Reactive hot melt resin composition, and cured products, encapsulants, insulating materials, and laminates using the resin composition.

Abstract

The present invention provides a reactive hot-melt resin composition, etc., capable of forming a flexible, insulating, moisture-resistant, and moisture-heat-resistant cured film. [Solution] A reactive hot melt resin composition comprising a urethane (meth)acrylate, which is a reaction product using polyol (A), polyisocyanate (B), and active hydrogen group-containing (meth)acrylate (C) as essential raw materials, wherein the polyol (A) comprises an alicyclic polyester polyol (A1) having structural units derived from an alicyclic polycarboxylic acid or its acid anhydride and structural units derived from a linear polyhydric alcohol, and an alicyclic polyester polyol (A2) having structural units derived from an alicyclic polycarboxylic acid or its acid anhydride and structural units derived from a side-chain polyhydric alcohol.

Description

[Technical Field]

[0001] This disclosure relates to a reactive hot-melt resin composition. [Background technology]

[0002] For example, in component mounting boards, encapsulating resins are used to protect components such as wiring from moisture and dust. Patent Document 1 discloses an energy-ray curable resin composition containing urethane acrylate that can be used for encapsulating optical devices and the like. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 6099999 [Overview of the project] [Problems that the invention aims to solve]

[0004] When an energy-ray-curable resin composition is applied to an adherend in a thick film of several millimeters and cured to seal it, the energy-ray-curable resin composition undergoes curing shrinkage. If the flexibility is low, the curing shrinkage cannot be mitigated, which may cause cracks or fissures in the cured product of the energy-ray-curable resin composition. Furthermore, curing shrinkage may cause the cured product to lift or peel off from the adherend, resulting in poor adhesion of the cured product to the adherend. Moreover, sealing materials are required to have high physical properties such as insulation, moisture resistance, and heat and humidity resistance, but it can be difficult to achieve both flexibility in the cured product of the energy-ray-curable resin composition and these physical properties.

[0005] The inventors are investigating the use of a reactive hot-melt resin composition that combines two characteristics: rapid cooling and solidification after application and rapid curing by active energy ray irradiation, as an alternative to energy ray-curable resin compositions. The above-mentioned energy ray curable resin compositions are similar to those described above. There are challenges.

[0006] This disclosure has been made in view of the above circumstances and provides a reactive hot-melt resin composition capable of forming a flexible, insulating, moisture-resistant, and moisture-heat-resistant cured film. [Means for solving the problem]

[0007] This disclosure includes the following embodiments. [1] A reactive hot melt resin composition comprising a urethane (meth)acrylate, which is a reaction product using a polyol (A), a polyisocyanate (B), and an active hydrogen group-containing (meth)acrylate (C) as essential raw materials, wherein the polyol (A) comprises an alicyclic polyester polyol (A1) having structural units derived from an alicyclic polycarboxylic acid or its acid anhydride and structural units derived from a linear polyhydric alcohol, and an alicyclic polyester polyol (A2) having structural units derived from an alicyclic polycarboxylic acid or its acid anhydride and structural units derived from a side-chain polyhydric alcohol. [2] The reactive hot melt resin composition according to [1], wherein the total content of the alicyclic polyester polyol (A1) and alicyclic polyester polyol (A2) in the total amount of the polyol (A) is in the range of 40% to 100% by mass per 100% by mass of the polyol (A). [3] The reactive hot melt resin composition according to [1] or [2] above, wherein the content ratio of alicyclic polyester polyol (A1) to alicyclic polyester polyol (A2) [(A1) / (A2)] is in the range of 0.1 to 3.0 by mass ratio. [4] The reactive hot melt resin composition according to any one of [1] to [3] above, wherein the content of amorphous aromatic polyester polyol (A3) in the polyol (A) is in the range of 0% to 30% by mass per 100% by mass of the polyol (A). [5] The reactive hot melt resin composition according to any one of [1] to [4] above, wherein the content of crystalline polyester polyol (A4) in the polyol (A) is in the range of 0% to 30% by mass per 100% by mass of the polyol (A). [6] The reactive hot melt resin composition according to any one of [1] to [5] above, further comprising a photopolymerization initiator. [7] A cured product of any of the reactive hot melt resin compositions described in [1] to [6] above. [8] A sealing material comprising the reactive hot melt resin composition described in any of [1] to [6] above. [9] An insulating material comprising the reactive hot melt resin composition described in any of [1] to [6] above.

[10] A laminate comprising an adherend and a cured product of any of the reactive hot melt resin compositions described in [1] to [6] above, provided on the adherend. [Effects of the Invention]

[0008] The reactive hot-melt resin composition of this disclosure can form a cured film with excellent flexibility, insulation, moisture resistance, and heat resistance. For this reason, the reactive hot-melt resin composition of this disclosure is useful as a sealing material for electronic components such as circuit boards. [Modes for carrying out the invention]

[0009] I. Reactive Hot Melt Resin Compositions The reactive hot-melt resin composition of this disclosure (hereinafter sometimes abbreviated as the resin composition of this disclosure) contains at least a urethane (meth)acrylate which is a reactant made from a polyol (A), a polyisocyanate (B), and an active hydrogen group-containing (meth)acrylate (C) as essential raw materials, wherein the polyol (A) includes a polyester polyol (A1) having structural units derived from an alicyclic polycarboxylic acid or its acid anhydride and structural units derived from a linear polyhydric alcohol, and a polyester polyol (A2) having structural units derived from an alicyclic polycarboxylic acid or its acid anhydride and structural units derived from a side-chain polyhydric alcohol.

[0010] The reactive hot-melt resin composition of this disclosure, by including specific polyester polyols (A1) and (A2), can form a cured film with excellent insulating properties, moisture heat resistance, and moisture resistance. Furthermore, the reactive hot-melt resin composition of this disclosure can form a highly flexible film, thereby mitigating the curing shrinkage stress generated during the curing reaction by active energy rays, suppressing lifting and peeling from the adherend, and achieving good adhesion to the adherend.

[0011] In addition, as a reactive hot-melt resin composition with high moisture resistance, there is a moisture-curable resin composition containing a urethane prepolymer. However, when forming a thick film coating with this moisture-curable resin composition, bubbles are likely to occur and it may not cure sufficiently. On the other hand, according to the reactive hot-melt resin composition of the present disclosure, since it contains urethane (meth)acrylate and the curing reaction proceeds by irradiation with active energy rays, even when forming a thick film coating, the curing reaction proceeds sufficiently to the inside of the coating, and it is possible to suppress curing failure due to bubble generation and deterioration of the physical properties of the sealing member. Therefore, the reactive hot-melt resin composition of the present disclosure enables free design of the film thickness of the cured film according to the application and the place of use. Furthermore, according to the reactive hot-melt resin composition of the present disclosure, since it can be applied in a heat-melted state and solidified by cooling to form a coating film before curing, it can exhibit initial setting properties, does not cause stickiness, and can have good workability.

[0012] The reactive hot-melt resin composition of the present disclosure is a hot-melt resin composition that can be cured by irradiation with active energy rays (an active energy ray-curable hot-melt resin composition). Hereinafter, the materials constituting the reactive hot-melt resin composition of the present disclosure and the characteristics of the resin composition will be described in detail. In the present invention, “(meth)acrylate” means “methacrylate or acrylate”, “(meth)acrylic” means “methacrylic or acrylic”, and “(meth)acryloyl” means “methacryloyl or acryloyl”.

[0013] Also, in the present disclosure, “crystalline” means that a peak of crystallization heat or melting heat can be confirmed in DSC (differential scanning calorimetry) measurement in accordance with JIS K7121:2012, and “amorphous” means that the above peak cannot be confirmed.

[0014] [Urethane (meth)acrylate] The urethane (meth)acrylate in this disclosure is a reaction product comprising a polyol (A), a polyisocyanate (B), and an active hydrogen group-containing (meth)acrylate (C) as essential components. The urethane (meth)acrylate in this disclosure has a urethane bond and a (meth)acryloyl group. Preferably, the (meth)acryloyl group is present at least one or both ends of the urethane (meth)acrylate.

[0015] <Polyol (A)> The polyol (A) above comprises at least an alicyclic polyester polyol (A1) having structural units derived from an alicyclic polycarboxylic acid or its acid anhydride and structural units derived from a linear aliphatic polyhydric alcohol, and an alicyclic polyester polyol (A2) having structural units derived from an alicyclic polycarboxylic acid or its acid anhydride and structural units derived from a branched aliphatic polyhydric alcohol.

[0016] Alicyclic polyester polyol (A1) having structural units derived from linear aliphatic polyhydric alcohols can exhibit high flexibility, while alicyclic polyester polyol (A2) having structural units derived from branched aliphatic polyhydric alcohols can exhibit high hydrophobicity. The reactive hot-melt resin composition of this disclosure, by combining the above two components as the polyol (A) constituting the urethane (meth)acrylate, can exhibit high flexibility even after curing, suppress curing shrinkage, and exhibit excellent hygroscopicity and heat resistance.

[0017] <<Alicyclic polyester polyol (A1)>> Alicyclic polyester polyol (A1) has structural units derived from alicyclic polycarboxylic acid or its acid anhydride and structural units derived from linear aliphatic polyhydric alcohol. In other words, alicyclic polyester polyol (A1) requires alicyclic polycarboxylic acid or its acid anhydride and linear aliphatic polyhydric alcohol as essential raw materials.

[0018] Linear aliphatic polyhydric alcohols are aliphatic polyhydric alcohols that do not have hydrocarbon groups in their side chains. Examples of linear aliphatic polyhydric alcohols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, and 1,10-decanediol. These structural units derived from linear aliphatic polyhydric alcohols may be present individually or in combination of two or more types in the alicyclic polyester polyol (A1).

[0019] The above-mentioned alicyclic polycarboxylic acids or their anhydrides refer to compounds in which a carboxyl group or an acid anhydride group is bonded to an alicyclic structure, regardless of the presence or absence of aromatic rings in other structural parts. As the above alicyclic polycarboxylic acid, alicyclic dicarboxylic acids are preferred, for example, dimer acid, cyclopropane-1α,2α-dicarboxylic acid, cyclopropane-1α,2β-dicarboxylic acid, cyclopropane-1β,2α-dicarboxylic acid, cyclobutane-1,2-dicarboxylic acid, cyclobutane-1α,2β-dicarboxylic acid, cyclobutane-1α,3β-dicarboxylic acid, cyclobutane-1α,3α-dicarboxylic acid, (1R)-cyclopentane-1β,2α-dicarboxylic acid, trans-cyclopentane-1,3-dicarboxylic acid, (1β,2β)-cyclopentane-1,3-dicarboxylic acid, (1β,3β)-cyclopentane-1,3-dicarboxylic acid, (1S,2S)-1,2-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid Examples include saturated alicyclic dicarboxylic acids such as chlorohexanedicarboxylic acid, 1,1-cycloheptanedicarboxylic acid, cuban-1,4-dicarboxylic acid, 2,3-norbornanedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydrophthalic acid, and tetrahydrophthalic acid; and unsaturated alicyclic dicarboxylic acids having one or two unsaturated double bonds in the ring, such as 1-cyclobutene-1,2-dicarboxylic acid, 3-cyclobutene-1,2-dicarboxylic acid, 1-cyclopentene-1,2-dicarboxylic acid, 4-cyclopentene-1,3-dicarboxylic acid, 1-cyclohexene-1,2-dicarboxylic acid, 2-cyclohexene-1,2-dicarboxylic acid, 3-cyclohexene-1,2-dicarboxylic acid, 4-cyclohexene-1,3-dicarboxylic acid, and 2,5-hexadiene-1α,4α-dicarboxylic acid.

[0020] Furthermore, examples of acid anhydrides of the above-mentioned alicyclic polycarboxylic acids include the acid anhydrides of the alicyclic dicarboxylic acids mentioned above, specifically hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylnadic anhydride, nadic anhydride, glutaric anhydride, methyltetrahydrophthalic anhydride, dimethyltetrahydrophthalic anhydride, norbornenedicarboxylic anhydride, methylbicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, bicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, bicyclo[2.2.1]hepta-5-ene-2,3-dicarboxylic anhydride, methylbicyclo[2.2.1]hepta-5-ene-2,3-dicarboxylic anhydride, cyclopentanetetracarboxylic anhydride, and the like. Furthermore, hydrogenated phthalic anhydride derivatives such as derivatives of hexahydrophthalic anhydride (3-methyl-hexahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride) and derivatives of tetrahydrophthalic anhydride (1,2,3,6-tetrahydrophthalic anhydride, 3-methyl-1,2,3,6-tetrahydrophthalic anhydride, 4-methyl-1,2,3,6-tetrahydrophthalic anhydride, methylbutenyl-1,2,3,6-tetrahydrophthalic anhydride, etc.) can also be used as alicyclic dicarboxylic acid anhydrides.

[0021] These structural units derived from alicyclic dicarboxylic acids or their acid anhydrides may be present individually or in combination of two or more types in the alicyclic polyester polyol (A1).

[0022] The number-average molecular weight of the alicyclic polyester polyol (A1) is preferably in the range of 500 to 100,000, more preferably in the range of 1,000 to 7,000, and even more preferably in the range of 2,000 to 5,000, from the viewpoint of easily exhibiting the effects of the alicyclic polyester polyol (A1). The number-average molecular weight of the above alicyclic polyester polyol (A1) is shown as the value measured by gel permeation chromatography (GPC) under the conditions described in the examples below.

[0023] <<Alicyclic polyester polyol (A2)>> Alicyclic polyester polyols (A2) have structural units derived from alicyclic polycarboxylic acids and structural units derived from branched aliphatic polyhydric alcohols. In other words, alicyclic polyester polyols (A2) require alicyclic polycarboxylic acids and branched aliphatic polyhydric alcohols as essential raw materials.

[0024] Branched aliphatic polyhydric alcohols are aliphatic polyhydric alcohols having at least one hydrocarbon group in their side chains. Examples of branched aliphatic polyhydric alcohols include 1,2-propylene glycol, 2-methyl-1,3-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-ethyl-2-butylpropanediol, dimer diols (which are reduced dimer acids derived from the dimerization of unsaturated monocarboxylic acids such as oleic acid, linoleic acid, linolenic acid, and erucic acid), 2,4-diethyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and neopentyl glycol mono(hydroxypivalate) (HPN). These structural units derived from branched aliphatic polyhydric alcohols may be present individually or in combination of two or more types in the alicyclic polyester polyol (A2).

[0025] The details of the alicyclic polycarboxylic acid, which is the raw material for alicyclic polyester polyol (A2), are the same as the details of the alicyclic polycarboxylic acid, which is the raw material for "alicyclic polyester polyol (A1)" described above. The structural units derived from the alicyclic polycarboxylic acid may be present in alicyclic polyester polyol (A2) alone or in pairs or more.

[0026] The number-average molecular weight of the alicyclic polyester polyol (A2) is preferably in the range of 500 to 10000, more preferably in the range of 1000 to 7000, and even more preferably in the range of 2000 to 5000, from the viewpoint of easily exhibiting the effects of the alicyclic polyester polyol (A2). The number-average molecular weight of the above alicyclic polyester polyol (A2) is shown as the value measured by gel permeation chromatography (GPC) under the conditions described in the examples below.

[0027] <<Amorphous aromatic polyester polyol (A3)>> The polyol (A) above preferably includes amorphous aromatic polyester polyol (A3) in addition to alicyclic polyester polyols (A1) and (A2).

[0028] As the amorphous aromatic polyester polyol (A3) described above, for example, a reaction product of a compound having two or more hydroxyl groups and a polybasic acid can be used. The compound having two or more hydroxyl groups and the polybasic acid are compounds in which at least one has an aromatic ring. Examples of such amorphous aromatic polyester polyol (A3) include a reaction product of an alkylene oxide adduct of bisphenol A and a polybasic acid, and a reaction product of a polyol and a polybasic acid having an aromatic ring.

[0029] The alkylene oxide adduct of bisphenol A is obtained by adding an alkylene oxide to the phenolic hydroxyl group of bisphenol A. The alkylene preferably has 1 to 10 carbon atoms. Examples of alkylene oxides having such an alkylene include ethylene oxide and propylene oxide.

[0030] Furthermore, the average number of moles of alkylene oxide added to 1 mole of bisphenol A is preferably in the range of 2 moles to 10 moles, and more preferably in the range of 4 moles to 8 moles.

[0031] Examples of polyols include branched polyols such as 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,2-butanediol, 1,3-butanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-propanediol, 2-methyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, neopentyl glycol, trimethylolethane, and trimethylolpropane. These compounds may be used individually or in combination of two or more. Among these, neopentyl glycol is preferred.

[0032] Examples of polyols other than branched polyols include ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and glycerin. These compounds may be used individually or in combination of two or more.

[0033] When the amorphous aromatic polyester polyol (A3) is a reaction product of a polyol and a polybasic acid having an aromatic ring, the polyol can be appropriately selected from the polyols described above, but aliphatic and / or alicyclic polyols are preferred.

[0034] Examples of the polybasic acids mentioned above include adipic acid, glutaric acid, pimelic acid, suberic acid, dimer acid, sebacic acid, undecanedicarboxylic acid, hexahydroterephthalic acid, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, and the like. These compounds may be used individually or in combination of two or more.

[0035] The number-average molecular weight of the amorphous aromatic polyester polyol (A3) is preferably in the range of 500 to 10,000, more preferably in the range of 1,000 to 5,000, and even more preferably in the range of 1,000 to 3,000. The number-average molecular weight of the amorphous aromatic polyester polyol (A3) is the value measured by gel permeation chromatography (GPC).

[0036] The content of amorphous aromatic polyester polyol (A3) is preferably in the range of 0% to 30% by mass, more preferably in the range of 5% to 25% by mass, and even more preferably in the range of 10% to 20% by mass, per 100% by mass of polyol (A). By setting the content of amorphous aromatic polyester polyol (A3) in polyol (A) within the above range, the moisture resistance of the resin composition of this disclosure can be further enhanced. If the content is too high, the hydrophobicity may decrease.

[0037] <<Crystalline polyester polyol (A4)>> The polyol (A) described above may further contain crystalline polyester polyols (A4) other than alicyclic polyester polyols (A1) and (A2). By further including crystalline polyester polyols (A4) in the polyol (A), the adhesive properties of the resin composition of this disclosure can be further enhanced. As the crystalline polyester polyol (A4), for example, a reaction product of a compound having two or more hydroxyl groups and a polybasic acid; polycaprolactone polyol, etc. may be used. Furthermore, the crystalline polyester polyol (A4) may include aromatic polyester polyols (crystalline aromatic polyester polyols) other than the amorphous aromatic polyester polyol (A3) described above.

[0038] Examples of compounds having two or more hydroxyl groups include ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, trimethylolpropane, trimethylolethane, and glycerin. These compounds may be used individually or in combination of two or more. Among these, one or more selected from the group consisting of butanediol, hexanediol, octanediol, and decanediol are preferred because they enhance crystallinity and provide even better adhesion.

[0039] Examples of the polybasic acids mentioned above include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, and dodecanedioic acid. These compounds may be used individually or in combination of two or more. Among these, one or more selected from the group consisting of succinic acid, adipic acid, sebacic acid, and dodecanedioic acid are preferred because they enhance crystallinity and provide even better adhesion.

[0040] As the caprolactone polyol mentioned above, for example, a reaction product of a compound having two or more hydroxyl groups and ε-caprolactone can be used.

[0041] The number-average molecular weight of the above crystalline polyester polyol (A4) is preferably in the range of 500 to 10,000 and more preferably in the range of 1,000 to 6,000 when using the reaction product of the compound having two or more hydroxyl groups and the polybasic acid, and preferably in the range of 5,000 to 200,000 and more preferably in the range of 10,000 to 100,000 when using the polycaprolactone polyol. The number-average molecular weight of the crystalline polyester polyol (A4) is shown as the value measured by gel permeation chromatography (GPC).

[0042] The content of crystalline polyester polyol (A4) is preferably in the range of 0% to 30% by mass, more preferably in the range of 5% to 25% by mass, and even more preferably in the range of 10% to 20% by mass, per 100% by mass of polyol (A). By setting the content of crystalline polyester polyol (A4) in polyol (A) within the above range, the adhesiveness of the resin composition of this disclosure can be further improved. If the content is too high, the curing time may be shortened and the pot life may be shortened, and if it is too low, the solidification of the resin composition of this disclosure may be slow and the workability may be poor.

[0043] <<Polyol (A)>> The total content of alicyclic polyester polyol (A1) and alicyclic polyester polyol (A2) in the total amount of polyol (A) is preferably in the range of 40% to 100% by mass, more preferably in the range of 50% to 90% by mass, and even more preferably in the range of 60% to 80% by mass. By setting the total content of alicyclic polyester polyol (A1) and (A2) in polyol (A) within the above range, the hydrophobicity of the resin composition of this disclosure is improved, and excellent moisture resistance can be achieved.

[0044] Furthermore, in the polyol (A) described above, the content ratio of alicyclic polyester polyol (A1) to alicyclic polyester polyol (A2) [(A1) / (A2)] can be in the range of 0.1 to 3.0 by mass ratio, with a range of 0.2 to 2.5 being preferred, a range of 0.3 to 2.0 being more preferred, a range of 0.4 to 1.5 being even more preferred, and a range of 0.5 to 1.0 being particularly preferred. By setting the content ratio of alicyclic polyester polyol (A1) to alicyclic polyester polyol (A2) within the above range, the flexibility of the cured product of the resin composition of this disclosure can be increased.

[0045] <<Other Polyols (A5)>> The polyol (A) described above may include other polyols (A5) in addition to the polyester polyols (A1) to (A4) described above. Examples of other polyols (A5) include polyacrylic polyols, polycarbonate polyols, polyether polyols, polybutadiene polyols, amorphous aliphatic polyester polyols, etc. These may be used individually or in combination of two or more. The content of the other polyols (A5) described above is not particularly limited as long as it does not impair the functions exhibited by the reactive hot melt resin composition of this disclosure, but for example, it is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0% by mass, per 100% by mass of polyol (A).

[0046] <Polyisocyanate (B)> Polyisocyanate (B) is a compound having two or more isocyanate groups (-NCO). The number of isocyanate groups in polyisocyanate (B) can be, for example, 2 to 10.

[0047] The polyisocyanate (B) described above can be any known isocyanate compound. Examples of the polyisocyanate (B) include aliphatic diisocyanate compounds, alicyclic diisocyanate compounds, aromatic diisocyanate compounds, and modified versions thereof. These polyisocyanates (B) may be used individually or in combination of two or more.

[0048] Examples of aliphatic or alicyclic polyisocyanates include hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate. These may be used individually or in combination of two or more.

[0049] Examples of aromatic polyisocyanates include polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate isocyanate, phenylene diisocyanate, tolylene diisocyanate, and naphthalene diisocyanate. These may be used individually or in combination of two or more.

[0050] Among these, aromatic polyisocyanates are preferred, and diphenylmethane diisocyanate is more preferred, as they provide even better reactivity and adhesion.

[0051] The amount of polyisocyanate (B) used is preferably in the range of 1% to 25% by mass, and more preferably in the range of 5% to 20% by mass, of the total mass of the raw materials constituting the urethane prepolymer.

[0052] The mixing ratio of the polyol (A) and polyisocyanate (B) described above is preferably in the range of 1.1 to 10.0, more preferably in the range of 1.1 to 5.0, and even more preferably in the range of 1.5 to 3.0, based on the equivalent ratio of the isocyanate groups of the polyisocyanate (B) to the hydroxyl groups of the polyol (A) (hereinafter referred to as [NCO / OH equivalent ratio]). When the above [NCO / OH equivalent ratio] is within the above range, it is possible to suppress the decrease in flexibility due to an excess amount of active hydrogen group-containing (meth)acrylate (C) in the reaction with the active hydrogen group-containing (meth)acrylate (C) described later, and the curing shrinkage associated with the decrease in flexibility.

[0053] <Active hydrogen group-containing (meth)acrylate (C)> The active hydrogen group-containing (meth)acrylate (C) is a (meth)acrylate having substituents that can react with isocyanate groups for urethane formation. Specific examples of active hydrogen groups include hydroxyl groups, carboxyl groups, amino groups, and imino groups. There are no particular restrictions on the number of active hydrogen groups in the (meth)acrylate containing active hydrogen groups, but it is preferable that there be two or fewer, and more preferably one, active hydrogen groups, from the viewpoint that all active hydrogen groups react with the isocyanate groups in the urethane prepolymer to eliminate the isocyanate groups.

[0054] Examples of active hydrogen group-containing (meth)acrylates (C) include hydroxyl group-containing (meth)acrylates, amino group-containing (meth)acrylates, and carboxyl group-containing (meth)acrylates.

[0055] Examples of the above-mentioned hydroxyl group-containing (meth)acrylates include monofunctional hydroxyl group-containing (meth)acrylates such as polyalkylene glycol mono(meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, ethylene glycol-propylene glycol block copolymer mono(meth)acrylate, and ethylene glycol-tetramethylene glycol copolymer mono(meth)acrylate; polyfunctional hydroxyl group-containing (meth)acrylates such as trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate; and polyalkylene glycol mono(meth)acrylates such as polyethylene glycol mono(meth)acrylate and polypropylene glycol mono(meth)acrylate. These can be used individually or in combination of two or more.

[0056] Examples of amino group-containing (meth)acrylates include monoalkyl (1-4 carbon atoms) aminoalkyl (2-6 carbon atoms) (meth)acrylates {aminoethyl, aminopropyl, methylaminoethyl, ethylaminoethyl, butylaminoethyl, or methylaminopropyl (meth)acrylate} and dialkyl (1-4 carbon atoms) aminoalkyl (2-6 carbon atoms) (meth)acrylates {dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, and dibutylaminoethyl (meth)acrylate, etc.}.

[0057] Examples of carboxyl group-containing (meth)acrylates include 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl phthalic acid, and 2-(meth)acryloyloxyethyl hexahydrophthalic acid.

[0058] Among the active hydrogen group-containing (meth)acrylates (C), hydroxyl group-containing (meth)acrylates are preferred.

[0059] The amount of active hydrogen group-containing (meth)acrylate (C) used is preferably in the range of 5.0 to 20.0 parts by mass, and more preferably in the range of 5.0 to 15.0 parts by mass, per 100 parts by mass of urethane prepolymer. The urethane prepolymer is a reaction product of polyol (A) and polyisocyanate (B), and the amount of urethane prepolymer refers to the total amount of reaction raw materials constituting the urethane prepolymer (polyol (A) and polyisocyanate (B), as well as any optional components in the urethane prepolymer). Furthermore, it is preferable that more than 50% and up to 100% of the total number of isocyanate groups in the urethane prepolymer (C), preferably in the range of 80% to 100%, be terminated (meth)acryloyl groups by active hydrogen group-containing (meth)acrylate (C).

[0060] <Urethane (meth)acrylate> The urethane (meth)acrylate in this disclosure is a polyester-based urethane (meth)acrylate. The number-average molecular weight of the above urethane (meth)acrylate is preferably in the range of 1,000 to 10,000, more preferably in the range of 1,500 to 8,000, and particularly preferably in the range of 2,000 to 7,000. Low viscosity can be achieved by having the number-average molecular weight of the urethane (meth)acrylate within the above range. If it is too low, the coating properties will be poor. The number-average molecular weight of the above urethane (meth)acrylate is the value measured by gel permeation chromatography (GPC) under the conditions described in the examples below.

[0061] The equivalent amount of (meth)acryloyl groups in the above-mentioned urethane (meth)acrylate is not particularly limited as long as it is possible to form a cured product with desired physical properties by photocuring reaction, but can be in the range of, for example, 800 g / equivalent to 2000 g / equivalent. Furthermore, it is preferable that the urethane (meth)acrylate does not have residual isocyanate groups (isocyanate groups of the urethane prepolymer (C) that have not reacted with the active hydrogen group-containing (meth)acrylate (C)), but it may have residual isocyanate groups to the extent that it does not impair the curing reaction by active energy rays or the effects of the resin composition disclosed herein. The proportion of residual isocyanate groups in the total number of (meth)acryloyl groups and residual isocyanate groups is preferably in the range of 0% to 20%, more preferably in the range of 0% to 10%, even more preferably in the range of 0% to 50%, and particularly preferably substantially 0%.

[0062] Urethane (meth)acrylate can be obtained by various known manufacturing methods. Specifically, these manufacturing methods include a one-shot method in which a polyol (A), polyisocyanate (B), and active hydrogen group-containing (meth)acrylate (C) are reacted at once, and a prepolymer method in which a urethane prepolymer is prepared by polyaddition reaction of polyol (A) and polyisocyanate (B), and then active hydrogen group-containing (meth)acrylate (C) is added to the urethane prepolymer. Among these, the prepolymer method is preferred from the viewpoint of structural control of urethane (meth)acrylate.

[0063] A method for preparing a urethane prepolymer by reacting a polyol (A) and a polyisocyanate (B) includes, for example, adding the polyol (A) and, if necessary, a known conventional urethane catalyst, heating to 20°C to 120°C, and continuously or intermittently adding a predetermined amount of the pre-polyol (A) to a reaction vessel containing the polyisocyanate (B), and reacting under conditions in which the isocyanate groups of the polyisocyanate (B) are in excess of the hydroxyl groups of the polyol (A).

[0064] The isocyanate group content (hereinafter abbreviated as "NCO%") of the above urethane prepolymer is more preferably in the range of 1% to 5% by mass, as this provides even better adhesion. The NCO% of urethane prepolymer (i) is shown as the value measured by potentiometric titration in accordance with JIS K1603-1:2007.

[0065] A method for reacting a urethane prepolymer obtained by the reaction of a polyol (A) and a polyisocyanate (B) with an active hydrogen group-containing (meth)acrylate (C) is, for example, to the urethane prepolymer, the active hydrogen group-containing (meth)acrylate (C) is added, and the mixture is heated to 20°C to 120°C, resulting in a mixture exhibiting isocyanate groups at 2270 cm⁻¹. -1 One method involves reacting the material until its infrared absorption spectrum disappears.

[0066] In the above reaction, the equivalent ratio (active hydrogen equivalent / isocyanate equivalent) between the active hydrogen group of the active hydrogen group-containing (meth)acrylate (C) and the isocyanate group in the urethane prepolymer is preferably in the range of 1 / 1 to 1.3 / 1.

[0067] In the above reaction, a urethane catalyst may be used. Examples of urethane catalysts include metal compounds such as organobismuth compounds, organotin compounds, and organotitanium compounds; and quaternary ammonium salts.

[0068] [Optional ingredients] The reactive hot-melt resin compositions of the present disclosure may contain a photopolymerization initiator. Examples of the above photopolymerization initiators include benzoin isobutyl ether, benzyl, 1-hydroxycyclohexyl phenyl ketone, benzoin ethyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2- Examples of photopolymerization initiators include molecular cleavage type initiators such as methyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, phenylglyoxylic acid methyl ester, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, as well as hydrogen abstraction type initiators such as benzophenone, 4-phenylbenzophenone, isophthalphenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 2,4-diethylthioxanthone, and 2-isopropylthioxanthone. These may be used alone or in combination of two or more types.

[0069] The photopolymerization initiator content in the reactive hot melt resin composition of this disclosure is preferably in the range of 0.0001% to 10% by mass, more preferably in the range of 0.001% to 5% by mass, and even more preferably in the range of 0.01% to 2% by mass, based on 100% by mass of the solid content of the reactive hot melt resin composition. By setting the photopolymerization initiator content within the above range, the cured product of the resin composition of this disclosure can obtain good curability through a curing reaction by active energy ray irradiation. Furthermore, no unreacted photopolymerization initiator remains in the cured product, and curing defects can be suppressed. Note that, in principle, the use of these photopolymerization initiators is not essential when using an electron beam as the active energy ray.

[0070] The reactive hot melt resin composition of this disclosure may further contain, as needed, plasticizers, photosensitizers, ultraviolet absorbers, antioxidants, polymerization inhibitors, silicone-based additives, fluorine-based additives, silane coupling agents, phosphate ester compounds, organic beads, inorganic fine particles, inorganic fillers, rheology control agents, defoaming agents, colorants, waxes, pigments, dyes, and the like.

[0071] The reactive hot-melt resin composition of this disclosure may contain a plasticizer from the viewpoint of further enhancing the effect of improving flexibility and reducing curing shrinkage. Examples of the plasticizer include dibutyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, diisooctyl phthalate, diisodecyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, trioctyl phosphate, epoxy plasticizers, toluene-sulfamide, chloroparaffin, adipic acid esters, castor oil, methyl acid phosphate (AP-1), and non-reactive liquid polymers such as acrylic oligomers.

[0072] The reactive hot-melt resin composition of this disclosure is obtained by mixing the components described above. Furthermore, since the reactive hot-melt resin composition of this disclosure can be melted by heating, it can be a solvent-free composition.

[0073] [Cured product] The cured product of this disclosure is obtained by curing the hot melt resin composition of this disclosure described above. Examples of the shape of the cured product include laminates, cast products, adhesive layers, coatings, films, etc.

[0074] The volume resistivity of the cured product of this disclosure is not particularly limited and can be set appropriately according to the required insulation performance. However, the volume resistivity at room temperature and the volume resistivity after standing for one week in a humid heat environment of 85°C and 85%RH (sometimes referred to as the volume resistivity after humid heat degradation) are independently set, for example, to 1 × 10⁻⁶. 13 Preferably, it is Ωcm or more, 1 × 10 14 Ωcm or more is more preferable, 1 × 10 15More preferably, it is above Ωcm. Further, the upper limit of the volume resistivity after normal temperature and damp heat deterioration is not particularly limited, but each is independently, for example, 1×10 20 Ωcm or less, and it may be 1×10 18 Ωcm or less. Also, the ratio of the volume resistivity after damp heat deterioration to the volume resistivity at normal temperature (sometimes referred to as the retention rate of the volume resistivity), [volume resistivity after damp heat deterioration] / [volume resistivity at normal temperature], is preferably 10% or more, more preferably 50% or more, and still more preferably 70% or more. The volume resistivity of the cured product of the resin composition of the present disclosure in the normal state and after damp heat deterioration is a value measured by the method described in the examples described later.

[0075] The moisture permeability of the cured product of the present disclosure is not particularly limited and can be appropriately set according to the thickness of the cured product and the required moisture resistance performance. However, a lower value is preferable because higher moisture resistance can be exhibited. The above moisture permeability can be, for example, 100 g / m 2 / 24h or less, preferably 80 g / m 2 / 24h or less, more preferably 70 g / m 2 / 24h or less, and still more preferably 60 g / m 2 / 24h. The moisture permeability of the cured product of the present disclosure is a value measured by the method described in the examples described later.

[0076] As a method for obtaining the cured product of the reactive hot melt resin composition of the present disclosure, for example, there is a method in which the reactive hot melt resin composition of the present disclosure is melted and then applied to an adherend, and photocuring is performed by irradiating the coating film with active energy rays.

[0077] The melting temperature of the reactive hot melt resin composition of the present disclosure can be appropriately set, but can be set, for example, in the range of 50°C to 150°C, and preferably in the range of 100°C to 140°C.

[0078] Methods for applying the reactive hot melt resin composition of this disclosure include, for example, coater methods such as roll coaters, spray coaters, T-die coaters, knife coaters, and comma coaters; and precision methods such as hand guns, dispensers, inkjet printing, screen printing, and offset printing.

[0079] The active energy rays used to irradiate the reactive hot melt resin composition of this disclosure are not particularly limited and include ultraviolet rays, electron beams, ionizing radiation such as alpha rays, beta rays, and gamma rays, but ultraviolet rays are preferred for their versatility. The ultraviolet light source is not particularly limited and includes, for example, germicidal lamps, ultraviolet fluorescent lamps, ultraviolet light-emitting diodes (UV-LEDs), carbon arcs, metal halide lamps, xenon lamps, chemical lamps, low-pressure mercury lamps, high-pressure mercury lamps for copying, medium-pressure or high-pressure mercury lamps, ultra-high-pressure mercury lamps, electrodeless lamps, metal halide lamps, and natural light.

[0080] The cumulative amount of ultraviolet light can be appropriately set according to the composition of the reactive hot melt resin composition and the thickness of the coating film of this disclosure, but for example, the cumulative amount is 0.05 J / cm². 2 ~50J / cm 2 A range of 0.1 J / cm² is preferred. 2 ~25J / cm 2 A range of 1 J / cm is more preferable. 2 ~10J / cm 2 A range of [specify range] is even more preferable. By setting the cumulative amount of ultraviolet light within the above range, the curing efficiency of the reactive hot melt resin composition of this disclosure is improved, and damage to the adherend due to heat generation can be prevented.

[0081] The thickness of the cured product of the hot melt resin composition disclosed herein is not particularly limited and can be set as appropriate depending on the application, but for example it can be in the range of 5 μm to 1 cm.

[0082] [Application] Applications of the hot melt resin composition disclosed herein include encapsulants, printed circuit board materials, resin casting materials, adhesives, insulating materials, adhesive films, and the like.

[0083] [Laminated structure] The laminate of the present disclosure comprises an adherend and a cured product of the reactive hot-melt resin composition of the present disclosure provided on the adherend. In particular, the adherend is preferably, for example, wiring, a component mounting substrate, etc.

[0084] The method for manufacturing the laminate of this disclosure is not particularly limited, and includes, for example, a method in which a molten reactive hot-melt resin composition of this disclosure is applied to a substrate and the coating is photocured by irradiating it with active energy rays. Details of this method are the same as those described in the [Cured Product] section above. The physical properties and thickness of the cured product in the laminate of this disclosure are also the same as those described in the [Cured Product] section above.

[0085] This disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of this disclosure and produces similar effects is included within the technical scope of this disclosure. [Examples]

[0086] The present disclosure will be explained in more detail below with reference to examples and comparative examples.

[0087] [Method for measuring number-average molecular weight] The number-average molecular weight is the value measured by gel permeation chromatography (GPC) under the following conditions.

[0088] Measurement device: High-speed GPC device (HLC-8220GPC manufactured by Tosoh Corporation) Columns: The following columns manufactured by Tosoh Corporation were used, connected in series. "TSKgel G5000" (7.8mm I.D. x 30cm) x 1 "TSKgel G4000" (7.8mm I.D. x 30cm) x 1 "TSKgel G3000" (7.8mm I.D. x 30cm) x 1 "TSKgel G2000" (7.8mmI.D. x 30cm) x 1 Detector: RI (Differential Refractometer) Column temperature: 40℃ Eluent: Tetrahydrofuran (THF) Flow rate: 1.0mL / min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass) Standard samples: Calibration curves were prepared using the following standard polystyrene samples.

[0089] (Standard polystyrene) TSKgel Standard Polystyrene A-500, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene A-1000, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene A-2500, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene A-5000, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-1, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-2, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-4, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-10, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-20, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-40, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-80, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-128, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-288, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-550, manufactured by Tosoh Corporation.

[0090] [Examples 1-6, Comparative Examples 1-3, Reference Example 1] <Synthesis of urethane (meth)acrylate> In a four-necked flask equipped with a stirrer, thermometer, inert gas inlet, and reflux condenser, each polyol raw material shown in Table 1 was charged in the proportions (parts by mass) shown in the same table, and dewatered by heating under reduced pressure at 90°C until the moisture content was 0.05% by mass or less. Next, after cooling the temperature in the reaction vessel to 60°C, each isocyanate raw material shown in Table 1 was added in the proportions (parts by mass) shown in the same table, and the temperature was raised to 110°C and reacted for about 3 hours until the isocyanate group content became constant to obtain a urethane prepolymer containing isocyanate groups. Furthermore, a hydroxyl group-containing acrylic monomer was added, and the infrared absorption spectrum was measured to determine the 2270 cm⁻¹ value originating from the isocyanate groups. -1 The reaction was carried out until the infrared absorption disappeared to obtain urethane (meth)acrylates (1) to (10). The molecular weights of each urethane (meth)acrylate are as shown in the table.

[0091] The abbreviations in Tables 1 and 2 refer to the following materials. <Polyol (A)> <<Alicyclic polyester polyols (A1 and A2)>> • Alicyclic PEs1: Amorphous polyester polyol obtained by reacting neopentyl glycol with hexahydrophthalic anhydride; number average molecular weight: 2,000 • Amorphous polyester polyol obtained by reacting alicyclic PEs2:1,6-hexanediol with hexahydrophthalic anhydride; number average molecular weight: 2,000 <<Amorphous aromatic polyester polyol (A3)>> Aromatic PEs1: Amorphous polyester polyol obtained by reacting bisphenol A propylene oxide 6 adduct, sebaciic acid, and isophthalic acid; number average molecular weight: 2,000 Amorphous polyester polyol obtained by reacting aromatic PEs2:1,6-hexanediol and phthalic anhydride; number average molecular weight: 2,000 <<Crystalline polyester polyol (A4)>> Crystalline polyester polyol obtained by reacting crystalline PEs1:1,6-hexanediol and dodecanediic acid; number average molecular weight: 3,500 <<Amorphous polyester polyol>> Amorphous PEs1: Amorphous polyester polyol obtained by reacting neopentyl glycol and adipic acid; number average molecular weight: 2,000 <Isocyanate (B)> MDI: 4,4'-diphenylmethane diisocyanate <Active hydrogen group-containing (meth)acrylate (C)> • 4HBA: 4-hydroxybutyl acrylate <Non-reactive liquid polymer> • UP1010: Acrylic oligomer (manufactured by Toagosei)

[0092] [Table 1]

[0093] [Table 2]

[0094] To each urethane (meth)acrylate, 1 part by mass of diphenyl (2,4,6-trimethylbenzoyl)phosphine oxide (IGM Resin, "TPO-N") was added as a photoinitiator to obtain the reactive hot melt resin compositions (1) to (10) shown in Tables 3 and 4.

[0095] [evaluation] The reactive hot-melt resin compositions (1) to (10) obtained in the examples and comparative examples, and the films produced using the reactive hot-melt resin compositions according to the following procedure, were used for the evaluations described below. The evaluation results are shown in Tables 3 and 4.

[0096] <Film Manufacturing> A reactive hot-melt resin composition was heated and melted at 120°C for 1 hour, and then coated onto a polyethylene terephthalate film using a roll coater to a thickness of 300 μm. The coating film was then exposed to an integrated light intensity of 800 mJ / cm² using a 4 kW high-pressure mercury lamp. 2 After curing by irradiating with ultraviolet light until it reached a certain temperature, the film, which is a cured product of the reactive hot melt resin composition, was obtained by curing in a constant temperature and humidity environment of 23°C and 50%RH for one week. In the production of the film using the reactive hot melt resin composition (10) of the reference example, the film was obtained by curing in a constant temperature and humidity environment of 23°C and 50%RH for one week without ultraviolet irradiation.

[0097] Furthermore, for the evaluation film described in "Evaluation 4. Moisture Resistance (Moisture Permeability)" below, the film was prepared using the method described above, except that the thickness was changed to 100 μm.

[0098] <Evaluation 1. Flexibility> <<Evaluation 1-1: Occurrence of cracks and fissures>> The film was folded at a 90° angle to check for any cracks or splits. ○: No cracks or fissures appear in the film. ×: The film has cracked or split.

[0099] <<Evaluation 1-2: Substrate adhesion>> A reactive hot-melt resin composition is applied to a glass substrate to a thickness of 5 mm, and then exposed to light from a 4 kW high-pressure mercury lamp with an integrated light intensity of 10,000 mJ / cm². 2 After irradiating with ultraviolet light to achieve the desired result, the film was cured for one week in a constant humidity environment of 23°C and 50%RH to form a film on a glass substrate. In the production of the film using the reactive hot melt resin composition (10) of the reference example, ultraviolet irradiation was not performed, and the film was cured for one week in a constant temperature and humidity environment of 23°C and 50%RH to form a film on a glass substrate. The glass substrate on which the film was formed was left undisturbed in an 85°C, 85% RH humid heat environment for one week. The glass substrate was then visually inspected from the substrate side to check for any lifting or peeling between the glass substrate and the film. ○: No lifting or peeling was observed. ×: Lifting or peeling was observed. -: Unable to evaluate due to foaming (peeled off due to air bubbles)

[0100] Reactive hot-melt resin compositions that met both evaluations 1-1 and 1-2 above were evaluated as having flexibility.

[0101] <Evaluation 2. Insulation 1 (Volume Resistivity under Normal Conditions)> A resistivity meter (Mitsubishi Chemical Corporation, resistivity meter "MCP-HT450") was connected to a box-type ring electrode probe (MCP-JB03) conforming to JIS K6911, and the volume resistivity (normal state) of the film was measured. The probe type was set to ASTM / JIS, and the measurement value was recorded after applying a voltage of 1000V for 1 minute. The volume resistivity was 1 × 10⁻⁶. 13 A value of Ωcm or higher was considered acceptable for the insulation performance evaluation.

[0102] <Evaluation 3. Insulation 2 (Volume resistivity after degradation due to moist heat)> The film was left standing in a humid heat environment of 85°C and 85%RH for one week, and then the volume resistivity of the film (volume resistivity after humid heat degradation) was measured using the method described in section <Evaluation 2. Insulation (volume resistivity under normal conditions)> above. 13 A value of Ωcm or higher was considered acceptable for the insulation performance evaluation.

[0103] <Evaluation 4. Moisture resistance (moisture permeability)> In accordance with JIS L1099 (A-1: Cup method using calcium chloride), the moisture permeability (g / m²) of a film (thickness 100 μm) was measured. 2 The moisture permeability was measured (24 hours). 2 A humidity resistance rating of 24 hours or less was deemed acceptable.

[0104] <Evaluation 5. Curability> A reactive hot-melt resin composition is applied to a glass substrate to a thickness of 5 mm, and then exposed to light from a 4 kW high-pressure mercury lamp with an integrated light intensity of 10,000 mJ / cm². 2After irradiating with ultraviolet light to achieve the desired result, the material was cured for one week in a constant humidity environment of 23°C and 50%RH, then left to stand for one day in a humid heat environment of 85°C and 85%RH, and its appearance was observed and judged according to the following criteria. For the production of the film using the reactive hot melt resin composition (10) of the reference example, ultraviolet irradiation was not performed, and after curing for one week in a constant temperature and humidity environment of 23°C and 50%RH, the material was left to stand for one day in a humid heat environment of 85°C and 85%RH, and its appearance was observed and judged according to the following criteria. ○: No air bubbles were observed in the cured material. ×: Air bubbles were observed in the cured material.

[0105] [Table 3]

[0106] [Table 4]

[0107] The results above suggest that the reactive hot-melt resin composition of the example can form a cured film with excellent flexibility, insulation, moisture resistance, and heat resistance. On the other hand, the reactive hot-melt resin compositions of Comparative Example 1 and Comparative Example 3 showed low volume resistivity under normal conditions and after degradation by humid heat, and also had high moisture permeability, suggesting that they were inferior in terms of insulation, humid heat resistance, and moisture resistance. Furthermore, the reactive hot-melt resin composition of Comparative Example 2 showed low flexibility in the cured film. The reactive hot melt resin composition (10) in the reference example does not contain 4HBA and is a moisture-curing hot melt resin composition. However, foaming was observed in the cured product, and the bubbles inhibited adhesion to the substrate. Furthermore, the generation of bubbles resulted in inferior curability compared to the active energy ray-curing hot melt resin compositions of Examples and Comparative Examples 1-3, suggesting that thick film formation is difficult.

Claims

1. A reaction product containing at least urethane (meth)acrylate, which is made from polyol (A), polyisocyanate (B), and active hydrogen group-containing (meth)acrylate (C) as essential raw materials. The polyol (A) comprises an alicyclic polyester polyol (A1) having structural units derived from an alicyclic polycarboxylic acid or its acid anhydride and structural units derived from a linear polyhydric alcohol, A alicyclic polyester polyol (A2) having structural units derived from alicyclic polycarboxylic acids or their acid anhydrides and structural units derived from side-chain polyhydric alcohols, A reactive hot melt resin composition containing [a specific substance].

2. The reactive hot melt resin composition according to claim 1, wherein the total content of the alicyclic polyester polyol (A1) and alicyclic polyester polyol (A2) in the total amount of the polyol (A) is in the range of 40% to 100% by mass per 100% by mass of the polyol (A).

3. The reactive hot melt resin composition according to claim 1, wherein the content ratio of alicyclic polyester polyol (A1) to alicyclic polyester polyol (A2) [(A1) / (A2)] is in the range of 0.1 to 3.0 by mass ratio.

4. The reactive hot-melt resin composition according to claim 1, wherein the content of amorphous aromatic polyester polyol (A3) in the polyol (A) is in the range of 0% to 30% by mass per 100% by mass of the polyol (A).

5. The reactive hot melt resin composition according to claim 1, wherein the content of crystalline polyester polyol (A4) in the polyol (A) is in the range of 0% to 30% by mass per 100% by mass of the polyol (A).

6. The reactive hot melt resin composition according to claim 1, further comprising a photopolymerization initiator.

7. A cured product of the reactive hot melt resin composition according to any one of claims 1 to 6.

8. A sealing material comprising the reactive hot-melt resin composition according to any one of claims 1 to 6.

9. An insulating material comprising the reactive hot melt resin composition according to any one of claims 1 to 6.

10. A laminate comprising an adherend and a cured product of a reactive hot-melt resin composition according to any one of claims 1 to 6 provided on the adherend.

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