Photosensitive components

Abstract

To provide a photosensitive composition that can suppress discoloration during curing and has excellent adhesion to the substrate and scratch resistance. [Solution] A photosensitive composition comprising a reaction product of the following compound (A) and the following compound (B), wherein the chlorine content is less than 100 ppm. Compound (A): 1,8-diisocyanato-4-isocyanatomethyloctane, or a prepolymer which is a reaction product of 1,8-diisocyanato-4-isocyanatomethyloctane and a polyol. The polyol has an average of 1.5 to 2.5 hydroxyl groups per molecule. Compound (B): (meth)acrylate or (meth)acrylamide which has at least one active hydrogen group per molecule.

Description

Technical Field

[0001] The present invention relates to a photosensitive composition.

Background Art

[0002] Urethane acrylate is mainly produced by the reaction of a difunctional or higher isocyanate with an acrylate having a hydroxy group or, depending on the design, a polyol. Urethane acrylate is a polymer that exhibits high hardness, flexibility, toughness, and weather resistance, and is used in a wide range of industries such as paints, adhesives, coating agents, and electronic materials.

[0003] As the isocyanate that is a raw material for urethane acrylate, a diisocyanate, which is a difunctional isocyanate, may be used. For the purpose of improving the physical properties of urethane acrylate and suppressing the vapor pressure to ensure the safety of handling workers, for example, an isocyanate polymer obtained by polymerizing a diisocyanate by a reaction represented by the following formulas (a) to (b) may be used as the isocyanate that is a raw material for urethane acrylate. In the following formulas (a) to (b), R represents a divalent organic group.

[0004]

Chemical formula

[0005] In the reaction represented by the above formula (a), an isocyanurate-type isocyanate polymer is obtained, and in the reaction represented by the above formula (b), a biuret-type isocyanate polymer is obtained.

[0006] On the other hand, when using a polymer of isocyanate as a raw material, drawbacks such as a high viscosity of the resulting urethane acrylate and poor compatibility with other polymerizable acrylates occur.

[0007] These drawbacks can be overcome by using 1,8-diisocyanato-4-isocyanatomethyloctane (hereinafter sometimes referred to as "TTI"), which is trifunctional yet has low viscosity, as the isocyanate raw material. A urethane (meth)acrylate using TTI as the isocyanate raw material is disclosed in Patent Document 1. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 61-042529 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] However, depending on the application, yellowing of the cured product can be a problem. The urethane acrylate composition disclosed in Patent Document 1 has room for improvement in suppressing yellowing. There is also room for improvement in adhesion to the substrate and scratch resistance. Therefore, the present invention aims to provide a photosensitive composition that can suppress discoloration during curing and has excellent adhesion to the substrate and scratch resistance. [Means for solving the problem]

[0010] In other words, the present invention includes the following embodiments. [1] A photosensitive composition comprising a reaction product of the following compound (A) and the following compound (B), wherein the chlorine content is less than 100 ppm. Compound (A): 1,8-diisocyanato-4-isocyanatomethyloctane, or a prepolymer which is a reaction product of 1,8-diisocyanato-4-isocyanatomethyloctane and a polyol. The polyol has an average of 1.5 to 2.5 hydroxyl groups per molecule. Compound (B): A (meth)acrylate or (meth)acrylamide having at least one active hydrogen group in one molecule. [2] The photosensitive composition according to [1], wherein the active hydrogen group is a hydroxyl group, an amino group, or a thiol group. [3] The photosensitive composition according to [1] or [2], wherein compound (B) is a monofunctional (meth)acrylate or monofunctional (meth)acrylamide having one photopolymerizable double bond. [4] The photosensitive composition according to any one of [1] to [3], wherein the compound (B) is a polyfunctional (meth)acrylate or polyfunctional (meth)acrylamide having two or more photopolymerizable double bonds. [5] The photosensitive composition according to any one of [1] to [4], wherein the equivalent ratio of the active hydrogen group of compound (B) to the NCO group of compound (A) is 0.30 or more and 1.50 or less. [6] A photosensitive composition according to any one of [1] to [5], wherein the chlorine content is less than 10 ppm. [7] A photosensitive composition according to any one of [1] to [6], wherein the chlorine content is less than 5 ppm. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a photosensitive composition that can suppress discoloration during curing and has excellent adhesion to the substrate and scratch resistance. [Modes for carrying out the invention]

[0012] Preferred embodiments of the present invention are described below. However, the present invention is not limited to the embodiments described below, and can be implemented with various modifications within the scope of its essence.

[0013] In this specification, when referring to IUPAC rules and the IUPAC Nomenclature rules established thereafter (except when specifically referring to IUPAC recommendations from other years), it means the "Organic and Biochemical Nomenclature" (revised 2nd edition, published in 1992 by Nankodo Publishing, Japan), which is based on the edition containing all the rules for organic and biochemistry and the rules for transliteration into Japanese, published in 1980 as a supplement to "The Domain of Chemistry" based on Recommendations 1979, and incorporates all subsequent revisions and recommendations. "Organic" refers to the general group of compounds subject to the nomenclature disclosed in said nomenclature. This group may also include those listed in the 1993 recommendation. However, the "organic" compounds subject to the above Nomenclature also include organometallic compounds and metal complexes. In this embodiment, unless otherwise specified, terms such as "organic group" and "substituent" mean a group composed of atoms that do not contain metal atoms and / or metalloids. Furthermore, in this embodiment, an "organic compound," "organic group," or "substituent" composed of atoms selected from H (hydrogen atom), C (carbon atom), N (nitrogen atom), O (oxygen atom), S (sulfur atom), Cl (chlorine atom), Br (bromine atom), and I (iodine atom) is preferably used.

[0014] The following explanation will make frequent use of the terms "aliphatic" and "aromatic." According to the IUPAC rules mentioned above, organic compounds are classified into aliphatic compounds and aromatic compounds. Aliphatic compounds are defined according to the definition of aliphatic compounds in accordance with the 1995 IUPAC Recommendation. This recommendation defines aliphatic compounds as "acyclic or cyclic, saturated or unsaturated carbon compounds, excluding aromatic compounds." In addition, the "aliphatic compound" used in the description of this embodiment includes both saturated and unsaturated, linear and cyclic ones, and refers to an "organic compound", "organic group" or "substituent" composed of atoms selected from the group consisting of the above-mentioned halogen atoms of H (hydrogen atom); C (carbon atom); N (nitrogen atom); O (oxygen atom); S (sulfur atom); Si (silicon atom); Cl (chlorine atom), Br (bromine atom) or I (iodine atom).

[0015] When an aromatic group such as an aralkyl group is bonded to an aliphatic group, it may be expressed as an "aliphatic group substituted with an aromatic group" or a "group composed of an aliphatic group to which an aromatic group is bonded" in this way. This is based on the reactivity in this embodiment, because the properties related to the reaction of a group such as an aralkyl group are extremely similar to the aliphatic reactivity rather than aromaticity. In addition, non-aromatic reactive groups including an aralkyl group, an alkyl group, etc. may be expressed as an "aliphatic group optionally substituted with an aromatic group", an "aliphatic group to which an aromatic group may be bonded", etc.

[0016] When explaining the general formula of a compound used in this specification, the definitions according to the Nomenclature rules defined by the above-mentioned IUPAC are used, but for the names of specific groups and the names of exemplified compounds, common names may be used. In addition, when the number of atoms, the number of substituents, and the number are described in this specification, they all represent integers.

[0017] In this specification, "active hydrogen" refers to a hydrogen atom bonded to an oxygen atom, a sulfur atom, a nitrogen atom, a silicon atom, etc. (excluding an aromatic hydroxy group), and a hydrogen atom of a terminal methine group. "Active hydrogen" is, for example, hydrogen contained in atomic groups such as -OH group, -C(=O)OH group, -C(=O)H group, -SH group, -SO3H group, -SO2H group, -SOH group, -NH2 group, -NH- group, -SiH group, -C≡CH group, etc.

[0018] Note that examples of the compound having a hydroxy group (-OH group) include an alcohol and an aromatic hydroxy compound.

[0019] "Alcohol" as used in this specification refers to "Compounds in which a hydroxy group, -OH, is attached to a saturated carbon atom: R3COH" described in the IUPAC definition (Rule C-201), and does not include aromatic hydroxy compounds in which the hydroxy group is attached to an aromatic ring.

[0020] "Aromatic hydroxy compound" as used in this specification refers to phenols "Compounds having one or more hydroxy groups attached to a benzene or other arene ring." described in the IUPAC definition (Rule C-202).

[0021] <Photosensitive composition> The photosensitive composition of this embodiment contains the reaction product of the following compound (A) and the following compound (B), and the chlorine content is less than 100 ppm. Compound (A): 1,8 - diisocyanato - 4 - isocyanatomethyloctane, or a prepolymer which is a reaction product of 1,8 - diisocyanato - 4 - isocyanatomethyloctane and a polyol having an average of 1.5 or more and 2.5 or less hydroxyl groups in one molecule. Compound (B): A (meth)acrylate or (meth)acrylamide having at least one active hydrogen group in one molecule.

[0022] Hereinafter, the details of compound (A) and compound (B) will be described.

[0023] ≪Compound (A)≫ In the present invention, compound (A) is an isocyanate component, and is either 1,8-diisocyanato-4-isocyanatomethyloctane, or a prepolymer which is a reaction product of 1,8-diisocyanato-4-isocyanatomethyloctane and a polyol.

[0024] TTI used as compound (A) is available by known methods. For example, it can be produced by the phosgene method, which is a common isocyanate synthesis method, i.e., the reaction of 4-aminomethyl-1,8-octanediamine with phosgene (e.g., Japanese Patent Publication No. 56-127341), or by thermal decomposition of a carbamate compound obtained by reacting an amine with at least one of urea and N-unsubstituted carbamic acid esters with an alcohol (carbamation reaction) (urea method) (e.g., International Publication No. 2014 / 157636).

[0025] Furthermore, a TTI prepolymer can also be used as the isocyanate component. This prepolymer is a reaction product of TTI and a polyol. The prepolymer is obtained by reacting TTI with a polyol having an average of 1.5 to 2.5 hydroxyl groups per molecule under NCO excess conditions, preferably with an NCO / OH equivalent ratio of 3 or higher. TTI has a very low vapor pressure at room temperature and low toxicity and irritancy, so it has the great advantage of being safe to handle both as TTI alone and as a prepolymer.

[0026] Examples of polyols having an average of 1.5 to 2.5 hydroxyl groups per molecule that can be used in the prepolymerization of TTI include polyester polyols, polyether polyols, polyolefin polyols, polyepoxy polyols, polycarbonate polyols, and diol compounds having 2 to 15 carbon atoms. These compounds can also be used in appropriate mixtures.

[0027] Examples of polyester polyols include polycondensation reaction products of dicarboxylic acids such as phthalic acid, adipic acid, azelaic acid, and sebacic acid with diols such as ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, diethylene glycol, and dipropylene glycol, as well as ring-opening polymerization reaction products of cyclic esters such as ε-caprolactone, using the above diols as initiators. In addition, oily diols obtained by treating one hydroxyl group from triglycerides of fatty acids having hydroxyl groups, such as castor oil, through dehydration reactions, can also be suitably used.

[0028] Examples of polyether diols include ordinary polypropylene glycol, polyethylene glycol, polytetramethylene glycol, and polypropylene glycol with ethylene oxide added to its terminus, as well as polypropylene glycol or polyethylene glycol whose physical properties have been improved using special diols such as bisphenol A as initiators.

[0029] Examples of polyolefin diols include polybutadiene homopolymers having hydroxyl groups at both ends, butadiene / styrene copolymers or butadiene / acrylonitrile copolymers also having hydroxyl groups at both ends, and hydrogenated polybutadiene having an average of 1.5 to 2.5 hydroxyl groups per molecule.

[0030] Examples of diol compounds with 2 to 15 carbon atoms include linear diols and branched diols. These diols can also be used in mixtures as appropriate.

[0031] TTI prepolymers can be synthesized by reacting TTI with a polyol. For example, the synthesis method disclosed in Japanese Patent Publication No. 61-042529 can be used.

[0032] ≪Compound (B)≫ Compound (B) is a (meth)acrylate or (meth)acrylamide having at least one active hydrogen group in one molecule. The active hydrogen group in compound (B) may be any active hydrogen group that reacts with the NCO group, but it is preferably a hydroxyl group, an amino group, or a thiol group.

[0033] Examples of compound (B) include compounds having carboxyl groups and carbon-carbon double bonds such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid; (meth)acrylic compounds having amide groups such as acrylamide, methacrylamide, diacetoneacrylamide, and N-methylacrylamide; (meth)acrylate compounds having hydroxyl groups or amino groups; and (meth)acrylamide compounds having hydroxyl groups or amino groups.

[0034] Typical examples of (meth)acrylates having a hydroxyl group include, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 1,4-cyclohexanedimethanol monoacrylate.

[0035] A typical example of a (meth)acrylamide compound having a hydroxyl group is, for example, N-(2-hydroxyethyl)(meth)acrylamide.

[0036] A typical example of a compound that has an amino group as an active hydrogen is (meth)acrylamide. Furthermore, R in the following general formula (II) 22 Compounds with relatively long chains, such as those extended by polyester or polyether bonds, have the characteristic of imparting elasticity to the cured resin. Examples of such compounds include those shown in the following general formulas (II-1) and (II-2).

[0037] [ka]

[0038] [ka]

[0039] [ka] (In the formula, R 21 , R 23 (Each represents either H or CH3, n is an integer from 1 to 10, and m is an integer from 2 to 10.)

[0040] An example of compound (B) is a monofunctional (meth)acrylate or monofunctional (meth)acrylamide having one photopolymerizable double bond. An example of compound (B) is a polyfunctional (meth)acrylate or polyfunctional (meth)acrylamide having two or more photopolymerizable double bonds.

[0041] If compound (B) is a compound having two or more photopolymerizable double bonds in one molecule, it is characterized by rapid curing and resin hardness after curing. Examples of such compounds include trimethylolpropane di(meth)acrylate, glycerin di(meth)acrylate, pentaerythritol tri(meth)acrylate, and tris(2-hydroxyethyl)isocyanurate di(meth)acrylate. Such compounds (B) can also be used in appropriate mixtures.

[0042] Examples of compounds (B) having a thiol group include 2-mercaptoethyl (meth)acrylate, 3-mercaptopropyl (meth)acrylate, 4-mercaptobutyl (meth)acrylate, and 6-mercaptohexyl (meth)acrylate.

[0043] Of the above compounds, compound (B) is particularly preferably 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, N-(2-hydroxyethyl)(meth)acrylamide, or pentaerythritol tri(meth)acrylate.

[0044] <<Optional Component>> (Polyfunctional (meth)acrylate and polyfunctional (meth)acrylamide without active hydrogen groups) One embodiment of the photosensitive composition may contain either or both of a polyfunctional (meth)acrylate and a polyfunctional (meth)acrylamide that have two or more (meth)acryloyl groups and no active hydrogen groups. The number of (meth)acryloyl groups is preferably 2 to 8, more preferably 3 to 6.

[0045] Either or both of the polyfunctional (meth)acrylate and the polyfunctional (meth)acrylamide without active hydrogen groups preferably have a total carbon number of 8 to 44, more preferably 12 to 34. Specifically, glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, sorbitol hexa(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, N-[tris(3-acrylamidopropoxymethyl)methyl]acrylamide, N,N-bis(2-acrylamidoethyl)acrylamide, N,N-1,2-ethanediylbis{N-[2-(acryloylamino)ethyl]acrylamide}, etc. may be mentioned. Among them, pentaerythritol tetra(meth)acrylate is preferable because it can impart excellent scratch resistance and abrasion resistance to the cured product.

[0046] If necessary, it may contain a radical polymerization inhibitor (hindered phenol compound, hindered amine compound, etc.) for suppressing thermal polymerization, and a catalyst that promotes the reaction of an active hydrogen compound and an isocyanate, such as a tin-based compound or a tertiary amine compound.

[0047] (Isocyanate compound) One embodiment of the photosensitive composition may include an isocyanate compound other than compound (A). Preferably, the isocyanate compound other than compound (A) is a compound represented by the following general formula (III) other than TTI (hereinafter sometimes referred to as "isocyanate compound (III)").

[0048] [ka]

[0049] In general formula (III), R 31 This is an organic group with n31 valency, where n31 is an integer between 1 and 8 (inclusive).

[0050] R 31 When is an aliphatic hydrocarbon group, specific examples of isocyanate compounds (III) include aliphatic diisocyanates, aliphatic triisocyanates, and substituted cyclic aliphatic polyisocyanates.

[0051] Preferred isocyanate compounds (III) include, for example, 2-isocyanatoethyl acrylate (AOI), 2-isocyanatoethyl methacrylate (MOI), 2-isocyanatoethyl-2,6-diisocyanatohexanoate (LTI), lysine methyl ester diisocyanate (LDI), diisocyanatopentane (PDI), diisocyanatohexane (HDI), methylenebis(cyclohexyl isocyanate) (HMDI), 1,3-bis(isocyanatomethyl)cyclohexane (HXDI), 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI), diisocyanatoxylene (XDI), diisocyanatodiphenylmethane (MDI), and diisocyanatotoluene (TDI). These isocyanate compounds can be used as is, but when creating energy-ray curable compositions, they are modified into urethane (meth)acrylate before use.

[0052] If a preferred isocyanate is manufactured using a method that does not involve phosgene, the amount of chlorine introduced is also reduced, which is preferable. Isophorone diisocyanate is an example of such a method.

[0053] The chlorine content of the photosensitive composition is less than 100 ppm, preferably less than 10 ppm, and more preferably less than 5 ppm. In one embodiment of the photosensitive composition, the chlorine content may be 0 ppm. Here, the chlorine content of the photosensitive composition is the ratio of the total amount of organic and inorganic chlorine to the composition obtained by the reaction of compound (A) and compound (B), and is a value based on mass. The chlorine content of the photosensitive composition can be measured by the following method.

[0054] [Method for measuring the chlorine content of a photosensitive composition] Dissolve 1 g of the photosensitive composition derived from compound (A) and compound (B) in 25 ml of ethylene glycol monobutyl ether, add 25 ml of propylene glycol solution in 1 N KOH, and boil for 20 minutes to obtain a sample solution. The obtained sample solution is subjected to potentiometric titration with an aqueous silver nitrate solution (concentration 0.01 mol / L). Specifically, the chlorine content in the photosensitive composition is calculated using the following formula. Chlorine content (ppm) = {(v-v0)×f×10×35.5} / W (W: Sample weight (g), v: Titration volume (mL), v0: Blank titration volume (mL), f: Factor of silver nitrate solution) For example, a potentiometric titrator can be used as the titration apparatus.

[0055] The reaction product of compound (A) and compound (B) has a urethane bond if the active hydrogen group of compound (B) is a hydroxyl group, and a urea bond if the active hydrogen group of compound (B) is an amino group.

[0056] The equivalent ratio of active hydrogen groups of compound B to NCO groups of compound (A) used in the reaction affects the physical properties of the product and therefore needs to be selected according to the purpose, but it is preferable that the NCO group / active hydrogen group ratio is between 0.3 and 1.5. If the NCO group / active hydrogen group ratio is less than 0.3, the concentration of (meth)acrylic groups in the product is low, resulting in poor curability, and if the NCO group / active hydrogen group ratio is greater than 1.50, there is a large amount of unreacted compound (B), which is not economical, so neither is preferable. However, this invention does not exclude the idea of ​​intentionally making the equivalent amount of compound (B) larger than the equivalent amount of isocyanate in compound (A) and using the excess compound (B) as a reactive solvent.

[0057] While all NCO groups in compound (A) may be reacted with the active hydrogen groups, it is also possible to partially react them, leaving unreacted NCO groups, thus creating a so-called dual-cure type that allows for not only UV curing but also room-temperature curing and thermal curing. For a dual-cure type, the NCO group / active hydrogen group ratio is preferably in the range of 0.1 to 0.99. In the range of 0.3 to 0.5, polymerization of the NCO group is preferred, making it easier to heat-cur. In the range of 0.5 to 0.9, UV curing is easier, and the range of 0.4 to 0.6 is the most preferable, as it provides a good balance between heat curing and UV curing.

[0058] In the case of a dual-cure type, there can be reactants in which all NCO groups of compound (A) react with the active hydrogen-containing monomer, reactants in which two groups react, reactants in which one group reacts, or reactants in which none react. Reactants with three groups reacting can be cured immediately by active ray irradiation and result in a highly hard cured product. Reactants with two groups reacting can be hardened by thermal curing even in areas where light is difficult to reach. Reactants with one group reacting can achieve hardness by room temperature curing without heating equipment or light irradiation equipment, and even if the isocyanate group cannot contribute to crosslinking, secondary effects such as improved adhesion can be expected due to its polarity.

[0059] <Method for producing a photosensitive composition> The photosensitive composition of this embodiment is obtained by reacting the NCO group of compound (A), which is a raw material, with the active hydrogen group of compound (B). One embodiment of the photosensitive composition can be produced by mixing compound (A) and compound (B) in a ratio such that the equivalent ratio of the functional groups of active hydrogen groups of compound (B) to the functional groups derived from the NCO group of compound (A) is 0.30 or more and 1.50 or less. One embodiment of the photosensitive composition may further be prepared by mixing, if necessary, one or both of a polyfunctional (meth)acrylate and a polyfunctional (meth)acrylamide that do not have active hydrogen groups with an isocyanate compound other than compound (A).

[0060] In one embodiment of the present invention, a photosensitive composition with a chlorine content of less than 100 ppm can be obtained by using compound (A) produced by a non-phosgene method as a raw material.

[0061] The reaction temperature for compound (A) and compound (B) is not limited, but is, for example, 130°C or lower, and preferably in the range of room temperature to 110°C. If the reaction temperature is too high, the double bonds in compound (B) will undergo thermal polymerization, resulting in polymer formation, which is undesirable.

[0062] During the reaction, if necessary, inert solvents such as aromatic hydrocarbons like benzene, toluene, and xylene; esters like butyl acetate, ethyl acetate, and ethylene glycol monoethyl ether acetate; ketones like 2-butanone and 4-methyl-2-pentanone; or photopolymerizable monomers such as styrene and (meth)acrylates that do not contain active hydrogen can be used as solvents. Furthermore, if necessary, radical polymerization inhibitors (hindered phenol compounds, hindered amine compounds, etc.) to suppress thermal polymerization during the reaction, or catalysts to promote the reaction between active hydrogen compounds such as tin compounds or tertiary amine compounds and isocyanates may be added.

[0063] When reacting the NCO group of compound (A), which is a raw material, with the active hydrogen group of compound (B), the reaction may be carried out by continuous addition or by single addition. If compound (B) has multiple active hydrogen groups, continuous addition in small amounts is preferred in order to suppress the increase in molecular weight.

[0064] Catalysts such as metals or amines may be used to accelerate the reaction between the NCO group and the active hydrogen group. Examples of catalysts commonly known as urethane reaction accelerating catalysts include organotin compounds such as dibutyltin dilaurate and amines such as DBU.

[0065] By using a prepolymer, which is a reaction product of TTI and a polyol, as compound (A), flexibility can be imparted to the cured product of the photosensitive composition. When using a prepolymer as compound (A), compound (B) may be reacted with the reaction product of TTI and a polyol, or a polyol may be reacted with the reaction product of TTI and compound (B). In the former case, the polyol can be added in a ratio such that the TTI does not gel during the reaction, and this range is such that the equivalent ratio of hydroxyl groups to isocyanate groups is 0.1 to 0.9 equivalents. In the range of 0.1 to 0.5, a balance between flexibility and hardness can be achieved, and in the range of 0.5 to 0.9, flexibility can be provided. There are no particular limitations on the type of polyol, but for diols, low molecular weight diols to polyether diols, polyester diols, and polycarbonate diols with molecular weights of several hundred to tens of thousands can be used. For triols, low molecular weight ones as well as polyester triols and polyether triols, which were listed as examples of diols, can be used.

[0066] The resulting photosensitive composition has the function of forming a tough resin coating film when irradiated with active energy rays in the presence of a suitable polymerization initiator. If the photosensitive composition has an NCO group, after curing with active energy rays, the areas that are not exposed to the active energy rays can be cured in a second stage by moisture curing or thermal curing with an active hydrogen compound. Alternatively, the NCO group can be thermoformed before irradiation with active energy rays, and then cured by irradiation with active energy rays. In this case, photosensitizers such as anthraquinone, 5-nitrofluorenone, and 5-nitroacenaphthene, as well as other polymerizable unsaturated resins, oligomers, and monomers can be added, and other fillers such as pigments and fillers can be added as needed.

[0067] Curing using active energy rays is performed by polymerizing double bonds such as (meth)acryloyl groups using various radical generation methods. When UV irradiation is performed, radicals are generated using photopolymerization initiators, while in the case of thermal polymerization, radicals are generated by heating using azo-based initiators, peroxide-based initiators, etc. Lamps used for UV irradiation include high-pressure mercury lamps, metal halide lamps, LED lamps, and excimer lamps, and are selected according to the purpose, such as wavelength and energy.

[0068] Another curing method is electron beam curing (EB curing), which does not require a polymerization initiator and allows for instantaneous curing. Among these curing methods, the method using UV light and a photopolymerization initiator is preferable because it allows for rapid curing in seconds, does not require thermal energy other than UV irradiation, and does not require special equipment like EB curing.

[0069] Dual-cure adhesives are already used in industry, and one of their advantages is that they utilize different curing methods to vary the degree of curing at each stage of the process. For example, in adhesive applications, one method involves first creating a weak crosslinking force by UV curing, and then performing sufficient heat curing to achieve the desired adhesive strength. Another method is the reverse, where UV curing is performed after heat curing.

[0070] The photosensitive composition of the present invention can be used in a variety of applications, but among them, electronic materials are particularly suitable applications due to its excellent transparency, adhesion, and scratch resistance. Urethane (meth)acrylate or urea (meth)acrylate can provide flexibility while maintaining toughness, thus solving the lack of flexibility of epoxy resins commonly used in electronic materials.

[0071] The applications of electronic materials are diverse, including the following, and the photosensitive composition of the present invention is used as a compounding agent for purposes such as adjusting the viscoelasticity and adhesive strength of the compounding composition.

[0072] Resists function as protective films against physical and chemical processes, playing a particularly important role in semiconductor manufacturing processes. They are used to protect specific areas during processing. The main types and applications are as follows:

[0073] The first type is photoresist, which is photosensitive and used in photolithography processes. It is widely used in the manufacturing of semiconductor wafers and printed circuit boards. It can be divided into several types. Positive resist is a resist in which the areas exposed to light or an electron beam become easily soluble, and is used by removing the exposed areas with a development solution after exposure. It is suitable for the manufacturing of fine patterns and is widely used in semiconductor manufacturing processes. Negative resist is a resist in which the exposed areas harden and the unexposed areas become easily soluble, and is used by removing the unexposed areas after exposure, and is suitable for devices with thick patterns or high sidewalls. Chemically amplified resist (CAR) is a method in which a chemical amplification reaction occurs when exposed, and it is possible to manufacture very fine patterns, and is used in advanced technologies such as extreme ultraviolet (EUV) lithography. Dry resist is a resist that is supplied as a thin film rather than a liquid, and is a method that makes it easy to obtain a uniform film thickness and enables precise patterning.

[0074] The second type is screen-printed resist, which is patterned using screen printing and is suitable for processing large areas.

[0075] The third is etching resist, which is used for partial protection during etching and possesses properties such as alkali resistance and acid resistance.

[0076] The fourth is solder resist, which is applied to the parts of a printed circuit board that are not to be soldered, and is used to prevent short circuits.

[0077] Underfill refers to the liquid-curable resin that is filled between the chip and the substrate during processes such as flip-chip bonding and wire bonding. It is used to improve the mechanical strength of the interconnection, enhance resistance to stress caused by differences in thermal expansion between materials, and prevent corrosion and degradation due to changes in humidity and temperature. Underfill can be further categorized into capillary underfill (CUF), which is diffused from the side of the chip by capillary action; no-flow underfill, which is applied to the substrate before the chip is attached and cured during the reflow process; and molded underfill (MUF), which seals the entire package and fills it with resin in one go.

[0078] Examples of adhesives used for displays include OCA (Optical Clear Adhesive) and OCR (Optical Clear Resin), which are used for touch panels. They are used to bond the cover glass to the touch panel and to fill gaps, thereby improving visibility.

[0079] A camera module is a camera component installed in devices such as smartphones and PCs. Adhesives are used to securely fix the lens, image sensor, and other optical components, and urethane (meth)acrylate is used as one of the components of these adhesives.

[0080] ACF (Anisotropic Conductive Film) is a film-like bonding material used to connect electronic components to a substrate. It is conductive in the compression direction (up and down) but insulating in the planar direction (left and right), thus possessing the characteristic of conducting electricity only in a specific direction. In this application, the photosensitive composition of the present invention may be used in combination with an epoxy resin, for example, to impart flexibility or improve adhesion.

[0081] Examples of semiconductor process materials classified as back-end materials include dicing tape and backgrind tape. Dicing tape is an adhesive tape used in semiconductor manufacturing processes to secure wafers and enable precise cutting. It also protects the wafer surface and minimizes damage during cutting. When using a photosensitive composition in this application, UV irradiation is used to reduce the adhesive strength and facilitate peeling. Backgrind tape is used in the backgrinding process, which involves thinly grinding the back surface of a wafer while protecting the front surface (circuit formation surface). It is peeled off when moving to the next process. The photosensitive composition may be formulated to adjust the peel strength.

[0082] Examples of adhesives for semiconductors include die attach films, die attach pastes, and dicing / die bonding tapes. Die attach films (DAFs) are primarily used to secure semiconductor chips to substrates and are used in chip mounting and stacking. DAFs provide flexibility while securely fixing the chip to the substrate, efficiently dissipating heat from the chip to stabilize device performance, reducing the risk of chip damage, and improving product reliability. In this application, photosensitive compositions may be used to impart flexibility and adhesion.

[0083] Die attach, also known as die bonding, refers to the process of joining a semiconductor to a substrate using adhesives or solder. Die attach paste, like die attach film, secures the semiconductor chip to the substrate, efficiently dissipating heat from the chip and minimizing stress on both the chip and the substrate. Die attach pastes are available in conductive and non-conductive types, selected according to the application. Photosensitive compositions may also be used in this application to adjust flexibility and adhesion.

[0084] Dicing / die bonding tape is a tape that combines the function of fixing the wafer during cutting (dicing) and the function of transferring the adhesive used for mounting and stacking (die bonding) the cut chips. By using this tape, the process of attaching the semiconductor chips cut from the wafer to the DAF can be eliminated, and if the thermal curing process can be omitted, damage to the wafer can be reduced. Another advantage is that the adhesive is transferred uniformly to the back surface at the chip size, so problems such as bleeding and tilting that occur with liquid adhesives are less likely to occur.

[0085] Photosensitive compositions are used as adhesive materials in various protective sheets, with protective films used during display inspection being a specific example. PET is an example of a film material used, and the photosensitive composition may be used after UV irradiation to enhance its adhesive strength following the positioning and bonding process.

[0086] The above are examples of the use of the photosensitive composition of the present invention in electronic materials applications, but the invention is not limited to these. [Examples]

[0087] The present invention will be described in detail below based on examples, but the scope of the present invention is limited to these examples. It is not limited to this. Below, "%" means "mass%" and "ppm" means "mass ppm".

[0088] <Manufacturing of photosensitive compositions> (Example 1) In a 500 mL four-necked flask, 162 g of 2-hydroxyethyl methacrylate (2-HEMA) and 100 g of TTI (NCO / OH equivalent ratio = 1.05) prepared by a non-phosgene method were reacted at 40°C for 2.5 hours using an oil bath with 0.17 g of dibutyltin laurate (DBTDL) as a catalyst. At this point, 0.22 g of dibutylhydroxytoluene (BHT) was added as a thermal polymerization inhibitor to obtain the photosensitive composition of Example 1.

[0089] (Examples 2-5) A photosensitive composition was synthesized according to the method of Example 1. The formulation, reaction conditions, and chlorine content of the obtained photosensitive composition are shown in Tables 1 and 2, and the obtained physical properties are shown in Table 3. The abbreviations in Table 1 refer to the following: 2-HEMA:2-hydroxyethyl methacrylate 4-HBA:4-hydroxybutyl acrylate PETA: Pentaerythritol triacrylate

[0090] (Comparative Examples 1-5) The reaction was carried out in the same manner as in Examples 1 to 5 using chlorine-containing TTI (hereinafter referred to as Y-TTI) produced by the phosgene method. The formulation, reaction conditions, and total chlorine content of the resulting photosensitive composition are shown in Tables 1 and 2, and the obtained physical properties are shown in Table 3.

[0091] <Method for measuring the chlorine content of a photosensitive composition> The chlorine content of the obtained photosensitive composition was measured by the following method. One g of the photosensitive composition was dissolved in 25 ml of ethylene glycol monobutyl ether, and 25 ml of propylene glycol solution in 1 N KOH was added to this solution. The mixture was boiled for 20 minutes to obtain the sample solution. The obtained sample solution was subjected to potentiometric titration with an aqueous silver nitrate solution (concentration 0.01 mol / L). Specifically, the chlorine content in the photosensitive composition was calculated using the following formula. Total chlorine content (ppm) = {(v-v0)×f×10×35.5} / W (W: Sample weight (g), v: Titration volume (mL), v0: Blank titration volume (mL), f: Factor of silver nitrate solution) A potentiometric titrator manufactured by Kyoto Electronics Manufacturing Co., Ltd. was used as the titration apparatus.

[0092] <Evaluation Method> [Evaluation 1] Grid pattern adhesion 1. Manufacturing of the coating film (Examples 1-3, Comparative Examples 1-3) The synthesized photosensitive composition was diluted with n-butyl acetate to a ratio of 50% solids, and then a photoinitiator (1-hydroxycyclohexyl phenyl ketone) was added at a ratio of 2 wt% / solids to prepare a paint composition.

[0093] Then, the required number of repositionable paper adhesive tapes were attached as spacers to both ends of the ABS sheet (Sumitomo Bakelite Co., Ltd., "EAR-802" (product name)) and the polymethyl methacrylate sheet (PMMA sheet, Mitsubishi Rayon Co., Ltd., "Acrylite" (product name)).

[0094] Next, each paint composition was dropped onto the top of the board and applied using a glass rod (8 mm in diameter) to achieve a dry film thickness of 20-30 μm. Then, it was cured for 10 minutes at 23°C in a 50% RH atmosphere, followed by baking at 100°C for 5 minutes. Finally, UV irradiation was performed for 10 minutes using a small UV irradiation device (Oak Manufacturing Co., Ltd.'s Handy UV-300) to form the coating film.

[0095] (Examples 4-5, Comparative Examples 4-5) The synthesized photosensitive composition and SETALUX1152 (Ornex Co., Ltd.) were blended in a ratio of NCO / OH = 1.0, then diluted with n-butyl acetate to a ratio of 50% solids, and finally a photoinitiator (1-hydroxycyclohexyl phenyl ketone) was added at a ratio of 2 wt% / solids to create a paint composition.

[0096] Then, the required number of repositionable paper adhesive tapes were attached as spacers to both ends of the ABS sheet (Sumitomo Bakelite Co., Ltd., "EAR-802" (product name)) and the polymethyl methacrylate sheet (PMMA sheet, Mitsubishi Rayon Co., Ltd., "Acrylite" (product name)).

[0097] Next, each paint composition was dropped onto the top of the board and applied using a glass rod (8 mm in diameter) to achieve a dry film thickness of 20-30 μm. Then, it was cured for 10 minutes at 23°C in a 50% RH atmosphere, followed by baking at 100°C for 5 minutes. Next, it was irradiated with UV light for 10 minutes using a small UV irradiation device (Oak Manufacturing Co., Ltd.'s Handy UV-300), and then baked at 120°C for 30 minutes to create the coating film.

[0098] 2. Evaluation of adhesion Adhesion was evaluated according to the cross-cut method of JIS K5600-5-6:1999. A utility knife was used to make cuts in the coating film, creating 100 squares of 1mm x 1mm size. Cellophane tape was then applied to the cut surface of the coating film, peeled off, and the number of remaining squares was measured. Adhesion was evaluated based on the measured number of squares according to the following evaluation criteria.

[0099] [Evaluation Criteria] A: The one with 100 squares. B: Those with 80 or more squares but less than 100 squares C: Those with 50 or more squares but less than 80 squares. D: Those with fewer than 50 cells

[0100] [Evaluation 2] Scratch resistance 1. Manufacturing of the coating film (Examples 1-3, Comparative Examples 1-3) The paint was created in the same way as in [Evaluation 1]. Next, the required number of repositionable paper adhesive tapes were attached as spacers to both ends of an ABS plate (Sumitomo Bakelite Co., Ltd., "EAR-802" (product name)). Then, each paint composition was dropped onto the top of the plate and coated using a glass rod (8 mm in diameter) to achieve a dry film thickness of 20-30 μm. After curing for 10 minutes at 23°C in a 50% RH atmosphere, the plate was baked and dried at 100°C for 5 minutes. Finally, the plate was irradiated with UV light for 10 minutes using a small UV irradiation device (Oak Manufacturing Co., Ltd. Handy UV-300) to form a coating film.

[0101] (Examples 4-5, Comparative Examples 4-5) The paint was created in the same way as in [Evaluation 1]. Next, the required number of repositionable paper adhesive tapes were attached as spacers to both ends of an ABS plate (Sumitomo Bakelite Co., Ltd., "EAR-802" (product name)). Then, each paint composition was dropped onto the top of the plate and coated using a glass rod (8 mm in diameter) to achieve a dry film thickness of 20-30 μm. After curing for 10 minutes at 23°C in a 50% RH atmosphere, the plate was baked at 100°C for 5 minutes. Then, UV irradiation was performed for 10 minutes using a small UV irradiation device (Oak Manufacturing Co., Ltd. Handy UV-300), followed by baking at 120°C for 30 minutes to create the coating film.

[0102] 2. Evaluation of scratch resistance The gloss of the sample coated panels was measured using a gloss meter (BYK, haze-gloss version 3.40) under a reflection angle of 20°, and this was defined as the initial gloss value. Next, a wear test was conducted using a flat surface wear tester (PA-300A, manufactured by Daiei Kagaku Seiki Co., Ltd.) under the following conditions.

[0103] (Test conditions) • Load capacity: 280g • Stroke speed: 60 strokes / minute • Number of strokes: 30 back and forth • Stroke length: 10cm • Jig: Stainless steel cylinder, Φ1.6cm • Abrasion-resistant paper: 281Q Wet Dry Polishing Paper (manufactured by 3M)

[0104] After the abrasion test, the test area was gently rinsed with water to avoid damaging it, and the moisture was carefully wiped off with a cloth. Then, it was left to stand for 24 hours under conditions of 23°C and 50%RH, and the gloss at a reflection angle of 20° was measured, similar to the initial gloss measurement. The scratch recovery rate (%) was calculated using the formula below, and the scratch resistance was evaluated based on the scratch recovery rate according to the following evaluation criteria. (Scratch recovery rate) = (20° gloss value after wear) / (Initial 20° gloss value) × 100

[0105] [Evaluation Criteria] A: Those with a wound recovery rate of 95% or higher. B: Those with a wound recovery rate of 80% or more but less than 95% C: Those with a wound recovery rate of 50% or more but less than 80% D: Those with a wound recovery rate of less than 50%

[0106] [Rating 3] Yellow Index 1. Manufacturing of the coating film (Examples 1-3, Comparative Examples 1-3) The paint was created in the same way as in [Evaluation 1]. Next, the required number of repositionable paper adhesive tapes were attached as spacers to both ends of a PP board (manufactured by Takiron CI Co., Ltd., "PPEP310A" (product name)). Then, each coating composition was dropped onto the top of the board and coated using a glass rod (8 mm in diameter) to achieve a dry film thickness of 20-30 μm. After curing for 10 minutes at 23°C in a 50% RH atmosphere, the board was baked and dried at 100°C for 5 minutes. Finally, UV irradiation was performed for 10 minutes using a small UV irradiation device (Handy UV-300 from Oak Manufacturing Co., Ltd.) to form a coating film.

[0107] (Examples 4-5, Comparative Examples 4-5) The paint was created in the same way as in [Evaluation 1]. Next, the required number of repositionable paper adhesive tapes were attached as spacers to both ends of a PP board (manufactured by Takiron CI Co., Ltd., "PPEP310A" (product name)). Then, each paint composition was dropped onto the top of the board and coated using a glass rod (8 mm in diameter) to achieve a dry film thickness of 20-30 μm. Next, the board was cured for 10 minutes at 23°C in a 50% RH atmosphere, followed by baking at 100°C for 5 minutes. Then, UV irradiation was performed for 10 minutes using a small UV irradiation device (Handy UV-300 from Oak Manufacturing Co., Ltd.), followed by baking at 120°C for 30 minutes to create the coating film.

[0108] 2. Evaluation of Yellow Index The coating was peeled off the PP board, and the yellow index (YI) at 25°C was measured using a spectrophotometer (SE6000, manufactured by Nippon Denshoku Co., Ltd.). The color change was evaluated based on the following evaluation criteria.

[0109] [Evaluation Criteria] A:YI<1.0 B: 1.0 ≤ YI < 1.5 C: 1.5 ≤ YI < 3 D:3≦YI

[0110] [Table 1]

[0111] [Table 2]

[0112] [Table 3]

[0113] As shown in the results above, the cured product of the photosensitive composition of the example, which contains a reaction product of compound (A) and compound (B) and has a chlorine content of less than 100 ppm, was able to suppress discoloration during curing and exhibited excellent adhesion to the substrate and scratch resistance.

Claims

1. A photosensitive composition comprising a reaction product of the following compound (A) and the following compound (B), wherein the chlorine content is less than 100 ppm. Compound (A): 1,8-diisocyanato-4-isocyanatomethyloctane, or a prepolymer that is a reaction product of 1,8-diisocyanato-4-isocyanatomethyloctane and a polyol. The polyol has an average of 1.5 to 2.5 hydroxyl groups per molecule. Compound (B): A (meth)acrylate or (meth)acrylamide having at least one active hydrogen group in one molecule.

2. The photosensitive composition according to claim 1, wherein the active hydrogen group is a hydroxyl group, an amino group, or a thiol group.

3. The photosensitive composition according to claim 1 or 2, wherein the compound (B) is a monofunctional (meth)acrylate or monofunctional (meth)acrylamide having one photopolymerizable double bond.

4. The photosensitive composition according to claim 1 or 2, wherein the compound (B) is a polyfunctional (meth)acrylate or polyfunctional (meth)acrylamide having two or more photopolymerizable double bonds.

5. The photosensitive composition according to claim 1 or 2, wherein the equivalent ratio of the active hydrogen group of compound (B) to the NCO group of compound (A) is 0.30 or more and 1.50 or less.

6. The photosensitive composition according to claim 1 or 2, wherein the chlorine content is less than 10 ppm.

7. The photosensitive composition according to claim 1 or 2, wherein the chlorine content is less than 5 ppm.

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