to 6 and Comparative Examples 1 to 3.

[0032] (Melting Point) Using a differential scanning calorimeter (trade name: X-DSC7000, manufactured by Hitachi High-Tech Science Corporation), the sample was heated from 200°C to 350°C at a heating rate of 10°C / min, then cooled from 350°C to 200°C at a cooling rate of 10°C / min, and heated a second time from 200°C to 350°C at a heating rate of 10°C / min. The melting point was determined from the peak of the melting curve that occurred during the second heating process. In Table 1, melting points of 200 to 220°C are indicated by "〇", those of 220 to 250°C by "+", those above 250°C by "++", and those below 200°C by "-".

[0033] (Melt flow rate (MFR)) According to ASTM D1238, the mass of polymer (g / 10 min) flowing from a nozzle with an inner diameter of 2.1 mm and a length of 8 mm at 295°C under a load of 6.6 kg was determined using a Melt Indexer G-01 (manufactured by Toyo Seiki Seisakusho Co., Ltd.) per 10 min. In Table 1, MFR values are indicated as "-" for values less than 7.0, "〇" for values between 7.0 and 18.0, "+" for values between 18.0 and 29.0, and "++" for values greater than 29.0.

[0034] A known extrusion molding machine was used to produce the extrusion molded bodies, with the maximum cylinder temperature during extrusion being 350°C and the mold temperature being 300°C. Tubular extrusion molded bodies with an inner diameter of 4 mm and a wall thickness of 1 mm were produced. Sheet-shaped extrusion molded bodies with a thickness of 0.5 mm were produced.

[0035] The tubular extrusion molded articles were measured for their specified properties, specifically, inner surface roughness, ion elution amount, metal ion elution amount, and specific metal ion elution amount. The sheet-like extrusion molded articles were subjected to performance tests, specifically, measurement of water vapor permeability, MEK permeability, abrasion test, and measurement of 95°C load deflection rate.

[0036] (Inner surface roughness (Ra)) The tubular extrusion molded product was split lengthwise, and its inner surface was measured according to the method described in JIS standard (B0601). In Table 1, inner surface roughness (Ra) of 0.25 μm or less is indicated as "Good", and that of more than 0.25 μm is indicated as "Poor".

[0037] (Measurement of ion elution, metal ion elution, specific metal elution) The tubular extrusion molding was heated at 95°C for 1 hour, and water with an electrical conductivity of 0.5 mS / m or less at 25°C was enclosed inside. The concentration was then measured by inductively coupled plasma (ICP) analysis, and the amount of ion elution per unit inner surface area of the tubular extrusion molding was calculated. Table 1 shows the amount of ion elution of 7,500 μg / m 2 If it is higher, mark it as "×", and if it is higher, mark it as 7500 μg / m 2 ~5500μg / m 2 "△", 5500μg / m 2 ~4500μg / m 2"Yes", 4500μg / m 2 Those with less are indicated by "◎".

[0038] In addition, Table 1 shows that the amount of metal ions eluted was 5500 μg / m 2 If it is higher, mark it as "×", and if it is higher, mark it as 5500 μg / m 2 ~5000μg / m 2 "△", 5000μg / m 2 ~4500μg / m 2 "Yes", 4500μg / m 2 The following are indicated by "◎".

[0039] Furthermore, the total amount of elution of the 16 main metals based on SEMI F57-0314 was calculated as the amount of specific metal elution. 2 If it is higher, mark it as "×", and if it is 14 μg / m 2 The following are indicated as "〇".

[0040] (Water vapor permeability) After the sheet-like extrudate was left at 60°C for 24 hours, a test specimen was prepared from the extrudate. 2 10 g of water was placed in a container, covered with a sheet test piece, and a PTFE gasket was placed between the test pieces and fastened to seal the container. The sheet test piece was left in contact with the water at a temperature of 95°C for 60 days, then removed and left at room temperature for 2 hours, after which the amount of mass loss was measured. The water vapor permeability (g / m) was calculated using the following formula: 2 ) was measured. Water vapor permeability (g / m 2 )=mass loss (g) / transmission area (m 2 ) Table 1 shows the water vapor permeability of 600g / m 2 If it is more than this, mark it with "x", 600g / m 2 ~500g / m 2 "△", 500g / m 2 ~400g / m 2 "〇", 400g / m 2 The following are indicated by "◎".

[0041] (Methyl ethyl ketone (MEK) permeability) The sheet-shaped extrudate was left at 60°C for 24 hours, and then a sheet-shaped test piece was prepared from the extrudate. 2 10 g of MEK was placed in a container, covered with a sheet-like test piece, and a PTFE gasket was placed between them and the container was sealed. The sheet-like test piece was kept in contact with the MEK at a temperature of 60°C for 60 days, then removed and left at room temperature for 1 hour, after which the mass loss was measured.

[0042] MEK permeability (g / m 2 ) was calculated using the following formula: MEK permeability (g / m 2 )=mass loss (g) / transmission area (m 2 ) Table 1 shows the MEK permeability of 85g / m 2 If more, mark with "x", 85g / m 2 ~80g / m 2 "△", 80g / m 2 ~75g / m 2 "〇", 75g / m 2 The following are indicated by "◎".

[0043] (wear test) The sheet-like extrusion molded product was left at 60°C for 24 hours before being used as a test specimen. The test specimen was fixed to the test stand of a Taber abrasion tester (No. 101 Special Taber Abrasion Tester, manufactured by Yasuda Seiki Seisakusho Co., Ltd.), and an abrasion test was performed using the Taber abrasion tester under the following conditions: a load of 500 g, an abrasion wheel CS-10 (ground 20 times with abrasive paper #240), and a rotation speed of 60 rpm. The weight of the test specimen after 1,000 rotations was measured, and the same test specimen was then subjected to another 10,000 rotations and the weight of the test specimen was also measured.

[0044] The amount of wear was calculated using the following formula. Wear amount (mg)=M1-M2 M1: Test piece weight (mg) after 1000 rotations M2: Test piece weight (mg) after 10,000 rotations In Table 1, wear amounts greater than 17 mg are indicated by "x", 17 to 15 mg by "△", 15 to 13 mg by "〇", and 13 mg or less by "◎".

[0045] (95℃ load deflection rate) After leaving the sheet-like extrusion molded product at 60°C for 24 hours, a test piece of 80 mm x 10 mm was cut out from the extrusion molded product and heated in an electric furnace at 100°C for 20 hours. Except for using the obtained test piece, testing was carried out in accordance with the method described in JIS KK 7191-1 using a heat distortion tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.) under the conditions of a test temperature of 30 to 150°C, a heating rate of 120°C / hour, a bending stress of 1.8 MPa, and the flatwise method.

[0046] The deflection rate under load was calculated using the following formula: A sheet with a small deflection rate under load at 95°C has excellent rigidity at high temperatures. Load deflection rate (%) = a2 / a1 x 100 a1: thickness of test piece before test (mm) a2: Deflection at 95℃ (mm) In Table 1, load deflection rates of more than 70% are indicated by "x", 70 to 60% by "△", 60 to 50% by "◯", and 50% or less by "◎".

[0047] [Table 1]

[0048] [Table 2]

[0049] As is clear from Table 1, the extrusion molded articles of each Example, compared to the extrusion molded articles of each Comparative Example, are tubular articles molded from a resin that does not contain halogen elements, has an ether bond or an ethylene structure, and has a melting point of 200°C or higher, and have an electric conductivity of 0.5 mS / m or less at 25°C, and the amount of ion elution into water is 7500 μg / m 2It was found that tubular extrusion molded articles having an inner surface roughness (Ra) of 0.25 μm or less are non-halogenated, avoid environmental issues, and have excellent physical properties such as low water vapor permeability, low chemical permeability, abrasion resistance, and rigidity at high temperatures. Furthermore, the extrusion molded articles of Examples 1 to 3 had low amounts of specific metal elution and all physical properties were rated as "good" or better, confirming that they can be suitably used, particularly for piping for chemicals and ultrapure water used in the manufacture of semiconductors, liquid crystals, etc.

Claims

1. A tubular extrusion molded product made of a resin that does not contain halogen elements, has an ether bond or an ethylene structure, and has a melting point of 200°C or higher, and has an electric conductivity of 0.5 mS / m or less at 25°C and an ion elution amount into water of 7500 μg / m ２ and the arithmetic mean roughness (Ra) of the inner surface is 0.25 μm or less. Extrusion molding.

2. The amount of ions eluted into water with an electrical conductivity of 0.5 mS / m or less at 25°C is 5500 μg / m ２ Below is the The extrusion molded article according to claim 1 .

3. The total amount of elution of aluminum, barium, boron, calcium, chromium, copper, iron, lead, lithium, magnesium, manganese, nickel, potassium, sodium, strontium, and zinc measured in accordance with SEMI F57-0314 is 14 μg / m 2 Below is the The extrusion molded article according to claim 1 .

4. The total amount of elution of aluminum, barium, boron, calcium, chromium, copper, iron, lead, lithium, magnesium, manganese, nickel, potassium, sodium, strontium, and zinc measured in accordance with SEMI F57-0314 is 14 μg / m 2 Below is the The extrusion molded article according to claim 2.

5. The melt flow rate of the resin at 295°C is 7.0 to 18.0 g / 10 min. The extrusion molded article according to any one of claims 1 to 4.

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