Resin material and resin composition

Abstract

The present invention relates to a resin material containing: a compound A having a (meth) acryloyl group; a compound B having two or more thiol groups; and a photoradical initiator having a 5% weight loss temperature of 200 DEG C or more, the compound A including a compound A-1 having three or more (meth) acryloyl groups, and at least one of the compound A and the compound B having a disulfide bond.

Description

Technical Field

[0001] The present invention relates to a resin material and a resin composition. Background Art

[0002] A photo-softenable composition that can be softened by light irradiation is used for various purposes. For example, Patent Document 1 discloses an image forming apparatus including a recording member having a resin layer formed of a photo-softenable composition.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Laid-Open No. 11-190883 Summary of the Invention

[0006] Technical Problem to be Solved by the Invention

[0007] A resin composition exhibiting photo-softening properties is desired for applications such as adhesives and coating materials having peelability. In the molecular structure designed to ensure photo-softening properties, there is room for improvement in terms of heat resistance. It is speculated that a photo-softenable composition that can withstand the heating process can expand applications such as adhesives and coating materials.

[0008] An object of the present invention is to provide a resin material that imparts a resin composition having excellent heat resistance and exhibiting photo-softening properties. An object of the present invention is to provide a resin composition having excellent heat resistance and exhibiting photo-softening properties.

[0009] Means for Solving the Technical Problem

[0010] The present invention provides the following [1] to [6] in several aspects.

[0011] [1] A resin material containing: a compound A having a (meth)acryloyl group; a compound B having two or more thiol groups; and a photo radical initiator having a 5% weight loss temperature of 200°C or higher, wherein the compound A includes a compound A-1 having three or more (meth)acryloyl groups, and at least one of the compound A and the compound B has a disulfide bond in the molecule.

[0012] [2] The resin material according to [1], wherein the compound A further includes a compound A-2 having two (meth)acryloyl groups.

[0013] [3] The resin material according to [1] or [2], wherein the radical initiator is a compound that imparts a benzoyl radical by light irradiation, and the ratio of the number of moles of the benzoyl radical to the number of moles of the compound A-1 is 21 / 20 or more.

[0014] [4] A resin composition containing: a reaction product of a compound A having a (meth)acryloyl group and a compound B having two or more mercapto groups; and a photo radical initiator with a 5% weight loss temperature of 200 °C or higher, wherein the compound A includes a compound A-1 having three or more (meth)acryloyl groups, and at least one of the compound A and the compound B has a disulfide bond in the molecule.

[0015] [5] The resin composition according to [4], wherein the compound A further includes a compound A-2 having two (meth)acryloyl groups.

[0016] [6] The resin composition according to [4] or [5], wherein the radical initiator is a compound that imparts a benzoyl radical upon light irradiation, and the molar ratio of the benzoyl radical to the molar number of the compound A-1 is 21 / 20 or more.

[0017] Advantages of the Invention

[0018] According to the present invention, a resin material capable of providing a resin composition with excellent heat resistance and exhibiting photo-softening properties can be provided. According to the present invention, a resin composition with excellent heat resistance and exhibiting photo-softening properties can be provided. Brief Description of the Drawings

[0019] Figure 1 It is a diagram showing a test piece made for adhesion evaluation.

[0020] Figure 2 It is a graph showing the evaluation results of the photo-responsiveness of the storage modulus G' of the resin composition.

[0021] Figure 3 It is a graph showing the evaluation results of the photo-responsiveness of tanδ of the resin composition.

[0022] Figure 4 It is a photograph showing the appearance of the resin composition after light irradiation. (A) shows the result of Example 1, (B) shows the result of Example 2, and (C) shows the result of Example 3.

[0023] Figure 5 It is a graph showing the adhesion measurement results.

[0024] Figure 6 It is a graph showing the results of the storage modulus, loss modulus, and tanδ at high temperature for Example 3 and Comparative Example 1. (A) shows the result of Example 3, and (B) shows the result of Comparative Example 1.

[0025] Figure 7It is a photograph showing the appearance of the shear test piece after the adhesion force measurement. (a) shows the appearance of the shear test piece before the measurement, (b) shows the peeling state of the sample without light irradiation, (c) shows the peeling state after light irradiation, and (d) shows the appearance of the shear test piece shown in (c) after cleaning. Detailed Embodiments

[0026] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

[0027] In this specification, the term "process" includes not only an independent process, but also, even in a case where it cannot be clearly distinguished from other processes, as long as the intended effect of the process is achieved, it is also included in this term. The numerical range represented by "~" means a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively.

[0028] In this specification, regarding the content of each component in the resin material or the resin composition, in a case where there are a plurality of substances corresponding to each component, unless otherwise specified, it means the total amount of the plurality of substances. Unless otherwise specified, the exemplified materials can be used alone, one kind, or in combination of two or more kinds.

[0029] In the numerical ranges described step by step in this specification, the upper limit value or the lower limit value of the numerical range of a certain step can be replaced with the upper limit value or the lower limit value of the numerical range of other steps. In the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range can also be replaced with the values shown in the examples. "A or B" means that as long as either A or B is included, both can also be included. In this specification, "(meth)acryloyl" is methacryloyl or acryloyl. In this specification, the "weight average molecular weight" and the "number average molecular weight" are polystyrene conversion values obtained by gel permeation chromatography (GPC) and using a calibration curve based on standard polystyrene. In this specification, "room temperature" means 25 ± 10°C.

[0030] In this specification, "photo-softening property" means the property of being softened by light irradiation. Among the softening properties, for example, a decrease in the elastic modulus and an increase in the loss tangent (tanδ) are included. In this specification, the "softened product of the resin composition" means a state in which the elastic modulus decreases and a state in which the loss tangent (tanδ) increases, etc., based on the resin composition before light irradiation. A resin composition showing a photo-softening property is a composition that is softened by light irradiation to give a jelly-like substance or a liquid substance.

[0031] The resin material according to this embodiment contains a compound A having a (meth)acryloyl group, a compound B having two or more thiol groups, and a photo radical initiator having a 5% weight loss temperature of 200 °C or higher. At least one of the compound A and the compound B has a disulfide bond (-S-S-) in the molecule.

[0032] The compound A includes a compound A-1 having three or more (meth)acryloyl groups. The compound A-1 is a compound having three or more groups selected from the group consisting of a methacryloyl group and an acryloyl group in one molecule. Regarding the upper limit of the number of (meth)acryloyl groups of the compound A-1, for each molecule, it can be, for example, 10 or less, 8 or less, 6 or less, or 4 or less. The compound A-1 can be a compound having three or more (meth)acryloyl groups.

[0033] The molecular weight or weight average molecular weight of the compound A-1 can be 150 or more, 500 or more, or 1000 or more, and can also be 50000 or less, 10000 or less, or 2000 or less.

[0034] Examples of the compound A-1 include a compound having a trimethylolpropane skeleton and having three or more (meth)acryloyl groups, a compound having a pentaerythritol skeleton and having three or more (meth)acryloyl groups, and a compound having an isocyanurate skeleton and having three or more (meth)acryloyl groups.

[0035] The compound A-1 having a trimethylolpropane skeleton can be, for example, a compound represented by the following formula (a1).

[0036]

[0037] In the formula (a1), R 1 represents a hydrogen atom or a methyl group, and L 1 represents an alkylene group. n1, n2, and n3 each independently represent 0 or an integer of 1 or more. When there are a plurality of R 1 , they can be the same or different from each other. The number of carbon atoms of the alkylene group represented by L 1 can be 2 or more, and can also be 10 or less, 6 or less, or 3 or less. The alkylene group represented by L 1 can be, for example, an ethylene group (-CH 2 -CH 2 -). When there are a plurality of L 1 , they can be the same or different from each other. The sum n1 + n2 + n3 of n1, n2, and n3 can be, for example, 0 or more or 6 or more, and can also be 27 or less, 20 or less, or 9.

[0038] Examples of commercially available products of compound A-1 having 3 (meth)acryloyl groups include FANCRYL FA-133A (manufactured by Showa Denko Materials Co., Ltd.), FA-132A, FA-137A, FA-133M, FA-137M (all manufactured by Showa Denko Materials Co., Ltd.), NK ESTERA-TMPT, NK ESTERA-TMPT-9EO, NK ESTERA-T-20E, NK ESTERA-GLY-3E, NK ESTERA-GLY-9E, NK ESTERA-GLY-20E, NK ESTERA-9300 (all manufactured by SHIN-NAKAMURA CHEMICAL CO,LTD.), TMPTA, EBECRYL160S, OTA480 (all manufactured by DAICEL-ALLNEX LTD.), Viscoat#295, Viscoat#300 (both manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD.), EBECRYL4513, EBECRYL8465, EBECRYL9260, EBECRYL8701, KRM8667, and KRM8296 (all manufactured by DAICEL-ALLNEX LTD.). Examples of commercially available products of compound A-1 having 4 or more (meth)acryloyl groups include EBECRYL4265, EBECRYL4587, EBECRYL4666, EBECRYL8210, EBECRYL8606, EBECRYL1290, EBECRYL5129, EBECRYL8254, EBECRYL8301R, KRM8200, KRM8904, KRM8452, EBECRYL220 (all manufactured by DAICEL-ALLNEX LTD.), NK ESTERA-TMMT, NK ESTERA-TM-35E, NK ESTERA-D-TMP, NK ESTERA-DPH, NK ESTERA-9550, NK ESTERA-DPH-12E, and NK ESTERTPOA-50 (all manufactured by SHIN-NAKAMURA CHEMICAL CO,LTD.), etc.

[0039] Compound A may also contain compound A-2 having 2 (meth)acryloyl groups. Compound A-2 is a compound having 1 or more groups selected from the group consisting of a methacryloyl group and an acryloyl group. Compound A-2 also contains a linking group that links 2 (meth)acryloyl groups.

[0040] The molecular weight or weight-average molecular weight of Compound A-2 may be 150 or more, 500 or more, or 1000 or more, and may also be 50000 or less, 10000 or less, or 2000 or less.

[0041] Compound A-2 may be, for example, a compound represented by the following formula (a2).

[0042]

[0043] In formula (a2), R 2 represents a hydrogen atom or a methyl group. L 2 represents an alkylene group. When there are a plurality of Rs 2 they may be the same or different from each other. L 2 The alkylene group represented by L may have 2 or more carbon atoms, and may also have 10 or less, 6 or less, or 3 or less carbon atoms. L 2 The alkylene group represented by L may be, for example, ethylene (-CH 2 -CH 2 -). m represents an integer of 1 or more. m may be 2 or more or 3 or more. The upper limit of m may be, for example, 10 or less, 8 or less, 6 or less, or 5 or less. When there are a plurality of Ls 2 they may be the same or different from each other.

[0044] As commercially available products of Compound A-2, for example, FANCRYL FA-220 (manufactured by Showa Denko Materials Co., Ltd.), NK ESTER HD-N, NK ESTER NOD-N, NK ESTER DOD-N, NK ESTER NPG, NK ESTER 701, NK ESTER 2G, NK ESTER 3G, NK ESTER 4G, NK ESTER 9G, NK ESTER 14G, NK ESTER 23G, NK ESTER 9PG, NK ESTER DCP, NK ESTER BPE-80N, NK ESTER BPE-100, NK ESTER BPE-200, NK ESTER BPE-500, NK ESTER BPE-900, NK ESTER BPE-1300N, NK ESTER A-HD-N, NK ESTER A-NOD-N, NK ESTER A-DOD-N, NK ESTER A-NPG-N, NK ESTER 701A, NK ESTER A-200, NK ESTER A-400, NK ESTER A-600, NK ESTER A-1000, NK ESTER APG-200, NK ESTER APG-400, NK ESTER APG-700, NK ESTER A-PTMG65, NK ESTER A-DCP, NK ESTER ABE-300, NK ESTER A-BPE-4, NK ESTER A-BPE-10, NK ESTER A-BPE-20 (all manufactured by SHIN-NAKAMURA CHEMICAL CO, LTD.), EBECRYL 210, EBECRYL 230, EBECRYL 270, EBECRYL 4858, EBECRYL 8402, EBECRYL 8804, EBECRYL 8807, EBECRYL 9270, EBECRYL 8191, Violet Light TM UV-2000B, Violet Light TM UV-3000B, Violet Light TM UV-3200B, Violet Light TM UV-3300B, Violet Light TM UV-3310B, Violet Light TM UV-3500BA, Violet Light TM UV-3520EA, Violet Light TM UV-3700B and Violet Light TM UV-6640B (all manufactured by Mitsubishi Chemical Corporation), etc.

[0045] Based on the total amount of the resin material, the content of Compound A (the total content of Compound A-1 and Compound A-2) may be 1% by mass or more, 3% by mass or more, or 5% by mass, and may also be 99% by mass or less, 97% by mass or less, or 95% by mass or less.

[0046] Based on the total amount of the resin material, the content of Compound A-1 may be 1% by mass or more, 3% by mass or more, or 5% by mass or more, and may also be 90% by mass or less, 50% by mass or less, or 15% by mass or less.

[0047] Based on the total amount of the resin material, the content of Compound A-2 may be 1% by mass or more, 3% by mass or more, or 5% by mass or more, and may also be 99% by mass or less, 97% by mass or less, or 95% by mass or less.

[0048] The ratio of the number of moles of Compound A-1 to the total number of moles of Compound A (the total number of moles of Compound A-1 and Compound A-2) may be 0.05 or more, 0.1 or more, or 0.2 or more, and may also be 0.5 or less, 0.4 or less, or 0.3 or less. When the ratio of the number of moles of Compound A-1 to the total number of moles of Compound A is 0.5 or less, the light softening property is further improved. When the ratio of the number of moles of Compound A-1 to the total number of moles of Compound A is 0.05 or more, the thermoplasticity is further reduced and the mechanical properties at high temperatures are more excellent.

[0049] When Compound A has a disulfide bond in the molecule, the number of disulfide bonds in Compound A-1 or Compound A-2 may be, for example, 1 to 1000 or 4 to 50.

[0050] Compound B is a compound having 2 or more mercapto groups (-SH) in one molecule. The upper limit of the number of mercapto groups per molecule of Compound B may be, for example, 10 or less, 8 or less, 6 or less, 4 or less, or 3 or less. Compound B may be a compound having 2 mercapto groups.

[0051] When Compound B has a disulfide bond in the molecule, the number of disulfide bonds in Compound B may be, for example, 1 to 1000 or 4 to 50.

[0052] The molecular weight or weight-average molecular weight of Compound B may be 100 or more, 1000 or more, or 3000 or more, and may also be 50000 or less, 30000 or less, or 10000 or less.

[0053] Compound B can be a compound (e.g., a polymer or oligomer) having a linear molecular chain and terminal groups, with disulfide bonds in the molecular chain. In this case, the terminal groups in Compound B can be thiol groups. When Compound B is such a compound, it is easier to form a cured product with excellent photo-softening properties. The molecular chain in Compound B can contain disulfide bonds and polyether chains, or can be composed of disulfide bonds and polyether chains.

[0054] Compound B can be, for example, of formula (1): a compound represented by HS-(A-S-S) p -A-SH (Compound (1)). In the formula, A represents a polyether chain. Multiple A's can be the same or different respectively. p represents an integer of 1 or more. p can be, for example, 1 or more, 4 or more, or 1000 or less. Compound B is a compound obtained by elongating the chain of Compound (1).

[0055] The polyether chain as A can be, for example, a polyoxyalkylene chain. The polyether chain as A can be, for example, a group represented by -A 1 -O-A 2 -O-A 3 -. A 1 ~A 3 can each independently be an alkylene group, or can be an alkylene group having 1 to 2 carbon atoms (e.g., methylene, ethylene). Examples of the polyether chain as A include -CH 2 CH 2 -O-CH 2 -O-CH 2 CH 2 - etc.

[0056] As commercially available products of Compound B, for example, THIOKOL LP series (dithiols having disulfide bonds, manufactured by TORAYFINE CHEMICALS CO., LTD.) can be cited. Compound B can be used alone in one kind, or two or more kinds can be used in combination. Compound B can also be obtained by converting the reactive functional groups of a raw material compound having reactive functional groups and disulfide bonds at the terminals into thiol groups. Examples of the reactive functional groups in the raw material compound include carboxyl groups, hydroxyl groups, etc. Examples of the raw material compound having reactive functional groups and disulfide bonds at the terminals include 3,3'-dithiobispropionic acid, dithiodiethanol, cystamine, etc.

[0057] Based on the total mass of the resin material, the content of Compound B can be 1% by mass or more, 3% by mass or more, 5% by mass or more, 30% by mass or more, or 50% by mass or more, or can be 99% by mass or less, 97% by mass or less, or 95% by mass or less.

[0058] The ratio of the number of moles of the mercapto group in Compound B to the number of moles of the (meth)acryloyl group in Compound A can be, for example, 0.90 or more, or 0.95 or more, and can also be 1.1 or less, or 1.05 or less. When the ratio of the number of moles of the mercapto group in Compound B to the number of moles of the (meth)acryloyl group in Compound A is within the above range, the reduction in photo-softening property is further suppressed, and the reduction in the storage stability of the resin composition is also further suppressed.

[0059] A photo-radical initiator is a component that generates radicals upon light irradiation. As the photo-radical initiator, for example, a component used as a photo-polymerization initiator can be used. Examples of the photo-radical initiator include a hydrogen abstraction type photo-radical polymerization initiator that generates radicals by abstracting hydrogen from other molecules upon light irradiation, and an intramolecular cleavage type photo-radical polymerization initiator that generates two radicals by photo-cleavage of itself upon light irradiation. From the viewpoint of more excellent photo-softening property, the photo-radical initiator can be an intramolecular cleavage type photo-radical polymerization initiator.

[0060] Examples of the hydrogen abstraction type photo-radical initiator include hexaarylbiimidazole (HABI) compounds, benzophenone compounds, thioxanthone compounds, fluorenone compounds, α-diketone compounds, and the like.

[0061] Examples of the intramolecular cleavage type photo-radical initiator include benzyl ketal type photo-radical initiators, α-aminoalkyl phenyl ketone type photo-radical initiators, α-hydroxyalkyl phenyl ketone type photo-radical initiators, α-hydroxyacetophenone type photo-radical initiators, acylphosphine oxide type photo-radical initiators, and the like.

[0062] The 5% weight loss temperature of the photo-radical initiator is 200 °C or higher. The 5% weight loss temperature is the temperature at the moment when the mass of the sample decreases by 5% from the initial value in thermogravimetric analysis in which the temperature is raised and the mass change of the sample is measured. From the viewpoint of further improving the heat resistance of the resin composition, the 5% weight loss temperature of the photo-radical initiator can be 210 °C or higher, 220 °C or higher, 230 °C or higher, 240 °C or higher, or 250 °C or higher, and can also be 340 °C or lower, 330 °C or lower, 320 °C or lower, 310 °C or lower, or 300 °C or lower.

[0063] As a photo radical initiator having a 5% weight loss temperature of 200°C or higher, examples include 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propanone (5% weight loss temperature: 204°C), 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propanone (5% weight loss temperature: 220°C), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (5% weight loss temperature: 248°C), 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one (5% weight loss temperature: 248°C), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (5% weight loss temperature: 241°C), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (5% weight loss temperature: 253°C), and their polymers.

[0064] From the viewpoints of further suppressing curing inhibition, further suppressing the decrease in storage modulus during curing, and solubility in the resin component, the photo radical generator can be an α-aminoalkyl phenyl ketone type photo radical initiator or 2-(dimethylamino)-2-(4-methylbenzyl)-1-[4-morpholin-4-yl-phenyl)butan-1-one.

[0065] From the aspect of further more excellent photo softening properties, the photo radical initiator can be a compound that generates two or more single radicals per molecule of the photo radical initiator upon light irradiation and does not generate double radicals. Examples of such a photo radical initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropanone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide.

[0066] The photo radical initiator may be a compound that imparts a benzoyl radical upon light irradiation. The compound that imparts a benzoyl radical upon light irradiation refers to a compound that cleaves through a photoreaction to generate a benzoyl radical. Examples of the compound that imparts a benzoyl radical upon light irradiation include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butane-1-one, 2,4,6-trimethylbenzoyl-diphenyl-oxide, and bis(2,4,6-trimethylbenzoyl)-phenyl-oxide.

[0067] Based on the total amount of the resin material, the content of the photo radical initiator may be 3% by mass or more, 5% by mass or more, or 10% by mass or more, and may also be 30% by mass or less, 20% by mass or less, or 15% by mass or less.

[0068] From the aspect of further improving the photo softening property, the ratio of the number of moles of the photo radical initiator to the number of moles of compound A-1 may be 1 or more, 1.5 or more, 2 or more, 3 or more, 5 or more, 8 or more, 10 or more, 12 or more, 14 or more, or 16 or more. The ratio of the number of moles of the photo radical initiator to the number of moles of compound A-1 may be 20 or less, 18 or less, 16 or less, 14 or less, 12 or less, 10 or less, 8 or less, 6 or less, 4 or less, or 2 or less, for example.

[0069] From the aspect of further improving the photo softening property, the ratio of the number of moles of the photo radical initiator to the number of moles of compound B may be 0.2 or more, 0.5 or more, 0.7 or more, 0.9 or more, or 1.1 or more. The ratio of the number of moles of the photo radical initiator to the number of moles of compound B may be 3.0 or less, 2.0 or less, or 1.5 or less.

[0070] From the aspect of further improving the photo softening property, the ratio of the number of moles of the benzoyl radical to the number of moles of compound A-1 may be 21 / 20 or more. From the aspect of further improving the photo softening property, the ratio of the number of moles of the benzoyl radical to the number of moles of compound A-1 may be 2 or more, 3 or more, or 4 or more. The ratio of the number of moles of the benzoyl radical to the number of moles of compound A-1 may be 20 or less, 15 or less, 12 or less, 10 or less, 8 or less, 6 or less, 4 or less, or 2 or less, for example.

[0071] The resin material may also contain a catalyst. By further containing a catalyst, the reaction between compound A and compound B is further promoted. Examples of the catalyst include amine compounds and phosphorus compounds.

[0072] The amine compound may be, for example, a tertiary amine compound or a secondary amine compound. Examples of the amine compound include dicyandiamide, trimethylamine, triethylamine, tripropylamine, tributylamine, tri-n-octylamine, dimethylethylamine, dimethylpropylamine, dimethylbutylamine, dimethyl-n-octylamine, 1,4-diazabicyclo[2.2.2]octane, 1,8-diazabicyclo[5.4.0]undec-7-ene, benzyldimethylamine, 4-methyl-N,N-dimethylbenzylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 4-dimethylaminopyridine.

[0073] From the viewpoints of easier rapid curing at room temperature and easier adjustment of the open time, etc., the catalyst may be 1,8-diazabicyclo[5.4.0]undec-7-ene or its salt, or a phosphorus compound.

[0074] Based on the total amount of the resin material, the content of the catalyst may be 0.02% by mass or more, 0.1% by mass or more, or 1% by mass or more, and may also be 3% by mass or less, 2.5% by mass or less, or 2% by mass or less.

[0075] The resin material may further contain components other than compound A, compound B, the photo radical initiator, and the catalyst (other components). Examples of the other components include plasticizers, tackifiers and other tackiness-imparting agents, antioxidants, colorless dyes, sensitizers, coupling agents and other adhesion improvers, polymerization inhibitors, light stabilizers, defoaming agents, fillers, chain transfer agents, thixotropy-imparting agents, flame retardants, mold release agents, surfactants, lubricants, antistatic agents and other additives. These additives can be well-known additives. When the resin material contains other components, based on the total amount of the resin material, the total content of the other components may be 0 to 95% by mass, 0.01 to 50% by mass, or 0.1 to 10% by mass.

[0076] The resin material can be a varnish of a resin material diluted with a solvent. As the solvent, for example, aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, p-cymene; aliphatic hydrocarbons such as hexane, heptane; cycloalkanes such as methylcyclohexane; cyclic ethers such as tetrahydrofuran, 1,4-dioxane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, γ-butyrolactone; carbonates such as ethylene carbonate, propylene carbonate; amides (NMP) such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, etc. Based on the total mass of the varnish, the content of the solid components in the varnish, that is, the total content other than the solvent in the varnish, can be 10 to 95% by mass or 15 to 70% by mass or 20 to 50% by mass.

[0077] The resin material can be prepared, for example, by a method including a step of mixing or kneading the above-mentioned respective components. The mixing and kneading can be carried out by appropriately combining common dispersers such as a stirrer, a kneader, a three-roll mill, a ball mill, a bead mill, etc.

[0078] The resin composition according to the present embodiment contains a reaction product of compound A and compound B and a photo radical initiator having a 5% weight loss temperature of 200 °C or higher. The resin composition according to the present embodiment is a cured product of the above resin material. The specific forms of compound A, compound B, and the photo radical initiator are the same as those described in the resin material.

[0079] As a method for obtaining the resin composition, for example, a method of reacting the above resin material can be cited. The reaction temperature of the resin material can be, for example, 0 to 200 °C, or 30 to 150 °C, or 60 to 100 °C. The time for maintaining the above reaction temperature can be, for example, 0.1 to 168 hours, or 72 hours or less, 24 hours or less, 12 hours or less, 6 hours or less, 4 hours or less, 3 hours or less, or 2 hours or less.

[0080] More specifically, the reaction product of compound A and compound B is formed by the Michael addition reaction of the (meth)acryloyl group in compound A and the thiol group in compound B.

[0081] The reaction product of compound A and compound B has a structure represented by formula (I): *-C(=O)-CHR-CH 2 -S-* and a disulfide bond. In formula (I), R represents a hydrogen atom or a methyl group, and * represents a bonding site. The disulfide bond can be present in the main chain and / or side chain of the reaction product. Considering the further improvement of the photo softening property, the disulfide bond can be present in the main chain of the reaction product.

[0082] The reaction product of Compound A and Compound B may contain a compound including a structure represented by the following formula (x1).

[0083]

[0084] In formula (x1), R 1 , L 1 , n1, n2 and n3 have the same meanings as in formula (a1), A and p have the same meanings as in formula (1), and * represents a bonding site. When there are multiple Rs 1 , Ls 1 , As and ps in formula (x1), they may be the same or different respectively.

[0085] The reaction product of Compound A and Compound B may contain a compound including a structure represented by the following formula (x2).

[0086]

[0087] In formula (x2), R 2 , L 2 , m have the same meanings as in formula (a2), A and p have the same meanings as in formula (1), and * represents a bonding site. When there are multiple Rs 2 , As and ps in formula (x2), they may be the same or different respectively.

[0088] The number average molecular weight Mn of the resin composition may be 1000 or more, 2000 or more, 3000 or more, 5000 or more, 6000 or more, or 6500 or more, and may also be 200000 or less, 100000 or less, or 50000 or less.

[0089] The weight average molecular weight Mw of the resin composition may be 1,000 or more, 3,000 or more, 5,000 or more, 10,000 or more, 15,000 or more, 20,000 or more, 25,000 or more, 30,000 or more, or 40,000 or more, and may also be 1000,000 or less, 400,000 or less, or 100,000.

[0090] The storage modulus G' of the resin composition may be 1 kPa or more, 10 kPa or more, or 100 kPa or more, and may also be 100000 kPa or less, 10000 kPa or less, or 2000 kPa or less.

[0091] The storage modulus G' of the resin composition can be measured by the method described in the following examples.

[0092] From the aspect of more excellent heat resistance of the resin composition, the 5% weight loss temperature T of the resin composition d5％It can be 210 °C or higher, 220 °C or higher, 230 °C or higher, 240 °C or higher, or 250 °C or higher, and can also be 310 °C or lower, 300 °C or lower, 290 °C or lower, 280 °C or lower, or 270 °C or lower. The 5% weight loss temperature T of the resin composition d5％ can be measured by the method described in the examples below.

[0093] The shear adhesion of the resin composition at 25 °C can be 10 N / cm 2 or higher, 20 N / cm 2 or higher, or 50 N / cm 2 or higher. The shear adhesion of the resin composition at 100 °C can be 10 N / cm 2 or higher, or 20 N / cm 2 or higher, and can also be 50 N / cm 2 or lower. The shear adhesion of the resin composition can be measured by the method described in the examples below.

[0094] The resin composition has the property of softening upon light irradiation. The light during light irradiation can be, for example, light including light with a wavelength of 365 nm or a wavelength of 405 nm. By irradiating such light, the resin composition can be softened. The exposure amount of light irradiation can be, for example, 1000 mJ / cm 2 or higher. In this specification, the exposure amount refers to the product of the illuminance (mW / cm 2 ) and the irradiation time (seconds). The light irradiation can be performed directly on the irradiation object or through glass or the like. The light source for light irradiation is not particularly limited, and examples include LED lamps, mercury lamps (low pressure, high pressure, ultra-high pressure, etc.), metal halide lamps, excimer lamps, xenon lamps, etc. Among them, the light source for light irradiation can be an LED lamp, a mercury lamp, or a metal halide lamp.

[0095] By irradiating the resin composition with light, the photo radical initiator in the resin composition cleaves the disulfide bond (-S-S-) in the reaction product of compound A and compound B. As a result, the crosslinking of the reaction product of compound A and compound B decreases and softens, or the reaction product of compound A and compound B is depolymerized and softened. Since it softens upon light irradiation, the resin composition can also be referred to as a photo-softenable composition.

[0096] The number average molecular weight Mn of the resin composition after light irradiation (photo-softened product) can be 100,000 or lower, 50,000 or lower, 20,000 or lower, 10,000 or lower, and can also be 1000 or higher, 3000 or higher, 5000 or higher, or 5500 or higher.

[0097] The weight-average molecular weight Mw of the photo-softening substance can be 300,000 or less, 150,000 or less, 60,000 or less, 60,000 or less, or 30,000 or less, and can also be 10,000 or more or 15,000 or more.

[0098] The Mn and Mw of the photo-softening substance can be measured by the methods described in the examples below.

[0099] Generally, the storage modulus G' of the photo-softening substance is lower than the storage modulus G' of the resin composition. The storage modulus G' of the photo-softening substance can be 8 kPa or less, 5 kPa or less, 3 kPa or less, or 1 kPa or less, and can also be 0.001 kPa or more or 0.005 kPa or more.

[0100] The loss elastic modulus G'' of the photo-softening substance can be 0.10 kPa or more, 0.20 kPa or more, 0.30 kPa or more, 0.50 kPa or more, 0.70 kPa or more, 1.0 kPa or more, 3.0 kPa or more, or 5.0 kPa or more, and can also be 10 kPa or less, 5 kPa or less, 3 kPa or less, or 1 kPa or less.

[0101] The loss tangent tanδ of the photo-softening substance can be 1.0 or more, 1.2 or more, 1.5 or more, 1.8 or more, or 2.0 or more, and can also be 45 or less, 35 or less, 25 or less, 15 or less, 5 or less, or 1.5 or less. The loss tangent tanδ is represented by the ratio of the loss elastic modulus G'' to the storage modulus G' (G'' / G').

[0102] The storage modulus G', loss elastic modulus G'', and tanδ of the photo-softening substance can be measured by the methods described in the examples below.

[0103] The resin composition can be formed into various shapes. For example, a cured product formed into a film shape can be used as a film. A cured product formed into a block shape can be used as a block. The method for forming a cured product into a film shape or a block shape is not particularly limited, and known methods can be applied.

[0104] The resin material and resin composition can be used, for example, in applications such as adhesives, pressure-sensitive adhesives, coating materials, protective materials, parts, and pick-up materials for materials. The adhesive can be used, for example, as an adhesive that can be peeled off without damaging the adherend after temporarily fixing the adherend to a substrate. The adhesive containing the resin material or resin composition exhibits adhesiveness even at a high temperature of 100°C due to its excellent heat resistance. Therefore, the adhesive containing the resin material or resin composition can also be used as an adhesive that can be peeled off by irradiating light at room temperature after undergoing a high-temperature process.

[0105] The adhesive composition according to this embodiment contains a compound A having a (meth)acryloyl group, a compound B having two or more thiol groups, and a photo radical initiator having a 5% weight loss temperature of 200 °C or higher. In this adhesive composition, compound A includes a compound A-1 having three or more (meth)acryloyl groups, and at least one of compound A and compound B has a disulfide bond in the molecule. In this adhesive composition, the specific forms of compound A, compound B, the photo radical initiator, and other components can adopt the above forms.

[0106] The adhesive composition can form a cured product of the adhesive composition through the reaction of compound A and compound B, and can function as an adhesive layer for adhering two or more adherends. The reaction conditions of compound A and compound B can be as described above.

[0107] The cured product of the adhesive composition has photo softening properties. Therefore, the cured product of the adhesive composition can be separated by light irradiation without damaging two or more adherends. The softened product remaining on the adherend can be removed by a solvent as needed. The conditions of light irradiation can be the above conditions.

[0108] The adherend can be, for example, a fine structure, a fragile adherend, or an adherend susceptible to physical stress. Examples of the fine structure include microchannels, micro wiring, and micro bumps. Examples of the fragile adherend include ultra-thin film wafers and glass. Examples of the adherend susceptible to physical stress include soft tissues and cells.

[0109] An adherend according to one embodiment includes: a first adherend, a second adherend, and an adhesive layer that bonds the first adherend and the second adherend to each other. The adhesive layer contains a cured product of the adhesive composition. The adherend can be manufactured by a method including a process of bonding the first adherend and the second adherend via the adhesive composition. The curing conditions can be the above reaction conditions. The adherend can be separated by light irradiation even after undergoing a high-temperature process.

[0110] A method for separating an adherend according to one embodiment includes a process of irradiating light to the adhesive layer of the adherend to separate the first adherend and the second adherend. Since the adhesive layer contains a cured product of the photocurable composition described above, by irradiating light, the cured product of the photocurable composition can be melted and the adherends can be easily separated from each other. The adherends can be separated by light irradiation even after undergoing a high-temperature process.

[0111] In the method for separating an adherend, the type of light, the light source, etc. during light irradiation can be the same as above.

[0112] Examples

[0113] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.

[0114] 1-1. Materials to be tested

[0115] The materials for synthesis were used as purchased.

[0116] As the compound having two or more thiol groups, THIOKOL LP-55 (manufactured by TORAY FINECHEMICALS CO., LTD., SH% = 1.8%) was used. As the compound having two (meth)acryloyl groups, polyethylene glycol diacrylate (FANCRYL FA-220; manufactured by Showa Denko Materials Co., Ltd.) was used. As the compound having three or more (meth)acryloyl groups, trimethylolpropane triacrylate (FANCRYL FA-133; manufactured by Showa Denko Materials Co., Ltd.) was used. As the curing catalyst, 2,4,6-tris(dimethylaminomethyl)phenol (ADEKA HARDENER EHC-30; manufactured by ADEKA CORPORATION) was used. As the photo radical initiator, 2-(dimethylamino)-2-(4-methylbenzyl)-1-[4-morpholin-4-yl-phenyl)butan-1-one (Omnirad-379EG; manufactured by IGM Resins B.V., 5% weight loss temperature: 248 °C) was used.

[0117] [Table 1]

[0118]

[0119] 1-2. Preparation of resin composition and evaluation film

[0120] The materials were blended in a 100 mL plastic ointment jar, heated at 95 °C for 1 hour, and then stirred for 3 minutes at 2000 rpm using a rotation-revolution mixer (Awatori Rentaro ARE-310; manufactured by THINKY CORPORATION) to complete the blending. The composition obtained together with the spacer of the target film thickness was sandwiched between the release surfaces of two sheets of release PET (FILMBYNA DB-50 (manufactured by FUJIMORI KOGYO CO., LTD.)), and the film obtained by peeling the release film after curing at room temperature for 1 week was used as the test specimen for various evaluations. The completion of the reaction was confirmed based on the results of infrared absorption spectroscopy measurement. When the integral value of the peak of the double bond of the acryloyl group near 810 cm -1 was reduced by 95% or more compared to that before polymerization, the reaction was considered complete.

[0121] 1-3. Light irradiation

[0122] During UV irradiation, a UV irradiation device (manufactured by Panasonic Industrial Devices SUNX Co., Ltd., power supply: AicureUJ30, 365 nm LED lamp head: ANUJ6186, 405 nm LED lamp head: ANUJ6189) was used. Regarding the irradiation conditions, measurements were made using a 365 nm light receiver and a 405 nm light receiver respectively with an illuminometer UIT-250 (manufactured by Ushio Inc.).

[0123] 1-4. Mechanical property evaluation

[0124] A glass stage for microscope observation and an 8 mm disk rotor were used as options for a viscoelasticity measuring device (manufactured by TA Instruments, product name: DHR-2). The evaluation sample was irradiated with light using the UV irradiation device described in "1-3. Light irradiation" from the bottom surface of the glass stage, and thus the change in viscoelasticity with respect to light irradiation was evaluated. Measurements were carried out under the conditions that the gap between the stage and the rotor was 500 ± 200 μm, the frequency was 1 Hz, and the displacement was 1%. During the measurement, a film with a film thickness of 500 ± 200 μm obtained by the method of "1-2. Preparation of resin composition and evaluation film" was punched into a cylindrical film with a diameter of 8 mm. The temperature dependence of viscoelasticity was measured by replacing the glass stage for microscope observation with a peltier plate.

[0125] 1-5. Adhesion evaluation

[0126] As Figure 1 shown, the resin composition obtained by the method of "1-2. Preparation of resin composition and evaluation film" was sandwiched between two glass slides (S-1112; manufactured by Matsunami Glass Ind., Ltd.) or two polycarbonate plates so as to have an adhesive area in the shape of a circle with a diameter of 10 - 13 mm and an adhesive layer thickness of 100 ± 20 μm, and left standing at room temperature for 1 week, thereby obtaining a shear test piece.

[0127] Completion of curing was confirmed by infrared absorption spectroscopy, and the state where the integral value of the peak of acryloyl near 810 cm -1 was reduced by more than 95% compared with that before reaction was defined as the completion of curing.

[0128] For the obtained shear test pieces, the shear adhesion strength was measured at 25°C and 100°C environments using Autograph AGS-X manufactured by Shimadzu Corporation at a tensile speed of 10 mm / minute.

[0129] 1-6. GPC Measurement

[0130] Regarding the measurement of molecular weight, using Chromaster manufactured by High-Tech Science Corporation, GL-A130-S, GL-A150-S, and GL-A160-S were used in the column, RI was used as the detector, and the measurement was carried out at a temperature of 35°C. A THF (tetrahydrofuran) solution with a sample concentration of 1 wt% was prepared and used as the GPC sample. The molecular weight conversion value was calculated using a calibration curve of standard polystyrene molecules. The film with a thickness of 500 ± 100 μm obtained by the method of "1-2. Preparation of Resin Composition and Evaluation Film" was sandwiched between two glass slides (S-1111; manufactured by Matsunami Glass Ind., Ltd.) and irradiated with LED light with an irradiation wavelength of 365 nm or 405 nm for 120 seconds, and the photo-melted viscous liquid was used as the sample. 2 Irradiating with LED light with an irradiation wavelength of 365 nm or 405 nm for 120 seconds, and thus using the photo-melted viscous liquid as the sample.

[0131] 1-7. Thermogravimetry-Differential Thermal Analysis (TG-DTA)

[0132] Regarding thermogravimetry-differential thermal analysis, EXSTAR TG / DTA7200 manufactured by SII Nano Technology Inc. was used. Approximately 10 mg of the film sample obtained by the method of "1-2. Preparation of Resin Composition and Evaluation Film" was placed in the sample pan, nitrogen was flowed at a flow rate of 300 mL / minute, and the temperature was raised from room temperature to about 300°C at a rate of 10°C / minute to confirm the 5% weight loss temperature.

[0133] 2-1. Characteristics of Resin Composition

[0134] A linear resin composition was synthesized by Michael addition of a polysulfide, which is a terminal bifunctional thiol (molecular weight of about 3700) having a disulfide bond in the chain, and polyethylene glycol diacrylate. This was set as the resin composition of Comparative Example 1. A crosslinked site was imparted by substituting a part of the diacrylate in the composition of the resin composition of Comparative Example 1 with polyethylene glycol triacrylate. The resin compositions thus obtained were set as Examples 1 to 4. The thiol group (mercapto group) and acryloyl group of the raw materials were blended so that the molar ratio became 1:1.

[0135] The following were studied: how (1) the distance between crosslinking points (crosslinking amount and crosslinking density) and (2) the blending amount of Omnirad-379EG in the resin composition affect the change in mechanical properties accompanying photodegradation.

[0136] First, the distance between crosslinking points (crosslinking amount and crosslinking density) of the resin composition was studied. According to the blending amounts in Tables 2 and 3, the blending amount of Omnirad-379 was fixed, and the distance between crosslinking points (crosslinking amount and crosslinking density) was adjusted by adjusting the blending amounts of diacrylate and triacrylate. Table 2 shows the molar ratios of the blended materials, the distance between crosslinking points, and the results of finger touch tests. Table 3 shows the blending weight ratios of each blend.

[0137] The curing method was carried out with reference to the reaction of thiol groups and acryloyl groups reported previously. By blending 2 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol (ADEKA HARDENER EHC-30; manufactured by ADEKA CORPORATION) as a catalyst, the Michael addition reaction of thiol groups and acryloyl groups was carried out at room temperature. The curing rate was calculated based on the measurement results of infrared absorption spectra. The state where the integral value of the peak of acryloyl groups near 810 cm -1 in the measurement results of infrared absorption spectra decreased by more than 95% compared with that before polymerization was defined as the completion of polymerization. Regarding the distance between crosslinking points Mc, since a trifunctional monomer was used as the crosslinking site, one molecule of triacrylate itself was regarded as a crosslinking point, and the influence of plastic components such as photoinitiators was excluded for calculation. The results of evaluating the mechanical properties and photo-softening properties of the obtained resin composition are shown in Table 4.

[0138] [Table 2]

[0139]

[0140] [Table 3]

[0141]

[0142] [Table 4]

[0143]

[0144] Since the obtained resin composition uses a polysulfide containing a polyether chain as a raw material, it shows a low elasticity of 1 MPa or less.

[0145] As shown in Tables 2 to 4, as the molar ratio and weight ratio of triacrylate (shortening of the distance between crosslinking points and increase in crosslinking density) increase, an increase in storage modulus and a decrease in tanδ and viscosity are confirmed.

[0146] The adhesiveness, i.e., the presence or absence of stickiness, between the films formed from the resin compositions of Examples 1 to 4 and Comparative Example 1 was confirmed. As a result, the viscosity disappeared in the films formed from the resin compositions in which the blending amount of triacrylate relative to polysulfide was 33.3% or more in terms of molar ratio and the distance between crosslinking points was about 8000 g / mol or less.

[0147] In the resin compositions of the examples, since they have a crosslinked structure, an improvement effect in heat creep resistance can be expected. Also, in the resin compositions of the examples, since they have a crosslinked structure, an improvement effect in chemical resistance and heat aging resistance can be expected. Therefore, the resin compositions of the examples can be preferably used as engineering plastics, for example. It was shown that the 5% weight loss temperature of the resin composition did not vary greatly due to the difference in the distance between crosslinking points, and the free radical initiator and the structure of the resin were the controlling factors.

[0148] Next, the photo-softening properties of the resin compositions of Examples 1 to 4 and Comparative Example 1 were evaluated. The results of measuring the viscoelasticity by irradiating the resin compositions of Examples 1 to 4 and Comparative Example 1 with LED light having a wavelength of 405 nm for 2 seconds every 10 seconds are shown in 2 and Figure 2 and Figure 3 . Figure 2 shows the evaluation results of the photo-responsiveness of G' of the resin composition, and also shows the results of repeatedly irradiating with LED light having a wavelength of 405 nm for 2 seconds every 10 seconds after 10 seconds from the start of measurement. 2 The results of repeatedly irradiating with LED light having a wavelength of 405 nm for 2 seconds every 10 seconds after 10 seconds from the start of measurement. The resin compositions of the examples showed photo-softening properties. Figure 3 shows the evaluation results of the photo-responsiveness of tanδ of the resin composition, and also shows the results of repeatedly irradiating with LED light having a wavelength of 405 nm for 2 seconds every 10 seconds after 10 seconds from the start of measurement. 2 The resin compositions of Examples 3 and 4 in which the molar ratio of triacrylate to polysulfide is 13.3% or less showed particularly excellent photo-softening properties. In the resin compositions of Examples 3 and 4, the irradiation amount was 2000 mJ / cm Figure 4 is a photograph showing the appearance of the resin composition after light irradiation. (A) shows the result of Example 1, (B) shows the result of Example 2, and (C) shows the result of Example 3. Regarding the resin composition of Example 1 in which the molar ratio of triacrylate to polysulfide is 66.7%, the tanδ after light irradiation of 30 J / cm 2 showed about 1 and was in a gel state. The photo-softening properties of the resin compositions of Examples 3 and 4 in which the molar ratio of triacrylate to polysulfide is 13.3% or less were particularly excellent. In the resin compositions of Examples 3 and 4, the irradiation amount was 2000 mJ / cm 2 or more and the value of tanδ exceeded 2.0 and was in a liquid state, and the storage modulus became 10000 Pa or less.

[0149] GPC measurement of the resin composition after photo-softening was carried out, and as a result, a negative correlation was confirmed between the number-average molecular weight of the resin composition after photo-softening and the blending amount of the photo-radical initiator. On the other hand, a positive correlation was confirmed between the weight-average molecular weight of the resin composition after photo-softening and the viscosity of the resin composition after photo-softening and the blending amount (crosslinking amount) of triacrylate.

[0150] Since it is speculated that the benzoyl radical among the radicals generated from Omnirad-379EG contributes to the cleavage of the disulfide bond, it is considered that 1 mole of the disulfide bond is cleaved by 2 moles of Omnirad-379EG. That is, the number of moles of the molecular chain ends newly generated in the resin composition due to photo-softening is equal to the number of moles of the photo-radical initiator. It is considered as follows: the number of molecular chain ends and the number-average molecular weight are inversely proportional, so a negative correlation was confirmed between the number-average molecular weight of the resin composition after photo-softening and the blending amount of the photo-radical initiator.

[0151] When the softening phenomenon of the resin composition is regarded as the destruction of the network structure, it is considered that the photo-softenable resin composition is first liquefied by cleaving all the crosslinks. That is, in order to be liquefied by photo-softening, it is expected that the number of bonds to be cleaved needs to exceed the crosslinking points at least. In the blending with a molar ratio of photo-radical initiator to triacrylate of 2:1, the cleavage points = the crosslinking points, so this blending is considered to be on the borderline of whether it can be liquefied by photo-softening. Since it is speculated that the molar ratio of Example 1 is 120 of the photo-radical initiator to 66.7 of triacrylate, and the number of bonds cleaved relative to 66.7 moles of the crosslinking points is 60.0 moles, it is expected that Example 1 shows photo-softening property but is a composition that is not easily liquefied. In fact, the resin composition of Example 1 after light irradiation shows photo-softening property but remains in a jelly state without liquefaction. In the resin compositions other than Example 1, since the bonds above the number of crosslinking points are sufficiently cleaved, liquefaction based on photo-softening is observed. It is shown as follows: the degree of photo-softening property can be adjusted, for example, by the crosslinking amount of the resin composition and the blending amount of the photo-radical initiator.

[0152] The hypothetical reaction formula for the photo-softening of the resin composition is shown in Scheme 3. Scheme 3 shows the reaction in which the benzoyl radical contributes to the cleavage of the disulfide bond and the reaction of cyclization by the exchange reaction of the sulfur radical with the intramolecular disulfide.

[0153] Scheme 3:

[0154]

[0155]

[0156] 2-2. Characteristics as an adhesive based on photo-softening

[0157] In the resin composition obtained in "2-1. Characteristics of the resin composition", the characteristics as an adhesive were evaluated for the resin composition of Example 3 in which the molar ratio of triacrylate to polysulfide was set to 13.3%. The results of the adhesive strength measurement are shown in Table 5 and Figure 5 .

[0158] [Table 5]

[0159]

[0160] It was confirmed that: The shear adhesive strength before light irradiation in the resin composition of Example 3 was 86 N / cm at 25 °C in a polycarbonate substrate 2 , and exhibited an adhesive strength at the level of a normal OCR (Optical Clear Resin) at 25 °C. The shear adhesive strength before light irradiation in the resin composition of Example 3 was 26 N / cm even in a high-temperature environment of 100 °C 2 . As described above, the resin composition of Example 3 does not soften by heating and exhibits adhesive strength. The shear adhesive strength of the resin composition of Example 3 after light softening was measured by the following steps. First, an LED lamp with a wavelength of 405 nm (illuminance 1000 mW / cm 2 ) was irradiated on the resin part of the shear test piece made using the resin composition of Example 3 for 5 seconds. The resin composition of Example 3 after the obtained light irradiation had a deviation due to a minute force, which was the force set and fixed in the Autograph for adhesive strength measurement. There was no peak in the measured value of the shear adhesive strength in the resin composition of Example 3 after light irradiation and values below the noise could not be measured. That is, it can be said that in the resin composition of Example 3 after light irradiation, the shear adhesive strength and the stress applied to the substrate are infinitely close to zero.

[0161] Figure 6 For the results of the storage modulus, loss elastic modulus, and tan δ at high temperature of Example 3 and Comparative Example 1, (A) represents the results of Example 3, and (B) represents the results of Comparative Example 1. Before light irradiation, in the resin composition of Example 3, no decrease in the storage modulus was confirmed even on the high-temperature side. In the resin composition of Comparative Example 1, a decrease in the storage modulus on the high-temperature side was confirmed and softening occurred due to heat.

[0162] Figure 7The figure shows the appearance of the shear test piece after the adhesion force measurement using the resin composition of Example 3. (a) shows the appearance of the shear test piece before the measurement, (b) shows the peeling state of the sample without light irradiation, (c) shows the peeling state after light irradiation, and (d) shows the appearance of the shear test piece shown in (c) after cleaning. In the sample before photo-softening with a polycarbonate plate having a high adhesion force as the adherend, the cured product aggregated and broke on both sides of the adherend and remained. In the sample after photo-softening, the liquid remained on both sides of the adherend. The cleanability of the liquid after photo-softening was also high. By flowing acetone for several seconds for cleaning, it was possible to confirm the removal of the residue from the glass surface.

[0163] From the above results, it can be expected that the resin materials and resin compositions of the examples will be developed as adhesives that can be easily peeled off. After temporarily fixing adherends that are easily affected by physical stress, such as microchannels, micro-wiring, and micro-bumps, fragile ultra-thin film wafers, glass, significantly soft tissues, and cells, etc., to a certain substrate, the adhesives can be peeled off without damaging the adherends. Since the resin compositions of the examples exhibit sufficient adhesion force even at a high temperature of 100 °C, it can be expected to be applied as a high-performance temporary fixing adhesive that can be peeled off by light irradiation at room temperature after undergoing a high-temperature process, for example.

Claims

1. A resin material, comprising: Compound A having a (meth)acryloyl group; Compound B having two or more mercapto groups; and A photo radical initiator with a 5% weight loss temperature of 200 °C or higher, Said Compound A includes Compound A-1 having three or more (meth)acryloyl groups, At least one of said Compound A and said Compound B has a disulfide bond in the molecule.

2. The resin material according to claim 1, wherein, Said Compound A further includes Compound A-2 having two (meth)acryloyl groups.

3. The resin material according to claim 1 or 2, wherein, Said radical initiator is a compound that imparts a benzoyl radical upon light irradiation, The molar ratio of said benzoyl radical to the molar number of said Compound A-1 is 21 / 20 or more.

4. A resin composition, comprising: The reaction product of Compound A having a (meth)acryloyl group and Compound B having two or more mercapto groups; and A photo radical initiator with a 5% weight loss temperature of 200 °C or higher, Said Compound A includes Compound A-1 having three or more (meth)acryloyl groups, At least one of said Compound A and said Compound B has a disulfide bond in the molecule.

5. The resin composition according to claim 4, wherein, Said Compound A further includes Compound A-2 having two (meth)acryloyl groups.

6. The resin composition according to claim 4, wherein, Said radical initiator is a compound that imparts a benzoyl radical upon light irradiation, The molar ratio of said benzoyl radical to the molar number of said Compound A-1 is 21 / 20 or more.

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