Release agent composition, release layer, and release sheet

Abstract

To provide a release agent composition that can form a release layer with excellent release properties for thermosetting resins. [Solution] A release agent composition comprising a block copolymer (A) having a first segment and a second segment, and a melamine-based crosslinking agent (B), wherein the first segment is a polymer segment formed from monomer components including a hydroxyl group-containing monomer represented by general formula (1) and an alicyclic hydrocarbon group-containing monomer represented by general formula (2), and the second segment is a polymer segment formed from monomer components including a long-chain alkyl group-containing monomer represented by general formula (3).

Description

[Technical Field]

[0001] The present invention relates to a release agent composition, a release layer, and a release sheet. [Background technology]

[0002] A release sheet is a material such as a plastic film having a release layer on the surface of the base material, and is used in the manufacturing process of printed circuit boards, flexible circuit boards, multilayer printed circuit boards, etc.

[0003] As components of the release layer, compounds having a siloxane skeleton are widely used because they exhibit excellent release properties, as disclosed in, for example, Patent Documents 1 and 2.

[0004] As a component of a release layer that does not have a siloxane skeleton, for example, Patent Document 3 discloses that a resin film of a long-chain alkyl group-containing acrylic polymer and a melamine resin exhibits release properties to polyester adhesive tape.

[0005] Furthermore, Patent Document 4 discloses a specific block copolymer included in a release agent composition that has a good pot life even when a crosslinking agent is used. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2004-306344 [Patent Document 2] Japanese Patent Publication No. 2011-219630 [Patent Document 3] Japanese Patent Publication No. 2018-115224 [Patent Document 4] International Publication No. 2020 / 196373 [Overview of the project] [Problems that the invention aims to solve]

[0007] In a release sheet used in the manufacturing process of electronic components such as semiconductor devices, it has been pointed out that a silicon component derived from a compound having a siloxane skeleton may migrate onto the electronic component, causing problems such as poor conductivity. The release layers disclosed in Patent Documents 1 and 2 use a compound having a siloxane skeleton and have the above problems.

[0008] With the miniaturization and high functionality of electronic devices, printed wiring boards are required to have finer patterns, reduced mounting areas, and higher component mounting densities. Therefore, printed wiring boards use multilayer substrates such as double-sided substrates provided with through-holes for forming interlayer connections to electrically connect different wiring layers, or build-up wiring boards in which an insulating layer and a conductor circuit are sequentially formed on a core material and multilayered by interlayer connections such as via holes.

[0009] In such a printed wiring board, the through-hole portion is generally subjected to hole filling with a filler made of a thermosetting resin containing an epoxy resin. When filling the filler into the through-holes formed on the substrate, a release sheet is attached to the substrate to close one opening of the through-hole and is peeled off after the filler is cured. At this time, the release sheet is required to be peeled off with a light force at the adhesion portion with the thermosetting resin. The release layers specifically disclosed in Patent Documents 3 and 4 do not have a siloxane skeleton, but the peelability to a adherend mainly composed of a thermosetting resin is insufficient.

[0010] The present invention has been made in view of the above circumstances, and an object thereof is to provide a release agent composition capable of forming a release layer excellent in peelability to a thermosetting resin.

Means for Solving the Problems

[0011] The present invention is a release agent composition containing a block copolymer (A) having a first segment and a second segment and a melamine-based crosslinking agent (B), and the first segment has the general formula (1):

Chemical formula

[0012] The present invention also relates to the release agent composition preferably used for a thermosetting resin as an adherend.

[0013] The present invention also relates to a release layer formed from the release agent composition.

[0014] The present invention also relates to a release sheet provided with the release layer on the surface of a substrate.

[0015] The present invention also relates to the release sheet having a release force of 0.6 (N / 25 mm) or less when peeled at a speed of 300 mm / min at 180° with respect to a thermosetting resin. [Advantages of the Invention]

[0016] Since the release agent composition of the present invention uses a specific block copolymer and a melamine-based crosslinking agent in combination, a release layer excellent in releasability to a thermosetting resin can be formed.

Mode for Carrying Out the Invention

[0017] Hereinafter, the present invention will be described in more detail. In the present invention, “(meth)acrylate” means a general term including both acrylate and methacrylate.

[0018] <Block copolymer (A)> The block copolymer of the present invention is a block copolymer (A) having a first segment and a second segment.

[0019] <First segment> The first segment is represented by the general formula (1):

Chemical formula

Chemical formula

[0020] In the general formula (1), X 1 is an organic bonding group, and examples of X 1 include an alkylene group, a polyoxyalkylene group, an arylene group, etc., and an alkylene group and a polyoxyalkylene group are preferable.

[0021] X 1 When is an alkylene group, an alkylene group having 1 to 8 carbon atoms is preferable, and from the viewpoint of causing a polarity difference with the long-chain alkyl group in the second segment and promoting surface segregation at the long-chain alkyl group site, it is more preferable that the number of carbon atoms is 1 to 4. X 1When is an alkylene group, examples of hydroxyl group-containing monomers represented by the general formula (1) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate, and among these, 2-hydroxyethyl (meth)acrylate is preferred.

[0022] X 1 is a polyoxyalkylene group (-C a H 2a -(OC a H 2a In the case of )n-), a is preferably a polyoxyalkylene group of 2 to 4, for example, an oxyethylene group (-C2H4O-), an oxypropylene group (-C3H6O-), an oxytetramethylene group (-C4H8O-), etc. 1 When the material contains two or more oxyalkylene groups, the arrangement of the various oxyalkylene groups may be in a block or random configuration. Furthermore, from the viewpoint of the efficiency of hydroxyl group introduction in the block copolymer, the average number of added moles of polyoxyalkylene groups, n, is preferably between 1 and 15. 1 is a polyoxyalkylene group (-C a H 2a -(OC a H 2a In the case of )n-), examples of hydroxyl group-containing monomers represented by the general formula (1) include ethylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, propylene glycol mono(meth)acrylate, and polypropylene glycol mono(meth)acrylate.

[0023] At least one hydroxyl group-containing monomer represented by the general formula (1) may be used, and two or more types may be used in combination.

[0024] In the above general formula (2), R 3 R is an alicyclic hydrocarbon group, 3Examples of these groups include cyclohexyl, norbornyl, isobornyl, dicyclopentanyl, dicyclopentenyl, dicyclopentenyloxyethyl, and adamantyl groups, with polycyclic groups such as norbornyl, isobornyl, dicyclopentanyl, dicyclopentenyl, dicyclopentenyloxyethyl, and adamantyl groups being preferred. These organic groups may be unsubstituted or substituted. Examples of substituents include alkyl groups, alkenyl groups, cycloalkyl groups, and aryl groups. Examples of alicyclic hydrocarbon group-containing monomers represented by the general formula (2) include isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and adamantyl (meth)acrylate, among which isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate are preferred. More preferably, dicyclopentanyl (meth)acrylate.

[0025] At least one alicyclic hydrocarbon group-containing monomer represented by the general formula (2) may be used, and two or more may be used in combination.

[0026] The hydroxyl group-containing monomer represented by the general formula (1) is preferably present in an amount of 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, in the monomer components constituting the first segment, from the viewpoint of increasing the crosslinking density of the release layer and improving hardness. Furthermore, from the viewpoint of increasing the surface segregation of the block copolymer during release layer formation and improving release properties, it is preferably present in an amount of 50% by mass or less, and more preferably 45% by mass or less, in the monomer components constituting the first segment.

[0027] The alicyclic hydrocarbon group-containing monomer represented by general formula (2) is preferably present in an amount of 50% by mass or more, and more preferably 55% by mass or more, in the monomer components constituting the first segment, from the viewpoint of maintaining the surface orientation of the long-chain alkyl group derived from the long-chain alkyl group-containing monomer represented by general formula (3) and improving the peelability to thermosetting resins. Furthermore, it is preferably present in an amount of 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, in the monomer components constituting the first segment.

[0028] The total amount of the hydroxyl group-containing monomer represented by the general formula (1) and the alicyclic hydrocarbon group-containing monomer represented by the general formula (2) is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, of the monomer components constituting the first segment.

[0029] The monomer components constituting the first segment may include other monomers other than the hydroxyl group-containing monomer represented by general formula (1) and the alicyclic hydrocarbon group-containing monomer represented by general formula (2), provided that they satisfy the preferred range of each monomer component described above. These other monomers may be any known radical polymerizable monomers, but from the viewpoint of controlling the orientation of the alicyclic alkyl group, for example, alkyl group-containing (meth)acrylates having linear or branched chains with 1 to 24 carbon atoms; fluorine atom-containing (meth)acrylates having groups in which one or more hydrogen atoms of an alkyl group having linear or branched chains with 1 to 12 carbon atoms are substituted with fluorine atoms; and alkoxy group-terminated and polyalkylene glycol group-containing (meth)acrylates are preferred. Examples of alkyl group-containing (meth)acrylates having linear or branched chains with 1 to 24 carbon atoms include methyl (meth)acrylate, butyl (meth)acrylate, dodecyl (meth)acrylate, and octadecyl (meth)acrylate. Examples of fluorine-containing (meth)acrylates having a group in which one or more hydrogen atoms of a linear or branched alkyl group having 1 to 12 carbon atoms are substituted with fluorine atoms include 1H,1H,2H,2H-nonanafluoro-n-hexyl (meth)acrylate, 1H,1H,2H,2H-tridecafluoro-n-octyl (meth)acrylate, and 1H,1H,2H,2H-heptadecafluoro-n-decyl (meth)acrylate. Examples of alkoxy-terminated and polyalkylene glycol-containing (meth)acrylates include poly(ethylene glycol)methyl ether (meth)acrylate. Two or more of these other monomers can be used in combination.

[0030] <Second Segment> The second segment is given by general formula (3): [ka] (In general formula (3), R 4 R is a hydrogen atom or a methyl group, 5The polymer segment is formed by monomer components containing a long-chain alkyl group-containing monomer represented by ), where is an alkyl group having 12 to 24 carbon atoms.

[0031] In the above general formula (3), R 5 The alkyl group has 12 to 24 carbon atoms, and from the viewpoint of improving peelability, it is preferable that it has 16 to 22 carbon atoms. Examples of long-chain alkyl group-containing monomers represented by the general formula (3) include hexadecyl (meth)acrylate, octadecyl (meth)acrylate, icosyl (meth)acrylate, and docosyl (meth)acrylate. Among these, octadecyl (meth)acrylate is preferred because it has a high peelability-improving effect and is also preferable from the viewpoint of monomer handling.

[0032] At least one long-chain alkyl group-containing monomer represented by the general formula (3) may be used, and two or more types can be used in combination.

[0033] The long-chain alkyl group-containing monomer represented by the general formula (3) is preferably present in an amount of 85% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, from the viewpoint of locally crystallizing the long-chain alkyl groups together, lowering the surface free energy, and improving peelability, in the monomer components constituting the second segment.

[0034] The monomer components constituting the second segment may include other monomers besides the long-chain alkyl group-containing monomers, provided that they satisfy the preferred range of the long-chain alkyl group-containing monomers described above. These other monomers may be any known radical polymerizable monomers, but from the viewpoint of adjusting peelability and the physical properties of the peeled layer, for example, (meth)acrylates containing alkyl groups having 1 to 11 linear or branched chains; fluorine atom-containing (meth)acrylates having groups in which one or more hydrogen atoms of an alkyl group having 1 to 12 linear or branched chains are substituted with fluorine atoms; (meth)acrylates containing alkoxy group-terminated and polyalkylene glycol groups; and (meth)acrylates containing reactive functional groups such as hydroxyl groups, epoxy groups, carboxyl groups, and amino groups. Examples of the alkyl group-containing (meth)acrylates having 1 to 11 linear or branched chains include methyl (meth)acrylate, butyl (meth)acrylate, and decyl (meth)acrylate. Examples of fluorine-containing (meth)acrylates having a group in which one or more hydrogen atoms of a linear or branched alkyl group having 1 to 12 carbon atoms are substituted with fluorine atoms include 1H,1H,2H,2H-nonanafluoro-n-hexyl(meth)acrylate, 1H,1H,2H,2H-tridecafluoro-n-octyl(meth)acrylate, and 1H,1H,2H,2H-heptadecafluoro-n-decyl(meth)acrylate. Examples of (meth)acrylates containing an alkoxy group terminus and a polyalkylene glycol group include poly(ethylene glycol)methyl ether(meth)acrylate. Preferred (meth)acrylates containing a reactive functional group include 2-hydroxyethyl(meth)acrylate, glycidyl(meth)acrylate, and (meth)acrylic acid. Two or more of these other monomers can be used in combination.

[0035] In the total monomer components forming the block copolymer (A), the proportion of the hydroxyl group-containing monomer represented by the general formula (1) is preferably 1% by mass or more and 30% by mass or less. From the viewpoint of increasing the crosslinking density of the release layer and improving hardness, the proportion of the hydroxyl group-containing monomer represented by the general formula (1) is more preferably 5% by mass or more, and even more preferably 10% by mass or more, in the total monomer components forming the block copolymer (A). Furthermore, from the viewpoint of increasing the surface segregation of the block copolymer during release layer formation and improving release properties, it is more preferably 25% by mass or less, and even more preferably 20% by mass or less, in the total monomer components forming the block copolymer (A).

[0036] In the total monomer components forming the block copolymer (A), the proportion of alicyclic hydrocarbon group-containing monomers represented by the general formula (2) is preferably 5% by mass or more and 45% by mass or less. From the viewpoint of controlling the surface orientation of long-chain alkyl groups, the proportion of alicyclic hydrocarbon group-containing monomers represented by the general formula (2) is more preferably 10% by mass or more, and even more preferably 15% by mass or more, in the total monomer components forming the block copolymer (A), and from the viewpoint of improving the hardness of the release layer, it is more preferably 40% by mass or less, and even more preferably 35% by mass or less, in the total monomer components forming the block copolymer (A).

[0037] In the total monomer components forming the block copolymer (A), the proportion of the long-chain alkyl group-containing monomer represented by the general formula (3) is preferably 45% by mass or more and 90% by mass or less. From the viewpoint of locally crystallizing the long-chain alkyl groups together, lowering the surface free energy, and improving peelability, the proportion of the long-chain alkyl group-containing monomer is more preferably 50% by mass or more, and even more preferably 55% by mass or more, in the total monomer components forming the block copolymer (A). Furthermore, from the viewpoint of achieving both improved crosslinking density of the peelable layer and improved pot life, it is more preferably 85% by mass or less, and even more preferably 80% by mass or less, in the total monomer components forming the block copolymer (A).

[0038] The proportion of the monomer component forming the first segment in the total monomer components forming the block copolymer (A) is preferably 10% by mass or more and 50% by mass or less. From the viewpoint of increasing the crosslinking density of the release layer and improving hardness, the proportion of the monomer component forming the first segment is more preferably 20% by mass or more, and even more preferably 30% by mass or more, in the total monomer components forming the block copolymer (A). From the viewpoint of improving release properties, it is more preferably 47% by mass or less, and even more preferably 45% by mass or less, in the total monomer components forming the block copolymer (A).

[0039] <Method for producing block copolymer (A)> The method for producing the block copolymer (A) of the present invention can be obtained using known methods for producing block copolymers and is not limited in any way, but examples include anionic polymerization and polymerization using polymeric peroxide. Examples of such polymerization methods include bulk polymerization, suspension polymerization, solution polymerization, and emulsion polymerization.

[0040] The polymerization method using the polymeric peroxide is a polymerization method that uses a compound having two or more peroxy (peroxide) bonds in one molecule as a polymerization initiator. Examples of the polymeric peroxide include the various polymeric peroxide compounds disclosed in Japanese Patent Publication No. 5-59942. At least one polymeric peroxide may be used, and two or more may be used in combination.

[0041] The polymeric peroxide is defined by general formula (4): [ka] Compounds having a structure represented by (general formula (4), where m represents an integer from 1 to 10, and n represents an integer from 2 to 20), general formula (5): [ka] Compounds having the structure represented by (in general formula (5), n represents an integer from 2 to 20) are preferred. Also, because of their excellent release properties from thermosetting resins, general formula (6): [ka] Compounds having the structure represented by (general formula (6), where n is an integer from 2 to 20) are even more preferred.

[0042] The polymerization method using the polymeric peroxide includes, for example, a first step of using the polymeric peroxide as a polymerization initiator and polymerizing a long-chain alkyl group-containing monomer represented by the general formula (3) in a solution (polymerization solvent) to obtain a solution of a polymer having a second segment containing a peroxy bond in which a peroxy bond has been introduced in the chain; and a second step of adding a hydroxyl group-containing monomer represented by the general formula (1) and an alicyclic hydrocarbon group-containing monomer represented by the general formula (2) to the obtained solution of the polymer having the second segment containing a peroxy bond to obtain a block copolymer (A) consisting of a first segment and a second segment. In addition, in the polymerization method using the polymeric peroxide, as the first step, a hydroxyl group-containing monomer represented by the general formula (1) and an alicyclic hydrocarbon group-containing monomer represented by the general formula (2) may be added to obtain a solution of a polymer having a first segment containing a peroxy bond, and then as the second step, a long-chain alkyl group-containing monomer represented by the general formula (3) may be added to polymerize.

[0043] The aforementioned solution (polymerization solvent) should be one that can produce block copolymer (A). Examples of the aforementioned solution (polymerization solvent) include acetone, 2-butanone, 3-methyl-2-butanone, 2-pentanone, 3-pentanone, 2-methyl-3-pentanone, 3-methyl-2-pentanone, 4-methyl-2-pentanone, 2,4-dimethyl-3-pentanone, 4,4-dimethyl-2-pentanone, 2-hexanone, 3-hexanone, cyclopentanone, cyclohexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-methyl-3-hexanone, 5-methyl Ketone solvents such as methyl-2-hexanone and 5-methyl-3-hexanone; methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, methyl trimethylacetate, isobutyl acetate, sec-butyl acetate, pentyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, isobutyl propionate, tert-butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyrate, butyrate Examples of solvents include ester solvents such as isopropyl acid, methyl isobutyrate, ethyl isobutyrate, methyl 2-methylbutyrate, methyl caproate, and cellosolve acetate; hydrocarbon solvents such as benzene, toluene, ethylbenzene, xylene, phenol, cyclohexane, hexane, isohexane, isohexene, heptane, octane, isooctane, nonane, isononane, decane, undecane, dodecane, tridecane, and isoparaffinic solvents (manufactured by NOF Corporation, trade names: NAS-3, NAS-4, NAS-5H); nitrogen-containing solvents such as formamide, acetamide, dimethylformamide, dimethylacetamide, and acetonitrile; halogenated solvents such as 1,1,2,-trifluoro-1,2,2-trichloroethane, tetrachlorodifluoroethane, methylchloroform, hexafluoroisopropanol, (meth)paraxylenehexafluoride, perfluorohexane, and perfluoroheptane; and dimethyl sulfoxide and tetrahydrofuran. The aforementioned solution (polymerization solvent) can be used in combination of two or more types.

[0044] Furthermore, the amount of polymeric peroxide used is preferably 0.5 to 20 parts by mass, and more preferably 2 to 15 parts by mass, per 100 parts by mass of monomer components constituting the block copolymer (A). The temperature at which the polymerization reaction is carried out is appropriately changed depending on the type of polymeric peroxide used, but for industrial production, it is preferably 30 to 150°C, and more preferably 40 to 100°C.

[0045] The block copolymer (A) preferably has a weight-average molecular weight (Mw) of 5,000 to 200,000, more preferably 8,000 to 150,000, and even more preferably 10,000 to 100,000. The weight-average molecular weight (Mw) can be determined under the following conditions. If the weight-average molecular weight is less than 5,000, the difference in the composition ratio of monomer components in each block copolymer becomes large, which may reduce the peelability. On the other hand, if the weight-average molecular weight exceeds 200,000, there is a possibility of insufficient solubility when preparing the peeling agent composition.

[0046] <Measurement conditions for weight-average molecular weight (Mw)> Analyzer: TOSOH HLC-8320GPC Column: TSKgel SuperMulbipore HZ-M (manufactured by Tosoh Corporation) Eluent:THF Flow rate: 0.35ml / min Detector: RI Column temperature: 40℃ Sample concentration: 0.2 wt% Sample injection volume: 10 μL Standard sample: Standard polystyrene

[0047] <Removal agent composition> The release agent composition of the present invention comprises the block copolymer (A) and a melamine-based crosslinking agent (B). From the viewpoint of use in release sheets used in the manufacturing process of electronic components such as semiconductor elements, the release agent composition is preferably non-silicone. Here, "non-silicone" means that the release agent composition substantially does not contain compounds having a siloxane skeleton, and in the release agent composition, the amount of compounds having a siloxane skeleton is preferably 100 ppm or less, more preferably 10 ppm or less, and most preferably 0 ppm (not containing any compounds having a siloxane skeleton).

[0048] As the melamine-based crosslinking agent (B), for example, melamine, methylolated melamine derivatives obtained by condensing melamine with formaldehyde, compounds partially or completely etherified by reacting methylolated melamine with a lower alcohol, and mixtures thereof can be used. Specifically, the melamine-based crosslinking agent (B) is a compound of general formula (7): [ka] (In general formula (7), R 6 ~R 11 It is preferable that the compound has a structure represented by ) where each independently represents a hydrogen atom, an imino group, a methylol group, or an alkoxymethyl group such as a methoxymethyl group or a butoxymethyl group, and n represents an integer of 1 or more. 6 ~R 11 The substituents shown preferably have at least one methylol group, as this provides excellent release properties from thermosetting resins.

[0049] Examples of commercially available melamine-based crosslinking agents (B) include Cymel 300, Cymel 301, Cymel 303LF, Cymel 350, Cymel 370N, Cymel 771, Cymel 325, Cymel 327, Cymel 703, Cymel 712, Cymel 701, Cymel 266, Cymel 267, Cymel 285, Cymel 232, Cymel 235, Cymel 236, Cymel 238, Cymel 272, Cymel 212, and Cymel 25. 3. Cymel 254, Cymel 202, Cymel 207, Mycoat 506 (all manufactured by Ornex Japan Co., Ltd.), Nikarac MW-30M, Nikarac MW-30, Nikarac MW-30HM, Nikarac MW-390, Nikarac MW-100LM, Nikarac MX-750LM, Nikarac MW-22, Nikarac MS-21, Nikarac MS-11, Nikarac MW-24X, Nikarac MS-001, Nikarac MX-002, Nikarac MX-730, Nikarac MX-750, Nikarac MX-708, Nikarac MX-706, Nikarac MX-042, Nikarac MX-035, Nikarac MX-45, Nikarac MX-43, Nikarac MX-417, Nikarac MX-410 (all manufactured by Sanwa Chemical Co., Ltd.), Uban 20SB, Uban 20SE60, Uban 21R, Uban 22R, Uban 122, Uban 125 Examples include Yuban 220, Yuban 225, Yuban 228, Yuban 2020 (all manufactured by Mitsui Chemicals, Inc.), Amidia J-820-60, Amidia L-109-65, Amidia L-117-60, Amidia L-127-60, Amidia 13-548, Amidia G-821-60, Amidia L-110-60, Amidia L-125-60, Amidia L-166-60B (all manufactured by DIC Corporation).

[0050] Furthermore, to accelerate the thermal curing of the melamine-based crosslinking agent (B), an acidic catalyst such as p-toluenesulfonic acid may be used.

[0051] In the release agent composition, the total amount of block copolymer (A) and melamine-based crosslinking agent (B) is preferably 10 to 90% by mass of block copolymer (A), and more preferably 20 to 45% by mass, from the viewpoint of release properties to thermosetting resins.

[0052] Furthermore, the release agent composition of the present invention may include a polymer (C) having a functional group that is reactive with the melamine-based crosslinking agent (B), from the viewpoint of imparting functions other than release properties, such as chemical resistance, oil repellency, and scratch resistance, to the release layer.

[0053] The polymer (C) having a functional group that is reactive with the melamine-based crosslinking agent (B) can be any polymer having a functional group that is reactive with the functional group of the melamine-based crosslinking agent (B) (reactive functional group). Examples of such reactive functional groups include hydroxyl groups, carboxyl groups, and amino groups. From the viewpoint of minimizing the adverse effects on objects in contact with the peeled layer, hydroxyl groups are preferred, as they are less likely to cause reactions involving the transfer of protons if they remain in the peeled layer after the crosslinking reaction.

[0054] From the viewpoint of improving the durability of the release layer, the polymer (C) preferably has a total reactive functional value of about 20 to 200 mg / KOH per 1 g of polymer (C), and more preferably about 30 to 160 mg / KOH. Examples of polymer (C) include poly(meth)acrylic resins, polyvinyl acetate resins, polyvinyl ether resins, polyester resins, urethane resins, fluororesins, polyalkylene glycols, polyalkyleneimines, methylcellulose, hydroxycellulose, and starches. Two or more types of polymer (C) can be used in combination.

[0055] In the aforementioned release agent composition, when the polymer (C) is used, the amount of polymer (C) is preferably 25 parts by mass or more, more preferably 50 parts by mass or more, more preferably 900 parts by mass or less, and more preferably 400 parts by mass or less, per 100 parts by mass of the block copolymer (A), from the viewpoint of achieving both release properties due to the block copolymer and chemical resistance and other functions due to the polymer.

[0056] The aforementioned release agent composition can be prepared by diluting it with an organic solvent. The organic solvent can be the same as that exemplified as the polymerization solvent. The release agent composition typically has a solid content concentration of about 0.1 to 50% by mass, and preferably about 1 to 20% by mass.

[0057] The aforementioned release agent composition may optionally contain a curing catalyst, pH adjuster, preservative, ultraviolet absorber, antioxidant, light stabilizer, rheology control agent, antistatic agent, organic particles, inorganic particles, colorant, flame retardant, leveling agent, and the like.

[0058] <Exfoliation layer> The release layer of the present invention is formed from the release agent composition, and is produced, for example, by applying the release agent composition (solution) to a substrate, drying and removing the solvent, etc., to form the layer on the substrate. Various conventionally known methods can be used for the application, such as gravure coating, roll coating, blade coating, knife coating, bar coating, spray coating, and spin coating. For the drying, it is preferable to appropriately adjust the drying temperature and time depending on the solvent used, melamine-based crosslinking agent (B), etc., but it is usually 60 to 200°C for about 10 seconds to 10 minutes. In addition, different drying conditions may be combined.

[0059] Examples of the substrate include plastic substrates such as acrylic resins, polyester resins, polycarbonate resins, triacetate cellulose resins, and polyethylene terephthalate resins; and paper substrates such as high-quality paper and coated paper. The shape of the substrate is not particularly limited, but from the viewpoint of suitability as a release sheet, films and sheets are preferred. Furthermore, various functional layers such as primer layers and adhesive layers; and surface treatment layers such as corona treatment, UV ozone treatment, and plasma treatment may be appropriately provided between the substrate and the release layer.

[0060] From the viewpoint of manufacturability and functionalization, the film thickness of the release layer is preferably 0.01 to 100 μm, and more preferably 0.1 to 10 μm.

[0061] <Release sheet> The release sheet of the present invention has a release layer provided on the surface of the substrate. Examples of applications for the release sheet include a support for forming materials such as synthetic leather and green sheets for electronic materials, and protection of adhesive layers. However, applications using a thermosetting resin as the substrate are more preferable. Suitable thermosetting resins include, for example, thermosetting adhesives, thermosetting fillers, and thermosetting encapsulants. Furthermore, the main component of the thermosetting resin is preferably an epoxy compound. Specifically, it is a compound having one or more epoxy groups in one molecule, and any generally known epoxy compound is applicable. Examples include polyglycidyl ethers of polyhydric phenols such as bisphenol-type epoxy resins derived from epichlorohydrin and bisphenol A or bisphenol F, and epoxy novolac resins derived from epichlorohydrin and phenol novolac or cresol novolac. Other examples include polyglycidyl esters of polycarboxylic acids, alicyclic epoxys, polyglycidyl ethers of polyhydric alcohols, and polyglycidyl compounds of polyhydric amines. These can be used individually or in combination of two or more. In particular, the release sheet is preferably 0.6 (N / 25mm) or less, more preferably 0.4 (N / 25mm) or less, and even more preferably 0.2 (N / 25mm) or less, when peeled 180° from the thermosetting resin at a speed of 300 mm / min. The method for measuring the "peeling force" will be described later. [Examples]

[0062] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0063] <Production of block copolymer (A)> <Synthesis Example 1> 73.9 g of toluene was added to a reaction vessel equipped with a thermometer, stirrer, and reflux condenser, and heated to 70°C while blowing in nitrogen gas. Then, while maintaining the temperature and nitrogen atmosphere in the reaction vessel, a monomer solution consisting of 20.0 g of 2-hydroxyethyl methacrylate, 25.0 g of dicyclopentanyl methacrylate, and 106.4 g of toluene, and a polymerization initiator solution consisting of 16.7 g of polymeric peroxide (n=10) having the structure represented by the general formula (6) were added simultaneously over 1 hour, and the polymerization reaction was carried out for a further 3 hours to obtain a polymer solution having a first segment containing a peroxy bond. Subsequently, a monomer solution of 55.0 g of octadecyl methacrylate and 22.3 g of toluene was added over 1 hour, and the polymerization reaction was carried out for 2 hours. Then, the temperature was further raised to 80°C and the polymerization reaction was carried out for 3 hours to obtain a polymerization solution containing a block copolymer (A) having a first segment and a second segment. The obtained polymerization solution was diluted with toluene to obtain a solution containing the block copolymer (A) (solid content concentration 30% by mass). Based on the GPC measurement method described above, the analysis revealed a Mw of 51,000 and an Mw / Mn ratio of 3.5.

[0064] <Synthesis Example 2, Comparative Synthesis Example 1> Except for changing the monomer components and their proportions as shown in Table 1, the same procedure as in Synthesis Example 1 described above was performed to obtain a solution containing block copolymer (A) or (A'). The measurement results for Mw and Mw / Mn are also shown in Table 1.

[0065] <Comparative Synthesis Example 2> 106.4 g of toluene was added to a reaction vessel equipped with a thermometer, stirrer, and reflux condenser, and heated to 70°C while blowing in nitrogen gas. Then, while maintaining the temperature and nitrogen atmosphere in the reaction vessel, a monomer solution consisting of 20.0 g of 2-hydroxyethyl methacrylate, 25.0 g of dicyclopentanyl methacrylate, 55.0 g of octadecyl methacrylate, and 88.1 g of toluene was added simultaneously over 1 hour to a polymerization initiator solution consisting of 2.2 g of di(3,5,5-trimethylhexanoyl) peroxide (trade name: Perloyl 355, manufactured by NOF Corporation) and 22.0 g of toluene. The polymerization reaction was carried out for a further 9 hours to obtain a polymerization solution containing random copolymer (A''). The obtained polymerization solution was diluted with toluene to obtain a solution containing random copolymer (A'') (solid content concentration 30% by mass). Analysis based on the GPC measurement method described above showed a Mw of 46,000 and an Mw / Mn ratio of 3.2.

[0066] [Table 1]

[0067] [Table 2]

[0068] In Tables 1 and 2, HEMA is 2-hydroxyethyl methacrylate; 50PET800 is polyethylene glycol-tetramethylene glycol-monomethacrylate (product name: Bremmer 55PET-800, manufactured by NOF Corporation, average number of moles of oxyethylene groups added: 10, average number of moles of oxytetramethylene groups added: 5, the arrangement of oxyethylene and oxytetramethylene groups is blocked). DCPMA is dicyclopentanyl methacrylate; SMA represents octadecyl methacrylate.

[0069] <Example 1> <Manufacturing of release agent composition> A release agent composition was obtained by mixing 2.39 g of a solution containing the block copolymer (A) obtained in Synthesis Example 1 (solid content concentration: 30% by mass, solvent: toluene), 3.59 g of a melamine-based crosslinking agent (product name: Nikalac MS-11 (manufactured by Sanwa Chemical Co., Ltd., active ingredient: 60% by mass)), and 0.13 g of p-toluenesulfonic acid and 93.89 g of toluene as a curing catalyst.

[0070] <Preparation of release sheets> The release agent composition obtained above was applied to a PET film (product name: TA061, manufactured by Toyobo Co., Ltd.) using a bar coater (No. 02, manufactured by Daiichi Rika Co., Ltd., wet film thickness 4.6 μm), and then heated and cured in a 150°C forced-air oven for 1 minute to produce a release sheet. The obtained release sheet was evaluated as described below. The evaluation results are shown in Table 3 or Table 4.

[0071] <Evaluation of peelability> To evaluate the peelability, an epoxy adhesive (product name: Detanite XNR3503, manufactured by Nagase ChemteX Corporation) was applied to the surface of the release layer of the above-mentioned release sheet to a thickness of 25 μm using an applicator. A PET film (product name: TA061, manufactured by Toyobo Co., Ltd.) with an easy-adhesion side was then bonded to the adhesive, and the test specimens were prepared by curing at 80°C for 1 hour. The peel test was conducted in accordance with JIS-0237. Specifically, the peel force (N / 25 mm) was measured and evaluated by applying the force required to peel the PET film from the obtained test specimens using a tensile tester (measuring device: AGS-H 500N (manufactured by Shimadzu Corporation), tensile speed: 300 mm / min, tensile angle: 180°). The peel force (N / 25 mm) is the average value of three different test specimens. Based on the peel force (N / 25 mm) results, evaluation was performed according to the following criteria, with a score of ○ or higher considered a pass. ◎:0.2(N / 25mm) or less ○: More than 0.2 (N / 25mm) and less than 0.6 (N / 25mm) △: More than 0.6 (N / 25mm) and less than 0.9 (N / 25mm) ×: More than 0.9(N / 25mm)

[0072] <Examples 2-7, Comparative Examples 1-4> In each example and comparative example, the same procedure as in Example 1 was followed, except that the types and amounts of each raw material were changed as shown in Table 3 or Table 4. After obtaining the release agent composition and release sheet, the same evaluation as described above was performed. The evaluation results are shown in Tables 3 and 4.

[0073] [Table 3]

[0074] [Table 4]

[0075] In Tables 3 and 4, M-1 is a melamine-based crosslinking agent (product name: Nikalac MS-11, manufactured by Sanwa Chemical Co., Ltd., methylol-based, solids content 60%); M-2 is a melamine-based crosslinking agent (product name: Amidia L-105-60, manufactured by DIC Corporation, fully alkyl type, solids content 60%); I-1 is an isocyanate-based crosslinking agent (product name: Coronate HK, manufactured by Tosoh Corporation, HDI-based, 100% solids, 20.4% NCO content); Polymer (C) represents acrylic polyol (product name: Thermolac SU-100ADT, manufactured by Soken Chemical Co., Ltd., active ingredient 50%, hydroxyl value 80 mgKOH / g).

[0076] As is clear from the evaluation results in Table 3, Examples 1 to 7 showed excellent release properties against thermosetting resins.

[0077] On the other hand, as is clear from the evaluation results in Table 4, Comparative Examples 1 to 4 exhibited insufficient release properties against thermosetting resins. Specifically, Comparative Examples 1 and 4 had poor release properties because their release agent compositions did not contain a melamine-based crosslinking agent (B). Furthermore, Comparative Examples 2 and 3 also had poor release properties because their release agent compositions did not contain a block copolymer (A).

Claims

1. A release agent composition containing a block copolymer (A) having a first segment and a second segment, and a melamine-based crosslinking agent (B). The first segment is given by general formula (1): 【Chemistry 1】 (In general formula (1), R １ X is a hydrogen atom or a methyl group, １ is an organic bonding group. ) A hydroxyl group-containing monomer represented by ) General formula (2): 【Chemistry 2】 (In general formula (2), R ２ R is a hydrogen atom or a methyl group, ３ This is an alicyclic hydrocarbon group.) The polymer segment is formed by monomer components containing an alicyclic hydrocarbon group-containing monomer represented by ), The second segment is given by general formula (3): 【Transformation 3】 (In general formula (3), R ４ R is a hydrogen atom or a methyl group, ５ A release agent composition characterized by a polymer segment formed by a monomer component containing a long-chain alkyl group-containing monomer represented by (where is an alkyl group having 12 to 24 carbon atoms).

2. The release agent composition according to claim 1, characterized in that it is used on a thermosetting resin as the adherend.

3. A release layer characterized by being formed from the release agent composition described in claim 1 or 2.

4. A release sheet characterized in that the release layer described in claim 3 is provided on the surface of the substrate.

5. The release sheet according to claim 4, characterized in that the release force when peeling a thermosetting resin at a speed of 300 mm / min and 180° is 0.6 (N / 25 mm) or less.

Images