JP2012057136A - Resin composition for forming transparent film, laminate, and method for producing transparent film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for forming a transparent film which is excellent in hardness, flexibility, UV-resistant characteristics, heat resistance, and the like, and to provide a laminate utilizing the composition.SOLUTION: The resin composition for preparing the transparent film includes: a prepolymer obtained by the reaction of an alkoxysilane compound having a reactive functional group with a polythiol compound having two or more thiol groups in one molecule; and a curing auxiliary. A method for producing the transparent film comprises the steps of: obtaining the prepolymer by reacting the alkoxysilane compound having reactive functional group with the polythiol compound having two or more thiol groups in one molecule; preparing the resin composition for forming the transparent film containing the prepolymer and the curing auxiliary; applying the resin composition for forming the transparent film onto a substrate and curing it.

Description

The present invention relates to a resin composition for forming a transparent film, a laminate, and a method for producing a transparent film.

In recent years, a touch panel is used as an input device to a portable information terminal whose market is increasing. This touch panel is a device for inputting data by directly touching the display screen with a finger, a pen, or the like. Currently, about 90% of the touch panels are referred to as resistive film systems. A resistive film type touch panel generally has a touch side plastic substrate in which a transparent conductive thin film such as a tin-doped indium oxide (ITO) film is laminated on one side of a transparent plastic substrate, and an ITO film on one side of a transparent substrate such as glass. The transparent conductive thin film is laminated with a transparent substrate on the display side through an insulating spacer so that the transparent conductive thin films face each other. Then, the input is performed by pressing the touch input surface of the touch side plastic substrate with a pen or a finger (referred to as the surface opposite to the transparent conductive thin film), and the transparent conductive thin film on the touch side plastic substrate and the display side transparent substrate. The transparent conductive thin film is contacted.

However, in such a resistive film type touch panel, by repeating the input operation, that is, by repeatedly contacting the transparent conductive thin film of the touch side plastic substrate and the transparent conductive thin film of the display side transparent substrate, the touch side Problems such as damage to the surface, wear of the transparent conductive thin film of the touch side plastic substrate (base film), generation of cracks, and peeling from the base material occur. Therefore, in order to solve such a problem, generally, a hard coat layer made of a synthetic resin is provided between the touch side surface and the transparent plastic substrate and the transparent conductive thin film.

Conventionally, acrylic or methacrylic resins or the like have been often used as such hard coat layers (for example, Patent Document 1 and Patent Document 2). In addition, a hard coat layer made of a urethane acrylate resin obtained by modifying an acrylic resin has been studied (for example, Patent Document 3).

JP 2004-182765 A JP 2005-254470 A JP 2001-147777 A

A hard coat layer formed from a conventional acrylic or methacrylic resin has a problem of poor flexibility although it is excellent in hardness. Therefore, when molding the touch panel surface, there is a problem with the transferability of the mold surface due to lack of flexibility, there is a problem that cracks occur, and the hard coat layer may fall off from the base material. There was a problem that the moldability was limited. Further, the hard coat layer made of urethane acrylate resin has flexibility, but has low hardness, and there is room for improvement in terms of inferior scratch resistance and wear resistance.

In addition, touch panels are often applied to mobile devices and car navigation systems, and materials for hard coat layers are required to have higher UV resistance and heat resistance than conventional products in addition to the above properties. Yes.

As described above, as a raw material that can be used for a hard coat layer, particularly a hard coat layer for a touch panel, development of a material excellent in hardness, flexibility, UV resistance, and heat resistance is desired. Under such circumstances, it is an object of the present invention to provide a resin composition for forming a transparent film that satisfies the above characteristics, and a laminate using the composition.

As a result of intensive studies, the present inventors have obtained a transparent film excellent in balance between flexibility and hardness by using a resin composition for forming a transparent film having a specific composition and manufactured by a specific procedure. As a result, the present invention was completed.

That is, the first aspect of the present invention is:
The present invention relates to a transparent film-forming resin composition containing a prepolymer obtained by a reaction between an alkoxysilane compound having a reactive functional group and a polythiol compound having two or more thiol groups in one molecule, and a curing aid.

The reactive functional group is preferably a group having a carbon-carbon unsaturated bond.

The curing aid is preferably an acid and / or an acid precursor. More preferably, the acid is an organic acid. The acid precursor is preferably a photoacid generator and / or a thermal acid generator.

A 2nd aspect of this invention is related with a laminated body provided with the transparent base film formed from the said composition on the plastic base material and this plastic base material.

The third aspect of the present invention is:
A prepolymer is obtained by reacting an alkoxysilane compound having a reactive functional group with a polythiol compound having two or more thiol groups in one molecule,
A transparent film-forming resin composition containing the prepolymer and a curing aid is prepared,
The present invention relates to a method for producing a transparent film in which the resin composition for forming a transparent film is applied on a substrate and cured.

The reaction between the alkoxysilane compound and the polythiol compound is preferably performed under ultraviolet irradiation or under heating.

The transparent film formed from the resin composition for forming a transparent film of the present invention is excellent in hardness and flexibility, UV resistance, and heat resistance. Therefore, it is a material suitable for use as a hard coat layer.

[Resin composition for forming transparent film]
The resin composition for forming a transparent film of the present invention comprises:
(1) Transparent film formation containing a prepolymer obtained by reaction of an alkoxysilane compound having a reactive functional group and a polythiol compound having two or more thiol groups in one molecule, and (2) a curing aid Resin composition.

[Alkoxysilane compound having a reactive functional group]
First, an alkoxysilane compound having a reactive functional group will be described. The alkoxysilane compound functions as a hard segment of the transparent film. Although it does not restrict | limit especially as an alkoxysilane compound which has a reactive functional group, What forms amorphous silica by a hydrolysis and a condensation reaction is preferable.

In the present specification, the “reactive functional group” of the alkoxysilane compound specifically means a functional group that undergoes an addition reaction with a thiol group (mercapto group (—SH)). Such reactive functional groups are not particularly limited, but include groups having carbon-carbon unsaturated bonds such as vinyl groups, allyl groups, and alkenyl groups, and epoxy groups, styryl groups, acryloxy groups, methacryloxy groups, halo groups. Preferred examples include isocyanate groups. Among these, since the carbon-carbon unsaturated bond can be a reaction point when the polythiol compound described later undergoes a crosslinking reaction, a group having a carbon-carbon unsaturated bond such as a vinyl group, an allyl group, and an alkenyl group is particularly preferable.

Examples of the alkoxysilane compound having a reactive functional group include an alkoxy group having about 1 to 4 carbon atoms and a silane compound having a reactive functional group. Specifically, trimethoxyvinylsilane, triethoxyvinylsilane, Alkoxy vinyl silanes such as vinyl triisopropoxy silane, vinyl tri n-propoxy silane, vinyl tris (2-methoxyethoxy) silane, vinyl tri n-butoxy silane, vinyl tri sec-butoxy silane, vinyl triisobutoxy silane; allyl trimethoxy silane, allyl tri Alkoxyallylsilanes such as ethoxysilane; 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-acryloxypropylmethyldimethoxysilane, and 3-acryloxy Acryloxyalkyl-alkoxysilanes such as propylmethyldiethoxysilane; 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, and 3-methacryloxypropylmethyldiethoxy Methacryloxyalkyl-alkoxysilanes such as silane; halogen-containing silanes such as trimethylchlorosilane and 3-chloropropyltrimethoxysilane; α-glycidoxymethyltrimethoxysilane, α-glycidoxymethyltriethoxysilane, α-glycid Xylethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, γ-glycidoxypro Pyrtrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) -ethyltrimethoxy Silane and epoxy group-containing silanes such as β- (3,4-epoxycyclohexyl) -ethyltriethoxysilane; styryl group-containing silanes such as p-styryltrimethoxysilane; ureido groups such as 3-ureidopropyltriethoxysilane ( _{-NH (C = O) NH 2} ) containing silane; isocyanate group-containing silane such as 3-isocyanate propyl triethoxysilane; and can be given these hydrolysates.

These may be used alone or in combination of two or more. Of these, alkoxysilanes having one or more carbon-carbon unsaturated bonds in one molecule are preferable from the viewpoint of reactivity and the like, alkoxyvinylsilanes are more preferable, and trialkoxyvinylsilanes are particularly preferable. When using 2 or more types of an alkoxysilane compound together, it is preferable to contain at least 1 type of alkoxysilane which has one or more carbon-carbon unsaturated bonds in 1 molecule.

[Polythiol compound]
Next, the polythiol compound will be described. The polythiol compound used in the present invention is not particularly limited as long as it has two or more thiol groups (mercapto group (-SH)) in one molecule. For example, 1 obtained by esterification reaction of a polyol such as ethylene glycol dimercaptopropionate and a mercapto organic acid (for example, thioglycolic acid, 3-mercaptopropionic acid, thioacetic acid, thiolactic acid, thiomalic acid, thiosalicylic acid, etc.) Dithiol compounds having two thiol groups in the molecule, trimethylolpropane tris (mercaptopropionate), pentaerythritol tetrakis (mercaptopropionate), dipentaerythritol hexa (mercaptopropionate), tris (mercaptopropionyloxyethyl) ) By reaction of polythiol compound having 3 or more thiol groups in one molecule obtained by esterification reaction of polyol such as isocyanurate and mercapto organic acid, epoxy compound and hydrogen sulfide. Terminal thiol group-containing thiol compound, 1,4-butanedithiol, 1,6-hexanedithiol, alkylpolythiol compound such as 1,10-decanedithiol, terminal obtained by thiolation of hydroxyl group of polyol compound Examples include thiol group-containing thiol compounds.

Among them, a polythiol compound obtained by an esterification reaction between a polyol and a mercapto organic acid is preferable, and in particular, a polythiol compound having 3 or more thiol groups in one molecule, particularly trimethylolpropane tris (mercaptopropionate) (TMMP). ) Is preferred.

The content of the polythiol compound is not particularly limited, but when the alkoxysilane compound is 100 parts by mass, the lower limit is usually 20 parts by mass, preferably 30 parts by mass, more preferably 40 parts by mass, and the upper limit is 200 parts by mass. Preferably it is 150 mass parts, More preferably, it is 120 mass parts. When the amount of the polythiol compound is too small, the flexibility of the produced transparent film tends to be insufficient, and when the amount is too large, the hardness of the produced transparent film tends to be insufficient.

Next, the alkoxysilane compound and the polythiol compound are reacted to form a prepolymer. The prepolymer is not particularly limited, but it is preferable that the prepolymer is prepared under the condition of addition polymerization between the alkoxysilane compound and the polythiol compound by ultraviolet irradiation or heating after mixing the alkoxysilane compound and the polythiol compound. In this case, the obtained prepolymer contains a partial addition polymer of an alkoxysilane compound and a polythiol compound as main components.

When the above reaction is performed under ultraviolet irradiation, it is not particularly limited, but it is preferable to irradiate ultraviolet rays with an integrated irradiation amount of 300 mJ / ml or more and 15 J / ml or less.

When performing the said reaction under a heating, although it does not specifically limit, It is preferable to heat at 20 degreeC or more and 150 degrees C or less for 30 minutes to 2 hours.

The prepolymer formation reaction is controlled based on the reaction rate of the raw material. The said reaction rate can obtain | require the residual SH mass in a reaction product by iodine oxidation titration, and can obtain | require it from ratio with SH mass in the raw material before reaction. The iodine oxidation titration is not particularly limited, but can be performed using an automatic titration apparatus, for example, an automatic titration apparatus COM-2500 manufactured by Hiranuma Sangyo Co., Ltd., an indicator electrode PT-301, and a comparative electrode RE-201. An example of a specific procedure for iodine oxidation titration will be described. First, a titration sample is prepared by dissolving a reaction product in a methanol / chloroform (1: 1 (vol: vol)) mixed solvent. Next, potentiometric titration can be performed on the sample using a 0.05 mol / L iodine solution as a titrant. The SH mass can be obtained using the inflection point of the titration curve as the end point of titration. The reaction rate can be calculated according to the following formula.
Reaction rate (%)
= {[(SH mass in raw material)-(Remaining SH mass in product)] / (SH mass in raw material)} × 100

The reaction rate is preferably 70% (mass / mass) or more, more preferably 85% (mass / mass) or more, and ultraviolet irradiation or heating is performed. When the reaction rate is low, the hardness of the obtained transparent film is insufficient, and the heat resistance and UV resistance tend to be low. Needless to say, the upper limit of the reaction rate is 100% (mass / mass).

[Curing aid]
The transparent film-forming resin composition of the present invention is prepared by further blending the above-mentioned prepolymer with a curing aid and necessary components. Although it does not specifically limit as a hardening adjuvant, An acid and / or an acid precursor are mentioned.

As the acid, an organic acid is preferable. Examples of organic acids include organic carboxylic acids and organic sulfonic acids.

The organic carboxylic acid is not particularly limited, and examples thereof include an aliphatic compound, an aromatic compound, and an alicyclic compound in which one or two or more hydrogens are substituted with a carboxy group. For example, aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, heptanoic acid, aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid, benzoic acid , Phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, cinnamic acid and other aromatic carboxylic acids, tartaric acid, citric acid, lactic acid, malic acid and other hydroxy acids, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoro Substituent-containing acetic acid such as acetic acid, nitroacetic acid and triphenylacetic acid can be mentioned.

As the organic sulfonic acid, aliphatic, aromatic, cycloaliphatic or the like containing one or more sulfo groups or a polymer containing sulfo groups can be used.

Examples of those containing one sulfo group include methanesulfonic acid, ethanesulfonic acid, 1-propanesulfonic acid, 1-butanesulfonic acid, 1-hexanesulfonic acid, 1-heptanesulfonic acid, 1-octanesulfonic acid, 1-nonanesulfonic acid, 1-decanesulfonic acid, 1-pentadecanesulfonic acid, 2-bromoethanesulfonic acid, 3-chloro-2-hydroxypropanesulfonic acid, trifluoromethanesulfonic acid, trifluoroethanesulfonic acid, colistin methanesulfone Acid, 2-acrylamido-2-methylpropanesulfonic acid, aminomethanesulfonic acid, 1-amino-2-naphthol-4-sulfonic acid, 2-amino-5-naphthol-7-sulfonic acid, 3-aminopropanesulfonic acid N-cyclohexyl-3-aminopropanesulfone Benzenesulfonic acid, alkylbenzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, ethylbenzenesulfonic acid, propylbenzenesulfonic acid, butylbenzenesulfonic acid, pentylbenzenesulfonic acid, hexylbenzenesulfonic acid, heptylbenzenesulfonic acid, octylbenzene Sulfonic acid, nonylbenzenesulfonic acid, decylbenzenesulfonic acid, hexadecylbenzenesulfonic acid, 2,4-dimethylbenzenesulfonic acid, dipropylbenzenesulfonic acid, 4-aminobenzenesulfonic acid, o-aminobenzenesulfonic acid, m- Aminobenzenesulfonic acid, 4-amino-2-chlorotoluene-5-sulfonic acid, 4-amino-3-methylbenzene-1-sulfonic acid, 4-amino-5-methoxy-2-methylbenze Sulfonic acid, 2-amino-5-methylbenzene-1-sulfonic acid, 4-amino-2-methylbenzene-1-sulfonic acid, 5-amino-2-methylbenzene-1-sulfonic acid, 4-amino-3 -Methylbenzene-1-sulfonic acid, 4-acetamido-3-chlorobenzenesulfonic acid, 4-chloro-3-nitrobenzenesulfonic acid, p-chlorobenzenesulfonic acid, naphthalenesulfonic acid, methylnaphthalenesulfonic acid, propylnaphthalenesulfonic acid, butyl Naphthalenesulfonic acid, pentylnaphthalenesulfonic acid, 4-amino-1-naphthalenesulfonic acid, 8-chloronaphthalene-1-sulfonic acid, naphthalenesulfonic acid formalin polycondensate, melaminesulfonic acid formalin polycondensate, anthraquinonesulfonic acid, pyrene Examples include sulfonic acid It is done.

Examples of those containing two or more sulfo groups include ethanedisulfonic acid, butanedisulfonic acid, pentanedisulfonic acid, decanedisulfonic acid, o-benzenedisulfonic acid, m-benzenedisulfonic acid, p-benzenedisulfonic acid, and toluenedisulfonic acid. , Xylene disulfonic acid, chlorobenzene disulfonic acid, fluorobenzene disulfonic acid, dimethylbenzene disulfonic acid, diethylbenzene disulfonic acid, aniline-2,4-disulfonic acid, aniline-2,5-disulfonic acid, 3,4-dihydroxy-1,3 Benzene disulfonic acid, naphthalene disulfonic acid, methyl naphthalene disulfonic acid, ethyl naphthalene disulfonic acid, pentadecyl naphthalene disulfonic acid, 3-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 1- Cetamide-8-hydroxy-3,6-naphthalenedisulfonic acid, 2-amino-1,4-benzenedisulfonic acid, 1-amino-3,8-naphthalenedisulfonic acid, 3-amino-1,5-naphthalenedisulfonic acid, 8-amino-1-naphthol-3,6-disulfonic acid, 4-amino-5-naphthol-2,7-disulfonic acid, 4-acetamido-4′-isothiocyanotostilbene-2,2′-disulfonic acid, Examples include 4-acetamido-4′-maleimidyl stilbene-2,2′-disulfonic acid, naphthalene trisulfonic acid, dinaphthylmethane disulfonic acid, anthraquinone disulfonic acid, and anthracene sulfonic acid.

Examples of the acid precursor include salts, esters, anhydrides, and peroxides of the acid. In addition, a photoacid generator or a thermal acid generator that generates an acid by light irradiation is also preferably used. Here, the photoacid generator refers to a substance that is neutral in a normal state but generates a cation (acid) when irradiated with ultraviolet rays or an electron beam. The thermal acid generator is a substance that is neutral in a normal state but generates a cation (acid) under heating.

Although it does not specifically limit as said photo-acid generator, A sulfonium salt derivative [Sulphonic acid ester (1, 2, 3- Tri (methylsulfonyloxy) benzene etc. arylalkane sulfonate (especially _C6-10 aryl _C1-2)] Alkanesulfonate); 2,6-dinitrobenzyltoluenesulfonate, benzointosylate nadonoarylbenzenesulfonate (especially C _6-10 aryltoluenephosphonate optionally having a benzoyl group); 2-benzoyl-2-hydroxy-2-phenyl aralkyl benzenesulfonate such as ethyl toluenesulfonate (especially optionally C _6-10 aryl -C _1-4 alkyl toluene sulfonates have a benzoyl group); disulfonic acid, such as diphenyl sulfone; Lewis acid salt (G Phenylsulfonium hexafluorophosphate, triarylsulfonium hexafluoroantimony, triarylsulfonium salts such as triphenylsulfonium methanesulfonyl (especially triphenylsulfonium salts))], phosphonium salt derivatives, diarylhalonium salt derivatives [diaryliodonium salts Examples include Lewis acid salts (such as diphenyliodonium hexafluorophosphate), diazonium salt derivatives (such as Lewis acid salts such as p-nitrophenyldiazonium hexafluorophosphate), diazomethane derivatives, and triazine derivatives. In particular, Lewis acid salts (Lewis acid salts such as phosphonium salts) are preferable. More specifically, the product name Silicone CATA 211 (4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, manufactured by Arakawa Chemical Industries, Ltd.) can be mentioned. A photo-acid generator may be used individually by 1 type, and may use 2 or more types.

The thermal acid generator is not particularly limited, but p-toluenesulfonic acid cyclohexyl, methylsulfonic acid cyclohexyl, p-toluenesulfonic acid n-hexyl, methylsulfonic acid n-hexyl, p-toluenesulfonic acid neopentyl, methylsulfone. Sulfonates such as neopentyl acid, hexyloxyethyl p-toluenesulfonate, hexyloxyethyl methylsulfonate, 1-benzyloxy-2-propyl p-toluenesulfonate, 1-benzyloxy-2-propyl methylsulfonate, In addition, ammonium salts, phosphonium salts, and the like can be used. A thermal acid generator may be used individually by 1 type, and may use 2 or more types. Moreover, you may use it in combination with the above-mentioned photo-acid generator.

The amount of the curing aid is not particularly limited, but when the alkoxysilane compound is 100 parts by mass, the lower limit of the total amount of the curing aid is preferably 0.01 parts by mass, and 0.05 parts by mass. More preferably. The upper limit of the total amount of the curing aid is preferably 10 parts by mass, and more preferably 6 parts by mass. If there are too few curing aids, the curing reaction that produces a transparent coating will not proceed sufficiently, the hardness of the resulting transparent coating will tend to be insufficient, and if there are too many curing aids, the light transmittance of the resulting transparent coating will be low. There is a tendency to decrease. A hardening adjuvant may be used independently and may be used in combination of 2 or more type. When using 2 or more types of hardening adjuvants, it is preferable that the total amount of all the hardening adjuvants is the said range.

The resin composition for forming a transparent film of the present invention may optionally contain additives such as a stabilizer, and may be diluted with a solvent for the purpose of adjusting the viscosity. Although it does not specifically limit as a solvent used for dilution, Ketones, ester, ethers, alcohol, etc. are mentioned, Other well-known solvents can also be used. Particularly preferred are methyl ethyl ketone, ethyl acetate, methoxypropyl acetate, xylene and dimethylformamide. These solvents may be used alone or as a mixed solution of two or more. Moreover, the leveling agent for improving applicability | paintability may be included.

Although it does not specifically limit, When diluting with the said solvent, when the weight of solid content is 100 mass parts, the minimum of the quantity of the solvent becomes like this. Preferably it is 1 mass part, More preferably, it is 20 mass parts. The upper limit is preferably 100 parts by mass, more preferably 60 parts by mass.

Further, although not particularly limited, when the leveling agent is included, the lower limit of the content is preferably 0.01 parts by mass when the weight of the solid content is 100 parts by mass. The upper limit is preferably 10 parts by mass, more preferably 5 parts by mass.

The resin composition for forming a transparent film of the present invention may contain a sol of inorganic fine particles in order to change the refractive index of the transparent film layer. Specific examples of such sols include zinc oxide, silicon dioxide, aluminum oxide, titanium oxide, zirconium oxide, tin oxide, beryllium oxide, antimony oxide, tungsten oxide, cerium oxide, zinc stannate dispersed in an organic solvent. Examples thereof include sols of zinc antimonate, tantalum oxide, iron oxide, lead oxide and the like. These may be used singly or in combination of two or more. A complex oxide sol may also be used. Furthermore, a mixture with a complex oxide may be used.

When the inorganic fine particle sol is included, it is not particularly limited, but the lower limit of the content is preferably 1 part by mass, more preferably 30 parts by mass, when the alkoxysilane compound is 100 parts by mass. The upper limit is preferably 400 parts by mass, more preferably 200 parts by mass.

In order to further improve the hardness of the transparent coating layer, the resin composition for forming a transparent coating of the present invention may contain another alkoxysilane other than the alkoxysilane compound having the reactive functional group described above. Other alkoxysilanes include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane. , Alkoxysilanes such as hexyltrimethoxysilane, hexyltriethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, halogenated silanes such as trifluoropropyltrichlorosilane, hexamethyldisilazane, etc. And siloxanes such as silazane, polymethoxysiloxane, and polyethoxysiloxane.

The resin composition for forming a transparent film of the present invention may contain other organic prepolymers in order to further improve the hardness of the transparent film layer. As an example, triallyl isocyanurate polymer (or oligomer) (Tyke (R) prepolymer, commercially available as Nippon Kasei Co., Ltd.) or allyl isophthalate prepolymer (Daiso Co., Ltd., “Daiso Isodap, DAIP”) (Product name)).

[Laminate]
The present invention also relates to a laminate comprising a plastic substrate and a transparent film formed on the plastic substrate from the resin composition for forming a transparent film.

The plastic substrate is not particularly limited, but is a thermoplastic resin such as cellulose triacetate, polyester, polyamide, polyimide, polypropylene, polystyrene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polymethyl methacrylate, polycarbonate, polyurethane, etc. A stretched or unstretched film or a multilayer sheet obtained by laminating these in two to five layers can be used. The multilayer sheet can be obtained by coextrusion molding or lamination through an adhesive.

The thickness of the plastic substrate is determined depending on the material, configuration or application. As the substrate, a film having a thickness of 25 μm to 250 μm is preferable, and a stretched polyester having a thickness of 75 μm to 180 μm (especially polyethylene). A terephthalate) film is more preferred.

[Method for producing transparent film]
Transparent film
-A prepolymer is obtained by reacting an alkoxysilane compound having a reactive functional group with a polythiol compound having two or more thiol groups in one molecule,
-Prepare a resin composition for forming a transparent film containing the prepolymer and a curing aid,
-It manufactures by apply | coating this resin composition for transparent film formation on a base material, and making it harden | cure.

The reaction between the alkoxysilane compound having a reactive functional group and the polythiol compound having two or more thiol groups in one molecule is preferably carried out under ultraviolet (UV) irradiation or heating. By this reaction, addition polymerization proceeds between the alkoxysilane compound and the polythiol compound, and a prepolymer containing an addition polymer such as an oligomer or a polymer is obtained.

A resin composition for forming a transparent film is prepared by adding the above-mentioned curing aid and other necessary components to the obtained prepolymer and mixing them. Other necessary components are not particularly limited, and examples thereof include the above-mentioned stabilizer, solvent, leveling agent, inorganic fine particle sol, and the like.

Next, the obtained resin composition for forming a transparent film is applied onto a substrate and cured. The coating method is not particularly limited, such as a roll coating method, a gravure coating method, a bar coating method, a spin coating method, or a dipping method.

It does not specifically limit as a hardening method, For example, the thermosetting by heating, the photocuring by irradiation of light, such as an ultraviolet-ray and visible light, etc. are mentioned. It is preferable to irradiate light rays (particularly ultraviolet rays) having an integrated irradiation amount of 100 mJ / cm ² or more and 500 mJ / cm ² or less.

In the case of containing a photoacid generator, ultraviolet light irradiation generates a Bronsted acid or Lewis acid starting species from the photoacid generator, which reacts with the prepolymer to advance curing, thereby forming a transparent film. It is formed. In addition, heating (generally 50 ° C. to 200 ° C.) can be performed as necessary.

When a thermal acid generator is contained, the starting species of Bronsted acid or Lewis acid is generated from the thermal acid generator by heating, and by reacting with the prepolymer, curing proceeds and a transparent film is formed. The

The average thickness of the transparent coating is not particularly limited, but the lower limit is preferably 0.5 μm, more preferably 1 μm, and the upper limit is preferably 30 μm, more preferably 10 μm.

The surface of the plastic substrate is preferably subjected to pretreatment such as alkali treatment, plasma treatment, and ultraviolet treatment as necessary.

The transparent film formed by the above method is not particularly limited, but has a pencil hardness of generally H or higher, more preferably 2H or higher. In the present specification, “pencil hardness” refers to a value measured according to JIS K5600-5-4.

The transparent coating is not particularly limited, but the minimum diameter of the mandrel that does not cause cracks in the mandrel test is preferably 5 mm or less, more preferably 3 mm or less. In the present specification, the “mandrel test” refers to a test performed according to JIS K5600-5-1.

Examples of the present invention will be described below, but the present invention is not limited to these examples. In the following examples and comparative examples, “part” means “part by mass” unless otherwise specified.

In the following examples and comparative examples, the reaction rate, pencil hardness, flexibility, UV resistance, and heat resistance were evaluated as follows.

(Reaction rate in prepolymer formation reaction)
The reaction rate in the prepolymer formation reaction was determined by iodine oxidation titration according to the following procedure. First, a titration sample was prepared by dissolving the reaction product in a methanol / chloroform (1: 1 (vol: vol)) mixed solvent. Next, the sample was subjected to potentiometric titration using an automatic titrator COM-2500 manufactured by Hiranuma Sangyo Co., Ltd., an indicator electrode PT-301, and a comparative electrode RE-201 using a 0.05 mol / L iodine solution as a titrant. The residual SH mass at the end point was determined with the inflection point of the titration curve as the end point of the titration. The reaction rate was calculated according to the following formula.
Reaction rate (%)
= {[(SH mass in raw material)-(Remaining SH mass in product)] / (SH mass in raw material)} × 100

(Evaluation of pencil hardness and flexibility)
The resin composition for forming a transparent film was applied to one surface of a 125 μm-thick polyester film A-4100 (plastic base material, manufactured by Toyobo Co., Ltd.) by spin coating, and irradiated with ultraviolet rays at 300 mJ / cm ^2. Then, it was heated and dried at 120 ° C. for 20 minutes to produce a laminate having a transparent film having a thickness of 5 μm.

The pencil hardness of the transparent film was measured according to JIS K5600-5-4, and the hardness of the hardest pencil that did not cause scratch marks was taken as the pencil hardness of the transparent film.

Further, the flexibility of the laminate having a transparent film was evaluated according to the method of a mandrel test (JIS K5600-5-1). In this method, it was bent with a mandrel bending test apparatus and the diameter (curvature) of the mandrel was changed to observe whether or not the laminate was cracked. The minimum diameter of the mandrel that did not crack was recorded.

(Evaluation of UV resistance and heat resistance)
A transparent film-forming resin composition was applied on a 1.3 mm glass plate by a spin coating method, irradiated with 300 mJ / cm ^{2 of} ultraviolet light, and then dried by heating at 120 ° C. for 20 minutes to provide a transparent film. The body was made.

The laminate was subjected to a UV resistance test for 500 hours using an ultraviolet fade meter (model U48H) manufactured by Suga Test Instruments Co., Ltd. The 20-degree specular gloss (JISK5600-4-7) before and after the UV resistance test was measured using a gloss meter (model GM-3D) manufactured by Murakami Color Research Laboratory. Similarly, the haze before and after the UV resistance test was measured using a Nippon Denshoku haze meter (model NDH2000).

Further, a heat resistance test at 150 ° C. for 120 hours was performed on the glass substrate laminate produced in the same manner. The 20-degree specular gloss before and after the test (JISK5600-4-7) was measured using a gloss meter (model GM-3D) manufactured by Murakami Color Research Laboratory. Moreover, the haze before and behind a heat test was similarly measured using the Nippon Denshoku haze meter (model NDH2000).

Example 1
100 parts of KBM1003 trimethoxyvinylsilane (TMVS) manufactured by Shin-Etsu Chemical Co., Ltd. and 95 parts of trimethylolpropane tris (mercaptopropionate) (TMMP) manufactured by SC Organic Chemical Co., Ltd. were stirred and irradiated with ultraviolet rays at 3 J / ml. To obtain a reaction product. When the reaction rate of this reaction product was examined, it was 95%. Using this reaction product, a transparent film forming resin composition having the following composition was prepared.

[Transparent film-forming resin composition 1]
TMVS / TMMP reactant 195 parts Methoxypropyl acetate (solvent, manufactured by Kanto Chemical Co., Ltd.) 57 parts Silicolyse CATA211 (4-isopropyl-4'-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, photoacid generator , Manufactured by Arakawa Chemical Industries, Ltd., trade name) 2 parts, cyclohexyl p-toluenesulfonate (thermal acid generator, manufactured by Tokyo Chemical Industry Co., Ltd.) 4 parts

Based on the above-mentioned method, the resin composition 1 for forming a transparent film was coated on a polyester film, and the pencil hardness and flexibility of the obtained transparent film were evaluated. The obtained transparent film had a thickness of 5 μm. The pencil hardness of this transparent film was 2H. In addition, the laminate having the corresponding bright film does not crack even when it has a curvature of 2 mm in the mandrel test (JIS K5600-5-1) (that is, the minimum diameter of the mandrel that does not cause cracking is 2 mm or less). It was flexible.

Furthermore, based on the above-mentioned method, the said resin composition 1 for transparent film formation was coated on the glass plate, and the laminated body which has a transparent film was obtained. The laminate was subjected to a UV resistance test for 500 hours using an ultraviolet fade meter (model U48H) manufactured by Suga Test Instruments Co., Ltd. When the front and back 20-degree specular gloss (JISK5600-4-7) was measured using a gloss meter (model GM-3D) manufactured by Murakami Color Research Laboratory Co., Ltd., a high retention rate of 90% or more was shown. Further, when the haze before and after the UV resistance test was similarly measured using a Nippon Denshoku haze meter (model NDH2000), the haze was 3.0 or less even after the test, and the optical transparency was excellent.

Further, when a heat resistance test at 150 ° C. for 120 hours was performed, the 20-degree specular gloss showed a high retention rate of 85% or more, and the haze was 3.0 or less, which was excellent in optical transparency stability.

(Example 2)
The same operation as in Example 1 was performed except that the photoacid generator and thermal acid generator of the resin composition 1 for forming a transparent film used in Example 1 were changed to 4 parts of acetic acid manufactured by Wako Pure Chemical Industries, Ltd. A resin composition 2 for forming a transparent film was obtained. A transparent film was prepared from the transparent film-forming resin composition 2 in the same manner as in Example 1. The obtained transparent film was evaluated for pencil hardness, flexibility, UV resistance, and heat resistance based on the above-described methods. The results are shown in Table 2.

Example 3
Example 1 except that the photoacid generator and thermal acid generator of the resin composition 1 for forming a transparent film used in Example 1 were changed to 0.05 parts of p-toluenesulfonic acid manufactured by Wako Pure Chemical Industries, Ltd. The same operation was performed to obtain a resin composition 3 for forming a transparent film. In the same manner as in Example 1, a transparent film was prepared from the resin composition 3 for forming a transparent film. The obtained transparent film was evaluated for pencil hardness, flexibility, UV resistance, and heat resistance based on the above-described methods. The results are shown in Table 2.

Example 4
The same operation as in Example 1 was performed except that the photoacid generator and thermal acid generator of the transparent film-forming resin composition 1 used in Example 1 were changed to 4 parts of oxalic acid manufactured by Wako Pure Chemical Industries, Ltd. Thus, a resin composition 4 for forming a transparent film was obtained. A transparent film was prepared from the resin composition 4 for forming a transparent film by the same method as in Example 1. The obtained transparent film was evaluated for pencil hardness, flexibility, UV resistance, and heat resistance based on the above-described methods. The results are shown in Table 2.

(Example 5)
For transparent film formation, the same operation as in Example 1 was performed except that 49 parts of tetraethoxysilane (TEOS) manufactured by Tama Chemical Industry Co., Ltd. was further added to the resin composition 1 for transparent film formation used in Example 1. A resin composition 5 was obtained. A transparent film was prepared from the resin composition 5 for forming a transparent film by the same method as in Example 1. The obtained transparent film was evaluated for pencil hardness, flexibility, UV resistance, and heat resistance based on the above-described methods. The results are shown in Table 2.

(Example 6)
The same operation as in Example 1 was performed except that 49 parts of methyl silicate-51 (polymethoxysiloxane, trade name) manufactured by Fuso Chemical Industry Co., Ltd. was further added to the resin composition 1 for forming a transparent film used in Example 1. It performed and the resin composition 6 for transparent film formation was obtained. A transparent film was prepared from the resin composition 6 for forming a transparent film by the same method as in Example 1. The obtained transparent film was evaluated for pencil hardness, flexibility, UV resistance, and heat resistance based on the above-described methods. The results are shown in Table 2.

(Example 7)
The same operation as in Example 1 was carried out except that 49 parts of Nippon Kasei's Tyke prepolymer (an oligomer of triallyl isocyanurate, trade name) was further added to the transparent film-forming resin composition 1 used in Example 1. Thus, a resin composition 7 for forming a transparent film was obtained. A transparent film was formed from the resin composition 7 for forming a transparent film by the same method as in Example 1. The obtained transparent film was evaluated for pencil hardness, flexibility, UV resistance, and heat resistance based on the above-described methods. The results are shown in Table 2.

(Example 8)
100 parts of KBE1003 triethoxyvinylsilane (TEVS) manufactured by Shin-Etsu Chemical Co., Ltd. and 74 parts of trimethylolpropane tris (mercaptopropionate) (TMMP) manufactured by SC Organic Chemical Co., Ltd. were stirred and irradiated with ultraviolet rays at 3 J / ml. To obtain a reaction product. When the reaction rate of this reaction product was examined, it was 93%. Using this reaction product, a transparent film forming resin composition having the following composition was prepared.

[Transparent film-forming resin composition 8]
TMVS / TMMP reaction product 193 parts Methoxypropyl acetate (solvent, manufactured by Kanto Chemical Co., Ltd.) 51 parts Siliconolyse CATA211 (4-isopropyl-4'-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, photoacid generator , Manufactured by Arakawa Chemical Industries, Ltd., trade name) 2 parts, cyclohexyl p-toluenesulfonate (thermal acid generator, manufactured by Tokyo Chemical Industry Co., Ltd.) 4 parts

Based on the above-mentioned method, the resin composition 8 for forming a transparent film was prepared. A transparent film was prepared from the transparent film forming resin composition 8 in the same manner as in Example 1. The obtained transparent film was evaluated for pencil hardness, flexibility, UV resistance, and heat resistance based on the above-described methods. The results are shown in Table 2.

(Comparative Example 1)
100 parts of KBM1003 trimethoxyvinylsilane (TMVS) manufactured by Shin-Etsu Chemical Co., Ltd., 95 parts of trimethylolpropane tris (mercaptopropionate) (TMMP) manufactured by SC Organic Chemical Co., Ltd., 57 parts of methoxypropyl acetate manufactured by Kanto Chemical Co., Ltd. Furthermore, 2 parts of photoacid generator Silicolys CATA211 manufactured by Arakawa Chemical Industries, Ltd. and 4 parts of thermal acid generator p-toluenesulfonate cyclohexyl manufactured by Tokyo Chemical Industry Co., Ltd. were added and mixed. One side of a 125 μm thick polyester film A-4100 (plastic base material, manufactured by Toyobo Co., Ltd.) was applied by spin coating, irradiated with 300 mJ / cm ^{2 of} ultraviolet light, and then heated and dried at 120 ° C. for 20 minutes. Thus, a laminate having a transparent film was produced. The pencil hardness of this transparent film was H. In addition, the laminate having the corresponding bright film does not crack even when it has a curvature of 2 mm in the mandrel test (JIS K5600-5-1) (that is, the minimum diameter of the mandrel that does not cause cracking is 2 mm or less). It was flexible. In the same manner, this coating film is applied to a 1.3 mm glass plate by a spin coating method, irradiated with 300 mJ / cm 2 of ultraviolet rays, and then heated and dried at 120 ° C. for 20 minutes to produce a laminate having a transparent film. did. The plate was subjected to a UV resistance test for 500 hours using an ultraviolet fade meter (model U48H) manufactured by Suga Test Instruments Co., Ltd. The 20-degree specular gloss (JISK5600-4-7) before and after this was measured using a gloss meter (model GM-3D) manufactured by Murakami Color Research Laboratory Co., Ltd., and it was not satisfactory at 85% or less. Moreover, when the haze before and after UV resistance test was similarly measured using the Nippon Denshoku Industries Co., Ltd. haze meter (model NDH2000), haze was 5.0 or more after the test, and optical transparency was deteriorating. . Further, when a glass plate produced in the same manner was subjected to a heat-resistant and transparent stability test at 150 ° C. for 120 hours, the 20-degree specular gloss was not satisfactory at 85% or less after the test, and the haze was 5. The optical transparency stability was deteriorated to 0 or more.

(Comparative Example 2)
100 parts of triacetoxyvinylsilane (TAVS) manufactured by Shin-Etsu Chemical Co., Ltd., 60 parts of trimethylolpropane tris (mercaptopropionate) manufactured by SC Organic Chemical Co., Ltd., 53 parts of reagent methoxypropyl acetate manufactured by Wako Pure Chemical Industries, Ltd. 2 parts of photoacid generator Silicolys CATA211 manufactured by Arakawa Chemical Industries, Ltd., 3 parts of thermal acid generator p-toluenesulfonate cyclohexyl manufactured by Tokyo Chemical Industry Co., Ltd., and tetraethoxysilane (TEOS) manufactured by Tama Chemical Industries, Ltd. 40 parts of was added. This resin composition was applied to one surface of the polyester film used in Example 1 by a spin coating method, but the paint did not get wet with the paint film and did not repel.

(Comparative Example 3)
100 parts of triacetoxyvinylsilane (TAVS) manufactured by Shin-Etsu Chemical Co., Ltd., 60 parts of trimethylolpropane tris (mercaptopropionate) manufactured by SC Organic Chemical Co., Ltd., 53 parts of reagent methoxypropyl acetate manufactured by Wako Pure Chemical Industries, Ltd. 2 parts of photoacid generator Silicolys CATA211 manufactured by Arakawa Chemical Industries, Ltd., 3 parts of thermal acid generator p-toluenesulfonate cyclohexyl manufactured by Tokyo Chemical Industry Co., Ltd., and methyl silicate-51 manufactured by Fuso Chemical Industries, Ltd. 40 parts of methoxysiloxane, trade name) was added. This resin composition was applied to one surface of the polyester film used in Example 1 by spin coating, but the resin composition was repelled on the polyester film and did not form a coating.

(Comparative Example 4)
100 parts of triacetoxyvinylsilane (TAVS) manufactured by Shin-Etsu Chemical Co., Ltd., 60 parts of trimethylolpropane tris (mercaptopropionate) manufactured by SC Organic Chemical Co., Ltd., 53 parts of reagent methoxypropyl acetate manufactured by Wako Pure Chemical Industries, Ltd. 2 parts of photoacid generator Silicolys CATA211 manufactured by Arakawa Chemical Industries, Ltd., 3 parts of thermal acid generator p-toluenesulfonate cyclohexyl manufactured by Tokyo Chemical Industry Co., Ltd. 40 parts of a nurate oligomer (trade name) were added. However, the tie prepolymer did not dissolve in the paint and could not be applied.

(Comparative Example 5)
Of the components of the resin composition 1 for forming a transparent film used in Example 1, the same operation as in Example 1 was carried out except that the photoacid generator and the thermal acid generator were not used, to prepare a resin composition. This resin composition was applied to one surface of the polyester film used in Example 1 by a spin coating method, but was not cured and did not form a coating film.

(Comparative Example 6)
100 parts urethane acrylate UA122P (trade name) manufactured by Shin-Nakamura Chemical Co., Ltd., 4 parts photopolymerization initiator Irgacure 184 (trade name) manufactured by Ciba Specialty Chemicals Co., Ltd. Reagent methoxypropyl acetate manufactured by Wako Pure Chemical Industries, Ltd. 53 parts were mixed to prepare a resin composition. A transparent film was prepared from this resin composition by the same method as in Example 1, and the pencil hardness, flexibility, UV resistance, and heat resistance were evaluated based on the above-described methods for the transparent film. As a result, although it was excellent in flexibility, UV resistance, and heat resistance, the pencil hardness was as soft as 3B, which was insufficient as the hardness required for the hard coat layer.

(Comparative Example 7)
Nippon Kayaku Co., Ltd. dipentaerythritol hexaacrylate (DPHA) 100 parts, Ciba Specialty Chemicals photopolymerization initiator Irgacure 184 (trade name), Wako Pure Chemical Industries, Ltd. reagent ethanol 35 parts Were mixed to prepare a resin composition. A transparent film was prepared from this resin composition by the same method as in Example 1, and the pencil hardness, flexibility, UV resistance, and heat resistance were evaluated based on the above-described methods for the transparent film. As a result, in the mandrel test (JIS K5600-5-1), a crack was generated with a curvature of 10 mm, which was not satisfactory in terms of flexibility. When a UV resistance test was conducted for 500 hours, the coating film was peeled off from the glass plate, and the UV resistance was not satisfactory.

Tables 1 and 3 show the composition of the resin compositions obtained in the above Examples and Comparative Examples and the reaction rates of the raw materials in the prepolymer formation reaction. Moreover, the film thickness of the transparent film obtained by the said Example and the comparative example, the measurement result of pencil hardness (JIS K5600-5-4), and a mandrel test (JIS K5600-5-1), heat resistance, evaluation of heat resistance property The results are shown in Tables 2 and 4 below. In addition, the symbol used in the table | surface represents the following.

(A) Alkoxysilane compound A1: Trimethoxyvinylsilane A2: Triethoxyvinylsilane A3: Triacetoxyvinylsilane

(B) Polythiol compound TMMP: trimethylolpropane tris (mercaptopropionate)

(C) Curing aid C1: Photoacid generator Silicolys CATA211 (4-isopropyl-4'-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, trade name, manufactured by Arakawa Chemical Industries, Ltd.)
C2: thermal acid generator p-toluenesulfonic acid cyclohexyl C3: acetic acid C4: p-toluenesulfonic acid C5: oxalic acid

<Solvent>
MPA: Methoxypropyl acetate EtOH: Ethanol

<Other additives>
TEOS: Tetraethoxysilane MS-51: Methyl silicate 51 (polymethoxysiloxane, trade name, manufactured by Fuso Chemical Industries, Ltd.)
TAICPP: Tyke prepolymer (triallyl isocyanurate oligomer, trade name, manufactured by Nippon Kasei Co., Ltd.)

As can be seen from Table 2, the transparent coatings obtained from the transparent coating forming resin compositions of the examples all have sufficient pencil hardness, good flexibility, heat resistance, and UV resistance. Was also excellent. On the other hand, in Comparative Example 1 in which the same raw material as in Example 1 was used and the composition was prepared without forming a prepolymer, the hardness was lower than in Example 1, and the heat resistance and UV resistance were also low. It became clear that it was remarkably inferior. The same applies to the case where Examples 5 to 7 are compared with Comparative Examples 2 to 4. Thus, it is clear by comparing these results that it is important to first react an alkoxysilane compound and a polythiol compound to obtain a prepolymer, and then to mix with a curing aid.

Furthermore, from the result of Comparative Example 5 that does not contain a curing aid such as an acid generator, it can be seen that a coating film cannot be obtained only from a prepolymer of alkoxysilane and polythiol, and a curing aid is essential.

The resin composition for forming a transparent film of the present invention is commercially available in terms of pencil hardness, flexibility, UV resistance, and heat resistance, as can be seen by comparing with the evaluation results of the commercial products of Comparative Examples 6 and 7. It turns out that it is superior to goods.

Claims (13)

A transparent film-forming resin composition comprising a prepolymer obtained by a reaction between an alkoxysilane compound having a reactive functional group and a polythiol compound having two or more thiol groups in one molecule, and a curing aid. The composition according to claim 1, wherein the reactive functional group is a group having a carbon-carbon unsaturated bond. The composition according to claim 1, wherein the curing aid is an acid and / or an acid precursor. The composition according to claim 3, wherein the acid is an organic acid. 4. The composition according to claim 3, wherein the acid precursor is a photoacid generator and / or a thermal acid generator. A plastic substrate;
A laminate comprising a transparent film formed from the composition according to any one of claims 1 to 5 on the plastic substrate. A prepolymer is obtained by reacting an alkoxysilane compound having a reactive functional group with a polythiol compound having two or more thiol groups in one molecule,
A transparent film-forming resin composition containing the prepolymer and a curing aid is prepared,
A method for producing a transparent film, wherein the resin composition for forming a transparent film is applied on a substrate and cured. The production method according to claim 7, wherein the reaction between the alkoxysilane compound and the polythiol compound is performed under ultraviolet irradiation. The production method according to claim 7, wherein the reaction between the alkoxysilane compound and the polythiol compound is performed under heating. The manufacturing method according to any one of claims 7 to 9, wherein the reactive functional group is a group having a carbon-carbon unsaturated bond. The said hardening adjuvant is an acid and / or a precursor of an acid, The manufacturing method as described in any one of Claims 7-10. The method according to claim 11, wherein the acid is an organic acid. The production method according to claim 11, wherein the acid precursor is a photoacid generator and / or a thermal acid generator.