CA1222684A - Decorative laminate - Google Patents
Decorative laminateInfo
- Publication number
- CA1222684A CA1222684A CA000437866A CA437866A CA1222684A CA 1222684 A CA1222684 A CA 1222684A CA 000437866 A CA000437866 A CA 000437866A CA 437866 A CA437866 A CA 437866A CA 1222684 A CA1222684 A CA 1222684A
- Authority
- CA
- Canada
- Prior art keywords
- laminate
- article
- layer
- adhesive
- release layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B44—DECORATIVE ARTS
- B44C—PRODUCING DECORATIVE EFFECTS; MOSAICS; TARSIA WORK; PAPERHANGING
- B44C1/00—Processes, not specifically provided for elsewhere, for producing decorative surface effects
- B44C1/16—Processes, not specifically provided for elsewhere, for producing decorative surface effects for applying transfer pictures or the like
- B44C1/165—Processes, not specifically provided for elsewhere, for producing decorative surface effects for applying transfer pictures or the like for decalcomanias; sheet material therefor
- B44C1/17—Dry transfer
- B44C1/1712—Decalcomanias applied under heat and pressure, e.g. provided with a heat activable adhesive
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65C—LABELLING OR TAGGING MACHINES, APPARATUS, OR PROCESSES
- B65C9/00—Details of labelling machines or apparatus
- B65C9/20—Gluing the labels or articles
- B65C9/24—Gluing the labels or articles by heat
Landscapes
- Decoration By Transfer Pictures (AREA)
- Laminated Bodies (AREA)
Abstract
HEAT TRANSFER PAD DECORATION AND SUBSTRATES THEREFORE
ABSTRACT OF THE DISCLOSURE
A decorative laminate and method of transferring designs onto articles. The laminate is formed of a transfer substrate affixed to a support member. The transfer substrate is composed of a protective layer, an ink layer, and an adhesive/release layer. Optionally, a carrier layer is provided between the resinous layer and the ink layer. In many applications the protective coating layer may be omitted. The laminate is applied to an article using a heated silicone rubber transfer pad to which the transfer substrate adheres during the transfer process.
ABSTRACT OF THE DISCLOSURE
A decorative laminate and method of transferring designs onto articles. The laminate is formed of a transfer substrate affixed to a support member. The transfer substrate is composed of a protective layer, an ink layer, and an adhesive/release layer. Optionally, a carrier layer is provided between the resinous layer and the ink layer. In many applications the protective coating layer may be omitted. The laminate is applied to an article using a heated silicone rubber transfer pad to which the transfer substrate adheres during the transfer process.
Description
~22~6~
HEAT TRANSFER PAD DECORATION ANn SU13STRAT~S T~IEREFOR
BACK(~ROUNr~ OF TIIE~ IMVE:NTION
~_ _ __ _ 1. Field of the Invention __ The present invention relates to heat transfer decoration, as well as to the decoration of objects using a deformable pad. The invention further relates to the design of labels transferrable by these methods.
HEAT TRANSFER PAD DECORATION ANn SU13STRAT~S T~IEREFOR
BACK(~ROUNr~ OF TIIE~ IMVE:NTION
~_ _ __ _ 1. Field of the Invention __ The present invention relates to heat transfer decoration, as well as to the decoration of objects using a deformable pad. The invention further relates to the design of labels transferrable by these methods.
2. ~escription of the Prior Art A widely employed prio,r art method for imprinting designs onto articles using a heat transfer labelling process employs a paper base sheet or web coated with a label consisting of a release layer over which a design is imprinted in ink. In one successful technique of heat transfer decoration, labels of the above description are transferred to bottles or other articles using heat and pressure by feeding the article to a transfer site, where the preheated label-bearing web is impressed against the bottle to transfer the label. Patents illustrative of the above method and apparatus, commonly assigned with the present application, include U.S. Patent Nos. 2,981,432;
3,064,714; 3,079,97~; 3,20~,897; 3,231,448; 3,261,734; and
4,214,937. This decorating technique, w~ile highly successful in achieving high quality label transfer to bottles and similar articles, suffers certain limitations 2~ in the decoration of articles of unusual shape. Since the laminate is transferred directly to the article from a broad continuous web, the laminate lacks sufficient flexibility to conform to surfaces having compound or sharp curvature. The method is therefore not easily adaptable to imprinting objects having surfaces of compoun~ or irregular curvature or recessed panels.
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~ 2 ~
Another type of apparatus which possesses special advantages in the decoration of objects of unusual conformation is the so-called pad-transfer decorator.
This apparatus utilizes a deformable pad, typically comprised of a silicone elastomer. The pad receives an ink impression to be transferred to an article by pressing against an intaglio plate which had been previously coated with ink with any e~cess ink removed. The împression-bearing pad is then presse'd against the article to be labelled, to which it imparts the ink impression. The deformable pad is adaptable to a wide varie~y of article conformations. This decorative method and apparatus involves assembly-line equipment of a simpler design than the above-discussed heat-transfer decorators, and therefore re~uires fewer adjus.ments in retooling to articles of a va.iety of sizes and shapes. ~owever, this process only transfers one color of ink at a time, and is thus slow and cu~bersome if multicolored designs are required. Also, since there is no protective coating covering the ink design, it is left exposed directly to the environment upon transfer to the article.
U.S~ Patent ~o. 3,887,420 discloses the use of a silicone rubber p~d to transfer designs from a decorative Iaminate to ceramic articles. The laminate includes a base layer such as a paper sheet overlayed with a coating of wax. The wax coating is ~oated with a film layer (Fi-lm B), which in turn is overcoated with an ink design layer and a second film (Film A). As the laminate is heated to within a narrow ten degree temperature range, Film A is alleged to become adhesive while the wax coating and Film B become molten and nonadhesive. The transfer pad purportedly sticks to Film A when it is pressed against the laminate so that as the transfer pad is withdrawn, the ~2~ 68~
substrate composed of the paper sheet and wax coating separates from the remainder of the laminate. The laminate adhering to the transEer pad is pressed onto a ceramic article, and the temperature of the laminate is dropped to within a narrow ten degree temperature range. At this temperature, Film B becomes adhesive and Film A is alleged to exhibit diminished adhesion.
Thus, as the laminate is pressed onto the article with Film B
contacting the article, the laminate is alleged to adhere to the article and released from the transfer pad as the pad is withdrawn.
The film layers A and B are each adhesive over only a very narrow ten degree temperature range, making it imprac-ticable to control the described process within the context of an automated process, since each Eilm layer must in turn be heated or cooled to within the required ten degree temperature range to make the process workable. Precise heating or cooling of Film A
and Film B to within such narrow temperature ranges is impossible to achieve or control within the split second time intervals required by an automated assembly process. This reference does not disclose the use of an independent pad heater, nor details of pad composition, surface texture, or other parameters important to its implementation. Furthermore, the inclusion of a wax layer to form part of the decorative substrate has the disadvantage that as the substrate is released from Film B there will be a strong tendency for a portion of the wax to remain attached to Film B. This will interfere with the adhesive characteristics of Film B as the laminate is transferred from the transfer pad to an object.
122268~
U.S. Patent No. 3,616,176 discloses a heat transEer laminate of a type related to that disclosed in U.S. Patent 3,616,015. In U.S. Patent 3,616,176 the laminate is composed of a base sheet, with a polyamide layer covering the base sheet and a decorative ink layer covering the polyamide layer. Sufficient heat is applied to the laminate to heat the polyamide layer at or above its softening point, and the laminate is then pressed onto the surface of an article with the decorative ink layer coming into direct contact. Upon withdrawal of the heat source, the polyamide layer cools LO a temperature below its softening point and the base sheet is removed. The decorative layer becomes fused or heat sealed to the article. Since the polyamide layer lies over the decorative layer, it does not contact the article direc-tly and therefore does not function as a contact adhesive.
The decorative laminate disclosed in U.S. Patent 3,616,176 has a significant disadvantage that since the base sheet is in contact with the laminate as it is imprinted onto the article, the laminate lacks sufficient flexibility to satisfactorily imprint surfaces having compound or sharp curvature.
A further heat transfer label of the type shown in U.S.
Patent No. 3,616,015 known to the Applicant is composed of a carrier member (base sheet) overcoated in designated regions with a release layer and an ink design layer. Optionally, a barrier layer is included between -the release layer and the ink layer.
The release layer is typically composed of a polymerization product of a diamine with the dimer of a fatty acid and is contoured to reduce the halo effect of the label as it is -transEerred onto an article. The optional barrier layer may be ~2~6~
formed of an aroma-tic acid-based polyes-ter covering and overlapping -the release layer by a margin. This form oE label does not suggest a solution to the above-men-tioned limitations of the heat transfer labelling process.
Yet another heat transfer label of the type shown in U.S. Patent No. 3,616,015 known to the Applicant is composed of a carrier member (base sheet) overcoated in designated regions with a release wax layer, a protective layer, an ink design layer, and an adhesive layer. The protective layer provides enhanced chemical resistance for the heat transfer label and permits the heat transfer label to resist distortion during the heat transfer process. The protective layer is typically composed of an aromatic acid-based polyester and a rosin ester. This form of label does not suggest a solution to the above-mentioned limitations of the heat transfer labelling process.
Accordingly, it is an object of the present invention to provide decorative methods suitable for automated transfer of labels to articles, and substrates to be transferred by this method. It is a particular object of such method and apparatus that it combine the advantages of adaptability to a variety of article sizes and shapes and multicolored label capabilities.
Another object of the invention is that the technique be readily adapted to rapid and efficient operation. A related object is a multicolored decoration capability without the need for successive decorative stages.
~ et another object of the invention is the provision of a decorative process which is adaptable to a variety of artlcles. Such technique, for example, should be suited to the _ 5 1~2~
decoration oE plastic, glass, and ceramic articles.
Still another object oE the invention is the achievement of high quality decora-tion of articles. The apparatus of the invention should impart a desired image completely and without significant distortion. A particular object in -this regard is the provision of high gloss images. A
further object of the invention is the provision of durable, reasonably inexpensive decoration.
Another object of the invention is to provide a decorative laminate which achieves multicolor pad -transfer decoration ln a single transfer operation.
Another object of the invention is to provide a decorative laminate which permanently adheres to any article ! without subsequent firing of the laminate.
A further object of the invention is to achieve a pad transfer method which satisfies the above criteria while being compatible with automated operation.
6~3~
S~ ~ARY ~F T~F, INVFNTInN
In accomplishing the foregoing and related objects, the invention provides 8 transfer process employing a decorative laminate including a ~esign and transfer substrate which are transferred from a support member to a transfer pad and thence to an article. The support member is heated to a first temperature, permitting separation of the transfer substrate which adheres to the pad. The surface of the pad is advan~ageously at a second, somewhat lower temperature. The transfer substrate is pressed against the article forming an adhesive bond thereto, and is released by the pad.
In the preferred embodiment, the transfer substrate includes an adhesive/release layer which is softened by the heating of the support member and separated therefrom during the first transfer. This layer also functions as an adhesive, forming a permanent bond to the article during the second transfer. ~he transfer substrate further includes an ink design layer over the adhesive layer. Optionally, the substrate includes a protective coating layer over the ink layer; this layer may be omitted in many applications.
nptionally, the transfer substrate further includes a barrier ~ayer intermediate the adhesive/release layer and the ink layer. The barrier layer, where included, functions to prevent absorption of ink into the resin~us coating.
The invention has the advantage that the transfer substrate may be composed vf either a single colored decorative design or a multicolored decorative design including halftone colors. Another advantage of the invention is that the transfer substrate may be transferred to virtually any type of article irrespective , ,. '' 11 ~
~ ~2 ~
of its sh~pe or degree of surface curvature without causing distortion to the desi~n imprint. Thus, the article may, for example, be composed of ceramic, glass, plastic, paper foil, and a variety of polymeric materials, and the surface to which the transfer substrate is transposed may be flat or include compound curves, irregular surfaces, or recessed panels.
The decorative lamina,te of the preferred embodiment includes a paper shee~ or web, which is coated on one side ~- 10 with the various layers constituting the transfer substrate. m e transfer substrate includes a resinous coating layer in contact with the support (i.e., the adhesive/release layer), an ink layer covering the resinous coating layer and a protective coating layer over the ink layer. The use of a resinous adhesivelrelease layer distinguishes the transfer substrate of the invention from those of the prior art incorporating a wax release l~yer or the like, which cannot also successfully function as an adhesive layer.
2n In the preferred embodiment, the barrier layer where include~ is of the same composition as the protective coating.
A preferred for~ulation for the adhesive/release layer is a polyamide resin made from the polymerization of `~
~ diamine with a dimer of a fatty acid~ Preferably, this layer includes a plasticizer such as castor oil, w~ich may be modified by the addition of erucamide (a fatty amide of cis-13-decosenoic acid). Partic~larly favorable , properties are achieved in this layer when it co~prises at least 80 percen~ by weight polyamide resin, the balance being a plasticizer.
Additional plasticizer may be included in the formulation of the adhesive/release layer to increase its ~Z~26~3~
fluidity. Where erucamide is included in the adhesive/release layer the above-mentioned proportions are suitably adjusted so that the polyamide resin comprises at least 7~ percent of the formulation, more preferably between 70 and 90 percent. Advantageously, in the adhesive/release layer as so modified the ratio o plasticizer to erucamide is in the range 5/1 to 15/1.
The preferred polyamide resin is composed of the polymerization product of a linear methylene dlamine and dimerized fatty acid. Specific polyamide resins which have been found to be particularly suitable are the polymerization products of hexamethylene diamine and dimerized linoleic acid, and tetramethylene diamine and dimerized oleic acid.
Alternative constituents for the resinous coating may include polyterpenes, vinyl ~oluene/alpha methyl styrene copo~ymers and ethylene/vinyl acetate copolymers. These constituents may be used without additional additives, or plasticizers such as castor oil may be added with or without erucamide.
A preferred plasticizer is castor oil. Alternative plasticizers may include rosin esters, chlorinated paraffins, aliphatic esters, epoY~y esters, alkyl aromatic phthalates, glycol esters, and alkyl aromatic phosphates.
Applicants have found that a preferred composition for the dried protective coating and optional barrier layer consists of the combination of a polymer (i) which is a film forming, multiaromatic, acid-based polyester, preferably linear which is reinforced by a second polymer (ii) containing bulky ring structures such as polymerized rosin esters. The multiaromatic acid-based polyester (Polymer (i)) should comprise between about 50 to 80 percent by weight of the dried protective coating layer or 6~34 the optional barrier layer with the polymerized rosin ester (Polymer (ii)) comprising the balance of the mixture, i.e. between about 20 to 50 percent by weight.
The multiaromatic ~cid-based polyester (Polymer (i)) is preferably composed of the polymer condensation products of polyester formin~ reactants of one or more glycol6 reacted with napthalic pr phthalic acidsO
A preferred rosin est~r (Polymer ~ ) is forme~
typically of the reaction product of a polyhydric alcohol, maleic anhydride or phenol aldehyde reacted with rosin acids such as abietic and pimaric acids. ~he rosin ester (Polymer (ii)) is preferably composed of methyl abietate, methyl hydroabietate, glyceryl hydroabietate or ester gum, The ink layer may be composed of a single colored ink or may include a multiplicity of differently colored inks.
The ink may be composed of any conventional nitrocellulose ink, preferably a polyamide-nitrocellulose ink.
Alternatively, inks having an acrylic polyester, or vinyl base are al60 particularly suitable.
If the transfer su~strate does not include a protective layer, the ink layer is preferably composed of an isobutyl methacrylate ink modified with maleic rosin and p~lyisoprene. Alternatively, inks having a polyamide-nitrocellulose or vinyl base may be-adopted if the substrate does include a pr~ective layer, i The basis wei~ht of the dried resinous coating layer may advantageously fall in ~he range 1.5 to 15 lbs./ream, and the dried protective coating layer or barrier layer from about 0.5 to 3 lbs./ream (3000 6q. ft. per ream).
In a preferred implementation of the transfer process, heat is conducted through an exposed undersurface of a support web, supplied ~rom a heated platen or the :
., .
7~
~ Z ~2 6~ ~
like. Sufficient heat is supplied to tackify the protective coatin~ layer (or ink layer, where the protective coatin~ is omitted) and to æoften and begin to melt the adhesive/release layer. As a result, the protective coating adheres to the surface of the transfer pad, and the softened resinous coating is released from the support web. A ~uitable platen temperature to achieve the above objects is in the range 330F to 420F, more preferably between 340~F and 3~0F, for automatic operation.
The transfer pad is heated to a surface temperature around 100~ - 200F lower than the platen's temperature. The heating of the transfer pad occurs as a natural result of the label pick-up process whereby the ~5 pad at least indirec~ly contacts the heated p~aten. The heated pad serves to maintain the adhesive/release layer in a softened, tackified state and permits the eventual release of the transfer substrate. An illustrative temperature range is between about 150F - 300F. The various temperatures are dependent on the mechanical design of the transfer apparatus, and will tend to be lower for a given label chemistry wi~h higher transfer pressures and lower cycle speeds.
A preferred composi~ion for the transfer pad is an - -elastomeric material. Silicone rubber has the advantagesof being easily m~lded in a variety of configurations, and having suitable deformability as-known in the prior pad transfer art. In the present invention, this material enjoys the additional significant advantage of withstanding the elevated temperatures which are characteristic of the transfer process. A particular property of some importance in the transfer of smooth, glossy labels is that the pad surface have a relatively smooth texture.
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:1~22~34 As will be understood from the Eoregoing discussion, according to -the invention there is provided a process for transEerring a decorative laminate from a support to an article, comprising the steps:
heating the laminate, which is comprised of a nonwax-based adhesive/release layer in contact with the support, and a design layer, to a first temperature above the melting point of said adhesive/release layer, said laminate not having a wax-based release layer intermediate said adhesive/release layer and the support;
heating the surface of an elastomeric member to a second temperature below said first temperature;
contacting the laminate under pressure with the heated elastomeric member so that the laminate adheres to the elastomeric member and separates from the support upon withdrawal of said elastomeric member;
impressing the laminate against the article to bond the adhesive/release layer thereto; and withdrawing the elastomeric member from the article, whereupon the laminate remains permanently adhered to the article.
In a further aspect, is is provided that the time interval between contact of the laminate against the article and withdrawal of the elastomeric member from the article leaving the laminate permanently adhered to said article is in a range between abou-t 0.01 and 0.2 seconds.
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In a further aspect it is provided tha-t the nonwax-based adhesive/release layer may comprise a polymerization product of a diamine with a dimerized Eatty acid.
DESCRIPTION OF THE DRAWINGS
Other aspects of the invention will become more apparent after considering several illustrative embodimen-ts of the invention taken in conjunction with the drawings:
FIG. 1 is an elevated view of the decorative laminate of the invention and the transfer pad before the transfer pad is pressed onto the laminate.
FIG. 2 is an elevated view of the decorative laminate of the invention and the transfer pad after contact is made between the pad and the laminate and the support released.
FIG. 3 is an elevated view of the decorative laminate of the invention with inclusion of a barrier layer.
FIG. 4 is an elevated view of the decorative laminate of the invention without a protective coating layer.
FIG. 5 is an elevated view of the decorative laminate of the invention without a protective coating layer and with inclusion of a barrier layer.
DETAILED DESCRIPTION
A preferred embodiment of the decorative laminate of the invention is shown in Figure 1. The decorative laminate 5 of the invention is composed of a support 10, typically a substrate composed of a paper sheet or web which is affixed at least on one side to a transfer substrate 7. Transfer substrate 7 as best shown in Figures 1 and 2, is preferably composed of a resinous coa-ting layer 20, an ink layer 30 and a protective coating 40.
- 12(a) -~1 ~2Z6i~'~
Optionally, as shown in Figure 3, the laminate 5 and substrate 7 may include a barrier layer 25 between ink layer 30 and resinous coating 20.
Laminate 5 is formed by providing support 10 with a nonwax-based adhesive/release resinous coa-ting 20 on at least one side o:E support 10. The transfer substrate 7 of the present invention excludes use of a wax-based release layer intermediate the adhesive/release resinous coating 20 and support 10. The adhesive/release resinous coating 20 is in direct contact with support 10. Resinous coating 20 is overcoated with an ink layer 30 composed of letters or designs imprinted in ink. Ink layer 30 does not contact support 10. Ink layer 30 is in turn provided with an overcoating of protective coating layer 40. The transfer substrate 7 may also be provided with a resinous barrier coating between ink layer 30 and resinous coatiny 20.
The barrier coating 25 illustrated in Figure 3 may typically be of the same composition as protective coating 40 and prevents absorption of the ink into the resinous coating 20. Use of a protective coating layer 40 is particularly advantageous when the container con-tents includes corrosive or abrasive elements such as alcohol, cosmetics, toiletries, ~ood and dairy products, beverages or frozen goods.
Alternatively, the protective coating layer 40 may be omitted from the transfer substrate 7 as illustrated in Figures 4 and 5. Protective coating layer 40 may be omitted in labelling applications, particularly wherein the transfer substrate 7 will not be exposed to harsh - 12(b) -J.~2ZZ68 chemical6 or corrosive elements, for example when applied to tags or containers holdin~ chemically inactive material. In such case the transfer substrate 7 may be composed of resinous coatin~ 20 overcoated with an ink layer 30 as illustrated in Figure 4.
The transfer substrate 7 without a protective coating layer is affixed to support 1~ as shown in Figure 4 to form a decorative laminate 5. A barrier layer 25 may be included between ink layer 30 and resinous coating 20 to form a transfer substrate 7 as illustrated in Figure 5 which does not have a protective coating layer. Ihe barrier layer 25 prevents absorption of the ink into the resinous coating 20.
The laminate of the invention is particu~arly suitable for use in automated processes. In the process of the invention a support 10 typically in the form of a weh carrying a plurality of transfer substrate 7 aligned in sin~le rows are passed under a flexible transfer pad 50. ~he transfer pad 50, preferably composed of silicon rubber and support substrate 10 are each first heated.
Transfer pad 50 is then pressed onto substrate 7 as it is passed under the pad 50 so that the pad comes into contact with the protective coating layer 40 or ink layer 30 if the substrate 7 does not include a protective layer 40.
As the transfer pad 50 is w;thdrawn, substrate 7 adheres to the pad and the suppoFt 1 0 separates from substra~e 7. --Substrate 7 is then pressed onto an article so that the resinous coating layer 20 contac~s the article. As the transfer pad 50 is withdrawn it separate from substrate 7, and substrate 7 adheres to the article. A permanent bond between resinous coating layer 20 and the article then forms. If substrate 7 includes a protective coating 40, the ink design in ink layer 30 is distinctly visible through protective coating 40 after su~strate 7 has been transferred to the article. Protective coating 40 dries to a smooth, glossy finish which protects ink layer 30 from the environment.
In the first step of the process, sufficient heat is applied to the exposed surface of supp~rt 10, to heat the substrate to a temperature which is above ~he melting point of the resinous coating 20. Support 10 is heated to a temperature t-ypically between about 50F to 150F
above the melting point of the resinous coating 20.
Typically, support 10 is heated to between about 330F
to 420F, more preferably 340F - 360F, so that the protective coating 40 (or ink layer 30, if protective coating is not included in substrate 7) becomes tacky, and resinous coating 20 softens and begins to melt enough to permit the support to be removed from transfer substrate 7. The rubber transfer pad 50, preferably composed of silicon rubber, having a smooth contact surface is heated to a temperature which is lower than the temperature to ?0 which support 10 is heated, preferably 100 to 20nF
lower than the temperature of support 10. Typically, the transfer pad sn is heated to between about 150~ to 300F, more preferably 150F - 250F. The various disclosed temperatures are dependent on the mechanical characteristic~ of the transfer apparatus as well as the label chem~stry and will genèrally be lower at higher transfer pressures and lower cycle speeds.
Transfer pad 50 will be heated as a normal incident of the transfer process, inasmuch as it will periodically, at least indirectly, contact the n~eans for heating support 10. If this heating effect is insufficient in the context of a given system, an independent heater should be provided for pad 50.
~22~ 4 In a second step oE the process, as shown in Figure L t the ho-t transfer pad 50 is pressed against laminate 10 so as to make pressure contact with the protec-tive coating 40 or ink layer 30 in the event protective coating 40 is omitted. The transfer pad is then withdrawn in a third step, as shown in Figure 2, at which time coating 20 splits to separate from support 10 thus releasing support 13. The coating 40 or ink layer 30 is sufficiently adhesive that the subs-trate 7 adheres to the transfer pad. Thus, the substrate 7 is left in adhesive contact with the transfer pad 50 and resinous coating 20 is exposed to the environment.
In a fourth step of the process, the hot transfer pad 50 and adhering substrate 7 is then pressed onto a surface of either a flat or three-dimensional object including articles having compound curves, irregular surfaces, or recessed panels so that the exposed coa-ting layer 20 comes into pressure contact with the article. The article may consist of any of a wide range of materials including ceramic, plastic, or glass.
The time interval between steps three and four is preferably less than about 1 second, more preferably between about 0.01 to 0.2S second. With the preferred composition for coating 20 disclosed in Table I, coating 20 will be sufficiently tacky up to temperatures from about 150C to 300~C.
As coating 20 comes into contact with article 60, it exhibits a tacky adhesive quality which is greater than the adhesive force between substra-te 7 and transfer pad 50. Pad 50 is withdrawn from article 60 in a Eifth step of the process. The time in-terval be-tween the moment of contact of substrate 7 with :lZ;~;~684 the article and the moment oE withdrawal of pad 50 away from the article is preferably less than about 1 second and as low as about 0.01 second, preferably be-tween 0.01 and 0.20 second. Thus the total time interval as measured from the moment of withdrawal of the transEer pad 50 from support 10 to release transfer substrate 7 from support 10 until the moment of withdrawal of transfer pad 50 from the article leaving substrate 7 permanently adhered thereto is preferably between about 0.02 and 0.45 second. The foregoing time intervals are most readily achieved if transfer pad 50 is in the shape of a cylindrical roller.
Thus, as transfer pad 50 is withdrawn from article 60 substrate 7 remains in adhesive contact with the article. Coating 20 also functions to permanently bond substrate 7 to the article as the substrate is left to dry under ambient conditions. Thus, the resinous coating layer 20 may be termed an "adhesive/release"
layer, in that it provides the unique dual functionality as a release layer to permit separation of substrate 10 in one step of the process, and ultimately as a permanent adhesive to bond the ink layer 30 to an article.
As the substrate 7 cools on the article, protective coating 40 when included in the substrate forms a hard, protective lac~uer coating over ink layer 30 forming a chemical and abrasion resistant protective layer, thus sealing the ink layer from exposure to moisture vapor, oxygen, grease, and other corrosive elemen-ts in the environment. The resulting laminate has the property that the design~ which may be either a single or multiple colored designr shows distinctly therethrough regardless of the type of curva-ture of the surface to which it has been ~2;~684 applied and regardless of whether the article is composed oE
ceramic, glass, or plastic. Furthermore, the outline oE ~he protective coating layer 40 or -the resinous coating 20 on the article is essentially invisible to normal inspection.
The coating layer 20 and protective coating 40 remain permanently affixed to article 60 as an integral part of the transfer substrate. When coating 40 is not included in substrate 7, ink layer 30 is exposed directly to the environment. The aEEixed substrate is not subjected to firing, but it should be appreciated that if article 60 is composed of glass, an inorganic Elux material may be - 16(a) -1~22 added to form ink layer 30. In thi6 case, if ~ubstrate 7 is exp~sed to high temperature firing, the organic lsyers 20 and 40 are volatilized leavin~ ink layer 30 fused to - the article.
The preferred compositions of the respective layers comprising the decorative laminate 7 are set forth as follows with reference made to the accompanying tables:
, . . .
Support (10~:
The support 10 may be any support member or web to hold imprint substrate 7 securely attached thereto.
~owever, it is preferable to have support 10 composed of a paper sheet more preferably a paper sheet that is clay-coated to improve its smoo~hness quality and to retard penetration of the reino~s coatin~ 2n into the paper 1~ sheet as heat is applied to the back of ~he paper. The paper sheet may be any type of paper preferably Kraft-type '1, paper having a thickness of between about 2 to 2.5 mils and a basis ~eight of hetween about 26 to 40 lbs./ream (3~00 sq. ft. per ream3.
2n Resinous Coatin~ Layer (20):
Coating layer 2~ is preferably composed of a p~lyamide resin having 2 softening point advantageously be~ween about 96C - 105C. Ihe polyamide ~esin i~
p~eferably co~pose~ of the polymerization product o~ a linear methylene diamine and dimerized fatty acid. A
polyamide resin which has been determined to be particularly advanta~eous i~ the polymerization products of hexamethy~ene diamine and dimerized linoleic acid, and tetramethylene diamine and dimeri2ed oleic acid. Ihe formulation shown in Table 1 is particularly suitable for resinous coatin~ layer 20, since it has been discovered to have the required release properties permitting the easy .
1~
removal of substrate 1 n in one step of the process and - ultimately as a per~anent adhesive to bond ink layer 30 to article 60 in another step as discussed in ~he foregoing.
The resinous coating layer may alternatively be composed of other materials such as polyterpenes, vinyl toluene/alpha methyl styrene copolymers and ethylene vinyl acetate copolymers.
The coating layer 20 i;s made preferably by admixing the components shown in Ta~le I in the weight proportions by weight indicated in Table I to form a polyamide resinous so~ution. The mixture is prepared at ambient temperature and utilizing conventional mixing equipment.
The preferred polyamide resin shown in Table I is so]d under the tradename EMEREZ 1537 by Emery Industries of Cincinnati, ~H. The polyamide resin EMEREZ 153' is the polymerization product of the type above-mentioned, namely, the product of a methylene diamine such as hexamethylenediamine and a dimerized fatty acid such as dimerized linoleic acid. It has a softening point between 110 to 120C, a ~iscosity at 160C of 3.5 to 5 DO
poise, a ~ardner color index (max.) of 4.~, an acid value of 4.0 max., and density at 25C of ~.1 lbs./gal.
The resinous solution is typically prepared by dissolving the polyamide resin EMEREZ 1537 in isopropyl 25 alcohol and toluene in the proportions indicated in Table I and then modifying the resulting solution with about 4 to 16 percent by weight castor oil plasticizer and further by the addition of 2 to ~ percent by weight of erucamide (egO Kenamide E). The resulting polyamide resinous 30 dispersion has a typical preferred composition a~ set forth in Table I.
Erucamide is a fatty amide of cis - 13 - decosenoic 3 acid sold under the tradename KENAMIDE E by Humko Sheffield Chemical Div. of Kraftco Corp., Memphis, ~N.
':
.-l 9 The erucamide additive permits the use of an increased amount of castor oil p~asticizer which enhances the fluidity of the resinous coating layer. The fatty amide KENAMIDE-E has an average molecular weight of 335, S an iodine value between about 70 to 80, a capillary melting point of about 76 to 86C and a Gardner color maximum of 5.
The polyamide resinous solution having a typical composition illustrated in,~Table I may be applied to the support 10 by any conventional printing methods, for example, by gravure, silk screen, offset, or flexographic printing methods. ~owever, the gra w re method is preferred because better process print can be realized by this method as well as better economy and color consistency with long runs. After the coating is applied to substrate 10 and dried, the solvents are evaporated and - the resulting dried resinous coating (20) has a typical preferred composition as shown in Table I.
The dried resinous coating (2~) covering support 10 has a basis weight preferably of between about 1.5 to 15 lbs./ream, more preferably between about 3 to 5 lbs./ream (300n s~. ft. per ream) and has a melt viscosity in the ran~e of 3.5 to 8.5 poise at 160C.
Ink Layer 30:
Ink layer 30 may be composed of any conventional type of ink of any color including halftone colors. ~he inks which are preferable have the property that they do not soak into the resinous coating when applied without a barrier layer. The present invention has the advantage that multicolored inks can be used to produce a multicolored design image, that is, multicolored design images transferable in one pass.
A preferred ink is a polyamide-nitrocellulose ink.
In this type ink the polyamide is a dimerized fatty acid ' 1! 1 ~222~84 2~
copolymerized with a linear diamine which constitutes about ~0 weight percent of the ink and the remainder is ; essentially nitrocellulose. ~lternative inks having an acrylic, polyester, or vinyl base may also be employed.
If a protective coating 40 is not included in transfer substrate 7 as illustrated in Figures 4 and 5, ink layer 30 is preferably composed of an isobutyl methacrylate-type ink which exhibits suitable adhesive and release characteristics to~allow substrate 7 to be transferred to pad 50 and thence released therefrom as substrate 7 is pressed onto an article. A preferred ink of this type has been determined to be an ink having isobutyl methacrylate binder modified with maleic rosin and polyisoprene.
Protective Coatin~ ~ayer (40) The protective coating layer 40 has a preferred formulaticn shown in Table II. It is composed essentially of a film-forming, multiaromatic, acid-based polyester designated polymer (i) and a second reinforcing poly~er (ii) which contains a bulky ring structure such as a polyrnerized rosin ester. The reinforcing polyrner (ii) desirably may constitute between about 20 to 50 weight percent and preferably about 20 weight percent of the dried protective layer (40). The polymers ti~ and (ii) should be soluble in the sarne or miscible solvents, such as toluene and methye~hyl ketone. Advantageously, the polyrners (i) a~d (ii) may have a refractive index of about 1.5.
The multiarornatic acid-based polyester (Polymer (i)) is preferably composed of the reaction products of the polymer condensation products of polyester forming reactants of one or more glycols reacted with naphthalic, or phthalic acids.
. .
2~;~4 A preferred polyester polymer (i~ is a ]inear multiaromatic acid-based polyester such as that available under the trademark VITEL PE200 or VITEL PE222 from ~oodyear Company of Akron, OH. The polyesters sold under the above VITEL trademark are aromatic acid-based polyesters having yellow, amorphous granules of Acid Number from 1 to 10, preferably 1 to 4, a Shore nurometer hardness of about 75 ~o 80 D, a specific gravity of about 1.25, and a ring and ball ~oftening point of about 150 to 170C.
A preferred reinforcing polyester polymer (ii) is a rosin ester for~ed typically by reaction of polyhydric alcohols, maleic anhydride or phenol aldehyde and rosin acids such as abietic and pimaric acids. The rosin ester, (Poly~er (ii)) is preferably composed of methyl abietate, methyl hydroahietate, glyceryl hydroabietate, or ester gum.
A preferred reinforcing polymer (ii) of this type is sold under the trademark NEOLY~ 23-75T from ~ercules Chemical Company of Wilmington, Delaware.
A preferred protective coating layer 40 is formed of a polyester solution having the typical preferred composition se~ forth in Table II. The polyester Tesinous solution is prepared by admixing the constituents in the proportions set forth in Table II utilizing conventional mixing techni~ues. The polyester resinous solution is coated onto ink layer 30 by conventional printing methods such as by gra w re, silk screen offset, or flexographic methvds. However~ the gra w re method is preferred because better process print and sharper coloring can be realized by this printing method as well as better economy and color consistency with long runs.
~ Z Z 2 ~
After the coating is applied to ink layer 30 and dried, the solvents are evaporated and the resulting dried protective coating has a typical preferred composition as shown in Table 11. The dried protective coating layer 40 has a basis weight preferably between about 0.5 to 3 lbs./ream (3000 sq. ft. per ream).
Additionally, the same preferred formulation above described and as shown in Table II or the dried protective coating layer 4~b may be used as an optional barrier layer 25 between ink layer 30 and the resinous coating layer 20. Ihe method of preparing the barrier layer may also be the same as above-described for preparing the protective coating 40 by utilizing the same preferred polyester resinous solution formùlation illustrated in ~able II. If a barrier coating is used, the dried barrier layer between ink layer 30 and resinous coating 20 typically has a basis weight of between about 0.5 to 3 lbs./ream. Inclusion of a barrier coating is optional) but its use further protects ink layer 30 from 2~ having moisture vapor, oxygen, and grease absorbed to it through resinous coating 20.
Transfer Pad 50:
The transfer pad is preferably composed of silicone rubber. It has been found to be advantageous to provide 2~ the silicone rubber pad with a smooth surface and a convex curvature facing transfer substrate 7 so that the transfer sub~trate 7 has a smooth, glossy surface after it has been transferred to the article. Any commercially available room temperature or heat curable silicone rubber may be suitable to make the pad. For example, the pad may be formed by casting room temperature vulcanizable silicone rubber with a suitable curing agent in propurtion typically of 10 parts by weight silicone rubber to 1 part ,, ~22 by weight curing agent. A suitable room temperature vulcanizable silicone rubber can be purchased under the tradename RTV 700, and the curing agent under the : tradename B~TA 5, both available from General ~lectric Company of Pittsfield, MA. ~he cast silicone rubber pad product preferably has a Shore A hardness of about 4 to : 35.
~Z6~9 T A B E E
POLYAMIDE RESINOUS SOLUTION:
_ercent by Wei~ht Polyamide Resin ~eg. EMEREZ 1537) 25.5 Solvent 1 Isopropyl Alcohol 49.0 Solvent 2 ~oluene . _21 . Q
P]as~icizer - Castor ni~ 3.0 _ Erucamide (eg . KEI~AMIrlE E) _1 . 5 1 00 .0 DRIED RESINOUS COA~IMG (20):
Polyamide Resin Seg. EMEREZ 1537) 85.0 . Plasticizer ; Castor Oil 10.0 Erucamide (eg. KENAMInE E) ~.0 1 00 .0 .
J
~22Z6~1 T A B L E II
POLYESTER RESINOUS SOLUTION:
Percent by Wei~ht Polyester Polymer (i) (eg. VITEL PE-200 or VITEL PE-222) ,~ .20.0 Reinforcing Polyester Polymer (ii) (eg. NEOLYN 23-75 T) 5.0 Solvent Methylethyl ketone 75.0 DRlED PROTECTIVE LAYER (40) Po]yester Polymer ~i) (eg. VITEL PE-200 or VITEL PE-222) ~0.0 Polyester Polymer (ii~
(eg. NEOLYN 23-75 T) 20.0 100.0 :~2;~6~34 Examples of the process of the invention and preferred method of making the product are given as follows EXAMPLE I
A support 1~ in the form ~f paper web carrying a multiplicity of transfer substrates 7 ali~ned in single rows were passed under a silicone rubber transfer pad 50 having a smooth surface. ,!An automatic conveyer ~as usefl to pass the transfer substrates 7 to and under the transfer pad 50. The paper web was composed of Kraft-type paper having a basis weight of between about 20 to 40 pounds per ream and the substrate 7 was made in accordance with the specification set forth in Exampl~ II. As the paper web (support tO) passed along the conveyor, the support 10 was heated to a temperature of about 350F.
At this temperature level the protective-coating 40 became tacky and the resinous coating softened and began to melt.
The silicone transfer rubber pad 50 was heated to between ab~ut 200 to 250F. As each heated substrate 7 in turn passed under hot transfer pad 50, the smooth surface of the transfer pad made pressure contact with protective coatin~ 40 in an automatic operation. ~s transfer pad 50 was withdrawn, the resinous coating 20 partially separated from supp~r~ 10, thus releasing substrate 7 from support 10 exposing coating 20 to the environment, with coating 40 adhered to the ~ransfer pad.
The transfer pad ~0 and adhering substrate 7 was then pressed onto the surface of an article 60 which was conveyed to the vicinity of the transfer pad. Article 60 was comprised of a polyethylene, and had compound curves and irre~ular 6urfaces.
6~34 The time interval between the moment of release of substrate 7 from s~pport 1~ to the moment of contact of substra~e 7 with the article was about one second.
As the transfer pad 50 was withdrawn from article 6~, substrate 7 remained in adhesive contact with the article in a permanent bond hetween the resinous coating layer 20 and the article. The ink design in ink layer 30 was distinctly visible through protective coating 40 after substrate 7 had been trans~erred to the article. Upon cooling, protective coating 40 developed a smooth, glossy finish protecting ink layer 30 from the environment. The time interval between the moment of contact of substrate 7 ~ith article 60 and the moment of withdrawal of pad 50 away from the article was about 0.5 second.
The paper web (support 10~ which was affixed with the remaining substrates 7 was conveyed automatically under transfer pad 50~ As each substrate 7 in turn passed under the transfer pad, the above-described sequence was repeated to ~ranspose a substrate 7 from the web to another article. The process was repeated automatically until all the artic]es on the assembly line were imprinted with a substrate 7.
EXAMPL~ II
A web of support 10 composed of Y.raft-type pape~
~5 sheet having a basis weight of about 26 to 40 lbs.~ream was fed through a gravure printer. The resin~us coating (20) is formed over predesignated portions on the paper sheet by utilizing conventional gravure printing to apply the polyamide resinous solution to the paper sheet.
The polyamide resinous solution may be prepared in accordance with the formulation set forth in Table I as described in the foregoing. To facilitate the application ~ , of the resinous solution, it may be diluted further with solvent as desired preferably so that its viscosity is about 25 sec. as ~easured with a ~4 Ford cup. As the paper web was passed through the gra w re printer, a
.
~ 2 ~
Another type of apparatus which possesses special advantages in the decoration of objects of unusual conformation is the so-called pad-transfer decorator.
This apparatus utilizes a deformable pad, typically comprised of a silicone elastomer. The pad receives an ink impression to be transferred to an article by pressing against an intaglio plate which had been previously coated with ink with any e~cess ink removed. The împression-bearing pad is then presse'd against the article to be labelled, to which it imparts the ink impression. The deformable pad is adaptable to a wide varie~y of article conformations. This decorative method and apparatus involves assembly-line equipment of a simpler design than the above-discussed heat-transfer decorators, and therefore re~uires fewer adjus.ments in retooling to articles of a va.iety of sizes and shapes. ~owever, this process only transfers one color of ink at a time, and is thus slow and cu~bersome if multicolored designs are required. Also, since there is no protective coating covering the ink design, it is left exposed directly to the environment upon transfer to the article.
U.S~ Patent ~o. 3,887,420 discloses the use of a silicone rubber p~d to transfer designs from a decorative Iaminate to ceramic articles. The laminate includes a base layer such as a paper sheet overlayed with a coating of wax. The wax coating is ~oated with a film layer (Fi-lm B), which in turn is overcoated with an ink design layer and a second film (Film A). As the laminate is heated to within a narrow ten degree temperature range, Film A is alleged to become adhesive while the wax coating and Film B become molten and nonadhesive. The transfer pad purportedly sticks to Film A when it is pressed against the laminate so that as the transfer pad is withdrawn, the ~2~ 68~
substrate composed of the paper sheet and wax coating separates from the remainder of the laminate. The laminate adhering to the transEer pad is pressed onto a ceramic article, and the temperature of the laminate is dropped to within a narrow ten degree temperature range. At this temperature, Film B becomes adhesive and Film A is alleged to exhibit diminished adhesion.
Thus, as the laminate is pressed onto the article with Film B
contacting the article, the laminate is alleged to adhere to the article and released from the transfer pad as the pad is withdrawn.
The film layers A and B are each adhesive over only a very narrow ten degree temperature range, making it imprac-ticable to control the described process within the context of an automated process, since each Eilm layer must in turn be heated or cooled to within the required ten degree temperature range to make the process workable. Precise heating or cooling of Film A
and Film B to within such narrow temperature ranges is impossible to achieve or control within the split second time intervals required by an automated assembly process. This reference does not disclose the use of an independent pad heater, nor details of pad composition, surface texture, or other parameters important to its implementation. Furthermore, the inclusion of a wax layer to form part of the decorative substrate has the disadvantage that as the substrate is released from Film B there will be a strong tendency for a portion of the wax to remain attached to Film B. This will interfere with the adhesive characteristics of Film B as the laminate is transferred from the transfer pad to an object.
122268~
U.S. Patent No. 3,616,176 discloses a heat transEer laminate of a type related to that disclosed in U.S. Patent 3,616,015. In U.S. Patent 3,616,176 the laminate is composed of a base sheet, with a polyamide layer covering the base sheet and a decorative ink layer covering the polyamide layer. Sufficient heat is applied to the laminate to heat the polyamide layer at or above its softening point, and the laminate is then pressed onto the surface of an article with the decorative ink layer coming into direct contact. Upon withdrawal of the heat source, the polyamide layer cools LO a temperature below its softening point and the base sheet is removed. The decorative layer becomes fused or heat sealed to the article. Since the polyamide layer lies over the decorative layer, it does not contact the article direc-tly and therefore does not function as a contact adhesive.
The decorative laminate disclosed in U.S. Patent 3,616,176 has a significant disadvantage that since the base sheet is in contact with the laminate as it is imprinted onto the article, the laminate lacks sufficient flexibility to satisfactorily imprint surfaces having compound or sharp curvature.
A further heat transfer label of the type shown in U.S.
Patent No. 3,616,015 known to the Applicant is composed of a carrier member (base sheet) overcoated in designated regions with a release layer and an ink design layer. Optionally, a barrier layer is included between -the release layer and the ink layer.
The release layer is typically composed of a polymerization product of a diamine with the dimer of a fatty acid and is contoured to reduce the halo effect of the label as it is -transEerred onto an article. The optional barrier layer may be ~2~6~
formed of an aroma-tic acid-based polyes-ter covering and overlapping -the release layer by a margin. This form oE label does not suggest a solution to the above-men-tioned limitations of the heat transfer labelling process.
Yet another heat transfer label of the type shown in U.S. Patent No. 3,616,015 known to the Applicant is composed of a carrier member (base sheet) overcoated in designated regions with a release wax layer, a protective layer, an ink design layer, and an adhesive layer. The protective layer provides enhanced chemical resistance for the heat transfer label and permits the heat transfer label to resist distortion during the heat transfer process. The protective layer is typically composed of an aromatic acid-based polyester and a rosin ester. This form of label does not suggest a solution to the above-mentioned limitations of the heat transfer labelling process.
Accordingly, it is an object of the present invention to provide decorative methods suitable for automated transfer of labels to articles, and substrates to be transferred by this method. It is a particular object of such method and apparatus that it combine the advantages of adaptability to a variety of article sizes and shapes and multicolored label capabilities.
Another object of the invention is that the technique be readily adapted to rapid and efficient operation. A related object is a multicolored decoration capability without the need for successive decorative stages.
~ et another object of the invention is the provision of a decorative process which is adaptable to a variety of artlcles. Such technique, for example, should be suited to the _ 5 1~2~
decoration oE plastic, glass, and ceramic articles.
Still another object oE the invention is the achievement of high quality decora-tion of articles. The apparatus of the invention should impart a desired image completely and without significant distortion. A particular object in -this regard is the provision of high gloss images. A
further object of the invention is the provision of durable, reasonably inexpensive decoration.
Another object of the invention is to provide a decorative laminate which achieves multicolor pad -transfer decoration ln a single transfer operation.
Another object of the invention is to provide a decorative laminate which permanently adheres to any article ! without subsequent firing of the laminate.
A further object of the invention is to achieve a pad transfer method which satisfies the above criteria while being compatible with automated operation.
6~3~
S~ ~ARY ~F T~F, INVFNTInN
In accomplishing the foregoing and related objects, the invention provides 8 transfer process employing a decorative laminate including a ~esign and transfer substrate which are transferred from a support member to a transfer pad and thence to an article. The support member is heated to a first temperature, permitting separation of the transfer substrate which adheres to the pad. The surface of the pad is advan~ageously at a second, somewhat lower temperature. The transfer substrate is pressed against the article forming an adhesive bond thereto, and is released by the pad.
In the preferred embodiment, the transfer substrate includes an adhesive/release layer which is softened by the heating of the support member and separated therefrom during the first transfer. This layer also functions as an adhesive, forming a permanent bond to the article during the second transfer. ~he transfer substrate further includes an ink design layer over the adhesive layer. Optionally, the substrate includes a protective coating layer over the ink layer; this layer may be omitted in many applications.
nptionally, the transfer substrate further includes a barrier ~ayer intermediate the adhesive/release layer and the ink layer. The barrier layer, where included, functions to prevent absorption of ink into the resin~us coating.
The invention has the advantage that the transfer substrate may be composed vf either a single colored decorative design or a multicolored decorative design including halftone colors. Another advantage of the invention is that the transfer substrate may be transferred to virtually any type of article irrespective , ,. '' 11 ~
~ ~2 ~
of its sh~pe or degree of surface curvature without causing distortion to the desi~n imprint. Thus, the article may, for example, be composed of ceramic, glass, plastic, paper foil, and a variety of polymeric materials, and the surface to which the transfer substrate is transposed may be flat or include compound curves, irregular surfaces, or recessed panels.
The decorative lamina,te of the preferred embodiment includes a paper shee~ or web, which is coated on one side ~- 10 with the various layers constituting the transfer substrate. m e transfer substrate includes a resinous coating layer in contact with the support (i.e., the adhesive/release layer), an ink layer covering the resinous coating layer and a protective coating layer over the ink layer. The use of a resinous adhesivelrelease layer distinguishes the transfer substrate of the invention from those of the prior art incorporating a wax release l~yer or the like, which cannot also successfully function as an adhesive layer.
2n In the preferred embodiment, the barrier layer where include~ is of the same composition as the protective coating.
A preferred for~ulation for the adhesive/release layer is a polyamide resin made from the polymerization of `~
~ diamine with a dimer of a fatty acid~ Preferably, this layer includes a plasticizer such as castor oil, w~ich may be modified by the addition of erucamide (a fatty amide of cis-13-decosenoic acid). Partic~larly favorable , properties are achieved in this layer when it co~prises at least 80 percen~ by weight polyamide resin, the balance being a plasticizer.
Additional plasticizer may be included in the formulation of the adhesive/release layer to increase its ~Z~26~3~
fluidity. Where erucamide is included in the adhesive/release layer the above-mentioned proportions are suitably adjusted so that the polyamide resin comprises at least 7~ percent of the formulation, more preferably between 70 and 90 percent. Advantageously, in the adhesive/release layer as so modified the ratio o plasticizer to erucamide is in the range 5/1 to 15/1.
The preferred polyamide resin is composed of the polymerization product of a linear methylene dlamine and dimerized fatty acid. Specific polyamide resins which have been found to be particularly suitable are the polymerization products of hexamethylene diamine and dimerized linoleic acid, and tetramethylene diamine and dimerized oleic acid.
Alternative constituents for the resinous coating may include polyterpenes, vinyl ~oluene/alpha methyl styrene copo~ymers and ethylene/vinyl acetate copolymers. These constituents may be used without additional additives, or plasticizers such as castor oil may be added with or without erucamide.
A preferred plasticizer is castor oil. Alternative plasticizers may include rosin esters, chlorinated paraffins, aliphatic esters, epoY~y esters, alkyl aromatic phthalates, glycol esters, and alkyl aromatic phosphates.
Applicants have found that a preferred composition for the dried protective coating and optional barrier layer consists of the combination of a polymer (i) which is a film forming, multiaromatic, acid-based polyester, preferably linear which is reinforced by a second polymer (ii) containing bulky ring structures such as polymerized rosin esters. The multiaromatic acid-based polyester (Polymer (i)) should comprise between about 50 to 80 percent by weight of the dried protective coating layer or 6~34 the optional barrier layer with the polymerized rosin ester (Polymer (ii)) comprising the balance of the mixture, i.e. between about 20 to 50 percent by weight.
The multiaromatic ~cid-based polyester (Polymer (i)) is preferably composed of the polymer condensation products of polyester formin~ reactants of one or more glycol6 reacted with napthalic pr phthalic acidsO
A preferred rosin est~r (Polymer ~ ) is forme~
typically of the reaction product of a polyhydric alcohol, maleic anhydride or phenol aldehyde reacted with rosin acids such as abietic and pimaric acids. ~he rosin ester (Polymer (ii)) is preferably composed of methyl abietate, methyl hydroabietate, glyceryl hydroabietate or ester gum, The ink layer may be composed of a single colored ink or may include a multiplicity of differently colored inks.
The ink may be composed of any conventional nitrocellulose ink, preferably a polyamide-nitrocellulose ink.
Alternatively, inks having an acrylic polyester, or vinyl base are al60 particularly suitable.
If the transfer su~strate does not include a protective layer, the ink layer is preferably composed of an isobutyl methacrylate ink modified with maleic rosin and p~lyisoprene. Alternatively, inks having a polyamide-nitrocellulose or vinyl base may be-adopted if the substrate does include a pr~ective layer, i The basis wei~ht of the dried resinous coating layer may advantageously fall in ~he range 1.5 to 15 lbs./ream, and the dried protective coating layer or barrier layer from about 0.5 to 3 lbs./ream (3000 6q. ft. per ream).
In a preferred implementation of the transfer process, heat is conducted through an exposed undersurface of a support web, supplied ~rom a heated platen or the :
., .
7~
~ Z ~2 6~ ~
like. Sufficient heat is supplied to tackify the protective coatin~ layer (or ink layer, where the protective coatin~ is omitted) and to æoften and begin to melt the adhesive/release layer. As a result, the protective coating adheres to the surface of the transfer pad, and the softened resinous coating is released from the support web. A ~uitable platen temperature to achieve the above objects is in the range 330F to 420F, more preferably between 340~F and 3~0F, for automatic operation.
The transfer pad is heated to a surface temperature around 100~ - 200F lower than the platen's temperature. The heating of the transfer pad occurs as a natural result of the label pick-up process whereby the ~5 pad at least indirec~ly contacts the heated p~aten. The heated pad serves to maintain the adhesive/release layer in a softened, tackified state and permits the eventual release of the transfer substrate. An illustrative temperature range is between about 150F - 300F. The various temperatures are dependent on the mechanical design of the transfer apparatus, and will tend to be lower for a given label chemistry wi~h higher transfer pressures and lower cycle speeds.
A preferred composi~ion for the transfer pad is an - -elastomeric material. Silicone rubber has the advantagesof being easily m~lded in a variety of configurations, and having suitable deformability as-known in the prior pad transfer art. In the present invention, this material enjoys the additional significant advantage of withstanding the elevated temperatures which are characteristic of the transfer process. A particular property of some importance in the transfer of smooth, glossy labels is that the pad surface have a relatively smooth texture.
.
:1~22~34 As will be understood from the Eoregoing discussion, according to -the invention there is provided a process for transEerring a decorative laminate from a support to an article, comprising the steps:
heating the laminate, which is comprised of a nonwax-based adhesive/release layer in contact with the support, and a design layer, to a first temperature above the melting point of said adhesive/release layer, said laminate not having a wax-based release layer intermediate said adhesive/release layer and the support;
heating the surface of an elastomeric member to a second temperature below said first temperature;
contacting the laminate under pressure with the heated elastomeric member so that the laminate adheres to the elastomeric member and separates from the support upon withdrawal of said elastomeric member;
impressing the laminate against the article to bond the adhesive/release layer thereto; and withdrawing the elastomeric member from the article, whereupon the laminate remains permanently adhered to the article.
In a further aspect, is is provided that the time interval between contact of the laminate against the article and withdrawal of the elastomeric member from the article leaving the laminate permanently adhered to said article is in a range between abou-t 0.01 and 0.2 seconds.
~226~3~
In a further aspect it is provided tha-t the nonwax-based adhesive/release layer may comprise a polymerization product of a diamine with a dimerized Eatty acid.
DESCRIPTION OF THE DRAWINGS
Other aspects of the invention will become more apparent after considering several illustrative embodimen-ts of the invention taken in conjunction with the drawings:
FIG. 1 is an elevated view of the decorative laminate of the invention and the transfer pad before the transfer pad is pressed onto the laminate.
FIG. 2 is an elevated view of the decorative laminate of the invention and the transfer pad after contact is made between the pad and the laminate and the support released.
FIG. 3 is an elevated view of the decorative laminate of the invention with inclusion of a barrier layer.
FIG. 4 is an elevated view of the decorative laminate of the invention without a protective coating layer.
FIG. 5 is an elevated view of the decorative laminate of the invention without a protective coating layer and with inclusion of a barrier layer.
DETAILED DESCRIPTION
A preferred embodiment of the decorative laminate of the invention is shown in Figure 1. The decorative laminate 5 of the invention is composed of a support 10, typically a substrate composed of a paper sheet or web which is affixed at least on one side to a transfer substrate 7. Transfer substrate 7 as best shown in Figures 1 and 2, is preferably composed of a resinous coa-ting layer 20, an ink layer 30 and a protective coating 40.
- 12(a) -~1 ~2Z6i~'~
Optionally, as shown in Figure 3, the laminate 5 and substrate 7 may include a barrier layer 25 between ink layer 30 and resinous coating 20.
Laminate 5 is formed by providing support 10 with a nonwax-based adhesive/release resinous coa-ting 20 on at least one side o:E support 10. The transfer substrate 7 of the present invention excludes use of a wax-based release layer intermediate the adhesive/release resinous coating 20 and support 10. The adhesive/release resinous coating 20 is in direct contact with support 10. Resinous coating 20 is overcoated with an ink layer 30 composed of letters or designs imprinted in ink. Ink layer 30 does not contact support 10. Ink layer 30 is in turn provided with an overcoating of protective coating layer 40. The transfer substrate 7 may also be provided with a resinous barrier coating between ink layer 30 and resinous coatiny 20.
The barrier coating 25 illustrated in Figure 3 may typically be of the same composition as protective coating 40 and prevents absorption of the ink into the resinous coating 20. Use of a protective coating layer 40 is particularly advantageous when the container con-tents includes corrosive or abrasive elements such as alcohol, cosmetics, toiletries, ~ood and dairy products, beverages or frozen goods.
Alternatively, the protective coating layer 40 may be omitted from the transfer substrate 7 as illustrated in Figures 4 and 5. Protective coating layer 40 may be omitted in labelling applications, particularly wherein the transfer substrate 7 will not be exposed to harsh - 12(b) -J.~2ZZ68 chemical6 or corrosive elements, for example when applied to tags or containers holdin~ chemically inactive material. In such case the transfer substrate 7 may be composed of resinous coatin~ 20 overcoated with an ink layer 30 as illustrated in Figure 4.
The transfer substrate 7 without a protective coating layer is affixed to support 1~ as shown in Figure 4 to form a decorative laminate 5. A barrier layer 25 may be included between ink layer 30 and resinous coating 20 to form a transfer substrate 7 as illustrated in Figure 5 which does not have a protective coating layer. Ihe barrier layer 25 prevents absorption of the ink into the resinous coating 20.
The laminate of the invention is particu~arly suitable for use in automated processes. In the process of the invention a support 10 typically in the form of a weh carrying a plurality of transfer substrate 7 aligned in sin~le rows are passed under a flexible transfer pad 50. ~he transfer pad 50, preferably composed of silicon rubber and support substrate 10 are each first heated.
Transfer pad 50 is then pressed onto substrate 7 as it is passed under the pad 50 so that the pad comes into contact with the protective coating layer 40 or ink layer 30 if the substrate 7 does not include a protective layer 40.
As the transfer pad 50 is w;thdrawn, substrate 7 adheres to the pad and the suppoFt 1 0 separates from substra~e 7. --Substrate 7 is then pressed onto an article so that the resinous coating layer 20 contac~s the article. As the transfer pad 50 is withdrawn it separate from substrate 7, and substrate 7 adheres to the article. A permanent bond between resinous coating layer 20 and the article then forms. If substrate 7 includes a protective coating 40, the ink design in ink layer 30 is distinctly visible through protective coating 40 after su~strate 7 has been transferred to the article. Protective coating 40 dries to a smooth, glossy finish which protects ink layer 30 from the environment.
In the first step of the process, sufficient heat is applied to the exposed surface of supp~rt 10, to heat the substrate to a temperature which is above ~he melting point of the resinous coating 20. Support 10 is heated to a temperature t-ypically between about 50F to 150F
above the melting point of the resinous coating 20.
Typically, support 10 is heated to between about 330F
to 420F, more preferably 340F - 360F, so that the protective coating 40 (or ink layer 30, if protective coating is not included in substrate 7) becomes tacky, and resinous coating 20 softens and begins to melt enough to permit the support to be removed from transfer substrate 7. The rubber transfer pad 50, preferably composed of silicon rubber, having a smooth contact surface is heated to a temperature which is lower than the temperature to ?0 which support 10 is heated, preferably 100 to 20nF
lower than the temperature of support 10. Typically, the transfer pad sn is heated to between about 150~ to 300F, more preferably 150F - 250F. The various disclosed temperatures are dependent on the mechanical characteristic~ of the transfer apparatus as well as the label chem~stry and will genèrally be lower at higher transfer pressures and lower cycle speeds.
Transfer pad 50 will be heated as a normal incident of the transfer process, inasmuch as it will periodically, at least indirectly, contact the n~eans for heating support 10. If this heating effect is insufficient in the context of a given system, an independent heater should be provided for pad 50.
~22~ 4 In a second step oE the process, as shown in Figure L t the ho-t transfer pad 50 is pressed against laminate 10 so as to make pressure contact with the protec-tive coating 40 or ink layer 30 in the event protective coating 40 is omitted. The transfer pad is then withdrawn in a third step, as shown in Figure 2, at which time coating 20 splits to separate from support 10 thus releasing support 13. The coating 40 or ink layer 30 is sufficiently adhesive that the subs-trate 7 adheres to the transfer pad. Thus, the substrate 7 is left in adhesive contact with the transfer pad 50 and resinous coating 20 is exposed to the environment.
In a fourth step of the process, the hot transfer pad 50 and adhering substrate 7 is then pressed onto a surface of either a flat or three-dimensional object including articles having compound curves, irregular surfaces, or recessed panels so that the exposed coa-ting layer 20 comes into pressure contact with the article. The article may consist of any of a wide range of materials including ceramic, plastic, or glass.
The time interval between steps three and four is preferably less than about 1 second, more preferably between about 0.01 to 0.2S second. With the preferred composition for coating 20 disclosed in Table I, coating 20 will be sufficiently tacky up to temperatures from about 150C to 300~C.
As coating 20 comes into contact with article 60, it exhibits a tacky adhesive quality which is greater than the adhesive force between substra-te 7 and transfer pad 50. Pad 50 is withdrawn from article 60 in a Eifth step of the process. The time in-terval be-tween the moment of contact of substrate 7 with :lZ;~;~684 the article and the moment oE withdrawal of pad 50 away from the article is preferably less than about 1 second and as low as about 0.01 second, preferably be-tween 0.01 and 0.20 second. Thus the total time interval as measured from the moment of withdrawal of the transEer pad 50 from support 10 to release transfer substrate 7 from support 10 until the moment of withdrawal of transfer pad 50 from the article leaving substrate 7 permanently adhered thereto is preferably between about 0.02 and 0.45 second. The foregoing time intervals are most readily achieved if transfer pad 50 is in the shape of a cylindrical roller.
Thus, as transfer pad 50 is withdrawn from article 60 substrate 7 remains in adhesive contact with the article. Coating 20 also functions to permanently bond substrate 7 to the article as the substrate is left to dry under ambient conditions. Thus, the resinous coating layer 20 may be termed an "adhesive/release"
layer, in that it provides the unique dual functionality as a release layer to permit separation of substrate 10 in one step of the process, and ultimately as a permanent adhesive to bond the ink layer 30 to an article.
As the substrate 7 cools on the article, protective coating 40 when included in the substrate forms a hard, protective lac~uer coating over ink layer 30 forming a chemical and abrasion resistant protective layer, thus sealing the ink layer from exposure to moisture vapor, oxygen, grease, and other corrosive elemen-ts in the environment. The resulting laminate has the property that the design~ which may be either a single or multiple colored designr shows distinctly therethrough regardless of the type of curva-ture of the surface to which it has been ~2;~684 applied and regardless of whether the article is composed oE
ceramic, glass, or plastic. Furthermore, the outline oE ~he protective coating layer 40 or -the resinous coating 20 on the article is essentially invisible to normal inspection.
The coating layer 20 and protective coating 40 remain permanently affixed to article 60 as an integral part of the transfer substrate. When coating 40 is not included in substrate 7, ink layer 30 is exposed directly to the environment. The aEEixed substrate is not subjected to firing, but it should be appreciated that if article 60 is composed of glass, an inorganic Elux material may be - 16(a) -1~22 added to form ink layer 30. In thi6 case, if ~ubstrate 7 is exp~sed to high temperature firing, the organic lsyers 20 and 40 are volatilized leavin~ ink layer 30 fused to - the article.
The preferred compositions of the respective layers comprising the decorative laminate 7 are set forth as follows with reference made to the accompanying tables:
, . . .
Support (10~:
The support 10 may be any support member or web to hold imprint substrate 7 securely attached thereto.
~owever, it is preferable to have support 10 composed of a paper sheet more preferably a paper sheet that is clay-coated to improve its smoo~hness quality and to retard penetration of the reino~s coatin~ 2n into the paper 1~ sheet as heat is applied to the back of ~he paper. The paper sheet may be any type of paper preferably Kraft-type '1, paper having a thickness of between about 2 to 2.5 mils and a basis ~eight of hetween about 26 to 40 lbs./ream (3~00 sq. ft. per ream3.
2n Resinous Coatin~ Layer (20):
Coating layer 2~ is preferably composed of a p~lyamide resin having 2 softening point advantageously be~ween about 96C - 105C. Ihe polyamide ~esin i~
p~eferably co~pose~ of the polymerization product o~ a linear methylene diamine and dimerized fatty acid. A
polyamide resin which has been determined to be particularly advanta~eous i~ the polymerization products of hexamethy~ene diamine and dimerized linoleic acid, and tetramethylene diamine and dimeri2ed oleic acid. Ihe formulation shown in Table 1 is particularly suitable for resinous coatin~ layer 20, since it has been discovered to have the required release properties permitting the easy .
1~
removal of substrate 1 n in one step of the process and - ultimately as a per~anent adhesive to bond ink layer 30 to article 60 in another step as discussed in ~he foregoing.
The resinous coating layer may alternatively be composed of other materials such as polyterpenes, vinyl toluene/alpha methyl styrene copolymers and ethylene vinyl acetate copolymers.
The coating layer 20 i;s made preferably by admixing the components shown in Ta~le I in the weight proportions by weight indicated in Table I to form a polyamide resinous so~ution. The mixture is prepared at ambient temperature and utilizing conventional mixing equipment.
The preferred polyamide resin shown in Table I is so]d under the tradename EMEREZ 1537 by Emery Industries of Cincinnati, ~H. The polyamide resin EMEREZ 153' is the polymerization product of the type above-mentioned, namely, the product of a methylene diamine such as hexamethylenediamine and a dimerized fatty acid such as dimerized linoleic acid. It has a softening point between 110 to 120C, a ~iscosity at 160C of 3.5 to 5 DO
poise, a ~ardner color index (max.) of 4.~, an acid value of 4.0 max., and density at 25C of ~.1 lbs./gal.
The resinous solution is typically prepared by dissolving the polyamide resin EMEREZ 1537 in isopropyl 25 alcohol and toluene in the proportions indicated in Table I and then modifying the resulting solution with about 4 to 16 percent by weight castor oil plasticizer and further by the addition of 2 to ~ percent by weight of erucamide (egO Kenamide E). The resulting polyamide resinous 30 dispersion has a typical preferred composition a~ set forth in Table I.
Erucamide is a fatty amide of cis - 13 - decosenoic 3 acid sold under the tradename KENAMIDE E by Humko Sheffield Chemical Div. of Kraftco Corp., Memphis, ~N.
':
.-l 9 The erucamide additive permits the use of an increased amount of castor oil p~asticizer which enhances the fluidity of the resinous coating layer. The fatty amide KENAMIDE-E has an average molecular weight of 335, S an iodine value between about 70 to 80, a capillary melting point of about 76 to 86C and a Gardner color maximum of 5.
The polyamide resinous solution having a typical composition illustrated in,~Table I may be applied to the support 10 by any conventional printing methods, for example, by gravure, silk screen, offset, or flexographic printing methods. ~owever, the gra w re method is preferred because better process print can be realized by this method as well as better economy and color consistency with long runs. After the coating is applied to substrate 10 and dried, the solvents are evaporated and - the resulting dried resinous coating (20) has a typical preferred composition as shown in Table I.
The dried resinous coating (2~) covering support 10 has a basis weight preferably of between about 1.5 to 15 lbs./ream, more preferably between about 3 to 5 lbs./ream (300n s~. ft. per ream) and has a melt viscosity in the ran~e of 3.5 to 8.5 poise at 160C.
Ink Layer 30:
Ink layer 30 may be composed of any conventional type of ink of any color including halftone colors. ~he inks which are preferable have the property that they do not soak into the resinous coating when applied without a barrier layer. The present invention has the advantage that multicolored inks can be used to produce a multicolored design image, that is, multicolored design images transferable in one pass.
A preferred ink is a polyamide-nitrocellulose ink.
In this type ink the polyamide is a dimerized fatty acid ' 1! 1 ~222~84 2~
copolymerized with a linear diamine which constitutes about ~0 weight percent of the ink and the remainder is ; essentially nitrocellulose. ~lternative inks having an acrylic, polyester, or vinyl base may also be employed.
If a protective coating 40 is not included in transfer substrate 7 as illustrated in Figures 4 and 5, ink layer 30 is preferably composed of an isobutyl methacrylate-type ink which exhibits suitable adhesive and release characteristics to~allow substrate 7 to be transferred to pad 50 and thence released therefrom as substrate 7 is pressed onto an article. A preferred ink of this type has been determined to be an ink having isobutyl methacrylate binder modified with maleic rosin and polyisoprene.
Protective Coatin~ ~ayer (40) The protective coating layer 40 has a preferred formulaticn shown in Table II. It is composed essentially of a film-forming, multiaromatic, acid-based polyester designated polymer (i) and a second reinforcing poly~er (ii) which contains a bulky ring structure such as a polyrnerized rosin ester. The reinforcing polyrner (ii) desirably may constitute between about 20 to 50 weight percent and preferably about 20 weight percent of the dried protective layer (40). The polymers ti~ and (ii) should be soluble in the sarne or miscible solvents, such as toluene and methye~hyl ketone. Advantageously, the polyrners (i) a~d (ii) may have a refractive index of about 1.5.
The multiarornatic acid-based polyester (Polymer (i)) is preferably composed of the reaction products of the polymer condensation products of polyester forming reactants of one or more glycols reacted with naphthalic, or phthalic acids.
. .
2~;~4 A preferred polyester polymer (i~ is a ]inear multiaromatic acid-based polyester such as that available under the trademark VITEL PE200 or VITEL PE222 from ~oodyear Company of Akron, OH. The polyesters sold under the above VITEL trademark are aromatic acid-based polyesters having yellow, amorphous granules of Acid Number from 1 to 10, preferably 1 to 4, a Shore nurometer hardness of about 75 ~o 80 D, a specific gravity of about 1.25, and a ring and ball ~oftening point of about 150 to 170C.
A preferred reinforcing polyester polymer (ii) is a rosin ester for~ed typically by reaction of polyhydric alcohols, maleic anhydride or phenol aldehyde and rosin acids such as abietic and pimaric acids. The rosin ester, (Poly~er (ii)) is preferably composed of methyl abietate, methyl hydroahietate, glyceryl hydroabietate, or ester gum.
A preferred reinforcing polymer (ii) of this type is sold under the trademark NEOLY~ 23-75T from ~ercules Chemical Company of Wilmington, Delaware.
A preferred protective coating layer 40 is formed of a polyester solution having the typical preferred composition se~ forth in Table II. The polyester Tesinous solution is prepared by admixing the constituents in the proportions set forth in Table II utilizing conventional mixing techni~ues. The polyester resinous solution is coated onto ink layer 30 by conventional printing methods such as by gra w re, silk screen offset, or flexographic methvds. However~ the gra w re method is preferred because better process print and sharper coloring can be realized by this printing method as well as better economy and color consistency with long runs.
~ Z Z 2 ~
After the coating is applied to ink layer 30 and dried, the solvents are evaporated and the resulting dried protective coating has a typical preferred composition as shown in Table 11. The dried protective coating layer 40 has a basis weight preferably between about 0.5 to 3 lbs./ream (3000 sq. ft. per ream).
Additionally, the same preferred formulation above described and as shown in Table II or the dried protective coating layer 4~b may be used as an optional barrier layer 25 between ink layer 30 and the resinous coating layer 20. Ihe method of preparing the barrier layer may also be the same as above-described for preparing the protective coating 40 by utilizing the same preferred polyester resinous solution formùlation illustrated in ~able II. If a barrier coating is used, the dried barrier layer between ink layer 30 and resinous coating 20 typically has a basis weight of between about 0.5 to 3 lbs./ream. Inclusion of a barrier coating is optional) but its use further protects ink layer 30 from 2~ having moisture vapor, oxygen, and grease absorbed to it through resinous coating 20.
Transfer Pad 50:
The transfer pad is preferably composed of silicone rubber. It has been found to be advantageous to provide 2~ the silicone rubber pad with a smooth surface and a convex curvature facing transfer substrate 7 so that the transfer sub~trate 7 has a smooth, glossy surface after it has been transferred to the article. Any commercially available room temperature or heat curable silicone rubber may be suitable to make the pad. For example, the pad may be formed by casting room temperature vulcanizable silicone rubber with a suitable curing agent in propurtion typically of 10 parts by weight silicone rubber to 1 part ,, ~22 by weight curing agent. A suitable room temperature vulcanizable silicone rubber can be purchased under the tradename RTV 700, and the curing agent under the : tradename B~TA 5, both available from General ~lectric Company of Pittsfield, MA. ~he cast silicone rubber pad product preferably has a Shore A hardness of about 4 to : 35.
~Z6~9 T A B E E
POLYAMIDE RESINOUS SOLUTION:
_ercent by Wei~ht Polyamide Resin ~eg. EMEREZ 1537) 25.5 Solvent 1 Isopropyl Alcohol 49.0 Solvent 2 ~oluene . _21 . Q
P]as~icizer - Castor ni~ 3.0 _ Erucamide (eg . KEI~AMIrlE E) _1 . 5 1 00 .0 DRIED RESINOUS COA~IMG (20):
Polyamide Resin Seg. EMEREZ 1537) 85.0 . Plasticizer ; Castor Oil 10.0 Erucamide (eg. KENAMInE E) ~.0 1 00 .0 .
J
~22Z6~1 T A B L E II
POLYESTER RESINOUS SOLUTION:
Percent by Wei~ht Polyester Polymer (i) (eg. VITEL PE-200 or VITEL PE-222) ,~ .20.0 Reinforcing Polyester Polymer (ii) (eg. NEOLYN 23-75 T) 5.0 Solvent Methylethyl ketone 75.0 DRlED PROTECTIVE LAYER (40) Po]yester Polymer ~i) (eg. VITEL PE-200 or VITEL PE-222) ~0.0 Polyester Polymer (ii~
(eg. NEOLYN 23-75 T) 20.0 100.0 :~2;~6~34 Examples of the process of the invention and preferred method of making the product are given as follows EXAMPLE I
A support 1~ in the form ~f paper web carrying a multiplicity of transfer substrates 7 ali~ned in single rows were passed under a silicone rubber transfer pad 50 having a smooth surface. ,!An automatic conveyer ~as usefl to pass the transfer substrates 7 to and under the transfer pad 50. The paper web was composed of Kraft-type paper having a basis weight of between about 20 to 40 pounds per ream and the substrate 7 was made in accordance with the specification set forth in Exampl~ II. As the paper web (support tO) passed along the conveyor, the support 10 was heated to a temperature of about 350F.
At this temperature level the protective-coating 40 became tacky and the resinous coating softened and began to melt.
The silicone transfer rubber pad 50 was heated to between ab~ut 200 to 250F. As each heated substrate 7 in turn passed under hot transfer pad 50, the smooth surface of the transfer pad made pressure contact with protective coatin~ 40 in an automatic operation. ~s transfer pad 50 was withdrawn, the resinous coating 20 partially separated from supp~r~ 10, thus releasing substrate 7 from support 10 exposing coating 20 to the environment, with coating 40 adhered to the ~ransfer pad.
The transfer pad ~0 and adhering substrate 7 was then pressed onto the surface of an article 60 which was conveyed to the vicinity of the transfer pad. Article 60 was comprised of a polyethylene, and had compound curves and irre~ular 6urfaces.
6~34 The time interval between the moment of release of substrate 7 from s~pport 1~ to the moment of contact of substra~e 7 with the article was about one second.
As the transfer pad 50 was withdrawn from article 6~, substrate 7 remained in adhesive contact with the article in a permanent bond hetween the resinous coating layer 20 and the article. The ink design in ink layer 30 was distinctly visible through protective coating 40 after substrate 7 had been trans~erred to the article. Upon cooling, protective coating 40 developed a smooth, glossy finish protecting ink layer 30 from the environment. The time interval between the moment of contact of substrate 7 ~ith article 60 and the moment of withdrawal of pad 50 away from the article was about 0.5 second.
The paper web (support 10~ which was affixed with the remaining substrates 7 was conveyed automatically under transfer pad 50~ As each substrate 7 in turn passed under the transfer pad, the above-described sequence was repeated to ~ranspose a substrate 7 from the web to another article. The process was repeated automatically until all the artic]es on the assembly line were imprinted with a substrate 7.
EXAMPL~ II
A web of support 10 composed of Y.raft-type pape~
~5 sheet having a basis weight of about 26 to 40 lbs.~ream was fed through a gravure printer. The resin~us coating (20) is formed over predesignated portions on the paper sheet by utilizing conventional gravure printing to apply the polyamide resinous solution to the paper sheet.
The polyamide resinous solution may be prepared in accordance with the formulation set forth in Table I as described in the foregoing. To facilitate the application ~ , of the resinous solution, it may be diluted further with solvent as desired preferably so that its viscosity is about 25 sec. as ~easured with a ~4 Ford cup. As the paper web was passed through the gra w re printer, a
- 5 coatin~ of the polyamide resinous solution was uniformly applied to cover predesignated portions on a side of the paper sheet.
The coated paper was then passed through a conventional convective coater dryer -wherein the coating is dried at about 200 to 250F evaporating the solvents and producing a dried resinous coating layer (20) having a composition typically as shown in Table I and a basis weight of between about 1.5 to 15 lbs./ream (3000 sq. ft./ream).
The dried web was then passed in sequence through a gra~re printer wherein the neAt layer, eg., ink layer 30 cornposed of isobutylmethacrylate ink modi~ied with maleic rosin and polyisoprene was applied over the dried resinous coatin~, A single ink color or multicolored inks including halftones may be applied to produce an imprint design or any number of colors. The substrate overcoated with ink layer 30 was further passed sequentially to conventional convective drying carried out at about 200 to 250F to dry the ink.
Ihe dried substrate was then a8ain passed through a grawre printer wherein the polyester resinous solution was applied over ink layer 30. A polyester resinous solution was then applied in accordance with the formulation set forth in Table II as described in the foregoing. However, to facilitate application of this solution by gra w re imprinting, the solution was first further diluted with solvent to yield a viscosity of about 20 seconds as measured with a ~4 Ford cup.
:~2~ 68 The substrate overcoated with the polyester resinous solution was dried in conventional convective coater dryers operatin~ at about 200F to 250F until the polyester resinous solution dried to form a dried protective layer 40 having the typical preferred composition shown in Table II, and a basis weight of between about 0.5 to 3 lbs.~ream~
~~PLE III
A label-bearing web was produced as in Example II
' 10 with the following modification. Prior to applying ink layer 30, the substrate overcoated with dried resinous coating 20 was passed through a gravure printer in order to apply a barrier coating 25 over ink layer 3n. The harrier coa~ing,25 was compose~ of the same polyes~er resinous so~ution shown in Table II. The barrier coating was dried in conventional convective coater driers at about 200F to 250F, forming a barrier having typically the same composition as that of the dried protective layer 40 set forth in Table II and a basis weight between about 0.5 to 3 lbs./ream. Thus, the ' substrate 7 was formed of a coating layer 20, optional barrier layer 25, ink layer 30 and dried protective coating 40.
ln practice, rows of individual substrates 7 may be printed onto support substrate 10 in mass production automated fashion.
EXAMPLE IV
The process of the invention was carried out in accordance with Example II and the laminate 5 and substrate 7 were manufactured as set forth in Example II
except that ink layer 30 was not overcoated with , . .
iZ2~68 3n protective coating 40. Instead substrate 7 was formed as illustrated in Figures 4 or 5 with the free surface of ink layer 3n exposed. Thus, in the process of the invention as transfer pad 50 was pressed onto substrate 7 the pad made direct contact with the exposed surface of ink layer 30 and after substrate 7 was transferred to article 60 the free surface of ink layer 30 was left exposed to the environment. In accomplishing this embodiment of the invention, ink layer 3~ was formed by employing an ink formed of conventional pigment, a binder solvent, and a binder composed of a film-forming isobutyl methacrglate ink modified with maleic rosin and polyisoprene. The isobutyl methacrylate was present in the hinder in an - amount between about 60 to 80 percent by weight of the binder, the maleic rosin between about 15 to 25 percent by weight and the polyisoprene between about 5 to 15 percent by weight of the binder. A typical preferred binder used in forming ink layer 30 was composed of 70 parts by weight isobutyl methacrylate modified with 20 parts by weight ma~eic rosin and 10 parts by weight polyisoprene. The ink layer 30 was coated onto resinous coating 20 or alternatively onto barrier layer 25 and dried in the manner set forth in Example Il to form the substrate 7 illustrated in Figures 4 and 5 ~espectivel~ e dried ink layer 3~ had a basis weight of between about 0.5 to 2 lbs./ream.
lt was found that the ink layer 30 in this embodiment exhibited the required adhesive characteristics to permit transfer of substrate 7 to transfer pad 50 and thence to article 60 when the process of the invention was carried out as set forth in ~,xample I. Upon transfer of substrate 7 onto article 60, the ink design in ink layer 30 was left indelibly imprinted on article 60. Ink layer 30 exhibited !
1~2684 abrasion and corrosion resisting properties sufficient to permit a variety of applications, particularly where article 60 contains chemically inactive and nontoxic components and where article 60 is not intended to come into contact frequently with highly abrasive materials.
Although the transfer~substrate 7 is removed from substrate 10, transferred to heated pad 50 and then to the desired article within the context of an automated process in the foregoing description, it should be appreciated that other variations including manual transfer of substrate 7 are also within the scope of the present invention. The preferre~ substrate compositions disclosed herein admit suitable substitutions for the various components, within the scope of the adhesive/release laminate and the process for transferring this laminate to articles. The invention, therefore, is not intended to be limited to the description in the specification but only by the claims and equivalents thereof.
The coated paper was then passed through a conventional convective coater dryer -wherein the coating is dried at about 200 to 250F evaporating the solvents and producing a dried resinous coating layer (20) having a composition typically as shown in Table I and a basis weight of between about 1.5 to 15 lbs./ream (3000 sq. ft./ream).
The dried web was then passed in sequence through a gra~re printer wherein the neAt layer, eg., ink layer 30 cornposed of isobutylmethacrylate ink modi~ied with maleic rosin and polyisoprene was applied over the dried resinous coatin~, A single ink color or multicolored inks including halftones may be applied to produce an imprint design or any number of colors. The substrate overcoated with ink layer 30 was further passed sequentially to conventional convective drying carried out at about 200 to 250F to dry the ink.
Ihe dried substrate was then a8ain passed through a grawre printer wherein the polyester resinous solution was applied over ink layer 30. A polyester resinous solution was then applied in accordance with the formulation set forth in Table II as described in the foregoing. However, to facilitate application of this solution by gra w re imprinting, the solution was first further diluted with solvent to yield a viscosity of about 20 seconds as measured with a ~4 Ford cup.
:~2~ 68 The substrate overcoated with the polyester resinous solution was dried in conventional convective coater dryers operatin~ at about 200F to 250F until the polyester resinous solution dried to form a dried protective layer 40 having the typical preferred composition shown in Table II, and a basis weight of between about 0.5 to 3 lbs.~ream~
~~PLE III
A label-bearing web was produced as in Example II
' 10 with the following modification. Prior to applying ink layer 30, the substrate overcoated with dried resinous coating 20 was passed through a gravure printer in order to apply a barrier coating 25 over ink layer 3n. The harrier coa~ing,25 was compose~ of the same polyes~er resinous so~ution shown in Table II. The barrier coating was dried in conventional convective coater driers at about 200F to 250F, forming a barrier having typically the same composition as that of the dried protective layer 40 set forth in Table II and a basis weight between about 0.5 to 3 lbs./ream. Thus, the ' substrate 7 was formed of a coating layer 20, optional barrier layer 25, ink layer 30 and dried protective coating 40.
ln practice, rows of individual substrates 7 may be printed onto support substrate 10 in mass production automated fashion.
EXAMPLE IV
The process of the invention was carried out in accordance with Example II and the laminate 5 and substrate 7 were manufactured as set forth in Example II
except that ink layer 30 was not overcoated with , . .
iZ2~68 3n protective coating 40. Instead substrate 7 was formed as illustrated in Figures 4 or 5 with the free surface of ink layer 3n exposed. Thus, in the process of the invention as transfer pad 50 was pressed onto substrate 7 the pad made direct contact with the exposed surface of ink layer 30 and after substrate 7 was transferred to article 60 the free surface of ink layer 30 was left exposed to the environment. In accomplishing this embodiment of the invention, ink layer 3~ was formed by employing an ink formed of conventional pigment, a binder solvent, and a binder composed of a film-forming isobutyl methacrglate ink modified with maleic rosin and polyisoprene. The isobutyl methacrylate was present in the hinder in an - amount between about 60 to 80 percent by weight of the binder, the maleic rosin between about 15 to 25 percent by weight and the polyisoprene between about 5 to 15 percent by weight of the binder. A typical preferred binder used in forming ink layer 30 was composed of 70 parts by weight isobutyl methacrylate modified with 20 parts by weight ma~eic rosin and 10 parts by weight polyisoprene. The ink layer 30 was coated onto resinous coating 20 or alternatively onto barrier layer 25 and dried in the manner set forth in Example Il to form the substrate 7 illustrated in Figures 4 and 5 ~espectivel~ e dried ink layer 3~ had a basis weight of between about 0.5 to 2 lbs./ream.
lt was found that the ink layer 30 in this embodiment exhibited the required adhesive characteristics to permit transfer of substrate 7 to transfer pad 50 and thence to article 60 when the process of the invention was carried out as set forth in ~,xample I. Upon transfer of substrate 7 onto article 60, the ink design in ink layer 30 was left indelibly imprinted on article 60. Ink layer 30 exhibited !
1~2684 abrasion and corrosion resisting properties sufficient to permit a variety of applications, particularly where article 60 contains chemically inactive and nontoxic components and where article 60 is not intended to come into contact frequently with highly abrasive materials.
Although the transfer~substrate 7 is removed from substrate 10, transferred to heated pad 50 and then to the desired article within the context of an automated process in the foregoing description, it should be appreciated that other variations including manual transfer of substrate 7 are also within the scope of the present invention. The preferre~ substrate compositions disclosed herein admit suitable substitutions for the various components, within the scope of the adhesive/release laminate and the process for transferring this laminate to articles. The invention, therefore, is not intended to be limited to the description in the specification but only by the claims and equivalents thereof.
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for transferring a decorative laminate from a support to an article, comprising the steps:
heating the laminate, which is comprised of a nonwax-based adhesive/release layer in contact with the support, and a design layer, to a first temperature above the melting point of said adhesive/release layer, said laminate not having a wax-based release layer intermediate said adhesive/release layer and the support;
heating the surface of an elastomeric member to a second temperature below said first temperature;
contacting the laminate under pressure with the heated elastomeric member so that the laminate adheres to the elastomeric member and separates from the support upon withdrawal of said elastomeric member;
impressing the laminate against the article to bond the adhesive/release layer thereto; and withdrawing the elastomeric member from the article, whereupon the laminate remains permanently adhered to the article.
heating the laminate, which is comprised of a nonwax-based adhesive/release layer in contact with the support, and a design layer, to a first temperature above the melting point of said adhesive/release layer, said laminate not having a wax-based release layer intermediate said adhesive/release layer and the support;
heating the surface of an elastomeric member to a second temperature below said first temperature;
contacting the laminate under pressure with the heated elastomeric member so that the laminate adheres to the elastomeric member and separates from the support upon withdrawal of said elastomeric member;
impressing the laminate against the article to bond the adhesive/release layer thereto; and withdrawing the elastomeric member from the article, whereupon the laminate remains permanently adhered to the article.
2. A process as defined in Claim 1 wherein the transferred laminate on the article is not subjected subsequently to firing.
3. A process as defined in Claim 1 wherein the adhesive/release layer comprises a polymerization product of a diamine with a dimerized fatty acid.
4. A process as defined in Claim 1 wherein the laminate further comprises a protective layer over said design layer.
5. A process as defined in Claim 1 wherein the laminate further comprises a barrier layer intermediate the adhesive/release layer and the design layer.
6. A process as defined in Claim 1 wherein the first temperature is in the range 330 degrees F. - 420 degrees F.
7. A process as defined in Claim 1 wherein the second temperature is in the range from 150 degrees F - 300 degrees F.
8. A process as defined in Claim 1 wherein the elastomeric member comprises silicone rubber having a smooth, convex surface.
9. A process for transferring a decorative laminate from a support to an article, comprising the steps:
heating the laminate, which is comprised of a non-wax-based adhesive/releaser layer in contact with the support, and a design layer, to a first temperature above the melting point of said adhesive/release layer, said laminate not having a wax-based release layer intermediate said adhesive/release layer and the support;
heating the surface of an elastomeric member to a second temperature below said first temperature;
contacting the laminate under pressure with the heated elastomeric member so that the laminate adheres to the elastomeric member and separates from the support upon withdrawal of said elastomeric member;
impressing the laminate against the article to bond the adhesive/release layer thereto; and withdrawing the elastomeric member from the article, whereupon the laminate remains permanently adhered to the article, the time interval between contact of the laminate against the article and withdrawal of the elastomeric member from the article leaving the laminate permanently adhered to said article is in a range between about 0.01 and 0.2 seconds.
heating the laminate, which is comprised of a non-wax-based adhesive/releaser layer in contact with the support, and a design layer, to a first temperature above the melting point of said adhesive/release layer, said laminate not having a wax-based release layer intermediate said adhesive/release layer and the support;
heating the surface of an elastomeric member to a second temperature below said first temperature;
contacting the laminate under pressure with the heated elastomeric member so that the laminate adheres to the elastomeric member and separates from the support upon withdrawal of said elastomeric member;
impressing the laminate against the article to bond the adhesive/release layer thereto; and withdrawing the elastomeric member from the article, whereupon the laminate remains permanently adhered to the article, the time interval between contact of the laminate against the article and withdrawal of the elastomeric member from the article leaving the laminate permanently adhered to said article is in a range between about 0.01 and 0.2 seconds.
10. A process as defined in Claim 9 wherein the transferred laminate on the article is not subjected subsequently to firing.
11. A process for transferring a decorative laminate from a support to an article, comprising the steps:
heating the laminate, which is comprised of a nonwax-based adhesive/release layer in contact with the support, said adhesive/release layer comprising a polymerization product of a diamine with a dimerized fatty acid, and a design layer, to a first temperature above the melting point of said adhesive/release layer, said laminate not having a wax-based release layer intermediate said adhesive/release layer and the support;
heating the surface of an elastomeric member to a second temperature below said first temperature;
contacting the laminate under pressure with the heated elastomeric member so that the laminate adheres to the elastomeric member and separates from the support upon withdrawal of said elastomeric member;
impressing the laminate against the article to bond the adhesive/release layer thereto; and withdrawing the elastomeric member from the article, whereupon the laminate remains permanently adhered to the article.
heating the laminate, which is comprised of a nonwax-based adhesive/release layer in contact with the support, said adhesive/release layer comprising a polymerization product of a diamine with a dimerized fatty acid, and a design layer, to a first temperature above the melting point of said adhesive/release layer, said laminate not having a wax-based release layer intermediate said adhesive/release layer and the support;
heating the surface of an elastomeric member to a second temperature below said first temperature;
contacting the laminate under pressure with the heated elastomeric member so that the laminate adheres to the elastomeric member and separates from the support upon withdrawal of said elastomeric member;
impressing the laminate against the article to bond the adhesive/release layer thereto; and withdrawing the elastomeric member from the article, whereupon the laminate remains permanently adhered to the article.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US47390683A | 1983-03-10 | 1983-03-10 | |
| US473,906 | 1983-03-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1222684A true CA1222684A (en) | 1987-06-09 |
Family
ID=23881506
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000437866A Expired CA1222684A (en) | 1983-03-10 | 1983-09-28 | Decorative laminate |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0138809B1 (en) |
| JP (1) | JPS60500854A (en) |
| CA (1) | CA1222684A (en) |
| DE (1) | DE3377634D1 (en) |
| WO (1) | WO1984003473A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| MY101876A (en) * | 1986-01-14 | 1992-02-15 | Minnesota Mining & Mfg | Composite useful for paint transfer and methods of use and preparation thereof. |
| GB8610692D0 (en) * | 1986-05-01 | 1986-06-04 | Brittains Tr Ltd | Transfer |
| US5215826A (en) * | 1990-09-25 | 1993-06-01 | Rexham Industries Corp. | Surfacing film with thermoformable carrier layer |
| DE102017104658B4 (en) * | 2017-03-06 | 2022-06-23 | Leonhard Kurz Stiftung & Co. Kg | Method for producing a decal and a decal and method for decorating surfaces of objects |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL132089C (en) * | 1900-01-01 | |||
| US2268262A (en) * | 1941-12-30 | Configurable platen fob label | ||
| US3616176A (en) * | 1967-11-07 | 1971-10-26 | Gen Mills Inc | Polyamide decal |
| US3887420A (en) * | 1971-04-30 | 1975-06-03 | Pictorial Prod Inc | Offset transfer of decalcomanias |
| US4288479A (en) * | 1973-09-24 | 1981-09-08 | Design Cote Corp. | Radiation curable release coatings |
| CA1064775A (en) * | 1974-06-03 | 1979-10-23 | Katherine A. Kingston | Heat transfer labelling |
| FR2300841A1 (en) * | 1975-02-13 | 1976-09-10 | Noridem Etudes Procede | Transfer printing sheets - with paper etc. carrier, multilayer print film and zein-contg. release layer |
| US4016021A (en) * | 1976-03-29 | 1977-04-05 | Fleur Lee | Heat sealing unit and method of making same |
| US4068033A (en) * | 1976-11-17 | 1978-01-10 | Commercial Decal, Inc. | Heat-releasable decalcomanias and adhesive composition therefor |
| US4187223A (en) * | 1976-12-29 | 1980-02-05 | Sterling Drug Inc. | 3-[4-(Disubstituted-amino)phenyl]-3-(diphenylamino)phthalides |
| JPS5465614A (en) * | 1977-11-01 | 1979-05-26 | Toppan Printing Co Ltd | Copying sheet for polyamide |
| US4303717A (en) * | 1979-08-23 | 1981-12-01 | Commercial Decal, Inc. | Heat release layer for decalcomanias |
| US4373984A (en) * | 1980-07-16 | 1983-02-15 | Voorwood Company | Machine for applying transfer foil to a shaped edge of a substrate |
| US4597815A (en) * | 1980-11-29 | 1986-07-01 | Nissha Printing Co., Ltd. | Transfer printing |
-
1983
- 1983-04-12 WO PCT/US1983/000518 patent/WO1984003473A1/en active IP Right Grant
- 1983-04-12 DE DE8383901669T patent/DE3377634D1/en not_active Expired
- 1983-04-12 EP EP19830901669 patent/EP0138809B1/en not_active Expired
- 1983-04-12 JP JP50168183A patent/JPS60500854A/en active Pending
- 1983-09-28 CA CA000437866A patent/CA1222684A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| EP0138809A4 (en) | 1985-07-30 |
| EP0138809B1 (en) | 1988-08-10 |
| DE3377634D1 (en) | 1988-09-15 |
| JPS60500854A (en) | 1985-06-06 |
| EP0138809A1 (en) | 1985-05-02 |
| WO1984003473A1 (en) | 1984-09-13 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |