IMPROVED RELEASE COATINGS

Abstract: Excellent release surfaces are formed by curing a composition which is a dispersion of a reactive silicone present in an amount of from 1 to 30% by weight of the composition as a discontinuous phase in a continuous phase of a reactive resin comprising a reactive oligomer and optionally a reactive monomer. The product has a silicone release surface with silicone anchored in the coating. The surface is for releasable contact with a pressure-sensitive adhesive. Heat, electron beam and/or ultraviolet radiation may be used to achieve cure.

Description: IMPROVED RELEASE COATINGS 0 Background of the Invention The construction of pressure sensitive adhesi products presents a variety of materials selecti problems. Basic to any construction is the selection 5 a suitable release surface. A label, for instance, is normally comprised of a fa stock which may range from paper to a plastic film su as .polyester film or even metal; a release liner havi a silicone release surface, and a pressure-sensiti 0 adhesive layer, normally rubber or acrylic based contact with the face stock and the silicone relea surface. In self-wound products, a silicone release m be applied to the face stock opposite the side to whi the adhesive is applied. 5 Conventional siliconereleasecoatings areessential 100% by weight as a silicone resin on a solids basis a by weight the most expensive raw material in label a tape constructions. It would be desirable to reduce t amount of silicone employed as this would reduce t - cost of the silicone release surface. Reducing silico content, however, has a normal effect of increasing t bond to the release surface. As dilution occurs a poi is reached where the bond becomes so great that t adhesive may sever the silicone material from t _ substrate, normally paper, to which it was applied a in effect transfer the silicone to the adhesive to th detriment of the ability to bond the adhesive to anothe surface. U.S. Patent 4,288,479 to Brack is directed to release coatings which contain a waxy material of limited com¬ patibility with a liquid monomer or prepoly er. Upo application to a film, the waxy material migrates to th surface. Radiation is applied to cure the polymer. Th waxy material which include silicones are described as generally non-reactive in the polymerizable liquid bu can contain reactive groups. In Example 65 of the Brac patent, there is described a release composition containin a silicone rubber which was a polydimethyl siloxane wit some unsaturation. On radiation there was stated to b formed a surface releasable with respect to a removabl adhesive. We have found that the composition is no functional for permanent pressure sensitives which diffe from removable adhesives in that adhesive bond grow with time. As established here, the combination welde together. See Example 5 herein. The present invention is directed to nove formulations of substantially reduced silicone conten which display excellent release properties. Summary of the Invention There is provided a substrate having bonded theret a cured release coating having a silicone release surfac for contact with a pressure-sensitive adhesive formed b coreaction of components of a coating composition of silicone comprised of dimethyl siloxane polymers, prefer ably a reactive silicone and a resin preferably a reactiv resin. The silicone is present in an amount of fro about 1 to about 30 percent by weight of the coatin composition and anchored to the coating so as to b substantially non-transferable to a pressure-sensitiv adhesive. The silicone release surface is functional release permanent and removable pressure-sensitive adh sive. Cure is preferably induced by the action of hea actinic radiation and/or electron beam radiation, provid in a quantity sufficient to anchor the silicone to t resin whereby the silicone becomes substantially no transferableto apressure-sensitive adhesive. Ultraviol and/or electron beam radiation is presently preferred. The silicones employed preferably have a molecul weight of at least about 2,000, preferably 10,000 or mor It is presently preferred that the products formed by curing a coating comprised of from about 1 about 30 percent by weight, preferably from about 5 about 30, most preferably from about 5 to about 15 perce by weight, of a reactive silicone dispersed as a disco tinuous phase in a reactive resin present in an amou of from about 99 to about 70 percent by weight, preferab from about 95 to about 70 percent by weight, more prefe ably from about 95 to about 85 percent by weight, of t combination of the reactive silicone and reactive resi -The reactive resin contains from about 50 to 100 perce by weight reactive oligomer and from about 50 to 0 perce by weight reactive monomer based as the total weight reactive oligomer and reactive monomer. The reacti monomer is used to control viscosity prior to cure. To enable good coatability, the dispersion preferab has a viscosity of from about 300 to about 10,000 cp There may also be included in the system as required phot initiators, colorants and the like. The invention enables tailoring of the silico release surface to the product. Useful products wi have TLMI (Tape and Label Manufacturers Institute) pe under Keil conditions of no greater than about 400 N/ For tapes the TLMI peel should be no greater than abo 400 N/M, more typically 100 to 200 N/M. For tags and labels a "high release specification has a TLMI peel up to about 60 to about 100 N/M; a "medium" release has a TLMI peel of about 20 to about 50 N/M; and a "low release" has a TLMI peel of less than about 20. Again all peel values are reported for Keil conditions, namely afte aging at a load of 0.25 psi for 20 hours at 70 β C. Brief Description of the Drawings FIG. 1 illustrates Carver release in grams per in as a function of aging at room temperature for the co position described in Example 1. FIG. 2, the Carver release is for the same compositi except for aging at 140 β F. FIG. 3 illustrates the release as a function silicone content of the coating at the time of cure. FIG. 4 illustrates the same release but after agi for 28 days at room temperature. FIG. 5 is for the same composition but after agi 28 days at 140 β F. FIG. 6 shows the effect of concentrations of pho initiator on the release force and its effect with tim Attached drawing marked "Prior Art" depicts t accepted effect on a control release additive on a silico release material. As can be appreciated by inspectio the-release force remains fairly constant until some poi is reached where the force increases dramatically. the scale, zero designates no control release additi while 1 designates no silicone polymer. Detailed Description There is provided in accordance with the present invention a substrate having thereon a cured coating of silicone release surface for contact with a pressure- sensitive adhesive. The coating is formed by coreaction of a silicone comprised of dimethyl siloxane polymers, preferably a reactive silicone and a resin, preferably a reactive resin comprising a reactive oligomer. Under curing conditions induced by application of sufficient heat, electron beam (EB) radiation and/or actinic radiation, preferably ultraviolet (UV) radiation, the silicone is anchored to the cured coating and is rendered substantially non-transferable to a pressure-sensitive adhesive in contact with the release surface. The dimethyl siloxane polymer content of the coating is from about 1 to about 30 percent by weight on the total weight of the constituents of the coating with the anchored silicone preferentially concentrated at the surface provided for contact with a pressure-sensitive adhesive. The cured coating may be achieved using silicone-monomer combina¬ tionso Preferential presence of silicone at the surface may be achieved by partial to total incompatibility of the silicone and the resin, or by structural rearrangement of a silicone-resin surface. What is critical is that the silicone is sufficiently anchored to the surface and substantially non-transferable to a pressure-sensitive adhesive. Anchoring may be mechanical and/or chemical. The desired products have a Carver release as define herein of less than about 100 grams per inch. Carve release is determined by applying Scotch™ 610 tape t the release surface under a pressure of 6000 psi for 6 seconds then measuring force required to achieve releas at a peel rate of 12 inches per minute. As used herein, by the term "silicone" there is mea dimethyl siloxanepolymers consisting of alternate silico and oxygen atoms with methyl groups attached to silicon The general structure is: CH 3 CH 3 CH 3 OSi 0 Si OSi CH 3 CH 3 X CH 3 wherein "x" is an integer. By the term "reactive silicone" there is meant silicone end capped and/or mid-chain substituted wit groups reactive on application of heat and/or energ with reactive groups of the resin. The presently preferre reactive groups are acrylic, mercapto and/or oxirane. By the term "resin" there is meant an organic moiet which is combinable with the silicone and reactive wit silicone and/or reactive silicone under action of heat actinic radiation and/or electron beam radiation t cause anchoring, preferably preferential surface anchorin of the silicone to the resin. By the term "reactive resin" there is meant a resi comprising reactive oligomers containing groups whic are reactive with the reactive groups of a reactiv silicone. The presently 'preferred reactive oligomer contain reactive acrylic, mercapto and/or oxirane groups The reactive resin may include a reactive monomer use to control viscosity, although not necessary to utilit of the silicones. By the term "reactive monomer" there is meant monomer which coreact with the reactive silicone and/or th reactive oligomer of the reactive resin and which ar effective in reducing viscosity of coating compositio used to form the end products of this invention. It i preferred that the reactive monomer be a multifunctiona monomer preferably a multifunctional acrylate. By the term "silicone release surface" there is meant a surface which will release from a pressure sen¬ sitive adhesive substantially without transfer of release material to the adhesive and having a TLMI peel under Keil conditions of no greater than about 400 N/M. It is presently preferred that the products of the invention be formed by coating a substrate such as paper then curing the coating, where the coating is comprised of from about 1 to about 30 percent by weight, preferably about 5 to about 30 percent by weight, more preferably about 5 to about 15 percent by weight, of a reactive silicone dispersed as a discontinuous phase in a reactiv resin present in an amount of from about 99 to about 70 percent by weight, preferably from about 95 to about 70 percent by weight, more preferably from about 95 t about 85 percent by weight of the combination of th reactive silicone and reactive resin. The reactiv resin contains from about 50 to 100 percent by weigh reactive oligomer and from about 50 to 0 percent b weight reactive monomer based as the total weight o reactive oligomer and reactive monomer. The reactiv monomer is used to control viscosity prior to cure. There may also be included in the system as require photoinitiators, colorants and the like. To enable good coatability, the dispersion shoul have a viscosity of from 300 to about 10,000 cps. Vis cosity can, as indicated, be adjusted by the addition o reactive monomers. While not bound by theory, it is presently believe that surface reorientation occurs to form the silicon release surface. Reorientation can occur either prior to, during or following cure, as it has been observed, th quality of release of the silicone release surface ca increase with time, even a fairly short time span, an then level out. Improved release is attributed to th amount of silicone at the surface. The cured coating believed similar to block or graft copolymers havi oligomer blocks bound to the silicone blocks with pre erential presence of silicone at the surface as oppos to the body of the coating. The coating typically has glass transition temperature of at least 0°C, preferab greater than about 20°C. Critical to the use of a dispersion is that t proportion of reactive silicone and reactive resin rema as a coatable dispersion in which the reactive silico is as the dispersed phase and the reactive resin is t continuous phase. Once a certain level of reacti silicone monomer content is reached, phase inversi begins, to the end of forming a system in which t reactive resin is the dispersed phase and the reacti silicone is the continuous phase. When this is complet the cured product will become rubbery and behave like conventional silicone release coating which requires high concentration of silicone before a suitable releas level is achieved. In the practice of the invention, the dispersion i coated in a conventional manner onto a substrate which ma be any grade of paper, including the papers of low grade cardboard, polymeric films and the like. Cure is to b sufficiently complete, such that substantially no silicon transfers to a pressure-sensitive adhesive to which th silicone release surface contacts. Avoidance of transfe is the result of the silicone being anchored to coatin body and not available to transfer to the pressure-sen sitive adhesive. Electron beam cure has a particular benefit, sinc it can initiate reaction of resins with substantiall non-reactive silicones to produce a functional releas surface. The ability of the coating to accept colorant is a desirable feature for establishing the presence an uniformity of the release coating. What is produced by the practice of the inventio is a unique product of low silicone content but having silicone release surface having excellent release prop erties. The coating is hard and substantially non-stretch able and aggressively bound to the substrate to which i is applied. Substantially complete cure insures agains transfer to the adhesive during the lifetime of a laminat or self-wound product. The release coatings of thi invention provides the advantage that the release forc can be relatively constant over broad range of strippin speeds without the silicone substantially transferrin to the adhesive surface. High holdout can be achieve on low grade papers and monomers can be used not only t adjust viscosity but also adjust release force. In the following Examples TLMI Release is by Tes Method VII LD-468 and PSTC Test No. 2. Loop Tack is b PSTC - Test No. 5. Keil release values are after agin under a force of 0.25 psi for'20 hours at 70"C. TLMI mean Tape and Label Manufacturers Institute and PSTC mean Pressure Sensitive Tape Council. Except for the removabl adhesive identified as part of Example 1, the adhesive employed in the Examples were permanent rubber base and/or acrylic based pressure-sensitive adhesives. EXAMPLE 1 fFIGS. 1-6) A master batch of a resin coating designated as AE 508 was formed of 72 parts by weight acrylated epox oligomer (Celanese 3703) supplied by Celanese Corp * . , 1 parts by weight hexanedioldiacrylate (HDODA) and 1 parts by weight diethoxyacetophenone (DEAP) . From 80-9 parts of the master batch was mixed with 20-5 part Dehesive™ VP-1530, a mixture acrylated and thiol and func tional polysiloxanes, available from Stauffer-Wacke Silicones Co. (S-1530 herein) . The mixtures were prepar in select increments of weight percent silicone. The coating mixtures were applied on clay coat gloss paper. The coated paper was exposed to the UV radiati given off by two medium pressure mercury vapor lamps 200 watts/inch at web speed of 50 feet per minute. Th corresponds to an energy input of about 5 kilojoules p square meter. Exposure resulted in cure to a hard glos film which was dry to the touch. Completeness of cu was determined by laminating Scotch™ 610 tape manufa tured by 3M, under pressure and measuring the for required to delaminate the construction or remove t tape. Release which is stable and low over time witho substantially detackifying the adhesive is one indicatio of complete cure. Cured coatings with varying amounts of S-1530 wer tested using the Carver release test which consists o laminating the cured release liner to Scotch™ 610 tap under a pressure of 6,000 psi for 60 seconds, and measurin force required to achieve release at a peel rate of 1 inches per minute (ipm) . Release measurements wer modified to include a 1200' ' inches per minute (ipm) rate The release test as applied to aged samples was afte aging with the test tape applied just before measurin release values. The initial formulation consisted of 90% AE 508 an 10% S-1530. As shown in FIGS. 1 and 2, the initia Carver Release values were between 80-100 grams. Agin at room temperature or 140°F, resulted in a rapid declin to a stable release level within the range of 20-50 grams FIGS. 3, 4 and 5 show the results of varying th concentration of S-1530 on Initial Peel (FIG. 3) afte room temperature (RT) aging (FIG. 4) and elevated te pera ture aging (FIG. 5) . The results display a phenomeno that appears to be related to phase transition. As silicone content increases there is reached a point where a transition to a rubbery phase occurs. The system then behaves in a conventional way, with release force de- creasing with an increase in silicone content. More particularly, FIG. 3 shows the initial Carver Release results and shows low initial releases (both 12 and 1200 ipm) in the range of 3%-5% S-1530. In the range of 10%-40% S-1530 initial release values increase, with 1200 ipm releases actually appearing to be lower than 12 ipm. By 40%, S-1530 12 ipm release values decline while 1200 ^ ipm releases increase rapidly and appear to level off above 50% S-1530. FIGS. 4 and 5 show the Carver release values for samples aged 28 days at RT and 140°F. Formulations in the 5%-20% S-1530 range yield release values in the range of 20-40 grams with minimal differences between 12 and 120Θ ipm releases. Above about 30% S-1530, the release values climb rapidly, peak, and then decline as the percentage of S-1530 increases beyond 40%. The range beyond 60% S-1530 is again characterized by a marked difference between 12 and 1200 ipm release values. The region up to 20 percent is hard and glassy with desirabl release values. Above about 30% S-1530 a phase inversio occurs to a rubbery phase which is characteristic o conventional release liners. The concentration of photoinitiator diethyl aceto phenone (DEAP) in the formulation has a significan effect on the initial Carver release values of lab samples. As shown in FIG. 6, the formulation with an excessiv amount of DEAP (20%) yields initially high Carver releas values, which subsequently age down to a level simila to formulations with l%-5% DEAP. This is similar to th aging down observed in FIGS. 1 and 2 are for formulation having a concentration of 10.8% DEAP. Constructions using a rubber based hot melt removab adhesive and a high tack, high peel rubber based h melt adhesive, were made and found to have acceptab low release from the surface to 10% S-1530. Constructio using 4, 6 and 10% S-1530 were prepared using a removab adhesive. Formulations using 6 and 10% S-1530 had l release whereas the formulation using 4% silicone h tighter release as measured by subjective testing. EXAMPLE 2 There was evaluated the performance of AE-508 wi various reactive silicones as against their performanc as homopolymers. The control was a standard thermall cured silicone release liner. The reactive silicone were S-450, an end acrylated silicone known as RC-45 supplied by Goldsmith Chemical Corporation; S-1559, mixture of acrylated and mercapto functional silicon known as Dehesive™ VP-1559 supplied by Stauffer Wacker Silicone Corp.; S-4818, an end and in chain acrylate silicone known as IC-4818-38 supplied by Lord Chemica Company and S-5360 and S-6350, each end and in chai acrylated silicones known respectively as Ebecryl 19 6360 and 19-6350, supplied° ' by U.C.B. Radcure Inc. Table 1 shows performance with an acrylic adhesiv while Table 2 shows performance with a rubber base adhesive. In the Table, homopolymer means 100% of th reactive silicone; copolymer means 80% by weight AE-50 and 20% by weight reactive silicone. In each instanc the coating was formed on a super calendered kraft pape and EB cured at a dosage of 30 kGy. The conclusion drawn was that the copolymers serve as useful release agents as did the most costly homo polymers. TABLE 1 TXTCL Beel 300 iomW/M) loop Tack (NM) Homopolvmer 3 Dav Keil 3 Dav S-450 69 54 450 S-1559 22 44 340 S-4818 18 40 405 S-6360 134 1 138 1 335 S-6350 119 168 130 Copolymer S-450 64 1 362 165 S-1559 36 28 2 455 S-4818 30 1 ' 2 37 2 445 S-6360 60 1*2 46 1 ' 2 515 S-6350 87-.--. 111 2 515 Control 400 X Release Pickoff at Slow Speeds 2 Zippy Release TABLE 2 TTM1 Peel 300 ipm(N/M) Loop Tack (N M) Homopolvmer 3 Day Keil 3 Dav Keil S-450 4 7 1895 1980 S-1559 5 8 1615 1655 S-4818 3 5 1575 1715 S-6360 5 22 2 1720 1850 S-6350 8 12 2 1065 1280 Copolymer S-450 7 10 1870 1835 S-1559 6 5 1790 1655 S-4818 4 4 1770 1495 S-6360 26 2 39 1 1990 1750 S-6350 14 2 20 2 1950 1695 Control 1625 1590 T Release Pickoff at Slow Speeds 2 Zippy Release EXAMPLE 3 The following is to show the effect of using t different oligomer and monomer combinations to enab control of release. With reference to Table 2, resi 19-6810, 19-6830 and 19-6657 are acrylated polyeste sold by U.C.B. Radcure, Inc.; PES-166 and PES-169 a acrylated urethanes sold by Polymer Systems Corporatio "BPA diacryl" is an acrylated bisphenol-A epoxy resi C-9003 is an aliphatic triacrylate. The control was commercial release liner having a 100% silicone surfac The adhesive employed was a tackified Kraton-1107, styrene-isoprene, styrene-isoprene-styrene resin rubb manufactured and sold by Shell Chemical Company. T formulation in each instance was 70% by weight resin monomers, 20% by weight hexanedioldiacrylate (HDODA) a 10% by weight S-1559. Cure was by electron beam at dosage of 30 kGy in the presence of 200-250 ppm oxyge Results shown in Table 3 established that epoxy, uretha and polyester oligomers gave low release values where an aliphatic oligomer gave higher release. TABLE 3 Resin Description TLMI : RELEASE (NM) LOOP TACK (N/ One Day Keil One Day Kei 19-6810 Polyester 7 14 590 630 19-6830 Polyester 34 26 980 690 19-6657 Polyester 19 22 690 710 PES-166 Urethane 1 10 690 710 PES-169 Urethane 8 11 670 650 SR-349 BPA Diacryl 1 19. 690 590 C-9003 Aliphatic Triac 75 88 590 530 Control — — 850 650 EXAMPLE 4 In Example 65 of U.S. Patent 4,228,479 to Brack, there is disclosed a potential formulation for a release surface. The formulation was prepared with certain substitutions made because of the lack of availability of components. The substitutions were not believed to modify the per formance as the controlling ingredient was the silicon employed. The base formulations are shown in Table 4. TABLE 4 COMPONENTS EXAMPLE.65 FORMUEATION A 66 Parts Trifunctional Urethane PES-166DifunctionalUrethane 68 Parts 1,4-Butane Diol Diacrylate 1,6 Hexane Diol Diacrylate 50 Parts Acrylated Epoxidized Soya Oil same 72 Parts Trimethylolprop. Tri Aery same 1.5 Parts 2-Hydroxy Ethyl Acrylate 1,4-Butane Diol Monoacrylate 2 Parts Stearyl Acrylate same 5 Parts_W-982 Silicone Gum (0.2% vinyl) Several Variations 16 Parts Benzoin Isobutyl Ether Benzoin Isopropyl Ether Since Brack taught the use of a silicone of lo functionality there was employed as a representative o the silicone contemplated by the patentee, 0.2% VOC, whic was a 0.2% vinyl end capped polydimethyl siloxane. Thei performance with respect to a hot melt rubber base adhesiv and an acrylic adhesive are formulations A to B of Table 5 and 6. UV cured formulations as suggested by Brac were regarded as nonfunctional as a release surface a the Keil values for the loop tack could not even b measured due to welding. It was surprisingly found tha high energy dosage available by electron beam cure coul produce functional release materials. When formulatio A was used with the silicones of the instant invention namely formulations C and D, they as well as formula tions E to H at all times a functional release surfac formed under both UV and EB conditions. In the process a master batch of all components except the silic formulation was prepared. The various formulations w prepared by taking a portion of the master batch adding the silicone and photo-initiators as requir Samples were coated on super-calendared kraft paper cured by either UV or EB radiation. The cured sampl were then laminated to freshly prepared dry adhesives polyester films. They were aged for one day under Ke conditions (70°C, 0.25 psi for 20 hours) and TLMI relea measured at 300 inches per minute; the results includi loop tack data measured are reported in Tables 5 (rubb based permanent adhesive) and 6 (acrylic based permane adhesive) . TABLE 5 Form Resin Silicone SI% Cure τu_r Release(N/M) Loop Tack(N/M One 1 Day Keil One Dav Kei A A 0.2% VEC+BIPE 1.8 UV 40 WEID 1340 — B A 0.2% VEC+BIPE 10 UV 35 WELD 700 — C A S-1559 1.8 EB 7 32 1880 183 D A S-1559 10 EB 7 24 1450 172 E AE-508 S-1559+BIPE 10 UV 2 1 1000 90 F AE-508 S-1559+12BIPE 10 UV 2 1 1240 92 G AE-508 S-1559+12DEAP 10 UV , 35 5 1140 115 H AE-508 S-1559 10 EB 6 12 1635 170 Control 100 _=, 3 8 1700 175 Form = Formulation TABEE 6 Form Resin Silicone SI% Cure TTMI Release(N/M) I_oooTack(N/M) One Dav ' Keil One Dav pξdl A A 0.2% VEC+BIPE 1.8 UV 140 WELD — =— B A 0.2% VEC+BIPE 10 UV 160 WEID ___, — C A S-1559 1.8 EB 110 93 420 520 D A S-1559 10 EB 100 30 370 340 E AE-508 S-1559+BIPE 10 UV 30 55 300 220 F AE-508 S-1559+12BIPE 10 UV 25 50 _____ 300 G AE-508 S-1559+12DEAP 10 UV 55 67 __ 160 H AE-508 S-1559 10 EB 70 100 420 550 Control 100 _____ 100 150 400 220 Cure Dose: Ε__&=30K3y;UV=2x200Watt≤/Inch Lamps, 50 ft/min. VP-1559 Radiation Curable Silicone Coating from SWS Silicones 0.2% VEC = 0.2% Vinyl Encapped Polydimethylsiloxane BIPE=6% Benzoin Isopropyl Ether, 12BIPE=12% Benzoin Isopropyl Ether 12DEAP=12% Diethoxyacetophenone Form — Formulation EXAMPLE 5 Formulation AE-508 was as abase formulation employin GE 479-1866 an experimental epoxy functional silicon provided by General Electric Company, Silicone Product Division. The formulations are shown in Table 7 an Carver release results reported after UV cure using lamps at 200 watts per inch at a web speed of 50 feet pe minute are shown in Table 8. Results are high average o highest value. TABLE 7 Formulation. Percent By Weight B AE-508 95 94 89 GE 479-1866 5 5 10 Additional __ιotoinitiator 0 1 1 TABLE 8 Carver Peel in grams/inch at Formulation A B C I. 12 ipm at R.T., initial 55 7 (a) 7 days 13 10 3 14 days 11 - - 28 days 7 4 3 140"F 7 days 13 12 8 14 days 24 20 4 28 days 13 7 4 II. 1200 ipm at R.T., initial 195 65 62 7 days 48 54 68 14 days 54 60 77 28 days 54 61 64 140°F - 7 days 45 48 53 14 days 57 60 71 28 days 48 52 42 (a) Too low to measure EXAMPLE 6 Tests were conducted to show the effect of using the different oligomers and silicone combinations to enable control of release. With reference to Table 9, resin Valspar™ S-9783-002 a mixture of acrylated oligomers provided by Valspar Co. was mixed with S-450 in varying amounts coated and EB cured (30kGy) on a polypropylene release backing. Peel was measured with respect to a permanent rubber based pressure sensitive adhesive. TABLE 9 KEIL -450 OLIGOMER RELEASE (N/M) 180° PEEL (N/M) 95 300 460 90 170 440 85 120 440 EXAMPLE 7 The data of Table 10 shows the effect of using the different monomer combinations on release. The monomers were pentaarythritoltriacrylate (PETA) , hexanediol¬ diacrylate (HDODA) and 2-ethylhexyl acrylate (2EHA) . TABLE 10 KEEL RELEASE LOOP TACK S-450 2-EHA % PETA % HDODA (N/M) (NM) _ 75 80 600 25 25 25 9 650 25 50 170 400 EXAMPLE 8 A mixture of 20 parts trimethylopropanetriacrylate, 40 parts Celrad 3201, an acrylated polyester from Celanese, Inc., 10 parts N-vinylpyrrolidone and 1.5 parts S-6350 and-2 parts photo initiator was coated onto crepe paper and cured with enough actinic (UV) radiation to give a hard dry film. The release liner was Keil aged against a permanent rubber based pressure sensitive adhesive. The Keil release forces were 80-150 N/M with minimal loss of adhesive tack.

Claims: WHAT IS CLAIMED IS: 1. A product comprising a substrate having bonded thereto a cured release coating having a silicone release surface for releasable contact with a pressure-sensitive adhesive said coating formed by coreaction of a silicone comprised of dimethyl siloxane polymers and a resin contained in a coating composition applied to the sub¬ strate, the silicone being present in an amount of from about 1 to about 30 percent by weight of the coating and sufficiently anchored to the coating to be substantially non-transferable to a pressure-sensitive adhesive. 2. A product as claimed in claim 1 in which the silicone is present in an amount of from 5 to about 15 percent by weight of the coating. 3. A product comprising substrate having bonded thereto a cured release coating having a silicone release surface for releasable contact with a pressure-sensitive adhesive said coating formed by coreaction of silicone present in an amount of from about 1 to about 30 percent by weight of the coating and a resin contained in a coating composition applied to the substrate, the cure induced by exposure of the applied coating to the action of energy supplied by heat, actinic radiation, electron beam radiation, or combinations thereof induced in a sufficient amount to anchor the silicone to the coating whereby the silicone is substantially non-transferable to a pressure-sensitive adhesive. 4. A product as claimed in claim 3 in which the silicone is present in an amount of from about 5 to about 15 percent by weight of the coating. 5. A product comprising a substrate having bonded thereto a cured release coating having a silicone release surface for releasable contact with a pressure-sensitive adhesive and said coating formed by coreaction of a reactive silicone present in an amount of from about 1 to about 30 percent by weight of the coating and a reactive resin comprised of reactive oligomers contained in a coating composition applied to the substrate, the cure induced by the action of energy supplied by heat, actinic radiation, electron beam radiation, or a combination thereof and induced in an amount sufficient to anchor the silicone to the coating whereby the silicone is substantially non-transferable to a pressure-sensitive adhesive. 6. A product as claimed in claim 5 in which the silicone is present in an amount of from about 5 to about 15 percent by weight of the coating. 7. A product comprising a substrate having bonded thereto a cured release coating having a silicone release surface for releasable contact with a pressure-sensitive adhesive and said coating formed by coreaction of a reactive silicone present in an amount of from about 1 to about 30 percent by weight of the coating and a resin comprised of reactive oligomers, said reactive silicone being at least partially immiscible in said coating composition, the cure induced by the action of energy supplied by heat, actinic radiation, electron beam radia- tion, or a combination thereof induced to the coated substrate in sufficient amount to anchor the silicone to the coating whereby the silicone is substantially non- transferable to a pressure-sensitive adhesive. 8. A product as claimed in claim 7 in which the silicone is present in an amount of from about 5 to about 15 percent by weight of the coating. 9. A product as claimed in claim 1 which includes a colorant. 10. A product as claimed in claim 7 which includes a colorant. 11. A product comprising a substrate having coating on at least one side thereof with a cured coating composi¬ tion comprised of from about 1 to about 30 percent by weight of the coating composition of a reactive silicone dispersed as a discontinuous phase in about 99 to about 70 percent by weight of the coating composition or con¬ tinuous reactive resin phase comprising from about 50 to 100"percent by weight of the oligomer reactive with said reactive silicone and from about 50 to 0 percent by weight of the reactive resin of a reactive monomer, said reactive silicone being a polydimethyl siloxane having a molecular weight of at least about 2000 and having pendent therefrom sufficient reactive groups to react with the reactive groups of the oligomer, said coating being cured on exposure to the action of electron beam radiation, ultraviolet radiation, heat or a combination thereof to form cured coating having a silicone release surface for releasable contact with a pressure-sensitive adhesive with substantially all of the silicone contained in the coating composition being anchored to the cured coating and substantially non-transferable to a pressure-sensitive adhesive. 12. A product as claimed in claim 11 in which the reactive silicone is present in an amount of from about 5 to about 15 percent by weight of the coating composition. 13. A product as claimed in claim 11 in which the oligomers are selected from the group consisting of acrylated epoxies, acrylated polyesters, acrylated poly- urethanes and mixtures thereof. 14. A product as claimed in claim 11 in which the reactive monomer is a multifunctional monomer. 15. A product as claimed in claim 12 in which the reactive monomer is a multifunctional monomer. 16. A product as claimed in claim 15 in which the reactive silicone is present in an amount of from about 5 to about 15 percent by weight of the coating composition. 17. A product as claimed in claim 11 in which the reactive groups of the silicone are selected from the group consisting of acrylic groups and mercaptos groups, oxiranes and mixtures thereof. 18. A product as claimed in claim 12 in which the reactive groups of the silicone are selected from the group consisting of acrylic groups, mercapto groups, oxiranes and mixtures thereof. 19. A product as claimed in claim 16 in which the reactive groups of the silicone are selected from the group consisting of acrylic groups, mercapto groups, oxiranes and mixtures thereof. 20. A curable coating composition comprising from about 1 to about 30 percent by weight of the coating composition of a reactive silicone dispersed as a discon¬ tinuous phase in 99 to 70 percent by weight of the coating composition of reactive resin phase comprising: (i) from 50 to 100 percent by weight of the reactive resin of an oligomer reactive with said reactive silicone and (ii) from about 50 to 0 percent by weight of the reactive resin of a reactive monomer, said reactive silicone being a polydimethyl siloxane having a molecular weight of at least about 2000 and having pendent therefrom sufficient reactive groups to react with the reactive group of the oligomer on exposure to the action of electron beam radiation, ultraviolet radiation or heat to form a cured coating having a silicone release surface releas¬ able from a pressure-sensitive adhesive and in which substantially all of the silicone contained in the com¬ position is anchored to the coating to substantially prevent transfer of the coating to a pressure-sensitive adhesive. 21. A curable composition as claimed in claim 20 in which the reactive silicone is present in an amount of from about 5 to about 15 percent by weight of the coating composition. 22. A curable coating as claimed in claim 20 in which the oligomers are selected from the group consisting of acrylated epoxies, acrylated polyesters, acrylated polyurethanes and mixtures thereof. 23. A curable coating as claimed in claim 20 in which the reactive monomer is a multifunctional monomer. 24. A curable coating as claimed in claim 22 in which the reactive monomer is a multifunctional monomer. 25. A curable composition as claimed in claim 24 in which the reactive silicone is present in an amount of from about 5 to about 15 percent by weight of the coating composition. 26. A curable coating as claimed in claim 20 in which the reactive groups of the silicone are selected from the groups consisting of acrylic groups, mercapto groups, oxirane groups and mixtures thereof. 27. A curable coating as claimed in claim 21 in which the reactive groups of the silicone are selected from the groups consisting of acrylic groups, mercapto groups, oxirane groups and mixtures thereof. 28. A curable coating as claimed in claim 25 in which the reactive groups of the silicone are selected from the groups consisting of acrylic groups, mercapto groups, oxirane groups and mixtures thereof. 29. A curable coating composition comprising: (a) from about 5 to about 15 percent by weight of the coating composition of a reactive silicone having reactive groups selected from acrylic groups, mercapto groups, oxirane groups and mixtures thereof, dispersed as discontinuous phase in a from 95 to about 85 percent by weight of the coating composition of a continuous reactive resin phase comprising: (i) from about 50 to 100 percent by weight of the reactive resin of an oligomer reactive with said reactive silicone and selected from the group consisting of acrylated epoxy resins, acrylated polyester resins, acrylated urethane resins and mixtures thereof, and (ii) from 50 to about 0 percent by weight of the reactive resin of at least one acrylated multi- functional monomer, said reactive silicone being a poly- dimethylsiloxane having a molecular weight of at least about 2,000, said composition having a viscosity of from about 300 to about 10,000 centipoise and curable on exposure to the action of electron beam radiation, ultra- violet radiation or heat, or a combination thereof, to form a cured coating having a silicone release surface opposed the substrate to which the coating has been applied for releasable contact with a pressure-sensitive adhesive and in which substantially all of the silicone contained in the composition is anchored in the coating and substantially nontransferable to a pressure-sensitive adhesive. 30. A process for producing a release coated sub- strate which comprises: (a) applying to a substrate a coating composi¬ tion comprising: (i) from about 1 to about 30 percent by weight of the composition of a reactive silicone dispersed as a discontinuous phase in from about 99 to about 70 percent by weight of the coating composition of a continuous reactive resin phase comprising: (ii) from about 50 to 100 percent by weight of reactive resin phase of an oligomer reactive with said reactive silicone, and (iii) from about 50 to 0 percent by weight of the reactive resin phase of a reactive monomer, said reactive silicone being a poly- dimethylsiloxane having a molecular weight of at least about 2,000 and havingpendenttherefrom sufficient reactive groups to react with the reactive groups of the oligomer; (b) exposing the coating to the action of sufficient electron beam radiation, ultraviolet radiation or heat or a combination thereof to form a cured coating having a silicone release surface for releasable contact with a pressure-sensitive adhesive and in which substantially all of the silicone groups are anchored in the cured coating and substantially non-transferable to a pressure-sensitive adhesive. 31. A process as claimed in claim 30 in which coating composition has a viscosity of from about 300 to about 10,000 centipoise. 32. A process as claimed in claim 30 in which the oligomers are selected from the group consisting of acrylated epoxies, acrylated polyesters, and acrylated polyurethanes and mixtures thereof. 33. A process as claimed in claim 30 in which the reactive monomer is a multifunctional monomer. 34. A process as claimed in claim 32 in which the reactive monomer is a multifunctional monomer. 35. A process coating as claim in claim 30 in which the reactive groups of the silicone are selected from the groups consisting of acrylic groups, mercapto groups, oxirane groups and mixtures thereof. 36. A curable coating as claimed in claim 32 in which the reactive groups of the silicone are selected from the groups consisting of acrylic groups, mercapto groups, oxirane groups and mixtures thereof. 37. A curable coating as claimed in claim 34 in which the reactive groups of the silicone are selected from the group consisting of acrylic groups and mercapto groups and mixtures thereof. 38. A process for forming a release coating substrate which comprises: (a) applying to the substrate a coating com¬ prising: (i) from about 5 to about 15 percent by weight of the coating of a reactive silicone having reactive groups selected from acrylic groups, mercapto groups, oxirane groups and mixtures thereof, dispersed as discontinuous phase in from about 95 to about 85 percent by weight of the coating of a continuous reactive resin phase comprising: (ii) from 50 to 100 percent by weight of the reactive resin of an oligomer reactive with said reactive silicone and selected from the group consisting of acrylated epoxy resins, acrylated polyester resins, acrylated urethane resins and mixtures thereof, and (iii) from about 50 to 0 percent by weight of the reactive resin of at least one multi¬ functional monomer, said reactive silicone being a polydimethyl-siloxane having a molecular weight of at least about 2,000, said coating composition having a viscosity of from about 300 to about 10,000 centipoise; (b) subjecting the coating to the action of sufficient electron beam radiation, ultraviolet radiation or heat or a combination thereof to form a cured coating having a silicone release surface for releasable contact with a pressure-sensitive adhesive and in which substan¬ tially all of silicone is anchored in the cured coating and substantially non-transferable to a pressure-sensitive adhesive. 39. A product comprising substrate having bonded thereto a cured release coating having a silicone release surface for releasable contact with a pressure-sensitive adhesive, said coating formed by coreaction of silicone present in an amount of from about 1 to about 30 percent by weight of the coating and a resin contained in a coating composition applied to the substrate, the cure induced by exposure of the applied coating to the action of energy supplied by ultraviolet radiation, electron beam radiation, or a combination thereof induced in a sufficient amount to anchor the silicone to the coating whereby the silicone is substantially non-transferable to a pressure-sensitive adhesive. 40. A product as claimed in claim 39 in which the silicone is present in an amount of from about 5 to about 30 percent by weight of the coating. 41. A product as claimed in claim 39 in which the silicone is present in an amount of from 5 to about 15 percent by weight of the coating. 42. A product comprising a substrate having coating on at least one side thereof with a cured coating composi¬ tion comprised of from about 1 to about 30 percent by weight of the coating composition of a reactive silicone dispersed as a discontinuous phase in about 99 to about 70 percent by weight of the coating composition or con- tinuous reactive resin phase comprising from about 50 100 percent by weight of the oligomer reactive with sai reactive silicone and from about 50 to 0 percent weight of the reactive resin of a reactive monomer, sai reactive silicone being a polydimethyl siloxane having molecular weight of at least about 2000 and having pende therefrom sufficient reactive groups to react with t reactive groups of the oligomer, said coating being cure on exposure to the action of electron beam radiation ultraviolet radiation, or a combination thereof to fo cured coating having a silicone release surface releasabl from a pressure-sensitive adhesive with substantiall all of the silicone contained in the coating compositio being anchored to the cured coating. 43. A product as claimed in claim 42 in which th reactive silicone is present in an amount of from abou 5 to about 30 percent by weight of the coating composition 44. A product as claimed in claim 42 in which th reactive silicone is present in an amount of from abou 5 to about 15 percent by weight of the coating composi tion. 45. A curable coating composition comprising fro about 1 to about 30 percent by weight of the coatin composition of a reactive silicone dispersed as a discon tinuous phase in 99 to 70 percent by weight of the coatin composition of reactive resin phase comprising: (i) from 50 to 100 percent by weight of th reactive resin of an oligomer reactive with said reactiv silicone and (ii) from about 50 to 0 percent by weight o the reactive resin of a reactive monomer, said reactiv silicone being a polydimethyl siloxane having a molecula weight of at least about 2000 and having pendent therefrom sufficient reactive groups to react with the reactive group of the oligomer on exposure to the action of electron beam radiation, ultraviolet radiation or a combination thereof to form a cured coating having a silicone release surface for releasable contact with a pressure-sensitive adhesive and in which substantially all of the silicone contained in the composition is anchored to the coating to prevent transfer to a pressure-sensitive adhesive. 46. A curable composition as claimed in claim 45 in which the reactive silicone is present in an amount of from about 5 to about 30 percent by weight of the coating composition. 47. A curable composition as claimed in claim 45 in which the reactive silicone is present in an amount of "from about 5 to about 15 percent by weight of the coating composition. 48. A process for producing a release coated sub¬ strate which comprises: (a) applying to'a substrate a coating composi¬ tion comprising: (i) from about 1 to about 30 percent by weight of the composition of a reactive silicone dispersed as a discontinuous phase in from about 99 to about 70 percent by weight of the coating composition of a continuous reactive resin phase comprising: (ii) from about 50 to 100 percent by weight of reactive resin phase of an oligomer reactive with said reactive silicone, and (iii) from about 50 to 0 percent by weight of the reactive resin phase of a reactive monomer, said reactive silicone being a pol dimethylsiloxane having a molecular weight at least about 2,000 and having pendent therefr sufficient reactive groups to react with t reactive groups of the oligomer; (b) exposing the coating to the action sufficient electron beam radiation, ultraviolet radiati or a combination thereof to form a cured coating havi a silicone release surface for releasable contact with pressure-sensitive adhesive and in which substantiall all of the silicone groups are anchored in the cure coating and substantially non-transferable to a pressur sensitive adhesive. 49. A process as claimed in claim 48 in whic reactive silicone is present in an amount of from abou 5 to about 30 percent by weight of the composition. 50. A process as claimed in claim 48 in whic reactive silicone is present in an amount of from abou 5 to about 15 percent by weight of the composition.

Inventors: KRAY WILLIAM D, LIN KENNETH S C, PUSKADI FRANK, STORY MICHAEL E, WELCH FRANK J, WILSON DOUGLAS WAYNE, KRAY, WILLIAM, D., LIN, KENNETH, S., C., PUSKADI, FRANK, STORY, MICHAEL, E., WELCH, FRANK, J., WILSON, DOUGLAS, WAYNE
Applicants: AVERY INTERNATIONAL CORP, AVERY INTERNATIONAL CORPORATION
Application year: 1988
Main classification: B32B9
IPC codes: B05D3, B05D7, B32B7, B32B27, C08F299, C09D183, C09D201, C09J4, C09J7