Optical softening resin composition, method for producing softened product of optical softening resin composition, curable resin composition and cured product thereof, and pattern film and method for producing the same

Abstract

The present invention discloses a photo-softenable resin composition, which contains: a compound having a disulfide bond; and a radical scavenger. Further, the present invention discloses a curable resin composition, which contains: a monomer having a disulfide bond and a functional group; a monomer having a substituent capable of reacting with the functional group; and a radical scavenger.

Description

Technical Field

[0001] The present invention relates to a photo-softenable resin composition, a method for producing a softened product of the photo-softenable resin composition, a curable resin composition and a cured product thereof, and a pattern film and a method for producing the same. Background Art

[0002] A photo-softenable resin composition that is 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 photo-softenable resin composed of a photo-softenable resin 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 main object of the present invention is to provide a novel photo-softenable resin composition.

[0008] Means for Solving the Technical Problem

[0009] One aspect of the present invention provides a photo-softenable resin composition. The photo-softenable resin composition contains: a compound having a disulfide bond; and a radical scavenger. When such a photo-softenable resin composition is irradiated with light, the disulfide bond in the compound having a disulfide bond is decomposed (broken) to generate a thiyl radical. At this time, in the photo-softenable resin composition, if a radical scavenger is present, the thiyl radical reacts with the radical scavenger. Therefore, it is speculated that: the compound having a disulfide bond is depolymerized, and the photo-softenable resin composition is softened. This reaction is considered to be an irreversible reaction. When the radical scavenger is a hydrogen donor, the main component in the softened product of the photo-softenable resin composition is speculated to be a compound having a thiol (SH) group, which is generated by the thiyl radical stealing a hydrogen atom from the hydrogen donor. On the other hand, when the radical scavenger is a photo-radical initiator, the following reaction mechanism is also predicted: the photo-induced radicals generated from the photo-polymerization initiator directly react with the disulfide bond, thereby initiating the formation of a photo-induced radical-sulfide bond and the generation of a thiyl radical, and the thiyl radical reacts with other photo-induced radicals, that is, the compound having a disulfide bond itself does not undergo a depolymerization cleavage reaction.

[0010] A compound having a disulfide bond can be a copolymer, which comprises: a monomer unit having a disulfide bond and a functional group; and a monomer unit having a substituent capable of reacting with the functional group. Such a copolymer is usually a solid (solid component) at 25°C, so it can be used in the form of a film, a block, etc. by removing volatile components such as solvents from the varnish of the photo-softenable resin composition.

[0011] The photo-softenable resin composition may further contain a sensitizer.

[0012] Another aspect of the present invention relates to a method for producing a softened product of a photo-softenable resin composition. The method for producing the softened product includes the following steps: irradiating the above photo-softenable resin composition with light to obtain a softened product of the photo-softenable resin composition.

[0013] Another aspect of the present invention relates to a curable resin composition. The curable resin composition contains: a monomer having a disulfide bond and a functional group; a monomer having a substituent capable of reacting with the functional group; and a radical scavenger. Such a curable resin composition can be polymerized by a method other than light irradiation (such as heating, etc.) through the reaction of these monomers to form a cured product. The obtained cured product can be used in the form of a film, a block, etc.

[0014] The curable resin composition may further contain a curing catalyst. And the curable resin composition may further contain a sensitizer.

[0015] Another aspect of the present invention relates to the cured product of the above curable resin composition. The curing of the curable resin composition can be carried out in the following manner: reacting a monomer having a disulfide bond and a functional group and a monomer having a substituent capable of reacting with the functional group to polymerize. The cured product is a copolymer, which comprises a monomer unit having a disulfide bond and a functional group and a monomer unit having a substituent capable of reacting with the functional group, that is, the cured product contains: a compound having a disulfide bond and a radical scavenger. That is, the cured product is a form of the above photo-softenable resin composition. Therefore, the cured product can be softened by light irradiation.

[0016] Another aspect of the present invention relates to a pattern film. The pattern film has a pattern and contains the cured product of the above photo-softenable resin composition or the above curable resin composition.

[0017] Another aspect of the present invention relates to a method for manufacturing a pattern film. The method for manufacturing the pattern film includes the following steps: a patterning step of patterning at least a part of the cured product of the above-mentioned photo-softenable resin composition or the above-mentioned curable resin composition by irradiating light; and a developing step of developing the cured product of the patterned photo-softenable resin composition or curable resin composition. The developing step may include a step of developing by performing water washing.

[0018] Advantages of the Invention

[0019] According to the present invention, a novel photo-softenable resin composition can be provided. Further, according to the present invention, a method for manufacturing a softened product of a photo-softenable resin composition, which uses the above-mentioned photo-softenable resin composition, can be provided. Furthermore, according to the present invention, a novel curable resin composition and its cured product can be provided. And, according to the present invention, a pattern film and a method for manufacturing the same, which use the above-mentioned curable resin composition and its cured product, can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a graph showing the change in the elastic modulus and loss tangent (tanδ) of the photo-softenable resin film of Example 1 at 25°C with respect to the light irradiation time. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

[0022] In this specification, the "photo-softenable resin composition" means a resin composition having a property of being softened by light irradiation (for example, the elastic modulus decreases, the loss tangent (tanδ) increases, the hardness decreases, etc.). In this specification, the "softened product of the photo-softenable resin composition" means a state in which the elastic modulus has decreased, the loss tangent (tanδ) has increased, the hardness has decreased, etc., based on the photo-softenable resin composition before light irradiation.

[0023] Moreover, in this specification, the term "step" not only includes an independent step, but also includes a case where it cannot be clearly distinguished from other steps as long as it can achieve the desired function of the step. Also, 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.

[0024] In addition, in this specification, the content of each component in the composition, when there are multiple substances corresponding to each component in the composition, unless otherwise specified, means the total amount of these multiple substances present in the composition. Also, unless otherwise specified, the exemplified materials can be used alone or in combination of two or more.

[0025] In addition, for the numerical ranges described step by step in this specification, the upper limit value or the lower limit value of the numerical range at a certain stage can be replaced with the upper limit value or the lower limit value of other stages. Also, for the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range can be replaced with the value shown in the examples.

[0026] In addition, in this specification, the so-called “(meth)acryloyl” means acryloyl or methacryloyl, and the same applies to other similar usages. The so-called “A or B” means that as long as it includes any one of A and B, it can also include both.

[0027] [Photo-softening resin composition]

[0028] A photo-softening resin composition according to one embodiment contains: a compound having a disulfide bond (hereinafter, sometimes referred to as component (A)); and a radical scavenger (hereinafter, sometimes referred to as component (B)).

[0029] (A) component: a compound having a disulfide bond

[0030] The (A) component has a disulfide bond, and this disulfide bond can generate sulfur radicals by light irradiation. The (A) component can be any compound having a disulfide bond (-S-S-), and there is no particular limitation. However, considering that the (A) component will be low-molecular-weighted by light irradiation, it can be a high-molecular-weight component such as a polymer or an oligomer. The (A) component can be used alone as one kind, or in combination of two or more kinds. The (A) component preferably has multiple (two or more) disulfide bonds.

[0031] The (A) component is, for example, a copolymer obtained by reacting a monomer having a disulfide bond and a functional group (hereinafter, sometimes referred to as “(A-1) component”) with a monomer having a substituent capable of reacting with the functional group (hereinafter, sometimes referred to as “(A-2) component”). In other words, the (A) component can be the reaction product of the (A-1) component and the (A-2) component, that is, a copolymer containing monomer units of the (A-1) component and monomer units of the (A-2) component.

[0032] Examples of the functional group in the component (A-1) include a mercapto group, a carboxyl group, a hydroxyl group, an amino group, etc. The functional group in the component (A-1) may be, for example, at least one selected from the group consisting of a mercapto group, a carboxyl group, and a hydroxyl group. From the viewpoint of high molecular weight, the number of functional groups in the component (A-1) may be two or more. On the other hand, the less the crosslinking degree of the component (A) is, the more likely it is to be softened into a liquid state when the photo-softenable resin composition is irradiated with light. Therefore, as the component (A-1), a monomer having two functional groups is preferably used. When using a plurality of monomers having different numbers of functional groups, it is preferable to increase the use ratio of the monomer having two functional groups. Based on the total amount of the component (A-1), the ratio of the monomer having two functional groups may be 75 to 100% by mass, 85 to 100% by mass, or 90 to 100% by mass. Based on the total amount of the component (A-1), the ratio of the monomer having three or more functional groups may be 0 to 10% by mass, 0 to 15% by mass, or 0 to 25% by mass.

[0033] Examples of commercially available products of the component (A-1) include THIOKOL LP series (polysulfide polymer, manufactured by Toray Fine Chemicals Co., Ltd.), 3,3'-dithiobispropionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), dithiodiethanol (manufactured by Tokyo Chemical Industry Co., Ltd.), etc. These components (A-1) may be used alone or in combination of two or more.

[0034] (A-2) component is a monomer having a substituent capable of reacting with a functional group, and can be used as long as it has a substituent capable of reacting with a functional group, and there is no particular limitation. Examples of the substituent include a group containing a cyclic ether (for example, a glycidyl group, etc.), an isocyanate group, a (meth)acryloyl group, an aldehyde group, an amino group, a hydroxyl group, a carboxyl group, etc. The substituent in the component (A-2) may be, for example, at least one selected from the group consisting of a group containing a cyclic ether, an isocyanate group, and a (meth)acryloyl group. From the viewpoint of high molecular weight, the number of substituents in the component (A-2) may be two or more. On the other hand, the less the crosslinking degree of the component (A) is, the more likely it is to be softened into a liquid state when the photo-softenable resin composition is irradiated with light. Therefore, as the component (A-2), a monomer having two substituents is preferably used. When using a plurality of monomers having different numbers of substituents, it is preferable to increase the use ratio of the monomer having two functional groups.

[0035] In one mode of the component (A-2), based on the total amount of the component (A-2), the proportion of monomers having a substitution base number of 3 or more can be 20% by mass or more, 30% by mass or more, 40% by mass or more, or 50% by mass or more, and can be 90% by mass or less or 75% by mass or less. Based on the total amount of the component (A-2), the proportion of monomers having a substitution base number of 2 can be 10% by mass or more or 25% by mass or more, and can be 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less.

[0036] In other modes of the component (A-2), based on the total amount of the component (A-2), the proportion of monomers having a substitution base number of 2 can be 75 to 100% by mass, 85 to 100% by mass, or 90 to 100% by mass. Based on the total amount of the component (A-2), the proportion of monomers having a substitution base number of 3 or more can be 0 to 10% by mass, 0 to 15% by mass, or 0 to 25% by mass.

[0037] Examples of the component (A-2) include: monomers having two or more cyclic ether-containing groups in one molecule; monomers having two or more isocyanate groups in one molecule; monomers having two or more (meth)acryloyl groups in one molecule; monomers having two or more amino groups in one molecule; monomers having two or more isocyanate groups and (meth)acryloyl groups in one molecule; monomers having two or more cyclic ether-containing groups and alkoxysilyl groups in one molecule; monomers of the following combinations, which are compounds having two or more isocyanate groups in one molecule or compounds having two or more cyclic ether-containing groups in one molecule, and compounds having the following group and alkoxysilyl groups in one molecule, where the group is an amino group, an acid anhydride skeleton, or a thiol group; monomers of the following combinations, which are compounds having two or more isocyanate groups in one molecule and compounds having a hydroxyl group and (meth)acryloyl group in one molecule; monomers of the following combinations, etc., which are compounds having two or more cyclic ether-containing groups in one molecule and compounds having a carboxyl group and (meth)acryloyl group in one molecule. These components (A-2) can be used alone or in combination of two or more.

[0038] As suitable combinations of the (A-1) component and the (A-2) component, for example, combinations of a monomer having a disulfide bond and a thiol group or a hydroxyl group and at least one selected from the group consisting of monomers having two or more cyclic ether-containing groups in one molecule, monomers having two or more (meth)acryloyl groups in one molecule, and monomers having two or more isocyanate groups in one molecule can be cited; combinations of a monomer having a disulfide bond and a carboxyl group and at least one selected from the group consisting of monomers having two or more cyclic ether-containing groups in one molecule, monomers having two or more amino groups in one molecule, and monomers having two or more isocyanate groups in one molecule.

[0039] When reacting the (A-1) component and the (A-2) component to obtain the (A) component, i.e., the copolymer, the reaction ratio of these components can be appropriately adjusted based on the functional group equivalent of the (A-1) component and the substituent equivalent of the (A-2) component. The reaction of the (A-1) component and the (A-2) component can be carried out while heating. The reaction temperature can be, for example, 0 to 200 °C, and the reaction time can be, for example, 0.1 to 240 hours.

[0040] When reacting the (A-1) component and the (A-2) component, a curing catalyst (hereinafter sometimes referred to as the “(A-3) component”) can be used as needed. The (A-3) component can be arbitrarily selected according to the types of the functional groups of the (A-1) component and the substituents of the (A-2) component. When reacting a monomer having a thiol group or a hydroxyl group as a functional group as the (A-1) component and a monomer having an isocyanate group or a (meth)acryloyl group as a substituent as the (A-2) component, the (A-3) component can be, for example, a tin-based catalyst or an amine-based catalyst. When reacting a monomer having a carboxyl group as a functional group as the (A-1) component and a monomer having a cyclic ether-containing group as a substituent as the (A-2) component, the (A-3) component can be, for example, an amine-based catalyst or a phosphorus-based catalyst.

[0041] Examples of the tin-based catalyst include dibutyltin dilaurate, dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dioctyltin dilaurate, dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, tributyltin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, tin 2-ethylhexanoate, etc.

[0042] Examples of the amine-based catalyst include triethylamine, triethylenediamine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), etc.

[0043] As the phosphorus-based catalyst, examples thereof include: triphenylphosphine and its addition reactants, (4-hydroxyphenyl)diphenylphosphine, bis(4-hydroxyphenyl)phenylphosphine, and tris(4-hydroxyphenyl)phosphine.

[0044] The content of the component (A-3) may be 0.005 to 10% by mass, 0.01 to 5% by mass, or 0.02 to 3% by mass based on the total of the components (A-1) and (A-2).

[0045] The molecular weight or weight-average molecular weight of the component (A) may be 200 to 10000000, 1000 to 2000000, or 2500 to 1000000. Further, the weight-average molecular weight is a polystyrene conversion value, which is obtained by conversion using a calibration curve of standard polystyrene by gel permeation chromatography (GPC).

[0046] The content of the component (A) (the total of the components (A-1) and (A-2)) may be 0.1% by mass, 0.5% by mass or more, 1% by mass or more, 5% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, or 80% by mass or more, and may be 99.5% by mass or less, 99% by mass or less, 98% by mass or less, 95% by mass or less, or 90% by mass or less based on the total amount of the photo-softening resin composition.

[0047] Component (B): Radical scavenger

[0048] The component (B) is a component that reacts with the sulfur radicals generated by light irradiation in the component (A). Examples of such a component (B) include: compounds that generate radicals capable of reacting with sulfur radicals upon light irradiation (e.g., photo radical polymerization initiators, etc.). The component (B) may be used alone or in combination of two or more.

[0049] Examples of the photo radical polymerization initiator include, for example, intramolecular cleavage type photo radical polymerization initiators, dehydrogenation type photo radical polymerization initiators, etc. Examples of the intramolecular cleavage type photo radical polymerization initiators include, for example: benzyl ketal type photo radical polymerization initiators; α-hydroxyacetophenone type photo radical polymerization initiators; benzoin type photo radical polymerization initiators; aminobenzophenone type photo radical polymerization initiators; oxime ketone type photo radical polymerization initiators; acylphosphine oxide type photo radical polymerization initiators; titanocene type photo radical polymerization initiators; S-phenyl thiosalicylic acid ester polymerization initiators; high molecular weight derivatives of these polymerization initiators, etc. Examples of the dehydrogenation type photo radical polymerization initiators include, for example: benzophenone type photo radical polymerization initiators, thioxanthone type photo radical polymerization initiators, anthraquinone photo radical polymerization initiators, etc. When the component (B) contains a photo radical polymerization initiator, there is a tendency to promote the cleavage of the disulfide bond of the component (A) and make it easier to generate sulfur radicals.

[0050] Examples of the component (B) other than the photo radical polymerization initiator include, for example: spin traps, antioxidants, polymerization inhibitors, hydrogen donors, etc.

[0051] Examples of the spin trap include, for example: PBN (N-tert-butyl-α-phenyl nitrone), DMPO (5,5-dimethyl-1-dihydro-1H-pyrrole-N-oxide), etc.

[0052] Examples of the antioxidant include, for example: hindered amine type antioxidants, phenolic antioxidants, etc.

[0053] Examples of the polymerization inhibitor include, for example: hydroquinone, hydroquinone monomethyl ether, benzoquinone, p-tert-butylcatechol, 2,6-di-tert-butyl-4-methylphenol, pyrogallol and other quinones.

[0054] Examples of the hydrogen donor include, for example: bis[4-(dimethylamino)phenyl]methane, bis[4-(diethylamino)phenyl]methane, N-phenylglycine, leuco crystal violet, mercaptobenzoxazole, mercaptobenzimidazole, mercaptobenzotriazole, etc.

[0055] The content of the component (B), based on the total amount of the photo-softening resin composition, may be 0.5% by mass or more, 1% by mass or more, 3% by mass or more, or 5% by mass or more. The more the content of the component (B), the more likely it is to be softened into a liquid state (liquid) when the photo-softening resin composition is irradiated with light. The content of the component (B), based on the total amount of the photo-softening resin composition, may be 50% by mass or less, 40% by mass or less, 30% by mass or less, or 20% by mass or less.

[0056] A photo-softening resin composition may further contain a sensitizer (hereinafter sometimes referred to as "(C) component").

[0057] (C) component: sensitizer

[0058] As the sensitizer, known triplet sensitizers can be used without particular limitation. Examples of the sensitizer include benzoic acid-based photosensitizers, amine-based photosensitizers, etc. The (C) component can be used alone or in combination of two or more.

[0059] The content of the (C) component, based on the total amount of the photo-softening resin composition, can be 0.1 to 10% by mass, 0.5 to 8% by mass, or 1 to 5% by mass.

[0060] The photo-softening resin composition may contain additives as other components, such as 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, etc. These additives can use known additives. The total amount of the content of other components, based on the total amount of the photo-softening resin composition, can be 0 to 95% by mass, 0.01 to 50% by mass, or 0.1 to 10% by mass.

[0061] The photo-softening resin composition can be made into a varnish of a diluted photo-softening resin composition using a solvent (hereinafter sometimes referred to as "(D) component"). Examples of the (D) component include 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 such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone (NMP), etc. The (D) component can be used alone or in combination of two or more.

[0062] The solid content concentration in the varnish, based on the total mass of the varnish, can be 10 to 80% by mass.

[0063] The photo-softening resin composition can be prepared, for example, by mixing or kneading the (A) component, the (B) component, and the components added as needed. Mixing and kneading can be carried out by appropriately selecting and combining ordinary mixers, kneaders, three-roll mills, ball mills, bead mills, etc.

[0064] When the component (A) is a copolymer containing monomer units of the component (A-1) and monomer units of the component (A-2), the photo-softening resin composition can be prepared, for example, by a method including the following steps: mixing or kneading the component (A-1), the component (A-2), the component (B), the component (A-3), and components added as needed, and reacting the component (A-1) with the component (A-2) to synthesize the component (A) (the reaction product of the component (A-1) and the component (A-2)). In such a method, the reaction temperature can be, for example, 0 to 200°C, and the reaction time can be, for example, 0.1 to 240 hours. At this time, the component (B) may be deactivated depending on the type of the component (A-3). Therefore, the photo-softening resin composition can also be prepared, for example, by a method including the following steps: a first step of mixing or kneading the component (A-1), the component (A-2), the component (A-3), and components added as needed to obtain a mixture containing the component (A) (the reaction product of the component (A-1) and the component (A-2)); and a second step of adding the component (B) to the mixture and mixing or kneading to obtain the photo-softening resin composition. At this time, the mixture preferably contains a solvent. In such a method, the reaction temperature in the first step and the second step can be, for example, 0 to 200°C, and the reaction time can be, for example, 0.1 to 240 hours.

[0065] The photo-softening resin composition can be formed into a film shape and used as a photo-softening resin film. Also, it can be formed into a block shape and used as a photo-softening resin block. The method of forming the photo-softening resin composition into a film shape or a block shape is not particularly limited, and known methods can be applied.

[0066] The storage modulus of the photo-softening resin composition (the cured product of the curable resin composition described later) at 25°C can be 0.01 MPa (10,000 Pa) or more from the viewpoints of micro-viscosity or non-viscosity, tackifying property, slit processability, stamping processability, masking property, etc., 0.05 MPa (50,000 Pa) or more from the viewpoints of barrier property, moisture resistance, adhesiveness, etc., and 1 MPa (1,000,000 Pa) or more from the viewpoints of operability, etc. The storage modulus of the photo-softening resin composition at 25°C is not particularly limited and can be, for example, 1000 MPa or less. In this specification, the loss tangent (tanδ) at 25°C means the value measured by the method described in the examples.

[0067] The loss tangent (tanδ) of the photo-softenable resin composition (the cured product of the curable resin composition described later) at 25°C can be 1.2 or less, 1.1 or less, or 1.0 or less from the viewpoints of micro-viscosity or non-viscosity, tackifying property, slit processability, stamping processability, operability, etc. In this specification, the loss tangent (tanδ) at 25°C means the value measured by the method described in the examples.

[0068] The hardness (type E) of the photo-softenable resin composition (the cured product of the curable resin composition described later) can be E10 or more from the viewpoints of micro-viscosity or non-viscosity, tackifying property, slit processability, stamping processability, shielding property, etc., can be E20 or more from the viewpoints of barrier property, moisture resistance, adhesiveness, etc., and can be E40 or more from the viewpoints of operability, etc. In this specification, the hardness means the value measured by the method described in the examples.

[0069] The ratio of the storage modulus of the photo-softenable resin composition after light irradiation (i.e., the softened product of the photo-softenable resin composition) at 25°C to the storage modulus of the photo-softenable resin composition before light irradiation at 25°C (storage modulus of the photo-softenable resin composition after light irradiation at 25°C / storage modulus of the photo-softenable resin composition before light irradiation at 25°C) can be 0.7 or less from the viewpoints of bendability, formability, stress resistance, moisture resistance, reparability, etc., can be 0.5 or less from the viewpoints of wettability, embeddability, adhesiveness, reparability, etc., and can be 0.3 or less from the viewpoints of meltability, solubility, fluidity.

[0070] The ratio of the loss tangent (tanδ) of the photo-softenable resin composition after light irradiation (i.e., the softened product of the photo-softenable resin composition) at 25°C to the loss tangent (tanδ) of the photo-softenable resin composition before light irradiation at 25°C (loss tangent of the photo-softenable resin composition after light irradiation at 25°C / loss tangent of the photo-softenable resin composition before light irradiation at 25°C) can be 1.1 or more, 1.2 or more, or 1.3 or more from the viewpoints of micro-viscosity or non-viscosity, tackifying property, slit processability, stamping processability, operability, etc.

[0071] The viscosity of the photo-softenable resin composition (the cured product of the curable resin composition described later) after light irradiation at 25°C can be 1000000 mPa·s (1000 Pa·s) or less from the viewpoints of wettability, embeddability, adhesiveness, reparability, etc., and can be 100000 mPa·s (100 Pa·s) or less from the viewpoints of meltability, solubility, fluidity. In this specification, the viscosity at 25°C means the value measured by the method described in the examples.

[0072] The photo-softenable resin composition of the present embodiment has the following properties: The disulfide bond (-S-S-) in the component (A) is cleaved by light irradiation, so the compound having a disulfide bond is depolymerized and can be softened. The photo-softenable resin composition of the present embodiment can be softened into a liquid (liquid state). Moreover, the photo-softenable resin composition of the present embodiment has the property of being easily formed into a film shape or a block shape. By utilizing such properties, the photo-softenable resin composition of the present embodiment can be applied to, for example, the use of a photoresist in photolithography, and can be used as a photosensitive resin composition or a photosensitive resin film. The photosensitive resin composition or the photosensitive resin film can be patterned by light irradiation (exposure), and can be further developed by water washing after light irradiation (exposure). The photo-softenable resin composition of the present embodiment is suitable for forming a pattern film.

[0073] The photo-softenable resin composition of the present embodiment can also be applied to various uses such as the following: a softening agent or a peelability-imparting agent for a pressure-sensitive adhesive tape; an adhesive for a slightly sticky or non-sticky film; a partial softening agent for a coating material, a pressure-sensitive adhesive, or an adhesive; a partial softening agent for a molding material; an ultra-low elastic film that can be subjected to stamping and is obtained by light irradiation after stamping; a moisture-proof agent; a coating film of a capsule that can be softened and dissolved by light irradiation; a thickening agent, etc., whose viscosity can be reduced by light irradiation.

[0074] [Method for producing a softened product of a photo-softenable resin composition]

[0075] A method for producing a softened product of a photo-softenable resin composition according to an embodiment includes the following steps: irradiating the above photo-softenable resin composition with light to obtain a softened product of the photo-softenable resin composition.

[0076] The light in the light irradiation is not particularly limited, and can be, for example, ultraviolet light or visible light. The wavelength of the light in the light irradiation can be 150 to 830 nm. The light irradiation can be carried out, for example, using a light irradiation device under the condition of an irradiation dose of 100 mJ / cm 2 or more. Furthermore, the irradiation dose means the product of the illuminance and the irradiation time (seconds). And, as a light source for ultraviolet light or visible light irradiation, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, an LED lamp, etc. can be cited. The light irradiation can be directly carried out on the photo-softenable resin composition, or can be carried out through glass or the like.

[0077] The light irradiation of the photo-softenable resin composition can be carried out while heating. The heating conditions can be, for example, 40 to 200 °C.

[0078] [Curable resin composition and its cured product]

[0079] The curable resin composition of one embodiment contains (A-1) component, (A-2) component, and (B) component. The curable resin composition of this embodiment can react (A-1) component and (A-2) component to form a high molecular weight by a method other than light irradiation (for example, heating, etc.). When heating is used to react (A-1) component and (A-2) component, the heating temperature can be, for example, 40 to 200°C, and the heating time can be, for example, 0.1 to 48 hours. The obtained cured product can be used in the form of a film, etc., which can be used in adhesives, coating materials, etc. In addition, the obtained cured product contains a copolymer (that is, (A) component) and (B) component, and the copolymer contains monomer units of (A-1) component and monomer units of (A-2) component. That is, the cured product is one form of the above-mentioned light-softening resin composition. Therefore, the cured product can be softened by light irradiation.

[0080] The curable resin composition may also contain a curing catalyst. In addition, the curable resin composition may also contain a sensitizer, other components, a solvent, etc. The types and contents of the components contained in the curable resin composition are the same as the types and contents of the components contained in the light-softening resin composition. Thus, repeated descriptions are omitted. Furthermore, the content of component (A) corresponds to the total content of component (A-1) and component (A-2).

[0081] The cured product of the curable resin composition of one embodiment is one mode of the above-mentioned photosoftening resin composition. Therefore, the cured product of the curable resin composition has the property of being softened by light irradiation. The cured product of the curable resin composition of this embodiment can be softened into a liquid (liquid state). Moreover, the cured product of the curable resin composition of this embodiment has the property of being easily formed into a film or block. By utilizing such a property, the photosoftening resin composition of this embodiment can be applied to the use of a photoresist for photolithography, and can be used as a photosensitive resin composition or a photosensitive resin film. The photosensitive resin composition or the photosensitive resin film can be patterned by light irradiation (exposure), and can further be developed by washing with water after light irradiation (exposure). Moreover, the cured product of the curable resin composition of this embodiment can be used for various purposes exemplified in the above-mentioned photosoftening resin composition.

[0082] [Pattern film and method for producing the same]

[0083] A pattern film according to an embodiment has a pattern and contains a cured product of the above-mentioned photo-softenable resin composition or the above-mentioned curable resin composition. The cured product of the above-mentioned photo-softenable resin composition or the above-mentioned curable resin composition can be patterned by light irradiation (exposure), and can be further developed by water washing after light irradiation (exposure). Therefore, these components can be used to form a pattern film.

[0084] A method for manufacturing a pattern film according to an embodiment includes the following steps: a patterning step of patterning at least a part of the cured product of the above-mentioned photo-softenable resin composition or the above-mentioned curable resin composition by light irradiation (exposure); and a developing step of developing the patterned cured product of the photo-softenable resin composition or the curable resin composition. The developing step may include a step of developing by water washing.

[0085] Examples

[0086] Hereinafter, examples are given to specifically illustrate the present invention. However, the present invention is not limited to these examples.

[0087] <Example 1>

[0088] [Preparation of curable resin composition]

[0089] The following components were uniformly mixed and further dehydrated under reduced pressure with stirring for 1 hour. These components are: 100 parts by mass of THIOKOL LP-55 (having 2 mercapto groups, manufactured by Toray Fine Chemicals Co., Ltd.) as component (A-1); 6.3 parts by mass of diphenylmethane diisocyanate (having 2 isocyanate groups, manufactured by Nippon Polyurethane Industry Co., Ltd., trade name MILLIONATE MT) as component (A-2); and 10 parts by mass of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (manufactured by IGM Resins B.V., trade name Omnirad TPO) and 5 parts by mass of 2-isopropylthioxanthone (manufactured by Tokyo Chemical Industry Co., Ltd.) as component (B). Thereafter, the pressure was increased to normal pressure with nitrogen, and 0.02 part by mass of dibutyltin dilaurate (manufactured by Tokyo Fine Chemical CO., LTD., trade name LL-101) as component (A-3) was added and uniformly mixed to obtain a curable resin composition.

[0090] [Production of evaluation sample (photo-softenable resin composition)]

[0091] Prepare two pieces of release polyethylene terephthalate (PET, manufactured by Fujimori Kogyo Co., Ltd., trade name BD-50) with a thickness of 50 μm. Using the two pieces of release PET, sandwich the curable resin composition prepared by the above operation so that the thickness of the curable resin composition becomes 300 μm, thereby fabricating a laminate. Heat the obtained laminate at 85 °C for 12 hours to cure the curable resin composition, thereby obtaining a photo-softenable resin film (a cured film of the curable resin composition), which is the evaluation sample.

[0092] [Evaluation of the evaluation sample]

[0093] Using a viscoelasticity measuring device (manufactured by Anton Paar Japan K.K., trade name MCR-301), irradiate ultraviolet light on the evaluation sample from the light-transmitting bottom, thereby measuring the changes in the storage modulus and loss tangent (tanδ) at 25 °C with respect to the light irradiation time. The light irradiation is carried out as follows: Use an LED lamp (manufactured by Panasonic Industrial Devices SUNX Co., Ltd., trade name Aicure UJ30 / ANUJ6187), and under the conditions of a wavelength of 405 nm and an illuminance of 1000 mW / cm 2 , continuously irradiate for 150 seconds. Figure 1 is a graph showing the changes in the dynamic elastic modulus and loss tangent (tanδ) of the photo-softenable resin film of Example 1 at 25 °C with respect to the light irradiation time. The photo-softenable resin film of Example 1 is approximately in a liquid state when the irradiation dose is 50000 mJ / cm 2 (50 seconds after the start of light irradiation), and is a high-viscosity liquid after the light irradiation ends. In Table 1, the results of the storage modulus and loss tangent (tanδ) of the photo-softenable resin composition at 25 °C at each time point are shown, and the time points are: before light irradiation, 50 seconds after the start of light irradiation, and after the light irradiation ends (150 seconds after the start of light irradiation).

[0094] [Table 1]

[0095]

[0096] <Example 2>

[0097] (Example 2-1)

[0098] [Preparation of the curable resin composition]

[0099] The components (A-1), (A-2) and (B) in the amounts (unit: parts by mass) described in Table 2 were added to a 125 mL ointment jar, and mixed for 3 minutes at 2000 rpm using a stirrer (manufactured by THINKY CORPORATION, trade name: Dual Planetary Mixer ARE-310). Subsequently, each ointment jar was heated at 100 °C for 1 hour, and then the stirrer was used again to mix for 3 minutes at 2000 rpm, and it was confirmed that the component (B) had completely dissolved. The component (A-3) in the amount (unit: parts by mass) described in Table 2 was added to the ointment jar at 25 °C, and mixed for 3 minutes at 2000 rpm using a stirrer, thereby obtaining a curable resin composition.

[0100] [Preparation of Evaluation Sample (Photo-Softening Resin Composition)]

[0101] The obtained curable resin composition was poured into a silicone resin container having a length of 5 cm, a width of 5 cm and a depth of 1 cm, and the curable resin composition was allowed to stand at 25 °C for 1 week to cure (react the component (A-1) with the component (A-2)). The photo-softening resin composition (the cured product of the curable resin composition) was taken out from the silicone resin container, and a photo-softening resin block (the cured product block of the curable resin composition) having a length of 5 cm, a width of 5 cm and a depth of 1 cm was obtained. And, different from the photo-softening resin block, the curable resin composition was coated on a silicon wafer using a coater so as to have a length of 10 cm, a width of 10 cm and a film thickness of 0.01 cm, and the curable resin composition was allowed to stand at 25 °C for 1 week to cure, thereby obtaining a photo-softening resin film (the cured product film of the curable resin composition).

[0102] [Evaluation of Evaluation Sample]

[0103] (Hardness before Light Irradiation)

[0104] Using the obtained photo-softening resin block, the hardness was measured by the method (Type C) defined in Japanese Industrial Standard JIS K7312 and the method (Type E) defined in Japanese Industrial Standard JIS K6253-3. As the hardness tester, an Asker rubber hardness tester Type C (manufactured by KOBUNSHI KEIKI CO., LTD.) or a Type E hardness tester (manufactured by TECLOCK Co., Ltd.) was used. The results are shown in Table 2.

[0105] (Viscosity after Light Irradiation)

[0106] Using a conveyor belt type LED exposure machine with a wavelength of 365 nm, at 1000 mW / cm 2 and 20000 mJ / cm2 Under the conditions of 2 , irradiate the photo-softenable resin film on the silicon wafer with light. The photo-softenable resin film becomes a liquid due to light irradiation. Scrape the generated liquid with a spatula, and use a viscoelasticity measuring device (manufactured by Anton Paar Japan K.K., trade name MCR-301) to measure the viscosity at 25°C. The results are shown in Table 2.

[0107] (Example 2-2)

[0108] Except for using the components and amounts (unit: parts by mass) described in Table 2, operate in the same manner as in Example 2-1 to obtain a curable resin composition. And, prepare an evaluation sample in the same manner as in Example 2-1, and conduct the same evaluation as in Example 2-1. The results are shown in Table 2.

[0109] (Example 2-3)

[0110] Except for using the components and amounts (unit: parts by mass) described in Table 2 and not performing the operation of heating each ointment jar at 100°C for 1 hour, operate in the same manner as in Example 2-1 to obtain a curable resin composition. And, prepare an evaluation sample in the same manner as in Example 2-1, and conduct the same evaluation as in Example 2-1. The results are shown in Table 2.

[0111] (Example 2-4)

[0112] Except for using the components and amounts (unit: parts by mass) described in Table 2, operate in the same manner as in Example 2-1 to obtain a curable resin composition. And, prepare an evaluation sample in the same manner as in Example 2-1, and conduct the same evaluation as in Example 2-1. The results are shown in Table 2.

[0113] (Example 2-5)

[0114] [Preparation of Photo-softenable Resin Composition]

[0115] Add the components (A-1), (A-2), (A-3) and the solvent in the amounts (unit: parts by mass) described in Table 2 to a 500 mL flask, and stir at 80°C for 24 hours to react the component (A-1) with the component (A-2). Then, add the component (B) in the amounts (unit: parts by mass) described in Table 2 at 25°C, and stir at 25°C for 30 minutes to obtain a varnish of the photo-softenable resin composition.

[0116] [Preparation of Evaluation Sample]

[0117] The obtained varnish of the photo-softenable resin composition was applied onto a silicon wafer using a coater so that the film thickness became 100 μm, and dried at 80 °C for 5 hours to obtain a photo-softenable resin film with a film thickness of 100 μm. Subsequently, the photo-softenable resin film with a film thickness of 100 μm was cut into pieces with a length of 5 cm and a width of 5 cm, and a photo-softenable resin block with a length of 5 cm, a width of 5 cm, and a height of 1 cm was obtained by overlapping 100 pieces of the photo-softenable resin film.

[0118] [Evaluation of the evaluation samples]

[0119] Using the obtained photo-softenable resin film and photo-softenable resin block, the same evaluation as in Example 2-1 was carried out. The results are shown in Table 2.

[0120] Details of each component shown in Table 2 are as follows.

[0121] Component (A-1): A monomer having a disulfide bond and a functional group

[0122] · A-1: THIOKOL LP-55 (number of mercapto groups is 2, manufactured by Toray Fine Chemicals Co., Ltd.).

[0123] Component (A-2): A monomer having a substituent capable of reacting with a functional group

[0124] · A-2-1: 1,4-butanediol diacrylate (number of acryloyl groups is 2, manufactured by Showa Denko Materials Co., Ltd., trade name FA-124AS).

[0125] · A-2-2: Diphenylmethane diisocyanate (number of isocyanate groups is 2, manufactured by TOSOH CORPORATION, trade name MILLIONATE MT).

[0126] Component (A-3): A curing catalyst

[0127] · A-3-1: 1,8-diazabicyclo[5.4.0]undec-7-ene (manufactured by SAN-APRO LTD., trade name DBU)

[0128] · A-3-2: 1,5-diazabicyclo[4.3.0]non-5-ene (manufactured by SAN-APRO LTD., trade name DBN)

[0129] Component (B): A curing catalyst

[0130] · B-1: Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (manufactured by IGM Resins B.V., trade name Omnirad TPO).

[0131] · B-2: 2-Hydroxy-2-methyl-1-phenylpropanone (manufactured by IGM Resins B.V., trade name Omnirad 1173).

[0132] (D) Component: Solvent

[0133] · D-1: Toluene (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0134]

[0135] <Example 3>

[0136] [Production of photosensitive resin film (film of photo-softenable resin film or cured product of curable resin composition)]

[0137] In an ointment pot, 9.75 parts by mass of THIOKOL LP-3 (number of mercapto groups is 2, manufactured by Toray Fine Chemicals Co., Ltd.) as the (A-1) component and 0.25 parts by mass of diazabicycloundecene (manufactured by SAN-APRO LTD., trade name DBU) as the (A-3) component were added, and using a stirrer (manufactured by THINKY CORPORATION, trade name planetary mixer ARE-310), they were mixed for 3 minutes under the condition of 2000 rpm to obtain a first mixed solution. Subsequently, the following components were added to another ointment pot, using the same stirrer as above and mixing for 3 minutes under the condition of 2000 rpm, and after heating each ointment pot at 100 °C for 1 hour, they were mixed for 3 minutes under the condition of a frequency of 2000 rpm to obtain a second mixed solution. The components are: 5.30 parts by mass of THIOKOL LP-3 as the (A-1) component; 1.86 parts by mass of polyethylene glycol diacrylate (number of acryloyl groups is 2, manufactured by Showa Denko Materials Co., Ltd., trade name FA-240S) and 1.69 parts by mass of NK ESTER ATM-35E (number of acryloyl groups is 4, manufactured by SHIN-NAKAMURA CHEMICAL CO., LTD., trade name) as the (A-2) component; and 2.5 parts by mass of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (manufactured by IGM Resins B.V., trade name Omnirad TPO) as the (B) component. Subsequently, 0.15 parts by mass of the first mixed solution was added to the ointment pot containing the second mixed solution at 25 °C, mixed for 1.5 minutes at a frequency of 2000 rpm, and then, in such a manner that the film thickness became 50 μm, the mixed solution was quickly coated on a copper plate using a coater, and cured under the conditions of 60 °C for 24 hours to obtain a photosensitive resin film with a film thickness of 50 μm.

[0138] [Discussion on the Fabrication of Pattern Films]

[0139] Through a mask with a circular opening of 1 mmΦ, the obtained photosensitive resin film was irradiated with i-rays (mercury spectral line with a wavelength of 365 nm) of an incident high-pressure mercury lamp with an illuminance of 5 mW / cm 2 for 30 minutes. Then, after developing the photosensitive resin film irradiated with i-rays for 3 minutes using a water washer at 25°C, drying was carried out. When the dried photosensitive resin film was confirmed, it was found that a circular opening of 1 mmΦ was formed on the copper plate. This result implies that a pattern film can be formed by using this photosensitive resin film.

Claims

1. A photo-softenable resin composition, comprising: a compound having a disulfide bond; and a radical scavenger, which is a compound that generates radicals capable of reacting with sulfur radicals upon light irradiation, the compound having a disulfide bond is a copolymer, the copolymer comprising: a monomer unit having a disulfide bond and a functional group; and a monomer unit having a substituent capable of reacting with the functional group, the functional group includes a thiol group, the radical scavenger includes a photo radical polymerization initiator selected from intramolecular cleavage type photo radical polymerization initiators and dehydrogenation type photo radical polymerization initiators, the intramolecular cleavage type photo radical polymerization initiator is one or more selected from benzyl ketal type photo radical polymerization initiators, α-hydroxyacetophenone type photo radical polymerization initiators, benzoin type photo radical polymerization initiators, aminobenzophenone type photo radical polymerization initiators, oxime ketone type photo radical polymerization initiators, acylphosphine oxide type photo radical polymerization initiators, titanocene type photo radical polymerization initiators, and S-phenyl thiosalicylate polymerization initiators, the dehydrogenation type photo radical polymerization initiator is one or more selected from benzophenone type photo radical polymerization initiators, thioxanthone type photo radical polymerization initiators, and anthraquinone photo radical polymerization initiators.

2. The photo-softenable resin composition according to claim 1, further comprising a sensitizer.

3. A method for producing a softened product of a photo-softenable resin composition, which comprises the following steps: performing light irradiation on the photo-softenable resin composition according to claim 1 or 2 to obtain a softened product of the photo-softenable resin composition.

4. A curable resin composition, comprising: a monomer having a disulfide bond and a functional group; a monomer having a substituent capable of reacting with the functional group; and a radical scavenger, which is a compound that generates radicals capable of reacting with sulfur radicals upon light irradiation, the functional group includes a thiol group, the radical scavenger includes a photo radical polymerization initiator selected from intramolecular cleavage type photo radical polymerization initiators and dehydrogenation type photo radical polymerization initiators, the intramolecular cleavage type photo radical polymerization initiator is one or more selected from benzyl ketal type photo radical polymerization initiators, α-hydroxyacetophenone type photo radical polymerization initiators, benzoin type photo radical polymerization initiators, aminobenzophenone type photo radical polymerization initiators, oxime ketone type photo radical polymerization initiators, acylphosphine oxide type photo radical polymerization initiators, titanocene type photo radical polymerization initiators, and S-phenyl thiosalicylate polymerization initiators, the dehydrogenation type photo radical polymerization initiator is one or more selected from benzophenone type photo radical polymerization initiators, thioxanthone type photo radical polymerization initiators, and anthraquinone photo radical polymerization initiators.

5. The curable resin composition according to claim 4, further comprising a curing catalyst.

6. The curable resin composition according to claim 4 or 5, further comprising a sensitizer.

7. A cured product of a curable resin composition, wherein the curable resin composition is the curable resin composition according to any one of claims 4 to 6.

8. A pattern film having a pattern and comprising a cured product of the photo-softenable resin composition according to claim 1 or 2 or the curable resin composition according to claim 7.

9. A method for manufacturing a pattern film, which comprises the following steps: A patterning step of patterning by irradiating light on at least a part of the photo-softenable resin composition according to claim 1 or 2 or the cured product of the curable resin composition according to claim 7; and A developing step of developing the patterned photo-softenable resin composition or the cured product of the curable resin composition.

10. The method for manufacturing a pattern film according to claim 9, wherein, the developing step includes a step of developing by washing with water.

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