JP6714414B2 - Active energy ray curable resin composition, sealing material and cushioning material made of the cured product - Google Patents

Description

The present invention relates to an active energy ray-curable resin composition and a cured product thereof, more specifically, an active energy ray-curable resin composition having excellent shape accuracy and productivity in discharge coating and having a low hardness and a high buffering property. The present invention relates to a sealing material and a cushioning material made of a cured product.

Along with the miniaturization of portable information terminal devices such as mobile phones and smartphones and electronic devices such as digital cameras, the miniaturization and integration of components have been advanced. For example, the sealing materials (packings, gaskets, etc.) used for the housings of these devices are also shifting to a design having a narrow line width, and at present, a sealing material having a width of about 1 mm is used. In addition, cushioning materials (shock absorbing materials) and vibration damping materials used in small camera units and actuator units built into these devices are also becoming smaller. Components such as these sealing materials, cushioning materials, and vibration damping materials are often made of soft materials, and due to their softness, the line width of the sealing materials becomes thin, and the sizes of cushioning materials and vibration damping materials are extremely small. In that case, it becomes difficult to assemble it as a component into a housing or the like, which lowers productivity and causes an increase in cost.

As measures against this, in Patent Document 1 and Patent Document 2, a liquid sealing material such as an ultraviolet curable resin is applied in a bead shape (linear shape) by ejecting from a needle to a portion where the sealing material is mounted on a housing or the like (hereinafter, "Needle application"), and the bead-shaped ejection body is cured by ultraviolet rays to directly form the sealing material and at the same time, to mount the sealing material on the housing (so-called cured-in-place construction method: hereinafter referred to as CIP construction method). Has been done. Further, for the purpose of improving the dischargeability (coatability) of such a liquid sealing material and the shape retention of the applied bead-shaped discharge body before curing, Patent Document 1 discloses that a UV-curable resin is used. A technique of adding silica particles is described, and Patent Document 2 describes a technique of setting the viscosity of a coating material such as an ultraviolet curable resin to about 1 to 1000 Pa·s at a coating temperature.

On the other hand, when a sealant or cushioning material is incorporated into a member such as a casing that is thinned for downsizing, if the resilience is large, the casing or the like is easily deformed. Is required to have low resilience, that is, sufficiently soft and low hardness. In addition, portable information terminal devices, digital cameras, wearable electronic devices, etc. are compact and integrated with electronic components.In recent years, various sensors have been mounted. For the purpose of preventing the operation, the sealing material and the cushioning material are required to have better cushioning and vibration damping properties.

Therefore, in Patent Document 3 and Patent Document 4, an energy ray curable resin composition in which an acrylic compound and a polyfunctional thiol compound are mixed is proposed as a constitution of an ultraviolet curable resin for obtaining a flexible sealing material. Patent Documents 5 to 7 propose a photocurable resin composition using an acrylic monomer, and Patent Document 8 proposes an active energy ray curable resin composition in which a urethane acrylate oligomer and an acrylic monomer are mixed. ..

JP, 07-088430, A JP 2004-289943 A JP, 2010-254853, A JP, 2010-260918, A JP 2004-26919 A International Publication No. 2002/044299 JP, 2014-80498, A JP, 2003-105320, A

However, in the techniques described in Patent Document 1 and Patent Document 2, in order to narrow or narrow the line width of the sealing material, the smaller the diameter of the needle discharge port, the more difficult it is to discharge the liquid sealing material, If the bead-shaped discharge body expands in diameter or the viscosity of the liquid sealing material is lowered to give priority to the dischargeability, the bead-shaped discharge body is sagged after application to widen the line width of the sealing material, and the desired thinness is obtained. There are problems and problems that it is difficult to obtain a seal material having a line width.

Further, although Patent Documents 1 and 2 describe that an ultraviolet curable resin is cured to obtain a sealing material, a sealing material having sufficient flexibility and high cushioning/vibration damping property is provided. The structure of the ultraviolet curable resin for obtaining the same has not been studied. Further, since the energy ray-curable resin compositions described in Patent Documents 3 and 4 contain a large amount of a cross-linking agent composed of a polyfunctional thiol in an acrylic compound, the number of cross-linking points increases and the softness is sufficient. It was difficult to obtain a cured product such as a sealing material having And also about the resin composition described in patent documents 5-8, hardened|cured material, such as a sealing material and a cushioning material, having sufficient flexibility could not be obtained. As described above, the structure of the active energy ray-curable resin for obtaining a sealing material or a cushioning material having sufficient flexibility and high cushioning/vibration damping properties has not been sufficiently studied.

The present invention has been made in view of the above points, and an object thereof is to reduce the diameter of a needle discharge port to obtain a sealing material having a fluidity and a thixotropy suitable for the CIP method and a thin line width. Even in the case, an active energy ray that forms a cured product that has excellent coatability and shape accuracy, and has sufficient flexibility (low hardness) and high buffering/vibration resistance (large loss coefficient) after curing. It is to provide a curable resin composition.

Another object of the present invention is to provide a sealing material, a cushioning material, a vibration damping material, etc. having sufficient flexibility (low hardness) and high shock absorbing/vibrating characteristics (large loss coefficient). is there.

In order to solve the above problems, the active energy ray-curable resin composition of the present invention comprises a photopolymerizable oligomer (A), a photopolymerizable monomer (B), a photopolymerization initiator (C) and a thixotropy imparting agent (D). The photopolymerizable oligomer (A) is a urethane (meth)acrylate having a mass average molecular weight of 5000 or more, and the photopolymerizable monomer (B) contains the following formula (1) (wherein R ₁ is (Meth)acryloyl compound (b1) represented by hydrogen atom or methyl group, and n represents 0 or 1, respectively, is contained in an amount of 20 to 60% by mass based on the total mass of the photopolymerizable monomer (B). The total content (A+B) of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B) is the photopolymerizable oligomer (A), the photopolymerizable monomer (B) and the photopolymerization initiator (C). Of 94 to 99.99 mass% with respect to the total mass (A+B+C) of the photopolymerizable monomer (B), and the content of the photopolymerizable monomer (B) is the total mass of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B). It is 80 to 99 mass% with respect to (A+B), and the thixotropy-imparting agent (D) is the total (A+B+C) of the photopolymerizable oligomer (A), the photopolymerizable monomer (B) and the photopolymerization initiator (C). ) 1 to 40 parts by mass relative to 100 parts by mass, in the uncured state, the viscosity in the range of shear rate 1 s ^-1 is 10 to 5000 Pa·s and the range of shear rate 0.1 to ¹ s ^-1 . The thixotropy coefficient in is 1.1 to 10.

Adopting urethane (meth)acrylate having a mass average molecular weight of 5000 or more as the photopolymerizable oligomer (A) constituting the active energy ray-curable resin composition gives the cured product sufficient flexibility and low hardness. A cured product can be obtained. Further, the (meth)acryloyl compound (b1) represented by the formula (1) is contained in an amount of 20 to 60% by mass based on the total mass of the photopolymerizable monomer (B), which improves the loss factor of the cured product and is excellent. It can realize excellent cushioning and anti-vibration properties. In addition, the total content (A+B) of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B) is calculated based on the total amount of the photopolymerizable oligomer (A), the photopolymerizable monomer (B) and the photopolymerization initiator (C). The curing reaction is suitably performed by setting the content to 94 to 99.99 mass% with respect to the total mass (A+B+C). Further, by setting the content of the photopolymerizable monomer (B) to 80 to 99 mass% with respect to the total mass (A+B) of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B), a cured product It is possible to achieve both excellent loss coefficient (high loss coefficient) and flexibility (low hardness). Then, the thixotropy imparting agent (D) is used in an amount of 1 to 40 parts by mass with respect to 100 parts by mass of the total (A+B+C) of the photopolymerizable oligomer (A), the photopolymerizable monomer (B) and the photopolymerization initiator (C). By containing it, suitable thixotropy can be obtained while achieving both a loss coefficient (high loss coefficient) and flexibility (low hardness). Further, in the uncured state, the viscosity at a shear rate of 1 s ⁻¹ is 10 to 5000 Pa·s and the thixotropy coefficient in the range of a shear rate of 0.1 to ¹ s ⁻¹ is 1.1 to 10 to obtain the CIP method. It is possible to obtain an active energy ray-curable resin composition having excellent fluidity and thixotropy, and having excellent coatability and shape accuracy even when the diameter of the needle discharge port is reduced. Then, the active energy ray-curable resin composition having each constitution of the present invention has an E hardness (JIS K6253 compliant) of 50 or less and has a dynamic viscoelasticity by being irradiated with an active energy ray to be cured. It has physical properties that the loss coefficient at 10 Hz in measurement (JIS K72444-10) is 0.3 or more, and has sufficient flexibility (low hardness) and excellent buffering/vibration resistance (large loss coefficient). Cured products can be formed.

Further, the polymerizable monomer (B) in the active energy ray-curable resin composition of the present invention further has the following formula (2) (wherein R ₂ is a hydrogen atom or a methyl group, and W ₁ is an ethylene group or a propylene group). , P each represents an integer of 0 to 4). It is also preferable that the (meth)acryloyl compound (b2) is included. This makes it possible to obtain a resin composition which further improves the above-mentioned loss coefficient and forms a cured product having enhanced buffering properties.

In addition to the (meth)acryloyl compound (b2) represented by the above formula (2), the photopolymerizable monomer (B) in the active energy ray-curable resin composition of the present invention further has the following formula (3) (In the formula, R ₃ represents a hydrogen atom or a methyl group, W ₂ represents an ethylene group or a propylene group, and q represents an integer of 1 to 20, respectively), and a (meth)acryloyl compound (b3) represented by The content of the (meth)acryloyl compound (b3) represented by the formula (3) is represented by the (meth)acryloyl compound (b2) represented by the formula (2) and the content of the (meth)acryloyl compound (b3) represented by the formula (3). ) It is also preferable that it is 0.1 to 5 mass% with respect to the total mass (b2+b3) of the acryloyl compound (b3). As a result, a resin composition having excellent cushioning properties and capable of forming a cured product with reduced compression set is obtained.

In addition to the (meth)acryloyl compound (b1) represented by the above formula (1), the photopolymerizable monomer (B) in the active energy ray-curable resin composition of the present invention further has the following formula ( 4) (in the formula, R ₄ represents a hydrogen atom or a methyl group, R ₅ represents an alkyl group, W ₃ represents an alkylene group, and r represents an integer of 1 to 20, respectively), and is a (meth)acryloyl compound (b4). ) and the following formula (5) (wherein, R ₆ is hydrogen or methyl, R ₇ is a methylene group including molecular weight is represented by 110 the following functional groups respectively.) (meth) acryloyl compound ( b5) is contained and the content of the (meth)acryloyl compound (b4) represented by the formula (4) is represented by the (meth)acryloyl compound (b4) represented by the formula (4) and the formula (5). It is also preferably 70 to 99 mass% with respect to the total mass (b4+b5) of the (meth)acryloyl compound (b5). As a result, a resin composition that can further reduce the compression set of the cured product can be obtained. The compression set in the present specification is a value of the compression set after being held for 23 hours under a 25% compression condition under a temperature environment of 70° C., which is indicated by JIS K6262.

The photopolymerizable monomer (B) in the active energy ray-curable resin composition of the present invention is represented by the (meth)acryloyl compound (b4) represented by the above formula (4) and the above formula (5) ( In addition to the (meth)acryloyl compound (b5), it is further represented by the following formula (6) (in the formula, R ₈ represents hydrogen or a methyl group, and R ₉ represents an alkyl group having 5 or more carbon atoms). The alkyl (meth)acrylate compound (b6) is contained, and the content of the alkyl (meth)acrylate compound (b6) represented by the formula (6) is the (meth)acryloyl compound (b4) represented by the formula (4). ), the (meth)acryloyl compound (b5) represented by the formula (5) and the alkyl (meth)acrylate compound (b6) represented by the formula (6) in a total mass (b4+b5+b6) of 1 to 50% by mass. It is also preferable to have. As a result, a resin composition that forms a cured product having further excellent compression set can be obtained.

It is also preferable that the thixotropy-imparting agent (D) in the active energy ray-curable resin composition of the present invention is fine silica particles, and the carbon content of the fine silica particles is less than 0.5% by mass. As a result, a substance suitable as a thixotropy-imparting agent is selected.

It is also preferable that the photopolymerization initiator (C) in the active energy ray-curable resin composition of the present invention is composed of at least two kinds of compounds, and at least one kind is a phosphine compound or an aminoalkylphenone compound. As a result, the stickiness of the surface of the cured product cured by irradiation with light energy rays is reduced or the compression set is improved.

In addition, the sealing material or the cushioning material of the present invention is preferably made of a cured product of the above-mentioned active energy ray-curable resin composition. As a result, a sealing material and a cushioning material having excellent flexibility and cushioning/vibration damping properties can be obtained.

According to the present invention, it is possible to provide an active energy ray-curable resin composition having the following excellent effects, and a sealing material and a cushioning material made of the cured product.
(1) The active energy ray-curable resin composition of the present invention has excellent dischargeability at the time of applying a needle, is less likely to cause radial expansion (Swell) of the bead-shaped discharge body, and has a discharge shape accuracy of the bead-shaped discharge body. Since the shape is high and the shape retention after coating is excellent, it is possible to form a sealing material or a cushioning material having high shape accuracy with high productivity.
(2) The cured product of the active energy ray-curable resin composition of the present invention has a low hardness and a large loss coefficient, so that it is a sealing material, a cushioning material, or a vibration damping material that is excellent in flexibility and cushioning/vibration resistance. It is possible to obtain materials and the like.
(3) Further, by adjusting the components contained in the photopolymerizable monomer (B) constituting the active energy ray-curable resin composition of the present invention, the loss coefficient of the cured product can be further improved or the cured product can be improved. The compression set can be reduced.
(4) The active energy ray-curable resin composition of the present invention is suitable for forming a bead-shaped sealing material or the like which is needle-coated using a needle having an inner diameter of 1 mmφ or less. When a needle having an extremely small diameter of 0.75 mmφ or less is used, the bead-shaped ejection body is not likely to undergo a radial expansion (Swell), the bead-shaped ejection body has excellent diameter accuracy, and the shape retention after coating is high. Has the effect. Further, since the cured product has a low hardness and a large loss coefficient, it is excellent in flexibility, cushioning property, and vibration damping property. Therefore, it is possible to obtain a sealing material that is flexible and has excellent cushioning properties, a cushioning material that has excellent shock absorbing properties, and a vibration damping material while realizing an extremely fine wire diameter, and to reduce the size of electronic devices that incorporate these. Contribute to cost reduction.

It is explanatory drawing which shows the coating device which discharges the active energy ray curable resin composition of this invention in a bead shape, forms a bead-shaped discharge body, and irradiates an active energy ray, and the mode of coating. It is a schematic diagram which shows the coating pattern of the test bead-shaped discharge body in an Example.

The active energy ray-curable resin composition of the present invention (hereinafter sometimes simply referred to as a resin composition or a curable resin composition) comprises a photopolymerizable oligomer (A), a photopolymerizable monomer (B), It contains a photopolymerization initiator (C) and a thixotropy imparting agent (D). When the active energy ray resin composition of the present invention is irradiated with an active energy ray, the mixed composition of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B) is polymerized and cured. Hereinafter, each component will be described in detail.

1. Photopolymerizable oligomer (A)
The photopolymerizable oligomer (A) used in the active energy ray-curable resin composition of the present invention is a component that has a polymerizable functional group that can be cured by active energy rays and contributes to the loss coefficient after curing. It is a urethane (meth)acrylate having a plurality of ether bonds in the molecule and a mass average molecular weight of 5000 or more. The mass average molecular weight of the photopolymerizable oligomer (A) is more preferably 10,000 or more, and further preferably 20,000 or more from the viewpoint of improving the loss coefficient of the cured product. When the number of polymerizable functional groups of the photopolymerizable oligomer (A) is less than 2, unpolymerized photopolymerizable oligomer bleeds on the surface of the cured product of the active energy ray curable resin composition. Therefore, the cured product may have a problem of sealing property and appearance, and when the number is 5 or more, the crosslinking density becomes too high and the hardness thereof may become high. The presence of an ether bond in the molecule of the photopolymerizable oligomer (A) is indispensable because it greatly contributes to the flexibility of the molecular structure of urethane (meth)acrylate, and further to the reduction in hardness (repulsion) of the cured product. .. The mixing ratio of the photopolymerizable oligomer (A) is 1 to the total mass (A+B) of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B) described later from the viewpoint of lowering the hardness of the cured product. 20 mass% is preferable, 1-15 mass% is more preferable, 3-10 mass% is still more preferable. Specific examples of the photopolymerizable oligomer (A) include the Shiko (registered trademark) series manufactured by Nippon Synthetic Chemical Industry Co., Ltd. (for example, UV-2000B, UV-3000B, UV-3200B, UV-3210EA, UV-3300B, (UV-3500BA, UV-3520TL, UV-3700B, etc.) and Art Resin (registered trademark) series manufactured by Negami Kogyo Co., Ltd. (for example, UN-5590, UN-6202, UN-6301, KHP-22, TFX-1N, etc.). Hitaroid (registered trademark) series manufactured by Hitachi Chemical Co., Ltd., SUA series manufactured by Asia Kogyo Co., Ltd., KUA series manufactured by KSM Co., Ltd., and KAYARAD (registered trademark) series UX manufactured by Nippon Kayaku Co., Ltd. It is not limited.

2. Photopolymerizable monomer (B)
The photopolymerizable monomer (B) used in the active energy ray-curable resin composition of the present invention has a polymerizable functional group that can be cured by active energy rays, and is polymerized with the above-mentioned photopolymerizable oligomer (A). It is a possible ingredient. The photopolymerizable monomer (B) contains at least a monomer component composed of the (meth)acryloyl compound (b1) represented by the above general formula (1).

2-1. (Meth)acryloyl compound (b1)
This (meth)acryloyl compound (b1) (hereinafter sometimes referred to as the first (meth)acryloyl compound (b1)) has a (meth)acryloyl group and a phenyl group at the molecular end, as shown in the general formula (1). A phenoxyphenyl acrylate or a phenoxybenzyl acrylate having a group and a molecular structure having an aromatic ring, that is, a benzene ring, in its molecule, wherein n is 0 or 1. In the (meth)acryloyl compound (b1) represented by the general formula (1), R ₁ is a hydrogen atom or a methyl group. Further, the coordination of the phenoxy group to the benzene ring in the molecular chain may be any of the ortho position, the meta position and the para position, and from the viewpoint of an effective three-dimensional structure that exerts the effect of the present invention, the meta position is Particularly preferred. Therefore, as the compound represented by the formula (1), m-phenoxyphenyl acrylate and m-phenoxybenzyl acrylate are particularly preferably used. In general formula (1), the loss coefficient of the cured product tends to decrease as n increases, but n may be 2 or more depending on the desired loss coefficient. However, materials having n of 0 and n of 2 or more are not in the market, and production cost increases when they are synthesized and used. Therefore, at the present time, n is preferably 1 from the viewpoint of productivity. In addition, the proportion of the (meth)acryloyl compound (b1) in the total mass of the photopolymerizable monomer (B) is preferably 20 to 60% by mass, and 20 to 50% by mass, from the viewpoint of reducing the hardness of the cured product. More preferably, 30-40 mass% is still more preferable. When the ratio of the (meth)acryloyl compound (b1) is less than 20% by mass, the loss coefficient of the cured product is not sufficiently improved, and when it exceeds 60% by mass, the E hardness increases and the composition becomes hard. Absent. By using the (meth)acryloyl compound (b1) represented by the formula (1) as the photopolymerizable monomer (B) constituting the resin composition of the present invention, the loss factor is large and the buffering/vibration resistance is high. A cured product having excellent properties is obtained.

Further, from the viewpoint of achieving both excellent loss coefficient (high loss coefficient) and flexibility (low hardness) of the cured product, the mixing ratio of the photopolymerizable monomer (B) is such that the photopolymerizable oligomer (A) and the photopolymerizable 80-99 mass% is preferable with respect to the total mass (A+B) of a monomer (B), 85-99 mass% is more preferable, 90-97 mass% is still more preferable. If the blending ratio of the photopolymerizable monomer (B) is less than 80% by mass, the cured product becomes hard, and if it exceeds 99% by mass, the photopolymerizable oligomer (A) and the photopolymerizable monomer (B) are crosslinked. Too few points are not preferable because sufficient hardness as a sealing material or a cushioning material cannot be obtained, or the compression set becomes large. As the compound that constitutes the photopolymerizable monomer (B), in addition to the (meth)acryloyl compound (b1) described above, any monomer compound that can be polymerized with the photopolymerizable oligomer (A) can be used as the (meth)acryloyl compound (b1). It can be used in combination with. Among these, as examples of other monomer compounds constituting the photopolymerizable monomer (B), the monomer compounds represented by the above general formulas (2) to (6) will be described in detail below.

2-2. (Meth)acryloyl compound (b2)
This (meth)acryloyl compound (b2) (hereinafter sometimes referred to as the second (meth)acryloyl compound (b2)) has a (meth)acryloyl group and a phenyl group at the molecular end as represented by the general formula (2). It has a group and further has an ethyl ether or propyl ether in the molecule. In the (meth)acryloyl compound (b2) represented by the general formula (2), R ₂ is a hydrogen atom or a methyl group, W ₁ is an ethylene group or a propylene group, and p is an integer of 0 to 4 is there. The molecular weight of the (meth)acryloyl compound (b2) is more preferably 192 to 325. In the case of a compound having a molecular weight of the (meth)acryloyl compound (b2) of less than 192, that is, a compound having no moiety represented by a glycol group, an increase in hardness of the cured product due to a decrease in acrylic equivalent (increase in impact resilience), This is because the curing shrinkage amount at the time of curing may increase and the shape accuracy may decrease, and when the molecular weight is 326 or more, the loss coefficient of the cured product may decrease and the buffering property may decrease. Specific examples of the compound represented by the formula (2) include phenoxyethyl acrylate, phenoxypropyl acrylate, phenoxydiethylene glycol acrylate, phenoxydipropylene glycol acrylate, phenoxytriethylene glycol acrylate, phenoxytripropylene glycol acrylate, and phenoxyethyl meta. Acrylate, phenoxypropylmethacrylate, phenoxydiethyleneglycolmethacrylate, phenoxydipropyleneglycolmethacrylate, phenoxytriethyleneglycolmethacrylate, etc., among which, from the viewpoint of the balance between hardness and loss coefficient, phenoxydiethyleneglycol acrylate, phenoxydiethylene Propylene glycol acrylate and phenoxydiethylene glycol methacrylate are preferably used. As the photopolymerizable monomer (B) constituting the resin composition of the present invention, in addition to the first (meth)acryloyl compound (b1), the (meth)acryloyl compound (b2) represented by the formula (2) is added. By adopting it, it is possible to obtain a cured product having a larger loss coefficient and excellent buffering properties and vibration damping properties.

2-3. (Meth)acryloyl compound (b3)
When the (meth)acryloyl compound (b2) represented by the general formula (2) is used as the photopolymerizable monomer (B) in addition to the first (meth)acryloyl compound (b1), the above general formula is used. It is more preferable to use it in combination with the (meth)acryloyl compound (b3) represented by (3). This reduces the compression set of the cured product. This (meth)acryloyl compound (b3) (hereinafter sometimes referred to as the third (meth)acryloyl compound (b3)) is a compound represented by the general formula (3) at each end of the molecule. It has a group and further has a molecular structure having ethyl ether or propyl ether in the molecule. In the (meth)acryloyl compound (b3) represented by the general formula (3), R ₃ is a hydrogen atom or a methyl group, and W ₂ is an ethylene group or a propylene group. Regarding the value of q, when q=0, that is, when there is no ethyl ether or propyl glycol unit, the cured product may be too hard, and when q exceeds 20, the value of the compression set of the cured product is May be large, so that it is preferably an integer of 1 to 20, more preferably 3 to 20, and even more preferably 5 to 20. Specific examples of the (meth)acryloyl compound represented by formula (3) include Kyoeisha Chemical Co., Ltd. light ester (EG, 2EG, 3EG, 4EG, 9EG, 14EG), Kyoeisha Chemical Co., Ltd. light acrylate (registered trademark). ) Series (3EG-A, 4-EG-A, 9EG-A, 14EG-A), KAYARAD (registered trademark) series (PEG400DA) manufactured by Nippon Kayaku Co., Ltd., Aronix (registered trademark) series manufactured by Toagosei Co., Ltd. (M-220, M-225, M-240, M-270), Shin Nakamura Chemical Co., Ltd. NK ester (A-200, A-400, A-600, APG-100, APG-200, APG-). 400, APG-700) and the like.

The mixing ratio of the second (meth)acryloyl compound (b2) and the third (meth)acryloyl compound (b3) is such that the second (meth)acryloyl compound (b2) and the third (meth)acryloyl compound (b3) are mixed. It is preferable that the ratio of the third (meth)acryloyl compound (b3) is 0.1 to 5 mass% with respect to the total mass of When the proportion of the third (meth)acryloyl compound (b3) is less than 0.1% by mass, it is difficult to obtain the effect of reducing the compression set, and when it exceeds 5% by mass, the E hardness increases and the composition becomes hard. At the same time, the value of the loss coefficient may be reduced, and the impact absorption performance may be deteriorated.

2-4. (Meth)acryloyl compound (b4)
This (meth)acryloyl compound (b4) (hereinafter sometimes referred to as the fourth (meth)acryloyl compound (b4)) can be polymerized by irradiation with an active energy ray as shown in the general formula (4) ( It has a (meth)acryloyl group at one position in the molecule and has a molecular structure having an oligoglycol unit and an alkyl group in the molecule. In the (meth)acryloyl compound (b4) represented by the general formula (4), R ₄ is a hydrogen atom or a methyl group, R ₅ is an alkyl group, and W ₃ is an alkylene group. Regarding the value of r, when r exceeds 20, the physical properties of the cured product may deteriorate, such as the hardness becoming large under low temperature conditions and the low resilience not being exhibited, and the compression set becoming large. It is preferably an integer of 1 to 20.

Further, the (meth)acryloyl monomer (b4) includes a (meth)acryloyl monomer (b4-1) having r of 1 to 5 or less and a (meth)acryloyl monomer having r of 6 to 20 or less in the general formula (4). (B4-2) and the content of the (meth)acryloyl monomer (b4-2) contained in the (meth)acryloyl monomer (b4) is preferably 1% by mass or more and less than 90% by mass. If the content of the (meth)acryloyl monomer (b4-2) is less than 1% by mass, the E hardness of the cured product may increase, and if it is 90% by mass or more, the compression set of the cured product may increase. This is because. Examples of the compound represented by the general formula (4) include (meth)acryloyl monomer (b4-1), specifically, butoxyethyl acrylate, ethoxydiethylene glycol acrylate, methoxydipropylene glycol acrylate, methoxytriethylene glycol acrylate, Examples thereof include methoxytetraethylene glycol acrylate, methoxypentaethylene glycol acrylate, and methacrylates of these compounds. As the (meth)acryloyl monomer (b4-2), specifically, Light acrylate (registered trademark) 130A (product of Kyoeisha Chemical Co., Ltd.), light ester 130MA (product of Kyoeisha Chemical Co., Ltd.), Shin Nakamura Chemical Co., Ltd. AM-130G, S-12E, S-20E and the like manufactured by the company can be mentioned. As the photopolymerizable monomer (B) constituting the resin composition of the present invention, in addition to the first (meth)acryloyl compound (b1), the (meth)acryloyl compound (b4) represented by the formula (4) is added. By adopting this, a cured product having low hardness, excellent flexibility and reduced compression set can be obtained.

2-5. (Meth)acryloyl compound (b5)
When the (meth)acryloyl compound (b4) represented by the general formula (4) is used as the photopolymerizable monomer (B) in addition to the first (meth)acryloyl compound (b1), the above general formula is used. It is more preferable to use it in combination with the (meth)acryloyl compound (b5) represented by (5). This further reduces the compression set of the cured product. This (meth)acryloyl compound (b5) (hereinafter sometimes referred to as the fifth (meth)acryloyl compound (b5)) has a (meth)acryloyl group in the molecule as shown in the general formula (5). It has a molecular structure having a hydroxyl group in the molecule as well as having a position. In the (meth)acryloyl compound (b5) represented by the general formula (5), R ₆ is a hydrogen atom or a methyl group, and R ₇ is a functional group having a molecular weight of 110 or less including a methylene group. Is preferred. Of these, when R ₇ does not contain a methylene group (for example, when R ₇ is hydrogen), sufficient curing does not occur after irradiation with active energy rays and the compression set of the cured product becomes large, It is difficult to obtain desirable physical properties as a sealing material or a cushioning material such as stickiness on the surface. When the molecular weight of R ₇ is 111 or more, the cured product tends to have a large compression set and a large E hardness. .. Specific examples of the (meth)acryloyl compound represented by the formula (5) include 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 2-hydroxypentyl acrylate, 2-hydroxyhexyl acrylate, 2-hydroxyheptyl acrylate, and 2 -Hydroxy-3-phenoxypropyl acrylate, 3-butoxy-2-hydroxypropyl acrylate, and methacrylates of these compounds can be mentioned.

When the fourth (meth)acryloyl compound (b4) and the fifth (meth)acryloyl compound (b5) are used in combination, the content of the fourth (meth)acryloyl compound (b4) is It is preferable that the total amount (b4+b5) of the (meth)acryloyl compound (b4) of 4 and the fifth (meth)acryloyl compound (b5) is 70 to 99% by mass. When the compounding ratio of the fifth (meth)acryloyl compound (b5) is less than 1% by mass, the effect of reducing compression set may be small, and when it exceeds 30% by mass, the effect of reducing E hardness may be small. Because there is.

2-6. Alkyl (meth)acrylate compound (b6)
As the photopolymerizable monomer (B), in addition to the first (meth)acryloyl compound (b1), a (meth)acryloyl compound (b4) represented by the general formula (4) and a general formula (5) When it is used in combination with the (meth)acryloyl compound (b5), it is more preferable that the alkyl (meth)acrylate compound (b6) represented by the general formula (6) is also used in combination. This further reduces the compression set of the cured product and imparts flexibility. The alkyl (meth)acrylate compound (b6) has a molecular structure having a (meth)acrylic ester moiety and an alkyl group, as in the general formula (6). In the alkyl (meth)acrylate compound (b6) represented by the general formula (6), R ₈ is a hydrogen atom or a methyl group, R ₉ is an alkyl group, and the carbon number thereof is 5 or more. It is preferable, 5 to 17 is more preferable, and 6 to 14 is further preferable. If the alkyl group has 4 or less carbon atoms, the compression set becomes large, and volatilization occurs due to the heat generated during irradiation with the active energy ray, which is undesirable as it affects the use environment as outgas. When the number of carbon atoms in the alkyl group is 18 or more, the physical properties of the cured product such as the hardness of the cured product after active energy ray irradiation not being reduced and the low resilience not being exhibited or the compression set becoming large. May decrease, so the range of 5 to 17 carbon atoms is preferable. Specific examples of the alkyl(meth)acrylate compound represented by the formula (6) include pentyl(meth)acrylate, hexyl(meth)acrylate, heptyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, octyl(meth). Examples thereof include acrylate, nonyl(meth)acrylate, decyl(meth)acrylate, undecyl(meth)acrylate, lauryl(meth)acrylate, myristyl(meth)acrylate, cetyl(meth)acrylate and the like.

When the fourth (meth)acryloyl compound (b4), the fifth (meth)acryloyl compound (b5) and the alkyl (meth)acrylate compound (b6) are used in combination, they are represented by the formula (6). The content of the alkyl (meth)acrylate compound (b6) is represented by the formula (4) (meth)acryloyl compound (b4), the formula (5) (meth)acryloyl compound (b5) and the formula (6). It is preferable to add 1 to 50 mass% of the total mass (b4+b5+b6) of the alkyl (meth)acrylate compound (b6). When the blending ratio of the alkyl (meth)acrylate compound (6) is less than the above range, the E hardness of the cured product may be increased and the flexibility may be lost. The blending ratio of the alkyl (meth)acrylate compound (6) Is larger than the above range, the compression set of the cured product may increase.

3. Photopolymerization initiator (C)
The active energy ray-curable resin composition of the present invention contains a photopolymerization initiator (C) for initiating the polymerization of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B). The photopolymerization initiator (C) is preferably used in combination of at least two kinds of compounds, one of which is preferably a phosphine compound or an aminoalkylphenone compound, and a phosphine compound and an aminoalkylphenone compound. It is more preferable to use the compound in combination.

When a phosphine-based compound is used as the photopolymerization initiator (C), energy on the long wavelength side of near-ultraviolet rays can be effectively utilized in the polymerization initiation reaction, so that the internal curability of the active energy ray-curable resin composition is enhanced. It is also effective in reducing the compression set of the cured product. The above-mentioned phosphine compound is a compound containing a phosphine oxide group represented by P=O in the molecule, and more specifically, a compound in which a phosphine group and an acyl group are bonded in the molecule. is there. Specific examples of the phosphine compound include, but are not limited to, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, and 2,2. Monoacylphosphine oxide compounds such as 6-dichlorobenzoyldiphenylphosphine oxide and 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide; bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2 ,6-Dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide and other bisacylphosphine oxide compounds; 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2,4,6-trimethylbenzoylphenyl Phosphinic acid ethyl ester, 2,4,6-trimethylbenzoylphenylphosphinic acid phenyl ester and their analogs are well known, and commercially available products include LUCIRIN (registered trademark) TPO and TPO-L manufactured by BASF. IRGACURE (registered trademark) 819 and the like.

When an aminoalkylphenone compound is used as the photopolymerization initiator (C), the energy in the short to medium wavelength range of near-ultraviolet light can be effectively utilized for the curing initiation reaction, and therefore the surface of the active energy ray-curable resin composition The effect of improving the curability of is obtained, and the stickiness of the surface of the cured product can be reduced. The aminoalkylphenone compound is not particularly limited, but is 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone, 2-(dimethylamino)-2-[( 4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one and their Analogs and the like are well known, and commercially available products include IRGACURE (registered trademark) series 907, 369, 379EG manufactured by BASF.

The mixing ratio of the photopolymerization initiator (C) is 0.01 to 6 with respect to the total mass (A+B+C) of the photopolymerizable oligomer (A), the photopolymerizable monomer (B) and the photopolymerization initiator (C). It is preferable to set it as mass %, it is more preferable to set it as 0.1-5 mass %, and it is more preferable to set it as 0.5-3 mass %. If the mixing ratio of the photopolymerization initiator is less than 0.01% by mass, the curing due to irradiation with active energy rays does not proceed sufficiently, and if it exceeds 6% by mass, unreacted light remaining in the polymer structure after curing remains unreacted. This is because the polymerization initiator volatilizes into outgas, which may cause a problem when incorporated into an electronic device. Therefore, the total content (A+B) of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B) is equal to that of the photopolymerizable oligomer (A), the photopolymerizable monomer (B) and the photopolymerization initiator (C). The total mass (A+B+C) is preferably in the range of 94 to 99.99% by mass, more preferably 95 to 99.9% by mass, and further preferably 97 to 99.5% by mass. preferable.

4. Thixotropic agent (D)
In the active energy ray-curable resin composition of the present invention, a thixotropy imparting agent (D) is added to a resin material component composed of the above-mentioned photopolymerizable oligomer (A), photopolymerizable monomer (B) and photopolymerization initiator (C). ) Is blended and dispersed. The thixotropy-imparting agent (D) is added by being dispersed in a resin material to impart thixotropy, that is, a property that viscosity is high in a low shear rate region and viscosity is reduced in a high shear rate region. It refers to all agents, for example, a compound that swells when added to a resin material and forms a gradual stitch structure by a relatively weak bonding force such as hydrogen bonding force and van der Waals force. Can be mentioned. These are commercially available as paint additives under the names of anti-sagging agent, anti-settling agent, thixotropic agent and the like. The resin composition in which the thixotropy-imparting agent is uniformly dispersed has a high apparent viscosity in the low shear rate region because the gentle stitch structure is retained, and the stitch structure is broken by the shear force in the high shear rate region. Therefore, it has the property of lowering the viscosity.

Specific examples of the thixotropy imparting agent (D) include long-chain fatty acid ester polymers, amide wax, oxidized polyethylene wax, sulfate ester anion activators, polycarboxylic acids, amine salts of polycarboxylic acids, and polyethers. Organic compounds such as, and finely divided silica, calcium carbonate, ground calcium carbonate, bentonite, inorganic fine particles such as sepiolite, Teflon (registered trademark), resin fine particles such as silicone can be preferably used, and the shape of the fine particles is spherical, A rod shape, a scale shape, or the like can be appropriately used. Among these, as the thixotropy-imparting agent (D) in the present invention, silica fine particles are more preferable, and fumed silica fine particles are further preferable, from the viewpoint of the balance between fluidity and thixotropy. Among the fumed silica fine particles, hydrophilic silica fine particles which have not been subjected to the hydrophobic treatment are particularly preferably used. By using hydrophilic silica fine particles as the thixotropy-imparting agent (D), a desired viscosity before curing can be obtained with a small amount of addition, and the cured product after curing also has an increase in E hardness (JIS K6253 compliant). It can be suppressed to a slight level, and a large loss coefficient can be maintained. Here, the fumed silica fine particles are a general term for aggregates obtained by treating a silane compound in a high temperature atmosphere, and the obtained aggregates are, like glass, a compound consisting of silicon, oxygen and hydrogen, It is generally called hydrophilic silica. Further, the fumed silica fine particles are industrially used in various fields, and a treatment called hydrophobization may be performed depending on the use and the manufacturing method. The hydrophobic treatment is performed by treating hydrophilic silica with a compound having an organic functional group containing carbon, and therefore the hydrophobic silica fine particles contain a carbon component. Therefore, from the viewpoint of having hydrophilicity, the carbon content of the silica fine particles is preferably low, and specifically, the carbon content of the silica fine particles is less than 0.5% by mass based on the entire silica fine particles, and more preferably Is 0.3% by mass or less, more preferably 0.1% by mass or less, and it is particularly preferable that no carbon component is contained.
Specific examples of silica fine particles include AEROSIL (registered trademark) of Aerosil Japan, REOLOSIL (registered trademark) of Tokuyama Corporation, CAB-O-SIL (registered trademark) of CABOT, and WACKER HDK (registered trademark) manufactured by Asahi Kasei Wacker. , NIPSIL (registered trademark) manufactured by Nippon Silica Industry Co., Ltd., Sylisia (registered trademark) manufactured by Fuji Silysia Ltd., and TOKUSIL (registered trademark) manufactured by Tokuyama Corporation.

Fine particles such as the silica fine particles are mixed with the active energy ray-curable resin composition and dispersed to form a network structure while the primary particles aggregate, and thixotropy is imparted due to this network structure. It The primary particle size of the fine particles is selected so that the dispersibility in the resin material, the thixotropy imparting effect, and the viscosity are in the preferred state of the present invention, specifically, 0.002 to 10 μm is preferable, and 0 is more preferable. 0.005 to 1 μm, and more preferably 0.007 to 0.1 μm. The numerical value of the primary particle size of the fine particles is obtained by measuring the longest diameter of the contour of each of the primary particle images of 1000 randomly selected fine particles in an image at a magnification at which the primary particles can be visually observed by SEM or TEM (transmission electron microscope). , Is a value obtained by arithmetic mean. The specific surface area corresponding to the primary particle size (DIN 66131 compliant BET method), if the fine particles are of silica, a 0.3~600m ² / g, more preferably from 3~430m ² / g, more preferably Is 30 to 600 m ² /g.

The compounding amount of the thixotropy imparting agent (D) is 1 to 40 parts by mass with respect to 100 parts by mass of the total (A+B+C) of the photopolymerizable oligomer (A), the photopolymerizable monomer (B) and the photopolymerization initiator (C). When the silica fine particles are used as the thixotropy imparting agent (D), 2 to 30% by mass is more preferable, 3 to 20% by mass is further preferable, and 3 to 15% by mass is particularly preferable. When the amount of the thixotropy-imparting agent (D) added is less than 1% by mass, good thixotropy cannot be obtained, and when it exceeds 40% by mass, the E hardness of the cured product becomes too large and the loss coefficient becomes small. Is.

If necessary, the active energy ray-curable resin composition of the present invention may contain other additives as long as the effects of the present invention are not impaired. Other additives include, for example, fillers, and include not only powder fillers but also conductive agents, static eliminators, flame retardants, buffer improvers and colorants. As an example of these, examples of the powder filler include crystalline silica, fused silica, calcium carbonate, talc, mica, alumina, aluminum hydroxide or white carbon. Further, carbon black, expanded graphite powder, powdered graphite, metal fine particles, or the like can be used for imparting conductivity or static elimination. As the flame retardant, a powdered organic halogen compound, red phosphorus, antimony trioxide, expanded graphite, magnetite, aluminum hydroxide or the like can be used. As the buffer property improving agent, a hollow filler having an organic shell (for example, Expancel (registered trademark) manufactured by Nippon Philite Co., Ltd.) can be used. Examples of the colorant include various pigments and dyes, and these additives may be appropriately selected and used depending on the application.

Further, the active energy ray for curing the active energy ray-curable resin composition of the present invention means infrared rays, visible rays, ultraviolet rays, X-rays, electron rays, alpha rays, beta rays or gamma rays, and ultraviolet rays are particularly preferable. Used for. The ultraviolet rays in the present invention include near ultraviolet rays (near UV, wavelength 200 to 380 nm), far ultraviolet rays (wavelength 10 to 200 nm) and extreme ultraviolet rays (extreme UV, wavelength 1 to 10 nm). These active energy rays can be used alone or in combination of two or more. The source of these active energy rays is not particularly limited as long as it can be cured in a short time after coating or applying the resin composition on the substrate to be coated, and examples thereof include a low pressure mercury lamp, a high pressure mercury lamp, and an excimer. It is possible to use a known generating means such as an ultraviolet (excimer UV) lamp, a halide lamp, an LED light or a laser. Further, examples of the infrared ray source include a lamp, a resistance heating plate, a laser, and the like, and examples of the visible ray source include direct sunlight, a lamp, a fluorescent lamp, an LED light, a laser, and the like. As the electron beam source, for example, a device utilizing a thermoelectron generated from a commercially available tungsten filament, a cold cathode system generating a high voltage pulse in a metal, and an ionized gaseous molecule and a metal electrode An example is a secondary electron type device that uses secondary electrons generated by collision. Further, examples of the source of alpha rays, beta rays, and gamma rays include fission materials such as Co60, and for gamma rays, a vacuum tube or the like that causes accelerated electrons to collide with the anode can be used. These active energy rays may be irradiated alone or in combination of two or more.

5. Physical Properties of Active Energy Ray-Curable Resin Composition The active energy ray-curable resin composition of the present invention has the function of the present invention that diameter expansion (Swell) of a bead-shaped discharge does not easily occur and that shape retention after coating is high. In order to achieve the effect, at a shear rate of 1 s ^-1 , the uncured viscosity is 10 to 5000 Pa·s (JIS Z8803 compliant cone-plate type rotational viscometer 25°C) and the shear rate is 0.1 to ^{1 s -1} . It is important that the thixotropy coefficient in the range is 1.1-10.

First, the viscosity will be described in detail. The active energy ray-curable resin composition of the present invention is a thixotropy-imparting agent, exhibits thixotropic properties, and exhibits the characteristics of a non-Newtonian fluid, so the viscosity of the active energy ray-curable resin composition of the present invention is apparent. It refers to viscosity, which will be described below as apparent viscosity. The apparent viscosity of the active energy ray-curable resin composition of the present invention in an uncured state (hereinafter, may be simply referred to as apparent viscosity) is the “viscosity measured by a cone-plate rotational viscometer” in JIS Z8803 (1991). According to “Measurement method”, the value is preferably a value at a shear rate of 1.0 s ⁻¹ at 25° C. The uncured state is a state in which the active energy ray-curable resin composition is not irradiated with the active energy ray for curing. The apparent viscosity of the active energy ray-curable resin composition of the present invention is preferably 10 to 5000 Pa·s, more preferably 20 to 5000 Pa·s, further preferably 30 to 1000 Pa·s, and particularly preferably 50 to 800 Pa·s. .. If the apparent viscosity is less than 10 Pa·s, it will flow too much after being discharged from the needle or the like, resulting in poor shape retention, and if it exceeds 5000 Pa·s, it will be difficult to discharge from the needle or the like and the tensile stress at the time of application However, it is easy to break or the diameter expansion easily occurs, which is not preferable. The apparent viscosity is 5% or less when the thixotropy-imparting agent (D) is dispersed in the photopolymerizable oligomer (A), the photopolymerizable monomer (B) and the photopolymerization initiator (C) and then left to stand. When it becomes /day, it is preferable that the viscosity and the thixotropy coefficient are in the ranges.

The thixotropy coefficient (hereinafter, also simply referred to as thixotropy coefficient) of the active energy ray-curable resin composition of the present invention, when it is less than 1.1, causes excessive flow after ejection from the needle, resulting in shape retention. Inferior, when it is more than 10, the ejection from the needle becomes difficult, the bead-shaped ejection body is easily broken due to the tensile stress at the time of application, or the diameter expansion easily occurs. Preferably, 2-9 are more preferable, and 2.5-8 are still more preferable. Here, the above-mentioned thixotropy coefficient (T.I.) is the apparent viscosity η (D ₁ ) at the shear rate D ₁ measured by the JIS Z8803 compliant cone-plate type rotational viscometer (25° C.) and the shear rate D ₂ And the apparent viscosity η(D ₂ ) in Equation (1) are values obtained by the following mathematical formula 1 (provided that 0.1 s ⁻¹ ≦D ₁ <D ₂ ≦1 s ⁻¹ ). Here, the thixotropy coefficient varies depending on the combination of the shear rate D ₁ and the shear rate D ₂ , but the active energy ray-curable resin composition of the present invention has a shear rate within the range of 0.1 to ^{1 s −1} . The thixotropy coefficient determined by the following mathematical formula 1 from the respective viscosities at arbitrary shear rates D ₁ and D ₂ is within the range of 1.1 to 10. The shear rate is generally selected as D ₂ =D ₁ ×10.

The active energy ray-curable resin composition of the present invention, within the range of combination of apparent viscosity and thixotropic coefficient, by adjusting the apparent viscosity and thixotropy coefficient, dischargeability, shape retention of the bead-shaped discharge body, low diameter. It is possible to variously adjust the balance of the expansiveness (shape accuracy) and the strength of elasticity against the tensile stress at the time of application. The adjustment of the apparent viscosity and the thixotropy coefficient, for example, in the case of discharging and coating at a low pressure, the thixotropy coefficient so that the shape of the bead-shaped discharge body coated while adjusting the apparent viscosity to the lower limit side is maintained. When the composition is adjusted, on the other hand, when coating is performed by discharging at a high pressure, the apparent viscosity is adjusted to the upper limit side, and the thixotropic coefficient that reduces the apparent viscosity in the high shear rate region is adjusted to suppress the radial expansion. do it. If the combination of the apparent viscosity and thixotropy coefficient of the present invention deviates from the range, the effects of the present invention are difficult to obtain. Specifically, when the apparent viscosity is less than 10 Pa·s and the thixotropy coefficient is less than 1.1, ejection is facilitated, but it is unfavorable because it excessively flows after ejection and the shape retention is poor. Further, when the apparent viscosity is more than 5000 Pa·s and the thixotropy coefficient is more than 10, the discharge pressure becomes high and the discharge becomes difficult. In addition, the tensile stress at the time of coating tends to cause breakage and the diameter expansion may occur. It is not preferable because it becomes easier.

6. Physical Properties of Cured Product of Active Energy Ray-Curable Resin Composition A cured product obtained by irradiating the active energy ray-curable resin composition of the present invention with active energy rays to cure has an E hardness (JIS K6253 compliant) of 50 or less. And the loss coefficient at 10 Hz in dynamic viscoelasticity measurement (according to JIS K7244-10) is 0.3 or more. When the cured product falls within this range of physical properties, it has low hardness and low repulsion, and exhibits excellent buffering properties and vibration damping properties. Further, since the compression set can be reduced by appropriately adjusting the compounding components of the polymerizable monomer (B), it is also suitable as a sealing material. Particularly when applied to a sealing material, the compounding component of the active energy ray-curable resin composition is adjusted so that the value of compression set is 50% or less, more preferably 45% or less, and further preferably 30% or less. do it.

7. Container filled with active energy ray-curable resin composition The active energy ray-curable resin composition of the present invention is used for forming a sealing material or the like in a state of being filled in a container. The container in the present invention is a container in which the active energy ray-curable resin composition of the present invention is filled/enclosed in the container and is sold as a “container in which the active energy ray-curable resin composition is filled/enclosed”. For example, a syringe, a tube, etc. can be mentioned. Therefore, the container according to the present invention is provided with a fluid storage portion, a fluid inlet, a fluid outlet, a piston or impeller for injecting/injecting the fluid, a cap or a seal, etc., and can store the fluid. Included is a container having the capability of pouring and/or dispensing a quantity. This container is further used with a needle-shaped coating portion that can be discharged in a bead shape, but the needle-shaped coating portion may be attached to the container in advance, or it is integrally formed. May be. Further, when the active energy ray curable resin is an ultraviolet curable resin, it is preferable to use a light shielding container in order to prevent curing of natural light by ultraviolet rays.

The container filled with the active energy ray-curable resin composition may be provided with one selected from a fluid inlet, a fluid outlet, a piston or an impeller for injecting or injecting a fluid, a cap, a seal and the like. The most frequently used ones are containers such as syringes and tube-shaped containers. For example, in the case of a tube type container, a type that has a fluid inlet and a fluid outlet, a type that has both a fluid inlet and a fluid outlet and has only one outlet, and an initial fluid inlet and a fluid outlet A type that closes the fluid injection port and leaves only the fluid injection port after injecting the fluid while holding it, a type that initially has a fluid injection port and a fluid injection port, but closes both after injecting the fluid, a fluid injection There are various types of means for closing the inlet and the fluid outlet, such as a type selected from a stopper, a cap with a rotary groove, heat sealing, or sticking of a seal. The container includes heating means, cooling means, decompression means, pressurization means, suction means, evaporation means, motor, hydraulic means, pneumatic means, metering means, dustproof means, handling assisting means, display means, generated gas releasing means. A backflow prevention means, a temperature detection means, or the like may be provided together.

8. Method for producing active energy ray-curable resin composition The active energy ray-curable resin composition for a sealant of the present invention is produced by a known method for producing a resin composition. Specifically, for example, a kneader such as a single screw extruder, a twin screw extruder, a kneader, a Banbury mixer or a roll mill is used, and a photopolymerizable oligomer (A), a photopolymerizable monomer (B) and a photopolymerizable monomer (B) are used. It is manufactured by adding the thixotropy imparting agent (D) to a resin material obtained by kneading the initiator (C) and uniformly dispersing the thixotropy imparting agent.

9. Sealing material using active energy ray-curable resin composition and method for producing the same The active energy ray-curable resin composition of the present invention is discharged in a bead form from a needle-shaped coating section by a pressurizing means to form a bead-like discharge body. Simultaneously or subsequently, the bead-shaped ejection member is irradiated with an active energy ray to be cured to form a bead-shaped sealing material. Since the sealing material of the present invention has good sealing properties and low hardness and low repulsion, it can be stably used without distorting the housing due to the repulsive force of the sealing material. Further, since the compression set is small and the sealing property is excellent in reliability over time, it is suitable as a sealing material for a small and thin casing.

The method for manufacturing the sealing material will be described in detail with reference to FIG. 1 as an example. FIG. 1(a) shows a front view of a coating apparatus 9 for producing the bead-shaped sealing material 1, and FIG. 1(b) shows a right side view thereof. As shown in these FIGS. 1(a) and 1(b), the container 5 filled with the active energy ray-curable resin composition of the present invention can be three-dimensionally moved and controlled in the XYZ axis directions. It is attached to the coating device 9. In the present embodiment, the container 5 is supplied with high-pressure air as a pressurizing means via the pressurized air supply pipe 90. As shown in FIGS. 1( a) to 1 (c ), the container 5 including the needle-shaped coating part 4 moves according to a seal-shaped drawing pattern programmed in the three-dimensional coating device 9 in advance, The active energy ray-curable resin composition for a sealing material is discharged in a bead form from the needle-shaped coating part 4 provided at the lower end of 5 onto the surface of the substrate 20 to be coated placed on the sample stage (stage) B. To form the bead-shaped ejection body 10. Next, the bead-shaped ejection body 10 is irradiated with the active energy rays from the active energy ray irradiation unit 8 to crosslink the active energy ray-curable resin composition for a sealing material that constitutes the bead-shaped ejection body 10 to form a bead-shaped ejection body. 10 is cured and the sealing material 1 is obtained. As the pressurizing means for discharging the active energy ray-curable resin composition for a sealing material from the needle-shaped coating portion 4 of the container 5, a pressurized air type using high pressure air is illustrated in FIG. 1, but a hydraulic or gear pump type is used. Known materials can be applied. The bead-shaped ejection member 10 can be cured by irradiation with active energy rays at any time after ejection, but from the viewpoint of maintaining the shape of the bead-shaped ejection member 10, a needle-shaped coating that forms the bead-shaped ejection member. It is preferable that the discharge from the working unit 4 is almost the same time. Further, in the case of manufacturing a higher sealing material, the bead-shaped ejection bodies 10 may be applied twice so that the bead-shaped ejection bodies are superposed on the formed bead-shaped ejection bodies so that the bead-shaped ejection bodies 10 are stacked in two stages. The shape and diameter of the bead-shaped sealing material can be adjusted by the discharge hole diameter of the needle-shaped coating portion and the coating conditions. The inner diameter (in the case of a circle) of the discharge hole of the needle-shaped coating portion can be appropriately selected depending on the application, but if it is 1 mm or less, the action and effect of the present invention is predominantly exhibited as compared with the prior art, and 0.75 mm or less , And more preferably, it is remarkably exhibited at 0.5 mm or less. The coating conditions include the discharge speed from the needle-shaped coating portion and the moving speed of the needle (more precisely, the moving speed of the needle discharge port). The discharge speed from the needle is appropriately adjusted by the viscosity and the thixotropy coefficient of the active energy ray-curable resin composition, but since the discharge speed depends on the discharge pressure, if the discharge speed is too high (the discharge pressure is too large. However, since the bead-shaped discharge body is twisted or shaken during discharge, the discharge state becomes unstable, and problems such as large radial expansion (swell) easily occur, which is not preferable. The moving speed of the needle-shaped coating part is appropriately adjusted in balance with the discharging speed. As the moving speed becomes higher than the discharging speed, the bead-shaped discharging body and the needle-shaped coating material discharged onto the substrate to be coated are adjusted. Although the tensile stress applied to the bead-shaped discharge body is increased between the discharge port of the working part and the active energy ray-curable resin composition of the present invention, since it has a strong elasticity, the moving speed is higher than that of the conventional product. can do. Further, by utilizing the advantage of the strength of the body, the moving speed of the needle-shaped coating portion may be increased and the tensile stress may be intentionally applied to reduce the diameter of the bead-shaped discharge body. .. However, if the moving speed is too high, the bead-shaped ejection body is cut, or the diameter of the bead-shaped ejection body becomes extremely small, and the bead-shaped sealing material does not function, which is not preferable.

10. A cushioning material using the active energy ray-curable resin composition and a method for producing the same. The active energy ray-curable resin composition of the present invention is discharged in a bead shape or a dot shape from a needle-shaped coating section by a pressure means. A buffer material can be formed at a desired position by irradiating the ejection body with an active energy ray and curing it as a body simultaneously or subsequently. Since the cushioning material of the present invention has a large loss coefficient, it has excellent cushioning performance. The method of adjusting the shape and diameter of the pressurizing means and the cushioning material are the same as those of the above-mentioned sealing material, and will be omitted.

11. Other Uses of Cured Product of Active Energy Ray-Curable Resin Composition The cured product of the active energy ray-curable resin composition of the present invention is a bead from at least two acting members from a needle-shaped coating portion by a pressing means. The discharge bodies in the form of dots or dots, and at the same time or subsequently, by irradiating the discharge bodies with an active energy ray to cure, various functions, for example, waterproof, dustproof, vibration-proof, It can also be suitably applied to applications such as vibration damping, stress relaxation, gap complementation, rattling prevention, deviation prevention, and collision noise reduction. Further, the structure is not limited to the case of being arranged between the two action members, and for example, a structure in which a plurality of bead-shaped or dot-shaped cured coatings are arranged on the surface of the casing by the CIP method, and impacts from the outside collide with each other. It is also effective for the purpose of exerting a cushioning effect when it is used, or for the application of one side open form, such as when applied to the structure that exerts sealing property or cushioning property only when opposing members come close to each other. ..
Further, the excellent coatability of the active energy ray-curable resin composition of the present invention is remarkably exhibited when the inner diameter of the discharge hole of the needle-shaped coating portion is 1 mm or less. Even when the inner diameter of the discharge hole exceeds 1 mm, it is excellent in coating properties, shape retention properties, low rebound after curing, buffer properties, and the like, and therefore can be suitably applied to such applications.

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

Table 1 shows the specifications of the photopolymerizable oligomer (A), the photopolymerizable monomer (B), the photopolymerization initiator (C), and the thixotropy imparting agent (D) used in Examples and Comparative Examples described below. ~ Shown in Table 4. The weight average molecular weight of each of the materials A-1 to A-3 of the photopolymerizable oligomer (A) shown in Table 1 is a measured value by a gel permeation chromatography (GPC) method, and specifically, as a measuring device, SHODEX. Manufactured by GPC-104 (separation column LF-404 (three connected), guard column LF-G, RI detector RI-74S (both manufactured by SHODEX)), tetrahydrofuran as an eluent, and a sample concentration of 10 mg. /4 mL, eluent flow rate 0.3 mL/min, and column temperature 40° C.

The photopolymerizable monomer (B) shown in Table 2 was prepared using the material B-1 (n=0) or the material B-2 (n=1) as the first (meth)acryloyl compound (b1), respectively. Material B-3 as the (meth)acryloyl compound (b2), Material B-4 as the third (meth)acryloyl compound (b3), and Material B-as the fourth (meth)acryloyl compound (b4) 5 (r=3, corresponding to the (meth)acryloyl compound (b4-1)) and the material B-6 (r=13, corresponding to the (meth)acryloyl compound (b4-2)) were B- A mixture of 5:B-6=64:36 was used, the material B-7 was used as the fifth (meth)acryloyl compound (b5), and the sixth alkyl(meth)acrylate compound (b6) was used. The material B-8 was used, and the material B-9 was used as another acryloyl compound. Of these, the material B-1, m-phenoxyphenyl acrylate, was produced and used in an amount required in the following Examples and Comparative Examples. As a specific production method, 200 mL of acetone is put in a 500 mL eggplant-shaped flask, 18.62 g of m-phenoxyphenol and 7.455 g of potassium chloride are added with stirring, and the solvent is added after refluxing for 2 hours. Evaporation gave a powder. The obtained powder was dispersed in 100 mL of tetrahydrofuran in a 500 mL eggplant-shaped flask while stirring, and then stirred with 9.051 g of acryloyl chloride at 70° C. for 12 hours under reflux and then the solvent under reduced pressure. Was distilled off to obtain m-phenoxyphenyl acrylate of material B-1. For m-phenoxyphenol and potassium chloride, reagent products manufactured by Sigma-Aldrich were used, and for acetone and tetrahydrofuran, anhydrous products manufactured by Tokyo Kasei were used.

As the photopolymerizable initiator (C) in the following examples and comparative examples, a mixture of the materials C-1 and C-2 shown in Table 3 at C-1:C-2=1:1 is used. I was there.

The method for measuring the physical properties of the resin composition (uncured product) and the cured product and the method for evaluating the effect thereof in Examples and Comparative Examples are as follows.
(1) Apparent Viscosity According to JIS Z8803 (conical-flat-plate rotational viscometer), a Brookfield cone-plate viscometer DT-3T is used, and the apparent viscosity at 25° C. is 1.0 s ⁻¹ . The viscosity was measured.

(2) Thixotropy coefficient The thixotropy coefficient was calculated using the above mathematical formula 1 from the apparent viscosities at shear rates of 0.1 s ⁻¹ and 1.0 s ⁻¹ measured by the same measurement method as in (1) Apparent viscosity.

(3) Loss factor (buffer)
An active energy ray-curable resin composition was formed into a sheet on a transparent PP film so as to have a thickness of 2 mm after curing, and was irradiated with ultraviolet rays of 365 Jm at ² J/cm ² each from the top and bottom to cure the resin composition. .. A sheet-shaped cured product having a thickness of 2 mm was punched out into a diameter of 29 mm and molded to obtain a measurement sample. For the measurement, a rheometer (ARES-G2, manufactured by TA Instruments Japan Co., Ltd.) was used to measure the loss coefficient at 25° C. and 10 Hz (according to JIS K7244-10). The cushioning property is evaluated from the measured loss factor. When the loss factor is 0.3 or more, the cushioning property is "○" (good), and when the loss factor is less than 0.3, the buffering property is "x" (non-conforming). I decided.

(4) Hardness (flexibility)
An active energy ray-curable resin composition was formed into a sheet shape on a transparent PET film so that the thickness after curing was 2 mm, and ultraviolet rays of 365 nm were irradiated from the top surface and the bottom surface at ² J/cm ² each to be cured. .. Five sheet-shaped cured products having a thickness of 2 mm thus obtained were stacked to obtain a measurement sample. The E hardness was measured by using a type E durometer according to JIS K6253. The flexibility was evaluated from the measured E hardness, and the flexibility was evaluated as “◯” (pass: good) when the E hardness was 50 or less, and the flexibility was “x” (failed) when the E hardness was over 50. ..

(5) Compression set The active energy ray-curable resin composition was cast into a transparent resin mold having a diameter of 13 mm and a height of 6.3 mm, and ultraviolet rays of 365 nm were respectively irradiated from the top and bottom surfaces at ² J/cm ^2. The cured product was used as a measurement sample. In accordance with JIS K-6262, the strain rate after holding for 23 hours under a 25% compression condition in a temperature environment of 70° C. was measured and evaluated, and when the compression set was 45% or less, “◯” (pass: good), 45 The case of more than% was judged as "x" (fail).

(6) Diameter accuracy: reduction in diameter expansion (Swell) of the bead-shaped discharge body A light-shielding syringe in which a needle having an inner diameter of 0.5 mm has a circular cross-sectional shape of the discharge port is filled with an active energy ray-curable resin composition The prepared container was attached to an air pressure type dispensing device (Model Shotmaster (registered trademark) 200DS manufactured by Musashi Engineering Co., Ltd.) to which an ultraviolet irradiation device was attached. By applying air pressure of 150 kPa, the active energy ray-curable resin composition was discharged from a needle having an inner diameter of 0.5 mm to form a bead-shaped ejection body, and at the same time, UV irradiation was performed to obtain a bead-shaped cured material. The cross-sectional outer diameter (coating width) of the bead-shaped cured product was measured with a microscope (MM-800/LFA, magnification: 20 times, manufactured by Nikon Corporation), and the ratio ODb/ of the discharge needle inner diameter IDn and the bead-shaped cured product outer diameter ODb/ It was evaluated by IDn. When the ratio was 1.5 or less, the diameter accuracy was “◯” (pass: good), and when the ratio was more than 1.5, the diameter accuracy was “x” (fail).

(7) Coatability (Dischargeability)
An air pressure type dispensing device in which a container filled with an active energy ray-curable resin composition in a light-shielding syringe equipped with a needle having an ejection port having a circular cross-sectional shape and an inner diameter of φ0.5 mm is provided with an ultraviolet irradiation device ( It was attached to a model shot master (registered trademark) 200DS manufactured by Musashi Engineering Co., Ltd. While applying an air pressure of 150 kPa, the active energy ray-curable resin composition was discharged in a bead shape at 16 mm/s from a needle having an inner diameter of 0.5 mm, and the needle was moved at a speed of 15 mm/s. A bead-shaped discharge body having the pattern shown was formed. At this time, when the active energy ray-curable resin composition can be ejected from the needle at 16 mm/s, the coatability is "○" (pass: good), and the ejection is possible, but the needle moving speed (15 mm/s) Also, the composition having a low discharge speed and a bead-shaped discharge body that easily extends has a coating property of “△” (pass: acceptable), and the composition having a significantly low discharge speed or a composition that is difficult to discharge has a coating property of “x” ( Rejected).

(8) Shape-retaining property of bead-shaped ejection body in an uncured state A container in which an active energy ray-curable resin composition is filled in a light-shielding syringe in which a needle having an ejection port having a circular cross-sectional shape and an inner diameter of 0.5 mm is mounted Was attached to an air pressure type dispensing device (Model Shotmaster (registered trademark) 200DS manufactured by Musashi Engineering Co., Ltd.) to which an ultraviolet irradiation device was attached. A bead-shaped ejection body was formed on a glass plate (Soda glass manufactured by Hiraoka Glass Co., Ltd.) at the same speed as the ejection speed of the active energy ray-curable resin composition from a needle having an inner diameter of 0.5 mm and the moving speed of the needle. .. The bead-shaped discharge body was left to stand for 30 seconds, and the shape change (degree of sagging) of the bead-shaped discharge body was observed. As an evaluation standard, the width and height of the bead-shaped discharge body were measured with a microscope (MM-800-LFA manufactured by Nikon), and the ratio of the line height to the line width (height/width) was 0.9 to. In the case of 1, the shape retention is "◎" (pass: excellent), in the case of 0.8 to less than 0.9, the shape retention is "○" (pass: good), 0.5 to less than 0.8. In this case, the shape retention was “Δ” (pass: acceptable), and when it was less than 0.5, the shape retention was “x” (failed).

[Example 1]
In a plastic container with a lid, as shown in Table 5, 15 parts by mass of the material A-1 as the photopolymerizable oligomer (A) and the first (meth)acryloyl compound (b1) constituting the photopolymerizable monomer (B) were used. ) As material B-1 (n=0) in 17 parts by mass, second (meth)acryloyl compound (b2) as material B-3 in 67.2 parts by mass, third (meth)acryloyl compound (b3) As a material B-4, 0.8 parts by mass was used, and the total amount of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B) was 100 parts by mass. To this, 1.0 part by mass of a mixture of materials C-1 and C-2 at a mass ratio of 1:1 as a photopolymerizable initiator (C), and material D-1 as a thixotropy-imparting agent (D). 6.4 parts by mass were added. Next, this mixture was kneaded at 2000 rpm for 3 minutes using a rotation/revolution mixer (product name: Awatori Rentaro (registered trademark) ARE-250, a product of Shinky Co., Ltd.) to cure the active energy ray-curable resin. A composition was obtained. A part of this active energy ray-curable resin composition was filled in a light-shielding syringe having an internal volume of 50 mL, and a centrifugal defoaming machine for syringe (product name: Awatron (registered trademark) AW-50, product of Musashi Engineering Co., Ltd.) was used. Defoaming treatment was performed to prepare a container filled with the active energy ray-curable resin composition, which was used as a sample for evaluation of diameter accuracy, coatability, and shape retention of the bead-shaped discharge body. On the other hand, the remaining active energy ray-curable resin composition that was not filled in the light-shielding syringe was used as a sample for measuring apparent viscosity, thixotropy coefficient, loss coefficient, hardness and compression set. The physical properties of the active energy ray-curable resin composition obtained in Example 1 were measured and evaluated using these samples.

[Examples 2 to 6]
The active energy ray-curable resin compositions of Examples 2 and 3 and the container filled with the same were obtained in the same manner as in Example 1 except that the respective components were blended as shown in Table 5. Further, the same method as in Examples 1 to 3 was performed except that the material B-2 (n=1) was used as the first (meth)acryloyl compound (b1) constituting the photopolymerizable monomer (B). The active energy ray-curable resin compositions of Examples 4 to 6 and the container filled with them were obtained. The physical properties of the respective active energy ray-curable resin compositions obtained in Examples 2 to 6 were measured and evaluated in the same manner as in Example 1. The results are shown in Table 5.

[Examples 7 to 12]
In a plastic container with a lid, as shown in Table 6, 10 parts by mass of the material A-1 as the photopolymerizable oligomer (A) and the first (meth)acryloyl compound (b1) constituting the photopolymerizable monomer (B) were used. 18) by mass of the material B-1 (n=0) as a) and a mixture of the materials B-5 and B-6 as the fourth (meth)acryloyl compound (b4) at a mass ratio of 64:36. 2 parts by mass, 4.8 parts by mass of the material B-7 as the fifth (meth)acryloyl compound (b5) are taken, and the total amount of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B) is 100 parts by mass. Part and To this, 1.0 parts by mass of a mixture of materials C-1 and C-2 as a photopolymerizable initiator (C) at a mass ratio of 1:1 and material D-2 as a thixotropy imparting agent (D) were added. 9 parts by mass was added. This mixture was kneaded in the same manner as in Example 1 to obtain the active energy ray-curable resin composition of Example 7 and a container filled with the same. Further, the active energy ray-curable resin compositions of Examples 8 to 9 and containers filled with the same were obtained in the same manner as in Example 7, except that the components were mixed as shown in Table 6. Moreover, it implemented by the method similar to Example 7-9 except having used the material B-2 (n=1) as a 1st (meth)acryloyl compound (b1) which comprises a photopolymerizable monomer (B). The active energy ray-curable resin compositions of Examples 10 to 12 and containers filled with them were obtained. In the same manner as in Example 1, the physical properties of the active energy ray-curable resin compositions obtained in Examples 7 to 12 were measured and evaluated. The results are shown in Table 6.

[Examples 13 to 18]
In a plastic container with a lid, as shown in Table 7, 15 parts by mass of the material A-1 as the photopolymerizable oligomer (A) and the first (meth)acryloyl compound (b1) constituting the photopolymerizable monomer (B) were used. 17 parts by mass of the material B-1 (n=0), 0.8 parts by mass of the material B-4 as the third (meth)acryloyl compound (b3), and 67 parts of the material B-9 as the other acryloyl compound. .2 parts by mass, and the total amount of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B) was 100 parts by mass. To this, 1.0 parts by mass of a mixture of materials C-1 and C-2 as a photopolymerizable initiator (C) at a mass ratio of 1:1 and material D-2 as a thixotropy imparting agent (D) were added. 9 parts by mass was added. This mixture was kneaded in the same manner as in Example 1 to obtain the active energy ray-curable resin composition of Example 13 and a container filled with the same. Further, the active energy ray-curable resin compositions of Examples 14 to 15 and the container filled with the same were obtained in the same manner as in Example 13 except that the components were mixed as shown in Table 7. Moreover, it implemented by the method similar to Examples 13-15 except having used the material B-2 (n=1) as a 1st (meth)acryloyl compound (b1) which comprises a photopolymerizable monomer (B). The active energy ray-curable resin compositions of Examples 16 to 18 and containers filled with them were obtained. In the same manner as in Example 1, the physical properties of each active energy ray-curable resin composition obtained in Examples 13 to 18 were measured and evaluated. The results are shown in Table 7.

[Examples 19 to 22]
In a plastic container with a lid, as shown in Table 8, 15 parts by mass of the material A-2 as the photopolymerizable oligomer (A) and the first (meth)acryloyl compound (b1) constituting the photopolymerizable monomer (B) were used. ) As material B-1 (n=0) in 34 parts by mass, second (meth)acryloyl compound (b2) as material B-3 in 50.4 parts by mass, third (meth)acryloyl compound (b3) As a material B-4, 0.6 parts by mass was used, and the total amount of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B) was 100 parts by mass. To this, 1.0 part by mass of a mixture of materials C-1 and C-2 at a mass ratio of 1:1 as a photopolymerizable initiator (C), and material D-1 as a thixotropy-imparting agent (D). 6.4 parts by mass were added. This mixture was kneaded in the same manner as in Example 1 to obtain the active energy ray-curable resin composition of Example 19 and a container filled with the same. Further, the active energy ray-curable resin compositions of Examples 20 to 22 and the container filled with the same were obtained by the same method as in the above-mentioned example except that the components were mixed as shown in Table 8. In the same manner as in Example 1, the physical properties of each active energy ray-curable resin composition obtained in Examples 19 to 22 were measured and evaluated. The results are shown in Table 8.

[Examples 23 to 28]
The active energy ray-curable resin compositions of Examples 23 to 24 and Examples 26 to 27 and the container filled with the same were prepared in the same manner as in the above Example, except that the respective components were blended as shown in Table 9. Obtained. Further, in a plastic container with a lid, as shown in Example 25 in Table 9, 20 parts by mass of the material A-1 as the photopolymerizable oligomer (A) and the first (constituting the photopolymerizable monomer (B)) were used. 32 parts by mass of the material B-1 (n=0) as the (meth)acryloyl compound (b1), 47.44 parts by mass of the material B-3 as the second (meth)acryloyl compound (b2), and the third (meth) ) 0.56 parts by mass of the material B-4 was used as the acryloyl compound (b3), and the total amount of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B) was 100 parts by mass. 5.26 parts by mass of the material D-3 as a thixotropy-imparting agent (D) was added thereto, the mixture was allowed to stand at 100° C. for 15 minutes, and the contents were stirred while the thixotropy-imparting agent (D) was melted. After cooling to room temperature, 1.0 part by mass of a mixture of materials C-1 and C-2 at a mass ratio of 1:1 was added as a photopolymerizable initiator (C), and the mixture was rotated/revolved. (Product name: Awatori Rentaro (registered trademark) ARE-250, product of Shinky Co., Ltd.) was kneaded at 2000 rpm for 3 minutes to obtain an active energy ray-curable resin composition of Example 25. Further, an active energy ray-curable resin composition of Example 28 and a container filled with the same were obtained in the same manner as in Example 25, except that the components were blended as shown in Example 28 of Table 9. .. In the same manner as in Example 1, the physical properties of the active energy ray-curable resin compositions obtained in Examples 23 to 28 were measured and evaluated. The results are shown in Table 9.

[Examples 29 to 49]
The active energy ray-curable resin compositions of Examples 29 to 49 and the container filled with the same were obtained in the same manner as in Example 1 except that the respective components were blended as shown in Tables 10 to 14. In the same manner as in Example 1, the physical properties of each active energy ray-curable resin composition obtained in Examples 29 to 49 were measured and evaluated. The results are shown in Tables 10-14.

[Comparative Examples 1 to 25]
The active energy ray-curable resin compositions of Comparative Examples 1 to 21 and Comparative Examples 23 to 24 and the same are filled in the same manner as in Example 1 except that the respective components are blended as shown in Tables 15 to 19. Got a container. Further, the active energy ray-curable resin compositions of Comparative Example 22 and Comparative Example 25 and the same were prepared in the same manner as in Example 25, except that the respective components were blended as shown in Comparative Example 22 and Comparative Example 25 of Table 19. A container filled with was obtained. The physical properties of the respective active energy ray-curable resin compositions obtained in Comparative Examples 1 to 25 were measured and evaluated in the same manner as in Example 1. The results are shown in Tables 15 to 19.

From the evaluation results of Examples 1 to 49 shown in Tables 5 to 14, the active energy ray-curable resin composition of the present invention is excellent in diameter accuracy, needle coatability and shape retention, and the cured product is E It was found that the hardness was 50 or less and the loss coefficient was 0.3 or more, and the flexibility and the cushioning property were excellent. In addition, although not described in the evaluation column of Tables 5 to 9, the active energy ray-curable resin compositions of Examples 1 to 25 are needles for evaluation of diameter accuracy, coatability and shape retention. Even when the coating was performed using a needle having an inner diameter of φ1 mm, the same result was obtained as when a needle having an inner diameter of φ0.5 mm was used. Further, it has been found that the compression set can be reduced by adjusting the constituent components and the mixing ratio thereof within the range of the constitution of the present invention. The configuration of the present invention and its effects will be described in detail with reference to the results of this example and comparative examples.

(1) About Photopolymerizable Monomer (B) Consists of a first (meth)acryloyl compound (b1), a second (meth)acryloyl compound (b2) and a third (meth)acryloyl compound (b3). Comparison of evaluation results of Example group (Examples 1 to 6, 19 to 20, 23 to 25, 29 to 30, 33 to 34 and 37 to 38) and Comparative Example 1, evaluation result of Example 39 and Comparative Example 2 Of the evaluation results of Example 40 and Comparative Example 3, the (meth)acryloyl compound (b1) as the photopolymerizable monomer (B), the fourth (meth)acryloyl compound (b4) and the fifth ( (Meth)acryloyl compound (b5) as a group of examples (Examples 7 to 12, 21 to 22, 26 to 28, 31 to 32, 35 to 36, 41 to 49) and Comparative Example 4 In comparison, Examples 13 to 18 and Comparative Example 5 in which the first (meth)acryloyl compound (b1) as a photopolymerizable monomer (B) and 2-ethylhexyldiethylene glycol acrylate as another acryloyl compound were the main components. From the comparison of the evaluation results of 1., since the photopolymerizable monomer (B) contains the first (meth)acryloyl compound (b1), the loss factor of the cured product is improved, and the other (meth)acryloyl compound having a different structure is obtained. It was found that the same effect can be obtained even when the photopolymerizable monomer (B) is constituted by combining the components. Further, from the evaluation results of Examples 1 to 49, the loss coefficient of the cured product is improved regardless of whether n in Formula 1 is 0 or 1 as the (meth)acryloyl compound (b1) of Formula 1 above. I understood it. Moreover, the comparison of the evaluation results of Examples 1 to 3 and Comparative Examples 6 to 7 in which the addition amount of the first (meth)acryloyl compound (b1) was changed, and the results of Examples 10 to 12 and Comparative Examples 8 to 9 were compared. From the comparison of the evaluation results, when the content of the first (meth)acryloyl compound (b1) is less than 20% by mass, the effect of improving the loss factor is small, and when it exceeds 60% by weight, the hardness becomes too high. It has been found that the range is preferably 20 to 60 mass% of the total mass of the photopolymerizable monomer (B).

(2) Photopolymerizable Oligomer (A) From the comparison of the evaluation results of Examples 19 to 22 and Comparative Examples 10 to 13 in which the molecular weight of the photopolymerizable oligomer (A) is different, the active energy ray curability of the present invention is shown. It has been found that the molecular weight of the photopolymerizable oligomer (A) used in the resin composition is preferably 5,000 or more because the loss coefficient is decreased and the hardness becomes too high when the molecular weight is less than 5,000.

(3) Regarding the range of (A+B)/(A+B+C) From the comparison of the evaluation results of Example 2 and Comparative Example 14 and the comparison of the evaluation results of Example 11 and Comparative Example 15, the photopolymerizable oligomer (A), The total content (A+B) of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B) based on the total mass (A+B+C) of the photopolymerizable monomer (B) and the photopolymerization initiator (C) is 99.99% by mass. It was found that if the amount exceeds 9% by mass, the compounding amount of the photopolymerization initiator (C) is too small and the curing due to irradiation with active energy rays does not proceed sufficiently. When the value of (A+B)/(A+B+C) is less than 85% by mass, the photopolymerization initiator (C) is excessively contained in the resin composition, so that the unreacted polymer structure after curing does not react. It was observed that the photopolymerization initiator of No. 1 remained and the photopolymerization initiator contained in the cured product volatilized to generate outgas. Therefore, it was found that (A+B)/(A+B+C) should be in the range of 85% by mass to 99.99% by mass.

(4) About the range of B/(A+B) From the comparison of the evaluation results of Examples 33 to 36 and Comparative Examples 16 to 19, the total mass (A+B) of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B) was obtained. When the content of the photopolymerizable monomer (B) with respect to (4) is less than 80% by mass, the hardness of the cured product is too large, and when it exceeds 99% by mass, the compression set becomes large, and therefore 80 to 99% by mass. It has been found that the range is preferable.

(5) Regarding the range of D/(A+B+C) Based on the evaluation results of Example 2 and Comparative Examples 21 to 22 and the evaluation results of Example 11 and Comparative Examples 23 to 24, addition of the thixotropy imparting agent (D) When the ratio is less than 1% by mass based on 100 parts by mass of the total (A+B+C) of the photopolymerizable oligomer (A), the photopolymerizable monomer (B) and the photopolymerization initiator (C), the viscosity of the resin composition And the thixotropy coefficient becomes too low, the shape retention and diameter accuracy of the bead-shaped discharge body deteriorate, and when it exceeds 40% by mass, the viscosity becomes too high, the coatability decreases, and the hardness of the cured product increases. Therefore, it was found that it is preferable to set the content in the range of 1 to 40 parts by mass because the loss coefficient decreases. Further, from the evaluation results of Example 25 and Example 28, the effect of the present invention can be obtained regardless of whether silica fine particles are used or amide wax is used as the thixotropy-imparting agent (D). Do you get it.

(6) Viscosity and thixotropy coefficient in uncured state When the evaluation results of Comparative Examples 20 to 25 are examined, in the uncured state of the resin composition, the shear rate of the active energy ray-curable resin composition is 1 s ^-1 . When the thixotropy coefficient in the viscosity range of 10 to 5000 Pa·s and 0.1 to ¹ s ⁻¹ is out of the range of 1.1 to 10, the coatability of the resin composition and the shape-retaining property and diameter of the bead-shaped discharge body are obtained. It has been found that it is necessary to be within the scope of the present invention because the accuracy decreases.

(7) Combination of (meth)acryloyl compound (b1) with other (meth)acryloyl compound Example in which the photopolymerizable monomer (B) further contains a second (meth)acryloyl compound (b2) And the loss factors in the evaluation results of the examples containing the fourth (meth)acryloyl compound (b4) and the fifth (meth)acryloyl compound (b5) as the constitution of the photopolymerizable monomer (B). Then, it was found that the resin composition containing the second (meth)acryloyl compound (b2) exhibited an excellent loss coefficient value. On the other hand, the resin composition further containing the fourth (meth)acryloyl compound (b4) and the fifth (meth)acryloyl compound (b5) is more compressed than the resin composition further containing the (meth)acryloyl compound (b2). It was found that the permanent set was improved.

(8) About the range of b3/(b2+b3) From the evaluation results of Example 2 and Examples 37 to 40, the mixing ratio of the third (meth)acryloyl compound (b3) contained in the photopolymerizable monomer (B) was determined to be It has been shown that compression set is reduced with increasing size. From the viewpoint of reducing the hardness and flexibility of the cured product and also reducing the compression set, the blending ratio of the (meth)acryloyl compound (b3) to the total mass (b2+b3) of the third (meth)acryloyl compound (b3) is It has been found that a range of 0.1-5% by weight is preferred.

(9) Range of b6/(b4+b5+b6) From the evaluation results of Examples 45 to 49, the photopolymerizable monomer (B) was blended with the (meth)acryloyl compound (b4) and the (meth)acryloyl compound (b5). It was found that, by further adding the alkyl (meth)acrylate compound (b6), the compression set can be further reduced while keeping the loss coefficient high. And especially the compounding ratio of the alkyl (meth)acrylate compound (b6) is based on the total mass (b4+b5+b6) of the (meth)acryloyl compound (b4), the (meth)acryloyl compound (b5) and the alkyl (meth)acrylate compound (b6). On the other hand, it was found that 1 to 50 mass% is preferable.

The cured product of the active energy ray-curable resin composition of the present invention has a large loss coefficient and excellent buffering properties and vibration damping properties, as well as low hardness, high flexibility and low repulsion property, so that electronic devices incorporating the same, etc. The impact resistance can be improved and it contributes to the improvement of quality. Further, the active energy ray-curable resin composition of the present invention is preferably used for forming a bead-shaped or dot-shaped sealing material or cushioning material by needle coating, such as a sealing material or cushioning material in a narrow space portion. It is ideal for forming a device, and contributes to downsizing and cost reduction of electronic devices that incorporate it.

DESCRIPTION OF SYMBOLS 1 Bead-shaped sealing material 10 Bead-shaped discharge body 11 Active energy ray curable resin composition 4 Needle-shaped coating part 5 Container filled with active energy ray curable resin composition 8 Active energy ray irradiation unit 9 Three-dimensional control type Coater 90 Pressure air supply tube B Sample stand (stage)

Claims (9)

Contains a photopolymerizable oligomer (A), a photopolymerizable monomer (B), a photopolymerization initiator (C) and a thixotropy imparting agent (D),
The photopolymerizable oligomer (A) is a urethane (meth)acrylate having a mass average molecular weight of 5000 or more,
The photopolymerizable monomer (B) has a (meth)acryloyl compound (b1) represented by the following formula (1) (wherein R ₁ represents a hydrogen atom or a methyl group, and n represents 0 or 1). ) Is contained in an amount of 20 to 60% by mass based on the total mass of the photopolymerizable monomer (B),

The total content (A+B) of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B) is the photopolymerizable oligomer (A), the photopolymerizable monomer (B), and the photopolymerization initiator ( 94 to 99.99 mass% with respect to the total mass (A+B+C) of C),
The content of the photopolymerizable monomer (B) is 80 to 99 mass% with respect to the total mass (A+B) of the photopolymerizable oligomer (A) and the photopolymerizable monomer (B),
The thixotropy imparting agent (D) is 1 to 40 with respect to 100 parts by mass of the total (A+B+C) of the photopolymerizable oligomer (A), the photopolymerizable monomer (B) and the photopolymerization initiator (C). Includes parts by mass,
In the uncured state, the viscosity at a shear rate of 1 s ⁻¹ is 10 to 5000 Pa·s and the thixotropic coefficient is 1.1 to 10 in the range of a shear rate of 0.1 to ¹ s ^−1. Ray curable resin composition. The photopolymerizable monomer (B) further has the following formula (2) (in the formula, R ₂ represents a hydrogen atom or a methyl group, W ₁ represents an ethylene group or a propylene group, and p represents an integer of 0 to 4). The (meth)acryloyl compound (b2) represented by these is contained, The active energy ray curable resin composition of Claim 1 characterized by the above-mentioned.

The photopolymerizable monomer (B) further has the following formula (3) (in the formula, R ₃ represents a hydrogen atom or a methyl group, W ₂ represents an ethylene group or a propylene group, and q represents an integer of 1 to 20). (Meth)acryloyl compound (b3) represented by

The content of the (meth)acryloyl compound (b3) represented by the formula (3) is such that the (meth)acryloyl compound (b2) represented by the formula (2) and the (meth)acryloyl compound represented by the formula (3). It is 0.1 to 5 mass% with respect to the total mass (b2+b3) of the compound (b3), The active energy ray-curable resin composition according to claim 2. The photopolymerizable monomer (B) further includes
(Meth)acryloyl represented by the following formula (4) (in the formula, R ₄ represents a hydrogen atom or a methyl group, R ₅ represents an alkyl group, W ₃ represents an alkylene group, and r represents an integer of 1 to 20). A compound (b4),

Formula (5) (wherein, R ₆ is hydrogen or methyl, R ₇ is a methylene group including molecular weight 110 The following functional groups respectively.) Represented by (meth) acryloyl compound (b5) is Included,

The content of the (meth)acryloyl compound (b4) represented by the formula (4) is such that the (meth)acryloyl compound (b4) represented by the formula (4) and the (meth)acryloyl compound represented by the formula (5). 70-99 mass% with respect to the total mass (b4+b5) of the compound (b5), The active energy ray-curable resin composition according to claim 1. The photopolymerizable monomer (B) is further represented by the following formula (6) (in the formula, R ₈ represents hydrogen or a methyl group, and R ₉ represents an alkyl group having 5 or more carbon atoms). An alkyl (meth)acrylate compound (b6) is contained,

The content of the alkyl (meth)acrylate compound (b6) represented by the formula (6) is the (meth)acryloyl compound (b4) represented by the formula (4), or the (meth) represented by the formula (5). It is 1 to 50 mass% with respect to the total mass (b4+b5+b6) of the acryloyl compound (b5) and the alkyl (meth)acrylate compound (b6) represented by the above formula (6). Active energy ray curable resin composition of. The active energy ray according to any one of claims 1 to 5, wherein the thixotropy imparting agent (D) is silica fine particles, and the carbon content of the silica fine particles is less than 0.5% by mass. Curable resin composition. 7. The photopolymerization initiator (C) is composed of at least two kinds of compounds, and at least one kind is a phosphine compound or an aminoalkylphenone compound, 7. Active energy ray curable resin composition of. A sealing material comprising a cured product of the active energy ray-curable resin composition according to any one of claims 1 to 7. A cushioning material comprising a cured product of the active energy ray-curable resin composition according to any one of claims 1 to 7.

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