WO2010103944A1

WO2010103944A1 - Resin composition for formation of transparent coating layer, and laminate

Info

Publication number: WO2010103944A1
Application number: PCT/JP2010/053197
Authority: WO
Inventors: 長川敬一; 川▲崎▼徳明; 苅田和紗; 松川公洋
Original assignee: 堺化学工業株式会社; 地方独立行政法人大阪市立工業研究所
Priority date: 2009-03-13
Filing date: 2010-03-01
Publication date: 2010-09-16
Also published as: KR20120013304A; JPWO2010103944A1; CN102307953A; TW201035226A

Abstract

A coating composition for forming, without using any lubricant or the like, a transparent coating layer which exhibits scratch resistance, wear resistance, excellent flexibility, and sufficient hardness; and a laminate using the composition. Provided are a resin composition for the formation of a transparent coating layer, which is characterized by containing both (A) an organosilicon compound having a reactive functional group and (B) a polythiol compound; a process for the production of the composition; and a laminate.

Description

Resin composition for forming transparent coating layer and laminate

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

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 (referring to 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, as such a hard coat layer, an acrylic or methacrylic resin or the like has been often used (for example, Patent Document 1, Patent Document 2 and the like), but a hard coat layer formed from an acrylic or methacrylic resin. However, although it was excellent in hardness, there was a problem that flexibility was inferior. 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.

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). This hard coat layer has flexibility while having low hardness and scratch resistance. -There was room for practical improvement in terms of poor wear resistance.

On the other hand, it has been attempted to modify the hard coat layer by adding an additive to a varnish containing a resin. For example, it has been studied to enhance slip characteristics by adding a filler and forming an uneven shape on the surface, or to add slipperiness by adding silicone oil (for example, Patent Document 4). In addition, it has been studied to increase slipperiness and wear resistance by forming a coating film using a varnish to which a lubricant such as fatty acid amide or wax is added. However, the filler may impair transparency depending on the refractive index and particle size of the filler, and the amount of the filler is limited. In the case of lubricants, as a result of improved surface slipperiness, load collapse occurs when stacking and transporting plate-shaped product materials, and adhesion is inhibited when the surfaces are joined with an adhesive during assembly. There was a problem of waking up. In addition, there is an inconvenience that a label or the like is dropped when the final product is affixed, and the end user cannot affix a decorative label or a note such as a caution on the surface.

JP 2004-182765 A JP 2005-254470 A JP 2001-147777 A JP 2003-11292 A

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 that satisfies all of flexibility, hardness, scratch resistance, and wear resistance has been desired.

Under such circumstances, the present invention relates to a surface material such as a plastic substrate, and has a scratch resistance and an abrasion resistance without using a lubricant, has excellent flexibility, and has a sufficient hardness. An object of the present invention is to provide a resin composition for forming a transparent coating layer for forming a film, and a laminate using the composition.

As a result of intensive studies, the present inventors have obtained a transparent coating film having a specific composition, specifically, a composition containing an organosilicon compound and a polythiol compound, which has an excellent balance between flexibility and hardness. As a result, the present invention was completed.

That is, the first aspect of the present invention relates to a resin composition for forming a transparent coating layer, wherein the resin composition for forming a transparent coating layer includes the following components (A) and (B):
(A) an organosilicon compound having a reactive functional group, and
(B) Polythiol compound.

The composition is preferably one having a curable under irradiation with ultraviolet rays of 500 mJ / cm ² or more 2,000 mJ / cm ² or less of the total irradiation amount.

In one preferred embodiment, the resin composition for forming a transparent coating layer of the present invention further contains (C) a photoacid generator. In the case of containing the photoacid generator of component (C), the composition preferably has curability under irradiation of ultraviolet rays with an integrated dose of 100 mJ / cm ² or more and less than 500 mJ / cm ^2. is there.

In the above composition, the organosilicon compound (A) preferably contains at least part of a compound having one or more carbon-carbon unsaturated bonds in one molecule.

The organosilicon compound is preferably vinyltriacetoxysilane.

The second aspect of the present invention is:
A plastic substrate;
A laminate having a transparent coating layer formed from the resin composition for forming a transparent coating layer,
The transparent coating layer is provided on at least one side of the surface of the base material,
The transparent coating layer also relates to a laminate having a pencil hardness of 2H or more and a minimum mandrel diameter of 5 mm or less that does not cause cracks in the mandrel test.

The third aspect of the present invention is:
(A) coating a resin composition containing an organosilicon compound having a reactive functional group and (B) a polythiol compound on a substrate;
Curing the composition to obtain a transparent coating,
In the step of obtaining the transparent film, comprising irradiating the composition with ultraviolet rays,
The present invention relates to a method for producing a transparent coating.

In a preferred embodiment, integrated irradiation dose of ultraviolet rays to the composition is 500 mJ / cm ² or more 2,000 mJ / cm ² or less.

In another preferred embodiment, the resin composition further contains (C) a photoacid generator,
The cumulative amount of ultraviolet rays applied to the composition is 100 mJ / cm ² or more and less than 500 mJ / cm ² .

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

[Resin composition for forming transparent coating layer]
The resin composition for forming a transparent coating layer of the present invention has the following components:
(A) an organosilicon compound having a reactive functional group, and
(B) A composition containing a polythiol compound.

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

In the present specification, the “reactive functional group” of the organosilicon compound specifically means a mercapto reactive group, that is, a functional group that undergoes an addition reaction with a mercapto (—SH) group. 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, and isocyanate groups. Etc. are mentioned as preferable examples. Of these, a group having a carbon-carbon unsaturated bond is particularly preferred.

The organosilicon compound (A) may be one kind or a mixture of two or more kinds, but the organosilicon compound (A) has one carbon-carbon unsaturated bond as described above in one molecule. It is preferable to include at least a part of the compound having the above.

Although it does not specifically limit as an organosilicon compound (A) which has a reactive functional group, For example, the organosilicon compound represented by a following formula and its hydrolyzate are mentioned.
R ¹ _a R ² _b Si (OR ³ ) _{4- (a + b)}
R ¹ _a R ² _b SiX _{4- (a + b)}
(Wherein R ¹ is unsubstituted or substituted with a reactive functional group selected from the group consisting of a vinyl group, an epoxy group, a styryl group, an acryloxy group, a methacryloxy group, and an isocyanate group. R ² is an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a cycloalkyl group having 2 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or 6 to 6 carbon atoms. R ³ is an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxyalkyl group having 2 to 10 carbon atoms, An arylalkyl group having 7 to 10 carbon atoms, an alkyloyl group having 2 to 10 carbon atoms, X is a halogen atom, a = 1, 2, or 3, b = 0, 1 or 2, and a + b = 1, Or 3).

Specific examples of the component (A) represented by the above formula include tetraalkoxysilanes such as tetraethoxysilane; alkylalkoxysilanes such as methyltrimethoxysilane; vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltriacetoxy. Vinyl alkoxysilanes such as silane; γ-methacryloxyalkyl-alkoxysilanes such as γ-methacryloxypropyltrimethoxysilane and γ-methacryloxypropyltriethoxysilane; halogen-containing silanes such as trimethylchlorosilane; α-glycidoxymethyltri Methoxysilane, α-glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxy Tiltlyethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3 , 4-epoxycyclohexyl) -ethyltrimethoxysilane, and β- (3,4-epoxycyclohexyl) -ethyltriethoxysilane-containing silanes; γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane And amino group-containing silanes such as N-β (aminoethyl) -γ-aminopropylmethyldimethoxysilane and N-β (aminoethyl) -γ-aminopropylmethyldiethoxysilane, and hydrolysates thereof. Can do. These may be used alone or in combination of two or more. Of these, vinyl alkoxysilane is preferable from the viewpoint of reactivity and the like, and vinyltriacetoxysilane is particularly preferable.

The component (A) preferably contains at least a part of a compound having one or more carbon-carbon unsaturated bonds in one molecule. Since the carbon-carbon unsaturated bond can be a reaction point when the polythiol compound described later undergoes a crosslinking reaction, the component (A) preferably has one or more carbon-carbon unsaturated bonds in one molecule.

[Polythiol compound]
Next, the polythiol compound as the component (B) will be described. The polythiol compound used in the present invention is not particularly limited as long as it has two or more mercapto (-SH) groups 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 mercapto groups in the molecule, trimethylolpropane tris (mercaptopropionate), pentaerythritol tetrakis (mercaptopropionate), dipentaerythritol hexa (mercaptopropionate), tris (mercaptopropionyloxyethyl) ) Reaction of polythiol compound having 3 or more mercapto groups in one molecule obtained by esterification reaction of polyol such as isocyanurate and mercapto organic acid, epoxy compound and hydrogen sulfide Thus obtained terminal thiol group-containing thiol compound, 1,4-butanedithiol, 1,6-hexanedithiol, alkylpolythiol compound such as 1,10-decanedithiol, and terminal obtained by thiolation of the hydroxyl group of the polyol compound Examples include thiol group-containing thiol compounds.

Especially, the thiol compound obtained by esterification reaction of a polyol and a mercapto organic acid is preferable, and especially the thiol compound which has three or more mercapto groups in 1 molecule is preferable.

The content of the component (B) is not particularly limited, but when the component (A) is 100 parts by weight, it is usually 20 to 130 parts by weight, preferably 30 to 100 parts by weight, more preferably 40 to 80 parts by weight. is there. When the component (B) is too small, the flexibility of the produced transparent film tends to be insufficient, and when it is too much, the hardness of the produced transparent film tends to be insufficient.

[Photoacid generator]
In one preferred embodiment of the resin composition for forming a transparent coating layer of the present invention, in addition to the above (A) and (B), (C) a photoacid generator may further be contained.

The photoacid generator of component (C) used in the present invention is not particularly limited, and examples thereof include those that generate a Bronsted acid or Lewis acid starting species by light irradiation such as diphenyliodonium salt and triphenylsulfonium salt. .

When the component (C) is included, the amount is not particularly limited, but when the component (A) is 100 parts by weight, it is preferably 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, The amount is preferably 0.5 to 3 parts by weight. When the component (C) is too small, the curing reaction for producing the transparent film does not proceed sufficiently, the hardness of the produced transparent film tends to be insufficient, and when it is too much, the light transmittance of the produced transparent film tends to decrease. There is.

The resin composition for forming a transparent coating layer of the present invention may optionally contain additives such as stabilizers, 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 not particularly limited, when diluted with the above solvent, the amount of the solvent is preferably 0 to 100 parts by weight, more preferably 20 to 50 parts by weight when the weight of the solid content is 100 parts by weight. is there.

Further, although not particularly limited, when the leveling agent is included, the content thereof is preferably 0.01 to 10 parts by weight, more preferably 0.01 when the solid content is 100 parts by weight. ~ 5 parts by weight.

The resin composition for forming a transparent coating layer of the present invention may contain a sol of inorganic fine particles in order to change the refractive index of the transparent coating 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 composite oxide of a plurality of sols may also be used. Furthermore, a mixture with a complex oxide may be used.

When the sol of the inorganic fine particles is included, the content is not particularly limited, but the content is preferably 0 to 400 parts by weight, more preferably 30 to 200 parts by weight when the component (A) is 100 parts by weight. is there.

[Laminate]
The present invention also relates to a laminate having a plastic substrate and a transparent coating layer formed from the above composition. In the laminate of the present invention, the transparent coating layer is provided on at least one side of the surface of the plastic substrate, the pencil hardness is 2H or more, and the minimum diameter of the mandrel that does not crack in the mandrel test Is 5 mm or less.

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, methyl polymethacrylate, polycarbonate, polyurethane. 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.

Further, the thickness of the plastic substrate is determined depending on the material, composition or use, but a film of 25 μm to 250 μm is preferable, and a stretched polyester (particularly polyethylene terephthalate) film of 75 to 180 μm is more preferable.

The method for producing the transparent coating layer is not particularly limited, but in general, a resin composition containing (A) an organosilicon compound having a reactive functional group and (B) a polythiol compound is coated on a substrate. And a step of curing the composition to obtain a transparent film, and in the step of obtaining the transparent film, a transparent film is produced by a method comprising irradiating the composition with ultraviolet rays.

The method for applying the resin composition for forming a transparent coating layer 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. Especially, the resin composition for transparent film layer formation of this invention has photocurability, especially ultraviolet-curing property. Is not particularly limited, when not containing a photo acid generator of the component (C) is preferably irradiated with ultraviolet light of 500 mJ / cm ² or more 2,000 mJ / cm ² or less of the total irradiation amount. In the case where the photoacid generator of component (C) is not contained, if the cumulative irradiation amount of ultraviolet rays at the time of curing is 500 mJ / cm ² or less, curing is insufficient, and as a result, sufficient hardness (approximately pencil hardness) However, there is a risk that a transparent film having a hardness higher than H, preferably a hardness higher than 2H may not be obtained.

On the other hand, when the composition contains the photoacid generator of component (C), the cumulative irradiation amount of ultraviolet rays at the time of curing is not particularly limited, but is typically 100 mJ / cm ² or more, and 100 mJ A transparent film with sufficient hardness can be obtained even with an integrated irradiation dose of / cm ² or more and less than 500 mJ / cm ² . Note Needless to say, in the case of containing the component (C) photoacid generator, when irradiated with ultraviolet rays of 500 mJ / cm ² or more 2,000 mJ / cm ² or less of the total irradiation amount, sufficient hardness transparent A coating can be obtained.

In the case of containing the (C) component photoacid generator, the initiation of Bronsted acid or Lewis acid is generated from the (C) component photoacid generator by ultraviolet irradiation, and the reaction of the (A) component When the organosilicon compound having a functional functional group and the polythiol compound (B) react simultaneously, curing proceeds and a transparent film is formed. Moreover, heating etc. can also be performed as needed.

The average thickness of the transparent coating layer is not particularly limited, but is preferably 0.5 to 30 μm, more preferably 1 to 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 has a pencil hardness of 2H or higher. In the present specification, “pencil hardness” refers to a value measured according to JIS K5600-5-4. The value of pencil hardness is JIS K5600-5-4, preferably H or higher, more preferably 2H or higher.

The transparent coating has a minimum mandrel diameter of 5 mm or less that does not cause cracks in the mandrel test. In the present specification, the “mandrel test” refers to a test performed in accordance with JIS K5600-5-1. The minimum diameter value of the mandrel that does not crack is preferably 10 mm or less, more preferably 5 mm or less.

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, “parts” means “parts by weight” unless otherwise specified.

In the following examples and comparative examples, the pencil hardness was specified according to JIS K5600-5-4. The mandrel test was conducted based on JIS K5600-5-1.

<Relationship between UV irradiation and properties of transparent film>
(Example 1)
On one surface of a polyester film A-4100 having a thickness of 125 μm (plastic base material, manufactured by Toyobo Co., Ltd.), a transparent coating layer forming resin composition 1 having the following composition was applied by a spin coating method. Ultraviolet rays were irradiated using a metal halide lamp UVL3000M2O type lamp manufactured by Co., Ltd. The amount of irradiation at this time was 600 mJ / cm ^{2 when} measured with an ultraviolet illuminance meter UVP365-01 manufactured by Iwasaki Electric Co., Ltd. After irradiation, the laminate was heated and dried at 120 ° C. for 20 minutes to prepare a laminate having a transparent film. The transparent film thus obtained had an average thickness of 5 μm. The transparent film had a pencil hardness of 2H. In addition, the laminate having the transparent film has flexibility in a mandrel test so as not to crack even when the curvature is 2 mm (that is, the minimum diameter of the mandrel that does not cause cracking is 2 mm or less). there were. The results are also shown in Table 1.

[Resin composition 1 for forming transparent coating layer]
-(A) Organosilicon compound vinyl triacetoxysilane (Shin-Etsu Chemical Co., Ltd.) 100 parts-(B) Polythiol compound trimethylolpropane tris (Mercaptopropionate) (SC Organic Chemical Co., Ltd.) 60 parts Solvent methoxypropyl acetate (manufactured by Wako Pure Chemical Industries, Ltd.) 53 parts

(Example 2)
Except having changed the polythiol compound into 77 parts of tris (mercaptopropionyloxyethyl) isocyanurate, the same operation as Example 1 was performed and the laminated body provided with the transparent film was obtained. While measuring the average film thickness and pencil hardness of the obtained transparent film, a mandrel test was performed. The results are shown in Table 1.

Example 3
Except having changed the polythiol compound into 53 parts of pentaerythritol tetrakis (mercaptopropionate), the same operation as Example 1 was performed and the laminated body provided with the transparent film was obtained. While measuring the average film thickness and pencil hardness of the obtained transparent film, a mandrel test was performed. The results are shown in Table 1.

(Example 4)
On one surface of a 125 μm thick polyester film A-4100 (plastic substrate, manufactured by Toyobo Co., Ltd.), a transparent coating layer forming resin composition having the following composition was applied by spin coating, and ultraviolet rays were applied at 200 mJ / After irradiation with cm ² , the laminate having a transparent film was prepared by heating and drying at 120 ° C. for 20 minutes. The transparent film thus obtained had a thickness of 5 μm. The pencil hardness of this transparent film was 2H. Further, the laminate having the transparent coating 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. The results are also shown in Table 1.

[Transparent film layer forming resin composition 2]
-(A) Organosilicon compound vinyl triacetoxysilane (Shin-Etsu Chemical Co., Ltd.) 100 parts-(B) Polythiol compound trimethylolpropane tris (Mercaptopropionate) (SC Organic Chemical Co., Ltd.) 60 parts (C) Photoacid generator Silicolice CATA211 (photoacid generator, manufactured by Arakawa Chemical Industries, Ltd., trade name) 1 part Solvent methoxypropyl acetate (manufactured by Wako Pure Chemical Industries, Ltd.) 53 parts

(Example 5)
The same operation as in Example 4 was performed except that the polythiol compound was changed to 77 parts of tris (mercaptopropionyloxyethyl) isocyanurate to obtain a laminate having a transparent film. While measuring the average film thickness and pencil hardness of the obtained transparent film, a mandrel test was performed. The results are shown in Table 1.

(Example 6)
The same operation as in Example 4 was performed except that the polythiol compound was changed to 53 parts of pentaerythritol tetrakis (mercaptopropionate) to obtain a laminate having a transparent film. While measuring the average film thickness and pencil hardness of the obtained transparent film, a mandrel test was performed. The results are shown in Table 1.

(Example 7)
Except not adding a photo-acid generator, operation similar to Example 4 was performed and the laminated body provided with the transparent film was obtained. While measuring the average film thickness and pencil hardness of the obtained transparent film, a mandrel test was performed. The results are shown in Table 1.

(Example 8)
Except not adding a photo-acid generator, operation similar to Example 5 was performed and the laminated body provided with the transparent film was obtained. While measuring the average film thickness and pencil hardness of the obtained transparent film, a mandrel test was performed. The results are shown in Table 1.

Example 9
Except not adding a photo-acid generator, operation similar to Example 6 was performed and the laminated body provided with the transparent film was obtained. While measuring the average film thickness and pencil hardness of the obtained transparent film, a mandrel test was performed. The results are shown in Table 1.

(Comparative Example 1)
On one surface of the polyester film used in Example 1, a transparent film layer-forming resin composition having the following composition was applied by spin coating, and irradiated with ultraviolet rays at 300 mJ / cm ^{2 and} then heated at 120 ° C. for 20 minutes. A laminate having a transparent coating was prepared by drying. The transparent film thus obtained had a thickness of 5 μm. The pencil hardness of the transparent film was 2H, but the laminate having the transparent film was cracked with a curvature of 10 mm in the mandrel test (that is, the minimum diameter of the mandrel without cracks exceeded 5 mm). The flexibility was not satisfactory.
[Transparent film layer forming resin composition 3]
・ (A) 100 parts of organosilicon compound vinyltriacetoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) ・ (C) photoacid generator Silicolys CATA211 (photoacid generator, manufactured by Arakawa Chemical Co., Ltd., trade name) 1 Parts / solvent methoxypropyl acetate (manufactured by Wako Pure Chemical Industries, Ltd.) 10 parts

(Comparative Example 2)
On one surface of the polyester film used in Example 1, a transparent film layer-forming resin composition having the following composition was applied by spin coating, and irradiated with ultraviolet rays at 300 mJ / cm ^{2 and} then heated at 120 ° C. for 20 minutes. Although dried, the curing reaction did not proceed and a transparent film could not be obtained.
[Resin Composition 4 for Forming Transparent Film Layer]
・ (B) 100 parts of polythiol compound trimethylolpropane tris (mercaptopropionate) (manufactured by SC Organic Chemical Co., Ltd.) ・ (C) photoacid generator Silicolyse CATA211 (photoacid generator, manufactured by Arakawa Chemical Industries, Ltd.) , Product name) 1 part, solvent methoxypropyl acetate (manufactured by Wako Pure Chemical Industries, Ltd.) 30 parts

(Comparative Example 3)
On one surface of the polyester film used in Example 1, a transparent film layer-forming resin composition having the following composition was applied by spin coating, and irradiated with ultraviolet rays at 300 mJ / cm ^{2 and} then heated at 120 ° C. for 20 minutes. A laminate having a transparent coating was prepared by drying. The transparent film thus obtained had a thickness of 5 μm. The pencil hardness of this transparent film was 2H, but the laminate having the transparent film was satisfactory in terms of flexibility because a crack occurred at a curvature of 10 mm in the mandrel test (JIS K5600-5-1). It wasn't possible.
[Transparent film layer forming resin composition 5]
・ Main part DPHA (polyfunctional acrylate, Nippon Kayaku Co., Ltd., trade name) 100 parts ・ Additive Irgacure 184 (Photopolymerization initiator, Ciba Specialty Chemicals Co., Ltd., trade name) 4 parts ・ Solvent ethanol (Wako Pure Chemical Industries, Ltd.) 35 parts

(Comparative Example 4)
On one surface of the polyester film used in Example 1, a transparent film layer-forming resin composition having the following composition was applied by spin coating, and irradiated with ultraviolet rays at 300 mJ / cm ^{2 and} then heated at 120 ° C. for 20 minutes. A laminate having a transparent coating was prepared by drying. The transparent film thus obtained had a thickness of 5 μm. In the mandrel test (JIS K5600-5-1), this transparent film was flexible with no curvature at a curvature of 3 mm, but the pencil hardness was 3B, which is not satisfactory in terms of hardness. There wasn't.
[Resin Composition 6 for Forming Transparent Film Layer]
・ Main agent UA122P (urethane acrylate, trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.) 100 parts ・ Additive Irgacure 184 (photopolymerization initiator, trade name, manufactured by Ciba Specialty Chemicals, Inc.) 4 parts ・ Solvent methoxypropyl 53 parts of acetate (manufactured by Wako Pure Chemical Industries, Ltd.)

The film thickness of the transparent film obtained in Examples 1 to 9 and Comparative Examples 1 to 4, the measurement result of pencil hardness (JIS K5600-5-4), and the evaluation result of the mandrel test (JIS K5600-5-1) are shown. Shown in Tables 1 and 2 below. In addition, the symbol used in the table | surface represents the following.
(A) Organosilicon compound A1: Vinyltriacetoxysilane

(B) Polythiol compound B1: Trimethylolpropane tris (mercaptopropionate)
B2: Tris (mercaptopropionyloxyethyl) isocyanurate B3: Pentaerythritol tetrakis (mercaptopropionate)

(C) Photoacid generator Silicolys CATA211

Solvent MPA: Methoxypropyl acetate EtOH: Ethanol

As shown in the results of Table 1, it was found that the transparent film layer-forming resin composition of the present invention can provide a transparent film excellent in flexibility without cracks even in the mandrel test. Furthermore, it was found that a transparent film having a high pencil hardness of 2H can be obtained by irradiating with an ultraviolet ray having an accumulated irradiation amount of 600 mJ / cm ² . Even when the cumulative amount of UV irradiation is relatively low at 200 mJ / cm ² , a transparent film having sufficient hardness and excellent flexibility can be obtained by blending the photoacid generator (C). I understood that. Compared with the results of Comparative Examples 1 to 4 in Table 2 in which both hardness and flexibility cannot be achieved, the transparent film obtained from the resin composition for forming a transparent film layer of the present invention has physical properties required as a hard coat layer. It is clear that it is sufficiently equipped.

<Evaluation of physical properties for various formulations in (C) photoacid generator>
(Example 10)
On one side of a 125 μm thick polyester film A-4100 (plastic substrate, manufactured by Toyobo Co., Ltd.), a transparent coating layer forming resin composition having the following composition was applied by spin coating, and ultraviolet rays were applied at 300 mJ / After irradiation with cm ² , the laminate having a transparent film was prepared by heating and drying at 120 ° C. for 20 minutes. The transparent film thus obtained had a thickness of 5 μm. The pencil hardness of this transparent film was 2H. Further, the laminate having the transparent coating 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. The results are also shown in Table 3.
[Resin composition 7 for forming transparent coating layer]
-(A) Organosilicon compound vinyl triacetoxysilane (Shin-Etsu Chemical Co., Ltd.) 100 parts-(B) Polythiol compound trimethylolpropane tris (Mercaptopropionate) (SC Organic Chemical Co., Ltd.) 60 parts Silico-Leasing CATA211 (photoacid generator, manufactured by Arakawa Chemical Industries, Ltd., trade name) 1 part methoxypropyl acetate (manufactured by Wako Pure Chemical Industries, Ltd.) 53 parts

(Example 11)
A transparent film was obtained in the same manner as in Example 10, except that 17 parts of tetraethoxysilane (TEOS) was further added to the transparent film layer forming resin composition used in Example 1. While measuring the average film thickness and pencil hardness of the obtained transparent film, a mandrel test was performed. The results are shown in Table 3.

Example 12
A transparent film was obtained in the same manner as in Example 10 except that the polythiol compound was changed to 77 parts of tris (mercaptopropionyloxyethyl) isocyanurate. While measuring the average film thickness and pencil hardness of the obtained transparent film, a mandrel test was performed. The results are shown in Table 3.
(Example 13)

A transparent film was obtained in the same manner as in Example 10 except that the polythiol compound was changed to 53 parts of pentaerythritol tetrakis (mercaptopropionate). While measuring the average film thickness and pencil hardness of the obtained transparent film, a mandrel test was performed. The results are shown in Table 3.
(Example 14)

A transparent film was obtained in the same manner as in Example 10 except that the polythiol compound was changed to 56 parts of dipentaerythritol hexa (mercaptopropionate). While measuring the average film thickness and pencil hardness of the obtained transparent film, a mandrel test was performed. The results are shown in Table 3.

(Example 15)
The same operation as in Example 1 was performed except that 0.2 part of a surface conditioning agent BYK333 manufactured by Big Chemie Japan Co., Ltd. was further added to the resin composition for forming a transparent film layer used in Example 10, and a transparent film was formed. Obtained. While measuring the average film thickness and pencil hardness of the obtained transparent film, a mandrel test was performed. The results are shown in Table 3.

(Example 16)
A transparent film was obtained in the same manner as in Example 1 except that the organosilicon compound was changed to 100 parts of vinyltrimethoxysilane and the polythiol compound was changed to 90 parts of trimethylolpropane tris (mercaptopropionate). While measuring the average film thickness and pencil hardness of the obtained transparent film, a mandrel test was performed. The results are shown in Table 3.

Table 3 below shows the film thickness, pencil hardness (JIS K5600-5-4) measurement results, and mandrel test (JIS K5600-5-1) evaluation results of the transparent coatings obtained in Examples 10 to 16 above. . In addition, the symbol used in the table | surface represents the following.
(A) Organosilicon compound A1: Vinyltriacetoxysilane A2: Vinyltrimethoxysilane

(B) Polythiol compound B1: Trimethylolpropane tris (mercaptopropionate)
B2: Tris (mercaptopropionyloxyethyl) isocyanurate B3: Pentaerythritol tetrakis (mercaptopropionate)
B4: Dipentaerythritol hexa (mercaptopropionate)

(C) Photoacid generator Silicolyse CATA211 (common to all Examples and Comparative Examples except Comparative Examples 3 and 4 which were not used)

Solvent MPA: Methoxypropyl acetate

Other TEOS: Tetraethoxysilane BYK333: Surface conditioner (manufactured by Big Chemie Japan Co., Ltd.)

As shown in the results of Table 3, even when the formulation is changed, the pencil hardness is H or higher, and generally has a high hardness of 2H or higher in the presence of the photoacid generator under the condition that the cumulative irradiation amount is 300 mJ / cm ^2. In addition, it has been found that a transparent coating excellent in flexibility and free from cracks can be obtained in the mandrel test. Compared with the results of Comparative Examples 1 to 4 in Table 2 in which both hardness and flexibility cannot be achieved, the transparent film obtained from the resin composition for forming a transparent film layer of the present invention has physical properties required as a hard coat layer. It is clear that it is sufficiently equipped.

Claims

A resin composition for forming a transparent coating layer, comprising the following components (A) and (B):
(A) an organosilicon compound having a reactive functional group, and
(B) Polythiol compound.
The composition according to claim 1, further comprising (C) a photoacid generator.
The composition according to claim 1 or 2, wherein the organosilicon compound (A) contains at least a compound having at least one carbon-carbon unsaturated bond in one molecule.
500 mJ / cm 2 or more 2,000 mJ / cm composition of claim 1 having the curability 2 under irradiation with the following total irradiation amount of the ultraviolet.
The composition according to claim 2, which has curability under irradiation with ultraviolet rays having an integrated dose of 100 mJ / cm 2 or more and less than 500 mJ / cm 2 .
The composition according to any one of claims 1 to 5, wherein the organosilicon compound is vinyltriacetoxysilane.
A plastic substrate;
A laminate having a transparent coating layer formed from the composition according to any one of claims 1 to 6,
The transparent coating layer is provided on at least one side of the surface of the base material,
The transparent coating layer is a laminate having a pencil hardness of 2H or more and a minimum mandrel diameter of 5 mm or less that does not cause cracks in a mandrel test.
(A) coating a resin composition containing an organosilicon compound having a reactive functional group and (B) a polythiol compound on a substrate;
Curing the composition to obtain a transparent coating,
In the step of obtaining the transparent coating, comprising irradiating the composition with ultraviolet rays,
A method for producing a transparent coating.
Integrated irradiation dose of ultraviolet rays to the composition, 500 mJ / cm 2 or more 2,000 mJ / cm 2 or less The method of claim 8, wherein.
The resin composition further contains (C) a photoacid generator,
The method according to claim 8, wherein an integrated dose of ultraviolet rays to the composition is 100 mJ / cm 2 or more and less than 500 mJ / cm 2 .