Active energy beam-curable resin composition

Abstract

The present invention addresses the problem of providing an active energy beam-curable resin composition having excellent tack-free properties on the surface of a cured film.　As a means of solving the foregoing, provided is an active energy beam-curable resin composition containing components (A), (B), (C), and (D): Said composition is characterized in that: (A) is a urethane acrylate having a polytetramethylene ether skeleton and / or a polytrimethylene ether skeleton; (B) is at least one photopolymerization initiator selected from the group consisting of benzophenone derivatives, methyl benzoyl formate derivatives, and alpha-hydroxyacetophenone derivatives; (C) is fumed silica; and (D) is a reactive diluent having a (meth) acryloyl group. and (C) the fumed silica. Said composition is also characterized in that: when the total of the component (A) and the component (D) is 100 parts by mass, the (C) fumed silica content is 4 parts by mass or more; and the surface tack of a cured film cured by LED light having 365 nm in the presence of air is 20 gf / cm 2 or less.

Description

Active energy ray-curable resin composition

[0001] The present invention relates to an active energy ray-curable resin composition.

[0002] Active energy ray-curable resin compositions have been widely used in coating applications, curable liquid gaskets (CIPG), and other applications due to their ability to cure in a short time.

[0003] In active energy ray-curable resin compositions used for the above-mentioned applications, if the cured surface is exposed to air (oxygen) during photocuring, oxygen inhibition occurs, causing the cured surface to become uncured or to become tacky. In particular, active energy ray-curable resin compositions used for coating applications and CIPG applications are required to have a tack-free cured surface to prevent adhesion of dirt to the cured surface and adhesion of substrates to each other.

[0004] As such an active energy ray-curable resin composition, a photocurable composition containing specific components such as an elastomer (A), a monomer (B) having a (meth)acryloyl group, and a photopolymerization initiator (C) has been proposed (see, for example, Patent Document 1).

[0005] Japanese Patent Application Laid-Open No. 2022-174718

[0006] However, the photocurable composition described in Patent Document 1 does not exhibit sufficient tack-free properties. The photocurable composition described in Patent Document 1 uses a metal halide lamp with a strong curing action to cure the composition (see paragraph

[0074] of Patent Document 1), and even when cured with a light source with a narrow wavelength range and a low energy level such as an LED, the composition does not exhibit tack-free properties to a degree that allows practical use, resulting in the problem of insufficient tack-free properties.

[0007] Therefore, there is a need for the development of an active energy ray-curable resin composition that provides a cured film surface that exhibits excellent tack-free properties.

[0008] An object of the present invention is to provide an active energy ray-curable resin composition that provides a coating surface that exhibits excellent tack-free properties after curing.

[0009] As a result of extensive research, the present inventors have discovered a coating composition containing specific components (A) to (D), in which the content of fumed silica as component (C) is 4 parts by mass or more per 100 parts by mass of the total of components (A) and (D), and which has a surface tackiness of 20 gf / cm when cured with 365 nm LED light in the presence of air. 2 The present inventors have found that the above object can be achieved by using the following active energy ray-curable resin composition, and have thus completed the present invention.

[0010] That is, the present invention relates to the following active energy ray-curable resin composition: 1. An active energy ray-curable resin composition containing the following components (A), (B), (C), and (D): (A) a urethane acrylate having a polytetramethylene ether skeleton and / or a polytrimethylene ether skeleton, (B) at least one photopolymerization initiator selected from the group consisting of benzophenone derivatives, methyl benzoylformate derivatives, and α-hydroxyacetophenone derivatives, (C) fumed silica, and (D) a reactive diluent having a (meth)acryloyl group, the content of the fumed silica (C) being 4 parts by mass or more per 100 parts by mass of the total of the components (A) and (D), and a cured film cured with 365 nm LED light in the presence of air having a surface tackiness of 20 gf / cm 22. An active energy ray-curable resin composition according to Item 1, wherein the polytetramethylene ether skeleton of component (A) is polytetramethylene ether. 3. An active energy ray-curable resin composition according to Item 1 or 2, wherein the polyisocyanate-derived skeleton of component (A) is derived from an aliphatic polyisocyanate. 4. An active energy ray-curable resin composition according to Item 1 or 2, wherein the polyisocyanate-derived skeleton of component (A) is derived from an isophorone diisocyanate derivative and / or a 4,4'-methylenebis(cyclohexyl isocyanate) derivative. 5. An active energy ray-curable resin composition according to any one of Items 1 to 4, wherein component (D) contains a reactive diluent having a (meth)acryloyl group, the SP value of which calculated by Fedors' formula is 9.1 or less, in an amount of 10% by mass to 100% by mass, based on 100% by mass of the entire component (D). 6. Item 5. The active-energy ray-curable resin composition according to any one of Items 1 to 4, wherein the component (D) contains a reactive diluent having a (meth)acryloyl group, the SP value of which is calculated by the Fedors equation is 9.1 or less, in an amount of 0% by mass or more and less than 10% by mass, relative to 100% by mass of the entire component (D), and the component (C) contains methacrylo-modified fumed silica.

[0011] The active energy ray-curable resin composition of the present invention can provide a film surface that exhibits excellent tack-free properties after curing.

[0012] The present invention will be described in detail below.

[0013] 1. Active Energy Ray-Curable Resin Composition The active energy ray-curable resin composition of the present invention is an active energy ray-curable resin composition containing the following components (A), (B), (C), and (D): (A) a urethane acrylate having a polytetramethylene ether skeleton and / or a polytrimethylene ether skeleton; (B) at least one photopolymerization initiator selected from the group consisting of benzophenone derivatives, methyl benzoylformate, and α-hydroxyacetophenone derivatives; (C) fumed silica; and (D) a reactive diluent having a (meth)acryloyl group; the content of the fumed silica (C) is 4 parts by mass or more per 100 parts by mass of the total of the components (A) and (D), and the surface tackiness of a cured film when cured with LED light of 365 nm in the presence of air is 20 gf / cm. 2 The active energy ray-curable resin composition having the above characteristics contains the specific components (A) to (D) and the content of fumed silica (C) is a specific content of 4 parts by mass or more, relative to 100 parts by mass of the total of components (A) and (D), thereby enabling the cured coating surface to exhibit excellent tack-free properties.

[0014] In recent years, tack-free technology has been achieved by blending multifunctional acrylates, high-melting-point materials, or high-Tg materials. However, the cured products obtained using these technologies are very hard, making them unsuitable for conformal coatings and CIPG applications, which require flexibility.

[0015] The active energy ray-curable resin composition of the present invention contains the above-mentioned specific components (A) to (D), and the content of fumed silica (C) is a specific content of 4 parts by mass or more, based on 100 parts by mass of the total of components (A) and (D), thereby enabling the cured coating surface to exhibit excellent tack-free properties, and the composition can be cured with a light source with a weak curing action, such as an LED lamp, without using a metal halide lamp with a strong curing action, and can obtain a cured surface that exhibits sufficient tack-free properties. In particular, the active energy ray-curable resin composition of the present invention provides flexibility to the cured product by containing component (D), but also exhibits excellent tack-free properties by containing the above-mentioned components (A) to (C).

[0016] Furthermore, since the active energy ray-curable resin composition of the present invention has the above-mentioned constitution, it is not necessary to use a (meth)acrylate monomer with a high glass transition point, and therefore the cured film has excellent flexibility and low-temperature properties.

[0017] The active energy ray-curable resin composition of the present invention will be described in detail below.

[0018] The active energy ray-curable resin composition of the present invention has a surface tackiness of 20 gf / cm when cured with 365 nm LED light in the presence of air. 2 The surface tack of the cured film is 20gf / cm or less. 2 If the surface tack exceeds 18 gf / cm, sufficient tack-free properties cannot be exhibited. 2 Preferably less than 15gf / cm 2 Less than 10 gf / cm is more preferable. 2 Less than 8gf / cm is more preferable. 2 Particularly preferred is 5 gf / cm 2 Less than 2gf / cm is most preferable. 2 The lower limit of the surface tackiness is not particularly limited, and the lower the better. 2 , 0.5gf / cm 2 , 1gf / cm 2 , 2gf / cm 2 , 3gf / cm 2 etc.

[0019] The surface tackiness of the above-mentioned active energy ray-curable resin composition of the present invention after curing is measured by the following measurement method.

[0020] Surface tack of the cured film: An active energy ray curable resin composition was dropped onto a polyethylene terephthalate (PET) film, and a liquid film 50 mm wide and 0.5 mm thick was created using a film applicator. The liquid film was irradiated with 365 nm LED light in the presence of air at an intensity of 300 mW / cm. 2 , cumulative light intensity 18000mJ / cm 2 A cured film is prepared by irradiating the film under the conditions of 1.1 kgf. The prepared cured film is fixed so that it does not move, and a stainless steel cylinder with a diameter of 24 mm is pressed against the surface of the cured film with a force of 1.1 kgf for 1 minute. The cylinder is then pulled vertically at a rate of 5 mm / min and peeled off from the cured film. The maximum force (gf) applied during the peeling is measured, and the surface area of ​​the attached surface of the cylinder (12 x 12 x π = 452 mm) is calculated. 2 ) to obtain the surface tack value (gf / cm 2 ) is calculated.

[0021] Hereinafter, each component constituting the active energy ray-curable resin composition of the present invention will be described in detail.

[0022] Component (A) The component (A) is a urethane acrylate having a polytetramethylene ether skeleton and / or a polytrimethylene ether skeleton.

[0023] The urethane acrylate having a polytetramethylene ether skeleton is not particularly limited as long as it has at least one polytetramethylene ether skeleton in its structure, and may have a polyamide skeleton, a polyester skeleton, or other skeleton in addition to the polytetramethylene ether skeleton, as long as the effects of the present invention are not impaired. Furthermore, the structure may contain a functional group such as a hydroxyl group.

[0024] Specific examples of the polytetramethylene ether skeleton include skeletons represented by the following formula (1).

[0025]

[0026] In formula (1), A １ ~A ８ are the same or different and represent hydrogen, alkyl groups such as methyl, ethyl, propyl (n-propyl, isopropyl), butyl (n-butyl, isobutyl, sec-butyl, tert-butyl), and n-pentyl; halogen groups such as chlorine, bromine, and fluorine; hydroxyl, carboxyl, amino, cyano, and nitro groups. n represents an integer of 1 or more, and * represents a bond.

[0027] In the above formula (1), A １ ~A ８ are the same or different and are preferably functional groups containing no active hydrogen, more preferably hydrogen or a hydrocarbon group, and even more preferably hydrogen.

[0028] In the above formula (1), n ​​is preferably a natural number from 1 to 60, more preferably a natural number from 3 to 56, even more preferably a natural number from 9 to 42, particularly preferably a natural number from 9 to 28, and most preferably a natural number from 9 to 14.

[0029] There are no particular restrictions on the molecular weight of the polyol that constitutes component (A), but it is preferably from 200 to 4,000, more preferably from 250 to 3,000, even more preferably from 650 to 2,000, and most preferably from 650 to 1,000. When the molecular weight of the constituent polyol is within the above range, tackiness can be reduced.

[0030] The polyether for forming the polytetramethylene ether skeleton is preferably polytetramethylene ether glycol or a polytetramethylene ether glycol derivative, and among these, polytetramethylene ether glycol is preferred because it allows the coating surface after curing of the active energy ray-curable resin composition to exhibit superior tack-free properties.

[0031] The urethane acrylate having a polytrimethylene ether skeleton is not particularly limited as long as it has at least one polytrimethylene ether skeleton in its structure, and may have a polyamide skeleton, a polyester skeleton, or other skeleton in addition to the polytrimethylene ether skeleton, as long as the effects of the present invention are not impaired. Furthermore, the structure may contain a functional group such as a hydroxyl group.

[0032] Specific examples of the polytrimethylene ether skeleton include skeletons represented by the following formula (2).

[0033]

[0034] In formula (2), B １ ~B ６ are the same or different and represent hydrogen, alkyl groups such as methyl, ethyl, propyl (n-propyl, isopropyl), butyl (n-butyl, isobutyl, sec-butyl, tert-butyl), and n-pentyl; halogen groups such as chlorine, bromine, and fluorine; hydroxyl, carboxyl, amino, cyano, and nitro groups. n represents an integer of 1 or more, and * represents a bond.

[0035] In the above formula (2), B １ ~B ６ are the same or different and preferably represent a functional group not containing active hydrogen, more preferably represent hydrogen or a hydrocarbon group, and even more preferably represent hydrogen.

[0036] In the above formula (2), n is preferably a natural number from 1 to 70, more preferably a natural number from 4 to 69, still more preferably a natural number from 11 to 52, particularly preferably a natural number from 11 to 39, and most preferably a natural number from 11 to 20.

[0037] Examples of polyethers for forming the polytrimethylene ether skeleton include polytrimethylene glycol, polytrimethylene glycol derivatives, etc. Among these, polytrimethylene glycol is preferred because it allows the coating surface after curing of the active energy ray-curable resin composition to exhibit superior tack-free properties.

[0038] The component (A) may have either a polytetramethylene ether skeleton or a polytrimethylene ether skeleton, or may have both of them.

[0039] The urethane acrylate of component (A) has a polyisocyanate skeleton and constitutes component (A) together with the polytetramethylene ether skeleton and / or polytrimethylene ether skeleton. The polyisocyanate skeleton constituting component (A) is preferably an aliphatic polyisocyanate skeleton derived from an aliphatic polyisocyanate. The use of an aliphatic polyisocyanate skeleton improves the flexibility of the film formed after the active energy ray-curable resin composition is cured, and yellowing of the film can be suppressed.

[0040] Examples of the aliphatic polyisocyanate skeleton include an isophorone diisocyanate skeleton derived from an isophorone diisocyanate derivative, and a 4,4'methylenebis(cyclohexyl isocyanate) skeleton derived from a 4,4'methylenebis(cyclohexyl isocyanate) derivative. Among these, the 4,4'methylenebis(cyclohexyl isocyanate) skeleton is preferred.

[0041] The component (A) may have one of the above polyisocyanate skeletons alone, or may have two or more of them in combination.

[0042] The content of component (A), based on 100% by mass of the active energy ray-curable resin composition, is preferably 1 to 50% by mass, more preferably 4 to 50% by mass, even more preferably 4 to 40% by mass, even more preferably 4 to 35% by mass, even more preferably 9 to 30% by mass, and even more preferably 11 to 27% by mass. When the lower limit of the content of component (A) is within the above range, the coating surface after curing of the active energy ray-curable resin composition can exhibit better tack-free properties. When the upper limit of the content of component (A) is within the above range, the viscosity of the active energy ray-curable resin composition becomes appropriate, further improving coatability.

[0043] The content of component (A) relative to the total of component (A) and component (D), which will be described later, is preferably 1 to 50 mass%, more preferably 5 to 50 mass%, even more preferably 5 to 40 mass%, even more preferably 5 to 35 mass%, even more preferably 10 to 30 mass%, and even more preferably 12 to 28 mass%. When the lower limit of the content of component (A) is within the above range, the coating surface after curing of the active energy ray-curable resin composition can exhibit superior tack-free properties. When the upper limit of the content of component (A) is within the above range, the viscosity of the active energy ray-curable resin composition becomes appropriate, further improving coatability.

[0044] The number of functional groups in component (A) is preferably 1.5 to 2.5, more preferably 1.8 to 2.2, even more preferably 1.9 to 2.1, and most preferably 2.0. When the lower limit of the number of functional groups in component (A) is within the above range, the coating surface after curing of the active energy ray-curable resin composition can exhibit superior tack-free properties. When the upper limit of the number of functional groups in component (A) is within the above range, the elongation of the active energy ray-curable resin composition can be further improved.

[0045] The functional group concentration of the (meth)acryloyl group in component (A) is not particularly limited, but is preferably 0.125 to 2.000 mmol / g, more preferably 0.125 to 0.500 mmol / g, more preferably 0.153 to 0.280 mmol / g, and most preferably 0.180 to 0.220 mmol / g. By setting the lower limit of the functional group concentration in component (A) within the above range, the viscosity of the active energy ray-curable resin composition becomes appropriate, further improving the coatability. By setting the upper limit of the number of functional groups in component (A) within the above range, the elongation of the active energy ray-curable resin composition is further improved.

[0046] The method for synthesizing the urethane acrylate of component (A) can be a conventionally known method and is not particularly limited. For example, an oligomer in which a hydroxy compound having a (meth)acryloyl group is bonded to the hydroxyl groups at both ends of a polyol via a diisocyanate compound can be used, or an oligomer in which an isocyanate compound having a (meth)acryloyl group is bonded can also be used.

[0047] Component (B) Component (B) is at least one photopolymerization initiator selected from the group consisting of benzophenone derivatives, methyl benzoylformate derivatives, and α-hydroxyacetophenone derivatives. By including component (B), radicals are generated by light, making it possible to efficiently initiate radical polymerization.

[0048] Specific examples of the benzophenone derivative include benzophenone, 4-methylbenzophenone, 4-phenylbenzophenone, and 4-(p-tolylthio)benzophenone.

[0049] Specific examples of the methyl benzoylformate derivatives include methyl benzoylformate, ethyl benzoylformate, methyl 2-methylbenzoylformate, methyl 3-methylbenzoylformate, and methyl 4-methylbenzoylformate.

[0050] Specific examples of α-hydroxyacetophenone derivatives include 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, and 2,2'-dihydroxy-2,2'-dimethyl-1,1'-[methylenebis(4,1-phenylene)]bis(propan-1-one).

[0051] Among the above, benzophenone derivatives and α-hydroxyacetophenone derivatives are preferred, and benzophenone derivatives are more preferred, in that they can more efficiently initiate polymerization.

[0052] The component (B) may be used alone or in combination of two or more.

[0053] The content of component (B) is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the total of component (A) and component (D), which will be described later. By having the content of component (B) within this range, the hardness of the active energy ray-curable resin composition after curing can be appropriately adjusted, and the cured coating surface can exhibit better tack-free properties.

[0054] Component (C) Component (C) is fumed silica.

[0055] In the present invention, the content of component (C) is 4 parts by mass or more, relative to 100 parts by mass of the total of component (A) and component (D), which will be described later. If the content of component (C) is less than 4 parts by mass, the tack-free properties of the coating surface after curing of the active energy ray-curable resin composition will decrease. The content of component (C) is preferably 4.5 parts by mass or more, more preferably 5 parts by mass or more, and even more preferably 7 parts by mass or more. There is no particular upper limit for the content of component (C), and it may be 20 parts by mass, 15 parts by mass, or 10 parts by mass, relative to 100 parts by mass of the total of component (A) and component (D).

[0056] The fumed silica is not particularly limited, and known fumed silica such as hydrophilic fumed silica having many hydrophilic silanol groups (Si—OH) on the surface, and hydrophobic fumed silica in which the silanol groups on the surface are blocked with alkylsilane and / or dimethylpolysiloxane can be used.

[0057] The fumed silica may be surface-modified. Examples of such modifications include methacrylo-modification and amino group-modification. Among these, methacrylo-modification is preferred because it allows the coating surface to exhibit superior tack-free properties after curing of the active energy ray-curable resin composition.

[0058] The average primary particle diameter of the fumed silica is preferably 5 nm to 50 μm. By using such fumed silica, it is possible to impart good thixotropy to the active energy ray-curable resin composition of the present invention, resulting in excellent coatability. In addition, it is possible to make the active energy ray-curable resin composition of the present invention transparent, and sufficient curability can be obtained even when irradiated with ultraviolet rays or the like.

[0059] Component (D) Component (D) is a reactive diluent having a (meth)acryloyl group. By including the component (D), the cured product of the active energy ray-curable resin composition becomes flexible. Therefore, the active energy ray-curable resin composition of the present invention can exhibit excellent tack-free film surface, despite the flexibility of the cured product.

[0060] Component (D) is not particularly limited as long as it has a (meth)acryloyl group and acts as a reactive diluent, such as a monofunctional (meth)acrylic acid ester monomer having one unsaturated bond in the molecule.

[0061] In this specification, a "reactive diluent" refers to a diluent having a viscosity of 2000 mPa·s or less at 23°C. The viscosity of component (D) is preferably 1000 mPa·s or less, more preferably 500 mPa·s or less, even more preferably 300 mPa·s or less, particularly preferably 200 mPa·s or less, and most preferably 100 mPa·s or less. When the upper limit of the viscosity of component (D) is within the above range, the viscosity of the active energy ray-curable resin composition becomes appropriate, and the coatability is further improved.

[0062] Specific examples of the monofunctional (meth)acrylic acid ester monomer include chain alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 1-ethylheptyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, 1-butylamyl (meth)acrylate, lauryl (meth)acrylate, and octadecyl (meth)acrylate; and chain alkyl (meth)acrylates such as isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, phenoxy polyethylene glycol (meth)acrylate, and nonyl phenoxy polyethylene glycol (meth)acrylate. (Meth)acrylates having a cyclic structure such as phenoxy polyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, phenoxy (meth)acrylate, phenoxyethyl (meth)acrylate, alkylphenoxy (meth)acrylate, and alkylphenoxyethyl (meth)acrylate; hydroxyalkyl (meth)acrylates or 2-hydroxy (meth)acrylates having a hydroxyl group such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, and 2-hydroxylauryl (meth)acrylate; and mono(meth)acrylates of oligo- or polyoxyalkylene glycols such as diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, dipropylene glycol mono(meth)acrylate, trimethylene glycol mono(meth)acrylate, and polypropylene glycol (meth)acrylate. These may be used alone or in combination of two or more.

[0063] Among these, it is preferable to use at least one selected from the group consisting of (meth)acrylic acid ester monomers having an acyclic (straight-chain or branched-chain) hydrocarbon structure, (meth)acrylic acid ester monomers having a cyclic structure such as an aromatic skeleton, (meth)acrylic acid ester monomers having an aromatic skeleton and modified with ethylene oxide, and (meth)acrylic acid ester monomers having a heterocycle such as tetrahydrofuran in the molecule. Among these, it is particularly preferable to use a (meth)acrylic acid ester monomer having an acyclic (straight-chain or branched-chain) hydrocarbon structure in the molecule, from the viewpoint of making the cured product of the active energy ray-curable resin composition more flexible.

[0064] Examples of (meth)acrylic acid ester monomers having an acyclic (straight-chain or branched-chain) hydrocarbon structure include n-butyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, and isodecyl (meth)acrylate. Examples of (meth)acrylates having an aromatic skeleton and modified with ethylene oxide include phenoxypolyethylene glycol (meth)acrylate and nonylphenoxypolyethylene glycol (meth)acrylate, and examples of (meth)acrylic acid ester monomers having a cyclic structure such as an aromatic skeleton include phenoxyethyl (meth)acrylate.

[0065] Among these, phenoxy polyethylene glycol (meth)acrylate, isodecyl (meth)acrylate, etc. are particularly preferred.

[0066] The SP value of component (D), calculated by Fedors' formula, is preferably 9.1 or less, more preferably 9.0 or less, even more preferably 8.9 or less, and particularly preferably 8.8 or less. By setting the lower limit of the SP value of component (D) within the above range, the coating surface after curing of the active energy ray-curable resin composition can exhibit better tack-free properties. The lower limit of the SP value is not particularly limited, and may be, for example, 8.0, 8.3, or 8.7.

[0067] The SP value of component (D) calculated by Fedors' formula may be greater than 9.1. Even if the SP value exceeds 9.1, when component (C) contains methacrylo-modified fumed silica, the coating surface after curing of the active energy ray-curable resin composition can exhibit superior tack-free properties. The lower limit of the SP value of component (D) is, for example, 9.2, 9.3, 9.4, 9.5, etc. The upper limit of the SP value of component (D) is, for example, 11.0, 10.8, 10.5, 10.3, 10.2, etc.

[0068] Component (D) preferably contains 10% by mass to 100% by mass of a reactive diluent having a (meth)acryloyl group, with the SP value calculated by Fedors' formula being 9.1 or less, based on the total mass of component (D). By setting the lower limit of the content of the reactive diluent having a (meth)acryloyl group, with the SP value being 9.1 or less, within the above range, the coating surface after curing of the active energy ray-curable resin composition can exhibit better tack-free properties. Furthermore, the higher the content of the reactive diluent having a (meth)acryloyl group, with the SP value being 9.1 or less, relative to the total mass of component (D), the better the tack-free properties can be exhibited, which is advantageous. When component (D) contains a reactive diluent having a (meth)acryloyl group, whose SP value calculated by Fedors' formula is 9.1 or less, within the above content range, the remainder of component (D) may be a reactive diluent having a (meth)acryloyl group, whose SP value calculated by Fedors' formula is greater than 9.1.

[0069] When component (D) contains a reactive diluent having a (meth)acryloyl group, the SP value of which calculated by Fedors' formula is 9.1 or less, in an amount of 0% by mass or more but less than 10% by mass, based on 100% by mass of the entire component (D), component (C) is preferably methacryloyl-modified fumed silica. In this case, by using methacryloyl-modified fumed silica as component (C), the coating surface after curing of the active energy ray-curable resin composition can exhibit superior tack-free properties. Note that when component (C) contains methacryloyl-modified fumed silica, if component (D) contains a reactive diluent having a (meth)acryloyl group, the SP value of which calculated by Fedors' formula is 9.1 or less, within the above range, the remainder of component (D) may be a reactive diluent having a (meth)acryloyl group, the SP value of which calculated by Fedors' formula is greater than 9.1.

[0070] The glass transition point (Tg) of the component (D) is preferably −80 to 15° C., more preferably −70 to 10° C., more preferably −70 to 0° C., more preferably −70 to −10° C., and even more preferably −70 to −20° C. When the glass transition point of the component (D) is within the above range, the cured product obtained by curing the active energy ray-curable resin composition of the present invention has appropriate flexibility, making it suitable for use in coating applications and CIPG applications.

[0071] The content of component (D) is preferably 50 to 99% by mass, more preferably 60 to 95% by mass, and even more preferably 70 to 90% by mass, relative to 100% by mass of the total of components (A) and (D). By having the content of component (D) within the above range, the hardness and viscosity of the active energy ray-curable resin composition after curing can be appropriately adjusted.

[0072] Other Components Polymerization inhibitors, adhesion promoters, leveling agents, antifoaming agents, antioxidants, flame retardants, etc. may be added to the active energy ray-curable resin composition of the present invention as appropriate depending on the purpose, etc.

[0073] The glass transition temperature (Tg) of the cured product of the active energy ray-curable resin composition of the present invention after curing is preferably −50 to 30° C., more preferably −40 to 10° C., and even more preferably −40 to 0° C. When the glass transition temperature of the cured product is within the above range, the cured product has appropriate flexibility and can be suitably used for coating applications and CIPG applications. By having the above-mentioned configuration, the active energy ray-curable resin composition of the present invention not only has flexibility in the cured product, but also allows the film surface after curing to exhibit excellent tack-free properties.

[0074] In this specification, the glass transition temperature (Tg) of the cured product is measured by the following method.

[0075] Measurement method for the glass transition temperature (Tg) of the cured product: An active energy ray curable resin composition is dropped onto a release-treated polyethylene terephthalate (PET) film, and a liquid film 50 mm wide and 0.5 mm thick is created using a film applicator. The liquid film is irradiated with 365 nm LED light in the presence of air at an intensity of 300 mW / cm. 2 , cumulative light intensity 18000mJ / cm 2 A cured film is prepared by irradiating the film under these conditions. The prepared cured film is cut into strips measuring 4 mm x 32 mm to prepare test specimens. The test specimens are used to measure dynamic viscoelasticity, and the temperature at which tan δ reaches its peak is taken as the glass transition point (Tg) of the cured product. Dynamic viscoelasticity measurements are performed in tensile mode at a frequency of 1 Hz, with the temperature rising from -80 to 130°C at a heating rate of 5°C / min.

[0076] The method for producing the active energy ray-curable resin composition of the present invention is not particularly limited, and the composition can be produced by a conventional method. For example, the active energy ray-curable resin composition can be produced by kneading the above-mentioned components (A) to (D) and, if necessary, other components, using a temperature-controllable kneader, such as a planetary mixer, a twin-screw mixer, a high-shear mixer, a butterfly mixer, or a rotation-revolution mixer.

[0077] Although the embodiments of the present invention have been described above, the present invention is not limited to these examples, and it goes without saying that the present invention can be embodied in various forms without departing from the spirit of the present invention.

[0078] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0079] The raw materials used in the examples and comparative examples are as follows:

[0080] Component (A) Urethane acrylates (A-1) to (A-19) of component (A) were synthesized according to the following procedure. The liquid temperature of polyol (a1) was adjusted to 60 to 70°C. Polyisocyanate (a2) and a bismuth catalyst (manufactured by Nitto Kasei Co., Ltd., product name: Neostan U-600) were added thereto and reacted at 100°C to obtain intermediate (a3). Thereafter, 2-acryloyloxyethyl isocyanate (Karenzu AOI, manufactured by Resonac Co., Ltd.) and a bismuth catalyst were added as a (meth)acrylating agent and the reaction was further continued to obtain the desired urethane acrylate.

[0081] The polyol (a1) and polyisocyanate (a2) were added in a ratio such that the hydroxyl value of the intermediate (a3) ​​was 0.206 mmol / g, and the amount of 2-acryloyloxyethyl isocyanate was such that the functional group concentration of the (meth)acryloyl group in the urethane acrylate was 0.200 mmol / g or less.

[0082] (A-1): urethane acrylate (polyether), a1 = polytetramethylene glycol (manufactured by Mitsubishi Chemical Corporation, product name: PTMG-1000) (molecular weight 1,000), a2 = 4,4'-methylenebiscyclohexyldiisocyanate (H 12 MDI) (manufactured by Covestro, product name: Desmodur W), functional group concentration of (meth)acryloyl group 0.200 mmol / g

[0083] (A-2): urethane acrylate (polyether), a1 = modified polytetramethylene glycol (manufactured by Hodogaya Chemical Co., Ltd., product name: PTG-L1000) (molecular weight 1,000), a2 = 4,4'-methylenebiscyclohexyl diisocyanate (manufactured by Covestro, product name: Desmodur W), functional group concentration of (meth)acryloyl group 0.200 mmol / g

[0084] (A-3): urethane acrylate (polyether), a1 = polytrimethylene glycol (manufactured by Austin Chemical Company, product name: Velvetol H1000) (molecular weight 1,000), a2 = 4,4'-methylenebiscyclohexyl diisocyanate (manufactured by Covestro, product name: Desmodur W), functional group concentration of (meth)acryloyl group 0.200 mmol / g

[0085] (A-4): urethane acrylate (polyether), a1 = polypropylene glycol (AGC, product name: Exenol 1020) (molecular weight 1,000), a2 = 4,4'-methylenebiscyclohexyl diisocyanate (Covestro, product name: Desmodur W), (meth)acryloyl functional group concentration 0.200 mmol / g

[0086] (A-5): urethane acrylate (polyester), a1 = polyester polyol consisting of 3-methyl-1,5-pentanediol and adipic acid (manufactured by Kuraray Co., Ltd., product name: Kuraray Polyol P1010) (molecular weight 1,000), a2 = 4,4'-methylenebiscyclohexyl diisocyanate (manufactured by Covestro Co., Ltd., product name: Desmodur W), (meth)acryloyl functional group concentration 0.200 mmol / g

[0087] (A-6): urethane acrylate (conjugated diene), a1 = terminal hydroxyl group-modified polybutadiene (manufactured by Cray Valley, product name: Krasol LBHP2000) (molecular weight 1,000), a2 = 4,4'-methylenebiscyclohexyl diisocyanate (manufactured by Covestro, product name: Desmodur W), functional group concentration of (meth)acryloyl group 0.200 mmol / g

[0088] (A-7): urethane acrylate (polycarbonate), a1 = polycarbonate polyol consisting of 3-methyl-1,5-pentanediol and 1,6-hexanediol (manufactured by Kuraray Co., Ltd., product name: Kuraray Polyol C-1090) (molecular weight 1,000), a2 = 4,4'-methylenebiscyclohexyl diisocyanate (manufactured by Covestro Co., Ltd., product name: Desmodur W), functional group concentration of (meth)acryloyl group 0.200 mmol / g

[0089] (A-8): Telechelic acrylic polymer (acryloyl-terminated polyacrylate), manufactured by Kaneka Corporation, product name XMAP RC100C

[0090] (A-9): Telechelic acrylic polymer (terminal acryloyl-modified polyisobutylene), manufactured by Kaneka Corporation, product name EPION EP400V

[0091] (A-10) to (A-13): The same as (A-1) except that the molecular weight of a1 was 650, 2,000, 3,000, or 4,000, respectively.

[0092] (A-14) to (A-18): The intermediates (a3) ​​were the same as (A-1), except that the hydroxyl value was 0.281 mmol / g, 0.481 mmol / g, 1.903 mmol / g, 0.158 mmol / g, or 0.132 mmol / g, and the functional group concentrations of (meth)acryloyl groups were 0.270 mmol / g, 0.450 mmol / g, 1.500 mmol / g, 0.155 mmol / g, or 0.130 mmol / g, respectively.

[0093] (A-19): The same as (A-1) except that a2 was changed to isophorone diisocyanate (IPDI) (manufactured by Covestro, product name: Desmodur I).

[0094] Urethane acrylate (A-20), component (A), was synthesized according to the following procedure. The liquid temperature of polyol (a1) was adjusted to 70-80°C. Polyisocyanate (a2) was added thereto and reacted at 70-80°C to obtain intermediate (a3). Subsequently, 2-hydroxyethyl acrylate (2HEA) as a (meth)acrylating agent and a bismuth catalyst were added, and the reaction was further carried out to obtain the desired urethane acrylate.

[0095] The polyol (a1) and polyisocyanate (a2) were added in a ratio such that the isocyanate group concentration of intermediate (a3) ​​was 0.206 mmol / g, and the amount of 2-hydroxyethyl acrylate (2HEA) was such that the functional group concentration of the (meth)acryloyl group of the urethane acrylate was 0.200 mmol / g or less.

[0096] (A-20): urethane acrylate (polyether), a1 = polytetramethylene glycol (manufactured by Mitsubishi Chemical Corporation, product name: PTMG-1000), a2 = 4,4'-methylenebiscyclohexyl diisocyanate (manufactured by Covestro, product name: Desmodur W)

[0097] (B) Ingredients: (B-1): Benzophenone, manufactured by IGM Resins, product name: Omnirad BP flakes; (B-2): 4-methylbenzophenone, manufactured by IGM Resins, product name: Omnirad 4MBP; (B-3): 4-phenylbenzophenone, manufactured by IGM Resins, product name: Omnirad 4PBZ; (B-4): Methyl benzoylformate, manufactured by IGM Resins, product name: Omnirad MBF; (B-5): 1-Hydroxycyclohexyl phenyl ketone, manufactured by IGM Resins, product name: Omnirad-184; (B-6): 2-Hydroxy-2-methylpropiophenone, manufactured by IGM Resins, product name: Omnirad-1173; (B-7): 2,2-Dimethoxy-2-phenylacetophenone, manufactured by IGM Resins, product name: Omnirad-651. (B-8): 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone, manufactured by IGM Resins, product name Omnirad-369; (B-9): 2-methyl-4'-(methylthio)-2-morpholinopropiophenone, manufactured by IGM Resins, product name Omnirad-907; (B-10): diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, manufactured by IGM Resins, product name Omnirad-TPO.

[0098] (C) Components (C-1): Hydrophilic fumed silica, manufactured by Tokuyama Corporation, product name Reolosil QS-20L (C-2): Hydrophobic fumed silica, manufactured by Tokuyama Corporation, product name Reolosil MT-10 (C-3): Methacrylo-modified fumed silica, manufactured by Evonik Corporation, product name Aerosil R711 (C-4): Calcium carbonate, manufactured by Maruo Calcium Co., Ltd., product name Kalfain M-200 (C-5): Zirconia fine particles, manufactured by Nippon Shokubai Co., Ltd., product name Zircostar HR-101 (C-6): Halloysite, manufactured by Fimatec Co., Ltd., product name Dragonite HP-A

[0099] (D) Components (D-1): Aliphatic reactive diluent, linear C4, manufactured by Mitsubishi Chemical Corporation, product name butyl acrylate, SP value according to Fedors formula 8.82, Tg -55°C (D-2): Aliphatic reactive diluent, linear C8, manufactured by Osaka Organic Chemical Industry Ltd., product name NOAA (n-octyl acrylate), SP value according to Fedors formula 8.74, Tg -65°C (D-3): Aliphatic reactive diluent, linear C12, manufactured by Osaka Organic Chemical Industry Ltd., product name LA (lauryl acrylate), SP value according to Fedors formula 8.70, Tg -23°C (D-4): Aliphatic reactive diluent, branched C8, manufactured by Mitsubishi Chemical Corporation, product name 2-ethylhexyl acrylate, SP value according to Fedors formula 8.62, Tg -70°C (D-5): Aliphatic reactive diluent, branched C10, manufactured by Osaka Organic Chemical Industry, Ltd., product name IDAA (isodecyl acrylate), SP value according to Fedors formula 8.61, Tg -62°C. (D-6): Polyether reactive diluent, manufactured by Kyoeisha, product name Light Acrylate EC-A (ethoxy-diethylene glycol acrylate), SP value according to Fedors formula 9.08, Tg -70°C. (D-7): Alicyclic reactive diluent, manufactured by Osaka Organic Chemical Industry, Ltd., product name Viscoat #155, CHA (cyclohexyl acrylate), SP value according to Fedors formula 9.26, Tg -15°C. (D-8): Heterocyclic reactive diluent, manufactured by Osaka Organic Chemical Industry, Ltd., product name Viscoat #150, THFA (tetrahydrofurfuryl acrylate), SP value according to Fedors formula 9.54, Tg -12°C. (D-9): Aromatic-containing reactive diluent, aromatic type, manufactured by Osaka Organic Chemical Industry Co., Ltd., product name Viscoat #160, BZA (benzyl acrylate), SP value according to Fedors' formula 10.14, Tg 6°C. (D-10): Aromatic-containing reactive diluent, ether type, manufactured by Kyoeisha, product name Light Acrylate PO-A (phenoxyethyl acrylate), SP value according to Fedors' formula 10.12, Tg -22°C.

[0100] (Examples and Comparative Examples) The above-mentioned raw materials were charged into a stirring kneader equipped with a heating device in the blending amounts shown in Tables 1 to 6. The mixture was stirred and mixed at 20 to 60°C for 15 to 60 minutes to produce an active energy ray-curable resin composition.

[0101] (Evaluation Method) The following evaluations were carried out for the Examples and Comparative Examples.

[0102] Surface tack of the cured film An active energy ray curable resin composition was dropped onto a polyethylene terephthalate (PET) film, and a liquid film 50 mm wide and 0.5 mm thick was created using a film applicator. The liquid film was irradiated with 365 nm LED light in the presence of air at an intensity of 300 mW / cm. 2 , cumulative light intensity 18000mJ / cm 2 A cured film was prepared by irradiating under the conditions of 1.1 kgf. The prepared cured film was fixed so that it would not move, and a stainless steel cylinder with a diameter of 24 mm was pressed against the surface of the cured film with a force of 1.1 kgf for 1 minute. The cylinder was then pulled vertically at a rate of 5 mm / min and peeled off from the cured film. The maximum force (gf) applied during the peeling was measured, and the surface area of ​​the attached surface of the cylinder (12 x 12 x π = 452 mm) was calculated. 2 ) to obtain the surface tack value (gf / cm 2 ) was calculated.

[0103] Glass transition temperature (Tg) of the cured product: An active energy ray-curable resin composition was dropped onto a release-treated polyethylene terephthalate (PET) film, and a liquid film 50 mm wide and 0.5 mm thick was created using a film applicator. The liquid film was irradiated with 365 nm LED light at an intensity of 300 mW / cm in the presence of air. 2 , cumulative light intensity 18000mJ / cm 2 A cured film was prepared by irradiating the film under these conditions. The prepared cured film was cut into strips measuring 45 mm x 32 mm to prepare test specimens. The test specimens were used to measure dynamic viscoelasticity, and the temperature at which tan δ reached its peak was taken as the glass transition point (Tg) of the cured product. The dynamic viscoelasticity measurements were performed in tensile mode at a frequency of 1 Hz, with the temperature rising from -80 to 130°C at a heating rate of 5°C / min.

[0104] Measurement method for elongation of cured product An active energy ray curable resin composition was applied to a glass plate with a thickness of 1 mm and a size of approximately 100 mm x 100 mm on a release PET film attached to the glass plate. The applied resin composition was irradiated with 365 nm LED light at an illuminance of 100 mW / cm. 2The film was then irradiated with light for 100 seconds to prepare a cured film. No. 3 dumbbell specimens were punched out of the cured film to prepare test pieces. The elongation at break of the dumbbell specimens was measured in accordance with JIS K 6251:2007, Vulcanized and thermoplastic rubber - Determination of tensile properties. The test was conducted at 23°C and a pulling speed of 500 mm / min.

[0105] Method for Evaluating Coatability: A UV-blocking syringe (PSY-10EU-OR) manufactured by Musashi Engineering was filled with an active energy ray-curable resin composition and degassed using a vacuum-type planetary centrifugal mixer. A float wiper plunger (FLP-10E) manufactured by Musashi Engineering was then fitted into the syringe. A plastic needle (20 gauge, PN-20G-B) manufactured by Musashi Engineering was then attached to the tip of the syringe. The syringe filled with the resin composition was then discharged using an air pulse digital dispenser (ML-6000X) manufactured by Musashi Engineering. Dischargeability was evaluated according to the following criteria, based on the digital dispenser's required discharge pressure: 5: Dischargeable at a discharge pressure of less than 200 kPa; 4: Dischargeable at a discharge pressure of 200 kPa or more but less than 250 kPa; 3: Dischargeable at a discharge pressure of 250 kPa or more but less than 300 kPa. 2: Discharge is possible at a discharge pressure of 300 kPa or more and less than 350 kPa. 1: Discharge is not possible at a discharge pressure of 350 kPa.

[0106] The results are shown in Tables 1 to 6. In Tables 1 to 6, the numerical values ​​for the blending ratios are in parts by mass, with the total of components (A) and (D) being 100 parts by mass.

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

Claims

1. An active energy ray-curable resin composition containing the following components (A), (B), (C), and (D), (A) a urethane acrylate having a polytetramethylene ether skeleton and / or a polytrimethylene ether skeleton, (B) at least one photoinitiator selected from the group consisting of a benzophenone derivative, a methyl benzoylformate derivative, and an α-hydroxyacetophenone derivative, (C) fumed silica, (D) a reactive diluent having a (meth)acryloyl group, wherein the content of the fumed silica (C) is 4 parts by mass or more based on 100 parts by mass in total of the components (A) and (D), and the surface tack of the cured film cured with 365 nm LED light in the presence of air is 20 gf / cm 2 or less. An active energy ray-curable resin composition characterized by the above.

2. The active energy ray-curable resin composition according to claim 1, wherein the polytetramethylene ether skeleton of the component (A) is polytetramethylene ether.

3. The active energy ray-curable resin composition according to claim 1, wherein the polyisocyanate skeleton of the component (A) is derived from an aliphatic polyisocyanate.

4. The active energy ray-curable resin composition according to claim 1, wherein the polyisocyanate skeleton of the component (A) is derived from an isophorone diisocyanate derivative and / or a 4,4'-methylenebis(cyclohexyl isocyanate) derivative.

5. The active energy ray-curable resin composition according to claim 1, wherein the component (D) contains a reactive diluent having a (meth)acryloyl group and having an SP value calculated by Fedors' formula of 9.1 or less, with the total amount of the component (D) being 100% by mass, in an amount of 10% by mass or more and 100% by mass or less.

6. The active energy ray-curable resin composition according to claim 1, wherein the component (D) contains a reactive diluent having a (meth)acryloyl group and having an SP value calculated by Fedors' formula of 9.1 or less, with the total amount of the component (D) being 100% by mass, in an amount of 0% by mass or more and less than 10% by mass, and the component (C) contains methacrylo-modified fumed silica.

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