JP7047292B2 - Laminated film for fiber adhesion and / or fiber sheet surface protection - Google Patents

Description

The present invention relates to a thermosetting composition for fiber adhesion and / or fiber sheet surface protection, and more particularly, it is used for bonding fibers of fibers such as carbon fibers and glass fibers to each other and protecting the surface of a fiber sheet made of such fibers. It relates to a thermosetting composition to be obtained.

Fiber reinforced plastic is a composite material in which fibers such as carbon fiber and glass fiber are put into the plastic as a reinforcing material to improve the strength, and is used as a lightweight and strong material, that is, a material having a high specific strength. .. Such fiber reinforced plastics have been used for sports equipment, aircraft, and artificial satellites because of their excellent mechanical properties. However, due to the expectation of improved fuel efficiency due to weight reduction, it is expected that the application to the automobile field will be expanded in the future. There is.
Among fiber reinforced plastics, for example, carbon fiber in carbon fiber reinforced plastic is required to be lightweight, high strength, and impregnated with resin, and carbon fiber reinforced plastic is formable, productive (shortening of curing time, workability), and recyclable. Properties and shape stability are required.

Examples of the production of carbon fiber reinforced plastic include a prepreg method using a prepreg which is a sheet-shaped intermediate base material in which carbon fibers are impregnated with an uncured resin. In this prepreg method, after laminating a plurality of prepregs, the prepreg method is used. A carbon fiber reinforced plastic is produced by curing an uncured resin.
Examples of such a resin include a thermoplastic resin and a thermosetting resin. However, when a thermoplastic resin is used, a high molecular weight resin is used in order to maintain an appropriate strength, so that the viscosity becomes high. There is a problem that it is difficult to impregnate carbon fibers, and there is a problem in terms of adhesiveness.
On the other hand, for example, a thermosetting resin such as the thermosetting resin epoxy disclosed in Patent Document 1 is likely to impregnate carbon fibers, but the cured fiber is generally less flexible, so that the surface of the cured fiber is The cracks may occur in the fiber, and the cracks may reduce the strength.

Japanese Patent Application Laid-Open No. 2003-201388

Therefore, in the present invention, under such a background, the fiber adhesion and / or the fiber sheet surface protection laminated film, which has high flexibility of the cured fiber after curing and good adhesion to the fiber, and the laminated film for protecting the surface of the fiber sheet, and It is an object of the present invention to provide a thermosetting composition for fiber adhesion and / or fiber sheet surface protection.

However, as a result of diligent research in view of such circumstances, the present inventor has used a thermosetting composition containing a urethane (meth) acrylate-based oligomer (A), even after being thermoset by heating. The present invention has been completed by finding that a cured product having flexibility is obtained and the adhesiveness between the thermosetting composition and the fiber is good.

That is, the gist of the present invention is a laminated film for fiber adhesion and / or fiber sheet surface protection in which a layer [I] made of a thermosetting composition [i] and a support film [II] are laminated. , The thermosetting composition [i] contains a urethane (meth) acrylate-based oligomer (A) , a binder polymer (B) and a thermosetting initiator (C) , and is a urethane (meth) acrylate-based oligomer (A). A laminated film for fiber adhesion and / or fiber sheet surface protection, characterized in that the weight average molecular weight is 500 to 50,000 .

In the laminated film for fiber adhesion and / or fiber sheet surface protection of the present invention, since the thermosetting composition [i] contains a urethane (meth) acrylate-based oligomer (A), it is polymerized as the temperature rises due to heating. The cured product has flexibility even after the thermosetting is started, and the adhesiveness between the thermosetting composition [i] and the fibers is improved, and the adhesiveness between the fibers and the surface smoothness of the fiber sheet are improved. Excellent design such as glossiness.
Further, in the prepreg method, after the layer [I] made of the thermosetting composition [i] laminated on the support film [II] is laminated on the fiber sheet made of fibers, the thermosetting composition is subjected to a hot press or the like. By thermosetting [i], a fiber-reinforced plastic can be produced in a short time, so that it is excellent in productivity and workability.

Further, the heat-curable composition for fiber adhesion and / or fiber sheet surface protection of the present invention can only be a composition constituting layer [I] in the fiber adhesion and / or fiber sheet surface protection laminated film of the present invention. Not in RTM (resin injection molding) method, hand lay-up molding method, SMC press molding method, BMC molding method, FW (filament winding) method, drawing molding method, pin winding molding method and other fiber reinforced plastic manufacturing methods. It can be used and has the effect of being excellent in design such as adhesion between fibers, surface smoothness of fiber reinforced plastic, and glossiness.

Hereinafter, the configuration of the present invention will be described in detail, but these are examples of desirable embodiments, and the present invention is not specified in these contents.

The laminated film of the present invention is a laminated film for fiber adhesion and / or fiber sheet surface protection in which a layer [I] made of a thermosetting composition [i] and a support film [II] are laminated.
Hereinafter, the thermosetting composition [i] will be described.
In the following, the laminated film for fiber adhesion and / or fiber sheet surface protection of the present invention may be simply abbreviated as "laminated film", and the cured thermosetting composition [i] is referred to as "cured product [i]. The layer [I] composed of the uncured thermosetting composition [i] may be referred to as "thermosetting composition layer [I]", and the thermosetting composition after curing may be referred to as "thermosetting composition layer [I]". The layer [I] composed of [i] may be referred to as "cured layer [I]".

The thermosetting composition [i] used in the present invention is a resin composition that can be cured by heat and contains a compound having an unsaturated group. Examples of the compound having an unsaturated group include a reactive oligomer and a reactive monomer having one or more unsaturated groups. The thermosetting composition [i] used in the present invention is a urethane (meth) acrylate. It contains at least the system oligomer (A).
More preferably, the thermosetting composition [i] contains the urethane (meth) acrylate-based oligomer (A), the binder polymer (B), and the thermosetting initiator (C), and the fiber adhesion and / or Alternatively, it is a thermosetting composition for protecting the surface of a fiber sheet.
Hereinafter, each component will be described.

<Urethane (meth) acrylate-based oligomer (A)>
The urethane (meth) acrylate-based oligomer (A) used in the present invention has an effect of imparting appropriate elasticity to the cured layer [I] and increasing the flexibility of the cured layer [I].
As the urethane (meth) acrylate-based oligomer (A) used in the present invention, for example, a hydroxyl group-containing (meth) acrylate-based compound (a1), a polyvalent isocyanate-based compound (a2), and a polyol-based compound (a3) are reacted. Examples thereof include the obtained urethane (meth) acrylate-based oligomer (A).
In addition, (meth) acrylate represents acrylate or methacrylate, and (meth) acrylic represents acrylic or methacrylic.

The weight average molecular weight of the urethane (meth) acrylate-based oligomer (A) used in the present invention is preferably 500 to 50,000, and particularly preferably 1,000 to 30,000. If the weight average molecular weight is too small, the cured layer [I] tends to be brittle, and if it is too large, the cured layer [I] tends to be too hard and the impact resistance tends to decrease.

The above weight average molecular weight is the weight average molecular weight converted to the standard polystyrene molecular weight, and is used in high performance liquid chromatography ("Shodex GPC system-11 type" manufactured by Showa Denko Co., Ltd.), column: Shodex GPC KF-806L (excluded). Limit molecular weight: 2 × ¹⁰⁷ , separation range: 100 to 2 × ¹⁰⁷ , theoretical number of stages: 10,000 stages / piece, filler material: styrene-divinylbenzene copolymer, filler particle size: 10 μm) It can be measured by using series.

The viscosity of the urethane (meth) acrylate-based oligomer (A) at 60 ° C. is preferably 500 to 150,000 mPa · s, particularly preferably 500 to 120,000 mPa · s, and even more preferably 1,000 to 100,000 mPa · s.・ S. If the viscosity is out of the above range, the coatability when the thermosetting composition [i] is applied to the support film [II] tends to decrease.
The viscosity can be measured with an E-type viscometer.

[Hydroxy group-containing (meth) acrylate compound (a1)]
Examples of the hydroxyl group-containing (meth) acrylate compound (a1) include hydroxyalkyl (meth) acrylates (for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth). Acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, etc.), 2-hydroxyethylacryloyl phosphate, 2- (meth) acryloyloxyethyl-2-hydroxypropylphthalate, caprolactone-modified 2-hydroxy Ethyl (meth) acrylate, dipropylene glycol (meth) acrylate, fatty acid-modified-glycidyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, 2-hydroxy-3- (meth) acrylicloy Loxypropyl (meth) acrylate, glycerindi (meth) acrylate, 2-hydroxy-3-acryloyl-oxypropylmethacrylate, pentaerythritol tri (meth) acrylate, caprolactone-modified pentaerythritol tri (meth) acrylate, ethylene oxide-modified pentaerythritol tri Examples thereof include (meth) acrylate, dipentaerythritol penta (meth) acrylate, caprolactone-modified dipentaerythritol penta (meth) acrylate, and ethylene oxide-modified dipentaerythritol penta (meth) acrylate.

Among these, a hydroxyl group (meth) acrylate-based compound having one ethylenically unsaturated group is preferable because it can alleviate the curing shrinkage during the formation of the cured layer [I], and particularly preferably 2-hydroxyl. With hydroxyalkyl (meth) acrylates such as ethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-hydroxyhexyl (meth) acrylate. Further, it is preferable to use 2-hydroxyethyl (meth) acrylate in terms of excellent reactivity and versatility.
In addition, these can be used alone or in combination of two or more.

[Multivalent isocyanate compound (a2)]
Examples of the polyvalent isocyanate-based compound (a2) include aromatic-based compounds such as tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, phenylenedi isocyanate, and naphthalene diisocyanate. Polyisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, lysine triisocyanate; hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis Alicyclic polyisocyanates such as (isocyanatomethyl) cyclohexane; or trimeric or multimer compounds of these polyisocyanates; allophanate-type polyisocyanates; bullet-type polyisocyanates; water-dispersed polyisocyanates (for example, Nippon Polyurethane Industry) "Aquanate 100", "Aquanate 110", "Aquanate 200", "Aquanate 210", etc.) manufactured by Co., Ltd.); and the like.

Among these, aliphatic diisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate; hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1, An alicyclic diisocyanate such as 3-bis (isocyanatomethyl) cyclohexane is preferably used, and isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated xylylene diisocyanate are particularly preferably used because the curing shrinkage is small. Preferably, isophorone diisocyanate is used because of its excellent reactivity and versatility.

[Polyform compound (a3)]
Examples of the polyol compound (a3) include ethylene glycol in addition to polyether-based polyols, polyester-based polyols, polycarbonate-based polyols, polyolefin-based polyols, polybutadiene-based polyols, (meth) acrylic-based polyols, polysiloxane-based polyols, and the like. , Ethylene glycol, alkylene glycol such as neopentylglucol, and the like.

Examples of the polyether-based polyol include alkylene structure-containing polyether-based polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polybutylene glycol, and polyhexamethylene glycol, and random or block co-weights of these polyalkylene glycols. Glycol etc. can be mentioned.

Examples of the polyester-based polyol include three types of components: a condensation polymer of a polyhydric alcohol and a polyvalent carboxylic acid; a ring-opening polymer of a cyclic ester (lactone); a polyhydric alcohol, a polyvalent carboxylic acid, and a cyclic ester. Examples include the reactants of the above.

Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,4-tetramethylenediol, 1,3-tetramethylenediol, and 2-methyl-1,3-tri. Methylenediol, 1,5-pentamethylenediol, neopentylglycol, 1,6-hexamethylenediol, 3-methyl-1,5-pentamethylenediol, 2,4-diethyl-1,5-pentamethylenediol, glycerin , Trimethylol propane, trimethylol ethane, cyclohexanediols (1,4-cyclohexanediol, etc.), bisphenols (bisphenol A, etc.), sugar alcohols (xylitol, sorbitol, etc.) and the like.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids such as malonic acid, maleic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid and dodecandionic acid; 1,4. An alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, paraphenylenedicarboxylic acid and trimellitic acid can be mentioned.

Examples of the cyclic ester include propiolactone, β-methyl-δ-valerolactone, ε-caprolactone and the like.

Examples of the polycarbonate-based polyol include a reaction product of a polyhydric alcohol and phosgene; a ring-opening polymer of a cyclic carbonate ester (alkylene carbonate or the like).

Examples of the polyhydric alcohol include polyhydric alcohols exemplified in the description of the polyester-based polyol, and examples of the alkylene carbonate include ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, hexamethylene carbonate and the like. Be done.

The polycarbonate polyol may be a compound having a carbonate bond in the molecule and having a hydroxyl group at the end, and may have an ester bond together with the carbonate bond.

Examples of the polyolefin-based polyol include those having a homopolymer or copolymer of ethylene, propylene, butene or the like as a saturated hydrocarbon skeleton and having a hydroxyl group at the molecular terminal thereof.

Examples of the polybutadiene-based polyol include those having a copolymer of butadiene as a hydrocarbon skeleton and having a hydroxyl group at the molecular terminal thereof.
The polybutadiene-based polyol may be a hydrogenated polybutadiene polyol in which all or part of the ethylenically unsaturated group contained in the structure is hydrogenated.

Examples of the (meth) acrylic acid polyol include those having a (meth) acrylic acid ester having at least two hydroxyl groups in the molecule of the polymer or copolymer, and the (meth) acrylic acid ester includes such ester. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, (meth) acrylic. Examples thereof include (meth) acrylic acid alkyl esters such as 2-ethylhexyl acid, decyl (meth) acrylate, dodecyl (meth) acrylate, and octadecyl (meth) acrylate.

Examples of the polysiloxane-based polyol include dimethylpolysiloxane polyol and methylphenylpolysiloxane polyol.

Among these, polyester-based polyols and polyether-based polyols are preferable, and polyester-based polyols are particularly preferable in that they are excellent in mechanical properties such as flexibility at the time of curing.

The weight average molecular weight of the polyol compound (a3) is preferably 500 to 8000, particularly preferably 550 to 5000, and even more preferably 600 to 3000. If the molecular weight of the polyol compound (a3) is too large, the mechanical properties of the cured layer [I] tend to decrease during curing, and if it is too small, the curing shrinkage tends to be large and the stability tends to decrease.

The above weight average molecular weight is the weight average molecular weight converted to the standard polystyrene molecular weight, and is used in high performance liquid chromatography ("Shodex GPC system-11 type" manufactured by Showa Denko Co., Ltd.), column: Shodex GPC KF-806L (excluded). Limit molecular weight: 2 × ¹⁰⁷ , separation range: 100 to 2 × ¹⁰⁷ , theoretical number of stages: 10,000 stages / piece, filler material: styrene-divinylbenzene copolymer, filler particle size: 10 μm) It can be measured by using series.

The urethane (meth) acrylate-based oligomer (A) usually contains the hydroxyl group-containing (meth) acrylate-based compound (a1), the polyvalent isocyanate-based compound (a2), and the polyol-based compound (a3) collectively or separately in a reactor. It can be produced by charging and reacting with. Further, the reaction product obtained by previously reacting the polyol compound (a3) with the polyhydric isocyanate compound (a2) is reacted with the hydroxyl group-containing (meth) acrylate compound (a1) to form a urethane (meth) acrylate. The system oligomer (A) can also be produced, and this production method is useful in terms of reaction stability and reduction of by-products.

A known reaction means can be used for the reaction between the polyol compound (a3) and the polyhydric isocyanate compound (a2). At that time, for example, the molar ratio of the isocyanate group in the polyvalent isocyanate compound (a2) to the hydroxyl group in the polyol compound (a3) is usually about 2n: (2n-2) (n is an integer of 2 or more). This enables an addition reaction with the hydroxyl group-containing (meth) acrylate-based compound (a1) after obtaining a terminal isocyanate group-containing urethane (meth) acrylate-based compound in which an isocyanate group remains.

A known reaction is also carried out in the addition reaction between the reaction product obtained by reacting the polyol compound (a3) and the polyhydric isocyanate compound (a2) in advance with the hydroxyl group-containing (meth) acrylate compound (a1). Means can be used.

The reaction molar ratio of the reaction product to the hydroxyl group-containing (meth) acrylate compound (a1) is, for example, that the polyvalent isocyanate compound (a2) has two isocyanate groups and the hydroxyl group-containing (meth) acrylate compound (a1). ) Has one hydroxyl group, the reaction product: the hydroxyl group-containing (meth) acrylate compound (a1) is about 1: 2, and the polyvalent isocyanate compound (a2) has three isocyanate groups. When the hydroxyl group-containing (meth) acrylate compound (a1) has one hydroxyl group, the reaction product: the hydroxyl group-containing (meth) acrylate compound (a1) is about 1: 3.

In the addition reaction between this reaction product and the hydroxyl group-containing (meth) acrylate compound (a1), urethane is terminated when the residual isocyanate group content of the reaction system becomes 0.5% by weight or less. The (meth) acrylate-based oligomer (A) is obtained.

In the reaction between the polyol compound (a3) and the polyhydric isocyanate compound (a2), and further the reaction between the reaction product and the hydroxyl group-containing (meth) acrylate compound (a1), a catalyst is used for the purpose of promoting the reaction. It is also preferable to use. Examples of such a catalyst include organic metal compounds such as dibutyltin dilaurate, trimethyltin hydroxide, and tetra-n-butyltin; zinc octoeate, tin octoenate, cobalt naphthenate, bismuth chloride, and bismuth chloride. Metal salts of; triethylamine, benzyldiethylamine, 1,4-diazabicyclo [2,2,2] octane, 1,8-diazabicyclo [5,4,0] undecene, N, N, N', N'-tetramethyl- Amine-based catalysts such as 1,3-butanediamine and N-ethylmorpholin; inorganic bismuth compounds such as bismuth nitrate, bismuth bromide, bismuth iodide and bismuth sulfide, as well as organic bismuth compounds such as dibutyl bismuth dilaurate and dioctyl bismuth dilaurate. , 2-Ethylhexanoic acid bismuth salt, naphthenic acid bismuth salt, isodecanoic acid bismuth salt, neodecanoic acid bismuth salt, lauric acid bismuth salt, maleic acid bismuth salt, stearate bismuth salt, oleic acid bismuth salt, linoleic acid bismuth salt, Examples include bismuth-based catalysts such as bismuth acetate, bismuth bismuth neodecanoate, disalicylic acid bismuth salt, and organic acid bismuth salt such as di bismuth acid bismuth salt; among them, dibutyltin dilaurate, 1,8-diazabicyclo [ 5,4,0] Undesen is suitable.

Further, in the reaction between the polyol compound (a3) and the polyvalent isocyanate compound (a2), and further in the reaction between the reaction product and the hydroxyl group-containing (meth) acrylate compound (a1), it reacts with the isocyanate group. Organic solvents having no functional groups, such as esters such as ethyl acetate and butyl acetate; ketones such as methyl ethyl ketone and methyl isobutyl ketone; aromatics such as toluene and xylene; and the like can be used.

The reaction temperature is usually 30 to 90 ° C., preferably 40 to 80 ° C., and the reaction time is usually 2 to 10 hours, preferably 3 to 8 hours.

The urethane (meth) acrylate-based oligomer (A) used in the present invention preferably has 20 or less ethylenically unsaturated groups, and particularly preferably 10 in terms of utilizing the adhesiveness with fibers. It has the following ethylenically unsaturated groups, and more preferably 5 or less ethylenically unsaturated groups. The lower limit of the number of ethylenically unsaturated groups is usually 2.

<Binder polymer (B)>
The binder polymer (B) in the present invention is used for the purpose of appropriately adjusting the viscosity of the uncured thermosetting composition [i], and is, for example, a (meth) acrylic resin, a polyurethane resin, or an epoxy resin. And so on. Above all, the (meth) acrylic resin (B1) is preferable in terms of facilitating the adjustment of the viscosity.
Hereinafter, the (meth) acrylic resin (B1) will be described more specifically.

[(Meta) acrylic resin (B1)]
The (meth) acrylic resin (B1) in the present invention is obtained by polymerizing a monomer component containing a (meth) acrylic monomer. As the (meth) acrylic resin (B1), one type may be used alone or two or more types may be used in combination.

The (meth) acrylic resin (B1) preferably contains a (meth) acrylic acid ester-based monomer (b1) as a main polymerization component, and if necessary, a functional group-containing monomer (b2) and other copolymerization. The sex monomer (b3) can also be used as a copolymerization component.
Examples of the (meth) acrylic acid ester-based monomer (b1) include an aliphatic (meth) acrylic acid ester-based monomer such as (meth) acrylic acid alkyl ester and an aromatic-based monomer such as (meth) acrylic acid phenyl ester. Examples thereof include (meth) acrylic acid ester-based monomers.

For such (meth) acrylic acid alkyl ester, the number of carbon atoms of the alkyl group is usually 1 to 12, particularly preferably 1 to 8, and more preferably 1 to 4, specifically, for example, methyl (meth). ) Acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-propyl (meth) acrylate, n-hexyl (meth) acrylate, 2 -Ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate And so on. Examples of the (meth) acrylic acid phenyl ester include benzyl (meth) acrylate and phenoxyethyl (meth) acrylate.
Examples of the other (meth) acrylic acid ester-based monomer (b1) include tetrahydrofurfuryl (meth) acrylate and the like. These can be used alone or in combination of two or more.

Among such (meth) acrylic acid ester-based monomers (b1), methyl (meth) acrylate, n-butyl (meth) acrylate, 2 -Ethylhexyl (meth) acrylate is preferably used.

Examples of the functional group-containing monomer (b2) include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an alkoxy group-containing monomer, a phenoxy group-containing monomer, an amide group-containing monomer, an amino group-containing monomer, other nitrogen-containing monomers, and a glycidyl group. Examples thereof include a monomer, a phosphate group-containing monomer, a sulfonic acid group-containing monomer, and the like, and these can be used alone or in combination of two or more.

Examples of the hydroxyl group-containing monomer include a primary hydroxyl group-containing monomer, a secondary hydroxyl group-containing monomer, and a tertiary hydroxyl group-containing monomer. Examples of the primary hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 8-hydroxyoctyl. Primary hydroxyl group-containing (meth) acrylic acid hydroxyalkyl ester such as (meth) acrylate, 10-hydroxydecyl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl (meth) acrylate; caprolactone-modified 2-hydroxyethyl Caprolactone-modified monomers such as (meth) acrylate; 2-acryloyloxyethyl-2-hydroxyethylphthalic acid; N-methylol (meth) acrylamide; N-hydroxyethyl (meth) acrylamide and the like can be mentioned. Examples of the secondary hydroxyl group-containing monomer include secondary hydroxyl group-containing (meth) acrylic acid hydroxyalkyl esters such as 2-hydroxypropyl (meth) acrylate and 2-hydroxybutyl (meth) acrylate; 2-hydroxy-3-phenoxy. Examples thereof include propyl (meth) acrylate; 3-chloro-2-hydroxypropyl (meth) acrylate; 2-hydroxy-3-phenoxypropyl (meth) acrylate. Examples of the tertiary hydroxyl group-containing monomer include 2,2-dimethyl-2-hydroxyethyl (meth) acrylate and the like.

Further, as the hydroxyl group-containing monomer, for example, a polyethylene glycol derivative such as diethylene glycol mono (meth) acrylate and polyethylene glycol mono (meth) acrylate, a polypropylene glycol derivative such as polypropylene glycol mono (meth) acrylate, and polyethylene glycol-polypropylene glycol-mono. Oxyalkylene-modified monomers such as (meth) acrylate, poly (ethylene glycol-tetramethylene glycol) mono (meth) acrylate, and poly (propylene glycol-tetramethylene glycol) mono (meth) acrylate may be used.

Examples of the carboxyl group-containing monomer include michel addition of acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, acrylamide N-glycolic acid, silicic acid, and (meth) acrylic acid. (For example, acrylic acid dimer, methacrylate dimer, acrylic acid trimmer, methacrylate trimmer, tetramer acrylic acid, tetramer methacrylate, etc.), 2- (meth) acryloyloxyethyl dicarboxylic acid monoester (eg, 2-acryloyloxyethyl). Succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, 2-acryloyloxyethyl phthalic acid monoester, 2-methacryloyloxyethyl phthalic acid monoester, 2-acryloyloxyethyl hexahydrophthalic acid monoester, 2-methacryloyl Oxyethyl hexahydrophthalic acid monoester, etc.) and the like. The carboxyl group-containing monomer may be used as it is as an acid, or may be used in the form of an alkali-neutralized salt.

Examples of the alkoxy group-containing monomer include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, and 2-butoxydiethylene glycol. (Meta) acrylate, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, octoxypolyethylene glycol- Examples thereof include aliphatic (meth) acrylic acid esters such as polypropylene glycol-mono (meth) acrylate, lauroxypolyethylene glycol mono (meth) acrylate, and stearoxypolyethylene glycol mono (meth) acrylate, and examples thereof include phenoxy group-containing monomers. Is an aromatic (meth) acrylate such as 2-phenoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol-polypropylene glycol (meth) acrylate, and nonylphenolethylene oxide adduct (meth) acrylate. Acrylate ester of acrylate and the like can be mentioned.

Examples of the amide group-containing monomer include acrylamide, methacrylamide, N- (n-butoxyalkyl) acrylamide, N- (n-butoxyalkyl) methacrylamide, N, N-dimethyl (meth) acrylamide, N, N-. Examples thereof include diethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, acrylamide-3-methylbutylmethylamine, dimethylaminoalkylacrylamide, and dimethylaminoalkylmethacrylamide.

Examples of the amino group-containing monomer include dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, and quaternized products thereof.
Examples of the nitrogen-containing monomer other than the amide group-containing monomer and the amino group-containing monomer include acryloylmorpholin and the like.

Examples of the glycidyl group-containing monomer include glycidyl (meth) acrylate and allyl glycidyl ether.

Examples of the phosphoric acid group-containing monomer include 2- (meth) acryloyloxyethyl acid phosphate and bis (2- (meth) acryloyloxyethyl) acid phosphate.

Examples of the sulfonic acid group-containing monomer include olefin sulfonic acid such as ethylene sulfonic acid, allyl sulfonic acid and methallyl sulfonic acid, 2-acrylamide-2-methyl propane sulfonic acid, styrene sulfonic acid or a salt thereof and the like. ..

Examples of the other copolymerizable monomer (b3) include acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, vinyl acetate, vinyl propionate, vinyl stearate, vinyl chloride, vinylidene chloride, alkyl vinyl ether, vinyl toluene, and the like. Examples thereof include monomers such as vinylpyridine, vinylpyrrolidone, itaconic acid dialkyl ester, fumaric acid dialkyl ester, allyl alcohol, acrylic chloride, methyl vinyl ketone, N-acrylamide methyltrimethylammonium chloride, allyltrimethylammonium chloride, and dimethylallylvinyl ketone.

For the purpose of increasing the molecular weight, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and propylene glycol di (meth) acrylate , Compounds having two or more ethylenically unsaturated groups such as divinylbenzene can also be used in combination.

In the (meth) acrylic resin (B1), the content ratio of the (meth) acrylic acid ester-based monomer (a1), the functional group-containing monomer (b2), and the other copolymerizable monomer (b3) is (meth) acrylic acid. The ester-based monomer (b1) is preferably 10 to 100% by weight, particularly preferably 20 to 95% by weight, and the functional group-containing monomer (b2) is preferably 0 to 90% by weight, particularly preferably 5 to 80% by weight. The other copolymerizable monomer (b3) is preferably 0 to 50% by weight, particularly preferably 5 to 40% by weight.

The (meth) acrylic resin (B1) in the present invention is methyl in that it has excellent compatibility with the urethane (meth) acrylate-based oligomer (A) and that the hardness of the cured product [i] is adjusted. It is preferably a polymer containing (meth) acrylate as a polymerization component, particularly preferably a polymer containing methyl methacrylate as a polymerization component, and further preferably polymethyl methacrylate.

In the present invention, the (meth) acrylic resin (B1) can be produced by polymerizing the above-mentioned monomer components (b1) to (b3). Such polymerization can be carried out by conventionally known methods such as solution radical polymerization, suspension polymerization, bulk polymerization and emulsion polymerization. For example, in an organic solvent, a polymerization monomer such as the above (meth) acrylic acid ester-based monomer (b1), a functional group-containing monomer (b2), and another copolymerizable monomer (b3), and a polymerization initiator (azobisisobuty). Lonitrile, azobisisobutyvaleronitrile, benzoyl peroxide, etc.) are mixed or dropped, and polymerized in a refluxed state or at 50 to 90 ° C. for 2 to 20 hours.

Examples of the organic solvent used in the polymerization reaction include aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as hexane; esters such as ethyl acetate and butyl acetate; n-propyl alcohol and isopropyl alcohol. Such as aliphatic alcohols; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; and the like.

The glass transition temperature (Tg) of the (meth) acrylic resin (B1) is usually 40 to 120 ° C, preferably 60 to 110 ° C. If the glass transition temperature is too high, the amount of the (meth) acrylic resin (B1) that can be blended when preparing the thermosetting composition [i] is limited, and the uncured thermosetting composition [i] is used. The viscosity adjustment range is narrowed, and the durability of the cured product [i] tends to decrease, or the cured product [i] tends to become too hard and the strength decreases. If the glass transition temperature is too low, the thermal durability of the cured product [i] tends to decrease. Tends to decline.

The glass transition temperature (Tg) is calculated from the following Fox formula.
1 / Tg = w1 / Tg1 + w2 / Tg2 + ... Wk / Tgk
However, Tg is the glass transition temperature of the copolymer, Tg1, Tg2, ..... Tgk is the Tg of the homopolymer of each monomer component, and w1, w2, ... ..... wk represents the mole fraction of each monomer component, and w1 + w2 + ..... wk = 1.

The weight average molecular weight of the (meth) acrylic resin (B1) thus obtained is usually 10,000 to 3 million, preferably 20,000 to 2.5 million.
If the weight average molecular weight is too small, the uncured thermosetting composition [i] tends to be soft, the adhesiveness becomes higher than necessary, and the handleability tends to decrease, and the cured product [i]. Tends to become brittle. Further, if the weight average molecular weight is too large, the viscosity of the thermosetting composition [i] before coating on the support film [II] becomes too high, or it becomes difficult to increase the concentration. There is a tendency to reduce workability, and further, the flexibility of the thermosetting composition layer [I] before curing is reduced, making it difficult to wind the laminated film of the present invention into a roll. Tend.
The above weight average molecular weight is based on standard polystyrene molecular weight conversion, and is used in high performance liquid chromatography (manufactured by Japan Waters, "Waters 2695 (main body)" and "Waters 2414 (detector)"), column: Platex GPC KF. -806L (exclusion limit molecular weight: 2 × 10 ⁷ , separation range: 100 to 2 × 10 ⁷ , theoretical plate number: 10,000 stages / piece, filler material: styrene-divinylbenzene copolymer, filler particle size: 10 μm ) Can be measured by using three series.

In the present invention, the content ratio (weight ratio) of the urethane (meth) acrylate-based oligomer (A) and the binder polymer (B) is usually set to: urethane (meth) acrylate-based oligomer (A): binder polymer (B) = 10 :. It is 90 to 90:10, preferably 30:70 to 80:20, and particularly preferably 40:60 to 70:30. If the amount of the urethane (meth) acrylate-based oligomer (A) is too large (the amount of the binder polymer (B) is too small), adhesiveness develops on the surface of the cured layer [I] after curing, which hinders the subsequent process. , The curing shrinkage of the cured layer [I] becomes large, which tends to cause cracks in the cured layer [I], and the amount of the urethane (meth) acrylate-based oligomer (A) is too small (the binder polymer (B)). (Too many), the thermosetting composition layer [I] becomes too hard, and the handling of the laminated film of the present invention causes cracks in the thermosetting composition layer [I], and the laminated film of the present invention is used. There is a tendency that the followability when laminating the fiber sheet or the like on the fiber layer and the flexibility of the cured fiber product are also deteriorated.

<Thermal polymerization initiator (C)>
The thermal polymerization initiator (C) in the present invention is not particularly limited, and examples thereof include azobis-based compounds and peroxide-based compounds.
Examples of the azobis-based compound include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis 2,4-dimethylvaleronitrile, and dimethyl. -2,2'-azobisisobutyrate, 1,1'-azobis (cyclohexane-1-carbonitrile), 1,1'-azobis (1-acetoxy1-phenylethane), 2,2'-azobis ( 4-methoxy-2,4-dimethylvaleronitrile) and the like can be mentioned.
Examples of the peroxide compound include diisobutyryl peroxide, cumylperoxyneodecanoate, di-n-propylperoxydicarbonate, diisopropylperoxydicarbonate, di-sec-butylperoxycarbonate, 1,1 3,3-Tetramethylbutylperoxyneodecanoate, di (4-t-butylcyclohexyl) peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, t-hexylperoxyneodecanoate, t-butylperoxyneo Decanoate, t-butylperoxyneoheptanoate, t-hexylperoxypivalate, t-butylperoxypivalate, di (3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, 1,1,3 , 3-Tetramethylbutylperoxy-2-ethylhexanoate, dissuccinic peroxide peroxide, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, t-hexylperoxy-2-ethylhexanoate Ate, di (4-methylbenzoyl) peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, 1,1'-di (t-hexylperoxy) cyclohexane, 1,1-di (t-butylpoel) Oxy) Cyclohexane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymalonic acid, t-butylperoxylaurate, t-hexylperoxybenzoate, t-butylperoxyacetate, t-butylbenzoyl peroxide, dicumyl peroxide, t -Butyl cumyl peroxide, di-t-butyl peroxide, diisopropylbenzene hydroperoxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide and the like can be mentioned.
These thermal polymerization initiators (C) may be used alone or in combination of two or more.

Of these, it is a peroxide-based compound in that less gas is generated during curing, and specifically, for example, dilauroyl peroxide, 1,1'-di (t-hexylperoxy) cyclohexane, 1,1-. Di (t-butylperoxy) cyclohexane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymalonic acid, t-butylperoxylaurate, t-hexylperoxybenzoate, t-butylperoxyacetate, t-butylbenzoyl peroxide, dik Milperoxide, t-butylcumylperoxide, di-t-butylperoxide, diisopropylbenzenehydroperoxide, and diisopropylbenzenehydroperoxide are preferred.

In addition, as these auxiliaries, triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (Mihiler ketone), 4,4'-diethylaminobenzophenone, 2-dimethylaminoethyl benzoic acid, 4-dimethylaminobenzoic acid Ethyl, 4-dimethylaminobenzoic acid (n-butoxy) ethyl, 4-dimethylaminobenzoate isoamyl, 4-dimethylaminobenzoate 2-ethylhexyl, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, etc. are used in combination. It is also possible.

The content of the thermosetting initiator (C) in the thermosetting composition [i] includes a urethane (meth) acrylate-based oligomer (A) component, a binder polymer (B) component, and a reactive monomer (D) component described later. When the total amount of the non-volatile content is 100 parts by weight, it is preferably 0.1 to 30 parts by weight, particularly preferably 0.5 to 20 parts by weight, and further preferably 1 to 10 parts by weight.
If the content of the thermal polymerization initiator (C) is too small, the cured layer [I] is insufficiently cured and sufficient elasticity or hardness cannot be obtained, and the cured layer [I] tends to become brittle and unable to perform its function. If the content is too large, the thermosetting initiator (C) tends to bleed out during storage of the thermosetting composition layer [I], and crystals tend to precipitate in the cured layer [I]. be.

<Reactive monomer (D) having one or more unsaturated groups>
The thermosetting composition [i] in the present invention preferably further contains a reactive monomer (D) having one or more unsaturated groups.
As the reactive monomer (D) having one or more unsaturated groups, for example, a monofunctional monomer, a bifunctional monomer, a trifunctional or higher monomer, another ethylenically unsaturated monomer and the like can be used.

As the monofunctional monomer, a monomer containing one ethylenically unsaturated group is used, for example, styrene, vinyltoluene, chlorostyrene, α-methylstyrene, methyl (meth) acrylate, ethyl (meth) acrylate, and acrylonitrile. , Vinyl acetate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (meth) acrylate , 2-Hydroxy-3-phenoxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, glycidyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) Acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, n-butyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate , Nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate, n-stearyl (meth) acrylate, benzyl (meth) acrylate, phenolethylene oxide-modified (meth) acrylate, nonylphenolpropylene Half-ester (meth) acrylate of phthalic acid derivatives such as oxide-modified (meth) acrylate, 2- (meth) acryloyloxy-2-hydroxypropylphthalate; furfuryl (meth) acrylate, carbitol (meth) acrylate, benzyl (meth) Acrylate, butoxyethyl (meth) acrylate, allyl (meth) acrylate, acryloylmorpholine, 2-hydroxyethylacrylamide, N-methylol (meth) acrylamide, N-vinylpyrrolidone, 2-vinylpyridine, 2- (meth) acryloyloxy Ethyl acid phosphate monoester and the like can be mentioned.

As the bifunctional monomer, a monomer containing two ethylenically unsaturated groups is used, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol. Di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide Modified bisphenol A type di (meth) acrylate, propylene oxide modified bisphenol A type di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,6-hexanediol ethylene oxide modified di (meth) acrylate, glycerin Di (meth) acrylate, pentaerythritol di (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, phthalic acid diglycidyl ester di (meth) acrylate, hydroxypivalic acid modification. Examples thereof include neopentyl glycol di (meth) acrylate, isocyanuric acid ethylene oxide-modified diacrylate, and 2- (meth) acryloyloxyethyl acid phosphate diester.

As the trifunctional or higher-functional monomer, a monomer containing three or more ethylenically unsaturated groups is used, for example, trimethylolpropanetri (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol tetra (meth). Acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tri (meth) acryloyloxyethoxytrimethylol propane, glycerin Polyglycidyl ether poly (meth) acrylate, isocyanuric acid ethylene oxide-modified tri (meth) acrylate, ethylene oxide-modified dipentaerythritol penta (meth) acrylate, ethylene oxide-modified dipentaerythritol hexa (meth) acrylate, ethylene oxide-modified pentaerythritol tri Examples thereof include (meth) acrylate, ethylene oxide-modified pentaerythritol tetra (meth) acrylate, and succinic acid-modified pentaerythritol tri (meth) acrylate.

In addition to the above, examples of the other ethylenically unsaturated monomer include a michael adduct of acrylic acid or a 2-acryloyloxyethyl dicarboxylic acid monoester, and examples of the michael adduct of acrylic acid include acrylic acid dimer and methacrylic acid. Examples thereof include acid dimer, acrylic acid trimmer, methacrylic acid trimmer, acrylic acid tetramer, and methacrylic acid tetramer. Examples of the 2-acryloyloxyethyl dicarboxylic acid monoester, which is a carboxylic acid having a specific substituent, include 2-acryloyloxyethyl succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, and 2-acryloyl. Examples thereof include oxyethyl phthalic acid monoester, 2-methacryloxyethyl phthalic acid monoester, 2-acryloyloxyethyl hexahydrophthalic acid monoester, and 2-methacryloxyethyl hexahydrophthalic acid monoester. Further, oligoester acrylate can also be mentioned.

As the reactive monomer (D) having one or more unsaturated groups in the present invention, a bifunctional monomer and a polyfunctional monomer having a trifunctional or higher functionality are preferable, and the bifunctional monomer and the trifunctional or higher functional monomer are particularly preferable. It is the mentioned polyfunctional (meth) acrylate compound (D1).

The content of the reactive monomer (D) in the thermosetting composition [i] is 100 parts by weight when the total non-volatile content of the urethane (meth) acrylate-based oligomer (A) component and the binder polymer (B) component is 100 parts by weight. In addition, it is preferably 1 to 100 parts by weight, particularly preferably 3 to 80 parts by weight, and further preferably 5 to 70 parts by weight.
If the content of the reactive monomer (D) is too small, the flexibility of the thermosetting composition layer [I] tends to decrease and the processability tends to decrease, and if it is too large, the cured layer [I] becomes hard. It tends to be too brittle due to reduced impact resistance.

The thermosetting composition [i] in the present invention includes, if necessary, a plasticizer, an antioxidant, a solvent, a surface tension modifier, a stabilizer, a chain transfer agent, a surfactant and the like. Additives may be added.

<Laminated film for fiber adhesion and / or fiber sheet surface protection>
The laminated film for fiber adhesion and / or fiber sheet surface protection of the present invention has a structure in which a layer [I] composed of a thermosetting composition [i] and a support film [II] are laminated.

Examples of the support film [II] include a polyethylene terephthalate (PET) film, a release PET film, a polypropylene film, a polyethylene film, a polyethylene naphthalate film, a polyvinyl alcohol-based film, an ethylene vinyl alcohol copolymerization system film, and the like, or a resin layer. It is preferable to use a paper or the like laminated on the surface of the film.
Above all, in terms of heat resistance during film formation and curing of the thermosetting composition layer [I], a PET film, a release PET film that has undergone a mold release treatment, or a paper in which a resin layer is laminated on the surface thereof ( Hereinafter, it is particularly preferable to use a release paper). When a mold release PET film or a release paper is used, the mold release treatment and the formation of the resin layer may be performed on only one side of the film or paper or on both sides.
The thickness of the support film [II] is preferably 5 μm or more, particularly preferably 10 to 200 μm, and further preferably 20 to 100 μm.

In the laminated film for fiber adhesion and / or fiber sheet surface protection of the present invention, the protective film [III] is laminated on the side of the thermosetting composition layer [I] on which the support film [II] is not laminated. You may.
The protective film [III] is used for the purpose of preventing the transfer of the heat-curable composition layer [I] having adhesiveness to the support film [II] when the laminated film of the present invention is made into a roll. The protective film [III] used is, for example, a polyethylene film, a release PET film, a polypropylene film, a polyvinyl alcohol-based film, an ethylene vinyl alcohol copolymerization system film, a polytetrafluoroethylene film, and nylon. Examples thereof include a film and a release paper, and among them, a release PET film and a release paper are preferable.
The thickness of the protective film [III] is preferably 5 μm or more, particularly preferably 10 to 200 μm, and further preferably 15 to 100 μm.

As a method for producing the laminated film of the present invention, for example, an oven in which the thermosetting composition [i] is uniformly applied to one side of the support film [II] and the temperature is usually increased to 50 to 120 ° C. or sequentially. Then, usually, a method of drying for 1 to 60 minutes to form a thermosetting composition layer [I] can be mentioned. Further, when the protective film [III] is used, a method of forming the thermosetting composition layer [I] and then pressure-laminating the protective film [III] on the upper surface of the layer [I] can be mentioned. ..

In the laminated film of the present invention, when used for bonding fibers or protecting the surface of a fiber sheet, the thickness of the thermosetting composition layer [I] is preferably 50 μm or more, particularly 80 to 500 μm, and further 100 to 300 μm. Is preferable.
In the laminated film of the present invention, when the cured layer [I] obtained by curing the thermosetting composition layer [I] is imparted with design, the thickness of the thermosetting composition layer [I] is 100 μm or more. Is preferable, and in particular, 150 to 500 μm, more preferably 250 to 300 μm.
If the thickness of the thermosetting composition layer [I] is too thin, the number of layers to be laminated in order to obtain an appropriate thickness for adhering the fibers or protecting the surface of the fiber sheet becomes too large, and the laminating process becomes complicated. It tends to be too expensive, or it tends to be difficult to obtain a suitable thickness for adhesion or surface protection. Further, if the thickness is too thick, it tends to take too much time to dry the thermosetting composition [i] to form the thermosetting composition layer [I].

The laminated film of the present invention thus obtained can be used for adhering fibers such as carbon fibers and glass fibers to each other and for protecting the surface of a fiber sheet made of such fibers.
Examples of the fiber in the present invention include reinforcing fibers such as glass fiber, carbon fiber, aramid fiber, boron fiber, alumina fiber and silicon carbide fiber, and two or more of these fibers may be mixed and used. Glass fiber and carbon fiber are preferably used in order to obtain a molded product that is lighter and more durable.
The form and arrangement of the fiber sheets are not particularly limited, and examples thereof include sheets in which bundles of fibers are aligned in one direction, woven fabrics (cloths), mats, knits, and non-woven fabrics.

An exemplary method for producing a prepreg using the laminated film of the present invention or the thermosetting composition for fiber adhesion and / or fiber sheet surface protection of the present invention will be outlined.
As a method for producing a prepreg using the laminated film of the present invention, for example, a fiber sheet and a laminated film are laminated, a support film [II] of the laminated film is peeled off, and another laminated film is used as a fiber. A method of further laminating the sheet or the heat-curable composition layer [I], peeling off the support film [II], and then heating and pressurizing the fiber sheet to impregnate the fiber sheet with the heat-curable composition [i] can be mentioned. Examples of the method of heating and pressurizing include press molding, autoclave molding, internal pressure molding and the like.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded.
In the example, "%" and "part" mean a weight standard.
The following are prepared as each component.

<Urethane (meth) acrylate-based oligomer (A)>
The following bifunctional urethane acrylate-based oligomer (A1) was prepared as the urethane (meth) acrylate-based oligomer (A1).
(A1): Isophorone diisocyanate 30.6 g (0.138 mol), bifunctional polyester polyol (hydroxyl value 145 mgKOH / g, number average) in a four-necked flask equipped with a thermometer, a stirrer, a water-cooled condenser, and a nitrogen gas inlet. Molecular weight 800) 53.2 g (0.069 mol), 0.04 g of 2,6-di-tert-butyl cresol as a polymerization inhibitor, and 0.02 g of dibutyltin dilaurate as a reaction catalyst were charged and reacted at 70 ° C. for 6 hours. 16.2 g (0.140 mol) of 2-hydroxyethyl acrylate was charged and reacted at 60 ° C. for 3 hours, and the reaction was terminated when the residual isocyanate group became 0.1%, and a bifunctional urethane acrylate-based oligomer (bifunctional urethane acrylate-based oligomer) ( A1) (weight average molecular weight 5,600, viscosity at 60 ° C. 56,000 mPa · s) was obtained.

<Binder polymer (B)>
(B1): Polymethylmethacrylate ("Dianal BR-83" manufactured by Mitsubishi Rayon Co., Ltd.)

<Thermal polymerization initiator (C)>
(C1): 1,1'-di (t-hexylperoxy) cyclohexane (NOF Corporation "Perhexa HC")

<Reactive monomer (D) having one or more unsaturated groups>
(D1): Polyethylene glycol diacrylate ("A-200" manufactured by Shin Nakamura Chemical Industry Co., Ltd.)

<Epoxy resin (E)>
(E1): Bisphenol A type epoxy resin ("jER828" manufactured by Mitsubishi Chemical Corporation)

<Epoxy curing agent (F)>
(F1): 1-Methylimidazole (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)

[Example 1]
A urethane (meth) acrylate-based oligomer is obtained by combining an oligomer solution in which a urethane (meth) acrylate-based oligomer (A1) is diluted with 2-butanone to 75% and a resin solution in which a binder polymer (B1) is diluted with ethyl acetate to 40%. (A1) and the binder polymer (B1) were mixed so as to have a non-volatile content weight ratio of 56:44 (A1: B1). Further, the reactive monomer (D1) was mixed so as to be 20 parts with respect to 100 parts of the total non-volatile content of the urethane (meth) acrylate-based oligomer (A1) and the binder polymer (B1).
Next, the thermal polymerization initiator (C1) is mixed so that the amount of the mixture of (A1), (B1), and (D1) is 2 parts with respect to 100 parts of the non-volatile content, and the heat becomes 60% of the non-volatile content concentration. A solution of the curable composition [i-1] was obtained.
This thermosetting composition [i-1] solution was applied onto a polyester film [II] having a thickness of 30 μm using an applicator with a gap of 0.35 mm, and this was applied at 60 ° C. for 3 minutes and further at 80 ° C. for 3 minutes. By drying for a minute, a thermosetting composition layer [I-1] having a thickness of 100 μm was formed, and a laminated film for fiber adhesion (hereinafter, also simply abbreviated as “laminated film”) was obtained.
The obtained laminated film for fiber adhesion was used and evaluated as follows.

(Flexibility of fiber sheet)
Two glass fiber sheets (manufactured by Unitika, 100 mm × 20 mm, thickness 1 mm) are prepared, and the thermosetting composition layer of the laminated film for fiber adhesion is placed on one glass fiber sheet [I-1]. The thermosetting composition layer [I-1] is formed on the glass fiber sheet by laminating the surfaces of the above and peeling off the polyester film [II], and further, the thermosetting composition layer [I-1] is formed. ], The surface of the thermosetting composition layer [I-1] of the second fiberglass bonding laminated film was attached again, and the polyester film [II] was peeled off. A remaining one glass fiber sheet is provided on the second thermosetting composition layer [I-1], and a 200 μm thermosetting composition layer [I-1] is provided between the two glass fiber sheets. Formed. By applying a pressure of 4.2 MPa to this laminate with a press machine heated to 150 ° C. and pressing for 1 minute, the thermosetting composition layer [I-1] is cured while impregnating the glass fiber sheets on both sides. The two glass fiber sheets were bonded together. Then, as a result of bending the 50 mm portion in the middle of the sheet in the longitudinal direction at 90 ° so as to follow a rod having a diameter of 5 mm, the thermosetting composition layer [I-1] was impregnated into the glass fiber sheet and cured. No cracks were found on the surface of the cured fiber, and a cured fiber with high flexibility was obtained.

[Comparative Example 1]
Two parts of the epoxy curing agent (F) are added to 100 parts of the non-volatile content of the epoxy resin (E) and mixed for 1 minute, and then the obtained epoxy resin is mixed with a glass fiber sheet (manufactured by Unitika, 100 mm × 20 mm in size,). (Thickness 1 mm) is coated to a thickness of 200 μm, covered with a glass fiber sheet, and pressed at 4.2 MPa with a press machine heated to 150 ° C. for 1 minute to form two glass fiber sheets. Adhesion was performed. As a result of performing the same bending evaluation as in Example 1 on the obtained cured fiber, cracks were found on the surface.

The evaluation results of Example 1 and Comparative Example 1 are summarized in Table 1.
In the table, "◯" indicates that no crack was observed on the surface of the cured fiber, and "x" indicates that a crack was observed on the surface of the cured fiber.

From the above results, for fiber adhesion and / or fiber sheet surface protection in which the layer [I] composed of the thermosetting composition [i] of the present invention containing the urethane (meth) acrylate-based oligomer (A) is laminated. By laminating a fiber sheet on a laminated film and performing a heat pressing treatment, a highly flexible fiber cured product can be obtained. Therefore, it is shown that the laminated film of the present invention is useful for adhering the fiber sheet. Was done. That is, the laminated film of the present invention has good workability and productivity, and has excellent adhesiveness of the fiber sheet. Further, the laminated film of the present invention is bonded and the surface of the thermosetting fiber-reinforced plastic becomes smooth, and the surface smoothness is excellent, so that the design formability is also excellent.

Claims (6)

A laminated film for fiber adhesion and / or fiber sheet surface protection in which a layer [I] composed of a thermosetting composition [i] and a support film [II] are laminated.
The thermosetting composition [i] contains a urethane (meth) acrylate-based oligomer (A) , a binder polymer (B), and a thermopolymerization initiator (C) .
A laminated film for fiber adhesion and / or fiber sheet surface protection, wherein the urethane (meth) acrylate-based oligomer (A) has a weight average molecular weight of 500 to 50,000 . Urethane (meth) acrylate-based oligomer (A) formed by reacting a hydroxyl group-containing (meth) acrylate-based compound (a1), a polyvalent isocyanate-based compound (a2), and a polyol-based compound (a3). The laminated film for fiber adhesion and / or fiber sheet surface protection according to claim 1, which is a compound. The laminated film for fiber adhesion and / or fiber sheet surface protection according to claim 1 or 2 , wherein the binder polymer (B) is a (meth) acrylic resin (B1). The fiber adhesion and / or fiber according to any one of claims 1 to 3 , wherein the thermosetting composition [i] further contains a reactive monomer (D) having one or more unsaturated groups. Laminated film for sheet surface protection. The laminated film for fiber adhesion and / or fiber sheet surface protection according to any one of claims 1 to 4 , wherein the thickness of the layer [I] composed of the thermosetting composition [i] is 50 μm or more. Further, any of claims 1 to 5 , wherein the protective film [III] is laminated on the side where the support film [II] of the layer [I] made of the thermosetting composition [i] is not laminated. The above-mentioned laminated film for fiber adhesion and / or fiber sheet surface protection.