CA2032521A1

CA2032521A1 - Pressure-sensitive adhesive release liner

Info

Publication number: CA2032521A1
Application number: CA 2032521
Authority: CA
Inventors: Thomas C. Epple
Original assignee: Individual
Current assignee: Avery Dennison Corp
Priority date: 1989-05-08
Filing date: 1990-05-03
Publication date: 1990-11-09
Also published as: KR0154338B1; WO1990013419A1; KR920700902A; EP0425644A4; JPH03505559A; JP2908016B2; AU5649590A; US5084317A; EP0425644A1

Abstract

A release liner (10) comprising a thermoplastic film (12) having a release surface (16) including a cured silicone coating (14) for use in moldable pressure-sensitive adhesive fastening tapes (18) and laminates (30) including a moldable or formable layer. The rheological properties of the thermoplastic film (12) at elevated temperatures are used to achieve mold conformability and retention of uniform release characteristics.

Description

~'v;~J
WO 90tl3419 PCr/USgO/0246 PRESSURE-SENSITIVE A~HESIVE RELEASE J,JNER
_ _ _ _ BACRGROUND OF INVENTION AND PRIOR ART

The present invention relates to release liners comprising a thermoplastic film having a cured silicone coatina which provides a liner re1ease surface, moldable pressure-sensitive adhesive fastenin~
tapes including such release liners and to the use of the release liners and tapes in laminates including a moldable or formable layer which may be molded h~
application of heat and pressure.
The release liner may be used to protect or cover a surface of the laminate to be molded. The release liner is particularly useful in the molding of laminates including a formable~layer comprisin~ a flat workpiece or sheet material blank and a pressure-sensitive adhesive layer having an outer surface covered hy the release liner. Of course, the laminate may be provided by the combination of a formable layer and a fastening tape comprising the pres~re-sensitive adhesive layer and release liner. The desired degree of adhesion or releasability of the liner is provided by the silicone coating on the release surface of the liner. In such molding applications, it is necessarv to achieve both good mold conformability and retention of uniform releasability.
In presPnt practice, the release liner does not itself consist of a moldable material and the liner may tend to assume a non-conforming shape which includes wrinkles or folds. Poor mold conformability is encountered in the molding of compl2x shape~ as well as even relatively simple shapes involving non-uniform .

7 ~
~090tl~1~ i PCTt~S90/U2462 extension of portions of the laminate. Typically, release liners including a paper layer ar~
unsatisfactory since they do not provide s~fficient elongation to accommodate complex n~old sh~pas which may include surfaces defined by compound curves ~nd/or require extension of laminate portion.s in angularlv intersectin~ directions.
The molding process tends to increase the adhesion or release force between the release liner and the surfaee to which it is secured. The exact phenomenon of the undesirable increase in releas2 force is not known, but it is deemed to be a change in the release surface and/or silicone coating due to migration of silicone away from the release surface of the liner and/or penetration of the release surface by the pressure-sensitive adhesive~
The present invention has been ~ound especially advantageous in the thermoforming of carpet materials including a pressure-sensitive adhesive layer for installation of the molded carpet. Various thermo-formin~ techniques are discussed in Irwin, Dave, Intro-duction to Thermoformin~1 Modern Plastics Enc~clonedia, pp. 286-292, 1988. In the thermof~rming of carpet materials, a matched mold formine technique i5 llSed with the carpet material being shaped in a clearance between the closed mold halves. The carpet is heated to a temperature in the range of 200 F. to 450 F. and then molded at a pressure of several thousand psi.
Applicants are not aware of any successful prior release liners or techniques for thermoforming a car-pet, pressure-sensitive adhesive and release liner laminate.

WO90/13419 ~ 2 I PCT~US90/02462 U.S. Patent A,405,668 di~closes the use of pressure-sensitive adhesive coated fiber strands embedded in the backina of carpet materia]s ~or installation thereof after removal of a ~olyethylene sheet release layer. This patent also proposes automotive interior applications wherein the carpet materials are molded followin~ the removal of the polyethylene sheet release layer in order to simultaneously effect the molding and adhering of the carpet material.
U.S. Patent 2,986,777 disc]oses a carpet molding technique for automotive interior floor carpets. The carpet is molded or shaped ~etween mating dies to set the back of the carpet. This patent does not disclose the use of an installation adhesive for the carpet.
The use of a plastic film such as polyethylene film at a mold surface to improve the surface of a poured concrete part and better conform the part surface with the mold is disclosed in U.S.
Patent 4,331,628. The plastic film i9 heat-softened and a vacuum is applied to make the film be~ter con~orm to the mold surface.
~ .S. Pa~ent 2,343,930 discloses a cre~ed web coated with plastic which is melted during molding to carry the web to a more exact mold shape. U.S. Patents 4,350,551 and 4,443,507 disclose molding processes wherein an intermediate layer of a thermoplastic or thermosetting film is melted during the molding process to accommodate relative movement between adjacent layers.

W~ g~/1~19 ~ ~ 3 ;~ .J~.l PCT/US90/0~62~

SI~MARY OF INVE~TION

In accordance wi.th the present invention, the rheological properties of thermoplastics at elevated temperatures are used to achieve mold conformabi.].ity and retention of uniform release characteristics in a silicone coated release liner for use in a moldin~
process. The thermoplastic is selected 90 that it becomes sufficiently supple due to softenina or mel.ting to assure mold replication while limi~ing deformation and/or flow to thereby substantially maintain the integrity and continuity of the release surface.
The silicone coating is applied to at least one surface of a film of the thermoplastic and cured at a temperature ~hich avoids unnecessary softeni.ng n.f the thermoplastic film in order to provide~a uniform and continuous silicone coating. Thereafter, the li~er may be exposed to relatively higher temperatures in ~he molding process in reliance upon the rheo~o~ical properties of the thermoplastic film to maintain the integrity and continuity of the cured silicone coating.
Molding temperatures exceeding the melt temperature of the thermoplastic and/or causing the melting of t.he film during molding have not been found to significantly increase the release force and uniform release characteristics have been maintained.
The film may include a single layer of the thermoplastic material or polymer, blends of polymers or filled polymers or consist of multiple layers including one layer that provides desired rheological and surface properties and another layer which provides physical film properties such as tear, elongation, and tensile properties. The single or multiple layer film may be produced in conventional manners such as by wo go/l~lg 2 ~ ~ h ~ f~ .~ PCT/US90tO~62 casting, calendering and extrusion includin~ blown ~ilm processing. Further laminating and coextrudiny techniques may be used to form multiple layer films.
A wide range of thermoplastic materials may be used to provide acceptable mold conformability for molding or thermoforming operations. Acceptable mold conformability or similar phrases herein used in connection with thermoplas~ic films and release liners indicate the ability o~ such films and liners to be shaped during a molding process to suhstanti.ally duplicate or replicate the mold and to be substantially free of wrinkles, ~olds, and other threa dimensional irregularities.
The specific molding ~onditions may fa~r the use of particular thermoplastic materials. Generally, acceptable mold conformability is balanced against retention of release properties. If the deformation or flow displacement of the thermoplastic material at the molding temperature and pressure is too high, t.he silicone coating is di.srupted and the release force may be increased to an unacceptable value ln that area. If the release force is too great, manual removal of the liner from large workpieces is fatiguing and the liner may tear so as to require additional time for its removal in pieces.
A 20 to 50% increase in the releas2 force due to the thermoforming of carpet materials has been observed by applicants prior to the development of the present invention. Such increases in the liner release force may causa the release force to become excessive and inhibit the clean separation of the liner from the pressure-sensitive adhesive. By use of thermoplastic films as described hereinafter, acceptable mold wo go/1~lg 2 ~ 3 ~ PCT/US90/0~62 conformability may be achieved with no significant increase in the release force.
It has been found that the mold conformability of a thermoplastic film for ~iven molding conditions is related to its defl~ction temperature under flexural load determined according to ASTM D648-82. This test measures the temperature at which a selected deformation occurs when a load of either 66 psi or 264 psi is applied at the midpoint of a sized beam ot the thermoplastic material immersed in a heating oil medium. The deflection temperature is a measure of the softening temperature o~ the thermoplastic material. A higher deflection temperature indicates a decreased degree of shapeability and mold conformability at given molding conditions. Accordingly, the conformability ~f the release liner for a given molding process may be correlated with the deflection temperature of the thermoplastic film used in the liner. Thermoplastic films of relatively low deflection temperatures tend to give improved conformability for given molding conditions. Satisfactory results have been obtained for thermoplastic films having deflection temperatures from about 80 to 250 F. at a 264 psi loa~ and from about 90 to 300 F. at a 66 psi load.
The integrity and continuity of the silicone coating on the thermoplastic film may be maintained during the molding process even if the thermoplastic film melts provided the melted or molten thermopla~tic does not readily flow. The maintenance of t.he integrity and continuity of the cured silicone coating upon melting of the thermoplastic are related to ~he melt index of the thermoplastic. Melt index is used herein to identify the flow rate in g/10 mins. o~tained WO~0/1341~ 2~^32~2 ~ PCr/lJSgO/0~462 with an extrusion plastometer for a thermoplastic material as determined in accordance with AS~M D1238-86, condition 190/2.16. The 190~2.16 designation indicates a measured test temperature of 190 C. and a total load including the piston weight o~ 2.16 kg.
~ecreasing melt index values reduce the risk of liner film and silicone coating degradation or disruption for given molding conditions. The melt index should be in the range of about 0.15 to about 20 g/10 min., and more preferably, in the range of from about 0.5 to about 15 g/10 min.
As indicated above, a suitable silicone coating is applied to the thermoplastic ~ilm to provide the release surface of the liner. Since the thermoplastic material is selected to he~ome supple or melt at temperatures expected to be e~perienced in the molding process, the silicone cure temperature ~hould not exceed such tsmperatures. Therma~ curing silicones having sufficiently low curing temperatllres mu~t be used or a radiation curing silicon~ may be used. In the latter case, the silicone cure may be by ultraviolet or electron beam radiation.
In the drawings, which are high~y schematic, the thickness of the various layers is not to scale.

BRIEF DESCRIPTION OF THE DRA~INGS
FIG. 1 is a schematic cross-section of a release liner according to the invention;
FIG. 2 is a view similar to FIG. 1 illustrating the u~e of the release liner shown in FIG.
l as a principal component in a fastening tape having a double liner construction;

W09U/1~19 ~ 3 ~ PCT/VS~0/~62 FIG 2a ic a view similar to FIG. 2 illustrating the use of the release liner shown in FIG.
l as a principal component in a ~astening tape having a self-wound construction;
FI~. 3 is a view similar to FIG. l, but on a smaller scale, illustrating the fa~tening tape shown in FIG. 2 applied to a carpet material to be thermoformed;
FIG. 4 ie a schematic perspective view illustrating the carpet material of FIG. 3 after it has been molded to the shape of a map pocket for use in an automotiYe door; and FIG. 5 is a view similar to FIG. l illustrating another embodiment of a release liner according to the in~ention.

DETAILED DESCRIPTION OF THE INVRNTION

A release liner l0 according to the invention is shown in FIG. l. The liner l0 includes a thermoplastic film or layer 12 having a silicone coating 14 applied to 2 surface thereof to provi~e a liner release surface 16. The liner lO ;s generally prepared in rolls of predetermined width and indefinite length.
The film 12 is formed of a thermoplastic matPrial having rheological properties suitable for the particular molding process. The thermoplastic material should have a deflection temperature such that the ~ilm 12 becomes sufficiently supple due to softening or melting during molding to assure conformability. On thP other hand, the melt index of the thermoplastic material should be sufficiently low to prevent WO90/l~l9 2 ~ 2 :~ PCT/US90/0~2 degradation of the release surface 16 due to exces~ive flow, thinning or disruption of the film 12.
Examples of suitable thermoplastic polymers or materials for use in forming the film 12 include vinyl polymers, polyolefins, polystyrenes and ionomers.
Preferred thermoplastics include polyvinylchloride, polyethylene, polypropylene, polypropylene copolvmers, polystyrene and ethylene/methacrylic acid copolymer ionomers. The most pre~erred thermoplastics comprise ethylene/methacrylic acid copolymer ionomers having a melt index in the range of 0.15 to 20, and more preferably, in the range of 0.5 to about 15. Such ionomers are sold under the trademark Surlyn by E.I.
DuPont de Nemours.
The thickness of the film 12 is not very critical and may range from 2 to 20 m~ls. The thickness of the film 12 may be varied in order to assure adequate web handling characteristics.
The silicone coatin~ 14 may be formed by application of commercially a~ailable thermal or radiation cure silicones to the film 14. Low curlng temperature silicones are used to ~orm the silicone coating and enable the use of thermoplastic having relative low temperature softening and melting properties for improved mold conformability.
Generally, the silicone curing temperature will be less than the temperature to which the film is heated during the molding process and should not exceed the meltin~
temperature of the thermoplastic. For this reason, it - may be con~enient to use a radiation curable silicone wherein curing is effected at room temperature.
Suitable radiation curable silicones include that sold by the Goldschmidt Company under the product designations RC 710 and RC 720.

W090/1~1~ hr ~ ~ ;J ~ PCT/US9~/024~2 The silicone coating 14 is applied at a weight of from about 0.2 to 6.0 grams/sq meter. ~ow weight thin coatings provide satisfactory retention of release values in many applications. However, improved retention of release values may be obtained by the use of heavier weight thicker coatings in somq applications. As molding conditions ~ecome increasingly severe, heavier weight thicker coatings tend to become more effective in retaining release values or limiting the increases in such values.
Referring to FIG. 2, a simple form of a fastening tape 18 comprises a pressure-sensitive adhesive layer 20 mounted to the release surface 16 of the liner 10. The layer 20 may comprise either an acrylic or rubber based pressure-sensitive adhesive which are well known in the art. The'layer 20 may be initially coated onto a paper carrier and then laminated to the liner 10. Fastening tapes are also manufactured in roll form with a predetermined width and an indefinite length. To enable self-winding of the fastening tape 18, a conventional release liner 22 comprising a silicone coated paper may he applied to the exposed surface of the layer 20 to provide a "double liner" construction. Alternatively, a second silicone coating 14' may be applied to the opposite surface of the film 12 to provide a fastening tape 18' having a self-wound construction enabled by a release surface 16' as shown in FIG. 2a. The release surface 16' has a lower release value than the release surface 16 with respect to tha adhesive layer 20. Thus, the adhesive layer 20 separates from the release surface 16' during unwinding of a roll of fastening tape 18' and the silicone coating 14' remains adhered to the surface of liner 10 remote of the silicone coating 14.

W~90/1~19 2 ~ 3 2 ~ 2 ~ P~T/VSgU/02462 Referring to FIG. 3, the fastening tape 18 i5 shown applied to a carpet material 24. The carpet material 24 is of conventional construction and includes a fiber pile 26 secured to a backing 28, and it is manufactured and typically processed in roll form. In automotive applications, the bacXing 28 may comprise an extruded or heat laminated layer of polyethylene. For added dimensional stability, a non-woven material may be embedded in the polyethylene.
The fastening tape 18 may be laminated to the carpet material 24 at room temperature. To that end, the release liner 22 is removed and the exposed surface of the pressure-sensitive adhesive layer 20 i9 laminated to the backing 28 of the carpet material 24.
If the self-wound construction of f astening tape l8'is used, the adhesive layer 20 is exposed as the tape is unwound and it may be laminated to the backin~ 28. In either case, the lamination will usually be done in roll form to provide a laminate 30 of predet.ermined width and indefinite length. Accordingly, a workpiece or blank of the carpet laminate 30 may be cut to size, molded and subsequently adhesively mounted or installed.
The laminate 30 include~ a frontside 30a comprising the fiber pile 26 and a backside 30b comprising the liner lO. The frontside 30a provides a dura~le and decorative surface which may be used in automotive interior applications. The liner lO
protects the adhesive layer 20 from contamination prior to installation of the laminate. During the molding process, the liner also cooperates to achieve mold conformability and retention of uniform adhesive release characteristics.

WO90/1~19 ~ JJ ~ 3~ ~ PCT/U590/0~2!

Referring to FIG. 4, a molded maR pocket 32 formed of the laminate 30 is shown. The map pock2t 32 is prepared by initially heating a suitably sized workpiece of the laminate 30 in an oven to a temperature in the range of about ~00 to 4500 F. If infrared heating is used, only the hackside 30b of the laminate 30 is exposed to tha heaters. The heated piece of laminate 30 is then placed in a matched mold, the halves of which are closed at a pressure ranging up to several tons. The molding cycle may be from 5 to 90 seconds depending upon the construction of the particular laminate and the shap~. The mold may be cooled in order to improve the retention of the molded shape. Upon removal from the mold, the laminate edges are trimmed and the molded part is completed.
As shown in FIG. 4, the map~pocket 32 is ready for installation upon removal o~ the liner 10.
The liner lO is manually removed by pulling it from the adhesive layer 20 with separation occurring at the release surface lh. The map pocket 32 is then adhesively mounted or installed by merely pressing it against a support surface on the automobile door (not shown).
Prior to the present invention, it was not possi~le to mold a carpet material with a pressure-sensitive adhesive and liner to a confi~uration such as that of the map pocket 32. Prior art liners such as those usin~ paper matarials tended to wrinkle and otherwise form an unsatisfactory irregular surface.
The prior art failure was primarily due to the compound curves o~ the lower corners of the map pocket 32.

wc~ 90~ 9 2 ~ ~ 2 ^~ 2 ~ Pcr/US~/0~62 Referring to FIG. 5, a release liner 34 includes multiple-layer thermoplas~ic film 36, silicone coating 38 and release surface 40. The film 36 includes ~irst and second layers 42 and 44 of different thermoplastic materials.
The layers 42 and 44 are securely joined together. To that end, the film 36 may be produced by laminating or coextruding the layers. The layers 42 and 44 may each be made o~ the thermoplastic ma~.erials as described above with respect to the film 12.
The properties of the film 36 will be a composite of the properties of tha layers 42 an~ 44.
For example, the layer 44 may be of a Surlyn thermoplastic material in order to achieve optimum surface-type characteristics in respect to the maintenance of the releasa surface 40~ The layer 42 may be a polyethylene which provi.de~ satisf~ctory bu~k fi.lm properti.es at a relati~ely lower cost as compared with Surlyn. The combination of Surlyn and the polyethylene may be coextruded. Of course, combinations of other thermoplastic materi.als or blends or multiple layers may be used.
In accordance with the present invention, r~l.ease liners inc].uding a th2rmo~1astic f;.lm of ~r'.yn l601 were prepared and evaluated ;n a test mold;.ng proce~llr2 as described below. The results o~ thesa tasts are reported in Table T.
In the following Exampl2s 1 to 4, a ~si.x m;1 thick film of Surlyn 1601, commercially ava;.~able from suppliers such as Consolidated Thermoplastics Films of Arlington Heights, Illir.ois, was provided with a radiation curable silicone coating using conventional coating techniques. The silicone coating comprised a 55/45 weight percent blend of radiation curahle wo go/l~lg 2 ~ 3 ~ ~ 2 L PCT/US90/02462 silicones sold by the Goldschmidt Company with product desi~nations RC 710 and RC 720. The silicone coating was cured by electron beam at 175 kv energy and a 3.0 mega rad dose. In this manner, a 2.5 g/sq. meter silicone coating was provided on one side of the Surlyn film to form a release surface. In Examples 2 and 4, a 2.5 g/sq. meter cured coating comprising a 30f70 weight percent blend of RC 710 and RC 720 was provided on the opposite side of the f ilm to make a self-wound construction of the type shown in FIG. 2a of the drawings. In Examples 1 and 3, a silicone-coated paper release liner was used to provide a double liner construction as generally illustrated in FIG. ~A of the drawings.
In all of the examples, a proprietary rubber based adhesive as indicated in Exampl~ 5 of V.S. Patent 4,820,746 was used. The adhesive was double coated onto the silicone coating of the paper release ]iner in an amount,sufficient to provide a total adhesive weight of about 250 g/sq. meter.
The silicone coated release surface of the Surlyn film of Examples 1 and 3 was laminated at room temperature to the cured adhesive layer on the paper release liner, and the resulting laminate was wound to provide the double liner roll stock. In Examples 2 and 4, the release surface provided by the 55/45 blend of RC 710 and RC 720 silicone coating was similarly laminated to the adhesive layer on the paper release liner. The paper release liner was then separated since the laminate was a self-wound construction.
The release liners of Examples 1 - A were applied to an automotive grade ~arpet material having a 12 oz~yd2 non~oven needlepunch polypropylene fiber pi 1R
and a 10 mil thick backing of polyethylene having a WO~/13419 2 ~ ~ 2 5 2 ~ PCT/VS90/0~6Z

polyester nonwoven laminated to its backside. (In the case of Examples 3 and 4, the silicone paper liner wa~
removed and the exposed pressure-sensitive adhesive layer was applied to the carpet backing.) In all cases, the liners were applied using a nip roll at room temperature. Thereafter, the carpet and liner laminate was heated in an oven at 280 F. for one mlnute and then immediately placed in a mold at 2,000 psi for one minute in order to allow cooling of the lamin~te. In each of the examplas, tha Surlyn film was deemed to have melted during processing since Surlyns have melt points less than 210 F.
TABLE I
Release Forcel (g/2" width) Exam~le Before Moldin~ After Moldina l 137 137 4 2~6 228 As indicated in Table I, the release force was measured before and after molding using PSTC-2 test procedure as set forth in Pressure Sensitive Tape Council Test Methods, 5th Edition. A Tag and Label Manufacturing Institute ITLMI) release and adhesion tester was used and the samples were tested at 300 in/min.
In all of the examples, no siqnificant increase in the release force was observed due to the molding process. The release force in Example ~ is considered to be con~tant; the slight decrease in value 1 Reported in grams~2" wide sample per TL~I testar.
2 Silicone coating was not uniform.

W~90tl~l9 ~ 3 ~ PCT/US90/0~6 after molding is within testin~ variat.ion. Increases in the release force due to the molding process may be acceptable provided the release force does not become excessive in the further processing. For example, release forces in excess of 600 g~2" sample width tend to inhibit manual removal of a liner from larger workpieces.
It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or el;.minating details wi.thout dsparting from the fair qcope of the t.eaching contained in this disclosure. ~he invention is therefore not limited to particular details of thi.s disclosure except to the extent that the following claims are neces~ari].y so limited.

Claims

CLAIMS:

1. A release liner having improved mold conformability for use in a laminate including a formable layer and a pressure-sensitive adhesive layer to be molded at an elevated temperature in a mold, said release liner including a film of thermoplastic material or blends of materials having a release surface including a cured silicone coating for releasable attachment to said adhesive layer with a predetermined release force prior to molding, said silicone coating being cured at a temperature less than said elevated temperature, said film having a deflection temperature and a melt index such that said film becomes supple during molding to conform with the mold while limiting the deformation and flow of the thermoplastic film to substantially prevent degradation of said release surface and thereby to substantially maintain said releasable attachment with said predetermined release force.

2. A release liner according to claim 1, wherein said silicone coating is cured by radiation.

3. A release liner according to claim 1, wherein said film has a melt temperature less than said elevated temperature and melts during molding.

4. A release liner according to claim 2, wherein said thermoplastic material is selected from the group consisted of vinyl polymers, polyolefins, polystyrenes and ionomers.

5. A release liner according to claim 4, wherein said thermoplastic material has a deflection temperature measured in the range of from about 80° F.
to about 250° F. at a 264 psi load.

6. A release liner according to claim 5, wherein said thermoplastic material has a melt index in the range of from about 0.15 g/10 min to about 20 g/10 min.

7. A release liner according to claim 1, wherein said film includes at least two layers of different thermoplastic materials.

8. A release liner according to claim 2, wherein said film includes first and second layers, said first layer including said release surface and primarily providing said film with rheological characteristics to substantially prevent degradation of said release surface at said elevated temperature, and said second layer primarily provides said film with improved physical film properties.

9. A release liner according to claim 2, wherein said film comprises first and second layers of thermoplastic materials, said first layer being a layer of an ethylene/methacrylic acid copolymer ionomer, and said second layer being a layer of polyethylene.

10. A release liner according to claim 2, wherein said thermoplastic material is an ethylene/methacrylic acid copolymer ionomer having a melt index in the range of from about 0.5 g/10 min. to about 15 g/10 min.

11. A fastening tape wherein said tape includes a release liner according to claim 1, 6 or 8 and a pressure-sensitive adhesive layer releasably attached to said release surface of said liner.

12. A laminate including a formable layer secured to a fastening tape according to claim 11, said formable layer being releasably secured to a side of said pressure-sensitive adhesive layer remote from said liner.

13. A laminate including a formable layer, a pressure-sensitive adhesive layer having a first side secured to said laminate and a second side releasably secured to a release liner according to claim 1, 6 or 8.

14. A laminate according to claim 13, wherein said formable layer comprises a carpet material having a pile extending from a backing which is secured to said first side of said pressure-sensitive adhesive layer, said carpet material being moldable by thermoforming at a temperature in the range of 200° F.
to 450° F.

15. A method of making a release liner having improved mold conformability for use in a laminate to be molded at an elevated temperature in a mold, said laminate including a formable layer and an adhesive layer releasably attached to a release surface of said release liner which includes a silicone coating, comprising the steps of providing a film of thermoplastic material having a deflection temperature and a melt index such that said film becomes sufficiently supple at said elevated temperature to conform with said mold while limiting the deformation and flow of the thermoplastic material of the film to substantially prevent degradation of said release surface, applying said silicone coating to said release surface of said film, and curing said silicone coating at a temperature lower than said elevated temperature to provide said release surface.

16. A method according to claim 15, wherein the step of curing said silicone coating comprises radiation curing said silicone coating.

17. A method according to claim 15, wherein said film consists of two layers of different thermoplastic materials and the step of providing said film includes coextruding said two layers of thermoplastic materials.

18. A method according to claim 17, wherein said two different thermoplastic materials are polyethylene and ethylene/methacrylic acid copolymer ionomer.

19. A fastening tape having improved mold conformability for use in a laminate including a formable layer, said fastening tape comprising a pressure-sensitive adhesive layer having a first side adapted to be attached to said formable layer and a second side releasably attached to a release liner, said release liner including a film of thermoplastic material or blends of materials, said film having a release surfaces attached to said second side of said adhesive layer, said release surf ace including a cured silicone coating, said laminate being moldable at an elevated temperature exceeding the deflection temperature of said thermoplastic film and the temperature at which said silicone coating is cured.

20. A fastening tape according to claim 19, wherein said thermoplastic material is selected from the group consisted of vinyl polymers, polyolefins, polystyrenes and ionomers.

21. A fastening tape according to claim 20, wherein said thermoplastic material has a melt index in the range of from about 0.15 g/10 min to about 20 g/10 min.

22. A fastening tape according to claim 21, wherein said film includes at least two layers of different thermoplastic materials.

23. A fastening tape according to claim 19, wherein said thermoplastic material is an ethylene/methacrylic acid copolymer ionomer having a melt index in the range of from about 0.5 g/10 min. to about 15 g/10 min.

24. A moldable laminate having improved mold conformability including a formable layer, a pressure-sensitive adhesive layer having a first side adhered to said formable layer and a second side releasably attached to a release liner, said release liner comprising a thermoplastic film having a release surface attached to said second side of said adhesive layer, said release surface including a cured silicone coating, said laminate being moldable at an elevated temperature exceeding the deflection temperature of said thermoplastic film and the temperature at which said silicone coating is cured.

25. A laminate according to claim 24, wherein said formable layer comprises a carpet material.

26. A laminate according to claim 25, wherein said carpet material is adapted to be molded by thermoforming at a temperature in the range of 200° F.
to 450° F.

27. A laminate according to claim 24 or 26, wherein said silicone coating is cured by radiation.

28. A laminate according to claim 27, wherein said thermoplastic film has a melt temperature which is less than said elevated temperature.

29. A method of molding a laminate including a formable layer and an adhesive layer covered by a release liner, said release liner comprising a film of thermoplastic material including a release surface having a cured silicone coating releasably attached to said adhesive layer with a predetermined release force comprising the steps of molding said laminate in a mold with heat and pressure to shape said formable layer and cause said film to become sufficiently supple to conform with said mold while limiting the deformation and flow of the thermoplastic material of the film to substantially prevent a change of said release surface and thereby to substantially maintain said releasable attachment to said adhesive layer with said predetermined release force.

30. A method according to claim 29, wherein the step of molding said laminate includes causing said thermoplastic material to melt.

31. A method according to claim 30. wherein said formable layer comprises a carpet having a pile and a backing, said adhesive layer is a pressure-sensitive adhesive having a first face secured to said backing and an opposite second face secured to said release surface of said liner, and the step of molding said laminate includes thermoforming at a temperature in the range of 200° F. to 450° F.