Resin material and resin composition

Abstract

A resin material is disclosed. The resin material contains: a compound A having two or more isocyanate groups; 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. And at least one of the compound A and the compound B has a disulfide bond in the molecule.

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-softenability is desired for applications such as an adhesive and a coating material having peelability. In a molecular structure designed to ensure photo-softenability, there is room for improvement in terms of heat resistance. It is speculated that a photo-softenable composition capable of withstanding a 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-softenability. Another object of the present invention is to provide a resin composition having excellent heat resistance and exhibiting photo-softenability.

[0009] Means for Solving the Technical Problem

[0010] The present invention provides the resin material described in [1] or [2] and the resin composition described in [3] or [4].

[0011] [1] A resin material containing: a compound A having two or more isocyanate groups; 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 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 photo radical initiator is a compound that generates two or more monoradicals per molecule of the photo radical initiator by light irradiation and does not generate biradicals.

[0013] [3] A resin composition comprising: a reaction product of a compound A having two or more isocyanate groups and a compound B having two or more thiol groups; and a photo radical initiator with a 5% weight loss temperature of 200 °C or higher, wherein at least one of the compound A and the compound B has a disulfide bond in the molecule.

[0014] [4] The resin composition according to [3], wherein the photo radical initiator is a compound that generates two or more monoradicals per molecule of the photo radical initiator upon light irradiation and does not generate biradicals.

[0015] Advantages of the Invention

[0016] According to the present invention, there is provided a resin material for imparting a resin composition having excellent heat resistance and exhibiting photo softening properties. Further, according to the present invention, there is provided a resin composition having excellent heat resistance and exhibiting photo softening properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a graph showing the change in storage modulus (G') with respect to elapsed time for Examples 1 to 5.

[0018] Figure 2 It is a graph showing the change in loss tangent (tanδ) with respect to elapsed time for Examples 1 to 5. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

[0020] In this specification, the term "process" includes not only independent processes, but also those that are included in this term even when they cannot be clearly distinguished from other processes as long as the intended function of the process is achieved. Further, the numerical range indicated by "~" represents a range that includes the numerical values before and after "~" as the minimum value and the maximum value, respectively.

[0021] Further, in this specification, regarding the content of each component in the resin material or the resin composition, when there are multiple substances corresponding to each component, unless otherwise specified, it means the total amount of these multiple substances. Further, unless otherwise specified, the exemplified materials can be used alone or in combination of two or more.

[0022] Also, within the numerical ranges described step by step in this specification, the upper or lower limit value of the numerical range in a certain stage can be replaced with the upper or lower limit value of the numerical range in other stages. Also, in the numerical ranges described in this specification, the upper or lower limit value of the numerical range can be replaced with the value 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 addition, the "weight average molecular weight" is the polystyrene conversion value obtained by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene. In this specification, "room temperature" means 25°C.

[0023] In this specification, "photo-softening property" means the property of softening upon light irradiation. Among the softening properties, for example, it includes a decrease in elastic modulus, an increase in loss tangent (tanδ), etc. In this specification, the "softened product of the resin composition" means a state in which the elastic modulus decreases, a state in which the loss tangent (tanδ) increases, etc., based on the resin composition before light irradiation. A resin composition exhibiting photo-softening property means a composition that softens upon light irradiation to give a jelly-like or liquid-like substance.

[0024] [Resin material]

[0025] The resin material of the present embodiment contains a compound A having two or more isocyanate groups, a compound B having two or more thiol groups, and a photo-radical initiator with 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.

[0026] (Compound A)

[0027] Compound A is a compound having two or more isocyanate groups in one molecule. Regarding the upper limit of the number of isocyanate groups of compound A, for each molecule, it can be, for example, 10 or less, 8 or less, 6 or less, or 4 or less. Compound A can be a compound having two or three isocyanate groups.

[0028] The molecular weight or weight average molecular weight of compound A can be 150 or more, and can also be 10000 or less, 1000 or less, or 600 or less.

[0029] In one embodiment, compound A can include a compound A1 having two isocyanate groups and a compound A2 having three isocyanate groups. By increasing the content of the compound A1 having two isocyanate groups, the flexibility of the resin composition can be improved. On the other hand, by increasing the content of the compound A1 having three isocyanate groups, the crosslinking degree can be increased and rigidity can be imparted.

[0030] As the compound A1 having two isocyanate groups, for example, aliphatic diisocyanates such as ethylene diisocyanate, propylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, etc.; alicyclic diisocyanates such as isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, norbornane diisocyanate, 1,4-isocyanatocyclohexane, 1,3-bis(isocyanatomethyl)-cyclohexane, 1,3-bis(2-isocyanatopropyl-2-yl)-cyclohexane, etc.; aromatic diisocyanates such as toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylene diisocyanate, 1,5-naphthalene diisocyanate, etc. Among them, the compound A1 can be an aliphatic diisocyanate or hexamethylene diisocyanate (HDI).

[0031] As the compound A2 having three isocyanate groups, for example, triphenylmethane-4,4',4''-triisocyanate, 1,3,5-triisocyanatobenzene, 1,3,5-tris(isocyanatomethyl)cyclohexane, 1,3,5-tris(isocyanatomethyl)benzene, 2,6-diisocyanatohexanoic acid-2-isocyanatoethyl ester, etc. As the compound A2 having three isocyanate groups, for example, the trimer of the above compound A1, etc. Among them, the compound A2 can be the trimer of an aliphatic diisocyanate or the trimer of hexamethylene diisocyanate (HDI).

[0032] In the compound A, the isocyanate group can be protected by a blocking agent. The compound A in which the isocyanate group is protected by a blocking agent is usually stable at room temperature, but when heated to a temperature above the dissociation temperature of the blocking agent, free isocyanate groups are generated. As the blocking agent, methyl ethyl ketoxime (MEKO, dissociation temperature 130 °C), dimethylpyrazole (DMP, dissociation temperature 110 °C), diethyl malonate (DEM, dissociation temperature 110 °C), active methylene compounds (dissociation temperature 90 °C), etc. can be cited.

[0033] Based on the total amount of the resin material, the content of the compound A (for example, the total content of the compound A1 and the compound A2) can be 1% by mass or more, 2% by mass or more, or 3% by mass or more, and can also be 35% by mass or less, 18% by mass or less, or 9% by mass or less.

[0034] In one embodiment, the ratio of the number of moles of compound A1 to the total number of moles of compound A (the total number of moles of compound A1 and compound A2) (the number of moles of compound A1 / the total number of moles of compound A (the total number of moles of compound A1 and compound A2)) can be 0.5 or more. If this ratio is 0.5 or more, the flexibility of the resin composition can be improved. In this case, this ratio can be 0.7 or more, or 0.9 or more. The upper limit of this ratio can be 1 or less. Also, in one embodiment, this ratio can be less than 0.5. If this ratio is less than 0.5, the crosslinking degree can be increased and rigidity can be imparted. In this case, this ratio can be 0.3 or less, or 0.1 or less. The lower limit of this ratio can be 0 or more.

[0035] In one embodiment, the ratio of the number of moles of compound A2 to the number of moles of compound B described below (the number of moles of compound A2 / the number of moles of compound B) can be 0.50 or less, 0.30 or less, or 0.15 or less. If this ratio is 0.50 or less, there is a tendency for the resin composition to have excellent photo-softening property (photo-melting property). The lower limit of this ratio can be 0 or more, or more than 0.

[0036] When compound A (compound A1 and compound A2) has a disulfide bond in the molecule, the number of disulfide bonds in one molecule can be, for example, 1 to 1000 or 4 to 50.

[0037] (Compound B)

[0038] Compound B is a compound having two or more mercapto groups (-SH) in one molecule. Regarding the upper limit of the number of mercapto groups of compound B, for each molecule, it can be, for example, 10 or less, 8 or less, 6 or less, or 4 or less. Compound B can be a compound having two mercapto groups.

[0039] The molecular weight or weight-average molecular weight of compound B can be 300 or more, 500 or more, or 1000 or more, and can also be 50000 or less, 10000 or less, or 5000 or less.

[0040] When compound B has a disulfide bond in the molecule, the number of disulfide bonds in one molecule can be, for example, 1 to 1000 or 4 to 50.

[0041] Compound B can be a compound having a linear molecular chain and terminal groups, and having a disulfide bond in the molecular chain (for example, a polymer or oligomer). In this case, the terminal groups in compound B can be mercapto groups. When compound B is such a compound, it is easier to form a cured product having excellent photo-softening property. The molecular chain in compound B can contain a disulfide bond and a polyether chain, or can be composed of a disulfide bond and a polyether chain.

[0042] 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. The multiple As can be the same or different respectively. p represents an integer of 1 or more. p can be, for example, 1 or more or 4 or more, and can also be 1000 or less. Compound B is a compound that elongates the chain of Compound (1).

[0043] 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 (for example, methylene, ethylene). Examples of the polyether chain as A include -CH 2 CH 2 -O-CH 2 -O-CH 2 CH 2 - etc.

[0044] Examples of commercially available products of Compound B include the THIOKOL LP series (dithiols having disulfide bonds, manufactured by TORAYFINE CHEMICALS CO., LTD.) etc. Compound B can be used alone in one kind, or can be used in combination of two or more kinds. Compound B can also be obtained by converting the reactive functional groups (for example, carboxyl group, hydroxyl group) and disulfide bonds of a compound having reactive functional groups and disulfide bonds at the terminals into thiol groups. Examples of the compound having reactive functional groups and disulfide bonds at the terminals include 3,3'-dithiobispropionic acid, dithiodiethanol, cystamine, etc.

[0045] Based on the total amount of the resin material, the content of Compound B can be 20% by mass or more, 40% by mass or more, or 60% by mass or more, and can also be 95% by mass or less, 92% by mass or less, or 90% by mass or less.

[0046] The ratio of the number of moles of the thiol groups in Compound B to the number of moles of the isocyanate groups in Compound A can be, for example, 0.90 or more or 0.95 or more, and can also be 1.10 or less or 1.05 or less.

[0047] (Photo radical initiator)

[0048] 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 photopolymerization initiator can be used. As the photo radical initiator, an intramolecular cleavage type photo radical polymerization initiator that generates two radicals by photolytic cleavage of itself upon light irradiation can be cited.

[0049] As the intramolecular cleavage type photo radical initiator, a benzyl ketal type photo radical initiator, an α-aminoalkyl phenyl ketone type photo radical initiator, an α-hydroxyalkyl phenyl ketone type photo radical initiator, an α-hydroxyacetophenone type photo radical initiator, an acylphosphine oxide type photo radical initiator, etc. can be cited.

[0050] The 5% weight loss temperature of the photo radical initiator is 200 °C or higher. The 5% weight loss temperature means 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 aspect 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. The upper limit of the 5% weight loss temperature of the photo radical initiator can be, for example, 340 °C or lower, 330 °C or lower, 320 °C or lower, 310 °C or lower, or 300 °C or lower.

[0051] As the photo radical initiator having a 5% weight loss temperature of 200 °C or higher, for example, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (5% weight loss temperature: 253 °C), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (5% weight loss temperature: 204 °C), 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one (5% weight loss temperature: 220 °C), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one (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), and their polymers, etc. can be cited.

[0052] From the viewpoint of more excellent photo-softening properties, the photo-radical initiator can be a photo-radical initiator that generates two or more monoradicals per molecule of the photo-radical initiator upon light irradiation and does not generate biradicals. Examples of such photo-radical initiators include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 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)-butan-1-one

[0053] Based on the total amount of the resin material, the content of the photo-radical initiator can be 3% by mass or more, 5% by mass or more, or 10% by mass or more, and can also be 30% by mass or less, 20% by mass or less, or 15% by mass or less.

[0054] From the viewpoint of further improving the photo-softening properties, the molar ratio of the photo-radical initiator to the molar amount of compound A2 (molar amount of photo-radical initiator / molar amount of compound A2) can be 1 or more, 1.5 or more, or 2 or more.

[0055] From the viewpoint of further improving the photo-softening properties, the molar ratio of the photo-radical initiator to the molar amount of compound B (molar amount of photo-radical initiator / molar amount of compound B) can be 0.2 or more, 0.5 or more, or 0.7 or more.

[0056] The resin material may further contain a curing catalyst. Here, the curing catalyst is a component for promoting the reaction between compound A and compound B. Examples of the curing catalyst include amine compounds and phosphorus compounds. Among them, the curing catalyst can be an amine compound.

[0057] The amine compound can be, for example, a secondary amine compound or a tertiary 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, 4-dimethylaminopyridine, etc.

[0058] Based on the total amount of the resin material, the content of the curing catalyst can be 0.001% by mass or more, 0.01% by mass or more, or 0.015% by mass or more, and can also be 3% by mass or less, 2% by mass or less, or 1% by mass or less.

[0059] The resin material may further contain components other than compound A, compound B, the photo-radical initiator, and the curing catalyst (other components). Examples of the other components include plasticizers; tackifiers and other tackiness-imparting agents; antioxidants; colorless dyes; sensitizers; adhesion improvers such as coupling agents; polymerization inhibitors; light stabilizers; defoamers; fillers; chain transfer agents; thixotropy-imparting agents; flame retardants; mold release agents; surfactants; lubricants; antistatic agents and other additives. These additives can be those 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 can be 0 to 95% by mass, 0.01 to 50% by mass, or 0.1 to 10% by mass.

[0060] The resin material can be used as a varnish of the resin material diluted with a solvent. Examples of the solvent include aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, and p-cymene; aliphatic hydrocarbons such as hexane and heptane; cycloalkanes such as methylcyclohexane; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; amides (NMP) such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. 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, 15 to 70% by mass, or 20 to 50% by mass.

[0061] 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 stirrers, kneaders, three-roll mills, ball mills, and bead mills.

[0062] [Resin Composition]

[0063] The resin composition of the present embodiment contains a reaction product of compound A and compound B and a radical initiator having a 5% weight loss temperature of 200°C or higher. The resin composition of 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.

[0064] As a method for obtaining the resin composition, for example, a method of reacting the above compound A and compound B can be mentioned. The reaction temperature of compound A and compound B can be, for example, 0 to 200°C, or can also be 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 can also be 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.

[0065] More specifically, the reaction product of compound A and compound B is formed by the ethyl thiocarbamate reaction of the isocyanate group in compound A and the thiol group in compound B.

[0066] The reaction product of compound A and compound B has a structure represented by the formula (I): *-NH-C(=O)-S-* and a disulfide bond. In the formula (I), * represents a bonding bond. The disulfide bond can exist in at least one of the main chain and the side chain of the reaction product. From the aspect of further improving the photo-softening property, the disulfide bond can exist in the main chain of the reaction product.

[0067] The reaction product of compound A and compound B may contain a compound including a structure represented by the following formula (x1).

[0068]

[0069] In the formula (x1), A and p have the same meanings as in the formula (1), and * represents a bonding bond.

[0070] The storage modulus G' of the resin composition at 25°C can be 10 kPa or more, 30 kPa or more, 50 kPa or more, or 100 kPa or more, or can also be 100000 kPa or less, 10000 kPa or less, or 1000 kPa.

[0071] The storage modulus G' and the loss elastic modulus G'' of the resin composition at 25°C can be measured by the method described in the following examples. And, the loss tangent (tanδ) is represented by the ratio of the loss elastic modulus G'' to the storage modulus G' (G'' / G').

[0072] From the aspect of further improving the heat resistance of the resin composition, the 5% weight loss temperature T of the resin composition d5％ can be 200°C or more, 220°C or more, 240°C or more, 250°C or more, or 260°C or more. The 5% weight loss temperature T of the resin composition d5％ can be measured by the method described in the following examples.

[0073] 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 (1 J / cm 2 ) or more. In this specification, the exposure amount refers to the product of the illuminance (mW / cm 2 ) and the irradiation time (seconds). 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.

[0074] 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 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.

[0075] The number average molecular weight Mn of the resin composition after light irradiation (photo-softened product) can be 50,000 or less, 30,000 or less, or 10,000 or less, and can also be 1000 or more, 2000 or more, or 3000 or more.

[0076] The weight average molecular weight Mw of the photo-softened product can be 200,000 or less, 150,000 or less, or 100,000 or less, and can also be 1000 or more, 3000 or more, or 5000 or more. If Mw is 200,000 or less, there is a tendency for the resin composition to be sufficiently softened and have excellent peelability. In particular, if Mw is 100,000 or less, there is a tendency for the resin composition after light irradiation to have high fluidity, and the peelability and cleanability are more excellent.

[0077] The Mn and Mw of the photo-softened product can be measured by the methods described in the following examples.

[0078] Generally, the storage modulus G' of the photo-softened product at 25°C is lower than the storage modulus G' of the resin composition at 25°C. The storage modulus G' of the photo-softened product at 25°C can be 100 kPa or less, 10 kPa or less, or 6 kPa or less, and can also be 0.001 kPa or more or 0.005 kPa or more.

[0079] The storage modulus G' and loss elastic modulus G'' of the photo-softened product at 25°C can be measured by the methods described in the following examples.

[0080] The viscosity of the photo-softening material at 25°C can be 5000 Pa·s or less, 2500 Pa·s or less, or 300 Pa·s or less. The viscosity of the photo-softening material can be measured by the method described in the following examples.

[0081] 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 a known method can be applied.

[0082] The resin material and the resin composition can be used, for example, in applications such as adhesives, pressure-sensitive adhesives, coating materials, protective materials, parts, or 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 the substrate. The adhesive containing the resin material or the 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 the resin composition can also be used as an adhesive that can be peeled off by light irradiation at room temperature after undergoing a high-temperature process.

[0083] [Method for Separating Adhesive Composition, Adherend, and Adhered Object]

[0084] The adhesive composition of the present embodiment contains: compound A having two or more isocyanate groups; compound B having two or more thiol groups; and a photo-radical initiator having a 5% weight loss temperature of 200°C or higher, 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, other components, etc. can be the above forms.

[0085] 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.

[0086] Since the cured product of the adhesive composition has photo-softening properties, it can be separated by light irradiation without damaging two or more adherends. The softened material remaining on the adherend can be removed by a solvent as needed. The conditions for light irradiation can be the above conditions.

[0087] 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.

[0088] The adherend of this 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 an 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. Even after undergoing a high-temperature process, the adherend can be separated by light irradiation.

[0089] The method for separating adherends of this 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 above-described photocurable composition, by irradiating light, the cured product of the photocurable composition can be melted and the adherends can be easily separated from each other. Even after undergoing a high-temperature process, the adherends can be separated by light irradiation.

[0090] In the method for separating adherends, the type of light, light source, etc. during light irradiation can be the same as above.

[0091] Examples

[0092] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.

[0093] 1-1. Materials to be tested

[0094] The materials for synthesis were used as purchased.

[0095] · Compound A

[0096] (A1-1) Hexamethylene diisocyanate (Millionate HDI, manufactured by TOSOH CORPORATION)

[0097] (A2-1) 1,3,5-Tris(6-isocyanatohexyl-1-yl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (Desmodur N-3300 (HDI trimer), manufactured by Sumika Covestro Urethane Co., Ltd.)

[0098] · Compound B

[0099] (B-1) Polysulfide polymer (THIOKOL LP-55 (manufactured by TORAY FINE CHEMICALS CO., LTD., SH% = 1.8%))

[0100]

[0101] · Photo radical initiator

[0102] (C-1) 2,4,6-Trimethylbenzoyl-diphenylphosphine oxide (Omnirad-TPO, manufactured by IGM Resins B.V., 5% weight loss temperature: 253 °C)

[0103] (c-1) 2-Hydroxy-2-methyl-1-phenylpropanone (Omnirad-1173, manufactured by IGM Resins B.V., 5% weight loss temperature: 101 °C)

[0104] (c-2) 2,2-Dimethoxy-2-phenylacetophenone (Omnirad-651, manufactured by IGM Resins B.V., 5% weight loss temperature: 170 °C)

[0105] ·Curing catalyst

[0106] (D-1) Triethylamine (TEA, manufactured by Tokyo Chemical Industry Co., Ltd.)

[0107] 1-2. Preparation of resin materials and production of resin composition films

[0108] Using the composition ratios shown in Table 1 (unit: parts by mass), the test materials were blended in the following order. First, Compound B and the curing catalyst were blended in a 30 mL plastic ointment jar. At this time, the blending amount of Compound B was adjusted so that the content of the curing catalyst became 1% by mass based on the total amount of Compound B and the curing catalyst. Next, the blend was stirred for 1.5 minutes at a rotation speed of 2000 rpm using a planetary mixer (Awatori Rentaro ARE-310, manufactured by THINKY CORPORATION) to obtain Mixture a. Next, the remaining Compound B and the photoinitiator were blended in a 30 mL plastic ointment jar, and the blend was stirred for 1.5 minutes at a rotation speed of 2000 rpm using the same planetary mixer, and heated at 95 °C for 1 hour. After heating, the blend was further stirred for 1.5 minutes at a rotation speed of 2000 rpm using the same planetary mixer and cooled to room temperature, and Compound A was added to obtain Mixture b. Next, Mixture a and Mixture b were blended in a 30 mL plastic ointment jar, and the blend was stirred for 1.5 minutes at a rotation speed of 2000 rpm to prepare the resin materials of Examples 1 to 5 and Comparative Examples 1 and 2. The molar ratios of Compound A, Compound B, and the photoinitiator in the resin materials are shown in Table 2.

[0109] The obtained resin material and a spacer with a film thickness of 500 μm were sandwiched between the release surfaces of two release PET films (FILMBYNA DB-50 (manufactured by Fujimori Kogyo Co., Ltd.)), and the film (resin composition film) obtained by peeling the release film after curing at room temperature for 1 week was used for the following evaluations. In addition, the completion of curing (polymerization) was confirmed by infrared absorption spectroscopy measurement, and the time when the integral value of the peak of the isocyanate near 2260 cm -1 decreased by more than 90% compared with that before polymerization was judged as the completion of curing (polymerization).

[0110] [Table 1]

[0111]

[0112] [Table 2]

[0113]

[0114] 1-3. Light irradiation

[0115] A UV irradiation device (manufactured by Panasonic Industrial Devices SUNX Co., Ltd., power supply: Aicure UJ30, 405 nm LED head: ANUJ6189) was used for UV irradiation. Regarding the irradiation conditions, measurement was performed using a 405 nm optical receiver with an illuminometer UIT-250 (manufactured by Ushio Inc.).

[0116] 1-4. Thermogravimetry-differential thermal analysis (TG-DTA)

[0117] For the thermogravimetry-differential thermal analysis of the resin composition, EXSTAR TG / DTA 7200 manufactured by SIINano Technology Inc. was used. Approximately 10 mg was taken from the film with a film thickness of 500 ± 100 μm obtained by the method of "1-2. Preparation of resin material and production of resin composition film" and placed on a sample pan. Nitrogen was flowed at a flow rate of 300 mL / min, and the temperature was raised from room temperature to about 300 °C at a rate of 10 °C / min to confirm the 5% weight loss temperature. The results are shown in Table 3.

[0118] The 5% weight loss temperatures of the resin compositions of Examples 1 to 5 were all 200 °C or higher. In contrast, the 5% weight loss temperatures of the resin compositions of Comparative Examples 1 and 2 were both less than 200 °C, and the heat resistance was insufficient. Therefore, in the resin compositions of Comparative Examples 1 and 2, "1-5. Mechanical property evaluation", "1-6. Viscosity measurement" and "1-7. GPC measurement" were not carried out.

[0119] 1-5. Mechanical property evaluation

[0120] A glass stage for microscopic 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 the change in viscoelasticity with respect to light irradiation was evaluated. For the measurement, it was carried out under the conditions of a gap of 600 ± 100 μm between the stage and the rotor, a frequency of 1 Hz, and a displacement of 1% at 25°C. In the viscoelasticity measurement before light irradiation, a film with a thickness of 500 ± 100 μm obtained by the method of "1-2. Preparation of Resin Material and Fabrication of Resin Composition Film" was punched into a cylindrical shape with a diameter of 8 mm and used as the measurement sample. In the viscoelasticity measurement after light irradiation, the measurement sample before light irradiation was irradiated with 405 nm LED light for 2 seconds every 10 seconds at an illuminance of 500 mW / cm 2 and the sample in the state after light irradiation at an exposure of 30 J / cm 2 was used as the measurement sample. The results are shown in Table 3.

[0121] Figure 1 is a graph showing the change in storage modulus (G') with respect to elapsed time for Examples 1 to 5. Figure 2 is a graph showing the change in loss tangent (tanδ) with respect to elapsed time for Examples 1 to 5. The resin compositions of Examples 1 to 5 showed photo-softening (photo-melting), and almost all the samples liquefied after light irradiation. The resin composition of Example 1 in which all the isocyanate compounds in the resin composition were (A2-1) had a tanδ of about 1.5 even after light irradiation at 30 J / cm 2 and was a jelly-like substance close to a liquid state in the finger-touch test. On the other hand, in the resin composition of Example 2 in which the blending amount of (A2-1) was reduced in the resin composition of Example 1, after light irradiation at 3 J / cm 2 , tanδ exceeded 3 and liquefied. From the photo-softening (photo-melting) test, it was found that resin compositions in which the ratio of the number of moles of (A2-1) to the number of moles of (B-1) was 0.15 or less tended to have particularly excellent photo-softening (photo-melting). These resin compositions showed a liquid state with an exposure of 2 J / cm 2 or more and a tanδ exceeding 2.0, and the storage modulus was also 10,000 Pa or less.

[0122] 1-6. Viscosity Measurement

[0123] Regarding the viscosity at 25°C of the photo-softened product, the measurement sample for the viscoelasticity measurement after light irradiation in "1-5. Mechanical Property Evaluation" was measured at a shear rate of 10 s -1For the direct measurement, the average value after 10 to 70 seconds from the start of the measurement was set as the viscosity of the photo-softening material. The results are shown in Table 3.

[0124] 1-7. GPC Measurement

[0125] Regarding the measurement of the molecular weight (weight-average molecular weight Mw and number-average molecular weight Mn) of the photo-softening material, by gel permeation chromatography (GPC), using Chromaster manufactured by High-Tech Science Corporation., GL-A130-S, GL-A150-S, and GL-A160-S were used in the column, and RI was used as the detector. The measurement was carried out at a temperature of 35°C. A THF solution with a sample concentration of 1 mass% was prepared and used as the GPC sample. Moreover, the molecular weight conversion value was calculated by using a calibration curve with standard polystyrene. The film with a film thickness of 500 ± 100 μm obtained by the method of "1-2. Preparation of Resin Material and Fabrication of Resin Composition Film" was sandwiched between two glass slides (S-1111, manufactured by Matsunami Glass Ind., Ltd.), and the viscous liquid that was photo-softened (photo-melted) by irradiating 405 nm LED light at an illuminance of 1000 mW / cm 2 for 120 seconds was used as the sample for molecular weight measurement. The results are shown in Table 3.

[0126]

[0127] Through the above, it was confirmed that the resin material of the present invention imparts a resin composition with excellent heat resistance and exhibits photo-softening properties. Also, it was confirmed that the resin composition of the present invention has excellent heat resistance and exhibits photo-softening properties.

Claims

1. A resin material, comprising: Compound A having two or more isocyanate groups; Compound B having two or more mercapto groups; and A photo-radical initiator with 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 in the molecule.

2. The resin material according to claim 1, wherein the photo-radical initiator is 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.

3. A resin composition, comprising: A reaction product of Compound A having two or more isocyanate groups 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, At least one of the Compound A and the Compound B has a disulfide bond in the molecule.

4. The resin composition according to claim 3, wherein the photo-radical initiator is 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.

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