CA1068993A - Pressure sensitive adhesive coated laminate and method for making same - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A pressure sensitive adhesive coated laminate composed of a top facing layer, a continuous interlater of a pressure sensitive adhesive, a bottom release surface, and interposed between the release surface and the pressure sensitive adhesive layer, a non-continuous uniformly distributed layer of a material which produces a low zero-minute peel value in the pressure sensitive adhesive layer so that the laminate can be easily applied to a substrate and removed and repositioned or straightened, if necessary, and which provides an increase in peel value over a period of time to provide a more permanent installation. The laminate is suitable for use as decorative and/or protective covering as well as adhesive tapes, labels, and the like.

Description

~8~3 BACKGROUND OF THE INVENTION

1. Field of the Invention . ._ _ This invention pertains to the field of laminates having a pressure sensitive adhesive layer. More particularly, thls invention relates to pressure sensitive adhesive coated laminates for covering substrates for decorative and/or protective purposes or for adhesive tapes, labels, and the like.

2~ Description of the Prior Art .
The development of pressure sensitive adhesive systems has resulted in their use in a great variety of areas, such as, for tapes, decals, decorative and protective coverings in sheet form for walls, furniture, and the like, self-stick floor coverings, and generally, for any purpose ; wherein it is desired to adhere an article ~o a substrate.
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Because of the increased movement towards the so~called "do-it-yourself" type of home improvements and decorating, many articles, such as, wall coverings, counter coverings, tile appliques, shelving covers and edgings, and the like, are now sold with pressure sensitive adhesive coatings thereon. Such pressure sensitive adhesive coatings facilitate the application of such articles to the desired substrate hy eliminating the need to apply a separate adhesive or to utilize another type of securing device, such as nails, screws, staples, etc.

One of the problems with such pressure sensitive adhesive coated articles is that, in use, they are extremely difficult to position and, if necessary, reposition, even immediately after the application to the substrate. This pxoble~ is particularly severe with articles which are in the form of decorative and protective sheets coated with a pressure sensitive adhesive, and which are used to cover substrates, e.g., walls, cabinet tops, furniture, etc. Very often, such sheets or laminates possess decorative patterns on the outer face and it is important that the proper matching of the patterns from adjacent sheets be obtained~ Moreover, it is often important that the seams between adjacent sheets be straightr uniform, and parallel.

1(~68993 Another problem which arises, particularly with larger pieces or sheets, such as, when one is attempting to cover a large piece of furniture or large wall area, is the difficulty in handling the sheet and the avoidance of touching of one area of the pressure sensitive adhesive coated side of the sheet with another area of the same side. When this occurs, the sheet will fold and the respective touching areas must be pulled apart. This can become extremely cumbersome, particu-larly with large sheets.

It also can result in removal of areas of the pressure sensitive adhesive coating when an attempt is made to pull the touching areas apart and cause discontinuities of the pressure sensitive adhesive coating as well as produce torn, stretched or wrinkled areas in the facing sheet which is usually made from paper or plastic sheeting or film.

Additionall~, on application of the laminate to a substrate, folds, wrinkles, and bubbles often appear. These are relatively difficult to remove because of the aggressive-ness of the pressure sensitive coated sheet for the substrate.
This can be particularly troublesome when the facing layer is relatively thin, such as, for example, a thin film of vinyl.

The difficulty o~ handling the larger size sheets is further increased by their affinity for picking up electrostatic charges. This problem often makes it very cumbersome to keep the sheet from touching the substrate, e.g., a wall, etcO, before the sheet is properly positioned. Once the sheet has touched the wall, it is difficult to remove and replace it in the proper position.

8~3i93 ~ 1 SUM~ARY OF THE INVENTION
Applicants have discovered a new laminate of the type comprising a facing layer, generally of a decorative or protective material having inner and outer surfaces, and a layer of a pressure sensitive adhesive ad~acent to the inner surface, with which the above noted problems attend~nt to the commercially available laminates of this type are minimized.
Conventionally, such laminates are provided with a bottom layer of a release sheet or release surface adjacent to the pressure sensitive adhesive layer.
Particularly, applicants have discovered that by depositing on the surface of the pressure sensitive adhesive layer, a substantially uniformly distributed, dis-continuous layer of a material possessing certain chemical and physical properties as defined hereinafter, a pressure sens-itive adhes:ive laminate is obtained which is easily positioned and adhered to the substrates, and which can be removed, and, if necessary, repositioned with ease during the application time.
Specifically, the materîal used as a non-continuous layer is a polysiloxane which is non-tacky, but is of an appropriate molecular weight so that it is, by itself coatable, or can be rendered coatable, e.g., by dilution or emulsification, for purposes of manufacture of the laminate.
When a release sheet or release surface is present, the polysiloxane layer is interposed as an interlayer between the release layer and the pressure sensitive adhesive layer, .,. j ~ .
, : : :, 9~3 By virtue of the effect which the interlayer material exerts on the pressure sensitive adhesive, the laminate, at the time of removal Erom the release surface, i.e., when it is about to be applied to the substrate, possesses a relatively low peel value, i.e., a low degree oE afEinity for the substrate. ~s a consequence, if, when applied to the sub-strate, the particular sheet is not straight or in the desired position, it is easily removed for repositioning. Moreover, if two areas of the pressure sensitive adhesive coated side 10 of the sheet should touch one another, they are easily pulled ~;
apart without disturbing the uniformity of the coating of the pressure sensitive adhesive or stretching or wrinkling ;
of the facing layer.
Furthermore, any air bubbles or wrinkles which occur in the laminate on application to the substrate, ma~ be easily removed by smoothing with hand pressure.
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~613~3 The present invention the~,in one aspect, resides in a laminate which comprises: (a) a facing layer havlng an outer surface and an inner surface; (b) a substantially continuous . .
layer of a pressure sensltive adhesive adjacent to the inner surface of the facing layer; (cl means or decreasing the "zero peel value" of the facing layer-pressure sensitive adhesive layer combination, said means comprising a discontinuous, uniformly distributed layer of a coatable polysiloxane adjacent to the surface of the pressure sensitive adhesive layer, said polysiloxane being formed from monomeric units having structures (I) and (II) as follows:

(I) ~ 1 51 - O ~

and (II) 3 ~ O ~

wherein Rl is selected from the group consisting of: -(i) phenyl; (ii) methyl; (iii) tolyl;
(iv) R ~ 7 C = C

~ ~ -6a-: :~ . .

~6~3~93 wherein R7 and R8 may be the same or different and may be hydrogen, methyl, or ethyl, and wherein when Rl is group Ci~, (ii), Ciii) or (:iv), the prime mole percent of structure (I) is from about 0.5 to S0 and the prime mole percent of structure (lI) is from 99.5 to 50, and (v) polyoxyalkylene having the structural formula R5(OC2H5~n(Oc3H6)moR6 wherein R6 is a monovalent hydrocarbon group having from 1 to 10 carbon atoms, R5 is an alkylene group having at least two carbon atoms, n and m are numbers, and the sum of n and m is such that the oxyalkylene block R6O(C3H6O)m(C2H50)n, has a molecular weight of at least 1500, from 1~ to 60 weight percent of the oxyalkylene units are oxyethylene units, and wherein there are at least three units having structure (I) and at least 40 units having structure (II) and wherein the oxyalkylene block constitutes from 85 to 30 weigth percent o.f the polysiloxane polymer; R2 may be methyl, ethyl, or phenyl;
and R3, and R4 may be the same or different and may be methyl ;~
or ethyl.
In another aspect, this invention resides in a stock of a plurality of sheets, each sheet being a self-adhesive laminate which comprises: (a) a facing layer having an outer surface and an inner surface, the outer surface being a release surface; (b) a substantially continuous layer of a pressure sensitive adhesive adjacent to and contiguous with the inner surface of the facing layer; and (c) means for decreasing the "zero peel value" of the facing layer-pressure sensitive adhesive layer combination, said means comprising a discontinuous, uniformly distributed layer of a coatable polysiloxane between the pressure sensitive adhesive layer ~ -6b-, .
r .

~8~93 and the reIease surface, said polysiloxane being formed frommonomeric units having structures CI~ and (~ as follows:

(I) R

-~ li o~
L ~ 1 and (II) 3 _ ~i - O--I ~ ,:

wherein Rl is selected from the group consisting of: (i~

phenyl; (ii) methyl; (iii) tolyl; (iv~ R~ H

C = C--;

wherein R7 and R8 may be the same or different and may be hydrogen, methyl, or ethyl, and wherein when R1 is group (i~, (ii~, (iii) or (iv), the prime mole percent of structure (I) is from about 0.5 to 50 and the prime mole;percent of structure (II) is from about 99.5 to 50, and (v) polyoxy-alkylene having the structural formula -R5~0c2~5)n(0c3H6)moR6 wherein R6 is a monovalent hydrocarbon group having from 1 to 10 carbon atoms, R5 is an alkylene yroup having at least two ~ -6c-1~6~ 3 carbon atoms, n and m are'numbers, and the sum of n and m is such that the oxyal~ylene ~lock R6O(C3H6O~m(C2~I5Oln~ has a molecular weight of at least 1500, from 15 to 60 weight percent of the oxyalkylene units are oxyethylene units, and wherein there are at least three units having structure (I) and at least 40 units having structure (IIl and wherein the oxyalkylene block constitutes from 85 to 30 weight percent of the polysiloxane polymer; R2 may be methyl, ethyl, or phenyl; ~ :
R3, and R4 may be the same or different and may be methyl or ethyl, wherein the sheets are stacked such that the poly-siloxane layer of one sheet is immediately adjacent to the release surface of the next sheet in the stack.
The present invention, in a further aspect, resides in the improvement in a method for maklng a laminate wherein a first sheet having a release surface thereon is coated with a pressure sensitive adhesive to form a first laminate, and the first laminate is then subjected to conditions suitable to dry or cure the pressure sensitive adhesive, and the pressure ;~
sensitive adhesive side of the thus treated first laminate is married to the inner surface of a facing layer having inner and outer surfaces~ the improvement in question comprising coating the release surface prior to t~e coating of the pressure sensitive adhesive thereon with means for decreasing the "zero peel value" of the facing layer-pressure sensitive adhesive layer combination, said means comprising a uniform and discontinuous layer of a coatable polysiloxane, said polysiloxane being formed from monomeric units having struc~
tur~s (I) and (II) as follows:

~ -6d-`~1 .

~61~9~ ~

(I~ Rl li oL

and CII) 3 _ _ ,.

~ S' - 0~ :

wherein Rl is selected rom the group consisting of (i~ phenyl;

(ii) methyl; (iii) tolyl; (iv) R~ H :
/C =

wherein R7 and R8 may be the same or different and may be hydrogen, methyl, or ethyl, and wherein when Rl is group (i), (ii), (iii) or (iv), the prime mole percent of structure (I) is from about 0.5 to 50 and the prime mole percent of structure (II) is from about 99O5 to 50, and (v) polyoxyalkylene having the structural formula -R5(OC2~5)n(OC3~6)m 6 6 is a monovalent hydrocarbon group ha~ing from 1 to 10 carbon atoms, R5 is an alkylene group having at least two carbon atoms, n and m are numbers, and the sum of n and m is such that the oxyalkylene block R6O(C3H6O)m(C2H5 ~n~
weight of at least 1500, from 15 to 60 weight percent of the oxyalkylene units are oxyethylene units, and wherein there ~ -6e- :

~0~8~93 are at least three units having structure CI~ and at least 40 units havi.ng structure (II~ and wherein the oxyalkylene block constitutes from 85 to 30 weight percent of the polysiloxane polymer; R2 may be methyl, ethyl, or phenyl; and R3, and R4 may be the same or different and may be methyl or ethyl.

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~ 3 BRIEF DESCRIPTION OF THE DRAWING

Figs. 1, 2, 3, 4, and 5, are sequential cross-sectional diagrams illustrating the formation of a laminate in accordance with the present invention.
Fig. 6 is a schematic drawing of a process in accordance with the present invention.
Fig. 7 is a drawing similar to Fig. 6 of another process in accordance with the present invention.
Fig. 8 is a drawing similar to FigO 6 of yet another process in accordance with the present invention.
Fig. 9 is a photograph of the pressure sensitive adhesive coated side of the laminate 18 of Fig. 5.
Fig. 10 is a photograph of droplets 12 on layer 10 of Fig.5.
Fig. 11 is a graph of peel values determined at different aging times on an acrylic coated test surface for laminates prepared using different laminating pressures.

Fig. 12 is a graph showing the variation in peel value with residence time on an acrylic coated test surface for samples prepared using varying concentrations of polysiloxane material and zero laminating pressure.
Fig. 13 is a graph showing the change in peel value with resident time on an acrylic coated test surface for samples prepared using varying concentrations of polysiloxane material with a 165 line quadrangular cell gravure xoll.
Fig. 14 is a graph similar to that of Fig. 11 wherein a 120 line quadrangular cell gravure roll was used.
Fig. 15 is a graph similax to that of Fig. 11 wherein an 80 line quadrangular cell roll was used.

lal6~g93 Fig. 16 is a graph showing the variation in peel value with resident time on an acrylic coated test surface for samples prepared using a 10% concentration by weight of poly~
siloxane material and gravure rolls having different cell volumes.

DESCRIPTION OF THE PREFERRED
E~BODI~ENT
Referring to the figures, Fig. 1 shows a conventional backing layer 10 used for a pressure sensitive adhesive laminate, This material is generally referred to as a release sheet, although, in actuality, it may be fabricated from t~o separate ,' components, namely a supporting sheet, such as, kraft paper or other material having sufficient dimensional stability to act as a supporting sheet, and a coating of a release material thereon. Such sheets may also be impregnated with the release material.
The most well known and economical type release sheet used presently is an unbleached kraft paper directly coated on one or both sides with a cured silicone. It is possible~
however, to use other release materials, such as, glassine papers, spun bonded synthetic non-wovens, e,g,, polyethylene, or continuous films of extruded synthetics, e.g., polyesters, ~;
polyethylene, polypropylene, "Cellophane"*, and the like, which possess release properties in the untreated state, Generally, however, the inherent release properties of such films are not sufficient and must be improved by coating with release compositions, such as, the cured silîcones mentioned hereinabove, *Trademark for a brand of regenerated cellulose film produced from viscose by treatment with sulfuric acid and/or ammonium salts.

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31g3 Such release sheets or surfaces, and methods for their ;
preparation are well known. Typically, the paper or backing sheet is dipped into a bath oE a silicone release agent, or coated on one or both sides with the release agent, and then cured. Such methods are described in U.S. Patent No 3,503,782 of Elwyn C. Ayres, granted March 31, 1970. Alternately, the release material may be knife or roller coated onto a sheet.
In any event, regardless what type release material is used, it is necessary only, that the surface ll of the support~ ;
ing or backing sheet 10 possess properties of good release with respect to pressure sensitive adhesive materials.
Alternately, the release surface can be the outer - surface of the facing layer 10 of the laminate such that the laminate is rolled upon itself as described hereinafter ~ith a reference to Figs. 7 and 8. The release properties may be ;~
an inherent quality of the outer surface of the facing layer or a quality imparted through conventionally known finishing -~
or coating techniques.
Disposed on top of the backing sheet 10 is a sub~
stantially uniformly distributed, discontinuous layer of a polysiloxane material designated generally as 12. This material is described in detail hereinafter and is disposed on the surface ~ -of the backing sheet in the form of small droplets or beads~
As used herein, the terms "droplets" or "beads"
means a relatively fine dispersion of small droplets or beads~ of the interlayer formed on release surface 10. The nature of these droplets is discussed in detail hereinafter with respect to Figs. 10 and 11.

_ g _ . .,: . . ..

1(~089'~ ~
The non-continuous layer 12 may be deposited on backing sheet 10 by numerous methods which are conventional in the art.
The choice of kechnique may depend on the nature of the release layer and the nature of the facing layer, as well as the phys-ical characteristics of the polysiloxane, i.e., viscosity, liquid nature, etc. Thus, for example, it is possible to spray the material on to the sheet or to use a padding roll, kiss roller, rotogravure roll and the like. Depending on the method of application, it is possible to control the depositicn of the liquid material on the backing sheet, in terms of uniformity of application as well as discontinuity of the film.
If the polysiloxane material is applied in the form of a solution or emulsion for purposes of the coating procedure used, it will be necessary, of course, to remove the diluen~, i.e., solvent or dispersing mediums. Such removal is conven-tionally effected by heating to evaporate the ~aterial to be removed.

Reerring now to Fig. 3, a layer of a pressure sensitive adhesive material is then coated on top of the backing sheet-polysiloxane combination of Fig. 2 to form a laminate sometimes referred to hereinafter as a "first laminate". The coating of the pressure sensitive adhesive layer 14 may be accomplished by conventional methods, e.g., knife-coating, spraying, roller coating, gravure roll, and the like.

l~6~as ~

¦ The pressure sensitive adhesive 14 may be one from a well ¦ known class of adhesive materials generally available in the art.
¦ Typically, such an adhesive comprises a two component system, ¦ one component of which is a polymer or resin which is ¦ intrinsically tacky, such as, a tacky elastomer, or has inter-¦ mixed therewith, a resin imparting tackiness and a second ¦ component which is a tack controlling component to reduce the ¦ tack of the adhesive layer to the desired peel bond value. The ¦ second component also imparts cutting properties to the adhesive layer so that it will cut when the transferrable film, i.e., the ¦ facing layer is cut.

¦ Also, as shown in Fig. 5, it is important in the use of ¦ conventional pressure sensitive adhesive materials that the adhesive layer, 14, remain with the facing layer, and not with ¦ the release layer 10 upon stripping.
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¦ The second component is preferably a readily deformable ¦ material in order to allow the adhesive layer to make adequate ¦ contact with the receiving surface of the substrate which may be rough in texture. The tack controlling component is usually present in concentrations of from about 6 to 65 parts per 100 ¦ parts of the total tacky compound.

I

l Intrinsically tacky polymers include polyacrylic or meth-!~ acrylic esters and acids; polyvinyl ethers; co-polymers of ¦ vinyl ethers and the aforesaid acrylic compounds; polyisobutylene and polybutenes; natural rubber; synthetic polyisoprene;
polyvinylesters; polychloroprene; polybutadiene and co-polymers of butadiene with styrene.

Tackifying resins include hydrocarbon resins, terpene resins, such as, polybeta-pinene resin; resin derivatives, such as, hydrogenated resins and esters and liquid mixtures of polymeric styrene and homologues. Preferred materials are polyvinylbutylether; polyvinylethylether; polyvinyl-methylether; polybutylacrylate or co-polymers of butylacrylate and methacrylate.
A detailed description of such materials is set forth in U. S. Patent No, 3,432,376 of Kenneth J~ Reed et al., granted March 11, 1979, said patent being assigned to Letraset Limited.
Subsequent to the application of pressure sensitive adhesive layer 14, the laminate is subjected to a drying or ~ curing step, such as, for example, heating, ultra violet irra-; diation, electron beam irradiation, and other methods which are conventionally used for such pressure sensitive adhesive materials. Understandably, the particular method used will be dependent upon the nature of the pressure sensitive adhesive material used; however, such methods are conventional in the art.
2~ The pressure sensitive adhesive materials conventionally used are either soluble or dispersible in water or organic solvents. Also, materials have been developed which are them-selves liquids, or possess relatively high solids content, but nevertheless can be coated or applied without dilution or emulsification. Also known are materials known as the "hot melt" type which are rendered coatable by heatingO ;

106~993 However, the particular type of pressure sensitive material used is not critical so long as it fulfills its func~ion as a pressure sensitive adhesive and does not adversely affect the other desirable properties of the laminate.

-Subsequent to the curing step, a facing layer 16 is married to the first laminate of Fig. 3 to form the final laminate shown in Fig. 4.

Facing layer 16 is generally a ~heet-like material which can be decorative or protective in nature and can be wood, including wood veneer, metal, such as, metal foil, paper or a plastic film forming material, eOg., vinyl polymers such as, polyvinyl chloride, polyvinylidene chloride, copolymers of polyvinyl chloride and polyvinylidene chloride; polyolefins, e.g., polypropylene, polyethylene; polyesters, etc., woven or non-woven fabric, and the~like. Typically, the facing layer may have a dacorative pattern embossed, printed, or otherwise imposed thereon~ Alternately, the facing layer may be composed of two or more separate sub-layersO

For example, it is possible ~o use a top layer which is substantially transparent sheet of a protective film, e.g., polyvinyl chloride, polyvinylidene chloride, copolymers of polyvinyl chloride and polyvinylidene chloride; polyester, polypropylene~ polyethylene, polyacrylate, urethane~, hard surfaced resins, etc., and a lower sheet which may be composed of the same type materials a~ described hereinabove with respect to a single facing layer.

1~6~993 Generally, such a transparent layer can serve the function both of protecting the decorative pattern of the bottom facing sheet, and in addition, can itself contribute to the over-all decorative appearance of the laminate, as by producing a shiny effect or high gloss.

Other types of decorative facing layers, such as, flocked fabrics or films, and polymeric films, such as, polyester films having a thin deposit of metal thereon (metalized), vinyl films coated with resin-pigment combinations in a decorative pattern, and the like can be used as the facing layer.

Fig. 5 shows the method of utilization of the laminate in accordance with the present invention wherein components 12, 14, and 16, generally designated as 18, are separated from backing sheet 10.

On separation of the layers, an effective amount of the droplets of polysiloxane lay~r 12 is removed from release layer 10 and remains with pressure sensitive adhesive layer 14. Thus, the polysiloxane interlayer material 12 possesses a greater affinity for the pressure sensitive adhesive material of layer 14 than for the release surface ll of sheet 10. Consequently, although a relatively small residue of the polysiloxane may remain on the removed release surface ll, the amount of the polysiloxane carried away from the release surface ll by adhesive layer 14 is that amount which is effective to produce the desired reduction in "zero peel value" (as defined herein-after) of the laminate 18.
, .

Il 106~3993 It is understood, of course, that Fig. S represents an approximate schematic view of the disposition of the droplets on the surface of the pressure sensitive adhesive layer. Thus, when viewed microscopically, the pressure sensitive adhesive layer is not smooth but, possesses a surface having concave and convex portions. Consequently, the droplets may be disposed at the bottom of a concavity or on the top or side of a convex portion.

After stripping backing layer 10 from layers 18, the combination of layers designated 18 may be applied to the desired substrate, e.g., furniture, walls, cabinet surfaces, etc. By virtue of the unique properties of laminate 18 bestowed on it by the presence of droplets 12, it is possible to easily position layer 18 on to the substrate, to ~asily remove it and to reposition it if necessary. Moreover, as noted hereinabove, if various portions of the pressure sensitive adhesive side of laminate 18 should touch one another, they are easily pulled apart without disturbing the uniformity of the pressure sensitiv~
adhesive layerO ~onsequently, the usual tangles, wrinkles, creases, stretches, etc., frequently encountered with pressure sensitive coated material of this type are avoidedO

8~ 3 : ,.
More particularly, the unique and highly unexpected properties of the present invention reside in the relative physical properties of the interlayer material composing drop-lets 12 to the pressure sensitive adhesive and the release materlal of backing sheet 10. It should be noted, in this re-gard, that once the laminate 18 is properly placed on the substrate, after a period of time, its adhesion to the substrate becomes essentially permanent and similar to that of conventional laminates of this type having the conventional pressure sensitive adhesive coated surfaces.
The method of forming laminates of the general type shown in Fig. 4 are well known as illustrated by U.S~
Patent No. 3,554,835 of Burton D. Morgan, granted January 12, 1971, and U.S. Patent No. 3,130,113 of David Silman, granted ~pril 12, 1964.
Referring now to Fig. 6, a method for forming the laminate as described hereinabove comprises first coating a sheet of backing material 20 which suitably may be a kraft paper or other supportive sheet as defined hereinafter Erom roll 22 which turns in the direction indicated by arrow A
with a suitable release material 24, such as, a silicone, ~ ;
or one of the other conventional materials used for this purpose.

~68~93 The means for coating such material are well known, and as shown, a knife coater, 26, is utilized in the schematic.
Thereafter, the coated sheet is passed thru curing oven 28 which utilizes a conventional curing means, such as, heat, ionizing radiation, etc., to appropriately cure or set the release material. This produces a release surface 11 on sheet 30.

Relsase sheet 30 is then coated with the interlayer material from reservoir 32 utilizing gravure station 34.

As described hereinafter, this interlayer material possesses unique properties with respect to the release layer so that it forms beads or droplets thereon. The thus coated sheet is passed through a diluent removal step, e.g., a heating oven 35, to remove any diluent or solvent used for application of the interlayer. Ordinarily, the diluent removal step is carried out by heating at about 130-200F although, of course, this depends on the diluent used.

It is noted, in this regard, that as used herein, the t`erm "diluent" refers to the carrying medium used for the polysiloxane material. Thus, this includes not only solvents in which the polysiloxane is soluble, but also liquids in which the polysiloxane material may not be soluble but can be dispersed or emulsified.

Thereafter, the release sheet coated with the interlayer material is coated with a pressure sensitive adhesive 36 using a knife 38. Of course, various methods are known to the art for applying pressure sensitive adhesives and any of these conventional thods coald te used.

After application of the pressure sensitive adhes~ive 36, the coated release sheet 30 is passed through oven 40 which utLl:Lzes conventional drying methods Eor pressure sensitive adhesive materials. Typically, temperatures in the range from about 190 to 280 F for about 5 to 20 seconds are used, For pressure sensitive adhesives which are in a prepolymer form, a curing treatment is generally required. Such treatments are conventional in the art and may utilize heat and/or ionizing radiation including both ultra violet curing as well as electron beam curing.
Typically, the pressure sensitive adhe$~ive layer 14 has a composition as described above and generally has a thickness in the range from about 0.1 to 7 mils, and preferably from about 0.3 to 2 mils (1/1000 of an inch). Generally, it is coated in an amount from about 0.5 to 8.0 mg./cm .
Thereafter, the thus coated and cured sheet desig-nated as 42 is married to an appropriate decorative or protective facing layer 44 unrolled from roll 46. The two layers are married by passing through nip rolls 48 in a manner well known in the art. The pressure of nip rolls 48 generally ranges from 20-80 psi. Thereafter, the finished laminate is rolled onto roll 50 which revolves in the direction indicated by arrow B, The overall thickness of the laminate is determined by the general end purpose for which it is to be used. Obviously, flexibility as well as weight would be factors which can be varied depending on this end purpose. Generally, however, in the sheet form of the present laminate intended for application by the consumer for general protective and decorating purposes the over all laminate thickness excluding the release layer is in the range from about 3 to 8 mils and preferably is from about 3.5 to 5.0 mils.

~1 10689~
The foregoing described process is generally referred to in the art as an indirect type coating process. That is to say, it is a process for forming the laminate of the present inven-tion wherein the polysiloxane and pressure sensitive adhesive material are coated on to the release layer first, and the thus coated release layer is subsequently married to the facing layer.
When, either in use or in subsequent processing, the release layer is peeled from the facing layer, the pressure sensitive adhe,sive,c,oating remains with the facing layer. Thus, the layers which are to remain with the facing layer are indirectly coated thereon by first coating them on to the release surface ~, ¦,and t,hen,transferring the layers by virtue of the peeling step.

The other type of coating process conventionally used in the art is known as the direct type process. This process will be described in detail with reference to Fig. 8, hereinafter~
However, generally, it refers to the process wherein the pressura s,ens,it,ive adhesive and ~olys~loxane layers are coated directly on to the inner surface of ~he facing layer and then the release layer is married to the thus coated facing layer. The ultimate product~obtained, is, of course, the same in either case.

Referring now to Fig. 7, an indirect coating process is shown wherein the final laminate does not possess a separate release layer. Rather, the final laminate is generally in roll form and is composed of a facing layer which possesses an outer surface and an inner surface,~ the outer surface being a release surface. A substantially continuous layer of a pressure sensitive adhesive material is adjacent to and contiguous with 106~3993 the inner surface of the facing layer and the discon~inuous, uniformly distributed layer of the coatable polysiloxane is disposed between the pressure sensitive adhesive and the outer release surface of the facing layer.

In use, it is thus necessary only to unwind the facing layer from the roll whereupon it is ready for use since there is no separate release layer to peel. This form is particularly useful when the laminate is in the form of narrow tape and the like.

Such a roll may be formed utilizing the process depicted in Fig. 7 wherein roll 100 which is a roll of backin~ sheet as described hereinabove havi~g a.release surface 102 is unwound in the direction shown by arrow C. At gravure station 104, tha uniform, but discontinuous polysiloxane layex as described herein is applied to form a first laminate 106 which proceeds.through drying oven 108. The dried first laminate is then coated with a pressure sensitive adhesive material 112 using coating knife 114 to form a second laminate 1160 The second laminate is passed through drying or curing oven 118. Thereafter, the dried second laminate 120 is married to facing layer 122 which is unwound from roll 124 in the direction indicated by arrow D.
The marrying operation is carried out by passing the combination of layers 120 and 122 through nip rolls 126.

1~68~93 It is noted that facing layer 122 possesses an inner surface 130 and an outer surface 1320 The outer surface possesses release properties. That is to say, outer surface 132 has been treated in such a manner so as to possess or is composed of a material which~inherently possesses good release properties relative to the pressure sensitive adhesive material used.
i Thereafter, married laminate 128 is passed through separator rolls 134 whereupon the release sheet 102 is separated . ,, ... .. ,from t~e f.inal,llaminate.l36. At the separation point-designated as E, the pressure sensitive adhesive layer and the uniform, but discontinuous polysiloxane layer remain with the inner surface 130 of-acing lay.er 122 to form final laminate 136.

Release sheet 102 is wound on~o roll 138 which may ,be r.eused.~, F.inal,.laminate.136 is wound onto roll 140-in a direc- .
tion indicated by arrow F. Thus, by virtue of the winding oper-ation, the final laminate 136 is rolled upon itself such that the polysiloxane..coa~ed.,surf.ace 142 is immediately adjacent to and contiguous with the outer release surface 132 of the facing layer. As rolled, the laminate i~ now ready ~or cutting, packaging and use by the consumer or final user. -It is also noted that it is possible, in such an indirectcoating.pro~ess wherein the final laminate is produced in roll form without a separate release layer, for release sheet 102 to be disposed in the form of an endless belt which would avoid rewinding it onto roll 138.

~06139 ~3 Fig. 8 illustrates yet another method by which the laminate of the present invention can be produced in roll form without the presence of a separate release sheet in the final roll.
Particularly, Fig. 8 shows the direct method of coating referred to hereinabove. In this method, roll 200 of a facing layer having an outer surface 202 which possesses release properties and an inner surface 204 is unwound from roll 200 in the direction indicated by arrow G. The inner surface of facing layer 204 is coated with pressure sensitive adhesive material 206 using knife coater 208 to form a first laminate 210. First laminate 210 is passed to drying oven 212 and the dried first laminate 214 is coated with a discontinuous, but uniform film of the polysiloxane described herein at gravure coating station 216 to form a second laminate 218. This second laminate 218 is passed through drying oven 220 to form final laminate 222 which is then rolled up'on itself into roll 224 by winding in the direction indicated by arrow H. By virtue of winding in this direction, it is clear that the inner surface 204 of the fac-ing layer which has thereon the coating of pressure sensitive adhesive and the discontinuous layer of the polysiloxane is rolled such that the polysiloxane layer is adjacent to the outer release surface 202 of the final laminate.

It is further clear that the process depicted in Fig. 8 could be carried out such that subsequent to exiting oven 220, laminate 222 may be married to a separate release sheet in the manner shown in FigO 6 to form a final product having a separate release sheet.

In the case when the final product does not have a separate release sheet, it is possible to place it in stack form rather than in the form of a roll. Thus, referring to Fig. 8, after exiting oven 220, the laminate 222 may be cut into separate and equally sized pieces or sheets and the separate sheets can be stacked one upon the other such that the polysiloxane layer of one sheet is immediately adjacent or next to the release surface of the facing layer of the next sheet in the stack. In usa, therefore, it is only necessary to peel off the top sheet whereupon the next, uncovered sheet, presents itself for further use.

In the following discussion, reference will be made only to that embodiment of the present laminate wherein a separate release layer is present. It is clear, however, that the discussion also is applicable in all respects to those embodi-ments of the present laminate wherein a separate release layer is not present.

11~6F~993 The laminate of the present invention possesses a number of unique and advantageous properties as compared to laminates generally used for the same type of purpose which have been previously known. The disadvantages of such prior laminates have been outlined hereinabove. More particularly, hy virtue of the nature of the polysiloxane used as an interlayer material in the laminate of the present invention as well as its unifoxm, but discontinuous disposition on the pressure sensitive adhesive layer (once the release layer or surface has been removed) the present laminate, over all, is substantially easie,r to,h~andle with respect to its application to a substrate than are prior known laminates.

Thus, generally, the present laminate (after separation of the release layer), upon being initially positioned on to the desired substrate, for example~ a wall, can be easily removed without any adverse affects should it be desired to reposition the laminate. This might occur, for example~ in the case where the laminate, in its initial application to the substrate, was not straight, or possessed w,rinkles, or bubbles. ,In such a case, the laminate may be easily removed by the applier without stretching the laminate or difficulty in pulling it from the substrate.

Moreover, should the laminate~ during application~ become folded upon itself so that different areas of the pressure sensitive adhesive surface touch one another, they, in turn can be easily pulled apart without difficulty by the applier~
and without adversely affecting the laminate for purposes of its reapp-lication.

1 ~6~3993 Additionally, once the laminate has been applied to the satisfaction of the applier, it possesses sufficient adhesion to the substrate, so as to remain in the position applied.
Also, over a period of time, for example, 20 minutes to an hour, the adhesion, or peel value as it is hereinafter defined, increases to a sufficiently high value to produce a permanent application on the substrate.

It is difficult to quantify the ease or difficulty writh whiçh the laminate can be initially applied or after such initial application, removed from the substrate. Thus, the ease of application of the laminate depends on the skill of the person applying the laminate as well as the nature of the particular substrate to which it is being applied~ Many types of su~strates, for example, walls, composed of painted ~Ll board, painted-cinder block or plastic, etc., will be -encountered by the typical us~r of this laminate, i.e., the consumer. As a result, depending on the particular nature of the end use, .the ease of application and specific properties with respect to degree of adherence encountered with each of the different types of substrates will vary in an undeterminakle manner. ~

Unquestionably, however, for any given substrate, the pexson using the present laminate will encounter substantially less difficulty in applying the laminate of the present inven-tion as compared to use of the prior art laminates, iOe., a laminate without the specific interlayer required in the presant invention.

1~;

~ I

106899 ~

Specificallyl in addition to a facing layer and a pressure sensitive adhesive layer, the laminate of the present invention possesses means for decreasing the "zero peel value" (as defined hereinafter) of the facing layer-pressure sensitive adhesive layer combination composed of a discontin-uous, uniformly distributed layer of a coatable polysiloxane adjacent to the pressure sensitive adhesive layer.

When a release surface or release layer is present in the laminate, the polysiloxane layer is disposed as an inter-layer between the pressure sensitive adhesive layer and the release surface or release layer.

Thus, by virtue of the presence of the polysiloxane interlayer of the present laminate, there i5 produced a substantially decreased initial adhesion of the laminate for a particular substrate as compared to that which would be encountered with a laminate not possessing the polysiloxane interlayer.

i ~L06~3993 Additionally, however, the amount of actual adhesion at the time of initial application of the laminate to the substrate is sufficient so as to assure that the laminate will remain adhered to the substrate and not separate by virtue of the laminate's own.weight.

Moreover, as noted hereinabove, the adhesion of ~he laminate of the present invention to the substrate builds up within a reasonable amount of time so as to provide a permanent ~installatio~ wkich is. ess.en.tially equivalent.to that obtained . with a laminate without the interlayer of the present invention.

:- . .. Yet.a.f.ur.ther~advantage o~ the present invention is its-unusual characteristic of regenerating relatively low zero peel values thereinafter defined) after a substantial residence time . . o~a substrate. ~That is to say, if the present laminate is applied to a given substrate and allowed to remain for a given period of time, e.g., eight hours, upon removal from the sub-strate (assuming such removal can be effected without mutilating or destroying the substrate or laminate~, it has been found that the laminate will exhibit a relatively low zero peel value.
.~ . Thus, the unique.properties of the present laminate with respect to its ease of initial application are not destroyed by virtue of such application, but continue to reappear should it be necessary to remove .the laminate from the given substrate.

1~6~g~3 Another important feature of the laminate of the present invention is its excellent slip characteristics relative to the substrate. While this characteristic depends to some extent on the substrate involved, invariably, the lateral slip is substantially better with the present laminate tha~ with a Control Laminate (defined hereinafter).

As used herein, the term "slip" means the ability of the laminate to slide on the substrate under light hand pressure. This property is quite difficult to quantify, although it is quite noticeable to the applier. Thus, for example, on applying the present laminate to a wall, by virtue of the excellent slip properties of the laminate, it can be actually placed against the wall, and, while being held against the wall with light hand pressure, slidably moved about the wall surface.

This property also manifests itself with respect to the ability of the laminate to slide across itself when one portion of the pressure sensitive surface touches another portion of the pressure sensitive surface.

.~

106~9~33 In order to more quantitatively characterize the improved properties of the present laminate, the discussion following hereinafter will utilize a number of defined terms relating to the degree of adhesion of the laminate to a given substrate after a specified amount of time. Additionally, because, as noted above, many different types of substrates will be encountered, in an attempt to generally characterize the substrates, the defined values will be further limited to specific test substrate materials which are also described in detail hereinafter.

Additionally, in characterizing the properties of the present laminate, it is necessary to define such characteristics in terms of the difference between those same characteristics possessed by a Control Laminate. Such a Control Laminate consists of a laminate which is identical to the laminate of the present invention, except for the fact that it does not possess the polysiloxane interlayer of the present invention between the pressure sensitive adhesive layer and the release layer.

~ Referring now to the material utilized as the interlayer, ; it must be devoid of certain properties which, if possessed~
would make it unsuitable for use in the present laminate.
That is to say, if it possessed such properties, the r~sulting laminate would not possess the advantages of the present lam-inate. For example, the interlayex material should possess a sufficient affinity for the pressure sensitive adhesive layer.
':' ~ ;8~93 If it does not possess a sufficient affinity for the pressure sensitive adhesive layer, then, as noted above, an effective amount of the interlayer material upon stripping of the release layer from the laminate, will not be available for use on that portion of the laminate which is actually applied to the sub-strate, i.e., the pressure sensitive adhesive coated layer.

In this respect, the polysiloxane utilized as the inter-layer material in the present invention may be qualitatively chara~terized-a~-a non-rele-ase material. That is to say,-in the art, a "release material" is generally considered to be one which possesses relatively low affinity for a pressure sensitive adhesive and which easily separates from the pressur~^Seh~sitive adhesive on peeling.

owever,-in the-present invention, the polysiloxane-used, preferentially remains with the pressure sensitive adhesive layer rather then the release surface. Consequently, in this context, the polysiloxane-possesses "non release" properties~

Additionally, the interlayer material cannot be miscible with the pressure sensitive adhesive material used. If it is, it will be completely absorbed or distributed into the pressure sensitive adhesive material of the laminate, and will not be available to engage the substrate surface when the laminate is applied to the substrate. Thus, it is important that the polysiloxane be present at the pressure sensitive adhesive substrate interface at the time of application.

::`

106~993 In a similar manner, the interlayer material must possess certain other properties in order to make it suitable for use in the present laminate. Thus, the interlayer material must possess the capacity of forming a non-continuous film on the surface to be coated. Generally, in practice, this film is seen as a series of small beads or minute droplets as the interlayer material is disposed onto the surface. A material which is not capable of forming such a discontinuous film, would not produce a laminate having the desired properties.

As used herein, the term "uniform, but discontinuous", is meant to imply that the interlayer material is uniformly distributed over the surface of the release sheet, but that it is not a continuous film. As noted hareinabove, the interlayer material is in the form of a multiplicity of small beads or droplets, thus forming a discontinuous film. However, it is apparent, that the interlayer material cannot be uniformly distributed in the form of relatively large globules, which, while large, are spaced equal distances apart on the surface of the release sheet.- Thus, a typical distribution of the inter-layer material on the pressure sensitive adhesive surface would have a multiplicity of such small droplets or beads within each ;~
square inch of surface area of the pressure sensitive adhesive.
,~
A typical, but not necessarily critical type of distribu-tion on the pressure sensitive adhesive layer is shown in FigO 9.
This is a photograph taken o~ a laminate wherein a dye was in-cluded in the interlayer material prior to coating so that it could be visually distinguished from the pressure sensitive ad-hesive. The release layer, after preparation of the laminate in the manner disclosed herein, was then peeled from the facing layer-pressure sensitive adhesive combination, i.e., component 18 of Fig. 5, and a photograph was ~aken of the pressure sensitive ; ~ ayer The dark areas represent the colored interlayer material.

~06~3993 . ~

Fig. 10 is a photograph similar to that of Fig. 9 however, this is a view of the release surEace of Fig. 2 aEter the polysiloxane (containing a dye) was applied thereto by gravure roll.
The arrow des:Lgnated A indicates the direction from which the photograph was taken. It is clear, Erom a comparison of Figs. 9 and 10 that the configuration of the polysiloxane droplets on the pressure sensitive adhesive layer, after peeling from the release surface, corresponds essentially to the configuration of the droplets at the time of application of the polysiloxane to the release surface, e.g., at gravure station 34 of Fig. 6.
It is further apparent that the polysiloxane material could be distributed in a variety of patterns resulting in somewhat less than complete coverage of the droplets on the pressure sensitive adhesive layer. For example, the polysiloxane could be distributed in the form of a plurality of very thin parallel or crisscross ribbons or lines on the pressure sensitive adhesive surface. Such a configuration would, of course, produce a uniform and discontinuous film and the properties of the resulting laminate would differ only in degree from the preferred form of the configuration described therein, i.e~, a uniform distribution -of beads or droplets.
Also important is the capability of the interlayer material to be coated onto the desired surface. This character-istic is referred to herein as the property of being "coatable"
which is intended to have -that meaning conventionally given to it in the laminating art, with reference to the coating of films, whether continuous or discontinuous, onto surfaces during the preparation of such laminates. That is to say, the material must be in a physical form suitable for allowing it to be spread or sprayed onto a surface in a relatively thin continuous or dis-continuous film. Thus, for example, in order for a pressure sensitive ` ::

~ 1068993 adhesive material to be used in such a laminate, it must be either coatable, in and of itself~ or be capable of being put into a form whereby it can be coated.

Consequently, the property of being coatable, as that term is used herein, does not necessarily mean, that the interlayer material, in and of itself, must be of such a viscosity (or molecular weight), that it can be coated without further dilution or emulsification. It is sufficient that the material be susceptible to such dilution or emulsification, or other treatment, so as to allow it to be applied in a uniform, but discontinuous film onto the desired surfacer Typically, for example, such material can be formed into an emulsion (generally an aqueous emulsion) or dissolved in an appropriate solvent.

If the interlayer material cannot be coated onto a surface, then, as is apparent, it cannot be used to make the .r laminate of the present invention.

Understandably, the molecular weight, or the viscosity of the interlayer material is a factor in determining whether or not the material will be coatable in accordance with the above definition. Considering the nature of the specific interlayer materials defined hereinbelow, it is clearly within the skill of the art worker to adjust the molecular weight, and/or the viscosity of the material so that it is coatable.

ll 10681~93 With respect to the characterizing parameters used herein, the following constitute defined terms:

1. PEEL VALUE
Die-cut 1" x 6" samples of the laminate are mounted on 2" x 6" surfaces of "Stainless Steel" r "SBR" or "Acrylic"
suraces, as defined hereinafter. The specimens of the laminate are mounted by first removing the backing release sheet and placing the adhesive coated component in the center of the test panel. The specimen is smoothed onto the panel lightly with the hand leaving the last inch of the specimen free from the panel. Thereafter, a strip of the backing paper that was removed is placed under the last free inch in order to provide means for lifting the specimen from the test panel.

The specimen is then rolled using a 4-1/2 pound rubber hand roller for 15 seconds in each direction employing no additional hand pressure, i.e., the total pressure is supplied by the weight of the roll itself.

The sample is then allowed to remain at room temp-erature for the specified period of time. In the case of the peel value at zero time, the specimen is removed from the panel with 10-15 seconds actual elapsed time from the time of mounting.

The test panel is mounted into the lower jaw of an Instron machine Model No. TM-Z360-011, and the free end of the strip of backing paper is placed in the upper jaw. The sample is then peeled back on itself at an angle of 1$0 for a distance of 2.48 inches and the average peel a~hesion strength is recorded in grams per inch of width This value represents the peel value for the indicated time period.

1~68~93 This procedure was used to determine all peel values referred to herein.
2. STAINLESS STEEL SURFACE
The stainless steel surEace is a sample of stalnless steel conforming to QQ-S-766, Class 302 or 304 (AISI
302 or 304) stainless steel having a bright annealed finish.
The surface roughness height is 2.0 micro inches + 1.0 micro inches arithmatical average deviation from the mean line, as ob-tained from the Pressure Sensitive Tape Council, 1201 Waukegan Road, Glenview, Illinois 60025.

3. "ACRYLIC" SURFACE
A 3/8" standard wallboard surface painted with two coats (with a roller) of an interior white acrylic based latex `
paint (DuPont) ("Lucite"* 2360 interior latex paint).

4. "SBR" SURFACE r A 3/8" standard wallboard surface painted with two coats (with a roller) of styrene-butadiene rubber based paint ~ ;
(Sherwin Williams Latex Interior Edgewater Blue).

5. All viscosities were measured at about 25 C
(room temperature) using a Brookfield Synchro-Lectric, Model LVT
viscometer and are reported in centipoises (cps).

' , *Trademark : , : , , : :
,.

~L~36~ 3 Referring no~ in greater detatl to the interlayer material, those materials ~hich ~e have found to possess all of the above noted properties, and to produce the desired advantageous properties in the presently claimed laminate are coatable poly-siloxanes formed from monomeric units having structure~ (1) and (II) as follows:

(I) Rl :
lo !i o 1~

R2 :. ~
.,. . ~ ..

and (II) R3 .~ _ ~ ~
- - ji -O- ~ ;

~689g3 wherein Rl is selected from the group consisting of:

(i) phenyl;
(ii) methyl;
(iii) tolyl;
(iv) wherein R7 and R8 may be the same or different ...
. and may be hydrogen, methyl, or ethyl, and wherein when Rl is group (i), (ii~, (iii) or . (iv), the prime mole percent of structure (I) is .~ from about 0.5 to 50 and the prime mole percent of structure (II) is from about 99.5 to 50, and (v) polyoxyalkylene having the structural formula . . .
.. . -R (C2H5)n(Oc3H6)m 6 wherein R6 is a monovalent hydrocarbon group . ~ having~from 1 to 10 carbon atoms, R5 is an alkylene . group having at least two carbon atoms, n and m are numbers, and the sum of n and m is such that the oxyalkylene block R6O(C3H6O)m(C2H5O)n, has a molecular weight o~ at least 1500, from 15 to 60 weight percent of the oxyalkylene units are oxyethylene units, and wherein there are at least three units having structure (I) and at least 40 units having structure (II) and wherein the oxyalkylene block constitutes from 85 ~o 30 weight percent of the polysiloxane polymer;
R2 may be methyl, ethyl, or phenyl; and R3, and R~ may be the same or different and may be methyl or ethyl.

~6~93 .

Preferred are thos.e polysiloxanes wherein Rl is phenyl, R2 is phenyl or methyl, and R3 and R~ are methyl~ Such.
polysiloxanes are particularly desirable when x is from about 0.5 to 30 and ~ is from about 99.5 to 70Ø Generally, wh.en Rl is phenyl an.d R2, R3, and R4 are methyl, in accordance with th.e above, the preferred polysiloxane has a number average molecular weight from about 25,000 to 250,000, although, here again, the prime factor in determining molecular weight is the ability ~
to coat or to render the polysiloxane coatable. Particularly, `
preferred is a polysiloxane wherein Rl is phenyl, and x is about 4.5, and the number average molecular weight is about 70,000.
Also desirable are polysiloxanes having the ahove :~
structural formula wherein Rl is methyl. In this case, it is ;
clear that x would equal y. Generally, such polysiloxanes:
have a viscosity in the range from about 60 x 10 to ~ 20 x 106 cps. ~
: Another preferred polys.iloxane with.in the scope of '~
the above formula is that wherein Rl is a vinyl group and x is 20 from about 40 to 60, and y is from about 60 to 40, and the number average molecular weight i5 in th.e range from about 5 x 105 to 1 x 1o6.
As used herein, the term "prime mole percent" is the :-number ratio of the x type to y type siloxane units. .
Such polysiloxanes as w-ell as methods for their :~
production are conventional and are described in detail i:n U.S. Patent No. 2,560,498 of Earl L. Warrick, issued July 10, 1951.

:

- 38 - ::

1i[~689~3 :

Another class of desirable polysiloxanes are those wherein Rl is the polyoxyalkylene block described hereinabove.
Me thods for preparing this class of materials are described in U.S. Patent 3,505,377 of Morehouse, granted April 7, 1970, and U.S, Patent Reissue 27,541, granted December 1972.
Particularly preferred in this class is a hydrolytically stable silicone surfactant composition containing a dimethyl-siloxane-oxyalkylene block copolymer wherein the oxyalkylene block of the copolymer contains oxyethylene and oxypropylene units and which possess a viscosity at room temperature of about 2250 Cps. (measured with a number ~ spindle at 30 r.p.m.), It is noted that inasmuch as the silixane polymers utilized as the interlayer materials in the present laminate, must be coatable, they are, generally, not cross-linked, nor do they cross-link over a period of time under normal storage conditions or in the absence of cross-linking agents.
Typically, the polysiloxanes which can be used in the present invention have the structural formula:

~39--~ L1~683~3 wherein Rl, R2, R3, P~4 and the prime mole percent or number of structural units designated I and II are as defined above. Rg and Rlo are polymer chain terminal groups. Due to the relatively long length of the polymer chains, the particular groups consti-tuting Rg and Rlo are present in trace amounts. Consequently, the effect of such groups, even if they are chemically reactive, .
i.e. r can react with certain of the other chemical entities in the polymer, is minimal, and, as a practical matter, undetect-able. Thus, while it is pre~erred that Rg and Rlo are hydrogen or saturated lower alkyl, e g., having 1 to 10 carbon atoms, the particular chemical nature of such terminal groups i5 not critical so long, of course, as the groups do not adversely effect the desired properties of the polysiloxane.
. , The subscrip~t "n" represents the molecural weight of the : polymer and, as discussed hereinabove, is such that the polysil-oxane is coatable.
. ~
The polysiloxane materials utilized in preparing the laminate of the present invention may be deposited or applied ont the release surface usinc3 a variety of techniques well known and conventional in the artO Thus, for example, the polysiloxane, whether it is used as is, or diluted either in a solvent or an aqueous emulsion may be applied using a gravure roll~, knife over-roll, a reverse roll coating technique, the so-called flexographi printing technique, or a controlled spray. It is thus within the skill of the art to/use any of these techniques~to apply the polysiloxane material and to regulate the parameters affecting the deposition, e.g., concentration, roll speed, etc., so as to deposit a uniform discontinuous film in accordance with ~he description hereinabove.

-~968~93 Insofar as the actual physical form of the poly~
siloxane material with respect to the deposition technique is concerned, any type of conventional organic solvent e,g., aliphatic and aromatic organic solvents can be used. The con-trolling factor in the selection of such a solvent is merely that it be one which is commercially available and does not have an adverse influence on either the economics of the process or product and of course, does not adversely af~ect the product itself.
Alternately, the polysiloxanes may be incorporated `~ into an aqueous emulsion using conventionally known emulsifying agents and conventional emulsifying techniques. Here again, such techniques are well known to the skilled artisan in this technical field.
It is further possible, depending on the viscosity of the undiluted polysiloxane material, to use it as is, without a diluent.
The amount of the deposit can vary over a wide range and depends on the specific polysiloxane which is used as well as the technique used for coating and other parameters which would be characteristic of the specific process being used. However, conventional art techniques would be used to adjust and to optimize these parameters in order to optimize the product properties.
For example, if a rotogravure deposition technique is used with a solution of the polysiloxane in an appropriate organic solvent, the concentration of the solution would vary depending on the specific type of rotogravure roll used, i.e. ?

the number of lines per inch, and the design on the rotogravure roll, e.g., straight line, pyramidal, etc.

11~6~3993 We have found, generally, that such solutions will most preferably have a concentration from about 0.125 to 15~ by weight in the given solvent. Within this concentration range~ using rotogravure or spray techniques, it is possible to deposit from about 0.002 to about 1.0 gram per square meter on a dry weight basis of the polysiloxane and this generally will lead to a product having properties within an optimal range.

In any event, the specific manner of deposition should be regulated so as to produce a substantial decrease in the zero peel value of the product as compared to a control laminate and to provide for a twenty minute peel value of at least about 100 grams. Preferably, the reduction in the zero peel value as compared to the zero peel value of the control laminate is in the range of at least greater than about 25%.
It is possihle, of course, that for a specific purpose, the skilled artisan might desire to decrease the percent reduction in the zero peel as compared to the control laminate.

All of the above mentioned deposition techniques lend themselves to the formation of a uniform but discontinuous film of the polysiloxane material onto the release surface or the pressure sensitive adhesive surface dependin~ on whether a direct or indirect coating process is used. As no~ed, a typical illustration of such a uniform but discontinuous deposit is shown in Figs. 9 and 10.

~ ~,89~3 The Eollowing examples illustrate the present invention:

A release sheet was prepared from kraft paper (42 pounds per ream) by coating it with a conventional silicone re-lease Einish, for example, "Dow Corning Syloff 23"* with DC 23A
catalyst, the amount of coating being about 0.5 pounds per ream.
The paper was coated on the machine finished side. The coating was carried out using an 80 line quadrangular gravure coating roll.
The solids content of the silicone release material in "Tolusol 50~'** (a l:l mix of toluene and heptane) was 3.8%.
After coating, the coated paper was subjected to drying and cur-ing conditions in an oven at about 350 to 400F for about one minute.
The kraft paper used, in the usual commercial em-bodiments, generally carries printed information, e.g., applic-ation instructions, suggested use, measuring scales to facili-tate cutting, etc., on the non-release side.
A solution of 3% to 10% by weight of a phenyl methyl dimethylpolysiloxane containing about 4.5 prime mole percent of phenylmethylsiloxane groups and having a viscosity of 18,000 cps (number 4 spindle at 30 rpm) was prepared in "Tolusol 50"
solvent. It was applied to the above prepared release paper using a 165 line quadrangular gravure roll. The thus coated release sheet was dried at a temperature of about 160 to 180 F
for about 15 to 30 seconds using heat circulating ovens. The deposit of the polysiloxane material was in the form of a uni-formly distributed discontinuous film similar to that illus-trated in ~ig. 10 hereof. The dried deposit of the polysil-oxane on the release sheet was thus about 0.17 to 0.5 grams/m *Trademark **Trademark ~689~
A pressure sensitive adhesive was then coated onto the thus treated release layer with the polysiloxane thereon. For this purpose, an aqueous emulsion of an acrylic-vinyl acetate copolymeric pressure sensitive adhesive having a solids content oE about 50.0% by weight, a visco~sity of 481 cps (#3 spindle at 60 rpm) and a plasticity of 1.7mm (hereinafter reEerred to as "P.S.A. 1") was used. The adhesive was applied by reverse roll coating. Alternately, a 55 line quadrangular gravure roll can be used. The dry deposit of the pressure sensitive ad~
hesive ranged from about 1 to 2 milligrams per square centi-meter.
Thereafter, the sheet coated with the pressure sensitive adhesive was dried at about 240 F for about 5-10 seconds to remove the water from the emulsion.
Finally, a polyvinyl chloride film having a thickness of about 3.5 mils was married to the thus coated release sheet by passing the combination through a nip at a pressure of about 30 psi. The Einal product was rolled into a suitable package for subsequent cutting and packaging.
Alternately, other commercial pressure sensitive adhesives may be used. For example~ an acrylic-vinyl acetate copolymer (water base) having a solids content of about 53.0%
by weight, a viscosity of 837 cps (#3 spindle at 60 rpm~ and a plasticity of 2.70 mm (hereinafter referred to as "P.S.A. 2"), an all butyl polyacrylate based pressure sensitive adhesive, (water base) having a solids content of 57% by weight, a vis- ' cosity of 302 cps (#3 spindle at 60 rpm) and a plasticity oE
1.64 mm (hereinafter referred to as "P.S.A. 3"), or an organic solvent base pressure sensitive adhesive, such as, an acrylic-~6~ 3 vinyl acetate polymer having a solids content of about 32.3%
by weight, a viscosity of 491 cps. (#2 spindle at 30 rpm) and a plasticity oE 1.53 mm. (hereinafter referred to as P.S.A. 4) may be used. These are typical of the commercially available pressure sensitive adhesives which are conventionally used for preparation of these types of laminates.
Depending on the specific pressure sensitive adhesive and type of release surface used, the preferred method of deposition, i.e., concentration of the polysiloxane in the dîluent can vary. For example, with the P.S.A.l and P.S.A.3, the preferred concentration is from about 8 to 10% by weight, whereas with P.S.A.2, a concentration of about 3 to 5% by weight is preferred.
In addition to the above described acrylic based pressure sensitive adhesive materials, the laminate of the ~ -present invention can be prepared using other conventional pres-sure sensitive adhesive systems, such as, those composed of styrene-butadiene, a highly stabilized ester resin and an anti-oxidant. A typical formulation of such an adhesive system can be prepared by mixing 100 parts of styrene-butadiene having 23.5% bound styrene ("Ameripol 1011"* manufactured by B.F. Goodrich) w-ith 75 parts of a highly stabilized ester resin ("Floral 85"** manufactured by Hercules, Inc.) and two parts of an anti oxidant, such as, for example 2,2'-methylene-bis (4-methyl 6-t-butyl phenol), ("Antioxidant #2246~'*** manufactured by American Cyanamid).

*Trademark **Trademark ***Trademark . .
:: .. ' , ~

':

1061~93 _ _ A series of laminates in accordance with the present invention were prepared using the process conditions and components and procedures set forth in Example 1. However, a series of three different polysiloxanes were used, and were applied in solution concentrations ranging from 5 to 15 weight percent. Additionally, two different pressure sensitive adhesives were used. Thus, each particular polysiloxane material and each concentration level was utilized to prepare a laminate sample with each one of the two different pressure sensitive adhesives.

Thereafter~ the zero minute and twenty minute peel values were determined. Also determined were the peel v~alues of.the samples. af.ter...they had aged for 16 hours and .
7 days, respectively, although the 7 day peel value was determined only on the stainless steel surface. The results of.these analyses are set forth in Table 1 hereo~. ..

The pressure sensitive adhesives used were P.S.A.l, and P.S.A.4.

The polysiloxanes used were the phenylmethyldimethyl polysiloxane of Example 1, hereinafter referxed to as inter-layer A, a dimethylpolysiloxane having a viscosity of about 60,000 cps (rsferred to hereinafter as interlayer B), and a dimethylsiloxane-oxyalkylene blo~k copolymer containing oxyethylene and oxypropylene units and having a viscosity of about 2250 (referred to hereinafter as interlayer C3.

106E~993 The application of the solutions of the polysiloxanes was performed using a 165 line quadrangular cell rotogravure roll.

Additionally, two control samples were prepared using each of the pressure sensitive adhesives. These control samples were p.repared.in ~n identical manner to each of the other samples except that the polysiloxane interlayer was not presentO

The results obtained are set forth in Table lo 3t6~3 l l ~ 1~ N ~ ~I N ¦ N 0~ 0 1-) 1 0 '7~ N l O
CO ~ D ~ a~ tn I~ _l ~ ct) ~D ~ ~r . ~ . . .
.' . . W
~D ~D N O ~ ~ ~O~ N 0 O ~ ~ I` O t` O 11'~ 0 . t:~
~`4 t~ _I O 1~ ~ l ~D 0~ N ~ a) ~D t` _~ O ~D O O I ~ Z
~ CD~I 0~ ~ ~ o~ a~ r~ . ~

I~ . U~ . ~ ~ ! . _. : . ~ : ~ I 11 .~ ~
O th 0~ O "~ u~) N cr~ O D N O ~-- ~7 1--1` 0 ~ ~D ~1 IJ~ N
D . . F~
. ~ U~ T ~ 3 o ~D ~~D .~ ~ o ~ er co o o ~ o~ ~ ,, c~ o ~ ~ .
.~1~ . ~_1 E~
. . . . . ~3 . . ,~.~ .,, .' . P~ o~ o ~ o c~ o ~ ~ U~ O C~ ~ o ~ ~ ~ 'co ~ , W j ~, ,. , , ....
. C~ O~' ~ ~ ~ ~ ~ o -~ ~ _J ~ ~D ~ O O 1~ ~
~3 i~! ~ ~; ~ ~ ~ ~ ~r~n u7 u~ I~ I~ U) ~ t` l~ ~ ~ E~

O O ~) N N N ~ N o Ul o ~r t~ ~o S~l ~ ~ 'I '~1 :C ~i .. , .. .- ,~ ~ o . . i. ' ~ ~ . ~ i, , ~ ' ~ U) Ir~ ~ _I ~D ~ 'r ~ t` ~ O ~ In N ~ Cl:~ ~ ~ ~ U~
u l.q It) a~ ~ N t~ N o t~ a~ ~ ~ ~ ~ :~ O ~) N ~ ~ N O H
. t t~ oo~n ~ ~ J ~ ~ r) ~ ~ n ~Zz . ! . . . . ~ ~ . . ~2 .. . . . ~ p: I ' . . . . E~ .
~r; ~ ~r c~ ~ co ~ In u~ ~D er ~ O ~D ' ~ ~ O ~¢
P ~ ~ o o ~D ~1~ ~ t~ ~ O o~ ul ~ r u~ ~ ~ 3 Z 1~; O r--~ ~1 ~ r~ ~D r--~ ~ ~ ~ ~I co ~r ~I C~ ~ H li~
. o a~ ~ o .~ ~c~ ~I N ~1 - . 0.~ ~ ~ ~ N ~ ~ ~ ~r ~ t~ .~ Q .. . .
t~ ~n ~ N el~ _I N ~ ~1 ~ ~ ~1 ~r ~_I ~ u~ o~ t--~1 ~C
U~ 1~ 0 L~ D ~ a~ ~D N ~ o ~ ~ ~i ~ o o~ ~ ~r ~:1 . ~a u~ n ~1 _I~ _I c~3 _I ~ N ~1 ~ N ~1 ~ N ~ Z
, . ......................... ~;~
~ ~s~ c~
. ~ O O ?¢ ~ ~C f~ ¢ ~ f:l ~ ~ o ~ ~ .
- ~-1 ~r ~ U~ . . . . O . . ., ~ , H
~? ~ ~ ~ ~ ~~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ E~
~ ~ c e~ c~ o c) o ~ ~ ~ ~ m m a: m ~a m z ~

U~ ~ ~ ~ o ~ d~ O ~ P O j ~ ¦ ~

-4B- , As can be seen from the data in Table 1, by control-ling the amount of the polysiloxane deposited, the desired de~
crease in the ~ero peel value can be obtained.
As further shown Erom the 20 minute peel value and the extended application peel values, i.e., 16 hours and 7 days, a significant build up in the peel value is effected as the peel values approach those of the controls.
For purposes of subjective evaluation, in separate tests, each of the samples obtained was hand tested for ease of application of a 6 foot long 18 inch wide sample onto a wall having each of the above defined surfaces. In each case, those samples in accordance with the present invention exhibited remarkably easier application properties to the wall than did the corresponding control samples. Thus, samples C through T
could be easily applied to the wall, easily removed therefrom for repositioning or straightening, did not exhibit as many wrinkles or air bubbles, and the wrinkles and air holes that were present were easily smoothed out or removed, in contrast to the control samples which presented much more difficulty with respect to these subjective parameters.
In the samesubjectivemanner, the samples were checked for "slip" as defined hereinabove and the capaci-ty to be pulled apart when two portions of the pressure sensitive adhesive sur-face touch one another. For this latter characteristic~ a portion of the sample was folded upon itself and pressed with strong hand pressure and then peeled apart. In each instance, the samples prepared in accorda~ce with the present invention were easily peeled with no noticeable pulling of the adhesive layer.

_ ~9 _

6~3993 Moreover, when each of the control samples were folded adhesive-side to adhesive-side, and pressed together under strong hand pressure, it was difficult, i~ not impossible, to peel the two sides from one another without significant stretching of the vinyl and distortion of the pressure sensitive adhesive surface.

A series of experiments was carried out to illustrate the effect of different methods of application of the polysiloxane material. In these tests, the procedures set forth in Example 1 were followed, except for the variables defined hereinbelow.
The pressure sensitive adhesive material used was P.S.A. 1, and the polysiloxane was interlayer A.
.
Various concentrations of the polysiloxane in Tolusol 50 were applied using a 165 line quadrangular gravure roll at various application pressures.

In order to effect zero pressure of the roll~ the pressure sensitive adhesive material was directly coated onto the vinyl film and then the various concentration solutions of the polysiloxane were directly coated onto the surface o the pressure sensitive adhesive using a 165 line gravure rollO
The product was then dried and was not subjected to a laminat-ing nip. However, a release sheet was applied to the surface by hand in order to protect the surface from contamination.

8~93 Also, in order to effect zero preasure, a series. of polyvinyl chloride film samples having the press.ure sensitive adhesive material coated thereon in the conventional manner were sprayed using solutions of the polysiloxane material which varied in concentration. The spraying was carried out using a Eifty pound air pressure, a #36 nozzle, with one pas.s at 14 inches from the surface of the adhesive.
Additionally, several solutions of differing con-centrations of the polysiloxane were applied to the release sheet with a 165 line quadrangular gravure roll, and then the film was laminated to the thus coated and dried release sheet using nip pressures of 10, 20, 40, and 80 pounds per square inch.
The peel values at zero time, at 5, 10, and 6Q
minutes were determined.
The results of the test with. the 5% solution of the polysiloxane are shown in Fig. 11. As can be seen from this figure~ for those samples wherein the polysiloxane was used, significant and substantial decreases in the initial peel values were obtained as compared to that o:E the control s~mple :
which was prepared in the conventional manner using a fifty pound nip pressure for the lamination.
.

1~36~1993 Fig. 12 shows the change in peel value with time for solutions of the polysiloxane having varying concentrations when such solutions were sprayed onto the pressure sensitive adhesive.

. In each case, it is seen that by virtue of the use of the polysiloxane interlayer of the present invention, significant decreases in the peel values at zero time and in the range from 20 to 30 minutes can be obtained. Moreover, these peel values build up in time to provide a permanen~
adhesion of the laminate to the particular substrate.

This data further illustrates the manner in which the process parameters can be varied to achieve different degrees of change in the initial peel value from the control in accordance with the desire of the skilled artisan and the specific end use intended for ~he laminate.

A series of samples were prepared using the procedures se~ forth in Example 1 hereinabove and utilizing P.S~A. 1 and interlayer A as the polysiloxane material.

::~ ~ :
Various concentrations of the polysiloxane in Tolusol 50 were used and were applied to the release sheet using 80, 120, and 165 line quadrangular cell gravure rolls.

Depending on the concentration of the solution and the size cells of the gravure roll, the amount of deposit and zero peel value varied. It is noted that the 80 line roll possesses larger cells than the 165 line roll. In fact, in 10~,99J

¦ terms of volumetric capacity, the 80 line roll deposits 2.6 times ¦ as much volume per cell as compared to the 165 line roll ¦ and the 120 line roll deposits 1.6 times as much volume per ¦ cell as the 165 line roll.

¦ The peel values of the various samples produced after ¦ various ageing times starting with zero time as defined herein I were measuredO
I
Figs~ 11, 12, and 13, show the variation in peel value with time for samples prepared using varying concentrations of the polysiloxane deposited with gravure rolls having 165 lines per inch, 120 lines per inch, and 80 lines per inch, respectively. As shown in these figures, in each and every case, the same general trend with respect to decreasing in~tial peel value is observed as the amount of polysiloxane material is increased either by virtue of the concentration used with a given gravure roll or by virtue of using a larger cell gravure rolll Fig. 14 shows the change in peel value with time for a specific concentration solution of the polysiloxane (10~ by weight) with changing cell volumP in the gravure roll. Thus, as can be seen, a significan~ decrease in the zero peel values from that of the control axe realized and also, with increasing volume of the gravure roll cells, a general decrease in the peel value for any given time period is observed.

The same general trend is seen for other concen rations of the polysiloxane material.

:
61~9~3 The laminate as prepared in Example 1 in accordance with the present invention using P.S.A. 1, was subjected to a series of peel tests at various times in conjunction with a control. Particularly, samples of each of the laminates were adhered to an acrylic painted test substrate for periods of zero minutes, 20 minutes, 1 hour, 3 hours, 5 hours, and 16 hours. The peel value at each of these periods of time was then measured. Additionally, a~ter having the peel value measured at the specified time, each sample was then rea~hered to the substrate and tested for zero peel and 20 minutes peel.
These latter two values arP referred to in this example as "repeat zero peel", and "repeat 20 minute peel". Thus for example, considering the sample which was allowed to remain on the substrate for one hour, after it was removed and the one hour peel value determined, the sample was then reapplied to the acrylic substrate for determination of its repeat zero peel, and repeat 20 minute peelO The results from these tests are tabulated in Table 2.

.. . . .~
.

l~b8993 TABLE _ LAMINATE
OF PRESENT
CONTROL __INVENTION
~_ . . Peel Value Peel Value Zero 0 463` 251 Minutes 0 373 192 .,, ~.~. .. 20 Min. -~ 587 ~ 304 . ~ . .
~ . . ~
20 Min. 629 394 Minutes ReE~at 0 429 221 . - Repeat 20 Min. 580 _ _ 333 One 1 Hour 729 449 Hour Repeat 0 478 255 Repeat _ 20 Minutes 670 _ _ _379 Three 3 Hours 801 574 Hours ~ 467 287 _ _ 20 Minutes _ 665 _ _ 372 Five 5 Hours 777 585 . . Hours Re~eat 0/`! 510 284 ~ep~
. ~ _ 20 Minutes 653 _ _ 407 Sixteen 16 Hours 993 627 Hours ~ 587 334 . _ 20 Minutes 74 Q _ _ _ _9 , -55-, ~068993 As shown in Table 2, one of the very desirable character-istics of the laminate in accordance with the present invention is khat even after a significant amount of time, the peel value is not so hi~h as to adversely affect the substrate should it be desired to remove the laminate from the substrate; although the peel value does build up to a level which is more than adequate for a permanent installation. Moreover, upon such removal, the repeat zero peel which the laminate exhibits is relatively low. Thus, upon removal from the substrate even after the extended period of time, i.e., 16 hours in this case, the laminate exhibits peel values which are sufficiently low so as to facilitate the reapplication of the laminate to a substrate with essentially the same ease with which it was initially secured to the substrate.

ExAMæLE 6 __ _ Siliconized ~42 machine finished paper (designated herein as MF #42) and siliconized kraft paper having a polyethylene coating were gravure coated using a 165 line quadrangular cell gravure roll and varying concentrations of interlayer A as used in Example 1 in Tolusol 50 solvent. The samples were subsequently dried in an oven. Half of the samples were coated with 0.35 ounces per square yard ~dry weight~ of P~SoA~ 1 pressure sensitive adhesive and the remaining half were coated with 0.33 ounces per square yard (dry weight~ of P.S.A. 4 adhesive. Control samples werein interlayer A was not used were also produced.

106899~

The adhesive coating was dried in an oven and a 3.5 mil polyvinyl chloride film was married on~o the thus dried adhesive at the oven exit and passed through a nip roller ak a 40 pounds per square inch pressure.

A series of the Control samples were used for direct coating of the interlayer material onto the adhesive surface.
Fo~r ~his,~p~urpois~e~ he lel~ase sheet was removed ~rom the Control sample (controls having both types of pressure sensitive adhesives utilized for this) and interlayer A was applied , usi~g a 16S line r~ll directly onto the surface of the adhesive. The volatiles were driven off in an oven and the release sheet was relaminated to the directly coated r . pressure~sensitive adhesive-vinyl combination by passing -~-through a 40 psi nip roll.

. Fox ~h~se samples which were directly coated, tes-ts -- ---wherein the interlayer material was dyed showed tha~ essPntially none of the interlayer material was removed upon stripping of the relçase sheet. ~hus, in the indirect coating process, wherein the interlayer material is coated onto the release layer, upon stripping the release layer from the remainder of the laminate, a very small amount of the dyed interlayer material is observed to adhere to the release surface.

In c~ntrast, on using the direct application approach as described hereinabove, and on subsequent peeling of the release layer, relatively little, if any residue of the interlayer material can be seen on the release surface.

As a result, it can be assumed that 100% of the polysiloxane remains on the pressure sensitive adhesive.
Consequently, the actual amount of interlayer material on the adhesive surface can be calculated from a knowledge of the concentration of the original application solution of the interlayer material, the volume of the cells of the rotogravure roll, and the specific gravities of the solutions used.

On each of the samples thus prepared, peel values at zero time, 5 minutes, and 20 minutes were determined. A
summary of the results obtained with these tests is set forth in Table 3.

` .

1 1~96~ 3 .,~ ~ O

oU~ o ~ o o o U~
O ~ r~ O ~ O ~ ~D N ~ ~ ~ <S~
W ~ W-rl ~D ~1 u~ o t~)o 1~,1 ~ o ~r-l rl ~ ~ ~ O ~;) O O O O O O O
~:: h ~ ) U ~ . . . . .
00 ~ O ~ o o o: o o o o o O ~ P~ ~ h ~:
o a~ a~ o H ~ ~
__ O ~ h oo ~ ~ ~ O O 1- 0 ~D O O O
O ~ ~ u~ ~_i ~ ~ ~ 1~ ~, , ~ ~ ~ r~
~ l d~-rl l h .. ~ ~ nU U U
O :~ h h O h C) h O h t~
,5:: ~ ~
PJ ~ ~ h ~ hrU h ~:4 H a H ~ H ~ H

~ a~
H-~l N o ~ o ul o N ,1 o o o o o o o o ~ au ON
~ ~0 ~ o o o o o o o o ~¢ ' H~
. 8 .,, ~W ~
h ~1 ~1 u~ Lr n1 w ~ . ~ ~ ~ u~
~ ,1-,1 ~ n ,1 o ,1 o ~ ~n ~ h h--l t~ o o ~1 o,~ o o o o~ 3 C~ O H :~ ~P

a~ a) ~ a a) N N
~ ~P # ~ ~ #
~' . ~1 . --I w ,1 w ~ w ,1 ~ - -, Q~ ~ :4 ~40 o O 0 14 1:4 0 0 0 0 ~; I
~ I
~ U~

~ 1068993 The data in Table 3 illustrates the variation in the percent reduction in zero peel as compared with the control with respect to the use of different adhesives as well as different types of release sheets and methods of application. However, in each and every case, a significant reduction in the ~ero peel value was obtained when the inter-layer in accordance with the present invention was used.

This data also indicates that the direct method of application appears to be somewhat more efficient than the indirect method. However, at the present time, the direct method is not as commercially preferred. This is primarily due to the difficulty in carrying the facing layer through a series of processing steps. Thus, in the indirect method it is the release sheet which is carried through the various process steps and the facing layer, which generally tends to have less dimensional stability than the release sheet, only enters at the very last step in the process.

The last column in Table 3 sets forth the amount of polysiloxane deposit required for each pressure sensitive ^~
adhesive-release sheet combination and method to give a 25 percent reduction in pePl value as compared to the Control.
These values were determined by graphically plotting the variation in percent reduction of the peel value with the amount of polysiloxane deposited and tabulating the amount of deposit at the 25 percent reduction point. It is thus - l ~
1 ~1196~3~3193 apparent that these values are independent of the concentration of the polysiloxane solution.

Having thus described our invention, what we desire to secure and claim by Letters Patent is:
~ .

Claims (48)

1. A laminate which comprises:
(a) a facing layer having an outer surface and an inner surface;
(b) a substantially continuous layer of a pressure sensitive adhesive adjacent to the inner surface of the facing layer;
(c) means for decreasing the "zero peel value" of the facing layer-pressure sensitive adhesive layer combination, said means comprising a discontinuous, uniformly distributed layer of a coatable polysiloxane adjacent to the surface of the pressure sensitive adhesive layer, said polysiloxane being formed from monomeric units having structures (I) and (II) as follows:

(I) and (II ) wherein R1 is selected from the group consisting of:

(i) phenyl;
(ii) methyl;
(iii) tolyl;
(iv) wherein R7 and R8 may be the same or different and may be hydrogen, methyl, or ethyl, and wherein when R1 is group (i), (ii), (iii) or (iv), the prime mole percent of structure (I) is from about 0.5 to 50 and the prime mole percent of structure (II) is from about 99.5 to 50, and (v) polyoxyalkylene having the structural formula ' -R5(OC2H5)n(OC3H6)mOR6 wherein R6 is a monovalent hydrocarbon group having from 1 to 10 carbon atoms, R5 is an alkylene group having at least two carbon atoms, n and m are numbers, and the sum of n and m is such that the oxyalkylene block R6O(C3H6O)m(C2H5O)n, has a molecular weight of at least 1500, from 15 to 60 weight percent of the oxyalkylene units are oxyethylene units, and wherein there are at least three units having structure (I) and at least 40 units having structure (II) and wherein the oxyalkylene block constitutes from 85 to 30 weight percent of the polysiloxane polymer;
R2 may be methyl, ethyl, or phenyl, and R3, and R4 may be the same or different and may be methyl or ethyl.

2. The laminate of claim 1 wherein the polysiloxane is present in an amount effective to substantially decrease the "zero peel value" from the "zero peel value" of a control laminate wherein the polysiloxane layer is absent.

3. The laminate of claim 2 wherein the polysiloxane is present in an amount effective to decrease the "zero peel value"
of the laminate by at least about 25 percent from the "zero peel value" of the control laminate.

4. A laminate which comprises:
(a) a facing layer having an outer surface and an inner surface;
(b) a backing layer having a release surface;
(c) a substantially continuous layer of a pressure sensitive adhesive between the release surface and the inner surface of the facing layer; and (d) means for decreasing the "zero peel value"
of the facing layer-pressure sensitive adhesive layer combination, said means comprising a discontinuous, uniformly distributed layer of a coatable polysiloxane between the pressure sensitive adhesive layer and the release surface, said polysiloxane being formed from monomeric units having structures (I) and (II) as follows:

(I) and (II) wherein R1 is selected from the group consisting of:

(i) phenyl;
(ii) methyl;
(iii) tolyl;
( iv) wherein R7 and R8 may be the same or different and may be hydrogen, methyl, or ethyl, and wherein when R1 is group (i), (ii), (iii) or (iv), the prime mole percent of structure (I) is from about 0.5 to 50 and the prime mole percent of structure (II) is from about 99.5 to 50, and (v) polyoxyalkylene having the structural formula -R5(OC2H5)n(OC3H6)mOR6 wherein R6 is a monovalent hydrocarbon group having from 1 to 10 carbon atoms, R5 is an alkylene group having at least two carbon atoms, n and m are numbers, and the sum of n and m is such that the oxyalkylene block R6O(C3H6O)m(C2H5O)n, has a molecular weight of at least 1500, from 15 to 60 weight percent of the oxyalkylene units are oxyethylene units, and wherein there are at least three units having structure (II) and at least 40 units having structure (II) and wherein the oxyalkylene block constitutes from 85 to 30 weight percent of the polysiloxane polymer;
R2 may be methyl, ethyl, or phenyl; and R3, and R4 may be the same or different and may be methyl or ethyl.

5. The laminate of claim 4 wherein the polysiloxane is present in an amount effective to substantially decrease the "zero peel value" from the "zero peel value" of a control laminate wherein the polysiloxane layer is absent.

6. The laminate of claim 5 wherein the polysiloxane is present in an amount effective to decrease the "zero peel value" of the laminate by at least about 25% from the "zero peel value" of the control laminate.

7. The laminate of claim 4 wherein the polysiloxane is present in an amount effective to produce a "zero peel value"
of less than about 600 grams on a stainless steel test surface and less than about 500 grams on "acrylic" and "SBR" test surfaces.

8. The laminate of claim 4 wherein the amount of said polysiloxane is in the range from about 0.0023 to 1.0 gram per square meter on a dry weight basis,

9. The laminate of claim 4 wherein R1 is phenyl, and R2, R3 and R4 are methyl.

10. The laminate of claim 9 wherein the prime mole percent of structure (I) is from about 0.5 to 30 and the prime mole percent of structure (II) is from about 99.5 to 70.

11. The laminate of claim 9 wherein the prime mole percent of structure (I) is about 4.5 and the prime mole percent of structure (II) is about 95.5.

12. The laminate of claim 9 wherein the polysiloxane possesses a number average molecular weight of from about 35,000 to 250,000.

13. The laminate of claim 4 wherein R1 is phenyl, R2 is phenyl, and R3 and R4 are methyl, .

14. The laminate of claim 4 wherein R1 is methyl, the prime mole percents of structures (I) and (II) are equal, and the polysiloxane possesses a viscosity in the range from about 60 x 103 to 20 x 106 cps.

15. The laminate of claim 4 wherein R1 is and R7 and R8 are H, the prime mole percent of structure (I) is from about 40.0 to 60.0 and the prime mole percent of structure II is from about 60.0 to 40.0, and the polysiloxane possesses a molecular weight in the range from about 5 x 105 to 1 x 106.

16. The laminate of claim 4 wherein R1 is polyoxy-alkylene and R2, R3, and R4 are methyl and the viscosity of the polysiloxane is about 2250 cps.

17. The laminate of claim 4 wherein the facing layer is selected from the group consisting of woven, knitted, and non-woven textile fabrics, metal foils, paper, a continuous film of a polymer selected from the group consisting of vinyl polymers, polyolefins, polyesters, and such polymeric films having metallic coatings thereon.

18. The laminate of claim 4 when in the form of any one of the following: tile appliques, decorative wall covering, floor covering, labels, decals, tapes or shelf edging.

19. The laminate of claim 4 wherein the facing layer is itself composed of a bottom decorative layer and a top, trans-parent protective layer.

20. A laminate in roll form, said laminate comprising:
(a) a facing layer having an outer surface and an inner surface, the outer surface being a release surface;

(b) a substantially continuous layer of a pressure sensitive adhesive adjacent to and contiguous with the inner surface of the facing layer; and (c) means for decreasing the "zero peel value"
of the facing layer-pressure sensitive adhesive layer combination, said means comprising a discontinuous, uniformly distributed layer of a coatable polysiloxane between the pressure sensitive adhesive layer and the release surface, said poly-siloxane being formed from monomeric units having structures (I) and (II) as follows:

(I) and (II) wherein R1 is selected from the group consisting of:

(i) phenyl;
(ii) methyl;
(iii) tolyl;
(iv) wherein R7 and R8 may be the same or different and may be hydrogen, methyl, or ethyl, and wherein when R1 is group (i), (ii), (iii) or (iv), the prime mole percent of structure (I) is from about 0.5 to 50 and the prime mole percent of structure (II) is from about 99.5 to 50, and (v) polyoxyalkylene having the structural formula -R5(OC2H5)n(OC3H6)mOR6 wherein R6 is a monovalent hydrocarbon group having from 1 to 10 carbon atoms, R5 is an alkylene group having at least two carbon atoms, n and m are numbers, and the sum of n and m is such that the oxyalkylene block R6O(C3H6O)m(C2H5O)n, has a molecular weight of at least 1500, from 15 to 60 weight percent of the oxyalkylene units are oxyethylene units, and wherein there are at least three units having structure (I) and at least 40 units having structure (II) and wherein the oxyalkylene block constitutes from 85 to 30 weight percent of the polysiloxane polymer;
R2 may be methyl, ethyl, or phenyl; and R3, and R4 may be the same or different and may be methyl or ethyl

21. The laminate of claim 20 wherein the polysiloxane is present in an amount effective to substantially decrease the "zero peel value" from the "zero peel value" of a control laminate wherein the polysiloxane layer is absent.

22. The laminate of claim 21 wherein the polysiloxane is present in an amount effective to decrease the "zero peel value"
of the laminate by at least about 25% from the "zero peel value"
of the control laminate.

23. A laminate which comprises:
(a) a facing layer having an outer surface and an inner surface;
(b) a backing layer having a release surface;
(c) a substantially continuous layer of a pressure sensitive adhesive between the inner surface of the facing layer and the release surface, said pressure sensitive adhesive being selected from the group consisting of water based acrylic-acetate copolymeric adhesives, water based polybutylacrylate adhesives; and solvent based acrylic-vinyl acetate copolymeric adhesives; and (d) means for decreasing the "zero peel value" of the facing layer-pressure sensitive adhesive layer combination, said means comprising a dis-continuous, uniformly distributed layer of a coatable polysiloxane between the pressure sensitive adhesive layer and the release surface, said polysiloxane being formed from monomeric units having structures (I) and (II) as follows:

(I) and (II) wherein R1 is phenyl, and R2, R3 and R4 are methyl and the prime mole percent of structure (I) is about 4.5 and the prime mole percent of structure (II) is about 95.5 and the viscosity of the polysiloxane is in the range from about 13,000 to 18,000 cps.

24. The laminate of claim 23 wherein the release sheet is paper having a silicone release coating thereon.

25. The laminate of claim 23 wherein the amount of the pressure sensitive adhesive is in the range from about 0.5 to 8.0 mg/cm2.

26. The laminate of claim 23 wherein the amount of polysiloxane is from at least about 0.0002 grams per square meter.

27. A stack of a plurality of sheets, each sheet being a self-adhesive laminate which comprises:
(a) a facing layer having an outer surface and an inner surface, the outer surface being a release surface;
(b) a substantially continuous layer of a pressure sensitive adhesive adjacent to and contiguous with the inner surface of the facing layer;
and (c) means for decreasing the "zero peel value"
of the facing layer-pressure sensitive adhesive layer combination, said means comprising a discontinuous, uniformly distributed layer of a coatable polysiloxane between the pressure sensitive adhesive layer and the release surface, said polysiloxane being formed from monomeric units having structures (I) and (II) as follows:

(I) and (II) wherein R1 is selected from the group consisting of:
(i) phenyl;
(ii) methyl;
(iii) tolyl;
(iv) = wherein R7 and R8 may be the same or different and may be hydrogen, methyl, or ethyl, and wherein when R1 is group (i), (ii), (iii) or (iv), the prime mole percent of structure (I) is from about 0.5 to 50 and the prime mole percent of structure (II) is from about 99.5 to 50, and (V) polyoxyalkylene having the structural formula -R5(OC2H5)n(OC3H6)OR6 wherein R6 is a monovalent hydrocarbon group having from 1 to 10 carbon atoms, R5 is an alkylene group having at least two carbon atoms, n and m are numbers, and the sum of n and m is such that the oxyalkylene block R6O(C3H6O)m(C2H5O)n, has a molecular weight of at least 1500, from 15 to 60 weight percent of the oxyalkylene units are oxyethylene units, and wherein there are at least three units having structure (I) and at least 40 units having structure (II) and wherein the oxyalkylene block constitutes from 85 to 30 weight percent of the polysiloxane polymer;
R2 may be methyl, ethyl, or phenyl; and R3, and R4 may be the same or different and may be methyl or ethyl, wherein the sheets are stacked such that the polysiloxane layer of one sheet is immediately adjacent to the release surface of the next sheet in the stack.

28. In a method for making a laminate wherein a first sheet having a release surface thereon is coated with a pressure sensitive adhesive to form a first laminate, and the first laminate is then subjected to conditions suitable to dry or cure the pressure sensitive adhesive, and the pressure sensitive adhesive side of the thus treated first laminate is married to the inner surface of a facing layer having inner and outer surfaces, the improvement which comprises coating the release surface prior to the coating of the pressure sensitive adhesive thereon with means for decreasing the "zero peel value" of the facing layer-pressure sensitive adhesive layer combination, said means comprising a uniform and discontinuous layer of a coatable polysiloxane, said polysiloxane being formed from monomeric units having structures (I) and (II) as follows:

(I) and (II) wherein R1 is selected from the group consisting of:

(i) phenyl;
(ii) methyl;
(iii) tolyl;
(iv) ;

wherein R7 and R8 may be the same or different and may be hydrogen, methyl, or ethyl, and wherein when R1 is group (i), (ii), (iii) or (iv), the prime mole percent of structure (I) is from about 0.5 to 50 and the prime mole percent of structure (II) is from about 99.5 to 50, and (v) polyloxyalkylene having the structural formula -R5(OC2H5)n(OC3H6)mOR6 wherein R6 is a monovalent hydrocarbon group having from 1 to 10 carbon atoms, R5 is an alkylene group having at least two carbon atoms, n and m are numbers, and the sum of n and m is such that the oxyalkylene block R6O(C3H6O)m(C2H5O)n, has a molecular weight of at least 1500, from 15 to 60 weight percent of the oxyalkylene units are oxyethylene units, and wherein there are at least three units having structure (I) and at least 40 units having structure (II) and wherein the oxyalkylene block constitutes from 85 to 30 weight percent of the polysiloxane polymer;
R2 may be methyl, ethyl, or phenyl; and R3, and R4 may be the same or different and may be methyl or ethyl.

29. The method of claim 28 wherein the polysiloxane is coated in an amount effective to substantially decrease the "zero peel value" from the "zero peel value" of a control laminate wherein the polysiloxane layer is absent.

30. The method of claim 28 wherein the polysiloxane is coated in an amount effective to decrease the "zero peel value"
of the laminate by at least about 25 percent from the "zero peel value" of the control laminate.

31. The method of claim 28 wherein the polysiloxane is applied in an amount effective to produce a "zero peel value" of less than about 600 grams on a stainless steel test surface and less than about 500 grams on "acrylic" and "SBR" test surfaces.

32. The method of claim 28 wherein the amount of polysiloxane coated is in the range from about 0.002 to 1.0 gram per square meter on a dry weight basis.

33. The method of claim 28 wherein R1 is phenyl, and R2, and R3, and R4 are methyl.

34. The method of claim 33 wherein the prime mole percent of structure (I) is from about 0.5 to 30 and the prime mole percent of structure (II) is from about 99.5 to 70.

35. The method of claim 34 wherein the prime mole percent of structure (I) is about 4.5 and the prime mole percent of structure (II) is about 95.5.

36. The method of claim 33 wherein the molecular weight of the polysiloxane is from about 35,000 to 250,000.

37. The method of claim 28 wherein R1 is phenyl r R2 is phenyl, and R3 and R4 are methyl.

38. The method of claim 28 wherein R1 is methyl, the rime mole percents of structure (I) and (II) are equal and he viscosity of the polysiloxane is in the range from about 60 x 103 to 20 x 106 cps.

39. The method of claim 28, wherein R1 is and R7 and R8 are H, the prime mole percent of structure (I) is from about 40.0 to 60.0 and the prime mole percent of stucture (II) is from about 60.0 to 40.0, and the polysiloxane possesses a molecular weight from about 5 x 105 to 1 x 106.

40. The method of claim 28 wherein the facing layer is selected from the group consisting of woven, knitted, and non-woven textile fabrics, metal foils, paper, a continuous film of a polymer selected from the group consisting of vinyl polymers, polyolefins, polyesters, and such polymeric films having metallic coatings thereon.

41. The method of claim 28, wherein the facing layer is itself composed of a bottom decorative layer and a top, transparent protective layer.

42. The method of claim 28, wherein the polysiloxane is dissolved in a solvent and the solution thereof is applied to the release surface and thereafter the solvent is removed from the applied polysiloxane.

43. The method of claim 42, wherein the concentration of the polysiloxane in the solution is from about 0.125 to 15 weight percent based on the weight of the solution.

44. The method of claim 28, wherein the polysiloxane is applied in the form of an aqueous emulsion.

45. The method of claim 28, wherein the outer surface of the facing layer possesses release properties and wherein, subsequent to the marrying step, the first sheet is peeled from the laminate to form a second laminate composed of the facing layer, the pressure sensitive adhesive layer, and the polysiloxane layer, and wherein the second laminate is rolled upon itself such that the polysiloxane layer is next to the outer surface of the facing layer.

46. In a method for making a laminate wherein a facing layer having outer and inner surfaces is coated with a layer of a pressure sensitive adhesive to form a first laminate and the first laminate is then subjected to conditions suitable to cure or dry the pressure sensitive adhesive to produce a second laminate, and the pressure sensitive adhesive side of the second laminate is married to a release surface, the improve-ment which comprises applying to the pressure sensitive adhesive side of the second laminate prior to marrying the release sur-face thereto, means for decreasing the "zero peel value" of the facing layer-pressure sensitive adhesive layer combination, said means comprising a uniform and discontinuous layer of a coatable polysiloxane, said polysiloxane being formed from monomeric units having structure (I) and (II) as follows:

(I) and (II) wherein R1 is selected from the group consisting of:

(i) phenyl;
(ii) methyl;
(iii) tolyl;
(iv) wherein R7 and R8 may be the same or different and may be hydrogen, methyl, or ethyl, and wherein when R1 is group (i), (ii), (iii) or (iv), the prime mole percent of structure (I) is from about 0.5 to 50 and the prime mole percent of structure (II) is from about 99.5 to 50, and (v) polyoxyalkylene having the structural formula -R5(OC2H5)n(OC3H6)mOR6 wherein R6 is a monovalent hydrocarbon group having from 1 to 10 carbon atoms, R5 is an alkylene group having at least two carbon atoms, n and m are numbers, and the sum of n and m is such that the oxyalkylene block R6O(C3H6O)m(C2H5O)n, has a molecular weight of at least 1500, from 15 to 60 weight percent of the oxyalkylene units are oxyethylene units, and wherein there are at least three units having structure (I) and at least 40 units having structure (II) and wherein the oxyalkylene block constitutes from 85 to 30 weight percent of the polysiloxane polymer;
R2 may be methyl, ethyl, or phenyl; and R3, and R4 may be the same or different and may be methyl or ethyl.

47. The method of claim 46 wherein the outer surface of the facing layer is the release surface and the marrying step is carried out by rolling the first laminate upon itself such that the polysiloxane layer is next to the outer surface of the facing layer.

48. The method of claim 46 wherein the outer surface of the facing layer is the release surface and wherein the marry-ing step is carried out by cutting the second laminate into separate essentially equally sized pieces and stacking one piece upon another such that the polysiloxane layer of one piece is next to the outer surface of the facing layer of the next piece in the stack.