Energy ray curable polymer, energy ray curable resin composition containing the polymer, coating solution, resin film forming film, and method for producing laminate

Abstract

The present invention provides an energy ray curable resin composition that exhibits high uniformity during component mixing and possesses desired delayed curing properties and film-forming properties. [Solution] A newly synthesized energy-ray curable polymer having a (meth)acryloyl group and a group containing a β-dicarbonyl structure is used as the main component of the energy-ray curable resin composition.

Description

Technical Field

[0001] The present invention relates to an energy ray-curable polymer, an energy ray-curable resin composition containing the polymer, a coating solution, a resin film-forming film, and a method for producing a laminate. In particular, the present invention relates to an energy ray-curable resin composition exhibiting desired delayed curability and film-forming properties, a coating solution and a resin film-forming film containing the same, and a method for producing a laminate using the coating solution or the resin film-forming film. The present invention also relates to an energy ray-curable polymer used as a main component of such an energy ray-curable resin composition.

Background Art

[0002] A resin composition that cures by energy rays such as ultraviolet rays (energy ray-curable resin composition) is, for example, a composition in which a liquid composition changes (cures) to a solid composition by irradiation with energy rays. Since the step of drying the liquid is unnecessary, the energy ray-curable resin composition is used as an adhesive or a coating agent in various applications such as printing, medical, and beauty.

[0003] When energy rays reach the energy ray-curable component contained in the energy ray-curable composition, the curing reaction starts. Therefore, when the object to be adhered has a complex shape or a large thickness, there is a region in the composition where it is difficult for energy rays to reach, and the curing becomes insufficient.

[0004] Patent Document 1 discloses an active energy ray-curable composition characterized by containing a photo base generator, a double bond-containing compound, and a β-dicarbonyl compound. According to Patent Document 1, it is disclosed that this active energy ray-curable composition is not inhibited from curing by oxygen and the reaction proceeds and cures even after the light irradiation is finished.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] The active energy ray-curable composition of Patent Document 1 has the above advantages. However, in order for the curing reaction to proceed reliably, it is necessary to uniformly mix a photo-base generator, a double bond-containing compound, and a β-dicarbonyl compound. However, it is difficult to uniformly mix the three components, and when the mixing is insufficient, a good film may not be obtained when forming a resin film from the active energy ray-curable composition.

[0007] The present invention has been made in view of such a situation, and provides an energy ray-curable resin composition having high uniformity during component mixing, desired delayed curability and film-forming properties, a coating solution and a resin film-forming film containing the same, and a method for producing a laminate using the coating solution or the resin film-forming film.

MEANS FOR SOLVING THE PROBLEMS

[0008] Aspects of the present invention are as follows. (1) An energy ray-curable polymer having a (meth)acryloyl group and a group containing a β-dicarbonyl structure.

[0009] (2) The energy ray-curable polymer according to (1), having a weight average molecular weight of 50,000 or more.

[0010] (3) The energy ray-curable polymer according to (1), wherein the group containing the β-dicarbonyl structure is a group containing a β-ketoester structure.

[0011] (4) The energy ray-curable polymer according to (3), wherein the group containing the β-ketoester structure is a group containing an acetoacetic acid ester structure.

[0012] (5) The energy ray-curable polymer according to (1), which is solid at 23°C.

[0013] (6) An energy ray curable polymer according to any of (1) to (5) above, Including a photobase generator, Energy ray curable resin composition.

[0014] (7) The energy ray curable resin composition according to (6), wherein the photobase generator is a nonionic photobase generator.

[0015] (8) The energy ray curable resin composition according to (7), wherein the nonionic photobase generator has a group containing the structure shown in the following formula.

[0016] [ka] (In the formula, Rv, Rw, Rx, Ry, and Rz are organic groups.)

[0017] (9) A coating solution comprising the energy ray curable resin composition described in (6) above.

[0018] (10) A resin film-forming film made of the energy ray-curable resin composition described in (6) above.

[0019] (11) A step of applying the coating liquid described in (9) to at least one of the first adherend and the second adherend, The process involves applying the coating solution and then irradiating the coating solution or the dried coating solution with energy rays. A method for manufacturing a laminate, comprising the step of forming a laminate by bonding the first adherend and the second adherend via the coating liquid after irradiation with an energy ray.

[0020] (12) A step of attaching the resin film forming film described in (10) to at least one of the first adherend and the second adherend, The process involves applying the resin film-forming film and then irradiating the resin film-forming film with energy rays. A method for manufacturing a laminate, comprising the step of forming a laminate by bonding the first adherend and the second adherend via the resin film-forming film after irradiation with energy rays.

[0021] (13) A method for manufacturing a laminate according to (11), wherein at least one of the first adherend and the second adherend is an adherend that blocks energy rays.

[0022] (14) The method for manufacturing a laminate according to (12), wherein at least one of the first adherend and the second adherend is an adherend that blocks energy rays. [Effects of the Invention]

[0023] According to the present invention, instead of using two components, a double bond-containing compound and a β-dicarbonyl compound, a newly synthesized energy-ray curable polymer having a (meth)acryloyl group and a group containing a β-dicarbonyl structure is used as the main component of the energy-ray curable resin composition. This improves the uniformity during component mixing and makes it possible to provide an energy-ray curable resin composition with desired delayed curing properties and film-forming properties, a coating solution and a resin film-forming film containing the same, and a method for producing a laminate using the coating solution or the resin film-forming film. [Brief explanation of the drawing]

[0024] [Figure 1] Figure 1 is a schematic cross-sectional view of an example of a resin film forming sheet according to this embodiment. [Figure 2] Figure 2 is a schematic cross-sectional view of an example of a composite sheet for forming a resin film according to this embodiment. [Modes for carrying out the invention]

[0025] The present invention will be described in detail below with reference to the drawings, based on specific embodiments. First, the main terms used in this specification will be explained.

[0026] A workpiece refers to a plate-like body to which the resin film-forming film provided by the resin film-forming sheet according to this embodiment is attached, and which is then separated into individual pieces. The resin film-forming film is attached to the back surface of the workpiece. Examples of workpieces include circular wafers (including those having an orientation flat), rectangular panel-level packages, and strips (strip-shaped substrates) with molded resin encapsulation. Among these, wafers are preferred from the viewpoint of easily obtaining the effects of the present invention. Wafers may be semiconductor wafers such as silicon wafers, gallium arsenide wafers, silicon carbide wafers, gallium nitride wafers, and indium phosphate wafers, or insulating wafers such as glass wafers, lithium tantalate wafers, and lithium niobate wafers. They may also be reconfigured wafers made of resin and semiconductors used in the manufacture of fan-out packages, etc. From the viewpoint of easily obtaining the effects of the present invention, semiconductor wafers or insulating wafers are preferred as wafers, and semiconductor wafers are more preferred.

[0027] Workpiece fragmentation refers to the process of dividing a workpiece into individual circuit components to obtain individual workpiece fragments. For example, if the workpiece is a wafer, the individual workpiece fragments are chips; if the workpiece is a panel-level package or a strip (a strip-shaped substrate) with molded resin encapsulation, the individual workpiece fragments are semiconductor packages.

[0028] The "front surface" of a workpiece refers to the surface on which circuits, electrodes, etc., are formed, while the "back surface" of a workpiece refers to the surface on which circuits, etc., are not formed. The electrodes may be convex electrodes such as bumps.

[0029] A "primary surface" refers to a surface that makes up a plate-like object and has a larger area than the other surfaces. Typically, a plate-like object has two primary surfaces and other sides, and the two primary surfaces are opposite each other. In a workpiece, the "front surface" and "back surface" are the primary surfaces.

[0030] The term "(meth)acrylate" is used to refer to both "acrylate" and "methacrylate." Similarly, "(meth)acryloyl" is used to refer to both "acryloyl" and "methacryloyl." The same applies to other similar terms.

[0031] "Energy rays" refer to ultraviolet rays, electron beams, etc., and are preferably ultraviolet rays.

[0032] Unless otherwise specified, the "weight-average molecular weight" is a polystyrene-converted value measured by gel permeation chromatography (GPC). This measurement method is performed, for example, using a Tosoh Corporation high-speed GPC instrument "HLC-8120GPC" with high-speed columns "TSK guard column HXL-H", "TSK Gel GMHXL", and "TSK Gel G2000 HXL" (all manufactured by Tosoh Corporation) connected in that order, at a column temperature of 40°C and a liquid delivery rate of 1.0 mL / min, with a differential refractometer as the detector.

[0033] The release film is a film that supports the resin film-forming film in a way that allows it to be peeled off. The term "film" is used as a concept that includes sheets, without limiting the thickness.

[0034] In descriptions of compositions such as energy-ray curable resin compositions, the mass ratios are based on the active ingredient (solid content), and unless otherwise specified, the solvent is not included.

[0035] (1. Energy ray curable polymer) The energy-curable polymer of this embodiment is a compound that hardens when irradiated with energy rays in the presence of a photobase generator. This hardening reaction is also called Michael addition. The energy-curable polymer is a component that hardens upon irradiation with energy rays, and is responsible for film-forming properties, flexibility, etc., and is the main component for forming a hard resin film after hardening. In this embodiment, the energy-curable polymer has a (meth)acryloyl group and a group containing a β-dicarbonyl structure. It is preferable that the energy-curable polymer has two or more (meth)acryloyl groups and two or more groups containing a β-dicarbonyl structure in one molecule. The (meth)acryloyl group and the group containing a β-dicarbonyl structure may be bonded to the main chain of the energy-curable polymer or to the side chain.

[0036] The energy-ray curable polymer preferably has a weight-average molecular weight of 50,000 or more, more preferably 90,000 or more and 700,000 or less, and particularly preferably 120,000 or more and 550,000 or less. Here, "weight-average molecular weight" is as explained above. The energy-ray curable polymer may be crosslinked with a crosslinking agent in at least a portion of it, or it may not be crosslinked. Having a weight-average molecular weight within the above range imparts appropriate film-forming properties and flexibility to the energy-ray curable resin composition containing it.

[0037] In this embodiment, the (meth)acryloyl group is a group represented as -C(=O)-CHR=CH2 (where R is H or CH3).

[0038] A β-dicarbonyl structure is a structure in which one carbonyl group has another carbonyl group at the β position. In this embodiment, the β-dicarbonyl structure is preferably a β-ketoester structure shown in the following formula Y. This makes it easier to obtain a resin film with better adhesion to the adherend in the energy ray curable resin composition.

[0039] [ka] In formula Y, R 1 and R 2 R indicates an organic group. 1 and R 2 At least one of the components has a bonding hand to the main chain or side chain of the energy-ray curable polymer.

[0040] Furthermore, the β-ketoester structure is R in the above formula Y. 1 It is preferable that the structure is an acetoacetate ester structure in which R is a methyl group. In this case, R 2 It has binding bonds to the main chain or side chains of the energy-ray curable polymer.

[0041] In energy-ray curable polymers, the molar ratio of (meth)acryloyl groups to groups containing a β-dicarbonyl structure (=(meth)acryloyl group / group containing a β-dicarbonyl structure) is preferably 0.33 or more and 3 or less, more preferably 0.5 or more and 2 or less, and preferably 0.67 or more and 1.5 or less.

[0042] From the viewpoint of imparting appropriate film-forming properties when manufacturing resin film-forming films, it is preferable that the energy-ray curable polymer be in a solid state (non-fluid at room temperature) at room temperature (23°C). Furthermore, the glass transition temperature (Tg) of the energy-ray curable polymer is preferably -40°C or higher, and more preferably in the range of -35°C or higher and 25°C or lower.

[0043] A more specific example of an energy-ray curable polymer is an acrylic resin obtained by reacting an acrylic polymer (p1) having a functional group that can react with groups of other compounds and a group containing a β-dicarbonyl structure with an energy-ray curable compound (p2) having a group that reacts with the functional group and a (meth)acryloyl group.

[0044] Examples of functional groups that can react with groups of other compounds include hydroxyl groups, carboxyl groups, amino groups, substituted amino groups (groups having a structure in which one or two hydrogen atoms of an amino group are replaced by a group other than a hydrogen atom), and epoxy groups. In this embodiment, the functional group is preferably a hydroxyl group.

[0045] (1.1. Acrylic polymer having functional groups (p1)) Examples of acrylic polymers (p1) having functional groups and groups containing a β-dicarbonyl structure include those obtained by copolymerizing a (meth)acrylic monomer having a functional group, a (meth)acrylic monomer without a functional group, and a (meth)acrylic monomer having a group containing a β-dicarbonyl structure. In addition to these monomers, polymers may also be obtained by copolymerizing monomers other than (meth)acrylic monomers (non-(meth)acrylic monomers).

[0046] Examples of (meth)acrylic monomers having functional groups include hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, substituted amino group-containing monomers, epoxy group-containing monomers, and the like.

[0047] Examples of hydroxyl group-containing monomers include hydroxyalkyl (meth)acrylate.

[0048] Examples of monomers containing a carboxyl group include (meth)acrylic acid and carboxyalkyl esters of (meth)acrylic acid such as 2-carboxyethyl methacrylate.

[0049] Among the (meth)acrylic monomers having functional groups, hydroxyl group-containing monomers are preferred.

[0050] The acrylic polymer (p1) may consist of only one functional group-containing (meth)acrylic monomer, or two or more. If there are two or more, their combination and ratio can be arbitrarily selected.

[0051] Examples of (meth)acrylic monomers that do not have functional groups include (meth)acrylic acid esters having aromatic groups, such as alkyl (meth)acrylates, which have a chain structure with 1 to 18 carbon atoms, including alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), octadecyl (meth)acrylate (stearyl (meth)acrylate); and aryl (meth)acrylates such as phenyl (meth)acrylate.

[0052] The acrylic polymer (p1) may consist of only one (meth)acrylic monomer that does not have a functional group, or it may consist of two or more types. If there are two or more types, their combination and ratio can be arbitrarily selected.

[0053] Examples of non-(meth)acrylic monomers include olefins such as ethylene and norbornene; vinyl acetate; and styrene.

[0054] The non-(meth)acrylic monomers constituting the acrylic polymer (p1) may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0055] Examples of (meth)acrylic monomers having a β-dicarbonyl structure include 2-(acetoacetyloxy)ethyl methacrylate (AAEM) and 2-(acetoacetyloxy)ethyl acrylate.

[0056] The acrylic polymer (p1) may consist of only one (meth)acrylic monomer having a group containing a β-dicarbonyl structure, or it may consist of two or more types. If there are two or more types, their combination and ratio can be arbitrarily selected.

[0057] In the acrylic polymer (p1), the ratio (content) of the amount of constituent units derived from the functional group-containing (meth)acrylic monomer to the total amount of constituent units is preferably 0.1 to 50% by mass, more preferably 0.5 to 40% by mass, and particularly preferably 1 to 30% by mass, based on the mass of the monomer. By having the ratio within this range, the content of the energy-ray-curable group ((meth)acryloyl group) in the acrylic resin (energy-ray-curable polymer) obtained by the reaction of the acrylic polymer (p1) with the energy-ray-curable compound (p2) can be adjusted so that the degree of curing of the energy-ray-curable resin composition containing the polymer is within a desirable range.

[0058] In the acrylic polymer (p1), the proportion (content) of constituent units derived from (meth)acrylic monomers having a β-dicarbonyl structure is preferably 0.2 to 60% by mass, more preferably 1 to 50% by mass, and particularly preferably 2 to 40% by mass, based on the mass of the monomer. Having the proportion within this range allows the degree of curing of the energy-ray curable resin composition containing the polymer to be adjusted to a preferred range.

[0059] The weight-average molecular weight (Mw) of the acrylic polymer (p1) is preferably 50,000 or more, more preferably 90,000 or more and 700,000 or less, and particularly preferably 120,000 or more and 550,000 or less.

[0060] Furthermore, the acrylic polymer (p1) may be a random copolymer or a block copolymer, and known polymerization methods can be employed. For example, the acrylic polymer (p1) can be synthesized by carrying out a polymerization reaction of the above monomer mixture in the presence of a radical polymerization initiator.

[0061] Examples of radical polymerization initiators include organic peroxides and azo compounds. Examples of organic peroxides include diacyl peroxides such as lauroyl peroxide and benzoyl peroxide; peroxyketals such as 1,1-bis(t-butylperoxy)cyclohexane and 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane; peroxydicarbonates such as diisopropyl peroxydicarbonate and di-2-ethylhexyl peroxydicarbonate; and peroxyesters such as t-butylperoxy-2-ethylhexanoate and t-butylperoxyisobutyrate.

[0062] Examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitride), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2'-azobis(2-methylpropionate), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-hydroxymethylpropionitrile), and 2,2'-azobis[2-(2-imidazolin-2-yl)propane]. These can be used individually or in combination of two or more.

[0063] The amount of radical polymerization initiator used is typically 0.0001 to 0.1000 moles, preferably 0.0005 to 0.0050 moles, per 1 mole of total monomers used in the polymerization reaction.

[0064] The conditions for a radical polymerization reaction are not particularly limited as long as the desired polymerization reaction proceeds. The heating temperature is usually 40 to 150°C, and the reaction time can be appropriately set within the range of 1 minute to 24 hours. Radical polymerization may be carried out without a solvent, or solvents commonly used in radical polymerization may be used. Examples of solvents that can be used include organic solvents such as benzene, toluene, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetone, methyl ethyl ketone (MEK), chloroform, carbon tetrachloride, tetrahydrofuran (THF), ethyl acetate, and trifluoromethylbenzene, as well as aqueous organic solvents such as methanol, ethanol, isopropanol, n-butanol, ethyl cellosolve, butyl cellosolve, and 1-methoxy-2-propanol, and water.

[0065] Polymerization is usually carried out under atmospheric pressure, but it may also be carried out under pressurized or reduced pressure. After the polymerization reaction is complete, the solvent and remaining monomers may be removed under reduced pressure by conventional methods, or purified by precipitation filtration, reprecipitation, or column separation.

[0066] (1.2. Energy-ray curable compounds (p2)) The energy-ray curable compound (p2), which has a group that reacts with the functional group of the acrylic polymer (p1) and a (meth)acryloyl group, preferably has a group that reacts with the functional group of the acrylic polymer (p1) and has one or more selected from the group consisting of isocyanate groups, epoxy groups, and carboxyl groups, and more preferably has a group that has an isocyanate group. If the energy-ray curable compound (p2) has, for example, a group that has an isocyanate group, this isocyanate group readily reacts with the hydroxyl group of the acrylic polymer (p1) which has a hydroxyl group as a functional group.

[0067] The number of (meth)acryloyl groups in one molecule of the energy-ray curable compound (p2) is not particularly limited and can be appropriately selected, for example, by considering the physical properties and structure of the cured product (i.e., resin film) of the energy-ray curable resin composition formed from the energy-ray curable polymer and the photobase generator.

[0068] Examples of energy-ray-curable compounds (p2) include 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, and 1,1-(bisacryloyloxymethyl)ethyl isocyanate; Acryloyl monoisocyanate compounds obtained by the reaction of a diisocyanate compound or polyisocyanate compound with hydroxyethyl (meth)acrylate; Examples include acryloyl monoisocyanate compounds obtained by the reaction of a diisocyanate compound or polyisocyanate compound with a polyol compound and hydroxyethyl (meth)acrylate.

[0069] Among these, the energy-ray-curable compound (p2) is preferably 2-acryloyloxyethyl isocyanate or 2-methacryloyloxyethyl isocyanate.

[0070] The energy-ray-curable compound (p2) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0071] In the synthesis of an energy-ray-curable polymer, the ratio of the amount of functional groups derived from the acrylic polymer (p1) to the amount of groups derived from the energy-ray-curable compound (p2) that react with the functional groups of the acrylic polymer (p1) is preferably 20 to 100 mol%, more preferably 35 to 100 mol%, and particularly preferably 50 to 100 mol%. In the synthesis of an energy-ray-curable polymer, the ratio of the amount of (meth)acryloyl groups derived from the energy-ray-curable compound (p2) in the energy-ray-curable polymer to the amount of functional groups derived from the acrylic polymer (p1) is preferably 20 to 120 mol%, more preferably 35 to 110 mol%, and particularly preferably 50 to 105 mol%.

[0072] By appropriately controlling the composition of the energy-ray curable polymer within the above range, the adhesive strength of the resin film can be increased. Note that if the energy-ray curable compound (p2) is a polyfunctional compound (having two or more (meth)acryloyl groups in one molecule), the upper limit of its content may exceed 100 mol%.

[0073] (2. Energy ray curable resin composition) The energy-ray curable resin composition comprises the above-mentioned energy-ray curable polymer and a photobase generator. The energy-ray curable polymer contained in the energy-ray curable resin composition may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0074] In 100 parts by mass of the energy-ray curable resin composition, the content of the energy-ray curable polymer is preferably 10 to 99.9 parts by mass, more preferably 40 to 99.7 parts by mass, and particularly preferably 60 to 99.5 parts by mass. By blending the energy-ray curable polymer in the above proportions, it is easier to obtain an energy-ray curable resin composition exhibiting the desired delayed curing properties and film-forming properties, and it is easier to obtain a resin film with better adhesion to the adherend.

[0075] Energy-ray curable resin compositions are compositions used to form a resin film on an adherend. The resin film is the cured product of the energy-ray curable resin composition. For example, when the resin film is an adhesive film, an adhesive solution containing the energy-ray curable resin composition is usually applied to one adherend, the other adherend is bonded to the applied surface, and then cured by irradiation with energy rays to form an adhesive film that bonds the adherends together.

[0076] However, if the substrates to be bonded are impermeable to energy rays, even if energy rays are applied after the substrates are bonded together, the amount of energy radiation reaching the coated surface will be zero or extremely low. As a result, there was a problem in that the energy ray-curable resin composition did not harden and the substrates could not be sufficiently bonded together.

[0077] Therefore, one method for bonding such adherends is to apply an adhesive solution to one adherend, irradiate it with energy rays, and then bond the other adherend. In this case, the energy-ray curable resin composition is required to undergo a slow curing reaction after energy ray irradiation (delayed curing). If the resin hardens immediately after energy ray irradiation and a resin film is formed, the surface of the cured resin film will not have tack, and therefore the other adherend will not stick when bonded.

[0078] The energy-ray curable resin composition according to this embodiment contains a newly synthesized energy-ray curable polymer and a photobase generator, thereby possessing the delayed curing properties described above.

[0079] (2.1. Photobase Generator) In this embodiment, the energy-ray curable resin composition contains a photobase generator as a catalyst to control the deprotonation reaction of the β-dicarbonyl structure contained in the energy-ray curable polymer. The photobase generator, also called a photoanionic polymerization initiator, is a compound that generates a base upon irradiation with energy rays. The generated base causes deprotonation of the β-dicarbonyl structure, and a Michael addition reaction with the (meth)acryloyl group proceeds, curing the energy-ray curable resin composition. Since the generation of the base can be controlled by irradiation with energy rays, the reaction between the (meth)acryloyl group and the β-dicarbonyl structure contained in the energy-ray curable polymer can be controlled, resulting in a latent curing agent with excellent storage stability.

[0080] The photobase generator may be an ionic photobase generator having ionic bonds in its molecular structure (ionic type photobase generator) or a nonionic photobase generator not having ionic bonds in its molecular structure (nonionic type photobase generator). In this embodiment, a nonionic type photobase generator is preferred from the viewpoint of storage stability of the energy ray curable resin composition containing the photobase generator. If the requirement for storage stability is low, an ionic type photobase generator can also be used.

[0081] Examples of ionic photobase generators include compounds containing carboxylate salts, salts containing borate anions, quaternary ammonium salts, carbamates, etc., in their molecular structure. Examples of such compounds include (8E)-8-ethylidene-4-methoxy-5,6,7,8-tetrahydronaphthalene-1-carboxylic acid 1,8-diazabicyclo[5,4,0]undeca-7-ene, 1,2-disopropyl-3-[bis(dimethylamino)methylene]guanidium 2-(3-benzoylphenyl)propinate, 1,2-dicyclohexyl-4,4,5,5-tetramethyldiguadium n-butyltriphenylborate, and 2-(9-oxoxanthene-2-yl)propionic acid 1,5,7-triazabicyclo[4,4,0]deca-5-ene.

[0082] Examples of nonionic photobase generators include those represented by the following general formula (α1).

[0083] [ka]

[0084] In equation (α1), n ​​represents an integer between 0 and 4. Rα 11 Rα represents at least one substituent selected from the group consisting of C1-C18 alkyl groups, C2-C18 alkenyl groups, C2-C18 alkynyl groups, C6-C12 aryl groups, C1-C18 acyl groups, C7-C18 alloyl groups, nitro groups, cyano groups, C1-C18 alkoxy groups, C1-C18 alkylthio groups, hydroxyl groups, and halogen atoms. 12represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, an aryl group having 6 to 12 carbon atoms, an acyl group having 1 to 18 carbon atoms, an aroyl group having 7 to 18 carbon atoms, a nitro group, a cyano group, an alkoxy group having 1 to 18 carbon atoms, an alkylthio group having 1 to 18 carbon atoms, a hydroxyl group or a halogen atom. Xα1 represents an amino group.

[0085] In formula (α1), n usually represents an integer of 0 to 4, preferably an integer of 1 to 2, and more preferably 2. When n is 2, the substitution position of R1 is -CHRα on the benzene ring specified in formula (α1). 12 - is preferably the 4-position and 5-position when the bonding position with -NO2 is the 2-position and the bonding position with - is the 1-position.

[0086] In formula (α1), Rα 11 represents at least one substituent selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, an aryl group having 6 to 12 carbon atoms, an acyl group having 1 to 18 carbon atoms, an aroyl group having 7 to 18 carbon atoms, a nitro group, a cyano group, an alkoxy group having 1 to 18 carbon atoms, an alkylthio group having 1 to 18 carbon atoms, a hydroxyl group and a halogen atom. When there are a plurality of Rα 11 they may be different from each other.

[0087] Examples of the alkyl group having 1 to 18 carbon atoms represented by Rα in formula (α1) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group and an n-dodecyl group, etc., and preferably an alkyl group having 2 to 6 carbon atoms.

[0088] Rα in formula (α1) 11 ​​Examples of alkenyl groups with 2 to 18 carbon atoms represented by include vinyl group, propenyl group, 1-butenyl group, iso-butenyl group, 1-pentenyl group, 2-pentenyl group, 2-methyl-1-butenyl group, 3-methyl-1-butenyl group, 2-methyl-2-butenyl group, 2,2-dicyanovinyl group, 2-cyano-2-methylcarboxylvinyl group, and 2-cyano-2-methylsulfonvinyl group.

[0089] Rα in equation (α1) 11 Examples of alkynyl groups with 2 to 18 carbon atoms represented by include the ethynyl group, 1-propynyl group, and 1-butynyl group.

[0090] Rα in equation (α1) 11 Examples of aryl groups having 6 to 12 carbon atoms that can be represented by this include phenyl groups, naphthyl groups, and tolyl groups, with aryl groups having 6 to 10 carbon atoms being preferred.

[0091] Rα in equation (α1) 11 Examples of acyl groups having 1 to 18 carbon atoms represented by include formyl group, acetyl group, ethyl carbonyl group, n-propyl carbonyl group, iso-propyl carbonyl group, n-butyl carbonyl group, n-pentyl carbonyl group, iso-pentyl carbonyl group, neo-pentyl carbonyl group, 2-methylbutyl carbonyl group, and nitrobenzyl carbonyl group.

[0092] Rα in equation (α1) 11 Examples of alloyl groups with 7 to 18 carbon atoms represented by this symbol include benzoyl groups, toluyl groups, naphthoyl groups, and phthaloyl groups.

[0093] Rα in equation (α1) 11 Examples of alkoxy groups having 1 to 18 carbon atoms represented by include methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, iso-butoxy group, sec-butoxy group, t-butoxy group, n-pentoxy group, iso-pentoxy group, neo-pentoxy group, n-hexyloxy group, and n-dodecyloxy group.

[0094] Rα in equation (α1) 11 Examples of alkylthio groups having 1 to 18 carbon atoms represented by include methylthio group, ethylthio group, n-propylthio group, iso-propylthio group, n-butylthio group, iso-butylthio group, sec-butylthio group, t-butylthio group, n-pentylthio group, iso-pentylthio group, 2-methylbutylthio group, 1-methylbutylthio group, neo-pentylthio group, 1,2-dimethylpropylthio group, and 1,1-dimethylpropylthio group.

[0095] Rα in equation (α1) 11 Examples of halogen atoms represented by include fluorine, chlorine, bromine, and iodine atoms.

[0096] Rα in equation (α1) 11 The group is preferably an alkoxy group having 1 to 18 carbon atoms, more preferably an alkoxy group having 1 to 10 carbon atoms, even more preferably an alkoxy group having 1 to 4 carbon atoms, and particularly preferably a methoxy group. Rα 11 If there are multiple Rα 11 Preferably, the group is an alkoxyl group, and all Rα 11 It is more preferable that the group is an alkoxyl group.

[0097] In formula (α1), Rα 12 The characters represent a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, an aryl group having 6 to 12 carbon atoms, an acyl group having 1 to 18 carbon atoms, an alloyl group having 7 to 18 carbon atoms, a nitro group, a cyano group, an alkoxy group having 1 to 18 carbon atoms, an alkylthio group having 1 to 18 carbon atoms, a hydroxyl group, or a halogen atom.

[0098] Rα in equation (α1) 12 The Rα group represented by is an alkyl group having 1 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, an aryl group having 6 to 12 carbon atoms, an acyl group having 1 to 18 carbon atoms, an alloyl group having 7 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, an alkylthio group having 1 to 18 carbon atoms, and a halogen atom. 11Examples of the same groups represented by include alkyl groups having 1 to 18 carbon atoms, alkynyl groups having 2 to 18 carbon atoms, aryl groups having 6 to 12 carbon atoms, acyl groups having 1 to 18 carbon atoms, alloyl groups having 7 to 18 carbon atoms, alkoxy groups having 1 to 18 carbon atoms, alkylthio groups having 1 to 18 carbon atoms, and halogen atoms.

[0099] Rα in equation (α1) 12 Preferably, the element is a hydrogen atom or an alkyl group having 1 to 18 carbon atoms; more preferably, a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; even more preferably, a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; and particularly preferably, a hydrogen atom.

[0100] In formula (α1), Xα1 represents an amino group. The amino group represented by Xα1 in formula (α1) may be either a substituted amino group or an unsubstituted amino group (NH2 group), and the substituted amino group may be either a monosubstituted amino group or a disubstituted amino group.

[0101] In this embodiment, it is preferable that Xα1 has a group containing the structure shown in the following formula (α1-X).

[0102] [ka] In the formula, Rv, Rw, Rx, Ry, and Rz are organic groups. More preferably, Rv is single-bonded to the ester group in the general formula (α1), and Rw, Rx, Ry, and Rz are alkyl groups or cycloalkyl groups. Even more preferably, Rw, Rx, Ry, and Rz are alkyl groups having 3 or fewer carbon atoms, and particularly preferably, Rw, Rx, Ry, and Rz are methyl groups.

[0103] Specific examples of compounds represented by formula (α1) include the following compounds (α1-1) to (α1-8).

[0104] [ka]

[0105] Furthermore, as a nonionic photobase generator, coumaric acid-type photobase generators represented by the following general formula (α2) can also be mentioned, due to their superior material stability and better base generation efficiency upon irradiation with energy rays.

[0106] [ka]

[0107] In general formula (α2), Rα 21 and Rα 22 Each of these is independently a hydrogen atom or an organic group, and they may be the same or different. Rα 21 and Rα 22 These may be bonded together to form a cyclic structure, or they may contain heteroatom bonds. However, Rα 21 and Rα 22 At least one of them is an organic group. Rα 23 and Rα 24 Each of these is independently a hydrogen atom, a halogen atom, a hydroxyl group, a mercapto group, a sulfide group, a silyl group, a silanol group, a nitro group, a nitroso group, a sulfino group, a sulfo group, a sulfonate group, a phosphinate group, a phosphinyl group, a phosphono group, a phosphonato group, or an organic group, and may be the same or different. Rα 25 , Rα 26 , Rα 27 and Rα 28 Each of these is independently a hydrogen atom, a halogen atom, a hydroxyl group, a mercapto group, a sulfide group, a silyl group, a silanol group, a nitro group, a nitroso group, a sulfino group, a sulfo group, a sulfonate group, a phosphinate group, a phosphinyl group, a phosphono group, a phosphonato group, an amino group, an ammonia group, or an organic group, and may be the same or different. Rα 25 , Rα 26 , Rα 27 and Rα 28 These may be composed of two or more atoms bonded together to form a cyclic structure, and may also contain heteroatom bonds. Rα 29 is a hydrogen atom or an organic group.

[0108] In general formula (α2), Rα 21 and Rα 22 From the viewpoint of the basicity of the resulting base, it is preferable that both are alkyl groups or that they form a cyclic alkylene chain bonded to each other, and most preferably that they form a cyclic alkylene chain bonded to each other. The number of carbon atoms constituting the alkyl group or alkylene chain is preferably 1 to 20, and more preferably 1 to 8.

[0109] Also, Rα 21 -N-Rα 22 It is preferable that the group is one that constitutes the structure shown in formula (α1-X) above. In formula (α1-X) above, Rv, Rw, Rx, Ry and Rz are organic groups. More preferably, Rv is single-bonded to the carbonyl group in the general formula (α2) above, and the group containing CN, Rw and Rx is Rα 21 C(the Rα 21 The group containing C, Ry, and Rz, which is the same as C in Rα 22 More preferably, Rw, Rx, Ry, and Rz are alkyl groups or cycloalkyl groups, particularly preferably Rw, Rx, Ry, and Rz are alkyl groups having 3 or fewer carbon atoms, and most preferably Rw, Rx, Ry, and Rz are methyl groups.

[0110] In general formula (α2), Rα 23 and Rα 24 The atoms are preferably hydrogen atoms or alkyl groups, and most preferably both are hydrogen atoms. The alkyl group preferably has 1 to 20 carbon atoms, and more preferably 1 to 8 carbon atoms.

[0111] In general formula (α2), Rα 25 , Rα 26 , Rα 27 and Rα 28The atoms are preferably hydrogen atoms, alkyl groups, or alkoxy groups, and most preferably all hydrogen atoms. The alkyl group preferably has 1 to 20 carbon atoms, and more preferably 1 to 8 carbon atoms. The alkoxy group preferably has 1 to 20 carbon atoms, and more preferably 1 to 8 carbon atoms.

[0112] In general formula (α2), Rα 29 The protecting group is preferably a hydrogen atom or an organic group that can be deprotected by irradiation and / or heating of energy rays, and most preferably a hydrogen atom.

[0113] The following compounds (α2-1) and (α2-2) are preferred as coumaric acid-type compounds represented by the general formula (α2), with (α2-1) being more preferred.

[0114] [ka]

[0115] Furthermore, a urethane compound (α3-1) represented by the following general formula is also preferred as a nonionic photobase generator.

[0116] [ka]

[0117] Furthermore, oxime ester compounds are also preferred as nonionic photobase generators. Any oxime ester compound that generates basic substances upon light irradiation can be used. Compounds having two oxime ester groups in the molecule can also be suitably used, and specifically, oxime ester compounds having a carbazole structure represented by the following general formula (α4) can be mentioned.

[0118] [ka]

[0119] In the general formula (α4), Xα4 represents a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a phenyl group, a phenyl group (substituted with an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms, or a dialkylamino group), and a naphthyl group (substituted with an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an amino group, an alkylamino group having an alkyl group having 1 to 8 carbon atoms, or a dialkylamino group), and Yα4 and Zα4 represent a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a halogen group, a phenyl group, a phenyl group (substituted with an alkyl group having 1 to 17 carbon atoms, or a dialkylamino group having 1 to 8 carbon atoms). Arα4 represents a bond or an alkylene, vinylene, phenylene, biphenylene, pyridylene, naphthylene, thiophene, anthrylene, thienylene, furylene, 2,5-pyrrole-diyl, 4,4'-stilbene-diyl, 4,2'-styrene-diyl, and n is 0 or It is an integer 1.

[0120] In particular, in the general formula (α4) above, Xα4 and Yα4 are preferably a methyl group or an ethyl group, Zα4 is preferably a methyl group or a phenyl group, n is preferably 0, and Arα4 is preferably a bond, phenylene, naphthylene, thiophene, or thienylene.

[0121] Furthermore, preferred carbazole oxime ester compounds can also be listed as compounds that can be represented by the following general formula (α5).

[0122] [ka]

[0123] In general formula (α5), Rα 51 Rα represents an alkyl group having 1 to 4 carbon atoms, or a phenyl group which may be substituted with a nitro group, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. 52 Rα represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group which may be substituted with an alkyl group or alkoxy group having 1 to 4 carbon atoms. 53 Rα represents an alkyl group having 1 to 20 carbon atoms, which may be linked by an oxygen atom or a sulfur atom, and which may be substituted with a phenyl group, or a benzyl group having 1 to 4 carbon atoms, which may be substituted with an alkoxy group. 54 Xα5 represents a nitro group or an acyl group represented as Xα5-C(=O)-. Xα5 represents an aryl group, thienyl group, morpholino group, thiophenyl group, or a structure shown in the following formula, which may be substituted with an alkyl group having 1 to 4 carbon atoms.

[0124] [ka]

[0125] Among the nonionic photobase generators described above, coumaric acid type photobase generators represented by the general formula (α2) are preferred, and compounds shown in (α2-1) are more preferred.

[0126] In 100 parts by mass of the energy-ray curable resin composition, the content of the photobase generator is preferably 0.1 to 10 parts by mass, 0.3 to 8 parts by mass, 0.5 to 6 parts by mass, or 0.7 to 5 parts by mass. By blending the photobase generator in the above proportions, it is easier to obtain an energy-ray curable resin composition exhibiting the desired delayed curing properties, and it is easier to obtain a resin film with better adhesion to the substrate.

[0127] Furthermore, the photobase generator can be synthesized as a condensate by referring to examples described in, for example, Japanese Patent Publication No. 2009-80452, Japanese Patent Publication No. 2011-52214, Japanese Patent Publication No. 2021-177210, Japanese Patent Publication No. 2019-45735, etc.

[0128] (2.2. Filler) In this embodiment, the energy-ray curable resin composition may contain a filler. By including a filler, the resin film obtained by curing the energy-ray curable resin composition has a more easily adjustable coefficient of thermal expansion. By bringing this coefficient of thermal expansion closer to that of the adherend, the reliability of adhesion to the adherend via the resin film is further improved. Furthermore, the inclusion of a filler in the energy-ray curable resin composition results in a rigid resin film, and the moisture absorption rate of the resin film can be reduced, further improving the reliability of adhesion to the adherend via the resin film.

[0129] The filler may be either an organic or inorganic filler, but an inorganic filler is preferred from the viewpoint of dimensional stability at high temperatures.

[0130] Preferred inorganic fillers include, for example, powders of silica, alumina, talc, calcium carbonate, red iron oxide, silicon carbide, boron nitride, etc.; beads formed from these inorganic fillers in a spherical shape; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; glass fibers, etc. Among these, silica and surface-modified silica are preferred. Surface-modified silica is preferably surface-modified with a coupling agent, and more preferably with a silane coupling agent.

[0131] The average particle size of the filler is preferably 0.02 to 10 μm, 0.05 to 5 μm, or 0.10 to 3 μm.

[0132] By setting the average particle size range of the filler to the above range, the handling properties of the energy-ray-curable resin composition are improved. As a result, the quality of the energy-ray-curable resin composition tends to be more stable.

[0133] In this specification, unless otherwise specified, "average particle size" refers to the particle diameter (D50) at 50% integration in the particle size distribution curve obtained by laser diffraction scattering.

[0134] The amount of filler in an energy-ray-curable resin composition, when the total weight is 100 parts by mass, is preferably determined according to the form in which the energy-ray-curable resin composition is used. For example, in the case of a liquid coating solution containing an energy-ray-curable resin composition, the amount of filler is preferably at least one of 0.5 to 60 parts by mass, 1 to 50 parts by mass, 1.5 to 45 parts by mass, or 2 to 20 parts by mass. In the case of a resin film-forming film made from an energy-ray-curable resin composition, the amount of filler is preferably at least one of 15 to 80 parts by mass, 30 to 70 parts by mass, 35 to 65 parts by mass, or 40 to 60 parts by mass.

[0135] By setting the lower limit of the filler content to the above value, adhesive reliability is further improved. Furthermore, by setting the upper limit of the filler content to the above value, the handling properties of the energy ray curable resin composition are improved.

[0136] (2.3. Colorants) The energy-ray curable resin composition may contain a coloring agent. When the resin film is used as a protective film as described later, the back surface of the adherend, such as a chip, is concealed, thereby blocking various electromagnetic waves generated within the electronic device and reducing malfunctions of the chip.

[0137] As a coloring agent, known substances such as organic pigments, organic dyes, and inorganic pigments can be used. In this embodiment, inorganic pigments are preferred.

[0138] Examples of inorganic pigments include carbon black, cobalt-based dyes, iron-based dyes, chromium-based dyes, titanium-based dyes, vanadium-based dyes, zirconium-based dyes, molybdenum-based dyes, ruthenium-based dyes, platinum-based dyes, ITO (indium tin oxide)-based dyes, and ATO (antimony tin oxide)-based dyes. Among these, carbon black is particularly preferred. Carbon black can block electromagnetic waves across a wide wavelength range.

[0139] The amount of colorant in the energy-ray curable resin composition is not particularly limited, but it is preferable that the colorant content, when the total weight of the energy-ray curable resin composition is 100 parts by mass, be in at least one of the following ranges: 0.01 to 10 parts by mass, 0.03 to 7 parts by mass, or 0.05 to 4 parts by mass. Setting the upper limit of the colorant content to the above values ​​makes it easier to improve the energy-ray curability of the energy-ray curable resin composition.

[0140] The average particle size of the coloring agent (especially carbon black) is preferably 1-500 nm, 3-100 nm, or 5-50 nm. When the average particle size of the coloring agent is within the above range, it is easier to control the light transmittance to the desired range.

[0141] (2.4. Other Additives) The energy-ray curable resin composition may contain, to the extent that it does not impair the effects of the present invention, other additives such as, for example, non-energy-ray curable film-forming components (e.g., non-energy-ray curable acrylic resins, urethane resins, phenoxy resins, silicone resins, saturated polyester resins), coupling agents, crosslinking agents, plasticizers, antistatic agents, antioxidants, gettering agents, tackifiers, release agents, etc.

[0142] On the other hand, in this embodiment, from the viewpoint of film-forming properties, it is preferable that the composition is substantially free of isocyanate compounds and isothiocyanate compounds. Substantially free of isocyanate compounds and isothiocyanate compounds means that the total content of isocyanate compounds and isothiocyanate compounds is 1 part by mass or less per 100 parts by mass of the energy ray curable resin composition.

[0143] Furthermore, in this embodiment, from the viewpoint of delayed curing properties, it is preferable that the product is substantially free of photoradical initiators. Substantially free of photoradical initiators means that the content of photoradical initiators in 100 parts by mass of the energy ray curable resin composition is 0.1 parts by mass or less.

[0144] (3. Form of energy ray-curable resin composition when used) The energy-curable resin composition according to this embodiment can be used in a form that can be appropriately selected depending on the application. In this embodiment, it is preferable to use it as a coating liquid containing the energy-curable resin composition. It is also preferable to use it as a resin film-forming film made of the energy-curable resin composition.

[0145] (3.1. Application Solution) In this embodiment, the coating solution containing the energy ray-curable resin composition described above may be a coating solution consisting of a liquid energy ray-curable resin composition, or it may be a coating solution containing an energy ray-curable resin composition and a solvent.

[0146] From the viewpoint of delayed curing, the coating liquid is preferably used as an adhesive. The adhesive liquid is applied to the adherend and irradiated with energy rays, which initiates the curing reaction of the energy-ray curable resin composition. As described above, since this curing reaction is delayed, the tack of the irradiated surface is maintained even after irradiation with energy rays, allowing the adherends to bond together.

[0147] In the coating solution, the total mass of the energy-ray curable polymer and the photobase generator is preferably 80 parts by mass or more, more preferably 85 parts by mass or more, and even more preferably 90 parts by mass or more, per 100 parts by mass of solid content. This makes it easier to obtain a resin film with better adhesion to the adherend from the energy-ray curable resin composition.

[0148] The solvent should be selected according to the application and other factors, and should be suitable for use as a coating solution. Examples include aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as dichloromethane, dichloroethane, and trichloromethane; alcohols such as methanol, ethanol, propanol, butanol, and 1-methoxy-2-propanol; ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, and cyclohexanone; esters such as ethyl acetate and butyl acetate; and cellosolve solvents such as ethyl cellosolve.

[0149] If the coating solution contains a solvent, the solid content concentration of the coating solution can be set to any range depending on the application. In this embodiment, the solid content concentration is preferably 10% by mass or more and 70% by mass or less, and more preferably 15% by mass or more and 55% by mass or less. The viscosity of the coating solution can also be set to any range within which it can be applied to the substrate.

[0150] A coating solution containing an energy-ray curable resin composition is obtained by thoroughly mixing an energy-ray curable polymer, a photobase generator, other additives such as fillers as needed, and a solvent.

[0151] (3.2. Resin film forming film) In this embodiment, the resin film-forming film made of the energy-curable resin composition described above forms a resin film by irradiation with energy rays.

[0152] The resin film-forming film may be used as a protective film (protective film-forming film) to protect the back surface of chips or the like that have circuits on their surface. It may also be used as an adhesive film-forming film to bond adherends together. Furthermore, it may be used as a film to form a protective film that exposes the upper part of a convex electrode such as a bump formed on a wafer, and covers and protects the wafer surface and the lower part of the convex electrode. Similar to the coating liquid, it is preferable to use it as an adhesive film-forming film from the viewpoint of delayed curing properties. That is, even after irradiating the adhesive film-forming film with energy rays, the tack of the irradiated surface is maintained, so adherends can be bonded together.

[0153] In 100 parts by mass of the resin film-forming film, the total mass of the energy-ray curable polymer and the photobase generator is preferably 30 parts by mass or more, more preferably 35 parts by mass or more, and even more preferably 40 parts by mass or more. This makes it easier to obtain a resin film with better adhesion to the adherend.

[0154] The thickness of the resin film-forming film is not particularly limited, but is preferably 100 μm or less, 80 μm or less, 60 μm or less, or 45 μm or less. Alternatively, the thickness of the resin film-forming film is preferably 4 μm or more, 6 μm or more, or 8 μm or more. The thickness of the resin film-forming film can be arbitrarily selected and set from the above upper and lower limits. When the thickness of the resin film-forming film is within the above range, the performance of the resulting resin film is better.

[0155] Note that the thickness of a resin film refers to the total thickness of the resin film-forming film. For example, the thickness of a resin film-forming film composed of multiple layers refers to the sum of the thicknesses of all the layers that make up the resin film-forming film.

[0156] Resin film-forming films are typically used in the form of resin film-forming sheets or resin film-forming composite sheets.

[0157] The resin film forming sheet 1 according to this embodiment has the configuration shown in Figure 1. The resin film forming film 10 has two opposing main surfaces 10a and main surface 10b. A first release film 21 that supports the resin film forming film 10 is placed on main surface 10a, and a second release film 22 that supports the resin film forming film 10 is placed on main surface 10b.

[0158] Furthermore, the composite sheet for forming a resin film comprises a resin film forming film and a support sheet for supporting the resin film forming film. The support sheet is not a release film and has a configuration that can support the resin film forming film. An example of a support sheet is an adhesive sheet having a base material and an adhesive layer.

[0159] Specifically, as shown in Figure 2, the composite sheet 2 for resin film formation has a structure comprising: an adhesive sheet 4, which serves as a support sheet, having an adhesive layer 42 laminated on one side of a base material 41; a resin film forming film 10, which is laminated so that its main surface 10a is in contact with the adhesive layer 42 of the adhesive sheet 4; and a release film 23 placed on the main surface 10b of the resin film forming film 10. Furthermore, a jig adhesive layer (not shown) may be placed on the peripheral edge of the resin film forming film 10. The jig adhesive layer is a layer for adhering the composite sheet for resin film formation to a jig such as a ring frame. It is preferable that the first release film 21, the second release film 22, and the release film 23 are all release films in which a silicone-based release agent layer is formed on one side of a polyethylene terephthalate (PET) film.

[0160] The resin film-forming film can be manufactured by known methods. For example, it can be manufactured using the coating solution described above. First, the coating solution described above is applied to the release surface of the first release film 21 using a coating machine such as a roll coater, knife coater, roll knife coater, air knife coater, die coater, bar coater, gravure coater, or curtain coater. If necessary, the solvent of the coating solution is removed by drying to form a resin film-forming film on the first release film 21. In this embodiment, the components contained in the energy ray curable resin composition are easily mixed uniformly, so a good film (resin film-forming film) is formed.

[0161] When manufacturing the resin film forming sheet 1, it is obtained by further laminating the release surface of the second release film 22 to the exposed surface of the resin film forming film formed on the first release film 21.

[0162] Furthermore, when manufacturing the composite sheet 2 for resin film formation, a laminate including an adhesive sheet and a sheet for resin film formation can be used. The adhesive sheet can be manufactured by known methods. For example, a coating solution containing a composition constituting the adhesive layer is prepared, applied to the release surface of the third release film, and dried as necessary to form an adhesive layer on the third release film. Next, a substrate is bonded to the exposed adhesive layer to obtain an adhesive sheet in which the third release film is placed on the adhesive layer.

[0163] Next, the second release film of the resin film forming sheet is peeled off, and the third release film of the adhesive sheet is peeled off, and the resin film forming film and the adhesive layer are bonded together to obtain a composite sheet for forming a resin film. The resin film forming film may be cut to the size of the substrate to which it is to be attached (e.g., a wafer) or a size close to the substrate at an appropriate time, if necessary.

[0164] (4. Method for manufacturing laminates) As an example of using the coating solution according to this embodiment, a method for producing a laminate in which a first adherend and a second adherend are laminated via a resin film (adhesive film) is used with a coating solution containing the energy-ray curable resin composition described above. The method for producing the laminate according to this embodiment comprises at least the following steps 1 to 3. Step 1: A step of applying a coating solution containing the above-described energy ray curable resin composition to at least one of the first adherend and the second adherend. Step 2: After applying the coating solution, the process involves irradiating the coating solution or the dried coating solution with energy rays. Step 3: After energy ray irradiation, the first adherend and the second adherend are bonded together via a coating solution to form a laminate.

[0165] Known methods can be used to apply the coating solution. Examples include coating methods such as die coaters, curtain coaters, spray coaters, slit coaters, and knife coaters; printing methods such as screen printing and inkjet printing; and dispensing methods such as dispensers. In this embodiment, the components contained in the energy ray curable resin composition are easily mixed uniformly, resulting in the formation of a good film.

[0166] Furthermore, if the coating solution contains a solvent, it may be dried as needed. For example, drying conditions can be set to a temperature of 50-100°C and a drying time of 30 seconds to 5 minutes.

[0167] Furthermore, as an example of the use of the resin film-forming film, we illustrate a method for manufacturing a laminate in which a first adherend and a second adherend are laminated with a resin film (adhesive film) in between, using a resin film-forming film (adhesive film-forming film) made of the energy ray-curable resin composition described above. In this case, the method for manufacturing the laminate according to this embodiment comprises at least the following steps 1 to 3. Step 1: A step of attaching a resin film-forming film made of the above-described energy-ray curable resin composition to at least one of the first adherend and the second adherend. Step 2: After applying the resin film-forming film, the resin film-forming film is irradiated with energy rays. Step 3: After energy ray irradiation, the first adherend and the second adherend are bonded together via a resin film forming film to form a laminate.

[0168] Whether the manufacturing method uses a coating solution or a resin film-forming film, as is clear from steps 1 to 3, the first adherend and the second adherend are bonded together after irradiating the energy ray-curable resin composition contained in the coating solution or resin film-forming film with energy rays. After curing is complete, a laminate is obtained in which the first adherend and the second adherend are laminated together via a resin film (adhesive film).

[0169] As described above, the energy-curable resin composition according to this embodiment exhibits delayed curing properties upon energy irradiation, so that tack remains on the irradiated surface for a certain period after irradiation, allowing for good adhesion between the first adherend and the second adherend. When a coating liquid or resin film-forming film containing an energy-curable resin composition that does not exhibit delayed curing properties is used, curing is completed immediately after energy irradiation, so the tack is lost before the first adherend and the second adherend can be bonded together, making it impossible to bond the first adherend and the second adherend.

[0170] In particular, even if at least one of the first and second adherends is an adherend that blocks energy rays, or even if both the first and second adherends are adherends that block energy rays, the first adherend and the second adherend can be bonded well. Examples of adherends that block energy rays include adherends that reflect energy rays and adherends that absorb energy rays.

[0171] Furthermore, as another example of the use of the resin film forming film, we will illustrate a method of forming a resin film on a workpiece, and then separating the workpiece with the resin film into individual pieces to produce resin film-coated workpiece pieces. The method for producing resin film-coated workpiece pieces according to this embodiment comprises at least the following steps 1 to 3. Step 1: A step of attaching a resin film-forming film made of the energy ray-curable resin composition described above to the back surface of the workpiece. Step 2: The process of irradiating the attached resin film-forming film with energy rays to form a resin film on the back surface of the workpiece, thereby obtaining a workpiece with a resin film. Step 3: A step to separate the resin-coated workpiece into individual pieces and obtain multiple resin-coated workpiece pieces.

[0172] In this embodiment, the resin film forming film is preferably a protective film forming film. The workpiece is preferably a wafer, and more preferably a semiconductor wafer. Therefore, the resin film-coated workpiece pieces are preferably protective film-coated chips, and more preferably protective film-coated semiconductor chips.

[0173] In the above examples of the use of coating liquids and resin film-forming films, the illuminance and light intensity of the energy rays should be set to conditions that allow the energy ray-curable resin composition to cure sufficiently. For example, the illuminance of the energy rays should be 30 to 280 mW / cm². 2 The light intensity of the energy rays is 500-5000 mJ / cm². 2 That's all you need to do.

[0174] (5. Variant) In the embodiments described above, the curing reaction was controlled using a photobase generator that generates bases by irradiating it with energy rays. However, a photobase generator that generates bases by heating in addition to energy ray irradiation may also be used. Furthermore, heating in addition to energy ray irradiation may further promote the Michael addition reaction by the bases released by the energy ray irradiation. The heating temperature in this case is preferably 50 to 200°C.

[0175] By using such a photobase generator, it is possible to appropriately cure energy-ray-curable resin compositions by selecting between curing reactions by energy ray irradiation and curing reactions by heating, depending on the application, and controlling the delayed curing properties.

[0176] Although embodiments of the present invention have been described above, the present invention is not limited in any way to the embodiments described above, and may be modified in various ways within the scope of the present invention. [Examples]

[0177] The invention will be described in more detail below using examples, but the present invention is not limited to these examples.

[0178] A coating solution containing an energy-ray curable resin composition was prepared using the following components.

[0179] (Energy-ray curable polymer) Energy-curable polymers (A1) to (A3) having acryloyl groups and groups containing β-dicarbonyl structures were synthesized by the following method.

[0180] <Energy ray curable polymer (A1)> In a 500 mL separable four-necked flask, 90 parts by mass of methyl ethyl ketone (MEK) as the solvent, 270 parts by mass of ethyl acetate, and 0.075 parts by mass of azobisisobutyronitrile (AIBN) as the initiator were heated to 100°C in an oil bath under a nitrogen atmosphere with stirring, and then refluxed. Under reflux, a mixture of 78.5 parts by mass of n-butyl acrylate (BA), 14.0 parts by mass of 2-(acetoacetyloxy)ethyl methacrylate (AAEM), and 7.5 parts by mass of 2-hydroxyethyl acrylate (HEA) was slowly added dropwise, and the mixture was allowed to react for 12 hours. The viscosity of the solution was adjusted by evaporating the solvent under reduced pressure and by adding a mixed solvent of MEK / ethyl acetate = 1 / 3 (by mass ratio) to obtain an acrylic polymer solution with a solid content of 38% by mass. The obtained acrylic polymer had a BA / AAEM / HEA (mass ratio) of 78.5 / 14.0 / 7.5, contained hydroxyl groups and groups including β-dicarbonyl structures, had a weight-average molecular weight of approximately 150,000, a dispersion degree of 2.7, and a glass transition temperature (Tg) of -25°C.

[0181] 263 parts by mass (100 parts by mass in terms of solids) of the acrylic polymer solution obtained above were placed in a 500 mL separable four-necked flask. 0.139 parts by mass of dibutyltin dilaurate (DBTDL) and 113 parts by mass of a mixed solvent of MEK / ethyl acetate = 1 / 3 (mass ratio) were added, and the mixture was stirred at room temperature for 10 minutes. 9.12 parts by mass of 2-acryloyloxyethyl isocyanate (AOI) were slowly added dropwise, and the mixture was reacted at room temperature for 4 days in an amount such that the total number of isocyanate groups in AOI was equimolar to the total number of hydroxyl groups in the acrylic polymer, to obtain a solution of energy-ray curable polymer (A1). The obtained polymer (A1) contained acryloyl groups and groups containing β-dicarbonyl structures, had a weight-average molecular weight of approximately 170,000, a dispersion degree of 3.1, and a glass transition temperature (Tg) of -24°C. The solids concentration of the solution was 28% by mass. The polymer (A1) obtained by removing the solvent with a rotary evaporator was solid at room temperature (23°C) (non-fluid at room temperature).

[0182] <Energy-ray curable polymer (A2)> 57 parts by mass of BA, 28 parts by mass of AAEM, 15 parts by mass of HEA, 0.05 parts by mass of AIBN, and 180 parts by mass of ethyl acetate were charged, and the same reaction as for energy-ray curable polymer (A1) was carried out to obtain an acrylic polymer having hydroxyl groups and groups containing β-dicarbonyl structures, with a BA / AAEM / HEA (mass ratio) of 57 / 28 / 15. The obtained acrylic polymer was further reacted with AOI in an amount such that the total number of isocyanate groups in AOI was equimolar to the total number of moles of hydroxyl groups in the acrylic polymer to obtain a solution of energy-ray curable polymer (A2). The obtained polymer (A2) had a weight-average molecular weight of approximately 250,000 and a glass transition temperature (Tg) of -13°C. The polymer (A2) obtained by removing the solvent with a rotary evaporator was solid (non-fluid at room temperature) at room temperature (23°C).

[0183] <Energy-ray curable polymer (A3)> In the preparation of the energy-ray-curable polymer (A1), a solution of the energy-ray-curable polymer (A3) was obtained in the same manner as for polymer (A1), except that the amount of AIBN used as an initiator was 0.038 parts by mass. The obtained polymer (A3) had a weight-average molecular weight of approximately 280,000 and a glass transition temperature (Tg) of -25°C. After removing the solvent with a rotary evaporator, the polymer (A3) obtained was solid at room temperature (23°C) (non-fluid at room temperature).

[0184] For comparison, a polymer (A4) was synthesized that did not contain a (meth)acryloyl group but had a group containing a β-dicarbonyl structure. Similarly, a polymer (A5) was synthesized that contained a methacryloyl group but did not have a β-dicarbonyl structure.

[0185] <β-Dicarbonyl Structure-Containing Polymer (A4)> The polymer prepared in the production of the energy-curable polymer (A1) had a BA / AAEM / HEA (mass ratio) of 78.5 / 14.0 / 7.5, contained hydroxyl groups and β-dicarbonyl structures, had a weight-average molecular weight of approximately 150,000, a dispersion degree of 2.7, and a glass transition temperature (Tg) of -25°C, which was designated as the β-dicarbonyl structure-containing polymer (A4). The solvent was removed using a rotary evaporator.

[0186] <Methacryloyl group-containing polymer (A5)> A prepolymer was obtained by copolymerizing 80 parts by mass of 2-ethylhexyl acrylate (2EHA) and 20 parts by mass of HEA. This prepolymer was then reacted with 21.4 parts by mass of 2-methacryloyloxyethyl isocyanate (2-isocyanatoethyl methacrylate, hereinafter referred to as "MOI") (an amount such that the total number of isocyanate groups in 2-methacryloyloxyethyl isocyanate was 0.8 times the total number of moles of hydroxyl groups in the prepolymer) to obtain a methacryloyl group-containing polymer (A5) with a weight-average molecular weight of approximately 1,000,000 and a glass transition temperature of -61°C.

[0187] (Nonionic photobase generator) The compound (E)-N-(bis(dimethylamino)methylene)-3-(2-hydroxyphenyl)acrylamide), which has the following chemical structure, was used.

[0188] [ka]

[0189] (Photoradical initiator) IGM RESINS BV's "Omnirad® 907" 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one

[0190] Each of the above components was mixed in the proportions shown in Table 1 (based on solid content), and diluted with methyl ethyl ketone to a solid content concentration of 50% by mass to prepare a coating solution containing the resin composition.

[0191] (Preparation of sheets for resin film formation) We prepared a first release film (Lintec Corporation, SP-PET382150, 38 μm thick) in which a silicone-based release agent layer is formed on one side of a polyethylene terephthalate (PET) film, and a second release film (Lintec Corporation, SP-PET381031, 38 μm thick) in which a silicone-based release agent layer is formed on one side of a PET film.

[0192] The coating solution prepared above was applied to the release surface of the first release film using a knife coater so that the final thickness of the resin film-forming film would be as shown in Table 1. The film was then dried in an oven at 120°C for 2 minutes to form the resin film-forming film. Next, the release surface of the second release film was placed on top of the resin film-forming film and the two were bonded together to obtain a resin film-forming sheet consisting of the first release film, the resin film-forming film, and the second release film.

[0193] The resin film-forming film obtained from the resin film-forming sheet was used to evaluate film-forming properties, curability, and delayed curing properties using the following method.

[0194] (Evaluation of film-forming properties) The resin film-forming sheet was placed on a horizontal observation table so that the first release film (heavy-peel type release film) was in contact with the observation table. Next, the second release film (light-peel type release film) was peeled off, and the exposed resin film-forming film was visually observed at an angle of 40-50° from the surface and a distance of 30 cm, and evaluated according to the following criteria. The observation was performed under general-purpose fluorescent lighting. Good: The surface of the resin film-forming film was uniform (no irregularities or unevenness were observed). Defect: The surface of the resin film-forming film was uneven (irregularities such as bumps and ridges were observed).

[0195] (Measurement of shear bond strength) First, two polycarbonate sheets measuring 10 mm in width, 45 mm in length, and 1.5 mm in thickness were prepared. After 0.5 hours had elapsed since preparation, the resin film-forming sheet was cut to a size of 10 mm x 5 mm. The second release film (light release film) was peeled off, and the exposed resin film-forming film was attached to a 10 mm wide, 5 mm long area on one edge of one side of one of the polycarbonate sheets, and the first release film (heavy release film) was peeled off. The exposed resin film-forming film was exposed to ultraviolet light with a wavelength of 365 nm at an irradiance of 50 mW / cm². 2 The light intensity is 1600 mJ / cm². 2 The irradiation was performed in such a manner. Immediately afterward, one end of one side of the other polycarbonate sheet was attached to the irradiation surface, with an adhesive area of ​​50 mm². 2 (That is, 10mm wide and 5mm long), and the area where the two polycarbonate sheets overlap when viewed from above is also the same 50mm. 2 The two polycarbonate plates were overlapped in the lengthwise direction and secured with clips, then held at room temperature (23°C) for 1 hour to obtain a test specimen in which the two polycarbonate plates were bonded together with a resin film (adhesive film).

[0196] One end of one polycarbonate sheet without adhesive film was fixed with a fixture on the tensile testing machine, and the other end of the polycarbonate sheet without adhesive film was fixed with the other fixture on the tensile testing machine. The test specimens were pulled lengthwise at a tensile speed of 10 mm / min in an environment of 23°C and 50% relative humidity, and the adhesive film was peeled off in a manner that applied shear force. The stress when the two polycarbonate sheets were peeled off was expressed as the shear adhesive strength (N / 50mm). 2 ) was used. The results are shown in Table 1.

[0197] In addition, two other polycarbonate sheets were prepared, and test specimens were obtained using the same method as the evaluation described above, except that ultraviolet irradiation was omitted. The shear adhesive strength was then measured. The results are shown in Table 1.

[0198] (Evaluation of delayed hardening properties) In the measurement of shear bonding strength described above, the following criteria were used to evaluate the results based on the measurement results after holding the material for 1 hour under UV irradiation. The results are shown in Table 1. Good: Shear bond strength of 30N / 50mm 2 That was all. Defect: Shear bonding strength is 30N / 50mm 2 The film was either too weak or, due to UV irradiation, solidified, making it impossible to bond it to the other polycarbonate sheet.

[0199] [Table 1]

[0200] As shown in Table 1, the energy-curable resin composition of the present invention, comprising an energy-curable polymer having a (meth)acryloyl group and a group containing a β-dicarbonyl structure, and a photobase generator, can exhibit desired delayed curing properties and film-forming properties. Therefore, even when the adherends are bonded together after energy irradiation, sufficient adhesive strength can be achieved.

[0201] In polymer (A4) that does not contain a (meth)acryloyl group and has a group containing a β-dicarbonyl structure, Michael addition did not occur and curing did not occur even when used in combination with a photobase generator (Comparative Example 1).

[0202] When an energy-ray curable polymer (A1) containing a (meth)acryloyl group and a β-dicarbonyl structure was cured with a radical initiator, it solidified immediately upon UV irradiation, making it impossible to bond the other polycarbonate sheet after UV irradiation (Comparative Example 2).

[0203] When polymers containing methacryloyl groups (A5) and polymers having groups containing β-dicarbonyl structures (A4) were used, mixing of the two was difficult, and sufficient film-forming properties could not be obtained (Comparative Example 3). [Industrial applicability]

[0204] The energy-curable resin composition of the present invention can exhibit desired delayed curing properties and film-forming properties, and therefore can exhibit sufficient adhesive strength even when the adherends are bonded together after energy irradiation. [Explanation of Symbols]

[0205] 1…Sheet for forming resin film 10…Resin film forming film 21…First release film 22...Second release film 2… Composite sheet for resin film formation 10…Resin film forming film 4…Adhesive sheet (support sheet)

Claims

1. An energy-ray curable polymer having a (meth)acryloyl group and a group containing a β-dicarbonyl structure.

2. The energy ray curable polymer according to claim 1, wherein the weight-average molecular weight is 50,000 or more.

3. The energy ray curable polymer according to claim 1, wherein the group containing the β-dicarbonyl structure contains a group containing a β-ketoester structure.

4. The energy ray curable polymer according to claim 3, wherein the group containing the β-ketoester structure is a group containing an acetoacetic acid ester structure.

5. The energy ray curable polymer according to claim 1, which is solid at 23°C.

6. An energy ray curable polymer according to any one of claims 1 to 5, Including a photobase generator, Energy ray curable resin composition.

7. The energy ray curable resin composition according to claim 6, wherein the photobase generator is a nonionic photobase generator.

8. The energy ray curable resin composition according to claim 7, wherein the nonionic photobase generator has a group comprising the structure shown in the following formula. 【Chemistry 1】 (In the formula, Rv, Rw, Rx, Ry, and Rz are organic groups.)

9. A coating solution comprising the energy ray curable resin composition according to claim 6.

10. A resin film-forming film comprising the energy ray-curable resin composition according to claim 6.

11. A step of applying the coating liquid according to claim 9 to at least one of the first adherend and the second adherend, The process involves applying the coating solution and then irradiating the coating solution or the dried coating solution with energy rays. A method for manufacturing a laminate, comprising the step of forming a laminate by bonding the first adherend and the second adherend via the coating liquid after irradiation with an energy ray.

12. A step of attaching the resin film forming film according to claim 10 to at least one of the first adherend and the second adherend, The process involves applying the resin film-forming film and then irradiating the resin film-forming film with energy rays. A method for manufacturing a laminate, comprising the step of forming a laminate by bonding the first adherend and the second adherend via the resin film-forming film after irradiation with an energy ray.

13. A method for manufacturing a laminate according to claim 11, wherein at least one of the first adherend and the second adherend is an adherend that blocks energy rays.

14. A method for manufacturing a laminate according to claim 12, wherein at least one of the first adherend and the second adherend is an adherend that blocks energy rays.

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