CA2432784A1 - Color coated plastic pellets - Google Patents
Color coated plastic pellets Download PDFInfo
- Publication number
- CA2432784A1 CA2432784A1 CA002432784A CA2432784A CA2432784A1 CA 2432784 A1 CA2432784 A1 CA 2432784A1 CA 002432784 A CA002432784 A CA 002432784A CA 2432784 A CA2432784 A CA 2432784A CA 2432784 A1 CA2432784 A1 CA 2432784A1
- Authority
- CA
- Canada
- Prior art keywords
- pellets
- pigment
- plastic
- color
- coating
- 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.)
- Abandoned
Links
- 229920000426 Microplastic Polymers 0.000 title claims abstract description 12
- 239000000049 pigment Substances 0.000 claims abstract description 58
- 239000008188 pellet Substances 0.000 claims abstract description 57
- 238000000576 coating method Methods 0.000 claims abstract description 31
- 239000000025 natural resin Substances 0.000 claims abstract description 29
- 239000011248 coating agent Substances 0.000 claims abstract description 28
- 229920003023 plastic Polymers 0.000 claims abstract description 23
- 239000004033 plastic Substances 0.000 claims abstract description 23
- 239000002245 particle Substances 0.000 claims abstract description 20
- 238000002156 mixing Methods 0.000 claims abstract description 15
- 238000004519 manufacturing process Methods 0.000 claims abstract description 9
- 229920005992 thermoplastic resin Polymers 0.000 description 41
- 238000000034 method Methods 0.000 description 28
- 239000000203 mixture Substances 0.000 description 23
- 229920005989 resin Polymers 0.000 description 19
- 239000011347 resin Substances 0.000 description 19
- 239000000654 additive Substances 0.000 description 16
- 239000012141 concentrate Substances 0.000 description 16
- -1 polypropylene Polymers 0.000 description 12
- 230000000996 additive effect Effects 0.000 description 10
- 239000001993 wax Substances 0.000 description 8
- 239000003086 colorant Substances 0.000 description 7
- 239000008187 granular material Substances 0.000 description 7
- 239000004615 ingredient Substances 0.000 description 7
- 238000002844 melting Methods 0.000 description 7
- 230000008018 melting Effects 0.000 description 7
- 239000004793 Polystyrene Substances 0.000 description 6
- 239000001023 inorganic pigment Substances 0.000 description 6
- 238000011068 loading method Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 238000000465 moulding Methods 0.000 description 6
- 239000012860 organic pigment Substances 0.000 description 6
- 239000010410 layer Substances 0.000 description 5
- 238000010128 melt processing Methods 0.000 description 5
- 229920002223 polystyrene Polymers 0.000 description 5
- 235000002566 Capsicum Nutrition 0.000 description 4
- 239000006002 Pepper Substances 0.000 description 4
- 241000722363 Piper Species 0.000 description 4
- 235000016761 Piper aduncum Nutrition 0.000 description 4
- 235000017804 Piper guineense Nutrition 0.000 description 4
- 235000008184 Piper nigrum Nutrition 0.000 description 4
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 4
- 235000013980 iron oxide Nutrition 0.000 description 4
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 239000004594 Masterbatch (MB) Substances 0.000 description 3
- 239000004696 Poly ether ether ketone Substances 0.000 description 3
- 239000004952 Polyamide Substances 0.000 description 3
- 239000004698 Polyethylene Substances 0.000 description 3
- 238000001125 extrusion Methods 0.000 description 3
- 239000000155 melt Substances 0.000 description 3
- 229920002647 polyamide Polymers 0.000 description 3
- 229920000728 polyester Polymers 0.000 description 3
- 229920002530 polyetherether ketone Polymers 0.000 description 3
- 229920000573 polyethylene Polymers 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 229920000098 polyolefin Polymers 0.000 description 3
- 229920006324 polyoxymethylene Polymers 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 2
- 239000006057 Non-nutritive feed additive Substances 0.000 description 2
- 239000004642 Polyimide Substances 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 229920002877 acrylic styrene acrylonitrile Polymers 0.000 description 2
- 229920006397 acrylic thermoplastic Polymers 0.000 description 2
- 239000004676 acrylonitrile butadiene styrene Substances 0.000 description 2
- 150000001412 amines Chemical class 0.000 description 2
- 239000003963 antioxidant agent Substances 0.000 description 2
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 239000011247 coating layer Substances 0.000 description 2
- 238000009500 colour coating Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- QDOXWKRWXJOMAK-UHFFFAOYSA-N dichromium trioxide Chemical compound O=[Cr]O[Cr]=O QDOXWKRWXJOMAK-UHFFFAOYSA-N 0.000 description 2
- 238000005538 encapsulation Methods 0.000 description 2
- 230000009477 glass transition Effects 0.000 description 2
- 239000004611 light stabiliser Substances 0.000 description 2
- LYRFLYHAGKPMFH-UHFFFAOYSA-N octadecanamide Chemical compound CCCCCCCCCCCCCCCCCC(N)=O LYRFLYHAGKPMFH-UHFFFAOYSA-N 0.000 description 2
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 2
- 229920002285 poly(styrene-co-acrylonitrile) Polymers 0.000 description 2
- 229920000412 polyarylene Polymers 0.000 description 2
- 229920001707 polybutylene terephthalate Polymers 0.000 description 2
- 229920000515 polycarbonate Polymers 0.000 description 2
- 239000004417 polycarbonate Substances 0.000 description 2
- 229920000139 polyethylene terephthalate Polymers 0.000 description 2
- 239000005020 polyethylene terephthalate Substances 0.000 description 2
- 229920001721 polyimide Polymers 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- 238000005204 segregation Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- ISXSCDLOGDJUNJ-UHFFFAOYSA-N tert-butyl prop-2-enoate Chemical compound CC(C)(C)OC(=O)C=C ISXSCDLOGDJUNJ-UHFFFAOYSA-N 0.000 description 2
- 229920001169 thermoplastic Polymers 0.000 description 2
- 239000012815 thermoplastic material Substances 0.000 description 2
- 229920002397 thermoplastic olefin Polymers 0.000 description 2
- 239000004416 thermosoftening plastic Substances 0.000 description 2
- KJCVRFUGPWSIIH-UHFFFAOYSA-N 1-naphthol Chemical compound C1=CC=C2C(O)=CC=CC2=C1 KJCVRFUGPWSIIH-UHFFFAOYSA-N 0.000 description 1
- 125000003903 2-propenyl group Chemical group [H]C([*])([H])C([H])=C([H])[H] 0.000 description 1
- CGLVZFOCZLHKOH-UHFFFAOYSA-N 8,18-dichloro-5,15-diethyl-5,15-dihydrodiindolo(3,2-b:3',2'-m)triphenodioxazine Chemical compound CCN1C2=CC=CC=C2C2=C1C=C1OC3=C(Cl)C4=NC(C=C5C6=CC=CC=C6N(C5=C5)CC)=C5OC4=C(Cl)C3=NC1=C2 CGLVZFOCZLHKOH-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000004593 Epoxy Substances 0.000 description 1
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- 239000004606 Fillers/Extenders Substances 0.000 description 1
- 239000004609 Impact Modifier Substances 0.000 description 1
- 229920002292 Nylon 6 Polymers 0.000 description 1
- 229920002302 Nylon 6,6 Polymers 0.000 description 1
- 229930040373 Paraformaldehyde Natural products 0.000 description 1
- 229920001283 Polyalkylene terephthalate Polymers 0.000 description 1
- 239000004962 Polyamide-imide Substances 0.000 description 1
- 239000004721 Polyphenylene oxide Substances 0.000 description 1
- 239000004734 Polyphenylene sulfide Substances 0.000 description 1
- 229920000491 Polyphenylsulfone Polymers 0.000 description 1
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 1
- 239000005083 Zinc sulfide Substances 0.000 description 1
- YKTSYUJCYHOUJP-UHFFFAOYSA-N [O--].[Al+3].[Al+3].[O-][Si]([O-])([O-])[O-] Chemical compound [O--].[Al+3].[Al+3].[O-][Si]([O-])([O-])[O-] YKTSYUJCYHOUJP-UHFFFAOYSA-N 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 239000011354 acetal resin Substances 0.000 description 1
- XECAHXYUAAWDEL-UHFFFAOYSA-N acrylonitrile butadiene styrene Chemical compound C=CC=C.C=CC#N.C=CC1=CC=CC=C1 XECAHXYUAAWDEL-UHFFFAOYSA-N 0.000 description 1
- 229920000122 acrylonitrile butadiene styrene Polymers 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 150000001408 amides Chemical class 0.000 description 1
- 150000004056 anthraquinones Chemical class 0.000 description 1
- 239000002518 antifoaming agent Substances 0.000 description 1
- 239000004599 antimicrobial Substances 0.000 description 1
- 239000002216 antistatic agent Substances 0.000 description 1
- UHHXUPJJDHEMGX-UHFFFAOYSA-K azanium;manganese(3+);phosphonato phosphate Chemical compound [NH4+].[Mn+3].[O-]P([O-])(=O)OP([O-])([O-])=O UHHXUPJJDHEMGX-UHFFFAOYSA-K 0.000 description 1
- MYONAGGJKCJOBT-UHFFFAOYSA-N benzimidazol-2-one Chemical compound C1=CC=CC2=NC(=O)N=C21 MYONAGGJKCJOBT-UHFFFAOYSA-N 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 239000003139 biocide Substances 0.000 description 1
- 229920001400 block copolymer Polymers 0.000 description 1
- 238000000071 blow moulding Methods 0.000 description 1
- 239000000378 calcium silicate Substances 0.000 description 1
- 229910052918 calcium silicate Inorganic materials 0.000 description 1
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 description 1
- 238000003490 calendering Methods 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 229910000423 chromium oxide Inorganic materials 0.000 description 1
- 239000008199 coating composition Substances 0.000 description 1
- 229910000152 cobalt phosphate Inorganic materials 0.000 description 1
- ZBDSFTZNNQNSQM-UHFFFAOYSA-H cobalt(2+);diphosphate Chemical compound [Co+2].[Co+2].[Co+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O ZBDSFTZNNQNSQM-UHFFFAOYSA-H 0.000 description 1
- 239000004595 color masterbatch Substances 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- JGDFBJMWFLXCLJ-UHFFFAOYSA-N copper chromite Chemical compound [Cu]=O.[Cu]=O.O=[Cr]O[Cr]=O JGDFBJMWFLXCLJ-UHFFFAOYSA-N 0.000 description 1
- 239000002178 crystalline material Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- PPSZHCXTGRHULJ-UHFFFAOYSA-N dioxazine Chemical compound O1ON=CC=C1 PPSZHCXTGRHULJ-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000003670 easy-to-clean Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 239000000806 elastomer Substances 0.000 description 1
- 125000003700 epoxy group Chemical group 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N ferric oxide Chemical compound O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000009730 filament winding Methods 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 239000003063 flame retardant Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000003205 fragrance Substances 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 239000012760 heat stabilizer Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052595 hematite Inorganic materials 0.000 description 1
- 239000011019 hematite Substances 0.000 description 1
- HNMCSUXJLGGQFO-UHFFFAOYSA-N hexaaluminum;hexasodium;tetrathietane;hexasilicate Chemical class [Na+].[Na+].[Na+].[Na+].[Na+].[Na+].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].S1SSS1.S1SSS1.[O-][Si]([O-])([O-])[O-].[O-][Si]([O-])([O-])[O-].[O-][Si]([O-])([O-])[O-].[O-][Si]([O-])([O-])[O-].[O-][Si]([O-])([O-])[O-].[O-][Si]([O-])([O-])[O-] HNMCSUXJLGGQFO-UHFFFAOYSA-N 0.000 description 1
- 229920001519 homopolymer Polymers 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 229920000554 ionomer Polymers 0.000 description 1
- DCYOBGZUOMKFPA-UHFFFAOYSA-N iron(2+);iron(3+);octadecacyanide Chemical compound [Fe+2].[Fe+2].[Fe+2].[Fe+3].[Fe+3].[Fe+3].[Fe+3].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-] DCYOBGZUOMKFPA-UHFFFAOYSA-N 0.000 description 1
- WTFXARWRTYJXII-UHFFFAOYSA-N iron(2+);iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[O-2].[Fe+2].[Fe+3].[Fe+3] WTFXARWRTYJXII-UHFFFAOYSA-N 0.000 description 1
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 description 1
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 1
- YOBAEOGBNPPUQV-UHFFFAOYSA-N iron;trihydrate Chemical compound O.O.O.[Fe].[Fe] YOBAEOGBNPPUQV-UHFFFAOYSA-N 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- GWVMLCQWXVFZCN-UHFFFAOYSA-N isoindoline Chemical compound C1=CC=C2CNCC2=C1 GWVMLCQWXVFZCN-UHFFFAOYSA-N 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- MOUPNEIJQCETIW-UHFFFAOYSA-N lead chromate Chemical compound [Pb+2].[O-][Cr]([O-])(=O)=O MOUPNEIJQCETIW-UHFFFAOYSA-N 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- SBWRUMICILYTAT-UHFFFAOYSA-K lithium;cobalt(2+);phosphate Chemical compound [Li+].[Co+2].[O-]P([O-])([O-])=O SBWRUMICILYTAT-UHFFFAOYSA-K 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000006082 mold release agent Substances 0.000 description 1
- 238000010137 moulding (plastic) Methods 0.000 description 1
- 229920003052 natural elastomer Polymers 0.000 description 1
- 229920001194 natural rubber Polymers 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 238000005453 pelletization Methods 0.000 description 1
- DGBWPZSGHAXYGK-UHFFFAOYSA-N perinone Chemical compound C12=NC3=CC=CC=C3N2C(=O)C2=CC=C3C4=C2C1=CC=C4C(=O)N1C2=CC=CC=C2N=C13 DGBWPZSGHAXYGK-UHFFFAOYSA-N 0.000 description 1
- 150000002979 perylenes Chemical class 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 229920000110 poly(aryl ether sulfone) Polymers 0.000 description 1
- 229920002492 poly(sulfone) Polymers 0.000 description 1
- 229920002312 polyamide-imide Polymers 0.000 description 1
- 229920006260 polyaryletherketone Polymers 0.000 description 1
- 229920001748 polybutylene Polymers 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920006393 polyether sulfone Polymers 0.000 description 1
- 229920001601 polyetherimide Polymers 0.000 description 1
- 235000013824 polyphenols Nutrition 0.000 description 1
- 229920006380 polyphenylene oxide Polymers 0.000 description 1
- 229920000069 polyphenylene sulfide Polymers 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 229960003351 prussian blue Drugs 0.000 description 1
- 239000013225 prussian blue Substances 0.000 description 1
- RQGPLDBZHMVWCH-UHFFFAOYSA-N pyrrolo[3,2-b]pyrrole Chemical class C1=NC2=CC=NC2=C1 RQGPLDBZHMVWCH-UHFFFAOYSA-N 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 239000011342 resin composition Substances 0.000 description 1
- 239000012748 slip agent Substances 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 229940037312 stearamide Drugs 0.000 description 1
- 150000004763 sulfides Chemical class 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical class [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 229920003051 synthetic elastomer Polymers 0.000 description 1
- 239000005061 synthetic rubber Substances 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
- ZXQVPEBHZMCRMC-UHFFFAOYSA-R tetraazanium;iron(2+);hexacyanide Chemical compound [NH4+].[NH4+].[NH4+].[NH4+].[Fe+2].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-] ZXQVPEBHZMCRMC-UHFFFAOYSA-R 0.000 description 1
- 238000003856 thermoforming Methods 0.000 description 1
- JOUDBUYBGJYFFP-FOCLMDBBSA-N thioindigo Chemical compound S\1C2=CC=CC=C2C(=O)C/1=C1/C(=O)C2=CC=CC=C2S1 JOUDBUYBGJYFFP-FOCLMDBBSA-N 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- 238000001721 transfer moulding Methods 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
- 229910052984 zinc sulfide Inorganic materials 0.000 description 1
- DRDVZXDWVBGGMH-UHFFFAOYSA-N zinc;sulfide Chemical compound [S-2].[Zn+2] DRDVZXDWVBGGMH-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J3/00—Processes of treating or compounding macromolecular substances
- C08J3/20—Compounding polymers with additives, e.g. colouring
- C08J3/203—Solid polymers with solid and/or liquid additives
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J3/00—Processes of treating or compounding macromolecular substances
- C08J3/20—Compounding polymers with additives, e.g. colouring
- C08J3/22—Compounding polymers with additives, e.g. colouring using masterbatch techniques
- C08J3/226—Compounding polymers with additives, e.g. colouring using masterbatch techniques using a polymer as a carrier
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Processes Of Treating Macromolecular Substances (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
A process for preparing color coated plastic pellets comprises dispersing pigment in a carrier with a high-intensity mixer at a high shear rate in the absence of added heat energy for form plastic pigment particles, adding natural resin pellets to the plastic pigment particles within the high-intensity mixer, and mixing the plastic particles and natural resin pellets in the high-density mixer at a high shear rate in the absence of added heat energy to cause a coating of colored plastic to fuse to the surfaces of the natural resin pellets
Description
COLOR COATED PLASTIC PELLETS
FIELD OF THE INVENTION
This invention relates generally to color coated plastic pellets, and more particularly to a process for applying a pigment-containing coating to plastic pellets and the color coated plastic pellets produced thereby.
BACKGROUND OF THE INVENTION
A common method~of coloring plastics is to use color concentrate pellets. A color concentrate pellet is solid and is typically comprised of pigment and carrier.
The pigment colors the plastic. The carrier acts as a binder and generally also acts to "wet" the pigment so that the pigment will mix well with the resin or plastic to be colored and so that the pigment will be well dispersed throughout the final molded, extruded, cast, or otherwise formed plastic product.
In conventional color concentrate pellets, the pigment is mixed with a carrier, which is a thermoplastic resin material such as polypropylene, polyethylene, ABS, or polystyrene. These materials and the pellets produced thereby have a melting point in the range of 350°F to 400°F. To make these conventional color concentrate pellets, the pigment and carrier are mixed and heated to about 550°F to 600°F. The mixture melts and is mixed, and is extruded through an extruder and then solidifies and is cut into conventional pellet size, a cylinder about 1/8-inch in diameter and about 1/8 to 1/4 inch in length.
These conventional color concentrate pellets contain organic and inorganic pigments, and are typically 30 percent to 50 percent pigment by weight with the balance being thermoplastic resin.
These conventional pellets are then mixed with natural resin pellets of the same general size.and shape to effect coTorization. Natural resin pellets are pellets which have not yet been colored. Commercially sized natural resin pellets include those that are cylindrically shaped, are about 1/8 inch in diameter, and are about 1/8 to 1/4 inch long. Other commercially sized natural resin pellets, individually, have similar bulk or volume, but may have other regular geometric shapes or may have somewhat irregular shapes.
It is often the case, however, that a thermoplastic resin must be specially formulated or customized for a particular use or application, such as mold-in color processes, for example by including special additives for that use, such as pigments to achieve a particular color or a stabilizer package that meets the requirements of a particular use. In particular, thermoplastic resins may be customized to include certain pigments and/or colorants. It is often desirable that the manufactured articles have a particular color.
A particular color may, for example, enhance aesthetic appeal of the article or may even serve to help identify the particular brand or manufacturer.
Customizing the color or additive package of thermoplastic resins can, however, present problems.
LVhile the general purpose thermoplastic resin, or base resin, may be produced by continuous extrusion operations, colored thermoplastic resins or thermoplastic resins with special additive packages are typically required in much smaller amounts that are relatively expensive to produce. Manufacture, especially post-production cleaning, is extremely labor intensive.
The processing equipment (such as blenders, feeders, extruders, and pelletizing equipment) must be thoroughly cleaned after each particular color or customized blend in order to avoid contamination of the thermoplastic resins that will next be produced in the equipment. The cleaning process requires significant down time of the equipment during which no material is being manufactured, adding to the manufacturing costs of the specialized product.
Alternatively, colored articles have been produced by dry blending the uncolored thermoplastic resin with a color concentrate (also known as color masterbatch) in what is known in the art as a "salt and pepper blend."
The thermoplastic resin and the color concentrate used for such blends are typically of similar size pellets or pieces. The color concentrate is usually a minor amount by weight of the blend, typically only up to about 5percent by weight, and often much less. The salt and pepper blend is then introduced directly to the molding or forming equipment used to produce the final article.
The melt blending of the uncolored resin and the color concentrate must take place in the molding or forming equipment. This process, however, can result in color variations from piece to piece, or even in areas within the same piece, because of incomplete blending, particularly for low blending ratios of the color concentrate. Segregation of particular additives during packaging and transportation may also be experienced with dry blends and contribute to lack of homogeneity in the final formed articles.
It is also known to prepare color concentrates by a method of blending together a mixture of pigment, low molecular weight polyethylene wax, and thermoplastic polyolefin granules. The pigment and wax is included at relatively high levels, for example approximately 40percent by weight of the mixture. The wax dispersed the pigment forms a layer on the polymer granules. This masterbatch is blended with unmodified base polyolefins to form a "salt and pepper" blend. The high loading of pigment and dispersing wax is required by the masterbatch in order to achieve the desired final pigment loading in the salt and pepper blend. Such masterbatch-containing blends suffer from the same problems discussed above. In addition, the relatively thick coating of wax on the granules is undesirable for the reason that such thick coatings tend to easily chip and flake off, which could result in segregation and nonhomogeneity in the molded articles, as well as dust problems in production.
A novel method of preparing customized thermoplastic resins in which the pieces, typically pellets, of thermoplastic resin are coated with a coating that comprises a polymeric component and an additive component has now been discovered. The polymeric component of the coating has a melting point, softening point, or glass transition temperature that is lower than the melting point, softening point, or glass transition temperature of the thermoplastic resin body.
In a preferred embodiment, the coating is a color concentrate comprising a polymeric component and one or more pigments, optionally with other additives. In a preferred embodiment, a substantially even thickness of an outer layer of.the color coating is applied. The coated resin pieces or pellets are easy to handle and may be formed into articles using the same processes and in the same way as would resin pellets that have had the color or other additive integrally mixed in.
The color concentrate composition is coated onto the resin after the resin piece is formed. The customized thermoplastic resins of the invention may thus be produced in easy-to-clean equipment and without requiring down time of the equipment used to manufacture the thermoplastic resin body, resulting in a much more versatile and economical process. In addition, because each pellet or other body of the thermoplastic resin is in intimate contact with the pigment necessary to produce the desired customized resin, defects such as inhomogeneity, which are especially apparent when color is involved, are avoided. Further, the surfactants, water, amines, and resins with hydrophilic functiorialities required by the prior art compositions are not necessary for the coatings of the present invention.
U.S. Patent No. 5,846,607 discloses a process for customizing thermoplastic resins, by coating a thermoplastic resin body with a layer of a lower melting coating comprising a thermoplastic and a colorant. Wax, pigment, and natural resin pellets are processed at a temperature at which the coating is a melt, but at which the pellets remain solid. The coating may be applied to the natural resin pellets with the assistance of a high-intensity mixer. Thus, the process requires the addition of heat and is accomplished in a single mixing and coating process.
U.S. Patent No. 5,455,288 discloses a process for producing a color concentrate pellet, also made by a single process step. These pellets, however, are color concentrate granules which must then be let down by blending with additional natural resin pellets.
U.S. Patent No. 5,536,576 discloses natural resin pellets coated with a pigment. The pigment is dispersed in a liquid adhesive which is thereafter contacted with the natural resin pellets. Thus, the pellets bear a layer of colorant adhesively coated onto the surfaces of the pellets.
It would be desirable to prepare color coated plastic pellets by an energy-efficient process that would not substantially affect the inherent viscosity of the base pellets.
SUMMARY OF THE INVENTION
A process for preparing color coated plastic pellets has surprisingly been discovered. The process comprises the steps of:
dispersing pigment in a carrier within a high-intensity mixer at a high shear rate in the absence of added heat energy, to form plastic pigment particles;
adding natural resin pellets to the plastic pigment particles within the high-intensity mixer; and mixing the plastic pigment particles and natural resin pellets in the high-intensity mixer at a high shear rate in the absence of added heat energy, to cause a coating of colored plastic to fuse to the surfaces of the natural resin pellets.
The inventive process is particularly useful for preparing color coated plastic pellets from which a variety of plastic articles may be produced utilizing conventional plastic molding techniques.
FIELD OF THE INVENTION
This invention relates generally to color coated plastic pellets, and more particularly to a process for applying a pigment-containing coating to plastic pellets and the color coated plastic pellets produced thereby.
BACKGROUND OF THE INVENTION
A common method~of coloring plastics is to use color concentrate pellets. A color concentrate pellet is solid and is typically comprised of pigment and carrier.
The pigment colors the plastic. The carrier acts as a binder and generally also acts to "wet" the pigment so that the pigment will mix well with the resin or plastic to be colored and so that the pigment will be well dispersed throughout the final molded, extruded, cast, or otherwise formed plastic product.
In conventional color concentrate pellets, the pigment is mixed with a carrier, which is a thermoplastic resin material such as polypropylene, polyethylene, ABS, or polystyrene. These materials and the pellets produced thereby have a melting point in the range of 350°F to 400°F. To make these conventional color concentrate pellets, the pigment and carrier are mixed and heated to about 550°F to 600°F. The mixture melts and is mixed, and is extruded through an extruder and then solidifies and is cut into conventional pellet size, a cylinder about 1/8-inch in diameter and about 1/8 to 1/4 inch in length.
These conventional color concentrate pellets contain organic and inorganic pigments, and are typically 30 percent to 50 percent pigment by weight with the balance being thermoplastic resin.
These conventional pellets are then mixed with natural resin pellets of the same general size.and shape to effect coTorization. Natural resin pellets are pellets which have not yet been colored. Commercially sized natural resin pellets include those that are cylindrically shaped, are about 1/8 inch in diameter, and are about 1/8 to 1/4 inch long. Other commercially sized natural resin pellets, individually, have similar bulk or volume, but may have other regular geometric shapes or may have somewhat irregular shapes.
It is often the case, however, that a thermoplastic resin must be specially formulated or customized for a particular use or application, such as mold-in color processes, for example by including special additives for that use, such as pigments to achieve a particular color or a stabilizer package that meets the requirements of a particular use. In particular, thermoplastic resins may be customized to include certain pigments and/or colorants. It is often desirable that the manufactured articles have a particular color.
A particular color may, for example, enhance aesthetic appeal of the article or may even serve to help identify the particular brand or manufacturer.
Customizing the color or additive package of thermoplastic resins can, however, present problems.
LVhile the general purpose thermoplastic resin, or base resin, may be produced by continuous extrusion operations, colored thermoplastic resins or thermoplastic resins with special additive packages are typically required in much smaller amounts that are relatively expensive to produce. Manufacture, especially post-production cleaning, is extremely labor intensive.
The processing equipment (such as blenders, feeders, extruders, and pelletizing equipment) must be thoroughly cleaned after each particular color or customized blend in order to avoid contamination of the thermoplastic resins that will next be produced in the equipment. The cleaning process requires significant down time of the equipment during which no material is being manufactured, adding to the manufacturing costs of the specialized product.
Alternatively, colored articles have been produced by dry blending the uncolored thermoplastic resin with a color concentrate (also known as color masterbatch) in what is known in the art as a "salt and pepper blend."
The thermoplastic resin and the color concentrate used for such blends are typically of similar size pellets or pieces. The color concentrate is usually a minor amount by weight of the blend, typically only up to about 5percent by weight, and often much less. The salt and pepper blend is then introduced directly to the molding or forming equipment used to produce the final article.
The melt blending of the uncolored resin and the color concentrate must take place in the molding or forming equipment. This process, however, can result in color variations from piece to piece, or even in areas within the same piece, because of incomplete blending, particularly for low blending ratios of the color concentrate. Segregation of particular additives during packaging and transportation may also be experienced with dry blends and contribute to lack of homogeneity in the final formed articles.
It is also known to prepare color concentrates by a method of blending together a mixture of pigment, low molecular weight polyethylene wax, and thermoplastic polyolefin granules. The pigment and wax is included at relatively high levels, for example approximately 40percent by weight of the mixture. The wax dispersed the pigment forms a layer on the polymer granules. This masterbatch is blended with unmodified base polyolefins to form a "salt and pepper" blend. The high loading of pigment and dispersing wax is required by the masterbatch in order to achieve the desired final pigment loading in the salt and pepper blend. Such masterbatch-containing blends suffer from the same problems discussed above. In addition, the relatively thick coating of wax on the granules is undesirable for the reason that such thick coatings tend to easily chip and flake off, which could result in segregation and nonhomogeneity in the molded articles, as well as dust problems in production.
A novel method of preparing customized thermoplastic resins in which the pieces, typically pellets, of thermoplastic resin are coated with a coating that comprises a polymeric component and an additive component has now been discovered. The polymeric component of the coating has a melting point, softening point, or glass transition temperature that is lower than the melting point, softening point, or glass transition temperature of the thermoplastic resin body.
In a preferred embodiment, the coating is a color concentrate comprising a polymeric component and one or more pigments, optionally with other additives. In a preferred embodiment, a substantially even thickness of an outer layer of.the color coating is applied. The coated resin pieces or pellets are easy to handle and may be formed into articles using the same processes and in the same way as would resin pellets that have had the color or other additive integrally mixed in.
The color concentrate composition is coated onto the resin after the resin piece is formed. The customized thermoplastic resins of the invention may thus be produced in easy-to-clean equipment and without requiring down time of the equipment used to manufacture the thermoplastic resin body, resulting in a much more versatile and economical process. In addition, because each pellet or other body of the thermoplastic resin is in intimate contact with the pigment necessary to produce the desired customized resin, defects such as inhomogeneity, which are especially apparent when color is involved, are avoided. Further, the surfactants, water, amines, and resins with hydrophilic functiorialities required by the prior art compositions are not necessary for the coatings of the present invention.
U.S. Patent No. 5,846,607 discloses a process for customizing thermoplastic resins, by coating a thermoplastic resin body with a layer of a lower melting coating comprising a thermoplastic and a colorant. Wax, pigment, and natural resin pellets are processed at a temperature at which the coating is a melt, but at which the pellets remain solid. The coating may be applied to the natural resin pellets with the assistance of a high-intensity mixer. Thus, the process requires the addition of heat and is accomplished in a single mixing and coating process.
U.S. Patent No. 5,455,288 discloses a process for producing a color concentrate pellet, also made by a single process step. These pellets, however, are color concentrate granules which must then be let down by blending with additional natural resin pellets.
U.S. Patent No. 5,536,576 discloses natural resin pellets coated with a pigment. The pigment is dispersed in a liquid adhesive which is thereafter contacted with the natural resin pellets. Thus, the pellets bear a layer of colorant adhesively coated onto the surfaces of the pellets.
It would be desirable to prepare color coated plastic pellets by an energy-efficient process that would not substantially affect the inherent viscosity of the base pellets.
SUMMARY OF THE INVENTION
A process for preparing color coated plastic pellets has surprisingly been discovered. The process comprises the steps of:
dispersing pigment in a carrier within a high-intensity mixer at a high shear rate in the absence of added heat energy, to form plastic pigment particles;
adding natural resin pellets to the plastic pigment particles within the high-intensity mixer; and mixing the plastic pigment particles and natural resin pellets in the high-intensity mixer at a high shear rate in the absence of added heat energy, to cause a coating of colored plastic to fuse to the surfaces of the natural resin pellets.
The inventive process is particularly useful for preparing color coated plastic pellets from which a variety of plastic articles may be produced utilizing conventional plastic molding techniques.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is directed to a process for preparing color coated plastic pellets, comprising the steps of dispersing pigment in a carrier within a high-s intensity mixer at a high shear rate in the absence of added heart energy to form plastic pigment particles, adding natural resin pellets to the plastic pigment particles within the high-intensity mixer, and mixing the plastic pigment particles and the natural resin pellets in the high-intensity mixer at a high shear rate in the absence of added heat energy to cause a coating of colored plastic to fuse to the surfaces of the natural resin pellets.
The color coated plastic pellets of the invention have a thermoplastic resin body and an outer thermoplastic coating layer that at least partially covers the body. The coating includes a polymeric component that has an onset temperature for its melt processing range that is lower than the onset temperature of the melt processing range of the thermoplastic resin body. The coating also includes at least one colorant or pigment as the additive or as one of a plurality of additives.
The thermoplastic resin body is preferably a pellet.
Thermoplastic resins are customarily manufactured as pellets for later processing into the desired article.
The term "pellets" is understood and used herein to encompass various geometric forms, such as squares, trapezoids, cylinders, lenticular shapes, cylinders with diagonal faces, flakes, chunks, and substantially spherical shapes including a particle of powder or a larger-size sphere. While thermoplastic resins are often sold as pellets, the resin could be in any shape or size suitable for use in the equipment used to form the final article.
Typically, the thermoplastic resin body is a pellet which is cylindrical, approximately 3/32 to 5/32 inch in diameter, and preferably 4/32 inch (1/8 inch) in diameter. The length is typically about 1/8 to about 1/4 inch, preferably 1/8 inch. The 1/8-inch length size feeds better at the end user.
The thermoplastic resin body may comprise virtually any thermoplastic resin suitable for forming into articles by thermal processes, molding, extrusion, or other such processes that may be employed in the methods of the invention, with the proviso that the thermoplastic resin of the resin body must have an onset temperature for its melt processing range higher than the onset temperature of the melt processing range of the polymeric component of the outer coating layer. For example, and without limitation, the following thermoplastic materials may advantageously be used:
acrylonitrile-butadiene-styrene (ABS), acetal resins such as polyoxymethylene, acrylics, acrylonitrile (AN), allyl resins, cellulosics, epoxies, polyarylether ketones, polyether etherketones (PEEK), phenolics, polyamides (nylons), including polyamide-6, polyamide-6,6, polyamide-6,10, and so on; polyimides, polyamide-imide resins, polyolefins (TPO, including polyethylene, polypropylene, and polybutylene homopolymers and copolymers; polycarbonates; polyesters, including polyalkylene terephthalates such as polybutylene terephthalate (PBT) and polyethylene terephthalate (PET); polyimides and polyetherimides; polyphenylene oxide; polyarylene sulfites such as polyphenylene sulfite; polyarylene sulfides such as polyphenylene sulfide; polyvinyl resins, including polystyrene (PS) and copolymers of styrene such as styrene-acrylonitrile copolymer (SAN) and acrylic-styrene-acrylonitrile copolymer (ASA), polyvinyl polymers including polyvinyl chloride (PVC) and polyvinylphenylene chloride;
polyurethanes (TPU), and polysulfones, including polyarylether sulfones, polyether sulfones, and polyphenyl sulfones. Mixtures or block copolymers of two or more resins may also be used. Preferred materials for the thermoplastic resin body include polyesters, polyamides, polyolefins, polystyrenes and polystyrene copolymers, polyacetals, polycarbonates, acrylics, polyether etherketones, and mixtures of these.
Polyesters, polyamides, polystyrenes and polystyrene copolymers, and mixtures of these are especially preferred.
The thermoplastic resin body is substantially encapsulated by the coating. By "substantially to encapsulated" is meant that at least about three-quarters of.the surface of the thermoplastic resin body is coated, and preferably at least about nine-tenths of the resin body is coated. It is particularly preferred for the,coating to cover substantially all of the resin body. The coating of the customized thermoplastic resin has a thickness that will result in the desired weight ratio of coating composition to thermoplastic resin body composition when the two are formed into the final article. The weight ratio of coating to the thermoplastic resin may typically range at least about 0.1 percent by weight and up to about 10 percent by weight, based on the weight of the coated thermoplastic resin. Preferably, the coating is at least about 0.5 percent by weight and up to about 5 percent by weight, based on the weight of the coated thermoplastic resin.
Thus, the coating thickness may depend upon such factors as the surface area of the thermoplastic resin body that is coated and the concentration of the additive or additives in the coating compared to the desired concentration in the final blend of the resin body and coating. For a typical cylindrical pellet, the coating may be up to an average of about 300 microns thick. In a preferred embodiment, the average thickness of the coating for such a pellet may be at least about 10 microns and up to about 200 microns.
The coating comprises a polymeric component and an additive component. The polymeric component comprises one or more resins or polymers. Examples of suitable materials for the polymeric component include, without limitation, the thermoplastic materials mentioned above as suitable for the resin body, waxes, and mixtures of these. In a preferred embodiment, the polymeric component is a crystalline material.
The additive component of the coating includes at least one colorant additive. Examples of additional suitable additives include, without limitation, l0 plasticizers, thixotropes, optical brighteners, antioxidants, UV absorbers, hindered amine light stabilizers, hindered amide light stabilizers, heat stabilizers, flame retardants, conductive materials, nonfibrous reinforcements and particulate fillers such as talc, impact modifiers such as ionomers, maleated elastomers, and natural and synthetic rubber particles, processing aids such as lubricants, mold release agents, and slip agents, fragrances, antifoaming agents, antioxidants, antistatic agents, antimicrobials, biocides, and so forth.
The additive component of the coating comprises at least one pigment or colorant. Preferably, the pigment is present in an amount of up to about 8 percent by weight, and especially up to about 4 percent by weight, based on the weight of the customized thermoplastic resin. Suitable pigments are black, white, or color pigments, as well as extenders. Examples of useful pigments include, without limitation, titanium dioxide, zinc oxide, zinc sulfide, barium sulfate, aluminum silicate, calcium silicate, carbon black, black iron oxide, copper chromite black, yellow iron oxides, red iron oxides, brown iron oxides, ocher, sienna, umber, hematite, limonite, mixed iron oxides, chromium oxide, Prussian blue (ammonium ferrocyanide), chrome green, chrome yellow, manganese violet, cobalt phosphate, cobalt lithium phosphate, ultramarines, blue and green copper phthalocyanines, metallized and nonmetallized azo reds, gold, red, and purple quinacridones, mono-and diarylide yellows, naphthol reds, pyrrolo-pyrroles, anthraquinones, thioindigo, flavanthrone, and other vat pigments, benzimidazolone-based pigments, dioxazine, perylenes, carbazole violet, perinone, isoindoline, and so on.
In the present invention, it is normal to use combinations of organic and inorganic pigments.
Typically, in such a case the organic pigment is used as a toner to give vivid color, while the inorganic pigment, which tends to be non-transparent provides a more opaque color and fills up the color so as to reduce transparency. Typically, high levels of inorganic pigments are used in combination with lower levels of organic pigments. If the loading level is 90 percent by weight, the pigment may be 100 percent inorganic.
Alternatively, if a loading level of 90 percent pigment by weight is desired, up to about 40 percent organic pigment can be put in, with the balance being inorganic pigment. If a loading level of 70 percent pigment by weight is desired, up to about 40 percent organic pigment can be put in, with the balance being inorganic pigment. If a 60 percent loading level is desired, this could, for example, be achieved with 10 percent organic/50 percent inorganic, or 30 percent organic/30 percent inorganic, or 40 percent organic/20 percent inorganic.
The carrier is utilized to bind the pigment and also generally operates to wet the pigment so that it is more dispersible in the natural resin to be colored. Bis stearamide wax is a typical carrier. If dry powdered pigment is incorporated directly into natural resin, there is a tendency for it to form chunks and streaks, rather than to uniformly color the natural resin.
A carrier is not necessarily a single compound;
combinations of ingredients can be utilized as a carrier, which may also be referred to as a "carrier system". As utilized in the illustrated embodiments, the components of the carrier may have different melting points, but when mixed, the mixture or carrier will melt at about 160°F to about 210°F to about 220°F. The carrier has a melting point less than about 230°F, preferably at about or less than about 200°F. The color concentrate pellet, containing pigment and carrier, will melt.at about the same temperature as that of the carrier of which it is formed. It is desirable that the carrier utilized be compatible with a wide range of types of natural resin. When this is achieved, a single type pellet can be utilized to color a variety of different types of natural resins. In the conventional art, as described above, a plurality of different types of pellets of the same color are, or may be, needed to color the same plurality of types of natural resin. The Examples hereinafter disclose carriers which are useful in the practice of the present invention.
To make pellets in accordance with the present invention, it is preferable to utilize a high intensity, bowl-type mixer, such as is known in the art and is available from the Henschel Company in Germany. This type mixer is jacketed and hooked up to a cooling system. It has a large rotary impeller that mixes and agitates the ingredients. The pigment and carrier, both in powdered form, are placed in the bowl without preheating. The mixer agitates and whips the ingredients by means of the impeller. This action fractionally raises the temperature of the ingredients. Heat is thus substantially mechanical rather than electrical or gas combustion in origin. As the melting point is approached, the carrier softens and agglomerates with the pigment particles. The pigment becomes wetted, ground, solvated, and encapsulated by the carrier.
Encapsulation prevents the pigment from reagglomerating, and thus results in excellent pigment dispersion.
By "high intensity" mixer is meant a mixer that can apply about 10 horse power per cubic foot of material with high shear rate, with a maximum of 20,000 sec. sup.-1. Exemplary high intensity mixers include Banbury mixers, Prodex-Henschel mixers, and Welex-Papenmeier mixers. Such mixers typically have an impeller for mixing and applying energy to the batch, and a baffle for directing the motion of the product to the center of the vortex. Such mixers also have a jacket surrounding the mixing bowl so that cooling may be applied.
Generally, the mixer impeller is run at a tip speed of between about 2000 feet per minute (fpm) to about 4000 fpm, preferably between about 2500 fpm to about 3000 fpm. The degree of deflection of the mixer baffle may be adjusted from about 45° to about 0°, and preferably between about 15° to about 0°, where 0° refers to a radial orientation.
The particle surface will be heated to a temperature of at least about 10°C, preferably about 5°C, below the temperature at which the ingredients will soften and fuse. Persons skilled in the art recognize that mixing times will vary with the blending technique, apparatus and the choice of processing aid.
The particles will be mixed until their surface temperature is above that of the temperature required to soften the ingredients. Water may be passed through a water jacket to maintain control of the heating.
The high-intensity mixer is run until the power consumption drops to a level which indicates that the encapsulation process is complete. Granules, which are rounded, spherelike particles, are formed by this process. The granules are preferably about 10 microns to about 50 microns in diameter, and more preferably about 10 microns to about 30 microns in diameter. These granules can include up to about 90 percent pigment by weight. Processing the powdered pigment and carrier through the high intensity mixer can increase the bulk density of the mixture from about 1.75 times to about 3.5 times.
Thereafter, natural resin pellets are inserted into the high-intensity mixer, and the mixer is activated.
This may occur while the color particles are still warm, or after the color particles have been allowed to cool.
It is important to note that heat energy is at no time added to the ingredients nor the high-intensity mixer.
Thus, the present process is highly energy efficient.
During this second process step, the color coating fuses to the surfaces of the natural resin pellets.
Thereafter, the coated pellets may be cooled and removed from the high-intensity mixer for subsequent processing.
The coated pellets of the invention may be formed into articles according to any of the methods known in the art for thermal melt processing of thermoplastic resin compositions. For example, compression molding, vacuum molding, injection molding, thermoforming, blow molding, calendering, casting, extrusion, filament winding, laminating, rotational or slush molding, transfer molding, lay-up or contact molding, stamping, and combinations of these methods may be used with the customized thermoplastic resins formed by the present methods.
The color coated plastic pellets of the invention may be formed into any of the articles generally made with thermoplastic resins. Among the many possibilities are, without limitation, chair bases, electrical connectors and housing, automotive component including speaker grills, mirror housings, and fluid reservoirs, power tool housings, electrical appliance components such as refrigerator shelves and oven door handles, toys such as plastic building blocks, toothbrushes, and extruded films or layers.
In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be understood that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
The present invention is directed to a process for preparing color coated plastic pellets, comprising the steps of dispersing pigment in a carrier within a high-s intensity mixer at a high shear rate in the absence of added heart energy to form plastic pigment particles, adding natural resin pellets to the plastic pigment particles within the high-intensity mixer, and mixing the plastic pigment particles and the natural resin pellets in the high-intensity mixer at a high shear rate in the absence of added heat energy to cause a coating of colored plastic to fuse to the surfaces of the natural resin pellets.
The color coated plastic pellets of the invention have a thermoplastic resin body and an outer thermoplastic coating layer that at least partially covers the body. The coating includes a polymeric component that has an onset temperature for its melt processing range that is lower than the onset temperature of the melt processing range of the thermoplastic resin body. The coating also includes at least one colorant or pigment as the additive or as one of a plurality of additives.
The thermoplastic resin body is preferably a pellet.
Thermoplastic resins are customarily manufactured as pellets for later processing into the desired article.
The term "pellets" is understood and used herein to encompass various geometric forms, such as squares, trapezoids, cylinders, lenticular shapes, cylinders with diagonal faces, flakes, chunks, and substantially spherical shapes including a particle of powder or a larger-size sphere. While thermoplastic resins are often sold as pellets, the resin could be in any shape or size suitable for use in the equipment used to form the final article.
Typically, the thermoplastic resin body is a pellet which is cylindrical, approximately 3/32 to 5/32 inch in diameter, and preferably 4/32 inch (1/8 inch) in diameter. The length is typically about 1/8 to about 1/4 inch, preferably 1/8 inch. The 1/8-inch length size feeds better at the end user.
The thermoplastic resin body may comprise virtually any thermoplastic resin suitable for forming into articles by thermal processes, molding, extrusion, or other such processes that may be employed in the methods of the invention, with the proviso that the thermoplastic resin of the resin body must have an onset temperature for its melt processing range higher than the onset temperature of the melt processing range of the polymeric component of the outer coating layer. For example, and without limitation, the following thermoplastic materials may advantageously be used:
acrylonitrile-butadiene-styrene (ABS), acetal resins such as polyoxymethylene, acrylics, acrylonitrile (AN), allyl resins, cellulosics, epoxies, polyarylether ketones, polyether etherketones (PEEK), phenolics, polyamides (nylons), including polyamide-6, polyamide-6,6, polyamide-6,10, and so on; polyimides, polyamide-imide resins, polyolefins (TPO, including polyethylene, polypropylene, and polybutylene homopolymers and copolymers; polycarbonates; polyesters, including polyalkylene terephthalates such as polybutylene terephthalate (PBT) and polyethylene terephthalate (PET); polyimides and polyetherimides; polyphenylene oxide; polyarylene sulfites such as polyphenylene sulfite; polyarylene sulfides such as polyphenylene sulfide; polyvinyl resins, including polystyrene (PS) and copolymers of styrene such as styrene-acrylonitrile copolymer (SAN) and acrylic-styrene-acrylonitrile copolymer (ASA), polyvinyl polymers including polyvinyl chloride (PVC) and polyvinylphenylene chloride;
polyurethanes (TPU), and polysulfones, including polyarylether sulfones, polyether sulfones, and polyphenyl sulfones. Mixtures or block copolymers of two or more resins may also be used. Preferred materials for the thermoplastic resin body include polyesters, polyamides, polyolefins, polystyrenes and polystyrene copolymers, polyacetals, polycarbonates, acrylics, polyether etherketones, and mixtures of these.
Polyesters, polyamides, polystyrenes and polystyrene copolymers, and mixtures of these are especially preferred.
The thermoplastic resin body is substantially encapsulated by the coating. By "substantially to encapsulated" is meant that at least about three-quarters of.the surface of the thermoplastic resin body is coated, and preferably at least about nine-tenths of the resin body is coated. It is particularly preferred for the,coating to cover substantially all of the resin body. The coating of the customized thermoplastic resin has a thickness that will result in the desired weight ratio of coating composition to thermoplastic resin body composition when the two are formed into the final article. The weight ratio of coating to the thermoplastic resin may typically range at least about 0.1 percent by weight and up to about 10 percent by weight, based on the weight of the coated thermoplastic resin. Preferably, the coating is at least about 0.5 percent by weight and up to about 5 percent by weight, based on the weight of the coated thermoplastic resin.
Thus, the coating thickness may depend upon such factors as the surface area of the thermoplastic resin body that is coated and the concentration of the additive or additives in the coating compared to the desired concentration in the final blend of the resin body and coating. For a typical cylindrical pellet, the coating may be up to an average of about 300 microns thick. In a preferred embodiment, the average thickness of the coating for such a pellet may be at least about 10 microns and up to about 200 microns.
The coating comprises a polymeric component and an additive component. The polymeric component comprises one or more resins or polymers. Examples of suitable materials for the polymeric component include, without limitation, the thermoplastic materials mentioned above as suitable for the resin body, waxes, and mixtures of these. In a preferred embodiment, the polymeric component is a crystalline material.
The additive component of the coating includes at least one colorant additive. Examples of additional suitable additives include, without limitation, l0 plasticizers, thixotropes, optical brighteners, antioxidants, UV absorbers, hindered amine light stabilizers, hindered amide light stabilizers, heat stabilizers, flame retardants, conductive materials, nonfibrous reinforcements and particulate fillers such as talc, impact modifiers such as ionomers, maleated elastomers, and natural and synthetic rubber particles, processing aids such as lubricants, mold release agents, and slip agents, fragrances, antifoaming agents, antioxidants, antistatic agents, antimicrobials, biocides, and so forth.
The additive component of the coating comprises at least one pigment or colorant. Preferably, the pigment is present in an amount of up to about 8 percent by weight, and especially up to about 4 percent by weight, based on the weight of the customized thermoplastic resin. Suitable pigments are black, white, or color pigments, as well as extenders. Examples of useful pigments include, without limitation, titanium dioxide, zinc oxide, zinc sulfide, barium sulfate, aluminum silicate, calcium silicate, carbon black, black iron oxide, copper chromite black, yellow iron oxides, red iron oxides, brown iron oxides, ocher, sienna, umber, hematite, limonite, mixed iron oxides, chromium oxide, Prussian blue (ammonium ferrocyanide), chrome green, chrome yellow, manganese violet, cobalt phosphate, cobalt lithium phosphate, ultramarines, blue and green copper phthalocyanines, metallized and nonmetallized azo reds, gold, red, and purple quinacridones, mono-and diarylide yellows, naphthol reds, pyrrolo-pyrroles, anthraquinones, thioindigo, flavanthrone, and other vat pigments, benzimidazolone-based pigments, dioxazine, perylenes, carbazole violet, perinone, isoindoline, and so on.
In the present invention, it is normal to use combinations of organic and inorganic pigments.
Typically, in such a case the organic pigment is used as a toner to give vivid color, while the inorganic pigment, which tends to be non-transparent provides a more opaque color and fills up the color so as to reduce transparency. Typically, high levels of inorganic pigments are used in combination with lower levels of organic pigments. If the loading level is 90 percent by weight, the pigment may be 100 percent inorganic.
Alternatively, if a loading level of 90 percent pigment by weight is desired, up to about 40 percent organic pigment can be put in, with the balance being inorganic pigment. If a loading level of 70 percent pigment by weight is desired, up to about 40 percent organic pigment can be put in, with the balance being inorganic pigment. If a 60 percent loading level is desired, this could, for example, be achieved with 10 percent organic/50 percent inorganic, or 30 percent organic/30 percent inorganic, or 40 percent organic/20 percent inorganic.
The carrier is utilized to bind the pigment and also generally operates to wet the pigment so that it is more dispersible in the natural resin to be colored. Bis stearamide wax is a typical carrier. If dry powdered pigment is incorporated directly into natural resin, there is a tendency for it to form chunks and streaks, rather than to uniformly color the natural resin.
A carrier is not necessarily a single compound;
combinations of ingredients can be utilized as a carrier, which may also be referred to as a "carrier system". As utilized in the illustrated embodiments, the components of the carrier may have different melting points, but when mixed, the mixture or carrier will melt at about 160°F to about 210°F to about 220°F. The carrier has a melting point less than about 230°F, preferably at about or less than about 200°F. The color concentrate pellet, containing pigment and carrier, will melt.at about the same temperature as that of the carrier of which it is formed. It is desirable that the carrier utilized be compatible with a wide range of types of natural resin. When this is achieved, a single type pellet can be utilized to color a variety of different types of natural resins. In the conventional art, as described above, a plurality of different types of pellets of the same color are, or may be, needed to color the same plurality of types of natural resin. The Examples hereinafter disclose carriers which are useful in the practice of the present invention.
To make pellets in accordance with the present invention, it is preferable to utilize a high intensity, bowl-type mixer, such as is known in the art and is available from the Henschel Company in Germany. This type mixer is jacketed and hooked up to a cooling system. It has a large rotary impeller that mixes and agitates the ingredients. The pigment and carrier, both in powdered form, are placed in the bowl without preheating. The mixer agitates and whips the ingredients by means of the impeller. This action fractionally raises the temperature of the ingredients. Heat is thus substantially mechanical rather than electrical or gas combustion in origin. As the melting point is approached, the carrier softens and agglomerates with the pigment particles. The pigment becomes wetted, ground, solvated, and encapsulated by the carrier.
Encapsulation prevents the pigment from reagglomerating, and thus results in excellent pigment dispersion.
By "high intensity" mixer is meant a mixer that can apply about 10 horse power per cubic foot of material with high shear rate, with a maximum of 20,000 sec. sup.-1. Exemplary high intensity mixers include Banbury mixers, Prodex-Henschel mixers, and Welex-Papenmeier mixers. Such mixers typically have an impeller for mixing and applying energy to the batch, and a baffle for directing the motion of the product to the center of the vortex. Such mixers also have a jacket surrounding the mixing bowl so that cooling may be applied.
Generally, the mixer impeller is run at a tip speed of between about 2000 feet per minute (fpm) to about 4000 fpm, preferably between about 2500 fpm to about 3000 fpm. The degree of deflection of the mixer baffle may be adjusted from about 45° to about 0°, and preferably between about 15° to about 0°, where 0° refers to a radial orientation.
The particle surface will be heated to a temperature of at least about 10°C, preferably about 5°C, below the temperature at which the ingredients will soften and fuse. Persons skilled in the art recognize that mixing times will vary with the blending technique, apparatus and the choice of processing aid.
The particles will be mixed until their surface temperature is above that of the temperature required to soften the ingredients. Water may be passed through a water jacket to maintain control of the heating.
The high-intensity mixer is run until the power consumption drops to a level which indicates that the encapsulation process is complete. Granules, which are rounded, spherelike particles, are formed by this process. The granules are preferably about 10 microns to about 50 microns in diameter, and more preferably about 10 microns to about 30 microns in diameter. These granules can include up to about 90 percent pigment by weight. Processing the powdered pigment and carrier through the high intensity mixer can increase the bulk density of the mixture from about 1.75 times to about 3.5 times.
Thereafter, natural resin pellets are inserted into the high-intensity mixer, and the mixer is activated.
This may occur while the color particles are still warm, or after the color particles have been allowed to cool.
It is important to note that heat energy is at no time added to the ingredients nor the high-intensity mixer.
Thus, the present process is highly energy efficient.
During this second process step, the color coating fuses to the surfaces of the natural resin pellets.
Thereafter, the coated pellets may be cooled and removed from the high-intensity mixer for subsequent processing.
The coated pellets of the invention may be formed into articles according to any of the methods known in the art for thermal melt processing of thermoplastic resin compositions. For example, compression molding, vacuum molding, injection molding, thermoforming, blow molding, calendering, casting, extrusion, filament winding, laminating, rotational or slush molding, transfer molding, lay-up or contact molding, stamping, and combinations of these methods may be used with the customized thermoplastic resins formed by the present methods.
The color coated plastic pellets of the invention may be formed into any of the articles generally made with thermoplastic resins. Among the many possibilities are, without limitation, chair bases, electrical connectors and housing, automotive component including speaker grills, mirror housings, and fluid reservoirs, power tool housings, electrical appliance components such as refrigerator shelves and oven door handles, toys such as plastic building blocks, toothbrushes, and extruded films or layers.
In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be understood that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
Claims
1. A process for preparing color coated plastic pellets, comprising the steps of:
dispersing pigment in a carrier within a high-intensity mixer at a high shear rate in the absence of added heat energy, to form plastic pigment particles;
adding natural resin pellets to the plastic pigment particles within the high-intensity mixer; and mixing the plastic pigment particles and natural resin pellets in the high-intensity mixer at a high shear rate in the absence of added heat energy, to cause a coating of colored plastic to fuse to the surfaces of the natural resin pellets.
dispersing pigment in a carrier within a high-intensity mixer at a high shear rate in the absence of added heat energy, to form plastic pigment particles;
adding natural resin pellets to the plastic pigment particles within the high-intensity mixer; and mixing the plastic pigment particles and natural resin pellets in the high-intensity mixer at a high shear rate in the absence of added heat energy, to cause a coating of colored plastic to fuse to the surfaces of the natural resin pellets.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US25676400P | 2000-12-19 | 2000-12-19 | |
US60/256,764 | 2000-12-19 | ||
PCT/US2001/048723 WO2002049774A1 (en) | 2000-12-19 | 2001-12-12 | Color coated plastic pellets |
Publications (1)
Publication Number | Publication Date |
---|---|
CA2432784A1 true CA2432784A1 (en) | 2002-06-27 |
Family
ID=22973494
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002432784A Abandoned CA2432784A1 (en) | 2000-12-19 | 2001-12-12 | Color coated plastic pellets |
Country Status (3)
Country | Link |
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AU (1) | AU2002230937A1 (en) |
CA (1) | CA2432784A1 (en) |
WO (1) | WO2002049774A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL1035294C2 (en) * | 2008-04-14 | 2009-10-15 | Recomexx Ind B V | Device, method and article for providing an additive for a main plastic stream. |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5176751A (en) * | 1991-03-01 | 1993-01-05 | Thermocolor Corporation | Pellets useful in production of plastic resin materials |
US5455288A (en) * | 1994-01-26 | 1995-10-03 | Needham; Donald G. | Dustless color concentrate granules |
-
2001
- 2001-12-12 AU AU2002230937A patent/AU2002230937A1/en not_active Abandoned
- 2001-12-12 CA CA002432784A patent/CA2432784A1/en not_active Abandoned
- 2001-12-12 WO PCT/US2001/048723 patent/WO2002049774A1/en not_active Application Discontinuation
Also Published As
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AU2002230937A1 (en) | 2002-07-01 |
WO2002049774A1 (en) | 2002-06-27 |
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