CA1102276A - Radiation curing in the presence of steam - Google Patents
Radiation curing in the presence of steamInfo
- Publication number
- CA1102276A CA1102276A CA298,150A CA298150A CA1102276A CA 1102276 A CA1102276 A CA 1102276A CA 298150 A CA298150 A CA 298150A CA 1102276 A CA1102276 A CA 1102276A
- Authority
- CA
- Canada
- Prior art keywords
- substrate
- steam
- radiation
- improvement
- curable composition
- 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
Classifications
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06P—DYEING OR PRINTING TEXTILES; DYEING LEATHER, FURS OR SOLID MACROMOLECULAR SUBSTANCES IN ANY FORM
- D06P1/00—General processes of dyeing or printing textiles, or general processes of dyeing leather, furs, or solid macromolecular substances in any form, classified according to the dyes, pigments, or auxiliary substances employed
- D06P1/44—General processes of dyeing or printing textiles, or general processes of dyeing leather, furs, or solid macromolecular substances in any form, classified according to the dyes, pigments, or auxiliary substances employed using insoluble pigments or auxiliary substances, e.g. binders
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
- B05D3/04—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to gases
- B05D3/0486—Operating the coating or treatment in a controlled atmosphere
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
- B05D3/06—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to radiation
- B05D3/061—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to radiation using U.V.
- B05D3/065—After-treatment
- B05D3/067—Curing or cross-linking the coating
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
- D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
- D06N3/04—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D06N3/06—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds with polyvinylchloride or its copolymerisation products
- D06N3/08—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds with polyvinylchloride or its copolymerisation products with a finishing layer consisting of polyacrylates, polyamides or polyurethanes or polyester
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H25/00—After-treatment of paper not provided for in groups D21H17/00 - D21H23/00
- D21H25/04—Physical treatment, e.g. heating, irradiating
- D21H25/06—Physical treatment, e.g. heating, irradiating of impregnated or coated paper
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/22—Secondary treatment of printed circuits
- H05K3/28—Applying non-metallic protective coatings
Landscapes
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Paints Or Removers (AREA)
- Paper (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
- Surface Treatment Of Glass (AREA)
- Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
- Coating Of Shaped Articles Made Of Macromolecular Substances (AREA)
- Treatments Of Macromolecular Shaped Articles (AREA)
Abstract
TITLE: RADIATION CURING IN THE PRESENCE OF STEAM
ABSTRACT OF THE DISCLOSURE: Radiation-curable materials, such as decorative and protective coatings in the form of inks, coatings and films can be cured in an atmosphere of steam. In addition to facilitating high quality cured products, the steam absorbs infra-red radiation, allowing radiation curable materials to be used with heat sensitive substrates such as paper and textiles without injury thereto.
ABSTRACT OF THE DISCLOSURE: Radiation-curable materials, such as decorative and protective coatings in the form of inks, coatings and films can be cured in an atmosphere of steam. In addition to facilitating high quality cured products, the steam absorbs infra-red radiation, allowing radiation curable materials to be used with heat sensitive substrates such as paper and textiles without injury thereto.
Description
, -FIELD OI~ THE INVENTION
Th;s invention relates generally to radialion-curable materials an(l systems;
more particularly, it rela~es to the curing of racliation-curable materials in the presence of steam. In one aspeet, the invention relates to the eombination of a substrate, a racliation-curable compo~3ition adhered to at least part Or the substrate, a souree of racliation and steam interposed between the souree of radiation ancl the radiation-curable composition to contact the radiation curable composition. ~l another aspect, the invention relates to a method for euring a eomposition capable of free-rac1ieal initiated polymerization which comprises exposing said composition to a source of radiation in the presence of steam.
BACI~GROUND OF THE INVENTION
Reactions that occur during radiation curing are free radical in nature and free radicals are inhibited by oxygen. The styryl radical, for example, will react 106 times more readily with oxygen thclt with a styrene monomer and an acrylate will react 400 times more readily with oxygen than with an acrylate monomer. The effect of oxygen in inhibiting free radical reactions in radiation curing is well l~lown and two mechanisms are postulated. One is quenching or deactivation of the photo-aetivated sensitizer by oxygen; the other is reaction of oxygen with the polymer radicals .
By the quenching or deaetivation mechanism, 2 quenching of the activated state eompetes with hydrogen abstraction:
Th;s invention relates generally to radialion-curable materials an(l systems;
more particularly, it rela~es to the curing of racliation-curable materials in the presence of steam. In one aspeet, the invention relates to the eombination of a substrate, a racliation-curable compo~3ition adhered to at least part Or the substrate, a souree of racliation and steam interposed between the souree of radiation ancl the radiation-curable composition to contact the radiation curable composition. ~l another aspect, the invention relates to a method for euring a eomposition capable of free-rac1ieal initiated polymerization which comprises exposing said composition to a source of radiation in the presence of steam.
BACI~GROUND OF THE INVENTION
Reactions that occur during radiation curing are free radical in nature and free radicals are inhibited by oxygen. The styryl radical, for example, will react 106 times more readily with oxygen thclt with a styrene monomer and an acrylate will react 400 times more readily with oxygen than with an acrylate monomer. The effect of oxygen in inhibiting free radical reactions in radiation curing is well l~lown and two mechanisms are postulated. One is quenching or deactivation of the photo-aetivated sensitizer by oxygen; the other is reaction of oxygen with the polymer radicals .
By the quenching or deaetivation mechanism, 2 quenching of the activated state eompetes with hydrogen abstraction:
2 ll ;,C6H5CC6 El5 6HSCC6H5 1 \ R-H OH
~ C6IlsC C~115 -I R
benzopllenone Sinee reaetion with R-H is necessary for generating the initiating species, quenching by oxygen elearly reduces the efficiency of the curing process.
The secolld mechanism, of oxygen illhibition reaction with the polymer raclicals, impedes initiation and propagatiol1. Reaction of growing polymers (P) with 2 produces peroxy radicals (PO2) whieh are generally not effective in propagation, but rather undergo hydrogen abstraction from some H-donor (P.~H) thereby terminating the chain.
P~ -~ 2 ~ PO2 _ PO2H -~ R
The overall efLect is the formation oL short polymer chains resulting in a tacky or low gloss surfaee and poor eoating eharaeteristies.
Optimum eure conditions are presently obtained in cUI atmosphere of inert gas;
the generally available inert gases are nitrogen and earbon dioxide with nitrogen being the most widely used inert gas ancl it is usecl, in eurrent eommereial praetiee to replace oxygen on the surfaee of a eoated substrate prior to and cluring exposure to radiation. While injeetion of nitrogen is aeeeptable in some applications, it would not be aceeptable in a paper mill or a earpet mill, for example, where web widths lun from 40 to 180 inehes (about 1 to about ~L. 5 meters) and more and where the eost of injeeting nitrogen aeross sueh a width would be prohibitive.
The most common method of euring with ultra-violet (llV) radiation involves the use of medium pressure mereury vapor light sourees whieh, in addition to I~V
light, produee eonsiderable heat. The temperature at the surface oE a 200 watt/inch mercury lamp is about 800 C. These lamps are generally loeated from . 5 to 12 inehes (1. 3 to 31 em. ) above the surfaee of the substrate bearing the UV curable material and it is clear that substantial quantities of this heat (that is, infra-red radiation) are transmitted to the substrate. Attempts to cure I~V curable eompositions printed or coated on heat sensitive substrates such as thin paper, textiles ancl the like have not been sueeessful beeause oL the attendant damage (shrinking, warping, seorch-ing, melting) to the substrate.
DESCRIPTION OF T~IE INVENTION
_ _ .
It has no~ been found that radiation eurable materials, particularly those that polymeriæe, crosslink or cure via a free radical mechanism, can be successfully irradiated in the presenee of steam to provide dry~ high gloss, tacl; free curccl 7~
products; further, steam will transmit those forms of radiation effective to cure a variety of polymerizable, curable or crosslinkable compositions while at the same time absorbing inEra-red radiation. The invention is practiced most simply by blanketing a radiation curable composition with steam prior to and during irradia-tion.
The steam can come from any convenient source; since low pressure steam, at atmospheric pressure or slightly elevated -- Lor example up to about 5 PSI -- is preferred, the steam can be that available at most plants or can be easily produced by a conventional steam generator. The use of steam injectors or one or more air l~lives to distribute the steam over the surface of the substrate being printed or coated is a conventional expedient and need not be discussed in detail.
The steam should be superheated; by this it is meant that the steam should be heated to a temperature sufficiently high that it does not condense on the substrate ~ulder the conditions of use.
The use of steam thus provides three important advantages. First, it dis-places or otherwise reduces the oxygen content of the atmosphere surrounding the racliation curable composition so that high gloss coatings can be obtained. Steam is thus an effective inerting medium. Second, it absorbs infra red radiation so that the temperature of the substrate being printed or coated remaills at aul acceptable level.
Steam is thus all eLfective cooling medium. I~inally, steam is readily available at virtually every industrial enterprise in the world. Steam is cheap.
This combination of inerting and cooling properties with ready availability cmd low cost represents a substantial irnprovement over tl~e state of the art and makes such irradiation teclmology as UV curing available to industries such as the paper, textile culd printing-on-plastics industries, where UV curing is not now utilized be-cause of the disadvantages provided by the high cost and heat associated with the present state of the art.
Radiation curable materials useful herein can be coated, printed or laminated to a greater variety of substrates than was previously useful.
Thus, there can be used the relatively heat-resistant substrates currerltly in ;27~;
use such as glass, ceramic cmd metal as well as the lamin~tes usecl in the printed circuit board incl-lstry. These substrates are used in a variety of rorms inclucling wires, rocls, sheets, panels, ilms, abrics, cylinders, bottles and colltaincrs.
There can also be used various plastics in the form of wires, rocls, sheets, panels, films (including laminates of diferent plastics) fabrics (woven, non-woven and tuftecl -~ A-~32~
bottles and similar containers. These plastics include the thermost plastics such as phenolic, epoxy, polyester, polyurethane and polyimide. Now, these plastics also inclucle the well-known therrnoplastic materials based on the homopolymers and copolymers of ethylene, propylene, butylene, butadiene, styrene, acrylonitrile, vinyl cllloride, vinylidene chloride, vinyl acetate, vinyl methyl ether, allyl alcohol, vinyl pyrrolidone, vinyl alcohol, vinyl butyral, vinyl carbazole, acrylic acid, methyl acrylate, ethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, acrylamide, N, N-dimethyl acrylamids, methacrylamide, caprolactone, ethylene glycol, propylene glycol, terephthalic acid, adipic acid, caprolactam, ethylene oxicle, propylene oxide, siloxane, isocyanate, sulfone, phenyl sulfone, phenylene sulfide, phenylene carbonate, phenylene ether, phenylene oxide, acetal, etc.
There can also be used the various natural and modified natural products such as gutta percha, sill~, wool, cotton, cellulose acetate, methyl cellulose; there can be used wood and various woody materials and paper, includ;ng newsprint, tag stock, parchment, cardboard, bag stock and the like.
The radlat~on curable material can be applied to the substrate in a thickness ranging from O! 01 to more than 100 mils; the thickness will depend on the ultimate use of the product. Thicknesses of 0.2 to 2 mils are conventional.
The invention described herein can be used to polymerize, cure or crosslink radiation curable compositions containing at least one component having an ethyleni-cally unsaturated group capable of polymerization, curing or crosslinking via a free-radical initiated mechanism.
In many instances the radiation curable compositions will produce solid, dry products upon exposure to suitable radiation without the addition of any photosensiti-zer, activator, catalyst or initiator. When it is desirable to use a photosensiti~er, activaeor, catalyst or initiator, as is frequently the case with UV curable systems, they can be used singly or in combination, with the total amount varying from 0. 01 to 20 percent by weight of the composition; 0.1 to 5 percent is a prererred range.
Synergistic effects are observed with some combinations.
The general classes of photosensitizers include azo compounds, dyes, sulfur-containing compounds, metallic salts and complexes, oximes, polynuclear compounds, peroxides, various hologen-containin~ compounds and carbonyls. For coatings ancl 27~
., ~
inlcs the benzoill ethers, benæophenone and benzophenone-Michlers l~etone combinations are ~videly usecl.
Alllong the sensitizers, the aromatic carbonyl compounds are quite important;
there are included benzoin ancl the benzoin ethers including ben~oin methyl ether;
benzoin ethyl ether; benzoin allyl ether; benzoin propyl ether; benzoin isopropyl ether;
benzoin butyl ether; benzoin isobutyl ether; benzoin sec-butyl ether; benzoin thiophenyl ether; benzoin amyl ether; benzoin hexyl ether; benzoin oc-tyl ether; benzoin 2-ethylhexyl ether; benzoin nonyl ether; benzoin trimethyhexyl ether; ben~.oin diethyl ether; benzoin phenyl ether; hyclroxyethyl benzoin ether; ethylene glycol benzoin ether; 2-chloroethyl-I)enzoin ether; benzoin isobutoxymethyl ether; a-alkoxybenzoin ethers; benzoin carbamates;
benzophenone and derivatives of benzophenone including "Michler's Ketone"
4,1'-Bis(dimethylamino) benzophenone; p,p'-diaminobenzophenone; 4-(dimethylamino) benzophenone; p-clichloromethylbenzophenone; p-chlorobenzophenone; ~, 4'-bis (bromome-thyl) benzophenone; p-hydroxybenzophenone; 2-hydroxy-~-methoxybenzophenone-5-stllfonic acid; p-acryloxybenzophenone; o-methoxybenzophenone; p-methoxybe~zophenone; glyciclyl ethers of benzopllenone; vinyl-substituted benzophenone; 2-isopropenylbenzophenone;
monocar~oxyl-substituted benzophenone; polycarboxyl-substituted benzophenone;
p-nitrobenzophenone; m-benzophenonesulfonyl chloride; p-p'-bis(dimethylamino) thio-benzophenone; phenlthiomethylbenzophenone; benzylthiomethylbenzophenone; benzopina-colone; ~nthrone; benzanthrone; benzathronesuIfonyl chloride; ~3-fluorenone; hydroxy-fluorenones; amino1`1uorenones; 2-bromoethyl-9-fluorenonesulfonyl chloride; dibenzo-suberone; l-chloromethyl-6-chlorosulfonyl-2-naphthylphenyl ketone; n-methylacridone;
poly(vinyl benzophenone;
monoaryl ketones including acetophenone; chloroalkylphenyl ketones; o-methyl~ce-tophenone; a-bromoacetophenone; ortho-bromoacetophenone; trichloroacetophenone;
trichloroethylidineacetophenone; 2-2-dichloro-4'-tertiary-butylacetophenone; 2,2,2-trichloro-4'-tertiary-butylacetophenone; a-bromoisobutyrophenone; 2,2-dibromo-2(phenyl-sulfonyl) acetophenone; a,a-dialkoxyacetophenone; 2,2-clirnethoxyacetophenone; 2,2-dimethoxy-2-phenylacetophenone; 2, 2-diethoxyacetophenone; o-methoxyacetophenone;
m-methoxyacetophenone; p-methoxyacetophenone; 2-butoxy-2-phenylacetophenone;
2-phenylthio-2-pllenylcLcetophenone; ethyl bcn7,0ylacetate; pcara-aminophenyl ketones;
cyclohexylphenyl ketone; pivalophenone; vak~:rophenone; acetonaphtllolle;
- dilietones inc~ucling biacetyl; benzil climethyl l~etal; 2, 3-dibenzoyl-2-nol:bornene;
benzoylbenzal chloride; 2, 2-dibromo-2-(phenylsulfonyl) propanec~ione; a-naphthil;
2, 3-butaneclione; benzil; pentanedione; l-aryl-l, 2-propanediones; 2, 3-bornanedione;
phenylpyruvic acid; 2, 4-pentanedione;
xanthone and thioxanthenones includin~ 3, 6-bis(dimethylamino) thioxanthenone;
2 -chlorothioxallthenone;
thiol~etones including thiobenzophenone; p, p'- dimethoxythiobenzophenone;
p, p' -bis (dimethylElmino) thiobenzophenone;
sulfur containing compounds such as n-dodecyl mercaptan; 2-mercaptobenz,imi-dazole; diphenyl sulfide; cyclohexlphenylsulfide; benzoin thioethers; benzoin thiophenyl ether; phenylthiomethylbenzophenone; s, s'-diphenyl dithiocarbonate; calcium sulfide;
metallic selenides; metallic tellurides; diaryl disulfides; diphenyl disulfide; clithiolane;
dibenzoyldisulfide; dixanthate; benzothiazoles; 2,2'-dithiobis(benzothiazole); 2-mercapto-benzothiazole; thiazolines; thiocarbamates; dithiocarbamic esters; dithiocarbamic anhydrides; thiurams; toluene sulfonic acid; sulfonyl chlorides; m- (chlorosulfonyl)benzyl chloride; naphthalenesulfonyl chloride; 2-bromoethyl-9-fluorenonesulfonyl chloride;
2,2-dibromo-2(phenylsulfonyl) acetophenone; 2,2-dibromo 2(phenylsulfonyl) propanedione;
benzophenonesulfonyl chloride; diphenyl disulfone;
oximes including o-acyloximes; l-phenyl-1,2-propanedione-2-o-benzoyl oxime;
oxido-oxazole; benzylmonooime; biacetyl monooxime phenylcarbamatc;
azo and azido compounds including 2,2'-azobisisopropane; azobis-isobutyronitrile;
2-phenylazobisisobutyronitrile; azobisisobutyramide; azobis (isobutyl acetate); di-(2,4,6-tribromopbenyl)-4,4'-azobis(4-cyanovalerate); p-azidobenzaldehyde; b-napht~alenesulfonyl azide; diazomethane; bis(phenylsulfonyl) diazomethane; diazonaphthalenes; cliazothioethers;
quinone diazides; m,m'-azoxystyrene;
imidazoles including benzimidazoles; 2--methylbenzirnidazole; 2-mercaptol)enzimi-dazole; triphenyl-irmidazolyl dimers;
amines including triethylamine; n, n-dimethylbenzylamine; methylcliethanolamine;
ethyldiethanolamine; triethanolarnine; p-nilro aniline; n-acetyl-4-nil;ro-:l-naphthylamine;
ami-noanthraquinone;
ammonium salts such as bipyriclylilml sall; henzyltLimethylammonium chloride;
diazonium salts;
7~
halogenated organic compoullds such as chloroform; bromoform; iodoform;
carbon tetrachloride; carbon tetrabromide; ethylene dichloride; trichloroethylene;
trichloroethalle; bromotrichloroethalle; vinyl bro-mide; l, 2-dibromotetrafluoroethane;
iodoethane; diacylhalomethane; hexachloroethane; tetrachloroethane; hexachlorobenzene;
o-dichlorobenzene;
polynuclear compounds including napththalene; halogenated naphthalenes; 2, 3, 6-trimethylnaphthalene; a-naphthol; l-aminonaphthalene; l~methoxynaphthalene; 2, 3-diphenyl-quinoxaline; anthracene; aminoanthraquinone; phenanthrene; naphthacene; fluorene;
9-fluorenone; stilbene; trinitrofluorenone; polynuclear quinones;
useful quinones include p-benzoquinone; o-benzoquinonediazide; anthraquinone;
alkylantllraquinones; 2-methylanthraquinone; 2-ethylanthraquinone; 2-tertiary-butylan-thraquinone; 2-chloroanthraquinone; aminoanthraquinone; l, S-diaminoanthraquinone;
piperidlno-anthraquinones; anthraquinonesulfonyl chloride; benzanthraquinone; 1-4-napthoquinolle derivatives; phenanthrenequinones; a-chloroanthraquinone;
the metal salts and complexes include zinc chloride; zinc b~omide; zine sulfide;ferrie ehloride; chromium chloride; nickel chloride; tin chloride; stannous chloride;
vanadium tetrachloride; vanadium oxychloride; vanadium naph~henate; aluminum chloride;
aluminum bromide; aluminum iodide; silver halides; gold salts; sodium chloraurate;
mercury salts; mercury iodosulfide; titanium tetrachloride; cadmium sulficle; boron trifluoride; borou trichloride; ceric salts; thallium salts; uranyl salts; cobalt octoate;
cobalt naphthenate; magnesium oxide; zinc oxide; titanium dioxide; alumina; cupric oxide; chromium oxide; silver oxide compounds; metal ehelates; metal amine complexes;
cobalt edta complexes; iron edta complexes; metal acetylacetonate; mang,anese tris (acetylacetonate); metal salt-saccharic1e complexes; metal oxalato complexes; p-benzo-quinone complexes; copper (I) complexes; manganese carbonyl; rheniurn carbonyl;
osmium carbonyl; iron carbonyls; metal thiocarbonyls; trialkylaluminum; d;ethylalumi-num chloricle; triphenylmethyldiethyltitanium chloricle; bis (~,-chloroethyl) diethyltitanium;
tetrabenzyltitanium; ~errocene; cyclopentadienylmanganese tricarbonyls;
useful peroxides inclucle hydrogen peroxide; benzoylperoxide; tertiary-butyl peroctoate; t-butyl a-cyanoperacetate; t-butyl hydroperoxide; di-t-butyl peroxic1e;
cumene hydroperoxide; a-curnyl peroxicle; er~,rosterol peroxide; fluorenone llydroperoxic1e;
acetyl peroxide;
clyes that are userul include acridines; benzacridine; ben~idines; b-carotene;
chlorophyll; crystal violet; eosin; erythrosine; fluorescein; indanthrene yellow; irga~in yello~,v; metllyl violet; methylene blue; pyronine-G; rhodamines; riboflavin; rose bengal;
thiazine clyes; thionine; xanthene dyes; xanthophyll; iodoeosine;
The radiation curable compositions that can be polymerized, cured or cross-linked in accordance with this invention are those having at least one polymerizable ethylenically unsaturated &roup of structure Of these materials, one important class is characteri7.ed l~y the presence of at least one acrylyl or methacrylyl group of formula R O
CI12=1 -C -where R is hydrogen or methyl. Monomers, polymers, oligomers and compositions whose functionality is attributable to the presence of acrylate and/or methacrylate groups include acrylic acicl, methacrylic acid, acrylamide, methacrylamide, methyl aerylate, methyl methacrylate, ethyl acrylate, etbyl methaerylate, hexyl acrylate, cyelohexyl methacrylate, 2-ethylhexyl acrylate, butoxyethoxyethyl ac rylate, bicyclo [2.2.1] hept-2-yl acrylate, dicyclopentenyl acrylate, isodecyl aerylate, ethylene diacrylate, diethylene glycol diacrylate, glycerol diacrylate, glycerol triacrylate, ethylene dimethaerylate; ethylene glyeol diaerylate, ethylene glycol dimethacrylate, 1,2,4-butanetriol trimethacrylate, 1,ds-benzenediol dimethacrylate, 1,4-eyclohexanediol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, tetraethyleneglycol diaerylate, pentaerythritol mono-,di-,tri~or tetracrylate or mixt-lres thereof, pentaerythritol tri-or tetramethacrylate, 1,5-pentanediol climethacrylate, trimethylol propane mono.-di-, or triacrylate or mixtures thereor, 2-phenoxyethyl acrylate, glycidyl aerylate, 2~tl~xyethyl acrylate, 2-methoxythyl acrylate, 2-(n, n-diethylamino) ethyl acrylate, omega-methoxyethyl (hendecaoxyethylene) acrylate, omega-tridecoxyethyl (llendecaoxyethylene) acrylate, trimethoxya]lyloxymetllyl acrylate, I)icyclo [2. 2. 11 hept-2-en-5-ylmethyl acrylate, bicyclo [2.2.1] hept-2-en-5,6-diyl diacrylate, vinyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl acrylate, (rnethyl carba-myl) ethyl acrylate and the bis-aerylates ancl methacrylate of polyethylene glycols o~ molecular weight 200-1500.
One gro~p of acrylyl and melhacrylyl estors that are paLtic~ rly usorul have the geneL al formula M H
CM2=C--COOM' or (CH2=C--COO)rG.
Wllere the acrylyl compound has tbe formula M
CH2=C--COOM' M is H or Cl M is cyeloallcyl of 5 to 12 carbon atoms (such as cyclopentyl, dieyclopentyl, methyclyclopentyl, dimethylcyclopentyl, ete. ) cyeloalkenyl of 5 to 12 earbon atoms (such as cyclopentenyl, methylcyclo-pentenyl, dicyclopentenyl, bieyelo ~2. 2.1] hept-2-en-yl, etc. ) --Cp H2p M" or (Cq H2q )s Ccl H2q ~1 ;
where p is an integer Erom 1 to ` 10 q is an integer from 2 to 4 s is an integer from 0 to 4 M" is hydrogen, hydroxyl, phenoxy, alkoxy of 1 to 8 carbon atoms;
and where the aerylyl eompound has the formula H
(C~I2=C--C)r G
G is a polyvalent alkylene group of formula _CX EI2x-y--in whieh x is an integer from 2 to 8 _ is an integer from 0 to 2 (for example, divalant alkylene when y= O such as--C2H~ , C3HG
iso~C3HG ,--C6H1o--, neo~CGH12 etc; trivalent allcylene whell y-] sueh as fI12 fEI2 CH2--CH~CH2~, CH3CH2 C CH2 , IIO CI[2--f -CII
CH~ CI-12 or tetravalent alkylene when y is 2, such as I H2-- --CH2 ~CH2--~CH2_f--CH2-- and C~I CH2 CH
CH2-- --C~I2 Cl:I2--etc.) or G is a clivalent ether or ester group ot formula ~(CcL H2q )t Cq H2q or --(Cq H2q C)t Cq H2q where t is an integer from 1 to 5 and cl is an integer from 2 to a~
(such as oxyethylelle, oxypropylene, oxybutylene, polyoxyethylene, polyoxypropylene, polyoxybutylene, ete. ) and r is the valence of ~ and can be 2 to 4.
Triethyleneglycol diacrylate, tetraethylene glycol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate and pentacrythritol tetraacrylate are especially useful.
Aerylate or methacrylate functionality can be incorporated in polymers and oligomers having carboxyl, hydroxyl oxirane or isocyanate groups via reaction with acrylic monomèrs. Addition reactions of isocyanates to rorm urethanes or oxiranes to form esters are relatively straightforward. Other methods of acrylation involving eondensation or ester interchange reaotions are well known.
Thls, there can be used epoxy acrylates obtained by reacting an epoi~y resin with acrylic or methacrylic acid or obtained by reacting a hydroxyalhyl acrylate with an anhydride and reacting that product with a diepoxidé. Oils, such as soybean oil and linseed oil, can be epoxidized and acrylated.
Polyester resins, for example rrom a glycol-dibasic aGid condensation, can be aerylated by using acrylic or methacrylie aeid to eomplete the esterification.
, Another method uses the reaction of an anhydride with a mixture oE propylene oxide and glyeidyl aerylate to obtain an acrylated polyester.
Acrylated alkyci reslns are obtained by the reaction of, for example, a triol, dibasic acid, phthalic anhydride and a fatty acid such as hydrogenated castor oil.
After reaction is eomplete aerylation is aehieved by direet esterifieation with acrylic acid.
227~
Urethane acrylates can be prepared directly by the reaction of a cliisocyanate with an hyclroxyalkyl acrylate, such as ~-hyclroxyethyl acrylate. Oli~omers are ob-tained by using an isocyanate-terminated urethane prepolymer for reaction with the hydroxyalkyl acrylate. The urethane prepolymer can be of the polyether or polyester type.
Acrylate functionality can be incorporated in a variety of polymer backbones by incorporating glycidyl methacrylate into the polymer chain and then reacting the pendant oxirane groups with acrylic or methacrylic acid.
Other radiation curable systems are based on unsaturated polyesters such as are obtained from fumaric acid, D~ stilbenedicarboxylic acid, moleic acid, and cliallyl ether.
Cilmamate ester groups are also useful, for example in a polyvinyl alcohol--cinnamate ester combination and in conjunction with a variety of polymer materials:
polycarbonate cinnamate; polyurethane cinnamate; cinnamyliclene--malonate copolyesters;
bisphenol A-furmarate polyester-cinnamate; cinnamyl-modified poly(meth) acrylates;
polyepichlorohyclrin/cinnamate; poly(cinnamyl methacrylate); epoxy cinnamylidene acetate; carboxyeinnamate modified polyesters;
Radiation curable materials are also obtainable from the 2-phenylmoleimido group, allyl ester moleimide combinations, allthioether polymers, aromatic polysulfone polymer, polysiloxanes, eholcones, sorbic acid derivatives, itaconic acid derivatives and mixtures containing itaconic acid; polyuinyl alcohol, polyvinyl acetate, polyvinyl butyral.
~ nother radiation curable polymer system is based on the free-radical acldition of a thiol to an olelinic clouble bond:
R-SII ~ CM2=CHR' 3R-S-CM2-CI-12 R' When a polyene and a polythiol are admixed and a stimulus that generates free-radicals is present, rapid curing occurs by simultaneous chain extending and crosslinls-ing reactions.
Other crosslinkable, polymerizable or curable materials include the nitriles such as aerylonitrile and inethaerylonitrile; the olefins sueh as dodecene, styrene, 4-methylstryrene, alphamethylstyrene, cyclopentadiene, dicyclopentadiene, butacliene, l,D~-hexadiene, ~-mel;hyl-1-pentene, bicyclo[2.2. LJ hept-2-ene, bicyclo[2.2. L~ hept-2,5-diene, cyclohexene; the vinyl halicles such as vin5tl chloricle, vinylidene chloricle;
the vinyl esters such as vinyl acetate, vinyl butyrate, vinyl benzoate, v;nyl butyral, vinyl methacrylate, vinyl hepto, vinyl c rotonate; the vinyl ketones such as vinyl metllyl l~etone, villyl phcnyl ketone, ;sopropenyl methyl Icetone, clivinyl l;etonc, alplla-chloro-v;nyl rnethyl ketone, vinyl phenyl ketone; acrolein and methacrolein; the vinyl ethers and thioethers such as methyl vinyl ether, ethyl vinyl ether, divinyl ether, isopropyl vinyl ether, the butyl vinyl ethers, 2-ethylhexyl vinyl ether, vinyl 2-chloro-ether, vinyl 2-methoxyethyl e-ther, n-hexadecyl vinyl ether, vinyl methyl sulfide, vinyl ethylsulfide, clivinyl sulricle, l-chloroethyl vinyl sulfide, vinyl octadecyl sulf;de, vinyl 2-ethoxyethyl sulfide, vinyl phenyl sulfide, d;allyl sulfide; the miscellaneous sul~ur and nitrogen containing monomers such as divinyl sulfone, vinyl ethyl sulfone, vinyl sulfonic acicl, vinyl ethyl sulLoxide, sodium vinyl sulfonate, vinyl sulfonarnide, vinyl pyridine, N~v;nyl pyrollidone, N-vinyl carbazole. Other curable materials are read;ly apparent to one skillecl in the art of polymerization chemistry. The specific compounds mentioned are illustrative only and not all-inclusive. ~hey can be poly-merized alone or in mixtures of two or more thereof with the proportions thereof dependent upon the desire of the individual. They can also be blended with polymers.
Among the polymers that can be used one can include, for example, the polyolefins and modified polylefins, the vinyl polymers, the polyethers, the polyesters, the polylactones, the polyamides, the polyurethanes, the polyureas, the polysiloxanes, the polysulfides, the polysulfolles, the polyformaldchydes, the phenolformaldehyde polymers, th~e natural and modified natural polymers~ the heterocyclic polymers.
The term polymer as used herein includes the homopolymers and copolymers alld includes the olefin polymers and copolymers such as polyethylene, poly(ethylene/
propylene), poly-(ethylene/norbornadiene), poly(ethylene/vinyl acetate), poly(ethylene/
vinyl chloride), poly(ethylene/ethyl acrylate), poly(ethylene/acrylonitrile), poly(ethylene/
acrylic acid), poly(ethylene/styrene), poly(ethylene/vinyl ethyl ether), poly(ethylene/vinyl methyl ketone), polybutadiene, poly(butadiene/styrene/acrylonitrile), poly(vinylchloride), poly(vinylidene chloride), poly(vinyl acetate), poly(vinyl methyl ether), poly(vinyl butyral), polystyrene, poly(N-vinyl~carbazole), poly(acrylic acid), poly(methyl acrylate), poly (ethyl acrylate), polyacrylonitrile, polyacrylamide, poly(methacrylic acid), poly(metllyl methacrylate), poly(ethyl me~hacrylate), poly(N, N~-climethyl acrylamicle), poly(methacryl-amide), polycaprolactone, poly(caprolac~one/vinyl chloride), poly(el;hylene ~;lycol 2~
terephtllalate), poly(captolactam), poly(ethylene oxide), poly(propylene oxide), copoly-mers of ethylene o~i~e ancl propylene oxicle with startcrs conlaini n~ reac~ c hyclrogen atoms such as the mixed copolymer using ethylene glycol or flycerol or sucrose, etc., as starter, the natural and mocdidied natural polymers such as Kutta percha, cellulose, methyl cellulose, starch, silh, wool, ancl the s~iloxane polymers ancl copolymers, the polysulficles ancl polysulfones, the formalclehyde polymers such as polyformaldehyde, formalclehyde resins such as phenol-formaldehy~e, melamineformaldehyde, urea-formald-ehyde, aniline-formalclellyde and acetone formaldehyde.
The compositions that are treated by this invention can contain any of the known pigl~lents, ~illers, stabilizers, polymers or other aclditives conventionally addcd to coat;ng compositions in the cluantities usually employed; provided, however, that they are not employed in such quantities as will unduly interfere or prevent the curing or crosslinldng ancl that the polymers are clissolvecl or dispersed therein. It is known that some pigments and fillers for example, can be used in small arnounts but that they prevent the reaction from occurring when they are present in~large amounts because they absorb for example light energy and ultraviolet light cannot penetrate iJltO the interior of the mixture and cure it completely; therefore, such materials should be used within the quantity ranges that will permit the reaction to proceed properly. In some instances, however, the amount that can be used is less than usu~l in order that the filler or colorant not unduly interfere with the ability of the ultraviolet radiation to penetrate below the surface of the coating and prevent CUl'illg or crosslinking from occurring. These principles are known to those skillecl in the art of radiation ehemistry and do not require exterlsive discussion or elaboration, the same is true for the particular materials that can be used.
~2~
The invelltion is illustrated by the following examples:
EXAMPLE l A metal hood was constructed containing sixteen 1 jO00-watt mercury vapor lamps; the lamps were provided w;th aluminum rclectol s. Supcrllcltccl StCL1n1 (atmospheric pressure) was injectecl into the hoocl. A web of paper, 2 mils thick (.002" or 5.080 ~c 10 cm) was coated with a UV-curable composition, as inclicatecl below, to a thickness of about 0.2 mil (.0002" or 5.08 x 10 ~cm) and introduced into the hoocl; the distance between the paper and UV lamps was about 3/-i inches (1. 9]. cm).
The papel and coating were run at a speed to provide an exposure time to the UV
lamps of (; seconds. The paper emerged from the hood with the UV curable composi-tiOll EuLly cured to a harcd, dry, tack-free, glossy coating; the paper showed no sign of curling, warping, shrinking or the like.
Component Parts by Weight Polyester Binder 30 1, 6-hexanediol diacrylate 65 Dietho~yacetophenone a~
~lodaflo~Y
(1) a condensation polymer of propylene glycol and~
moleic and isophthalic aclds having a molecular weight Or about 5, 000 and an acid number of about 10;
(2) a resinous hydrooarbon l1ow eontrol agent from Monsanto Chemical Co.
It should be noted that an exposure perlod of ~ seconds is quite slow by paper industry standards, whore sl~ec(ls in (3XCCSS ol' 1, 000 reet l~eI' minutc (305 meters/min) are realized in printing ink on newsprint. In paper mills, line speeds on the order of 900 feet/lYIin. ( 122 meters/min) are more common. Thus exposure periods to the UV source can be from a fraction of a second to severaL seconcls.
Other factors to be consiclered in determinin~ the exr~osure tinle inclucle the thickness of the coating being used (typical thicknes.s are fronl 0.1 mil to 1 mil or even more) 2~;
ancl the reactivily Or the cur~ible coml~osition. In this l~ltter respect, it might l~e noted that UV eurable compositions formulated to eure in air will eure faster in an atmosphcre Or steam.
While a 2 mil paper substrclte and a 0. 2 rnil eoating werc not arfectecl by t:he heat producecl, from si~;teen 1, 000-watt mercury vapor lanlps, at a distance oE
~ C6IlsC C~115 -I R
benzopllenone Sinee reaetion with R-H is necessary for generating the initiating species, quenching by oxygen elearly reduces the efficiency of the curing process.
The secolld mechanism, of oxygen illhibition reaction with the polymer raclicals, impedes initiation and propagatiol1. Reaction of growing polymers (P) with 2 produces peroxy radicals (PO2) whieh are generally not effective in propagation, but rather undergo hydrogen abstraction from some H-donor (P.~H) thereby terminating the chain.
P~ -~ 2 ~ PO2 _ PO2H -~ R
The overall efLect is the formation oL short polymer chains resulting in a tacky or low gloss surfaee and poor eoating eharaeteristies.
Optimum eure conditions are presently obtained in cUI atmosphere of inert gas;
the generally available inert gases are nitrogen and earbon dioxide with nitrogen being the most widely used inert gas ancl it is usecl, in eurrent eommereial praetiee to replace oxygen on the surfaee of a eoated substrate prior to and cluring exposure to radiation. While injeetion of nitrogen is aeeeptable in some applications, it would not be aceeptable in a paper mill or a earpet mill, for example, where web widths lun from 40 to 180 inehes (about 1 to about ~L. 5 meters) and more and where the eost of injeeting nitrogen aeross sueh a width would be prohibitive.
The most common method of euring with ultra-violet (llV) radiation involves the use of medium pressure mereury vapor light sourees whieh, in addition to I~V
light, produee eonsiderable heat. The temperature at the surface oE a 200 watt/inch mercury lamp is about 800 C. These lamps are generally loeated from . 5 to 12 inehes (1. 3 to 31 em. ) above the surfaee of the substrate bearing the UV curable material and it is clear that substantial quantities of this heat (that is, infra-red radiation) are transmitted to the substrate. Attempts to cure I~V curable eompositions printed or coated on heat sensitive substrates such as thin paper, textiles ancl the like have not been sueeessful beeause oL the attendant damage (shrinking, warping, seorch-ing, melting) to the substrate.
DESCRIPTION OF T~IE INVENTION
_ _ .
It has no~ been found that radiation eurable materials, particularly those that polymeriæe, crosslink or cure via a free radical mechanism, can be successfully irradiated in the presenee of steam to provide dry~ high gloss, tacl; free curccl 7~
products; further, steam will transmit those forms of radiation effective to cure a variety of polymerizable, curable or crosslinkable compositions while at the same time absorbing inEra-red radiation. The invention is practiced most simply by blanketing a radiation curable composition with steam prior to and during irradia-tion.
The steam can come from any convenient source; since low pressure steam, at atmospheric pressure or slightly elevated -- Lor example up to about 5 PSI -- is preferred, the steam can be that available at most plants or can be easily produced by a conventional steam generator. The use of steam injectors or one or more air l~lives to distribute the steam over the surface of the substrate being printed or coated is a conventional expedient and need not be discussed in detail.
The steam should be superheated; by this it is meant that the steam should be heated to a temperature sufficiently high that it does not condense on the substrate ~ulder the conditions of use.
The use of steam thus provides three important advantages. First, it dis-places or otherwise reduces the oxygen content of the atmosphere surrounding the racliation curable composition so that high gloss coatings can be obtained. Steam is thus an effective inerting medium. Second, it absorbs infra red radiation so that the temperature of the substrate being printed or coated remaills at aul acceptable level.
Steam is thus all eLfective cooling medium. I~inally, steam is readily available at virtually every industrial enterprise in the world. Steam is cheap.
This combination of inerting and cooling properties with ready availability cmd low cost represents a substantial irnprovement over tl~e state of the art and makes such irradiation teclmology as UV curing available to industries such as the paper, textile culd printing-on-plastics industries, where UV curing is not now utilized be-cause of the disadvantages provided by the high cost and heat associated with the present state of the art.
Radiation curable materials useful herein can be coated, printed or laminated to a greater variety of substrates than was previously useful.
Thus, there can be used the relatively heat-resistant substrates currerltly in ;27~;
use such as glass, ceramic cmd metal as well as the lamin~tes usecl in the printed circuit board incl-lstry. These substrates are used in a variety of rorms inclucling wires, rocls, sheets, panels, ilms, abrics, cylinders, bottles and colltaincrs.
There can also be used various plastics in the form of wires, rocls, sheets, panels, films (including laminates of diferent plastics) fabrics (woven, non-woven and tuftecl -~ A-~32~
bottles and similar containers. These plastics include the thermost plastics such as phenolic, epoxy, polyester, polyurethane and polyimide. Now, these plastics also inclucle the well-known therrnoplastic materials based on the homopolymers and copolymers of ethylene, propylene, butylene, butadiene, styrene, acrylonitrile, vinyl cllloride, vinylidene chloride, vinyl acetate, vinyl methyl ether, allyl alcohol, vinyl pyrrolidone, vinyl alcohol, vinyl butyral, vinyl carbazole, acrylic acid, methyl acrylate, ethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, acrylamide, N, N-dimethyl acrylamids, methacrylamide, caprolactone, ethylene glycol, propylene glycol, terephthalic acid, adipic acid, caprolactam, ethylene oxicle, propylene oxide, siloxane, isocyanate, sulfone, phenyl sulfone, phenylene sulfide, phenylene carbonate, phenylene ether, phenylene oxide, acetal, etc.
There can also be used the various natural and modified natural products such as gutta percha, sill~, wool, cotton, cellulose acetate, methyl cellulose; there can be used wood and various woody materials and paper, includ;ng newsprint, tag stock, parchment, cardboard, bag stock and the like.
The radlat~on curable material can be applied to the substrate in a thickness ranging from O! 01 to more than 100 mils; the thickness will depend on the ultimate use of the product. Thicknesses of 0.2 to 2 mils are conventional.
The invention described herein can be used to polymerize, cure or crosslink radiation curable compositions containing at least one component having an ethyleni-cally unsaturated group capable of polymerization, curing or crosslinking via a free-radical initiated mechanism.
In many instances the radiation curable compositions will produce solid, dry products upon exposure to suitable radiation without the addition of any photosensiti-zer, activator, catalyst or initiator. When it is desirable to use a photosensiti~er, activaeor, catalyst or initiator, as is frequently the case with UV curable systems, they can be used singly or in combination, with the total amount varying from 0. 01 to 20 percent by weight of the composition; 0.1 to 5 percent is a prererred range.
Synergistic effects are observed with some combinations.
The general classes of photosensitizers include azo compounds, dyes, sulfur-containing compounds, metallic salts and complexes, oximes, polynuclear compounds, peroxides, various hologen-containin~ compounds and carbonyls. For coatings ancl 27~
., ~
inlcs the benzoill ethers, benæophenone and benzophenone-Michlers l~etone combinations are ~videly usecl.
Alllong the sensitizers, the aromatic carbonyl compounds are quite important;
there are included benzoin ancl the benzoin ethers including ben~oin methyl ether;
benzoin ethyl ether; benzoin allyl ether; benzoin propyl ether; benzoin isopropyl ether;
benzoin butyl ether; benzoin isobutyl ether; benzoin sec-butyl ether; benzoin thiophenyl ether; benzoin amyl ether; benzoin hexyl ether; benzoin oc-tyl ether; benzoin 2-ethylhexyl ether; benzoin nonyl ether; benzoin trimethyhexyl ether; ben~.oin diethyl ether; benzoin phenyl ether; hyclroxyethyl benzoin ether; ethylene glycol benzoin ether; 2-chloroethyl-I)enzoin ether; benzoin isobutoxymethyl ether; a-alkoxybenzoin ethers; benzoin carbamates;
benzophenone and derivatives of benzophenone including "Michler's Ketone"
4,1'-Bis(dimethylamino) benzophenone; p,p'-diaminobenzophenone; 4-(dimethylamino) benzophenone; p-clichloromethylbenzophenone; p-chlorobenzophenone; ~, 4'-bis (bromome-thyl) benzophenone; p-hydroxybenzophenone; 2-hydroxy-~-methoxybenzophenone-5-stllfonic acid; p-acryloxybenzophenone; o-methoxybenzophenone; p-methoxybe~zophenone; glyciclyl ethers of benzopllenone; vinyl-substituted benzophenone; 2-isopropenylbenzophenone;
monocar~oxyl-substituted benzophenone; polycarboxyl-substituted benzophenone;
p-nitrobenzophenone; m-benzophenonesulfonyl chloride; p-p'-bis(dimethylamino) thio-benzophenone; phenlthiomethylbenzophenone; benzylthiomethylbenzophenone; benzopina-colone; ~nthrone; benzanthrone; benzathronesuIfonyl chloride; ~3-fluorenone; hydroxy-fluorenones; amino1`1uorenones; 2-bromoethyl-9-fluorenonesulfonyl chloride; dibenzo-suberone; l-chloromethyl-6-chlorosulfonyl-2-naphthylphenyl ketone; n-methylacridone;
poly(vinyl benzophenone;
monoaryl ketones including acetophenone; chloroalkylphenyl ketones; o-methyl~ce-tophenone; a-bromoacetophenone; ortho-bromoacetophenone; trichloroacetophenone;
trichloroethylidineacetophenone; 2-2-dichloro-4'-tertiary-butylacetophenone; 2,2,2-trichloro-4'-tertiary-butylacetophenone; a-bromoisobutyrophenone; 2,2-dibromo-2(phenyl-sulfonyl) acetophenone; a,a-dialkoxyacetophenone; 2,2-clirnethoxyacetophenone; 2,2-dimethoxy-2-phenylacetophenone; 2, 2-diethoxyacetophenone; o-methoxyacetophenone;
m-methoxyacetophenone; p-methoxyacetophenone; 2-butoxy-2-phenylacetophenone;
2-phenylthio-2-pllenylcLcetophenone; ethyl bcn7,0ylacetate; pcara-aminophenyl ketones;
cyclohexylphenyl ketone; pivalophenone; vak~:rophenone; acetonaphtllolle;
- dilietones inc~ucling biacetyl; benzil climethyl l~etal; 2, 3-dibenzoyl-2-nol:bornene;
benzoylbenzal chloride; 2, 2-dibromo-2-(phenylsulfonyl) propanec~ione; a-naphthil;
2, 3-butaneclione; benzil; pentanedione; l-aryl-l, 2-propanediones; 2, 3-bornanedione;
phenylpyruvic acid; 2, 4-pentanedione;
xanthone and thioxanthenones includin~ 3, 6-bis(dimethylamino) thioxanthenone;
2 -chlorothioxallthenone;
thiol~etones including thiobenzophenone; p, p'- dimethoxythiobenzophenone;
p, p' -bis (dimethylElmino) thiobenzophenone;
sulfur containing compounds such as n-dodecyl mercaptan; 2-mercaptobenz,imi-dazole; diphenyl sulfide; cyclohexlphenylsulfide; benzoin thioethers; benzoin thiophenyl ether; phenylthiomethylbenzophenone; s, s'-diphenyl dithiocarbonate; calcium sulfide;
metallic selenides; metallic tellurides; diaryl disulfides; diphenyl disulfide; clithiolane;
dibenzoyldisulfide; dixanthate; benzothiazoles; 2,2'-dithiobis(benzothiazole); 2-mercapto-benzothiazole; thiazolines; thiocarbamates; dithiocarbamic esters; dithiocarbamic anhydrides; thiurams; toluene sulfonic acid; sulfonyl chlorides; m- (chlorosulfonyl)benzyl chloride; naphthalenesulfonyl chloride; 2-bromoethyl-9-fluorenonesulfonyl chloride;
2,2-dibromo-2(phenylsulfonyl) acetophenone; 2,2-dibromo 2(phenylsulfonyl) propanedione;
benzophenonesulfonyl chloride; diphenyl disulfone;
oximes including o-acyloximes; l-phenyl-1,2-propanedione-2-o-benzoyl oxime;
oxido-oxazole; benzylmonooime; biacetyl monooxime phenylcarbamatc;
azo and azido compounds including 2,2'-azobisisopropane; azobis-isobutyronitrile;
2-phenylazobisisobutyronitrile; azobisisobutyramide; azobis (isobutyl acetate); di-(2,4,6-tribromopbenyl)-4,4'-azobis(4-cyanovalerate); p-azidobenzaldehyde; b-napht~alenesulfonyl azide; diazomethane; bis(phenylsulfonyl) diazomethane; diazonaphthalenes; cliazothioethers;
quinone diazides; m,m'-azoxystyrene;
imidazoles including benzimidazoles; 2--methylbenzirnidazole; 2-mercaptol)enzimi-dazole; triphenyl-irmidazolyl dimers;
amines including triethylamine; n, n-dimethylbenzylamine; methylcliethanolamine;
ethyldiethanolamine; triethanolarnine; p-nilro aniline; n-acetyl-4-nil;ro-:l-naphthylamine;
ami-noanthraquinone;
ammonium salts such as bipyriclylilml sall; henzyltLimethylammonium chloride;
diazonium salts;
7~
halogenated organic compoullds such as chloroform; bromoform; iodoform;
carbon tetrachloride; carbon tetrabromide; ethylene dichloride; trichloroethylene;
trichloroethalle; bromotrichloroethalle; vinyl bro-mide; l, 2-dibromotetrafluoroethane;
iodoethane; diacylhalomethane; hexachloroethane; tetrachloroethane; hexachlorobenzene;
o-dichlorobenzene;
polynuclear compounds including napththalene; halogenated naphthalenes; 2, 3, 6-trimethylnaphthalene; a-naphthol; l-aminonaphthalene; l~methoxynaphthalene; 2, 3-diphenyl-quinoxaline; anthracene; aminoanthraquinone; phenanthrene; naphthacene; fluorene;
9-fluorenone; stilbene; trinitrofluorenone; polynuclear quinones;
useful quinones include p-benzoquinone; o-benzoquinonediazide; anthraquinone;
alkylantllraquinones; 2-methylanthraquinone; 2-ethylanthraquinone; 2-tertiary-butylan-thraquinone; 2-chloroanthraquinone; aminoanthraquinone; l, S-diaminoanthraquinone;
piperidlno-anthraquinones; anthraquinonesulfonyl chloride; benzanthraquinone; 1-4-napthoquinolle derivatives; phenanthrenequinones; a-chloroanthraquinone;
the metal salts and complexes include zinc chloride; zinc b~omide; zine sulfide;ferrie ehloride; chromium chloride; nickel chloride; tin chloride; stannous chloride;
vanadium tetrachloride; vanadium oxychloride; vanadium naph~henate; aluminum chloride;
aluminum bromide; aluminum iodide; silver halides; gold salts; sodium chloraurate;
mercury salts; mercury iodosulfide; titanium tetrachloride; cadmium sulficle; boron trifluoride; borou trichloride; ceric salts; thallium salts; uranyl salts; cobalt octoate;
cobalt naphthenate; magnesium oxide; zinc oxide; titanium dioxide; alumina; cupric oxide; chromium oxide; silver oxide compounds; metal ehelates; metal amine complexes;
cobalt edta complexes; iron edta complexes; metal acetylacetonate; mang,anese tris (acetylacetonate); metal salt-saccharic1e complexes; metal oxalato complexes; p-benzo-quinone complexes; copper (I) complexes; manganese carbonyl; rheniurn carbonyl;
osmium carbonyl; iron carbonyls; metal thiocarbonyls; trialkylaluminum; d;ethylalumi-num chloricle; triphenylmethyldiethyltitanium chloricle; bis (~,-chloroethyl) diethyltitanium;
tetrabenzyltitanium; ~errocene; cyclopentadienylmanganese tricarbonyls;
useful peroxides inclucle hydrogen peroxide; benzoylperoxide; tertiary-butyl peroctoate; t-butyl a-cyanoperacetate; t-butyl hydroperoxide; di-t-butyl peroxic1e;
cumene hydroperoxide; a-curnyl peroxicle; er~,rosterol peroxide; fluorenone llydroperoxic1e;
acetyl peroxide;
clyes that are userul include acridines; benzacridine; ben~idines; b-carotene;
chlorophyll; crystal violet; eosin; erythrosine; fluorescein; indanthrene yellow; irga~in yello~,v; metllyl violet; methylene blue; pyronine-G; rhodamines; riboflavin; rose bengal;
thiazine clyes; thionine; xanthene dyes; xanthophyll; iodoeosine;
The radiation curable compositions that can be polymerized, cured or cross-linked in accordance with this invention are those having at least one polymerizable ethylenically unsaturated &roup of structure Of these materials, one important class is characteri7.ed l~y the presence of at least one acrylyl or methacrylyl group of formula R O
CI12=1 -C -where R is hydrogen or methyl. Monomers, polymers, oligomers and compositions whose functionality is attributable to the presence of acrylate and/or methacrylate groups include acrylic acicl, methacrylic acid, acrylamide, methacrylamide, methyl aerylate, methyl methacrylate, ethyl acrylate, etbyl methaerylate, hexyl acrylate, cyelohexyl methacrylate, 2-ethylhexyl acrylate, butoxyethoxyethyl ac rylate, bicyclo [2.2.1] hept-2-yl acrylate, dicyclopentenyl acrylate, isodecyl aerylate, ethylene diacrylate, diethylene glycol diacrylate, glycerol diacrylate, glycerol triacrylate, ethylene dimethaerylate; ethylene glyeol diaerylate, ethylene glycol dimethacrylate, 1,2,4-butanetriol trimethacrylate, 1,ds-benzenediol dimethacrylate, 1,4-eyclohexanediol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, tetraethyleneglycol diaerylate, pentaerythritol mono-,di-,tri~or tetracrylate or mixt-lres thereof, pentaerythritol tri-or tetramethacrylate, 1,5-pentanediol climethacrylate, trimethylol propane mono.-di-, or triacrylate or mixtures thereor, 2-phenoxyethyl acrylate, glycidyl aerylate, 2~tl~xyethyl acrylate, 2-methoxythyl acrylate, 2-(n, n-diethylamino) ethyl acrylate, omega-methoxyethyl (hendecaoxyethylene) acrylate, omega-tridecoxyethyl (llendecaoxyethylene) acrylate, trimethoxya]lyloxymetllyl acrylate, I)icyclo [2. 2. 11 hept-2-en-5-ylmethyl acrylate, bicyclo [2.2.1] hept-2-en-5,6-diyl diacrylate, vinyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl acrylate, (rnethyl carba-myl) ethyl acrylate and the bis-aerylates ancl methacrylate of polyethylene glycols o~ molecular weight 200-1500.
One gro~p of acrylyl and melhacrylyl estors that are paLtic~ rly usorul have the geneL al formula M H
CM2=C--COOM' or (CH2=C--COO)rG.
Wllere the acrylyl compound has tbe formula M
CH2=C--COOM' M is H or Cl M is cyeloallcyl of 5 to 12 carbon atoms (such as cyclopentyl, dieyclopentyl, methyclyclopentyl, dimethylcyclopentyl, ete. ) cyeloalkenyl of 5 to 12 earbon atoms (such as cyclopentenyl, methylcyclo-pentenyl, dicyclopentenyl, bieyelo ~2. 2.1] hept-2-en-yl, etc. ) --Cp H2p M" or (Cq H2q )s Ccl H2q ~1 ;
where p is an integer Erom 1 to ` 10 q is an integer from 2 to 4 s is an integer from 0 to 4 M" is hydrogen, hydroxyl, phenoxy, alkoxy of 1 to 8 carbon atoms;
and where the aerylyl eompound has the formula H
(C~I2=C--C)r G
G is a polyvalent alkylene group of formula _CX EI2x-y--in whieh x is an integer from 2 to 8 _ is an integer from 0 to 2 (for example, divalant alkylene when y= O such as--C2H~ , C3HG
iso~C3HG ,--C6H1o--, neo~CGH12 etc; trivalent allcylene whell y-] sueh as fI12 fEI2 CH2--CH~CH2~, CH3CH2 C CH2 , IIO CI[2--f -CII
CH~ CI-12 or tetravalent alkylene when y is 2, such as I H2-- --CH2 ~CH2--~CH2_f--CH2-- and C~I CH2 CH
CH2-- --C~I2 Cl:I2--etc.) or G is a clivalent ether or ester group ot formula ~(CcL H2q )t Cq H2q or --(Cq H2q C)t Cq H2q where t is an integer from 1 to 5 and cl is an integer from 2 to a~
(such as oxyethylelle, oxypropylene, oxybutylene, polyoxyethylene, polyoxypropylene, polyoxybutylene, ete. ) and r is the valence of ~ and can be 2 to 4.
Triethyleneglycol diacrylate, tetraethylene glycol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate and pentacrythritol tetraacrylate are especially useful.
Aerylate or methacrylate functionality can be incorporated in polymers and oligomers having carboxyl, hydroxyl oxirane or isocyanate groups via reaction with acrylic monomèrs. Addition reactions of isocyanates to rorm urethanes or oxiranes to form esters are relatively straightforward. Other methods of acrylation involving eondensation or ester interchange reaotions are well known.
Thls, there can be used epoxy acrylates obtained by reacting an epoi~y resin with acrylic or methacrylic acid or obtained by reacting a hydroxyalhyl acrylate with an anhydride and reacting that product with a diepoxidé. Oils, such as soybean oil and linseed oil, can be epoxidized and acrylated.
Polyester resins, for example rrom a glycol-dibasic aGid condensation, can be aerylated by using acrylic or methacrylie aeid to eomplete the esterification.
, Another method uses the reaction of an anhydride with a mixture oE propylene oxide and glyeidyl aerylate to obtain an acrylated polyester.
Acrylated alkyci reslns are obtained by the reaction of, for example, a triol, dibasic acid, phthalic anhydride and a fatty acid such as hydrogenated castor oil.
After reaction is eomplete aerylation is aehieved by direet esterifieation with acrylic acid.
227~
Urethane acrylates can be prepared directly by the reaction of a cliisocyanate with an hyclroxyalkyl acrylate, such as ~-hyclroxyethyl acrylate. Oli~omers are ob-tained by using an isocyanate-terminated urethane prepolymer for reaction with the hydroxyalkyl acrylate. The urethane prepolymer can be of the polyether or polyester type.
Acrylate functionality can be incorporated in a variety of polymer backbones by incorporating glycidyl methacrylate into the polymer chain and then reacting the pendant oxirane groups with acrylic or methacrylic acid.
Other radiation curable systems are based on unsaturated polyesters such as are obtained from fumaric acid, D~ stilbenedicarboxylic acid, moleic acid, and cliallyl ether.
Cilmamate ester groups are also useful, for example in a polyvinyl alcohol--cinnamate ester combination and in conjunction with a variety of polymer materials:
polycarbonate cinnamate; polyurethane cinnamate; cinnamyliclene--malonate copolyesters;
bisphenol A-furmarate polyester-cinnamate; cinnamyl-modified poly(meth) acrylates;
polyepichlorohyclrin/cinnamate; poly(cinnamyl methacrylate); epoxy cinnamylidene acetate; carboxyeinnamate modified polyesters;
Radiation curable materials are also obtainable from the 2-phenylmoleimido group, allyl ester moleimide combinations, allthioether polymers, aromatic polysulfone polymer, polysiloxanes, eholcones, sorbic acid derivatives, itaconic acid derivatives and mixtures containing itaconic acid; polyuinyl alcohol, polyvinyl acetate, polyvinyl butyral.
~ nother radiation curable polymer system is based on the free-radical acldition of a thiol to an olelinic clouble bond:
R-SII ~ CM2=CHR' 3R-S-CM2-CI-12 R' When a polyene and a polythiol are admixed and a stimulus that generates free-radicals is present, rapid curing occurs by simultaneous chain extending and crosslinls-ing reactions.
Other crosslinkable, polymerizable or curable materials include the nitriles such as aerylonitrile and inethaerylonitrile; the olefins sueh as dodecene, styrene, 4-methylstryrene, alphamethylstyrene, cyclopentadiene, dicyclopentadiene, butacliene, l,D~-hexadiene, ~-mel;hyl-1-pentene, bicyclo[2.2. LJ hept-2-ene, bicyclo[2.2. L~ hept-2,5-diene, cyclohexene; the vinyl halicles such as vin5tl chloricle, vinylidene chloricle;
the vinyl esters such as vinyl acetate, vinyl butyrate, vinyl benzoate, v;nyl butyral, vinyl methacrylate, vinyl hepto, vinyl c rotonate; the vinyl ketones such as vinyl metllyl l~etone, villyl phcnyl ketone, ;sopropenyl methyl Icetone, clivinyl l;etonc, alplla-chloro-v;nyl rnethyl ketone, vinyl phenyl ketone; acrolein and methacrolein; the vinyl ethers and thioethers such as methyl vinyl ether, ethyl vinyl ether, divinyl ether, isopropyl vinyl ether, the butyl vinyl ethers, 2-ethylhexyl vinyl ether, vinyl 2-chloro-ether, vinyl 2-methoxyethyl e-ther, n-hexadecyl vinyl ether, vinyl methyl sulfide, vinyl ethylsulfide, clivinyl sulricle, l-chloroethyl vinyl sulfide, vinyl octadecyl sulf;de, vinyl 2-ethoxyethyl sulfide, vinyl phenyl sulfide, d;allyl sulfide; the miscellaneous sul~ur and nitrogen containing monomers such as divinyl sulfone, vinyl ethyl sulfone, vinyl sulfonic acicl, vinyl ethyl sulLoxide, sodium vinyl sulfonate, vinyl sulfonarnide, vinyl pyridine, N~v;nyl pyrollidone, N-vinyl carbazole. Other curable materials are read;ly apparent to one skillecl in the art of polymerization chemistry. The specific compounds mentioned are illustrative only and not all-inclusive. ~hey can be poly-merized alone or in mixtures of two or more thereof with the proportions thereof dependent upon the desire of the individual. They can also be blended with polymers.
Among the polymers that can be used one can include, for example, the polyolefins and modified polylefins, the vinyl polymers, the polyethers, the polyesters, the polylactones, the polyamides, the polyurethanes, the polyureas, the polysiloxanes, the polysulfides, the polysulfolles, the polyformaldchydes, the phenolformaldehyde polymers, th~e natural and modified natural polymers~ the heterocyclic polymers.
The term polymer as used herein includes the homopolymers and copolymers alld includes the olefin polymers and copolymers such as polyethylene, poly(ethylene/
propylene), poly-(ethylene/norbornadiene), poly(ethylene/vinyl acetate), poly(ethylene/
vinyl chloride), poly(ethylene/ethyl acrylate), poly(ethylene/acrylonitrile), poly(ethylene/
acrylic acid), poly(ethylene/styrene), poly(ethylene/vinyl ethyl ether), poly(ethylene/vinyl methyl ketone), polybutadiene, poly(butadiene/styrene/acrylonitrile), poly(vinylchloride), poly(vinylidene chloride), poly(vinyl acetate), poly(vinyl methyl ether), poly(vinyl butyral), polystyrene, poly(N-vinyl~carbazole), poly(acrylic acid), poly(methyl acrylate), poly (ethyl acrylate), polyacrylonitrile, polyacrylamide, poly(methacrylic acid), poly(metllyl methacrylate), poly(ethyl me~hacrylate), poly(N, N~-climethyl acrylamicle), poly(methacryl-amide), polycaprolactone, poly(caprolac~one/vinyl chloride), poly(el;hylene ~;lycol 2~
terephtllalate), poly(captolactam), poly(ethylene oxide), poly(propylene oxide), copoly-mers of ethylene o~i~e ancl propylene oxicle with startcrs conlaini n~ reac~ c hyclrogen atoms such as the mixed copolymer using ethylene glycol or flycerol or sucrose, etc., as starter, the natural and mocdidied natural polymers such as Kutta percha, cellulose, methyl cellulose, starch, silh, wool, ancl the s~iloxane polymers ancl copolymers, the polysulficles ancl polysulfones, the formalclehyde polymers such as polyformaldehyde, formalclehyde resins such as phenol-formaldehy~e, melamineformaldehyde, urea-formald-ehyde, aniline-formalclellyde and acetone formaldehyde.
The compositions that are treated by this invention can contain any of the known pigl~lents, ~illers, stabilizers, polymers or other aclditives conventionally addcd to coat;ng compositions in the cluantities usually employed; provided, however, that they are not employed in such quantities as will unduly interfere or prevent the curing or crosslinldng ancl that the polymers are clissolvecl or dispersed therein. It is known that some pigments and fillers for example, can be used in small arnounts but that they prevent the reaction from occurring when they are present in~large amounts because they absorb for example light energy and ultraviolet light cannot penetrate iJltO the interior of the mixture and cure it completely; therefore, such materials should be used within the quantity ranges that will permit the reaction to proceed properly. In some instances, however, the amount that can be used is less than usu~l in order that the filler or colorant not unduly interfere with the ability of the ultraviolet radiation to penetrate below the surface of the coating and prevent CUl'illg or crosslinking from occurring. These principles are known to those skillecl in the art of radiation ehemistry and do not require exterlsive discussion or elaboration, the same is true for the particular materials that can be used.
~2~
The invelltion is illustrated by the following examples:
EXAMPLE l A metal hood was constructed containing sixteen 1 jO00-watt mercury vapor lamps; the lamps were provided w;th aluminum rclectol s. Supcrllcltccl StCL1n1 (atmospheric pressure) was injectecl into the hoocl. A web of paper, 2 mils thick (.002" or 5.080 ~c 10 cm) was coated with a UV-curable composition, as inclicatecl below, to a thickness of about 0.2 mil (.0002" or 5.08 x 10 ~cm) and introduced into the hoocl; the distance between the paper and UV lamps was about 3/-i inches (1. 9]. cm).
The papel and coating were run at a speed to provide an exposure time to the UV
lamps of (; seconds. The paper emerged from the hood with the UV curable composi-tiOll EuLly cured to a harcd, dry, tack-free, glossy coating; the paper showed no sign of curling, warping, shrinking or the like.
Component Parts by Weight Polyester Binder 30 1, 6-hexanediol diacrylate 65 Dietho~yacetophenone a~
~lodaflo~Y
(1) a condensation polymer of propylene glycol and~
moleic and isophthalic aclds having a molecular weight Or about 5, 000 and an acid number of about 10;
(2) a resinous hydrooarbon l1ow eontrol agent from Monsanto Chemical Co.
It should be noted that an exposure perlod of ~ seconds is quite slow by paper industry standards, whore sl~ec(ls in (3XCCSS ol' 1, 000 reet l~eI' minutc (305 meters/min) are realized in printing ink on newsprint. In paper mills, line speeds on the order of 900 feet/lYIin. ( 122 meters/min) are more common. Thus exposure periods to the UV source can be from a fraction of a second to severaL seconcls.
Other factors to be consiclered in determinin~ the exr~osure tinle inclucle the thickness of the coating being used (typical thicknes.s are fronl 0.1 mil to 1 mil or even more) 2~;
ancl the reactivily Or the cur~ible coml~osition. In this l~ltter respect, it might l~e noted that UV eurable compositions formulated to eure in air will eure faster in an atmosphcre Or steam.
While a 2 mil paper substrclte and a 0. 2 rnil eoating werc not arfectecl by t:he heat producecl, from si~;teen 1, 000-watt mercury vapor lanlps, at a distance oE
3/~Linch (1.91 cm) for G seconds hecause of the effects of the s~eaml a question was raised coneerning extended exposure Or a heat sensitive substrate to the heat produced by the UV lamps; for example, could a line be stopped for extended periods without injury to the substrate caused by the heat from the UV lamps. The paper web of Example 1, a~ter being coated with the curable composition of that Example, was introduced to the hood and stopped under the UV lamps while the steam llo~ continued.
After a period of ten minutes of continuous exposure the paper was removed and e~amined; there was no clisco]oration, charring or other evidence of an advelse effect from the heat of the UV lamps.
E XAM PI. E 2 UV curable compositions prepared according to the following formula-tions, coated on thin paper and cured aecording to example 1, provide high gloss, taek-free coatings.
Components Composition, Parts by ~Veight II III IV V
PCP( ) 36.2 - - _ EPOA( ) a~. 8 'L. 5 E. D. (e) 16. 2 57. 0 5a,;. 559 . 5 47. 6 NPGDA( ) 1a~. 2 ] 8.1 17. 3 19 . 019. 0 HEA(e) 1~L. 2 9. o 8.1 9. 59 . 5 DCPA( ) 9.6 6.9 15.2 7.2 -L9.0 Sensitizer( ~1. 8 'L. 5 'L. 3 ~L. 84. 9 (a) 80% solutiorn of Union Carbide PCP-0300 polycaprolactone/toluene diisoeyanate oligomer in 20% hydro~yethyl aerylate (b) polyaerylate ur epo~siclizecl soya bean oil available rrom IJnion Carbide (c) epo~y diacrylate-reaction prod~ct o~ an epichlorohydrin/bispllenol A-type epoxy resin witll a stoichimetrie amo~lnt Or acrylic acid.
-l~-,76 (d) neopentyl glycol diacrylate (e) hydroxyethyl acrylate (f) clicyclopentenyl acrylate (g) ~. 5 parts benzophenone/0. 5 parts Michlers Ketone E:XAMPLE 3 Wllen the following ink composition is applied to a paper substrate and cured in the presence of steam in accordance with the conditions o~ Example 1, there is obtained dry, tack free printed paper.
Parts by Weight EPD~ (see E~iample 2) 55. 3 Ultraflex Microcrystalline WCLY 3.1 Pentaerythr;tol Tetraacrylate 27. 4 Benzophenone 4. 5 Michler's I~etone . 50 Phthalocyanine Blue Pigment 9. 2 A UV curable composition of the ene/thiol type is prepared as follows:
751 g. (0.38 n~ole) of a commercially available poly-(propylene ether) glycol sold under the tradename "Pluracol P 2010" by Wyandotte Chemical Co. are clegassed at room temperature for 3 hours and then charged to a dry resin kettle maintained under a nitrog~en atmosphere and cquipped with a condenser, stirrer, thermometer and gas inlet ancd outlet. 132 g. (0. 76 mole~ of tolylene - 2, 4 - diisocyanate are chargecl to the kettle and the kettle was heatecl for 2 hours at 120 C. with stirring under nitrogen.
After cooling 58 g. (l. O mole) of allyl alcohol are aclded ancl the mixture refluxed at 120 C. overnight. Excess allyl aloobol is stripped by vacuu-m overnight at 120 C.
The thus formed allyl terminated liquid prepolymer is representative of the ene component of an ene-thiol system.
A UV-curable composition has the following formulation Parts by Weight Allyl-terminatecd prepolymer 79.
Pentaerythritol tetrokis (B-mercaptopropionate) 15. 9 t~nh~n~n~ ~1. 7 7~
.
Wllen coated on paper and cured according to Example 1 in the presence of steam a dry coating is obtained. roug~h coatings are similarly obtained using Parts by Weight 1,2,4 - trivinylcyclohexalle 38 08 Pentaerytllritol tetrakis (B-mercaptopiopionate) 56. 07 Benzophenone 5 . 85 EX~MPLE 5 The composition of Example 3 is screened onto thin wh;te knit cotton Jersey and cured in the apparatus of Example 1 in the presence Or steam. Tack free, decorated jersey ;s obtained, with no damage to the substrate.
A red ink is prepared from Pa rts by Weight Pentaerythritol triacrylate 67 Arclor 1260( ) 9. 75 Samtolite MHP(2) 3. 25 Lithol Rubine Red pigment 20 (1) Monsanto Chemical Company's biphenyl containing G0% by weight chlorine (2) Monsanto Chemical Company's p-toluene sulfonamide~formaldehyde resin A glass bottle is printecl with this ink and exposed to UV light uncler the conditions of Example 1. A cured ink is obtained.
While glass is not normally considerecl to be heat sensitive in the same way as thin paper and textiles, glass bottles that have been screen printed with UV
curable inks and kept in close proximity to a UV source and the intense heat generated theroby, as could happon as the result Or a breakdown in solnc palt ol .a bott]lng plnllt, will begin to break. Here again, the use oL steam interposed between the UV source and the glass substrate will absorb the infra-red radiation and prevent damage.
It is noted that this invention, contemplating the use of steam to absorb infra-red radiation and as nn atmosphere In whlch IlV curah]e compositions are curecl, is independent of the speci~ic composition oi the UV curable composition or of the substratc
After a period of ten minutes of continuous exposure the paper was removed and e~amined; there was no clisco]oration, charring or other evidence of an advelse effect from the heat of the UV lamps.
E XAM PI. E 2 UV curable compositions prepared according to the following formula-tions, coated on thin paper and cured aecording to example 1, provide high gloss, taek-free coatings.
Components Composition, Parts by ~Veight II III IV V
PCP( ) 36.2 - - _ EPOA( ) a~. 8 'L. 5 E. D. (e) 16. 2 57. 0 5a,;. 559 . 5 47. 6 NPGDA( ) 1a~. 2 ] 8.1 17. 3 19 . 019. 0 HEA(e) 1~L. 2 9. o 8.1 9. 59 . 5 DCPA( ) 9.6 6.9 15.2 7.2 -L9.0 Sensitizer( ~1. 8 'L. 5 'L. 3 ~L. 84. 9 (a) 80% solutiorn of Union Carbide PCP-0300 polycaprolactone/toluene diisoeyanate oligomer in 20% hydro~yethyl aerylate (b) polyaerylate ur epo~siclizecl soya bean oil available rrom IJnion Carbide (c) epo~y diacrylate-reaction prod~ct o~ an epichlorohydrin/bispllenol A-type epoxy resin witll a stoichimetrie amo~lnt Or acrylic acid.
-l~-,76 (d) neopentyl glycol diacrylate (e) hydroxyethyl acrylate (f) clicyclopentenyl acrylate (g) ~. 5 parts benzophenone/0. 5 parts Michlers Ketone E:XAMPLE 3 Wllen the following ink composition is applied to a paper substrate and cured in the presence of steam in accordance with the conditions o~ Example 1, there is obtained dry, tack free printed paper.
Parts by Weight EPD~ (see E~iample 2) 55. 3 Ultraflex Microcrystalline WCLY 3.1 Pentaerythr;tol Tetraacrylate 27. 4 Benzophenone 4. 5 Michler's I~etone . 50 Phthalocyanine Blue Pigment 9. 2 A UV curable composition of the ene/thiol type is prepared as follows:
751 g. (0.38 n~ole) of a commercially available poly-(propylene ether) glycol sold under the tradename "Pluracol P 2010" by Wyandotte Chemical Co. are clegassed at room temperature for 3 hours and then charged to a dry resin kettle maintained under a nitrog~en atmosphere and cquipped with a condenser, stirrer, thermometer and gas inlet ancd outlet. 132 g. (0. 76 mole~ of tolylene - 2, 4 - diisocyanate are chargecl to the kettle and the kettle was heatecl for 2 hours at 120 C. with stirring under nitrogen.
After cooling 58 g. (l. O mole) of allyl alcohol are aclded ancl the mixture refluxed at 120 C. overnight. Excess allyl aloobol is stripped by vacuu-m overnight at 120 C.
The thus formed allyl terminated liquid prepolymer is representative of the ene component of an ene-thiol system.
A UV-curable composition has the following formulation Parts by Weight Allyl-terminatecd prepolymer 79.
Pentaerythritol tetrokis (B-mercaptopropionate) 15. 9 t~nh~n~n~ ~1. 7 7~
.
Wllen coated on paper and cured according to Example 1 in the presence of steam a dry coating is obtained. roug~h coatings are similarly obtained using Parts by Weight 1,2,4 - trivinylcyclohexalle 38 08 Pentaerytllritol tetrakis (B-mercaptopiopionate) 56. 07 Benzophenone 5 . 85 EX~MPLE 5 The composition of Example 3 is screened onto thin wh;te knit cotton Jersey and cured in the apparatus of Example 1 in the presence Or steam. Tack free, decorated jersey ;s obtained, with no damage to the substrate.
A red ink is prepared from Pa rts by Weight Pentaerythritol triacrylate 67 Arclor 1260( ) 9. 75 Samtolite MHP(2) 3. 25 Lithol Rubine Red pigment 20 (1) Monsanto Chemical Company's biphenyl containing G0% by weight chlorine (2) Monsanto Chemical Company's p-toluene sulfonamide~formaldehyde resin A glass bottle is printecl with this ink and exposed to UV light uncler the conditions of Example 1. A cured ink is obtained.
While glass is not normally considerecl to be heat sensitive in the same way as thin paper and textiles, glass bottles that have been screen printed with UV
curable inks and kept in close proximity to a UV source and the intense heat generated theroby, as could happon as the result Or a breakdown in solnc palt ol .a bott]lng plnllt, will begin to break. Here again, the use oL steam interposed between the UV source and the glass substrate will absorb the infra-red radiation and prevent damage.
It is noted that this invention, contemplating the use of steam to absorb infra-red radiation and as nn atmosphere In whlch IlV curah]e compositions are curecl, is independent of the speci~ic composition oi the UV curable composition or of the substratc
Claims (19)
1. In a process for printing or coating in which a sub-strate is coated or printed with a UV curable composition and thereafter exposed to UV radiation to cure the composition, the improvement which comprises interposing an atmosphere con-sisting substantially of steam between the UV source and the substrate to contact the UV curable composition.
2. The improvement of claim 1 in which superheated steam, at atmospheric or slightly above atmospheric pressure is blanketed over the UV curable composition.
3. The improvement of claim 1 in which the substrate is heat sensitive.
4. The improvement of claim 1 in which the substrate comprises paper, synthetic thermoplastic, cotton, wool, silk or rubber.
5. A method of coating or printing which comprises (a) coating or printing a substrate with a UV curable compo-sition comprising at least one ethylenically unsaturated component that polymerizes, crosslinks or cures via a free radical mechanism and at least one component that yields free radicals under the influence of UV radiation, (b) interposing an atmosphere consisting substantially of steam between a UV radiation source and the substrate to contact the UV curable composition and (c) exposing the substrate to UV radiation from said source to cure the UV curable composition.
6. The method of claim 5 in which the substrate is blan-keted with steam.
7. The method of claim 5 in which the substrate is heat sensitive.
8. A method of coating or printing on a heat sensitive substrate comprises (a) coating or printing the substrate with a UV curable composition comprising at least one ethylenically un-saturated component that polymerizes, crosslinks or cures via a free radical mechanism and at least one component that yields free radicals under the influence of UV
radiation, (b) blanketing the coated or printed product of step (a) with superheated steam and (c) exposing the coated or printed heat sensitive substrate to UV radiation through the steam blanket.
radiation, (b) blanketing the coated or printed product of step (a) with superheated steam and (c) exposing the coated or printed heat sensitive substrate to UV radiation through the steam blanket.
9. A method according to claim 8 in which the substrate comprises paper, cotton, wool, silk, rubber or synthetic thermo-plastic.
10. A method according to claim 8 in which the UV
curable composition contains at least one ethylenically unsatu-rated component selected from acrylyl and methacrylyl groups.
curable composition contains at least one ethylenically unsatu-rated component selected from acrylyl and methacrylyl groups.
11. A method according to claim 9 in which the substrate is paper.
12. A method according to claim 11 in which the sub-strate is newsprint, parchment, tab stock, bag stock, tag stock, or cardboard.
13. A method according to claim 8 in which the substrate comprises cotton, wool, silk, or other natural fiber.
14. A method according to claim 8 in which the substrate comprises synthetic thermoplastic.
15. In an irradiation process wherein there is irradiated a material that polymerizes, crosslinks or cures via a free radical mechanism, the improvement which comprises blanketing the material with an atmosphere consisting substantially of steam to reduce the oxygen content of the atmosphere surrounding the material during irradiation thereof.
16. The improvement of claim 15 in which the material contains an acrylyl or methacrylyl ester.
17. In an irradiation process wherein a substrate is irradiated with UV radiation, said irradiation providing appreciable heat to the substrate, the improvement which com-prises blanketing the substrate with an atmosphere consisting substantially of steam to reduce the heat transmitted to the substrate.
18. The improvement of claim 17 in which the substrate is heat-sensitive.
19. The improvement of claim 17 in which the substrate comprises paper, cotton, wool, silk, rubber or synthetic thermo-plastic.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US77423377A | 1977-03-04 | 1977-03-04 | |
| US774,233 | 1977-03-04 | ||
| US80613477A | 1977-06-13 | 1977-06-13 | |
| US806,134 | 1977-06-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1102276A true CA1102276A (en) | 1981-06-02 |
Family
ID=27118857
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA298,150A Expired CA1102276A (en) | 1977-03-04 | 1978-03-03 | Radiation curing in the presence of steam |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS53109579A (en) |
| CA (1) | CA1102276A (en) |
| DE (1) | DE2808931A1 (en) |
| FR (1) | FR2382278A1 (en) |
| GB (1) | GB1596827A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4975300A (en) * | 1987-12-31 | 1990-12-04 | Minnesota Mining And Manufacturing Company | Method for curing an organic coating using condensation heating and radiation energy |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5659645A (en) * | 1979-10-15 | 1981-05-23 | Ishizuka Glass Ltd | Decorating method for glass article |
| US4421782A (en) * | 1981-10-26 | 1983-12-20 | Armstrong World Industries, Inc. | Process for providing improved radiation-curable surface coverings and products produced thereby |
| US4420499A (en) * | 1981-10-26 | 1983-12-13 | Armstrong World Industries, Inc. | Process for providing improved radiation-curable surface coverings and products produced thereby |
| DE3318606A1 (en) * | 1983-05-21 | 1985-01-03 | Hansawerke Lürman, Schütte GmbH & Co, 2800 Bremen | METHOD AND DEVICE FOR HEAT-REGULATING |
| IE56391B1 (en) * | 1984-03-05 | 1991-07-17 | British Library Board | Treatment of archival material by graft polymerisation with monomer |
| US4507350A (en) * | 1984-03-08 | 1985-03-26 | Springs Industries, Inc. | Method of producing opaque printed textile fabrics with curing by free radical initiation and resulting printed fabrics |
| GB2180248B (en) * | 1985-09-12 | 1989-11-29 | British Library The | Treatment of archival material by graft polymerisation with monomers |
| DE3535954C2 (en) * | 1985-10-09 | 1994-05-26 | Schoeller Felix Jun Papier | Waterproof paper carrier for photographic recording materials |
| US4771078A (en) * | 1985-11-12 | 1988-09-13 | The Goodyear Tire & Rubber Company | Method of producing a foam from a radiation-curable composition |
| DE3630772A1 (en) * | 1986-09-10 | 1988-03-24 | Kaemmerer Gmbh | METHOD FOR ACCELERATING THE WHITE GRADE REGENERATION OF HEAT-TREATED PAPERS |
| EP0323061B1 (en) * | 1987-12-31 | 1993-07-14 | Minnesota Mining And Manufacturing Company | Method for curing an organic coating using condensation heating and radiant energy |
| ES2074351T3 (en) * | 1991-09-13 | 1995-09-01 | Ciba Geigy Ag | PROCEDURE FOR FIXING DYES WITH UV LIGHT. |
| JP4854859B2 (en) * | 2001-02-19 | 2012-01-18 | 株式会社クラレ | Surface modification method using ionizing radiation curable resin |
| NL1022165C2 (en) * | 2002-12-13 | 2004-07-15 | Tno | Muffle method and device. |
| CN106400545B (en) * | 2016-11-28 | 2018-09-21 | 江南大学 | UV resin stamp projection irradiation devices and algorithm |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT305604B (en) * | 1965-10-14 | 1973-03-12 | Chavannes Marc A | Method and device for coating a carrier material with a plastic solution or dispersion |
| US3520714A (en) * | 1966-12-28 | 1970-07-14 | Weyerhaeuser Co | Method of making a tack-free surface coating utilizing high energy radiation |
| FR2023759A1 (en) * | 1968-11-21 | 1970-08-21 | Continental Can Co | Coating articles with an olfin/unsaturated - acid copolymer |
| CA938915A (en) * | 1970-11-30 | 1973-12-25 | S. Miller Lewis | Curing of film surfaces by exposure to ultraviolet light |
| GB1386324A (en) * | 1971-07-21 | 1975-03-05 | Gen Electric | Method for coating substrates and apparatus employed in such method |
-
1978
- 1978-03-02 DE DE19782808931 patent/DE2808931A1/en not_active Withdrawn
- 1978-03-03 CA CA298,150A patent/CA1102276A/en not_active Expired
- 1978-03-03 JP JP2439978A patent/JPS53109579A/en active Pending
- 1978-03-03 FR FR7806172A patent/FR2382278A1/en not_active Withdrawn
- 1978-03-06 GB GB8853/78A patent/GB1596827A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4975300A (en) * | 1987-12-31 | 1990-12-04 | Minnesota Mining And Manufacturing Company | Method for curing an organic coating using condensation heating and radiation energy |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2382278A1 (en) | 1978-09-29 |
| JPS53109579A (en) | 1978-09-25 |
| DE2808931A1 (en) | 1978-09-07 |
| GB1596827A (en) | 1981-09-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1102276A (en) | Radiation curing in the presence of steam | |
| US5866628A (en) | Ultraviolet and electron beam radiation curable fluorescent printing ink concentrates and printing inks | |
| US3551311A (en) | Radiation-curable compositions | |
| DE69812468T3 (en) | An active radiation curable composition of a maleimide derivative and a method of curing same | |
| US4239866A (en) | Curable coating composition | |
| US4303696A (en) | Radiation curing of prepolymer coating compositions | |
| US4174307A (en) | Room-temperature-radiation-curable polyurethane | |
| US3926641A (en) | Photopolymerizable compositions comprising polycarboxysubstituted benzophenone reaction products | |
| US3989609A (en) | Radiation curable resistant coatings and their preparation | |
| US3713864A (en) | Method of printing or coating using actinic radiation setting of applied coating and coated product | |
| CN101925616A (en) | Photolatent amidine bases for redox curing of radically curable formulations | |
| US3551246A (en) | Radiation curable compositions | |
| US3551235A (en) | Radiation-curable compositions | |
| CA1106601A (en) | Register emboss and method | |
| DE2620309A1 (en) | RADIATION-CURABLE COATING COMPOUNDS, METHOD FOR THEIR PRODUCTION AND THEIR USE FOR THE PRODUCTION OF RELEASE COVERS | |
| US4961960A (en) | Photo-curable coating compositions | |
| DE69835773T2 (en) | Water-reactive energy-hardenable compositions containing mixed derivatives | |
| EP0632111B1 (en) | Coating process using radiation curable compositions | |
| DE1447029A1 (en) | Elastic, photopolymerizable material for making printing plates | |
| DE2651009A1 (en) | POLYDIORGANOSILOXANE COMPOUND THAT CAN BE CURED BY IRRADIATION | |
| JPS6390578A (en) | Ultraviolet curable paint composition | |
| DE2504335A1 (en) | MATERIALS POLYMERIZING UNDER THE EFFECT OF UV RAYS | |
| GB2326839A (en) | UV curable adhesive for stencil media | |
| USH304H (en) | Printing ink for use on flexible films | |
| JPS6042040B2 (en) | Method for manufacturing pressure-sensitive carbonless copy sheets using microcapsules formed in radiation-curable binder |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |