CA1141084A - Storage stable water-dilutable acid adducted epoxy based coating for metal food contact surfaces - Google Patents
Storage stable water-dilutable acid adducted epoxy based coating for metal food contact surfacesInfo
- Publication number
- CA1141084A CA1141084A CA000314869A CA314869A CA1141084A CA 1141084 A CA1141084 A CA 1141084A CA 000314869 A CA000314869 A CA 000314869A CA 314869 A CA314869 A CA 314869A CA 1141084 A CA1141084 A CA 1141084A
- Authority
- CA
- Canada
- Prior art keywords
- weight percent
- resin
- bisphenol
- diglycidyl ether
- acid
- 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
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 18
- 239000002184 metal Substances 0.000 title claims abstract description 18
- 239000002253 acid Substances 0.000 title claims abstract description 13
- 235000013305 food Nutrition 0.000 title claims abstract description 11
- 239000004593 Epoxy Substances 0.000 title claims description 21
- 238000000576 coating method Methods 0.000 title description 30
- 239000011248 coating agent Substances 0.000 title description 23
- 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 claims abstract description 73
- 229920005989 resin Polymers 0.000 claims abstract description 51
- 239000011347 resin Substances 0.000 claims abstract description 51
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 claims abstract description 42
- 239000008199 coating composition Substances 0.000 claims abstract description 38
- 229930185605 Bisphenol Natural products 0.000 claims abstract description 36
- GYZLOYUZLJXAJU-UHFFFAOYSA-N diglycidyl ether Chemical compound C1OC1COCC1CO1 GYZLOYUZLJXAJU-UHFFFAOYSA-N 0.000 claims abstract description 33
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 27
- 150000008064 anhydrides Chemical class 0.000 claims abstract description 20
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 17
- 229920003180 amino resin Polymers 0.000 claims abstract description 12
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims abstract description 10
- 150000001298 alcohols Chemical class 0.000 claims abstract description 10
- 150000005215 alkyl ethers Chemical class 0.000 claims abstract description 8
- 229910021529 ammonia Inorganic materials 0.000 claims abstract description 7
- 235000013361 beverage Nutrition 0.000 claims abstract description 6
- 238000004806 packaging method and process Methods 0.000 claims abstract description 5
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 claims description 42
- 239000000203 mixture Substances 0.000 claims description 28
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 claims description 24
- 239000007787 solid Substances 0.000 claims description 21
- 239000002904 solvent Substances 0.000 claims description 19
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 claims description 18
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 17
- 235000021355 Stearic acid Nutrition 0.000 claims description 16
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 claims description 16
- 239000008117 stearic acid Substances 0.000 claims description 16
- POAOYUHQDCAZBD-UHFFFAOYSA-N 2-butoxyethanol Chemical compound CCCCOCCO POAOYUHQDCAZBD-UHFFFAOYSA-N 0.000 claims description 13
- -1 alkoxyethanols Chemical class 0.000 claims description 11
- IPCSVZSSVZVIGE-UHFFFAOYSA-N hexadecanoic acid Chemical compound CCCCCCCCCCCCCCCC(O)=O IPCSVZSSVZVIGE-UHFFFAOYSA-N 0.000 claims description 10
- 150000002576 ketones Chemical class 0.000 claims description 9
- 150000002763 monocarboxylic acids Chemical class 0.000 claims description 9
- 239000000758 substrate Substances 0.000 claims description 7
- 239000000908 ammonium hydroxide Substances 0.000 claims description 6
- WQEPLUUGTLDZJY-UHFFFAOYSA-N n-Pentadecanoic acid Natural products CCCCCCCCCCCCCCC(O)=O WQEPLUUGTLDZJY-UHFFFAOYSA-N 0.000 claims description 6
- SRPWOOOHEPICQU-UHFFFAOYSA-N trimellitic anhydride Chemical group OC(=O)C1=CC=C2C(=O)OC(=O)C2=C1 SRPWOOOHEPICQU-UHFFFAOYSA-N 0.000 claims description 6
- DURPTKYDGMDSBL-UHFFFAOYSA-N 1-butoxybutane Chemical compound CCCCOCCCC DURPTKYDGMDSBL-UHFFFAOYSA-N 0.000 claims description 5
- DYCRDXOGOYSIIA-UHFFFAOYSA-N 1-hexoxyethanol Chemical compound CCCCCCOC(C)O DYCRDXOGOYSIIA-UHFFFAOYSA-N 0.000 claims description 5
- BNCADMBVWNPPIZ-UHFFFAOYSA-N 2-n,2-n,4-n,4-n,6-n,6-n-hexakis(methoxymethyl)-1,3,5-triazine-2,4,6-triamine Chemical group COCN(COC)C1=NC(N(COC)COC)=NC(N(COC)COC)=N1 BNCADMBVWNPPIZ-UHFFFAOYSA-N 0.000 claims description 5
- 235000021314 Palmitic acid Nutrition 0.000 claims description 5
- 229910052782 aluminium Inorganic materials 0.000 claims description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 5
- 239000011928 denatured alcohol Substances 0.000 claims description 4
- 239000003960 organic solvent Substances 0.000 claims description 3
- 150000003512 tertiary amines Chemical class 0.000 claims description 3
- 150000002762 monocarboxylic acid derivatives Chemical class 0.000 abstract description 16
- 150000001412 amines Chemical class 0.000 abstract description 4
- 235000011114 ammonium hydroxide Nutrition 0.000 abstract 1
- 239000011877 solvent mixture Substances 0.000 abstract 1
- 235000013405 beer Nutrition 0.000 description 14
- 235000019441 ethanol Nutrition 0.000 description 13
- 238000012360 testing method Methods 0.000 description 11
- 238000006243 chemical reaction Methods 0.000 description 10
- 239000000796 flavoring agent Substances 0.000 description 10
- 235000019634 flavors Nutrition 0.000 description 10
- 235000014113 dietary fatty acids Nutrition 0.000 description 8
- 229930195729 fatty acid Natural products 0.000 description 8
- 239000000194 fatty acid Substances 0.000 description 8
- 150000004665 fatty acids Chemical class 0.000 description 8
- 239000011541 reaction mixture Substances 0.000 description 8
- DKGAVHZHDRPRBM-UHFFFAOYSA-N Tert-Butanol Chemical compound CC(C)(C)O DKGAVHZHDRPRBM-UHFFFAOYSA-N 0.000 description 7
- 239000003822 epoxy resin Substances 0.000 description 7
- 229920000647 polyepoxide Polymers 0.000 description 7
- 239000008367 deionised water Substances 0.000 description 6
- 229910021641 deionized water Inorganic materials 0.000 description 6
- ZTJORNVITHUQJA-UHFFFAOYSA-N Heptyl p-hydroxybenzoate Chemical compound CCCCCCCOC(=O)C1=CC=C(O)C=C1 ZTJORNVITHUQJA-UHFFFAOYSA-N 0.000 description 5
- 125000004432 carbon atom Chemical group C* 0.000 description 5
- 235000019251 heptyl p-hydroxybenzoate Nutrition 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 150000001299 aldehydes Chemical class 0.000 description 4
- 238000009835 boiling Methods 0.000 description 4
- 238000010992 reflux Methods 0.000 description 4
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 3
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- NTIZESTWPVYFNL-UHFFFAOYSA-N Methyl isobutyl ketone Chemical compound CC(C)CC(C)=O NTIZESTWPVYFNL-UHFFFAOYSA-N 0.000 description 3
- UIHCLUNTQKBZGK-UHFFFAOYSA-N Methyl isobutyl ketone Natural products CCC(C)C(C)=O UIHCLUNTQKBZGK-UHFFFAOYSA-N 0.000 description 3
- ZMANZCXQSJIPKH-UHFFFAOYSA-N Triethylamine Chemical compound CCN(CC)CC ZMANZCXQSJIPKH-UHFFFAOYSA-N 0.000 description 3
- 230000002378 acidificating effect Effects 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 125000003700 epoxy group Chemical group 0.000 description 3
- 239000011888 foil Substances 0.000 description 3
- 238000009472 formulation Methods 0.000 description 3
- 229940043265 methyl isobutyl ketone Drugs 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- IMFACGCPASFAPR-UHFFFAOYSA-N tributylamine Chemical compound CCCCN(CCCC)CCCC IMFACGCPASFAPR-UHFFFAOYSA-N 0.000 description 3
- KBPLFHHGFOOTCA-UHFFFAOYSA-N 1-Octanol Chemical compound CCCCCCCCO KBPLFHHGFOOTCA-UHFFFAOYSA-N 0.000 description 2
- BBMCTIGTTCKYKF-UHFFFAOYSA-N 1-heptanol Chemical compound CCCCCCCO BBMCTIGTTCKYKF-UHFFFAOYSA-N 0.000 description 2
- XNWFRZJHXBZDAG-UHFFFAOYSA-N 2-METHOXYETHANOL Chemical compound COCCO XNWFRZJHXBZDAG-UHFFFAOYSA-N 0.000 description 2
- YIWUKEYIRIRTPP-UHFFFAOYSA-N 2-ethylhexan-1-ol Chemical compound CCCCC(CC)CO YIWUKEYIRIRTPP-UHFFFAOYSA-N 0.000 description 2
- SZNYYWIUQFZLLT-UHFFFAOYSA-N 2-methyl-1-(2-methylpropoxy)propane Chemical compound CC(C)COCC(C)C SZNYYWIUQFZLLT-UHFFFAOYSA-N 0.000 description 2
- ZPVFWPFBNIEHGJ-UHFFFAOYSA-N 2-octanone Chemical compound CCCCCCC(C)=O ZPVFWPFBNIEHGJ-UHFFFAOYSA-N 0.000 description 2
- PFCHFHIRKBAQGU-UHFFFAOYSA-N 3-hexanone Chemical compound CCCC(=O)CC PFCHFHIRKBAQGU-UHFFFAOYSA-N 0.000 description 2
- IWTBVKIGCDZRPL-UHFFFAOYSA-N 3-methylpentanol Chemical compound CCC(C)CCO IWTBVKIGCDZRPL-UHFFFAOYSA-N 0.000 description 2
- BWDBEAQIHAEVLV-UHFFFAOYSA-N 6-methylheptan-1-ol Chemical compound CC(C)CCCCCO BWDBEAQIHAEVLV-UHFFFAOYSA-N 0.000 description 2
- HGINCPLSRVDWNT-UHFFFAOYSA-N Acrolein Chemical compound C=CC=O HGINCPLSRVDWNT-UHFFFAOYSA-N 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- AMQJEAYHLZJPGS-UHFFFAOYSA-N N-Pentanol Chemical compound CCCCCO AMQJEAYHLZJPGS-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 230000001476 alcoholic effect Effects 0.000 description 2
- 239000011260 aqueous acid Substances 0.000 description 2
- DKPFZGUDAPQIHT-UHFFFAOYSA-N butyl acetate Chemical compound CCCCOC(C)=O DKPFZGUDAPQIHT-UHFFFAOYSA-N 0.000 description 2
- 239000004359 castor oil Substances 0.000 description 2
- 235000019438 castor oil Nutrition 0.000 description 2
- POULHZVOKOAJMA-UHFFFAOYSA-N dodecanoic acid Chemical compound CCCCCCCCCCCC(O)=O POULHZVOKOAJMA-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- ZEMPKEQAKRGZGQ-XOQCFJPHSA-N glycerol triricinoleate Natural products CCCCCC[C@@H](O)CC=CCCCCCCCC(=O)OC[C@@H](COC(=O)CCCCCCCC=CC[C@@H](O)CCCCCC)OC(=O)CCCCCCCC=CC[C@H](O)CCCCCC ZEMPKEQAKRGZGQ-XOQCFJPHSA-N 0.000 description 2
- KEMQGTRYUADPNZ-UHFFFAOYSA-N heptadecanoic acid Chemical compound CCCCCCCCCCCCCCCCC(O)=O KEMQGTRYUADPNZ-UHFFFAOYSA-N 0.000 description 2
- VKYKSIONXSXAKP-UHFFFAOYSA-N hexamethylenetetramine Chemical compound C1N(C2)CN3CN1CN2C3 VKYKSIONXSXAKP-UHFFFAOYSA-N 0.000 description 2
- ZSIAUFGUXNUGDI-UHFFFAOYSA-N hexan-1-ol Chemical compound CCCCCCO ZSIAUFGUXNUGDI-UHFFFAOYSA-N 0.000 description 2
- ZXEKIIBDNHEJCQ-UHFFFAOYSA-N isobutanol Chemical compound CC(C)CO ZXEKIIBDNHEJCQ-UHFFFAOYSA-N 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- FBUKVWPVBMHYJY-UHFFFAOYSA-N nonanoic acid Chemical compound CCCCCCCCC(O)=O FBUKVWPVBMHYJY-UHFFFAOYSA-N 0.000 description 2
- WWZKQHOCKIZLMA-UHFFFAOYSA-N octanoic acid Chemical compound CCCCCCCC(O)=O WWZKQHOCKIZLMA-UHFFFAOYSA-N 0.000 description 2
- 238000009928 pasteurization Methods 0.000 description 2
- XNLICIUVMPYHGG-UHFFFAOYSA-N pentan-2-one Chemical compound CCCC(C)=O XNLICIUVMPYHGG-UHFFFAOYSA-N 0.000 description 2
- FDPIMTJIUBPUKL-UHFFFAOYSA-N pentan-3-one Chemical compound CCC(=O)CC FDPIMTJIUBPUKL-UHFFFAOYSA-N 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- YKYONYBAUNKHLG-UHFFFAOYSA-N propyl acetate Chemical compound CCCOC(C)=O YKYONYBAUNKHLG-UHFFFAOYSA-N 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 235000020354 squash Nutrition 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 229920001187 thermosetting polymer Polymers 0.000 description 2
- SZHOJFHSIKHZHA-UHFFFAOYSA-N tridecanoic acid Chemical compound CCCCCCCCCCCCC(O)=O SZHOJFHSIKHZHA-UHFFFAOYSA-N 0.000 description 2
- ZDPHROOEEOARMN-UHFFFAOYSA-N undecanoic acid Chemical compound CCCCCCCCCCC(O)=O ZDPHROOEEOARMN-UHFFFAOYSA-N 0.000 description 2
- BIIBYWQGRFWQKM-JVVROLKMSA-N (2S)-N-[4-(cyclopropylamino)-3,4-dioxo-1-[(3S)-2-oxopyrrolidin-3-yl]butan-2-yl]-2-[[(E)-3-(2,4-dichlorophenyl)prop-2-enoyl]amino]-4,4-dimethylpentanamide Chemical compound CC(C)(C)C[C@@H](C(NC(C[C@H](CCN1)C1=O)C(C(NC1CC1)=O)=O)=O)NC(/C=C/C(C=CC(Cl)=C1)=C1Cl)=O BIIBYWQGRFWQKM-JVVROLKMSA-N 0.000 description 1
- MUTGBJKUEZFXGO-OLQVQODUSA-N (3as,7ar)-3a,4,5,6,7,7a-hexahydro-2-benzofuran-1,3-dione Chemical compound C1CCC[C@@H]2C(=O)OC(=O)[C@@H]21 MUTGBJKUEZFXGO-OLQVQODUSA-N 0.000 description 1
- OYHQOLUKZRVURQ-NTGFUMLPSA-N (9Z,12Z)-9,10,12,13-tetratritiooctadeca-9,12-dienoic acid Chemical compound C(CCCCCCC\C(=C(/C\C(=C(/CCCCC)\[3H])\[3H])\[3H])\[3H])(=O)O OYHQOLUKZRVURQ-NTGFUMLPSA-N 0.000 description 1
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 description 1
- FIDRAVVQGKNYQK-UHFFFAOYSA-N 1,2,3,4-tetrahydrotriazine Chemical compound C1NNNC=C1 FIDRAVVQGKNYQK-UHFFFAOYSA-N 0.000 description 1
- JYEUMXHLPRZUAT-UHFFFAOYSA-N 1,2,3-triazine Chemical compound C1=CN=NN=C1 JYEUMXHLPRZUAT-UHFFFAOYSA-N 0.000 description 1
- VZXTWGWHSMCWGA-UHFFFAOYSA-N 1,3,5-triazine-2,4-diamine Chemical compound NC1=NC=NC(N)=N1 VZXTWGWHSMCWGA-UHFFFAOYSA-N 0.000 description 1
- GYSCBCSGKXNZRH-UHFFFAOYSA-N 1-benzothiophene-2-carboxamide Chemical compound C1=CC=C2SC(C(=O)N)=CC2=C1 GYSCBCSGKXNZRH-UHFFFAOYSA-N 0.000 description 1
- HNAGHMKIPMKKBB-UHFFFAOYSA-N 1-benzylpyrrolidine-3-carboxamide Chemical compound C1C(C(=O)N)CCN1CC1=CC=CC=C1 HNAGHMKIPMKKBB-UHFFFAOYSA-N 0.000 description 1
- IDQBJILTOGBZCR-UHFFFAOYSA-N 1-butoxypropan-1-ol Chemical compound CCCCOC(O)CC IDQBJILTOGBZCR-UHFFFAOYSA-N 0.000 description 1
- CUZLJOLBIRPEFB-UHFFFAOYSA-N 1-methoxypropan-2-one Chemical compound COCC(C)=O CUZLJOLBIRPEFB-UHFFFAOYSA-N 0.000 description 1
- FRKWIUGOPAAFHI-UHFFFAOYSA-N 2,4,6-triethyl-2h-1,3,5-triazine-1,5,6-triamine Chemical compound CCC1N=C(CC)N(N)C(N)(CC)N1N FRKWIUGOPAAFHI-UHFFFAOYSA-N 0.000 description 1
- AXCCTNWOXQEKQA-UHFFFAOYSA-N 2,4,6-triphenyl-2h-1,3,5-triazine-1,5,6-triamine Chemical compound NN1C(C=2C=CC=CC=2)N=C(C=2C=CC=CC=2)N(N)C1(N)C1=CC=CC=C1 AXCCTNWOXQEKQA-UHFFFAOYSA-N 0.000 description 1
- LYANEXCVXFZQFF-UHFFFAOYSA-N 2-(2,5-dioxooxolan-3-yl)acetic acid Chemical compound OC(=O)CC1CC(=O)OC1=O LYANEXCVXFZQFF-UHFFFAOYSA-N 0.000 description 1
- FALRKNHUBBKYCC-UHFFFAOYSA-N 2-(chloromethyl)pyridine-3-carbonitrile Chemical compound ClCC1=NC=CC=C1C#N FALRKNHUBBKYCC-UHFFFAOYSA-N 0.000 description 1
- DWKNOLCXIFYNFV-HSZRJFAPSA-N 2-[[(2r)-1-[1-[(4-chloro-3-methylphenyl)methyl]piperidin-4-yl]-5-oxopyrrolidine-2-carbonyl]amino]-n,n,6-trimethylpyridine-4-carboxamide Chemical compound CN(C)C(=O)C1=CC(C)=NC(NC(=O)[C@@H]2N(C(=O)CC2)C2CCN(CC=3C=C(C)C(Cl)=CC=3)CC2)=C1 DWKNOLCXIFYNFV-HSZRJFAPSA-N 0.000 description 1
- BFSVOASYOCHEOV-UHFFFAOYSA-N 2-diethylaminoethanol Chemical compound CCN(CC)CCO BFSVOASYOCHEOV-UHFFFAOYSA-N 0.000 description 1
- ZNQVEEAIQZEUHB-UHFFFAOYSA-N 2-ethoxyethanol Chemical compound CCOCCO ZNQVEEAIQZEUHB-UHFFFAOYSA-N 0.000 description 1
- PFNHSEQQEPMLNI-UHFFFAOYSA-N 2-methyl-1-pentanol Chemical compound CCCC(C)CO PFNHSEQQEPMLNI-UHFFFAOYSA-N 0.000 description 1
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 description 1
- DFATXMYLKPCSCX-UHFFFAOYSA-N 3-methylsuccinic anhydride Chemical compound CC1CC(=O)OC1=O DFATXMYLKPCSCX-UHFFFAOYSA-N 0.000 description 1
- RHLVCLIPMVJYKS-UHFFFAOYSA-N 3-octanone Chemical compound CCCCCC(=O)CC RHLVCLIPMVJYKS-UHFFFAOYSA-N 0.000 description 1
- LDMRLRNXHLPZJN-UHFFFAOYSA-N 3-propoxypropan-1-ol Chemical compound CCCOCCCO LDMRLRNXHLPZJN-UHFFFAOYSA-N 0.000 description 1
- VPWNQTHUCYMVMZ-UHFFFAOYSA-N 4,4'-sulfonyldiphenol Chemical class C1=CC(O)=CC=C1S(=O)(=O)C1=CC=C(O)C=C1 VPWNQTHUCYMVMZ-UHFFFAOYSA-N 0.000 description 1
- ZVHAANQOQZVVFD-UHFFFAOYSA-N 5-methylhexan-1-ol Chemical compound CC(C)CCCCO ZVHAANQOQZVVFD-UHFFFAOYSA-N 0.000 description 1
- FVFVNNKYKYZTJU-UHFFFAOYSA-N 6-chloro-1,3,5-triazine-2,4-diamine Chemical compound NC1=NC(N)=NC(Cl)=N1 FVFVNNKYKYZTJU-UHFFFAOYSA-N 0.000 description 1
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 description 1
- 235000003255 Carthamus tinctorius Nutrition 0.000 description 1
- 244000020518 Carthamus tinctorius Species 0.000 description 1
- GHVNFZFCNZKVNT-UHFFFAOYSA-N Decanoic acid Natural products CCCCCCCCCC(O)=O GHVNFZFCNZKVNT-UHFFFAOYSA-N 0.000 description 1
- LCGLNKUTAGEVQW-UHFFFAOYSA-N Dimethyl ether Chemical compound COC LCGLNKUTAGEVQW-UHFFFAOYSA-N 0.000 description 1
- 235000010469 Glycine max Nutrition 0.000 description 1
- 244000068988 Glycine max Species 0.000 description 1
- 239000004284 Heptyl p-hydroxybenzoate Substances 0.000 description 1
- 239000005639 Lauric acid Substances 0.000 description 1
- 240000006240 Linum usitatissimum Species 0.000 description 1
- 235000004431 Linum usitatissimum Nutrition 0.000 description 1
- 229920000877 Melamine resin Polymers 0.000 description 1
- NIPNSKYNPDTRPC-UHFFFAOYSA-N N-[2-oxo-2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 NIPNSKYNPDTRPC-UHFFFAOYSA-N 0.000 description 1
- UEEJHVSXFDXPFK-UHFFFAOYSA-N N-dimethylaminoethanol Chemical compound CN(C)CCO UEEJHVSXFDXPFK-UHFFFAOYSA-N 0.000 description 1
- 239000005642 Oleic acid Substances 0.000 description 1
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 description 1
- 229930040373 Paraformaldehyde Natural products 0.000 description 1
- LGRFSURHDFAFJT-UHFFFAOYSA-N Phthalic anhydride Natural products C1=CC=C2C(=O)OC(=O)C2=C1 LGRFSURHDFAFJT-UHFFFAOYSA-N 0.000 description 1
- 239000004820 Pressure-sensitive adhesive Substances 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 230000002745 absorbent Effects 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- IKHGUXGNUITLKF-XPULMUKRSA-N acetaldehyde Chemical compound [14CH]([14CH3])=O IKHGUXGNUITLKF-XPULMUKRSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 125000001931 aliphatic group Chemical group 0.000 description 1
- 125000003545 alkoxy group Chemical group 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- OBETXYAYXDNJHR-UHFFFAOYSA-N alpha-ethylcaproic acid Natural products CCCCC(CC)C(O)=O OBETXYAYXDNJHR-UHFFFAOYSA-N 0.000 description 1
- DTOSIQBPPRVQHS-PDBXOOCHSA-N alpha-linolenic acid Chemical compound CC\C=C/C\C=C/C\C=C/CCCCCCCC(O)=O DTOSIQBPPRVQHS-PDBXOOCHSA-N 0.000 description 1
- 235000020661 alpha-linolenic acid Nutrition 0.000 description 1
- MASBWURJQFFLOO-UHFFFAOYSA-N ammeline Chemical compound NC1=NC(N)=NC(O)=N1 MASBWURJQFFLOO-UHFFFAOYSA-N 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- OBNCKNCVKJNDBV-UHFFFAOYSA-N butanoic acid ethyl ester Natural products CCCC(=O)OCC OBNCKNCVKJNDBV-UHFFFAOYSA-N 0.000 description 1
- JHIWVOJDXOSYLW-UHFFFAOYSA-N butyl 2,2-difluorocyclopropane-1-carboxylate Chemical compound CCCCOC(=O)C1CC1(F)F JHIWVOJDXOSYLW-UHFFFAOYSA-N 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 235000012343 cottonseed oil Nutrition 0.000 description 1
- 239000003431 cross linking reagent Substances 0.000 description 1
- MLUCVPSAIODCQM-NSCUHMNNSA-N crotonaldehyde Chemical compound C\C=C\C=O MLUCVPSAIODCQM-NSCUHMNNSA-N 0.000 description 1
- MLUCVPSAIODCQM-UHFFFAOYSA-N crotonaldehyde Natural products CC=CC=O MLUCVPSAIODCQM-UHFFFAOYSA-N 0.000 description 1
- 229960002887 deanol Drugs 0.000 description 1
- 239000003398 denaturant Substances 0.000 description 1
- XXJWXESWEXIICW-UHFFFAOYSA-N diethylene glycol monoethyl ether Chemical compound CCOCCOCCO XXJWXESWEXIICW-UHFFFAOYSA-N 0.000 description 1
- 239000012972 dimethylethanolamine Substances 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000004070 electrodeposition Methods 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 229920006334 epoxy coating Polymers 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 235000004426 flaxseed Nutrition 0.000 description 1
- 238000005227 gel permeation chromatography 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
- CATSNJVOTSVZJV-UHFFFAOYSA-N heptan-2-one Chemical compound CCCCCC(C)=O CATSNJVOTSVZJV-UHFFFAOYSA-N 0.000 description 1
- NGAZZOYFWWSOGK-UHFFFAOYSA-N heptan-3-one Chemical compound CCCCC(=O)CC NGAZZOYFWWSOGK-UHFFFAOYSA-N 0.000 description 1
- 239000004312 hexamethylene tetramine Substances 0.000 description 1
- 235000010299 hexamethylene tetramine Nutrition 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- YAQXGBBDJYBXKL-UHFFFAOYSA-N iron(2+);1,10-phenanthroline;dicyanide Chemical compound [Fe+2].N#[C-].N#[C-].C1=CN=C2C3=NC=CC=C3C=CC2=C1.C1=CN=C2C3=NC=CC=C3C=CC2=C1 YAQXGBBDJYBXKL-UHFFFAOYSA-N 0.000 description 1
- GJRQTCIYDGXPES-UHFFFAOYSA-N iso-butyl acetate Natural products CC(C)COC(C)=O GJRQTCIYDGXPES-UHFFFAOYSA-N 0.000 description 1
- FGKJLKRYENPLQH-UHFFFAOYSA-M isocaproate Chemical compound CC(C)CCC([O-])=O FGKJLKRYENPLQH-UHFFFAOYSA-M 0.000 description 1
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 description 1
- OQAGVSWESNCJJT-UHFFFAOYSA-N isovaleric acid methyl ester Natural products COC(=O)CC(C)C OQAGVSWESNCJJT-UHFFFAOYSA-N 0.000 description 1
- 239000010985 leather Substances 0.000 description 1
- 229960004488 linolenic acid Drugs 0.000 description 1
- KQQKGWQCNNTQJW-UHFFFAOYSA-N linolenic acid Natural products CC=CCCC=CCC=CCCCCCCCC(O)=O KQQKGWQCNNTQJW-UHFFFAOYSA-N 0.000 description 1
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical compound O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-UHFFFAOYSA-N 0.000 description 1
- 150000007974 melamines Chemical class 0.000 description 1
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 description 1
- 229960004011 methenamine Drugs 0.000 description 1
- 230000000813 microbial effect Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- DAZXVJBJRMWXJP-UHFFFAOYSA-N n,n-dimethylethylamine Chemical compound CCN(C)C DAZXVJBJRMWXJP-UHFFFAOYSA-N 0.000 description 1
- GNVRJGIVDSQCOP-UHFFFAOYSA-N n-ethyl-n-methylethanamine Chemical compound CCN(C)CC GNVRJGIVDSQCOP-UHFFFAOYSA-N 0.000 description 1
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 description 1
- 235000021313 oleic acid Nutrition 0.000 description 1
- 229960002969 oleic acid Drugs 0.000 description 1
- 125000000466 oxiranyl group Chemical group 0.000 description 1
- 229920002866 paraformaldehyde Polymers 0.000 description 1
- SQYNKIJPMDEDEG-UHFFFAOYSA-N paraldehyde Chemical compound CC1OC(C)OC(C)O1 SQYNKIJPMDEDEG-UHFFFAOYSA-N 0.000 description 1
- 229960003868 paraldehyde Drugs 0.000 description 1
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N phenol group Chemical group C1(=CC=CC=C1)O ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 1
- 239000003755 preservative agent Substances 0.000 description 1
- 230000002335 preservative effect Effects 0.000 description 1
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 1
- MCSINKKTEDDPNK-UHFFFAOYSA-N propyl propionate Chemical compound CCCOC(=O)CC MCSINKKTEDDPNK-UHFFFAOYSA-N 0.000 description 1
- 239000011342 resin composition Substances 0.000 description 1
- 238000007763 reverse roll coating Methods 0.000 description 1
- WBHHMMIMDMUBKC-XLNAKTSKSA-N ricinelaidic acid Chemical compound CCCCCC[C@@H](O)C\C=C\CCCCCCCC(O)=O WBHHMMIMDMUBKC-XLNAKTSKSA-N 0.000 description 1
- 229960003656 ricinoleic acid Drugs 0.000 description 1
- FEUQNCSVHBHROZ-UHFFFAOYSA-N ricinoleic acid Natural products CCCCCCC(O[Si](C)(C)C)CC=CCCCCCCCC(=O)OC FEUQNCSVHBHROZ-UHFFFAOYSA-N 0.000 description 1
- 229960004274 stearic acid Drugs 0.000 description 1
- 229940014800 succinic anhydride Drugs 0.000 description 1
- 239000003784 tall oil Substances 0.000 description 1
- TUNFSRHWOTWDNC-HKGQFRNVSA-N tetradecanoic acid Chemical compound CCCCCCCCCCCCC[14C](O)=O TUNFSRHWOTWDNC-HKGQFRNVSA-N 0.000 description 1
- YFTHZRPMJXBUME-UHFFFAOYSA-N tripropylamine Chemical compound CCCN(CCC)CCC YFTHZRPMJXBUME-UHFFFAOYSA-N 0.000 description 1
- 239000002383 tung oil Substances 0.000 description 1
- 239000003039 volatile agent Substances 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Abstract
ABSTRACT
A resin is provided which is the adduct of a monocarboxylic acid and a diglycidyl ether of a bisphenol or of a monocarboxylic acid, a bisphenol and a diglycidyl ether of a bisphenol, reacted with an anhydride to an Acid No. of 35 to 150. This resin is solubilized with a volatile amine, ammonia or NH4OH in a solvent mixture of water, alkoxyethanols, alcohols and alkyl ethers of diethylene glycol and combined with an aminoplast to produce a coating composition utilizable to coat surfaces that will contact a food or beverage, such as in metal packaging containers.
A resin is provided which is the adduct of a monocarboxylic acid and a diglycidyl ether of a bisphenol or of a monocarboxylic acid, a bisphenol and a diglycidyl ether of a bisphenol, reacted with an anhydride to an Acid No. of 35 to 150. This resin is solubilized with a volatile amine, ammonia or NH4OH in a solvent mixture of water, alkoxyethanols, alcohols and alkyl ethers of diethylene glycol and combined with an aminoplast to produce a coating composition utilizable to coat surfaces that will contact a food or beverage, such as in metal packaging containers.
Description
8'~L -STORAGE STABLE WATEfi-DILUTABLE ACID_ADDUCTED EPOXY
~ASED COATING FOR METAL FOOD CONTACT SURFACES
This invention relates to epoxy based resins water-solubilizable with ammonia or an amine and with water based coating compositions containing them.
It has been proposed to form water dilutable emulsions or dispersions containing epoxy resins for use as water based coatings. Such coatings have disadvantages and it is highly desirable to provide water-soluble epoxy based coatings. Prior epoxy based coatirgs have poor shelf life due to the presence of oxirane groups and/or unreacted anhydride.
In U.S. Patent No. 4,105,614 of K.G. Davis et al, granted August 8, 1978 there is disclosed a resin in which the epoxy groups of "~
there is aisclosed a resin in which the epoxy groups of a diglycidyl ether are capped with a bisphenol and the resultant material is reacted with an anhydride to provide water-solubilizable carboxyl groups. The resins of this invention utilizing a monocarboxylic acid, such 1as stearic acid, have advantages over the resins of U.S.
Patent No. 4,105,614.
1. Coatings made therefrom do not absorb n-heptyl p-hydroxybenzoate, a preservative used to stabilize unpasteurized beer.
~ASED COATING FOR METAL FOOD CONTACT SURFACES
This invention relates to epoxy based resins water-solubilizable with ammonia or an amine and with water based coating compositions containing them.
It has been proposed to form water dilutable emulsions or dispersions containing epoxy resins for use as water based coatings. Such coatings have disadvantages and it is highly desirable to provide water-soluble epoxy based coatings. Prior epoxy based coatirgs have poor shelf life due to the presence of oxirane groups and/or unreacted anhydride.
In U.S. Patent No. 4,105,614 of K.G. Davis et al, granted August 8, 1978 there is disclosed a resin in which the epoxy groups of "~
there is aisclosed a resin in which the epoxy groups of a diglycidyl ether are capped with a bisphenol and the resultant material is reacted with an anhydride to provide water-solubilizable carboxyl groups. The resins of this invention utilizing a monocarboxylic acid, such 1as stearic acid, have advantages over the resins of U.S.
Patent No. 4,105,614.
1. Coatings made therefrom do not absorb n-heptyl p-hydroxybenzoate, a preservative used to stabilize unpasteurized beer.
2. Coatings made therefrom have less effect on the flavor of beer on short term storage.
. ' ~
. ' ~
3. The coating formulations have higher solids content at application viscosity, which permits use of a single coating to attain coating weights necessary in standard applications. Application viscosity is generally 154-100 sec., preferably 25-70 sec., #2 Zahn cup.
4. The final coating formulation has better shelf life, as measured by viscosity change.
Insafar as is now known a resin system of this type and coatings containing thern have not been proposed.
This invention provides a water solubilzable resin that comprises an adduct of a monocarboxylic acid and a digly^idyl ether of a bisphenol or of a monocarboxylic acid, a bisphenol and a diglycidyl ether of a bisphenol, using an equivalent ratio of total monocarboxylic acid and bisphenol, if used, to diglycidyl ether between about 1:1 and about 1.2:1, further adducted with an anhydride in an amount sufficient to provide an acid number between about 35 and about 150.
It also provides a coating composition coMprising such resin and~an aminoplast, in a weight ratio between about 95:5 and about~70:30 solubilized with a volatile tertiary amineJ amrnonia or ammonium hydroxide to a pH of about 7.0 to about 9.1 in at least one solvent of the group alcohols, alkoxyethanols, ketones and alkyl ethers of diethylene glycol, each present in between about ane weight percent and abaut 20 weight percent of the weight of the final composition and diluted with water to a solids content between about 10 weight percent and about 25 weight percent.
It also provides substrates coated with such coating composition and metal packaging containers, interior coated with such coating composition and baked, containing a food or beverage.
The water dilutable resins of this invention are prepared by adducting sufficient monocarboxylic acid or Monocarboxylic acid and bisphenol to a diglycidyl ether of a bisphenol to react with all epoxy groups.
The diglycidyl ether is usually heated to about 80-90C
in a suitable solvent which is not only a solvent for the reaction but can be a component of a binary azeotrope with water. Then the monocarboxylic acid or monocarboxylic acid and bisphenol are added and the adduction is usually continued at about 150C for 2-3 hours until the epoxy value is 0.008 or less. This adduction reaction can be carried out in any order, i.e., monocarboxylic acid first followed by bisphenol, if used; or bisphenol, if used, first followed by monocarboxy-lic acid. It is preferred to react monocarboxylic acid, bisphenol and diglycidyl ether of a bisphenol, simultaneously.
Suitable solvents are ketones, ethers and esters. Non-lirniting examples of suitable solvents are methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ether and n-propyl acetate, n-butyl acetate, isobutyl acetate, n-propyl propionate and ethyl butyrate.
~etones are especially preferred.
The reaction mixture should be refluxed to remove all water that may be present. Anhydrous conditions are necessary before the anhydride is added.
After all water that may be present has been removed, an anhydride is added in an amount sufficient to provide an acid number between about 35 and about 150, preferably 40-90. Generally the reaction is carried out at about 100-120C for about 2-4 hours. The reaction of the anhydride is complete when the alcoholic acid number and the,aqueous acid number are substantially the same, usually within two units of each other. In order to ensure good shelf life, the anhydride number must be below about 6 and preferably zero. The anhydride number is the difference between the alcoholic acid number and the aqueous acid number.
An alkoxy ethanol boiling at about 130C or higher and other solvents, such as alcohols, are added to reduce solids content to between about 60 and about 75 weight percent.
The epoxy resin utilizable herein is a diglycidyl ether of a bisphenol, a class of compounds which are constituted by a pair of phenolic groups interlinked through an aliphatic bridge. While any of the bisphenols may be used, the compound 2,2-bis(p-hydroxyphenyl)propane, coMmonly known as bisphenol A, is more widely available in commerce and is preferred. The diglycidyl ethers of bisphenol A are readily available commercially. The epoxy resin, i.-e., the diglycidyl ether of a bisphenol, will have an epoxy equivalent weight between about 180 and about 2500.
The aliphatic rnonocarboxylic acids utilizable herein have between 8 and 18 carbon atoms and a molecular weight between about 140 and about 290.
Mixtures of monocarboxylic acids are contemplated.
Non-limiting examples of the aliphatic monocarboxylic acids and mixtures thereof are octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, ricinoleic acid, linseed fatty acids, safflower fatty acids, soya fatty acids, tall oil fatty acids, cottonseed fatty acids, castor oil fatty acids, dehydrated castor oil fatty acids and tung oil fatty acids.
The bisphenol that is adducted with the epoxy resin can be any bisphenol as disclosed hereinabove.
Preferably a bisphenol A is used. The equivalent ratio of total monocarboxylic acid and bisphenol, if used, to diglycidyl ether of a bisphenol will be between about 1:1 and about 1.2:1. The equivalent ratio of monocarboxylic acid to diglycidyl ether of a bisphenol will be between about 0.1:1 and about 1:1. The equivalent ratio of bisphenol to diglycidyl ether of a bisphenol will be between about 0.0:1 and about 0.9:1.
The basic purpose of using a bisphenol is to upgrade the molecular weight (MW) of the diglycidyl ether of a bisphenol to ensure sufficient molecular weight of the final acidic resin. If the diglycidyl ether of a bisphenol has sufficiently high molecular weight, a bisphenol is not used. In general, the molecular weight of the final resin, as measured by Gel Permeation Chromatography, will be between about 5,000 and about 25,000. Preferably the Mh~ should be between about 8,0Q0 and about 20,000. Most preferably, the MW should be between about 11,000 and about 13,000.
The preferred anhydride used in the resins of this invention is trimellitic anhydride. Other cyclic anhydrides which can be used include succinic anhydride, methyl succinic anhydride, tricarballylic anhydride, phthalic anhydride, hexahydrophthalic anhydride and maleic anhydride.
The amount of anhydride used should be sufficient to obtain an acid number of 35 to 150, preferably between about 40 and about 90, in order to ensure water solubility when the resin is neutralized.
In order to obtain good shelf life of the coating composition, there should be no unreacted anhydride groups. The amount of anhydride to be used can be readily calculated from the hydroxyl number of the monocarboxylic acid and bisphenol adducted epoxy.
In forming a coating composition containing the acidic resin, the resin is neutralized with a tertiary amine, ammonia or ammonium hydroxide to a pH of about 7.0 to about 9.1. Typical amines utilizable include triethylamine, tripropyl amine, dimethylethanol amine, diethylethanol amine, dimethylethyl amine and methyldiethyl amine.
The material used to thermoset the coating is a conventional aminoplast cross-linking agent. Such agents are well known in the art. There can be used any of the thermosetting alkylated arninoplast resins, such as the ureaaldehyde resins, the melaminealdehyde resins, the dicyandiamide-aldehyde resins and other aminoplast-aldehyde resins such as those triazine resins produced by the reaction of an aldehyde with formoguanamine, ammeline, 2-chloro-4,6-diamino-1,3,5-triazine, 2-phenyl-p-oxy-4,6-diamino-1,3,5-triazine, 6-methyl-2,4-diamino-173,5-triazine; 2,4,6-trihydrazine-1,3,5-triazine and 2,4,6-triethyl-triamino-1,3,5-triazine. The mono-, di- or triaralkyl or mono-, di- or triaryl melamines, for instance 2,4,6-triphenyltriamino-1,3,5-triazine are preferred. As aldehydes used to react with the amino compound to form the resinous matérial, one may use such aldehydes as formaldehyde, acetaldehyde, crotonic aldehyde, acrolein or compounds which engender aldehydes, such as hexamethylene-tetramine, paraldehyde, paraformaldehyde and the like.
The preferred aminoplast is hexamethoxymethylmelamine.
The weight ratio of acidic resin to aminoplast will be between about 95:5 and about 70:30.
The solvent system used in the coating composition will include alcohols, alkoxy ethanols, ketones and alkyl ethers of diethylene glycol. Suitable alcohols are those having between about 2 and about 8 carbon atoms and having a boiling point up to about 180C. Non-limiting examples of utilizable alcohols include special denatured ethanols (Formula 1), propanol, butanol, isobutanol, t-butanol, pentanol, hexanol, 2-methylpentanol, 3-methylpentanol, heptanol, isoheptanol, octanol, isooctanol and 2-ethylhexanol.
The alkoxy ethanols utilizable are those having between 1 and 6 carbon atoms in the alkoxy group.
I~on-limiting examples include methoxy ethanol, ethoxy ethanol, butoxy ethanol and hexoxy ethanol. Also utilizable are propoxy propanol and butoxy propanol.
The ketones utilizable are aliphatic ketones containing between 3 and 8 carbon atoms. Non-limiting examples of utilizable ketones are acetone, diethyl ketone, methylethyl ketone, methylpropyl ketone, methylisobutyl ketone, methylamyl ketone, methylhexyl ketone, ethylpropyl ketone, ethylbutyl ketone, ethylamyl ketone and methoxy acetone.
The utilizable alkyl ethers of diethylene glycol will contain between 1 and 4 carbon atoms in the alkyl group. Non-limiting examples include the monomethyl ether of diethylene glycol, the monoethyl ether of diethylene glycol and the monobutyl ether of diethylene glycol.
In general, alkylethanols, ketones and alkyl ethers of diethylene glycol are primarly solvents for resin and aminoplast. Lower alcohols, such as ethanol, t-butanol, also assist in wetting the surface being coated. Higher alcohols, such as isooctanol, also serve - as defoamants. In controlling viscosity of the final coating composition, higher boiling solvents, such as hexoxyethanol, tend to increase viscosity and lower boiling solvents, such as butoxyethanol and methyl ethyl ketone, tend to decrease viscosity.
- Although mixtures of organic solvents are highly pref`erred, satisfactory coating compositions can be prepared using a single methoxy ethanol, ketone or alkyl ether of diethylene glycol.
In the finished coating composition, the solids content (resin and aminoplast) will be between about 10 and about 25 weight percent, preferably about 20-23 weight percent. The volatile system (including arnine, ammonia or ammonium hydroxide) will be between about 90 weight percent and about 75 weight percent of the finished coating composition, preferably about 77-80 weight percent. About 65 to 90 weight percent of the volatile system will be water and the balance (35 to 10 weight percent) will be organic volatile solvents, including amine, ammonia or ammoniuM hydroxide.
Preferably, the ratio of water to organic volatiles will be about 70:30 to ~0:20 in the volatile system. Each component of the solvent system will be present in between about 1 weight percent and about 20 weight percent of the weight of the final composition. A
typical and preferred solvent system is defined in the working examples.
In the following illustrative examples all parts are parts by weight, unless otherwise indicated.
Example 1 Into a reaction kettle there was charged 55.4 parts of an 80 weight percent solids solution in methyl ethyl ketone (MEK) of a diglycidyl ether of bisphenol A
having an epoxy equivalent weight of 450-550 and an epoxy value of 0.22, based on solids. The solution was heated to ~8C (190F) and there were added 10.02 parts bisphenol A, 5.84 parts of a mixture of 70 weight percent stearic acid and 30 weight percnt palmitic acid, and 0.17 part tri-n-butylamine (catalyst). The reaction mixture was heated to 149C (300F), removing MEK
distillate as necessary. At 149C, the reaction mixture was held at total reflux for 2 hours and sampled for solids and epoxy value. Reflux was maintained until epoxy value was 0.008 maximum. Then, the reaction was cooled to 115C (240F), adjusting solids to 92 + 0.5 weight percent with MEK distillate. At 115C, there were added 5.95 parts trimellitic anhydride and the reaction was heated 118C (245F) for 2 hours. Then, the reaction mixture was sampled for anhydride number which was to be 6.0 maximum. After 2 1/2 hours at `l18C
the reaction was sampled for anhydride number and 15.06 parts n-butanol and 7.52 parts butoxy ethanol were added and held until the mixture was uniform. Final values for acid number, anhydride number, weight percent solids and molecular weight are set forth in Table 1.
Examples 2 through 9 A series of runs were carried out in a manner similar to Example l, with the following exceptions:
Example Z is a laboratory repeat cf Example 1; Example 3 is a pilot plant run of Example 1; Example 4 uses excess stearic acid; Example 5 uses less stearic acid; in Example 6 the stearic acid was reacted first, followed by bisphenol A; in Example 7, more stearic acid was used and less bisphenol A; Example 8 was the same as Example 2, except that the final solvent was butyl ether of diethylene glycol instead of the 2:1 weight ratio Mixture of butanol and butoxy ethanol used in the other examples; an in Example 9, a greater amount of trimellitic anhydride was used. Pertinent data and final values for these examples are set forth in Table 1 along with Example 1.
O O ~I N CO
O ~ N--. ~ N
~1 0 0 00 ~ 3 ~
~1 O O N N ~
cu ~~ o o ~--~i 0 0 00 ~ ^
~1 c~
. .
r~l O O OCJ~ N N ~
~D¦ O 0~ N tnt--~1 0 ~D ~1 .. -- --U~
~1 0 0 0 O
O t~
o o t~
~ O O O O ~I C~J ` N C) ~ 0 .. . _ .
H .. .... _ _.
~ ~ ~~ ~ E
E ~ r1 0 0 0 ~r ~ ~ cd K
~0~0~ ^ ~0 t--Ln N ¢
0 0 r1 ~
~11 o c~o~r .c 1--i 0 o o O o.es O ::1 ~ O-rl G C:l ~ 5~ 5 r3 ~ o o ~ o C O S: C~ ~ U~ ~ ~ V bO
~ ~ ~ 0 ~ ~3' a~
tlS o ~. ~ ~ ,~
u~ ~ ~ 3 c: C ~~`~
ii-Examples 10 and 11 Using the general procedure of Example 1, resins of this invention can be prepared using relatively low molecular weight diglycidyl ethers of bisphenol h. Example 10 is like Example 1 except for the use of a different epoxy resin. In Example 11, the diglycidyl ether of bisphenol A is upgraded in molecular weight with bisphenol A and then reacted with stearic acid.
The formulations, in parts, for these examples are set forth in Table II.
TABLE II
Example_10 Example_11 Epoxy resin X (1) 34.42 ---Epoxy resin Y (2) --- 33.88 EK 5-54 5'35 Bisphenol A 18.50 13.84 Stearic acid (3) 10.78 15.98 Tri-n-butylamine 0.31 0.19 TriDIellitic anhydride 6.30 6.30 Butoxy ethanol 8.05 12.23 n-Butanol 16.10 ---t-Butanol -~- 12.23 (1) Diglycidyl ether of bisphenol A. Epoxy equivalent is 185 - 192. Epoxy value is 0. 52.
(2) Diglycidyl ether of bisphenol A. Epoxy equivalent is 193 - 203.
(3) k,ixture 70 wt ~ stearic acid/30 wt p palmitic acid.
-13~
Example 12 This example demonstrates the preparation of a resin in which the epoxy is of sufficiently high molecular weight that no bisphenol A, but only stearic acid, was used. In a reaction kettle were charged 47.72 parts of diglycidyl ether of bisphenol A having an epoxy equivalent weight of 850 and 5.35 parts of methyl ethyl ketone (MEK). The mixture was heated to about 88C to dissolve the resin (about 55 minutes). Then, 15.98 parts stearic acid and 0.19 part tri-n-butylamine were added and the reaction mixture was heated to 150C, collecting about 146 g MEK distillate, and held at 150C
for 2 hours. After 1 1/2 hours, a sample of the reaction mixture showed an epoxy value of 0.004. The MEK distillate was added back to the reaction mixture and 6.30 parts trimellitic anhydride were added. The reaction mixture was heated to reflux at about 116C, removing 11-12 g MEK distillate and held at reflux form 2 1/2 hours. The mixture was sampled and then reduced with 12.23 parts butoxy ethanol and 12.23 parts t-butanol. The final values of the resin solution were:
Wt. % solids 68.8 Acid No. 65.8 Anhydride No. 3.6 Mol. Wt. 7,000 The following Examples 13 through 15 illustrate the preparation of coating compositions using the resins of this invention.
Example 1 3 A mixture of 28.93 parts of the product described in Example 1, 2.25 parts hexamethoxymethyl-melamine, 3.37 parts n-butanol, 0.30 part hexoxy ethanol and 0.37 part butyl ether of diethylene glycol was stirred until uniform, while not permitting the temperature to exceed 54C. Then, there were added 1.29 parts denatured alcohol (Synaso~), which contains denaturants in the proportions of 100 gallons of special denatured alcohol Formula 1, 1 gallon of methyl isobutyl ketone, 1 gallon ethyl acetate and 1 gallon aviation gasoline. This was stirred until uniform. There was added a premixed mixture of 1.30 parts aqueous ammonia (26 Baume) and 2.19 parts deionized water. This was stirred until uniform and then diluted with 60.00 parts deionized water.
The final coating composition has a solids content of 22.63 weight percent, containing 90.06 weight percent resin of Example 1 and 9.94 weight perce~nt hexa-mett.oxymethylmelamine. The pH was 8.5 - 9Ø
Examples 14 and 15 In an alternative mixing procedure, n-butanol, butoxy ethanol and hexamethoxymethylmelamine were charged and agitation was begun. The product described in Example 1 was added and stirred until uniform, not ~ermitting the temperature to exceed 49C. A premixed mixture of aqueous ammonia (26 Baume) and deionized water was added and stirred until uniform. Finally, the composition was diluted with deionized water to produce the final coating composition. The amounts of components, in parts, in each Example 14 and 15 and pertinent data on the final coating compositions are set forth in Table III.
*Tr~d~Erk . ~
JB~
TABLE III
Ex. 14 Ex. 15 n-Butanol 0. 86 2.99 Butoxy ethanol 3.26 4. 36 Hexamethoxymethylmelamine2.35 2.33 Example 1 product 30.03 29.73 Aqueous ammonia 1.25 1.36 Deionized water 2.00 1.98 Deionized water 60.25 57.25 Solids, wt ~ 23.5 23.27 pH 8.5-9.0 8.5-9.0 Resin/aminoplast, wt % 90/10 90/10 The coating composition of this invention is primarily useful for coating aluminum, tin plated steel, pretreated metals, steel and metals coated with the same or different resin composition (i.e., a second coat).
The coating composition can be used however for coating other substrates such as wood1 paper and leather. The most preferred and useful use of the coating composition is for interior coating of metal containers that will come in contact with food or beverages. Coating can be done by any coating procedure well known to those skilled in the art including direct rollcoating, reverse rollcoating, electrodeposition, spraying, flow coating and the like. The preferred method however in coating the interior of metal containers is by spraying. After coating the substrate, the coating is baked for about 5 seconds to about 5 minutes at between about 250F and about 600F. A typical bake is for about 2 minutes at about 400F.
The coating compositions of Examples 13, 14 and 15 were tested for adhesion, pasteurized adhesion and blush. The adhesion test is carried out by cross-hatching a coated area with individual score lines approximately 1/16 inch apart. The"Scotch"tape is firmly applied to the cross-hatched area and removed with a quick snap. The amount of coating remaining on the panel is viewed visually and rated on a 0-10 scale (10 = perfect adhesion). Pasteurization is carried out by immersing the coated panels in water at 145F for 30 minutes. Then the panels are wiped dry with absorbent to~els and the adhesion test is carried out as above described. The amount of blush is rated on the pasteurized panel using a scale of 0 to 10 in which 0 is very severe blush and 10 is no blush.
Example 16 Treated aluminum test panels were coated with the coating compositions of Examples 13, 14 and 15 with a bar coater to a film weight of 2.5 to 3.0 milligrams per square inch. These test panels showed an adhesion rating of 10 in the adhesion test. In the pasteurization test, the panels gave a rating of 10 adhesion and 10 on blush.
The effect of a coating on the flavor of a packaged product is determined in a Flavor Difference Evaluation. Bottles of commercial beer are chilled to about 40-45F and uncapped. Sheets of aluminum foil (1 nlil) are bar coated on both sides with the coating being evaluated and baked. Then, a sheet of foil is rolled lightly and inserted into each bottle of beer and the bottle is recapped with a new cap.
*~r~rk of 3-M Company for a brand of pressure-sensitive adhesive tape For cornparison, additional bottles of the same beer are provided with rolls of aluminum foil that have been coated on both sides with an accepted commercial coating for interior coating (solvent-based epoxy coating) and baked. The test coating and the control coating were baked for 30 seconds at 400F metal temperature.
After storage for 3 days at 100F, the bottles of beer are again chilled and taste rated by 9 experienced tasters comparing the test coatings vs. the control. The arithmetic average of the ratings is calculated (x). Then, all rating values outside x + 2 are excluded and another average is calculated as the quality rating (QR). The following rating scale was used on a basis of 1-9.
1 = no flavor difference 1.0 - 1.5 = excellent flavor 1.5 - 2.0 = very good flavor 2.0 - 2.5 = good flavor 2.5 - 3.0 = acceptable flavor >3.0 = not acceptable In unpasteurized beer, n-heptyl p-hydroxy benzoate is used in an amount of 12 ppm to inhibit microbial growth. It is highly desirable that a coating used to coat the interior of metal beer containers does not absorb an appreciable amount of the n-heptyl p-hydroxybenzoate (sold under the registered tradernark "Staypro").
This property is tested using a simulated beer, an aqueous solution of 8 volume percent ethanol and 12 ppm "Staypro." Metal beer containers are interior coated hith the coating composition under test and baked in the usual baking cycle, e.g., 2 minutes at 400F. Then, the containers are filled with simulated beer and stored at room temperature for one week. At the end of the week the simulated beer is analyzed to determine the amount of heptyl p-hydroxybenzoate remaining. This is done by measuring light transmission on a spectrophotometer at a wavelength of 255 millimicrons, in comparison with the original.
Examples 17, 18 and 19 ; Using resins as described in Examples 1 and 9 herein and in Example 1 of U.S.
Patent No. 4,105,614, coating formulations were prepared by the procedure of Example 14. Each formulation contained 1Q weight percent (on solids basis) hexamethoxymethylrnelamine and the volatile system had a volume percent ratio of water/.organic solids of 80/20.
The formulations were used in testing for beer flavor rating and for resistance to absorption of n-heptyl p-hydroxybenzoate. Pertinent data and test results are 2d set forth in Table IV.
TABLE IV
. .
Resin Description Beer Flavor Staypro Ex. Ex. Source QR ppm rem-aining 17 1 Herein 1.2 11.9 18 9 Herein 1.1 11.8 19 1 U.S. Patent 1.3 10.5 4,105,614 Storage stability (shelf life) of a coating composition is measured by the cl~ange in viscosity. A
significant increase in viscosity is not desirable. A
3D coating composition as described in Example 17 and, for -comparison, a coating composition as described in Example 19 were placed in lined coating containers and stored at 80F. Periodically the compositions were tested for viscosity at 80F using #2 Zahn cup. The results are set forth in Table V.
TABLE V
Viscosity, seconds Time, weeks Exarnple 17 Example 19 Initial 25 - 40 40 - 50
Insafar as is now known a resin system of this type and coatings containing thern have not been proposed.
This invention provides a water solubilzable resin that comprises an adduct of a monocarboxylic acid and a digly^idyl ether of a bisphenol or of a monocarboxylic acid, a bisphenol and a diglycidyl ether of a bisphenol, using an equivalent ratio of total monocarboxylic acid and bisphenol, if used, to diglycidyl ether between about 1:1 and about 1.2:1, further adducted with an anhydride in an amount sufficient to provide an acid number between about 35 and about 150.
It also provides a coating composition coMprising such resin and~an aminoplast, in a weight ratio between about 95:5 and about~70:30 solubilized with a volatile tertiary amineJ amrnonia or ammonium hydroxide to a pH of about 7.0 to about 9.1 in at least one solvent of the group alcohols, alkoxyethanols, ketones and alkyl ethers of diethylene glycol, each present in between about ane weight percent and abaut 20 weight percent of the weight of the final composition and diluted with water to a solids content between about 10 weight percent and about 25 weight percent.
It also provides substrates coated with such coating composition and metal packaging containers, interior coated with such coating composition and baked, containing a food or beverage.
The water dilutable resins of this invention are prepared by adducting sufficient monocarboxylic acid or Monocarboxylic acid and bisphenol to a diglycidyl ether of a bisphenol to react with all epoxy groups.
The diglycidyl ether is usually heated to about 80-90C
in a suitable solvent which is not only a solvent for the reaction but can be a component of a binary azeotrope with water. Then the monocarboxylic acid or monocarboxylic acid and bisphenol are added and the adduction is usually continued at about 150C for 2-3 hours until the epoxy value is 0.008 or less. This adduction reaction can be carried out in any order, i.e., monocarboxylic acid first followed by bisphenol, if used; or bisphenol, if used, first followed by monocarboxy-lic acid. It is preferred to react monocarboxylic acid, bisphenol and diglycidyl ether of a bisphenol, simultaneously.
Suitable solvents are ketones, ethers and esters. Non-lirniting examples of suitable solvents are methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ether and n-propyl acetate, n-butyl acetate, isobutyl acetate, n-propyl propionate and ethyl butyrate.
~etones are especially preferred.
The reaction mixture should be refluxed to remove all water that may be present. Anhydrous conditions are necessary before the anhydride is added.
After all water that may be present has been removed, an anhydride is added in an amount sufficient to provide an acid number between about 35 and about 150, preferably 40-90. Generally the reaction is carried out at about 100-120C for about 2-4 hours. The reaction of the anhydride is complete when the alcoholic acid number and the,aqueous acid number are substantially the same, usually within two units of each other. In order to ensure good shelf life, the anhydride number must be below about 6 and preferably zero. The anhydride number is the difference between the alcoholic acid number and the aqueous acid number.
An alkoxy ethanol boiling at about 130C or higher and other solvents, such as alcohols, are added to reduce solids content to between about 60 and about 75 weight percent.
The epoxy resin utilizable herein is a diglycidyl ether of a bisphenol, a class of compounds which are constituted by a pair of phenolic groups interlinked through an aliphatic bridge. While any of the bisphenols may be used, the compound 2,2-bis(p-hydroxyphenyl)propane, coMmonly known as bisphenol A, is more widely available in commerce and is preferred. The diglycidyl ethers of bisphenol A are readily available commercially. The epoxy resin, i.-e., the diglycidyl ether of a bisphenol, will have an epoxy equivalent weight between about 180 and about 2500.
The aliphatic rnonocarboxylic acids utilizable herein have between 8 and 18 carbon atoms and a molecular weight between about 140 and about 290.
Mixtures of monocarboxylic acids are contemplated.
Non-limiting examples of the aliphatic monocarboxylic acids and mixtures thereof are octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, ricinoleic acid, linseed fatty acids, safflower fatty acids, soya fatty acids, tall oil fatty acids, cottonseed fatty acids, castor oil fatty acids, dehydrated castor oil fatty acids and tung oil fatty acids.
The bisphenol that is adducted with the epoxy resin can be any bisphenol as disclosed hereinabove.
Preferably a bisphenol A is used. The equivalent ratio of total monocarboxylic acid and bisphenol, if used, to diglycidyl ether of a bisphenol will be between about 1:1 and about 1.2:1. The equivalent ratio of monocarboxylic acid to diglycidyl ether of a bisphenol will be between about 0.1:1 and about 1:1. The equivalent ratio of bisphenol to diglycidyl ether of a bisphenol will be between about 0.0:1 and about 0.9:1.
The basic purpose of using a bisphenol is to upgrade the molecular weight (MW) of the diglycidyl ether of a bisphenol to ensure sufficient molecular weight of the final acidic resin. If the diglycidyl ether of a bisphenol has sufficiently high molecular weight, a bisphenol is not used. In general, the molecular weight of the final resin, as measured by Gel Permeation Chromatography, will be between about 5,000 and about 25,000. Preferably the Mh~ should be between about 8,0Q0 and about 20,000. Most preferably, the MW should be between about 11,000 and about 13,000.
The preferred anhydride used in the resins of this invention is trimellitic anhydride. Other cyclic anhydrides which can be used include succinic anhydride, methyl succinic anhydride, tricarballylic anhydride, phthalic anhydride, hexahydrophthalic anhydride and maleic anhydride.
The amount of anhydride used should be sufficient to obtain an acid number of 35 to 150, preferably between about 40 and about 90, in order to ensure water solubility when the resin is neutralized.
In order to obtain good shelf life of the coating composition, there should be no unreacted anhydride groups. The amount of anhydride to be used can be readily calculated from the hydroxyl number of the monocarboxylic acid and bisphenol adducted epoxy.
In forming a coating composition containing the acidic resin, the resin is neutralized with a tertiary amine, ammonia or ammonium hydroxide to a pH of about 7.0 to about 9.1. Typical amines utilizable include triethylamine, tripropyl amine, dimethylethanol amine, diethylethanol amine, dimethylethyl amine and methyldiethyl amine.
The material used to thermoset the coating is a conventional aminoplast cross-linking agent. Such agents are well known in the art. There can be used any of the thermosetting alkylated arninoplast resins, such as the ureaaldehyde resins, the melaminealdehyde resins, the dicyandiamide-aldehyde resins and other aminoplast-aldehyde resins such as those triazine resins produced by the reaction of an aldehyde with formoguanamine, ammeline, 2-chloro-4,6-diamino-1,3,5-triazine, 2-phenyl-p-oxy-4,6-diamino-1,3,5-triazine, 6-methyl-2,4-diamino-173,5-triazine; 2,4,6-trihydrazine-1,3,5-triazine and 2,4,6-triethyl-triamino-1,3,5-triazine. The mono-, di- or triaralkyl or mono-, di- or triaryl melamines, for instance 2,4,6-triphenyltriamino-1,3,5-triazine are preferred. As aldehydes used to react with the amino compound to form the resinous matérial, one may use such aldehydes as formaldehyde, acetaldehyde, crotonic aldehyde, acrolein or compounds which engender aldehydes, such as hexamethylene-tetramine, paraldehyde, paraformaldehyde and the like.
The preferred aminoplast is hexamethoxymethylmelamine.
The weight ratio of acidic resin to aminoplast will be between about 95:5 and about 70:30.
The solvent system used in the coating composition will include alcohols, alkoxy ethanols, ketones and alkyl ethers of diethylene glycol. Suitable alcohols are those having between about 2 and about 8 carbon atoms and having a boiling point up to about 180C. Non-limiting examples of utilizable alcohols include special denatured ethanols (Formula 1), propanol, butanol, isobutanol, t-butanol, pentanol, hexanol, 2-methylpentanol, 3-methylpentanol, heptanol, isoheptanol, octanol, isooctanol and 2-ethylhexanol.
The alkoxy ethanols utilizable are those having between 1 and 6 carbon atoms in the alkoxy group.
I~on-limiting examples include methoxy ethanol, ethoxy ethanol, butoxy ethanol and hexoxy ethanol. Also utilizable are propoxy propanol and butoxy propanol.
The ketones utilizable are aliphatic ketones containing between 3 and 8 carbon atoms. Non-limiting examples of utilizable ketones are acetone, diethyl ketone, methylethyl ketone, methylpropyl ketone, methylisobutyl ketone, methylamyl ketone, methylhexyl ketone, ethylpropyl ketone, ethylbutyl ketone, ethylamyl ketone and methoxy acetone.
The utilizable alkyl ethers of diethylene glycol will contain between 1 and 4 carbon atoms in the alkyl group. Non-limiting examples include the monomethyl ether of diethylene glycol, the monoethyl ether of diethylene glycol and the monobutyl ether of diethylene glycol.
In general, alkylethanols, ketones and alkyl ethers of diethylene glycol are primarly solvents for resin and aminoplast. Lower alcohols, such as ethanol, t-butanol, also assist in wetting the surface being coated. Higher alcohols, such as isooctanol, also serve - as defoamants. In controlling viscosity of the final coating composition, higher boiling solvents, such as hexoxyethanol, tend to increase viscosity and lower boiling solvents, such as butoxyethanol and methyl ethyl ketone, tend to decrease viscosity.
- Although mixtures of organic solvents are highly pref`erred, satisfactory coating compositions can be prepared using a single methoxy ethanol, ketone or alkyl ether of diethylene glycol.
In the finished coating composition, the solids content (resin and aminoplast) will be between about 10 and about 25 weight percent, preferably about 20-23 weight percent. The volatile system (including arnine, ammonia or ammonium hydroxide) will be between about 90 weight percent and about 75 weight percent of the finished coating composition, preferably about 77-80 weight percent. About 65 to 90 weight percent of the volatile system will be water and the balance (35 to 10 weight percent) will be organic volatile solvents, including amine, ammonia or ammoniuM hydroxide.
Preferably, the ratio of water to organic volatiles will be about 70:30 to ~0:20 in the volatile system. Each component of the solvent system will be present in between about 1 weight percent and about 20 weight percent of the weight of the final composition. A
typical and preferred solvent system is defined in the working examples.
In the following illustrative examples all parts are parts by weight, unless otherwise indicated.
Example 1 Into a reaction kettle there was charged 55.4 parts of an 80 weight percent solids solution in methyl ethyl ketone (MEK) of a diglycidyl ether of bisphenol A
having an epoxy equivalent weight of 450-550 and an epoxy value of 0.22, based on solids. The solution was heated to ~8C (190F) and there were added 10.02 parts bisphenol A, 5.84 parts of a mixture of 70 weight percent stearic acid and 30 weight percnt palmitic acid, and 0.17 part tri-n-butylamine (catalyst). The reaction mixture was heated to 149C (300F), removing MEK
distillate as necessary. At 149C, the reaction mixture was held at total reflux for 2 hours and sampled for solids and epoxy value. Reflux was maintained until epoxy value was 0.008 maximum. Then, the reaction was cooled to 115C (240F), adjusting solids to 92 + 0.5 weight percent with MEK distillate. At 115C, there were added 5.95 parts trimellitic anhydride and the reaction was heated 118C (245F) for 2 hours. Then, the reaction mixture was sampled for anhydride number which was to be 6.0 maximum. After 2 1/2 hours at `l18C
the reaction was sampled for anhydride number and 15.06 parts n-butanol and 7.52 parts butoxy ethanol were added and held until the mixture was uniform. Final values for acid number, anhydride number, weight percent solids and molecular weight are set forth in Table 1.
Examples 2 through 9 A series of runs were carried out in a manner similar to Example l, with the following exceptions:
Example Z is a laboratory repeat cf Example 1; Example 3 is a pilot plant run of Example 1; Example 4 uses excess stearic acid; Example 5 uses less stearic acid; in Example 6 the stearic acid was reacted first, followed by bisphenol A; in Example 7, more stearic acid was used and less bisphenol A; Example 8 was the same as Example 2, except that the final solvent was butyl ether of diethylene glycol instead of the 2:1 weight ratio Mixture of butanol and butoxy ethanol used in the other examples; an in Example 9, a greater amount of trimellitic anhydride was used. Pertinent data and final values for these examples are set forth in Table 1 along with Example 1.
O O ~I N CO
O ~ N--. ~ N
~1 0 0 00 ~ 3 ~
~1 O O N N ~
cu ~~ o o ~--~i 0 0 00 ~ ^
~1 c~
. .
r~l O O OCJ~ N N ~
~D¦ O 0~ N tnt--~1 0 ~D ~1 .. -- --U~
~1 0 0 0 O
O t~
o o t~
~ O O O O ~I C~J ` N C) ~ 0 .. . _ .
H .. .... _ _.
~ ~ ~~ ~ E
E ~ r1 0 0 0 ~r ~ ~ cd K
~0~0~ ^ ~0 t--Ln N ¢
0 0 r1 ~
~11 o c~o~r .c 1--i 0 o o O o.es O ::1 ~ O-rl G C:l ~ 5~ 5 r3 ~ o o ~ o C O S: C~ ~ U~ ~ ~ V bO
~ ~ ~ 0 ~ ~3' a~
tlS o ~. ~ ~ ,~
u~ ~ ~ 3 c: C ~~`~
ii-Examples 10 and 11 Using the general procedure of Example 1, resins of this invention can be prepared using relatively low molecular weight diglycidyl ethers of bisphenol h. Example 10 is like Example 1 except for the use of a different epoxy resin. In Example 11, the diglycidyl ether of bisphenol A is upgraded in molecular weight with bisphenol A and then reacted with stearic acid.
The formulations, in parts, for these examples are set forth in Table II.
TABLE II
Example_10 Example_11 Epoxy resin X (1) 34.42 ---Epoxy resin Y (2) --- 33.88 EK 5-54 5'35 Bisphenol A 18.50 13.84 Stearic acid (3) 10.78 15.98 Tri-n-butylamine 0.31 0.19 TriDIellitic anhydride 6.30 6.30 Butoxy ethanol 8.05 12.23 n-Butanol 16.10 ---t-Butanol -~- 12.23 (1) Diglycidyl ether of bisphenol A. Epoxy equivalent is 185 - 192. Epoxy value is 0. 52.
(2) Diglycidyl ether of bisphenol A. Epoxy equivalent is 193 - 203.
(3) k,ixture 70 wt ~ stearic acid/30 wt p palmitic acid.
-13~
Example 12 This example demonstrates the preparation of a resin in which the epoxy is of sufficiently high molecular weight that no bisphenol A, but only stearic acid, was used. In a reaction kettle were charged 47.72 parts of diglycidyl ether of bisphenol A having an epoxy equivalent weight of 850 and 5.35 parts of methyl ethyl ketone (MEK). The mixture was heated to about 88C to dissolve the resin (about 55 minutes). Then, 15.98 parts stearic acid and 0.19 part tri-n-butylamine were added and the reaction mixture was heated to 150C, collecting about 146 g MEK distillate, and held at 150C
for 2 hours. After 1 1/2 hours, a sample of the reaction mixture showed an epoxy value of 0.004. The MEK distillate was added back to the reaction mixture and 6.30 parts trimellitic anhydride were added. The reaction mixture was heated to reflux at about 116C, removing 11-12 g MEK distillate and held at reflux form 2 1/2 hours. The mixture was sampled and then reduced with 12.23 parts butoxy ethanol and 12.23 parts t-butanol. The final values of the resin solution were:
Wt. % solids 68.8 Acid No. 65.8 Anhydride No. 3.6 Mol. Wt. 7,000 The following Examples 13 through 15 illustrate the preparation of coating compositions using the resins of this invention.
Example 1 3 A mixture of 28.93 parts of the product described in Example 1, 2.25 parts hexamethoxymethyl-melamine, 3.37 parts n-butanol, 0.30 part hexoxy ethanol and 0.37 part butyl ether of diethylene glycol was stirred until uniform, while not permitting the temperature to exceed 54C. Then, there were added 1.29 parts denatured alcohol (Synaso~), which contains denaturants in the proportions of 100 gallons of special denatured alcohol Formula 1, 1 gallon of methyl isobutyl ketone, 1 gallon ethyl acetate and 1 gallon aviation gasoline. This was stirred until uniform. There was added a premixed mixture of 1.30 parts aqueous ammonia (26 Baume) and 2.19 parts deionized water. This was stirred until uniform and then diluted with 60.00 parts deionized water.
The final coating composition has a solids content of 22.63 weight percent, containing 90.06 weight percent resin of Example 1 and 9.94 weight perce~nt hexa-mett.oxymethylmelamine. The pH was 8.5 - 9Ø
Examples 14 and 15 In an alternative mixing procedure, n-butanol, butoxy ethanol and hexamethoxymethylmelamine were charged and agitation was begun. The product described in Example 1 was added and stirred until uniform, not ~ermitting the temperature to exceed 49C. A premixed mixture of aqueous ammonia (26 Baume) and deionized water was added and stirred until uniform. Finally, the composition was diluted with deionized water to produce the final coating composition. The amounts of components, in parts, in each Example 14 and 15 and pertinent data on the final coating compositions are set forth in Table III.
*Tr~d~Erk . ~
JB~
TABLE III
Ex. 14 Ex. 15 n-Butanol 0. 86 2.99 Butoxy ethanol 3.26 4. 36 Hexamethoxymethylmelamine2.35 2.33 Example 1 product 30.03 29.73 Aqueous ammonia 1.25 1.36 Deionized water 2.00 1.98 Deionized water 60.25 57.25 Solids, wt ~ 23.5 23.27 pH 8.5-9.0 8.5-9.0 Resin/aminoplast, wt % 90/10 90/10 The coating composition of this invention is primarily useful for coating aluminum, tin plated steel, pretreated metals, steel and metals coated with the same or different resin composition (i.e., a second coat).
The coating composition can be used however for coating other substrates such as wood1 paper and leather. The most preferred and useful use of the coating composition is for interior coating of metal containers that will come in contact with food or beverages. Coating can be done by any coating procedure well known to those skilled in the art including direct rollcoating, reverse rollcoating, electrodeposition, spraying, flow coating and the like. The preferred method however in coating the interior of metal containers is by spraying. After coating the substrate, the coating is baked for about 5 seconds to about 5 minutes at between about 250F and about 600F. A typical bake is for about 2 minutes at about 400F.
The coating compositions of Examples 13, 14 and 15 were tested for adhesion, pasteurized adhesion and blush. The adhesion test is carried out by cross-hatching a coated area with individual score lines approximately 1/16 inch apart. The"Scotch"tape is firmly applied to the cross-hatched area and removed with a quick snap. The amount of coating remaining on the panel is viewed visually and rated on a 0-10 scale (10 = perfect adhesion). Pasteurization is carried out by immersing the coated panels in water at 145F for 30 minutes. Then the panels are wiped dry with absorbent to~els and the adhesion test is carried out as above described. The amount of blush is rated on the pasteurized panel using a scale of 0 to 10 in which 0 is very severe blush and 10 is no blush.
Example 16 Treated aluminum test panels were coated with the coating compositions of Examples 13, 14 and 15 with a bar coater to a film weight of 2.5 to 3.0 milligrams per square inch. These test panels showed an adhesion rating of 10 in the adhesion test. In the pasteurization test, the panels gave a rating of 10 adhesion and 10 on blush.
The effect of a coating on the flavor of a packaged product is determined in a Flavor Difference Evaluation. Bottles of commercial beer are chilled to about 40-45F and uncapped. Sheets of aluminum foil (1 nlil) are bar coated on both sides with the coating being evaluated and baked. Then, a sheet of foil is rolled lightly and inserted into each bottle of beer and the bottle is recapped with a new cap.
*~r~rk of 3-M Company for a brand of pressure-sensitive adhesive tape For cornparison, additional bottles of the same beer are provided with rolls of aluminum foil that have been coated on both sides with an accepted commercial coating for interior coating (solvent-based epoxy coating) and baked. The test coating and the control coating were baked for 30 seconds at 400F metal temperature.
After storage for 3 days at 100F, the bottles of beer are again chilled and taste rated by 9 experienced tasters comparing the test coatings vs. the control. The arithmetic average of the ratings is calculated (x). Then, all rating values outside x + 2 are excluded and another average is calculated as the quality rating (QR). The following rating scale was used on a basis of 1-9.
1 = no flavor difference 1.0 - 1.5 = excellent flavor 1.5 - 2.0 = very good flavor 2.0 - 2.5 = good flavor 2.5 - 3.0 = acceptable flavor >3.0 = not acceptable In unpasteurized beer, n-heptyl p-hydroxy benzoate is used in an amount of 12 ppm to inhibit microbial growth. It is highly desirable that a coating used to coat the interior of metal beer containers does not absorb an appreciable amount of the n-heptyl p-hydroxybenzoate (sold under the registered tradernark "Staypro").
This property is tested using a simulated beer, an aqueous solution of 8 volume percent ethanol and 12 ppm "Staypro." Metal beer containers are interior coated hith the coating composition under test and baked in the usual baking cycle, e.g., 2 minutes at 400F. Then, the containers are filled with simulated beer and stored at room temperature for one week. At the end of the week the simulated beer is analyzed to determine the amount of heptyl p-hydroxybenzoate remaining. This is done by measuring light transmission on a spectrophotometer at a wavelength of 255 millimicrons, in comparison with the original.
Examples 17, 18 and 19 ; Using resins as described in Examples 1 and 9 herein and in Example 1 of U.S.
Patent No. 4,105,614, coating formulations were prepared by the procedure of Example 14. Each formulation contained 1Q weight percent (on solids basis) hexamethoxymethylrnelamine and the volatile system had a volume percent ratio of water/.organic solids of 80/20.
The formulations were used in testing for beer flavor rating and for resistance to absorption of n-heptyl p-hydroxybenzoate. Pertinent data and test results are 2d set forth in Table IV.
TABLE IV
. .
Resin Description Beer Flavor Staypro Ex. Ex. Source QR ppm rem-aining 17 1 Herein 1.2 11.9 18 9 Herein 1.1 11.8 19 1 U.S. Patent 1.3 10.5 4,105,614 Storage stability (shelf life) of a coating composition is measured by the cl~ange in viscosity. A
significant increase in viscosity is not desirable. A
3D coating composition as described in Example 17 and, for -comparison, a coating composition as described in Example 19 were placed in lined coating containers and stored at 80F. Periodically the compositions were tested for viscosity at 80F using #2 Zahn cup. The results are set forth in Table V.
TABLE V
Viscosity, seconds Time, weeks Exarnple 17 Example 19 Initial 25 - 40 40 - 50
Claims (19)
1. A water solubilizable resin that comprises an adduct of a monocarboxylic acid and a diglycidyl ether of a bisphenol, or of a monocarboxylic acid, a bisphenol and a diglycidyl ether of a bisphenol, using an equivalent ratio of total monocarboxylic acid and bisphenol, if used, to diglycidyl ether between about 1:1 and about 1.2:1, further adducted with an anhydride in an amount sufficient to provide an acid number between about 35 and about 150.
2. The resin of Claim 1 wherein said bisphenol is bisphenol A.
3. The resin of Claim 2 wherein said anhydride is trimellitic anhydride and said acid number is between about 40 and about 90.
4. The resin of Claim 3 wherein said diglycidyl ether is the diglycidyl ether of bisphenol A
having an epoxy equivalent weight of 450 - 550, said monocarboxylic acid is a mixture of 70 weight percent stearic acid and 30 weight percent palmitic acid and the equivalent ratio of said monocarboxylic acid and bisphenol A to said diglycidyl ether is between about 1:1 and about 1.2:1.
having an epoxy equivalent weight of 450 - 550, said monocarboxylic acid is a mixture of 70 weight percent stearic acid and 30 weight percent palmitic acid and the equivalent ratio of said monocarboxylic acid and bisphenol A to said diglycidyl ether is between about 1:1 and about 1.2:1.
5. The resin of Claim 3 wherein said diglycidyl ether is the diglycidyl ether of bisphenol A
having an epoxy equivalent weight of about 850, said monocarboxylic acid is stearic acid and the equivalent ratio of stearic acid to said diglycidyl ether is about 1:1.
having an epoxy equivalent weight of about 850, said monocarboxylic acid is stearic acid and the equivalent ratio of stearic acid to said diglycidyl ether is about 1:1.
6. The resin of Claim 4 dissolved in a mixture of a C1-C4 alkoxyethanol and a C2-C4 alcohol to a solids content between about 60 and about 75 weight percent.
7. The resin of Claim 6 wherein said alkoxy-ethanol is butoxyethanol and said alcohol is butanol.
8. The resin of Claim 5 dissolved in a mixture of butoxyethanol and butanol.
9. A coating composition comprising the resin of Claim 1 and an aminoplast, in a weight ratio between about 95:5 and about 70:30,solubilized with a volatile tertiary amine, ammonia or ammonium hydroxide to a pH of from about 7.0 to about 9.1 in at least one solvent of the group of alcohols, alkoxyethanols, ketones and alkyl ethers of diethylene glycol, each present in between about 1 weight percent and about 20 weight percent of the weight of the final composition and diluted with water to a solids content between about 10 weight percent and about 25 weight percent.
10. The coating composition of Claim 9 wherein said resin is the resin of Claim 6.
11. The coating composition of Claim 9 wherein said resin is the resin of Claim 7, said aminoplast is hexamethoxymethylmelamine, the solvent is a mixture of butoxyethanol, butanol, methyl ethyl ketone, the butyl ether of diethylene glycol, hexoxyethanol and denatured alcohol, said volatile system contains about 80 weight percent water and about 20 weight percent organic solvents, and said solids content is about 20-23 weight percent.
12. A substrate coated with the coating composition of Claim 9 and baked.
13. A metal substrate coated with the coating composition of Claim 9 and baked.
14. A metal substrate coated with a coating composition comprising (Al a water solubilizable resin comprising an adduct of (1) a monocarboxylic acid comprising a mixture of 70 weight percent stearic acid and 30 weight percent palmitic acid and (2) the diglycidyl ether of bisphenol A having an epoxy equivalent weight of 450-550, the equivalent ratio of said monocarboxylic acid and bisphenol A to said diglycidyl ether being between about 1:1 and about 1.2:1, further adducted with trimellitic anhydride in an amount sufficient to provide an acid number between about 40 and about 90; said resin being dissolved in a mixture of a C1-C4 alkoxyethanol and a C2-C4 alcohol to a solids content between about 60 and about 75 weight percent; and (B) an aminoplast, in a weight ratio between about 95:5 and about 70:30; solubilized with a volatile tertiary amine, ammonia or ammonium hydroxide to a pH of from about 7.0 to about 9.1 in at least one solvent of the group of alcohols, alkoxyethanols, ketones and alkyl ethers of diethylene glycol, each present in between about 1 weight percent and about 20 weight percent of the final composition and diluted with water to a solids content between about 10 weight percent and about 25 weight percent; and baked.
15. A metal substrate coated with a coating composition as defined in claim 14 but further characterized in that the water-solubilizable resin (A) is dissolved in a mixture of butoxy-ethanol and butanol to a solids content between about 60 and about 75 weight percent; said aminoplast (B) is hexamethoxymethyl-melamine; the solvent in a mixture of butoxyethanol, butanol, methyl ethyl ketone, the butyl ether of diethylene glycol, hexoxy-ethanol and denatured alcohol; the volatile system contains about 80 weight percent water and about 20 weight percent organic solvents; and said solids content is about 20-23 weight percent;
and baked.
and baked.
16. A metal food packaging container interior coated with the coating composition of Claim 9 and baked, containing food or beverage.
17. A metal food packaging container interior coated with the coating composition defined in claim 14 and baked, containing food or beverage.
18. A metal food packaging container interior coated with the coating composition defined in claim 15 and baked, containing food or beverage.
19. The container of claim 17 wherein said metal is aluminum.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA000314869A CA1141084A (en) | 1978-10-30 | 1978-10-30 | Storage stable water-dilutable acid adducted epoxy based coating for metal food contact surfaces |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA000314869A CA1141084A (en) | 1978-10-30 | 1978-10-30 | Storage stable water-dilutable acid adducted epoxy based coating for metal food contact surfaces |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1141084A true CA1141084A (en) | 1983-02-08 |
Family
ID=4112760
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000314869A Expired CA1141084A (en) | 1978-10-30 | 1978-10-30 | Storage stable water-dilutable acid adducted epoxy based coating for metal food contact surfaces |
Country Status (1)
Country | Link |
---|---|
CA (1) | CA1141084A (en) |
-
1978
- 1978-10-30 CA CA000314869A patent/CA1141084A/en not_active Expired
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