JPH0366393B2 - - Google Patents
Info
- Publication number
- JPH0366393B2 JPH0366393B2 JP21521587A JP21521587A JPH0366393B2 JP H0366393 B2 JPH0366393 B2 JP H0366393B2 JP 21521587 A JP21521587 A JP 21521587A JP 21521587 A JP21521587 A JP 21521587A JP H0366393 B2 JPH0366393 B2 JP H0366393B2
- Authority
- JP
- Japan
- Prior art keywords
- aqueous solution
- chromate treatment
- treatment agent
- chromium
- organic resin
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 claims description 116
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 103
- 239000003795 chemical substances by application Substances 0.000 claims description 95
- 229910000831 Steel Inorganic materials 0.000 claims description 83
- 239000010959 steel Substances 0.000 claims description 83
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 78
- 229920005989 resin Polymers 0.000 claims description 68
- 239000011347 resin Substances 0.000 claims description 68
- 238000000576 coating method Methods 0.000 claims description 48
- 239000011651 chromium Substances 0.000 claims description 47
- 239000011248 coating agent Substances 0.000 claims description 47
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 46
- 239000007864 aqueous solution Substances 0.000 claims description 46
- 229910052804 chromium Inorganic materials 0.000 claims description 46
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 38
- 239000000843 powder Substances 0.000 claims description 38
- 239000000377 silicon dioxide Substances 0.000 claims description 38
- 229920002689 polyvinyl acetate Polymers 0.000 claims description 33
- 239000011118 polyvinyl acetate Substances 0.000 claims description 33
- 239000010419 fine particle Substances 0.000 claims description 29
- 238000004519 manufacturing process Methods 0.000 claims description 28
- 239000004593 Epoxy Substances 0.000 claims description 26
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 claims description 21
- 229920000647 polyepoxide Polymers 0.000 claims description 19
- 229920001353 Dextrin Polymers 0.000 claims description 18
- 239000004375 Dextrin Substances 0.000 claims description 18
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 claims description 18
- 235000019425 dextrin Nutrition 0.000 claims description 18
- 239000003822 epoxy resin Substances 0.000 claims description 18
- -1 polyethylene Polymers 0.000 claims description 16
- 239000000203 mixture Substances 0.000 claims description 12
- 238000010438 heat treatment Methods 0.000 claims description 11
- 238000000034 method Methods 0.000 claims description 11
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 9
- 229920001577 copolymer Polymers 0.000 claims description 7
- 229920002472 Starch Polymers 0.000 claims description 6
- 239000002904 solvent Substances 0.000 claims description 6
- 229920001721 polyimide Polymers 0.000 claims description 5
- 229920002050 silicone resin Polymers 0.000 claims description 5
- 108090000790 Enzymes Proteins 0.000 claims description 4
- 102000004190 Enzymes Human genes 0.000 claims description 4
- 239000004734 Polyphenylene sulfide Substances 0.000 claims description 4
- 238000010030 laminating Methods 0.000 claims description 4
- 229920000069 polyphenylene sulfide Polymers 0.000 claims description 4
- 239000008107 starch Substances 0.000 claims description 4
- 235000019698 starch Nutrition 0.000 claims description 4
- 230000003301 hydrolyzing effect Effects 0.000 claims description 3
- 229920006393 polyether sulfone Polymers 0.000 claims description 3
- 229920005749 polyurethane resin Polymers 0.000 claims description 3
- 239000004698 Polyethylene Substances 0.000 claims description 2
- 239000004642 Polyimide Substances 0.000 claims description 2
- 239000004743 Polypropylene Substances 0.000 claims description 2
- 229920000573 polyethylene Polymers 0.000 claims description 2
- 229920001155 polypropylene Polymers 0.000 claims description 2
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 claims description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 30
- 239000003638 chemical reducing agent Substances 0.000 description 22
- 239000010410 layer Substances 0.000 description 22
- 239000003973 paint Substances 0.000 description 22
- 229910001430 chromium ion Inorganic materials 0.000 description 21
- 230000000694 effects Effects 0.000 description 15
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 13
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 description 13
- 229910002012 Aerosil® Inorganic materials 0.000 description 12
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 11
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N titanium dioxide Inorganic materials O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 9
- 239000012153 distilled water Substances 0.000 description 8
- 229920000642 polymer Polymers 0.000 description 8
- 238000007127 saponification reaction Methods 0.000 description 8
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 8
- 229910002016 Aerosil® 200 Inorganic materials 0.000 description 7
- 238000001723 curing Methods 0.000 description 7
- 238000002360 preparation method Methods 0.000 description 7
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- IISBACLAFKSPIT-UHFFFAOYSA-N bisphenol A Chemical compound C=1C=C(O)C=CC=1C(C)(C)C1=CC=C(O)C=C1 IISBACLAFKSPIT-UHFFFAOYSA-N 0.000 description 6
- 238000005260 corrosion Methods 0.000 description 6
- 229920002451 polyvinyl alcohol Polymers 0.000 description 6
- 239000004372 Polyvinyl alcohol Substances 0.000 description 5
- KDYFGRWQOYBRFD-UHFFFAOYSA-N Succinic acid Natural products OC(=O)CCC(O)=O KDYFGRWQOYBRFD-UHFFFAOYSA-N 0.000 description 5
- 239000002253 acid Substances 0.000 description 5
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 5
- 230000007423 decrease Effects 0.000 description 4
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 4
- 239000000049 pigment Substances 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 150000005846 sugar alcohols Polymers 0.000 description 4
- 229920002261 Corn starch Polymers 0.000 description 3
- FDLQZKYLHJJBHD-UHFFFAOYSA-N [3-(aminomethyl)phenyl]methanamine Chemical compound NCC1=CC=CC(CN)=C1 FDLQZKYLHJJBHD-UHFFFAOYSA-N 0.000 description 3
- 239000003513 alkali Substances 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 238000005422 blasting Methods 0.000 description 3
- 150000001845 chromium compounds Chemical class 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000008120 corn starch Substances 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 230000018044 dehydration Effects 0.000 description 3
- 238000006297 dehydration reaction Methods 0.000 description 3
- RPUZVWKKWXPKIP-UHFFFAOYSA-H dialuminum;hydrogen phosphate Chemical compound [Al+3].[Al+3].OP([O-])([O-])=O.OP([O-])([O-])=O.OP([O-])([O-])=O RPUZVWKKWXPKIP-UHFFFAOYSA-H 0.000 description 3
- XPPKVPWEQAFLFU-UHFFFAOYSA-N diphosphoric acid Chemical compound OP(O)(=O)OP(O)(O)=O XPPKVPWEQAFLFU-UHFFFAOYSA-N 0.000 description 3
- 239000000945 filler Substances 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 3
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical compound O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-UHFFFAOYSA-N 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 230000035515 penetration Effects 0.000 description 3
- 229920000768 polyamine Polymers 0.000 description 3
- 239000009719 polyimide resin Substances 0.000 description 3
- 229940005657 pyrophosphoric acid Drugs 0.000 description 3
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 description 2
- 229910002018 Aerosil® 300 Inorganic materials 0.000 description 2
- 229930185605 Bisphenol Natural products 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- IMROMDMJAWUWLK-UHFFFAOYSA-N Ethenol Chemical compound OC=C IMROMDMJAWUWLK-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 239000004695 Polyether sulfone Substances 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 150000001408 amides Chemical class 0.000 description 2
- 150000001413 amino acids Chemical class 0.000 description 2
- 125000003118 aryl group Chemical group 0.000 description 2
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 2
- PXKLMJQFEQBVLD-UHFFFAOYSA-N bisphenol F Chemical compound C1=CC(O)=CC=C1CC1=CC=C(O)C=C1 PXKLMJQFEQBVLD-UHFFFAOYSA-N 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 239000011247 coating layer Substances 0.000 description 2
- 239000008119 colloidal silica Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000006482 condensation reaction Methods 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- QGBSISYHAICWAH-UHFFFAOYSA-N dicyandiamide Chemical compound NC(N)=NC#N QGBSISYHAICWAH-UHFFFAOYSA-N 0.000 description 2
- FPAFDBFIGPHWGO-UHFFFAOYSA-N dioxosilane;oxomagnesium;hydrate Chemical compound O.[Mg]=O.[Mg]=O.[Mg]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O FPAFDBFIGPHWGO-UHFFFAOYSA-N 0.000 description 2
- 238000010828 elution Methods 0.000 description 2
- 229920006334 epoxy coating Polymers 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 239000000295 fuel oil Substances 0.000 description 2
- NYMPGSQKHIOWIO-UHFFFAOYSA-N hydroxy(diphenyl)silicon Chemical compound C=1C=CC=CC=1[Si](O)C1=CC=CC=C1 NYMPGSQKHIOWIO-UHFFFAOYSA-N 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 150000003951 lactams Chemical class 0.000 description 2
- 229920000092 linear low density polyethylene Polymers 0.000 description 2
- 239000004707 linear low-density polyethylene Substances 0.000 description 2
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 description 2
- 239000000391 magnesium silicate Substances 0.000 description 2
- 229910052919 magnesium silicate Inorganic materials 0.000 description 2
- 235000019792 magnesium silicate Nutrition 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 150000002739 metals Chemical group 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000011342 resin composition Substances 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000002893 slag Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000001384 succinic acid Substances 0.000 description 2
- 229920001169 thermoplastic Polymers 0.000 description 2
- 229920001187 thermosetting polymer Polymers 0.000 description 2
- 239000004416 thermosoftening plastic Substances 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 229940100445 wheat starch Drugs 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- FWLHAQYOFMQTHQ-UHFFFAOYSA-N 2-N-[8-[[8-(4-aminoanilino)-10-phenylphenazin-10-ium-2-yl]amino]-10-phenylphenazin-10-ium-2-yl]-8-N,10-diphenylphenazin-10-ium-2,8-diamine hydroxy-oxido-dioxochromium Chemical compound O[Cr]([O-])(=O)=O.O[Cr]([O-])(=O)=O.O[Cr]([O-])(=O)=O.Nc1ccc(Nc2ccc3nc4ccc(Nc5ccc6nc7ccc(Nc8ccc9nc%10ccc(Nc%11ccccc%11)cc%10[n+](-c%10ccccc%10)c9c8)cc7[n+](-c7ccccc7)c6c5)cc4[n+](-c4ccccc4)c3c2)cc1 FWLHAQYOFMQTHQ-UHFFFAOYSA-N 0.000 description 1
- ZEHOVWPIGREOPO-UHFFFAOYSA-N 4,5,6,7-tetrachloro-2-[2-(4,5,6,7-tetrachloro-1,3-dioxoinden-2-yl)quinolin-8-yl]isoindole-1,3-dione Chemical compound O=C1C(C(=C(Cl)C(Cl)=C2Cl)Cl)=C2C(=O)N1C(C1=N2)=CC=CC1=CC=C2C1C(=O)C2=C(Cl)C(Cl)=C(Cl)C(Cl)=C2C1=O ZEHOVWPIGREOPO-UHFFFAOYSA-N 0.000 description 1
- WZSFTHVIIGGDOI-UHFFFAOYSA-N 4,5,6,7-tetrachloro-3-[2-methyl-3-[(4,5,6,7-tetrachloro-3-oxoisoindol-1-yl)amino]anilino]isoindol-1-one Chemical compound ClC1=C(Cl)C(Cl)=C(Cl)C2=C1C(NC1=CC=CC(NC=3C4=C(C(=C(Cl)C(Cl)=C4Cl)Cl)C(=O)N=3)=C1C)=NC2=O WZSFTHVIIGGDOI-UHFFFAOYSA-N 0.000 description 1
- 229910002020 Aerosil® OX 50 Inorganic materials 0.000 description 1
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 229920000945 Amylopectin Polymers 0.000 description 1
- 229910052582 BN Inorganic materials 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- FBPFZTCFMRRESA-FSIIMWSLSA-N D-Glucitol Natural products OC[C@H](O)[C@H](O)[C@@H](O)[C@H](O)CO FBPFZTCFMRRESA-FSIIMWSLSA-N 0.000 description 1
- FBPFZTCFMRRESA-JGWLITMVSA-N D-glucitol Chemical compound OC[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO FBPFZTCFMRRESA-JGWLITMVSA-N 0.000 description 1
- 229910000640 Fe alloy Inorganic materials 0.000 description 1
- 108010073178 Glucan 1,4-alpha-Glucosidase Proteins 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229920000271 Kevlar® Polymers 0.000 description 1
- 229910000861 Mg alloy Inorganic materials 0.000 description 1
- 229910001182 Mo alloy Inorganic materials 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- 229910001252 Pd alloy Inorganic materials 0.000 description 1
- 208000009344 Penetrating Wounds Diseases 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 229920000265 Polyparaphenylene Polymers 0.000 description 1
- 239000004721 Polyphenylene oxide Substances 0.000 description 1
- NRCMAYZCPIVABH-UHFFFAOYSA-N Quinacridone Chemical compound N1C2=CC=CC=C2C(=O)C2=C1C=C1C(=O)C3=CC=CC=C3NC1=C2 NRCMAYZCPIVABH-UHFFFAOYSA-N 0.000 description 1
- 229920002978 Vinylon Polymers 0.000 description 1
- 229910001080 W alloy Inorganic materials 0.000 description 1
- 206010052428 Wound Diseases 0.000 description 1
- 208000027418 Wounds and injury Diseases 0.000 description 1
- 229910001093 Zr alloy Inorganic materials 0.000 description 1
- PXIDXCRAEOLZSK-UHFFFAOYSA-N [Co].[Ni].[Cr].[Zn] Chemical compound [Co].[Ni].[Cr].[Zn] PXIDXCRAEOLZSK-UHFFFAOYSA-N 0.000 description 1
- XJNCHICLWKVTQA-UHFFFAOYSA-N [Mo].[W].[Cr].[Ni] Chemical compound [Mo].[W].[Cr].[Ni] XJNCHICLWKVTQA-UHFFFAOYSA-N 0.000 description 1
- CPTCUNLUKFTXKF-UHFFFAOYSA-N [Ti].[Zr].[Mo] Chemical compound [Ti].[Zr].[Mo] CPTCUNLUKFTXKF-UHFFFAOYSA-N 0.000 description 1
- UQZIWOQVLUASCR-UHFFFAOYSA-N alumane;titanium Chemical compound [AlH3].[Ti] UQZIWOQVLUASCR-UHFFFAOYSA-N 0.000 description 1
- ILRRQNADMUWWFW-UHFFFAOYSA-K aluminium phosphate Chemical compound O1[Al]2OP1(=O)O2 ILRRQNADMUWWFW-UHFFFAOYSA-K 0.000 description 1
- SNAAJJQQZSMGQD-UHFFFAOYSA-N aluminum magnesium Chemical compound [Mg].[Al] SNAAJJQQZSMGQD-UHFFFAOYSA-N 0.000 description 1
- APUPEJJSWDHEBO-UHFFFAOYSA-P ammonium molybdate Chemical compound [NH4+].[NH4+].[O-][Mo]([O-])(=O)=O APUPEJJSWDHEBO-UHFFFAOYSA-P 0.000 description 1
- 239000011609 ammonium molybdate Substances 0.000 description 1
- 235000018660 ammonium molybdate Nutrition 0.000 description 1
- 229940010552 ammonium molybdate Drugs 0.000 description 1
- 239000004760 aramid Substances 0.000 description 1
- 229920003235 aromatic polyamide Polymers 0.000 description 1
- UNTBPXHCXVWYOI-UHFFFAOYSA-O azanium;oxido(dioxo)vanadium Chemical compound [NH4+].[O-][V](=O)=O UNTBPXHCXVWYOI-UHFFFAOYSA-O 0.000 description 1
- IRERQBUNZFJFGC-UHFFFAOYSA-L azure blue Chemical compound [Na+].[Na+].[Na+].[Na+].[Na+].[Na+].[Na+].[Na+].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[S-]S[S-].[O-][Si]([O-])([O-])[O-].[O-][Si]([O-])([O-])[O-].[O-][Si]([O-])([O-])[O-].[O-][Si]([O-])([O-])[O-].[O-][Si]([O-])([O-])[O-].[O-][Si]([O-])([O-])[O-] IRERQBUNZFJFGC-UHFFFAOYSA-L 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- KDYFGRWQOYBRFD-NUQCWPJISA-N butanedioic acid Chemical compound O[14C](=O)CC[14C](O)=O KDYFGRWQOYBRFD-NUQCWPJISA-N 0.000 description 1
- CJOBVZJTOIVNNF-UHFFFAOYSA-N cadmium sulfide Chemical compound [Cd]=S CJOBVZJTOIVNNF-UHFFFAOYSA-N 0.000 description 1
- 239000001506 calcium phosphate Substances 0.000 description 1
- 229910000389 calcium phosphate Inorganic materials 0.000 description 1
- 235000011010 calcium phosphates Nutrition 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 150000001720 carbohydrates Chemical class 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 238000004210 cathodic protection Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- BIJOYKCOMBZXAE-UHFFFAOYSA-N chromium iron nickel Chemical compound [Cr].[Fe].[Ni] BIJOYKCOMBZXAE-UHFFFAOYSA-N 0.000 description 1
- 229910021446 cobalt carbonate Inorganic materials 0.000 description 1
- ZOTKGJBKKKVBJZ-UHFFFAOYSA-L cobalt(2+);carbonate Chemical compound [Co+2].[O-]C([O-])=O ZOTKGJBKKKVBJZ-UHFFFAOYSA-L 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 239000000306 component Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- XCJYREBRNVKWGJ-UHFFFAOYSA-N copper(II) phthalocyanine Chemical compound [Cu+2].C12=CC=CC=C2C(N=C2[N-]C(C3=CC=CC=C32)=N2)=NC1=NC([C]1C=CC=CC1=1)=NC=1N=C1[C]3C=CC=CC3=C2[N-]1 XCJYREBRNVKWGJ-UHFFFAOYSA-N 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- CRHLEZORXKQUEI-UHFFFAOYSA-N dialuminum;cobalt(2+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Al+3].[Al+3].[Co+2].[Co+2] CRHLEZORXKQUEI-UHFFFAOYSA-N 0.000 description 1
- 239000004205 dimethyl polysiloxane Substances 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000032050 esterification Effects 0.000 description 1
- 238000005886 esterification reaction Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 150000004676 glycans Chemical class 0.000 description 1
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 description 1
- 238000013007 heat curing Methods 0.000 description 1
- 229920001903 high density polyethylene Polymers 0.000 description 1
- 239000004700 high-density polyethylene Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- LPXDNEQTGPFOPF-UHFFFAOYSA-N hydron;1h-imidazol-1-ium;phosphate Chemical compound C1=CNC=N1.OP(O)(O)=O LPXDNEQTGPFOPF-UHFFFAOYSA-N 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000012784 inorganic fiber Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000012948 isocyanate Substances 0.000 description 1
- 150000002513 isocyanates Chemical class 0.000 description 1
- 239000004761 kevlar Substances 0.000 description 1
- JQJCSZOEVBFDKO-UHFFFAOYSA-N lead zinc Chemical compound [Zn].[Pb] JQJCSZOEVBFDKO-UHFFFAOYSA-N 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229920001684 low density polyethylene Polymers 0.000 description 1
- 239000004702 low-density polyethylene Substances 0.000 description 1
- 239000011656 manganese carbonate Substances 0.000 description 1
- 235000006748 manganese carbonate Nutrition 0.000 description 1
- 229940093474 manganese carbonate Drugs 0.000 description 1
- 229910000016 manganese(II) carbonate Inorganic materials 0.000 description 1
- XMWCXZJXESXBBY-UHFFFAOYSA-L manganese(ii) carbonate Chemical compound [Mn+2].[O-]C([O-])=O XMWCXZJXESXBBY-UHFFFAOYSA-L 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229920000609 methyl cellulose Polymers 0.000 description 1
- 239000001923 methylcellulose Substances 0.000 description 1
- DDTIGTPWGISMKL-UHFFFAOYSA-N molybdenum nickel Chemical compound [Ni].[Mo] DDTIGTPWGISMKL-UHFFFAOYSA-N 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- QELJHCBNGDEXLD-UHFFFAOYSA-N nickel zinc Chemical compound [Ni].[Zn] QELJHCBNGDEXLD-UHFFFAOYSA-N 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- ZZSIDSMUTXFKNS-UHFFFAOYSA-N perylene red Chemical compound CC(C)C1=CC=CC(C(C)C)=C1N(C(=O)C=1C2=C3C4=C(OC=5C=CC=CC=5)C=1)C(=O)C2=CC(OC=1C=CC=CC=1)=C3C(C(OC=1C=CC=CC=1)=CC1=C2C(C(N(C=3C(=CC=CC=3C(C)C)C(C)C)C1=O)=O)=C1)=C2C4=C1OC1=CC=CC=C1 ZZSIDSMUTXFKNS-UHFFFAOYSA-N 0.000 description 1
- 125000002467 phosphate group Chemical group [H]OP(=O)(O[H])O[*] 0.000 description 1
- 229940085991 phosphate ion Drugs 0.000 description 1
- 150000003014 phosphoric acid esters Chemical class 0.000 description 1
- DHRLEVQXOMLTIM-UHFFFAOYSA-N phosphoric acid;trioxomolybdenum Chemical compound O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.O=[Mo](=O)=O.OP(O)(O)=O DHRLEVQXOMLTIM-UHFFFAOYSA-N 0.000 description 1
- IYDGMDWEHDFVQI-UHFFFAOYSA-N phosphoric acid;trioxotungsten Chemical compound O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.OP(O)(O)=O IYDGMDWEHDFVQI-UHFFFAOYSA-N 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- IEQIEDJGQAUEQZ-UHFFFAOYSA-N phthalocyanine Chemical compound N1C(N=C2C3=CC=CC=C3C(N=C3C4=CC=CC=C4C(=N4)N3)=N2)=C(C=CC=C2)C2=C1N=C1C2=CC=CC=C2C4=N1 IEQIEDJGQAUEQZ-UHFFFAOYSA-N 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 229920000435 poly(dimethylsiloxane) Polymers 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920000767 polyaniline Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920000570 polyether Polymers 0.000 description 1
- 229920005862 polyol Polymers 0.000 description 1
- 150000003077 polyols Chemical class 0.000 description 1
- 229920001282 polysaccharide Polymers 0.000 description 1
- 239000005017 polysaccharide Substances 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 239000012744 reinforcing agent Substances 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000005488 sandblasting Methods 0.000 description 1
- CGFYHILWFSGVJS-UHFFFAOYSA-N silicic acid;trioxotungsten Chemical compound O[Si](O)(O)O.O=[W]1(=O)O[W](=O)(=O)O[W](=O)(=O)O1.O=[W]1(=O)O[W](=O)(=O)O[W](=O)(=O)O1.O=[W]1(=O)O[W](=O)(=O)O[W](=O)(=O)O1.O=[W]1(=O)O[W](=O)(=O)O[W](=O)(=O)O1 CGFYHILWFSGVJS-UHFFFAOYSA-N 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000004334 sorbic acid Substances 0.000 description 1
- 239000000600 sorbitol Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- NVKTUNLPFJHLCG-UHFFFAOYSA-N strontium chromate Chemical compound [Sr+2].[O-][Cr]([O-])(=O)=O NVKTUNLPFJHLCG-UHFFFAOYSA-N 0.000 description 1
- BDHFUVZGWQCTTF-UHFFFAOYSA-M sulfonate Chemical compound [O-]S(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-M 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 239000012756 surface treatment agent Substances 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 235000012222 talc Nutrition 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
- ISIJQEHRDSCQIU-UHFFFAOYSA-N tert-butyl 2,7-diazaspiro[4.5]decane-7-carboxylate Chemical compound C1N(C(=O)OC(C)(C)C)CCCC11CNCC1 ISIJQEHRDSCQIU-UHFFFAOYSA-N 0.000 description 1
- QORWJWZARLRLPR-UHFFFAOYSA-H tricalcium bis(phosphate) Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O QORWJWZARLRLPR-UHFFFAOYSA-H 0.000 description 1
- UNXRWKVEANCORM-UHFFFAOYSA-N triphosphoric acid Chemical compound OP(O)(=O)OP(O)(=O)OP(O)(O)=O UNXRWKVEANCORM-UHFFFAOYSA-N 0.000 description 1
- 235000013799 ultramarine blue Nutrition 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
- XLOMVQKBTHCTTD-UHFFFAOYSA-N zinc oxide Inorganic materials [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 1
- LRXTYHSAJDENHV-UHFFFAOYSA-H zinc phosphate Chemical compound [Zn+2].[Zn+2].[Zn+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O LRXTYHSAJDENHV-UHFFFAOYSA-H 0.000 description 1
- 229910000165 zinc phosphate Inorganic materials 0.000 description 1
- NDKWCCLKSWNDBG-UHFFFAOYSA-N zinc;dioxido(dioxo)chromium Chemical compound [Zn+2].[O-][Cr]([O-])(=O)=O NDKWCCLKSWNDBG-UHFFFAOYSA-N 0.000 description 1
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/24—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing hexavalent chromium compounds
- C23C22/33—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing hexavalent chromium compounds containing also phosphates
Landscapes
- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Laminated Bodies (AREA)
- Chemical Treatment Of Metals (AREA)
Description
（産業上の利用分野）
本発明は、有機樹脂系被覆鋼管の製造方法に関
し、更に詳しくは耐高温陰極剥離性が優れた有機
樹脂系被覆鋼管の製造方法に関する。
（従来の技術）
粉体エポキシ樹脂被覆鋼管をはじめとする有機
樹脂系被覆鋼管は、其の防食性能が優れているこ
とから、石油、天然ガス等の輸送パイプラインに
使用されることが多くなつて来た。通常、このよ
うなパイプラインは一度敷設されると長期間使用
されるため、電気防食が併用される。粉体エポキ
シ樹脂等の有機樹脂系被覆が施された鋼管は其の
運搬または敷設のハンドリング等に岩石や砂礫等
にあたつて、被覆に貫通傷が生ずるので、基の部
位の防食のため陰極防食が施される。ところが、
特に過防食の場合、防食電流によつて土壤水分が
電気分解を起こして、生成する水素とアルカリに
よつて被覆が剥離する陰極剥離と呼ばれる現象が
起こり、パイプラインの防食性が低下する欠点が
ある。
また、近年、重質油の輸送効率向上のため重質
油を加熱して低粘度化して輸送する処理等により
管内流送物が高温になり60℃を越える使用環境下
の耐陰極剥離性（以後、“耐高温陰極剥離性”と
称す）の向上が重要な課題になりつつある。
従来からは、有機樹脂系被覆鋼管の耐陰極剥離
性を向上させるために、予じめ鋼管の表面にクロ
メート処理を施す方法が提案されている。
例えば、特開昭52−14392号公報には、第３図
に示す如く、鋼管１の表面に６価クロムの化合物
とアミノ酸、酸アミド、ラクタム、飽和ポリカル
ボン酸あるいは不飽和ポリカルボン酸等の有機成
分を混合したクロメート処理剤層４を塗布して焼
付けたのち熱可塑性あるいは熱硬化性樹脂組成物
の粉体塗装塗膜５を積層した被覆鋼管の提案があ
る。
また、第４図に示す如く、上記のクロメート処
理剤層４の代わりに、クロム酸（CrO3）を糖類、
多価アルコール、一価アルコール、アルキロール
アミン、芳香族多価アルコール等の有機質の還元
剤でCr6+／全クロム＝0.35〜0.65の比率に部分還
元し、該還元物に微粒シリカを添加したクロメー
ト処理剤層６を積層した被覆鋼管、更には第５図
に示す如く、前記のクロメート処理剤層６のクロ
メート処理剤に微粒シリカとポリビニルアルコー
ル、メチルセルロース、ポリエチレンオキシド、
ヘキサメトキシメチルメラミン変性ポリヒドロキ
シエチルアクリレート等の非イオン系水溶性樹脂
を添加したクロメート処理剤層７を積層した被覆
鋼管がある。
（発明が解決しようとする問題点）
第３図、第４図及び第５図に示す被覆鋼管で
は、常温での耐陰極剥離性は比較的良好である
が、60℃を越える温度での耐高温陰極剥離性が極
めて悪い。本発明者らは、第３図、第４図及び第
５図に示す被覆鋼管について、クロメート処理剤
層の構造分析、60℃を越える熱水へのクロムイオ
ンの溶出量の測定を行つて検討した結果から推察
すると、概ね下記の理由により耐高温陰極剥離性
が悪いと考えられる。
先ず、第３図のクロメート処理剤層は可溶性６
価クロムを多量に含むため、60℃越で陰極剥離試
験を行うと被覆貫通傷部から侵入する熱水によつ
てクロメート被覆から６価クロムイオンが容易に
溶出して被覆が剥離する。第４図のクロメート処
理剤層では層内のクロム化合物と微粒子シリカと
の結合が弱いため、60℃越で陰極剥離試験を行う
と被覆貫通傷部から侵入する熱水によつてクロメ
ート被膜中の微粒子シリカが其の表面で水を吸着
して膨潤し、被覆が剥離するので、耐高温陰極剥
離性が悪い。
また、第５図のクロメート処理剤層では、クロ
メート被膜中のクロム化合物と微粒子シリカの間
および樹脂と微粒子シリカの間の結合が弱いの
で、60℃を越える高温域で陰極剥離試験を行うと
被覆貫通傷部から侵入する熱水によつてクロム化
合物と微粒子シリカの間、および樹脂と微粒子シ
リカの間の結合がはずれ、微粒子シリカがその表
面に水を吸着して膨潤し、被覆が剥離するので、
耐高温陰極剥離性が悪い。
上記の問題があり、従来技術を以つてしては、
60℃を越える高温域での耐陰極剥離性に優れた有
機樹脂系被覆鋼管を得ることが困難であつた。
本発明は、60℃を越える高温域での耐陰極剥離
性に優れた有機樹脂系被覆鋼管を提供するもので
ある。
（問題点を解決するための手段）
本発明者は、上述の問題点を解決すべく鋭意検
討を行つた結果、鋼管の外表面に、リン酸と無水
クロム酸の混合水溶液を高分子還元剤で部分的に
還元しリン酸とシリカ系微粒子を添加した混合物
からなるクロメート処理剤を塗布して焼付けたの
ち、有機樹脂系被覆を施すことによつて、高温で
の耐陰極剥離性の優れた有機樹脂系被覆鋼管が得
られることを見い出し、本発明に至つた。
すなわち、
(1) 鋼管の外表面に内側から順に、無水クロム酸
の水溶液に該水溶液中の全クロムに対する
PO4 3-の重量比が0.5〜2.0の範囲になるように
リン酸を混合した混合水溶液を、酵素でデンプ
ンを加水分解して得られ、かつ平均分子量が
50000〜250000の範囲のデキストリンで、該混
合水溶液中の全クロムに対する６価クロムの重
量比が0.35〜0.65の範囲になるように部分還元
し、かつ、シリカ微粒子を該混合水溶液中の全
クロムに対するSiO2の重量比が0.5〜2.5の範囲
になるように添加した混合物を加熱焼付けし、
得られるクロメート処理剤層に有機樹脂系被覆
を積層することを特徴とする耐高温陰極剥離性
の優れた有機樹脂系被覆鋼管の製造方法。
(2) 鋼管の外表面に内側から順に、無水クロム酸
の水溶液に該水溶液中の全クロムに対する
PO4 3-の重量比が0.5〜2.0の範囲になるように
リン酸を混合した水溶液を、
の分子構造を有し、かつ
ケン化度ｍ／ｍ＋ｎ×100（％）が80〜90％でか
つ平均分子量が60000〜140000の範囲の部分ケ
ン化ポリ酢酸ビニルで該混合水溶液中の全クロ
ムに対する６価クロムの重量比が0.35〜0.65の
範囲になるように部分還元し、かつシリカ微粒
子を該混合水溶液中の全クロムに対するSiO2
の重量比が0.5〜2.5の範囲になるように添加し
た混合物を加熱焼付けして得られるクロメート
処理剤層に、有機樹脂系被覆を積層することを
特徴とする耐高温陰極剥離性の優れた有機樹脂
系被覆鋼管の製造方法である。
本発明は第１図に示す如く、鋼管１の外表面に
内側から順に、リン酸と無水クロム酸の混合水溶
液を高分子還元剤で部分的に還元し、シリカ系微
粒子を添加した混合物を加熱焼付けして得られる
クロメート処理剤層２と有機樹脂系被覆層３を積
層したことを特徴とする高温での耐陰極剥離性の
優れた有機樹脂系被覆鋼管の製造方法に関するも
のである。
以下、本発明につき詳細に説明する。
本発明に用いる鋼管とは、炭素鋼、ステンレス
鋼等の合金鋼でできた管である。また鋼管の内面
の耐食性を改善したメツキ鋼管、二重管等も含ま
れる。例えば鋼管の内面に亜鉛、アルミニウム、
クロム、ニツケル、亜鉛−ニツケル、亜鉛−ニツ
ケル−コバルト−クロム等を施したメツキ鋼管や
下記の如き金属を内面に接合した二重管である。
該二重管は外層が鋼管で、内層が銅、アルミニウ
ム、チタン、ステンレス鋼、アルミニウム−マグ
ネシウム合金、ニツケル−クロム−鉄系合金、ニ
ツケル−モリブデン系合金、ニツケル−モルブデ
ン−クロム・タングステン系合金、チタン−パラ
ジウム系合金、チタン−モリブデン−ジルコニウ
ム系合金、チタン−アルミニウム．パナジウム系
合金等の金属または合金からなるもので外層が鋼
管であれば差支えない。
次に、本発明のクロメート処理層の形成に用い
るクロメート処理剤について説明する。
本発明で使用するクロメート処理剤とは、蒸留
水にリン酸と無水クロム酸（CrO3）を溶解させ
た水溶液を高分子還元剤で部分的に還元し、リン
酸、６価のクロムイオンと３価のクロムイオンを
混在させ、かつシリカ系微粒子を混合させたもの
であるが、必要に応じてリン酸の一部をピロリン
酸、トリポリリン酸等の縮合リン酸で置換えるこ
とができる。
６価から３価へのクロムの部分的還元に用いる
高分子還元剤としては、アミロペクチン分を多く
含むデンプン、例えばトウモロコシデンプンをア
ミログルコシターゼ等の加水分解酵素で部分的に
加水分解し、リン酸イオンとの反応によるリン酸
エステル化を容易にならしめたデキストリン（平
均分子量50000〜250000）あるいは
の分子構造を有し、かつ分子量が60000〜140000
の部分ケン化ポリ酢酸ビニルを用いる。
上記の高分子還元剤は分子量が極めて高いた
め、常温ではリン酸とクロム酸の混合水溶液に溶
解し難いので、該混合水溶液を80〜100℃に加熱
して添加し完全に溶解する。上記の方法で、リン
酸とクロム酸の混合水溶液に溶解した高分子還元
剤は、クロメート処理剤と其の加熱焼付け被膜の
分析結果、熱水に対するクロムイオンの溶出量測
定結果から推察するに、高分子還元剤の一部が分
解して６価クロムを３価クロムに還元すると同時
に、残りの高分子還元剤にクロムイオンが配位
し、このクロムイオンに更にリン酸が結合するた
めクロメート被膜を熱水に対して不溶解化するの
に著しい効果がある。
上記以外の高分子還元剤、例えばデンプン等の
酵素による部分加水分解を行わない多糖を用いる
場合には、前記のデキストリンや部分ケン化ポリ
酢酸ビニルを用いる場合に比較して、リン酸とク
ロム酸の混合水溶液に添加してもクロムイオンの
配位が不充分になるためクロメート被膜を熱水に
対して不溶解化する効果が小さい。
また、高分子還元剤として、前記の部分ケン化
ポリ酢酸ビニル以外の水溶性樹脂、例えば
の分子構造を有するポリビニルアルコールを用い
る場合には、置換基がすべて活性な水酸基になつ
ているため、リン酸とクロム酸の混合溶液に添加
するとクロム酸による酸化分解を受けやすく、ク
ロメート被膜を熱水に対して不溶解化する効果が
小さくなる。
また、高分子還元剤の代わりに、メチルアルコ
ール、コハク酸、ソルビトール等の低分子還元剤
を用いる場合には、リン酸とクロム酸の混合水溶
液に添加するとほとんど分解されてしまうのでク
ロメート被膜を熱水に対して不溶解化する効果が
ほとんどない。
前記の高分子還元剤のうちデキストリンは平均
分子量が50000〜250000の範囲のものを用いる。
デキストリンの平均分子量が50000未満ではクロ
メート被膜を熱水に対して不溶解化する効果がほ
とんどなく、250000越ではリン酸とクロム酸の混
合水溶液に溶解し難く塗布して得られる被膜の平
滑性を損うので望ましくない。
また、前記の部分ケン化ポリ酢酸ビニルは分子
量が60000〜140000の範囲であつて、かつケン化
度ｍ／ｍ＋ｎ×100が80〜90％の範囲のものを用い
る。部分ケン化ポリ酢酸ビニルの分子量が60000
未満ではクロメート被膜を熱水に対して不溶解化
する効果が小さく、140000越ではリン酸とクロム
酸の混合水溶液に溶解し難く塗布して得られる被
膜の平滑性を損うので望ましくない。また、部分
ケン化ポリ酢酸ビニルのケン化度が80％未満では
分子鎖に付加している水酸基の数の割合が少ない
のでリン酸エステルの生成が少なく、90％越では
分子鎖に付加している水酸基の数の割合いが多す
ぎるのでリン酸とクロム酸の混合水溶液に添加す
ると分解されやすいためクロメート被膜を熱水に
対して不溶解化する効果が低下する。
前記のデキストリンと部分ケン化ポリ酢酸ビニ
ルは全クロムに対する６価クロムの比率を所望の
比率に保持するために必要な量を用いる。所望の
比率とは全クロムに対する６価クロムの重量比が
0.35〜0.65の範囲である。
この比率に関しては全クロムに対する６価クロ
ムの重量比が0.35未満では鋼管表面とクロメート
被膜との接着性が低下し、該重量比が0.75越では
クロメート被膜を熱水に対して不溶解化する効果
が著しく低下する。
尚、上記の全クロムに対する６価クロムの重量
比を0.35〜0.65の範囲にするに要するデキストリ
ンの量はクロメート処理液中の全固形分に対する
重量比で0.008〜0.058の範囲であり、部分ケン化
ポリビニルアルコールの量はクロメート処理液中
の全固形分に対する重量比で0.009〜0.062の範囲
である。
また、前記のクロメート処理剤に添加するリン
酸は、クロメート処理剤と其の加熱焼付け被膜の
分析結果、熱水に対するクロムイオンの溶解量測
定結果から推察するに、
未分解のデキストリンまたは部分ケン化ポリ
酢酸ビニルにクロムイオンが配位した配位化合
物に結合する。
シリカ系微粒子表面の水酸基と結合し、この
水酸基と結合したリン酸基が更に遊離のクロム
イオン及び上記のクロムイオンが配位したデキ
ストリンまたは部分ケン化ポリ酢酸ビニルに結
合する。
等の効果によつて、クロメート被膜を一体化する
と共に、遊離のリン酸とクロムイオンが配位した
デキストリンあるいは部分ケン化ポリ酢酸ビニル
に結合したリン酸基の一部が、遊離の６価クロム
イオンと共に鋼管表面と反応してリン酸鉄クロム
化合物を生成して、クロメート被膜を鋼管表面に
強固に接着するので、クロメート被膜を熱水に対
して不溶解化させると共に陰極剥離試験の際のア
ルカリの発生に対しても被膜が剥離し難くなると
考えられる。
リン酸の添加量は全クロムに対するPO4 3-の重
量比が0.5〜2.0の範囲で添加する。リン酸添加量
が0.5未満では上記の効果がほとんどなく、2.0越
ではクロメート被膜内に遊離状態の可溶性リン酸
が残存するので返つてクロメート被膜を熱水に対
して不溶解化する効果が低下する。
また、前記のクロメート処理剤に添加するシリ
カ系微粒子としては、例えば日本アエロジル社製
のアエロジル200、アエロジル300、アエロジル
380、アエロジルOX50、日本シリカ工業社のニ
ツプシールL300、ニツプシールN300A、ニツプ
シールE200、ニツプシールE200A等のシリカ粒
子、
日本アエロジル社製のアエロジルCOK84、ア
エロジルMOX80、アエロジルMOX170等のシリ
カ−アルミナ微粒子、日産化学工業社製のスノー
テツクスＯ、スノーテツクスOL、スノーテツク
スOS、スノーテツクスOML、触媒化成工業社製
のCataloid SN，Cataloid SA，Cataloid S20L
等のコロイダルシリカ、日産化学工業社製のアル
ミナゾル100、アルミナゾル200等のシリカ−アル
ミナゾルのうちから、１種または２種以上を混合
して用いる。
上記のシリカ系微粒子は、クロメート処理剤と
其の加熱被膜の分析結果、熱水に対するリン酸イ
オンとクロムイオンの溶出量測定結果から推察す
るに、上記のシリカ系微粒子は、其の表面の水酸
基がクロメート処理剤中のリン酸イオン及びクロ
ムイオンが配位したデキストリンあるいは部分ケ
ン化ポリ酢酸ビニルと結合するので、クロメート
処理剤を鋼管表面に塗布して得られる被膜を一体
化し被膜からのリン酸イオンやクロムイオンの溶
出を防止するため、耐高温陰極剥離性を格段に向
上させると考えられる。
シリカ系微粒子の添加量は、クロメート処理液
中の全クロムに対するシリカ系微粒子の重量比が
0.5〜2.5の範囲になるように添加する。シリカ系
微粒子の添加量が0.5以下では上記の効果がほと
んどなく、添加量が2.5以上ではクロメート処理
剤の流動性が著しく悪化し、鋼管表面に塗布して
得られる被膜の平滑性を阻害するため好ましくな
い。
尚、クロメート被膜と有機樹脂系被覆との間の
接着性が不足する場合には、前記のクロメート処
理剤にメタバナジン酸アンモニウム、リン酸水素
二アルミニウム、モリブデン酸アンモニウム、炭
酸コバルト、炭酸マンガン等の金属塩、リンモリ
ブデン酸、リンタングステン酸、リンバナジン酸
等のリン・酸素酸の中から適宜選択の上、添加す
る。
前述の鋼管表面にクロメート処理剤を塗布する
前に、酸洗、サンドブラスト処理、グリツトブラ
スト処理、シヨツトブラスト処理等で管表面のス
ケール等を除去する。スケール等を除去した鋼管
表面にクロメート処理剤を塗布すると管表面の酸
化作用および塗布後の管加熱によつて６価のクロ
ムは還元され、シリカ系微粒子表面とリン酸との
間の脱水縮合反応、該脱水縮合物のリン酸基とク
ロムイオン及びクロムイオンが配位したデキスト
リンあるいは部分ケン化ポリ酢酸ビニルとの間の
脱水縮合反応が促進され、熱水に難溶性でかつ耐
アルカリ性の優れたクロメート被膜が生成する。
クロメート処理剤の焼付け温度は鋼管表面温度
で120〜300℃が適切である。鋼管表面温度が120
℃未満ではクロメート処理剤層の不溶解化に非常
に長い時間を必要とするため実用に適さず、300
℃越ではクロメート処理剤中のシリカ微粒子表面
とリン酸の結合切断が生じ遊離の可溶性リン酸が
生成するため、かえつてクロメート被膜の不溶解
性が低下し、耐熱水浸漬性が悪化する。また、ク
ロメート処理剤の付着量は全クロム重量として
100〜900mg/m2が望ましい。この付着量が100mg/
m2未満ではクロメート処理剤の効果が発揮され
ず、900mg/m2越では強固な被膜が形成されず接着
性が低下する。
次に、本発明に用いる有機樹脂系被覆について
説明する。
本発明でいう有機樹脂系被覆とは、エポキシ樹
脂、エポキシ・シリコーン樹脂、ポリイミド・エ
ポキシ樹脂、ポリフエニレンサルフアイド樹脂、
ポリエーテルスルフオン樹脂、ポリウレタン樹
脂、変性ポリエチレン、変性ポリプロピレン、変
性エチレン・プロピレン共重合体、変性ポリアミ
ド・プロピレン共重合体等の有機樹脂を主成分と
する粉体塗料、溶剤で希釈した溶剤型塗料及び液
状の無溶剤型塗料を塗布して硬化させた被覆であ
る。
上記の有機樹脂系塗料には、主成分である有機
樹脂の他に、顔料、充填強化剤、等を添加するこ
とができる。顔料とは、シリカ、シリカ・アルミ
ナ、ルチル型酸化チタン、ガラス、マピコ、ケイ
酸ジルコニウム、ケイ酸マグネシウム、タルク、
硫酸バリウム、アルミナ、ジンククロメート、ス
トロンチウムクロメート、シナミド鉛、亜酸化
鉛、リン酸亜鉛、リン酸アルミニウム、リン酸カ
ルシウム、ケイモリブテン酸、ケイタングステン
酸、リンモリブデン酸亜鉛等の一般市販の微粉末
状、フレーク状あるいはりん片状の顔料である
が、美観を要する場合には、更には、カドミウム
イエロー、ポリアゾイエロー、キノフタロンイエ
ロー、イソインドリノンイエロー、キナクリドン
イエロー、ベンガラレツド、ポリアゾブラウン、
アゾレーキイエロー、ペリレンレツド、フタロシ
アニンブルー、フタロシアニングリーン、ベンガ
ライエロー、アルミン酸コバルト、アニリンブラ
ツク、カーボンブラツク、ウルトラマリンブル
ー、アルミニウム微粉末等の着色顔料を添加する
こともできる。
また、充填強度剤とは、ガラス、スラグ、シリ
コンカーバイド、カーボン、ボロン、ボロンナイ
トライド、アルミナ等の無機繊維充填材、ナイロ
ン、ポリエステル、ビニロン、アラミド、ケブラ
ー等の有機繊維充填材である。
本発明に基づく有機樹脂系被覆鋼管は、例えば
第２図に示す製造法で得ることができる。すなわ
ち、スケール等を除去した鋼管１の表面に、クロ
メート処理剤塗布装置９によつて本発明によるク
ロメート処理剤を塗布し、加熱装置１０によつて
焼付ける。次いで、其の表面に有機樹脂被覆装置
１１によつて有機樹脂系被覆を施し、有機樹脂系
被覆鋼管を製造する。
有機樹脂被覆装置１１としては、有機樹脂系被
覆として粉体エポキシ樹脂塗料を用いる場合には
静電粉体塗装機、溶剤型および無溶剤型のエポキ
シ樹脂塗料、エポキシ−シリコン樹脂塗料、ポリ
フエニレンサルフアイド系塗料、ポリウレタン系
樹脂塗料、ポリイミド・エポキシ樹脂系塗料等を
用いる場合にはスプレー塗装機、ロールコーター
等の従来公知の方法の中から適宜選択して用いる
ことができる。なお、図中８は粉体エポキシ塗装
塗膜である。
本発明を具体的に説明するために、以下に本発
明によるクロメート処理剤の調合例と特開昭52−
143934号公報に相当するクロメート処理剤の比較
調合例及び有機樹脂系被覆鋼管の製造例を挙げ
る。
クロメート処理剤の調合例 １
次の溶液，，を作成した。
リン酸とクロム酸の混合水溶液
蒸留水247.6ｇにリン酸49.2ｇと無水クロム
酸76.8ｇを溶解させた。
５重量％部分ケン化ポリ酢酸ビニル水溶液
分子量88000で、かつケン化度が87％の部分
ケン化ポリ酢酸ビニルを蒸留水に加えて２時間
放置し、膨潤させた。次いで、この水溶液を98
℃に加温して完全溶解させ、部分ケン化ポリ酢
酸ビニルを５重量％含む水溶液を作成した。
10重量％アエロジル200水溶液
シリカ系微粒子として日本アエロジル社製の
アエロジル200を用いた。アエロジル200を蒸留
水に添加し、高速ミキサー（回転数300rpm）
で撹拌して分散させ、アエロジル200を10重量
％含む水溶液を作成した。
次に、上記ののリン酸とクロム酸の混合水溶
液373.6ｇに、の５重量％部分ケン化ポリ酢酸
ビニル水溶液106ｇを添加し、90℃に加温して６
価のクロムイオンの一部を３価のクロムイオンに
還元した。
該水溶液中の全クロムに対する６価クロムの重
量比は0.60、全クロムに対するPO4 3-の重量比は
1.16であつた。次いで、上記の還元水溶液に前記
の10重量％アエロジル200水溶液515.6ｇを添加
して分散させ、本発明によるクロメート処理剤Ａ
を作成した。該クロメート処理剤Ａ中の全クロム
に対するSiO2（アエロジル200）の重量比は1.29で
あつた。
クロメート処理剤の調合例 ２
前記のクロメート処理剤Ａの作成に用いる高分
子還元剤として部分ケン化ポリ酢酸ビニルの代わ
りに、平均分子量120000のデキストリンを添加
し、本発明によるクロメート処理剤Ｂを作成し
た。クロメート処理剤Ｂ中の全クロムに対する３
価クロムの重量比は0.38、全クロムに対する
PO4 3-の重量比は1.20、全クロム対するSiO2の重
量比は1.60であつた。
クロメート処理剤の比較調合例 １
比較材として、特開昭52−143934号公報に相当
するクロメート処理剤Ｃ，Ｄ，Ｅを作成した。
〔クロメート処理剤Ｃ〕
蒸留水700ｇに無水クロム酸76・８ｇとコハク
酸28.8ｇを溶解し、該水溶液にパルビツール酸
19.2ｇを加えて分散させ更に蒸留水を加えて１
のクロメート処理剤Ｃを作成した。
〔クロメート処理剤〕
無水クロム酸76.8ｇを蒸留水823ｇに溶解し、
これに小麦デンプン8.4ｇを加えて１時間加熱・
沸騰させ、６価のクロムイオンを部分的に還元さ
せた。該還元水溶液中の全クロムに対する３価ク
ロムの重量比は0.38であつた。該還元水溶液に前
記のアエロジル＃200を92ｇ加え、撹拌・分散さ
せクロメート処理剤Ｄを作成した。
〔クロメート処理剤Ｅ〕
無水クロム酸76.8ｇを蒸留水800ｇに溶解し、
これにトウモロコシデンプン3.4ｇを加えて１時
間加熱沸とうさせ、６価のクロムイオンを部分的
に還元させた。該還元水溶液中の全クロムに対す
る３価クロムの重量比は0.22であつた。該還元水
溶液に前記のアエロジル＃200を23ｇとタルク粉
（珪酸マグネシウム）23ｇを撹拌・分散させた後、
ポリビニルアルコール（日本合成化学工業社製、
ゴーセノールNM−11）の５％水溶液46ｇを加え
て分散させ、クロメート処理剤Ｅを作成した。
製造例 １
鋼管（200A×5500mm長×5.8mm厚）をグリツト
ブラスト処理し、其の表面に前記のクロメート処
理剤Ａ〜Ｅを全クロム付着量換算で280mg/m2塗布
し、230℃に加熱して焼付け、直ちに粉体エポキ
シ樹脂塗料（3M社製、スコツチコート206N）を
膜厚が400μになるように静電塗装して３分間加
熱硬化させ、次いで遠赤外線ヒーターで表面温度
を240℃にして４分間後加熱し、粉体エポキシ塗
装鋼管を製造した。
上記の粉体エポキシ塗装鋼管について、高温陰
極剥離試験（試験温度80℃、電解液３％NaCl、
電圧−1.5V〔Cu／CuSO4、標準電極〕、初期ホリ
デー径3.2mmφ、試験日数30日間）を行い、試験
終了後、塗膜の換算剥離半径
〔
(Industrial Application Field) The present invention relates to a method for producing an organic resin-coated steel pipe, and more particularly to a method for producing an organic resin-coated steel pipe with excellent high-temperature cathode peelability. (Prior art) Organic resin-coated steel pipes, including powdered epoxy resin-coated steel pipes, have excellent anti-corrosion properties, and are therefore increasingly being used in pipelines for transporting oil, natural gas, etc. I came. Usually, such pipelines are used for a long time once they are laid, so cathodic protection is usually used in combination. Steel pipes coated with organic resins such as powdered epoxy resins are exposed to rocks, gravel, etc. during transportation or handling during installation, which can cause penetration scratches in the coating. Corrosion protection is applied. However,
Particularly in the case of over-corrosion protection, a phenomenon called cathodic peeling occurs in which soil moisture is electrolyzed by the anti-corrosion current and the coating is peeled off by the generated hydrogen and alkali, resulting in a reduction in the corrosion protection of the pipeline. be. In addition, in recent years, in order to improve the transport efficiency of heavy oil, the material flowing in the pipe becomes high temperature due to processes such as heating the heavy oil to lower its viscosity before transporting, and cathodic peeling resistance ( Improving the "high temperature cathode peelability" (hereinafter referred to as "resistance to high temperature cathode peeling") is becoming an important issue. Conventionally, in order to improve the cathodic peeling resistance of an organic resin-coated steel pipe, a method has been proposed in which the surface of the steel pipe is previously subjected to chromate treatment. For example, JP-A-52-14392 discloses that, as shown in Figure 3, a hexavalent chromium compound and amino acids, acid amides, lactams, saturated polycarboxylic acids, unsaturated polycarboxylic acids, etc. are added to the surface of the steel pipe 1. There has been proposed a coated steel pipe in which a chromate treatment agent layer 4 containing an organic component is applied and baked, and then a powder coating film 5 of a thermoplastic or thermosetting resin composition is laminated thereon. Moreover, as shown in FIG. 4, instead of the above-mentioned chromate treatment agent layer 4, chromic acid (CrO 3 ) is
Partial reduction was performed using an organic reducing agent such as polyhydric alcohol, monohydric alcohol, alkylolamine, or aromatic polyhydric alcohol to a ratio of Cr 6+ /total chromium = 0.35 to 0.65, and fine silica was added to the reduced product. A coated steel pipe with a chromate treatment agent layer 6 laminated thereon, and further, as shown in FIG.
There is a coated steel pipe in which a chromate treatment agent layer 7 containing a nonionic water-soluble resin such as hexamethoxymethylmelamine-modified polyhydroxyethyl acrylate is laminated. (Problems to be Solved by the Invention) The coated steel pipes shown in Figs. 3, 4, and 5 have relatively good cathodic peeling resistance at room temperature, but the resistance to cathodic peeling at temperatures exceeding 60°C is poor. High temperature cathode removability is extremely poor. The present inventors investigated the coated steel pipes shown in Figures 3, 4, and 5 by analyzing the structure of the chromate treatment agent layer and measuring the amount of chromium ions eluted into hot water exceeding 60°C. Judging from the results, it is thought that the high temperature cathode peeling resistance is poor for the following reasons. First, the chromate treatment agent layer shown in Figure 3 is soluble 6
Because it contains a large amount of valent chromium, when a cathodic peel test is performed at temperatures above 60°C, the hexavalent chromium ions are easily eluted from the chromate coating by hot water that enters through the coating penetration wound, causing the coating to peel off. In the chromate treatment agent layer shown in Figure 4, the bond between the chromium compound in the layer and the particulate silica is weak, so when a cathode peel test is performed at temperatures exceeding 60°C, hot water that enters through the coating penetration flaws causes the chromate coating to break down. The particulate silica adsorbs water on its surface and swells, causing the coating to peel off, resulting in poor high-temperature cathode peelability. In addition, in the chromate treatment agent layer shown in Figure 5, the bond between the chromium compound in the chromate coating and the fine particle silica, and between the resin and the fine particle silica, is weak, so if a cathodic peel test is performed at a high temperature range exceeding 60°C, the coating The hot water that enters through the penetrating wound breaks the bond between the chromium compound and the particulate silica, and between the resin and the particulate silica, and the particulate silica absorbs water on its surface and swells, causing the coating to peel off. ,
Poor high temperature cathode peelability. Due to the above problems, with the conventional technology,
It has been difficult to obtain organic resin-coated steel pipes with excellent cathodic peeling resistance at high temperatures exceeding 60°C. The present invention provides an organic resin-coated steel pipe that has excellent cathode peeling resistance in a high temperature range exceeding 60°C. (Means for Solving the Problems) As a result of intensive studies to solve the above-mentioned problems, the present inventors applied a mixed aqueous solution of phosphoric acid and chromic anhydride to the outer surface of a steel pipe as a polymer reducing agent. After applying and baking a chromate treatment agent consisting of a mixture of phosphoric acid and silica-based fine particles that has been partially reduced with It was discovered that an organic resin coated steel pipe can be obtained, leading to the present invention. That is, (1) Apply an aqueous solution of chromic anhydride to the outer surface of the steel pipe, starting from the inside.
A mixed aqueous solution containing phosphoric acid such that the weight ratio of PO 4 3- is in the range of 0.5 to 2.0 is obtained by hydrolyzing starch with an enzyme, and the average molecular weight is
Dextrin in the range of 50,000 to 250,000 is partially reduced so that the weight ratio of hexavalent chromium to the total chromium in the mixed aqueous solution is in the range of 0.35 to 0.65, and the silica fine particles are reduced to the total chromium in the mixed aqueous solution. Heat and bake the mixture in which the weight ratio of SiO 2 is in the range of 0.5 to 2.5,
A method for manufacturing an organic resin-coated steel pipe with excellent high-temperature cathodic peelability, which comprises laminating an organic resin coating on the resulting chromate treatment agent layer. (2) Apply an aqueous solution of chromic anhydride to the outer surface of the steel pipe, starting from the inside, based on the total chromium in the aqueous solution.
An aqueous solution mixed with phosphoric acid such that the weight ratio of PO 4 3- is in the range of 0.5 to 2.0, Partially saponified polyvinyl acetate having a molecular structure of 80% to 90% and an average molecular weight of 60,000 to 140,000, based on the total chromium in the mixed aqueous solution. Partial reduction is performed so that the weight ratio of hexavalent chromium is in the range of 0.35 to 0.65, and silica fine particles are added to SiO 2 to the total chromium in the mixed aqueous solution.
An organic resin with excellent high-temperature cathodic peelability characterized by laminating an organic resin coating on the chromate treatment agent layer obtained by heating and baking a mixture in which the weight ratio of This is a method for manufacturing resin-coated steel pipes. As shown in FIG. 1, the present invention involves partially reducing a mixed aqueous solution of phosphoric acid and chromic acid anhydride with a polymer reducing agent and heating the mixture to which silica-based fine particles are added, sequentially from the inside to the outer surface of a steel pipe 1. The present invention relates to a method for manufacturing an organic resin-coated steel pipe with excellent cathode peeling resistance at high temperatures, characterized by laminating a chromate treatment agent layer 2 obtained by baking and an organic resin coating layer 3. Hereinafter, the present invention will be explained in detail. The steel pipe used in the present invention is a pipe made of alloy steel such as carbon steel and stainless steel. It also includes plated steel pipes, double-walled pipes, etc. that have improved corrosion resistance on the inner surface of steel pipes. For example, zinc, aluminum,
These are plated steel pipes coated with chromium, nickel, zinc-nickel, zinc-nickel-cobalt-chromium, etc., and double-walled pipes with the following metals bonded to the inner surface.
The outer layer of the double tube is a steel pipe, and the inner layer is made of copper, aluminum, titanium, stainless steel, aluminum-magnesium alloy, nickel-chromium-iron alloy, nickel-molybdenum alloy, nickel-molybdenum-chromium-tungsten alloy, Titanium-palladium alloy, titanium-molybdenum-zirconium alloy, titanium-aluminum. There is no problem as long as it is made of metal or alloy such as panadium alloy and the outer layer is a steel pipe. Next, the chromate treatment agent used for forming the chromate treatment layer of the present invention will be explained. The chromate treatment agent used in the present invention is an aqueous solution in which phosphoric acid and chromic anhydride (CrO 3 ) are dissolved in distilled water, and is partially reduced with a polymer reducing agent to produce phosphoric acid and hexavalent chromium ions. Although trivalent chromium ions and silica-based fine particles are mixed therein, part of the phosphoric acid can be replaced with condensed phosphoric acid such as pyrophosphoric acid or tripolyphosphoric acid, if necessary. As a polymeric reducing agent used for partial reduction of chromium from hexavalent to trivalent chromium, starch containing a large amount of amylopectin, such as corn starch, is partially hydrolyzed with a hydrolytic enzyme such as amyloglucosidase to form phosphate ions. Dextrin (average molecular weight 50,000-250,000) that facilitates phosphoric acid esterification by reaction with has a molecular structure and a molecular weight of 60,000 to 140,000.
Partially saponified polyvinyl acetate is used. Since the above polymer reducing agent has an extremely high molecular weight, it is difficult to dissolve in a mixed aqueous solution of phosphoric acid and chromic acid at room temperature, so the mixed aqueous solution is heated to 80 to 100° C. and added to completely dissolve. The polymer reducing agent dissolved in the mixed aqueous solution of phosphoric acid and chromic acid in the above method is estimated from the analysis results of the chromate treatment agent and its heat-baked coating, and the measurement results of the amount of chromium ions eluted in hot water. At the same time, part of the polymeric reducing agent decomposes and reduces hexavalent chromium to trivalent chromium, and at the same time, chromium ions are coordinated to the remaining polymeric reducing agent, and phosphoric acid is further bonded to this chromium ion, resulting in a chromate coating. It has a remarkable effect on making it insoluble in hot water. When using polymeric reducing agents other than those mentioned above, for example, polysaccharides that are not partially hydrolyzed by enzymes such as starch, phosphoric acid and chromic acid are used, compared to when using dextrin or partially saponified polyvinyl acetate. Even if it is added to a mixed aqueous solution, the coordination of chromium ions will be insufficient, so the effect of making the chromate film insoluble in hot water will be small. In addition, as a polymer reducing agent, water-soluble resins other than the above-mentioned partially saponified polyvinyl acetate, such as When using polyvinyl alcohol, which has a molecular structure of The effect of making it insoluble in water is reduced. In addition, when using a low-molecular reducing agent such as methyl alcohol, succinic acid, or sorbitol instead of a high-molecular reducing agent, most of it is decomposed when added to a mixed aqueous solution of phosphoric acid and chromic acid, so the chromate film cannot be heated. It has almost no effect of making it insoluble in water. Among the above polymer reducing agents, dextrin having an average molecular weight in the range of 50,000 to 250,000 is used.
When the average molecular weight of dextrin is less than 50,000, it has little effect on making the chromate film insoluble in hot water, and when it exceeds 250,000, it is difficult to dissolve in a mixed aqueous solution of phosphoric acid and chromic acid, and the smoothness of the film obtained when applied is reduced. It is undesirable because it causes damage. The partially saponified polyvinyl acetate used has a molecular weight in the range of 60,000 to 140,000 and a degree of saponification m/m+n×100 in the range of 80 to 90%. The molecular weight of partially saponified polyvinyl acetate is 60,000
If it is less than 140,000, the effect of making the chromate film insoluble in hot water is small, and if it exceeds 140,000, it is difficult to dissolve in a mixed aqueous solution of phosphoric acid and chromic acid, which impairs the smoothness of the coated film, which is not desirable. In addition, if the degree of saponification of partially saponified polyvinyl acetate is less than 80%, the proportion of hydroxyl groups added to the molecular chain is small, resulting in less phosphoric acid ester formation; Since the ratio of the number of hydroxyl groups present is too high, when added to a mixed aqueous solution of phosphoric acid and chromic acid, it is easily decomposed and the effect of making the chromate film insoluble in hot water is reduced. The above dextrin and partially saponified polyvinyl acetate are used in amounts necessary to maintain the ratio of hexavalent chromium to total chromium at a desired ratio. The desired ratio is the weight ratio of hexavalent chromium to total chromium.
It ranges from 0.35 to 0.65. Regarding this ratio, if the weight ratio of hexavalent chromium to total chromium is less than 0.35, the adhesion between the steel pipe surface and the chromate coating will decrease, and if the weight ratio exceeds 0.75, it will have an effect of making the chromate coating insoluble in hot water. decreases significantly. In addition, the amount of dextrin required to make the weight ratio of hexavalent chromium to total chromium in the range of 0.35 to 0.65 is in the range of 0.008 to 0.058 in terms of weight ratio to the total solid content in the chromate treatment solution. The amount of polyvinyl alcohol is in the range of 0.009 to 0.062 as a weight ratio to the total solid content in the chromate treatment solution. In addition, the phosphoric acid added to the chromate treatment agent mentioned above is inferred from the analysis results of the chromate treatment agent and its heat-baked film, and the measurement results of the amount of chromium ions dissolved in hot water. It binds to a coordination compound in which chromium ions are coordinated to polyvinyl acetate. It binds to a hydroxyl group on the surface of the silica-based fine particles, and the phosphoric acid group bound to this hydroxyl group further binds to free chromium ions and dextrin or partially saponified polyvinyl acetate to which the chromium ions are coordinated. Due to these effects, the chromate film is integrated, and some of the phosphate groups bonded to dextrin or partially saponified polyvinyl acetate, in which free phosphoric acid and chromium ions are coordinated, become free hexavalent chromium. It reacts with the surface of the steel pipe together with ions to form an iron chromium phosphate compound, which firmly adheres the chromate film to the surface of the steel pipe, making the chromate film insoluble in hot water and preventing alkali during cathodic peeling tests. It is thought that the coating becomes difficult to peel off even when the occurrence of . The amount of phosphoric acid added is such that the weight ratio of PO 4 3- to total chromium is in the range of 0.5 to 2.0. If the amount of phosphoric acid added is less than 0.5, there is almost no effect as described above, and if it exceeds 2.0, free soluble phosphoric acid remains in the chromate film, and the effect of making the chromate film insoluble in hot water decreases. . In addition, examples of the silica-based fine particles to be added to the chromate treatment agent include Aerosil 200, Aerosil 300, and Aerosil 300 manufactured by Nippon Aerosil Co., Ltd.
380, Aerosil OX50, silica particles such as Nippushial L300, Nippushial N300A, Nippushial E200, Nippushial E200A from Nippon Silica Kogyo Co., Ltd., silica-alumina fine particles such as Aerosil COK84, Aerosil MOX80, Aerosil MOX170 from Nippon Aerosil Co., Ltd., Nissan Chemical Industries, Ltd. Snowtex O, Snowtex OL, Snowtex OS, Snowtex OML manufactured by Catalysts & Chemicals, Catalyst Chemical Industry Co., Ltd. Cataloid SN, Cataloid SA, Cataloid S20L
and silica-alumina sols such as Alumina Sol 100 and Alumina Sol 200 manufactured by Nissan Chemical Industries, Ltd., or a mixture of two or more thereof. Inferred from the analysis results of the chromate treatment agent and its heated coating, and the measurement results of the elution amount of phosphate ions and chromium ions in hot water, the silica-based fine particles mentioned above have hydroxyl groups on their surface. The chromate treatment agent combines with dextrin or partially saponified polyvinyl acetate coordinated with phosphate ions and chromium ions in the chromate treatment agent, so the coating obtained by applying the chromate treatment agent to the steel pipe surface is integrated, and the phosphoric acid from the coating is combined with the chromate treatment agent. Since it prevents the elution of ions and chromium ions, it is thought that the high-temperature cathode peeling resistance is significantly improved. The amount of silica particles added is determined by the weight ratio of silica particles to the total chromium in the chromate treatment solution.
Add in a range of 0.5 to 2.5. If the amount of silica-based fine particles added is less than 0.5, the above effect will hardly be achieved, and if the amount added is more than 2.5, the fluidity of the chromate treatment agent will deteriorate significantly, and the smoothness of the coating obtained by applying it to the steel pipe surface will be impaired. Undesirable. If the adhesion between the chromate film and the organic resin coating is insufficient, metals such as ammonium metavanadate, dialuminum hydrogen phosphate, ammonium molybdate, cobalt carbonate, manganese carbonate, etc. may be added to the chromate treatment agent. It is added after appropriately selecting from among salts, phosphorus/oxyacids such as phosphomolybdic acid, phosphotungstic acid, and phosphovanadate. Before applying the above-mentioned chromate treatment agent to the surface of the steel pipe, scale etc. on the pipe surface are removed by pickling, sandblasting, grit blasting, shot blasting, etc. When a chromate treatment agent is applied to the surface of a steel pipe from which scale has been removed, hexavalent chromium is reduced by the oxidation effect on the pipe surface and heating of the pipe after application, and a dehydration condensation reaction occurs between the surface of silica-based fine particles and phosphoric acid. The dehydration condensation reaction between the phosphoric acid groups of the dehydration condensate and chromium ions and chromium ion-coordinated dextrin or partially saponified polyvinyl acetate is promoted, resulting in a product that is poorly soluble in hot water and has excellent alkali resistance. A chromate film forms. The appropriate baking temperature for the chromate treatment agent is a steel pipe surface temperature of 120 to 300°C. Steel pipe surface temperature is 120
If the temperature is below 300°C, it will take a very long time to insolubilize the chromate treatment agent layer, making it unsuitable for practical use.
If the temperature is exceeded, the bond between the surface of the silica particles in the chromate treatment agent and phosphoric acid is broken and free soluble phosphoric acid is produced, which in turn reduces the insolubility of the chromate film and deteriorates its resistance to immersion in hot water. In addition, the amount of chromate treatment agent attached is expressed as the total chromium weight.
100-900mg/ m2 is desirable. This amount of adhesion is 100mg/
If it is less than 900 mg/m 2 , the effect of the chromate treatment agent will not be exhibited, and if it exceeds 900 mg/m 2 , a strong film will not be formed and the adhesiveness will decrease. Next, the organic resin coating used in the present invention will be explained. The organic resin coating in the present invention includes epoxy resin, epoxy silicone resin, polyimide epoxy resin, polyphenylene sulfide resin,
Powder coatings whose main components are organic resins such as polyether sulfone resins, polyurethane resins, modified polyethylene, modified polypropylene, modified ethylene-propylene copolymers, modified polyamide-propylene copolymers, etc., and solvent-based paints diluted with solvents. and a coating made by applying and curing a liquid solvent-free paint. In addition to the organic resin as the main component, pigments, filler reinforcing agents, etc. can be added to the above-mentioned organic resin paint. Pigments include silica, silica/alumina, rutile titanium oxide, glass, mapico, zirconium silicate, magnesium silicate, talc,
General commercially available fine powders and flakes such as barium sulfate, alumina, zinc chromate, strontium chromate, lead cinamide, lead zinc oxide, zinc phosphate, aluminum phosphate, calcium phosphate, silicomolybutenic acid, silicotungstic acid, zinc phosphomolybdate, etc. It is a pigment in the form of flakes or flakes, but when aesthetic appearance is required, it can also be used as cadmium yellow, polyazo yellow, quinophthalone yellow, isoindolinone yellow, quinacridone yellow, red red, polyazo brown,
Coloring pigments such as azo lake yellow, perylene red, phthalocyanine blue, phthalocyanine green, red iron yellow, cobalt aluminate, aniline black, carbon black, ultramarine blue, and fine aluminum powder can also be added. The filling strength agent is an inorganic fiber filler such as glass, slag, silicon carbide, carbon, boron, boron nitride, alumina, or the like, or an organic fiber filler such as nylon, polyester, vinylon, aramid, or Kevlar. The organic resin-coated steel pipe according to the present invention can be obtained, for example, by the manufacturing method shown in FIG. That is, the chromate treatment agent according to the present invention is applied to the surface of the steel pipe 1 from which scale and the like have been removed using the chromate treatment agent application device 9, and baked using the heating device 10. Next, an organic resin coating is applied to the surface by an organic resin coating device 11 to produce an organic resin coated steel pipe. The organic resin coating device 11 includes an electrostatic powder coating machine, solvent-based and solvent-free epoxy resin paint, epoxy-silicon resin paint, and polyphenylene resin paint when powdered epoxy resin paint is used as the organic resin coating. When using a fied-based paint, a polyurethane-based resin paint, a polyimide/epoxy resin-based paint, or the like, an appropriate method can be selected from conventionally known methods such as a spray coating machine and a roll coater. Note that 8 in the figure is a powder epoxy coating film. In order to specifically explain the present invention, a preparation example of the chromate treatment agent according to the present invention and JP-A-52-
A comparative preparation example of a chromate treatment agent and a manufacturing example of an organic resin-coated steel pipe corresponding to Publication No. 143934 are given below. Preparation example of chromate treatment agent 1 The following solution was prepared. Mixed aqueous solution of phosphoric acid and chromic acid 49.2 g of phosphoric acid and 76.8 g of chromic anhydride were dissolved in 247.6 g of distilled water. 5% by weight aqueous solution of partially saponified polyvinyl acetate Partially saponified polyvinyl acetate having a molecular weight of 88,000 and a degree of saponification of 87% was added to distilled water and allowed to stand for 2 hours to swell. Next, this aqueous solution was heated to 98
The mixture was heated to 0.degree. C. to completely dissolve it, and an aqueous solution containing 5% by weight of partially saponified polyvinyl acetate was prepared. 10% by weight Aerosil 200 aqueous solution Aerosil 200 manufactured by Nippon Aerosil Co., Ltd. was used as the silica-based fine particles. Add Aerosil 200 to distilled water and mix with high speed mixer (rotation speed 300 rpm)
The mixture was stirred and dispersed to create an aqueous solution containing 10% by weight of Aerosil 200. Next, 106 g of a 5% by weight partially saponified polyvinyl acetate aqueous solution was added to 373.6 g of the above mixed aqueous solution of phosphoric acid and chromic acid, and heated to 90°C.
Some of the valent chromium ions were reduced to trivalent chromium ions. The weight ratio of hexavalent chromium to total chromium in the aqueous solution is 0.60, and the weight ratio of PO 4 3- to total chromium is
It was 1.16. Next, 515.6 g of the 10% by weight Aerosil 200 aqueous solution was added and dispersed in the reduced aqueous solution to obtain the chromate treatment agent A according to the present invention.
It was created. The weight ratio of SiO 2 (Aerosil 200) to total chromium in the chromate treatment agent A was 1.29. Preparation Example of Chromate Treatment Agent 2 Dextrin with an average molecular weight of 120,000 was added instead of the partially saponified polyvinyl acetate as the polymer reducing agent used to create the above-mentioned chromate treatment agent A to create chromate treatment agent B according to the present invention. did. 3 for total chromium in chromate treatment agent B
The weight ratio of valent chromium to total chromium is 0.38.
The weight ratio of PO 4 3- was 1.20, and the weight ratio of SiO 2 to total chromium was 1.60. Comparative Preparation Example of Chromate Treatment Agents 1 As comparative materials, chromate treatment agents C, D, and E corresponding to JP-A-52-143934 were prepared. [Chromate treatment agent C] Dissolve 76.8 g of chromic anhydride and 28.8 g of succinic acid in 700 g of distilled water, and add parbituric acid to the aqueous solution.
Add 19.2g, disperse, and then add distilled water to make 1
Chromate treatment agent C was prepared. [Chromate treatment agent] Dissolve 76.8g of chromic anhydride in 823g of distilled water,
Add 8.4g of wheat starch to this and heat for 1 hour.
The mixture was boiled to partially reduce the hexavalent chromium ions. The weight ratio of trivalent chromium to total chromium in the reduced aqueous solution was 0.38. 92 g of Aerosil #200 was added to the reduced aqueous solution and stirred and dispersed to prepare chromate treatment agent D. [Chromate treatment agent E] Dissolve 76.8g of chromic anhydride in 800g of distilled water,
3.4 g of corn starch was added to this and boiled for 1 hour to partially reduce the hexavalent chromium ions. The weight ratio of trivalent chromium to total chromium in the reduced aqueous solution was 0.22. After stirring and dispersing 23 g of Aerosil #200 and 23 g of talcum powder (magnesium silicate) in the reduced aqueous solution,
Polyvinyl alcohol (manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.)
46 g of a 5% aqueous solution of Gohsenol NM-11) was added and dispersed to prepare chromate treatment agent E. Production example 1 A steel pipe (200A x 5500mm length x 5.8mm thickness) was subjected to grit blasting, and the above-mentioned chromate treatment agents A to E were applied to its surface at 280mg/ m2 in terms of total chromium coating amount, and heated to 230℃. After heating and baking, immediately apply electrostatically applied powder epoxy resin paint (Scotchicoat 206N, manufactured by 3M) to a film thickness of 400μ, heat cure for 3 minutes, and then raise the surface temperature to 240℃ using a far-infrared heater. After heating for 4 minutes, a powder epoxy coated steel pipe was produced. The above powder epoxy coated steel pipe was subjected to a high temperature cathodic peel test (test temperature 80℃, electrolyte 3% NaCl,
voltage -1.5V [Cu/CuSO 4 , standard electrode], initial holiday diameter 3.2mmφ, test days 30 days), and after the test, the converted peeling radius of the coating film [
【式】mm、ｘは試験後の塗膜 剥離直径〕を測定した結果を第１表に示した。[Formula] mm, x is the coating film after the test The results of measuring the peeled diameter are shown in Table 1.
【表】
第１表の結果から、剥離距離に著しい差が認め
られ、特に下地処理剤として、部分ケン化ポリ酢
酸ビニルを還元剤とし、リン酸とシリカ系微粒子
を添加した本発明によるクロメート処理剤Ａを用
いた場合及びデキストリンを還元剤とし、リン酸
とシリカ系微粒子を含む本発明によるクロメート
処理剤Ｂを用いた場合は、特開昭52−143934号公
報に相当するクロメート処理剤Ｃ，Ｄ，Ｅを用い
る場合に比較して、格段に優れた結果が得られる
ことが確認できた。
製造例 ２
製造例１と同じ方法で、クロメート処理剤Ａ中
の全クロムに対するPO4 3-（リン酸イオン）の重
量比を変えて、前記の粉体エポキシ塗装鋼管を製
造した。この粉体エポキシ塗装鋼管について、前
記の高温陰極剥離試験を行つた結果を、第６図に
示した。
第６図の結果から、クロメート処理剤Ａ中の全
クロムに対するPO4 3-の重量比が0.5〜2.0の範囲
で良好な耐高温陰極剥離性が発現する。従つて、
本発明に用いるクロメート処理剤には、リン酸を
全クロムに対するPO4 3-の重量比が0.5〜2.0の範
囲になるように添加する必要がある。
製造例 ３
製造例１と同じ方法で、クロメート処理剤Ａに
添加するリン酸の１／５重量を、
ピロリン酸
リン酸水素二アルミニウム
で置換えて、前記の粉体エポキシ塗装鋼管を作成
した。この粉体エポキシ塗装鋼管について、前記
の高温陰極剥離試験を行つた結果を、第２表に示
した。[Table] From the results in Table 1, a remarkable difference in peeling distance was observed, especially the chromate treatment according to the present invention in which partially saponified polyvinyl acetate was used as a reducing agent and phosphoric acid and silica-based fine particles were added as a surface treatment agent. When agent A is used and when chromate treatment agent B according to the present invention is used, which uses dextrin as a reducing agent and contains phosphoric acid and silica-based fine particles, chromate treatment agent C, which corresponds to JP-A-52-143934, It was confirmed that much better results were obtained compared to the case of using D and E. Production Example 2 The above-mentioned powder epoxy coated steel pipes were produced in the same manner as in Production Example 1 by changing the weight ratio of PO 4 3- (phosphate ion) to total chromium in chromate treatment agent A. The above-mentioned high-temperature cathode peeling test was conducted on this powder epoxy coated steel pipe, and the results are shown in FIG. From the results shown in FIG. 6, good high-temperature cathode peelability is exhibited when the weight ratio of PO 4 3- to total chromium in chromate treatment agent A is in the range of 0.5 to 2.0. Therefore,
Phosphoric acid must be added to the chromate treatment agent used in the present invention so that the weight ratio of PO 4 3- to total chromium is in the range of 0.5 to 2.0. Production Example 3 In the same manner as Production Example 1, 1/5 of the weight of phosphoric acid added to chromate treatment agent A was replaced with pyrophosphoric acid dialuminum hydrogen phosphate to produce the above-mentioned powder epoxy coated steel pipe. Table 2 shows the results of the high-temperature cathodic peeling test described above for this powder epoxy coated steel pipe.
【表】
第２表の結果から、クロメート処理剤Ａに添加
するリン酸の１／５重量をピロリン酸あるいはリ
ン酸水素二アルミニウムで置き換えても良好な耐
高温陰極剥離性が得られる。
製造例 ４
製造例１と同じ方法で、クロメート処理剤Ａ中
の全クロムに対するSiO2（アエロジル＃200）の
重量比を変えて、前記の粉体エポキシ塗装鋼管を
作成した。この粉体エポキシ塗装鋼管について、
前記の高温陰極剥離試験を行つた結果を、第７図
に示した。
第７図の結果から、クロメート処理剤Ａ中の全
クロムに対するSiO2の重量比が0.5〜2.5の範囲で
良好な耐高温陰極剥離性が得られた。従つて、本
発明に用いるクロメート処理剤にはシリカ系微粒
子を全クロムに対するSiO2の重量比が0.5〜2.5の
範囲になるように添加する必要がある。
製造例 ５
製造例１と同じ方法で、クロメート処理剤Ａ中
に添加するシリカ系微粒子を次のように変えて、
前記の粉体エポキシ塗装鋼管を作成した。
シリカ微粒子（日本アエロジル社製、アエロ
ジル＃200）
シリカ・アルミナ微粒子（日本アエロジル社
製、CoK84）
コロイダルシリカ（日産化学社製、スノーテ
ツクスＯ）
酸化チタン微粒子（チタン工業製、KR310）
これらの粉体エポキシ塗装鋼管について、前記
の高温陰極剥離試験を行つた結果を、第３表に
示した。[Table] From the results in Table 2, good high-temperature cathode peelability can be obtained even if 1/5 weight of the phosphoric acid added to chromate treatment agent A is replaced with pyrophosphoric acid or dialuminum hydrogen phosphate. Production Example 4 In the same manner as in Production Example 1, the above powder epoxy coated steel pipes were produced by changing the weight ratio of SiO 2 (Aerosil #200) to the total chromium in chromate treatment agent A. About this powder epoxy coated steel pipe,
The results of the high temperature cathode peeling test described above are shown in FIG. From the results shown in FIG. 7, good high-temperature cathode peelability was obtained when the weight ratio of SiO 2 to total chromium in chromate treatment agent A was in the range of 0.5 to 2.5. Therefore, it is necessary to add silica-based fine particles to the chromate treatment agent used in the present invention so that the weight ratio of SiO 2 to total chromium is in the range of 0.5 to 2.5. Production Example 5 Using the same method as Production Example 1, changing the silica-based fine particles added to chromate treatment agent A as follows,
The powder epoxy coated steel pipe described above was prepared. Silica fine particles (manufactured by Nippon Aerosil Co., Ltd., Aerosil #200) Silica/alumina fine particles (manufactured by Nippon Aerosil Co., Ltd., CoK84) Colloidal silica (manufactured by Nissan Chemical Co., Ltd., Snotex O) Titanium oxide fine particles (manufactured by Titanium Industries, Ltd., KR310)
Table 3 shows the results of the above-mentioned high-temperature cathode peeling test performed on these powder epoxy coated steel pipes.
【表】
第３表の結果から、クロメート処理剤Ａに添加
する微粒子としてシリカ系微粒子（シリカ微粒
子、シリカ・アルミナ微粒子及びコロイダルシリ
カ）を用いる場合にはいずれも良好な耐高温陰極
剥離性が得られるが、酸化チタン微粒子を用いる
場合には剥離が大きくなる。従つて、本発明に用
いるクロメート処理剤にはシリカ系微粒子を添加
する必要がある。
製造例 ６
製造例１と同じ方法で、クロメート処理剤Ａの
調合に用いる部分ケン化ポリ酢酸ビニルの分子量
を変えて、前記の粉体エポキシ塗装鋼管を作成し
た。この粉体エポキシ塗装鋼管について、前記の
高温陰極剥離試験を行つた結果を、第８図に示し
た。
第８図の結果から、クロメート処理剤Ａの調合
に用いる部分ケン化ポリ酢酸ビニルの分子量が
60000〜140000の範囲で良好な耐高温陰極剥離性
が得られる。従つて、本発明に用いるクロメート
処理剤に添加する部分ケン化ポリ酢酸ビニルの分
子量を60000〜140000の範囲にする必要がある。
製造例 ７
製造例１と同じ方法で、クロメート処理剤Ａの
調合に用いる部分ケン化ポリ酢酸ビニルのケン化
度を変えて、前記の粉体エポキシ塗装鋼管を作成
した。この粉体エポキシ塗装鋼管について、前記
の高温陰極剥離試験を行つた結果を第９図に示
す。第９図の結果から、クロメート処理剤Ａに添
加する部分ケン化ポリ酢酸ビニルのケン化度が80
〜90％の範囲で良好な耐高温陰極剥離性が得られ
る。従つて、本発明に用いるクロメート処理剤に
添加する部分ケン化ポリ酢酸ビニルのケン化度を
80〜90％の範囲にする必要がある。
製造例 ８
製造例１と同じ方法で、クロメート処理剤Ａの
調合に用いる部分ケン化ポリ酢酸ビニルを下記の
還元剤で置き換えて、前記の粉体エポキシ塗装鋼
管を作成した。
部分ケン化ポリ酢酸ビニル（分子量88000、
ケン化度87％）
デキストリン（平均分子量120000）
小麦デンプン
トウモロコシデンプン
コハク酸
メチルアルコール
ポリビニルアルコール
これらの粉体エポキシ塗装鋼管について、前記
の高温陰極剥離試験を行つた結果を、第４表に示
した。[Table] From the results in Table 3, when silica-based fine particles (silica fine particles, silica/alumina fine particles, and colloidal silica) are used as fine particles added to chromate treatment agent A, good high-temperature cathodic peelability can be obtained in all cases. However, when titanium oxide fine particles are used, peeling becomes large. Therefore, it is necessary to add silica-based fine particles to the chromate treatment agent used in the present invention. Production Example 6 In the same manner as in Production Example 1, the above powder epoxy-coated steel pipes were produced by changing the molecular weight of the partially saponified polyvinyl acetate used to prepare chromate treatment agent A. The above-mentioned high-temperature cathode peeling test was conducted on this powder epoxy coated steel pipe, and the results are shown in FIG. From the results shown in Figure 8, the molecular weight of the partially saponified polyvinyl acetate used for preparing chromate treatment agent A is
Good high-temperature cathode peelability can be obtained in the range of 60,000 to 140,000. Therefore, the molecular weight of the partially saponified polyvinyl acetate added to the chromate treatment agent used in the present invention needs to be in the range of 60,000 to 140,000. Production Example 7 In the same manner as in Production Example 1, the above-mentioned powder epoxy coated steel pipes were produced by changing the degree of saponification of the partially saponified polyvinyl acetate used in the preparation of chromate treatment agent A. FIG. 9 shows the results of the above-mentioned high-temperature cathode peeling test performed on this powder epoxy coated steel pipe. From the results shown in Figure 9, the degree of saponification of partially saponified polyvinyl acetate added to chromate treatment agent A is 80.
Good high-temperature cathode peelability can be obtained in the range of ~90%. Therefore, the degree of saponification of the partially saponified polyvinyl acetate added to the chromate treatment agent used in the present invention is determined by
It should be in the 80-90% range. Production Example 8 In the same manner as in Production Example 1, the partially saponified polyvinyl acetate used in the preparation of chromate treatment agent A was replaced with the following reducing agent to produce the above-mentioned powder epoxy coated steel pipe. Partially saponified polyvinyl acetate (molecular weight 88000,
Saponification degree: 87%) Dextrin (average molecular weight: 120,000) Wheat starch Corn starch Succinic acid Methyl alcohol Polyvinyl alcohol These powder epoxy coated steel pipes were subjected to the high temperature cathode peeling test described above, and the results are shown in Table 4.
【表】
第４表の結果から、クロメート処理剤の還元剤
として部分ケン化ポリ酢酸ビニルあるいはデキス
トリンを用いた場合にのみ良好な耐高温陰極剥離
性が得られた。従つて、本発明によるクロメート
処理剤の還元剤として部分ケン化ポリ酢酸ビニル
あるいはデキストリンを用いる必要がある。
製造例 ９
鋼管（200A×5500mm長×5.8mm厚）をグリツト
ブラスト処理し、其の表面に前記クロメート処理
剤Ａを全クロム付着量で380mg/m2塗布し、150℃
に加熱して焼付けた。このクロメート処理鋼管の
外表面に下記の有機樹脂塗料を塗布し、加熱硬化
させて本発明による有機樹脂系被覆鋼管を製造し
た。
無溶剤型エポキシ樹脂塗料（膜厚1.5mm）
（ビスフエノールＡ型エポキシ樹脂 80重量部
酸化チタン微粉末 20重量部
ｍ−キシレンジアミンの変性ポリアミン硬化
剤 33重量部）
溶剤型エポキシ樹脂塗料（膜厚600μ）
（上記100重量部にシンナー20重量部を混
合）
エポキシ・シリコーン樹脂塗料（膜厚1.8
mm）
（ビスフエノールＡ型エポキシ樹脂 70重量部
末端シラノール変性ポリジメチル・ジフエニ
ル・シロキサン 10重量部
酸化チタン微粉末 20重量部
ジシアンジアミド 16重量部
芳香族尿素化合物系硬化促進剤 ９重量部）
エポキシ・シリコーン樹脂塗料（膜厚2.5
mm）
ビスフエノールAD型エポキシ樹脂 70重量部
末端シラノール変性ポリジメチル・ジフエニ
ルシロキサン 10重量部
ガラスフレーク 20重量部
スラグチヨツプドフアイバー 20重量部
ジシアンジアミド 17重量部
イミダゾールリン酸塩系硬化促進剤 ９重量部
エポキシ・シリコーン樹脂塗料（膜厚
600μ）
（ビスフエノールAD型エポキシ樹脂 70重量部
末端シラノール変性ポリジメチルシロキサン
10重量部
酸化チタン粉末 20重量部
ｍ−キシレンジアミンの変性ポリアミン硬化
剤 30重量部）
ポリイミド・エポキシ樹脂塗料（膜厚600μ）
（ビスフエノールＦ型エポキシ樹脂 70重量部
ポリイミド樹脂 10重量部
シリカ・アルミナ微粉末 ３重量部
酸化チタン微粉末 20重量部
ｍ−キシレンジアミンの変性ポリアミン硬化
剤 28重量部）
ポリフエニレンサルフアイド樹脂塗料（膜厚
400μ）
（ポリフエニレンサルフアイド樹脂 80重量部
酸化チタン微粉末 20重量部
溶剤 30重量部）
ポリエーテルスルフオン樹脂塗料（膜厚
400μ）
（ポリエーテルスルフオン樹脂 80重量部
シリカ・アルミナ微粉末 10重量部
溶剤 33重量部）
ポリウレタン樹脂塗料（膜厚2.5mm）
（エポキシ変性ポリオール樹脂 60重量部
イソシアネート硬化剤 40重量部
フエノール変性クマロン樹脂 40重量部
偏平タルク粉 40重量部）
これらの有機樹脂系被覆鋼管について、前記の
高温陰極剥離試験を行つた結果を、第５表に示し
た。[Table] From the results in Table 4, good high-temperature cathodic peelability was obtained only when partially saponified polyvinyl acetate or dextrin was used as the reducing agent for the chromate treatment agent. Therefore, it is necessary to use partially saponified polyvinyl acetate or dextrin as a reducing agent for the chromate treatment agent according to the present invention. Manufacturing example 9 A steel pipe (200A x 5500mm length x 5.8mm thickness) was grit blasted, the chromate treatment agent A was applied to its surface with a total chromium coating amount of 380mg/ m2 , and the temperature was heated at 150℃.
It was heated and baked. The following organic resin paint was applied to the outer surface of this chromate-treated steel pipe and cured by heating to produce an organic resin-coated steel pipe according to the present invention. Solvent-free epoxy resin paint (film thickness 1.5 mm) (Bisphenol A type epoxy resin 80 parts by weight Titanium oxide fine powder 20 parts by weight Modified polyamine curing agent of m-xylene diamine 33 parts by weight) Solvent-free epoxy resin paint (film thickness 600μ) (mix 20 parts by weight of thinner with 100 parts by weight above) Epoxy silicone resin paint (film thickness 1.8
mm) (Bisphenol A type epoxy resin 70 parts by weight, silanol-terminated polydimethyl diphenyl siloxane 10 parts by weight, fine titanium oxide powder 20 parts by weight, dicyandiamide 16 parts by weight, aromatic urea compound curing accelerator 9 parts by weight) Epoxy silicone Resin paint (film thickness 2.5
mm) Bisphenol AD type epoxy resin 70 parts by weight Silanol-terminated polydimethyl diphenylsiloxane 10 parts by weight Glass flakes 20 parts by weight Slag tipped fiber 20 parts by weight Dicyandiamide 17 parts by weight Imidazole phosphate curing accelerator 9 Part by weight Epoxy/silicone resin paint (film thickness
600μ) (bisphenol AD type epoxy resin 70 parts by weight silanol-terminated polydimethylsiloxane)
10 parts by weight Titanium oxide powder 20 parts by weight Modified polyamine curing agent of m-xylene diamine 30 parts by weight) Polyimide/epoxy resin paint (film thickness 600μ) (Bisphenol F type epoxy resin 70 parts by weight Polyimide resin 10 parts by weight Silica/alumina Fine powder 3 parts by weight Titanium oxide fine powder 20 parts by weight Modified polyamine curing agent of m-xylene diamine 28 parts by weight) Polyphenylene sulfide resin paint (film thickness
400μ) (Polyphenylene sulfide resin 80 parts by weight Titanium oxide fine powder 20 parts by weight Solvent 30 parts by weight) Polyether sulfonate resin paint (film thickness
(400μ) (Polyether sulfone resin 80 parts by weight Silica/alumina fine powder 10 parts by weight Solvent 33 parts by weight) Polyurethane resin paint (film thickness 2.5 mm) (Epoxy modified polyol resin 60 parts by weight Isocyanate curing agent 40 parts by weight Phenol modified Coumaron Resin: 40 parts by weight Flat talcum powder: 40 parts by weight) Table 5 shows the results of the high-temperature cathode peeling test described above for these organic resin-coated steel pipes.
【表】
第５表の結果から、いずれの有機樹脂塗料を用
いた場合でも良好な耐高温陰極剥離性が得られ、
鋼管の下地処理に本発明によるクロメート処理剤
を用いれば良好な結果が得られる。
製造例 10
鋼管（200A×5500mm長×5.8mm厚）をグリツト
ブラスト処理し、其の表面に前記のクロメート処
理剤Ｂを全クロム付着量が590mg/m2になるように
塗布し、200℃に加熱して焼付けた。次いで、次
の有機樹脂の粉体塗料を静電塗装し、本発明によ
る有機樹脂系被覆鋼管を製造した。
無水マレイン酸変性低密度ポリエチレン
無水マレイン酸変性直鎖状低密度ポリエチレ
ン
無水マレイン酸変性高密度ポリエチレン
無水マレイン酸エチレン・プロピレン共重合
体
無水マレイン酸変性ポリアミド・プロピレン
共重合体
無水マレイン酸変性ポリプロピレン
ビニルシラン変性直鎖状低密度ポリエチレン
ビニルシラン変性エチレンプロピレン共重合
体
これらの有機樹脂系被覆鋼管について、前記の
高温陰極剥離試験を行つた結果を、第６表に示し
た。[Table] From the results in Table 5, good high-temperature cathode peelability was obtained no matter which organic resin paint was used.
Good results can be obtained by using the chromate treatment agent of the present invention in the surface treatment of steel pipes. Manufacturing example 10 A steel pipe (200A x 5500mm length x 5.8mm thickness) was grit blasted, the above-mentioned chromate treatment agent B was applied to its surface so that the total amount of chromium deposited was 590mg/ m2 , and the tube was heated at 200℃. It was heated and baked. Next, the following organic resin powder coating was applied electrostatically to produce an organic resin-coated steel pipe according to the present invention. Maleic anhydride modified low density polyethylene Maleic anhydride modified linear low density polyethylene Maleic anhydride modified high density polyethylene Maleic anhydride ethylene/propylene copolymer Maleic anhydride modified polyamide/propylene copolymer Maleic anhydride modified polypropylene Vinyl silane modified Linear low-density polyethylene Vinylsilane-modified ethylene propylene copolymer Table 6 shows the results of the high-temperature cathodic peel test described above for these organic resin-coated steel pipes.
【表】
第６表の結果から、いずれの有機樹脂の粉体塗
料を用いた場合でも良好な耐高温陰極剥離性が得
られ、鋼管の下地処理に本発明によるクロメート
処理剤を用いれば良好な結果が得られる。
（発明の効果）
製造例からも明らかな如く、本発明による有機
樹脂系被覆鋼管は、従来の有機樹脂系被覆鋼管に
比較して、下地に耐熱水性の優れたクロメート処
理剤層を有するので、耐高温陰極剥離性に格段に
優れるため、従来にない耐久性のある有機樹脂系
被覆鋼管を提供できることとなつた。[Table] From the results in Table 6, good high-temperature cathodic peeling resistance can be obtained no matter which organic resin powder coating is used, and good high-temperature cathodic peeling resistance can be obtained when the chromate treatment agent of the present invention is used for the base treatment of steel pipes. Get results. (Effects of the Invention) As is clear from the manufacturing examples, the organic resin-coated steel pipe according to the present invention has a chromate treatment agent layer on the base that has excellent hot water resistance compared to conventional organic resin-coated steel pipes. Because it has extremely high-temperature cathode peeling resistance, it has become possible to provide an organic resin-coated steel pipe with unprecedented durability.
第１図は本発明による有機樹脂系被覆鋼管の一
部断面図、第２図は本発明の一実施例を示す概略
説明図、第３図、第４図、第５図は従来法による
有機樹脂系被覆鋼管の一部断面図、第６図は粉体
エポキシ塗装鋼管のクロメート処理剤Ａ中の全ク
ロムに対するPO4 3-の重量比と高温陰極剥離試験
との関係を示すグラフ。第７図は粉体エポキシ塗
装鋼管のクロメート処理剤中の全クロムに対する
SiO2の重量比と高温陰極剥離試験との関係を示
すグラフ。第８図は粉体エポキシ塗装鋼管のクロ
メート処理剤Ａの部分ケン化ポリ酢酸ビニルの分
子量と高温陰極剥離試験との関係を示すグラフ。
第９図は粉体エポキシ塗装鋼管のクロメート処理
剤Ａに用いる部分ケン化ポリ酢酸ビニルのケン化
度と高温陰極剥離試験との関係を示すグラフ。
１…鋼管、２…リン酸とクロム酸の混合水溶液
をデキストリンまたは部分化ポリ酢酸ビニルで部
分的に還元し、シリカ系微粒子を添加し、加熱焼
付けしたクロメート処理剤層、３…有機樹脂系被
覆層、４…６価クロムの化合物と有機成分（アミ
ノ酸、酸アミド、ラクタム、飽和及び不飽和ポリ
カルボン酸）からなるクロメート処理層、５…熱
可塑性または熱硬化性樹脂組成物の粉体塗装塗
膜、６…クロム酸（CrO3）を還元剤（糖類、多
価アルコール、一価アルコール、アルキロールア
ミン、芳香族多価アルコール、亜リン酸）で部分
的に還元し、これに微粉シリカを添加したクロメ
ート処理剤層。７…クロム酸（CrO3）を還元剤
で部分的に還元し、これに微粉シリカと非イオン
系水溶性樹脂（ポリビニルアルコール、メチルセ
ルロール、ポリエチレンオキシド、ヘキサメトキ
シメチルメラミン変性ポリヒドロキシエチルアク
リレート）を添加したクロメート処理剤層、８…
粉体エポキシ塗装塗膜、９…クロメート処理剤塗
布装置、１０…加熱装置、１１…有機樹脂被覆装
置。
Fig. 1 is a partial sectional view of an organic resin-coated steel pipe according to the present invention, Fig. 2 is a schematic explanatory diagram showing one embodiment of the present invention, and Figs. FIG. 6 is a partial cross-sectional view of a resin coated steel pipe, and a graph showing the relationship between the weight ratio of PO 4 3- to total chromium in chromate treatment agent A of powder epoxy coated steel pipe and high temperature cathodic peeling test. Figure 7 shows the total chromium in the chromate treatment agent for powder epoxy coated steel pipes.
Graph showing the relationship between the weight ratio of SiO 2 and high temperature cathode peeling test. FIG. 8 is a graph showing the relationship between the molecular weight of partially saponified polyvinyl acetate of chromate treatment agent A for powder epoxy-coated steel pipes and high-temperature cathode peeling test.
FIG. 9 is a graph showing the relationship between the degree of saponification of partially saponified polyvinyl acetate used as chromate treatment agent A for powder epoxy-coated steel pipes and high-temperature cathode peeling test. 1... Steel pipe, 2... Chromate treatment agent layer obtained by partially reducing a mixed aqueous solution of phosphoric acid and chromic acid with dextrin or partial polyvinyl acetate, adding silica-based fine particles, and baking with heat, 3... Organic resin coating layer, 4... chromate treatment layer consisting of a compound of hexavalent chromium and an organic component (amino acid, acid amide, lactam, saturated and unsaturated polycarboxylic acid), 5... powder coating of thermoplastic or thermosetting resin composition Membrane, 6...Chromic acid (CrO 3 ) is partially reduced with a reducing agent (saccharide, polyhydric alcohol, monohydric alcohol, alkylolamine, aromatic polyhydric alcohol, phosphorous acid), and finely divided silica is added to this. Added chromate treatment agent layer. 7...Chromic acid (CrO 3 ) is partially reduced with a reducing agent, and then finely powdered silica and nonionic water-soluble resin (polyvinyl alcohol, methylcellulose, polyethylene oxide, hexamethoxymethylmelamine-modified polyhydroxyethyl acrylate) are added. Chromate treatment agent layer added with 8...
Powder epoxy coating film, 9... Chromate treatment agent coating device, 10... Heating device, 11... Organic resin coating device.
Claims (1)
の水溶液に該水溶液中の全クロムに対するPO4 3-
の重量比が0.5〜2.0の範囲になるようにリン酸を
混合した混合水溶液を、酵素でデンプンを加水分
解して得られ、かつ平均分子量が50000〜250000
の範囲のデキストリンで、該混合水溶液中の全ク
ロムに対する６価クロムの重量比が0.35〜0.65の
範囲になるように部分還元し、かつ、シリカ微粒
子を該混合水溶液中の全クロムに対するSiO2の
重量比が0.5〜2.5の範囲になるように添加した混
合物を加熱焼付けして得られるクロメート処理剤
層に有機樹脂系被覆を積層することを特徴とする
耐高温陰極剥離性の優れた有機樹脂系被覆鋼管の
製造方法。 ２ 鋼管の外表面に内側から順に、無水クロム酸
の水溶液に該水溶液中の全クロムに対するPO4 3-
の重量比が0.5〜2.0の範囲になるようにリン酸を
混合した水溶液を、 の分子構造を有し、かつ ケン化度ｍ／ｍ＋ｎ×100（％）が80〜90％でかつ 平均分子量が60000〜140000の範囲の部分ケン化
ポリ酢酸ビニルで該混合水溶液中の全クロムに対
する６価クロムの重量比が0.35〜0.65の範囲にな
るように部分還元し、かつシリカ微粒子を該混合
水溶液中の全クロムに対するSiO2の重量比が0.5
〜2.5の範囲になるように添加した混合物を加熱
焼付けして得られるクロメート処理剤層に、有機
樹脂系被覆を積層することを特徴とする耐高温陰
極剥離性の優れた有機樹脂系被覆鋼管の製造方
法。 ３ 有機樹脂系被覆として、エポキシ樹脂、エポ
キシ・シリコーン樹脂、ポリイミド・エポキシ樹
脂、ポリフエニレンサルフアイド樹脂、ポリエー
テルスルフオン樹脂、ポリウレタン樹脂、変性ポ
リエチレン、変性ポリプロピレン、変性エチレ
ン・プロピレン共重合体、変性ポリアシド・プロ
ピレン共重合体等の有機樹脂系の粉体塗料、溶剤
型塗料及び無溶剤型塗料を用いることを特徴とす
る特許請求の範囲第１項又は第２項記載の耐高温
陰極剥離性の優れた有機樹脂系被覆鋼管の製造方
法。[Claims] 1. On the outer surface of the steel pipe, starting from the inside, an aqueous solution of chromic anhydride is added with PO 4 3- based on the total chromium in the aqueous solution.
obtained by hydrolyzing starch with an enzyme in a mixed aqueous solution containing phosphoric acid such that the weight ratio of
The weight ratio of hexavalent chromium to the total chromium in the mixed aqueous solution is in the range of 0.35 to 0.65 with dextrin in the range of An organic resin system with excellent high-temperature cathode peelability, characterized by laminating an organic resin coating on a chromate treatment agent layer obtained by heating and baking a mixture added so that the weight ratio is in the range of 0.5 to 2.5. Method for manufacturing coated steel pipes. 2. On the outer surface of the steel pipe, starting from the inside, add PO 4 3- to the total chromium in the aqueous solution of chromic anhydride.
An aqueous solution mixed with phosphoric acid such that the weight ratio of Partially saponified polyvinyl acetate having a molecular structure of 80% to 90% and an average molecular weight of 60,000 to 140,000, based on the total chromium in the mixed aqueous solution. Partial reduction is carried out so that the weight ratio of hexavalent chromium is in the range of 0.35 to 0.65, and the silica fine particles are reduced so that the weight ratio of SiO 2 to the total chromium in the mixed aqueous solution is 0.5.
An organic resin-coated steel pipe with excellent high-temperature cathodic peelability, characterized in that an organic resin coating is laminated on a chromate treatment agent layer obtained by heating and baking a mixture added in a range of ~2.5. Production method. 3. As organic resin coating, epoxy resin, epoxy silicone resin, polyimide epoxy resin, polyphenylene sulfide resin, polyether sulfon resin, polyurethane resin, modified polyethylene, modified polypropylene, modified ethylene propylene copolymer, High-temperature cathodic peeling resistance according to claim 1 or 2, characterized in that an organic resin-based powder coating, a solvent-based coating, or a solvent-free coating is used, such as a modified polyacid/propylene copolymer. A method for manufacturing excellent organic resin-coated steel pipes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21521587A JPH01280545A (en) | 1987-08-31 | 1987-08-31 | Organic resin coated steel pipe with excellent cathode peeling resistance at high temperature |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21521587A JPH01280545A (en) | 1987-08-31 | 1987-08-31 | Organic resin coated steel pipe with excellent cathode peeling resistance at high temperature |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01280545A JPH01280545A (en) | 1989-11-10 |
| JPH0366393B2 true JPH0366393B2 (en) | 1991-10-17 |
Family
ID=16668603
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21521587A Granted JPH01280545A (en) | 1987-08-31 | 1987-08-31 | Organic resin coated steel pipe with excellent cathode peeling resistance at high temperature |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01280545A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2220192A1 (en) * | 1996-11-07 | 1998-05-07 | Masayasu Kojima | Lubricant surface-treated steel pipe for hydroforming use |
| KR101655931B1 (en) * | 2015-09-24 | 2016-09-08 | 주식회사 투에이취켐 | Hybrid powder coating material |
-
1987
- 1987-08-31 JP JP21521587A patent/JPH01280545A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01280545A (en) | 1989-11-10 |
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