JPS6324827B2 - - Google Patents
Info
- Publication number
- JPS6324827B2 JPS6324827B2 JP10613985A JP10613985A JPS6324827B2 JP S6324827 B2 JPS6324827 B2 JP S6324827B2 JP 10613985 A JP10613985 A JP 10613985A JP 10613985 A JP10613985 A JP 10613985A JP S6324827 B2 JPS6324827 B2 JP S6324827B2
- Authority
- JP
- Japan
- Prior art keywords
- resin
- seam
- thermoplastic resin
- paint
- layer
- 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
- 229920005989 resin Polymers 0.000 claims description 95
- 239000011347 resin Substances 0.000 claims description 95
- 239000003973 paint Substances 0.000 claims description 54
- 239000010410 layer Substances 0.000 claims description 50
- 229920001187 thermosetting polymer Polymers 0.000 claims description 49
- 229920005992 thermoplastic resin Polymers 0.000 claims description 47
- 239000011248 coating agent Substances 0.000 claims description 43
- 238000000576 coating method Methods 0.000 claims description 43
- -1 carbonate ester Chemical class 0.000 claims description 40
- 239000002245 particle Substances 0.000 claims description 38
- 229910000831 Steel Inorganic materials 0.000 claims description 36
- 239000010959 steel Substances 0.000 claims description 36
- 238000003466 welding Methods 0.000 claims description 23
- 238000000034 method Methods 0.000 claims description 22
- 239000000463 material Substances 0.000 claims description 21
- 229910052751 metal Inorganic materials 0.000 claims description 19
- 239000002184 metal Substances 0.000 claims description 19
- 239000011247 coating layer Substances 0.000 claims description 14
- 238000004519 manufacturing process Methods 0.000 claims description 14
- 239000000758 substrate Substances 0.000 claims description 14
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 13
- 239000011651 chromium Substances 0.000 claims description 13
- 229910052804 chromium Inorganic materials 0.000 claims description 13
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 claims description 13
- 239000002904 solvent Substances 0.000 claims description 10
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 claims description 8
- 229910000423 chromium oxide Inorganic materials 0.000 claims description 8
- 239000003822 epoxy resin Substances 0.000 claims description 8
- 229920000647 polyepoxide Polymers 0.000 claims description 8
- 229920000642 polymer Polymers 0.000 claims description 7
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 claims description 6
- 239000005011 phenolic resin Substances 0.000 claims description 6
- 150000002576 ketones Chemical class 0.000 claims description 5
- 229920001568 phenolic resin Polymers 0.000 claims description 5
- 229920000728 polyester Polymers 0.000 claims description 5
- 150000001732 carboxylic acid derivatives Chemical class 0.000 claims description 4
- 229920000098 polyolefin Polymers 0.000 claims description 4
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 claims description 3
- 239000004925 Acrylic resin Substances 0.000 claims description 3
- 229920000178 Acrylic resin Polymers 0.000 claims description 3
- 229920000877 Melamine resin Polymers 0.000 claims description 3
- 239000004952 Polyamide Substances 0.000 claims description 3
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 3
- 229920001807 Urea-formaldehyde Polymers 0.000 claims description 3
- 239000002612 dispersion medium Substances 0.000 claims description 3
- 238000001704 evaporation Methods 0.000 claims description 3
- 229920000554 ionomer Polymers 0.000 claims description 3
- 229920002647 polyamide Polymers 0.000 claims description 3
- 229920000515 polycarbonate Polymers 0.000 claims description 3
- 239000004417 polycarbonate Substances 0.000 claims description 3
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 claims description 2
- 239000004202 carbamide Substances 0.000 claims description 2
- 150000001244 carboxylic acid anhydrides Chemical class 0.000 claims description 2
- 150000001733 carboxylic acid esters Chemical class 0.000 claims description 2
- 230000008020 evaporation Effects 0.000 claims description 2
- 239000004640 Melamine resin Substances 0.000 claims 1
- 150000007942 carboxylates Chemical class 0.000 claims 1
- 239000010408 film Substances 0.000 description 27
- 239000000243 solution Substances 0.000 description 25
- 230000007797 corrosion Effects 0.000 description 19
- 238000005260 corrosion Methods 0.000 description 19
- 239000005029 tin-free steel Substances 0.000 description 19
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 16
- 229920001577 copolymer Polymers 0.000 description 15
- 238000012360 testing method Methods 0.000 description 12
- 239000012298 atmosphere Substances 0.000 description 11
- 238000012545 processing Methods 0.000 description 11
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 10
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 9
- 125000004432 carbon atom Chemical group C* 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- 239000000178 monomer Substances 0.000 description 8
- 230000004888 barrier function Effects 0.000 description 7
- 238000001816 cooling Methods 0.000 description 7
- 239000007789 gas Substances 0.000 description 7
- 229910052742 iron Inorganic materials 0.000 description 7
- 229920001169 thermoplastic Polymers 0.000 description 7
- 125000002947 alkylene group Chemical group 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 239000001257 hydrogen Substances 0.000 description 6
- 229910052739 hydrogen Inorganic materials 0.000 description 6
- 229910052760 oxygen Inorganic materials 0.000 description 6
- 239000000843 powder Substances 0.000 description 6
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 6
- 229920002554 vinyl polymer Polymers 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 5
- 239000004698 Polyethylene Substances 0.000 description 5
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 5
- 239000002253 acid Substances 0.000 description 5
- 230000008901 benefit Effects 0.000 description 5
- 238000011156 evaluation Methods 0.000 description 5
- 229920000573 polyethylene Polymers 0.000 description 5
- 238000004826 seaming Methods 0.000 description 5
- 239000007787 solid Substances 0.000 description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 4
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical class [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 239000006185 dispersion Substances 0.000 description 4
- ILRSCQWREDREME-UHFFFAOYSA-N dodecanamide Chemical compound CCCCCCCCCCCC(N)=O ILRSCQWREDREME-UHFFFAOYSA-N 0.000 description 4
- 238000010828 elution Methods 0.000 description 4
- 150000002148 esters Chemical class 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 150000002430 hydrocarbons Chemical class 0.000 description 4
- 239000011261 inert gas Substances 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 239000007921 spray Substances 0.000 description 4
- 230000001954 sterilising effect Effects 0.000 description 4
- 238000004659 sterilization and disinfection Methods 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 239000002344 surface layer Substances 0.000 description 4
- JHPBZFOKBAGZBL-UHFFFAOYSA-N (3-hydroxy-2,2,4-trimethylpentyl) 2-methylprop-2-enoate Chemical compound CC(C)C(O)C(C)(C)COC(=O)C(C)=C JHPBZFOKBAGZBL-UHFFFAOYSA-N 0.000 description 3
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 3
- 229920002126 Acrylic acid copolymer Polymers 0.000 description 3
- GVNWZKBFMFUVNX-UHFFFAOYSA-N Adipamide Chemical compound NC(=O)CCCCC(N)=O GVNWZKBFMFUVNX-UHFFFAOYSA-N 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 3
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- 239000005977 Ethylene Substances 0.000 description 3
- 241000227653 Lycopersicon Species 0.000 description 3
- 235000007688 Lycopersicon esculentum Nutrition 0.000 description 3
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 150000001336 alkenes Chemical class 0.000 description 3
- 125000000217 alkyl group Chemical group 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 125000000732 arylene group Chemical group 0.000 description 3
- 238000005452 bending Methods 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 238000005536 corrosion prevention Methods 0.000 description 3
- 238000005868 electrolysis reaction Methods 0.000 description 3
- 238000005530 etching Methods 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 229930195733 hydrocarbon Natural products 0.000 description 3
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 3
- 235000015067 sauces Nutrition 0.000 description 3
- 238000005476 soldering Methods 0.000 description 3
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 239000004593 Epoxy Substances 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- JHWNWJKBPDFINM-UHFFFAOYSA-N Laurolactam Chemical compound O=C1CCCCCCCCCCCN1 JHWNWJKBPDFINM-UHFFFAOYSA-N 0.000 description 2
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 2
- 229920000299 Nylon 12 Polymers 0.000 description 2
- 239000004721 Polyphenylene oxide Chemical group 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- 238000004833 X-ray photoelectron spectroscopy Methods 0.000 description 2
- 229920006222 acrylic ester polymer Polymers 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 150000001298 alcohols Chemical class 0.000 description 2
- 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 2
- 238000004140 cleaning Methods 0.000 description 2
- 238000012937 correction Methods 0.000 description 2
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 238000002003 electron diffraction Methods 0.000 description 2
- 239000005007 epoxy-phenolic resin Substances 0.000 description 2
- 238000011049 filling Methods 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical compound O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-UHFFFAOYSA-N 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000012046 mixed solvent Substances 0.000 description 2
- 239000007800 oxidant agent Substances 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- IWDCLRJOBJJRNH-UHFFFAOYSA-N p-cresol Chemical compound CC1=CC=C(O)C=C1 IWDCLRJOBJJRNH-UHFFFAOYSA-N 0.000 description 2
- 238000010422 painting Methods 0.000 description 2
- 239000008188 pellet Substances 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 229920000570 polyether Chemical group 0.000 description 2
- 229920000139 polyethylene terephthalate Polymers 0.000 description 2
- 239000005020 polyethylene terephthalate Substances 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000011253 protective coating Substances 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 229910000679 solder Inorganic materials 0.000 description 2
- 235000014347 soups Nutrition 0.000 description 2
- 239000004416 thermosoftening plastic Substances 0.000 description 2
- MRERMGPPCLQIPD-NBVRZTHBSA-N (3beta,5alpha,9alpha,22E,24R)-3,5,9-Trihydroxy-23-methylergosta-7,22-dien-6-one Chemical compound C1C(O)CCC2(C)C(CCC3(C(C(C)/C=C(\C)C(C)C(C)C)CCC33)C)(O)C3=CC(=O)C21O MRERMGPPCLQIPD-NBVRZTHBSA-N 0.000 description 1
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- XQUPVDVFXZDTLT-UHFFFAOYSA-N 1-[4-[[4-(2,5-dioxopyrrol-1-yl)phenyl]methyl]phenyl]pyrrole-2,5-dione Chemical compound O=C1C=CC(=O)N1C(C=C1)=CC=C1CC1=CC=C(N2C(C=CC2=O)=O)C=C1 XQUPVDVFXZDTLT-UHFFFAOYSA-N 0.000 description 1
- PBLZLIFKVPJDCO-UHFFFAOYSA-N 12-aminododecanoic acid Chemical compound NCCCCCCCCCCCC(O)=O PBLZLIFKVPJDCO-UHFFFAOYSA-N 0.000 description 1
- BJELTSYBAHKXRW-UHFFFAOYSA-N 2,4,6-triallyloxy-1,3,5-triazine Chemical compound C=CCOC1=NC(OCC=C)=NC(OCC=C)=N1 BJELTSYBAHKXRW-UHFFFAOYSA-N 0.000 description 1
- SLXKOJJOQWFEFD-UHFFFAOYSA-N 6-aminohexanoic acid Chemical compound NCCCCCC(O)=O SLXKOJJOQWFEFD-UHFFFAOYSA-N 0.000 description 1
- XDOLZJYETYVRKV-UHFFFAOYSA-N 7-Aminoheptanoic acid Chemical compound NCCCCCCC(O)=O XDOLZJYETYVRKV-UHFFFAOYSA-N 0.000 description 1
- UQXNEWQGGVUVQA-UHFFFAOYSA-N 8-aminooctanoic acid Chemical compound NCCCCCCCC(O)=O UQXNEWQGGVUVQA-UHFFFAOYSA-N 0.000 description 1
- FERIUCNNQQJTOY-UHFFFAOYSA-N Butyric acid Natural products CCCC(O)=O FERIUCNNQQJTOY-UHFFFAOYSA-N 0.000 description 1
- MMEZEOFKMBMDGP-UHFFFAOYSA-N C(O)(O)=O.CC Chemical compound C(O)(O)=O.CC MMEZEOFKMBMDGP-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 229920000298 Cellophane Polymers 0.000 description 1
- BRLQWZUYTZBJKN-UHFFFAOYSA-N Epichlorohydrin Chemical compound ClCC1CO1 BRLQWZUYTZBJKN-UHFFFAOYSA-N 0.000 description 1
- 239000004716 Ethylene/acrylic acid copolymer Substances 0.000 description 1
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 1
- 229920002302 Nylon 6,6 Polymers 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 229920002396 Polyurea Polymers 0.000 description 1
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 1
- 229920003182 Surlyn® Polymers 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- BWVAOONFBYYRHY-UHFFFAOYSA-N [4-(hydroxymethyl)phenyl]methanol Chemical compound OCC1=CC=C(CO)C=C1 BWVAOONFBYYRHY-UHFFFAOYSA-N 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 239000000443 aerosol Substances 0.000 description 1
- 239000005456 alcohol based solvent Substances 0.000 description 1
- GZCGUPFRVQAUEE-SLPGGIOYSA-N aldehydo-D-glucose Chemical compound OC[C@@H](O)[C@@H](O)[C@H](O)[C@@H](O)C=O GZCGUPFRVQAUEE-SLPGGIOYSA-N 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 229920000180 alkyd Polymers 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 239000002216 antistatic agent Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 239000003849 aromatic solvent Substances 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- 238000001479 atomic absorption spectroscopy Methods 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000001045 blue dye Substances 0.000 description 1
- 239000007767 bonding agent Substances 0.000 description 1
- 125000000484 butyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 235000014171 carbonated beverage Nutrition 0.000 description 1
- 150000001734 carboxylic acid salts Chemical class 0.000 description 1
- 150000001735 carboxylic acids Chemical class 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 1
- 239000008199 coating composition Substances 0.000 description 1
- 238000005097 cold rolling Methods 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 239000007859 condensation product Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 238000007334 copolymerization reaction Methods 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- ZXJXZNDDNMQXFV-UHFFFAOYSA-M crystal violet Chemical compound [Cl-].C1=CC(N(C)C)=CC=C1[C+](C=1C=CC(=CC=1)N(C)C)C1=CC=C(N(C)C)C=C1 ZXJXZNDDNMQXFV-UHFFFAOYSA-M 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 150000004985 diamines Chemical class 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000003618 dip coating Methods 0.000 description 1
- 239000000975 dye Substances 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000007720 emulsion polymerization reaction Methods 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 239000005038 ethylene vinyl acetate Substances 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000000796 flavoring agent Substances 0.000 description 1
- 235000019634 flavors Nutrition 0.000 description 1
- OIAUFEASXQPCFE-UHFFFAOYSA-N formaldehyde;1,3-xylene Chemical compound O=C.CC1=CC=CC(C)=C1 OIAUFEASXQPCFE-UHFFFAOYSA-N 0.000 description 1
- UPSIAUXDGWYOFJ-UHFFFAOYSA-N formaldehyde;furan Chemical compound O=C.C=1C=COC=1 UPSIAUXDGWYOFJ-UHFFFAOYSA-N 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 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 1
- 238000004817 gas chromatography Methods 0.000 description 1
- 238000010559 graft polymerization reaction Methods 0.000 description 1
- 238000009499 grossing Methods 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
- 239000008240 homogeneous mixture Substances 0.000 description 1
- 229920001519 homopolymer Polymers 0.000 description 1
- 238000007602 hot air drying Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- LDHBWEYLDHLIBQ-UHFFFAOYSA-M iron(3+);oxygen(2-);hydroxide;hydrate Chemical compound O.[OH-].[O-2].[Fe+3] LDHBWEYLDHLIBQ-UHFFFAOYSA-M 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000010409 ironing Methods 0.000 description 1
- QQVIHTHCMHWDBS-UHFFFAOYSA-L isophthalate(2-) Chemical compound [O-]C(=O)C1=CC=CC(C([O-])=O)=C1 QQVIHTHCMHWDBS-UHFFFAOYSA-L 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 239000005453 ketone based solvent Substances 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 125000005397 methacrylic acid ester group Chemical group 0.000 description 1
- 229920003146 methacrylic ester copolymer Polymers 0.000 description 1
- 229910052754 neon Inorganic materials 0.000 description 1
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Description
〔発明の詳細な説明〕
本発明は、樹脂保護被覆の溶性継目への密着性
に優れ、しかも継目の腐食防止作用がフランジ加
工、巻締加工、ビート加工、ネツクイン加工等の
加工後においても永続して保持される継目被覆テ
イン・フリー・スチール製溶接罐及びその製造法
に関する。
従来、製罐法としてはブリキ等の罐用素材を円
筒状に成形し、その両端縁部をハンダ、接着剤等
を用いてラツプシーム、ロツクシーム或いはこれ
らの組み合わせシームに接合する方法が一般に行
われている。しかしながら、この製罐方法ではシ
ーム部にかなりの面積が必要であり、資源節約の
点で問題があるとともに、ハンダ罐の場合にはハ
ンダによる好ましくない影響もあり、また接着罐
の場合には継目の強度及び耐久性の面で問題があ
る。更にハンダ及び接着剤による継目罐の場合に
は、側面継目にかなりの段差があるため罐蓋との
２重巻き締めに際して段差部での漏洩を屡々生じ
やすいという問題がある。
従来、ハンダ罐に代わる製罐法として絞りしご
き加工による無継目（シームレス）罐がある分野
では用いられているが、無継目罐は圧力による罐
胴側壁の変形が大であるため、バキユーム罐、即
ち内容物をレトルト殺菌する用途の罐に用いるこ
とは到底不可能である。
ハンダ罐に代わる製罐法の他の例として罐用素
材の両端縁部を溶接によりラツプ（重ね合わせ）
接合した溶接罐も既に知られている。このような
溶接罐は、ラツプシーム部の面積がハンダ罐に比
して著しく小であり、またシーム部の厚みも比較
的小さいため前述した段差に伴う問題が緩和さ
れ、更にハンダの様な格別な接合剤を必要としな
いという利点を有しているが、罐用素材の種類に
よつてはその製造操作が面倒であり、また継目の
耐腐食性、塗料密着性及び外観特性においても未
だ充分満足し得るものではなかつた。
例えば、圧延鋼板を電解クロム酸処理して得ら
れるテイン・フリー・スチールは、ブリキ等の罐
用素材に比して安価にしかも容易に入手でき、ま
たブリキ罐に認められる内容物中への錫溶出の問
題もなく更に耐腐食性及び塗料の密着性にも優れ
ているという利点を有しているが、このテイン・
フリー・スチール（以下に単にTFSと呼ぶこと
がある）の溶接継目を形成するには、高電気抵抗
の含クロム被覆層を除去して後溶接を行う必要が
あり、このために含クロム被覆層を除去した鋼板
基質露出面には不可避的に多孔質の厚い鋼酸化物
層が形成されること、及び溶接時の圧力により溶
融した鋼が継目断面部にはみ出し、このはみ出さ
れた鋼は一層このような酸化を受け易いことが問
題となる。
この鋼酸化物は性質においてもろく、しかも多
孔質であるため、これに保護樹脂被膜を施した場
合にも密着性に乏しく、内容物への鉄溶出や継目
の腐食を防止することが困難である。しかも、
TFS溶接罐が継目での被膜密着性や耐腐食性に
劣るという欠点は、この継目がフランジ加工、２
重巻締加工、ネツクイン加工、或いはビード加工
等の製罐上必要な苛酷な加工に賦され、内容物充
填後レトルト殺菌等の苛酷な熱水処理を受けるこ
とによつて一層倍加される。
このように不都合な鋼酸化物層を除去するため
に、溶接後のTFS罐を酸洗浄（ピツクリング）
に賦することが考えられるが、個々の溶接罐を酸
洗浄に賦することは操作及び設備の点で著しいコ
ストの増加をもたらすばかりではなく、処理後の
溶接罐においても、樹脂保護被覆の継目への密着
性は思つた程向上せず、継目の腐食防止作用、特
に加工後の腐食防止作用も然程改善されないこと
がわかつた。
このように、溶接TFS罐の継目の被覆には、
継目の金属基質そのものが塗料密着性等に欠ける
という問題に加えて、用いる被覆用塗料も継目へ
の密着性、腐食成分に対するバリヤー性及び二重
巻締等の加工性の組合せ特性に欠け、更に継目に
おける段差のあるカツトエツジを完全に被覆する
という目的にも末だ不満足なものであるという欠
点がある。
例えば、熱可塑性樹脂から成る被覆材料は、加
工性には優れているとしても、熱可塑性樹脂は継
目への密着性に欠けると共に、前述したバリヤー
性も低く、熱可塑性樹脂で被覆した継目は、内容
物等により容易に腐食や、硫化黒変等の欠点を生
じるようになる。
一方、熱硬化性樹脂から成る塗料は、継目への
密着性や腐食成分に対するバリヤー性には優れて
いるが、その反面加工性に欠けるのが欠点であ
り、継目を熱硬化性樹脂で被覆した罐体では、二
重巻線部分から金属溶出がひんぱんに生ずること
が認められる。
更に、これら何れの樹脂を使用する場合にも、
これらの塗料は溶液或いは溶融状態で継目に存在
する段差を埋めるように流動を生ずるから、カツ
トエツジの角の部分では塗膜が切れるか或いはそ
うでないとしても塗膜が著しく薄いものとなり、
また段差部の部分の塗膜には気泡が入り易い等、
素材のカツトエツジ部に完全な被覆を形成させる
ことは不可能に近い。
金属露出部があると内容物の種類によつては穴
開き缶、水素膨張缶等の重大な欠陥をもたらすと
同時に内容物のフレーバーをも著しく損うことに
なる。
本発明者等は、前述したTFS溶接罐の製造に
際して、継目の鋼板基質露出部におけるポーラス
な厚い鋼酸化物層の形成を抑制し、その代りに、
厚さが50乃至400オングストローム（Å）の範囲
にあるマグネタイト（Fe3O4）を主体とする緻密
な金属酸化物層を形成させると、罐継目の耐腐食
性、塗料密着性が向上すること、及びこの継目に
対して、熱硬化性樹脂と軟化点が一定の範囲にあ
る熱可塑性樹脂とを一定の量比で含有する塗料組
成物を施こすと、一方の樹脂が連続相、他方の樹
脂の少なくとも一部が分散相となつた被覆が、カ
ツトエツジ部をも含めて全ての継目に完全な形で
有効に形成され、その結果継目の全ての部分の完
全被覆、継目の耐腐食性及び継目への被膜密着性
に優れ、しかも種々の加工やレトルト殺菌に賦し
た場合にも、これらの利点が実質上損われない被
覆溶接シーム罐が得られることを見出した。
本発明によれば、金属クロム層及びその上のク
ロム酸化物層から成る被覆層を鋼板基質上に設け
た罐用素材を溶接により側面で接合した溶接継目
罐において、この側面継目は厚みが50乃至800オ
ングストロームの範囲にあるマグネタイトを主体
とする緻密な鋼酸化物から成る鋼板基質露出層を
有し、該側面継目の少くとも一方の表面部には熱
硬化性樹脂と50乃至300℃の環球法軟化点を有す
る熱可塑性樹脂とを、
20：80乃至１：99
の体積比で含有し、熱可塑性樹脂が被覆層中に連
続相の形で存在し、一方熱硬化性樹脂の一部は熱
可塑性樹脂連続相と継目内面側との界面に連続薄
層の形で存在し、残りの一部は前記連続相中に微
細な分散粒子の形で存在する被覆層が設けられて
いることを特徴とする継目を被覆した溶接罐が提
供される。
本発明によれば更に、側面に継目を有する溶接
罐胴の少なくとも一方の表面側継目に、樹脂塗料
を塗布し、次いでこの塗料を焼付けて継目を被覆
する塗膜を形成させることから成る継目被覆溶接
罐の製法において、該罐胴は金属クロム層及びそ
の上のクロム酸化物層から成る被覆層を鋼板基質
上に設けた罐用素材を溶接により側面で接合した
溶接継目罐であつて、この側面継目は厚みが50乃
至800オングストロームの範囲にあるマグネタイ
トを主体とする緻密な鋼酸化物から成る鋼板基質
露出層を有するものとし、前記樹脂塗料は、熱硬
化性樹脂の溶液から成る分散媒と0.1乃至80μｍの
数平均粒径と50乃至300℃の環球法軟化点とを有
する熱可塑性樹脂粒子の分散質とから成る塗料で
あり、前記塗料中の熱硬化性樹脂と熱可塑性樹脂
とは20：80乃至１：99の体積比で存在するものと
し、継目に塗布した塗料を、最初に前記溶液中の
溶媒の蒸発が生じ、次いで熱可塑性樹脂の軟化が
生じる条件下で焼付けることを特徴とする継目被
覆溶接罐の製造法が提供される。
本発明の溶接シーム罐を示す第１図において、
製罐用TFS素材１を円筒状に成型し、その両端
縁部２，２を重ね合わせ、後に詳述する特定の溶
接手段により接合して側面継目３を形成する。こ
の側面継目３の少なくとも内面側には、後に詳述
する樹脂乃至は樹脂組成物の被覆層４が形成され
ている。
この側面継目３及びその隣接部分を拡大して示
す第２図において、このTFS素材１そのものは、
鋼板基質５、金属クロム層６及び表面クロム酸化
物層７から成つているが、継目３の部分ではこれ
ら含クロム被覆層が除去されて鋼板基質４が露出
し、鋼酸化物層８が形成されている。
TFS素材における鋼板基質５は、例えば低炭
素鋼の冷間圧延により製造されるものであり、一
方金属クロム層６及びクロム酸化物層７の厚み
や、その比は溶接罐の用途や、罐の容積によつて
もかなり相違するが、一般に金属クロム層が10乃
至100mg／m2、特に20乃至80mg／m2、クロム酸化
物層が0.5乃至20mg／m2、特に１乃至10mg／m2の
被覆量を夫々有する。
本発明の重要な特徴の一つは、前述した鋼酸化
物層８をマグネタイト（Fe3O4）を主体とする緻
密な鋼酸化物から形成させると共に、その厚みを
50乃至800特に50乃至400オングストローム（Å）
の範囲に抑制する点に存する。
従来のTFS溶接罐においては、継目となるべ
き鋼板基質の露出面において、鋼酸化物層が1000
乃至3000Åの厚みに形成され、しかもこの酸化鉄
層は非常にポーラスであり、また化学組成的には
Fe原子に対する酸素原子の比が比較的大きいも
のを主体とするものである。この酸化鉄層は、非
常に雰囲気の影響を受け易く、例えば空気との比
較的短時間の接触で含水第２酸化鉄（所謂赤錆）
に容易に変化する傾向がみられる。
これに対して、本発明の溶接罐においては、鋼
酸化物層がマグネタイトを主体とする緻密な酸化
物から形成され、しかも厚みが50乃至800Åの極
めて薄いレベルに抑制されていることに関連し
て、塗膜の密着性、耐腐食性が顕著に向上し、継
目の加工後におけるこれらの特性が優れたレベル
に維持されるものである。例えば、このマグネタ
イト酸化物層の厚みが、上記範囲よりも小さい
と、塗膜の密着性が低下し、上記範囲よりも厚い
と加工後における塗膜の密着性や耐腐食性が低下
する。更に、酸化物層がマグネタイト主体の緻密
層から成ることは、耐腐食性の点で望ましい効果
をもたらす。
鋼酸化物層がマグネタイトから成る事実は、Ｘ
−線回折や電子線回折により確認でき、また酸化
物層の化学組成は、ESCA（Electron
Snectroscopy for Chemical Analysis）により、
表面Arガスでエツチングし、Ｏ、Feの原子濃度
比を測定することにより求め得る。また、厚みで
は、走査型電子顕微鏡Ｘ線マイクロアナライザー
で求め得る。
本発明の溶接シーム罐を製造するに当つて、守
らなければならない幾つかの制限が存在する。側
面継目の電気抵抗溶接は、TFS罐用素材を円筒
状に成形し、形成される重ね合わせ部を１対の電
極ローラー間に通過せしめるか、或は電極ワイヤ
ーを介して上下１対の電極ローラー間に通過せし
めることによつて行われるが、この溶接操作を不
活性雰囲気中で行い、且つ溶接部の表面温度が
550℃に低下するまでの雰囲気を不活性雰囲気と
することがまず重要である。溶接雰囲気及びその
後の放冷雰囲気を不活性雰囲気即ち非酸化性雰囲
気とすることは、酸化物の層厚を減少させ且つ鋼
酸化物をマグネタイトとするという点で２重の作
用効果を有している。
不活性雰囲気としては、窒素、アルゴン、ネオ
ン、水素、一酸化炭素等を使用することができ
る。上述した不活性気体の気流中に溶接接合部を
保持して作業を行うのが好ましいが、上記気体を
充填した密閉溶器内で作業を行つてもよい。
本発明の被覆溶接罐において、側面継目の幅は
罐の径によつても相違するが、0.2乃至1.2mmのよ
うな比較的小さい幅でよく、罐用素材の使用量を
少くできることも本発明の利点の１つである。
被覆された継目を拡大して示す第３図、この罐
胴の内面側に位置する継目３には、素材のカツト
エツジ９及び溶接の際金属素材の溶融が圧力によ
りはみ出したはみ出し部１０が存在している。こ
の継目３には、この部分を被覆する樹脂層４が設
けられている。この罐胴の内面は、前述した継目
３或いはその近傍の部分を除いて樹脂保護塗膜１
１で被覆されていてもよい。
本発明の重要な特徴は、この樹脂被覆層５を、
前記特定の体積比の熱硬化性樹脂と熱可塑性樹脂
とから構成すると共に、この内の一方の樹脂を連
続相、他方の樹脂の少なくとも一部を該連続相中
に分散した微細粒子相とすることにある。本発明
において、何れの樹脂が連続相を構成するかは、
両樹脂の体積比によつて決定され、熱硬化性樹脂
と熱可塑性樹脂とが、
１：99乃至20：80、特に
２：98乃至15：85
の体積比で存在する場合には、熱可塑性樹脂が連
続相で、熱硬化性樹脂の少なくとも一部が連続相
となる。
第３図は、前記熱可塑性樹脂は被覆層４中に連
続相１４の形で存在し、一方熱硬化性樹脂の一部
は熱可塑性樹脂連続相１４と継目内面側との界面
に連続薄層１５の形で存在し、残りの一部は前記
連続相中に微細な分散粒子１６の形で存在してい
る。
熱硬化性樹脂が金属への密着性や腐食性成分に
対するバリヤー性に優れている反面として加工性
に欠けること、及び一方熱可塑性樹脂が加工性に
優れている反面として、密着性及びバリヤー性に
欠けることは既に前述した通りである。
更に、熱硬化性樹脂溶液単独を継目３に塗布し
た場合には、この溶液は、カツトエツジ９或いは
はみ出し部１０の段差のある部分に流れ出し、こ
れによつてカツトエツジの角部１７の部分では塗
膜が切れたり或いは薄くなる等の欠点を生ずるこ
とも既に前述した。
これに対して、本発明に従い、熱硬化性樹脂溶
液を分散媒、熱可塑性樹脂粒子を分散質とし、し
かも熱硬化性樹脂と熱可塑性樹脂との体積比を前
述した範囲に選択すると、この塗料のチクソトロ
ピツクな性質により、継目３の角部１７上にも塗
料が厚盛りされた状態で、塗装及び焼付けが可能
となる。しかも厚盛りされた塗料の部分では熱可
塑性樹脂粒子がその表面に熱硬化性樹脂溶液を有
効に保持し、この溶液が段差の空隙部分に流出し
て塗膜が平滑化しようとする傾向を抑制する。
かくして、本発明の形態の塗料を使用すると、
カツトエツジの角部１６の部分においても、施さ
れたのとほぼ同様な厚みの塗膜を保持せしめるこ
とが可能となり、カツトエツジ９全体の完全な被
覆が可能となるのである。
本発明のこの好適な態様によれば、溶媒の蒸発
に伴つて、熱硬化性樹脂の一部は継目の金属面に
連続薄層１５の形で沈着し、他の一部は熱可塑性
樹脂粒子表面に沈着する。この状態で、塗膜の焼
付が更に進行し、熱可塑性樹脂粒子の溶融が行わ
れる。両樹脂の比率を前述した範囲に選択するこ
とにより、熱可塑性樹脂が連続相１４となり、そ
の粒子表面に残存した熱硬化性樹脂は微細な分散
相１６となつて、相の逆転が生じ、最後に熱硬化
性樹脂の硬化が完了する。
このように熱硬化性樹脂の一部が継目の金属面
の全てに密着した薄層の形で存在することによ
り、被覆の密着性及び耐腐食性が顕著に向上す
る。のみならず、この熱硬化性被覆は薄層、特に
0.01乃至5μｍの範囲に抑制されており、更にこの
上の熱可塑性被覆が連続相となつているため、加
工性の著しい改善がもたらされ、特にネツクイン
のような苛酷な加工を行つた場合にも、継目から
の金属溶出や腐食が顕著に抑制されるのである。
本発明の塗料に使用する熱可塑性樹脂粒子は、
50乃至300℃、特に120乃至270℃の環球法軟化点
を有することも本発明の目的に関して重要であ
る。即ち熱可塑性樹脂の軟化点が上記範囲よりも
低い場合には、両樹脂は均質な混合物となつて、
本発明の分散形態をとることは困難となり、カツ
トエツジの被覆能も、加工性及び耐腐食性も低下
する。一方、この軟化点が上記範囲よりも高い場
合には、加工性が本発明範囲内のものに比して劣
るようになり、また界面での相互接着が困難とな
るため、バリヤー性が低下するようになる。
この熱可塑性樹脂粒子は0.1乃至80ミクロン、
特に0.5乃至50ミクロンの数平均粒径を有するこ
とが望ましい。即ち、粒径が上記範囲よりも小さ
い場合及び大きい場合の何れの場合にも、厚盛り
塗装性、熱硬化性樹脂溶液の流展抑制の最適な組
合せが得られない傾向がある。
本発明に用いる塗料において、熱硬化性樹脂と
熱可塑性樹脂との体積比が、上記範囲の上限より
も高くなると熱可塑性樹脂を明確な連続にするこ
とが困難となり、カツトエツジの完全被覆が困難
となり、加工性も低下する傾向が著しい。また上
記範囲の下限よりも低くなると、被膜の密着性が
低下し、この部分の腐食を避けることが困難とな
る。
両樹脂相間の界面接着性を向上させるという見
地から、本発明においては、熱可塑性樹脂として
カルボン酸、カルボン酸塩、カルボン酸無水物、
カルボン酸エステル、カルボン酸アミド、ケト
ン、炭酸エステル、ユリア、ウレタン等に基ずく
カルボニル基
[Detailed Description of the Invention] The present invention provides excellent adhesion of a resin protective coating to soluble seams, and furthermore, the corrosion prevention effect of the seams is persistent even after processing such as flanging, seaming, beading, and neck-in processing. The present invention relates to a welded seam-coated, stain-free steel can that is held in place and to a method for manufacturing the same. Conventionally, can manufacturing methods generally involve forming a can material such as tin into a cylindrical shape, and joining both edges of the can to a lap seam, lock seam, or a combination of these seams using solder, adhesive, etc. There is. However, this method of making cans requires a considerable area at the seam, which poses problems in terms of resource conservation. There are problems in terms of strength and durability. Furthermore, in the case of cans with joints made of solder or adhesive, there is a problem in that since there is a considerable step at the side joint, leakage often occurs at the step when double-wrapping with the can lid. Conventionally, seamless cans made by drawing and ironing have been used as an alternative to soldering cans in fields where seamless cans are produced, but since seamless cans cause large deformation of the can body side walls due to pressure, vacuum cans, That is, it is completely impossible to use the container for retort sterilization of the contents. Another example of a can manufacturing method that replaces soldering cans is to wrap (overlap) both edges of the can material by welding.
Bonded welded cans are also already known. In such a welding can, the area of the lap seam is significantly smaller than that of a soldering can, and the thickness of the seam is also relatively small, which alleviates the problems associated with the step mentioned above, and furthermore, Although it has the advantage of not requiring a bonding agent, the manufacturing process may be troublesome depending on the type of can material, and the corrosion resistance of the seams, paint adhesion, and appearance characteristics are still not fully satisfactory. It was not possible. For example, tin-free steel obtained by electrolytically treating rolled steel sheets with chromic acid is cheaper and easier to obtain than can materials such as tinplate, and it also eliminates tin in the contents found in tin cans. It has the advantage of having no problems with elution and also has excellent corrosion resistance and paint adhesion.
To form a welded seam in free steel (hereinafter sometimes referred to simply as TFS), it is necessary to remove the high electrical resistance chromium-containing coating layer and perform post-welding; A thick, porous steel oxide layer is inevitably formed on the exposed surface of the steel plate substrate after the welding process has been removed, and molten steel protrudes into the joint cross section due to the pressure during welding, and this protruded steel becomes even more The problem is that it is susceptible to such oxidation. This steel oxide is brittle and porous in nature, so even when a protective resin coating is applied to it, it has poor adhesion, making it difficult to prevent iron from leaching into the contents and corrosion at seams. . Moreover,
The disadvantage of TFS welded cans is that the film adhesion and corrosion resistance at the seams are poor.
It is subjected to severe processing required for can manufacturing such as heavy seaming processing, neck-in processing, or bead processing, and is further doubled by undergoing severe hot water treatment such as retort sterilization after filling the contents. In order to remove this undesirable steel oxide layer, the TFS cans are acid cleaned (pickling) after welding.
However, subjecting individual welding cans to acid cleaning not only results in a significant increase in costs in terms of operation and equipment, but also in the welded cans after treatment, the seams of the protective resin coating are It was found that the adhesion to the surface did not improve as much as expected, and the corrosion prevention effect of the seam, especially the corrosion prevention effect after processing, was not improved as much. In this way, for coating the seams of welded TFS cans,
In addition to the problem that the metal substrate of the seam itself lacks paint adhesion, the coating paint used also lacks the combination of adhesion to the seam, barrier properties against corrosive components, and workability such as double seaming. The disadvantage is that it is also extremely unsatisfactory for the purpose of completely covering stepped cut edges at seams. For example, although a coating material made of thermoplastic resin has excellent processability, thermoplastic resin lacks adhesion to seams and also has poor barrier properties as described above, so seams coated with thermoplastic resin Depending on the contents, etc., defects such as corrosion and blackening due to sulfurization can easily occur. On the other hand, paints made of thermosetting resins have excellent adhesion to seams and barrier properties against corrosive components, but have the disadvantage of lacking workability. In the case, it is observed that metal elution frequently occurs from the double winding part. Furthermore, when using any of these resins,
These paints flow as a solution or in a molten state to fill in the steps that exist at the joints, so the paint film may break at the corners of the cut edges, or if not, the paint film will be extremely thin.
In addition, air bubbles tend to form in the paint film on the stepped parts, etc.
It is nearly impossible to form a complete coating on the cut edges of the material. Exposed metal parts can cause serious defects such as perforated cans or hydrogen-expanded cans depending on the type of contents, and can also significantly impair the flavor of the contents. The present inventors suppressed the formation of a porous thick steel oxide layer in the exposed portion of the steel plate matrix at the seam when manufacturing the TFS welded can, and instead
Forming a dense metal oxide layer mainly composed of magnetite (Fe 3 O 4 ) with a thickness in the range of 50 to 400 angstroms (Å) improves the corrosion resistance and paint adhesion of the can joint. , and when a coating composition containing a thermosetting resin and a thermoplastic resin having a softening point within a certain range in a certain ratio is applied to this seam, one resin becomes a continuous phase and the other resin becomes a continuous phase. A coating in which at least a portion of the resin is in the dispersed phase is effectively formed on all seams, including the cut edges, resulting in complete coverage of all parts of the seam, corrosion resistance of the seam and It has been found that it is possible to obtain a coated welded seam can which has excellent coating adhesion to the seam and which does not substantially lose these advantages even when subjected to various processing or retort sterilization. According to the present invention, in a welded seam can in which a can material in which a coating layer consisting of a metallic chromium layer and a chromium oxide layer thereon is provided on a steel plate substrate is joined at the side by welding, the side seam has a thickness of 50 mm. The steel plate has an exposed steel substrate layer consisting of a dense steel oxide mainly composed of magnetite in the range of 800 to 800 angstroms, and at least one surface of the side joint is coated with a thermosetting resin and a ring and ball at 50 to 300°C. A thermoplastic resin having a thermosetting point is contained in a volume ratio of 20:80 to 1:99, and the thermoplastic resin exists in the form of a continuous phase in the coating layer, while a part of the thermosetting resin A coating layer is provided that exists in the form of a continuous thin layer at the interface between the thermoplastic resin continuous phase and the inner surface of the seam, and the remaining part exists in the form of finely dispersed particles in the continuous phase. A welded can with characteristic seams covered is provided. According to the present invention, the seam coating further comprises applying a resin paint to at least one surface side seam of a welded can body having a seam on the side surface, and then baking the paint to form a coating film covering the seam. In the method for manufacturing a welded can, the can body is a welded seam can made by welding a can material in which a coating layer consisting of a metal chromium layer and a chromium oxide layer on top of the metal chromium layer is provided on a steel plate substrate. The side seam has an exposed steel substrate layer made of dense steel oxide mainly composed of magnetite and has a thickness in the range of 50 to 800 angstroms, and the resin coating is a dispersion medium made of a solution of a thermosetting resin. A paint consisting of a dispersoid of thermoplastic resin particles having a number average particle size of 0.1 to 80 μm and a ring and ball softening point of 50 to 300°C, and the thermosetting resin and thermoplastic resin in the paint are :80 to 1:99 by volume, and the paint applied to the joint is baked under conditions that first evaporate the solvent in the solution and then soften the thermoplastic resin. A method of manufacturing a seam-coated welded can is provided. In FIG. 1 showing the welded seam can of the present invention,
A TFS material 1 for making cans is formed into a cylindrical shape, and both end edges 2, 2 thereof are overlapped and joined by a specific welding means described in detail later to form a side seam 3. A coating layer 4 made of a resin or a resin composition, which will be described in detail later, is formed at least on the inner surface side of the side seam 3. In FIG. 2, which shows an enlarged view of the side seam 3 and its adjacent parts, the TFS material 1 itself is
It consists of a steel plate substrate 5, a metal chromium layer 6, and a surface chromium oxide layer 7, but at the joint 3, these chromium-containing coating layers are removed to expose the steel plate substrate 4, and a steel oxide layer 8 is formed. ing. The steel plate substrate 5 in the TFS material is manufactured, for example, by cold rolling of low carbon steel, and the thicknesses and ratios of the metal chromium layer 6 and chromium oxide layer 7 are determined by the use of the welded can and the can. Although it varies considerably depending on the volume, generally the metal chromium layer has a concentration of 10 to 100 mg/m 2 , especially 20 to 80 mg/m 2 , and the chromium oxide layer has a concentration of 0.5 to 20 mg/m 2 , especially 1 to 10 mg/m 2 . Each has its own coverage amount. One of the important features of the present invention is that the above-mentioned steel oxide layer 8 is formed from a dense steel oxide mainly composed of magnetite (Fe 3 O 4 ), and its thickness is
50 to 800 especially 50 to 400 angstroms (Å)
The point is to keep it within the range of . In conventional TFS welded cans, a steel oxide layer of 1,000
This iron oxide layer is formed with a thickness of 3000 Å and is extremely porous, and its chemical composition is
It mainly consists of those in which the ratio of oxygen atoms to Fe atoms is relatively large. This iron oxide layer is very susceptible to the influence of the atmosphere, for example, when it comes into contact with air for a relatively short time, it becomes hydrated ferric oxide (so-called red rust).
There is a tendency to change easily. In contrast, in the welding can of the present invention, the steel oxide layer is formed from a dense oxide mainly composed of magnetite, and the thickness is suppressed to an extremely thin level of 50 to 800 Å. As a result, the adhesion and corrosion resistance of the coating film are significantly improved, and these properties are maintained at an excellent level after the seam is processed. For example, if the thickness of the magnetite oxide layer is smaller than the above range, the adhesion of the coating film will be reduced, and if it is thicker than the above range, the adhesion and corrosion resistance of the coating film after processing will be reduced. Furthermore, the fact that the oxide layer is composed of a dense layer mainly composed of magnetite brings about a desirable effect in terms of corrosion resistance. The fact that the steel oxide layer consists of magnetite indicates that
- The chemical composition of the oxide layer can be confirmed by ray diffraction or electron diffraction, and the chemical composition of the oxide layer can be confirmed by ESCA (Electron Diffraction).
Snectroscopy for Chemical Analysis)
It can be determined by etching the surface with Ar gas and measuring the atomic concentration ratio of O and Fe. Further, the thickness can be determined using a scanning electron microscope and an X-ray microanalyzer. There are several limitations that must be adhered to in manufacturing the welded seam cans of the present invention. Electric resistance welding of side seams can be done by forming the TFS can material into a cylindrical shape and passing the formed overlapping part between a pair of electrode rollers, or by passing an electrode wire between a pair of upper and lower electrode rollers. This welding operation is carried out in an inert atmosphere, and the surface temperature of the welded part is
First of all, it is important to make the atmosphere an inert atmosphere until the temperature drops to 550°C. Making the welding atmosphere and the subsequent cooling atmosphere an inert atmosphere, that is, a non-oxidizing atmosphere, has a double effect in that it reduces the oxide layer thickness and converts the steel oxide into magnetite. There is. As the inert atmosphere, nitrogen, argon, neon, hydrogen, carbon monoxide, etc. can be used. Although it is preferable to carry out the work while holding the welded joint in a stream of the above-mentioned inert gas, it is also possible to carry out the work in a closed welder filled with the above-mentioned gas. In the coated welded can of the present invention, the width of the side seam varies depending on the diameter of the can, but the width can be relatively small such as 0.2 to 1.2 mm, and the present invention also allows the amount of can material used to be reduced. This is one of the advantages of FIG. 3 shows an enlarged view of the coated seam. In the seam 3 located on the inner surface of the can body, there are cut edges 9 of the material and an extruded part 10 where the melted metal material protrudes due to pressure during welding. ing. This seam 3 is provided with a resin layer 4 that covers this portion. The inner surface of this can body is coated with resin protective coating 1, except for the above-mentioned seam 3 or the vicinity thereof.
It may be coated with 1. An important feature of the present invention is that this resin coating layer 5 is
It is composed of a thermosetting resin and a thermoplastic resin in the specific volume ratio, and one of the resins is a continuous phase, and at least a part of the other resin is a fine particle phase dispersed in the continuous phase. There is a particular thing. In the present invention, which resin constitutes the continuous phase is determined by
It is determined by the volume ratio of both resins, and when the thermosetting resin and thermoplastic resin are present in a volume ratio of 1:99 to 20:80, especially 2:98 to 15:85, thermoplastic The resin is the continuous phase, and at least a portion of the thermosetting resin is the continuous phase. FIG. 3 shows that the thermoplastic resin exists in the form of a continuous phase 14 in the coating layer 4, while a part of the thermosetting resin forms a continuous thin layer at the interface between the thermoplastic resin continuous phase 14 and the inner surface of the seam. The remaining part is present in the form of finely dispersed particles 16 in the continuous phase. Although thermosetting resins have excellent adhesion to metals and barrier properties against corrosive components, they lack processability, while thermoplastic resins have excellent processability but have poor adhesion and barrier properties. What is missing is already mentioned above. Furthermore, when the thermosetting resin solution alone is applied to the seam 3, this solution flows out to the step part of the cut edge 9 or the protruding part 10, and as a result, the coating film does not form at the corner part 17 of the cut edge. It has already been mentioned above that there are disadvantages such as breakage or thinning. On the other hand, according to the present invention, when the thermosetting resin solution is used as the dispersion medium and the thermoplastic resin particles are used as the dispersoid, and the volume ratio of the thermosetting resin and the thermoplastic resin is selected within the above-mentioned range, the paint Due to the thixotropic nature of the material, it is possible to paint and bake with a thick layer of paint even on the corners 17 of the seam 3. Moreover, in areas where the paint is thickly applied, the thermoplastic resin particles effectively retain the thermosetting resin solution on the surface, suppressing the tendency for this solution to flow into the gaps between steps and smoothing out the paint film. do. Thus, using a coating of the form of the invention,
It is possible to maintain a coating film of approximately the same thickness as that applied even on the corners 16 of the cut edge, making it possible to completely cover the entire cut edge 9. According to this preferred embodiment of the invention, as the solvent evaporates, a portion of the thermosetting resin is deposited on the metal surface of the seam in the form of a continuous thin layer 15, and another portion is deposited in the form of thermoplastic resin particles. Deposit on surfaces. In this state, the baking of the coating film further progresses and the thermoplastic resin particles are melted. By selecting the ratio of both resins within the above-mentioned range, the thermoplastic resin becomes a continuous phase 14, and the thermosetting resin remaining on the particle surface becomes a fine dispersed phase 16, causing phase inversion, and finally The curing of the thermosetting resin is completed. Since a portion of the thermosetting resin is present in the form of a thin layer that adheres to all of the metal surfaces of the seam, the adhesion and corrosion resistance of the coating are significantly improved. In addition, this thermosetting coating can be applied in thin layers, especially
The thickness is suppressed to a range of 0.01 to 5 μm, and the thermoplastic coating on top of this is a continuous phase, resulting in a significant improvement in processability, especially when subjected to harsh processing such as NETSUIN. Also, metal elution and corrosion from the joints are significantly suppressed. The thermoplastic resin particles used in the paint of the present invention are:
It is also important for the purpose of the invention to have a ring and ball softening point of 50 to 300°C, in particular 120 to 270°C. That is, when the softening point of the thermoplastic resin is lower than the above range, both resins become a homogeneous mixture,
It becomes difficult to obtain the dispersion form of the present invention, and the coating ability of cut edges, workability and corrosion resistance are also reduced. On the other hand, if this softening point is higher than the above range, the processability will be inferior to that within the range of the present invention, and mutual adhesion at the interface will become difficult, resulting in a decrease in barrier properties. It becomes like this. This thermoplastic resin particle is 0.1 to 80 microns,
In particular, it is desirable to have a number average particle size of 0.5 to 50 microns. That is, in both cases where the particle size is smaller or larger than the above range, there is a tendency that the optimum combination of thick coating properties and suppression of flow of the thermosetting resin solution cannot be obtained. In the paint used in the present invention, if the volume ratio of the thermosetting resin to the thermoplastic resin is higher than the upper limit of the above range, it will be difficult to form a clear continuity of the thermoplastic resin, making it difficult to completely cover the cut edges. , there is a marked tendency for processability to decrease. Moreover, if it is lower than the lower limit of the above range, the adhesion of the coating will decrease, making it difficult to avoid corrosion in this area. From the viewpoint of improving the interfacial adhesion between both resin phases, in the present invention, carboxylic acids, carboxylic acid salts, carboxylic acid anhydrides,
Carbonyl group based on carboxylic acid ester, carboxylic acid amide, ketone, carbonate ester, urea, urethane, etc.
【式】を主鎖或いは側鎖に含有
する熱可塑性重合体を使用することが望ましい。
カルボニル基を12乃至1400meq（ミリイクイバレ
ント）／100ｇ重合体の濃度、特に50乃至
1200meq／100ｇ重合体の濃度で含有する熱可塑
性重合体を使用した場合に、加工性及び耐腐食性
の点で最も良好な効果が得られる。
このような熱可塑性重合体は、前述した官能基
を有する単量体を、重合或いは共重合のような手
段で重合体の主鎖中に組込むか、或いはグラフト
重合乃至は末端処理のような形で熱可塑性重合体
に結合させることにより得られる。またオレフイ
ン樹脂のような炭化水素系重合体にあつては、こ
の重合体を酸化処理することにより、前述した範
囲のカルボニル基を含有する熱可塑性樹脂とする
ことができる。
このような熱可塑性重合体の適当な例は、これ
に限定されるものでないが次の通りである。
(a) 一般式
或いは
式中R1は炭素数２乃至６のアルキレン基、
R2は炭素数２乃至24のアルキレン基又はアリ
ーレン基である、
で表わされる反復単位から成るポリエステル。
例ええば、ポリエチレンアジペート、ポリエ
チレンセバテート、ポリエチレンテレフタレー
ト、ポリテトラメチレンイソフタレート、ポリ
エチレンテレフタレート／イソフタレート、ポ
リテトラメチレンテレフタレート、ポリエチレ
ン／テトラメチレンテレフタレート、ポリエチ
レン／オキシベンゾエート。
(b) 一般式
式中、R3は水素原子又は低級アルキル基、
R4は水素原子、又は炭素数１乃至12のアルキ
ル基である。
の単量体のホモ重合体又は共重合体、或いは、
上記(3)の単量体とオレフイン類、又は他のビニ
ルモノマーとの共重合体或いはアクリル変性ポ
リオレフイン類。
例えば、ポリアクリル酸エステル、ポリメタ
クリル酸エステル、
エチレン／アクリル酸エステル共重合体、
アクリル酸エステル／アクリル酸共重合体、
エチレン／アクリル酸エステル／アクリル酸
共重合体、エチレン／アクリル酸共重合体、
スチレン／メタクリル酸エステル／アクリル
酸共重合体、
アクリル酸エステル／塩化ビニル共重合体、
アクリル酸エステルグラフトポリエチレン、
メタクリル酸エステル／塩化ビニル共重合
体、
スチレン／メタクリル酸エステル／ブタジエ
ン共重合体、
メタクリル酸エステル／アクリロニトリル共
重合体。
(c) 一般式
式中、R5は水素原子、アルキル基、又はフ
エニル基である、
のビニルエスルとオレフイン類又は他のビニル
モノマーとの共重合体或いはその部分ケン化
物。
例えば、エチレン−酢酸ビニル共重合体部分
ケン化物、
エチレン−プロピオン酸ビニル共重合体、
エチレン／酢酸ビニル共重合体、
アクリル酸エステル／酢酸ビニル共重合体、
塩化ビニル／酢酸ビニル共重合体。
(d) アイオノマー
オレフイン類と不飽和カルボン酸、或いは更
に他のビニルモノマーとの共重合体をアルカリ
金属、アルカリ土類金属、或いは有機塩基で中
和して得られる樹脂。
例えば、米国デユポン社から市販されている
サーリン類。
(e) 無水マレイン酸と他のビニルモノマーとの共
重合体或いは無水マレイン酸変性ポリオレフイ
ン
例えば、無水マレイン酸／スチレン共重合
体、
無水マレイン酸変性ポリプロピレン、
無水マレイン酸変性ポリエチレン。
(f) 一般式
式中R6は炭素数８乃至15の炭化水素基、で
表わされるポリカーボネート。
例えば、ポリ−ｐ−キシレングリコールビス
カーボネート、ポリ−ジオキシジフエニル−メ
タンカーボネート、ポリ−ジオキシジフエニル
エタンカーボネート、ポリ−ジオキシジフエニ
ル２，２−プロパンカーボネート、ポリ−ジオ
キシジフエニル１，１−エタンカーボネート。
(g) 一般式
又は
式中ｎは３乃至13の数、ｍは４乃至11の数で
ある
で表わされる反復単位から成るポリアミド類。
例えば、ポリ−ω−アミノカプロン酸、ポリ
−ω−アミノヘプタン酸、ポリ−ω−アミノカ
プリル酸、ポリ−ω−アミノペラゴイン酸、ポ
リ−ω−アミノデカン酸、ポリ−ω−アミノウ
ンデカン酸、ポリ−ω−アミノドデカン酸、ポ
リ−ω−アミノトリデカン酸、ポリヘキサメチ
レンアジパミド、ポリヘキサメチレンセバカミ
ド、ポリヘキサメチレンドデカミド、ポリヘキ
サメチレントリデカミド、ポリデカメチレンア
ジパミド、ポリデカメチレンセバカミド、ポリ
デカメチレンドデカミド、ポリデカメチレント
リデカミド、ポリドデカメチレンアジパミド、
ポリドデカメチレンセバカミド、ポリドデカメ
チレンドデカミド、ポリドデカメチレントリデ
カミド、ポリトリデカメチレンアジパミド、ポ
リトリデカメチレンセバカミド、ポリトリデカ
メチレンドデカミド、ポリトリデカメチレント
リデカミド、ポリヘキサメチレンアゼラミド、
ポリデカメチレンアゼラミド、ポリトリデカメ
チレンアゼラミド、ポリトリデカメチレンアゼ
ラミド。
(h) 一般式
又は
式中R7及びR8の各々は、炭素数１乃至13の
アルキレン基である、
で表わされる反復単位から成るポリ尿素。
例えば、ポリヘキサメチレン尿素、ポリヘプ
タメチレン尿素、ポリウンデカメチレン尿素、
ポリノナメチレン尿素。
(i) 一般式
又は
式中、R9は炭素数３乃至24のアルキレン基、
ポリエーテル残基又はポリエステル残基；R10
は炭素数３乃至24のアルキレン基又はアリーレ
ン基；R11は炭素数１乃至13のアルキレン基又
はアリーレン基；ｋは０又は１の数である：
で表わされるポリウレタン又はポリ尿素ウレタ
ン。
例えば、ポリテトラメチレンヘキサメチレン
ウレタン、ポリヘキサメチレンテトラメチレン
ウレタン、イソシアネート末端ポリエステル又
はポリエーテルをジアミン又は水で鎖伸長した
ポリ尿素ウレタン。
(j) ポリエチレン、ポリプロピレン、結晶性エチ
レンプロピレン共重合体の粒子を、酸素酸化、
オゾン酸化或いはその他の酸化剤等で酸化して
得られる樹脂粒子。
本発明の目的に特に望ましい樹脂は重要な順
に、ポリエステル、ポリカーボネート、ポリアミ
ド、アイオノマー、酸変性ポリオレフイン類であ
る。
これらの樹脂は、少なくともフイルムを形成し
得るに足る分子量を有すべきであり、これらの樹
脂粒子には所望に応じて、それ自体周知の配合
剤、例えば紫外線吸収剤、安定剤、滑剤、酸化防
止剤、顔料、染料、帯電防止剤等を、公知の処方
に従つて配合することができる。
熱可塑性樹脂を前述した粒度の粉体とするに
は、それ自体公知の任意の手段を用い得る。例え
ば、付加重合体の場合には、構成単量体を乳化重
合或いは懸濁重合することにより、所定粒度の樹
脂粒子を得ることができる。また、樹脂を冷却下
に粉砕する方法、或いは樹脂を高温で溶解した溶
液を冷却して樹脂を粒子の形に析出する方法、或
いは樹脂溶液を非溶媒と接触させて粒子の形に凝
固析出させる方法、或いは樹脂溶液を気流中に噴
霧して粒子の形に析出させる方法等が何れも採用
し得る。得られた樹脂粉末は、必要により篩分け
して所定粒度の樹脂粒子とする。
熱硬化性樹脂としては、従来塗料の用途に使用
されている熱硬化性樹脂は全て使用できる。その
適当な例は、フエノール・ホルムアルデヒド樹
脂、フラン−ホルムアルデヒド樹脂、キシレン−
ホルムアルデヒド樹脂、ケトン−ホルムアルデヒ
ド樹脂、尿素ホルムアルデヒド樹脂、メラミン−
ホルムアルデヒド樹脂、アルキド樹脂、不飽和ポ
リエステル樹脂、エポキシ樹脂、ビスマレイミド
樹脂、トリアリルシアヌレート樹脂、熱硬化型ア
クリル樹脂、シリコーン樹脂、油性樹脂等であ
り、これらは単独で或いは２種以上の組合せで使
用できる。
継目に対する密着性、耐腐食性の点で好適な熱
硬化性樹脂は、エポキシ樹脂成分と、フエノール
樹脂、尿素樹脂、メラミン樹脂及び熱硬化型アク
リル樹脂から成る群より選ばれた少なくとも１種
の熱硬化性樹脂との組合せから成るものであつ
て、これらの塗膜形成樹脂は、混合物の形で或い
は予備縮合物の形で塗料に使用する。
本発明に使用する塗料は、前述した熱硬化性樹
脂を適当な有機溶媒に溶解し、この溶液に熱可塑
性樹脂粒子を分散させることにより容易に得られ
る。この際、溶媒としては、熱硬化性樹脂を溶解
するが、熱可塑性樹脂を溶解しないものが選択さ
れる。一般には、キシレン、トルエン等の芳香族
溶媒；アセトン、メチルエチルケトン、シクロヘ
キサノン等のケトン系溶媒；エタノール、ブタノ
ール等のアルコール系溶媒；テトラヒドロフラ
ン、ジオキサン各種セロソルブ等の環状或いは線
状エーテル類；酢酸エチル、酢酸ブチル等のエス
テル類を単独或いは２種以上の組合せで使用す
る。熱可塑性樹脂粒子は分散液の形で熱硬化性樹
脂溶液に添加してもよい。
本発明に使用する塗料は、25℃の温度で、ガラ
ス板上、0.2mm3の試料量で滴下１分後に測定して
18.5乃至45度の接触角、特に19.0乃至43度の接触
角を有することが、カツトエツジ部を完全に覆う
厚盛り塗装を可能にするために特に望ましい。塗
料中の固形分濃度は、一般に５乃至50％の範囲か
ら、適度の作業性と厚盛り塗装性とが得られるよ
うに、樹脂の組合せに応じて適当な濃度を選べれ
ばよい。
罐体継目乃至はその近傍への塗料の塗布は、ロ
ーラ塗布、スプレー塗布、ハケ塗り、フローコー
ト浸漬塗料等のそれ自体公知の手段で行うことが
でき、粉末塗装の如き格別の手段を必要とせず、
従来の設備をそのまま利用できることが本発明の
顕著な利点である。
継目のカツトエツジの角部をも完全に被覆する
目的には、焼付後のカツトエツジの角部における
塗膜層が５乃至70ミクロンの範囲とすることが望
ましく、本発明で規定した塗料を使用すると、こ
のような塗膜形成が至つて容易である。
本発明によれば、継目に塗布した塗料を、最初
に前記溶液中の溶媒の蒸発が生じ、次いで熱可塑
性樹脂の軟化が生じる条件下で焼付け、前述した
構造の被覆を一挙に形成させる。加熱手段として
は、直火、熱オーブン、熱風オーブン、誘導加
熱、抵抗加熱、赤外線加熱等を用いることができ
る。用いる硬化条件は、熱硬化性樹脂が架橋によ
り網状化すると共に、熱硬化性樹脂と熱可塑性樹
脂との界面における接着が十分に生ずるように、
150乃至400℃の温度及び１秒乃至20分間の範囲か
ら適当な条件を選択する。
塗膜の機械的強度の点からは、用いる熱可塑性
樹脂は結晶性であることが望ましく、この場合に
は、塗膜中の熱可塑性樹脂の結晶化が抑制される
ように、塗膜の焼付温度からその樹脂の結晶化温
度よりも少なくとも10℃低い温度迄急冷すること
特に10秒以内、好適には１秒以内に急冷すること
が、加工性やバリヤー性（粒界での良好な接着に
よる耐腐食性）の点で望ましい。このような急冷
は、焼付後の塗膜を冷却水、液化窒素気流、冷風
等の冷却媒体と接触させるか、或いは塗膜焼付後
の継目を冷却ローラ等の冷却機構と接触させるこ
とにより容易に行い得る。
本発明による継目被覆罐は、内容物をレトルト
殺菌するバキユーム罐、炭酸飲料等を充填する内
圧罐、エアゾール罐等の種々の分野に用いること
ができる。
本発明を次の例で説明する。
本発明の実施例等に用いる熱硬化性樹脂溶液は
以下に述べる方法により作成した。
＜エポキシ・フエノール系樹脂溶液＞
石炭酸0.5モルとｐ−クレゾール0.5モルを37％
ホルムアルデヒド水溶液1.5モルに溶かし、触媒
としてアンモニア0.15モルを加えて95℃で３時間
反応させる。反応生成物はケトン、アルコール、
炭化水素などから成る混合溶剤で抽出し、水で洗
滌した後水層を取り除き、更に共沸法で残つた少
量の水分を除去し、冷却してレゾール型フエノー
ル樹脂の30％溶液を得る。上記レゾール型フエノ
ール樹脂溶液と予めケトン、エステル、アルコー
ル、炭化水素などから成る混合溶剤に溶解させて
得られた、ビスフエノールＡとエピクロルヒドリ
ンの縮合生成物で平均分子量2900のエポキシ樹脂
の30％溶液とを混合する。フエノール樹脂とエポ
キシ樹脂の重量比は40：60である。この混合物を
還流下で２時間予備縮合してエポキシ・フエノー
ル樹脂溶液とする。この溶液は実施例１、２およ
び参考例でのベース塗料として使用する。
溶接缶缶胴の製造方法が以下の通りである。
すなわち、以下の実施例２〜４のTFS溶接缶
では板厚0.17mm硬度Ｔ−４のTFS板に、エポキシ
フエノール系塗料（エポキシ系樹脂とフエノール
樹脂の比率１：１の混合物）を缶胴の継目部分に
あたる場所を除いて、焼付後の膜厚が内面側5μ、
外面側3μになるようにマージン塗装し、200℃の
熱風乾燥炉中で10分間焼付硬化させた後、７号缶
のボデーブランク（ブランクレングス206.4mm、
ブランクハイト104.5mm）に切断し次に接合部の
カツトエツジ近傍の重ね合わせ部となる部分の両
面ともカツトエツジより幅約１mmにわたつて表面
のクロム層および酸化クロム層を除くため切削法
でエツジクリーニングを行う。前記エツジクリー
ニング後のブランクを、ロールフオーマーにより
短辺が軸方向になるように円筒状にし、溶接ステ
ーシヨンで重ね合わせて固定した後、線電極を介
した２個のロール電極から成る不活性ガス供給ノ
ズルを設けた市販のシーム溶接機を用いて、成形
体の重ね合わせ部に押圧力（40Kg／mm2）を加え、
５／minの供給量の混合不活性ガス（窒素90モ
ル％、水素10モル％）気流中製缶スピード30ｍ／
minで溶接缶胴（211径内容積318.2ml７号缶）を
得た。溶接前の重ね合わせ巾は0.3mmで溶接後の
重ね合わせ巾は0.4mmであつた。
本発明における実缶試験評価並びに塗料の物性
評価並びに缶継目近傍の塗膜の構造評価および物
性評価、更に、溶接部の金属表面層の分析は次の
通り行う。
(1) 接触角
ガラス板としてMicro Slide Glass（１級、
厚さ0.9〜1.2mm）を用い、クロム混酸中に一昼
夜浸漬後、純水で十分に洗浄し、乾燥後デシケ
ーター中に絶乾保存して用いる。
測定は25℃の恒温室で行い、空気雰囲気中で
マイクロシリンジで所定の塗料を0.2mm3だけガ
ラス板上に滴下し、１分経過後の接触角をゴニ
オメーターにより直続する。
(2) 溶接部金属表面層の分析
表面酸化膜（マグネタイト）厚；溶接罐より
溶接ラツプのみを切り取り、テープで貼り合わ
せ、ほぼ８×８mmとし、サンプルとする。この
サンプルの表面をArガスでエツチングしなが
らESCAを用い、Ｏ、Feの原子濃度比を測定す
る。酸化物中の酸素は15Å／分の割合でエツチ
ングされ又、エツチングしていくと酸素は原子
濃度比10〜20％でほぼ一定となるため、酸化膜
厚としては酸素が20％以上の部分とする。
(3) 分散状態の観察
缶継目部分の硬化塗膜を引きはがし、継目に
平行に巾２mm長さ15mmの試験片を切り取る。こ
の試験片をエポキシ樹脂中に包埋固化させ、ス
テンレス製ミクロトームによる、缶継目に垂直
な断面を得るように約15μの厚さの薄片を切り
出す。
この薄片をブルーダイ（メチルバイオレツ
ト）水溶液中に常温で10分間浸漬し、熱硬化性
樹脂のみを選択的に染色した後に水でよく洗浄
し、光学顕微鏡によりその構造を、特に分散状
態に着目して、観察を行う。その際、視野中に
存在する粒子の平均的な粒径をも写真撮影した
後に測定する。なお以下では、平均粒径として
数平均粒径を用い、この場合ただ単に粒径もし
くは平均粒径と称する。
(4) 継目部分の被覆性（定電圧電解時の電流値）
所定の塗料を塗布後焼付硬化させた缶継目部
分を巾２cmにわたつて切り出し、この継目に直
角方向に巾３mm、平行方向に100mmの部分を除
いてビニールテープでシールして試験片とす
る。この試験片を３％食塩水より成る25℃の電
解液に３分間浸漬した後に炭素棒を対極に用
い、電圧10.0Vで10秒間にわたつて定電圧電解
を行い、その時に流れる平均の電流値を測定す
る。各試料で５試験片の測定値の算術平均値を
結果として採用する。
(5) 加工性
所定の塗料を塗布後焼付硬化させた缶継目部
分より、継目部を中心に巾40mm、長さ60mmにわ
たつて切り出し試験片とする。折り曲げ試験は
JIS K5 400、６・16耐屈曲性に従つて行う。
折り曲げ後の試験片を継目部を中心に巾３
mm、折り曲げ先端を中心に継目部と平行方向に
６mmの部分を除いてビニールテーブでシール
し、(4)と同様なる条件で、定電圧電解を行う。
いずれも５試験片の平均の結果として採用し
た。
(6) 密着性
焼付硬化後の溶接部の塗膜に１ミリ角の碁盤
目の切れ目を入れ、これにセロテープを密着し
た後に、はく離試験を行つた。任意の５缶につ
いて行い、全くはく離の認められないものを
〇、平均で１〜２点認められるものを△、それ
以上認められたものを×として以下の表では示
す。
(7) ネツクイン加工性
ネツクイン加工後に継目部分の被覆膜のはく
離、われ等の有無を各試料No.について任意に50
缶選んで観察する。
(8) 実缶試験の評価方法
(a) 水素発生量
開缶時に缶内のガス分を採取し、ガスクロ
マトグラフイーにより水素量を調べ、10缶の
算術平均値を示す。また、膨張缶については
そのまま膨張缶である事を示す。
(b) 溶出鉄量
アツプルドリンクとコンソメスープの場合
について行い、開缶の後内容品の全量を灰化
する。次にこの灰分を塩酸で再溶解した後、
上澄液を原子吸光分析して内容品中の鉄量を
求める。任意に選んだ10缶当たりの算術平均
値を結果として採用する。
(c) 孔あきおよび缶内面接合部の状態
缶詰を37℃で１年間保存した後、目視観察
して内容品（液）の漏洩の認められる缶詰に
ついては、開缶後缶継目近傍の補正部を顕微
鏡観祭し、貫通孔の認められるものを孔あき
缶とし、全試験缶数に対する孔あき缶の比で
示す。また、
実施例 １
ここでは、熱硬化型塗料として前記エポキシー
フエノール系樹脂溶液を用いた。熱可塑性樹脂と
しては、ナイロン１２（環球法で測定される軟化
点178℃カルボニル基濃度508meq当量／100ｇ）
を用い、上記樹脂ペレツトを機械粉砕して平均粒
径約25μの粉体を得、これを上記塗料に固形分の
熱可塑性樹脂と熱硬化性樹脂の体積比が表１に示
す値になるようにそれぞれ混合し、高速ミキサー
で20分間撹拌し、分散させ継目補正用塗料を得
た。前述の方法で測定したこれらの塗料の25℃ガ
ラス板上での接触角を表１に示す。
次に、上記各種塗料を先に述べた方法により溶
接加工して得られたTFS材から成る缶胴の継目
部分（マグネタイト厚さ220〜250Å）の内面およ
び外面にエアレススプレーガンを用い、スプレー
時の塗料温度を40〜70℃に保ちつつ巾約10mm、乾
燥塗膜の厚みが40μｍになるようにスプレー塗装
した後に、缶内面継目が上向きの状態で下部より
ホツトエアーを約10秒吹き当て、溶媒をほとんど
蒸発させた後に220℃のガスオーブン中で約60秒
かけて焼付硬化させ、継目部分を被覆した缶胴を
得た。続いて、この焼付塗膜の構造を前述の方法
に従つて観察する一方、この缶胴について表の各
項目について評価を行つた。
次に、上記方法で得られた継目を被覆した缶胴
を通常の方法により、ビード加工し、ネツクイ
ン、フランジ加工した後、内外面にエポキシ・フ
エノール系塗膜を有する呼び内径65.3mm缶用の
TFS蓋を二重巻締めし、得られた空缶にコンソ
メスープおよびトマトソースの２種類をそれぞれ
パツクし、前記と同じTFS蓋を真空巻締機によ
り二重巻締めした。これらの缶詰は118℃で90分
間加熱殺菌を行い、37℃で１年間貯蔵したのち、
各試料で100缶中任意に抽出した10缶について鉄
溶出量および水素量を調べ、更に任意に抽出した
50缶を開缶して缶胴継目部分の腐食状態を調べ
た。それぞれの結果を表１に示す。It is desirable to use a thermoplastic polymer containing [Formula] in its main chain or side chain.
Carbonyl groups at a concentration of 12 to 1400meq/100g polymer, especially 50 to
The best effects in terms of processability and corrosion resistance are obtained when using thermoplastic polymers containing a concentration of 1200meq/100g polymer. Such thermoplastic polymers are produced by incorporating monomers having the aforementioned functional groups into the main chain of the polymer by means such as polymerization or copolymerization, or by graft polymerization or terminal treatment. It can be obtained by bonding it to a thermoplastic polymer. Further, in the case of a hydrocarbon polymer such as an olefin resin, by oxidizing this polymer, it can be made into a thermoplastic resin containing carbonyl groups in the above-mentioned range. Suitable examples of such thermoplastic polymers include, but are not limited to: (a) General formula Or In the formula, R 1 is an alkylene group having 2 to 6 carbon atoms,
R 2 is an alkylene group or arylene group having 2 to 24 carbon atoms, and a polyester consisting of a repeating unit represented by the following. For example, polyethylene adipate, polyethylene sebatate, polyethylene terephthalate, polytetramethylene isophthalate, polyethylene terephthalate/isophthalate, polytetramethylene terephthalate, polyethylene/tetramethylene terephthalate, polyethylene/oxybenzoate. (b) General formula In the formula, R 3 is a hydrogen atom or a lower alkyl group,
R 4 is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. a homopolymer or copolymer of monomers, or
Copolymers or acrylic-modified polyolefins of the monomer (3) above and olefins or other vinyl monomers. For example, polyacrylic ester, polymethacrylic ester, ethylene/acrylic ester copolymer, acrylic ester/acrylic acid copolymer, ethylene/acrylic ester/acrylic acid copolymer, ethylene/acrylic acid copolymer , styrene/methacrylic ester/acrylic acid copolymer, acrylic ester/vinyl chloride copolymer, acrylic ester grafted polyethylene, methacrylic ester/vinyl chloride copolymer, styrene/methacrylic ester/butadiene copolymer, Methacrylic acid ester/acrylonitrile copolymer. (c) General formula A copolymer of a vinyl ester and an olefin or other vinyl monomer, or a partially saponified product thereof, wherein R 5 is a hydrogen atom, an alkyl group, or a phenyl group. For example, partially saponified ethylene-vinyl acetate copolymer, ethylene-vinyl propionate copolymer, ethylene/vinyl acetate copolymer, acrylic ester/vinyl acetate copolymer, vinyl chloride/vinyl acetate copolymer. (d) Ionomer A resin obtained by neutralizing a copolymer of olefins and unsaturated carboxylic acid, or further with other vinyl monomers, with an alkali metal, alkaline earth metal, or organic base. For example, Surlyn products are commercially available from DuPont in the United States. (e) Copolymers of maleic anhydride and other vinyl monomers or maleic anhydride-modified polyolefins, such as maleic anhydride/styrene copolymers, maleic anhydride-modified polypropylene, maleic anhydride-modified polyethylene. (f) General formula A polycarbonate represented by the formula in which R 6 is a hydrocarbon group having 8 to 15 carbon atoms. For example, poly-p-xylene glycol biscarbonate, poly-dioxydiphenyl-methane carbonate, poly-dioxydiphenyl ethane carbonate, poly-dioxydiphenyl 2,2-propane carbonate, poly-dioxydiphenyl 1 , 1-ethane carbonate. (g) General formula or Polyamides consisting of repeating units represented by the formula, where n is a number from 3 to 13 and m is a number from 4 to 11. For example, poly-ω-aminocaproic acid, poly-ω-aminoheptanoic acid, poly-ω-aminocaprylic acid, poly-ω-aminopelagoic acid, poly-ω-aminodecanoic acid, poly-ω-aminoundecanoic acid, poly-ω -Aminododecanoic acid, poly-ω-aminotridecanoic acid, polyhexamethylene adipamide, polyhexamethylene sebamide, polyhexamethylene dodecamide, polyhexamethylene tridecamide, polydecamethylene adipamide, polydeca Methylene sebamide, polydecamethylene dodecamide, polydecamethylene tridecamide, polydodecamethylene adipamide,
Polydodecamethylene sebamide, polydodecamethylene dodecamide, polydodecamethylene tridecamide, polytridecamethylene adipamide, polytridecamethylene sebacamide, polytridecamethylene dodecamide, polytridecamethylene tridecamide , polyhexamethylene azelamide,
Polydecamethylene azeramide, polytridecamethylene azeramide, polytridecamethylene azeramide. (h) General formula or A polyurea consisting of a repeating unit represented by the following, wherein each of R 7 and R 8 is an alkylene group having 1 to 13 carbon atoms. For example, polyhexamethylene urea, polyheptamethylene urea, polyundecamethylene urea,
Polynonamethylene urea. (i) General formula or In the formula, R 9 is an alkylene group having 3 to 24 carbon atoms,
Polyether residue or polyester residue; R 10
is an alkylene group or arylene group having 3 to 24 carbon atoms; R 11 is an alkylene group or arylene group having 1 to 13 carbon atoms; k is a number of 0 or 1. For example, polytetramethylenehexamethyleneurethane, polyhexamethylenetetramethyleneurethane, polyureaurethane obtained by chain-extending isocyanate-terminated polyester or polyether with diamine or water. (j) Oxygen oxidation,
Resin particles obtained by oxidation with ozone oxidation or other oxidizing agents. Particularly desirable resins for purposes of this invention are, in order of importance, polyesters, polycarbonates, polyamides, ionomers, and acid-modified polyolefins. These resins should have at least a sufficient molecular weight to form a film, and these resin particles may optionally contain compounding agents known per se, such as UV absorbers, stabilizers, lubricants, oxidants, etc. Inhibitors, pigments, dyes, antistatic agents, etc. can be blended according to known formulations. Any means known per se can be used to form the thermoplastic resin into a powder having the above-mentioned particle size. For example, in the case of an addition polymer, resin particles of a predetermined particle size can be obtained by subjecting the constituent monomers to emulsion polymerization or suspension polymerization. Alternatively, there is a method of crushing the resin while cooling, a method of cooling a solution in which the resin is dissolved at a high temperature to precipitate the resin in the form of particles, or a method of bringing the resin solution into contact with a non-solvent to coagulate and precipitate the resin in the form of particles. Alternatively, a method in which a resin solution is sprayed into an air stream and deposited in the form of particles can be adopted. The obtained resin powder is sieved if necessary to obtain resin particles of a predetermined particle size. As the thermosetting resin, all thermosetting resins conventionally used for paints can be used. Suitable examples are phenol-formaldehyde resins, furan-formaldehyde resins, xylene-formaldehyde resins,
Formaldehyde resin, ketone formaldehyde resin, urea formaldehyde resin, melamine
Formaldehyde resins, alkyd resins, unsaturated polyester resins, epoxy resins, bismaleimide resins, triallyl cyanurate resins, thermosetting acrylic resins, silicone resins, oil-based resins, etc., and these may be used alone or in combination of two or more. Can be used. Thermosetting resins suitable for adhesion to seams and corrosion resistance include an epoxy resin component and at least one thermosetting resin selected from the group consisting of phenolic resins, urea resins, melamine resins, and thermosetting acrylic resins. In combination with curable resins, these film-forming resins are used in the paint in the form of a mixture or in the form of a precondensate. The paint used in the present invention can be easily obtained by dissolving the above-mentioned thermosetting resin in a suitable organic solvent and dispersing thermoplastic resin particles in this solution. At this time, a solvent is selected that dissolves the thermosetting resin but does not dissolve the thermoplastic resin. In general, aromatic solvents such as xylene and toluene; ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone; alcohol solvents such as ethanol and butanol; cyclic or linear ethers such as tetrahydrofuran and dioxane and various cellosolves; ethyl acetate and acetic acid. Esters such as butyl may be used alone or in combination of two or more. The thermoplastic resin particles may be added to the thermosetting resin solution in the form of a dispersion. The paint used in the present invention was measured 1 minute after dropping a sample of 0.2 mm 3 on a glass plate at a temperature of 25°C.
It is particularly desirable to have a contact angle of 18.5 to 45 degrees, especially a contact angle of 19.0 to 43 degrees, in order to enable a thick coating that completely covers the cut edge. The solid content concentration in the paint may be selected from a range of generally 5 to 50% depending on the combination of resins so as to provide suitable workability and thick coating properties. Coating can be applied to the housing joint or its vicinity by means known per se, such as roller coating, spray coating, brush coating, flow coat dip coating, etc., and does not require special means such as powder coating. figure,
A significant advantage of the present invention is that conventional equipment can be used as is. In order to completely cover the corners of the cut edges of the seam, it is desirable that the coating layer at the corners of the cut edges after baking be in the range of 5 to 70 microns, and if the coating specified in the present invention is used, Forming such a coating film is extremely easy. According to the present invention, the paint applied to the seam is baked under conditions that first cause evaporation of the solvent in the solution and then softening of the thermoplastic resin, thereby forming a coating with the above-described structure all at once. As the heating means, direct flame, thermal oven, hot air oven, induction heating, resistance heating, infrared heating, etc. can be used. The curing conditions used are such that the thermosetting resin becomes reticulated by crosslinking and sufficient adhesion occurs at the interface between the thermosetting resin and the thermoplastic resin.
Appropriate conditions are selected from a temperature range of 150 to 400°C and a time period of 1 second to 20 minutes. From the point of view of the mechanical strength of the coating film, it is desirable that the thermoplastic resin used be crystalline, and in this case, the baking of the coating film should be Rapid cooling from temperature to a temperature at least 10°C below the crystallization temperature of the resin, particularly within 10 seconds, preferably within 1 second, improves processability and barrier properties (due to good adhesion at grain boundaries). Desirable in terms of corrosion resistance). Such rapid cooling can be easily achieved by bringing the baked paint film into contact with a cooling medium such as cooling water, a stream of liquefied nitrogen, or cold air, or by bringing the seam after the paint film into contact with a cooling mechanism such as a cooling roller. It can be done. The seam-covered can according to the present invention can be used in various fields, such as vacuum cans for retort sterilization of contents, internal pressure cans for filling carbonated drinks, etc., and aerosol cans. The invention is illustrated by the following example. Thermosetting resin solutions used in Examples of the present invention were prepared by the method described below. <Epoxy/phenolic resin solution> 0.5 mol of carbolic acid and 0.5 mol of p-cresol at 37%
Dissolve in 1.5 mol of formaldehyde aqueous solution, add 0.15 mol of ammonia as a catalyst, and react at 95°C for 3 hours. The reaction products are ketones, alcohols,
Extract with a mixed solvent consisting of hydrocarbons, wash with water, remove the aqueous layer, remove a small amount of remaining water using an azeotropic method, and cool to obtain a 30% solution of resol type phenolic resin. A 30% solution of an epoxy resin with an average molecular weight of 2900, which is a condensation product of bisphenol A and epichlorohydrin, obtained by dissolving the above resol type phenol resin solution in advance in a mixed solvent consisting of ketones, esters, alcohols, hydrocarbons, etc. Mix. The weight ratio of phenolic resin and epoxy resin is 40:60. This mixture is precondensed under reflux for 2 hours to give an epoxy-phenolic resin solution. This solution is used as a base coating in Examples 1, 2 and Reference Examples. The method for manufacturing a welded can body is as follows. That is, in the TFS welded cans of Examples 2 to 4 below, epoxyphenol paint (mixture of epoxy resin and phenol resin at a ratio of 1:1) was applied to the can body on a TFS plate with a thickness of 0.17 mm and a hardness of T-4. The film thickness after baking is 5μ on the inner surface, excluding the seam area.
After painting the margin to a thickness of 3μ on the outer surface and baking it in a hot air drying oven at 200℃ for 10 minutes, a No. 7 can body blank (blank length 206.4mm,
Then, edge cleaning was performed using a cutting method to remove the chromium layer and chromium oxide layer on both sides of the overlapping part near the cut edge of the joint part over a width of about 1 mm from the cut edge. conduct. The edge-cleaned blank was formed into a cylindrical shape using a roll former so that the short side was oriented in the axial direction, and after being stacked and fixed at a welding station, an inert gas consisting of two roll electrodes was applied via a wire electrode. Using a commercially available seam welder equipped with a supply nozzle, a pressing force (40 kg/mm 2 ) was applied to the overlapping part of the molded bodies.
Mixed inert gas (nitrogen 90 mol%, hydrogen 10 mol%) at a supply rate of 5/min, can making speed 30 m/min
A welded can body (No. 7 can of 211 diameter 318.2 ml) was obtained at min. The overlap width before welding was 0.3 mm, and the overlap width after welding was 0.4 mm. In the present invention, actual can test evaluation, physical property evaluation of the paint, structural evaluation and physical property evaluation of the paint film near the can joint, and analysis of the metal surface layer at the welded part are performed as follows. (1) Contact angle Micro Slide Glass (grade 1,
0.9 to 1.2 mm thick), immersed in chromium mixed acid for a day and night, thoroughly washed with pure water, dried, and stored in a desiccator to be absolutely dry before use. Measurements are carried out in a constant temperature room at 25°C, and 0.2 mm 3 of the specified paint is dropped onto a glass plate using a microsyringe in an air atmosphere, and the contact angle is directly measured using a goniometer after 1 minute has elapsed. (2) Analysis of the metal surface layer of the weld zone Surface oxide film (magnetite) thickness: Cut only the weld lap from the weld can and paste it together with tape to a size of approximately 8 x 8 mm and use it as a sample. While etching the surface of this sample with Ar gas, the atomic concentration ratio of O and Fe is measured using ESCA. Oxygen in the oxide is etched at a rate of 15 Å/min, and as the etching progresses, the atomic concentration ratio of oxygen becomes almost constant at 10 to 20%, so the oxide film thickness is at least 20% oxygen. do. (3) Observation of dispersion state Peel off the cured coating from the can joint and cut out a test piece 2 mm wide and 15 mm long parallel to the joint. This test piece is embedded and solidified in epoxy resin, and a thin section with a thickness of about 15 μm is cut out using a stainless steel microtome so as to obtain a cross section perpendicular to the can joint. This thin section was immersed in an aqueous solution of blue dye (methyl violet) for 10 minutes at room temperature to selectively stain only the thermosetting resin, then thoroughly washed with water, and its structure was examined using an optical microscope, paying particular attention to the dispersion state. and make observations. At this time, the average particle size of the particles present in the field of view is also measured after taking a photograph. In the following, the number average particle size will be used as the average particle size, and in this case it will simply be referred to as the particle size or average particle size. (4) Coverability of the joint part (current value during constant voltage electrolysis) After applying the specified paint and baking it to harden it, cut out the joint part of the can over a width of 2 cm, and cut out a width of 3 mm in a direction perpendicular to this joint, and a width of 3 mm in a parallel direction. Seal the sample with vinyl tape except for the 100mm section and use it as a test piece. After immersing this test piece in an electrolytic solution of 3% saline solution at 25°C for 3 minutes, constant voltage electrolysis was performed at a voltage of 10.0 V for 10 seconds using a carbon rod as a counter electrode, and the average current value flowing at that time was Measure. For each sample, the arithmetic mean value of the measurements of 5 specimens is taken as the result. (5) Processability Cut out a test piece 40 mm wide and 60 mm long from the joint part of the can after applying the specified paint and baking it to harden it, centering on the joint part. The bending test
Performed according to JIS K5 400, 6.16 bending resistance. After bending the test piece, the width is 3 with the seam in the center.
mm, seal with a vinyl tape except for a 6 mm section parallel to the seam centering on the bent tip, and perform constant voltage electrolysis under the same conditions as (4).
Both were adopted as the average results of 5 test pieces. (6) Adhesion A 1 mm square grid cut was made in the paint film of the welded part after baking and hardening, and after adhering cellophane tape to the cut, a peel test was conducted. The results are shown in the table below as ○ for cases in which no peeling was observed at all, △ for cases in which 1 to 2 points of peeling were observed on average, and × for cases in which more peeling was observed. (7) Netzukin processability After netzukin processing, each sample No.
Select a can and observe. (8) Evaluation method of actual can test (a) Amount of hydrogen generated When the can is opened, the gas inside the can is sampled, the amount of hydrogen is determined by gas chromatography, and the arithmetic mean value of 10 cans is shown. In addition, an expansion can is simply an expansion can. (b) Amount of eluted iron This is done for apple drink and consommé soup, and after opening the can, the entire contents are incinerated. Next, after redissolving this ash with hydrochloric acid,
The supernatant liquid is subjected to atomic absorption spectrometry to determine the amount of iron in the contents. The arithmetic mean value for 10 arbitrarily selected cans is used as the result. (c) Condition of perforations and inner joints of cans For canned goods that have been stored at 37°C for one year and are found to have leaked contents (liquid) by visual inspection, the correction part near the joint of the can after opening the can. The cans with through holes were observed under a microscope, and those with perforated holes were considered as perforated cans, and the ratio of perforated cans to the total number of test cans is shown. Further, in Example 1, the above-mentioned epoxy phenolic resin solution was used as a thermosetting paint. As a thermoplastic resin, nylon 12 (softening point measured by ring and ball method: 178°C, carbonyl group concentration: 508meq equivalent/100g)
The above resin pellets were mechanically pulverized to obtain a powder with an average particle size of about 25 μm, and this was added to the above paint so that the volume ratio of the solid content of thermoplastic resin and thermosetting resin was as shown in Table 1. and stirred for 20 minutes using a high-speed mixer to disperse and obtain a seam correction paint. Table 1 shows the contact angles of these paints on a glass plate at 25°C, as measured by the method described above. Next, an airless spray gun was used to spray the inner and outer surfaces of the joint part (magnetite thickness: 220 to 250 Å) of the can body made of TFS material obtained by welding the various paints by the method described above. After spray painting to a width of about 10 mm and a dry coating thickness of 40 μm while maintaining the paint temperature at 40 to 70°C, blow hot air from the bottom for about 10 seconds with the inner seam of the can facing upward to remove the solvent. After evaporating most of the material, the material was baked and hardened in a gas oven at 220° C. for about 60 seconds to obtain a can body with the seam covered. Subsequently, the structure of this baked coating film was observed according to the method described above, and the can body was evaluated for each item in the table. Next, the can body with the joints covered by the above method was beaded, tied in, and flanged by the usual method, and then a can body with a nominal inner diameter of 65.3 mm having an epoxy/phenol coating on the inner and outer surfaces was processed.
A TFS lid was double-sealed, two types of consommé soup and tomato sauce were packed into the resulting empty cans, and the same TFS lid was double-sealed using a vacuum seaming machine. These canned goods were heat sterilized at 118℃ for 90 minutes and stored at 37℃ for one year.
For each sample, 10 out of 100 cans were randomly extracted and the iron elution amount and hydrogen amount were examined, and further randomly extracted.
Fifty cans were opened and the state of corrosion at the can body joint was examined. The results are shown in Table 1.
【表】
参考例
（方法）
ここでは、熱可塑性樹脂粉体としてナイロン12
（軟化点178℃カルボニル基濃度508meq当量／100
ｇ）ペレツトを機械粉砕して得られる平均粒径約
5μｍの粉体を使用し、熱硬化性樹脂として前記
エポキシフエノール系樹脂溶液を使用した。固形
分約25％、固形分約25％、固形分中の熱可塑性樹
脂と熱硬化性樹脂の割合が90：10となるように、
希釈溶剤として熱硬化性樹脂溶液と同一の溶剤を
用いて高速ミキサーで塗料を作成した。
種々の異なる溶接部の金属表面層を得るため、
混合不活性ガス気流の流速として20／min（例
１）、５／min（例２）、また窒素ガス気流２
／min（例３）、比較のため窒素ガス0.2／min
（例４）、更に空気中でガスを流さない場合（例
５）の各条件で先に述べた方法により溶接加工を
行つて缶胴を得た。これらに加えてNo.１の試料を
更に70ｇ／の硫窒水溶液中で30秒間酸洗浄（ピ
ツクリング）を行つたものを例６とした。これら
の缶胴の継目部分の内面および外面にエアレスス
プレーガンを用い、前記塗料をスプレー時の塗料
温度を40〜70℃に保ちつつ巾約10mm、乾燥塗膜の
厚みが40μｍになるようにスプレー塗装した後に
缶内面継目が上向きの状態で下部よりホツトエア
ーを約10秒吹き当て、溶媒をほとんど蒸発させた
後に、220℃のガスオープン中で約60秒かけて焼
付硬化させ、継目部分を被覆した缶胴を得た。続
いてこの缶胴について、表に示す各項目の評価を
行い、塗料塗布前の溶接缶胴については、溶接部
の金属表面層の分析を行つた。
次に、上記方法で得られた継目を被覆した缶胴
を通常の方法により、ビード加工し、ネツクイン
加工、フランジ加工した後、内外面にエポキシ・
フエノール系塗膜を有する呼び内径65.3mm缶用の
TFS蓋を二重巻締めし、得られた空缶に90℃に
加熱したアツプルドリンクおよびトマトソースの
２種類をそれぞれ充填し、前記と同じTFS蓋を
真空巻締機により二重巻締めした。トマトソース
を充填した缶詰については118℃で90分間加熱殺
菌を行い、いずれの缶詰も37℃で１年間貯蔵した
のち、各試料で100缶中任意に抽出した10缶につ
いて鉄溶出量および水素量を調べ、更に任意に抽
出した50缶を開缶して缶胴継目部分の腐食状態を
調べた。それぞれ結果を表Ａに示す。[Table] Reference example (Method) Here, nylon 12 is used as the thermoplastic resin powder.
(Softening point 178℃ Carbonyl group concentration 508meq equivalent/100
g) Average particle size obtained by mechanically crushing pellets: approx.
Powder of 5 μm was used, and the above-mentioned epoxyphenol resin solution was used as the thermosetting resin. Solid content is approximately 25%, solid content is approximately 25%, and the ratio of thermoplastic resin and thermosetting resin in the solid content is 90:10.
A paint was prepared using a high-speed mixer using the same solvent as the thermosetting resin solution as a diluting solvent. To obtain various different weld metal surface layers,
The flow rate of the mixed inert gas stream is 20/min (Example 1), 5/min (Example 2), and nitrogen gas stream 2
/min (Example 3), nitrogen gas 0.2/min for comparison
Can bodies were obtained by welding according to the method described above under the following conditions (Example 4) and in the case of no gas flow in the air (Example 5). In addition to these, sample No. 1 was further acid-washed (pickled) for 30 seconds in a 70 g/nitrogen aqueous solution to prepare Example 6. Using an airless spray gun, spray the above-mentioned paint onto the inner and outer surfaces of the joints of these can bodies, maintaining the paint temperature at 40 to 70°C, so that the width of the paint film is approximately 10 mm and the thickness of the dried paint film is 40 μm. After painting, hot air was blown from the bottom for about 10 seconds with the inner seam of the can facing upwards to evaporate most of the solvent, and the seam was cured by baking in an open gas atmosphere at 220°C for about 60 seconds to cover the seam. I got the can body. Subsequently, this can body was evaluated for each item shown in the table, and for the welded can body before paint was applied, the metal surface layer of the welded part was analyzed. Next, the can body with the seams covered by the above method is beaded, tied in, and flanged using the usual method, and then the inner and outer surfaces are coated with epoxy.
For cans with a nominal inner diameter of 65.3 mm that have a phenolic coating.
The TFS lid was double-sealed, and the resulting empty cans were filled with apple drink and tomato sauce heated to 90°C, and the same TFS lid as above was double-sealed using a vacuum seaming machine. Canned goods filled with tomato sauce were heat sterilized at 118°C for 90 minutes, and all canned goods were stored at 37°C for one year. After that, the amount of iron eluted and the amount of hydrogen were determined for 10 randomly selected cans out of 100 cans for each sample. Furthermore, 50 randomly selected cans were opened and the state of corrosion at the can body joint was examined. The results are shown in Table A.
【表】【table】
第１図は、本発明の溶接缶の断面図であり、第
２図は、側面継目の内外金属表面部の１例を拡大
して示す断面図であり、第３図は、継目被覆缶の
要部の１例を拡大して示す断面図であつて、
引照数字１は製缶用TFS素材、２はその両端
縁部、３は側面継目、４は樹脂被覆膜、５は鋼基
質、８は鋼酸化物層、１４は熱可塑性樹脂の連続
相、１５は熱硬化性樹脂の連続薄膜層、１６は熱
硬化性樹脂の分散粒子を夫々示す。
FIG. 1 is a sectional view of a welded can of the present invention, FIG. 2 is an enlarged sectional view of an example of the inner and outer metal surfaces of a side seam, and FIG. 3 is a sectional view of a seam-coated can. It is an enlarged cross-sectional view of one example of the main parts, in which the reference number 1 is the TFS material for can manufacturing, 2 is the both end edges thereof, 3 is the side seam, 4 is the resin coating film, 5 is the steel substrate, 8 is a steel oxide layer, 14 is a continuous phase of thermoplastic resin, 15 is a continuous thin film layer of thermosetting resin, and 16 is a dispersed particle of thermosetting resin.
Claims (1)
ら成る被覆層を鋼板基質上に設けた罐用素材を溶
接により側面で接合した溶接継目罐において、こ
の側面継目は厚みが50乃至800オングストローム
の範囲にあるマグネタイトを主体とする緻密な鋼
酸化物から成る鋼板基質露出層を有し、該側面継
目の少くとも一方の表面部には熱硬化性樹脂と50
乃至300℃の環球法軟化点を有する熱可塑性樹脂
とを、 20：80乃至１：99 の体積比で含有し、熱可塑性樹脂が被覆層中に連
続相の形で存在し、一方熱硬化性樹脂の一部は熱
可塑性樹脂連続相と継目内面側との界面に連続薄
層の形で存在し、残りの一部は前記連続相中に微
細な分散粒子の形で存在する被覆層が設けられて
いることを特徴とする継目を被覆した溶接罐。 ２ 前記熱可塑性樹脂は、カルボン酸、カルボン
酸塩、カルボン酸無水物、カルボン酸エステル、
カルボン酸アミド、ケトン、炭酸エステル、ユリ
ア、ウレタン等に基ずくカルボニル基を主鎖或い
は側鎖に12乃至1400meq／100ｇ重合体の濃度で
有する樹脂である特許請求の範囲第１項の罐。 ３ 前記熱可塑性樹脂がポリエステル、ポリカー
ボネート、ポリアミド、アイオノマー或いは酸変
性ポリオレフインである特許請求の範囲第１項記
載の罐。 ４ 前記熱硬化性樹脂が、エポキシ樹脂とフエノ
ール樹脂、尿素樹脂、メラミン樹脂及び熱硬化型
アクリル樹脂の少なくとも１種との組合せから成
る特許請求の範囲第１項記載の罐。 ５ 側面に継目を有する溶接罐胴の少なくとも一
方の表面側継目に、樹脂塗料を塗布し、次いでこ
の塗料を焼付けて継目を被覆する塗膜を形成させ
ることから成る継目被覆溶接罐の製法において、
該罐胴は金属クロム層及びその上のクロム酸化物
層から成る被覆層を鋼板基質上に設けた罐用素材
を溶接により側面で接合した溶接継目罐であつ
て、この側面継目は厚みが50乃至800オングスト
ロームの範囲にあるマグネタイトを主体とする緻
密な鋼酸化物から成る鋼板基質露出層を有するも
のとし、前記樹脂塗料は、熱硬化性樹脂の溶液か
ら成る分散媒と0.1乃至80μｍの数平均粒径と50乃
至300℃の環球法軟化点とを有する熱可塑性樹脂
粒子の分散質とから成る塗料であり、前記塗料中
の熱硬化性樹脂と熱可塑性樹脂とは20：80乃至
１：99の体積比で存在するものとし、継目に塗布
した塗料を、最初に前記溶液中の溶媒の蒸発が生
じ、次いで熱可塑性樹脂の軟化が生じる条件下で
焼付けることを特徴とする継目被覆溶接罐の製造
法。[Scope of Claims] 1. A welded seam can in which a can material in which a coating layer consisting of a metallic chromium layer and a chromium oxide layer thereon is provided on a steel plate substrate is joined at the side surfaces by welding, and this side seam has a thickness. The steel sheet substrate has an exposed layer of dense steel oxide mainly composed of magnetite in the range of 50 to 800 angstroms, and at least one surface of the side joint is coated with thermosetting resin and 50 angstroms.
A thermoplastic resin having a ring and ball softening point of 300°C to 300°C is contained in a volume ratio of 20:80 to 1:99, with the thermoplastic resin existing in the form of a continuous phase in the coating layer, while the thermosetting resin A part of the resin exists in the form of a continuous thin layer at the interface between the thermoplastic resin continuous phase and the inner surface of the seam, and a coating layer is provided in which the remaining part exists in the form of fine dispersed particles in the continuous phase. A welded can with a seam covered. 2 The thermoplastic resin is a carboxylic acid, a carboxylate, a carboxylic anhydride, a carboxylic ester,
The can according to claim 1, which is a resin having carbonyl groups based on carboxylic acid amide, ketone, carbonate ester, urea, urethane, etc. in the main chain or side chain at a concentration of 12 to 1400 meq/100 g polymer. 3. The can according to claim 1, wherein the thermoplastic resin is polyester, polycarbonate, polyamide, ionomer, or acid-modified polyolefin. 4. The can according to claim 1, wherein the thermosetting resin is a combination of an epoxy resin and at least one of a phenolic resin, a urea resin, a melamine resin, and a thermosetting acrylic resin. 5. A method for manufacturing a seam-coated welded can, which comprises applying a resin paint to at least one surface side seam of a welded can body having a seam on the side surface, and then baking the paint to form a coating film that covers the seam,
The can body is a welded seam can made by welding a can material in which a coating layer consisting of a metal chromium layer and a chromium oxide layer on top of the metal chromium layer is provided on a steel plate substrate, and this side seam has a thickness of 50 mm. The steel plate substrate has an exposed layer of dense steel oxide mainly composed of magnetite with a thickness of 0.1 to 800 angstroms, and the resin coating has a number average particle size of 0.1 to 80 μm with a dispersion medium consisting of a solution of a thermosetting resin. It is a paint consisting of a dispersoid of thermoplastic resin particles having a particle size and a ring and ball softening point of 50 to 300°C, and the ratio of thermosetting resin and thermoplastic resin in the paint is 20:80 to 1:99. A seam-coated welding can, characterized in that the paint applied to the seam is baked under conditions that first cause evaporation of the solvent in the solution and then softening of the thermoplastic resin. manufacturing method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10613985A JPS61123538A (en) | 1985-05-20 | 1985-05-20 | Tin-free-steel welded can, joint thereof is coated, and manufacture thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10613985A JPS61123538A (en) | 1985-05-20 | 1985-05-20 | Tin-free-steel welded can, joint thereof is coated, and manufacture thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61123538A JPS61123538A (en) | 1986-06-11 |
| JPS6324827B2 true JPS6324827B2 (en) | 1988-05-23 |
Family
ID=14426034
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10613985A Granted JPS61123538A (en) | 1985-05-20 | 1985-05-20 | Tin-free-steel welded can, joint thereof is coated, and manufacture thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61123538A (en) |
-
1985
- 1985-05-20 JP JP10613985A patent/JPS61123538A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61123538A (en) | 1986-06-11 |
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