Vinyl-chloride-based resin composition, vinyl-chloride-based resin molded article, and pipe for ultrapure water

Abstract

The present invention provides a vinyl-chloride-based resin composition that makes it possible to suppress the adverse effects of leaching of calcium from a vinyl-chloride-based resin molded article and that makes it possible to increase the impact resistance of a vinyl-chloride-based resin molded article.　A vinyl-chloride-based resin composition according to the present invention comprises a vinyl-chloride-based resin, an acrylic-vinyl-chloride-based copolymer which is a copolymer of an acrylic copolymer and vinyl chloride monomer, and a thermal stabilizer, wherein the content of a component derived from the acrylic copolymer in 100 wt% of the vinyl-chloride-based resin composition is 1.5-5.5 wt%, and either (1) the amount of leached calcium from a vinyl-chloride-based resin molded article obtained by molding the vinyl-chloride-based resin composition is 0-30 μg per 1 m2 of surface area of the vinyl-chloride-based resin molded article, or (2) the vinyl-chloride-based resin composition is used for obtaining a pipe for ultrapure water.

Description

Vinyl chloride resin composition, vinyl chloride resin molded body, and ultrapure water piping

[0001] The present invention relates to a vinyl chloride resin composition containing a vinyl chloride resin. The present invention also relates to a vinyl chloride resin molded article using the vinyl chloride resin composition. The present invention also relates to a pipe for ultrapure water using the vinyl chloride resin molded article.

[0002] Vinyl chloride resins have excellent mechanical strength, weather resistance, heat resistance, and chemical resistance. For this reason, they are processed into various molded articles such as pipes, plates, and containers, and are used in many fields. Vinyl chloride resin pipes are known as vinyl chloride resin molded articles.

[0003] Furthermore, in the field of semiconductor manufacturing, etc., ultrapure water is used to wash semiconductors, etc. In order to prevent the growth of bacteria in the piping of ultrapure water in plants, it is desirable that the inner surface of the piping has as little unevenness as possible and is smooth.

[0004] Patent Document 1 discloses a vinyl chloride resin pipe with excellent smoothness on the inner surface of the piping and a method for manufacturing the same. This vinyl chloride resin pipe has a two-layer structure including an inner layer and an outer layer. The inner layer contains a rigid vinyl chloride resin, and the outer layer contains a material with antistatic properties. In the vinyl chloride resin pipe, the maximum height Ry of the inner surface as specified in JIS B0601 is 0.5 μm or less, and the maximum height Ry of the outer surface as specified in JIS B0601 is 0.05 μm or less.

[0005] Japanese Patent Application Laid-Open No. 2003-314752

[0006] The vinyl chloride resin pipe (piping) described in Patent Document 1 has an excellent smoothness on the inner surface of the pipe, and therefore can prevent bacterial growth within the pipe to some extent. However, in the case of ultrapure water pipes, simply having an excellent smoothness on the inner surface of the pipe may not be enough to maintain a sufficiently high quality of the ultrapure water flowing through the pipe.

[0007] Ultrapure water is obtained by removing most of the anions and metal ions using an ion exchange resin or the like.

[0008] Calcium ions remaining in ultrapure water are considered to be the main metal ions that cause deterioration in the water quality, such as the conductivity of ultrapure water. With conventional ultrapure water piping, it is difficult to sufficiently reduce the amount of calcium ions eluted from the piping when ultrapure water flows through the piping. As a result, it is difficult to sufficiently suppress the adverse effects of calcium elution in ultrapure water piping.

[0009] Furthermore, vinyl chloride resin pipes are required to have the property of not breaking when subjected to impact. That is, vinyl chloride resin pipes are also required to have high impact resistance. In particular, since ultrapure water piping is used in the manufacture of high-performance products, ultrapure water piping is particularly required to have excellent quality, such as impact resistance. However, conventional vinyl chloride resin pipes, such as ultrapure water piping, sometimes have low impact resistance.

[0010] An object of the present invention is to provide a vinyl chloride resin composition and a vinyl chloride resin molded article that can suppress the adverse effects of calcium elution from the vinyl chloride resin molded article and can improve the impact resistance of the vinyl chloride resin molded article. Another object of the present invention is to provide a piping for ultrapure water that uses the vinyl chloride resin molded article.

[0011] The present inventors have discovered a configuration that can maintain high quality water quality when ultrapure water or other water flows through a pipe, and further discovered a configuration that can also improve the impact resistance of the pipe.

[0012] This specification discloses the following vinyl chloride resin composition, vinyl chloride resin molded article, and ultrapure water piping.

[0013] Item 1. A composition comprising a vinyl chloride resin, an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, and a heat stabilizer, wherein the content of components derived from the acrylic copolymer is 1.5% by weight or more and 5.5% by weight or less in 100% by weight of the vinyl chloride resin composition, and when a vinyl chloride resin molded article obtained by molding the vinyl chloride resin composition is left in ultrapure water at 23°C for 7 days, calcium does not elute or the amount of calcium eluted is 1.5% by weight or less per 1 m of surface area of ​​the vinyl chloride resin molded article.２ The vinyl chloride resin composition has a particle size of 30 μg or less per unit area.

[0014] Item 2. A vinyl chloride resin composition comprising a vinyl chloride resin, an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, and a heat stabilizer, wherein the content of components derived from the acrylic copolymer is 1.5% by weight or more and 5.5% by weight or less based on 100% by weight of the vinyl chloride resin composition, and the vinyl chloride resin composition is used to obtain piping for ultrapure water.

[0015] Item 3. The vinyl chloride resin composition according to Item 1 or 2, wherein the content of the component derived from the acrylic copolymer is 2.5% by weight or more and 20.0% by weight or less, based on 100% by weight of the acrylic-vinyl chloride copolymer.

[0016] Item 4. The vinyl chloride resin composition according to any one of Items 1 to 3, wherein the content of the vinyl chloride resin is 20.0% by weight or more and 85.0% by weight or less, and the content of the acrylic-vinyl chloride copolymer is 80.0% by weight or more and 15.0% by weight or less, based on 100% by weight of the total of the vinyl chloride resin and the acrylic-vinyl chloride copolymer.

[0017] Item 5. The vinyl chloride resin composition according to any one of Items 1 to 4, which does not contain chlorinated polyethylene or contains chlorinated polyethylene in an amount of 1.0 part by weight or less per 100 parts by weight of the vinyl chloride resin and the acrylic-vinyl chloride copolymer combined.

[0018] Item 6. The vinyl chloride resin composition according to any one of Items 1 to 5, wherein the heat stabilizer includes an organotin heat stabilizer.

[0019] Item 7. The vinyl chloride resin composition according to any one of Items 1 to 6, wherein the content of the heat stabilizer is 0.1 parts by weight or more and 5.0 parts by weight or less per 100 parts by weight of the total of the vinyl chloride resin and the acrylic-vinyl chloride copolymer.

[0020] Item 8: A method for producing a polyvinyl chloride resin product, comprising: a vinyl chloride resin; an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer; and a heat stabilizer, wherein the content of components derived from the acrylic copolymer is 1.5% by weight or more and 5.5% by weight or less in 100% by weight of a vinyl chloride resin molded body; and when the vinyl chloride resin molded body is left in ultrapure water at 23°C for 7 days, calcium is not eluted or the amount of eluted calcium is 100% by weight per 1 m of the surface area of ​​the vinyl chloride resin molded body. ２ A vinyl chloride resin molded article having a particle size of 30 μg or less per unit area.

[0021] Item 9. A vinyl chloride resin molded body comprising a vinyl chloride resin, an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, and a heat stabilizer, wherein the content of components derived from the acrylic copolymer is 1.5% by weight or more and 5.5% by weight or less in 100% by weight of the vinyl chloride resin molded body, and the vinyl chloride resin molded body is used to obtain piping for ultrapure water.

[0022] Item 10. When a vinyl chloride resin molded body is left in ultrapure water at 23°C for 7 days, calcium is not eluted or the amount of calcium eluted is less than 1 / m2 of the surface area of ​​the vinyl chloride resin molded body. ２ Item 10. The vinyl chloride resin molded article according to Item 9, wherein the total weight of the polyvinyl chloride resin is 30 μg or less per unit area.

[0023] Item 11. The vinyl chloride resin molded article according to any one of Items 8 to 10, wherein the content of components derived from the acrylic copolymer is 2.5% by weight or more and 20.0% by weight or less, based on 100% by weight of the acrylic-vinyl chloride copolymer.

[0024] Item 12. The vinyl chloride resin molded article according to any one of Items 8 to 11, wherein the content of the vinyl chloride resin is 20.0% by weight or more and 85.0% by weight or less, and the content of the acrylic-vinyl chloride copolymer is 80.0% by weight or more and 15.0% by weight or less, based on a total of 100% by weight of the vinyl chloride resin and the acrylic-vinyl chloride copolymer.

[0025] Item 13. The vinyl chloride resin molded article according to any one of Items 8 to 12, which does not contain chlorinated polyethylene or contains chlorinated polyethylene in an amount of 1.0 part by weight or less per 100 parts by weight of the vinyl chloride resin and the acrylic-vinyl chloride copolymer combined.

[0026] Item 14. The vinyl chloride resin molded article according to any one of items 8 to 13, wherein the heat stabilizer includes an organotin heat stabilizer.

[0027] Item 15. The vinyl chloride resin molded article according to any one of Items 8 to 14, wherein the content of the heat stabilizer is 0.1 parts by weight or more and 5.0 parts by weight or less per 100 parts by weight of the total of the vinyl chloride resin and the acrylic-vinyl chloride copolymer.

[0028] Item 16. A pipe for ultrapure water, which is a single-layer pipe having a one-layer structure or a multi-layer pipe having a laminated structure of two or more layers, and one layer in the single-layer pipe or the innermost layer in the multi-layer pipe is the vinyl chloride resin molded article according to any one of Items 8 to 15.

[0029] The vinyl chloride resin composition according to the present invention comprises a vinyl chloride resin, an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, and a heat stabilizer. The content of components derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin composition according to the present invention is 1.5% by weight or more and 5.5% by weight or less. When a vinyl chloride resin molded article obtained by molding the vinyl chloride resin composition is allowed to stand in ultrapure water at 23°C for 7 days, calcium does not elute, or the amount of calcium eluted is 1.5% by weight or less per 1 m of the surface area of ​​the vinyl chloride resin molded article. ２ The vinyl chloride resin composition according to the present invention has the above-mentioned structure, and therefore can suppress the adverse effects of calcium elution from vinyl chloride resin molded articles and can increase the impact resistance of vinyl chloride resin molded articles.

[0030] The vinyl chloride resin composition according to the present invention comprises a vinyl chloride resin, an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, and a heat stabilizer. The content of components derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin composition according to the present invention is 1.5% by weight or more and 5.5% by weight or less. The vinyl chloride resin composition according to the present invention is used to obtain piping for ultrapure water. Because the vinyl chloride resin composition according to the present invention has the above-described configuration, it is possible to suppress the adverse effects of calcium elution from a vinyl chloride resin molded article and to increase the impact resistance of the vinyl chloride resin molded article.

[0031] The vinyl chloride resin molded article according to the present invention comprises a vinyl chloride resin, an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, and a heat stabilizer. The content of components derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin molded article according to the present invention is 1.5% by weight or more and 5.5% by weight or less. When the vinyl chloride resin molded article according to the present invention is left in ultrapure water at 23°C for 7 days, calcium does not elute, or the amount of calcium eluted is 1.5% by weight or less per 1 m of the surface area of ​​the vinyl chloride resin molded article. ２ The vinyl chloride resin molded article according to the present invention has the above-mentioned configuration, and therefore can suppress the adverse effects of calcium elution from the vinyl chloride resin molded article and can increase the impact resistance of the vinyl chloride resin molded article.

[0032] The vinyl chloride resin molded article according to the present invention comprises a vinyl chloride resin, an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, and a heat stabilizer. The content of components derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin molded article according to the present invention is 1.5% by weight or more and 5.5% by weight or less. The vinyl chloride resin molded article according to the present invention is used to obtain piping for ultrapure water. Since the vinyl chloride resin molded article according to the present invention has the above-described configuration, it is possible to suppress the adverse effects of calcium elution from the vinyl chloride resin molded article and to increase the impact resistance of the vinyl chloride resin molded article.

[0033] Fig. 1 is a cross-sectional view schematically showing a vinyl chloride resin pipe including a vinyl chloride resin molded article according to a first embodiment of the present invention. Fig. 2 is a cross-sectional view schematically showing a vinyl chloride resin pipe including a vinyl chloride resin molded article according to a second embodiment of the present invention.

[0034] The present invention will be described in detail below.

[0035] (Vinyl chloride resin composition) The vinyl chloride resin composition according to the present invention comprises a vinyl chloride resin, an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, and a heat stabilizer. The content of components derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin composition according to the present invention is 1.5% by weight or more and 5.5% by weight or less.

[0036] The vinyl chloride resin composition according to the present invention satisfies the following first feature or the following second feature.

[0037] First feature: When a vinyl chloride resin molding obtained by molding a vinyl chloride resin composition is left in ultrapure water at 23°C for 7 days, calcium is not eluted or the amount of eluted calcium is 1 / 2 m of the surface area of ​​the vinyl chloride resin molding. ２ It is less than 30 μg per unit.

[0038] Second Configuration: The vinyl chloride resin composition is used to obtain piping for ultrapure water.

[0039] Hereinafter, a vinyl chloride resin composition satisfying the first feature may be referred to as a vinyl chloride resin composition (1). A vinyl chloride resin composition satisfying the second feature may be referred to as a vinyl chloride resin composition (2).

[0040] In the vinyl chloride resin composition (1) according to the present invention, when a vinyl chloride resin molding obtained by molding the vinyl chloride resin composition (1) is left in ultrapure water at 23°C for 7 days, calcium is not eluted or the amount of eluted calcium is 1 / 2 m of the surface area of ​​the vinyl chloride resin molding. ２ It is less than 30 μg per unit.

[0041] The vinyl chloride resin composition (2) according to the present invention is used to obtain piping for ultrapure water. The vinyl chloride resin composition contains a vinyl chloride resin, an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, and a heat stabilizer, and the content of components derived from the acrylic copolymer is 1.5% by weight or more and 5.5% by weight or less based on 100% by weight of the vinyl chloride resin composition.

[0042] The vinyl chloride resin composition (2) satisfying the second feature preferably satisfies the first feature in addition to the second feature.

[0043] In the semiconductor manufacturing field and the like, ultrapure water is used to wash semiconductors and the like. Ultrapure water is obtained by removing most anions and metal ions using ion exchange resins and the like. In order to prevent deterioration of the quality of ultrapure water, it is desirable for the piping for ultrapure water to have low levels of impurities such as metal ions and TOC (total organic carbon), which are eluted from the piping when ultrapure water flows through the piping. Calcium ions remaining in ultrapure water are thought to be the main metal ions that cause deterioration of the water quality, such as the conductivity of ultrapure water.

[0044] In conventional piping for ultrapure water, it is difficult to sufficiently suppress the adverse effects of calcium elution. Furthermore, even in piping other than that for ultrapure water, if the amount of calcium elution can be reduced, the adverse effects of calcium elution can be reduced. In particular, if the amount of calcium elution can be reduced, it is possible to prevent deterioration in the quality of the water flowing through the piping.

[0045] As a result of investigations, the present inventors have found that, when preparing a vinyl chloride resin composition, the calcium content can be significantly reduced by using an acrylic-vinyl chloride copolymer, which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, together with a vinyl chloride resin, and by controlling the content of components derived from the acrylic copolymer within a specific range relative to 100% by weight of the vinyl chloride resin composition. Furthermore, the present inventors have found that the amount of calcium elution can be significantly reduced in a vinyl chloride resin molded article obtained by molding a vinyl chloride resin composition that uses the acrylic-vinyl chloride copolymer and contains a specific content of components derived from the acrylic copolymer.

[0046] The vinyl chloride resin compositions (1) and (2) according to the present invention, which have the above-mentioned features, can suppress the adverse effects of calcium elution from vinyl chloride resin molded articles. For example, when water flows through a vinyl chloride resin molded article obtained by molding the vinyl chloride resin compositions (1) and (2), the quality of the water can be maintained at a high level.

[0047] Furthermore, conventional vinyl chloride resin compositions sometimes have low impact resistance in vinyl chloride resin molded articles obtained by molding the vinyl chloride resin compositions. The present inventors have found that it is possible to improve the impact resistance of vinyl chloride resin molded articles obtained by molding a vinyl chloride resin composition that uses a specific acrylic-vinyl chloride copolymer and contains a specific amount of a component derived from the acrylic copolymer.

[0048] The vinyl chloride resin compositions (1) and (2) according to the present invention have the above-mentioned configuration, and in particular, contain a specific amount of a component derived from the acrylic copolymer, so that the vinyl chloride resin compositions (1) and (2) according to the present invention can improve the impact resistance of vinyl chloride resin molded articles obtained by molding the vinyl chloride resin compositions (1) and (2). For example, even when an impact is applied to the vinyl chloride resin molded article, cracks, breakage, and deformation are less likely to occur.

[0049] Furthermore, in order to prevent the propagation of bacteria within the ultrapure water pipes, it is desirable that the inner surface of the pipes has as few irregularities as possible and is smooth.

[0050] The vinyl chloride resin compositions (1) and (2) according to the present invention have the above-mentioned features, and in particular, the content of the component derived from the acrylic copolymer is not more than the above-mentioned upper limit, so that the surface smoothness of the vinyl chloride resin molded article can be improved, which also makes it possible to maintain high quality of water when it flows through the vinyl chloride resin molded article obtained by molding the vinyl chloride resin compositions (1) and (2).

[0051] In the vinyl chloride resin composition (1), the amount of calcium eluted when a vinyl chloride resin molded article obtained by molding the vinyl chloride resin composition (1) is left in ultrapure water at 23°C for 7 days (calcium elution amount in a calcium elution test) can be determined as follows.

[0052] The vinyl chloride resin composition (1) is molded to obtain a vinyl chloride resin molded article. The size and shape of the obtained vinyl chloride resin molded article are preferably a rectangular parallelepiped with a length of 12.0 mm, a width of 11.0 mm, and a thickness of 1.0 mm. Pressing may be performed to obtain a vinyl chloride resin molded article of this size and shape. The obtained vinyl chloride resin molded article is washed with pure water. After washing, the vinyl chloride resin molded article is placed in 500 mL of pure water and allowed to stand at 23°C for 7 days. After standing, the vinyl chloride resin molded article is removed from the pure water, and the calcium content in the pure water is measured. ICP emission spectrometry is preferably used to measure the calcium content.

[0053] In the calcium elution test of the vinyl chloride resin composition (1), the amount of calcium eluted was measured per m of the surface area of ​​the vinyl chloride resin molded article. ２ The calcium elution amount is preferably 0 μg or more per 1 m of the surface area of ​​the vinyl chloride resin molded article. When the calcium elution amount is 0 μg, no calcium elution occurs. In the calcium elution test of the vinyl chloride resin composition (1), the calcium elution amount is 1 μg per 1 m of the surface area of ​​the vinyl chloride resin molded article. ２ The amount of calcium elution is preferably 25 μg or less, more preferably 22.5 μg or less, even more preferably 20 μg or less, even more preferably 15 μg or less, even more preferably 12 μg or less, particularly preferably 10 μg or less, and most preferably 0 μg per unit area of ​​the vinyl chloride resin molded article. In the calcium elution test of the vinyl chloride resin composition (1), it is particularly preferable that no calcium elution occurs. When the amount of calcium elution is equal to or less than the upper limit, adverse effects due to calcium elution can be further prevented. In the calcium elution test of the vinyl chloride resin composition (1), the amount of calcium elution is 1 m / s of the surface area of ​​the vinyl chloride resin molded article. ２ The calcium elution amount may be 0 μg or more, more than 0 μg, 1.0 μg or more, 3.0 μg or more, or 5.0 μg or more per 1000 mg / kg body weight. In the calcium elution test for the vinyl chloride resin composition (2), it is preferable that the amount of calcium eluted satisfies the same upper limit as in the calcium elution test for the vinyl chloride resin composition (1). In the calcium elution test for the vinyl chloride resin composition (2), the amount of calcium eluted may satisfy the same lower limit as in the calcium elution test for the vinyl chloride resin composition (1). In the calcium elution test for the vinyl chloride resin composition (1) and the vinyl chloride resin composition (2), the range of the amount of calcium elution can be set by appropriately selecting the lower limit and the upper limit.

[0054] The content of the component derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin compositions (1) and (2) is 1.5% by weight or more and 5.5% by weight or less. Since the content of the component derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin compositions (1) and (2) is equal to or more than the lower limit and equal to or less than the upper limit, it is possible to suppress the adverse effects of calcium elution from the vinyl chloride resin molded article and to increase the impact resistance of the vinyl chloride resin molded article.

[0055] The components derived from the acrylic copolymer in the vinyl chloride resin compositions (1) and (2) are the components derived from the acrylic copolymer in the acrylic-vinyl chloride copolymer. In other words, the components derived from the acrylic copolymer in the acrylic-vinyl chloride copolymer are structural units (skeleton) derived from the acrylic copolymer in the acrylic-vinyl chloride copolymer.

[0056] An example of calculating the content of components derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin compositions (1) and (2) is shown below. The vinyl chloride resin compositions (1) and (2) contain 50% by weight of the acrylic-vinyl chloride copolymer in 100% by weight of the vinyl chloride resin compositions (1) and (2), and the acrylic-vinyl chloride copolymer contains 7% by weight of components derived from the acrylic copolymer in 100% by weight of the acrylic-vinyl chloride copolymer. In this case, the content of components derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin compositions (1) and (2) is calculated as 0.5 x 0.07 x 100 = 3.5% by weight.

[0057]

[0033] In 100% by weight of the vinyl chloride resin compositions (1) and (2), the content of the component derived from the acrylic copolymer is preferably 2.0% by weight or more, more preferably 2.5% by weight or more, even more preferably 3.0% by weight or more, particularly preferably 3.5% by weight or more, and is preferably 5.0% by weight or less, more preferably 4.5% by weight or less, even more preferably 4.0% by weight or less, particularly preferably 3.8% by weight or less. When the content of the component derived from the acrylic copolymer is above the lower limit, the impact resistance of the vinyl chloride resin molded article can be further improved. When the content of the component derived from the acrylic copolymer is below the upper limit, the adverse effects of calcium elution from the vinyl chloride resin molded article can be further suppressed, and the surface smoothness of the vinyl chloride resin molded article can be further improved.

[0058] In 100% by weight of the vinyl chloride resin compositions (1) and (2), the total content of the vinyl chloride resin and the acrylic-vinyl chloride copolymer is preferably 50.0% by weight or more, more preferably 55.0% by weight or more, even more preferably 60.0% by weight or more, even more preferably 65.0% by weight or more, even more preferably 70.0% by weight or more, particularly preferably 75.0% by weight or more, and most preferably 80.0% by weight or more, and is preferably less than 100.0% by weight, more preferably 99.99% by weight or less, even more preferably 99.9% by weight or less, even more preferably 99.8% by weight or less, even more preferably 99.5% by weight or less, particularly preferably 99.0% by weight or less, and most preferably 98.0% by weight or less. When the total content of the vinyl chloride resin and the acrylic-vinyl chloride copolymer is equal to or greater than the lower limit and equal to or less than the upper limit, the adverse effects of calcium leaching from the vinyl chloride resin molded article can be more effectively suppressed. Furthermore, the impact resistance of the vinyl chloride resin molded article can be improved even more effectively.

[0059] (Vinyl chloride resin molded article) The vinyl chloride resin molded article according to the present invention comprises a vinyl chloride resin, an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, and a heat stabilizer. The content of components derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin molded article according to the present invention is 1.5% by weight or more and 5.5% by weight or less.

[0060] The vinyl chloride resin molded article according to the present invention satisfies the following first feature or the following second feature.

[0061] First feature: When a vinyl chloride resin molded body is left in ultrapure water at 23°C for 7 days, calcium is not eluted or the amount of eluted calcium is 1 / 2 m of the surface area of ​​the vinyl chloride resin molded body. ２ It is less than 30 μg per unit.

[0062] Second Configuration: The vinyl chloride resin molded article is used to obtain piping for ultrapure water.

[0063] Hereinafter, a vinyl chloride resin molded product satisfying the first feature may be referred to as a vinyl chloride resin molded product (1), and a vinyl chloride resin molded product satisfying the second feature may be referred to as a vinyl chloride resin molded product (2).

[0064] In the vinyl chloride resin molded article (1) according to the present invention, when the vinyl chloride resin molded article (1) is left in ultrapure water at 23° C. for 7 days, calcium is not eluted or the amount of calcium eluted is less than 1 / m of the surface area of ​​the vinyl chloride resin molded article (1). ２ It is less than 30 μg per unit.

[0065] The vinyl chloride resin molded article (2) according to the present invention is used to obtain piping for ultrapure water. The vinyl chloride resin molded article contains a vinyl chloride resin, an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, and a heat stabilizer, and the content of components derived from the acrylic copolymer is 1.5% by weight or more and 5.5% by weight or less based on 100% by weight of the vinyl chloride resin molded article. Use of the vinyl chloride resin molded article for ultrapure water piping.

[0066] The vinyl chloride resin molded article (2) satisfying the second feature preferably satisfies the first feature in addition to the second feature.

[0067] In the semiconductor manufacturing field and the like, ultrapure water is used to wash semiconductors and the like. Ultrapure water is obtained by removing most anions and metal ions using ion exchange resins and the like. In order to prevent deterioration of the quality of ultrapure water, it is desirable for the piping for ultrapure water to have low levels of impurities such as metal ions and TOC (total organic carbon), which are eluted from the piping when ultrapure water flows through the piping. Calcium ions remaining in ultrapure water are thought to be the main metal ions that cause deterioration of the water quality, such as the conductivity of ultrapure water.

[0068] In conventional piping for ultrapure water, it is difficult to sufficiently suppress the adverse effects of calcium elution. Furthermore, even in piping other than that for ultrapure water, if the amount of calcium elution can be reduced, the adverse effects of calcium elution can be reduced. In particular, if the amount of calcium elution can be reduced, it is possible to prevent deterioration in the quality of the water flowing through the piping.

[0069] As a result of investigations, the present inventors have found that, when a vinyl chloride resin molded article is obtained, the calcium content can be significantly reduced by using an acrylic-vinyl chloride copolymer, which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, together with a vinyl chloride resin, and by controlling the content of components derived from the acrylic copolymer within a specific range relative to 100% by weight of the vinyl chloride resin composition.Furthermore, the present inventors have found that the amount of calcium elution can be significantly reduced in a vinyl chloride resin molded article that uses the acrylic copolymer and contains a specific content of components derived from the acrylic copolymer.

[0070] The vinyl chloride resin molded articles (1) and (2) according to the present invention have the above-mentioned configuration, and therefore can suppress the adverse effects of calcium elution from the vinyl chloride resin molded articles (1) and (2). For example, when water flows through the vinyl chloride resin molded articles (1) and (2), the quality of the water can be maintained at a high level.

[0071] Furthermore, conventional vinyl chloride resin molded articles sometimes have low impact resistance. The present inventors have found that vinyl chloride resin molded articles (1) and (2) using a specific acrylic-vinyl chloride copolymer and containing a specific content of a component derived from the acrylic copolymer can have improved impact resistance.

[0072] The vinyl chloride resin molded products (1) and (2) according to the present invention have the above-mentioned configuration, and in particular, since the vinyl chloride resin molded products (1) and (2) contain a specific amount of a component derived from the acrylic copolymer, the impact resistance of the vinyl chloride resin molded products (1) and (2) can be improved.

[0073] Furthermore, in order to prevent the propagation of bacteria within the ultrapure water pipes, it is desirable that the inner surface of the pipes has as few irregularities as possible and is smooth.

[0074] The vinyl chloride resin molded products (1) and (2) according to the present invention have the above-mentioned configuration, and in particular, the content of the component derived from the acrylic copolymer is not more than the above-mentioned upper limit, so that the vinyl chloride resin molded products (1) and (2) can have an improved surface smoothness, which also allows the quality of water to be maintained high when it flows through the vinyl chloride resin molded products (1) and (2).

[0075] The amount of calcium eluted when the vinyl chloride resin molded article (1) is left in ultrapure water at 23° C. for 7 days (calcium elution amount in a calcium elution test) is determined as follows.

[0076] The vinyl chloride resin molded body (1) is prepared. The size and shape of the vinyl chloride resin molded body (1) are preferably a rectangular parallelepiped with a length of 12.0 mm, a width of 11.0 mm, and a thickness of 1.0 mm. Pressing may be performed to obtain the vinyl chloride resin molded body (1) of this size and shape. A measurement sample (vinyl chloride resin molded body (1)) may be obtained using a vinyl chloride resin composition having the same composition as the vinyl chloride resin molded body (1). The vinyl chloride resin molded body (1) is washed with pure water. After washing, the vinyl chloride resin molded body (1) is placed in 500 mL of pure water and allowed to stand at 23°C for 7 days. After standing, the vinyl chloride resin molded body (1) is removed from the pure water, and the calcium content in the pure water is measured. ICP emission spectrometry is preferably used to measure the calcium content.

[0077] In the calcium elution test of the vinyl chloride resin molded article (1), the amount of calcium eluted was 1 / m2 of the surface area of ​​the vinyl chloride resin molded article (1). ２ The calcium elution amount is preferably 0 μg or more per 1 m of the surface area of ​​the vinyl chloride resin molded article (1). When the calcium elution amount is 0 μg, no calcium is eluted. In the calcium elution test of the vinyl chloride resin molded article (1), the calcium elution amount is 1 μg per 1 m of the surface area of ​​the vinyl chloride resin molded article (1). ２ The amount of calcium elution is preferably 25 μg or less, more preferably 22.5 μg or less, even more preferably 20 μg or less, even more preferably 15 μg or less, even more preferably 12 μg or less, particularly preferably 10 μg or less, and most preferably 0 μg per unit area of ​​the vinyl chloride resin molded product (1). In the calcium elution test of the vinyl chloride resin molded product (1), it is particularly preferable that no calcium is eluted. When the amount of calcium elution is equal to or less than the upper limit, adverse effects due to calcium elution can be further prevented. In the calcium elution test of the vinyl chloride resin molded product (1), the amount of calcium elution is 1 m / s of the surface area of ​​the vinyl chloride resin molded product. ２The calcium elution amount may be 0 μg or more, more than 0 μg, 1.0 μg or more, 3.0 μg or more, or 5.0 μg or more per unit area. In the calcium elution test for the vinyl chloride resin molded product (2), it is preferable that the amount of calcium elution satisfies the same upper limit as in the calcium elution test for the vinyl chloride resin molded product (1). In the calcium elution test for the vinyl chloride resin molded product (2), the amount of calcium elution may satisfy the same lower limit as in the calcium elution test for the vinyl chloride resin molded product (1). In the calcium elution test for the vinyl chloride resin molded product (1) and the vinyl chloride resin molded product (2), the range of the calcium elution amount can be set by appropriately selecting the lower limit and the upper limit.

[0078] The content of the component derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin molded products (1) and (2) is 1.5% by weight or more and 5.5% by weight or less. Since the content of the component derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin molded products (1) and (2) is equal to or more than the lower limit and equal to or less than the upper limit, it is possible to suppress the adverse effects of calcium elution from the vinyl chloride resin molded products (1) and (2) and to improve the impact resistance of the vinyl chloride resin molded products (1) and (2).

[0079] The components derived from the acrylic copolymer of the vinyl chloride resin molded products (1) and (2) are the components derived from the acrylic copolymer of the acrylic-vinyl chloride copolymer. In other words, the components derived from the acrylic copolymer of the acrylic-vinyl chloride copolymer are structural units (skeleton) derived from the acrylic copolymer of the acrylic-vinyl chloride copolymer.

[0080] Here is an example of how to calculate the content of components derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin molded bodies (1) and (2). The vinyl chloride resin molded bodies (1) and (2) contain 50% by weight of the acrylic-vinyl chloride copolymer in 100% by weight of the vinyl chloride resin molded bodies (1) and (2), and the acrylic-vinyl chloride copolymer contains 7% by weight of components derived from the acrylic copolymer in 100% by weight of the acrylic-vinyl chloride copolymer. In this case, the content of components derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin molded bodies (1) and (2) is calculated as 0.5 x 0.07 x 100 = 3.5% by weight.

[0081] The content of the component derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin molded products (1) and (2) is preferably 2.0% by weight or more, more preferably 2.5% by weight or more, even more preferably 3.0% by weight or more, particularly preferably 3.5% by weight or more, and is preferably 5.0% by weight or less, more preferably 4.5% by weight or less, even more preferably 4.0% by weight or less, particularly preferably 3.8% by weight or less. When the content of the component derived from the acrylic copolymer is above the lower limit, the impact resistance of the vinyl chloride resin molded products (1) and (2) can be further improved. When the content of the component derived from the acrylic copolymer is below the upper limit, the adverse effects of calcium leaching from the vinyl chloride resin molded products (1) and (2) can be further suppressed. Furthermore, when the content of the component derived from the acrylic copolymer is below the upper limit, the surface smoothness of the vinyl chloride resin molded products (1) and (2) can be further improved.

[0082] The total content of the vinyl chloride resin and the acrylic-vinyl chloride copolymer in 100% by weight of the vinyl chloride resin molded articles (1) and (2) is preferably 50.0% by weight or more, more preferably 55.0% by weight or more, even more preferably 60.0% by weight or more, even more preferably 65.0% by weight or more, even more preferably 70.0% by weight or more, particularly preferably 75.0% by weight or more, and most preferably 80.0% by weight or more, and is preferably less than 100.0% by weight, more preferably 99.99% by weight or less, even more preferably 99.9% by weight or less, even more preferably 99.8% by weight or less, even more preferably 99.5% by weight or less, particularly preferably 99.0% by weight or less, and most preferably 98.0% by weight or less. When the total content of the vinyl chloride resin and the acrylic-vinyl chloride copolymer is equal to or greater than the lower limit and equal to or less than the upper limit, the adverse effects of calcium leaching from the vinyl chloride resin molded article can be more effectively suppressed. Furthermore, the impact resistance of the vinyl chloride resin molded article can be improved even more effectively.

[0083] (Composition of vinyl chloride resin composition and vinyl chloride resin molded article) Hereinafter, the components contained in the vinyl chloride resin compositions (1) and (2) and the vinyl chloride resin molded articles (1) and (2) will be described. In the following description, the vinyl chloride resin compositions (1) and (2) may be referred to as vinyl chloride resin compositions. The vinyl chloride resin molded articles (1) and (2) may be referred to as vinyl chloride resin molded articles.

[0084] <Vinyl chloride resin> As the vinyl chloride resin, conventionally known vinyl chloride resins can be used. Examples of the vinyl chloride resin include (1) a homopolymer of a vinyl chloride monomer, (2) a copolymer of a vinyl chloride monomer and a polymerizable compound other than a vinyl chloride monomer, and (3) a graft polymer in which a vinyl chloride monomer or a vinyl chloride resin is graft-polymerized onto a polymer other than a vinyl chloride resin. The vinyl chloride resin may be used alone or in combination of two or more.

[0085] The polymerizable compound other than the vinyl chloride monomer is not particularly limited, and examples thereof include α-olefins having 16 or less carbon atoms (e.g., ethylene, propylene, and butylene); vinyl esters of aliphatic carboxylic acids having from 2 to 16 carbon atoms (e.g., vinyl acetate and vinyl propionate); alkyl vinyl ethers having 16 or less carbon atoms (e.g., butyl vinyl ether and cetyl vinyl ether); alkyl (meth)acrylates having 16 or less carbon atoms (e.g., methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate); aryl (meth)acrylates (e.g., phenyl (meth)acrylate); aromatic vinyls (e.g., styrene and α-substituted styrenes (e.g., α-methylstyrene)); vinyl halides (e.g., vinylidene chloride and vinylidene fluoride); and N-substituted maleimides (N-phenylmaleimide and N-cyclohexylmaleimide). The polymerizable compounds other than the vinyl chloride monomer may be used alone or in combination of two or more.

[0086] When the vinyl chloride resin is a copolymer, the copolymer may be a random copolymer, a block copolymer, or a graft copolymer.

[0087] The polymer other than the vinyl chloride resin to which the vinyl chloride monomer or vinyl chloride resin is graft polymerized is not particularly limited, and includes copolymers of α-olefins and vinyl esters (e.g., ethylene-vinyl acetate copolymer); copolymers of α-olefins, vinyl esters, and carbon monoxide (e.g., ethylene-vinyl acetate-carbon monoxide copolymer); copolymers of α-olefins and alkyl (meth)acrylates (e.g., ethylene-methyl (meth)acrylate copolymer and ethylene-ethyl (meth)acrylate copolymer); copolymers of α-olefins, alkyl (meth)acrylate, and carbon monoxide (e.g., ethylene-butyl (meth)acrylate-carbon monoxide copolymer); copolymers of two or more different α-olefins (e.g., ethylene-propylene copolymer); copolymers of unsaturated nitriles and dienes (e.g., acrylonitrile-butadiene copolymer); polyurethane; chlorinated polyolefins (e.g., chlorinated polyethylene and chlorinated polypropylene). The polymers other than the vinyl chloride resins may be used alone or in combination of two or more.

[0088] The content of the vinyl chloride-derived structural units in 100% by weight of the vinyl chloride resin is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and preferably 100% by weight or less, more preferably 98% by weight or less, and even more preferably 95% by weight or less. When the content of the vinyl chloride-derived structural units is above the lower limit, the flame retardancy can be further improved. When the content of the vinyl chloride-derived structural units is below the upper limit, the moldability of the vinyl chloride-based resin composition can be improved, and thermal decomposition of the vinyl chloride-based resin during molding of the vinyl chloride-based resin composition can be suppressed. Note that the vinyl chloride-derived structural units may be 100% by weight (total amount) in 100% by weight of the vinyl chloride-based resin.

[0089] The average degree of polymerization of the vinyl chloride resin is preferably 400 or more, more preferably 600 or more, even more preferably 620 or more, and preferably 2500 or less, more preferably 2000 or less, even more preferably 1600 or less, particularly preferably 1400 or less. When the average degree of polymerization of the vinyl chloride resin is equal to or greater than the lower limit, the mechanical strength of the vinyl chloride resin molded article can be increased. When the average degree of polymerization of the vinyl chloride resin is equal to or less than the upper limit, there is no need to apply high temperatures during molding of the vinyl chloride resin composition, and processability is further improved.

[0090] The average degree of polymerization of the vinyl chloride resin can be measured as follows: The vinyl chloride resin is dissolved in tetrahydrofuran (THF), filtered to remove unnecessary components, and the THF in the filtrate is dried to remove the resulting resin. The average degree of polymerization of the vinyl chloride resin is measured using the resin as a sample in accordance with JIS K6721 "Testing Methods for Vinyl Chloride Resins."

[0091] The chlorine content of the vinyl chloride resin is preferably 58% by weight or more, more preferably 60% by weight or more, even more preferably 62% by weight or more, and particularly preferably 64% by weight or more, and is preferably 75% by weight or less, more preferably 72% by weight or less, and even more preferably 70% by weight or less. When the chlorine content is equal to or more than the above lower limit and equal to or less than the above upper limit, the heat resistance of the vinyl chloride resin molded article can be improved.

[0092] The polymerization method for producing the vinyl chloride resin is not particularly limited. Examples of the polymerization method include suspension polymerization, emulsion polymerization, solution polymerization, bulk polymerization, and precipitation polymerization. From the viewpoint of efficiently obtaining the vinyl chloride resin, the polymerization method is preferably suspension polymerization, emulsion polymerization, solution polymerization, or precipitation polymerization.

[0093] The vinyl chloride resin does not have to be a chlorinated vinyl chloride resin. The vinyl chloride resin may be a chlorinated vinyl chloride resin. The chlorinated vinyl chloride resin is a resin obtained by chlorinating a vinyl chloride resin. In this specification, chlorinated vinyl chloride resins are included in vinyl chloride resins. In this specification, "chlorinated vinyl chloride resins" may also be referred to as "vinyl chloride resins."

[0094] The chlorinated vinyl chloride resin may be a commercially available product, such as H829, H716S, H727, H527, H516A, H547, H536, and H305 (all manufactured by Kaneka Corporation); HA-15E, HA-05E, HA-15F, HA-24F, HA-22H, HA-36F, HA-05K, HA-24K, HA-24L, HA-31K, HA-54K, and HA-58K (all manufactured by Tokuyama Sekisui Kogyo Co., Ltd.).

[0095] The content of the vinyl chloride resin in 100% by weight of the vinyl chloride resin composition or the vinyl chloride resin molded product is preferably 10% by weight or more, more preferably 20% by weight or more, even more preferably 30% by weight or more, particularly preferably 40% by weight or more, and most preferably 50% by weight or more, and is preferably 98% by weight or less, more preferably 97% by weight or less, even more preferably 96% by weight or less, and even more preferably 95% by weight or less. When the content of the vinyl chloride resin is not less than the above lower limit and not more than the above upper limit, the heat insulating property and fire resistance of the vinyl chloride resin molded product can be further improved.

[0096] The content of the vinyl chloride resin in a total of 100% by weight of the vinyl chloride resin and the acrylic-vinyl chloride copolymer is preferably 10.0% by weight or more, more preferably 15.0% by weight or more, even more preferably 20.0% by weight or more, even more preferably 25.0% by weight or more, even more preferably 30.0% by weight or more, particularly preferably 35.0% by weight or more, and most preferably 40.0% by weight or more, and is preferably 90.0% by weight or less, more preferably 85.0% by weight or less, even more preferably 80.0% by weight or less, even more preferably 75.0% by weight or less, even more preferably 70.0% by weight or less, particularly preferably 67.5% by weight or less, and most preferably 65.0% by weight or less. When the content of the vinyl chloride resin is above the lower limit, the moldability of the vinyl chloride resin composition can be further improved. When the content of the vinyl chloride resin is below the upper limit, greater flexibility can be imparted to the vinyl chloride resin molded article, and greater application stability can be imparted to the vinyl chloride resin molded article. Furthermore, when the content of the vinyl chloride resin is equal to or less than the upper limit, the impact resistance of the vinyl chloride resin molded article can be further improved.

[0097] <Acrylic-vinyl chloride copolymer> The vinyl chloride resin composition or the vinyl chloride resin molded article contains the acrylic-vinyl chloride copolymer in addition to the vinyl chloride resin. The acrylic-vinyl chloride copolymer is a copolymer of an acrylic copolymer and a vinyl chloride monomer. The acrylic-vinyl chloride copolymer may be a copolymer of an acrylic copolymer and a mixed vinyl chloride monomer. The acrylic-vinyl chloride copolymer is an impact modifier. Use of the acrylic-vinyl chloride copolymer can increase the impact resistance of the vinyl chloride resin molded article. The acrylic-vinyl chloride copolymer may be used alone or in combination of two or more types.

[0098] The average degree of polymerization of the acrylic-vinyl chloride copolymer is preferably 400 or more, more preferably 600 or more, even more preferably 620 or more, and is preferably 2500 or less, more preferably 2000 or less, even more preferably 1600 or less, and particularly preferably 1400 or less. When the average degree of polymerization of the acrylic-vinyl chloride copolymer is equal to or greater than the above-mentioned lower limit, the impact resistance and mechanical properties of the vinyl chloride resin molded article can be further improved. When the average degree of polymerization of the acrylic-vinyl chloride copolymer is equal to or less than the above-mentioned upper limit, the moldability of the vinyl chloride resin composition can be improved.

[0099] The average degree of polymerization of the acrylic-vinyl chloride copolymer can be measured as follows: The acrylic-vinyl chloride copolymer is dissolved in tetrahydrofuran (THF), and unnecessary components are removed by filtration. The THF in the filtrate is then dried to remove the resulting resin, and the average degree of polymerization of the acrylic-vinyl chloride copolymer is measured using the resin as a sample in accordance with JIS K6721 "Testing methods for vinyl chloride resins."

[0100] In a total of 100% by weight of the vinyl chloride resin and the acrylic-vinyl chloride copolymer, the content of the acrylic-vinyl chloride copolymer is preferably 10.0 wt% or more, more preferably 15.0 wt% or more, even more preferably 20.0 wt% or more, even more preferably 25.0 wt% or more, even more preferably 30.0 wt% or more, particularly preferably 35.0 wt% or more, most preferably 40.0 wt% or more, preferably 90.0 wt% or less, more preferably 85.0 wt% or less, even more preferably 80.0 wt% or less, even more preferably 75.0 wt% or less, even more preferably 70.0 wt% or less, particularly preferably 67.5 wt% or less, most preferably 65.0 wt% or less. When the content of the acrylic-vinyl chloride copolymer is above the lower limit, it is possible to impart greater flexibility to the vinyl chloride resin molded body and to impart greater construction stability to the vinyl chloride resin molded body. Furthermore, when the content of the acrylic-vinyl chloride copolymer is equal to or greater than the above lower limit, the impact resistance of the vinyl chloride resin molded article can be further improved, and when the content of the acrylic-vinyl chloride copolymer is equal to or less than the above upper limit, the moldability of the vinyl chloride resin composition can be further improved.

[0101] In 100% by weight of the acrylic-vinyl chloride copolymer, the content of the skeleton derived from the vinyl chloride monomer is preferably 70.0% by weight or more, more preferably 75.0% by weight or more, even more preferably 80.0% by weight or more, particularly preferably 85.0% by weight or more, and most preferably 90.0% by weight or more, and is preferably 99.0% by weight or less, more preferably 98.0% by weight or less, even more preferably 97.5% by weight or less, particularly preferably 97.0% by weight or less, and most preferably 96.5% by weight or less. When the content of the skeleton derived from the vinyl chloride monomer is at least the above lower limit, the moldability of the vinyl chloride resin composition can be further improved. When the content of the skeleton derived from the vinyl chloride monomer is at most the above upper limit, higher flexibility can be imparted to the vinyl chloride resin molded article, higher construction stability can be imparted to the vinyl chloride resin molded article, and the impact resistance of the vinyl chloride resin molded article can be further improved.

[0102] In 100% by weight of the acrylic-vinyl chloride copolymer, the content of the skeleton derived from the vinyl chloride mixed monomer is preferably 70.0% by weight or more, more preferably 75.0% by weight or more, even more preferably 80.0% by weight or more, particularly preferably 85.0% by weight or more, and most preferably 90.0% by weight or more, and is preferably 99.0% by weight or less, more preferably 98.0% by weight or less, even more preferably 97.5% by weight or less, particularly preferably 97.0% by weight or less, and most preferably 96.5% by weight or less. When the content of the skeleton derived from the vinyl chloride mixed monomer is above the above lower limit, the moldability of the vinyl chloride resin composition can be further improved. When the content of the skeleton derived from the vinyl chloride mixed monomer is below the above upper limit, higher flexibility can be imparted to the vinyl chloride resin molded article, higher construction stability can be imparted to the vinyl chloride resin molded article, and the impact resistance of the vinyl chloride resin molded article can be further improved.

[0103] The content of the component derived from the acrylic copolymer, based on 100% by weight of the acrylic-vinyl chloride copolymer, is preferably 1.0% by weight or more, more preferably 2.0% by weight or more, even more preferably 2.5% by weight or more, particularly preferably 3.0% by weight or more, and most preferably 3.5% by weight or more, and is preferably 30.0% by weight or less, more preferably 25.0% by weight or less, even more preferably 20.0% by weight or less, particularly preferably 15.0% by weight or less, and most preferably 10.0% by weight or less. When the content of the component derived from the acrylic copolymer is above the above-mentioned lower limit, the vinyl chloride resin molded article can be imparted with even greater flexibility and with even greater application stability. Furthermore, when the content of the component derived from the acrylic copolymer is above the above-mentioned lower limit, the impact resistance of the vinyl chloride resin molded article can be further improved. When the content of the component derived from the acrylic copolymer is below the above-mentioned upper limit, the moldability of the vinyl chloride resin composition can be further improved.

[0104] Examples of the acrylic-vinyl chloride copolymer include a graft copolymer comprising a backbone polymer of the acrylic copolymer and a polymer graft chain of a vinyl chloride monomer, and a graft copolymer comprising a backbone polymer of the acrylic copolymer and a polymer graft chain of a vinyl chloride mixed monomer. The vinyl chloride mixed monomer is a mixture of a vinyl chloride monomer and a monomer other than the vinyl chloride monomer. The acrylic-vinyl chloride copolymer exhibits a small change in flexibility between room temperature (23°C) and low temperatures (e.g., 0°C or below). Therefore, the use of the acrylic-vinyl chloride copolymer can impart high flexibility to a vinyl chloride resin molded article and high application stability to the vinyl chloride resin molded article. The use of the acrylic-vinyl chloride copolymer can enhance the impact resistance of the vinyl chloride resin molded article.

[0105] The acrylic-vinyl chloride copolymer is preferably in the form of particles and has a core-shell structure in which the acrylic copolymer (backbone polymer) constitutes the core and the graft chains constitute the shell, which can further enhance the impact resistance of the vinyl chloride resin molded article.

[0106] When the acrylic-vinyl chloride copolymer is in the form of particles, the core itself constituted by the acrylic copolymer (backbone polymer) preferably has a core-shell structure.

[0107] The acrylic copolymer constituting the acrylic-vinyl chloride copolymer is, for example, a copolymer of a (meth)acrylic monomer and a polyfunctional monomer.

[0108] The (meth)acrylic monomer preferably contains an alkyl(meth)acrylate monomer. Use of the alkyl(meth)acrylate monomer can further increase the flexibility of the vinyl chloride resin molded article.

[0109] The (meth)acrylic monomer preferably contains a first alkyl(meth)acrylic monomer having a homopolymer having a glass transition temperature of -140°C or higher and -20°C or lower. The glass transition temperature of a homopolymer obtained by polymerizing the first alkyl(meth)acrylic monomer alone is -140°C or higher and -20°C or lower. Use of the first alkyl(meth)acrylic monomer can further increase the flexibility of vinyl chloride resin molded articles. Only one type of the first alkyl(meth)acrylic monomer may be used, or two or more types may be used in combination.

[0110] The (meth)acrylic monomer may contain a second (meth)acrylic monomer other than the first alkyl(meth)acrylic monomer. The second (meth)acrylic monomer may be a (meth)acrylate monomer or an alkyl(meth)acrylate monomer. Only one type of the second (meth)acrylic monomer may be used, or two or more types may be used in combination.

[0111] Examples of the alkyl(meth)acrylic monomer include methyl(meth)acrylate, ethyl(meth)acrylate, n-propyl(meth)acrylate, isopropyl(meth)acrylate, n-butyl(meth)acrylate, isobutyl(meth)acrylate, sec-butyl(meth)acrylate, n-pentyl(meth)acrylate, n-hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, 2-methylheptyl(meth)acrylate, cumyl(meth)acrylate, n-octyl(meth)acrylate, isooctyl(meth)acrylate, isononyl(meth)acrylate, n-decyl(meth)acrylate, n-nonyl(meth)acrylate, and lauryl(meth)acrylate. One type of the (meth)acrylic monomer may be used alone, or two or more types may be used in combination.

[0112] The first alkyl(meth)acrylic monomer preferably has one (meth)acryloyl group and is preferably a monofunctional alkyl(meth)acrylic monomer.

[0113] The second (meth)acrylic monomer may be a (meth)acrylic monomer having no alkyl group, or may be a (meth)acrylate monomer having no alkyl group.

[0114] The second (meth)acrylic monomer preferably has one (meth)acryloyl group and is preferably a monofunctional (meth)acrylic monomer.

[0115] Examples of the polyfunctional monomer include di(meth)acrylate and tri(meth)acrylate. The polyfunctional monomer may be used alone or in combination of two or more kinds.

[0116] Examples of the di(meth)acrylate include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and trimethylolpropane di(meth)acrylate.

[0117] Examples of the tri(meth)acrylate include trimethylolpropane tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, and pentaerythritol tri(meth)acrylate.

[0118] Other examples of the polyfunctional monomer include acrylate compounds such as pentaerythritol tetra(meth)acrylate and dipentaerythritol hexa(meth)acrylate; diallyl compounds or triallyl compounds such as diallyl phthalate, diallyl maleate, diallyl fumarate, diallyl succinate, and triallyl isocyanurate; and divinyl compounds such as divinylbenzene and butadiene. Polyfunctional monomers other than these may also be used. The polyfunctional monomer preferably has two or more unsaturated double bonds. The polyfunctional monomer may be used alone or in combination of two or more.

[0119] In 100% by weight of the (meth)acrylic monomer, the content of the first alkyl(meth)acrylic monomer is preferably 50% by weight or more and preferably 100% by weight or less. The content of the second (meth)acrylic monomer is preferably 0% by weight or more (0% by weight (unused) or more than 0% by weight) and preferably 50% by weight or less. The (meth)acrylic monomer may contain only the first alkyl(meth)acrylic monomer, or may not contain the second (meth)acrylic monomer. The (meth)acrylic monomer may contain both the first alkyl(meth)acrylic monomer and the second (meth)acrylic monomer. For example, when two types of (meth)acrylic monomers are used, the content of the first alkyl(meth)acrylic monomer is preferably 50% by weight or more and less than 100% by weight, and the content of the second (meth)acrylic monomer is preferably more than 0% by weight and 50% by weight or less, based on 100% by weight of the (meth)acrylic monomers.

[0120] In 100% by weight of the (meth)acrylic monomers, the content of the first alkyl(meth)acrylic monomer is preferably 60% by weight or more and 100% by weight or less, and the content of the second (meth)acrylic monomer is preferably 0% by weight or more (0% by weight (unused) or more than 0% by weight) and 40% by weight or less. When the content of the first alkyl(meth)acrylic monomer is equal to or more than the above lower limit (more than the above lower limit) and equal to or less than the above upper limit, the flexibility of the vinyl chloride resin molded article at low temperatures can be further improved.

[0121] The acrylic copolymer is preferably a copolymer of 100 parts by weight of the (meth)acrylic monomer and 0.01 to 30 parts by weight of the polyfunctional monomer. From the viewpoint of further improving the production efficiency of the acrylic copolymer, the acrylic copolymer is preferably a copolymer of 100 parts by weight of the (meth)acrylic monomer and 0.1 to 10 parts by weight of the polyfunctional monomer.

[0122] When obtaining the acrylic-vinyl chloride copolymer, the vinyl chloride monomer alone may be used as a copolymerization component for the acrylic copolymer. Alternatively, the vinyl chloride mixed monomer (vinyl chloride monomer and a copolymerizable monomer other than vinyl chloride monomer) may be used. The copolymerizable monomer may be used alone or in combination of two or more.

[0123] Examples of the copolymerizable monomer include styrene compounds, diene compounds, (meth)acrylic acid amides, vinyl compounds, unsaturated dicarboxylic acid diesters, and glycidyl compounds.

[0124] Examples of the styrene compounds include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-tert-butoxystyrene, and chloromethylstyrene. Examples of the diene compounds include butadiene, 2,3-dimethylbutadiene, and isoprene. Examples of the (meth)acrylic acid amides include (meth)acrylic acid amide, N,N-dimethylamide, and N,N-propylamide. Examples of the vinyl compounds include (meth)acrylic acid anilide, (meth)acrylonitrile, acrolein, vinylidene chloride, N-vinylpyrrolidone, and vinyl acetate. Examples of the unsaturated dicarboxylic acid diesters include diethyl maleate, diethyl fumarate, and diethyl itaconate. Examples of the glycidyl compound include glycidyl (meth)acrylate, α-ethyl glycidyl (meth)acrylate, α-n-propyl glycidyl (meth)acrylate, α-n-butyl glycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 3,4-epoxyheptyl (meth)acrylate, α-ethyl-6,7-epoxyheptyl (meth)acrylate, allyl glycidyl ether, vinyl glycidyl ether, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, α-methyl-o-vinylbenzyl glycidyl ether, and the like. glycidyl ether, α-methyl-m-vinylbenzyl glycidyl ether, α-methyl-p-vinylbenzyl glycidyl ether, 2,3-diglycidyloxymethylstyrene, 2,4-diglycidyloxymethylstyrene, 2,5-diglycidyloxymethylstyrene, 2,6-diglycidyloxymethylstyrene, 2,3,4-triglycidyloxymethylstyrene, 2,3,5-triglycidyloxymethylstyrene, 2,3,6-triglycidyloxymethylstyrene, 3,4,5-triglycidyloxymethylstyrene, and 2,4,6-triglycidyloxymethylstyrene.

[0125] The acrylic-vinyl chloride copolymer is preferably in the form of particles and has a core-shell structure in which the acrylic copolymer (backbone polymer) constitutes the core and the graft chains constitute the shell, which can further enhance the impact resistance of the vinyl chloride resin molded article.

[0126] When the acrylic-vinyl chloride copolymer is in the form of particles, the core itself constituted by the acrylic copolymer (backbone polymer) preferably has a core-shell structure.

[0127] Examples of methods for producing the acrylic copolymer and the acrylic-vinyl chloride copolymer include bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization.

[0128] When obtaining the acrylic polymer and when obtaining the acrylic-vinyl chloride copolymer, it is preferable to use a polymerization initiator. The polymerization initiator is not particularly limited. The polymerization initiator is preferably an oil-soluble compound that is soluble in the monomer components and generates free radicals. The polymerization initiator may be used alone or in combination of two or more types.

[0129] The polymerization initiator is preferably a radical polymerization initiator. Examples of the polymerization initiator include organic peroxide compounds and azo compounds. Polymerization initiators other than these may also be used. Examples of the organic peroxide compound include lauroyl peroxide, t-butyl peroxypivalate, diisopropyl peroxydicarbonate, dioctyl peroxydicarbonate, t-butyl peroxyneodecanoate, and α-cumyl peroxyneodecanoate. Examples of the azo compound include 2,2-azobisisobutyronitrile and 2,2-azobis-2,4-dimethylvaleronitrile.

[0130] When obtaining the acrylic polymer and the acrylic-vinyl chloride copolymer, it is preferable to use a dispersant. The dispersant suspends and disperses droplets of the monomer components and stabilizes the dispersion. Only one type of dispersant may be used, or two or more types may be used in combination.

[0131] The dispersant is not particularly limited. Examples of the dispersant include poly(meth)acrylate, (meth)acrylate / alkyl acrylate copolymer, methyl cellulose, ethyl cellulose, hydroxypropyl methyl cellulose, polyethylene glycol, polyvinyl acetate and its partially saponified products, gelatin, polyvinylpyrrolidone, starch, and maleic anhydride / styrene copolymer. The dispersant may be used alone or in combination of two or more.

[0132] The amount (content) of the dispersant used relative to 100 parts by weight of the components used in polymerization (polymerizable components) is preferably 0.1 parts by weight or more, more preferably 1 part by weight or more, and even more preferably 3 parts by weight or more, and is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less.

[0133] <Impact modifiers other than acrylic-vinyl chloride copolymers (other impact modifiers)> Examples of the other impact modifiers include methyl methacrylate-butadiene-styrene copolymers (MBS), chlorinated polyethylene, acrylic rubber, etc. The other impact modifiers may be used alone or in combination of two or more.

[0134] The vinyl chloride resin composition or the vinyl chloride resin molded article may contain the chlorinated polyethylene. The chlorinated polyethylene is an impact modifier. The chlorinated polyethylene is known as the most common impact modifier. The chlorinated polyethylene is inexpensive. By using the acrylic-vinyl chloride copolymer and the chlorinated polyethylene in combination as the impact modifier, the cost of the vinyl chloride resin composition or the vinyl chloride resin molded article can be reduced. Only one type of the chlorinated polyethylene may be used, or two or more types may be used in combination.

[0135] On the other hand, the use of chlorinated polyethylene tends to increase the amount of calcium elution. This is thought to be due to the influence of the calcium component contained in the neutralizing agent used in the production of chlorinated polyethylene. Therefore, it is preferable that the content of chlorinated polyethylene in the vinyl chloride resin composition or the vinyl chloride resin molded product is low. It is more preferable that the vinyl chloride resin composition or the vinyl chloride resin molded product does not contain chlorinated polyethylene.

[0136] In the vinyl chloride resin composition or the vinyl chloride resin molded article, the content of the other impact modifier may exceed 0 parts by weight, may be 0.5 parts by weight or more, or may be 1.0 parts by weight or more, per 100 parts by weight of the vinyl chloride resin and the acrylic-vinyl chloride copolymer. The content of the other impact modifier is preferably 3.5 parts by weight or less, more preferably 3.0 parts by weight or less, and even more preferably 2.0 parts by weight or less, per 100 parts by weight of the vinyl chloride resin and the acrylic-vinyl chloride copolymer. When the content of the other impact modifier is below the upper limit, per 100 parts by weight of the vinyl chloride resin and the acrylic-vinyl chloride copolymer, the performance derived from the acrylic-vinyl chloride copolymer can be further enhanced. The range of the content of the other impact modifier per 100 parts by weight of the vinyl chloride resin and the acrylic-vinyl chloride copolymer can be set by appropriately selecting the lower limit and the upper limit.

[0137] The vinyl chloride resin composition or the vinyl chloride resin molded article preferably does not contain the chlorinated polyethylene, or contains the chlorinated polyethylene in an amount of 4.0 parts by weight or less per 100 parts by weight of the vinyl chloride resin and the acrylic-vinyl chloride copolymer. In the vinyl chloride resin composition or the vinyl chloride resin molded article, the amount of the chlorinated polyethylene may exceed 0 parts by weight, may be 0.5 parts by weight or more, or may be 1.0 part by weight or more per 100 parts by weight of the vinyl chloride resin and the acrylic-vinyl chloride copolymer. The amount of the chlorinated polyethylene per 100 parts by weight of the vinyl chloride resin is preferably 3.5 parts by weight or less, more preferably 3 parts by weight or less, even more preferably 2.0 parts by weight or less, particularly preferably 1.5 parts by weight or less, and most preferably 1.0 part by weight or less. When the amount of the chlorinated polyethylene is below the upper limit, the performance derived from the acrylic-vinyl chloride copolymer can be further enhanced. When the amount of the chlorinated polyethylene is below the upper limit, the amount of calcium elution can be further suppressed. The range of the content of the chlorinated polyethylene relative to 100 parts by weight of the total of the vinyl chloride resin and the acrylic-vinyl chloride copolymer can be set by appropriately selecting the lower limit and the upper limit.

[0138] <Heat Stabilizer> The heat stabilizer inhibits the decomposition of the vinyl chloride resin and also captures the hydrogen chloride generated during the decomposition of the vinyl chloride resin.

[0139] Examples of the heat stabilizer include an organotin-based heat stabilizer, a lead-based heat stabilizer, a barium-zinc-based heat stabilizer, a calcium-zinc-based heat stabilizer, and an organic acid metal salt-based heat stabilizer, etc. The heat stabilizers may be used alone or in combination of two or more.

[0140] Examples of the organotin-based heat stabilizer include tin mercapto-based stabilizers, tin malate-based stabilizers, and tin carboxylate-based stabilizers. Examples of the tin mercapto-based stabilizers include monoalkyltin mercapto, dialkyltin mercapto, monoalkyltin mercapto polymer, dialkyltin mercapto polymer, monoalkyltin mercapto sulfide, and dialkyltin mercapto sulfide. Examples of the tin malate-based stabilizers include monoalkyltin maleates, dialkyltin maleates, monoalkyltin maleate polymers, and dialkyltin maleate polymers. Examples of the tin carboxylate-based stabilizers include monoalkyltin carboxylates and dialkyltin carboxylates. The organotin-based heat stabilizers may be used alone or in combination of two or more.

[0141] Examples of the lead-based heat stabilizer include lead stearate, tribasic lead sulfate, tetrabasic lead sulfate, basic lead sulfite, dibasic lead phosphite, dibasic lead phthalate, tribasic lead maleate, dibasic lead stearate, and basic lead sulfite phosphite.

[0142] Examples of the organic acid metal salt-based heat stabilizer include barium stearate and zinc stearate.

[0143] From the viewpoint of improving the thermal stability of the vinyl chloride resin composition during heat molding and preventing initial coloration of the vinyl chloride resin molded article, the heat stabilizer is preferably an organotin-based heat stabilizer, and more preferably a tin mercapto-based stabilizer.

[0144] From the viewpoint of further reducing the toxicity of the vinyl chloride resin composition, it is preferable that the vinyl chloride resin composition does not contain the lead-based heat stabilizer. When the vinyl chloride resin molded article contains a lead-based heat stabilizer, it is preferable that the vinyl chloride resin composition does not contain a tin-based heat stabilizer from the viewpoint of suppressing the occurrence of defective appearance of the vinyl chloride resin molded article. From the viewpoint of further reducing the toxicity of the vinyl chloride resin composition and further reducing the environmental load, it is preferable that the vinyl chloride resin composition contains a barium-zinc-based heat stabilizer, a calcium-zinc-based heat stabilizer, or an organic acid metal salt-based heat stabilizer.

[0145] In the vinyl chloride resin composition or the vinyl chloride resin molded product, the content of the heat stabilizer is preferably 0.1 part by weight or more, more preferably 0.2 part by weight or more, even more preferably 0.3 part by weight or more, and preferably 5 parts by weight or less, more preferably 1.5 parts by weight or less, even more preferably 1.0 part by weight or less, and particularly preferably 0.9 parts by weight or less, per 100 parts by weight of the total of the vinyl chloride resin and the acrylic-vinyl chloride copolymer. When the content of the heat stabilizer is above the lower limit, the heat resistance and thermal stability of the vinyl chloride resin molded product can be further improved, and discoloration of the vinyl chloride resin molded product can be more effectively suppressed. When the content of the heat stabilizer is below the upper limit, an excessive decrease in the softening temperature of the vinyl chloride resin molded product can be suppressed, unintended deformation of the vinyl chloride resin molded product can be suppressed, and the flame retardancy of the vinyl chloride resin molded product can be improved. Furthermore, when the content of the heat stabilizer is below the upper limit, the impact resistance of the vinyl chloride resin molded product can be further improved. Furthermore, when the content of the heat stabilizer is equal to or less than the upper limit, the smoothness of the surface of the vinyl chloride resin molded article can be further improved.

[0146] In the vinyl chloride resin composition or the vinyl chloride resin molded article, the content of the organotin heat stabilizer is preferably 0.1 part by weight or more, more preferably 0.2 part by weight or more, even more preferably 0.3 part by weight or more, and preferably 1.5 parts by weight or less, more preferably 1.0 part by weight or less, and even more preferably 0.9 parts by weight or less, per 100 parts by weight of the total of the vinyl chloride resin and the acrylic-vinyl chloride copolymer. When the content of the organotin heat stabilizer is above the lower limit, the heat resistance and thermal stability of the vinyl chloride resin molded article can be further improved, and discoloration of the vinyl chloride resin molded article can be more effectively suppressed. When the content of the organotin heat stabilizer is below the upper limit, an excessive decrease in the softening temperature of the vinyl chloride resin composition can be suppressed. Furthermore, when the content of the organotin heat stabilizer is below the upper limit, the impact resistance of the vinyl chloride resin molded article can be further improved. Furthermore, when the content of the organotin heat stabilizer is below the upper limit, the surface smoothness of the vinyl chloride resin molded article can be further improved.

[0147] <Other Components> The vinyl chloride resin composition or the vinyl chloride resin molded article may contain additives as necessary. Examples of the additives include heat stabilization aids, antioxidants, lubricants, processing aids, heat resistance improvers, UV absorbers, antistatic agents, light stabilizers, fillers, colorants, and plasticizers. The additives may be used alone or in combination of two or more.

[0148] Examples of the heat stabilization aid include epoxidized soybean oil, phosphate ester, polyol, hydrotalcite, zeolite, etc. The heat stabilization aid may be used alone or in combination of two or more.

[0149] Examples of the antioxidant include phenol-based antioxidants, amine-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, etc. The antioxidants may be used alone or in combination of two or more.

[0150] Examples of the lubricant include internal lubricants and external lubricants. The internal lubricant is used to reduce the flow viscosity of the molten resin during molding and prevent frictional heat generation. Examples of the internal lubricant include butyl stearate, lauryl alcohol, stearyl alcohol, epoxy soybean oil, glycerin monostearate, stearic acid, and bisamide. The external lubricant is used to improve the sliding effect between the molten resin and the metal surface during molding. Examples of the external lubricant include paraffin wax, polyolefin wax, ester wax, and montanic acid wax. Only one type of the lubricant may be used, or two or more types may be used in combination.

[0151] Examples of the processing aid include acrylic processing aids. Examples of the acrylic processing aid include alkyl acrylate-alkyl methacrylate copolymers having a weight-average molecular weight of 100,000 to 2,000,000. Specific examples include n-butyl acrylate-methyl methacrylate copolymers and 2-ethylhexyl acrylate-methyl methacrylate-butyl methacrylate copolymers. Only one type of the processing aids may be used, or two or more types may be used in combination.

[0152] Examples of the heat resistance improver include α-methylstyrene-based and N-phenylmaleimide-based resins, etc. The heat resistance improver may be used alone or in combination of two or more.

[0153] Examples of the ultraviolet absorber include salicylic acid ester-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and cyanoacrylate-based ultraviolet absorbers. The ultraviolet absorbers may be used alone or in combination of two or more.

[0154] Examples of the light stabilizer include hindered amine light stabilizers, etc. The light stabilizers may be used alone or in combination of two or more.

[0155] Examples of the filler include calcium carbonate, talc, etc. The filler may be used alone or in combination of two or more.

[0156] Examples of the colorant include pigments and dyes. The colorant preferably contains a pigment. Examples of the pigment include organic pigments and inorganic pigments. Examples of the organic pigment include azo-based organic pigments, phthalocyanine-based organic pigments, threne-based organic pigments, and dye lake-based organic pigments. Examples of the inorganic pigment include oxide-based inorganic pigments, molybdenum chromate-based inorganic pigments, sulfide / selenide-based inorganic pigments, and ferrocyanide-based inorganic pigments.

[0157] The plasticizer is added to improve processability during molding. Examples of the plasticizer include dibutyl phthalate, di-2-ethylhexyl phthalate, and di-2-ethylhexyl adipate. The plasticizer may be used alone or in combination of two or more.

[0158] (Other details of the vinyl chloride resin composition and the vinyl chloride resin molded article, and their uses) The vinyl chloride resin molded article is formed using the vinyl chloride resin composition. The vinyl chloride resin composition can be used to obtain the vinyl chloride resin molded article. The vinyl chloride resin molded article is obtained by molding the vinyl chloride resin composition. The vinyl chloride resin molded article is a molded article of the vinyl chloride resin composition.

[0159] The vinyl chloride resin molded article is not particularly limited, and examples thereof include pipes, plates, and containers. The vinyl chloride resin molded article is preferably tubular. The vinyl chloride resin molded article may be plate-shaped. Plate-shaped articles include sheet-shaped and film-shaped articles.

[0160] The method for molding the vinyl chloride resin composition is not particularly limited, and examples of the method for molding the vinyl chloride resin composition include extrusion molding, injection molding, calendar molding, and press molding.

[0161] Examples of molding machines used for molding include single-screw extruders, twin-screw counter-rotating parallel extruders, twin-screw counter-rotating conical extruders, and twin-screw co-rotating extruders. The heating temperature when molding using the above molding machines is preferably 140°C or higher and preferably 190°C or lower.

[0162] The vinyl chloride resin composition or the vinyl chloride resin molded article can be suitably used to obtain a vinyl chloride resin pipe.

[0163] The vinyl chloride resin pipe is a single-layer pipe having a single layer structure or a multi-layer pipe having a laminated structure of two or more layers. In the vinyl chloride resin pipe, it is preferable that one layer of the single-layer pipe or the innermost layer of the multi-layer pipe is the vinyl chloride resin molded article described above (using the vinyl chloride resin molded article as one layer of the single-layer pipe or the innermost layer of the multi-layer pipe). The vinyl chloride resin molded article described above can also be used as the outermost layer or inner layer of the multi-layer pipe. In this case, too, concerns about the adverse effects of calcium elution from the vinyl chloride resin molded article are reduced. Since the adverse effects of calcium elution from the vinyl chloride resin molded article can be suppressed and the impact resistance of the vinyl chloride resin molded article can be increased, the vinyl chloride resin pipe is preferably a pipe for ultrapure water (using the vinyl chloride resin molded article as the innermost layer of a pipe for ultrapure water).

[0164] FIG. 1 is a cross-sectional view schematically showing a vinyl chloride resin pipe provided with a vinyl chloride resin molded article according to a first embodiment of the present invention.

[0165] The vinyl chloride resin pipe 11 includes a first layer 1. The first layer 1 is tubular. The vinyl chloride resin pipe 11 is a single-layer pipe including only the first layer 1. The first layer 1 is the vinyl chloride resin molded article described above.

[0166] The vinyl chloride resin pipe is preferably a single-layer pipe having a one-layer structure, and one layer of the single-layer pipe is preferably the vinyl chloride resin molded article. When the vinyl chloride resin pipe is a single-layer pipe, the single-layer pipe is the vinyl chloride resin molded article described above.

[0167] FIG. 2 is a cross-sectional view schematically showing a vinyl chloride resin pipe provided with a vinyl chloride resin molded article according to a second embodiment of the present invention.

[0168] The vinyl chloride resin pipe 11A includes a first layer 1A, a second layer 2A, and a third layer 3A. The second layer 2A is laminated on the outer surface of the first layer 1A. The third layer 3A is laminated on the outer surface of the second layer 2A. The first layer 1A, the second layer 2A, and the third layer 3A are each tubular. The first layer 1A is the innermost layer, the second layer 2A is an intermediate layer, and the third layer 3A is the outermost layer. The first layer 1A, the second layer 2A, and the third layer 3A each extend to both axial ends of the vinyl chloride resin pipe 11A. The vinyl chloride resin pipe 11A is a multi-layer pipe having a three-layer structure. The innermost layer of the first layer 1A, the second layer 2A, and the third layer 3A is the vinyl chloride resin molded article described above.

[0169] The vinyl chloride resin pipe is preferably a multi-layer pipe having a laminated structure of two or more layers, and the innermost layer of the multi-layer pipe is preferably the vinyl chloride resin molded article. When the vinyl chloride resin pipe is a multi-layer pipe, the multi-layer pipe has the layer of the vinyl chloride resin molded article described above as the innermost layer.

[0170] The multi-layer pipe preferably includes an inner layer and an outer layer disposed on the outer surface of the inner layer. In the multi-layer pipe, the outer layer is preferably laminated on the outer surface of the inner layer.

[0171] The multilayer pipe may have a two-layer laminate structure, a three-layer laminate structure, a three-layer or more laminate structure, a ten-layer or less laminate structure, or a five-layer or less laminate structure.

[0172] The multi-layer pipe may include an intermediate layer. The multi-layer pipe may have an intermediate layer between the inner layer and the outer layer. The multi-layer pipe preferably includes the inner layer, an intermediate layer disposed on the outer surface of the inner layer, and an outer layer disposed on the outer surface of the intermediate layer. The inner layer is a layer located inside the intermediate layer. The outer layer is a layer located outside the intermediate layer. The multi-layer pipe preferably includes the inner layer, intermediate layer, and outer layer in this order from the center toward the outside in the radial direction.

[0173] The inner layer may be a single layer or may be multiple layers. The inner layer may be a single layer, may be two layers, may be two or more layers, or may be three or more layers. The intermediate layer may be a single layer or may be multiple layers. The intermediate layer may be a single layer, may be two layers, may be two or more layers, or may be three or more layers. The outer layer may be a single layer or may be multiple layers. The outer layer may be a single layer, may be two layers, may be two or more layers, or may be three or more layers.

[0174] From the viewpoint of further increasing the mechanical strength and impact resistance of the vinyl chloride resin pipe, the vinyl chloride resin pipe is preferably a hard vinyl chloride resin pipe.

[0175] The thickness of the vinyl chloride resin molded article is preferably 0.3 mm or more, more preferably 0.5 mm or more, and even more preferably 1.0 mm or more, and is preferably 15 mm or less, more preferably 10 mm or less, and even more preferably 7.0 mm or less. When the thickness of the vinyl chloride resin molded article is not less than the above lower limit and not more than the above upper limit, the processability of the vinyl chloride resin molded article becomes even better.

[0176] The configuration of the layers other than the layer that is the vinyl chloride resin molded product is not particularly limited, and the material of the layers other than the layer that is the vinyl chloride resin molded product may or may not contain a vinyl chloride resin.

[0177] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0178] The following materials were prepared:

[0179] (Vinyl chloride resin) Vinyl chloride resin ("TS-1000R" manufactured by Tokuyama Sekisui Kogyo Co., Ltd., chlorine content 56.8% by weight, average degree of polymerization 1000)

[0180] (Acrylic-vinyl chloride copolymer) Acrylic-vinyl chloride copolymer ("AG-72P" manufactured by Tokuyama Sekisui Kogyo Co., Ltd., a copolymer (graft copolymer) of 7.0% by weight of acrylic polymer and 93.0% by weight of vinyl chloride monomer, average degree of polymerization 900)

[0181] (Heat stabilizer) Heat stabilizer (organotin-based heat stabilizer, methyltin mercapto, "KK6511" manufactured by Nitto Kasei Kogyo Co., Ltd.)

[0182] (Lubricant) Lubricant ("wax-OP" manufactured by Clariant Chemicals)

[0183] Examples 1 to 4 and Comparative Examples 1 to 4 Each component was mixed in the amounts shown in Tables 1 and 2 below, and a polyvinyl chloride resin sheet (composition) having a thickness of 1.0 mm was obtained under the following conditions.

[0184] [Conditions] Roll: Mixing roll manufactured by Yasuda Seiki Seisakusho Roll temperature: 190°C Roll time: 3 minutes (after wrapping)

[0185] (Evaluation) (1) Impact Resistance A plurality of the obtained sheets were stacked and pressed under the following conditions to obtain a pressed sample. For the pressed sample, a notched test piece was prepared in accordance with JIS K7111 "Charpy impact test method for rigid plastics," and the Charpy impact value was measured using the test piece. From the Charpy impact value, the impact resistance was evaluated according to the following criteria.

[0186] [Conditions] Press: Kodaira Manufacturing Co., Ltd. heat press molding machine (press surface material: SUS304) Press temperature: 190°C Press time: preheating 3 minutes + pressure 2 minutes Press pressure: 200 kgf / cm ２ Press sample thickness: 3.0 mm

[0187] [Impact resistance evaluation criteria] ○○: Charpy impact value is 15 J / m ２or more, or no fracture ○: Charpy impact value is 12 J / m ２ 15J / m or more ２ Less than △: Charpy impact value is less than 8 J / m ２ More than 12J / m ２ Less than ×: Charpy impact value is 8 J / m ２ less than

[0188] (2) Metal Leaching A plurality of the obtained sheets were stacked and pressed under the following conditions to obtain a pressed sample.

[0189] [Conditions] Press: Kodaira Manufacturing Co., Ltd. heat press molding machine (press surface material: SUS304) Press temperature: 190°C Press time: preheating 3 minutes + pressure 2 minutes Press pressure: 200 kgf / cm ２ Size and thickness of press sample: length 12.0 mm x width 11.0 mm x thickness 1.0 mm

[0190] Three of the above pressed samples and a 500 ml polytetrafluoroethylene container were prepared, and each was washed with pure water. The washed pressed samples and 500 ml of pure water were added to the 500 ml polytetrafluoroethylene container, and then the container was sealed with parafilm. After standing at 23°C for 7 days, the water was removed from the container, and calcium was quantified by ICP emission spectrometry. The surface area of ​​the vinyl chloride resin molded product (press sample) was 1 m ２ The metal elution was evaluated based on the amount of calcium eluted per unit area according to the following criteria.

[0191] [Criteria for determining metal elution] 〇〇: Calcium elution amount is 12 μg or less. 〇: Calcium elution amount is more than 12 μg and 20 μg or less. △: Calcium elution amount is more than 20 μg and 30 μg or less. ×: Calcium elution amount is more than 30 μg.

[0192] The compositions of the vinyl chloride resin compositions and the results are shown in Tables 1 and 2.

[0193]

[0194]

[0195] 1, 1A... First layer 2A... Second layer 3A... Third layer 11, 11A... PVC resin pipe

Claims

1. A composition comprising a vinyl chloride resin, an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, and a heat stabilizer, wherein the content of components derived from the acrylic copolymer is 1.5% by weight or more and 5.5% by weight or less in 100% by weight of the vinyl chloride resin composition, and when a vinyl chloride resin molding obtained by molding the vinyl chloride resin composition is left in ultrapure water at 23°C for 7 days, calcium does not elute or the amount of calcium eluted is 1.5% by weight or less per 1 m2 of surface area of ​​the vinyl chloride resin molding. ２ The vinyl chloride resin composition has a particle size of 30 μg or less per unit area.

2. A vinyl chloride resin composition comprising: a vinyl chloride resin; an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer; and a heat stabilizer, wherein the content of components derived from the acrylic copolymer is 1.5% by weight or more and 5.5% by weight or less in 100% by weight of the vinyl chloride resin composition, and the vinyl chloride resin composition is used to obtain piping for ultrapure water.

3. The vinyl chloride resin composition according to claim 1 or 2, wherein the content of components derived from the acrylic copolymer is 2.5% by weight or more and 20.0% by weight or less, based on 100% by weight of the acrylic-vinyl chloride copolymer.

4. The vinyl chloride resin composition according to any one of claims 1 to 3, wherein, based on a total of 100% by weight of the vinyl chloride resin and the acrylic-vinyl chloride copolymer, the content of the vinyl chloride resin is 20.0% by weight or more and 85.0% by weight or less, and the content of the acrylic-vinyl chloride copolymer is 80.0% by weight or more and 15.0% by weight or less.

5. The vinyl chloride resin composition according to any one of claims 1 to 4, which does not contain chlorinated polyethylene or contains chlorinated polyethylene in an amount of 1.0 part by weight or less per 100 parts by weight of the total of the vinyl chloride resin and the acrylic-vinyl chloride copolymer.

6. The vinyl chloride resin composition according to any one of claims 1 to 5, wherein the heat stabilizer comprises an organotin-based heat stabilizer.

7. The vinyl chloride resin composition according to any one of claims 1 to 6, wherein the content of the heat stabilizer is 0.1 parts by weight or more and 5.0 parts by weight or less per 100 parts by weight of the total of the vinyl chloride resin and the acrylic-vinyl chloride copolymer.

8. A vinyl chloride resin molding containing an acrylic-vinyl chloride copolymer, which is a copolymer of an acrylic copolymer and a vinyl chloride monomer, and a heat stabilizer, wherein the content of components derived from the acrylic copolymer in 100% by weight of the vinyl chloride resin molding is 1.5% by weight or more and 5.5% by weight or less, and when the vinyl chloride resin molding is left in ultrapure water at 23°C for 7 days, calcium does not elute or the amount of calcium elute is 1.5% by weight or less per 1 m2 of surface area of ​​the vinyl chloride resin molding. ２ A vinyl chloride resin molded article having a particle size of 30 μg or less per unit area.

9. A vinyl chloride resin molded body used to obtain piping for ultrapure water, comprising: a vinyl chloride resin; an acrylic-vinyl chloride copolymer which is a copolymer of an acrylic copolymer and a vinyl chloride monomer; and a heat stabilizer, wherein the content of components derived from the acrylic copolymer is 1.5% by weight or more and 5.5% by weight or less in 100% by weight of the vinyl chloride resin molded body.

10. When a vinyl chloride resin molded body is left in ultrapure water at 23°C for 7 days, does calcium not elute or does the amount of calcium elute per 1 m2 of surface area of ​​the vinyl chloride resin molded body ２ The vinyl chloride resin molded article according to claim 9, wherein the weight of the polyvinyl chloride resin is 30 μg or less per unit area.

11. The vinyl chloride resin molded article according to any one of claims 8 to 10, wherein the content of components derived from the acrylic copolymer is 2.5% by weight or more and 20.0% by weight or less, based on 100% by weight of the acrylic-vinyl chloride copolymer.

12. The vinyl chloride resin molded article according to any one of claims 8 to 11, wherein, based on a total of 100% by weight of the vinyl chloride resin and the acrylic-vinyl chloride copolymer, the content of the vinyl chloride resin is 20.0% by weight or more and 85.0% by weight or less, and the content of the acrylic-vinyl chloride copolymer is 80.0% by weight or more and 15.0% by weight or less.

13. The vinyl chloride resin molded article according to any one of claims 8 to 12, which does not contain chlorinated polyethylene or contains chlorinated polyethylene in an amount of 1.0 part by weight or less per 100 parts by weight of the total of the vinyl chloride resin and the acrylic-vinyl chloride copolymer.

14. The vinyl chloride resin molded article according to any one of claims 8 to 13, wherein the heat stabilizer comprises an organotin-based heat stabilizer.

15. The vinyl chloride resin molded article according to any one of claims 8 to 14, wherein the content of the heat stabilizer is 0.1 parts by weight or more and 5.0 parts by weight or less per 100 parts by weight of the total of the vinyl chloride resin and the acrylic-vinyl chloride copolymer.

16. A pipe for ultrapure water, which is a single-layer pipe having a single layer structure or a multi-layer pipe having a laminated structure of two or more layers, wherein one layer of the single-layer pipe or the innermost layer of the multi-layer pipe is a vinyl chloride resin molded article according to any one of claims 8 to 15.

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