Release liner for silicone pressure sensitive adhesive layer, and laminate and roll body including release liner

Abstract

[Objective] To provide a non-fluorine-based release liner that can be applied to a silicone pressure-sensitive adhesive layer and has excellent heat resistance stability in terms of release properties and peel strength, as well as a laminate and roll body that include the same. [Solution] A release liner for a silicone pressure-sensitive adhesive layer according to one embodiment of the present disclosure includes a substrate and a release layer on at least one surface of the substrate, the release layer containing a poly(meth)acrylic acid ester, the poly(meth)acrylic acid ester being a polymer of a polymerizable component containing an alkyl(meth)acrylate monomer having a branched alkyl group with 8 or more carbon atoms.

Description

[Technical field]

[0001] The present disclosure relates to release liners for silicone pressure sensitive adhesive layers, as well as laminates and rolls that include the release liners. [Background technology]

[0002] In recent years, release liners that can be applied to pressure-sensitive adhesive layers have been developed.

[0003] Patent Document 1 (JP 2015-183041(A)) discloses a release film for silicone adhesives that contains a polyvinyl acetal resin and a polymer having a structural unit derived from a monomer having a fluoroalkyl group, in which the fluorine atomic concentration in the surface vicinity of one of the main surfaces is 1.5 at% to 50 at%, and the difference between the fluorine atomic concentration in the surface vicinity of one of the main surfaces and the fluorine atomic concentration in the surface vicinity of the other main surface is 0.5 at% or more.

[0004] Patent Document 2 (JP 2001-240775(A)) discloses a release agent article in which a release agent precursor obtained by polymerizing a polymerizable composition for forming a release agent, which comprises a substrate and a release agent provided on the substrate, is further irradiated with radiation, the release agent containing a first alkyl(meth)acrylate having an alkyl group having 12 to 30 carbon atoms, a second alkyl(meth)acrylate having an alkyl group having 1 to 12 carbon atoms, and a polymerization initiator for the first alkyl(meth)acrylate and the second alkyl(meth)acrylate, and discloses that an acrylic pressure-sensitive adhesive sheet is attached to the release sheet, which is the release agent article. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-183041 A [Patent Document 2] Patent Publication No. 2001-240775 Summary of the Invention [Problem to be solved by the invention]

[0006] Silicone pressure sensitive adhesives are generally excellent in heat resistance, electrical insulation, chemical resistance, etc., and can be used over a wide temperature range. When applying a silicone pressure sensitive adhesive to a release liner, as disclosed in Patent Document 1, a fluorine-based release liner is generally used.

[0007] Although fluorine-based release liners have excellent releasability for silicone pressure-sensitive adhesives, they are more expensive than other release liners. Furthermore, from the viewpoint of preventing contamination by fluorine components, the use of fluorine-based materials tends to be restricted or suppressed. Furthermore, release liners used for single-sided tapes, double-sided tapes, and pressure-sensitive adhesive transfer tapes containing silicone pressure-sensitive adhesives may be required to have heat resistance stability of peel strength in addition to releasability.

[0008] [Problem] The present disclosure provides a non-fluorine-based and non-silicone release liner that can be applied to a silicone pressure-sensitive adhesive layer and has excellent heat stability of peelability and peel strength, as well as a laminate and roll body that include the release liner. [Means for solving the problem]

[0009] According to one embodiment of the present disclosure, there is provided a release liner for a silicone pressure sensitive adhesive layer, the release liner comprising a substrate and a release layer on at least one surface of the substrate, the release layer containing a poly(meth)acrylic acid ester, the poly(meth)acrylic acid ester being a polymer of a polymerizable component containing an alkyl (meth)acrylate monomer having a branched alkyl group having 8 or more carbon atoms.

[0010] According to another embodiment of the present disclosure, there is provided a laminate including a release liner and a silicone adhesive layer disposed on the release layer of the release liner.

[0011] According to another embodiment of the present disclosure, there is provided a laminate comprising, in order, a release liner, a silicone adhesive layer, and a second release liner.

[0012] According to another embodiment of the present disclosure, a roll body is provided that includes a release liner having release layers on both sides and a silicone pressure sensitive adhesive layer.

[0013] Effect of the Invention The present disclosure provides a non-fluorine-based and non-silicone release liner that can be applied to a silicone pressure-sensitive adhesive layer and has excellent releasability and heat stability of peel strength, as well as a laminate and roll body that include the release liner.

[0014] The above description is not intended to mean that all embodiments of the invention and all advantages of the invention are disclosed. [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic cross-sectional view of a laminate including a release liner and a silicone adhesive layer according to one embodiment of the present disclosure. [Diagram 2] 1 is a schematic cross-sectional view of a roll body including a release liner and a silicone adhesive layer according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] In the following, in order to explain representative embodiments of the present invention, the present invention will be explained in more detail with reference to the drawings as necessary, but the present invention is not limited to these embodiments.

[0017] In this disclosure, "non-fluorine-based and non-silicone-based" means non-fluorine-based and non-silicone-based, i.e. the materials used are neither fluorochemical materials nor silicone-based materials.

[0018] In the present disclosure, "heat resistance stability" refers to heat resistance peel stability; for example, even when a release liner is applied to a silicone pressure-sensitive adhesive and then heated or stored at high temperatures, the peel strength of the release layer to the silicone pressure-sensitive adhesive is stably maintained.

[0019] In this disclosure, "(meth)acrylic" means acrylic or methacrylic, "(meth)acrylate" means acrylate or methacrylate, and "(meth)acryloyl" means "acryloyl" or "methacryloyl".

[0020] In this disclosure, "polymerizable component" refers to a radically polymerizable component such as a (meth)acrylate monomer having a branched alkyl group with 8 or more carbon atoms.

[0021] As used herein, "curing" may also include the concept commonly referred to as "crosslinking."

[0022] In the present disclosure, for example, "on" in "a release layer disposed on a substrate" means that the release layer is disposed directly on the substrate, or that the release layer is disposed indirectly on the substrate with another layer interposed therebetween.

[0023] In the present disclosure, for example, the "order" in "comprising a release liner, a silicone adhesive layer, and a second release liner, in that order" means that, when focusing on the three components of the release liner, the silicone adhesive layer, and the second release liner, the laminate comprises these components in that order, and that another layer, such as a printed layer, may be interposed between these components, for example, between the silicone adhesive layer and the second release liner.

[0024] FIG. 1 is a schematic cross-sectional view of a laminate according to one embodiment of the present disclosure. The laminate 100 of FIG. 1 includes a release liner 101, a silicone adhesive layer 103, and a second release liner 105, in this order. Here, the release liner 101 may be referred to as a "first release liner" to distinguish it from the second release liner. The release liner 101 and the second release liner 105 may be the same or different from each other. In the laminate of the embodiment of FIG. 1, a release liner is applied to both sides of the silicone adhesive layer, but in other embodiments, a release liner may be applied to only one side of the silicone adhesive layer.

[0025] The release liner for the silicone pressure sensitive adhesive layer of the present disclosure has a release layer on at least one side of a substrate, the release layer comprising a polymer of a polymerizable component comprising an alkyl (meth)acrylate monomer having a branched alkyl group having 8 or more carbon atoms.

[0026] Such a release layer (sometimes referred to as a "bNSNF release layer") can reduce costs compared to a fluorine-based release layer. The bNSNF release layer can exhibit substantially the same release performance as a fluorine-based release layer with respect to a silicone adhesive layer (simply referred to as an "adhesive layer"), and can exhibit better release performance than a typical silicone-based release layer. Furthermore, the bNSNF release layer can exhibit superior heat resistance stability of peel strength compared to a fluorine-based release layer.

[0027] As shown in FIG. 1, when the release liners are applied to both sides of the adhesive layer, the release layers in the two release liners may be the same or different from each other. When the release layers are applied to both sides of the base material of the release liner, the release layers may be the same or different from each other. Here, the release layers being different from each other include, for example, in the case of the configuration of FIG. 1, the release layer of the release liner 101 is a bNSNF release layer, and the release layer of the second release liner 105 is a fluorine-based release layer, and other configurations in which the release layers are made of different materials, and the release layers of the release liner 101 and the second release liner 105 are both bNSNF release layers, but the peel strength of the adhesive layer relative to the release layer of the release liner 101 and the peel strength of the adhesive layer relative to the release layer of the second release liner are different from each other. As shown in FIG. 1, in a configuration in which the release layer has two release liners or a configuration in which a release layer is applied to both sides of the base material of the release liner, if either one has a bNSNF release layer, the cost can be reduced compared to a configuration in which both have fluorine-based release layers. However, in consideration of preventing contamination by fluorine components and further reducing costs, it is preferable that all release layers are bNSNF release layers in either configuration.

[0028] The release liner for the silicone pressure-sensitive adhesive layer of the present disclosure can be used, for example, as a single-sided tape or a double-sided tape, in addition to the embodiment as a pressure-sensitive adhesive transfer tape as shown in FIG. 1. Here, in the case of a single-sided tape, typically, a release layer is provided on one side of a release liner substrate, and a pressure-sensitive adhesive is applied to the side on which the release layer is not provided. With regard to a single-sided tape, there is also a broad mode in which a support is provided on one side of the pressure-sensitive adhesive layer, and a release liner is disposed on the opposite side of the pressure-sensitive adhesive layer (the release layer of the release liner is disposed in contact with the pressure-sensitive adhesive layer). When the single-sided tape is subjected to mechanical processing or the like before being applied to an adherend, this embodiment is typically used. With regard to a double-sided tape, a pressure-sensitive adhesive is applied to both sides of a support, and a release liner is disposed (so that the release layer of the release liner is in contact with the pressure-sensitive adhesive layer) on the surface of the pressure-sensitive adhesive applied to both sides of the support.

[0029] The release layer of the release liner of the present disclosure comprises a polymer of a polymerizable component that includes an alkyl (meth)acrylate monomer having a branched alkyl group having 8 or more carbon atoms (branched alkyl group). Such a polymerizable component may be referred to as a "polymerizable precursor composition" and a release agent containing such a polymer may be referred to as a "(meth)acrylic release agent."

[0030] In one embodiment, such a polymer has a viscosity of about 1.0×10 at 20° C. and a frequency of 1 Hz. 2 Pa ~ approx. 3.0×10 6 It has a storage modulus of 1.0 Pa.

[0031] The storage modulus is approximately 5.0 × 10 2 Pa or more, approximately 1.0×10 3 Pa or more, or about 1.5 x 10 3 Pa or more, and may be about 3.0×10 6 Pa or less, approximately 1.0×10 5 Pa or less, or about 1.0 x 10 4 It may be less than Pa.

[0032] Here, the storage modulus (G') is a value measured using a viscoelasticity measuring device (for example, rotary rheometer ARES-G2, manufactured by TA Instruments Japan Inc.) at 20°C and a frequency of 1 Hz in a shear mode.

[0033] From the viewpoint of releasability from the silicone pressure-sensitive adhesive layer, the number of carbon atoms in the branched alkyl group may be, for example, 10 or more, 14 or more, 18 or more, 20 or more, or 24 or more, and may be 36 or less, 34 or less, 32 or less, or 30 or less. Alkyl (meth)acrylates having a branched alkyl group having 8 or more carbon atoms may be used alone, or two or more of them may be used in combination.

[0034] The branched alkyl group having 8 or more carbon atoms may be either single-branched or multi-branched, but from the viewpoint of peelability, it is preferably single-branched.

[0035] The branched position of the branched alkyl group having 8 or more carbon atoms is preferably 2 or 4 from the viewpoint of peelability.

[0036] Examples of alkyl (meth)acrylates having a branched alkyl group with 8 or more carbon atoms include 2-ethylhexyl (meth)acrylate (8 carbon atoms), isononyl (meth)acrylate (9 carbon atoms), 2-hexyldodecyl (meth)acrylate (18 carbon atoms), 2-heptylundecyl (meth)acrylate (18 carbon atoms), 2-octyldecyl (meth)acrylate (18 carbon atoms), isostearyl (meth)acrylate (18 carbon atoms), 2-decyltetradecyl (meth)acrylate (24 carbon atoms), 2-dodecylhexadecyl (meth)acrylate (28 carbon atoms), and 2-tetradecyloctadecyl (meth)acrylate (32 carbon atoms). Such alkyl (meth)acrylates having a branched side chain can reduce the storage modulus and surface energy by reducing the crystallinity. Among these, 2-hexyldodecyl (meth)acrylate, 2-octyldecyl (meth)acrylate, 2-decyltetradecyl (meth)acrylate, 2-dodecylhexadecyl (meth)acrylate, 2-tetradecyloctadecyl (meth)acrylate, and isostearyl (meth)acrylate are preferred. Poly(meth)acrylic acid esters prepared using these can suitably reduce the surface energy of the release layer.

[0037] The content of the alkyl (meth)acrylate monomer having a branched alkyl group having 8 or more carbon atoms in the polymerizable precursor composition can be about 40% by weight or more, about 50% by weight or more, about 60% by weight or more, about 70% by weight or more, about 80% by weight or more, about 90% by weight or more, about 95% by weight or more, or about 99% by weight or more, based on the total amount of the alkyl (meth)acrylate monomer component. The upper limit of such monomer content can be about 100% by weight or less, about 100% by weight or less, about 95% by weight or less, about 90% by weight or less, about 80% by weight or less, about 70% by weight or less, about 60% by weight or less, or about 50% by weight or less.

[0038] In one embodiment, a polymerizable component is polymerized that includes an alkyl (meth)acrylate monomer having a branched alkyl group having 24 or more carbon atoms.

[0039] The long-chain alkyl portion of the branched alkyl group having 24 or more carbon atoms reduces the surface energy of the cured product of the (meth)acrylic release agent, and because the alkyl group is branched, the crystallinity of the cured product is reduced, and the storage modulus of the cured product is reduced. As a result, a release layer that exhibits smooth (no rattle) releasability over a wide range of peel speeds can be formed.

[0040] Examples of alkyl(meth)acrylate monomers having a branched alkyl group with 24 or more carbon atoms include 2-decyltetradecyl(meth)acrylate (number of carbon atoms: 24), 2-dodecylhexadecyl(meth)acrylate (number of carbon atoms: 28), and 2-tetradecyloctadecyl(meth)acrylate (number of carbon atoms: 32). The alkyl(meth)acrylates having a branched alkyl group with 24 or more carbon atoms may be used alone or in combination of two or more thereof.

[0041] The branched alkyl group having 24 or more carbon atoms is preferably a single branch, which ensures that the long-chain alkyl portion of the branched alkyl group is secured, and allows the formation of a release layer that exhibits suitable releasability with respect to the silicone pressure-sensitive adhesive layer.

[0042] The branching position of the branched alkyl group having 24 or more carbon atoms is preferably 2 or 4. As a result, the crystallinity of the cured product can be effectively reduced, and smoother peelability can be obtained.

[0043] The number of carbon atoms in the branched chain of the branched alkyl group having 24 or more carbon atoms is preferably 8 or more, 10 or more, or 12 or more. As a result, it is possible to ensure a plurality of long-chain alkyl moieties in the branched alkyl group, and to form a release layer that exhibits suitable releasability relative to the silicone pressure-sensitive adhesive layer.

[0044] The content of the alkyl (meth)acrylate monomer having a branched alkyl group having 24 or more carbon atoms in the polymerizable precursor composition can be about 90% by weight or more, about 95% by weight or more, or about 99% by weight or more, based on the total amount of the alkyl (meth)acrylate monomer component. The upper limit of the monomer content can be about 100% by weight or less, or less than about 100% by weight.

[0045] In one embodiment, the polymerizable precursor composition contains an alkyl(meth)acrylate monomer having a linear alkyl group in addition to an alkyl(meth)acrylate monomer having a branched alkyl group with 8 or more carbon atoms from the viewpoint of adjusting the peel strength. The alkyl(meth)acrylate monomer having a linear alkyl group may be used alone or in combination of two or more thereof.

[0046] The number of carbon atoms in the linear alkyl group can be 1 or more, 3 or more, 5 or more, 7 or more, 10 or more, or 12 or more, and can be 24 or less, 20 or less, 18 or less, 16 or less, 14 or less, or 12 or less.

[0047] Examples of alkyl (meth)acrylates having a straight chain alkyl group include butyl (meth)acrylate (4 carbon atoms), hexyl (meth)acrylate (6 carbon atoms), octyl (meth)acrylate (8 carbon atoms), decyl (meth)acrylate (10 carbon atoms), dodecyl (meth)acrylate (lauryl (meth)acrylate) (12 carbon atoms), tridecyl (meth)acrylate (13 carbon atoms), tetradecyl (meth)acrylate (14 carbon atoms), hexadecyl (meth)acrylate (cetyl (meth)acrylate) (16 carbon atoms), octadecyl (meth)acrylate (stearyl (meth)acrylate) (18 carbon atoms), and behenyl (meth)acrylate (22 carbon atoms).

[0048] The content of alkyl (meth)acrylate having a linear alkyl group in the polymerizable precursor composition can be about 60% by mass or less, about 50% by mass or less, about 45% by mass or less, about 40% by mass or less, about 35% by mass or less, about 30% by mass or less, about 20% by mass or less, about 15% by mass or less, or about 10% by mass or less, based on the total amount of alkyl (meth)acrylate monomer components.

[0049] In one embodiment, the polymerizable precursor composition contains a (meth)acrylate monomer having a radiation-active group on the side chain in addition to an alkyl (meth)acrylate monomer having a branched alkyl group with 8 or more carbon atoms. Such a monomer may be incorporated into the polymerizable precursor composition together with the monomer components described above to form a part of the polymer. The (meth)acrylate having a radiation-active group on the side chain may be used alone or in combination of two or more thereof.

[0050] Examples of (meth)acrylate monomers having a radiation-active group in the side chain include (meth)acrylate monomers having a benzophenone structure in the side chain and (meth)acrylate monomers having an acetophenone structure in the side chain. The radiation-active group (e.g., benzophenone structure and acetophenone structure) generates radicals when irradiated with radiation such as electron beams and ultraviolet rays. The generated radicals promote crosslinking of the polymerization product of the polymerizable precursor composition and bonding of the cured product generated by crosslinking with the substrate. As a result, the (meth)acrylic release agent can be cured efficiently with a low dose of radiation, the cohesive strength of the cured product and the adhesion of the cured product to the substrate are improved, and the transfer of the cured product to the silicone adhesive is suppressed. As a result of the suppression of the transfer of the cured product to the silicone adhesive, the residual adhesive strength of the silicone adhesive can be maintained at a high level.

[0051] Examples of (meth)acrylate monomers having a benzophenone structure in the side chain include 4-(meth)acryloyloxybenzophenone, 4-(meth)acryloyloxyethoxybenzophenone, 4-(meth)acryloyloxy-4'-methoxybenzophenone, 4-(meth)acryloyloxyethoxy-4'-methoxybenzophenone, 4-(meth)acryloyloxy-4'-bromobenzophenone, and 4-(meth)acryloyloxyethoxy-4'-bromobenzophenone.

[0052] An example of a (meth)acrylate monomer having an acetophenone structure in the side chain is O-(meth)acryloylacetophenone oxime.

[0053] The content of the (meth)acrylate monomer having a radiation active group on the side chain in the polymerizable precursor composition is preferably about 1% by mass or less, about 0.8% by mass or less, or about 0.5% by mass or less, based on the total amount of the alkyl (meth)acrylate monomer components. By setting the content of the (meth)acrylate monomer having a benzophenone structure on the side chain to about 1% by mass or less, it is possible to suppress an increase in the peeling force. The content of the (meth)acrylate monomer having a benzophenone structure on the side chain in the polymerizable precursor composition is preferably about 0.01% by mass or more, about 0.02% by mass or more, or about 0.05% by mass or more, based on the total amount of the alkyl (meth)acrylate monomer components. When the content of the (meth)acrylate monomer having a radiation active group on the side chain is about 0.01% by mass or more, it is possible to effectively promote crosslinking of the polymer (polymerization product) and bonding of the cured product to the substrate.

[0054] In one embodiment, the alkyl (meth)acrylate monomer having a branched alkyl group having 8 or more carbon atoms and the alkyl (meth)acrylate monomer having a linear alkyl group do not have polar functional groups such as carboxy groups, hydroxyl groups, nitrogen-containing groups (e.g., amino groups and amide groups), and phosphorus-containing groups on the alkyl group. In this embodiment, the cured product can maintain suitable release properties even after being exposed to high temperatures.

[0055] In one embodiment, the (meth)acrylic release agent contains a copolymer of an alkyl (meth)acrylate monomer having a branched alkyl group with 8 or more carbon atoms, an alkyl (meth)acrylate monomer having a linear alkyl group, and a (meth)acrylate monomer having a radiation-active group on the side chain. In addition, the release agent may contain a copolymer of an alkyl (meth)acrylate monomer having a branched alkyl group with 8 or more carbon atoms and an alkyl (meth)acrylate monomer having a linear alkyl group, and a copolymer of an alkyl (meth)acrylate monomer having a branched alkyl group with 8 or more carbon atoms and a (meth)acrylate monomer having a radiation-active group on the side chain.

[0056] A polymerizable precursor composition containing a polymerizable component such as a monomer is typically polymerized in the presence of a polymerization initiator. There are various polymerization modes, but solution polymerization, which is carried out by dissolving the polymerizable component in a solvent, is preferred because it can produce a high molecular weight polymer that is advantageous for film formation. When using solution polymerization, after the polymerization is completed, the solution of the polymerization product can be used as a (meth)acrylic polymer release agent.

[0057] Examples of the polymerization solvent include aliphatic hydrocarbons such as n-hexane and n-heptane, esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and mixed solvents thereof. In addition, a chain transfer agent or a chain extender can be used from the viewpoint of molecular weight control.

[0058] Examples of chain transfer agents include thiol compounds such as 2-mercaptoethanol, 3-mercapto-2-butanol, 3-mercapto-2-propanol, 3-mercapto-1-propanol, dodecanethiol, isooctyl thioglycolate, and 2-mercapto-ethylamine.

[0059] Examples of chain extenders include difunctional (meth)acrylic monomers such as 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate.

[0060] The solution polymerization of the polymerizable precursor composition can be carried out in an atmosphere of an inert gas such as nitrogen gas for about 2 hours to about 100 hours, usually at a reaction temperature of about 50°C to about 100°C.

[0061] As the polymerization initiator, a general polymerization initiator can be used. Examples of the polymerization initiator include azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylpropionic acid) dimethyl ester (dimethyl 2,2'-azobis(2-methylpropionate)), and peroxides such as benzoyl peroxide and lauroyl peroxide.

[0062] The amount of the polymerization initiator used is preferably about 0.005 parts by mass or more and about 0.5 parts by mass or less with respect to 100 parts by mass of the alkyl (meth) acrylate monomer component. By setting the amount of the polymerization initiator to about 0.005 parts by mass or more, a practical polymerization rate can be ensured. By setting the amount of the polymerization initiator to about 0.5 parts by mass or less, the molecular weight of the polymer can be increased to a level sufficient for forming a coating.

[0063] From the viewpoint of peeling force and handling property of polymerization reaction, the polymer contained in the (meth)acrylic release agent preferably has a weight average molecular weight of about 100000 or more, about 300000 or more, or about 500000 or more, about 5000000 or less, about 4000000 or less, about 3000000 or less, about 2000000 or less, about 1500000 or less, or about 1000000 or less. Here, in the present disclosure, "weight average molecular weight" means a weight average molecular weight calculated in terms of polystyrene by gel permeation chromatography (GPC).

[0064] The substrate is not particularly limited, and examples thereof include plastic films such as polyester (e.g., polyethylene terephthalate, polyethylene naphthalate, or polybutylene terephthalate), polyolefin (e.g., polyethylene), polyimide (e.g., Kapton (trade name) available from Toray DuPont Co., Ltd.), paper (e.g., craft paper), or a paper substrate coated with these plastic materials. A colored film may also be used as an example of the substrate. The colored film may be a mixture of dyes in plastic, colored paper, or a transparent film coated with colored ink. For example, an example of using a white film as a colored film will be described later. By using a colored film, the user can easily recognize the release sheet. Furthermore, a logo, instructions for use, etc. may be printed on the film. By using a colored film, the user can easily see these printed characters, etc.

[0065] The thickness of the substrate is not particularly limited and may be, for example, about 10 micrometers or more, about 15 micrometers or more, or about 20 micrometers or more, and may be about 300 micrometers or less, about 200 micrometers or less, or about 150 micrometers or less.

[0066] The coating amount of the release agent can vary according to the substrate.For example, the release agent is typically applied so that its dry thickness is about 0.01 micrometers or more and about 10 micrometers or less.When the substrate is a paper substrate coated with plastic film or plastic materials such as polyester and polyolefin, its dry thickness is generally about 0.05 micrometers or more and about 1 micrometer or less, and when the substrate is low in absorbency or low in smoothness, its dry thickness is generally about 0.1 micrometers or more and about 5 micrometers or less.

[0067] In one embodiment, the release liner is formed by coating at least one surface of a substrate with the release agent described above, followed by a drying process, a curing treatment by heat, a curing treatment by radiation (e.g., electron beam and ultraviolet light), or the like.

[0068] The release liner can be produced, for example, by the following procedure. The (meth)acrylic release agent is diluted with an aliphatic hydrocarbon such as n-hexane or n-heptane, an aromatic hydrocarbon such as toluene or xylene, an ester such as ethyl acetate or butyl acetate, a ketone such as methyl ethyl ketone or methyl isobutyl ketone, a halogenated hydrocarbon such as methylene chloride, or a mixed solvent thereof, as required, and then applied to a substrate in a predetermined thickness using a bar coater, a roll coater, a spray, or the like, and dried by heating as required to form a release precursor layer on the substrate. The dilution solvent may be the same as or different from the solvent used in solution polymerization.

[0069] Thereafter, the release precursor layer is irradiated with radiation such as electron beams or ultraviolet rays to form a release layer on the substrate. The release layer is adhered to the substrate by radiation irradiation. In this manner, a release liner can be obtained. For example, in the case of electron beam irradiation, the absorbed dose is usually about 1 kGy to about 100 kGy, although it depends on the thickness and composition of the release precursor layer. In the case of ultraviolet irradiation, the ultraviolet irradiation energy is usually about 10 mJ / cm, although it depends on the thickness and composition of the release precursor layer. 2 ~Approx. 3000mJ / cm 2 , preferably about 20 mJ / cm 2 ~about 500mJ / cm 2 Since ultraviolet irradiation does not require a large-scale device as in the case of electron beam irradiation, the release liner can be produced at low cost and with high productivity.

[0070] The release liner of the present disclosure includes the release layer described above, and therefore is able to exhibit suitable release performance for the silicone pressure-sensitive adhesive layer.

[0071] The silicone adhesive contained in the silicone adhesive layer that may be disposed on the release layer of the release liner is not particularly limited, but examples thereof include adhesives containing, as the main component, polyorganosiloxane, polydimethylsiloxane, polydiphenylsiloxane, polydimethyldiphenylsiloxane, etc. These silicone adhesives may be used alone or in combination of two or more thereof.

[0072] The silicone adhesive may be of a curable or non-curable type. Specific examples of such silicone adhesives include peroxide-curable silicones, addition-reactive silicones, electron beam or gamma ray-curable silicones, and modified silicones.

[0073] Peroxide curable silicones may be used to increase the cohesive strength by a curing (crosslinking) reaction that is a catalyst. Addition reactive curable silicones may be used to increase the cohesive strength by a hydrosilylation crosslinking reaction that uses a metal catalyst. Commercially available peroxide curable silicone adhesives and addition reactive silicone adhesives can be used. Commercially available peroxide curable silicone adhesives include, for example, DOWSIL (trade name) SH 4280 available from Dow Toray Co., Ltd. and KR-12 available from Shin-Etsu Chemical Co., Ltd. Commercially available addition reactive silicone adhesives include, for example, DOWSIL (trade name) SD 4570 available from Dow Toray Co., Ltd. and X-40-3004A available from Shin-Etsu Chemical Co., Ltd.

[0074] Examples of peroxides used as a curing agent (crosslinking agent) for peroxide-curable silicone adhesives include benzoyl peroxide, dicumyl peroxide, p-chlorobenzoyl peroxide, -2,4-dichlorobenzoyl peroxide, and di-t-butyl peroxide. The peroxides may be used alone or in combination of two or more thereof. The amount of peroxide used may be about 0.5 parts by mass to about 2.5 parts by mass per 100 parts by mass of the silicone adhesive.

[0075] Examples of metal catalysts used as curing agents (crosslinking agents) for addition-reactive silicone pressure-sensitive adhesives include platinum catalysts (e.g., chloroplatinic acid catalysts), other Group VIIIB (i.e., Groups 8, 9, and 10) catalysts, and hydrosilylation catalysts. The metal catalysts may be used alone or in combination of two or more of them. The amount of metal catalyst used may be about 0.5 parts by mass to about 1.5 parts by mass per 100 parts by mass of the silicone pressure-sensitive adhesive.

[0076] In one embodiment, an electron beam or gamma radiation curable silicone is used as the silicone adhesive. Silicone materials useful for the electron beam or gamma radiation curable silicone can include, for example, polydiorganosiloxanes, which include a polysiloxane backbone.

[0077] Such silicone materials can be non-functionalized silicone materials, which can be linear materials represented by the following formula, which represents a siloxane backbone containing aliphatic and / or aromatic substituents: [ka]

[0078] In formula (1), R1, R2, R3, and R4 are independently selected from the group consisting of alkyl groups and aryl groups, each R5 is an alkyl group, n and m are integers, and at least one of m or n is not 0. In some embodiments, one or more of the alkyl or aryl groups may contain a halogen substituent (e.g., fluorine). For example, in some embodiments, one or more of the alkyl groups may be -CH2CH2C4F9.

[0079] In some embodiments, R5 is a methyl group, i.e., the non-functionalized polydiorganosiloxane material is terminated with trimethylsiloxy groups. In some embodiments, R1 and R2 are alkyl groups and n is 0, i.e., the material is a poly(dialkylsiloxane). In some embodiments, the alkyl group is a methyl group, i.e., a poly(dimethylsiloxane) ("PDMS"). In some embodiments, R1 is an alkyl group, R2 is an aryl group, and n is 0, i.e., the material is a poly(alkylarylsiloxane). In some embodiments, R1 is a methyl group and R2 is a phenyl group, i.e., the material is a poly(methylphenylsiloxane). In some embodiments, R1 and R2 are alkyl groups and R3 and R4 are aryl groups, i.e., the material is a poly(dialkyldiarylsiloxane). In some embodiments, R1 and R2 are methyl groups and R3 and R4 are phenyl groups, i.e., the material is a poly(dimethyldiphenylsiloxane).

[0080] In some embodiments, the non-functionalized polydiorganosiloxane material can be branched. For example, one or more of the R1, R2, R3, and / or R4 groups can be linear or branched siloxanes containing alkyl or aryl (including halogenated alkyl or aryl) substituents and a terminal R5 group.

[0081] In this disclosure, a "non-functional group" is either an alkyl group or an aryl group consisting of carbon, hydrogen, or in some embodiments, halogen (e.g., fluorine) atoms. As used herein, a "non-functionalized polydiorganosiloxane material" is one in which the R1, R2, R3, R4, and R5 groups are non-functional groups.

[0082] Generally, functionalized silicone-based materials contain specific reactive groups (e.g., hydrogen, hydroxyl, vinyl, allyl, or acryl groups) attached to the starting polysiloxane backbone. As used herein, a "functionalized polydiorganosiloxane material" is one in which at least one of the R groups in formula (2) below is a functional group. [ka]

[0083] In some embodiments, the functionalized polydiorganosiloxane material is one in which at least two R groups are functional groups. In general, the R groups in formula (2) may be independently selected. In some embodiments, at least one functional group is selected from the group consisting of hydride groups, hydroxy groups, alkoxy groups, vinyl groups, epoxy groups, and acrylate groups.

[0084] In addition to functional R groups, the R groups may be non-functional groups, such as alkyl or aryl groups, including halogenated (e.g., fluorinated) alkyl and aryl groups. In some embodiments, the functionalized polydiorganosiloxane material may be branched. For example, one or more of the R groups may be linear or branched siloxanes having functional and / or non-functional substituents.

[0085] Electron beam or gamma radiation curable silicone adhesives can be prepared by combining one or more polydiorganosiloxane materials (e.g., silicone oils or fluids) with a suitable desired tackifying resin (e.g., MQ resin), coating the resulting mixture, and curing it using electron beam (E-beam) or gamma radiation. In general, any known additives useful in formulating adhesives can also be included.

[0086] In one embodiment, modified silicone is used as the silicone adhesive. Here, in the present disclosure, "modified silicone" refers to silicone in which a functional group (e.g., a functional group having a urethane structure) is added to the main chain of silicone. The modified silicone adhesive may be used alone or in combination of two or more thereof, or may be used in combination with the unmodified silicone adhesive as described above.

[0087] In one embodiment, the elastic modulus of the silicone pressure-sensitive adhesive layer containing the modified silicone at −20° C. or lower is about 2×10 5 Pa or more, approximately 5×10 5 Pa or more, or about 1×10 6 Pa or more and approximately 7 x 10 7 Pa or less, approximately 3×10 7 Pa or less, or about 2×10 7 The elastic modulus may be equal to or less than Pa. Here, the elastic modulus is a value measured using a viscoelasticity measuring device Discovery HR2 (available from TA Instrument, DE, USA) under the conditions of a parallel plate diameter of 8 mm, a heating rate of 3°C / min, a measurement temperature range of -65°C to 150°C, and a frequency of 1 Hz (6.28 radians / sec).

[0088] In one embodiment, the weight average molecular weight of the soft segment (silicone portion) of the modified silicone contained in the silicone pressure-sensitive adhesive layer is independently 5,000 or more, about 10,000 or more, about 15,000 or more, and about 70,000 or less, about 60,000 or less, or about 50,000 or less.

[0089] The modified silicone is a silicone having a functional group (e.g., a functional group having a urethane structure) added to the main chain of the silicone, and typically, the silicone portion constituting the main chain constitutes a soft segment, and the functional group portion constitutes a hard segment. In one embodiment, the mass ratio of the soft segment to the hard segment in the modified silicone contained in the silicone pressure-sensitive adhesive layer is soft segment:hard segment=about 1,000:about 1 to about 50:about 1, about 900:about 1 to about 100:about 1, or about 600:about 1 to about 200:about 1.

[0090] The modified silicone is not particularly limited, but may be, for example, at least one selected from the group consisting of silicone polyurea block copolymers, silicone polyoxamide block copolymers, and silicone polyoxamide-hydrazide block copolymers.

[0091] In one embodiment, the silicone polyurea block copolymer contains the reaction product of a polydiorganosiloxane diamine (which may be referred to as a "silicone diamine") polyisocyanate and, optionally, an organic polyamine. The silicone polyurea block copolymers may be used alone or in combination of two or more thereof.

[0092] Suitable silicone polyurea block copolymers are represented by repeating units of Formula I: [ka]

[0093] In formula I, each R is independently preferably an alkyl moiety having about 1 to 12 carbon atoms, e.g., a moiety optionally substituted with a trifluoroalkyl group or a vinyl group, or preferably, a group of formula R 2 (CH2) a CH=CH2 (wherein, R 2 Ha-(CH2) b - or (CH2) cR is a higher alkenyl group represented by the formula (I) (CH=CH-, a is 1, 2, or 3, b is 0, 3, or 6, and c is 3, 4, or 5), a cycloalkyl moiety having about 6 to 12 carbon atoms, optionally substituted with alkyl, fluoroalkyl, and vinyl groups, or an aryl moiety preferably having about 6 to 20 carbon atoms, such as an alkyl, cycloalkyl, fluoroalkyl, and vinyl group, or R is a perfluoroalkyl group as disclosed in U.S. Pat. No. 5,028,679. groups, fluorine-containing groups as disclosed in U.S. Pat. No. 5,236,997, and perfluoropolyether-containing groups as disclosed in U.S. Pat. Nos. 4,900,474 and 5,118,775; preferably, at least 50% of the R moieties are methyl groups, with the remainder being monovalent alkyl or substituted alkyl groups, alkenyl groups, phenyl groups, or substituted phenyl groups having 1 to 20 carbon atoms; each Z is a polyvalent group, preferably an arylene or aralkylene group having about 6 to 20 carbon atoms, preferably about 6 to 20 carbon atoms. Each Y is independently an alkylene group or a cycloalkylene group having 1 to 10 carbon atoms, preferably Z is 2,6-toluylene, 4,4'-methylenediphenylene, 3,3'-dimethoxy-4,4'-biphenylene, tetramethyl-m-xylylene, 4,4'-methylenedicyclohexylene, 3,5,5-trimethyl-3-methyleneticlohexylene, 1,6-hexamethylene, 1,4-cyclohexylene, 2,2,4-trimethylenehexylene, and mixtures thereof; wherein R is an alkylene group having 1 to 20 carbon atoms, preferably an aralkylene group or an arylene group having 6 to 20 carbon atoms; D is independently selected from the group consisting of hydrogen, an alkyl group having 1 to 10 carbon atoms, phenyl, and a group which completes a ring structure together with B or Y to form a heterocycle; in formula I, B is a polyvalent group selected from the group consisting of alkylene, aralkylene, cycloalkylene, polyalkylene oxides such as polyethylene oxide, polypropylene oxide, polytetramethylene oxide, and copolymers and mixtures thereof;m is a number from 0 to about 1,000, n is a number of at least 1, and p is a number of at least 10, preferably from about 15 to about 2,000, and more preferably from 30 to 1,500;

[0094] Useful silicone polyurea block copolymers are disclosed, for example, in U.S. Pat. Nos. 5,512,650, 5,214,119, and 5,461,134, WO 96 / 17726, WO 96 / 34028, WO 96 / 34030, and WO 97 / 40103.

[0095] An example of a useful silicone diamine for use in the synthesis of the silicone polyurea block copolymer is a polydiorganosiloxane diamine represented by Formula II below: Preferably, the polydiorganosiloxane diamine has a number average molecular weight of about 700 g / mol or greater. [ka]

[0096] In formula II, R, Y, D, and p are each defined as above.

[0097] Useful polydiorganosiloxane diamines can include any of the polydiorganosiloxane diamines within the scope of formula II. Among these, from the viewpoint of balance between applicability and peelability to wallpaper, and member retention, polydiorganosiloxane diamines having a number average molecular weight of about 700 g / mol or more, about 1000 g / mol or more, about 3000 g / mol or more, about 5000 g / mol or more, about 10000 g / mol or more, about 15000 g / mol or more, about 20000 g / mol or more, or about 25000 g / mol or more, and about 150000 g / mol or less, about 100000 g / mol or less, about 80000 g / mol or less, about 60000 g / mol or less, about 50000 g / mol or less, or about 40000 g / mol can be preferably used.

[0098] Polydiorganosiloxane diamines and suitable methods for synthesizing polydiorganosiloxane diamines are disclosed, for example, in U.S. Pat. Nos. 3,890,269, 4,661,577, 5,026,890, 5,276,122, WO 95 / 03354, and WO 96 / 35458.

[0099] Examples of useful polydiorganosiloxane diamines include polydimethylsiloxane diamine, polydiphenylsiloxane diamine, polytrifluoropropylmethylsiloxane diamine, polyphenylmethylsiloxane diamine, polydiethylsiloxane diamine, polydivinylsiloxane diamine, polyvinylmethylsiloxane diamine, poly(5-hexenyl)methylsiloxane diamine, and mixtures or copolymers thereof.

[0100] Suitable polydiorganosiloxane diamines are commercially available, for example, from SEH America Inc, Huls America Inc., CA. The polydiorganosiloxane diamines are preferably substantially pure and can be synthesized, for example, by methods such as those disclosed in U.S. Pat. No. 5,214,119. Such high purity polydiorganosiloxane diamines can be synthesized by a two-step reaction of cyclic organosilanes with bis(aminoalkyl)disiloxanes using anhydrous aminoalkyl functional silanolate catalysts, such as tetramethylammonium-3 aminopropyldimethylsilanolate, preferably in an amount of less than 1.15 wt.% based on the total amount of cyclic organosilanes. Particularly preferably, the polydiorganosiloxane diamines are synthesized using cesium and rubidium catalysts, such synthesis methods being disclosed, for example, in U.S. Pat. No. 5,512,650.

[0101] The polydiorganosiloxane diamine component can provide a means for adjusting the modulus of the synthesized silicone polyurea block copolymer. In general, high molecular weight polydiorganosiloxane diamines can result in low modulus copolymers, while low molecular weight polydiorganosiloxane polyamines can result in high modulus copolymers.

[0102] Examples of useful polyamines include those available from HUNTSMAN (Houston, Texas) under the trade names: JEFFAMINE® D-230 (i.e., a polyoxypropylene diamine having a number average molecular weight of 230 g / mol), JEFFAMINE® D-400 (i.e., a polyoxypropylene diamine having a number average molecular weight of 400 g / mol), JEFFAMINE® D-2000 (i.e., a polyoxypropylene diamine having a number average molecular weight of 2,000 g / mol), JEFFAMINE® D-4000, and JEFFAMINE® ED-2000. 001, and JEFFAMINE® EDR-148 (i.e., triethylene glycol diamine); polyoxyalkylene triamines, including polyoxyalkylene triamines available from HUNTSMAN under the trade names T-403, T-3000, and T-5000; and alkylene diamines containing ethylene diamine and polyalkylenes available from DuPont, Wilmington, Delaware, under the trade names Dytek® A and Dytek® EP.

[0103] The optional polyamine may provide a means for adjusting the modulus of the copolymer. By adjusting the concentration, type, and molecular weight of the organic polyamine, the modulus of the silicone polyurea block copolymer can be adjusted.

[0104] In one embodiment, the silicone polyurea block copolymer preferably contains up to about 3 moles of polyamine, more preferably from about 0.25 moles to about 2 moles. Preferably, the polyamine has a number average molecular weight of up to about 300 g / mol.

[0105] The polyisocyanate is not particularly limited, and for example, diisocyanates and triisocyanates can be used.

[0106] Examples of suitable diisocyanates include aromatic diisocyanates such as 2,6-toluene diisocyanate, 2,5-toluene diisocyanate, 2,4-toluene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, methylene bis(o-chlorophenyl diisocyanate), methylene diphenylene-4,4'-diisocyanate, polycarbonate diimide modified methylene diphenylene diisocyanate, (4,4'-diisocyanato-3,3',5,5'-tetraethyl)diphenylmethane, 4,4'-diisocyanato-3,3'-dimethoxybiphenyl (o-dianisidine diisocyanate), 5-chloro-2,4-toluene diisocyanate, and 1-chloromethyl-2,4-diisocyanate benzene, aromatic-aliphatic diisocyanates such as m-xylylene diisocyanate and tetramethyl-m-xylylene diisocyanate, aliphatic diisocyanates such as 1,4-diisocyanate butane, 1,6-diisocyanate hexane, 1,12-diisocyanate dodecane, and 2-methyl-1,5-diisocyanate pentane, and alicyclic diisocyanates such as methylenedicyclohexylene-4,4'-diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate), and cyclohexylene-1,4-diisocyanate.

[0107] Any triisocyanate that can react with polyamines, especially polydiorganosiloxane diamines, is suitable. Examples of suitable triisocyanates include the polyfunctional isocyanates produced from biurets, isocyanurates, and adducts. Examples of commercially available polyisocyanates are part of the series of polyisocyanates available from Bayer AG under the trade names DESMODUR (trade name) and MONDUR (trade name), from Asahi Kasei Corporation under the trade name DURANATE (trade name) and from Dow Plastics under the trade name PAPI (trade name).

[0108] The polyisocyanate is preferably present in a stoichiometric amount based on the amount of polydiorganosiloxane diamine and any optional polyamine.

[0109] Silicone polyurea block copolymers can be synthesized, for example, by solvent-based reactions, solventless reactions, or a combination thereof. Useful solvent-based processes are described, for example, by Tyagi et al., Segmented Organosiloxane Copolymers: 2. Useful solvent-based processes are described, for example, by Tyagi et al., Segmented Organosiloxane Copolymers: 2. Thermal and Mechanical Properties of Siloxane-Urea Copolymer, Polymer, vol. 25, December (1984), and U.S. Patent No. 5,214,119 (Leir). Useful methods for making silicone polyurea block copolymers are also described in, for example, U.S. Pat. Nos. 5,512,650, 5,214,119, 5,461,134, WO 96 / 35458, WO 98 / 17726, WO 96 / 34028, and WO 97 / 40103.

[0110] Adhesive compositions containing the silicone polyurea block copolymers can be prepared using, for example, a solvent-based reaction, a solventless reaction, or a combination thereof.

[0111] In solvent-based reactions, the MQ resin, if present, can be introduced before, during, or after the polyamine and polyisocyanate are introduced into the reaction mixture. The reaction of the polyamine and polyisocyanate can be carried out in a single solvent or a mixture of solvents. Preferably, the solvent does not react with the polyamine and polyisocyanate. It is preferred that the starting materials and the final product are thoroughly mixed in the solvent from midway through the polymerization reaction until the end of the polymerization reaction. These reactions can be carried out at room temperature or at a temperature up to the boiling point of the reaction solvent. The reaction is preferably carried out at ambient temperature, preferably up to 50°C.

[0112] When an MQ resin is present, in a substantially solvent-free reaction, a polyamine and a polyisocyanate are mixed with the MQ resin in a reaction vessel, the polyamine and the polyisocyanate can react to form a silicone polyurea block copolymer, and the product can react with the MQ resin to form a pressure sensitive adhesive composition.

[0113] One useful method involving solvent-based and solventless reactions when MQ resin is present is to prepare silicone polyurea block copolymer using solventless reaction, followed by mixing silicone polyurea block copolymer and MQ resin solution in solvent.Preferably, silicone polyurea block copolymer-based pressure-sensitive adhesive composition can be synthesized by the above-mentioned combination method that produces a mixture of silicone polyurea block copolymer and MQ resin.

[0114] In one embodiment, the silicone polyoxamide block copolymers and silicone polyoxamide-hydrazide copolymers have at least two repeat units of Formula A. [ka]

[0115] In formula A, R 1are each independently an alkyl, haloalkyl, aralkyl, alkenyl, or aryl, or an aryl substituted with an alkyl, alkoxy, or halo; each Y is independently an alkylene, aralkylene, or a combination thereof; each G is independently a bond or a group of the formula R 3 HN-G-NHR 3 From diamine to two -NHR 3 is a divalent residue corresponding to the residue obtained by removing the R 3 are each independently hydrogen or alkyl, or each R 3 G and R 3 and G together with the attached nitrogen form a heterocyclic group; each n is independently an integer from 0 to 1,500; each p is independently an integer from 1 to 10; and each q is independently an integer greater than or equal to 1, with at least 50% of q's being the integer 2.

[0116] R in formula A 1 Suitable alkyl groups for typically have 1 to 10, 1 to 6, or 1 to 4 carbon atoms. Exemplary alkyl groups include, but are not limited to, methyl, ethyl, isopropyl, n-propyl, n-butyl, and isobutyl. 1 Haloalkyl groups suitable for often have only a portion of the hydrogen atoms of the corresponding alkyl group replaced with halogen. Exemplary haloalkyl groups include chloroalkyl and fluoroalkyl groups having 1 to 3 halo atoms and 3 to 10 carbon atoms. 1 Alkenyl groups suitable for R often have 2 to 10 carbon atoms. Exemplary alkenyl groups include ethenyl, n-propenyl, and n-butenyl, which often have 2 to 8, 2 to 6, or 2 to 4 carbon atoms. 1Suitable aryl groups for have 6 to 12 carbon atoms. Phenyl is an exemplary aryl group. The aryl group can be unsubstituted or substituted with alkyl (e.g., alkyl having 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms), alkoxy (e.g., alkoxy having 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms), or halo (e.g., chloro, bromo, or fluoro). 1 Suitable aralkyl groups typically have an alkylene group having 1 to 10 carbon atoms and an aryl group having 6 to 12 carbon atoms. In some exemplary aralkyl groups, the aryl group is phenyl and the alkylene group has 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms (i.e., the structure of the aralkyl is alkylene-phenyl, where the alkylene is attached to the phenyl group).

[0117] In one embodiment, R in some repeat units of formula A 1 At least 40%, preferably at least 50%, of the groups are methyl. For example, R 1 At least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98%, or at least 99% of the groups may be methyl. 1 The groups may be selected from alkyl, haloalkyl, aralkyl, alkenyl, aryl, or aryl substituted with an alkyl, alkoxy, or halo having at least 2 carbon atoms.

[0118] Each Y in formula A is independently an alkylene, an aralkylene, or a combination thereof. Suitable alkylene groups typically have up to 10 carbon atoms, up to 8 carbon atoms, up to 6 carbon atoms, or up to 4 carbon atoms. Exemplary alkylene groups include methylene, ethylene, propylene, and butylene. Suitable aralkylene groups typically have an arylene group having 6 to 12 carbon atoms bonded to an alkylene group having 1 to 10 carbon atoms. In some exemplary aralkylene groups, the arylene moiety is phenylene. That is, the divalent aralkylene group is a phenylene-alkylene, where the phenylene is bonded to an alkylene having 1 to 10, 1 to 8, 1 to 6, or 1 to 4 carbon atoms. As used herein, with respect to the Y group, "combinations thereof" refers to a combination of two or more groups selected from alkylene groups and aralkylene groups. For example, the combination may be a single aralkylene bonded to a single alkylene (e.g., alkylene-arylene-alkylene). In one exemplary alkylene-arylene-alkylene combination, the arylene is phenylene and each alkylene has 1 to 10, 1 to 6, or 1 to 4 carbon atoms.

[0119] G in formula A is independently a bond or a group of formula R 3 HN-G-NHR 3 From the diamine compound, two amino groups (i.e., -NHR 3 When G is a bond, the copolymer is a silicone polyoxamide-hydrazide. In one embodiment, G is a bond and each R 3 is hydrogen.

[0120] When G is a residue unit, the copolymer is a silicone polyoxamide. The diamine may have primary or secondary amino groups. 3 The group is hydrogen or alkyl (e.g., alkyl having 1 to 10, 1 to 6, or 1 to 4 carbon atoms), or R 3 is R3 Together with the nitrogen to which both G and G are attached, G forms a heterocyclic group (e.g., R 3 HN-G-NHR 3 is piperazine. In most embodiments, R 3 is hydrogen or alkyl. In many embodiments, both amino groups in the diamine are primary amino groups (i.e., both R 3 The groups are hydrogen), and the diamine has the formula H2N-G-NH2.

[0121] In one embodiment, G is an alkylene, heteroalkylene, arylene, aralkylene, or combinations thereof. Suitable alkylenes often have 2 to 10, 2 to 6, or 2 to 4 carbon atoms. Exemplary alkylene groups include ethylene, propylene, butylene, and the like. Suitable heteroalkylenes often are polyoxyalkylenes, such as polyoxyethylenes having at least two ethylene units, polyoxypropylenes having at least two propylene units, or copolymers thereof. Suitable aralkylene groups typically contain an arylene group having 6 to 12 carbon atoms bonded to an alkylene group having 1 to 10 carbon atoms. Some exemplary aralkylene groups are phenylene-alkylenes, where the phenylene is bonded to an alkylene having 1 to 10 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. As used herein, with respect to the G group, "combinations thereof" refers to combinations of two or more groups selected from alkylene, heteroalkylene, polydiorganosiloxane, arylene, and aralkylene. For example, the combination may be an aralkylene bonded to an alkylene (e.g., alkylene-arylene-alkylene). In one exemplary alkylene-arylene-alkylene combination, the arylene is phenylene, and each alkylene has 1 to 10, 1 to 6, or 1 to 4 carbon atoms.

[0122] Each subscript n in formula A is independently an integer from 0 to 1,500. For example, subscript n may be an integer from at most 1,000, at most 500, at most 400, at most 300, at most 200, at most 100, at most 80, at most 60, at most 40, at most 20, or at most 10. The value of n is often at least 1, at least 2, at least 3, at least 5, at least 10, at least 20, or at least 40. For example, subscript n may be in the range of 40 to 1,500, 0 to 1,000, 40 to 1,000, 0 to 500, 1 to 500, 40 to 500, 1 to 400, 1 to 300, 1 to 200, 1 to 100, 1 to 80, 1 to 40, or 1 to 20.

[0123] Each subscript p is independently an integer from 1 to 10. For example, the value of p is often an integer at most 9, at most 8, at most 7, at most 6, at most 5, at most 4, at most 3, or at most 2. The value of p can be in the range of 1 to 8, 1 to 6, or 1 to 4.

[0124] Each subscript q is independently an integer greater than or equal to 1, and at least 50% of the q's are the integer 2. In one embodiment, at least 75%, at least 90%, at least 99%, or all of the q's are the integer 2.

[0125] In one embodiment, the silicone polyoxamide block copolymers and silicone polyoxamide-hydrazide block copolymers have the following formula: -R a -(CO)-NH-(wherein, R a is alkylene). Every carbonylamino group along the backbone of the copolymer material is part of an oxalylamino group (e.g., a -(CO)-(CO)-NH- group). That is, every carbonyl group along the backbone of the copolymer material is bonded to another carbonyl group and is part of an oxalyl group. More specifically, the copolymer contains multiple amino oxalylamino groups.

[0126] Silicone polyoxamide block copolymers and silicone polyoxamide-hydrazide block copolymers may be linear block copolymers (i.e., containing hard and soft blocks), and elastomers. They tend to have better solvent resistance than known polydiorganosiloxane polyoxamides. Some copolymers are insoluble, for example, in toluene or even tetrahydrofuran. Here, the following method can determine whether a copolymer is "insoluble" in a particular solvent. Approximately 1 g of sample copolymer was placed in a jar, about 100 g of the desired solvent was added, the jar was sealed, and placed on a roller at ambient temperature for about 4 hours. A copolymer sample is considered insoluble if 90% or more of its original mass is retained after drying to a constant weight.

[0127] Silicone polyoxamide block copolymers and silicone polyoxamide-hydrazide block copolymers can be prepared, for example, according to the methods of the present disclosure. The following method can be used to produce a copolymer material having at least two repeat units of formula B: [ka]

[0128] In formula B, R 1 are each independently an alkyl, haloalkyl, aralkyl, alkenyl, or aryl, or an aryl substituted with an alkyl, alkoxy, or halo; each Y is independently an alkylene, aralkylene, or a combination thereof; each G is independently a bond or a group of the formula R 3 HN-G-NHR 3 From diamine to two -NHR 3 is a divalent residue corresponding to the residue obtained by removing the R 3 are each independently hydrogen or alkyl, or each R 3 G and R 3 and G together with the nitrogen to which they are attached form a heterocyclic group; each n is independently an integer from 0 to 1,500.

[0129] R 1 , Y, G, and R 3 Suitable examples of are the same as those described above for formula A.

[0130] The first step of the method of the present disclosure may involve the use of a compound of formula C: [ka]

[0131] In formula C, p is an integer from 1 to 10.

[0132] The compound of formula C contains at least one polydiorganosiloxane segment and at least two oxalylamino groups. 1 , Y, and subscript n are as described for formula B, and p is an integer from 1 to 10. 2 The groups are each independently alkyl, haloalkyl, or aryl, or aryl substituted with alkyl, alkoxy, halo, or alkoxycarbonyl, or are bonded through N to formula D below. [ka]

[0133] In formula D, R 4 are each independently hydrogen, alkyl, or aryl, or R 4 together form a ring.

[0134] R in formula C 2Suitable alkyl and haloalkyl groups for often have 1 to 10, 1 to 6, or 1 to 4 carbon atoms. Tertiary alkyl (e.g., t-butyl) and haloalkyl groups can be used, but often there is a primary or secondary carbon atom directly attached (i.e., bonded) to the adjacent oxy group. Exemplary alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, and iso-butyl. Exemplary haloalkyl groups include chloroalkyl and fluoroalkyl groups, in which some, but not all, of the hydrogen atoms on the corresponding alkyl group are replaced with halo atoms. For example, the chloroalkyl or fluoroalkyl group can be chloromethyl, 2-chloroethyl, 2,2,2-trichloroethyl, 3-chloropropyl, 4-chlorobutyl, fluoromethyl, 2-fluoroethyl, 2,2,2-trifluoroethyl, 3-fluoropropyl, 4-fluorobutyl, and the like. R 2 Examples of suitable aryl groups include those having 6 to 12 carbon atoms, such as phenyl. The aryl group may be unsubstituted or substituted with alkyl (e.g., alkyl having 1 to 4 carbon atoms, such as methyl, ethyl, or n-propyl), alkoxy (e.g., alkoxy having 1 to 4 carbon atoms, such as methoxy, ethoxy, or propoxy), halo (e.g., chloro, bromo, or fluoro), or alkoxycarbonyl (e.g., alkoxycarbonyl having 2 to 5 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, or propoxycarbonyl).

[0135] The compound of formula C can include a single compound (i.e., all of the compounds have the same values ​​for p and n) or can include multiple compounds (i.e., the compounds have different values ​​for p, different values ​​for n, or different values ​​for both p and n). Compounds with different n values ​​have siloxane chains of different lengths. Compounds with at least two p values ​​have extended chains.

[0136] In one embodiment, the mixture is a first compound of formula C, where the subscript p is equal to 1, and a second compound of formula C, where the subscript p is equal to at least 2. The first compound can include a plurality of different compounds having different n values. The second compound can include a plurality of compounds having different p values, different n values, or different values ​​for both p and n. The mixture can contain at least 50% by weight of the first compound of formula C (i.e., p is equal to 1) and 50% or less by weight of the second compound of formula C (i.e., p is equal to at least 2), based on the total weight of the first and second compounds in the mixture. In some mixtures, the first compound is present in an amount of at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 98% by weight, based on the total amount of the compounds of formula C. The mixture often contains up to 50%, up to 45%, up to 40%, up to 35%, up to 30%, up to 25%, up to 20%, up to 15%, up to 10%, up to 5%, or up to 2% by weight of the second compound.

[0137] Different amounts of the chain extended compound of formula C in the mixture can affect the final properties of the elastomeric material of formula B. That is, the amount of the second compound of formula C (i.e., p is at least equal to 2) can be advantageously varied to provide an elastomeric material with a range of properties. For example, increasing the amount of the second compound of formula C can tailor the melt rheology (e.g., make the elastomeric material flow more easily when present as a melt), tailor the flexibility of the elastomeric material, decrease the modulus of the elastomeric material, or a combination thereof.

[0138] In the first step of the method of the present disclosure, a compound of formula C and a molar excess of a diamine of formula E are combined under reactive conditions. [ka]

[0139] R in formula E 3 The groups and G are as described for formula B.

[0140] The diamine of formula E may be optionally classified as an organic diamine or as a polydiorganosiloxane diamine with an organic diamine selected from, for example, alkylenediamines, heteroalkylenediamines, arylenediamines, aralkylenediamines, or alkylene-aralkylenediamines. Because the diamines have only two amino groups, the resulting polydiorganosiloxane polyoxamides and polyoxamide-hydrazides are linear block copolymers that are often elastomeric, melt at high temperatures, and are soluble in some common organic solvents. The diamines do not have polyamines with more than two primary or secondary amino groups. There may be tertiary amines that do not react with the compound of formula C.

[0141] Exemplary polyoxyalkylene diamines (i.e., G is a heteroalkylene where the heteroatom is oxygen) include, but are not limited to, those commercially available from HUNTSMAN (Woodlands, TX) under the trade names JEFFAMINE® D-230, JEFFAMINE® D-400, JEFFAMINE® D-2000, and JEFFAMINE® EDR-148 listed above, as well as JEFFAMINE® HK-511 (i.e., a polyether diamine containing both oxyethylene and oxypropylene groups and having a number average molecular weight of 220 g / mol) and JEFFAMINE® ED-2003 (i.e., a polyethylene glycol end-capped with polypropylene oxide and having a number average molecular weight of 2000 g / mol).

[0142] Exemplary alkylenediamines (i.e., G is alkylene) include, but are not limited to, ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, 2-methylpentamethylene-1,5-diamine (i.e., available from DuPont, Wilmington, Del. under the trade name DYTEK A), 1,3-pentanediamine (available from DuPont under the trade name DYTEK EP), 1,4-cyclohexanediamine, 1,2-cyclohexanediamine (available from DuPont under the trade name DHC-99), 4,4′-bis(aminocyclohexyl)methane, and 3-aminomethyl-3,5,5-trimethylcyclohexylamine.

[0143] Exemplary arylene diamines (i.e., G is an arylene, such as phenylene) include, but are not limited to, m-phenylene diamine, o-phenylene diamine, and p-phenylene diamine. Exemplary aralkylene diamines (i.e., G is an aralkylene, such as alkylene-phenyl) include, but are not limited to, 4-aminomethyl-phenylamine, 3-aminomethyl-phenylamine, and 2-aminomethyl-phenylamine. Exemplary alkylene-aralkylene diamines (i.e., G is an alkylene-aralkylene, such as alkylene-phenylene-alkylene) include, but are not limited to, 4-aminomethyl-benzylamine, 3-aminomethyl-benzylamine, and 2-aminomethyl-benzylamine.

[0144] Exemplary hydrazines (ie, G is a bond) include, but are not limited to, hydrazine and N,N'-diaminopiperidine.

[0145] In some preferred embodiments, the diamine of formula E is selected from the group consisting of hydrazine, 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 2-methyl-5-pentanediamine, 1,6-diaminohexane, and m-xylylenediamine.

[0146] Reaction of a compound of formula C with a molar excess of a diamine of formula E provides an amine-terminated polymer of formula F. [ka]

[0147] The reaction can be carried out using multiple compounds of formula C, multiple diamines, or combinations thereof. Multiple compounds of formula C with different number average molecular weights can be combined with a single diamine or multiple diamines under reaction conditions. For example, the compound of formula C can include a mixture of materials with different values, having different values ​​of n, different values ​​of p, or different values ​​of both n and p. Multiple diamines can include, for example, a first diamine that is an organic diamine and a second diamine that is a polydiorganosiloxane diamine. Similarly, a single compound of formula C can be combined with multiple diamines under reaction conditions.

[0148] The condensation reaction of the compound of formula C with the diamine is often carried out at room temperature or at an elevated temperature (e.g., at a temperature of up to about 250° C.). For example, the reaction can often be carried out at room temperature or at a temperature of up to about 100° C. In other examples, the reaction can be carried out at a temperature of at least about 100° C., at least about 120° C., or at least about 150° C. For example, the reaction temperature is often in the range of about 100° C. to about 220° C., about 120° C. to about 220° C., or about 150° C. to about 200° C. The condensation reaction is often complete in less than about 1 hour, less than about 2 hours, less than about 4 hours, less than about 8 hours, or less than about 12 hours.

[0149] The reaction can occur in the presence or absence of a solvent. A suitable solvent usually does not react with either the reactants or products involved in the reaction. Furthermore, a suitable solvent typically can keep all reactants and all products in solution throughout the process. Exemplary solvents include, but are not limited to, toluene, tetrahydrofuran, dichloromethane, aliphatic hydrocarbons (e.g., alkanes such as hexane), or mixtures thereof.

[0150] After the reaction is complete, the excess diamine and solvent, if any, are removed. The excess diamine can be removed, for example, by vacuum distillation.

[0151] The resulting amine-terminated polymer of formula F is then treated with an oxalate ester to utilize the amine end groups to form repeat units of formula F. Useful oxalate esters have the formula G: [ka]

[0152] The oxalate of formula G can be, for example, a compound of formula R 5 It can be prepared by reacting an alcohol of -OH with oxalyl dichloride. Commercially available oxalates of formula G (e.g., from Sigma-Aldrich (Milwaukee, WI) and VWR International (Bristol, CT)) include, but are not limited to, dimethyl oxalate, diethyl oxalate, di-n-butyl oxalate, di-tert-butyl-oxalate, bis(phenyl)oxalate, bis(pentafluorophenyl)oxalate, 1-(2,6-difluorophenyl)-2-(2,3,4,5,6-pentachlorophenyl)oxalate, and bis(2,4,6-trichlorophenyl)oxalate.

[0153] Particularly useful oxalate esters of formula G include, for example, the oxalate esters of phenol, ethanol, butanol, methyl ethyl ketone oxime, acetone oxime, and trifluoroethanol.

[0154] Any suitable reactor (e.g., glass vessel or general vessel equipped with a stirrer) or process can be used to prepare the silicone polyoxamide block copolymers and silicone polyoxamide-hydrazide block copolymers according to the methods of the present disclosure. The reaction can be carried out using a batch process, a semi-batch process, or a continuous process.

[0155] Any solvent present can be removed from the resulting polydiorganosiloxane polyoxamide or polyoxamide-hydrazide at the end of the reaction. This removal process is often carried out at a temperature of at least about 100° C., at least about 125° C., or at least about 150° C. This removal process is typically carried out at a temperature of less than about 300° C., less than about 250° C., or less than about 225° C.

[0156] It may be desirable to carry out the reaction in the absence of a solvent: in a solvent that is not compatible with both the reactants and the product, the reaction will be incomplete and the degree of polymerization will be low.

[0157] The amount of each of the peroxide-curable silicone, addition-reactive silicone, electron beam or gamma ray-curable silicone, and modified silicone in the silicone adhesive layer may be, independently, for example, about 30% by mass or more, about 35% by mass or more, about 40% by mass or more, about 45% by mass or more, or about 50% by mass or more, and may be about 90% by mass or less, about 85% by mass or less, about 80% by mass or less, about 75% by mass or less, about 70% by mass or less, about 65% by mass or less, about 60% by mass or less, or about 55% by mass or less, relative to the total amount of the adhesive layer.

[0158] The silicone pressure-sensitive adhesive layer may contain, as optional components, within the scope of the present disclosure, a tackifier (e.g., MQ resin), an antioxidant, an ultraviolet absorber, a light stabilizer, a heat stabilizer, a dispersant, a plasticizer, a flow improver, a surfactant, a leveling agent, a silane coupling agent, a catalyst, a filler, a pigment, a dye, etc. These optional components may be used alone or in combination of two or more thereof.

[0159] In one embodiment, the silicone adhesive layer contains an MQ resin (sometimes referred to as an "MQ tackifying resin").

[0160] Useful MQ resins include, for example, at least one selected from the group consisting of MQ silicone resins, MQD silicone resins, and MQT silicone resins. These MQ resins may have a number average molecular weight of about 100 or more, or about 500 or more, about 50,000 or less, or about 20,000 or less, and may have methyl substituents. Here, in the present disclosure, the "number average molecular weight" refers to the number average molecular weight in terms of polystyrene by gel permeation chromatography (GPC).

[0161] MQ silicone resins can include both non-functional and functional resins. Functional silicone resins have one or more functional groups including, for example, silicon-bonded hydrogen, silicon-bonded alkenyl, or silanol groups.

[0162] MQ silicone resin is R'3SiO 1 / 2 Units (M units) and SiO 4 / 2The MQ silicone resin is a copolymerizable silicone resin having a unit (Q unit). Such resins are disclosed, for example, in Encyclopedia of Polymer Science and Engineering, vol. 15, John Wiley Sons, New York, (1989), pp. 265-270, and in U.S. Pat. Nos. 2,676,182 (Daudi et al.), 3,627,851 (Brady), 3,772,247 (Flannigan) and 5,248,739 (Schmidt et al.). MQ silicone resins having functional groups are disclosed, for example, in U.S. Pat. No. 4,774,310 (Butler), which discloses a silyl hydride group, U.S. Pat. No. 5,262,558 (Kobayashi et al.), which discloses a vinyl group and a trifluoropropyl group, and U.S. Pat. No. 4,707,531 (Shirahata), which discloses a silyl hydride group and a vinyl group. The above resins can generally be prepared in a solvent. Dry or solvent-free MQ silicone resins can be prepared as disclosed in U.S. Patents 5,319,040 (Wengrovis et al.), 5,302,685 (Tsumula et al.), and 4,935,484 (Wolfgruber et al.).

[0163] MQD silicone resins are, for example, R'SiO 1 / 2 Unit (M unit), SiO 4 / 2 Units (Q units), and R'2SiO 2 / 2 It is a terpolymer having units (D units).

[0164] MQT silicone resin is R'3SiO 1 / 2 Units (M units) and SiO 4 / 2 Units (Q units), and R'SiO 3 / 2 It is a terpolymer (MQT resin) having units (T units).

[0165] MQ silicone resins are typically supplied in organic solvents. Commercially available MQ silicone resins include SilGrip® SR-545 MQ resin in toluene, available from Momentive Performance Materials Japan LLC, and MQOH resin in toluene, available from PCR, Inc. (Gainesville, Fla.). These organic solutions of MQ silicone resins may be used as provided by the supplier, or may be dried by any number of techniques known in the art to provide MQ silicone resins with 100% non-volatile content. Examples of suitable drying methods include, but are not limited to, spray drying, oven drying, and steam separation drying.

[0166] The amount of MQ resin in the adhesive layer may be, for example, about 30% by weight or more, about 35% by weight or more, about 40% by weight or more, about 45% by weight or more, or about 50% by weight or more, relative to the total amount of the adhesive layer, and may be about 70% by weight or less, about 65% by weight or less, about 60% by weight or less, about 55% by weight or less, or about 50% by weight or less.

[0167] The silicone pressure-sensitive adhesive layer may or may not have a support such as paper, a plastic film, a nonwoven fabric, or a foam layer.

[0168] The thickness of the silicone adhesive layer can be about 1 μm or more, about 5 μm or more, or about 10 μm or more, and about 100 μm or less, about 80 μm or less, or about 50 μm or less.Here, the thickness of the adhesive layer is the average thickness value at at least 5 arbitrary positions in the adhesive layer of the laminate measured by scanning electron microscope in the thickness direction of the laminate.Such a thickness measurement method can also be used for the thickness of each layer constituting the laminate.

[0169] In one embodiment, the peel strength of the silicone pressure-sensitive adhesive layer to the release layer of the release liner is about 10 N / 25 mm or less, about 7.5 N / 25 mm or less, about 5.0 N / 25 mm or less, about 3.0 N / 25 mm or less, or about 1.5 N / 25 mm or less, and about 0.01 N / 25 mm or more, about 0.02 N / 25 mm or more, about 0.05 N / 25 mm or more, about 0.10 N / 25 mm or more, or about 0.20 N / 25 mm or more. Here, the peel strength is the peel strength when the release liner is peeled off in a 180 degree direction at 300 mm / min in accordance with JIS Z 0237.

[0170] The method of applying the silicone adhesive to the release liner to obtain the laminate is not particularly limited, and examples thereof include solvent coating methods such as notch bar coating, knife coating, roll coating, reverse roll coating, gravure coating, wire wound rod coating, slot orifice coating, slot die coating, or extrusion coating, water-based coating methods, and hot melt coating methods.After applying the adhesive to the release liner, any process such as drying or curing may be applied as necessary.As described above, the laminate in which the silicone adhesive is applied to the release liner can be used for tapes such as single-sided tapes, double-sided tapes, and adhesive transfer tapes.

[0171] The tape of one embodiment includes a release liner having a release layer disposed thereon, and a silicone adhesive layer laminated on the release layer of the release liner. When the adhesive layer is used in a manner in which it is separated from the release sheet and attached to an adherend, the adhesive layer is also called an adhesive transfer tape.

[0172] The tape of this embodiment may further comprise a support substrate such as paper, a plastic film, a foam of (meth)acrylic resin, urethane resin, etc., or a nonwoven fabric, laminated on the side opposite to the release liner of the adhesive layer. In this embodiment, when the support substrate has a second adhesive layer on the side opposite to the adhesive layer side, the tape is in the form of a so-called double-sided tape. When the support substrate has no adhesive layer on the side opposite to the adhesive layer side, the tape is in the form of a so-called single-sided tape.

[0173] 1, a laminate 100 having a configuration in which release liners are applied to both sides of a silicone pressure-sensitive adhesive layer can be produced, for example, by applying an adhesive onto the release layer of release liner 101 (first release liner) to form silicone pressure-sensitive adhesive layer 103, and then adhering another second release liner 105 via the release layer sandwiched between them. A laminate having such a configuration can be used, for example, as a pressure-sensitive adhesive transfer tape.

[0174] The two release liners (i.e., the first release liner and the second release liner) included in the laminate having such a configuration may be the same type of release liner or different types of release liners. In one embodiment, the first release liner and the second release liner are both release liners having a bNSNF release layer, and the first release liner and the second release liner may be a release liner having a fluorine-based release layer and a release liner having a bNSNF release layer, or a release liner having a bNSNF release layer and a release liner having a fluorine-based release layer, respectively. It is also possible to use release liners having different bNSNF release layers for the first release liner and the second release liner. It is advantageous for the two release liners to be release liners having a bNSNF release layer from the viewpoints of cost and prevention of contamination by fluorine components.

[0175] From the viewpoint of usability of a laminate having such a configuration, the peel strength of the silicone pressure-sensitive adhesive layer to the release layer of the first release liner and the peel strength of the silicone pressure-sensitive adhesive layer to the release layer of the second release liner preferably differ from each other by at least about 2.0, at least about 2.5, or at least about 3.0, but not more than about 20, not more than about 10, not more than about 5.0, not more than about 4.5, or not more than about 4.0. With regard to the peel strengths of the two, the peel strength of the first pressure-sensitive adhesive layer to the release layer of the first release liner may be higher, or the peel strength of the second pressure-sensitive adhesive layer to the release layer of the second release liner may be higher.

[0176] 2 can be produced, for example, by coating one release layer of a release liner 201 having release layers on both sides with an adhesive, and winding it into a roll while forming a silicone adhesive layer 203. A roll having such a configuration can be used, for example, as an adhesive transfer tape.

[0177] The two release layers included in the roll body having such a configuration may be the same type of release layer or different types of release layers. In one embodiment, both of the two release layers are bNSNF release layers, and the two release layers can be a fluorine-based release layer and a bNSNF release layer, or a bNSNF release layer and a fluorine-based release layer, respectively. It is also possible to use different bNSNF release layers for the two release layers. From the viewpoints of cost, environmental issues, and prevention of contamination by fluorine components, it is advantageous for both of the two release layers to be bNSNF release layers.

[0178] From the viewpoint of usability of the roll body having such a configuration, the peel strength of the silicone pressure-sensitive adhesive layer to the release layer (first release layer) of the two release layers of the release liner is preferably different from the peel strength of the silicone pressure-sensitive adhesive layer to the other release layer (second release layer) by about 2.0 times or more, about 2.5 times or more, or about 3.0 times or more, about 20 times or less, about 10 times or less, about 5.0 times or less, about 4.5 times or less, or about 4.0 times or less. From the viewpoint of usability, it is preferable that the peel strength of the pressure-sensitive adhesive layer to the release layer arranged on the outer periphery of the roll body (i.e., the release layer on the side of reference symbol 201 in FIG. 2) is lower than the peel strength of the pressure-sensitive adhesive layer to the release layer arranged on the inner periphery of the roll body (i.e., the release layer on the opposite side of reference symbol 201 in FIG. 2).

[0179] The release liner, laminate, and roll body of the present disclosure may be provided with other layers such as a printed layer, a decorative layer, and a concealing layer, as necessary, to the extent that the effects of the present disclosure are not impaired. The other layers may be applied to all or part of the surface. EXAMPLES

[0180] Specific embodiments of the present disclosure are illustrated in the following examples, but the present invention is not limited to these embodiments. All parts and percentages are by weight unless otherwise stated. The numerical values ​​inherently contain errors due to the measurement principle and the measuring device. The numerical values ​​are expressed to significant digits with normal rounding.

[0181] Test Example 1 An adhesive tape prepared using the produced release liner was examined.

[0182] Table 1 shows the materials used. Here, "Mw" in the table means weight average molecular weight. "Linear", "branched" and "number of carbon atoms" refer to the alkyl of the alkyl (meth)acrylate monomer. Furthermore, for HCA-32, HCA-32 (2-tetradecyl octadecyl acrylate) was synthesized from the esterification reaction of 2-tetradecyl-1-octadecanol (iso-C32 alcohol) with acryloyl chloride using the reaction conditions and purification method described in Method 2 on pages 8-9 (column 14, line 63 to column 15, line 8) of U.S. Patent No. 8,137,807.

[0183] [Table 1]

[0184] Precursor polymer 1 These monomers were mixed so that the blending ratios of STA, ISA, and AEBP were 50.0 parts by mass, 50.0 parts by mass, and 0.2 parts by mass. The monomer mixture was diluted with a mixed solvent of ethyl acetate / n-heptane (50% by mass / 50% by mass) so that the monomer concentration was 50% by mass. Furthermore, 0.20 parts by mass of V-601 was added as an initiator relative to the (meth)acrylic acid alkyl ester component, and the system was purged with nitrogen for 2 minutes. Thereafter, the mixture was reacted in a thermostatic bath at 65°C for 48 hours to obtain a precursor polymer 1 in the form of a viscous solution.

[0185] Precursor polymers 2-12 Precursor polymers 2 to 12 were obtained in the same manner as precursor polymer 1 above, except that the formulation was changed as shown in Table 2. Note that in precursor polymer 10, the monomer mixture was diluted with ethyl acetate solvent to a monomer concentration of 40% by weight.

[0186] [Table 2]

[0187] Release Liner 1 Precursor polymer 1 was diluted to 1% by mass with a mixed solvent of toluene / MEK (50% by mass / 50% by mass). This diluted solution was coated on a polyester film (EMBLET (trade name) S-50) using a bar coater (#04). The solvent was then evaporated to form a release precursor layer having a thickness of about 0.1 micrometers.

[0188] The polyester film having the release precursor layer was irradiated with ultraviolet light in one pass at a line speed of 20 m / min under a nitrogen gas atmosphere using an ultraviolet irradiation device Heraeus (Hanau, Hessen, Germany), F300, medium pressure mercury lamp (H bulb)) to cure the release precursor layer, producing a release liner 1. During irradiation, the amount of ultraviolet light per pass measured with a radiation meter UV POWER PUCK (product name) II available from EIT was 350 mJ / cm. 2 (UVA 168mJ / cm 2 , UVB 158mJ / cm 2 , and UVC 24mJ / cm 2 ) was.

[0189] Release Liner 2~12 Release liners 2 to 12 were obtained in the same manner as the release liner 1, except that precursor polymers 2 to 12 in Table 2 were used for release liners 2 to 12. Precursor polymers 8 and 9 were diluted to 1.06% by mass with a mixed solvent of toluene / MEK / n-heptane (34% by mass / 33% by mass / 33% by mass). Precursor polymer 12 was diluted to 1.22% by mass with a single solvent of n-heptane.

[0190] Release Liners 13 and 14 (PCK-based Release Liners) Release liners 13 and 14 were obtained in the same manner as release liner 1, except that PCK was coated with the above precursor polymers 1 and 9, respectively, instead of a polyester film (EMBLET (trade name) S-50).

[0191] Release Liner 15~21 (Release Liner with White Film) Release liner 15 was obtained in the same manner as release liner 1 above, except that precursor polymer 9 was coated on white polyester film Crisper (trade name) K1212-100 instead of polyester film (EMBLET (trade name) S-50). Release liners 16 and 17 were obtained in the same manner as release liner 15, except that precursor polymer 9 was diluted to 1.5% by mass and 2.0% by mass, respectively, instead of 1.06% by mass. Release liner 18 was obtained in the same manner as release liner 17, except that precursor polymer 1 was coated at 2.0% by mass instead of precursor polymer 9 on white polyester film Crisper (trade name) K1212-100. Release liners 19 and 20 were obtained in the same manner as release liner 18, except that 2.0% by mass of precursor polymer 1 was coated on white polyester films DIAFOIL (trade name) W400-75 and Lumirror (trade name) #75-E20 instead of Crisper (trade name) K1212-100. Release liner 21 was obtained in the same manner as release liner 18, except that 1.0% by mass of precursor polymer 1 was coated on white polyester film DIAFOIL (trade name) W100-75 instead of Crisper (trade name) K1212-100 instead of 2.0% by mass of precursor polymer 1.

[0192] Preparation of adhesive tapes using the manufactured release liners having silicone polyurea block copolymer based adhesives The evaluation tape samples used in the examples and comparative examples were prepared by the following two methods.

[0193] (1) Apply the adhesive solution onto the prepared release liner (direct application) First, 60 parts by weight of SPU 33K, 100 parts by weight of XR37-B1795, 180 parts by weight of toluene, and 60 parts by weight of isopropyl alcohol were mixed to prepare an adhesive solution. Here, SPU 33K was prepared in the same manner as described in Example 28 of U.S. Patent No. 6,569,521. The adhesive solution was coated on the prepared release liner and dried at 105°C for 10 minutes. The thickness of the dried adhesive layer was about 50 micrometers. FD-75 was applied as a release liner on the adhesive layer to obtain an adhesive tape.

[0194] (2) Applying the prepared release liner to the adhesive layer (dry lamination) The above adhesive solution was coated on a release liner FD-75 and dried at 105° C. for 10 minutes. The thickness of the dried adhesive layer was about 50 micrometers. The prepared release liner was applied to the adhesive layer to obtain an adhesive tape.

[0195] The produced pressure-sensitive adhesive tapes were evaluated as follows, and the results are shown in Tables 3 to 6. In the tables, the release liners are abbreviated as "Liner 1," for example, release liner 1. In addition, "NSNF-based" in the tables means a non-fluorine-based and non-silicone-based release liner prepared using an alkyl (meth)acrylate monomer having a linear alkyl group without using an alkyl (meth)acrylate monomer having a branched alkyl group, and "bNSNF-based" means a non-fluorine-based and non-silicone-based release liner prepared using an alkyl (meth)acrylate monomer having a branched alkyl group.

[0196] Peel strength test: Peel strength of the adhesive layer to the release layer of the manufactured release liner The release liner FD-75 was peeled off from the adhesive tape, and a polyester film (COSMOSHINE (trade name) A4100) was attached to the adhesive layer of the adhesive tape. Next, the polyester film and the SUS panel were bonded via the double-sided tape sandwiched between them. The peel strength was measured when the manufactured release liner was peeled off in the 180 degree direction at a peel speed of 300 mm / min using a precision universal testing machine Autograph AG-X (Shimadzu Corporation, Kyoto City, Kyoto Prefecture, Japan). Here, when the peel strength exceeded 10 N / 25 mm, it was recorded as ">10" in the table. Table 3 shows the test results of the adhesive tape prepared by direct coating, Table 4 shows the test results when the adhesive tape prepared by direct coating was aged for several weeks in an environment of 50°C and 80% RH, and Table 5 shows the test results of the adhesive tape prepared by direct coating and the adhesive tape prepared by dry lamination.

[0197] Residual Adhesion Test The polyester film with the adhesive layer remaining on the SUS panel after the peel strength test was peeled off from the double-sided tape, and the adhesive layer exposed on the polyester film was attached to a SUS 304 (BA) panel. Using a precision universal testing machine Autograph AG-X (Shimadzu Corporation, Kyoto City, Kyoto Prefecture, Japan), the polyester film was left at room temperature for 30 minutes, and then peeled at a peel speed of 300 mm / min in the 180° direction to measure the adhesive strength as the residual adhesive strength. Please note that Table 6 also shows the residual adhesive strength of an adhesive tape prepared by the direct application method described above in (1) using two fluorine-based release liners (FD-75) as Reference Example 1.

[0198] [Table 3]

[0199] From the results in Table 3, it was found that the release layer of the non-fluorine-based and non-silicone-based bNSNF release liner of the present disclosure exhibits good release performance with respect to the silicone pressure-sensitive adhesive layer. In addition, it was also confirmed that, for example, by adjusting the polymer components, it is possible to separately produce release liners with light release properties and release liners with heavy release properties.

[0200] [Table 4]

[0201] The results in Table 4 confirm that the non-fluorinated and non-silicone bNSNF release liners of the present disclosure do not affect the physical properties (peel strength) even when subjected to aging treatment, and have excellent moist heat resistance of peel strength.

[0202] [Table 5]

[0203] The results in Table 5 confirm that the non-fluorine and non-silicone bNSNF release liners of the present disclosure have equivalent physical properties (peel strength) when applied by either the direct application method or the dry lamination method.

[0204] [Table 6]

[0205] The results in Table 6 confirm that the residual adhesive strength of the adhesive layer peeled from the non-fluorine-based and non-silicone-based bNSNF release liners of the present disclosure is equivalent to that of the fluorine-based release liner of Reference Example 1.

[0206] Preparation of adhesive tapes using the manufactured release liners having silicone polyoxamide block copolymer adhesives For the peel strength test and residual adhesion test, silicone polyoxamide block copolymer adhesives were used instead of silicone polyurea block copolymer adhesives. First, 60 parts by weight of SPO 20K, 100 parts by weight of XR37-B1795, and 140 parts of ethyl acetate were mixed to prepare an adhesive solution. Here, SPO 20K was prepared in the same manner as described in Example 12 of U.S. Pat. No. 8,765,881. Then, the adhesive solution was coated on the release liner FD-75 and dried at 105° C. for 10 minutes. The thickness of the dried adhesive layer was about 50 micrometers. Finally, the manufactured release liners (liner 1, liner 18 to liner 21) were applied to the adhesive layer, and an adhesive tape was obtained by dry lamination.

[0207] The peel strength test and residual adhesion test of the adhesive tape prepared using the silicone polyoxamide block copolymer adhesive were evaluated in the same manner as the adhesive tape prepared using the silicone polyurea block copolymer adhesive described above. The test results of the peel strength test and residual adhesion test are shown in Table 7.

[0208] [Table 7]

[0209] Test Example 2 The heat stability of the peel strength of the release liner for several silicone pressure sensitive adhesive tapes was evaluated.

[0210] The various materials used are shown in Table 8. Pressure sensitive adhesive tapes using the prepared release liners were prepared as follows, and the heat resistance stability of the release liners was evaluated.

[0211] [Table 8]

[0212] Examples 38 and 39 and Comparative Examples 4 to 6 A pressure-sensitive adhesive solution was prepared by mixing 100 parts by mass of DOWSIL (trade name) BY-24-740, 50 parts by mass of toluene, 1 part by mass of DOWSIL (trade name) BY-24-741, and 0.9 parts by mass of DOWSIL (trade name) SRX-212. This pressure-sensitive adhesive solution was coated on a substrate (COSMOSHINE (trade name) A4100), dried at 65°C for 5 minutes, and then dried at 120°C for 3 minutes. The thickness of the dried pressure-sensitive adhesive layer was about 30 micrometers. A release liner shown in Table 9 was applied onto this pressure-sensitive adhesive layer to obtain pressure-sensitive adhesive tapes of Examples 38 and 39 and Comparative Examples 4 to 6.

[0213] Examples 40 and 41 and Comparative Examples 7 to 9 An adhesive solution was prepared by mixing 100 parts by mass of DOWSIL (trade name) SH4280, 50 parts by mass of toluene, and 3 parts by mass of Niper (trade name) BMT-K40. This adhesive solution was coated onto a substrate (COSMOSHINE (trade name) A4100), dried at 65°C for 5 minutes, and then dried at 130°C for 10 minutes. The thickness of the dried adhesive layer was about 30 micrometers. A release liner shown in Table 9 was applied onto this adhesive layer to obtain adhesive tapes of Examples 40 and 41 and Comparative Examples 7 to 9.

[0214] Peel Strength Test The surface of the polyester film substrate (COSMOSHINE (trade name) A4100) of each adhesive tape prepared as described above was adhered to a SUS panel via double-sided tape. The peel strength was measured when the release liner was peeled off in a 180 degree direction at a peeling speed of 300 mm / min using a precision universal testing machine Autograph AG-X (Shimadzu Corporation, Kyoto City, Kyoto Prefecture, Japan). The measurement results are shown in Table 9. Here, the peel strength was measured using the adhesive tape after being left at room temperature (23±1°C, relative humidity 50±5%) for 24 hours and the adhesive tape after being left at 70°C for 3 days.

[0215] [Table 9]

[0216] The results in Table 9 show that in the pressure-sensitive adhesive tapes of Examples 38 and 39 and Examples 40 and 41, the peel strength of the release liner was stable both after being left at room temperature and after being left at 70°C, and did not change significantly.

[0217] Examples 42 and 49 and Comparative Examples 10 to 21 The heat stability of the release liners was evaluated using four commercially available silicone adhesive tapes: 3M (trade name) Polyimide-based Silicone Double-Sided Adhesive Tape 4390, 3M (trade name) Polyester Tape 8403, 3M (trade name) Heat-Resistant Polyimide Tape 5413, and Nitoflon (trade name) 903 UL.

[0218] For 3M (trade name) polyimide-based silicone double-sided adhesive tape 4390, first, one liner was peeled off, and the base material (COSMOSHINE (trade name) A 4100) was peeled off and applied onto the adhesive layer to obtain a single-sided adhesive tape. Next, this single-sided adhesive tape and 3M (trade name) polyester tape 8403, 3M (trade name) heat-resistant polyimide tape 5413, and Nitoflon (trade name) 903 UL, which are also silicone single-sided adhesive tapes, were applied onto the release liners shown in Tables 10 to 13, respectively, to obtain adhesive tapes of Examples 42 to 49 and Comparative Examples 10 to 21. Here, the silicone adhesive was applied to the release liner by pressing the silicone adhesive surface with a rubber roll having a weight of 5 kg back and forth to attach it to the release liner, and then leaving the laminate at room temperature (23±2°C, relative humidity 50±5%) for 24 hours.

[0219] This pressure-sensitive adhesive tape was subjected to the peel strength test in the same manner as in Example 38, and the measurement results are shown in Tables 10 to 13. Here, the peel strength was measured using the pressure-sensitive adhesive tape left at room temperature for 24 hours, the pressure-sensitive adhesive tape left at 100°C for 12 hours, and the pressure-sensitive adhesive tape left at 120°C for 1 hour.

[0220] [Table 10]

[0221] [Table 11]

[0222] [Table 12]

[0223] [Table 13]

[0224] The results in Tables 10 to 13 show that the pressure-sensitive adhesive tapes of Examples 42 to 49 had extremely high heat resistance stability. On the other hand, all of the commercially available release liners shown as comparative examples provided a heavy peel force depending on the environment.

[0225] Examples 50 to 57 As in Examples 42 to 49, the heat resistance stability of release liners 13 and 14 was evaluated using four commercially available silicone pressure-sensitive adhesive tapes. In the same manner as in Examples 42 to 49, release liners 13 and 14 were applied to the silicone adhesive surface of each of the commercially available silicone pressure-sensitive adhesive tapes shown in Tables 13 to 16 to obtain the pressure-sensitive adhesive tapes of Examples 50 to 57.

[0226] This pressure-sensitive adhesive tape was subjected to the peel strength test in the same manner as in Example 38, and the measurement results are shown in Tables 14 to 17. Here, the peel strength was measured using the pressure-sensitive adhesive tape left at room temperature for 24 hours and the pressure-sensitive adhesive tape left at 70°C for 3 days.

[0227] [Table 14]

[0228] [Table 15]

[0229] [Table 16]

[0230] [Table 17]

[0231] The results in Tables 14 to 17 show that the pressure-sensitive adhesive tapes of Examples 50 to 57 had stable peel strength even when using a PCK substrate, and had stable peel strength even at high temperatures.

[0232] It will be apparent to those skilled in the art that various modifications can be made to the above-described embodiments and examples without departing from the basic principles of the present invention. In addition, it will be apparent to those skilled in the art that various improvements and modifications can be made without departing from the spirit and scope of the present invention.

[0233] Explanation of symbols 100 Laminate 101 Release liner (first release liner) 103 Silicone adhesive layer 105 Second release liner 200 rolls 201 Release Liner 203 Silicone adhesive layer

Claims

1. A release liner for a silicone pressure sensitive adhesive layer, comprising: A substrate; a release layer on at least one side of the substrate; The release layer comprises a poly(meth)acrylic ester, the poly(meth)acrylic ester being a polymer of a polymerizable component that includes an alkyl (meth)acrylate monomer having a branched alkyl group having 8 or more carbon atoms.

2. 2. The release liner of claim 1, wherein the polymerizable component contains 40% by weight or more of an alkyl (meth)acrylate monomer having a branched alkyl group having 8 or more carbon atoms based on the total amount of alkyl (meth)acrylate monomer components.

3. 3. The release liner of claim 1 or 2, wherein the polymerizable component comprises an alkyl (meth)acrylate monomer having a linear alkyl group.

4. The release liner of claim 1 , wherein the polymerizable component comprises a (meth)acrylate monomer having a radiation-active group in a side chain.

5. The release liner of claim 1 , wherein the substrate comprises a white film.

6. A laminate comprising the release liner of claim 1 and a silicone adhesive layer disposed on the release layer of the release liner.

7. 7. The laminate according to claim 6, wherein a peel strength of the silicone pressure-sensitive adhesive layer to the release layer of the release liner is 10 N / 25 mm or less.

8. A release liner according to claim 1; A silicone adhesive layer; and a second release liner, in that order.

9. The release liner of claim 1 having a release layer on both sides thereof; and a silicone pressure sensitive adhesive layer.

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