CA1179590A

CA1179590A - Embossed laminates of contrasting color

Info

Publication number: CA1179590A
Application number: CA000289738A
Authority: CA
Inventors: Wilbur W. West
Original assignee: Formica Corp
Current assignee: Formica Corp
Priority date: 1976-12-21
Filing date: 1977-10-28
Publication date: 1984-12-18
Also published as: MX146825A; AU3022977A; ES465210A1; AU516807B2; AR220109A1; ZA776505B; BE862075A; NZ185602A; BR7707936A; SE7714539L

Abstract

ABSTRACT OF THE DISCLOSURE
The invention relates to a decorative laminate having registered embossment and color contrast comprising, in superimposed relationship, 1) a substrate of particleboard or phenolic resin impregnated sheets 2) a colorless, thermoset resin impregnated decor sheet 3) a coating of a pigmented, second thermoset resin positioned on said (2), the laminate surface containing valleys and protuberances each of a different color, the color of said (2) being evidenced at the valleys and the color of said second resin being evidenced at the protuberances.

Description

~ "
-_ 741 ll~Sg~

1 The techniques used to produce deep textured surfaces on decorative laminates encompass a design latitude heretofore not achieved by producing simulated patterns such as those occurrin~ in natural materials like sandstone, brick slate, mosaic, marble, leather, rough or weathered timber;
even material like rough woven goods such as jute, hemp.
~ any new designs, such as those simulating tiles or heavy woven cloth, have recently evolved. These designs must have appropriate color contrast and registry with the surface hill-to-valley configuration in order to be commer-cially attractive. Unfortunately, the problem of registra-tion of color and emobssing has proven very difficult to solve. The problem has plagued the industry, not only from the standpoint of the appeaxance of the finished laMinate but from the standpoint of the cost of the production of laminates having a substantially perfect registry of color and embossment, since their inception. ~mbossed laminates have been successfully produced, however, and laminates of substantially registered color and embossment have also been prepared (U.S. Patent Nos. 3,732,137 and 3,814,647).
The use of an encapsulated ink, as taught by U.S. 3,732,137, results in fine laminates of good color--embossment register. The method disclosed therein, however, is very expsnsive and requires extreme care in its use.
The use o~ a sheet containing encapsulated ink, of necessity, requires the concern of the manufacturer with ink coverage i.e. varying degrees of ink coverage across a specific laminate sheet and ink capsule depth, pressure distribution of the texturing plate, penetrability of the encapsulated ink through the overlay sheets of the laminate and accidental 11'7959[) 25,741 rupturing of the capsules during storage and transportation of prepared sheets before lamination, Control of the flow of the ink from the ruptured capsules and difficulty in utilizing opaque white and metallic inks are two more problems which plague the use of this system.
The method taught in U. S. Patent 3,814,647 obviates some of those difficulties mentioned above. This system consists of the application of a thermosetting ink to an embossed press plate die in registry with the embossing of the die. Subsequently, the ink press plate is impressed into a laminate assembly wherein the ink is transferred to the surface of the laminate in registry with the embossment. The patentee has formulated his ink so that it will release from the press plate die and transfer to the ~urface of the laminate without running or mlgrating ~ideways during the laminating step, U, S. Patent No, 3,661,672 teaches a method of forming a B-staged overlay transfer laminate from an embossing die, subsequently coating the embossed surface of the transfer laminate with color and then employing the temporary transfer laminate of an overlay on a separator which transfers embossing, overlay and color to the high pressure laminate during its production. This process is complex and involves the transfer of many sheets during laminate production.
A recently issued pAtent~ i,e, U,St Patent No.
3,968,2a8 discl~ses another system ~or creating colored~
embossed products by the process disclosed therein requires applying a colored powder to a co~tinq and this requires care in application and must be accompli~shed ~t the ti~e the product co~ponents axe about to be la~in~ted, 11'795~3V

25,741 SUMMAR~
A novel process for obtaining an exact regis~ry of color and embossment in high and low pressure laminate production has now been uncovered. This method is more commercially significant than previously known ~ystems because it i~ more economical and obviates many of the disadvantages of the prior procedures. When utilizing the novel process, there is no limit to dimension, design, depth of embossment or color which can be achieved. It avoids the mechanical registering of extraneous embossing media with decorative sheets in the laminates before or after pressing and the application of materials at press time.
According to the novel process, one may produce a decorative laminate having on its decorative surface, protrusions of any selected design, which protrus~ons are of a different color from the background surface of the laminate.
Furthermore, one may produce a decorative laminate in multi-color having protrusions which extend outwardly from the decorative surface of the laminate which protrusions have on their surface a different color than that of the background material in relief.
DESCRIPTION OF THE INVENTION
The novel invention constitutes a laminate assembly comprising - ~1) a rigidity imparting substrate,

(2) a fibrous decor sheet impregnated with a first thermosetting re~in, and

(3) an embossing press pl~te having a suxface with protuberant ~nd valley areas capable o~
being impressed into the upper~ost of s~id fibrous sheets and me~ns for preventing the embossing press plate from sticking to the li'7~S~)() 25,741 coated decor surface during l~mination~ and

(4) a layer of a pigmented second thermosetting resin positioned above said (1~ and ha~ing a flow sufficient to cause said second resin to flow more than said first resin.
The novel method hereof comprise~
a) consolidating the assembly described ~bove under heat and pressure to thereby effect a lamination of said fibrous sheets together, an embossment of the uppermost of the decor sheet and a migration of the pigmented resin from the areas of said embossment corresponding to the pro-tuberant areas of the embossed press plates to the valley areas thereof; and b) removing said embossing press plate from the resultant laminate so as to produce a dense laminate having embossed areas of contrasting color.
Fibrous core sheets are used as the rigidity 2Q imparting substrate in preparing the high pressure laminates of the present invention. They are usually paper sheets and, more preferably, kraft paper sheets. When such kraft paper sheets are used, it is preferred that they have a basis weight of between 40 lbs. (per 3000 sq. ft. ream) and 140 lbs.
and more preferably about 90 lbs. per ream.
The thermosetting resin used to impregnate such core sheets may be any suitAble resin known for such use but phenol/formaldehyde resin is pxeferred, When using such a resin, it is preferred to imp~egn~te and dry the impregnated sheets, by ~ethods known in the art,~ to a resin content o~
from about 25% to 45%~ and more preferably to a resin content of about 30%, based on the weight of resin solids i~n the 11'79S'':~V
.
25,741 impregnqted sheets~ The volatile content o~ the dxied im-pregnated sheet is pre~erably bet~een 5~ to l~r ~re preferably about 8%, based on the total weight o~ the heet, The solid color decorative sheet~ are also fibrous S sheets which are thermosetting resin impregnated and, more preferqbly, are opaque, pigmented alphacellulose and may carry a printed design. When the pre~erred paper sheets are employed, any suitable basis weight paper may be used to - advantage, but papers of from 40 lbs. (per 3000 sq. ft. ream) to 120 lbs. (per 3000 sq. ft. ream) are ~enerally preferred.
An alpha-cellulose paper is generally used in the preparation o~ the thermosetting resin-impregnated overlay, if desired, and may constitute any paper known for such use - in the production of conventional decorative plastic laminates.
Pre~erably, it is a wet strength alpha-cellulose paper having a basis weight of between 10 lbs. (per 3000 sq. ft. ream~
and 40 lbs. and, more preferably, 25 lbs. (per 3000 sq. ft.
ream). In its impregnated and cured condition, the overlay iæ substantially transparent.
When a low pressure decorative laminate is being produced, the decor sheet may also constitute any of the above-described decor sheets. The substrate, however, as mentioned above, comprises a particleboard ranging in thickness from about 1/8" to 1" which is produced in a manner known in the art. Medium density, mat ~ormed, wood particleboard and medium density, wood fiberboard substrates are preferred. An o~erlay sheet may or may not be employed.
The thermosettin~ xesins used ta impxegnate the decorative pqper sheet, in the low OX high pressure laminate production, and the overlay i~ used in the hi~h pressure lamin~tes, m~y be the same or di~erent ~nd ~a~ be any thermosetting resin sui~table ~or such purpose.

11795~V

1 For example, melamine-formaldehyde resins, melamine-urea--formaldehyde resins, unsaturated polyester resins and the like may be employed. If different resins are used to impregnate the different layers, care should be taken to ensure that the resins are compatible, that is, the resins must be capable of forming s~rong coherent bonds with each other under the conditions used for consolidation and no deleterious reactions between the resins should occur. It is preferred to use only one type of resin for the purposes mentioned, and more preferably, to use a melamine-formaldehyde resin for these purposes.
Various plasticizers and/or other modifiers may be incorporated into the impregnating resins in order to obtain improved plastic flow properties during the curing of the material. Other modifiers may also be employed to improve release from press plates, workability and other properties of the amino plastic resins, as is known in the art.
The embossing press plates used in the novel process of the instant invention can be prepared by etching or machining a design on a metal plate. Still further the raised printed design technique, as taught by Grosheim in U.S. 3,373,068, will also work well as an embossing medium in the instant invention.
The materials useful as the pigmented layer in the laminates o~ this invention consist of any of the above--described viscous thermosettable resins, i.e. liquid coating vehicles, or others known to those skilled in the art, pre-pared in either different colors, or shades of the same color or both depending upon the color of the background sheet. Any of the above-described impregnating resins used 11'75~59~

25,741 to i~pxegnate the decor and/or overlay sheet~ ma~ be used to form the pigmented layer. The pigmented second reSinous layer may comprise the same resin used in impregnating the decor and/or overlay sheets or may be a dif~erent resin.
The said pigmented layer is positioned above the substrate.
By "above the substrate" is meant that the pigmented layer can be positioned anywhere above the substrate but not applied to the substrate before heat and pressure consolidation. It may be formed and positioned by merely coating elther side of the decor sheet or the overlay sheet or it may be formed and positioned by treating i.e. impregnating or coating, a third sheet therewith and positioning the third sheet between the decor sheet and the overlay sheet or atop the decor sheet or overlay sheet per se. That is to say, the pigmented , re~in layer may be;
1. Coated pn the substrate side of the decor sheet.
2. Coated on the top side of the decor sheet.
3. Coated on the decor side of the overlay sheet.
4. Coated on the top of the overlay sheet.
2~ 5. Coated onto or impregnated into a third sheet and positioned between the decor sheet and the overlay sheet with either surface face up.
6. Coated onto or impregnated into a third sheet and positioned atop a clear overlay sheet with either surface face up.
Ii a third sheet i9 used, it may be o~ the consistency and type of a core sheet, a decor sheet or an overlay sheet, usually depending upon where it will be positioned in the laminate assembly be~ore heat and pressure consolidation but it is prefe~red that it be cleax and be of the consistenc~
and type as an overl~y sheet. More than one coating or third sheet i,e, 2 or 3, may be used in one laminate. If more than 11'7959~

25,741 one coating or third sheet is used, they may be of the same or dif~erent color.
The resin used in preparing the pi~mented resin is generally composed of the same basic material as used in impregnating the decorative and overlay sheet as discussed above. The resins are dif~erent to the extent, however, that they should contain varying amounts of thinner~ ~olvents, fillers, etc. so as to vary their viscosities and thereby cause the pigmented material to flow more than the other resin during the consolid~tion procedure.
The pigmented resin may be colored by the inclusion therein of any one of, or a combination of, inorganic or organic color pigments, extender pigments, metallic pigments etc. The amount of pigment added to the resin will vary from .5% to 20%, based on the total weight of the resin, and dependent upon the pigment used and resultant color contrast desired. Typical inorganic pigments useful include those iron pigments ranging in color from yellow through red, reddish--brown, brown to black. Such iron pigments include yellow ocher, raw and burnt sienna, and raw and burnt umber. Other useful inorganic color pigments include chrome yellow, cadmium sulfide, zinc yellow, cobalt blue, ultramarine blue, iron oxide, chrome green, chromium oxide green, chromium hydroxide green, lamp black, and white pigments such as titanium dioxide, titanium calcium, zinc oxide, zinc sulfide, antimony oxide, lithopone, etc. Although lead pigments may be used, they are preferably avoided because of the safety hazard involved in their use, Organic pigments which may be used include toluidine red, phthalocyanine blue and green, Vandyke bxown, ~lizarin~ madder l~ke, lithol redt ~nd the like.
Use~ul metall;~c pigments include Aluminum powder, S9~ `

25,741 copper powder, bronze powders available in various shades depending upon the alloy composition, zinc powder, gold and ~old-like powders, and the like. Any of the pigments and particularly the metallic pigments, may be used alone or in combination with each other or in combination with other ~pigments. Furthermore, both resins may be pigmented as long as the colors employed are different and one flows more than the other, as discussed herein.
It has been found that the pigmented thermo~etting resin composition, in sither a~color or shade different from the decorative background sheet, is preferably provided in the laminate assembly by applying it, as a coating of from

5 gram/sq. ft. to 20 grams/sq. ft., to one or more surfaces of the decorative sheet, the overlay sheet or the third sheet, while they are in web form. The impregnated and coated webs, after drying are then cut to the desired size before being incorporated into the laminate assembly. The surface of the sheet or sheets to which the coating is applied i9 90 chosen that in the finished laminate the colored layer formed by the coating operation preferably lies between the decorative and overlay sheets although other positioning there-of is po~sible.
The impregnating and coating processes are pre-erably carried out as two separate operations during which the web is first impregnated with the first thermosetting resin composition and then d~ied before application of the pigmented, second resin layer composition and subsequent drying. Alternatively, the first thexmosetting resin may be applied to the p~pex sheet to i~pxegnate it therewith and the coating o~ the pigmented resin c~n be applied, such as by knife coatingr before either the impxegnated resin is dried. Alsc~ the pigmented coatin~ may be applied first, g 117~590 25,741 dried ~r not dried, and the re~ult~nt sh~et can then be impre~nated with the other resln.
The impregnation of the decorative and overlay webs is carried out using any of the above resin varnishes known for such use. For example, when employing the preferred melamine-fonmaldehyde resin compositions, satisfactory laminates are produced when the resin composition i8 applied in the form of an approximately 50~ resin solids content varnish in a mixèd alcohol-water solvent. When impregnati'ng the decorative sheet, the amount of resin applied is pre-ferably from 25% to 40~, based on the weight of resin solids in the impregnated web after drying to a volatile content of between 2% and 6%, and preferably about 4%. When im-pregnating the overlay paper, the amount of resin applied is preferably from 50% to 70%, and more preferably from 55%
to 60%, based on the weight of resin solids in the impregnated paper after drying to a volatile content of from 3~ to 8%, ,~ and preferably from 4.5% to 6.5%. Webs prepared having these resin and volatile contents may be cut into sheets that possess the necessary characteristics for good bonding to take place in the subsequent heat-pressing operation during which the resin becomes substantially fully cured.
When the laminates of this invention are prepared by coating an,impregnated decor or overlay sheet or a third sheet, the coating composition employed should be of such a nature and consistency that it may be satis~actorily applied to the i~pregnated webs in a uni~orm and controlled manner by the apparatus used, Any suitable method for applying the coating may be used such as by using a xeverse roll coater~, a gravure cylInder~, an ~ix kni~e~ a spxa,~er or a brush, Flow promotors which can he added to the one resin 117~59~

25,741 in order to cauqe it to ~low more than the other resin include ethylene glycol phenyl ether, and the like, Amounts of flow promotor ranging from about 0%-10%, by weight, based on the weight of the resin to which it is added, may be used. Best results have been achieved using a pigmented resin which flows more than the non-pigmented resin, However, if both resins are pigmented, either one may possess the required greater flowability. The flow rate of the resin selected to form the pigmented layer can, of course, be such that the pigmented resin inherently flows more than the first impregnated resin and, in such cases, no flow promotor need be used.
The embossed areas of the resultant laminate, i.e.
those formed from the protuberances of the embossing plate and forming the valley~ of the final embo~sment in the fi~ished laminate ~urface should preferably be at least .007 inch deep. Depths of less than .007 inch are possible but not preferred because the color contrast is not as evident.
Laminates of muted color differentials can be produced using embossments of the~e lesser depths however.
The release sheets used in the pressing of laminates of this invention, if necessary, are well known in the art and may be any non-adherable paper or non-adherable aluminum foil. The non-adherable paper may be a parchment type of paper of which a plurality are available commercially. The non-adherable metal folls, as well as the laminate of paper and the non-adhexable foils, are also commerclally avallable.
Also suitable for this purpose are papers coated~ t~eated or impregnated wlth polypropylene or the pol~fluorocarbons and the like, Films of polypropylene may also be used.
Silicone oil treated papers m~y be used and are also commercially available, Papers coated with ~odium alginate ~1'7~59~

25,741 and other salts of alginic acid are also suitable for this purpose and are available commercially, When "low pressure"
laminates are being formed, no release sheet at all is necessary if the press plate has a releasing surface thereon.
The same is true, but to a lesser degree, when one is producing "high pressure' laminates.
The following examples are set forth for purposes of illustration only and are not to be construed as limi-tations on the present invention except as set forth in the appended claims. All parts and percentages are by weight unless otherwise specified.
EXAMPLE A
Preparation of Embossing Master A 51 x 125 inch steel plate is sanded and a commercially available black asbestos furnace cement is coated onto the sanded surface~ leveled and then sculptured into a decign representing a series of flat flagstones with grouting therebetween. The coating is hardened and dried for 48 hours at 100C. The design imparting plate is then used to prepare a series of master copies by pressing it against an assemblage of 8 laminations of saturating kraft paper which has been impregnated with a water-soluble phenolic resin to a 55% resin pick-up and a 14-20% flow level. An assembly is prepared preparatory to insertion into a laminating press of the following items reading from the bottom up.
16 - sheets of kraft paper cushion l - the design master with the fl~gstone design facing up 1 ~ a pape~ back aluminum caul stock sheet l - an aluminum foil rele~se sheet 8 - sheets of kraft paper impregnated with phenolic resin _ 12 _ ~17~359~

25,741 1 a ~elea~e .sheet 16 ~ ~heets o~ kraft paper cushion The asse~ly is placed in a laminat~ng pre~s and after the pressing cycle is complete it is removed, the S aluminum faced, pressure consolidated sheet~ o~ kraft paper are recovered with the opposite image of the design master on one face thereof. Namely the grout lines now are the protuberant areas of the laminate.
This recovered laminate is called a "master" and is trimmed and used, in conjunction with other similarly prepared maqters, to produce decorative laminates according to the instant invention as set forth hereinbelow.

A) Preparation of decor face sheet lS A yellow, alpha-cellulose, saturating grade of paper having a basis weight of 90 lbs./3000 sq, ft, is impregnated with a 50% unpigmented melamine/formaldehyde resin solution having a mole ratio of melamlne to formaldehyde of about 1:2. This solution is designated as solution "A".
After passing through the solution, the impregnated web is dried using a conventional paper treating machine. The gap of the meter rolls, the temperature and air flow are adjusted until the resin content of the sheet is 52% by weight, the volatile content is 6.9% and the resin flow content is 5~. The impregnated decorative sheet is remounted on a similar coating/impregnating machine and ~y means of a reverse roll coater is coated with solution "B" which comprises solution "A" containing 5%~ based on solids weight of the resin, of phthalocyanine blue pigment and 1~ of ethylene ~lycol phenylether as a flow promoter~ ~olution "B"
is applied to the top side of the decorative sheet to the extent that 15 gms~q ft. are added. The resultant 11'79S9V

25,741 decorative sheet is dried ~or 3 minutes at 135~C, The resin ~low is me~sured at 20~. Neither the coatin~ nor the impregnated resin composition is substantially advanced in its degree of cure.
B) Making of _ Decorative Lamina*e An assembly is prepared preparatory to insertion into a laminating press of the following items ~rom the bottom up:
(a) a plurality of plies of kraft paper impregnated with phenol-formaldehyde resin at 30% resin content, (b) the blue resin coated, impregnated, yellow decor sheet prepared under A, above, with the color coated side facing ~c), ~c) an aluminum foil releasing sheet and ~d) the embossing "master" from Example A, above, - with the flagstone design facing the blue resin coating of the decorative sheet.
The assembly is inserted into laminating press.
With the pack under a pressure of 1200 psi, the temperature of the press platens is raised to 290F within 30 minutes, held at this level for 20 minutes to accomplish curing of the resin~, and then returned to room temperature in another 30 minutes.
Upon removal from the press, the master plate is separated from the decorative laminate. The resultant decorative laminate has an attxactive embossed ~lat flagstone design with the high ~lat flagstone protubexant areas a blue color and the grout lines or valley a~eqs ~ cle~ yellow color. The depth of the embossment ~s 12 mils, _ 14 ~

~ ` "
11'~95''3~

25,741 EXAMPLE 2 Example 1 is repeated in all essential details except that a 26 lb./3000 sq. ft. alpha~cellulose overlaY
sheet is impregnated with clear melamine/formaldehyde resin and dried, The resultant overlay, which cont~ins a resin content of 65~, is then interposed between the ~lue pigmented coated decor surface and the aluminum release sheet, After the pressing, the results are the same as in Ex~mple 1.
EXA~LE 3 Example 2 is repeated in all essential details except that instead of the yellow decor sheet being coated with pigmented solution "B", the same coating is applied to one side of the dried impregnated overlay. In assembling the materials for pressing, the overlay is placed over the yellow decor sheet with the blue coated side of the overlay in an adjacent relationship with the decor surface. After the pressing, the laminate i9 examined and found comparable to Example 2.

Exæmple 1 is repeated in all essential details except the dried coating weight applied to the decor layer is 3 gms./sq. ft. After the pressing the laminate is examined and has good color contrast.

Example 1 is repeated except that the blue coating is applied to the side of the decor sheet adjacent the kraft paper core plies, Again the color contrast between the grout lines and the flagstones i9 excellent.
EX~MpLE 6 Exa~ple 1 is ~epeated in all essential details except that the yellow decox sheet ~s coated with a solution comprising solution "~", above, containing 1~4~ of a brown -11~9590 25,741 iron oxide pi~ment and 1% of ethylene glycol phen~l ether.
The "master" used carries a leather texture design~ After pressing, the laminate is recovered and examined~ The valley area is yellow to light brown whereas the raised part of the design is dark brown.

Example l is repeated in all essential details except that (a) the design imparting "master" has the configuration of burlap, (b) a black decor impregnated ~heet 0 i8 coated with a solution comprising solution "A", above, containing 5% of brown iron oxide pigment and l~ ethylene glycol phenylether. After pressing, a laminate is recovered with a three dimensional textured burlap design with the valley areas black and the relief or thread areas a pleasing brown color.

Example 1 is repeated in all details,lexcept that (a) a slate textured design imparting "master" is used and ! (b) a black color impregnated decor sheet is coated with a solution comprising ~olution "A", above, containing 1%
aluminum powder and 1% ethylene glycol phenylether. After pressing, the laminate is examined. The valley areas of the slate design are black whereas the broad flat relief portions of the slate are metallic aluminum and the laminate has an antique appearance.

Example 1 is repeated in all essential details except that a 3~4" particleboard core weighing 45 lbs./cu. ft.
is used in place of the plurality o~ resin impregnated core stock plies~ A~ter pressing ~or 4 minutes ~t 310aF
under ~ pre~sure o~ 325 psi~ a decorative p~nel is recovered having ~n attr~ctive embossed ~urface o~ contrasting color.

11'7~S90 l ~XAM~LFA 10 (Comparative) ~ xample 1 is repeated except that the yellow decor sheet is impregnated only with solution "A" containing the blue pigment. No other impregnation or color layer is added to the decor sheet. After pressin~, the laminate has a mottled blue to green overall appearance without contrast coloration.
EXAMPLE ll (Comparative) Example 3 is repeated except that a raw overlay paper is impregnated with solutlon "A" containing the blue pigment. No other impregnation or color layer is added to the overlay sheet. Ater pressing the laminate is examined, and the results are comparable to those obtained ln Example 10.
EXAMPLE 12 (Comparative) The blue pigmented coating of Exam~le 1 is applied to the top ply of the kraft impregnated paper core assembly adjacent to the yellow decor sheet. After pressing there is no contast coloration and the overall appearance is yellow.
EXAr~LE 13 A 26 pound basis weight, plasticized melamine/form-aldehyde resin impregnated overlay is coated with the blue pigmented coating of Example l. This overlay is then placed on top of the yellow pigmented decor sheet with the coated blue side away from the decor sheet. After pres~ing there is excellent color contrast between the grout lines and the flagstones.
EXAMPLE 14 (Comparative) Example 13 is repeated in all essential details except that the clear, coated, impregnated overlay is placed between the top ply of the kraft core and the yellow pigmented decor sheet with the blue pigmented coating facing away ~rom the core sheet. After pressing there is no contrast coloration and the overall appearance was yellow.

11'7959C~

25, 741 EXAMPLE 15 (Comparative) Example 1 is repeated in 411 essential details except that a melamine/formaldehyde resin impregnated overlay is reverse roll coated with a solution "A" containing 5%, based on the solids weight of the resin, of red iron oxide pigment and 1~ ethylene glycol phenylether as a ~low promoter. This red overlay sheet is placed under the blue coated yellow decor with the red side up. After pressing the laminate only showed the contrast o the blue and yellow 10 coloration. There was no evidence of any third color.

The procedure of Example 13 is repeated in all details except that the clear, coated overlay (third sheet) is placed between the yellow decor sheet and a regular 15 unpigmented melamine/formaldehyde resin impregnated overlay sheet with the coating facing the overlay sheet. An excellent color contrast between the flagstones and the grout lines is observed.

The procedure of Example 15 is again followed except that the coating on the clear, third sheet i9 facing the decor sheet. Again, excellent contrast is observed.

Again following the procedure of Example 14 except 25 that the clear, coated impregnated overlay (third sheet) is placed, with the coated side down, atop the overlay which comprises a normal a-cellulose sheet impregnated with an unpigmented melamine~ormaldehyde thermosettin~ resin, an excellent contrast between the color o~ the grout and that 30 o~ the ~lag~tones is achie~ed~

11795~3~

25,741 EXAMPLE 19 Example 17 is followed in all es~enti~l details except that the coating o~ the third sheet is facinq upward~.
Substantially identical results are obser~ed.
. .

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A heat and pressure consolidated laminate of registered embossment and color contrast comprising, in superimposed relation-ship, 1) a rigidity imparting substrate selected from the group consisting of particleboard and a plurality of phenol/
formaldehyde impregnated fibrous sheets, 2) a fibrous, decor sheet impregnated with a first colorless thermoset melamine/formaldehyde resin, and 3) a coating of from about 0.5 gram/sq.ft. to about 20 grams/sq.ft. of a pigmented, second thermoset melamine/formal-dehyde resin positioned on said (2), said coating containing from about 0.5% to about 20.0% of pigment, based on the total weight of said second resin the surface of said laminate containing an embossment consisting of protuberances and valleys each of which are of a different color, the color of said (2) being prim-arily evidenced at the valleys thereof and the color of said second resin being primarily evidenced at the protuberances thereof.

2. A method of producing an embossed laminate of registered embossment and color contrast which comprises (a) heat and pressure consolidating a laminate assembly comprising, in superimposed relationship, 1) a ridigity imparting substrate selected from the group consisting of particleboard and phenol/formaldehyde impreg-nated fibrous sheets, 2) a fibrous, decor sheet impregnated with a first colorless thermosetting melamine/formaldehyde resin, 3) an embossing press plate having a surface with pro-tuberant and valley areas capable of being impressed into the uppermost of said fibrous sheets and means for preventing the embossing plate from sticking to the decor sheet during lamination, and 4) a coating of from about 0.5 gram/sq.ft. to about 20 grams/sq.ft. of a pigmented, second thermosetting melamine/formal-dehyde resin positioned on said (2), said coating containing from about 0.5% to about 20% of pigment, based on the total weight of said second resin said second resin having a flow sufficient to cause said second resin to flow more than said first resin, (b) removing said embossing press plate from the resultant laminates, and (c) recovering the resultant laminate.

3. The method of claim 2 wherein said substrate comprises a plurality of phenol/formaldehyde impregnated paper sheets.

4. The method of claim 2 wherein said substrate comprises a particleboard core.

5. A laminate according to claim 1 in which the decor sheet is covered with an overlay sheet and said overlay sheet is comprised of an unpigmented, alpha-cellulose paper layer impregnated with a thermosetting melamine/formaldehyde resin.

6. The laminate of claim 1 wherein said substrate comprises a plurality of phenol/formaldehyde impregnated paper sheets.

7. The laminate of claim 1 wherein said substrate comprises a particleboard core.

8. The laminate of claim 1 wherein said coating is positioned adjacent to said substrate.

9. The laminate of claim 1 wherein said coating is positioned atop said decor sheet.

10. A method according to claim 2 wherein said coating is positioned adjacent to said substrate.

11. A method according to claim 2 wherein said coating is positioned atop said decor sheet.

12, A laminate according to claim 5 wherein said coating is positioned atop said decor sheet.

13. A method of forming a unitary decorative laminate having registered color and embossing, comprising:
(A) assembling in a stack from the bottom up (1) backing means for said decorative laminate, (2) a thermosetting resin impregnated fibrous print sheet with a color, (3) a dried opacifying coating comprising a thermosetting resin having dispersed therein finely divided pigment of a color contrasting with said first color, (4) a fibrous overlay sheet impregnated with a thermosetting resin, and (5) a sculptured pressing plate die having a surface with high areas and low areas capable of being impressed into the uppermost of said fibrous sheets, and means to prevent said sculptured pressing plate die from sticking to said over-lay sheet during lamination;
(B) applying to the upper and lower surfaces of said assembly sufficient heat and pressure to cure said resins to produce said unitary embossed decorative high pressure laminate by (1) effecting a lamination of said fibrous sheets together with each other and with said backing means;
(2) imparting the sculptured surface of said die to the upper-most of said fibrous sheets, and (3) effecting lateral flow of said opacifying thermosetting resin and pigment coating from the debossed portions beneath the surface of said laminate to the embossed portions of said laminate so that said first color is visible in said debossed portions and said contrasting color of said finely divided pigment is visible in said embossed portions;
and (C) stripping said sculptured die from the resultant laminated assembly so as to provide said laminate having areas of registered color and embossing.

14. A method in accordance with claim 13, for forming a high pressure decorative laminate, wherein said backing means comprise phenolic resin impregnated core sheets, wherein said print sheet comprises a melamine resin impregnated .alpha.-cellulose paper wherein said melamine resin is precured to a volatile content of about 3 - 5%, said overlay sheet comprises melamine resin impregnated .alpha.-cellulose paper, and said thermosetting resin in said coating comprises melamine resin, said coating being applied to the upper surface of said print sheet.

15. A decorative laminate having registered color and embossing, comprising a plurality of cured resin impregnated sheets laminated together, including a backing, a resin impregnated print sheet having a first color and located above said backing, and a generally transparent resin impregnat-ed protective overlay sheet above said print sheet, a layer of an opacifying mixture comprising resin and pigment having a second color, said opacifying mixture layer being located between said print sheet and said protective overlay sheet, said laminate having surface depth variations on its upper surface including embossed areas and debossed areas, said embossed areas having a concentrated quantity of said opacifying mixture between said transparent protective overlay sheet and said print sheet, and said debossed portions being relatively devoid of said opacifying mixture between said transparent protective overlay sheet and said print sheet, wherein there is separation of colors such that beneath said transparent protective overlay sheet in said debossed portions there is visible said first color of said print sheet, and in said embossed portions there is visible said second color of said pigment of said opacifying mixture and wherein said layer of said opacifying mixture is most opaque in the most embossed areas and becomes progressively more transparent toward the most debossed areas, to provide gradations in color between said first and second colors from said debossed areas to said embossed areas.

16. A decorative laminate in accordance with claim 15 wherein said opacifying layer was applied as a coating onto said print sheet as a liquid containing 5 to 10% by weight of said pigment based on the resin in said coating at the rate of 2 to 5 grams per square foot.

17. A method in accordance with claim 13 wherein in step B said assembly is pressed at approximately 1200 psi at a temperature on the order of 290°.

18. A laminate according to claim 1 wherein the phenol/
formaldehyde impregnated fibrous sheets comprise kraft paper sheets.

19. A laminate according to claim 1 or claim 18 wherein the fibrous decor sheet is a kraft paper sheet.