Curable composition and use thereof

Abstract

The present disclosure provides a curable composition and a use thereof. The curable composition comprises: (A) a block copolymer which comprises a resinous block X including an M unit of RA aRB (3-a)SiO1 / 2 (RA is a monovalent organic group including an alkenyl group, RB is a monovalent organic group including no alkenyl group, and a is an integer of 0-3) and a Q unit and a chain block Y including a D unit of RC bRD (2-b)SiO2 / 2 (RC is a monovalent organic group including an alkenyl group, RD is a monovalent organic group including no alkenyl group, and b is an integer of 0-2) and which has at least one alkenyl group per molecule on average; (B) an organohydrogensiloxane having a (meth)acryloyl group and Si-H; (C) a hydrosilylation catalyst; and (D) a radical polymerization initiator.

Description

Curable compositions and their uses

[0001] This disclosure relates to a curable composition and its uses.

[0002] This section provides background information related to this disclosure, which is not necessarily prior art. Curable compositions containing organopolysiloxanes are widely used in the manufacture of semiconductor wafers, electronic and electrical devices such as smartphones and tablet PCs, and display devices such as displays, because they have superior electrical insulation, heat resistance, cold resistance, adhesion, and transparency compared to acrylic and rubber-based pressure-sensitive adhesive compositions. For example, in the processing of semiconductor wafers, a laminate comprising an adhesive layer and a substrate is sometimes temporarily attached (fixed) to a component to be adhered to, and then peeled off the laminate from the component as the work progresses. Curable compositions containing organopolysiloxanes have conventionally been used as adhesives to form the adhesive layer in the laminate used in this operation. For example, Patent Document 1 proposes a curable composition that can form an adhesive layer that exhibits initial adhesive strength sufficient to temporarily fix to a component to be adhered to, while its adhesive strength decreases upon irradiation with high-energy rays, allowing it to be peeled off from the component.

[0003] International Publication No. 2023 / 120356

[0004] The various manufacturing processes for semiconductor wafers and the like described above are often carried out under high-temperature conditions. For example, in the process of attaching a metal layer or electronic circuits to the back surface of a semiconductor wafer after grinding, it may be exposed to high-temperature conditions of 200°C to 300°C. Due to the effects of such high temperatures, the adhesive layer described above deteriorates, and when the laminate containing the adhesive layer is peeled off from the material, a phenomenon occurs in which a portion of the deteriorated adhesive layer remains on the surface of the material (hereinafter, this phenomenon will be referred to as "adhesive residue").

[0005] This disclosure provides curable compositions and their applications. In some embodiments, this disclosure provides curable compositions that exhibit good initial tackiness, but whose tackiness may decrease upon irradiation with high-energy rays, and which can form cured products that do not leave adhesive residue.

[0006] In a first aspect, a curable composition is disclosed. The curable composition according to the embodiments disclosed herein comprises the following components (A) to (D): (A) R Ａ a R Ｂ （３－ａ） SiO 1 / 2 (R Ａ is a monovalent organic group containing an alkenyl group, R Ｂ is a monovalent organic group not containing an alkenyl group, and a is an integer of 0 or more and 3 or less.) and a resinous block X containing a Q unit, and R Ｃ ｂ R Ｄ （２－ｂ） SiO 2 / 2 (R Ｃ is a monovalent organic group containing an alkenyl group, R Ｄ is a monovalent organic group not containing an alkenyl group, and b is an integer of 0 or more and 2 or less.) and a chain block Y containing a D unit, and an organopolysiloxane block copolymer having at least one alkenyl group on average in one molecule, (B) an organohydrosiloxane having at least one (meth)acryloyl group and at least one silicon-bonded hydrogen atom in one molecule, (C) a hydrosilylation reaction catalyst, and (D) a radical polymerization initiator.

[0007] In a second aspect, a cured product is disclosed. The cured product according to the embodiments disclosed herein can be obtained by curing the curable composition which is the first aspect of the present disclosure. In a third aspect, a laminate is disclosed. The laminate according to the embodiments disclosed herein comprises a layer made of the cured product which is the second aspect of the present disclosure and a substrate. In a fourth aspect, a method for producing a laminate is disclosed. The method for producing a laminate according to the embodiments disclosed herein comprises a step of applying the curable composition which is the first aspect of the present disclosure onto a substrate, and a step of heating and curing the curable composition applied onto the substrate. These and other embodiments are described in detail below.

[0008] This disclosure provides curable compositions and their applications. In some embodiments, this disclosure provides curable compositions that exhibit good initial tackiness, but whose tackiness decreases upon irradiation with high-energy rays, and which can form cured products that do not leave adhesive residue.

[0009] Unless otherwise stated, unless implicitly stated in the context, or unless customary in the art, all "parts" and "%" are based on weight, all temperatures are in "°C", and all test methods are current as of the filing date of this disclosure. The term "M unit" means a siloxane unit in which three organic groups are bonded to a silicon atom and one oxygen atom is bonded to "R ３ SiO １／２ It is expressed as (R represents an organic group. The same applies below.) The term "D unit" refers to a siloxane unit in which two organic groups and two oxygen atoms are bonded to a silicon atom, and "R ２ SiO ２／２ It is expressed as ". The term "T unit" refers to a siloxane unit in which one organic group is bonded to a silicon atom and three oxygen atoms are bonded to it, and is expressed as "RSio ３／２ It is expressed as ". The term "Q unit" refers to a siloxane unit in which no organic group is bonded to the silicon atom, but four oxygen atoms are bonded to it, and is expressed as "SiO ４／２ The term "(meth)acryloyl" means acryloyl and / or methacryloyl. In this technical field, "(meth)acryloyl" is sometimes referred to as "(meth)acrylic". The term "acryloyl" is CH ２ = CH-C(=O)- refers to a structure represented by this CH-C(=O)-, and / or a structure in which at least one hydrogen atom of this structure is substituted with any group. The term "methacryloyl" refers to CH ２ = C(CH ３This refers to a structure represented as )-C(=O)-, and / or a structure in which at least one hydrogen atom of said structure is substituted with any group. The term "(meth)acrylate" means acrylate and / or methacrylate. The term "silicon-bonded hydrogen atom" means a hydrogen atom (Si-H) directly bonded to a silicon atom. The term "radical polymerization initiator" means a compound that can initiate radical polymerization by irradiation with high-energy rays, such as light (e.g., ultraviolet (UV), visible light, gamma rays, X-rays), alpha rays, electron beams, etc. The chemical structure of organopolysiloxanes is standard １ H, １３ C, and ２９ It can be determined by Si nuclear magnetic resonance (NMR) analysis. "Plasticity" refers to the plasticity measured according to the method specified in JIS K6249 (the thickness when a 4.2g spherical sample is subjected to a load of 1kgf for 3 minutes at 25°C is read to the nearest 1 / 100 mm, and this value is multiplied by 100). The term "raw rubber" means that the plasticity of polymers such as organopolysiloxanes is between 50 and 200. "Weight-average molecular weight" and "number-average molecular weight" refer to the polystyrene equivalent values ​​measured by gel permeation chromatography using toluene as the developing solvent. "Viscosity" refers to the value measured at 25°C using a B-type viscometer in accordance with the provisions of JIS K 7117-1:1999. The "degree of siloxane polymerization" (the average number of siloxane units contained in one organopolysiloxane molecule) can be derived from the chemical structure and number-average molecular weight of the organopolysiloxane, which can be identified by the method described above.

[0010] (Curable Composition) The curable composition of this disclosure comprises (A) a block copolymer, (B) an organohydrogensiloxane, (C) a hydrosilylation reaction catalyst, and (D) a radical polymerization initiator. The curable composition may also contain components other than components (A) to (D) (hereinafter referred to as "other components").

[0011] <(A) Block Copolymer> The (A) block copolymer is an organopolysiloxane block copolymer having a resinous block X containing M units and Q units, and a chain-like block Y containing D units. The (A) block copolymer has an average of one or more alkenyl groups per molecule. The curable composition may contain only one type of (A) block copolymer, or two or more types. In some embodiments, the alkenyl group contained in the (A) block copolymer may be an alkenyl group having 2 to 20 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms. Non-limiting examples of alkenyl groups contained in the (A) block copolymer include vinyl groups, allyl groups, isopropenyl groups, butenyl groups, isobutenyl groups, pentenyl groups, hexenyl groups, heptenyl groups, octenyl groups, and combinations thereof. In some embodiments, the alkenyl group may be at least one of a vinyl group and a hexenyl group, or it may be a vinyl group. Furthermore, the alkenyl group may have at least one hydrogen atom substituted with any chemical structure.

[0012] The M units contained in the resinous block X are "R Ａ a R Ｂ （３－ａ） SiO 1 / 2 This is represented as follows: The resinous block X may have only one type of M unit, or it may have two or more types. Ａ R is a monovalent organic group containing an alkenyl group, and this organic group is directly bonded to a silicon atom. Ａ The monovalent organic group containing an alkenyl group that constitutes the above-mentioned alkenyl group may be the alkenyl group itself, or it may be a group formed by combining the above-mentioned alkenyl group with a structure other than an alkenyl group (for example, a (meth)acryloyl group). In some embodiments, the monovalent organic group containing an alkenyl group may be an alkenyl group, or an alkenyl group having 2 to 20 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms, or at least one of a vinyl group and a hexenyl group, or a vinyl group. ＢThis is a monovalent organic group that does not contain an alkenyl group, and this organic group is directly bonded to a silicon atom. Ｂ Non-limiting examples of monovalent organic groups that do not contain alkenyl groups that constitute the group include alkyl groups, aryl groups, aralkyl groups, hydroxyl groups, and groups in which at least some of the hydrogen atoms of these groups are substituted with halogen atoms, as well as combinations thereof. In some embodiments, R Ｂ This may be an alkyl group, a phenyl group, an aralkyl group, or a combination thereof, or an alkyl group having 1 to 8 carbon atoms, or a methyl group. The subscript a is R included in the M unit. Ａ This represents the number and is an integer between 0 and 3. In some embodiments, a may be between 0 and 2, or 0 or 1, or 1 and 3, or 1 or 2, or 1 or 0. Note that the above R Ａ , R Ｂ , and a are independent of each other in multiple M units contained in the resinous block X, and may be the same in all of the multiple M units, or they may be different in each M unit.

[0013] The resinous block X is R as described above. Ａ a R Ｂ （３－ａ） SiO 1 / 2 The unit M is represented by SiO 4 / 2In addition to the Q units represented by , T units and D units may optionally be included. In some embodiments, the proportion of M units in the total siloxane units constituting the resinous block X (hereinafter referred to as "proportion of M units in resinous block X") may be 10 mol% or more, or 20 mol% or more, or 30 mol% or more, or 40 mol% or more, with the total number of siloxane units in resinous block X being 100 mol%, while at the same time, the proportion of M units in resinous block X may be 70 mol% or less, or 60 mol% or less, or 50 mol% or less. In some embodiments, the proportion of Q units in the total siloxane units constituting the resinous block X (hereinafter referred to as "the proportion of Q units in the resinous block X") may be 20 mol% or more, 30 mol% or more, 40 mol% or more, or 50 mol% or more, with the total number of siloxane units in the resinous block X being 100 mol%, while simultaneously, the proportion of Q units in the resinous block X may be 80 mol% or less, 70 mol% or less, or 60 mol% or less. In some embodiments, the sum of the proportion of M units and Q units in the total siloxane units constituting the resinous block X may be 60 mol% or more and 100 mol% or 70 mol% or more and 100 mol% or 80 mol% or more and 100 mol% or 90 mol% or more and 100 mol% or 95 mol% or more and 100 mol% or 98 mol% or more and 100 mol% or 100 mol% (i.e., the resinous block X does not contain either D units or T units).

[0014] In some embodiments, the ratio of moles of M units in the resinous block X to moles of Q units in the resinous block X (M units / Q units) may be 0.5 or more and 2.0 or less, or 0.6 or more and 1.7 or less, or 0.7 or more and 1.3 or less, or 0.7 or more and 0.9 or less.

[0015] The chain-like block Y is R as described above. Ｃ ｂ R Ｄ （２－ｂ） SiO 2 / 2Includes the D unit represented by R. Ｃ R is a monovalent organic group containing an alkenyl group, and this organic group is directly bonded to a silicon atom. Ｃ The monovalent organic group containing an alkenyl group that constitutes the above-mentioned alkenyl group may be the alkenyl group itself, or it may be a group formed by combining the above-mentioned alkenyl group with a structure other than an alkenyl group (for example, a (meth)acryloyl group). In some embodiments, the monovalent organic group containing an alkenyl group may be an alkenyl group, or an alkenyl group having 2 to 20 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms, or at least one of a vinyl group and a hexenyl group, or a vinyl group. Ｄ This is a monovalent organic group that does not contain an alkenyl group, and this organic group is directly bonded to a silicon atom. Ｄ Non-limiting examples of monovalent organic groups that do not contain alkenyl groups that constitute the group include alkyl groups, aryl groups, aralkyl groups, hydroxyl groups, and groups in which at least some of the hydrogen atoms of these groups are substituted with halogen atoms, as well as combinations thereof. In some embodiments, R Ｄ This may be an alkyl group, a phenyl group, an aralkyl group, or a combination thereof, or an alkyl group having 1 to 8 carbon atoms, or a methyl group.

[0016] The chain-like block Y contains at least the D units described above, and in some embodiments, has an M unit at its end. The chain-like block Y may also optionally contain at least one of the T units and the Q units. In some embodiments, the sum of the proportion of T units and Q units in the total siloxane units constituting the chain-like block Y may be 0 mol% to 20 mol%, or 0 mol% to 10 mol%, or 0 mol% to 5 mol%, or 0 mol% to 1 mol%, or 0 mol% to 0.5 mol%, or 0 mol% to 0.1 mol%, or 0 mol% (i.e., the chain-like block Y does not contain either T units or Q units), with the total number of siloxane units in the chain-like block Y being 100 mol%. In some embodiments, the chain-like block Y may have a structure in which multiple D units are linked together, connected to a resinous block at one end, and having an M unit at the other end (referred to as a "linear structure"). In some embodiments, the average number of repeating D units in the chain block Y may be 1,000 or more, or 2,000 or more. At the same time, the average number of repeating D units in the chain block Y may be 6,000 or less, or 3,000 or less. In some embodiments, the number-average molecular weight of the chain block Y may be 100,000 or more, or 200,000 or more. At the same time, the number-average molecular weight of the chain block Y may be 600,000 or less, or 300,000 or less.

[0017] The chain-like block Y may be bonded to the resin-like block X via any structure, or it may be directly bonded (linked) to the resin-like block X. In some embodiments, the (A) block copolymer may have a structure in which the chain-like block Y having the linear structure described above is linked to the resin-like block X (referred to as the "resin-linear structure"). When the chain-like block Y has a structure linked to the resin-like block X, the resin-like block X and the chain-like block Y may be linked by at least one of a siloxane bond and a sylalkylene bond, or they may be linked by a siloxane bond.

[0018] In some embodiments, the ratio of the weight of the resinous block X to the weight of the chain-like block Y (hereinafter sometimes abbreviated as "block X / block Y ratio") may be 0.60 or more, or 0.70 or more, or 0.80 or more, or 0.90 or more. At the same time, the block X / block Y ratio may be 1.50 or less, or 1.40 or less, or 1.30 or less, or 1.25 or less.

[0019] In some embodiments, the degree of siloxane polymerization of the (A) block copolymer may be 10 or more, or 25 or more. At the same time, the degree of siloxane polymerization of the (A) block copolymer may be 10,000 or less, or 2,000 or less. If the degree of siloxane polymerization of the (A) block copolymer is within the above range, the coatability of the curable composition is sufficiently ensured.

[0020] Here, (A) the block copolymer must have at least one alkenyl group on average per molecule. The alkenyl groups in (A) the block copolymer can react with silicon-bonded hydrogen atoms of other compounds (e.g., (B) organohydrogensiloxane) in the presence of (C) the hydrosilylation reaction catalyst. Furthermore, the alkenyl groups in (A) the block copolymer can contribute to the curing of the curable composition by reacting with other alkenyl groups (e.g., other alkenyl groups of (A) the block copolymer, or alkenyl groups that constitute part of the (meth)acryloyl group derived from (B) organohydrogensiloxane) through addition polymerization initiated by (D) the radical polymerization initiator.

[0021] In some embodiments, the average number of alkenyl groups contained in one molecule of (A) block copolymer may be 1 to 200, or 30 to 150, or 60 to 100. The location of the alkenyl groups in (A) block copolymer is not particularly limited. For example, (A) block copolymer may be any of the following i) to iii): i) resinous block X has alkenyl groups and chain block Y does not have alkenyl groups, ii) resinous block X does not have alkenyl groups and chain block Y has alkenyl groups, and iii) both resinous block X and chain block Y have alkenyl groups. In some embodiments, from the viewpoint of exhibiting high initial adhesion in the cured product while sufficiently reducing the adhesion by irradiation with high-energy rays, (A) block copolymer may have the structure described in i) or iii) above, or the structure described in iii) above.

[0022] In some embodiments, the (A) block copolymer may not have (meth)acryloyl groups.

[0023] (A) The method for preparing the block copolymer is not particularly limited. For example, it can be obtained by linking a precursor of resinous block X and a precursor of chain-like block Y by a condensation reaction or a hydrosilylation reaction. By employing such a method, a block copolymer (A) having a structure in which chain-like block Y is linked to resinous block X by the siloxane bond or sylalkylene bond described above can be prepared.

[0024] <(B) Organohydrogensiloxane> (B) Organohydrogensiloxane has one or more (meth)acryloyl groups and one or more silicon-bonded hydrogen atoms in one molecule. The silicon-bonded hydrogen atoms of (B) Organohydrogensiloxane undergo a hydrosilylation reaction with the alkenyl groups of (A) Block Copolymer upon heating in the presence of (C) Hydrosilylation Reaction Catalyst. This reaction introduces structures derived from (B) Organohydrogensiloxane (particularly (meth)acryloyl groups) into (A) Block Copolymer. In (A) Block Copolymer into which structures derived from (B) Organohydrogensiloxane have been introduced, the (meth)acryloyl groups can act as reaction sites for addition polymerization by irradiation with high-energy rays, contributing to an increase in the crosslinking density of the cured product. The curable composition may contain only one type of (B) organohydrogensiloxane, or it may contain two or more types.

[0025] In some embodiments, the number of (meth)acryloyl groups in one molecule of (B) organohydrogensiloxane may be one to five, one to three, or one. In some embodiments, the number of silicon-bonded hydrogen atoms in one molecule of (B) organohydrogensiloxane may be one to ten, one to six, one to four, two to ten, two to six, or two to four.

[0026] (B) Non-limiting examples of organohydrogensiloxanes include compounds represented by the following formula (1), compounds represented by the following formula (2), and combinations thereof.

[0027] R １ R independently represents a hydrogen atom, a methyl group, or a phenyl group. In some embodiments, R １ These may be hydrogen atoms or methyl groups, independently of each other. ２ R independently represents an alkyl group or an aryl group. In some embodiments, R ２These may be alkyl groups having 1 to 6 carbon atoms, and may be methyl or ethyl groups, independently of each other. １ is a single bond or -(CH ２ ) ｍ - (where m is an integer between 1 and 3). In some embodiments, Z １ ha- (CH ２ ) ３ - That's fine too.

[0028] R ３ R independently represents a hydrogen atom, a methyl group, or a phenyl group. In some embodiments, R ３ These may be hydrogen atoms or methyl groups, independently of each other. ４ R independently represents an alkyl group or an aryl group. In some embodiments, R ４ These may be alkyl groups having 1 to 6 carbon atoms, and may be methyl or ethyl groups, independently of each other. ２ is a single bond or -(CH ２ ) ｎ - (where n is an integer between 1 and 3). In some embodiments, Z ２ ha- (CH ２ ) ３ - That's fine too.

[0029] In some embodiments, the amount of (B) organohydrogensiloxane contained in the curable composition may be 1.0 part by weight or more, 2.0 parts by weight or more, 3.0 parts by weight or more, 4.0 parts by weight or more, or 5.0 parts by weight or more per 100 parts by weight of (A) block copolymer. At the same time, the amount of (B) organohydrogensiloxane contained in the curable composition may be 30.0 parts by weight or less, 20.0 parts by weight or less, 10.0 parts by weight or less, 7.0 parts by weight or less, or 5.0 parts by weight or less per 100 parts by weight of (A) block copolymer. If the content of (B) organohydrogensiloxane in the curable composition is within the above range, the increase in crosslinking density of the cured product by irradiation with high-energy rays can be further promoted, and the adhesive strength of the cured product can be further reduced. As a result, peeling of the cured product from the object to which it is attached can be further reduced, and adhesive residue can be further suppressed.

[0030] <(C) Hydrosilylation Reaction Catalyst> (C) Hydrosilylation reaction catalyst is a component that promotes the hydrosilylation reaction between alkenyl groups and silicon-bonded hydrogen atoms in the curable composition upon heating. In some embodiments, the cured product obtained by heating the curable composition and curing it by the hydrosilylation reaction can exhibit sufficient initial adhesion to the object to be adhered. The curable composition may contain only one type of (C) hydrosilylation reaction catalyst, or it may contain two or more types.

[0031] Non-limiting examples of hydrosilylation reaction catalysts include platinum-based catalysts, rhodium-based catalysts, palladium-based catalysts, iridium-based catalysts, iron-based catalysts, ruthenium-based catalysts, iron / cobalt-based catalysts, and combinations thereof. Among these, platinum-based catalysts are preferred because they can significantly accelerate the curing of the curable composition. In some embodiments, the platinum-based catalyst may be a platinum-alkenylsiloxane complex. Non-limiting examples of alkenylsiloxanes that can constitute a platinum-alkenylsiloxane complex include 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, dimethylsiloxane polymers with vinyldimethylsiloxy groups sealed at both ends; compounds in which at least some of the methyl groups of these alkenylsiloxanes are substituted with groups selected from the group consisting of nitriles, amides, dioxolanes, and sulfolanes, ethyl groups, phenyl groups, etc.; compounds in which at least some of the vinyl groups of these alkenylsiloxanes are substituted with allyl groups, hexenyl groups, etc.; and combinations thereof. In some embodiments, the hydrosilylation catalyst may be added in the form of an alkenylsiloxane solution. In some embodiments, the hydrosilylation catalyst may be a catalyst dispersed in a thermoplastic resin such as a silicone resin, polycarbonate resin, or acrylic resin, or a catalyst encapsulated in these resins.

[0032] The amount of (C) hydrosilylation catalyst contained in the curable composition is not particularly limited. In some embodiments, the amount of (C) hydrosilylation catalyst contained in the curable composition may be such that the weight of platinum is 0.1 ppm to 200 ppm, or 0.1 ppm to 150 ppm, or 0.1 ppm to 100 ppm, or 0.1 ppm to 50 ppm, relative to the total weight of solids in the curable composition. The "solids" in the curable composition refer to components that can form a cured product when the curable composition is subjected to a curing reaction, and do not include volatile components such as organic solvents that volatilize during heat curing.

[0033] <(D) Radical polymerization initiator> (D) The radical polymerization initiator is a component that can initiate an addition reaction between alkenyl groups (and / or (meth)acryloyl groups containing alkenyl groups) in the curable composition by irradiation with high-energy rays. In some embodiments, the curing of a cured product having sufficient initial tackiness obtained by heating the curable composition can be further advanced by irradiating it with high-energy rays. The cured product, which has been further cured in this way, has reduced tackiness and becomes easier to peel off from the object to which it is attached.

[0034] (D) Non-limiting examples of radical polymerization initiators include: α-ketol compounds such as 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, and 1-hydroxycyclohexylphenyl ketone; acetophenone compounds such as methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, and 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane-1; benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether; ketal compounds such as benzyldimethyl ketal; aromatic sulfonyl chloride compounds such as 2-naphthalenesulfonyl chloride; Examples include photoactive oxime compounds such as 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime; benzophenone compounds such as benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone; thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone; camphorquinone; halogenated ketones; acylphosphinoxides; acylphosphonates, and combinations thereof.

[0035] In some embodiments, the amount of (D) radical polymerization initiator contained in the curable composition may be 0.1 parts by weight or more, or 0.5 parts by weight or more, or 1.0 part by weight or more, per 100 parts by weight of (A) block copolymer. At the same time, the amount of (D) radical polymerization initiator contained in the curable composition may be 10 parts by weight or less, or 7.0 parts by weight or less, or 5.0 parts by weight or less, per 100 parts by weight of (A) block copolymer.

[0036] <Other Components> Other components that the curable composition may optionally contain are not particularly limited and include, for example, (E) organopolysiloxane resin, (F) organohydrogensiloxane, (G) acrylic monomer, (H) hydrosilylation reaction inhibitor, (I) siloxane component, and organic solvent, as detailed below. These can be used individually or in combination of two or more.

[0037] (E) The organopolysiloxane resin contains M units and Q units, has at least one alkenyl group on average per molecule, and the ratio of moles of M units to moles of Q units (M units / Q units) is 0.5 or more and 2.0 or less. By including the (E) organopolysiloxane resin having alkenyl groups in the curable composition, the hardness and initial tackiness of the cured product can be increased. Note that the (E) organopolysiloxane resin does not have chain-like blocks containing D units, and is a component that differs from the (A) block copolymer in at least this respect. In some embodiments, the ratio of moles of M units to moles of Q units in the (E) organopolysiloxane resin may be 0.6 or more and 1.8 or less, or 0.7 or more and 1.3 or less. In some embodiments, the sum of the proportion of M units and Q units in the total siloxane units constituting the (E) organopolysiloxane resin may be 80 mol% or more and 100 mol% or 90 mol% or more and 100 mol% or 95 mol% or more and 100 mol% or 98 mol% or more and 100 mol% or 100 mol% (i.e., the (E) organopolysiloxane resin contains neither D units nor T units), with the total number of siloxane units in the (E) organopolysiloxane resin being 100 mol%. In some embodiments, the weight-average molecular weight of the (E) organopolysiloxane resin may be 1,000 or more and 30,000 or less, or 2,000 or more and 20,000 or less. In some embodiments, the amount of (E) organopolysiloxane resin contained in the curable composition may be 4.0 parts by weight or more, or 8.0 parts by weight or more, or 12.0 parts by weight or more, or 15.0 parts by weight or more, per 100 parts by weight of (A) block copolymer. At the same time, the amount of (E) organopolysiloxane resin contained in the curable composition may be 40.0 parts by weight or less, or 35.0 parts by weight or less, or 30.0 parts by weight or less, per 100 parts by weight of (A) block copolymer.

[0038] (F) Organohydrogensiloxane does not have a (meth)acryloyl group and has, on average, at least one silicon-bonded hydrogen atom per molecule. The inclusion of (F) organohydrogensiloxane in the curable composition makes it easier to adjust the initial tackiness of the cured layer. In some embodiments, (F) organohydrogensiloxane may be a compound that does not have a (meth)acryloyl group and has, on average, at least two silicon-bonded hydrogen atoms per molecule. In some embodiments, the amount of (F) organohydrogensiloxane contained in the curable composition may be 0.4 parts by weight or more, or 0.8 parts by weight or more, or 1.2 parts by weight or more, per 100 parts by weight of (A) block copolymer. At the same time, the amount of (F) organohydrogensiloxane contained in the curable composition may be 20.0 parts by weight or less, or 15.0 parts by weight or less, or 10.0 parts by weight or less, per 100 parts by weight of (A) block copolymer.

[0039] (G) Acrylic monomer does not have silicon-bonded hydrogen atoms and has two or more (meth)acryloyl groups in one molecule. The inclusion of (G) acrylic monomer in the curable composition can further promote the increase in crosslinking density of the cured product by irradiation with high-energy rays, and further reduce the tackiness of the cured product. In some embodiments, (G) acrylic monomer may be a compound that does not have siloxane bonds.(G) Non-limiting examples of acrylic monomers include trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, polyoxyethylene-modified trimethylolpropane tri(meth)acrylate, polyoxypropylene-modified trimethylolpropane tri(meth)acrylate, polyoxyethylene / polyoxypropylene-modified trimethylolpropane tri(meth)acrylate, dimethylol tricyclodecane di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, phenylethylene glycol di(meth)acrylate, poly(ethylene glycol) di(meth)acrylate, poly(propylene glycol) di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate Acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,3-adamantanedimethanol di(meth)acrylate, o-xylylenedi(meth)acrylate, m-xylylenedi(meth)acrylate, p-xylylenedi(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, tris(acryloyloxy)isocyanurate, bis(hydroxymethyl)tricyclodecanedi(meth)acrylate Examples include (T) acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, polyoxyethylene-modified 2,2-bis(4-((meth)acrylooxy)phenyl)propane, polyoxypropylene-modified 2,2-bis(4-((meth)acrylooxy)phenyl)propane, and polyoxyethylene / polyoxypropylene-modified 2,2-bis(4-((meth)acrylooxy)phenyl)propane, as well as combinations thereof. In some embodiments, the amount of (G) acrylic monomer contained in the curable composition may be 0.1 parts by weight or more, or 0.2 parts by weight or more, per 100 parts by weight of (A) block copolymer.At the same time, the amount of (G) acrylic monomer contained in the curable composition may be 2.0 parts by weight or less, or 1.0 part by weight or less, per 100 parts by weight of (A) block copolymer.

[0040] (H) Hydrosilylation inhibitors are substances added to control the reaction rate between silicon-bonded hydrogen atoms and alkenyl groups in a curable composition. (H) Non-limiting examples of hydrosilylation inhibitors include: acetylene alcohols, e.g., methylbutynol, ethinylcyclohexanol, dimethylhexinol, and 3,5-dimethyl-1-hexyn-3-ol, 1-butyn-3-ol, 1-propyne-3-ol, 2-methyl-3-butyn-2-ol, 3-methyl-1-butyn-3-ol, 3-methyl-1-pentin-3-ol, 3-phenyl-1-butyn-3-ol, 4-ethyl-1-octin-3-ol, 3,5-dimethyl-1-hexyn-3-ol, and 1-ethynyl-1-cyclohexanol; olefinic siloxanes, e.g., 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, and 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane; En-yne compounds, such as 3-methyl-3-penten-1-yne and 3,5-dimethyl-3-hexen-1-yne; triazoles such as benzotriazole; phosphine; mercaptan; hydrazine; amines, such as tetramethylethylenediamine, 3-dimethylamino-1-propyne, n-methylpropargylamine, propargylamine, and 1-ethynylcyclohexylamine; fumarate esters, such as dialkyl fumarate (e.g., diethyl fumarate), dialkyl fumarate (e.g., diallyl fumarate), and dialkoxyalkyl fumarate; maleate esters, such as dialkyl maleate (e.g., diethyl maleate), dialkyl maleate (e.g., diallyl maleate); nitriles; ethers; carbon monoxide; alkenes, such as cyclooctadiene and divinyltetramethyldisiloxane; alcohols (excluding the acetylene alcohols mentioned above), such as benzyl alcohol; and combinations thereof. In some embodiments, the (H) hydrosilylation inhibitor may be a compound having two or more aliphatic carbon-carbon multiple bonds, such as diallyl maleate.In some embodiments, the amount of (H) hydrosilylation inhibitor contained in the curable composition may be 0.01 parts by weight or more, or 0.03 parts by weight or more, per 100 parts by weight of (A) block copolymer. At the same time, the amount of (H) hydrosilylation inhibitor contained in the curable composition may be 1.0 part by weight or less, or 0.5 parts by weight or less, per 100 parts by weight of (A) block copolymer.

[0041] The curable composition may or may not contain (I) a siloxane component that does not contain either a carbon-carbon multiple bond or a silicon atom bonded hydrogen atom in its molecule. Non-limiting examples of the (I) siloxane component include polydialkylsiloxanes (such as polydimethylsiloxane), MQ resins, condensates thereof, and combinations thereof. In some embodiments, the curable composition may contain (I) siloxane component in an amount of 0 parts by weight or more and less than 1.0 part by weight, or 0 parts by weight or more and less than 0.5 parts by weight, or 0 parts by weight or more and less than 0.1 parts by weight per 100 parts by weight of (A) block copolymer. By reducing the content of (I) siloxane component, peeling of the cured product from the adherend becomes even easier, and adhesive residue can be further suppressed.

[0042] Furthermore, the curable composition may contain an organic solvent as needed to adjust its viscosity and ensure its applicability. The type of organic solvent is not particularly limited as long as it is a compound that can dissolve all or some of the components of the composition, but those with a boiling point of 80°C or higher and 200°C or lower at 1 atmosphere are preferably used. Non-limited examples of organic solvents include aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, ester solvents, alcohol solvents, ether solvents, chlorinated aliphatic hydrocarbon solvents, solvent volatile oils, and combinations thereof. In some embodiments, the organic solvent may be an aromatic hydrocarbon solvent or toluene.

[0043] In some embodiments, the amount of organic solvent contained in the curable composition may be 0% to 80% by weight, or 0% to 60% by weight, or 20% to 80% by weight, or 20% to 60% by weight, based on 100% by weight of the total weight of the curable composition.

[0044] In addition to the components mentioned above, the curable composition may also contain components such as photosensitizers, adhesion promoters, antioxidants, light stabilizers, flame retardants, antistatic agents, pigments, dyes, and inorganic fine particles (reinforcing fillers, dielectric fillers, conductive fillers, thermally conductive fillers). These can be used individually or in combination of two or more.

[0045] <Preparation of Curable Composition> The method for preparing the curable composition is not particularly limited, and it can be prepared by mixing at least the above-mentioned components (A) to (D) by a known method. In addition, in order to suppress unintended curing during preparation, the temperature when mixing the various components may be less than 100°C or less than 50°C.

[0046] In some embodiments, the curable composition of the present disclosure obtained as described above may have both heat-curable and high-energy ray-curable properties.

[0047] (Cured Products) The cured products of this disclosure are obtained by curing the curable composition of this disclosure as described above. Non-limiting examples of methods for curing the curable composition include curing by heating, curing by irradiation with high-energy rays, and combinations thereof. In some embodiments, the curable composition of this disclosure may first be cured by heating to obtain a cured product (hereinafter, this cured product may be referred to as a "semi-cured product"), and then the semi-cured product may be further cured by irradiation with high-energy rays. In such embodiments, curing by heating may be a hydrosilylation reaction between an alkenyl group and a silicon atom-bonded hydrogen atom, and curing by irradiation with high-energy rays may be an addition reaction between alkenyl groups. The semi-cured product after heating exhibits good initial adhesion, while its adhesion can be significantly reduced by irradiation with high-energy rays. A cured product with significantly reduced adhesion is easy to peel off from the object to be adhered to and is less likely to leave adhesive residue.

[0048] The optical properties of the cured product are not particularly limited and may be set appropriately according to its application. In some embodiments, the cured product may be transparent. For example, for a layer made of a cured product with a thickness of 100 μm, the transmittance of light at a wavelength of 450 nm may be 80% or more, or 90% or more, or 95% or more, with the value for air being 100%.

[0049] (Laminate) The laminate of this disclosure comprises a layer made of the cured product of this disclosure described above (hereinafter sometimes abbreviated as "cured product layer") and a substrate. The laminate may also have components other than the cured product layer and the substrate. The material of the substrate constituting the laminate is not particularly limited, and any material such as paper, metal, or resin can be selected depending on the application of the laminate. In some embodiments, the substrate may be made of resin. Non-limiting examples of resins constituting the substrate include polyester resins, polyolefin resins, polyvinyl alcohol, polyvinylidene chloride, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyamide, polyimide, celluloses, fluororesins, polyethers, polystyrene resins, and combinations thereof. The shape of the substrate is not particularly limited, and any shape can be selected depending on the application of the laminate. In some embodiments, the substrate may be in the form of a film or a sheet. The substrate may also have known treatments applied to its surface. Non-limiting examples of such treatments include peel-off coating treatment, primer treatment, corona treatment, etching treatment, plasma treatment, scratch prevention, stain prevention, fingerprint prevention, anti-glare, anti-reflective, anti-static, and combinations thereof. Peel-off coating treatments include treatment with a peeling agent and the formation of irregularities on the surface of the substrate. Non-limiting examples of peeling agents include silicone-based peeling agents, fluorine-based peeling agents, alkyd-based peeling agents, fluorosilicone-based peeling agents, and combinations thereof. In some embodiments, the thickness of the substrate may be 1 μm or more, or 5 μm or more, or 10 μm or more, or 20 μm or more. At the same time, the thickness of the substrate may be 10,000 μm or less, or 8,000 μm or less, or 5,000 μm or less, or 1,000 μm or less, or 900 μm or less, or 800 μm or less.

[0050] The cured layer of the laminate can be given any function depending on the application of the laminate. The cured layer can function, for example, as an adhesive layer, dielectric layer, conductive layer, heat dissipation layer, insulating layer, and / or reinforcing layer. In some embodiments, the cured layer of the laminate may be a layer made of semi-cured material. Such a layer made of semi-cured material has sufficient initial adhesion and can therefore function particularly well as an adhesive layer. The cured layer may be a single-layer or multi-layer structure. The cured layer may also have known treatments applied to its surface, similar to the substrate described above. In some embodiments, the thickness of the cured layer may be 1 μm or more, or 5 μm or more, or 10 μm or more, or 20 μm or more. At the same time, the thickness of the cured layer may be 10,000 μm or less, or 8,000 μm or less, or 5,000 μm or less, or 1,000 μm or less, or 900 μm or less, or 800 μm or less.

[0051] (Method for Manufacturing Laminates) The method for manufacturing the laminate of the present disclosure, comprising a substrate and a cured layer, is not particularly limited. In some embodiments, the method for manufacturing the laminate includes at least a step of applying the curable composition of the present disclosure described above onto a substrate (hereinafter sometimes abbreviated as the "coating step") and a step of heating and curing the curable composition applied onto the substrate (heating step). The method for manufacturing the laminate may also include steps other than the coating step and the heating step, for example, a step of irradiating the semi-cured material on the substrate obtained by the heating step with high-energy rays (hereinafter sometimes abbreviated as the "high-energy ray irradiation step").

[0052] In the coating process, a curable composition is applied to a substrate to form a coating film of the curable composition. Non-limiting examples of coating methods include gravure coating, offset coating, offset gravure, roll coating, reverse roll coating, air knife coating, curtain coating, and comma coating. The thickness of the coating film on the substrate can be appropriately set according to the desired thickness of the cured material layer.

[0053] In the heating step, the curable composition is cured by a hydrosilylation reaction caused by heating, forming a layer of semi-cured material on the substrate. The conditions for heating the curable composition (coating film) on the substrate are not particularly limited. The heating temperature may be, for example, 80°C to 200°C, or 90°C to 150°C. The heating time may be, for example, 0.5 minutes to 90 minutes. In the laminate obtained after the heating step, the semi-cured material exhibits good initial adhesion to the object to be adhered.

[0054] In some embodiments, a high-energy ray irradiation step may be performed after the heating step. In the high-energy ray irradiation step, the semi-cured material on the substrate is further cured by radical polymerization (addition polymerization) initiated by the irradiation of high-energy rays. The laminate obtained after the high-energy ray irradiation step has reduced adhesive strength of the cured layer, making it easy to peel from the object to which it is attached, and less likely to leave adhesive residue. The irradiation conditions for the high-energy rays are not particularly limited. The following description will focus on the use of ultraviolet light as the high-energy ray, but this disclosure is not limited thereto. Non-limiting examples of ultraviolet light sources include high-pressure mercury lamps, medium-pressure mercury lamps, Xe-Hg lamps, deep UV lamps, and combinations thereof. The wavelength of the ultraviolet light is not particularly limited, but may be 280 nm to 400 nm, or 300 nm to 400 nm. The amount of ultraviolet light irradiation is not particularly limited, but may be 100 mJ / cm². ２ 10,000mJ / cm or more ２ , or 1,000 mJ / cm ２ 5,000mJ / cm or more ２ That's fine.

[0055] The applications of the curable compositions, cured products, and laminates of the present disclosure (hereinafter, these may be collectively abbreviated as "curable compositions, etc.") are not particularly limited. As described above, the curable compositions of the present disclosure can exhibit initial tackiness upon heating and then reduce tackiness by subsequent irradiation with high-energy rays, and are therefore preferably used in applications where temporary fixing is performed followed by peeling. Non-limiting examples of such applications include adhesive tapes (e.g., adhesive tapes for semiconductor processing), protective films intended for attachment and removal, bandages, low-temperature supports, transfer films, labels, emblems, and decorative or explanatory markings. In some embodiments, the curable compositions, etc. of the present disclosure can also be used in the manufacture of automotive parts, toys, electronic circuits, keyboards, panels, displays, sensors, speakers, actuators, generators, and the like. In some embodiments, the curable compositions of the present disclosure can also be used as adhesives (e.g., pressure-sensitive adhesives).

[0056] The curable compositions of this disclosure will be further described below based on examples, but this disclosure is not limited to the following examples. In the following description, Me represents a "methyl group" and Vi represents a "vinyl group". Various measurements and evaluations were performed according to the following procedure.

[0057] <Initial Adhesion> The curable composition was applied to one surface of a polyamide film (Unitika Corporation's "Uniamide" registered trademark, thickness: 50 μm) as a substrate, such that the thickness of the cured adhesive layer was 20 μm (application step). The curable composition on the substrate was cured by heating at 100°C for 5 minutes (heating step), and the resulting laminate of the adhesive layer (cured layer) and the substrate was cut to a width of 25 mm. The cut laminate and a stainless steel plate (SUS plate, Paltec Corporation) to be adhered were bonded together using a roller so that the adhesive layer and the SUS plate were in contact, to form a test specimen. From the test specimen obtained by the above procedure, the SUS plate was peeled off using the 180° peel test method (tensile speed: 300 mm / min) in accordance with JIS Z 0237, and the measured adhesive force (gf / 25 mm) was defined as the initial adhesion. In this disclosure, a measured adhesive strength of 30 gf / 25 mm or more was considered to indicate good initial adhesive strength. <Adhesive strength after UV irradiation> Test specimens were prepared using the same procedure as for "initial adhesive strength" above. The obtained test specimens were irradiated with ultraviolet light at a wavelength of 365 nm from the polyamide film side using a UV-LED ultraviolet irradiation device (manufactured by JATEC) (high-energy ray irradiation process). The amount of ultraviolet irradiation (integrated light dose) was 2,000 mJ / cm². ２The procedure was as follows: After irradiation with ultraviolet light, the SUS plate was peeled off the test piece using the same procedure as for "initial adhesion," and the measured adhesion force (gf / 25mm) was defined as "adhesion force after UV irradiation." <Adhesion force after UV irradiation + high temperature exposure> The test piece was prepared using the same procedure as for "initial adhesion" above. Furthermore, the high-energy ray irradiation process was carried out using the same procedure as for "adhesion force after UV irradiation" above. After irradiation with ultraviolet light, the test piece was placed in an environment of 260°C for 10 minutes (high temperature exposure). After high temperature exposure, the SUS plate was peeled off the test piece using the same procedure as for "initial adhesion," and the measured adhesion force (gf / 25mm) was defined as "adhesion force after UV irradiation + high temperature exposure." <Adhesive residue> After measuring the "adhesion force after UV irradiation + high temperature exposure" above, the surface of the SUS plate was visually observed to check for the presence or absence of white adhesive residue. If no adhesive residue was observed, it was judged as "A," and if adhesive residue was observed, it was judged as "B." <Adhesion Ratio> The adhesion ratio was calculated using the following formula: Adhesion Ratio = (Adhesion after UV irradiation + high-temperature exposure) / (Initial Adhesion). If the adhesion ratio is less than 1, it can be said that the adhesion of the adhesive layer has decreased due to UV irradiation. Note that the adhesion ratio values ​​in Tables 1 and 2 are the values ​​calculated using the above formula, rounded to the third decimal place.

[0058] <Synthesis Example 1: (A1) Block Copolymer> In a 1000 mL four-necked flask, the following average unit formula is used as the precursor of resinous block X: (Me ３ SiO 1 / 2 ) ０.４４ (SiO 4 / 2 ) ０.５６ (OH) ０.１３ 214.0 g of a 70 wt% xylene solution of MQ resin (hydroxyl group content: 3.1 wt%) represented by [formula], 150.0 g of terminally silanol-bound dimethylsiloxane / methylvinylsiloxane copolymer raw rubber (plasticity: 130, number average molecular weight: 188,000) as a precursor of chain block Y, and 245.0 g of toluene were added and mixed. 4.0 g of 30 wt% aqueous ammonia was added to the resulting mixture and stirred at 50°C for 8 hours, then the ammonia and water were removed by refluxing the toluene. The above procedure yielded the following average unit formula: (Me ３ SiO 1 / 2 ) ０.２３ (Me２ SiO 2 / 2 ) ０.４７ (MeViSiO 2 / 2 ) ０.０１ (SiO 4 / 2 ) ０.２９ (OH) ０．０４ A solution of 609 g containing the (A1) block copolymer represented by the formula was obtained. The obtained (A1) block copolymer had a resin-linear structure, and the ratio of block X / block Y was found to be 1.00. The average value of the number of repeating units of the D units constituting the chain-like block Y was 2,500.

[0059] <Synthesis Example 2: (A2) Block Copolymer> In a 1000 mL four-necked flask, as a precursor of the resinous block X, the following average unit formula: (Me ３ SiO 1 / 2 ) ０.４1 (Me ２ ViSiO 1 / 2 ) ０.０６ (SiO 4 / 2 ) ０.５３ (OH) ０．０７ A 73 wt% xylene solution (vinyl group content: 2 wt%, hydroxyl group content: 1.7 wt%) of an MQ resin represented by the formula, 275.0 g, as a precursor of the chain-like block Y, a dimethylsiloxane / methylvinylsiloxane copolymer rubber (plasticity: 130, number average molecular weight: 188,000) having both ends blocked with silanol groups, 200.0 g, and toluene, 320.0 g, were added and mixed. To the obtained mixture, 5.0 g of 30 wt% aqueous ammonia was added and stirred at 40 °C for 8 hours, and then ammonia and water were distilled off by refluxing toluene at 120 °C. By the above operation, the following average unit formula: (Me ３ SiO 1 / 2 ) ０.２１ (Me ２ ViSiO 1 / 2 ) ０.０３ (Me ２ SiO 2 / 2 ) ０.４８ (MeViSiO 2 / 2 ) ０.０１ (SiO 4 / 2 ) ０.２７ (OH) ０．０３A solution containing the (A2) block copolymer represented by [formula] was obtained. The obtained (A2) block copolymer had a resin-linear structure, and the ratio of block X to block Y was 1.00. The average number of repeats of the D units constituting the chain-like block Y was 2,500.

[0060] <Synthesis Example 3: (A3) Block Copolymer> In a 1000 mL four-necked flask, the following average unit formula is used as the precursor of resinous block X: (Me ３ SiO 1 / 2 ) ０.４1 (Me ２ Visio 1 / 2 ) ０.０６ (SiO 4 / 2 ) ０.５３ (OH) ０．０７ 340.0 g of a 73 wt% xylene solution of MQ resin (vinyl group content: 2 wt%, hydroxyl group content: 1.7 wt%) represented by [formula], 200.0 g of terminally silanol-bound dimethylsiloxane / methylvinylsiloxane copolymer raw rubber (plasticity: 130, number average molecular weight: 188,000) as a precursor of chain block Y, and 350.0 g of toluene were added and mixed. 5.0 g of 30 wt% aqueous ammonia was added to the resulting mixture and stirred at 40°C for 8 hours, then the ammonia and water were removed by refluxing toluene at 120°C. The above procedure yielded the following average unit formula: (Me ３ SiO 1 / 2 ) ０.２３ (Me ２ Visio 1 / 2 ) ０.０３ (Me ２ SiO 2 / 2 ) ０.４３ (MeViSIO 2 / 2 ) ０.０１ (SiO 4 / 2 ) ０.３０ (OH) ０．０３ A solution containing the (A3) block copolymer represented by [formula] was obtained. The obtained (A3) block copolymer had a resin-linear structure, and the ratio of block X to block Y was 1.00. The average number of repeats of the D units constituting the chain-like block Y was 2,500.

[0061] In addition to the block copolymers (A1) to (A3) above, the components used in the examples and comparative examples are as follows: (a4) End-terminated dimethylvinylsiloxy group-sealed polydimethylsiloxane raw rubber (vinyl group content: 0.01% by weight, plasticity: 160) (a5) End-terminated silanol group-sealed dimethylsiloxane / methylvinylsiloxane copolymer raw rubber (vinyl group content: 0.84% ​​by weight, plasticity: 130) (A6) Resin-linear structure-containing block copolymer prepared by the same procedure as synthesis example (2) of International Publication No. 2023 / 120356. The average unit formula for this block copolymer is: (Me ３ SiO 1 / 2 ) ０.２０ (Me ２ Visio 1 / 2 ) ０.０１３ (Me ２ R X SiO 1 / 2 ) ０.０１７ (Me ２ SiO 2 / 2 ) ０.５０ (SiO 4 / 2 ) ０.２７ (OH) ０．０３ It has R in the above average unit formula. Ｘ This means the following structure. (B1) 3-(1,1,3,3-tetramethyldisiloxanyl)propyl methacrylate (manufactured by Dow Chemical) (B2) Methacryloylpropyltris(dimethylsiloxy)silane (manufactured by Dow Chemical) (C1) Solution of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex with vinyldimethylsiloxy groups sealed at both ends (platinum concentration: 0.7 wt%) (D1) 2,2-dimethoxy-2-phenylacetophenone (manufactured by IGM RESINS B.V., "Omnirad 651", "Omnirad" is a registered trademark) (E1) Me ３ SiO 1 / 2 The unit M, represented by ViMe ２ SiO 1 / 2 The unit M is expressed as (M ＶｉAn organopolysiloxane resin containing units (Vinyl group content: 2.00% by weight, weight-average molecular weight: 7,200) and Q units in a molar ratio of 0.41:0.06:0.53 in that order (e2)Me ３ SiO 1 / 2 An organopolysiloxane resin containing M units and Q units in a molar ratio of 1.0:1.0 (vinyl group content: 0% by weight, weight-average molecular weight: 7,000) (F1) Dimethylsiloxane polymer with dimethylsiloxy groups sealed at both ends (silicon atom bonded hydrogen atom content: 0.13% by weight, viscosity: 15 mm ２ / s) (F2) Dimethylsiloxane / methylsiloxane copolymer with dimethylsiloxy groups sealed at both ends (silicon atom bonded hydrogen atom content: 0.75% by weight, viscosity: 5.5 mm) ２ / s) (G1) Trimethylolpropane trimethacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) (H1) Diallyl maleate (manufactured by Tokyo Chemical Industry Co., Ltd.) (H2) 1-Ethynyl-1-cyclohexanol (manufactured by Tokyo Chemical Industry Co., Ltd.) (I1) Condensation reaction product of component (i1) and component (i2) in a weight ratio of 60:40 (dehydration condensation reaction product of silanol groups) (i1) Me ３ SiO 1 / 2 MQ resin (weight-average molecular weight: 7,000) containing M units and Q units in a molar ratio of 1.0:1.0 (i2) Polydimethylsiloxane raw rubber (plasticity: 170)

[0062] <Examples 1-6 and Comparative Examples 1-3> Curable compositions were prepared by mixing each component shown in Table 1 or 2 below with toluene as an organic solvent. The amounts of each component shown in Tables 1 and 2 are all parts by weight (equivalent to solid content). The amount of toluene was adjusted as appropriate so that the solid content concentration of each curable composition was 50% by weight. In Table 1, "SiH / Vi" refers to the ratio of the total number of moles of silicon-bonded hydrogen atoms to the total number of moles of alkenyl groups (excluding alkenyl groups that constitute part of (meth)acryloyl groups) in each composition.

[0063]

[0064]

[0065] As shown in Table 1, the adhesive layers (semi-cured products) obtained by heating the curable compositions according to Examples 1 to 6 had an initial adhesive strength of 30 gf / 25 mm or more, and were able to temporarily fix the polyamide film substrate to the SUS plate to be adhered. Furthermore, the adhesive strength of the adhesive layer decreased (adhesion ratio less than 1) upon irradiation with ultraviolet light, and the adhesive properties changed to easily peelable. In addition, the adhesive layer maintained its transparency throughout the entire process from heating to ultraviolet irradiation. Therefore, the laminates created in Examples 1 to 6 are expected to have excellent usefulness as protective films, temporary fixing films, etc., when used in the manufacturing process of semiconductor wafers, display devices, electronic devices, etc.

[0066] On the other hand, as shown in Table 2, in Comparative Examples 1 and 2, which used curable compositions without (A) block copolymer, the adhesion ratio was 1 or higher, and the stability against heat treatment was low, making it impossible to achieve easy peelability. In addition, adhesive residue due to high-temperature exposure was observed in Comparative Examples 1 and 3.

[0067] This disclosure provides curable compositions and their applications. In some embodiments, this disclosure provides curable compositions that exhibit good initial tackiness, but whose tackiness decreases upon irradiation with high-energy rays, and which can form cured products that do not leave adhesive residue.

Claims

1. (A) R Ａ a R Ｂ （３－ａ） SiO 1 / 2 (R Ａ is a monovalent organic group containing an alkenyl group, R Ｂ is a monovalent organic group not containing an alkenyl group, and a is an integer of 0 or more and 3 or less.) and a resinous block X containing a Q unit, and R Ｃ ｂ R Ｄ （２－ｂ） SiO 2 / 2 (R Ｃ is a monovalent organic group containing an alkenyl group, R Ｄ is a monovalent organic group not containing an alkenyl group, and b is an integer of 0 or more and 2 or less.) and a chain block Y containing a D unit, and an organopolysiloxane block copolymer having at least 1 alkenyl group on average in 1 molecule, (B) an organohydrosiloxane having at least 1 (meth)acryloyl group and at least 1 silicon atom-bonded hydrogen atom in 1 molecule, (C) a hydrosilylation reaction catalyst, and (D) a radical polymerization initiator.

2. The curable composition according to claim 1, further comprising (E) an organopolysiloxane resin comprising M units and Q units, having on average at least one alkenyl group per molecule, and having a ratio of the number of moles of M units to the number of moles of Q units of 0.5 or more and 2.0 or less.

3. The curable composition according to claim 1, further comprising (F) an organohydrogensiloxane that does not have a (meth)acryloyl group and has, on average, at least one silicon atom-bonded hydrogen atom in one molecule.

4. The curable composition according to claim 1, further comprising (G) an acrylic monomer that does not have a silicon atom bonded to a hydrogen atom and has two or more (meth)acryloyl groups in one molecule.

5. The curable composition according to claim 1, wherein the (A) block copolymer has a structure in which the resinous block X and the chain-like block Y are linked together.

6. The curable composition according to claim 5, wherein the resinous block X and the chain-like block Y are linked by at least one of a siloxane bond and a sylalkylene bond.

7. The curable composition according to claim 1, wherein the number average molecular weight of the chain-like block Y is 100,000 or more.

8. The curable composition according to claim 1, wherein the average number of repeating units of the D unit contained in the chain-like block Y is 1,000 or more.

9. The curable composition according to claim 1, wherein the (A) block copolymer does not have a (meth)acryloyl group.

10. The curable composition according to claim 1, wherein the (B) organohydrogensiloxane comprises at least one of a compound represented by the following formula (1) and a compound represented by the following formula (2). In the above formula (1), R １ Each of these independently represents a hydrogen atom, a methyl group, or a phenyl group, and R ２ These independently represent an alkyl group or an aryl group, and Z １ is a single bond or -(CH ２ ) ｍ - (where m is an integer between 1 and 3). In the above formula (2), R ３ Each of these independently represents a hydrogen atom, a methyl group, or a phenyl group, and R ４ These independently represent an alkyl group or an aryl group, and Z ２ is a single bond or -(CH ２ ) ｎ - (where n is an integer between 1 and 3).

11. The curable composition according to claim 1, having both heat-curable properties and high-energy ray curable properties.

12. The curable composition according to claim 1, used as an adhesive.

13. The curable composition according to claim 1, wherein the content of a siloxane component that does not contain either a carbon-carbon multiple bond or a silicon atom bonded hydrogen atom in the molecule is 0 parts by weight or more and less than 1.0 part by weight per 100 parts by weight of the block copolymer (A).

14. A cured product formed using the curable composition described in any one of claims 1 to 13.

15. A laminate comprising a layer made of the cured product described in claim 14 and a substrate.

16. The laminate according to claim 15, which is an adhesive tape for semiconductor processing.

17. The laminate according to claim 15, wherein the substrate comprises at least one resin selected from the group consisting of polyester resins, polyolefin resins, polyvinyl alcohol, polyvinylidene chloride, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyamide, polyimide, celluloses, fluororesins, polyethers, and polystyrene resins.

18. A method for producing a laminate, comprising the steps of applying a curable composition according to any one of claims 1 to 13 onto a substrate, and heating and curing the curable composition applied onto the substrate.

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