CHLORINATED VINYL CHLORIDE RESIN COMPOSITION AND CHLORINATED VINYL CHLORIDE RESIN MOLDED BODY

Abstract

The present invention provides a chlorinated polyvinyl chloride resin composition capable of providing a molded article that is excellent in discoloration resistance and corrosion resistance and is not likely to cause environmental pollution as the amount of metal leached therefrom is small, and a chlorinated polyvinyl chloride resin molded article. The present invention relates to a chlorinated polyvinyl chloride resin composition containing: a chlorinated polyvinyl chloride resin; a thermal stabilizer; and at least one thioglycolic acid compound selected from the group consisting of thioglycolic acid and thioglycolic acid esters.

Claims

1. A chlorinated polyvinyl chloride resin composition comprising: a chlorinated polyvinyl chloride resin; a thermal stabilizer; and at least one thioglycolic acid compound selected from the group consisting of thioglycolic acid and thioglycolic acid esters.

2. The chlorinated polyvinyl chloride resin composition according to claim 1, wherein the thioglycolic acid compound is contained in an amount of 0.001% by mass or more.

3. The chlorinated polyvinyl chloride resin composition according to claim 1, wherein a mass ratio of an amount of the thioglycolic acid compound and an amount of the thermal stabilizer (amount of thioglycolic acid compound/amount of thermal stabilizer) is 0.001 to 10.0.

4. The chlorinated polyvinyl chloride resin composition according to claim 1, wherein the thioglycolic acid compound includes at least one selected from compounds represented by HSCH.sub.2COOR wherein R is H or an alkyl group.

5. The chlorinated polyvinyl chloride resin composition according to claim 1, wherein the thermal stabilizer contains tin.

6. A chlorinated polyvinyl chloride resin molded article comprising: a chlorinated polyvinyl chloride resin; a thermal stabilizer; and at least one thioglycolic acid compound selected from the group consisting of thioglycolic acid and thioglycolic acid esters.

7. The chlorinated polyvinyl chloride resin composition according to claim 2, wherein a mass ratio of an amount of the thioglycolic acid compound and an amount of the thermal stabilizer (amount of thioglycolic acid compound/amount of thermal stabilizer) is 0.001 to 10.0.

8. The chlorinated polyvinyl chloride resin composition according to claim 2, wherein the thioglycolic acid compound includes at least one selected from compounds represented by HSCH.sub.2COOR wherein R is H or an alkyl group.

9. The chlorinated polyvinyl chloride resin composition according to claim 3, wherein the thioglycolic acid compound includes at least one selected from compounds represented by HSCH.sub.2COOR wherein R is H or an alkyl group.

10. The chlorinated polyvinyl chloride resin composition according to claim 7, wherein the thioglycolic acid compound includes at least one selected from compounds represented by HSCH.sub.2COOR wherein R is H or an alkyl group.

11. The chlorinated polyvinyl chloride resin composition according to claim 2, wherein the thermal stabilizer contains tin.

12. The chlorinated polyvinyl chloride resin composition according to claim 3, wherein the thermal stabilizer contains tin.

13. The chlorinated polyvinyl chloride resin composition according to claim 4, wherein the thermal stabilizer contains tin.

14. The chlorinated polyvinyl chloride resin composition according to claim 7, wherein the thermal stabilizer contains tin.

15. The chlorinated polyvinyl chloride resin composition according to claim 8, wherein the thermal stabilizer contains tin.

16. The chlorinated polyvinyl chloride resin composition according to claim 9, wherein the thermal stabilizer contains tin.

17. The chlorinated polyvinyl chloride resin composition according to claim 10, wherein the thermal stabilizer contains tin.

Description

DESCRIPTION OF EMBODIMENTS

[0146] The present invention is more specifically described in the following with reference to, but not limited to, examples.

Example 1

(Preparation of Chlorinated Polyvinyl Chloride Resin Composition)

[0147] To 100 parts by mass of a chlorinated polyvinyl chloride resin [degree of chlorination: 67.2% by mass, amount of added chlorine: 10.4% by mass, degree of polymerization: 1,000] was added 0.6 parts by mass of a butyltin mercaptan compound (TVS #1380, available from Nitto Kasei Co., Ltd., dibutyltin mercaptide) as a thermal stabilizer. Further, 0.5 parts by mass of 2-ethylhexyl thioglycolate (available from Fujifilm Wako Pure Chemical Corporation) and 0.5 parts by mass of a partially saponified ester of montanic acid (LICOWAX OP, available from Clariant Japan) as a lubricant were added, followed by uniform mixing using a super mixer. Thus, a chlorinated polyvinyl chloride resin composition was obtained.

[0148] The amount (mol %) of the structural unit (b) and the mass equivalent (parts by mass) of the structural unit (b) of the obtained chlorinated polyvinyl chloride resin were determined by FT-NMR using JEOLJNM-AL-300. The NMR analysis can be performed by the method specified in R. A. Komoroski, R. G. Parker, J. P. Shocker, Macromolecules, 1985, 18, 1257-1265.

(Production of Chlorinated Polyvinyl Chloride Resin Molded Article)

[0149] The obtained chlorinated polyvinyl chloride resin composition was supplied to a conical counter-rotating twin screw extruder (SLM-50, available from Osada Seisakusho) with a diameter of 50 mm, and a sheet-shaped chlorinated polyvinyl chloride resin molded article was produced at a resin temperature of 210° C. and extrusion amount of 30 kg/hr using a die having a thickness of 2 mm and a width of 80 mm.

Example 2

[0150] A chlorinated polyvinyl chloride resin composition and a chlorinated polyvinyl chloride resin molded article were produced as in Example 1, except that the amount of 2-ethylhexyl thioglycolate (available from Fujifilm Wako Pure Chemical Corporation) added was changed to 5 parts by mass.

Examples 3 to 8

[0151] A chlorinated polyvinyl chloride resin composition and a chlorinated polyvinyl chloride resin molded article were produced as in Example 1, except that the chlorinated polyvinyl chloride resin used had a degree of polymerization, amount of added chlorine, and a structural unit (b) content as shown in Table 1.

Examples 9 and 10

[0152] A chlorinated polyvinyl chloride resin composition and a chlorinated polyvinyl chloride resin molded article were produced as in Example 1, except that the amount of the butyltin mercaptan compound (TVS #1380, available from Nitto Kasei Co., Ltd.) added was changed as shown in Table 1.

Examples 11 and 12

[0153] A chlorinated polyvinyl chloride resin composition and a chlorinated polyvinyl chloride resin molded article were produced as in Example 1, except that the butyltin mercaptan compound (TVS #1380, available from Nitto Kasei Co., Ltd.) was replaced by a thermal stabilizer of the type and in an amount as shown in Table 2.

[0154] The “Dibutyltin maleate compound” used was “STANN RC-709, available from Nitto Kasei Co., Ltd.” and the “Calcium alkylcarboxylate and zinc compound” used was “NT-231, available from Sakai Chemical Industry Co., Ltd”.

Examples 13 and 14

[0155] A chlorinated polyvinyl chloride resin composition and a chlorinated polyvinyl chloride resin molded article were produced as in Example 1, except that the amount of 2-ethylhexyl thioglycolate (available from Fujifilm Wako Pure Chemical Corporation) was changed as shown in Table 2.

Examples 15 and 16

[0156] A chlorinated polyvinyl chloride resin composition and a chlorinated polyvinyl chloride resin molded article were produced as in Example 1, except that 2-ethylhexyl thioglycolate (available from Fujifilm Wako Pure Chemical Corporation) was replaced by a thioglycolic acid compound of the type and in an amount as shown in Table 2.

[0157] The “Thioglycolic acid” used was “a product of Fujifilm Wako Pure Chemical Corporation” and the “Methoxybutyl thioglycolate” used was “a product of Tokyo Chemical Industry Co., Ltd.”

Examples 17 and 18

[0158] A chlorinated polyvinyl chloride resin composition and a chlorinated polyvinyl chloride resin molded article were produced as in Example 1, except that the amount of the partially saponified ester of montanic acid (LICOWAX OP, available from Clariant Japan, dropping point: 96° C. to 102° C., acid value: 9 to 14 mgKOH/g) added was changed as shown in Table 2.

Example 19

[0159] A chlorinated polyvinyl chloride resin composition and a chlorinated polyvinyl chloride resin molded article were produced as in Example 1, except that the amounts of the butyltin mercaptan compound (TVS #1380, available from Nitto Kasei Co., Ltd.) and 2-ethylhexyl thioglycolate (available from Fujifilm Wako Pure Chemical Corporation) were changed as shown in Table 2.

Comparative Example 1

[0160] A chlorinated polyvinyl chloride resin composition and a chlorinated polyvinyl chloride resin molded article were produced as in Example 1, except that 2-ethylhexyl thioglycolate (available from Fujifilm Wako Pure Chemical Corporation) was not added.

Comparative Example 2

[0161] A chlorinated polyvinyl chloride resin composition and a chlorinated polyvinyl chloride resin molded article were produced as in Comparative Example 1, except that the amount of the butyltin mercaptan compound (TVS #1380, available from Nitto Kasei Co., Ltd.) added was changed as shown in Table 2.

<Evaluation>

[0162] The following evaluations were performed on the chlorinated polyvinyl chloride resin molded articles obtained in the examples and comparative examples. Tables 1 and 2 show the results.

<Evaluation on Discoloration Resistance>

[0163] Each of the obtained chlorinated polyvinyl chloride resin molded articles was put in an oven at 205° C. and allowed to stand still for 90 minutes. The molded article was taken out and checked for discoloration. The checking was repeated every 10 minutes and the time at which discoloration was observed was recorded.

<Evaluation on Amount of Tin Leached>

[0164] Each of the obtained chlorinated polyvinyl chloride resin molded articles was immersed in test water (pH 5, 82° C.). Thirty days later, a sample solution was collected and the amount of tin leached was determined using an ICP mass analyzer (Varian 710-ES, available from Varian Inc.). The term “ND” in the tables means a value not more than the detection limit.

<Evaluation on Dehydrochlorination Amount>

[0165] An about 0.5-g portion of a measurement sample weighed from each of the obtained chlorinated polyvinyl chloride resin compositions was put into a glass test tube with a plug equipped with two glass tubes. Nitrogen gas was introduced (50 ml/min) into the test tube through one glass tube, and the test tube was heated in an oil bath (oil temperature: 195° C.) equipped with a stirrer. Hydrochloric acid generated in the test tube was brown into distilled water (100 ml) in a beaker through the other glass tube. Twenty minutes later, the pH value of the solution in the beaker was determined to calculate the dehydrochlorination amount based on the pH value.

<Evaluation on Corrosion Resistance>

[0166] An about 0.5-g portion of a sample was cut out from each of the obtained chlorinated polyvinyl chloride resin molded articles after 20 minutes of its production, and put in a dedicated glass test tube. A metal piece (1 cm in length×1 cm in width×0.3 cm in thickness) made of carbon steel S45C was enclosed with the sample in the test tube. Air was introduced into the test tube and the test tube was heated in an oil bath (oil temperature: 195° C.). The corrosion state (rust or the like) of the metal piece was checked.

[0167] The case where no corrosion was observed was rated ∘ (Good), the case where slight corrosion was observed was rated Δ (Fair), and the case where obvious corrosion was observed was rated x (Poor)

TABLE-US-00001 TABLE 1 Example 1 2 3 4 5 6 Composition Chlorinated polyvinyl Degree of polymerization 1000 1000 800 600 1000 1000 chloride resin Amount of added chlorine (mass %) 10.4 10.4 10.4 10.4 6.8 14.6 Structural unit (b) content (mol %) 20.8 20.4 20.4 20.1 15.1 24.8 Mass equivalent of structural 17.41 17.08 15.58 18.55 12.64 20.76 unit (b) (parts by mass) Amount (parts by mass) 100.0 100.0 100.0 100.0 100.0 100.0 Thermal stabilizer Butyltin mercaptan compound 0.6 0.6 0.6 0.6 0.6 0.6 (parts by mass) Butyltin maleate compound 0.0 0.0 0.0 0.0 0.0 0.0 Calcium alkylcarboxylate 0.0 0.0 0.0 0.0 0.0 0.0 and zinc compound Thioglycolic 2-Ethylhexyl thioglycolate 0.5 5.0 0.5 0.5 0.5 0.5 acid compound Thioglycolic acid 0.0 0.0 0.0 0.0 0.0 0.0 (parts by mass) Methoxybutyl thioglycolate 0.0 0.0 0.0 0.0 0.0 0.0 Lubricant Partially saponified 0.5 0.5 1.5 0.5 0.5 0.5 (parts by mass) ester of montanic acid Total (parts by mass) 101.6 106.1 102.6 101.6 101.6 101.6 Thioglycolic acid compound content relative to the entire 0.49 4.71 0.49 0.49 0.49 0.49 composition (mass %) Mass ratio (thioglycolic acid compound/thermal stabilizer) 0.83 8.33 0.83 0.83 0.83 0.83 Amount of thioglycolic acid compound relative to mass 0.029 0.293 0.032 0.027 0.040 0.024 equivalent of structural unit (b) Evaluation Corrosion resistance ∘ ∘ ∘ ∘ ∘ ∘ Discoloration resistance (min) 40 80 40 40 50 30 Amount of tin leached (ppb) 1.4 1.4 1.8 1.9 1.7 2.6 Dehydrochlorination amount (g) 0.32 0.06 0.3 0.31 0.25 0.38 Example 7 8 9 10 Composition Chlorinated polyvinyl Degree of polymerization 1000 1000 1000 1000 chloride resin Amount of added chlorine (mass %) 10.4 10.4 10.4 10.4 Structural unit (b) content (mol %) 22.1 18.4 20.8 20.8 Mass equivalent of structural 18.50 15.40 17.41 17.41 unit (b) (parts by mass) Amount (parts by mass) 100.0 100.0 100.0 100.0 Thermal stabilizer Butyltin mercaptan compound 0.6 0.6 1.2 3.6 (parts by mass) Butyltin maleate compound 0.0 0.0 0.0 0.0 Calcium alkylcarboxylate 0.0 0.0 0.0 0.0 and zinc compound Thioglycolic 2-Ethylhexyl thioglycolate 0.5 0.5 0.5 0.5 acid compound Thioglycolic acid 0.0 0.0 0.0 0.0 (parts by mass) Methoxybutyl thioglycolate 0.0 0.0 0.0 0.0 Lubricant Partially saponified 0.5 0.5 0.5 0.5 (parts by mass) ester of montanic acid Total (parts by mass) 101.6 101.6 102.2 104.6 Thioglycolic acid compound content relative to the entire 0.49 0.49 0.49 0.48 composition (mass %) Mass ratio (thioglycolic acid compound/thermal stabilizer) 0.83 0.83 0.42 0.14 Amount of thioglycolic acid compound relative to mass 0.027 0.032 0.029 0.029 equivalent of structural unit (b) Evaluation Corrosion resistance ∘ ∘ ∘ ∘ Discoloration resistance (min) 50 30 80 120 Amount of tin leached (ppb) 1.5 2.9 8.3 15.6 Dehydrochlorination amount (g) 0.18 0.43 0.28 0.24

TABLE-US-00002 TABLE 2 Example 11 12 13 14 15 16 Composition Chlorinated polyvinyl Degree of polymerization 1000 1000 1000 1000 1000 1000 chloride resin Amount of added chlorine (mass %) 104 10.4 104 104 10.4 10.4 Structural unit (b) content (mol %) 20.8 20.8 20.8 20.8 20.8 20.8 Mass equivalent of structural 17.41 17.41 17.41 17.41 17.41 17.41 unit (b) (parts by mass) Amount (parts by mass) 100.0 100.0 100.0 100.0 100.0 100.0 Thermal stabilizer Butyltin mercaptan compound 0.0 0.0 0.6 0.6 0.6 0.6 (parts by mass) Butyltin maleate compound 0.6 0.0 0.0 0.0 0.0 0.0 Calcium alkylcarboxylate 0.0 0.6 0.0 0.0 0.0 0.0 and zinc compound Thioglycolic 2-Ethylhexyl thioglycolate 0.5 0.5 0.015 1.6 0.0 0.0 acid compound Thioglycolic acid 0.0 0.0 0.0 0.0 0.5 0.0 (parts by mass) Methoxybutyl thioglycolate 0.0 0.0 0.0 0.0 0.0 0.5 Lubricant Partially saponified 0.5 0.5 0.5 0.5 0.5 0.5 (parts by mass) ester of montanic acid Total (parts by mass) 101.0 101.0 101.1 102.7 101.1 101.1 Thioglycolic acid compound content relative to the entire 0.50 0.50 0.015 1.56 0.49 0.49 composition (mass %) Mass ratio (thioglycolic acid compound/thermal stabilizer) 0.83 0.83 0.03 2.67 0.83 0.83 Amount of thioglycolic acid compound relative to mass 0.029 0.029 0.001 0.092 0.029 0.029 equivalent of structural unit (b) Evaluation Corrosion resistance ∘ ∘ ∘ ∘ ∘ ∘ Discoloration resistance (min) 30 30 30 60 30 30 Amount of tin leached (ppb) 1.4 ND 3.2 1.4 2.4 4.4 Dehydrochlorination amount (g) 0.45 0.31 0.48 0.18 0.57 0.44 Comparative Example Example 17 18 19 1 2 Composition Chlorinated polyvinyl Degree of polymerization 1000 1000 1000 1000 1000 chloride resin Amount of added chlorine (mass %) 10.4 10.4 10.4 10.4 10.4 Structural unit (b) content (mol %) 20.8 20.8 20.8 20.8 20.8 Mass equivalent of structural 17.41 17.41 17.41 17.41 17.41 unit (b) (parts by mass) Amount (parts by mass) 100.0 100.0 100.0 100.0 100.0 Thermal stabilizer Butyltin mercaptan compound 0.6 0.6 0.2 0.6 4.5 (parts by mass) Butyltin maleate compound 0.0 0.0 0.0 0.0 0.0 Calcium alkylcarboxylate 0.0 0.0 0.0 0.0 0.0 and zinc compound Thioglycolic 2-Ethylhexyl thioglycolate 0.5 0.5 2.4 0.0 0.0 acid compound Thioglycolic acid 0.0 0.0 0.0 0.0 0.0 (parts by mass) Methoxybutyl thioglycolate 0.0 0.0 0.0 0.0 0.0 Lubricant Partially saponified 2.5 4.8 0.5 0.5 0.5 (parts by mass) ester of montanic acid Total (parts by mass) 103.6 105.9 103.1 101.1 105.0 Thioglycolic acid compound content relative to the entire 0.48 0.47 2.33 0.0 0.0 composition (mass %) Mass ratio (thioglycolic acid compound/thermal stabilizer) 0.83 0.83 12.00 0.0 0.0 Amount of thioglycolic acid compound relative to mass 0.029 0.029 0.138 0.0 0.0 equivalent of structural unit (b) Evaluation Corrosion resistance ∘ ∘ ∘ x ∘ Discoloration resistance (min) 40 40 30 20 40 Amount of tin leached (ppb) 1.4 1.4 1.4 1.4 120 Dehydrochlorination amount (g) 0.32 0.32 0.82 0.67 0.44

INDUSTRIAL APPLICABILITY

[0168] The present invention can provide a chlorinated polyvinyl chloride resin composition capable of providing a molded article that is excellent in discoloration resistance and corrosion resistance and is not likely to cause environmental pollution as the amount of metal leached therefrom is small, and a chlorinated polyvinyl chloride resin molded article.