Resin composition

Abstract

To provide a resin composition which thickens at appropriate speed with lapse of time under room temperature, and has adhesion after thickening.SOLUTION: A resin composition is provided, containing vinyl ester resin (A), an ethylenic unsaturated group-containing resin (B), an ethylenic unsaturated group-containing monomer (C), a compound (D) which is at least one kind selected from oxides of a Group 2 element and hydroxides of the Group 2 element, and a compound (E) which is at least one kind selected from water and a hydroxy group-containing compound. The vinylester resin (A) has a weight average molecular weight Mw of 6,000 or more, and a ratio Mw / Mn of the weight average molecular weight Mw to a number average molecular weight Mn of 2.0 or more, and the ethylenic unsaturated group-containing resin (B) is at least one resin selected from a vinyl ester resin (B1) having a carboxy group and a weight average molecular weight Mw of less than 6,000, and an unsaturated polyester resin (B2) having a carboxy group and a weight average molecular weight Mw of less than 6,000.SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] In recent years, the aging of existing pipes buried underground, such as water supply pipes, sewer pipes, and power pipes, has become serious, and various methods for repairing them have been proposed. For example, Patent Document 1 discloses a method for repairing an existing pipe including a curing step of closely adhering a tubular lining material to the inner wall surface of an existing pipe buried underground, supplying compressed air to the inside of the lining material, and irradiating light on the inner surface of the lining material with a mobile light irradiation device introduced into the inside of the lining material to cure the lining material. Further, as the material of the lining material, a material in which an impregnated base material made of fibers or the like is impregnated with a photocurable resin composition can be used, and as the photocurable resin composition, a polymerizable resin such as an unsaturated polyester resin or a vinyl ester resin dissolved in a solvent such as styrene can be used.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The seamless type lining material for pipe rehabilitation is manufactured as a tubular lining material by impregnating a resin composition containing magnesium oxide or the like into a base material made of glass fiber or the like, thickening it to such an extent that the resin composition can be maintained in a state of being uniformly distributed and held in the base material, and then winding the base material spirally. The tubular lining material manufactured into a tube is lowered vertically from a high place and stored in a zigzag shape. At this time, if the adhesiveness of the overlapping portions of the base material impregnated with the resin composition is insufficient, the tubular shape cannot be maintained and it cannot be used for pipe rehabilitation purposes. The resin composition containing a vinyl ester resin used in the conventional lining material thickens by containing magnesium oxide, but the thickened resin composition has no adhesiveness, so there has been a problem that it cannot be applied to the seamless type lining material.

[0005] The present invention has been made under such circumstances, and an object thereof is to provide a resin composition that thickens at an appropriate rate with the passage of time at room temperature and has adhesiveness after thickening.

Means for Solving the Problems

[0006] That is, the present invention provides the following means. [1] A resin composition containing a vinyl ester resin (A), an ethylenically unsaturated group-containing resin (B), an ethylenically unsaturated group-containing monomer (C), a compound (D) which is at least one selected from oxides of Group 2 elements and hydroxides of Group 2 elements, and a compound (E) which is at least one selected from water and hydroxy group-containing compounds, wherein the vinyl ester resin (A) has a weight average molecular weight Mw of 6,000 or more and a ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn of 2.0 or more, and the ethylenically unsaturated group-containing resin (B) is at least one selected from a vinyl ester resin (B1) having a carboxy group and a weight average molecular weight Mw of less than 6,000 and an unsaturated polyester resin (B2) having a carboxy group and a weight average molecular weight Mw of less than 6,000. [2] The resin composition according to [1] above, wherein the vinyl ester resin (A) is contained in an amount of 50 to 70% by mass and the ethylenically unsaturated group-containing resin (B) is contained in an amount of 30 to 50% by mass, based on a total of 100% by mass of the vinyl ester resin (A) and the ethylenically unsaturated group-containing resin (B). [3] The resin composition according to [1] or [2] above, wherein the weight average molecular weight Mw of the vinyl ester resin (A) is 35,000 or less. [4] The resin composition according to any one of [1] to [3] above, wherein the weight average molecular weight Mw of the vinyl ester resin (A) is 15,000 or less. [5] The resin composition according to any one of [1] to [4] above, wherein the weight average molecular weight Mw of the vinyl ester resin (B1) is 2,000 or more. [6] The resin composition according to any one of [1] to [5] above, wherein the weight average molecular weight Mw of the vinyl ester resin (B1) is 3,000 to 5,000. [7] The resin composition according to any one of [1] to [6] above, wherein the weight average molecular weight Mw of the unsaturated polyester resin (B2) is 1,000 to 10,000. [8] The vinyl ester resin (A) is an addition reaction product of a resin precursor (P1), which is a reaction product of an epoxy compound (a-1) having two epoxy groups in one molecule, an unsaturated monobasic acid (a-2), and a polybasic acid anhydride (a-3), and a polybasic acid anhydride (a-4). The resin composition according to any one of [1] to [7] above, wherein the total amount of acid groups capable of reacting with epoxy groups derived from the polybasic acid anhydride (a-3) is 5 to 25 moles with respect to a total of 100 moles of epoxy groups of the epoxy compound (a-1). [9] The vinyl ester resin (B1) is a reaction product of a resin precursor (Q2) and an unsaturated polybasic acid (b1-4). The resin precursor (Q2) is a vinyl ester resin (B1-1), which is a reaction product of a resin precursor (Q1), which is a reaction product of an epoxy compound (b1-1) having two epoxy groups in one molecule and a bisphenol compound (b1-2), and an unsaturated monobasic acid (b1-3). The resin composition according to any one of [1] to [8] above.

[10] The unsaturated polyester resin (B2) is a reaction product of a diol (b2-1) and a polybasic acid (b2-2), and the polybasic acid (b2-2) includes an ethylenically unsaturated group-containing polybasic acid (b2-2-1) and an ethylenically unsaturated group-free polybasic acid (b2-2-2). The resin composition according to any one of [1] to [9] above.

[11] The vinyl ester resin (A) has an Mw / Mn of 3.0 or more and an acid value of 20 KOHmg / g or more. The resin composition according to any one of [1] to

[10] above.

[12] The ethylenically unsaturated group-containing resin (B) has an acid value of 20 KOHmg / g or more. The resin composition according to any one of [1] to

[11] above.

[13] The ethylenically unsaturated group-containing resin (B) is only the vinyl ester resin (B1). The resin composition according to any one of [1] to

[12] above.

[14] The ethylenically unsaturated group-containing resin (B) includes the vinyl ester resin (B1) and the unsaturated polyester resin (B2). The resin composition according to any one of [1] to

[12] above.

[15] The mass ratio of the vinyl ester resin (B1) to the unsaturated polyester resin (B2) (the vinyl ester resin (B1) / the unsaturated polyester resin (B2)) is 40 / 60 to 80 / 20. The resin composition according to

[14] above.

[16] The compound (D) is at least one selected from magnesium oxide, magnesium hydroxide, calcium oxide, and calcium hydroxide. The resin composition according to any one of [1] to

[15] above. [Effect of the Invention]

[0007] According to the present invention, a resin composition that thickens at a moderate rate with the passage of time at room temperature and has adhesiveness after thickening can be provided. [Brief Description of the Drawings]

[0008]

Figure 1

Mode for Carrying Out the Invention

[0009] The definitions and meanings of terms and notations in this specification are shown below. Preferred numerical ranges can be arbitrarily combined with each of the preferred lower limit value and upper limit value. (Meth)acrylic acid is a general term for acrylic acid and methacrylic acid. Similarly, (meth)acrylate is a general term for acrylate and methacrylate, and (meth)acryloyl is a general term for acryloyl and methacryloyl. The weight average molecular weight (Mw) and number average molecular weight (Mn) are standard polystyrene equivalent molecular weights determined by gel permeation chromatography (GPC) measurement. Specifically, they are measured by the method described in the examples described later. The molecular weight distribution is the calculated value of Mw / Mn. The acid value of the vinyl ester resin and the unsaturated polyester resin is the amount [mg] of potassium hydroxide (KOH) required to neutralize 1 g of the vinyl ester resin or unsaturated polyester resin, measured by a method conforming to JIS K6901:2008. Specifically, it is measured by the method described in the examples described later. The hydroxyl value of the vinyl ester resin is the amount [mg] of potassium hydroxide (KOH) required to neutralize acetic acid generated by acetylation of 1 g of the vinyl ester resin, measured by a method conforming to JIS K6901:2008. Specifically, it is measured by the method described in the examples described later. The viscosity of the resin composition is the value measured at a temperature of 25°C using a B-type viscometer. Specifically, it is measured by the method described in the examples described later.

[0010] [Resin Composition] The resin composition according to an embodiment of the present invention (hereinafter also referred to as the present embodiment) contains a vinyl ester resin (A), an ethylenically unsaturated group-containing resin (B), an ethylenically unsaturated group-containing monomer (C), a compound (D) which is at least one selected from oxides of Group 2 elements and hydroxides of Group 2 elements, and a compound (E) which is at least one selected from water and hydroxy group-containing compounds. The vinyl ester resin (A) has a weight average molecular weight Mw of 6,000 or more, and a ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn of 2.0 or more. The ethylenically unsaturated group-containing resin (B) is at least one selected from a vinyl ester resin (B1) having a carboxyl group and a weight average molecular weight Mw of less than 6,000, and an unsaturated polyester resin (B2) having a carboxyl group and a weight average molecular weight Mw of less than 6,000. By containing both the vinyl ester resin (A) having a predetermined weight average molecular weight and the ethylenically unsaturated group-containing resin (B) having a carboxyl group and a predetermined weight average molecular weight, the resin composition thickens at an appropriate rate with the passage of time at room temperature and has adhesiveness after thickening. The reason is not clear, but it is considered as follows.

[0011] Resin compositions containing vinyl ester resins used for lining materials and the like generally thicken because hydroxyl groups derived from vinyl ester resins, carboxylate anions derived from carboxyl groups, carbonyl groups, etc. coordinate with Group 2 element ions, apparently forming linear polymers. Since the resin composition of the present embodiment contains a relatively high molecular weight vinyl ester resin (A) having a weight average molecular weight Mw of 6,000 or more, it is considered to thicken at an appropriate rate with the passage of time even at room temperature. In addition, the resin composition of the present embodiment contains an ethylenically unsaturated group-containing resin (B) including at least one selected from a vinyl ester resin (B1) having a carboxyl group and having a weight average molecular weight Mw of less than 6,000, and an unsaturated polyester resin (B2) having a carboxyl group and having a weight average molecular weight Mw of less than 6,000. Such an unsaturated polyester resin (B2) is likely to form a polymer having a network structure that is not linear but reticular in appearance. As a result of forming a polymer having a reticular network structure, it is considered that adhesiveness is exhibited in the resin composition.

[0012] <Vinyl ester resin (A)> The vinyl ester resin (A) of the present embodiment is a resin having polymerizability due to an ethylenically unsaturated group, and has a weight average molecular weight Mw of 6,000 or more, and a ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn of 2.0 or more. The vinyl ester resin (A) may be used alone or in combination of two or more.

[0013] From the viewpoint of efficiently thickening, the content of the vinyl ester resin (A) in the resin composition is preferably 30.0% by mass or more, more preferably 40.0% by mass or more, still more preferably 50.0% by mass or more, based on 100% by mass in total of the vinyl ester resin (A) and the ethylenically unsaturated group-containing resin (B). From the viewpoint of further improving the adhesiveness after thickening, it is preferably 80.0% by mass or less, more preferably 75.0% by mass or less, still more preferably 70.0% by mass or less. That is, the content of the vinyl ester resin (A) in the resin composition is preferably 30.0 to 80.0% by mass, more preferably 40.0 to 75.0% by mass, still more preferably 50.0 to 70.0% by mass, based on 100% by mass in total of the vinyl ester resin (A) and the ethylenically unsaturated group-containing resin (B).

[0014] From the perspective of efficiently thickening, the content of the vinyl ester resin (A) in the resin composition is preferably 10.0% by mass or more, more preferably 15.0% by mass or more, still more preferably 20.0% by mass or more. From the perspective of further improving the adhesiveness after thickening, it is preferably 50.0% by mass or less, more preferably 45.0% by mass or less, still more preferably 40.0% by mass or less. That is, the content of the vinyl ester resin (A) in the resin composition is preferably 10.0 to 50.0% by mass, more preferably 15.0 to 45.0% by mass, still more preferably 20.0 to 40.0% by mass.

[0015] In one aspect of the present invention, from the perspective of efficiently obtaining the effects of the present invention, based on 100% by mass in total of the vinyl ester resin (A) and the ethylenically unsaturated group-containing resin (B), the vinyl ester resin (A) is preferably contained in an amount of 50 to 70% by mass, and the ethylenically unsaturated group-containing resin (B) is preferably contained in an amount of 30 to 50% by mass.

[0016] From the perspective of efficiently thickening, the weight average molecular weight Mw of the vinyl ester resin (A) is preferably 6,500 or more, more preferably 7,000 or more, still more preferably 7,500 or more. From the perspective of the ease of handling of the resin composition, it is preferably 35,000 or less, more preferably 25,000 or less, still more preferably 15,000 or less. That is, as an example, the weight average molecular weight Mw of the vinyl ester resin (A) is preferably 6,500 to 35,000, more preferably 7,000 to 25,000, still more preferably 7,500 to 15,000.

[0017] From the viewpoint of efficiently thickening, the number average molecular weight Mn of the vinyl ester resin (A) is preferably 1,000 or more, more preferably 1,200 or more, still more preferably 1,400 or more. From the viewpoint of the ease of handling of the resin composition, it is preferably 6,500 or less, more preferably 4,500 or less, still more preferably 3,000 or less. That is, as an example, the number average molecular weight Mn of the vinyl ester resin (A) is preferably from 1,000 to 6,500, more preferably from 1,200 to 4,500, still more preferably from 1,400 to 3,000.

[0018] From the viewpoint of easy control of the synthesis conditions, the Mw / Mn of the vinyl ester resin (A) is preferably 2.5 or more, more preferably 3.0 or more, still more preferably 4.0 or more. From the viewpoint of suppressing the variation in physical properties of the resin composition and controlling the thickening rate, it is preferably 18 or less, more preferably 12 or less, still more preferably 10 or less.

[0019] From the viewpoint of efficiently thickening the resin composition, the acid value of the vinyl ester resin (A) is preferably 20 KOHmg / g or more, more preferably 23 KOHmg / g or more, still more preferably 25 KOHmg / g or more. Also, from the viewpoint of suppressing excessive thickening, it is preferably 80 KOHmg / g or less, more preferably 60 KOHmg / g or less, still more preferably 50 KOHmg / g or less.

[0020] From the viewpoint of efficiently thickening the resin composition, the hydroxyl value of the vinyl ester resin (A) is preferably 30 KOHmg / g or more, more preferably 40 KOHmg / g or more, still more preferably 50 KOHmg / g or more. Also, from the viewpoint of suppressing excessive thickening, it is preferably 80 KOHmg / g or less, more preferably 75 KOHmg / g or less, still more preferably 70 KOHmg / g or less.

[0021] In one aspect of the present invention, it is preferable that the vinyl ester resin (A) has an Mw / Mn of 3.0 or more and an acid value of 20 KOHmg / g or more.

[0022] The vinyl ester resin (A) is not particularly limited as long as it is a vinyl ester resin having a weight average molecular weight Mw of 6,000 or more and a ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn of 2.0 or more. However, from the viewpoint of moderately increasing the viscosity at room temperature over time, a resin precursor (P1) which is a reaction product of an epoxy compound (a-1) having two epoxy groups in one molecule, an unsaturated monobasic acid (a-2), and a polybasic acid anhydride (a-3), and an addition reaction product of the polybasic acid anhydride (a-4). It is preferable that the total amount of acid groups capable of reacting with the epoxy groups derived from the polybasic acid anhydride (a-3) is 5 to 25 moles with respect to 100 moles of the total amount of the epoxy groups of the epoxy compound (a-1), which is a vinyl ester resin (A1). The vinyl ester resin (A1) contains a plurality of compounds as composition components, and it is common general knowledge for those skilled in the art that various complex reactions can occur involving a plurality of functional groups depending on the blending ratios and reaction conditions of these plurality of compounds. Therefore, it is impossible or impractical at the current level of technology to directly specify and comprehensively represent the specific chemical structure or properties of the vinyl ester resin (A1). Thus, in the present invention, the vinyl ester resin (A1) is specified by the composition of the raw materials.

[0023] In the vinyl ester resin (A1), the epoxy groups of the epoxy compound (a-1) react with the carboxyl groups of the unsaturated monobasic acid (a-2), causing the epoxy groups of the epoxy compound (a-1) to open and form hydroxy groups. The polybasic acid anhydride (a-3) undergoes ring-opening addition to the hydroxy groups, and the carboxyl groups generated by the ring-opening addition of the polybasic acid anhydride (a-3) further react with the unreacted epoxy groups of the epoxy compound (a-1) to crosslink and form a polymer. In addition, since the polybasic acid anhydrides (a-3) and (a-4) are added to the hydroxy groups generated by the ring-opening of the epoxy groups of the epoxy compound (a-1), the total amount of hydroxy groups decreases, and a rapid increase in viscosity immediately after preparing the resin composition can be suppressed. As a result, the impregnability of the fiber base material constituting the lining material is also improved. In addition, since carboxy groups are also introduced by the addition of polybasic acid anhydrides (a-3) and (a-4), the interaction with compound (D) is improved, and the thickening rate of the resin composition is improved.

[0024] When producing vinyl ester resin (A1), first, a resin precursor (P1) which is a reaction product of an epoxy compound (a-1) having two epoxy groups in one molecule, an unsaturated monobasic acid (a-2), and a polybasic acid anhydride (a-3) is obtained. The resin precursor (P1) can be obtained, for example, by mixing at least one of a solvent and a reactive diluent, if necessary, with the epoxy compound (a-1), the unsaturated monobasic acid (a-2), and the polybasic acid anhydride (a-3) in a reaction vessel capable of heating and stirring, and heating with mixing at 1 to 8 hours in the presence of an esterification catalyst, preferably at 70 to 150°C, more preferably at 80 to 140°C, still more preferably at 90 to 130°C.

[0025] The amount of the unsaturated monobasic acid (a-2) used when synthesizing the resin precursor (P1) is preferably such that the total amount of the acid groups of the unsaturated monobasic acid (a-2) is 65 to 95 moles, more preferably 70 to 90 moles, still more preferably 75 to 85 moles, relative to 100 moles of the total amount of the epoxy groups of the epoxy compound (a-1). If the total amount of the acid groups of the unsaturated monobasic acid (a-2) is 65 moles or more relative to 100 moles of the total amount of the epoxy groups of the epoxy compound (a-1), a sufficient amount of ethylenically unsaturated groups is introduced into the vinyl ester resin (A1), so that the resin composition is likely to exhibit good curability. Also, if the total amount of the acid groups of the unsaturated monobasic acid (a-2) is 95 moles or less, the reaction product of the epoxy compound (a-1) and the unsaturated monobasic acid (a-2) and the polybasic acid anhydride (a-3) are sufficiently crosslinked, and a resin composition having good thickening properties is easily obtained.

[0026] When synthesizing the resin precursor (P1), the amount of the polybasic acid anhydride (a-3) used is such that the total amount of acid groups capable of reacting with the epoxy groups of the epoxy compound (a-1) is 5 to 25 moles, preferably 7 to 23 moles, more preferably 9 to 22 moles, per 100 moles of the total amount of epoxy groups of the epoxy compound (a-1). When the total amount of acid groups derived from the polybasic acid anhydride (a-3) that can react with the epoxy groups is 5 moles or more per 100 moles of the total amount of epoxy groups of the epoxy compound (a-1), crosslinking between the epoxy compound (a-1) and the polybasic acid anhydride (a-3) increases the molecular weight, and the resin composition can be efficiently thickened. Also, when the total amount of acid groups derived from the polybasic acid anhydride (a-3) that can react with the epoxy groups is 25 moles or less, it is easy to control the degree of crosslinking of the epoxy compound (a-1), gelation during synthesis is suppressed, and the thickening rate of the resin composition is easily controlled.

[0027] The total amount of acid groups (the "acid groups" referred to here are the acid groups generated by hydrolysis of the polybasic acid anhydride (a-3). For example, when the polybasic acid anhydride (a-3) is a dibasic acid anhydride, the number of acid groups generated from 1 molecule is 2.) derived from the unsaturated monobasic acid (a-2) and the polybasic acid anhydride (a-3) used when synthesizing the resin precursor (P1) is preferably an amount such that it is 90 to 125 moles, more preferably 93 to 120 moles, and even more preferably 95 to 110 moles, per 100 moles of the total amount of epoxy groups of the epoxy compound (a-1). When the total amount of acid groups derived from the unsaturated monobasic acid (a-2) and the polybasic acid anhydride (a-3) is 90 moles or more per 100 moles of the total amount of epoxy groups of the epoxy compound (a-1), the amount of unreacted epoxy groups of the epoxy compound (a-1) is reduced, and the thickening rate of the resin composition is easily controlled. Also, when the total amount of acid groups derived from the unsaturated monobasic acid (a-2) and the polybasic acid anhydride (a-3) is 125 moles or less, gelation during synthesis is suppressed, and the remaining amount of unreacted unsaturated monobasic acid (a-2) and polybasic acid anhydride (a-3) is suppressed, and the thickening rate of the resin composition is easily controlled.

[0028] After obtaining the resin precursor (P1), the vinyl ester resin (A1) is obtained by reacting the resin precursor (P1) with the polybasic acid anhydride (a-4). By reacting the resin precursor (P1) with the polybasic acid anhydride (a-4), the epoxy compound (a-1) can be crosslinked or a carboxy group can be introduced into the resin precursor (P1) by the same reaction mechanism as that of the polybasic acid anhydride (a-3). That is, the polybasic acid anhydride (a-4) adds to the hydroxy group generated by the ring opening of the epoxy group of the epoxy compound (a-1) and generates a carboxy group. This carboxy group reacts with the unreacted epoxy group of the epoxy compound (a-1) and the crosslinking proceeds. After all the epoxy groups have reacted, the carboxy group derived from the polybasic acid anhydride (a-4) remains as it is, and a carboxy group is introduced into the resin.

[0029] The reaction between the resin precursor (P1) and the polybasic acid anhydride (a-4) is carried out, for example, by adding the polybasic acid anhydride (a-4) to the reaction vessel in which the resin precursor (P1) is synthesized and reacting at 70 to 150 °C, preferably 80 to 140 °C, more preferably 90 to 130 °C for 30 minutes to 4 hours in the presence of an esterification catalyst.

[0030] In the vinyl ester resin (A1), the amount of the polybasic acid anhydride (a-4) is preferably such that the total amount of the acid groups derived from the polybasic acid anhydride (a-4) is 3 to 40 moles, more preferably 3 to 35 moles, still more preferably 5 to 30 moles, and even more preferably 7 to 20 moles, per 100 moles of the total amount of the epoxy groups of the epoxy compound (a-1). If the total amount of acid groups derived from the polybasic acid anhydride (a-4) is 3 mol or more per 100 mol of the total amount of epoxy groups of the epoxy compound (a-1), the amount of carboxyl groups necessary for increasing the thickening rate of the resin composition is introduced into the vinyl ester resin (A1), and the hydroxyl groups generated by the ring-opening of the epoxy groups derived from the epoxy compound (a-1) are consumed by the addition of the polybasic acid anhydride (a-4), thereby suppressing the increase in viscosity after 1 hour from the preparation of the resin composition. Further, when the total amount of acid groups derived from the polybasic acid anhydride (a-4) is 60 mol or less, it becomes easier to control the thickening rate of the resin composition.

[0031] Examples of the esterification catalyst used for the production of the vinyl ester resin (A1), which is an addition reaction product of the resin precursor (P1) and the polybasic acid anhydride (a-4), include tertiary amines such as triethylamine, triethylenediamine, N,N-dimethylbenzylamine, N,N-dimethylaniline, 2,4,6-tris(dimethylaminomethyl)phenol, and diazabicyclooctane; phosphorus compounds such as triphenylphosphine and benzyltriphenylphosphonium chloride; diethylamine hydrochloride; quaternary ammonium salts such as trimethylbenzylammonium chloride and tetradecyldimethylbenzylammonium chloride; and lithium salts such as lithium chloride, lithium bromide, and lithium nitrate. These may be used alone or in combination of two or more. Among these, from the viewpoints of gently promoting the synthesis reaction rate of the vinyl ester resin, suppressing gelation, and easily controlling the molecular weight distribution appropriately, at least one selected from phosphorus compounds and quaternary ammonium salts is preferable, and at least one selected from quaternary ammonium salts is more preferable.

[0032] The esterification catalyst used when producing the resin precursor (P1) and the esterification catalyst used when producing the vinyl ester resin (A1) from the resin precursor (P1) may be the same or different. The amount of the esterification catalyst used is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 4 parts by mass, and still more preferably 0.1 to 3 parts by mass, based on 100 parts by mass in total of the epoxy compound (a-1), the unsaturated monobasic acid (a-2), and the polybasic acid anhydride (a-3), from the viewpoint of promoting the reaction while suppressing the thickening of the resin precursor (P1).

[0033] The solvents and reactive diluents used in the production of the vinyl ester resin (A1) are not particularly limited as long as they are solvents inert to the epoxy compound (a-1), the unsaturated monobasic acid (a-2), the polybasic acid anhydride (a-3), and the polybasic acid anhydride (a-4). For example, known solvents having a boiling point at 1 atm of 70 to 270°C such as methyl isobutyl ketone, benzyl methacrylate, ethylene glycol dimethacrylate, phenoxyethyl methacrylate, and styrene can be mentioned. The solvents may be used alone or in combination of two or more. As the reactive diluent, an ethylenically unsaturated group-containing monomer (C) inert to the epoxy compound (a-1), the unsaturated monobasic acid (a-2), the polybasic acid anhydride (a-3), and the polybasic acid anhydride (a-4) is preferable.

[0034] (Epoxy compound (a-1)) The epoxy compound (a-1) is a compound having two epoxy groups in one molecule, and monomers, oligomers, and polymers in general can be used, and its molecular weight and molecular structure are not particularly limited. The epoxy compound (a-1) may be used alone or in combination of two or more. Examples of the epoxy compound (a-1) include bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and bisphenol AF type epoxy resin; phenol novolac type epoxy resin; tert-butylcatechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidyl ester type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin having a butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexanedimethanol type epoxy resin, naphthylene ether type epoxy resin, and the like. Among them, from the viewpoint of suppressing the excessive increase in the viscosity reached by the resin composition and controlling the thickening rate, one or more selected from bisphenol type epoxy resins and phenol novolac type epoxy resins are preferable, and one or more selected from bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, and phenol novolac type epoxy resin are more preferable, and bisphenol A type epoxy resin is even more preferable.

[0035] From the viewpoint of controlling the thickening rate, the epoxy equivalent of the epoxy compound (a-1) is preferably 170 to 1,000, more preferably 170 to 500, still more preferably 170 to 400, and even more preferably 170 to 300.

[0036] From the viewpoint of ease of synthesis, the epoxy compound (a-1) is preferably liquid under the condition of 25°C, and those having an epoxy equivalent of 300 or less are preferably used.

[0037] (Unsaturated monobasic acid (a-2)) The unsaturated monobasic acid (a-2) is preferably a monocarboxylic acid having an ethylenically unsaturated group, and may be used alone or in combination of two or more. Examples of the unsaturated monobasic acid (a-2) include (meth)acrylic acid, crotonic acid, cinnamic acid, etc. Among them, from the viewpoints of versatility, reactivity during the synthesis of the vinyl ester resin (A1), and obtaining a resin composition having good curability, at least one selected from (meth)acrylic acid and crotonic acid is preferable, (meth)acrylic acid is more preferable, and from the viewpoint of chemical resistance, methacrylic acid is even more preferable.

[0038] (Polybasic acid anhydride (a-3)) The polybasic acid anhydride (a-3) is a compound having a plurality of carboxy groups in one molecule, and at least two carboxy groups are dehydrated and condensed to form an acid anhydride. Among these, dibasic acid anhydrides are preferable from the viewpoints of ease of synthesis, ease of controlling the molecular weight and acid value, and the thickening rate of the resin composition. The polybasic acid anhydride (a-3) may be used alone or in combination of two or more.

[0039] Examples of the polybasic acid anhydride (a-3) include maleic anhydride, phthalic anhydride, succinic anhydride, endomethylenetetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 3-methyl-1,2,3,6-tetrahydrophthalic anhydride, 4-methyl-1,2,3,6-tetrahydrophthalic anhydride, 3-methyl-hexahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride, methyl-3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride, trimellitic anhydride, etc. Among these, maleic anhydride and phthalic anhydride are preferable, and maleic anhydride is more preferable, from the viewpoints of availability, reactivity, ease of handling during synthesis, etc.

[0040] (Polybasic acid anhydride (a-4)) The polybasic acid anhydride (a-4) is a compound having a plurality of carboxy groups in one molecule, and at least two carboxy groups are dehydrated and condensed to form an acid anhydride. Among them, dibasic acid anhydrides are preferred from the viewpoints of ease of handling during the synthesis of the vinyl ester resin (A1), ease of controlling the molecular weight and acid value, and good viscosity characteristics of the resin composition. The polybasic acid anhydride (a-4) may be used alone or in combination of two or more. Specific examples of the polybasic acid anhydride (a-4) include the same ones as the polybasic acid anhydride (a-3), and maleic anhydride is more preferred. The polybasic acid anhydride (a-3) and the polybasic acid anhydride (a-4) may be the same or different.

[0041] <Ethylene unsaturated group-containing resin (B)> The ethylene unsaturated group-containing resin (B) of the present embodiment contains at least one selected from a vinyl ester resin (B1) having a carboxyl group and a weight average molecular weight Mw of less than 6,000 and an unsaturated polyester resin (B2) having a carboxyl group and a weight average molecular weight Mw of less than 6,000. The ethylene unsaturated group-containing resin (B) may contain the vinyl ester resin (B1) and not contain the unsaturated polyester resin (B2), may not contain the vinyl ester resin (B1) and contain the unsaturated polyester resin (B2), or may contain both the vinyl ester resin (B1) and the unsaturated polyester resin (B2).

[0042] From the viewpoint of further improving the adhesiveness after thickening, the acid value of the ethylene unsaturated group-containing resin (B) is preferably 20 KOHmg / g or more, more preferably 23 KOHmg / g or more, and still more preferably 25 KOHmg / g or more. Also, from the viewpoint of efficiently thickening the resin composition, it is preferably 80 KOHmg / g or less, more preferably 60 KOHmg / g or less, and still more preferably 50 KOHmg / g or less.

[0043] The content of the ethylenically unsaturated group-containing resin (B) in the resin composition is preferably 20.0% by mass or more, more preferably 25.0% by mass or more, still more preferably 30.0% by mass or more, from the viewpoint of further improving the adhesiveness after thickening, with respect to 100% by mass in total of the vinyl ester resin (A) and the ethylenically unsaturated group-containing resin (B). From the viewpoint of ensuring the thickening property of the resin composition, it is preferably 70.0% by mass or less, more preferably 60.0% by mass or less, still more preferably 50.0% by mass or less. That is, the content of the vinyl ester resin (A) in the resin composition is preferably 20.0 to 70.0% by mass, more preferably 25.0 to 60.0% by mass, still more preferably 30.0 to 50.0% by mass, with respect to 100% by mass in total of the vinyl ester resin (A) and the ethylenically unsaturated group-containing resin (B).

[0044] The content of the ethylenically unsaturated group-containing resin (B) in the resin composition is preferably 5.0% by mass or more, more preferably 6.0% by mass or more, still more preferably 7.0% by mass or more, from the viewpoint of further improving the adhesiveness after thickening. From the viewpoint of ensuring the thickening property of the resin composition, it is preferably 40.0% by mass or less, more preferably 35.0% by mass or less, still more preferably 30.0% by mass or less. That is, the content of the ethylenically unsaturated group-containing resin (B) in the resin composition is preferably 5.0 to 40.0% by mass, more preferably 6.0 to 35.0% by mass, still more preferably 7.0 to 20.0% by mass.

[0045] The ethylenically unsaturated group-containing resin (B) may contain the vinyl ester resin (B1) alone, may contain the unsaturated polyester resin (B2) alone, or may contain both the vinyl ester resin (B1) and the unsaturated polyester resin (B2). The ethylenically unsaturated group-containing resin (B) may be used alone or in combination of two or more.

[0046] The total content of the vinyl ester resin (B1) and the unsaturated polyester resin (B2) in the ethylenically unsaturated group-containing resin (B) is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and may be 100% by mass.

[0047] In one aspect of the present invention, the ethylenically unsaturated group-containing resin (B) preferably contains a vinyl ester resin (B1) from the viewpoints of efficiently thickening the resin composition and the strength physical properties and chemical resistance of the cured product, and more preferably consists only of the vinyl ester resin (B1). In another aspect of the present invention, the ethylenically unsaturated group-containing resin (B) preferably contains a vinyl ester resin (B1) and an unsaturated polyester resin (B2) from the viewpoint of further improving the adhesiveness. When the ethylenically unsaturated group-containing resin (B) contains a vinyl ester resin (B1) and an unsaturated polyester resin (B2), the mass ratio of the vinyl ester resin (B1) to the unsaturated polyester resin (B2) (vinyl ester resin (B1) / unsaturated polyester resin (B2)) is preferably 40 / 60 to 80 / 20, more preferably 50 / 50 to 70 / 30, and still more preferably 55 / 45 to 65 / 35.

[0048] [Vinyl ester resin (B1)] The vinyl ester resin (B1) has a carboxyl group and a weight average molecular weight Mw of less than 6,000. The vinyl ester resin (B1) may be used alone or in combination of two or more. The weight average molecular weight Mw of the vinyl ester resin (B1) is preferably 2,000 or more, more preferably 3,000 or more, still more preferably 3,200 or more, from the viewpoint of efficiently thickening, and is preferably 5,500 or less, more preferably 5,000 or less, still more preferably 4,800 or less, from the viewpoint of further improving the adhesiveness after thickening. That is, the weight average molecular weight Mw of the vinyl ester resin (B1) is preferably 2,000 to 5,500, more preferably 3,000 to 5,000, still more preferably 3,200 to 4,800.

[0049] The number average molecular weight Mn of the vinyl ester resin (B1) is preferably 400 or more, more preferably 600 or more, still more preferably 800 or more, from the viewpoint of efficiently thickening, and is preferably 3,000 or less, more preferably 2,500 or less, still more preferably 2,000 or less, from the viewpoint of further improving the adhesiveness after thickening. That is, the number average molecular weight Mn of the vinyl ester resin (B1) is preferably 400 to 3,000, more preferably 600 to 2,500, still more preferably 800 to 2,000.

[0050] The Mw / Mn of the vinyl ester resin (B1) is preferably 1.0 or more, more preferably 1.1 or more, still more preferably 1.3 or more, from the viewpoint of ease of synthesis control, and is preferably 3.0 or less, more preferably 2.7 or less, still more preferably 2.5 or less, from the viewpoint of suppressing the variation in physical properties of the resin composition and controlling the thickening rate.

[0051] The vinyl ester resin (B1) is not particularly limited as long as it is a vinyl ester resin having a carboxyl group and a weight average molecular weight Mw of less than 6,000. However, from the viewpoint of further improving the adhesiveness after thickening, it is a reaction product of a resin precursor (Q2) and an unsaturated polybasic acid (b1-4), and the resin precursor (Q2) is a reaction product of an epoxy compound (b1-1) having two epoxy groups in one molecule and a bisphenol compound (b1-2). It is preferably a vinyl ester resin (B1-1) which is a reaction product of a resin precursor (Q1) and an unsaturated monobasic acid (b1-3). The vinyl ester resin (B1-1) contains a plurality of compounds as its constituent components. It is common general knowledge in the art that depending on the blending ratios and reaction conditions of these plurality of compounds, etc., a plurality of functional groups can participate and various complex reactions can occur. Therefore, it is impossible or impractical at the current level of technology to directly specify and comprehensively represent the specific chemical structure or properties of the vinyl ester resin (B1-1). Thus, in the present invention, the vinyl ester resin (B1-1) is specified by the composition of its raw materials.

[0052] When producing the vinyl ester resin (B1-1), first, a resin precursor (Q1) which is a reaction product of an epoxy compound (b1-1) having two epoxy groups in one molecule and a bisphenol compound (b1-2) is obtained. The resin precursor (Q1) can be obtained, for example, by mixing an epoxy compound (b1-1) and a bisphenol compound (b1-2) with at least one of a solvent and a reactive diluent as necessary in a reaction vessel capable of heating and stirring, and heating with mixing at 1 to 3 hours in the presence of an esterification catalyst, preferably at 70 to 160°C, more preferably at 80 to 155°C, still more preferably at 90 to 150°C.

[0053] When synthesizing the vinyl ester resin (B1-1), the amount of the bisphenol compound (b1-2) used is preferably such that the total amount of the hydroxyl groups of the bisphenol compound (b1-2) is 10 to 70 moles, more preferably 15 to 60 moles, and even more preferably 20 to 55 moles, per 100 moles of the total amount of the epoxy groups of the epoxy compound (b1-1).

[0054] If the total amount of the hydroxyl groups of the bisphenol compound (b1-2) is 10 moles or more per 100 moles of the total amount of the epoxy groups of the epoxy compound (b1-1), the molecular weight distribution of the vinyl ester resin (B1) broadens, making it easier to control the final viscosity of the resin composition. Also, if the total amount of the bisphenol compound (b1-2) is 70 moles or less per 100 moles of the total amount of the epoxy groups of the epoxy compound (b1-1), it becomes easier to control the thickening rate of the resin composition.

[0055] After obtaining the resin precursor (Q1), the resin precursor (Q2) is obtained by reacting the resin precursor (Q1) with the unsaturated monobasic acid (b1-3). The reaction between the resin precursor (Q1) and the unsaturated monobasic acid (b1-3) is carried out, for example, by adding the unsaturated monobasic acid (b1-3) in the reaction vessel where the resin precursor (Q1) is synthesized, in the presence of an esterification catalyst, and heating with mixing at 70 to 150 °C, preferably 80 to 140 °C, and even more preferably 90 to 130 °C for 30 minutes to 4 hours.

[0056] When synthesizing the vinyl ester resin (B1), the amount of the unsaturated monobasic acid (b1-3) used is preferably such that the total amount of the acid groups of the unsaturated monobasic acid (b1-3) is 30 to 100 moles, more preferably 35 to 80 moles, and even more preferably 38 to 70 moles, per 100 moles of the total amount of the epoxy groups of the epoxy compound (b1-1).

[0057] If the total amount of the acid groups of the unsaturated monobasic acid (b1-3) is 30 mol or more with respect to 100 mol of the total amount of the epoxy groups of the epoxy compound (b1-1), a sufficient amount of ethylenically unsaturated groups is introduced into the vinyl ester resin (B1), so that the resin composition is likely to exhibit good curability. Further, from the viewpoints of controlling the thickening rate and suppressing the uneven distribution of the resin composition after curing, and from the viewpoint of production stability, it is preferable that the total amount of the acid groups of the unsaturated monobasic acid (b1-3) is 100 mol or less with respect to 100 mol of the total amount of the epoxy groups of the epoxy compound (b1-1).

[0058] After obtaining the resin precursor (Q2), the vinyl ester resin (B1) is obtained by reacting the resin precursor (Q2) with the unsaturated polybasic acid (b1-4). By this reaction, carboxy groups are introduced into the vinyl ester resin (B1). The reaction of the resin precursor (Q2) with the unsaturated polybasic acid (b1-4) is, for example, adding the unsaturated polybasic acid (b1-4) in the reaction vessel in which the resin precursor (Q2) is synthesized in the presence of an esterification catalyst, and heating while mixing at 70 to 150 ° C, preferably 80 to 140 ° C, more preferably 90 to 130 ° C for 30 minutes to 4 hours.

[0059] The amount of the unsaturated polybasic acid (b1-4) used when synthesizing the vinyl ester resin (B1-1) is preferably such that the total amount of the acid groups derived from the unsaturated polybasic acid (a-4) is 10 to 40 mol, more preferably 13 to 30 mol, and still more preferably 15 to 25 mol with respect to 100 mol of the total amount of the epoxy groups of the epoxy compound (b1-1).

[0060] If the total amount of the acid groups derived from the unsaturated polybasic acid (b1-4) is 10 mol or more with respect to 100 mol of the total amount of the epoxy groups of the epoxy compound (b1-1), a sufficient amount of carboxy groups is introduced into the vinyl ester resin (B1), so that the adhesiveness after thickening of the resin composition is improved. Further, from the viewpoint of controlling the thickening rate, it is preferable that the total amount of the acid groups derived from the unsaturated polybasic acid (b1-4) is 40 mol or less with respect to 100 mol of the total amount of the epoxy groups of the epoxy compound (b1-1).

[0061] The esterification catalyst used in the production of the vinyl ester resin (B1-1) may be the same as the esterification catalyst used in the production of the vinyl ester resin (A1). Also, the esterification catalyst used when producing the resin precursor (Q1), the esterification catalyst used when producing the resin precursor (Q2), and the esterification catalyst used when producing the vinyl ester resin (B1-1) from the resin precursor (Q2) may be the same or different. Also, in the production of the vinyl ester resin (B1-1), a solvent, a reactive diluent, a polymerization inhibitor, etc. may be used as necessary. Examples of the solvent and the reactive diluent used in the production of the vinyl ester resin (B1-1) are the same as those used in the production of the vinyl ester resin (A1), and the preferred embodiments are also the same.

[0062] The vinyl ester resin (B1) may contain a vinyl ester resin (B1-2) which is a reaction product of an epoxy compound (b1-1) having two or more epoxy groups in one molecule and an unsaturated monobasic acid (b1-3). When the resin composition contains the reaction product, the resin composition thickens more due to the interaction between the hydroxy group generated by the ring-opening of the epoxy group of the epoxy compound (b1-1) and the compound (D).

[0063] From the viewpoint of more efficiently thickening, the weight average molecular weight Mw of the vinyl ester resin (B1-2) is preferably 400 or more, more preferably 600 or more, still more preferably 800 or more, and from the viewpoint of controlling the thickening rate of the resin composition, it is preferably 2,000 or less, more preferably 1,500 or less, still more preferably 1,200 or less.

[0064] From the viewpoint of efficiently thickening the resin composition, the number average molecular weight Mn of the vinyl ester resin (B1-2) is preferably 400 or more, more preferably 500 or more, still more preferably 600 or more, and from the viewpoint of controlling the thickening rate of the resin composition, it is preferably 1,500 or less, more preferably 1,200 or less, still more preferably 1,000 or less.

[0065] From the viewpoint of ease of synthesis control, the Mw / Mn of the vinyl ester resin (B1-2) is preferably 1.05 or more, more preferably 1.1 or more, and from the viewpoint of suppressing variations in the physical properties of the resin composition and controlling the thickening rate, it is preferably 2.0 or less, more preferably 1.7 or less, and still more preferably 1.5 or less.

[0066] In the reaction product of the epoxy compound (b1-1) and the unsaturated monobasic acid (b1-3), the amount of the unsaturated monobasic acid (b1-3) is preferably such that the total amount of the acid groups of the unsaturated monobasic acid (b1-3) is 80 mol or more with respect to 100 mol of the total amount of the epoxy groups of the epoxy compound (b1-1), more preferably 90 mol or more, still more preferably 99 mol or more, and preferably 120 mol or less, more preferably 110 mol or less, and still more preferably 105 mol or less. If the total amount of the acid groups of the unsaturated monobasic acid (b1-3) is 80 mol or more with respect to 100 mol of the total amount of the epoxy groups of the epoxy compound (b1-1), a sufficient amount of ethylenically unsaturated groups is introduced into the resin, so that the resin composition is likely to exhibit good curability.

[0067] The content of the vinyl ester resin (B1-2) in the vinyl ester resin (B1) is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 35% by mass or less, and may be 0% by mass.

[0068] (Epoxy compound (b1-1)) The epoxy compound (b1-1) is a compound having two epoxy groups in one molecule, and monomers, oligomers, and polymers in general can be used, and its molecular weight and molecular structure are not particularly limited. The epoxy compound (b1-1) may be used alone or in combination of two or more. Specific examples of the epoxy compound (b1-1) are the same as those of the epoxy compound (a-1), and the preferred embodiments are also the same.

[0069] (Bisphenol compound (b1-2)) The bisphenol compound (b1-2) is not particularly limited in terms of its molecular weight and molecular structure. The bisphenol compound (b1-2) may be used alone or in combination of two or more. Examples of the bisphenol compound (b1-2) include bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol PH, bisphenol TMC, bisphenol Z, etc. Among them, from the viewpoint of controlling the thickening rate, at least one selected from bisphenol A, bisphenol E, bisphenol F, and bisphenol S is preferable, more preferably bisphenol A, bisphenol E, and bisphenol F, and even more preferably bisphenol A from the viewpoints of corrosion resistance, versatility, and cost.

[0070] (Unsaturated monobasic acid (b1-3)) The unsaturated monobasic acid (b1-3) is preferably a monocarboxylic acid having an ethylenic unsaturated group, and may be used alone or in combination of two or more. Examples of the unsaturated monobasic acid (b1-3) are the same as those of the unsaturated monobasic acid (a-2), and the preferred embodiments are also the same.

[0071] (Polybasic acid anhydride (b1-4)) The polybasic acid anhydride (b1-4) is a compound having a plurality of carboxy groups in one molecule, and at least two carboxy groups are dehydrated and condensed to form an acid anhydride. Among them, dibasic acid anhydrides are preferable from the viewpoints of ease of synthesis and good viscosity characteristics, etc. The polybasic acid anhydride (b1-4) may be used alone or in combination of two or more. Examples of the polybasic acid anhydride (b1-4) are the same as those of the polybasic acid anhydride (a-3), and the preferred embodiments are also the same.

[0072] [Unsaturated polyester resin (B2)] The unsaturated polyester resin (B2) has a carboxyl group. As the unsaturated polyester resin (B2), those obtained by subjecting a polybasic acid component containing an unsaturated dibasic acid and, if necessary, a saturated polybasic acid, and a polyhydric alcohol to an esterification reaction can be used. The unsaturated polyester resin (B2) may be used alone or in combination of two or more. From the viewpoint of efficiently thickening, the weight average molecular weight Mw of the unsaturated polyester resin (B2) is preferably 1,000 or more, more preferably 1,500 or more, still more preferably 2,000 or more. From the viewpoint of further improving the adhesiveness after thickening, it is preferably 10,000 or less, more preferably 8,000 or less, still more preferably 6,000 or less. That is, the weight average molecular weight Mw of the unsaturated polyester resin (B2) is preferably 1,000 to 10,000, more preferably 1,500 to 8,000, still more preferably 2,000 to 6,000.

[0073] From the viewpoint of efficiently thickening, the number average molecular weight Mn of the unsaturated polyester resin (B2) is preferably 400 or more, more preferably 500 or more, still more preferably 600 or more. From the viewpoint of further improving the adhesiveness after thickening, it is preferably 5,000 or less, more preferably 4,000 or less, still more preferably 3,000 or less.

[0074] From the viewpoint of ease of synthesis control, Mw / Mn of the unsaturated polyester resin (B2) is preferably 1.0 or more, more preferably 1.5 or more, still more preferably 2.0 or more. From the viewpoint of suppressing the variation in physical properties of the resin composition and controlling the thickening rate, it is preferably 10.0 or less, more preferably 8.0 or less, still more preferably 6.0 or less.

[0075] The unsaturated polyester resin (B2) is a reaction product of a diol (b2-1) and a polybasic acid (b2-2). From the viewpoint of further improving the tackiness after thickening, it is preferable that the polybasic acid (b2-2) contains an ethylenically unsaturated group-containing polybasic acid (b2-2-1) and an ethylenically unsaturated group-free polybasic acid (b2-2-2).

[0076] The unsaturated polyester resin (B2), which is a reaction product of a diol (b2-1) and a polybasic acid (b2-2), can be produced, for example, by reacting a diol (a2-1), an ethylenically unsaturated group-containing polybasic acid (a2-2-1), and an ethylenically unsaturated group-free polybasic acid (a2-2-2) in a reaction vessel capable of heating and stirring at 150 to 250 °C, preferably 170 to 240 °C, more preferably 180 to 230 °C for 8 to 15 hours.

[0077] The amount of the polybasic acid (b2-2) in the unsaturated polyester resin (B2) is preferably such that the total amount of the polybasic acid (b2-2) is 80 to 130 moles, more preferably 90 to 120 moles, and even more preferably 95 to 115 moles, based on 100 moles of the total amount of the diol (b2-1).

[0078] The content ratio (molar ratio) of the structural unit derived from the diol (b2-1) and the structural unit derived from the polybasic acid (b2-2) contained in the unsaturated polyester resin (B2) is preferably 40:60 to 60:40, more preferably 45:55 to 55:45, from the viewpoint of introducing a sufficient amount of carboxy groups into the vinyl ester resin (B2) and improving the tackiness after thickening of the resin composition.

[0079] (Diol (b2-1)) The diol (b2-1) is a compound having two hydroxyl groups in one molecule. From the viewpoint of further improving the tackiness after thickening, for example, alkanediol, glycol ether, etc. are preferably used. The diol may be used alone or in combination of two or more. Examples of the alkanediol include ethylene glycol, propylene glycol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol, 1,2-octanediol, 1,2-nonanediol, 1,4-cyclohexanediol, 1,8-octanediol, 1,9-nonanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2-bis(4-hydroxycyclohexyl)propane, and hydrides of bisphenol A, bisphenol F, and bisphenol S, etc. Examples of the glycol ether include diethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, etc. Among them, from the viewpoints of availability, ease of handling of the resin composition, and production cost, etc., 2-methyl-1,3-propanediol, ethylene glycol, propylene glycol, neopentyl glycol, diethylene glycol, dipropylene glycol, and hydride of bisphenol A are preferable, 2-methyl-1,3-propanediol, ethylene glycol, propylene glycol, neopentyl glycol, diethylene glycol, and dipropylene glycol are more preferable, and ethylene glycol, propylene glycol, and dipropylene glycol are even more preferable.

[0080] (Polybasic acid (b2-2)) The polybasic acid (b2-2) preferably contains an ethylenically unsaturated group-free polybasic acid (b2-2-1) and an ethylenically unsaturated group-containing polybasic acid (b2-2-2).

[0081] <<Polybasic acid without ethylenically unsaturated group (b2-2-1)>> The polybasic acid without ethylenically unsaturated group (b2-2-1) is a compound having two carboxy groups (including acid anhydrides) in one molecule and no ethylenically unsaturated group. The polybasic acid without ethylenically unsaturated group (b2-2-1) may be used alone or in combination of two or more. Examples of the polybasic acid without ethylenically unsaturated group (b2-2-1) include phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, tetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, hexahydrophthalic acid (1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid), naphthalenedicarboxylic acid, trimellitic acid, pyromellitic acid, chlorendic acid (het acid), tetrabromophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, succinic anhydride, chlorendic anhydride, trimellitic anhydride, pyromellitic anhydride, 4-methylphthalic acid, 5-methylisophthalic acid, 5-methylterephthalic acid and the like. Among them, phthalic anhydride is preferable from the viewpoint of further improving the adhesiveness after thickening.

[0082] From the viewpoint of further improving the adhesiveness after thickening, the content of the polybasic acid without ethylenically unsaturated group (b2-2-1) is preferably 20 mol% or more, more preferably 30 mol% or more, still more preferably 40 mol% or more, even more preferably 50 mol% or more, preferably 80 mol% or less, more preferably 75 mol% or less, still more preferably 70 mol% or less, and even more preferably 65 mol% or less, based on 100 mol% of the polybasic acid (b2-2). That is, the content of the polybasic acid without ethylenically unsaturated group (b2-2-1) is preferably 20 to 80 mol%, more preferably 30 to 75 mol%, still more preferably 40 to 70 mol%, and even more preferably 50 to 65 mol%, based on 100 mol% of the polybasic acid (b2-2).

[0083] <<Polybasic acid with ethylenically unsaturated group (b2-2-2)>> The ethylenically unsaturated group-containing polybasic acid (b2-2-2) is a compound having at least two carboxy groups (including acid anhydrides) and at least one ethylenically unsaturated group in one molecule. The ethylenically unsaturated group-containing polybasic acid (b2-2-2) may be used alone or in combination of two or more. Examples of the ethylenically unsaturated group-containing polybasic acid (b2-2-2) include maleic anhydride, fumaric acid, itaconic acid, citraconic acid, chloromaleic acid and the like. Among these, from the viewpoints of easy availability, ease of handling of the resin composition, manufacturing cost and the like, maleic anhydride and fumaric acid are preferable, and maleic anhydride is preferably used.

[0084] The content of the ethylenically unsaturated group-containing polybasic acid (b2-2-2) in the polybasic acid (b2-2) is preferably 20 mol% or more, more preferably 25 mol% or more, still more preferably 30 mol% or more, and preferably 80 mol% or less, more preferably 70 mol% or less, still more preferably 60 mol% or less, from the viewpoint of further improving the adhesiveness after thickening, based on 100 mol% of the polybasic acid (b2-2). That is, the content of the ethylenically unsaturated group-containing polybasic acid (b2-2-2) in the polybasic acid (b2-2) is preferably 20 to 80 mol%, more preferably 25 to 70 mol%, still more preferably 30 to 60 mol%, based on 100 mol% of the polybasic acid (b2-2).

[0085] <Ethylenically unsaturated group-containing monomer (C)> The ethylenically unsaturated group-containing monomer (C) of the present embodiment is a monomer having polymerizability due to an ethylenically unsaturated group. Examples of the ethylenically unsaturated group include a vinyl group (including an allyl group), a (meth)acryloyl group and the like. The ethylenically unsaturated group-containing monomer (C) may be used alone or in combination of two or more.

[0086] Examples of the monomer having a vinyl group include styrene derivatives such as styrene, p-chlorostyrene, vinyltoluene, α-methylstyrene, dichlorostyrene, divinylbenzene, tert-butylstyrene, vinylbenzyl butyl ether, vinylbenzyl hexyl ether, divinylbenzyl ether, etc.; vinyl acetate, diallyl fumarate, diallyl phthalate, triallyl isocyanurate, etc.

[0087] Examples of the monomer having a (meth)acryloyl group include (meth)acrylic acid, monofunctional (meth)acrylate, polyfunctional (meth)acrylate, acryloylmorpholine, 2-hydroxyethyl (meth)acrylamide, 2-hydroxyethyl-N-methyl (meth)acrylamide, 3-hydroxypropyl (meth)acrylamide, etc.

[0088] Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, stearyl (meth)acrylate, tridecyl (meth)acrylate, phenoxyethyl (meth)acrylate, dicyclopentenyl oxyethyl (meth)acrylate, ethylene glycol monomethyl ether (meth)acrylate, ethylene glycol monoethyl ether (meth)acrylate, ethylene glycol monobutyl ether (meth)acrylate, ethylene glycol monohexyl ether (meth)acrylate, ethylene glycol mono-2-ethylhexyl ether (meth)acrylate, diethylene glycol monomethyl ether (meth)acrylate, diethylene glycol monoethyl ether (meth)acrylate, diethylene glycol monobutyl ether (meth)acrylate, diethylene glycol monohexyl ether (meth)acrylate, diethylene glycol mono-2-ethylhexyl ether (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyl oxyethyl (meth)acrylate, tricyclodecanyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, allyl (meth)acrylate, and the like.

[0089] Examples of the polyfunctional (meth)acrylate include alkanediol di(meth)acrylates such as ethylene glycol di(meth)acrylate, 1,2-propylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate; polyoxyalkylene glycol di(meth)acrylates such as diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and polytetramethylene glycol di(meth)acrylate; trimethylolpropane di(meth)acrylate, glycerin di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, pentaerythritol diacrylate monostearate, 1,3-bis((meth)acryloyloxy)-2-hydroxypropane, ethoxylated bisphenol A di(meth)acrylate, tris-(2-(meth)acryloxyethyl) isocyanurate, and the like.

[0090] Among these, as the ethylenically unsaturated group-containing monomer (C), from the viewpoints of easy availability, good physical properties of the cured product, and production cost, styrene, methyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyl oxyethyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and ethoxylated bisphenol A di(meth)acrylate are preferable, and styrene, benzyl (meth)acrylate, ethylene glycol di(meth)acrylate, and ethoxylated bisphenol A di(meth)acrylate are more preferable.

[0091] From the viewpoint of reducing the viscosity of the resin composition immediately after production, the content of the ethylenically unsaturated group-containing monomer (C) in the resin composition is preferably 20.0% by mass or more, more preferably 30.0% by mass or more, still more preferably 35.0% by mass or more. From the viewpoint of efficiently thickening, it is preferably 80.0% by mass or less, more preferably 75.0% by mass or less, still more preferably 65.0% by mass or less. That is, the content of the ethylenically unsaturated group-containing resin (B) in the resin composition is preferably 20.0 to 80.0% by mass, more preferably 30.0 to 75.0% by mass, still more preferably 35.0 to 65.0% by mass.

[0092] <Compound (D)> The compound (D) of this embodiment is at least one selected from oxides of Group 2 elements and hydroxides of Group 2 elements. The compound (D) may be used alone or in combination of two or more. The compound (D) has an effect of thickening the resin composition over time by interacting with the carboxy groups and hydroxy groups of the vinyl ester resin (A) and the ethylenically unsaturated group-containing resin (B).

[0093] Examples of the Group 2 element oxides include magnesium oxide, calcium oxide, barium oxide, and the like. Examples of the Group 2 element hydroxides include magnesium hydroxide, calcium hydroxide, barium hydroxide, and the like. Among them, from the viewpoints of thickening effect, versatility, cost, etc., magnesium oxide, magnesium hydroxide, calcium oxide, and calcium hydroxide are preferable, and magnesium oxide is more preferable.

[0094] From the viewpoint of efficiently thickening, the content of the compound (D) in the resin composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.1% by mass or more. From the viewpoint of controlling to an appropriate thickening rate, it is preferably 6.0% by mass or less, more preferably 5.0% by mass or less, still more preferably 4.0% by mass or less. That is, the content of the ethylenically unsaturated group-containing resin (B) in the resin composition is preferably 0.01 to 6.0% by mass, more preferably 0.05 to 5.0% by mass, still more preferably 0.1 to 4.0% by mass.

[0095] <Compound (E)> The compound (E) of this embodiment is at least one selected from water and hydroxy group-containing compounds. By including the compound (E) in the resin composition, it becomes easier to control the thickening rate. Examples of the hydroxy group-containing compounds include alcohols having a boiling point of 50°C or higher such as benzyl alcohol, stearyl alcohol, and isostearyl alcohol. In addition, other examples include hydroxycarboxylic acids such as lactic acid, glycerin, polyols, (meth)acrylates containing a hydroxy group, and the like. These may be used alone or in combination of two or more. Among them, from the viewpoints of availability, cost, etc., water and alcohol are preferable, and water is more preferable.

[0096] The content of compound (E) in the resin composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.1% by mass or more from the viewpoint of controlling the thickening rate, and preferably 3.0% by mass or less, more preferably 2.0% by mass or less, still more preferably 1.0% by mass or less from the viewpoints of the strength and toughness of the cured product of the resin composition. That is, the content of the ethylenically unsaturated group-containing resin (B) in the resin composition is preferably 0.01 to 3.0% by mass, more preferably 0.05 to 2.0% by mass, still more preferably 0.1 to 1.0% by mass.

[0097] <Photoinitiator (F)> The resin composition of this embodiment may further contain a photoinitiator (F). As the photoinitiator (F), known photoinitiators such as intramolecular cleavage type photoinitiators can be used, and one or more kinds can be appropriately selected and used according to the wavelength of the irradiation light from the light source used when curing the resin composition. The resin composition containing the photoinitiator (F) becomes a cured product by irradiating it with a light source having an emission wavelength corresponding to the absorption wavelength of the photoinitiator (F).

[0098] The photoinitiator (F) is not particularly limited as long as it generates radicals upon light irradiation. For example, benzoin and its alkyl ethers such as benzoin, benzoin methyl ether, and benzoin ethyl ether; acetophenones such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, and 4-(1-t-butyldioxy-1-methylethyl)acetophenone; α-hydroxyalkylphenones such as 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl-1-phenyl-propan-1-one; anthraquinones such as 2-methylanthraquinone, 2-amylanthraquinone, 2-t-butylanthraquinone, and 1-chloroanthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, and 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone, 4-(1-t-butyldioxy-1-methylethyl)benzophenone, and 3,3’,4,4’-tetrakis(t-butyldioxycarbonyl)benzophenone; morpholines such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1-one, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1-one; acylphosphine oxides such as phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; xanthones, etc. can be mentioned.

[0099] From the perspective of reactivity, it is preferable to use an intramolecular cleavage type photoinitiator that does not require a hydrogen donor for the photoinitiator (F). Further, since it absorbs light with a wavelength of 315 to 460 nm to generate active species, 2,2-dimethoxy-2-phenylacetophenone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and 1-hydroxycyclohexyl phenyl ketone, which efficiently generate active species in the above wavelength range, are preferable.

[0100] From the viewpoint of curability, the content of the photoinitiator (F) in the resin composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and still more preferably 0.1% by mass or more. From the viewpoints of suppressing heat generation, cracks, etc. during curing of the resin composition, and the balance of physical properties such as strength, toughness, heat resistance, and chemical resistance of the cured product of the resin composition, it is preferably 3.0% by mass or less, more preferably 2.0% by mass or less, and still more preferably 1.0% by mass or less. That is, the content of the ethylenically unsaturated group-containing resin (B) in the resin composition is preferably 0.01 to 3.0% by mass, more preferably 0.05 to 2.0% by mass, and still more preferably 0.1 to 1.0% by mass.

[0101] <Other components> The resin composition of this embodiment can contain, as other components, for example, other resins, polymerization inhibitors, thixotropic agents, curing accelerators, catalysts, thickening aids, curing retardants, surfactants, interfacial modifiers, wetting dispersants, defoamers, leveling agents, coupling agents, light stabilizers, waxes, flame retardants, plasticizers, fillers, internal mold release agents, low shrinkage agents, toners, viscosity reducers, separation preventives, compatibilizers, pigments, and other additives. The content of the additive is not particularly limited as long as it does not inhibit the effects of the present invention.

[0102] The thixotropic agent can be used to adjust the miscibility and fluidity of the resin composition. Examples of the thixotropic agent include organic thixotropic agents and inorganic thixotropic agents. These can be used alone or in combination of two or more. When the resin composition of this embodiment contains a thixotropic agent, its content is preferably 0.01 to 5% by mass, more preferably 0.1 to 3% by mass in the composition.

[0103] Examples of the organic thixotropic agent include hydrogenated castor oil-based, amide-based, polyethylene oxide-based, vegetable oil polymerized oil-based, surfactant-based, and composite systems using these in combination. Specifically, "Flowon (registered trademark) SP-1000AF" (manufactured by Kyoeisha Chemical Co., Ltd.), "Disparon (registered trademark) 6900-20X" (Kusumoto Chemicals, Ltd.), etc. can be mentioned. Examples of the inorganic thixotropic agent include silica and bentonite that have been subjected to hydrophobic treatment or hydrophilic treatment. Specific examples of the hydrophobic inorganic thixotropic agent include "Rheolex (registered trademark) PM-20L" (manufactured by Tokuyama Corporation), "Aerosil (registered trademark) R-106" (manufactured by Nippon Aerosil Co., Ltd.), "CAB-O-SIL (registered trademark)" (manufactured by Cabot Corporation), and the like. Specific examples of the hydrophilic inorganic thixotropic agent include "Aerosil (registered trademark)-200" (manufactured by Nippon Aerosil Co., Ltd.). When using hydrophilic calcined silica, the combined use of the thixotropic modifiers "BYK (registered trademark)-R605" and "BYK (registered trademark)-R606" (both manufactured by BYK) is effective for appropriately controlling the thickening rate.

[0104] <Viscosity of the resin composition> From the perspective of impregnation into the fiber substrate, the viscosity at 25°C after 1 hour from the preparation of the resin composition is preferably 0.1 to 4.0 Pa·s, more preferably 0.2 to 3.5 Pa·s, and even more preferably 0.3 to 3.0 Pa·s. From the perspective of thickening property, the viscosity at 25°C after 2 days from the preparation of the resin composition is preferably 30 to 1,500 Pa·s, more preferably 40 to 1,000 Pa·s, and even more preferably 50 to 500 Pa·s. From the perspective of thickening property, the viscosity at 25°C after 5 days from the preparation of the resin composition is preferably 400 to 3,500 Pa·s, more preferably 450 to 2,500 Pa·s, even more preferably 500 to 2,200 Pa·s, and still more preferably 500 to 2,000 Pa·s.

[0105] [Manufacturing method of the resin composition] The resin composition according to this embodiment can be produced by mixing a vinyl ester resin (A), an ethylenically unsaturated group-containing resin (B), an ethylenically unsaturated group-containing monomer (C), a compound (D), and a compound (E). The other components may be added and mixed as necessary.

[0106] The mixing order is not particularly limited. For example, a vinyl ester resin (A) and an ethylenically unsaturated group-containing resin (B) are mixed and dissolved in an ethylenically unsaturated group-containing monomer (C), and a compound (D), a compound (E), and optionally other components are added and mixed to obtain a resin composition. The mixing method is not particularly limited, and for example, it can be carried out using a disperser, a planetary mixer, a kneader, etc. The kneading temperature is preferably 10 to 40°C, more preferably 15 to 30°C, and even more preferably 20 to 30°C from the viewpoint of ease of mixing and the like.

[0107] [Uses of the resin composition] Even when the resin composition of the present embodiment is made into a composite material with a fiber base material, a cured product having good physical properties can be obtained, and it is suitable for use as a lining material. Examples of the type of fiber of the fiber base material include organic fibers such as amide, aramid, vinylon, polyester, and phenol, so-called reinforcing fibers such as carbon fiber, glass fiber, metal fiber, and ceramic fiber from the viewpoint of mechanical strength and the like, and also composite fibers thereof. The fiber base material may be a single type or a combination of two or more types. Among these, aramid fiber, carbon fiber, and glass fiber are preferable, and glass fiber is more preferable from the viewpoints of strength, availability, price, etc., and glass fiber and polyester fiber having light transmissibility are even more preferable.

[0108] Examples of the form of the fiber base material include a sheet, chopped strand, chop, milled fiber, etc. Examples of the sheet include those formed by aligning a plurality of reinforcing fibers in one direction, two-directional fabrics such as plain weave and twill weave, multi-axial fabrics, non-crimp fabrics, non-woven fabrics, mats, knits, braids, paper made by papermaking of reinforcing fibers, etc. The form of the fiber base material may be a single type or a combination of two or more types, and may be a single layer or a plurality of layers laminated.

Examples

[0109] Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited by the following examples.

[0110] [Each material] Details of the compounds used in the following synthesis examples are shown below. ·Epoxy compound (1): Bisphenol A type epoxy resin; "jER (registered trademark) 834", manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 245 ·Epoxy compound (2): Bisphenol A type epoxy resin; "Epomic (registered trademark) R140P", manufactured by Mitsui Chemicals, Inc., epoxy equivalent 188 ·Tetradecyldimethylbenzylammonium chloride: "Nissan Cation (registered trademark) M2-100R", manufactured by NOF Corporation, purity over 90% by mass ·2,4,6-Tris(dimethylaminomethyl)phenol: "Seaquol TDMP", manufactured by Seiko Chemical Co., Ltd., purity over 95% by mass ·Triethylamine: manufactured by Daicel Corporation ·Benzyl methacrylate: "Light Ester BZ", manufactured by Kyoeisha Chemical Co., Ltd. ·Phenoxyethyl methacrylate: "Light Ester PO", manufactured by Kyoeisha Chemical Co., Ltd.

[0111] [Synthesis of vinyl ester resin] <Synthesis Example A1-a> Into a 5 L four-neck separable flask equipped with a stirrer, a reflux condenser, a gas inlet tube, and a thermometer, 1260 g of an epoxy compound (1), 0.7 g of methylhydroquinone as a polymerization inhibitor (0.04 parts by mass based on 100 parts by mass in total of the epoxy compound (a-1), the unsaturated monobasic acid (a-2), and the polybasic acid anhydride (a-3)), and 3.4 g of tetradecyldimethylbenzylammonium chloride as a catalyst (0.2 parts by mass based on 100 parts by mass in total of the epoxy compound (a-1), the unsaturated monobasic acid (a-2), and the polybasic acid anhydride (a-3)) were added, and the mixture was heated to 110 °C. Then, 350 g of methacrylic acid as the unsaturated monobasic acid (a-2) (the acid groups of methacrylic acid are 80 mol with respect to 100 mol of the total amount of epoxy groups of the epoxy compound (a-1)), and 100 g of maleic anhydride as the polybasic acid anhydride (a-3) (maleic anhydride is 20 mol with respect to 100 mol of the total amount of epoxy groups of the epoxy compound (a-1), that is, the total amount of acid groups capable of reacting with the epoxy groups derived from maleic anhydride is 20 mol with respect to 100 mol of the total amount of epoxy groups of the epoxy compound (a-1)) were added dropwise over about 30 minutes, and then reacted for about 4 hours to synthesize a resin precursor (P1). Next, 50 g of maleic anhydride as the polybasic acid anhydride (a-4) (maleic anhydride is 10 mol with respect to 100 mol of the total amount of epoxy groups of the epoxy compound (a-1), that is, the total amount of acid groups capable of reacting with the epoxy groups derived from maleic anhydride is 10 mol with respect to 100 mol of the total amount of epoxy groups of the epoxy compound (a-1)) was added, and the mixture was reacted for about 2 hours to obtain a vinyl ester resin (A1-a), which is a vinyl ester resin (A1). The reaction product containing this vinyl ester resin (A1-a) was cooled to 90 °C, and 950 g of benzyl methacrylate, which is an ethylenically unsaturated group-containing monomer (C) as a reactive diluent (35% by mass based on the total amount of the compounding components), was added to obtain a mixture (mass ratio 65 / 35) of the vinyl ester resin (A1-a) and benzyl methacrylate. Table 1 shows the compounding amounts of the respective components.

[0112] [Ethylenically unsaturated group-containing resin] <Synthesis Example B1-1-a> Into a 5 L four-neck separable flask equipped with a stirrer, a reflux condenser, a gas inlet tube, and a thermometer, 1260 g of an epoxy compound (2) and 358 g of bisphenol A as bisphenol (b1-2) (the total amount of hydroxyl groups of bisphenol A is 47 mol with respect to the total amount of epoxy groups of 100 mol of the epoxy compound (b1-1)) were placed and heated to 80 °C. Then, 3.2 g of tetradecyl dimethyl benzyl ammonium chloride (0.2 part by mass with respect to 100 parts by mass in total of the epoxy compound (b1-1) and bisphenol (b1-2)) was added as a catalyst, heated to 145 °C, and reacted for 1 hour to synthesize a resin precursor (Q-1). Next, after cooling to 110 °C, 1337 g of benzyl methacrylate (40% by mass based on the total amount of the compounding components) as a reactive diluent, 0.03 g of 5% copper naphthenate (0.002 part by mass with respect to 100 parts by mass in total of the epoxy compound (b1-1), bisphenol (b1-2), and unsaturated monobasic acid (b1-3)) as a polymerization inhibitor, 0.56 g of methylhydroquinone (0.03 part by mass with respect to 100 parts by mass in total of the epoxy compound (b1-1), bisphenol (b1-2), and unsaturated monobasic acid (b1-3)), 1.05 g of trimethylhydroquinone (0.056 part by mass with respect to 100 parts by mass in total of the epoxy compound (b1-1), bisphenol (b1-2), and unsaturated monobasic acid (b1-3)), and 5.0 g of tetradecyl dimethyl benzyl ammonium chloride (0.27 part by mass with respect to 100 parts by mass in total of the epoxy compound (b1-1), bisphenol (b1-2), and unsaturated monobasic acid (b1-3)) as an esterification catalyst were added and heated to 110 °C. 247 g of methacrylic acid as an unsaturated monobasic acid (b1-3) (the total amount of acid groups of methacrylic acid is 43 mol with respect to the total amount of epoxy groups of 100 mol of the epoxy compound (b1-1)) was added dropwise over about 30 minutes, and then reacted for about 2 hours to synthesize a resin precursor (Q-2).Next, 131 g of maleic anhydride was added as the unsaturated polybasic acid (b1-4) (20 mol of maleic anhydride with respect to the total amount of 100 mol of epoxy groups of the epoxy compound (b-1), that is, 20 mol of acid groups capable of reacting with the epoxy groups derived from maleic anhydride with respect to the total amount of 100 mol of epoxy groups of the epoxy compound (b1-1)), and the mixture was reacted for about 1 hour to obtain a vinyl ester resin (B1-1-a) which is a vinyl ester resin (B1-1) having a carboxy group and an Mw of 4239. This reaction product was cooled to 90 °C to obtain a mixture containing 60% by mass of the vinyl ester resin and 40% by mass of benzyl methacrylate based on the total mass of the compounding components. Table 2 shows the compounding amounts of the respective components.

[0113] <Synthesis Examples B1-1-b and B1-1-c> Synthesis was carried out in the same manner as in Synthesis Example B1-1-a, except that the compounding composition shown in Table 1 was used, to obtain vinyl ester resins (B1-1-b) and (B1-1-c) which are vinyl ester resins (B1-1). This reaction product was cooled to 90 °C to obtain a mixture containing 65% by mass of the vinyl ester resin and 35% by mass of benzyl methacrylate based on the total mass of the compounding components. Table 2 shows the compounding amounts of the respective components.

[0114] <Comparative Synthesis Example B1'-a> Into a 5 L four-neck separable flask equipped with a stirrer, a reflux condenser, a gas inlet tube, and a thermometer, 1512 g of an epoxy compound (2) and 429 g of bisphenol A (manufactured by Mitsubishi Chemical Corporation) (the total amount of hydroxyl groups of bisphenol A is 47 mol with respect to 100 mol of the total amount of epoxy groups of the epoxy compound (b1-1)) were placed and heated to 80 °C. Next, 3.9 g of triethylamine (0.2 part by mass with respect to 100 parts by mass of the total of the epoxy compound (b1-1), bisphenol (b1-2), and unsaturated monobasic acid (b1-3)) was added as a catalyst, and the mixture was heated to 145 °C and reacted for 1 hour to synthesize a resin precursor (Q-3). Then, after cooling to 110 °C, 429 g of styrene (10% by mass based on the total mass of the compounding components) as a reactive diluent, 0.04 g of 5% copper naphthenate (0.0019 part by mass with respect to 100 parts by mass of the total of the epoxy compound (b1-1), bisphenol (b1-2), and unsaturated monobasic acid (b1-3)) as a polymerization inhibitor, 1.3 g of trimethylhydroquinone (0.056 part by mass with respect to 100 parts by mass of the total of the epoxy compound (b1-1), bisphenol (b1-2), and unsaturated monobasic acid (b1-3)), and 6.9 g of 2,4,6-tris(dimethylaminomethyl)phenol (0.3 part by mass with respect to 100 parts by mass of the total of the epoxy compound (b1-1), bisphenol (b1-2), and unsaturated monobasic acid (b1-3)) as an esterification catalyst were added and heated to 110 °C. Then, 365 g of methacrylic acid (the total amount of acid groups of methacrylic acid is 53 mol with respect to 100 mol of the total amount of epoxy groups of the epoxy compound (b1-1)) as the unsaturated monobasic acid (b1-3) was added dropwise over about 30 minutes, and then heated to 130 °C and reacted for about 2 hours to produce a vinyl ester resin (B1’-a) having no carboxyl group. The reaction product containing this vinyl ester resin (B1’-a) was cooled to 90 °C, 0.13 g of hydroquinone (0.003 part by mass with respect to 100 parts by mass of the total of all compounding components) as a polymerization inhibitor and 1546 g of styrene as a reactive diluent (ethylenically unsaturated group-containing monomer (C)) were added to obtain a mixture containing 54% by mass of vinyl ester resin and 46% by mass of styrene based on the total mass of the compounding components. Table 2 shows the compounding amounts of the respective components.

[0115] <Comparative Synthesis Example B1'-b> Into a 5 L four-neck separable flask equipped with a stirrer, a reflux condenser, a gas inlet tube, and a thermometer, 1803 g of an epoxy compound (2) and 361 g of bisphenol A (the total amount of hydroxyl groups of bisphenol A is 33 mol with respect to 100 mol of the total amount of the epoxy compound (b1-1)) were placed and heated to 80°C. Next, 4.3 g of triethylamine (0.2 part by mass with respect to 100 parts by mass of the total of the epoxy compound (b1-1), bisphenol (b1-2), and unsaturated monobasic acid (b1-3)) was added as a catalyst, and the mixture was heated to 145°C and reacted for 1 hour to synthesize a resin precursor (Q-4). Then, after cooling to 110°C, 505 g of styrene (10% by mass based on the total mass of the compounding components) as a reactive diluent, 0.05 g of 5% copper naphthenate (0.0019 part by mass with respect to 100 parts by mass of the total of the epoxy compound (b1-1), bisphenol (b1-2), and unsaturated monobasic acid (b1-3)) as a polymerization inhibitor, 0.27 g of methylhydroquinone (0.01 part by mass with respect to 100 parts by mass of the total of the epoxy compound (b1-1), bisphenol (b1-2), and unsaturated monobasic acid (b1-3)), 1.5 g of trimethylhydroquinone (0.057 part by mass with respect to 100 parts by mass of the total of the epoxy compound (b1-1), bisphenol (b1-2), and unsaturated monobasic acid (b1-3)), and 5.3 g of 2,4,6-tris(dimethylaminomethyl)phenol (0.2 part by mass with respect to 100 parts by mass of the total of the epoxy compound (b1-1), bisphenol (b1-2), and unsaturated monobasic acid (b1-3)) as an esterification catalyst were added and heated to 110°C. Then, 454 g of methacrylic acid (the total amount of acid groups of methacrylic acid is 55 mol with respect to 100 mol of the total amount of epoxy groups of the epoxy compound (b1-1)) as the unsaturated monobasic acid (b1-3) was added dropwise over about 30 minutes, and the mixture was reacted for about 2 hours to synthesize a resin precursor (Q-5). Next, 33 g of fumaric acid (the acid groups of fumaric acid are 6 mol with respect to 100 mol of the total amount of epoxy groups of the epoxy compound (b1-1)) was added and reacted for about 1 hour to obtain a vinyl ester resin (B1'-b) having no carboxyl group. The reaction product containing this vinyl ester resin (B1’-b) was cooled to 90 °C, 1766 g of styrene was added as a reactive diluent (ethylenically unsaturated group-containing monomer (C)), and a mixture containing 54% by mass of vinyl ester resin and 46% by mass of styrene was obtained based on the total mass of the compounding components. Table 2 shows the compounding amounts of the respective components.

[0116] <Comparative Synthesis Example B1’-c> In Synthesis Example B1’-b, synthesis was carried out in the same manner except that the compounding composition shown in Table 2 was used, and a vinyl ester resin (B1’-c) having no carboxy group was obtained. The reaction product containing this vinyl ester resin (B1’-c) was cooled to 90 °C, 1830 g of styrene was added as a reactive diluent (ethylenically unsaturated group-containing monomer (C)), and a mixture containing 54% by mass of vinyl ester resin and 46% by mass of styrene was obtained based on the total mass of the compounding components. Table 2 shows the compounding amounts of the respective components.

[0117] <Comparative Synthesis Example B1’-d> Into a 5 L four-necked separable flask equipped with a stirrer, a reflux condenser, a gas introduction tube, and a thermometer, 2220 g of epoxy compound (2), 1.3 g of methylhydroquinone as a polymerization inhibitor (0.04 part by mass with respect to 100 parts by mass in total of epoxy compound (b1-1) and unsaturated monobasic acid (b1-3)), and 9.7 g of tetradecyldimethylbenzylammonium chloride as an esterification catalyst (0.3 part by mass with respect to 100 parts by mass in total of epoxy compound (b1-1) and unsaturated monobasic acid (b1-3)) were placed and heated to 110 °C. Then, 1015 g of methacrylic acid as unsaturated monobasic acid (the acid groups of methacrylic acid are 100 moles with respect to 100 moles of the total epoxy groups of epoxy compound (b1-1)) was added dropwise over about 30 minutes, then heated to 120 °C, and reacted for about 3 hours to produce a vinyl ester resin (B1’-d) having no carboxy group. The reaction product containing this vinyl ester resin (B1'-d) was cooled to 90 °C, and 1750 g of phenoxyethyl methacrylate was added as a reactive diluent (ethylenically unsaturated group-containing monomer (C)), and a mixture containing 65% by mass of vinyl ester resin and 35% by mass of phenoxyethyl methacrylate was obtained based on the total mass of the compounding components. Table 2 shows the compounding amounts of the respective components.

[0118] <Comparative Synthesis Example B1'-e> In Synthesis Example B1'-d, synthesis was carried out in the same manner except that the compounding composition shown in Table 2 was used, and a vinyl ester resin (B1'-e) was obtained. Table 2 shows the compounding amounts of the respective components.

[0119] <Synthesis Example B2-a> Into a 3 L four-neck separable flask equipped with a thermometer, a stirrer, an inert gas blowing tube, and a reflux condenser, as diol (b2-1), 330 g (30 mol) of ethylene glycol, 876 g (65 mol) of propylene glycol, and 119 g (5 mol) of dipropylene glycol, as ethylenically unsaturated group-containing polybasic acid (b2-2-2), 695 g (40 mol) of maleic anhydride, and as ethylenically unsaturated group-free polybasic acid (b2-2-1), 1574 g (60 mol) of phthalic anhydride were charged, and a condensation reaction was carried out at 215 °C for 10 hours to obtain an unsaturated polyester resin (B2-a) which is an unsaturated polyester resin (B2). The reaction product containing this unsaturated polyester resin (B2-a) was cooled to 90 °C, and 1725 g of styrene was added as a reactive diluent (ethylenically unsaturated group-containing monomer (C)), and a mixture containing 65% by mass of unsaturated polyester resin and 35% by mass of styrene was obtained based on the total mass of the compounding components. Table 3 shows the compounding amounts of the respective components.

[0120]

Table 1

[0121]

Table 2

[0122] [Measurement and Evaluation of Vinyl Ester Resin and Ethylene Unsaturated Group-Containing Resin]

[0123] [Measurement and Evaluation of Vinyl Ester Resin and Ethylene Unsaturated Group-Containing Resin] For the vinyl ester resin and the ethylene unsaturated group-containing resin obtained in the above synthesis examples, measurement and evaluation of the following items were carried out. The results of these measurements and evaluations are shown in Tables 1 to 3. In addition, as the measurement sample used for the measurement of acid value and hydroxyl value, a mixture containing the resin produced in the synthesis example and a reactive diluent (ethylene unsaturated group-containing monomer (C)) was used. The details of the mixture are shown in Table 4.

[0124] [Table 4]

[0125] [Acid Value] Based on JIS K6901:2008 "Partial Acid Value (Indicator Titration Method)", using an "Auto Burette UCB-2000" (manufactured by Hiranuma Sangyo Co., Ltd.), the acid value was determined by measuring the mass of potassium hydroxide required for neutralizing the acid component in the measurement sample using a mixed indicator of bromothymol blue and phenol red.

[0126] [Hydroxyl Value] For the hydroxyl value of the vinyl ester resin and the ethylene unsaturated group-containing resin, based on JIS K6901:2008 "Hydroxyl Value (Neutralization Titration Method)", the mass of potassium hydroxide required to neutralize the acetic acid generated by the acetylation of 1 g of the vinyl ester resin was measured to determine the hydroxyl value. In addition, the neutralization titration was carried out manually, and 1% phenolphthalein (ethanol solution) was used as the indicator.

[0127] <Weight-average molecular weight Mw, number-average molecular weight Mn, and molecular weight distribution Mw / Mn> The weight-average molecular weight Mw and number-average molecular weight Mn of the vinyl ester resin and the resin containing an ethylenically unsaturated group were measured by gel permeation chromatography (GPC) under the following measurement conditions and determined as the molecular weight in terms of standard polystyrene. The molecular weight distribution Mw / Mn was calculated from the values of the number-average molecular weight Mn and the weight-average molecular weight Mw.

[0128] 〔Measurement conditions〕 · Apparatus: High-performance liquid chromatograph "Prominence (registered trademark)" (manufactured by Shimadzu Corporation) · Column: "Shodex (registered trademark) LF-804" (manufactured by Resonac Co., Ltd.) · Detector: Differential refractometer "Shodex (registered trademark) RI-71S" (manufactured by Resonac Co., Ltd.) · Column temperature: 40 °C · Sample: 0.2 mass% tetrahydrofuran solution of vinyl ester resin or unsaturated polyester resin · Developing solvent: Tetrahydrofuran · Flow rate: 1.0 mL / min

[0129] [Production of resin composition] Using each vinyl ester resin and resin containing an ethylenically unsaturated group obtained in the above synthesis examples, a resin composition was produced. Details of the compounds used in the following examples and comparative examples are shown below. (Ethylenically unsaturated group-containing monomer (C)) · Bisphenol A dimethacrylate EO adduct: "NK Ester BPE-100", manufactured by Shin-Nakamura Chemical Co., Ltd. (Compound (D)) · Magnesium oxide: "Magmicron MD-4AM-2", manufactured by Mikuni Shikiso Co., Ltd., magnesium oxide content 30 mass% (estimated) (Thickener) · Hydrophobic silica: "Rheoseal PM-20L", manufactured by Tokuyama Corporation

[0130] <Example 1> As the vinyl ester resin (A), 26.2 parts by mass of vinyl ester resin (A1-a), as the ethylenically unsaturated group-containing resin (B), 10.8 parts by mass of unsaturated polyester resin (B2-a), as the ethylenically unsaturated group-containing resin (B’), 4.5 parts by mass of vinyl ester resin (B1’-e), as the ethylenically unsaturated group-containing monomer (C), 25.3 parts by mass of benzyl methacrylate, 10.5 parts by mass of ethylene glycol dimethacrylate, 15.7 parts by mass of bisphenol A dimethacrylate EO adduct, and 5.7 parts by mass of styrene were mixed. Then, 0.2 parts by mass of water as the compound (E), 0.07 parts by mass of 2,2-dimethoxy-2-phenylacetophenone and 0.12 parts by mass of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide as the photoinitiator (F), and 0.8 parts by mass of a thixotropic agent were added to the mixture. Using a disper (high-speed dispersion base "Homodisper 2.5 type" manufactured by Primix Corporation), the mixture was mixed at 2000 - 3000 rpm for 20 minutes. To this, 2 parts by mass of magnesium oxide (Magmicron MD-4AM-2) as the compound (D) was added and further mixed for about 1 minute to prepare a resin composition (X-1).

[0131] <Examples 2 - 8 and Comparative Examples 1 - 4> In Example 1, resin compositions (X-2) - (X-8) and (X’-1) - (X’-4) were obtained in the same manner except that the raw materials and blending ratios shown in Table 7 were used.

[0132] [Measurement and Evaluation of Resin Composition] For the resin compositions (X-1) - (X-8) and (X’-1) - (X’-4) obtained in the above Examples and Comparative Examples, measurements and evaluations were conducted on the moisture content, viscosity, thread pulling during peeling, resistance feeling during peeling, ball tack test, thickening property, and adhesiveness. The results of these measurements and evaluations are shown in Table 8.

[0133] <Moisture Content (Moisture Content in the Resin Composition Excluding Compound (D))> In the production of the above resin composition, 1.5 g of a resin composition (excluding compound (D)) obtained by mixing vinyl ester resin (A), ethylene unsaturated group-containing resin (B), ethylene unsaturated group-containing monomer (C), compound (E), and photopolymerization initiator (F) was collected, and the water content in the resin composition excluding compound (D) was measured by volumetric titration using the Karl Fischer moisture meter shown below. · Apparatus: "701 KF Titrino" (manufactured by Metrohm Japan Co., Ltd.) · Karl Fischer reagent: "Aquamicron (registered trademark) Titrant SS 3 mg" (manufactured by Mitsubishi Chemical Corporation) · Dehydrating solvent: chloroform / methanol = 3 vol% / 1 vol%

[0134] <Viscosity> Immediately after preparing resin compositions (X-1) to (X-8) and (X'-1) to (X'-4), 280 g of each was placed in a 300 ml container, sealed, and stored statically under normal humidity (relative humidity 50 - 60%) at 25°C. Subsequently, the viscosities at 25°C were measured 1 hour after the adjustment of the resin compositions (X-1) to (X-8) and (X'-1) to (X'-4), 2 days after the adjustment of the resin compositions, and 5 days after the adjustment of the resin compositions. For viscosity measurement, when the viscosity is more than 0 Pa·s and 100.0 Pa·s or less, an "RB80 viscometer" (manufactured by Toki Sangyo Co., Ltd.; rotor No. 3 - 4) was used, and when the viscosity is more than 100.0 Pa·s, an "HBDVE viscometer" (manufactured by Eihiro Seiki Co., Ltd.; T-bar spindle T-A - T-D, rotation speed: 1 rpm) was used. Table 5 shows the rotors and rotation speeds used according to the measured viscosity, and Table 6 shows the T-bar spindles used.

[0135]

Table 5

[0136]

Table 6

[0137] The viscosities of the resin compositions (X-1) to (X-8) and (X'-1) to (X'-4) were evaluated according to the following criteria. · 1 hour after adjusting the resin composition A: Viscosity is 0.1 to 3.0 Pa·s B: Viscosity is less than 0.1 Pa·s or more than 3.0 Pa·s · 2 days after adjusting the resin composition A: Viscosity is 30 to 1,500 Pa·s B: Viscosity is less than 30 Pa·s or more than 1,500 Pa·s · 5 days after adjusting the resin composition A: Viscosity is 400 to 3,500 Pa·s B: Viscosity is less than 400 Pa·s or more than 3,500 Pa·s

[0138] <Thickening property> The thickening property of the resin composition was evaluated according to the following evaluation criteria. A: The evaluations of the viscosity of the resin composition 2 days after adjusting the resin composition and the viscosity of the resin composition 5 days after adjusting the resin composition are A (good thickening property) B: Among the evaluations of the viscosity of the resin composition 2 days after adjusting the resin composition and the viscosity of the resin composition 5 days after adjusting the resin composition, at least one is B (poor thickening property)

[0139] <Thread drawing during peeling> Two pieces of roving cloth ("WR 570 C-100", manufactured by Nitto Boseki Co., Ltd.) were cut out into 100 mm × 200 mm, the two pieces were overlapped, and about 45 g of the resin composition was impregnated with a defoaming roller to obtain a laminate (glass content of about 40% by mass). The laminate was sandwiched between polyethylene terephthalate films cut out into 250 mm × 250 mm to obtain an evaluation laminate. The evaluation laminate was allowed to stand at room temperature and normal humidity (in the dark, relative humidity 50 to 60%), and 2 days or 7 days after adjusting the resin composition, the layers of the evaluation laminate were peeled by hand, and the presence or absence of thread drawing was evaluated visually according to the following evaluation criteria. A: Thread drawing present B: No thread drawing

[0140] <Resistance feeling during peeling> Two pieces of roving cloth (“WR 570 C-100”, manufactured by Nitto Boseki Co., Ltd.) were cut out to a size of 100 mm × 200 mm, and the two pieces were overlapped. Approximately 45 g of the resin composition was impregnated with a defoaming roller to obtain a laminate (glass content of about 40% by mass). The laminate was sandwiched between polyethylene terephthalate films cut out to a size of 250 mm × 250 mm to obtain a laminate for evaluation. The laminate for evaluation was allowed to stand at room temperature and normal humidity (in a dark place, relative humidity 50 to 60%), and two days or seven days after adjusting the resin composition, the layers of the laminate for evaluation were peeled off by hand, and the presence or absence of a resistance feeling was evaluated according to the following evaluation criteria. A: There is a resistance feeling B: There is a slight resistance feeling C: There is no resistance feeling Note that “There is a resistance feeling” means that force is required for peeling.

[0141] <Ball tack test> Two sheets of glass cloth (「WF 350 100 BS6」, manufactured by Nitto Boseki Co., Ltd.) were cut out into pieces of 100 mm × 200 mm, and the two pieces were overlapped. About 20 g of a resin composition was impregnated with a degassing roller to obtain a laminate (glass content of about 40%). The laminate had an unimpregnated portion of the resin composition of 100 mm × 100 mm and an impregnated portion of the resin composition of 100 mm × 100 mm, and was produced to have a thickness of 0.6 mm. The laminate was sandwiched between polyethylene terephthalate films cut out into pieces of 250 mm × 250 mm and placed on a glass plate to obtain a laminate for evaluation. The laminate for evaluation was allowed to stand at 23°C ± 3°C under normal humidity (in the dark, relative humidity 50 - 60%). Subsequently, two days or seven days after the resin composition was adjusted, the glass cloth layers of the laminate for evaluation were peeled off, and the peeled surface was used as the adhesive portion (resin composition impregnated portion) of the adhesive sheet. With reference to "14 Inclined Ball Tack" of JIS Z 0237:2022 (Adhesive Tape and Adhesive Sheet Test Methods), an inclined ball tack test (30° inclination) was carried out. Specifically, as shown in Fig. 1, a ball rolling device in which one of the laminates for evaluation with the glass cloth layers peeled off was placed on a pedestal having an inclination of 30° was used, and the test was conducted in accordance with "14.3 Test Method" of JIS Z 0237:2022 (Adhesive Tape and Adhesive Sheet Test Methods). One unimpregnated portion of the resin composition of the laminate for evaluation with the glass cloth layers peeled off was the auxiliary walking path (100 mm) in the inclined ball tack test, and the impregnated portion of the resin composition was installed so as to be the measurement portion (100 mm). From the results of the inclined ball tack test (30° inclination), Table 8 shows the maximum ball number (Measurement 1) at which the ball stopped for 5 seconds in the adhesive portion (resin composition impregnated portion) and the maximum ball number (Measurement 2) at which the ball made less than one rotation in 5 seconds in the adhesive portion.

[0142] <Adhesiveness> From the results of the inclined ball tack test, the adhesiveness was evaluated according to the following evaluation criteria. A: Those that satisfy the following Requirements 1 and 2 B: Those that do not satisfy at least one of the following Requirements 1 and 2 Requirement 1: The maximum ball number (Measurement 1) at which the ball stopped for 5 seconds in the adhesive portion is 5 or more Requirement 2: The maximum number of balls (Measurement 2) with less than one rotation of the ball within 5 seconds at the adhesion part is 7 or more.

[0143]

Table 7

[0144]

Table 8

[0145] The resin composition containing vinyl ester resin (A), ethylene unsaturated group-containing resin (B), ethylene unsaturated group-containing monomer (C), compound (D), and compound (E) was confirmed to thicken at an appropriate rate with the passage of time at room temperature and have adhesiveness after thickening.

Claims

1. a vinyl ester resin (A); an ethylenically unsaturated group-containing resin (B); an ethylenically unsaturated group-containing monomer (C); a compound (D) which is at least one selected from oxides of Group 2 elements and hydroxides of Group 2 elements; a resin composition containing at least one compound (E) selected from water and hydroxy group-containing compounds, wherein the vinyl ester resin (A) has a weight average molecular weight Mw of 6,000 or more and a ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn of 2.0 or more, and the ethylenically unsaturated group-containing resin (B) is at least one selected from a vinyl ester resin (B1) having a carboxy group and a weight average molecular weight Mw of less than 6,000 and an unsaturated polyester resin (B2) having a carboxy group and a weight average molecular weight Mw of less than 6,000.

2. The resin composition according to Claim 1, containing 50 to 70% by mass of the vinyl ester resin (A) and 30 to 50% by mass of the ethylenically unsaturated group-containing resin (B) with respect to a total of 100% by mass of the vinyl ester resin (A) and the ethylenically unsaturated group-containing resin (B).

3. The resin composition according to Claim 1 or 2, wherein the weight average molecular weight Mw of the vinyl ester resin (A) is 35,000 or less.

4. The resin composition according to Claim 1 or 2, wherein the weight average molecular weight Mw of the vinyl ester resin (A) is 15,000 or less.

5. The resin composition according to Claim 1 or 2, wherein the weight average molecular weight Mw of the vinyl ester resin (B1) is 2,000 or more.

6. The resin composition according to Claim 1 or 2, wherein the weight average molecular weight Mw of the vinyl ester resin (B1) is 3,000 to 5,000.

7. The resin composition according to Claim 1 or 2, wherein the weight average molecular weight Mw of the unsaturated polyester resin (B2) is 1,000 to 10,000.

8. The vinyl ester resin (A) is an addition reaction product of a resin precursor (P1) which is a reaction product of an epoxy compound (a-1) having two epoxy groups in one molecule, an unsaturated monobasic acid (a-2) and a polybasic acid anhydride (a-3) and a polybasic acid anhydride (a-4), and is a vinyl ester resin (A1). The resin composition according to claim 1 or 2, wherein the total amount of acid groups capable of reacting with epoxy groups derived from the polybasic acid anhydride (a-3) is 5 to 25 moles with respect to 100 moles of the total amount of epoxy groups of the epoxy compound (a-1).

9. The vinyl ester resin (B1) is a reaction product of a resin precursor (Q2) and an unsaturated polybasic acid (b1-4), and the resin precursor (Q2) is a reaction product of an epoxy compound (b1-1) having two epoxy groups in one molecule and a bisphenol compound (b1-2). The vinyl ester resin (B1-1) is a reaction product of the resin precursor (Q1) and an unsaturated monobasic acid (b1-3). The resin composition according to claim 1 or 2.

10. The unsaturated polyester resin (B2) is a reaction product of a diol (b2-1) and a polybasic acid (b2-2), The polybasic acid (b2-2) includes an ethylenically unsaturated group-containing polybasic acid (b2-2-1) and an ethylenically unsaturated group-free polybasic acid (b2-2-2). The resin composition according to claim 1 or 2.

11. The vinyl ester resin (A) has an Mw / Mn of 3.0 or more and an acid value of 20 KOHmg / g or more. The resin composition according to claim 1 or 2.

12. The ethylenically unsaturated group-containing resin (B) has an acid value of 20 KOHmg / g or more. The resin composition according to claim 1 or 2.

13. The ethylenically unsaturated group-containing resin (B) is only the vinyl ester resin (B1). The resin composition according to claim 1 or 2.

14. The ethylenically unsaturated group-containing resin (B) includes the vinyl ester resin (B1) and the unsaturated polyester resin (B2). The resin composition according to claim 1 or 2.

15. The mass ratio of the vinyl ester resin (B1) to the unsaturated polyester resin (B2) (the vinyl ester resin (B1) / the unsaturated polyester resin (B2)) is 40 / 60 to 80 / 20. The resin composition according to claim 14.

16. The compound (D) is at least one selected from magnesium oxide, magnesium hydroxide, calcium oxide, and calcium hydroxide. The resin composition according to claim 1 or 2.

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