JP2017068059A - Method for manufacturing light-transmitting hard coat laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a light-transmitting hard coat laminate having excellent light fastness and transparency as well as high hardness.SOLUTION: The method for manufacturing a light-transmitting hard coat layer includes a step of forming a coating film of a photocurable resin composition for a hard coat layer, the composition comprising silica particles, an acrylic polymer, a polyfunctional monomer, a specified amount of a hydroxyphenyl triazine compound, and a solvent; a step of forming a photocurable film for a hard coat layer by removing the solvent in the photocurable resin composition for a hard coat layer in the obtained coating film; and a step of forming a hard coat layer by heating the photocurable film for a hard coat layer at 50°C to 110°C in such a manner that an increment of haze value by the photocurable film for a hard coat layer is 0.5 or less at the time of starting irradiation with UV rays, and then irradiating the photocurable film for a hard coat layer with UV rays to cure while heating the film to maintain the above heating temperature.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a translucent hard coat laminate in which a hard coat layer is provided on a translucent substrate, which is used for the purpose of protecting the surface of a display device or the like, or as a window material or various transparent members. Is.

  An image display surface in an image display device such as a liquid crystal display, a CRT display, a projection display, a plasma display, or an electroluminescence display is required to be provided with scratch resistance so as not to be damaged during handling. In response to such demands, it has been common to improve the scratch resistance of the image display surface of an image display device by using a hard coat film having a hard coat layer provided on a substrate. The performance required for the hard coat film has been increasing in recent years, and there is a demand for a film having excellent hardness and light resistance.

  For example, Patent Document 1 describes an antireflection film containing a hindered amine light stabilizer as a means for improving weather resistance. Patent Document 2 describes that the hard coat layer contains an ultraviolet absorber as an antireflection film having excellent weather resistance. As the ultraviolet absorber, a benzotriazole-based ultraviolet absorber is used. The agent is used. Patent Document 3 describes a composition containing a specific amount of a resin component and a specific hydroxyphenyltriazine compound as a weatherproof composition that imparts high weather resistance to a building member such as a decorative sheet.

JP 2003-94573 A JP 2008-90067 A JP 2006-307142 A JP 2014-149520 A

The present applicant combines high hardness, scratch resistance and processability by forming a hard coat layer using a curable resin composition containing specific silica particles, a monomer, and a specific polymer. It discovered that a hard coat film was obtained (patent document 4).
However, even with the hard coat film of Patent Document 4, the light resistance is still insufficient.
As a result of earnest research by the present inventors, when a hard coat layer is formed using a curable resin composition containing a combination of a hydroxyphenyltriazine compound in silica particles, a specific monomer, and a specific polymer. It was found that it has excellent light resistance, but at the same time, it has been found that when a hydroxyphenyltriazine compound is combined with silica particles, a specific monomer, and a specific polymer, the hard coat layer becomes cloudy. It was.
Transparency is further required for the purpose of protecting the surface of a display device or the like, and for the translucent hard coat laminate used as a window material or various transparent members.

  This invention is made | formed in view of the said problem, and it aims at providing the manufacturing method of the translucent hard-coat laminated body which combines the outstanding light resistance and transparency, and high hardness.

The method for producing a translucent hard coat laminate of the present invention is as follows.
A silica particle, an acrylic polymer, a polyfunctional monomer having two or more ultraviolet curable groups in one molecule, a hydroxyphenyl triazine compound, and a solvent, wherein the hydroxyphenyl triazine compound is 100 parts by mass of the silica particles. Preparing a photocurable resin composition for a hard coat layer containing 1.9 to 20.0 parts by mass with respect to
A step of forming a coating film by applying the photocurable resin composition for a hard coat layer to at least one surface side of a translucent substrate;
In the coating film, by removing the solvent in the photocurable resin composition for the hard coat layer, a step of forming a photocurable film for the hard coat layer, and
After heating the photocurable film for hard coat layer at 50 ° C. to 110 ° C. so that the increase in haze due to the photocurable film for hard coat layer is 0.5 or less at the start of ultraviolet irradiation, the heating temperature is maintained. Thus, the method has a step of forming a hard coat layer by curing the photocurable film for a hard coat layer by irradiation with ultraviolet rays while heating.

  ADVANTAGE OF THE INVENTION According to this invention, the translucent hard-coat laminated body which combines the outstanding light resistance and transparency, and high hardness can be manufactured.

It is a schematic sectional drawing which shows an example of the manufacturing method of the translucent hard-coat laminated body of this invention.

Hereinafter, the detail about the manufacturing method of the translucent hard-coat laminated body of this invention is demonstrated.
The method for producing a translucent hard coat laminate of the present invention is
A silica particle, an acrylic polymer, a polyfunctional monomer having two or more ultraviolet curable groups in one molecule, a hydroxyphenyl triazine compound, and a solvent, wherein the hydroxyphenyl triazine compound is 100 parts by mass of the silica particles. Preparing a photocurable resin composition for a hard coat layer containing 1.9 to 20.0 parts by mass with respect to
A step of forming a coating film by applying the photocurable resin composition for a hard coat layer to at least one surface side of a translucent substrate;
In the coating film, by removing the solvent in the photocurable resin composition for the hard coat layer, a step of forming a photocurable film for the hard coat layer, and
After heating the photocurable film for hard coat layer at 50 ° C. to 110 ° C. so that the increase in haze due to the photocurable film for hard coat layer is 0.5 or less at the start of ultraviolet irradiation, the heating temperature is maintained. Thus, the method has a step of forming a hard coat layer by curing the photocurable film for a hard coat layer by irradiation with ultraviolet rays while heating.

1 (A), (B), (C), (D), (E), and (F) are schematic cross-sectional views showing an example of a method for producing a translucent hard coat laminate of the present invention. In the method for producing a translucent hard coat laminate of the present invention, first, the specific photocurable resin composition for hard coat layer is prepared (not shown). Next, the coating film 2 is formed by apply | coating the said photocurable resin composition for hard-coat layers to the at least one surface side of the translucent base | substrate 1 (FIG. 1 (A)). Subsequently, in the coating film 2, the coating film 2 ′ from which the solvent in the photocurable resin composition for the hard coat layer has been removed 4 (FIG. 1B), and then the photocurable film for the hard coat layer. 3 is formed (FIG. 1C).
Next, the amount of haze increase is set to 0 by heating 5 the photocurable film 3 for hard coat layer so that the amount of haze increase by the photocurable film for hard coat layer is 0.5 or less at the start of ultraviolet irradiation. It is set as 5 or less hard-coat layer photocurable film 3 '(FIG. 1 (D)). Next, the hard coat layer 10 is formed by curing the photocurable film 3 ′ for hard coat layer 3 by heating 5 with ultraviolet irradiation 6 so as to maintain the heating temperature (FIG. 1E). The translucent hard coat laminate 100 is manufactured. (FIG. 1 (F)). The hard coat layer 10 is composed of a cured product of the specific photocurable resin composition for hard coat layer.

  According to the present invention, using the specific photocurable resin composition for a hard coat layer, the hard coat layer has a haze increase amount of 0.5 or less at the start of ultraviolet irradiation. After heating the photocurable film for the coat layer, the photocurable film for the hard coat layer is cured by irradiating with ultraviolet rays while heating the photocurable film for the hard coat layer so as to maintain the heating temperature. Can produce a light-transmitting hard coat laminate that can be cured by UV irradiation while reducing the amount of haze increase caused by UV irradiation at the start of UV irradiation, and has both excellent light resistance, transparency, high hardness and scratch resistance be able to.

The curable resin composition containing a combination of a hydroxyphenyltriazine compound and silica particles, the specific polymer, and the specific monomer is applied, and after drying, the coating film becomes cloudy as it is cooled. Arise. The white turbidity does not occur in a curable resin composition containing silica particles, the specific polymer, and the specific monomer, and does not contain a hydroxyphenyltriazine compound, and does not contain silica particles. It does not occur in a curable resin composition containing a polymer, the specific monomer, and a hydroxyphenyltriazine compound, and the hydroxyphenyltriazine compound is combined with silica particles, the specific polymer, and the specific monomer. It is a peculiar problem caused by this. According to the analysis by the present inventors, in the curable resin composition as described above, after the solvent is removed by drying, the silica particles are dispersed by the interaction between the specific hydroxyphenyltriazine compound and the silica particles as it is cooled. Was localized and became cloudy. When the white turbid coating film is cured by irradiating with ultraviolet rays, a white turbid hard coat layer is obtained as it is.
After forming a coating film of the photocurable resin composition for a hard coat layer on at least one side of the translucent substrate, the process of removing the solvent in the coating film (drying) and the subsequent light irradiation process are continuous. Even if once performed in the drying step, the photocurable film for a hard coat layer obtained after drying is usually substantially cooled at the time of transport to the light irradiation step. Therefore, in a normal process, when the photocurable resin composition for hard coat layers used in the present invention is used, a hard coat layer that is clouded and has an increased haze value is obtained.

On the other hand, the present inventor found that even when the photocurable film for a hard coat layer was once clouded after the solvent was removed, the cloudiness disappeared or decreased by heating at an appropriate temperature again, and the cloudiness disappeared. It has been found that a hard coat layer with high transparency can be obtained using the specific photocurable resin composition for hard coat layer when ultraviolet irradiation is carried out while maintaining a reduced heating temperature.
After heating the photocurable film for hard coat layer at the specific temperature so that the increase in haze by the photocurable film for hard coat layer obtained after drying is 0.5 or less at the start of ultraviolet irradiation, the heating is performed. When the photocurable film for hard coat layer is heated and cured by ultraviolet irradiation so as to maintain the temperature, the photocurable resin composition for specific hard coat layer is used, and while having excellent light resistance, transparency is improved. A high hard coat layer can be obtained.

Moreover, according to this invention, a hard-coat layer can improve hardness and abrasion resistance because it contains a silica particle. Further, by using an acrylic polymer for the hard coat layer, it is possible to improve workability while maintaining high hardness.
Hereinafter, each process of the manufacturing method of the translucent hard coat laminated body of this invention is demonstrated.

1. Step of preparing a photocurable resin composition for a hard coat layer The photocurable resin composition for a hard coat layer used in the present invention is composed of silica particles, an acrylic polymer, and two or more ultraviolet curable groups in one molecule. A polyfunctional monomer, a hydroxyphenyl triazine compound, and a solvent, and the hydroxyphenyl triazine compound contains 1.9 to 20.0 parts by mass with respect to 100 parts by mass of the silica particles.
Hereinafter, each component in the photocurable resin composition for a hard coat layer (hereinafter sometimes simply referred to as “curable resin composition”) will be described.

(1) Silica particle In this invention, a silica particle is a component which contributes to the hardness improvement of a hard-coat layer.
The silica particles are preferably reactive silica particles having a reactive functional group. In the present invention, the reactive functional group is preferably a photocurable group, and particularly preferably an ultraviolet curable group capable of reacting with a polyfunctional monomer described later. Specific examples include ethylenically unsaturated bonds such as (meth) acryloyl groups, vinyl groups, allyl groups, and epoxy groups.

  In the present specification, (meth) acryloyl means at least one of acryloyl and methacryloyl, (meth) acrylate means at least one of acrylate and methacrylate, and (meth) acryl is at least one of acrylic and methacrylic. Means.

  The silica particles are preferably deformed silica particles in which a plurality of silica particles are bonded by inorganic chemical bonds. Among them, the irregular shaped silica particles are preferably reactive irregular shaped silica particles in which 3 to 20 silica particles having an average primary particle diameter of 1 nm to 100 nm are bonded by an inorganic chemical bond and have a reactive functional group on the surface. . The reactive irregularly shaped silica particles have a reactive functional group, so that they can undergo a curing reaction that crosslinks with the reactive irregularly shaped silica particles and the monomer, and can improve the scratch resistance and hardness of the hard coat layer. .

The average primary particle size of the silica particles used in the present invention is preferably in the range of 1 nm to 100 nm, more preferably in the range of 5 nm to 80 nm, from the viewpoint of hardness and transparency. The average secondary particle size of the silica particles used in the present invention is preferably in the range of 5 nm to 300 nm, more preferably in the range of 10 nm to 200 nm, from the viewpoint of hardness and transparency.
The average primary particle size of the silica particles constituting the reactive irregularly shaped silica particles is preferably in the range of 1 nm to 100 nm, and more preferably in the range of 5 nm to 80 nm. If the average primary particle size of the silica particles is small, only reactive deformed silica particles having a small average secondary particle size can be obtained, and sufficient hardness may not be imparted to the hard coat layer. In addition, if the average primary particle size of the silica particles is large, the average secondary particle size of the reactive deformed silica particles tends to be large, and if the average secondary particle size is large, the transparency of the hard coat layer is lowered and the transmittance is reduced. Deterioration and haze increase may occur.
The average secondary particle diameter of the reactive irregularly shaped silica particles is preferably in the range of 5 nm to 300 nm, and more preferably in the range of 10 nm to 200 nm. If the average secondary particle size of the reactive irregularly shaped silica particles is within the above range, it is easy to impart hardness to the hard coat layer and maintain the transparency of the hard coat layer.

  Here, the average primary particle size of the silica particles is determined by measuring the silica particles in the curable resin composition by a dynamic light scattering method, and the 50% particle size (d50 median) when the particle size distribution is expressed as a cumulative distribution. Diameter). The average primary particle size can be measured using a Microtrac particle size analyzer or a Nanotrac particle size analyzer manufactured by Nikkiso Co., Ltd. In addition, the average secondary particle size of the reactive irregular shaped silica particles can be determined by the same method as the average primary particle size in the curable resin composition. On the other hand, the average secondary particle size of the silica particles is such that, in the hard coat layer, the cross section of the hard coat layer is observed using an SEM photograph or a TEM photograph, and 100 observed cured reactive deformed silica particles are selected. The average value can be obtained.

  Silica particles do not exclude the use of particles having pores or porous structures inside the particles, such as hollow particles, but solid particles having no pores or porous structures inside the particles should be used. It is more preferable from the viewpoint of improving the hardness.

  The deformed silica particles are preferably formed by bonding the above silica particles by 3 to 20, more preferably 3 to 10, by an inorganic chemical bond. When the number of silica particles bonded by inorganic chemical bonds is small, it is substantially the same as monodisperse particles, and it is difficult to obtain a hard coat layer excellent in adhesion to the substrate, scratch resistance and pencil hardness. Moreover, when there are many silica particles couple | bonded by the inorganic chemical bond, the transparency of a hard-coat layer will fall, and the deterioration of the transmittance | permeability and the raise of a haze may be caused.

  Examples of inorganic chemical bonds include ionic bonds, metal bonds, coordinate bonds, and covalent bonds. Among these, bonds that do not disperse the bonded silica particles even when reactive deformed silica particles are added to the polar solvent, specifically, metal bonds, coordinate bonds, and covalent bonds are preferable, and covalent bonds are particularly preferable. Examples of the polar solvent include water and lower alcohols such as methanol, ethanol and isopropyl alcohol.

  As the particle state of the irregular-shaped silica particles, 3 to 20 silica particles are bonded by inorganic chemical bonds and aggregated particles (aggregated particles), and 3 to 20 silica particles are inorganic chemical bonds. And chain-like particles that are bound in a chain. Among these, from the viewpoint of increasing the hardness of the hard coat layer, chain particles are preferable as the particle state of the irregular shaped silica particles. Moreover, it is preferable that the chain particles are contained in at least a part of the irregular shaped silica particles.

  Here, when the deformed silica particles are chain particles, the average number of bonds of the silica particles is determined by observing the cross section of the hard coat layer using an SEM photograph or a TEM photograph, and selecting 100 observed deformed silica particles, The silica particles contained in the irregular shaped silica particles can be counted and obtained as an average value.

  The method for producing irregular shaped silica particles is not particularly limited as long as the silica particles bonded with inorganic bonds can be obtained, and conventionally known methods can be appropriately selected and used. For example, it can be obtained by adjusting the concentration or pH of the monodispersed silica particle dispersion and performing hydrothermal treatment at a high temperature of 100 ° C. or higher. At this time, if necessary, a binder component can be added to promote the binding of the silica particles. Further, ions may be removed by passing the silica particle dispersion used through an ion exchange resin. Such ion exchange treatment can promote the binding of silica particles. After the hydrothermal treatment, the ion exchange treatment may be performed again.

  The reactive irregularly shaped silica particles have at least a part of the surface coated with an organic component, and have a reactive functional group introduced by the organic component on the surface. Here, the organic component is a component containing carbon. Moreover, as an aspect in which at least a part of the surface is coated with an organic component, for example, a compound containing an organic component such as a silane coupling agent reacts with a hydroxyl group present on the surface of a silica particle, thereby In addition to the mode in which the organic component is bonded to the surface, or the mode in which the compound containing the organic component having an isocyanate group reacts with the hydroxyl group present on the surface of the silica particle, the organic component is bonded to a part of the surface. Examples include a mode in which an organic component is attached to a hydroxyl group present on the surface of the particle by an interaction such as hydrogen bonding, a mode in which silica particles are contained in the polymer particle, and the like.

At least a part of the surface is coated with an organic component, and as a method of preparing reactive deformed silica particles having a reactive functional group introduced by the organic component on the surface, the reactive functional group to be introduced into the reactive deformed silica particles Thus, a conventionally known method can be appropriately selected and used. Among these, from the viewpoint of suppressing aggregation of the reactive deformed silica particles and improving the hardness of the hard coat layer, any one of the following (i) and (ii) reactive deformed silica particles may be appropriately selected and used. preferable.
(I) saturated or unsaturated carboxylic acid, acid anhydride, acid chloride, ester and acid amide corresponding to the carboxylic acid, amino acid, imine, nitrile, isonitrile, epoxy compound, amine, β-dicarbonyl compound, silane, And in the presence of one or more surface modification compounds having a molecular weight of 500 or less selected from the group consisting of metal compounds having a functional group, the modified silica particles are dispersed in at least one of water and an organic solvent as a dispersion medium. Reactive deformed silica particles having a reactive functional group on the surface, obtained by
(Ii) a compound containing a reactive functional group to be introduced into the irregular-shaped silica particles before coating, a group represented by the following general formula (1), and a silanol group or a group that generates a silanol group by hydrolysis, metal oxide fine particles, Reactive deformed silica particles having a reactive functional group on the surface, obtained by bonding.
−Q ¹ −C (= Q ² ) −Q ³ − (1)
(In formula (1), Q ¹ represents NH, O or S, Q ² represents O or S, and Q ³ represents NH or a divalent or higher organic group.)
The reactive irregularly shaped silica particles (i) and (ii) can be prepared in the same manner as described in paragraphs 0048 to 0079 of JP-A-2014-149520.

  As the reactive irregularly shaped silica particles, powdered fine particles not containing a dispersion medium may be used, but it is preferable to use a fine particle in a solvent-dispersed sol because the dispersion step can be omitted and the productivity is high.

  The produced hard coat layer includes not only those in which the reactive functional group of the reactive deformed silica particles has reacted but also those in which the reactive functional group of the reactive deformed silica particles has not reacted. Also good.

The content of the silica particles is preferably in the range of 40% by mass to 70% by mass and more preferably in the range of 45% by mass to 60% by mass with respect to the total solid content of the curable resin composition. preferable. When the content is small, there is a possibility that sufficient hardness cannot be imparted to the hard coat layer. When the content is large, the filling rate is excessively increased, the adhesion between the reactive irregularly shaped silica particles and the monomer is deteriorated, and the hardness of the hard coat layer may be lowered.
Here, solid content means things other than a solvent among the components contained in curable resin composition.

(2) Acrylic polymer The acrylic polymer used for this invention is a component which contributes to the workability improvement of a translucent hard-coat laminated body.

The mass average molecular weight of the acrylic polymer is preferably in the range of 30,000 to 110,000, and more preferably in the range of 50,000 to 110,000, from the viewpoint of imparting flexibility to the hard coat layer and preventing cracks during processing. Is preferably in the range of 000, particularly preferably in the range of 60,000 to 80,000.
Here, the mass average molecular weight means a polystyrene equivalent value measured by gel permeation chromatography.

The acrylic polymer preferably has an acrylic equivalent in the range of 200 to 1,200, and more preferably in the range of 200 to 1,000.
Here, the acrylic equivalent indicates a value obtained by dividing the mass average molecular weight of the acrylic polymer by the number of (meth) acrylic groups in one molecule.

  The acrylic polymer is not particularly limited as long as it satisfies the above-mentioned mass average molecular weight and acrylic equivalent, but is a polymer of glycerol (meth) acrylate or a compound obtained by adding (meth) acrylic acid to glycidyl methacrylate. A polymer is preferred. Specifically, a polymer of an acrylic monomer represented by the following general formula (2) or (3) is preferably used.

In the chemical formula (2), R ^{1 to} R ³ are each independently an acryloyl group, a methacryloyl group, or a hydrogen atom, and one or more of R ^{1 to} R ³ are an acryloyl group or a methacryloyl group. That is, the glycerol (meth) acrylate represented by the chemical formula (2) may be monofunctional, bifunctional, or trifunctional.
In the above formula (3), R is an acryloyloxy group or a methacryloyloxy group.

As such an acrylic polymer, for example, BL-2002 manufactured by Seiko PMC Co., Ltd. may be mentioned.
Moreover, as an acrylic polymer, you may use individually by 1 type, and may mix and use 2 or more types suitably.

The content of the acrylic polymer is preferably in the range of 3% by mass to 20% by mass with respect to the total solid content of the curable resin composition, and more preferably in the range of 5% by mass to 10% by mass. More preferably, it is in the range of 6% by mass to 8% by mass. When the content of the acrylic polymer is within the above range, the workability of the translucent hard coat laminate can be improved while maintaining the hardness of the hard coat layer.
Moreover, content of an acrylic polymer can be set in the range of 5 mass parts-80 mass parts with respect to 100 mass parts of below-mentioned monomers, and may be in the range of 20 mass parts-40 mass parts. Preferably, it is in the range of 10 to 30 parts by mass.

(3) Polyfunctional monomer The polyfunctional monomer used in the present invention is a polyfunctional monomer having two or more ultraviolet curable groups in one molecule. When the reactive functional group of the polyfunctional monomer has cross-linking reactivity with the reactive functional group of the reactive deformed silica particle, the monomer is cross-linked with the reactive deformed silica particle to form a network structure and hard coat Further increase the hardness and scratch resistance of the layer. Specific examples of the ultraviolet curable group include an ethylenically unsaturated bond such as a (meth) acryloyl group, a vinyl group, and an allyl group, an epoxy group, and an oxetanyl group. The ultraviolet curable group of the polyfunctional monomer may be the same as or different from the ultraviolet curable group of the reactive irregularly shaped silica particles, but it is preferable that they can cross-link with each other.

  As the polyfunctional monomer, a light-transmitting monomer that transmits light when formed into a coating film is preferable, and a known ultraviolet curable resin or the like may be appropriately employed according to required performance. Examples of the ultraviolet curable resin include acrylate-based, epoxy-based, and oxetane-based resins. As the polyfunctional monomer, one type or two or more types of polyfunctional monomers can be used.

The polyfunctional monomer preferably has three or more ultraviolet curable groups from the viewpoint of increasing the crosslinking density. Examples of the polyfunctional monomer having three or more ultraviolet curable groups include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and dipentaerythritol penta (meth) acrylate. , Trimethylolpropane tri (meth) acrylate, trimethylolpropane hexa (meth) acrylate, and modified products thereof. In addition, as a modified body, an ethylene oxide modified body, a propylene oxide modified body, a caprolactone modified body, an isocyanuric acid modified body, etc. are mentioned.
Among them, as the polyfunctional monomer, pentaerythritol triacrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexaacrylate, pentaerythritol tetraacrylate, and dipentaerythritol pentaacrylate are preferably used, and dipentaerythritol hexaacrylate, penta Erythritol tetraacrylate and dipentaerythritol pentaacrylate are particularly preferably used.

  The content of the polyfunctional monomer is preferably in the range of 25% by mass to 44% by mass and preferably in the range of 30% by mass to 40% by mass with respect to the total solid content of the curable resin composition. More preferred. When the content is small, there is a possibility that sufficient hardness cannot be imparted to the hard coat layer. Further, if the content is large, the hardness of the hard coat layer is excessively increased, and the content of the acrylic polymer is relatively decreased, which may reduce the workability of the translucent hard coat laminate. .

(4) Hydroxyphenyl triazine compound The hydroxyphenyl triazine compound used in the present invention is a compound in which a hydroxyphenyl derivative is bonded to a carbon atom of a triazine derivative. The hydroxyphenyltriazine compound used in the present invention functions as an ultraviolet absorber. The hydroxyphenyltriazine-based compound used in the present invention has a high ultraviolet absorbing ability, and has durability, heat resistance, and alkali yellowing resistance. Since the hydroxyphenyltriazine-based compound used in the present invention has a high ultraviolet ray absorbing ability, it can sufficiently cut off ultraviolet rays even in the use of a thin film of about 10 μm, and high light resistance can be obtained.

  Examples of the hydroxyphenyltriazine compound used in the present invention include compounds represented by the following chemical formulas (A) to (E) and isomers thereof. These are preferred compounds, but are not limited thereto.

  As the hydroxyphenyltriazine compound used in the present invention, a commercially available product can be used. Hydroxyphenyltriazine compounds are commercially available, for example, under the trade names Tinuvin 400, Tinuvin 405, Tinuvin 479, Tinuvin 477, Tinuvin 460, etc. (above, manufactured by BASF).

  As the hydroxyphenyltriazine-based compound used in the present invention, among others, the compound represented by the chemical formula (C), and the commercially available product is the above-mentioned trade name Tinuvin 479. From the point that light resistance can be obtained with a relatively small amount of addition. The compound represented by the chemical formula (C) is preferable from the viewpoint that the effect of improving the light resistance is high by a combination with a hindered amine light stabilizer described later and an antioxidant.

  The hydroxyphenyltriazine compound used in the present invention is used so as to contain 1.9 parts by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the silica particles. By setting it as such content, the hard-coat laminated body which has the outstanding light resistance can be obtained, suppressing the cloudiness and the fall of surface hardness. Especially, it is preferable to contain 3.5 mass parts or more of the hydroxyphenyl triazine type compound used for this invention with respect to 100 mass parts of said silica particles from the point of light resistance. On the other hand, from the viewpoint of haze and hardness, the hydroxyphenyltriazine-based compound is preferably contained in 10.0 parts by mass or less with respect to 100 parts by mass of the silica particles.

(5) Solvent The solvent is not particularly limited, but a non-permeable solvent is preferable from the viewpoint of increasing the hardness of the translucent hard coat laminate. Here, the penetration refers to dissolving or swelling a permeable substrate described later.
Specific examples of the non-permeable solvent include methyl isobutyl ketone, propylene glycol monomethyl ether, normal propanol, isopropanol, normal butanol, sec-butanol, isobutanol, and tert-butanol.
In the present invention, it is preferable to use methyl isobutyl ketone from the viewpoint of suppressing cloudiness.

  In the photocurable resin composition for a hard coat layer used in the present invention, the content of the solvent may be appropriately adjusted depending on the coating method, and is not particularly limited.

(6) Polymerization initiator In this invention, it is preferable that the photocurable resin composition contains the polymerization initiator.
The polymerization initiator is decomposed by at least one of light and heat to generate radicals or cations to advance radical polymerization and cationic polymerization.
As the polymerization initiator, radical polymerization initiators, cationic polymerization initiators, radicals and cationic polymerization initiators can be appropriately selected and used.

  The radical polymerization initiator only needs to be capable of releasing a substance that initiates radical polymerization by at least one of light and heat. For example, examples of the photo radical polymerization initiator include imidazole derivatives, bisimidazole derivatives, N-aryl glycine derivatives, organic azide compounds, titanocenes, aluminate complexes, organic peroxides, N-alkoxypyridinium salts, thioxanthone derivatives, and the like. It is done. Specific examples include those described in JP 2010-102123 A and JP 2010-120182 A.

Moreover, the cationic polymerization initiator should just be able to discharge | release the substance which starts cationic polymerization by at least any one of light and a heat | fever. Examples of the cationic polymerization initiator include sulfonic acid ester, imide sulfonate, dialkyl-4-hydroxysulfonium salt, arylsulfonic acid-p-nitrobenzyl ester, silanol-aluminum complex, (η ⁶ -benzene) (η ⁵ -cyclopentadidiene). Enil) iron (II) and the like. Specific examples include those described in JP 2010-102123 A and JP 2010-120182 A.

  Examples of radical polymerization initiators and cationic polymerization initiators that can be used include aromatic iodonium salts, aromatic sulfonium salts, aromatic diazonium salts, aromatic phosphonium salts, triazine compounds, and iron arene complexes. Specific examples include those described in JP 2010-102123 A and JP 2010-120182 A.

  Among them, the polymerization initiator preferably has a relatively low absorption rate in the visible light region. This is because if the absorptance in the visible light region is high, the light transmittance of the light transmissive hard coat laminate may be lowered.

  The content of the polymerization initiator is preferably in the range of 2% by mass to 5% by mass with respect to the total solid content of the photocurable resin composition, preferably in the range of 2% by mass to 2.5% by mass. More preferably. If the content is small, the polymerization reaction of monomers or the like does not proceed sufficiently, and there is a possibility that sufficient hardness cannot be imparted to the hard coat layer. Moreover, when there is much content, polymerization reaction, such as a monomer, advances rapidly, and there exists a possibility that workability | operativity may fall or it may become a non-uniform hardened | cured material.

(7) Light stabilizer In this invention, it is preferable from the point of the light resistance improvement that the photocurable resin composition contains the light stabilizer further.
Examples of the light stabilizer used in the present invention include UV absorbers, radical scavengers, antioxidants, and the like different from the hydroxyphenyl triazine compounds. Examples of such light stabilizers include hindered amines and salicylic acid. And organic light stabilizers such as benzophenone, benzotriazole, cyanoacrylate, triazine, benzoate, and succinic anilide.
In order to combine with the hydroxyphenyl triazine compound used in the present invention, a hindered amine light stabilizer is particularly preferable. When the hydroxyphenyltriazine compound and the hindered amine light stabilizer are used in combination, the light resistance is further improved.

Examples of hindered amine light stabilizers include bis (2,2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyl) ester, 1,1-dimethylethyl hydroperoxide and octane. Reaction product, bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate, bis Mixture of (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate, dimethyl succinate and 4-hydroxy-2 , 2,6,6-tetramethyl-1-piperidineethanol and N, N ′, N ″, N ′ ″-tetrakis- (4,6-bis- (butyl- (N-methyl) -2,2,6,6-tetramethylpiperidin-4-yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10-diamine, and the like. It is not limited to.
Among these, it is preferable to use a hindered amine light stabilizer having an amino ether group from the viewpoint of improving light resistance.
As these hindered amine light stabilizers, commercially available ones can be used. For example, the product names Tinuvin 123, Tinuvin 144, Tinuvin 292, Tinuvin 4111 FDL, etc. (above, manufactured by BASF) are commercially available.

  When a hindered amine light stabilizer is used in the present invention, it is preferably contained in an amount of 0.5 to 5 parts by mass, more preferably 0.5 to 2 parts by mass with respect to 100 parts by mass of the silica particles.

Further, it is preferable to use a combination of antioxidants from the viewpoint of improving light resistance. As the antioxidant, a hindered phenol-based antioxidant is preferable from the viewpoint of light resistance.
Examples of the hindered phenol antioxidant include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,2′-thiodiethylbis [3- (3 , 5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, and the like. It is not something.
As these hindered phenolic antioxidants, commercially available ones can be used.

  When a hindered phenol-based antioxidant is used in the present invention, it is preferably contained in an amount of 0.5 to 5 parts by mass, and more preferably 0.5 to 2 parts by mass with respect to 100 parts by mass of the silica particles. preferable.

(8) Other components The photocurable resin composition used in the present invention may further contain other components as necessary. Examples of other components include surfactants, blue color materials, other ultraviolet curable resins such as urethane acrylate, antistatic agents, antiglare agents, and various sensitizers. As these other components, for example, those similar to those described in paragraphs 0103 to 0116 of JP2014-102123A can be suitably used.

  In the curable resin composition, silica particles, acrylic polymer, polyfunctional monomer, hydroxyphenyltriazine compound, the solvent, and other components such as a polymerization initiator are mixed in a solvent according to a general preparation method and dispersed. Can be prepared. For mixing and dispersing, a paint shaker or a bead mill can be used.

2. Step of forming a coating film on a translucent substrate This step is a step of forming a coating film by applying the photocurable resin composition for hard coat layer to at least one surface side of the translucent substrate. .
(1) Translucent substrate The translucent substrate used in the present invention is not particularly limited as long as it has optical transparency and satisfies the physical properties that can be used as the substrate of the translucent hard coat laminate. Usually, the light-transmitting substrate used in the light-transmitting hard coat laminate may be colorless or colored, but is required to have light transmittance.
Specifically, the transmissivity of the translucent substrate in the visible light region is preferably 80% or more, and more preferably 90% or more. This is because a light-transmitting hard coat laminate excellent in light transmittance can be obtained when the transmittance is in the above range.
Here, the transmittance as a measure of translucency in the present invention is the total light transmittance measured by the method defined in JIS K-7361.

  The shape of the translucent substrate used in the present invention is not limited to the shape of a roll film, sheet, plate or the like, and may be various molded products. It can select suitably according to the various uses mentioned later.

  Examples of the material for the translucent substrate include acrylate polymers, polycarbonates, polyesters, cellulose acylates, and cycloolefin polymers. Specific examples of the acrylate polymer include methyl poly (meth) acrylate, poly (meth) ethyl acrylate, methyl (meth) acrylate-butyl (meth) acrylate, and the like. Specific examples of the polycarbonate include aromatic polycarbonates based on bisphenols such as bisphenol A, and aliphatic polycarbonates such as diethylene glycol bisallyl carbonate. Specific examples of the polyester include polyethylene terephthalate and polyethylene naphthalate. Specific examples of cellulose acylate include cellulose triacetate, cellulose diacetate, and cellulose acetate butyrate. Specific examples of the cycloolefin polymer include norbornene polymers, monocyclic olefin polymers, cyclic conjugated diene polymers, vinyl alicyclic hydrocarbon polymer resins, and the like.

  The material of the translucent substrate may be appropriately selected depending on the application, and is not particularly limited. For example, in the case of the purpose of protecting the surface of a display device or the like, the material has a high transparency and a color. From the viewpoint of good taste, it is preferable to use at least one of an acrylate polymer and a polycarbonate. Among the acrylate polymers, polymethyl methacrylate is more preferable because of its high transparency.

  The translucent substrate may be a single layer or a laminate of a plurality of layers. In the case of a plurality of layers, the substrate has a plurality of resin layers. The number of resin layers may be two or more, and is preferably in the range of 2 to 5 layers.

When the substrate has three or more resin layers, the two outermost layers are the outermost resin layers, and the layers positioned inside the two outermost resin layers are the inner resin layers.
When the base has three or more resin layers, it is preferable that the pencil hardness of the two outermost resin layers positioned on both sides of the base is higher than the pencil hardness of the inner resin layer. By increasing the hardness of the outermost resin layer, it becomes easier to form a light-transmitting hard coat laminate with high hardness, and by reducing the hardness of the inner resin layer, stress caused by differences in thermal expansion coefficient, etc. is alleviated. This is because the inner resin layer becomes a cushion layer, and impact resistance such as ball drop resistance is improved. The difference in hardness between the outermost resin layer and the inner resin layer is preferably two or more steps, more preferably three or more steps, on the basis of pencil hardness. For example, the pencil hardness of the outermost resin layer is preferably HB or higher, and more preferably H or higher and 5H or lower. The pencil hardness of the inner resin layer is preferably H or less, for example, and more preferably 3B or more and HB or less.

When the substrate has a plurality of resin layers, the pencil hardness of the substrate is preferably 2H or more, and more preferably 3H or more. This is because the hardness of the translucent hard coat laminate can be further improved. The substrate preferably has a high pencil hardness, but it is usually 4H or less.
On the other hand, even when the substrate is a single layer, the pencil hardness of the substrate is preferably 2H or more.
The pencil hardness of the substrate can be measured by a pencil hardness test (4.9 N load) defined in JIS K5600-5-4 (1999).

Further, the substrate may or may not have flexibility.
The thickness of the substrate is not particularly limited.
In the case of a substrate having a shape such as a sheet or a plate that does not have flexibility, it is preferably 0.3 mm or more, and more preferably within a range of 0.3 mm to 5 mm. It is because sufficient impact resistance can be maintained within the above range. On the other hand, in the case of a flexible substrate such as a roll film, sheet, or plate, the thickness of the substrate can be set within a range of 10 μm to 500 μm, for example, although it varies depending on the material and configuration.
When the translucent substrate is a molded body, the molded body can be appropriately obtained by a known suitable molding method.
Further, the translucent substrate may be subjected to surface treatment such as saponification treatment, glow discharge treatment, corona discharge treatment, ultraviolet treatment, flame treatment and the like.

(2) Coating method The coating method of the said curable resin composition will be specifically limited if it can form a coating film by apply | coating the said photocurable resin composition uniformly on a translucent base | substrate. Instead, various methods such as a spin coating method, a dip method, a spray method, a slide coating method, a bar coating method, a roll coater method, a meniscus coater method, a flexographic printing method, a screen printing method, and a pea coater method can be used. What is necessary is just to select suitably according to the shape of a translucent base | substrate.
Moreover, it is preferable to adjust as the coating amount of the said photocurable resin composition on a translucent base | substrate so that the hard-coat layer of a desired film thickness may be obtained.
What is necessary is just to apply | coat to the at least one surface side of a translucent base | substrate, and when apply | coating to a polyhedron like a molded object, you may apply | coat continuously to two or more surfaces.

3. The process of forming the photocurable film for hard coat layers In this coating film, the hard coat layer is removed by removing the solvent in the photocurable resin composition for hard coat layers in the coating film formed as described above. This is a step of forming a photocurable film for use.
Examples of the method for removing the solvent include vacuum drying, heat drying, and combinations thereof. When drying at normal pressure, the substrate is preferably dried in a temperature range where the substrate does not deteriorate, and for example, it is preferably dried within a range of 30 ° C to 110 ° C.
In addition, the solvent in the photocurable resin composition for a hard coat layer is removed from the coating film of the photocurable resin composition for the hard coat layer, and an uncured product before ultraviolet irradiation is used as a light for the hard coat layer. It is called a curable film.

4). Step of forming a hard coat layer In this step, the hard coat layer photocurable film is formed at a temperature of 50 ° C to 50 ° C so that the increase in haze by the hard coat layer photocurable film is 0.5 or less at the start of ultraviolet irradiation. After heating at 110 ° C., the hard coat layer is formed by irradiating and curing the photocurable film for hard coat layer with ultraviolet rays while heating.

(1) Heating before starting ultraviolet irradiation The photocurable film for hard coat layer becomes clouded as it is cooled, and the haze due to the photocurable film for hard coat layer increases. In the present invention, even if the haze increase amount by the photocurable film for hard coat layer is once increased, specifically, the haze increase amount is 0.5% so that the haze increase amount becomes small at the start of ultraviolet irradiation. Heating is performed before the start of ultraviolet irradiation so as to be as follows. For example, the haze increase amount is set to 0.5 or less by heating the photocurable film for hard coat layer, whose haze increase amount is about 10 by cooling, before the start of ultraviolet irradiation.

In addition, in this invention, a haze value can be measured by the method based on JISK-7105, for example, can be measured with the haze meter HM150 by Murakami Color Research Laboratory.
The amount of haze increase by the photocurable film for hard coat layer is the haze value of the translucent substrate and the haze value of the portion where the photocurable film for hard coat layer is formed on the translucent substrate. And the difference between the haze values.
The amount of increase in haze at the start of UV irradiation is the haze value of the portion where the photocurable film for hard coat layer is formed on the translucent substrate in the heated state immediately before UV irradiation, and the heating It can obtain | require by measuring the haze value of the translucent base | substrate of a state.

The heating temperature for heating the photocurable film for hard coat layer so that the increase in haze due to the photocurable film for hard coat layer is 0.5 or less at the start of ultraviolet irradiation, the increase in haze is within the above range. However, it is preferably in a temperature range in which the substrate does not deteriorate, and is heated within a range of 50 ° C to 110 ° C. The heating temperature here can use the film surface temperature of the photocurable film for the hard coat layer as an index, and the film surface temperature can be measured by a non-contact thermometer (for example, a radiation thermometer). it can.
Among them, heating so that the film surface temperature of the photocurable film for hard coat layer at the start of ultraviolet irradiation is 60 ° C. to 80 ° C. reduces the increase in haze without adversely affecting the substrate, and is transparent. From the point that a hard coat layer having high properties can be obtained.

  As the heating means, for example, a hot plate, an oven, an IR heater or the like can be raised. Among these, an oven is preferable from the viewpoint of heating uniformly.

  In addition, after the step of removing the solvent, it is not cooled so that the amount of haze increase by the photocurable film for hard coat layer exceeds 0.5, and UV irradiation is performed while maintaining the heated state after removing the solvent. When it is set so that the process can be started, the heating before the start of the ultraviolet irradiation can be combined with the process of removing the solvent.

(2) Heating during UV irradiation Curing is performed by irradiating with UV while heating the photocurable film for hard coat layer so as to maintain the heating temperature at the start of UV irradiation.
Maintaining the heating temperature at the start of the ultraviolet irradiation does not have to be exactly the same temperature, and is a heating temperature that can maintain a state in which the amount of increase in haze by the photocurable film for hard coat layer is 0.5 or less. It only has to be held. Among these, it is preferable to perform ultraviolet irradiation while maintaining the same temperature as the heating temperature at the start of ultraviolet irradiation.
The heating means is preferably the same as the heating means used in the pre-ultraviolet irradiation heating from the viewpoint that the process can proceed continuously.

The heating temperature at the time of ultraviolet irradiation is preferably a temperature range in which the substrate does not deteriorate, and is set within a range of 50 ° C to 110 ° C.
Among them, the hard coat layer is hard to be cured by irradiating it with ultraviolet rays while being heated at 60 to 80 ° C., without adversely affecting the substrate, and the amount of increase in haze is reduced and the transparency is high. Is preferable from the point that can be obtained.

In addition, ultraviolet rays emitted from light rays such as ultra-high pressure mercury lamp, high pressure mercury lamp, low pressure mercury lamp, carbon arc, xenon arc, metal halide lamp can be used. The amount of irradiation with the energy radiation source of accumulative exposure at an ultraviolet wavelength of 365 nm, is preferably in the range of, for example, ^{50mJ / cm 2 ~5000mJ / cm 2} .

(3) Hard coat layer The hardness of the hard coat layer formed as described above was evaluated by a pencil hardness test (4.9 N load and 9.8 N load) defined by JIS K5600-5-4 (1999). it can. The pencil hardness at a 4.9N load of the hard coat layer is preferably 6H or more, more preferably 7H or more, and particularly preferably 9H or more. Moreover, it is preferable that the pencil hardness of a 9.8N load of a hard-coat layer is 4H or more.

  Further, the hard coat layer formed in the present invention has light transmittance. Specifically, the transmittance in the visible light region of the hard coat layer is preferably 80% or more, more preferably 90% or more, and more preferably 95% or more. This is because when the transmittance is in the above range, a hard coat layer having excellent transparency can be formed.

  Further, the haze value of the hard coat layer is appropriately determined according to the use and is not particularly limited, but is preferably 0.5 or less, particularly 0.4 or less, and particularly preferably 0.3 or less. It is because it can be set as the hard-coat layer excellent in transparency because haze value is the said range.

Further, as the light resistance of the hard coat layer formed in the present invention, the color difference Δb * before and after the test in the following light resistance test is preferably 1.0 or less, and further 0.6 or less. It is preferable.
(Light resistance test)
A sample was put into a xenon arc lamp type weather resistance tester (for example, Suga Test Instruments Co., Ltd. 7.5 kW Super Xenon Weather Meter SX75), xenon lamp, illuminance: 180 W / m ² (300-400 nm), inner filter: quartz, Outer filter: # 275 (borosilicate glass cut at 275 nm or less), optical properties (color tone b *) were evaluated according to JIS Z 8701: 1999 before and after 500 hours, and color difference Δb before and after light resistance test * Is calculated.

The hard coat layer preferably has antifouling properties. The antifouling property can be evaluated by wettability. Specifically, the wettability of the hard coat layer surface is appropriately determined according to the components used in the curable resin composition, and is not particularly limited. However, the contact angle of water droplets on the hard coat layer surface is preferably 90 ° or more, more preferably 100 ° or more, and even more preferably 110 ° or more. This is because if the wettability is as described above, the hard coat layer can exhibit good antifouling properties. On the other hand, the contact angle of the water droplet is usually 120 ° or less.
In addition, the contact angle of water droplets is obtained by using a contact angle measuring device CA-Z type manufactured by Kyowa Interface Science Co., Ltd. and dropping the water droplets from a microsyringe and measuring the contact angle with water 30 seconds later. be able to.

Moreover, when the translucent hard-coat laminated body of this invention is used for a touchscreen etc., it is preferable that a hard-coat layer has slipperiness. The slipperiness can be evaluated by a dynamic friction coefficient. The smaller the dynamic friction coefficient, the better the slipperiness. The coefficient of dynamic friction on the surface of the hard coat layer is, for example, 0.300 or less, preferably 0.200 or less, and more preferably 0.100 or less. This is because if the dynamic friction coefficient is too large, it may be difficult to perform a good touch operation on the surface of the hard coat layer.
The dynamic friction coefficient can be measured by a method based on JIS K7125. For example, a dynamic friction tester HEIDON Type HHS2000 manufactured by Shinto Kagaku Co., Ltd. is used, a stainless hard ball having a diameter of 10 mm, a load of 200 g, and a speed. The dynamic friction coefficient can be measured at 5 mm / sec.

The thickness of the hard coat layer is not particularly limited as long as desired hardness and workability can be exhibited, and can be, for example, about 5 μm to 40 μm, and in particular within the range of 10 μm to 30 μm. In particular, it is preferably in the range of 16 μm to 26 μm.
This is because if the hard coat layer is thin, sufficient hardness cannot be exhibited, and if it is thick, cracks and warpage may occur.

5. Translucent hard coat laminate The translucent hard coat laminate obtained by the production method of the present invention may or may not have flexibility.
The use of the translucent hard coat laminate obtained by the production method of the present invention is not particularly limited. For example, it is used for a contact image display device such as a touch panel, a liquid crystal display, a CRT display, a projection display, a plasma display, Non-contact image display device applications such as electroluminescence displays, solar cell applications such as dye-sensitized solar cells, and the like. Especially, it is preferable that the translucent hard coat laminated body of this invention is used as a front plate of a touch panel. This is because the front plate of the touch panel is a member in direct contact with a finger and high hardness is required.

  Moreover, since the translucent hard coat laminated body obtained by the manufacturing method of this invention has the outstanding light resistance, transparency, and high hardness, it is useful as various transparent members. Examples include plastic automobile windows, resin windows for buildings, road sound insulation walls, large-area transparent members such as arcades, transparent plastic parts such as goggles, shields for helmets, instruments such as instrument panels, and plastic houses. .

  Further, the haze value of the translucent hard coat laminate is appropriately determined according to the use and is not particularly limited, but is 0.8 or less, particularly 0.6 or less, particularly 0.5 or less. It is preferable. It is because it can be set as the translucent hard-coat laminated body excellent in transparency because haze value is the said range.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[Example 1]
(Preparation)
As a translucent substrate, a laminate in which polymethyl methacrylate (PMMA) and polycarbonate (PC) were laminated was prepared. The laminate had an overall thickness of 0.25 mm, a PMMA thickness of 70 μm, and a haze value of 0.2.
Reactive deformed silica having an average secondary particle size of 100 nm to 300 nm in which 3 to 10 silica particles having an average primary particle size of 55 nm are bonded by an inorganic chemical bond and having an ethylenically unsaturated bond as a reactive functional group. Using the particles, a dispersion of a solid content concentration of 40.0% by mass and a methyl isobutyl ketone (MIBK) solvent was prepared.

Pentaerythritol triacrylate (PETA) was prepared as a polyfunctional monomer. As a polymerization initiator, Irgacure 184 manufactured by Ciba Japan Co., Ltd. was prepared.
As an acrylic polymer, BL-2002 of Starlight PMC Co., Ltd., an acrylic polymer having a mass average molecular weight of 70,000 and an acrylic equivalent of 265 was used. The composition of BL-2002 manufactured by Seiko PMC Co., Ltd. is 30-40 parts by mass of acrylic resin, 60-70 parts by mass of methyl ethyl ketone, less than 1 part by mass of acetic acid, 2,6-di-tert-butyl-4-cresol. Less than 1 part by mass.
Tinuvin 479 (manufactured by BASF) was prepared as a hydroxyphenyltriazine compound. Methyl isobutyl ketone (MIBK) was prepared as a solvent.

(Preparation of photocurable resin composition)
A photocurable resin composition for a hard coat layer was prepared with the following composition.
<Composition of photocurable resin composition for hard coat layer>
Reactive irregularly shaped silica particle dispersion: 65.0 parts by mass (solid content concentration 40% by mass)
-Polyfunctional monomer: 19.0 parts by mass-Acrylic polymer: 11.0 parts by mass-Polymerization initiator: 1.0 part by mass-Hydroxyphenyltriazine-based compound: 0.5 parts by mass-Solvent: 4.0 parts by mass

(Formation of hard coat layer)
A photocurable resin composition for a hard coat layer is applied to the PMMA side of the laminate (haze 0.2) used as a translucent substrate by spin coating, and dried in an oven at a temperature of 80 ° C. for 8 minutes. The solvent in the coating film was removed, and a photocurable film for a hard coat layer was formed. The haze of the photocurable film for hard coat layer cooled to around room temperature was 1.1. When the photocurable film for hard coat layer was heated so that the film surface temperature of the photocurable film for hard coat layer was 80 ° C., the haze of the photocurable film for hard coat layer was 0.2. It was. Thus, the ultraviolet ray was irradiated, heating the hard-coat layer photocurable film at 80 degreeC in the state which the haze increase amount by the said photocurable film for hard-coat layers was set to 0 at the time of the ultraviolet irradiation start. A hard coat layer with a film thickness of 20 μm is formed by irradiating ultraviolet light with a central wavelength of 365 nm so that the integrated light quantity is 3000 mJ / cm ² to cure the photocurable film for the hard coat layer. A coated laminate was obtained.

[Examples 2 to 4]
In the composition of the photocurable resin composition for hard coat layer of Example 1, the light for hard coat layer of Example 1 was changed except that 0.5 part by mass of the hydroxyphenyltriazine compound was changed to the addition amount shown in Table 1. A hard coat layer having a thickness of 20 μm was formed in the same manner as in Example 1 in the same manner as the composition of the curable resin composition to obtain a translucent hard coat laminate.

[Example 5]
In addition to the composition of the photocurable resin composition for hard coat layer of Example 1, Tinuvin 123 (manufactured by BASF) as a hindered amine light stabilizer and Irganox 1035 (manufactured by BASF) as a hindered phenol antioxidant Prepared.
(Preparation of photocurable resin composition)
A photocurable resin composition for a hard coat layer was prepared with the following composition.
<Composition of photocurable resin composition for hard coat layer>
Reactive irregularly shaped silica particle dispersion: 65.0 parts by mass (solid content concentration 40% by mass)
Polyfunctional monomer: 19.0 parts by mass Acrylic polymer: 11.0 parts by mass Polymerization initiator: 1.0 part by mass Tinuvin 479: 0.5 parts by mass Tinuvin 123: 0.5 parts by mass Irga Knox 1035: 0.5 parts by mass Solvent: 2.5 parts by mass

[Comparative Example 1]
In the same manner as in Example 1, the photocurable resin composition for hard coat layer was applied by spin coating on the PMMA side of the laminate used as a substrate, and dried in an oven at a temperature of 80 ° C. for 8 minutes. The solvent in the coating film was removed to form a photocurable film for a hard coat layer. The haze of the photocurable film for hard coat layer cooled to around room temperature was 1.1. The film thickness is obtained by curing the photocurable film for the hard coat layer by irradiating with ultraviolet light having a central wavelength of 365 nm so that the integrated light quantity is 3000 mJ / cm ² without heating at room temperature (23 ° C.). A 20 μm hard coat layer was formed to obtain a translucent hard coat laminate.

[Comparative Example 2]
In the same manner as in Example 1 except that the hydroxyphenyltriazine-based compound is not added, the photocurable resin composition for a hard coat layer is applied to the PMMA side of the laminate used as a substrate by a spin coating method. It dried for 8 minutes in oven with a temperature of 80 degreeC, the solvent in a coating film was removed, and the photocurable film for hard-coat layers was formed. The haze of the photocurable film for hard coat layer cooled to around room temperature was 0.2. The film thickness is obtained by curing the photocurable film for the hard coat layer by irradiating with ultraviolet light having a central wavelength of 365 nm so that the integrated light quantity is 3000 mJ / cm ² without heating at room temperature (23 ° C.). A 20 μm hard coat layer was formed to obtain a translucent hard coat laminate.

[Comparative Example 3]
A photocurable resin composition for a hard coat layer was applied by spin coating to the PMMA side of the laminate used as a substrate in the same manner as in Example 1 except that no reactive deformed silica particle dispersion was added. Then, it was dried in an oven at a temperature of 80 ° C. for 8 minutes to remove the solvent in the coating film, and a photocurable film for a hard coat layer was formed. The haze of the photocurable film for hard coat layer cooled to around room temperature was 0.2. The film thickness is obtained by curing the photocurable film for the hard coat layer by irradiating with ultraviolet light having a central wavelength of 365 nm so that the integrated light quantity is 3000 mJ / cm ² without heating at room temperature (23 ° C.). A 20 μm hard coat layer was formed to obtain a translucent hard coat laminate.

[Comparative Example 4]
Hydroxyphenyltriazine-based compound (Tinuvin 479) was converted into benzotriazole-based UV absorber Tinuvin 900 (2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol). The photocurable resin composition for the hard coat layer was spin-coated on the PMMA side of the laminate (haze 0.2) used as the translucent substrate in the same manner as in Example 1 except that It was applied and dried in an oven at a temperature of 80 ° C. for 8 minutes, the solvent in the coating film was removed, and a photocurable film for a hard coat layer was formed. The haze of the photocurable film for hard coat layer cooled to around room temperature was 1.1. When the photocurable film for hard coat layer was heated so that the film surface temperature of the photocurable film for hard coat layer was 80 ° C., the haze of the photocurable film for hard coat layer was 0.2. It was. Thus, the ultraviolet ray was irradiated, heating the hard-coat layer photocurable film at 80 degreeC in the state which the haze increase amount by the said photocurable film for hard-coat layers was set to 0 at the time of the ultraviolet irradiation start. A hard coat layer with a film thickness of 20 μm is formed by irradiating ultraviolet light with a central wavelength of 365 nm so that the integrated light quantity is 3000 mJ / cm ² to cure the photocurable film for the hard coat layer. A coated laminate was obtained.

[Evaluation]
(Light resistance)
A sample was put into a xenon arc lamp type weather resistance tester (Suga Test Instruments Co., Ltd. 7.5 kW Super Xenon Weather Meter SX75) for evaluation. The conditions are inner filter: quartz, outer filter: # 275 (cut borosilicate glass 275 nm or less), xenon lamp, illuminance: 180 W / m ² (300-400 nm) before and after 500 hours optical characteristics (color b *) ) Was evaluated.
The tint b * was measured with an ultraviolet-visible near-infrared spectrophotometer V-7100 manufactured by JASCO Corporation according to JIS Z 8701: 1999.
Table 1 shows the color difference Δb * before and after the light resistance test.

(Haze)
Each haze value was measured with a haze / transmittance meter HM150 manufactured by Murakami Color Research Laboratory in accordance with JIS K-7105.
The haze of the photocurable film for hard coat layer upon cooling after removing the solvent from the coating film is the haze value of the portion where the photocurable film for hard coat layer is formed on the translucent substrate, and the translucent property The haze value of the substrate was measured, and the difference between the haze values was obtained.
The amount of increase in haze at the start of UV irradiation is the haze value of the portion where the photocurable film for hard coat layer is formed on the translucent substrate in the heated state immediately before UV irradiation, and the heating Then, the haze value of the translucent substrate in the wet state was measured, and the difference was determined by the difference in the haze value. In Comparative Example 1 in which heating was not performed immediately before ultraviolet irradiation, the haze value of the portion where the photocurable film for hard coat layer was formed on the transparent substrate immediately before ultraviolet irradiation and the haze of the transparent substrate. The difference was obtained from the value.
Table 1 shows the results of the haze increase amount of the photocurable film at the start of ultraviolet irradiation and the haze value of the translucent hard coat laminate.

(Transmittance)
The total light transmittance was measured by a haze / transmittance meter HM150 manufactured by Murakami Color Research Laboratory in accordance with JIS K-7361.

(Pencil hardness)
After adjusting the measurement samples of the translucent hard coat laminates of Examples and Comparative Examples for 2 hours under conditions of a temperature of 25 ° C. and a relative humidity of 60%, using a test pencil specified by JIS-S-6006, A pencil hardness test (9.8 N load) specified in JIS K5600-5-4 (1999) was performed on the surface of the hard coat layer, and the highest pencil hardness without damage was evaluated. The results are shown in Table 1.

(Adhesion)
As the adhesion evaluation test, the following cross-cut tape test was performed.
First, 11 cuts reaching the substrate are made on the surface of the hard coat layer using a cutter knife and a cutter guide to make 100 grids. The interval between the cuts is 1 mm.
Cellotape (registered trademark) (manufactured by Nichiban Co., Ltd.) is strongly pressure-bonded to the cross section, and the end of the tape is peeled off at an angle of 45 °, and the state of the cross section is observed. And

(appearance)
The sample was visually observed and judged.

(Summary of results)
A photocurable film for a hard coat layer is formed using a photocurable resin composition for a hardcoat layer containing a specific amount of a hydroxyphenyltriazine-based compound, and the amount of haze increase due to the photocurable film for a hardcoat layer is increased. After heating the photocurable film for hard coat layer so that it becomes 0.5 or less at the start of ultraviolet irradiation, the photocurable film for hard coat layer is irradiated with ultraviolet rays while heating the photocurable film for hard coat layer so as to maintain the heating temperature. In Examples 1 to 5 in which a hard coat layer was formed by curing, a translucent hard coat laminate having excellent light resistance, transparency, and high hardness could be produced.
In Example 5 in which a hindered amine-based light stabilizer and a hindered phenol-based antioxidant were further added to the photocurable resin composition for hard coat layer of Example 1, light resistance superior to that of Example 1 was obtained. A translucent hard coat laminate having the following characteristics was able to be produced.
On the other hand, a photocurable film for hard coat layer was formed using the same photocurable resin composition for hard coat layer as in Example, and the haze of the photocurable film for hard coat layer cooled to near room temperature increased. Thereafter, in Comparative Example 1 in which the hard coat layer was formed by curing by irradiation with ultraviolet rays without heating, the translucent hard coat laminate was low in transparency while haze was increased. In Comparative Example 1, the pencil hardness was as low as H. It is presumed that the surface hardness was lowered because the silica was localized and the resin between the silica was reduced, and it became easy to be damaged due to insufficient fixation.
Further, in Comparative Example 2 in which a photocurable film for hard coat layer was formed using a photocurable resin composition for hard coat layer that did not contain a hydroxyphenyltriazine-based compound compared to Example 1, it was cooled to around room temperature. The haze of the photocurable film for hard coat layer did not increase. However, in Comparative Example 2 in which no hydroxyphenyltriazine compound was used, a light-transmitting hard coat laminate having low light resistance was obtained.
Moreover, the comparative example 3 which formed the photocurable film for hard-coat layers using the photocurable resin composition for hard-coat layers which does not contain a silica particle compared with Example 1 is the hard-coat cooled to room temperature vicinity. The haze of the photocurable film for layers did not increase. However, in Comparative Example 3 containing no silica particles, a translucent hard coat laminate having low hardness was obtained.
Moreover, the comparison which formed the photocurable film for hard-coat layers using the photocurable resin composition for hard-coat layers containing the benzotriazole type ultraviolet absorber different from the hydroxyphenyl triazine type compound compared with Example 1 In Example 4, the haze of the photocurable film for hard coat layer cooled to near room temperature was increased, and after heating the photocurable film for hard coat layer as in Example 1, the heating temperature was maintained. The hard coat layer was formed by curing the photo-curable film for hard coat layer by irradiation with ultraviolet rays while heating. However, in Comparative Example 4 using a benzotriazole ultraviolet absorber, a light-transmitting hard coat laminate having a low hardness was obtained. The hydroxyphenyltriazine-based compound Tinuvin 479 has a strong absorption in the 330 nm region and does not inhibit the hard coat layer. Thus, a high surface hardness was obtained, whereas a benzotriazole-based ultraviolet absorber. The tinuvin 900 has an absorption spectrum having a strong absorption in the 360 nm region, which inhibits the hardening of the hard coat layer, and it is considered that the surface hardness could not be obtained.

DESCRIPTION OF SYMBOLS 1 Translucent base | substrate 2, 2 'Coating film 3, 3' Photocurable film for hard-coat layers 4 Solvent removal 5 Heating 6 Ultraviolet irradiation 10 Hard-coat layer 100 Translucent hard-coat laminated body

Claims (1)

A silica particle, an acrylic polymer, a polyfunctional monomer having two or more ultraviolet curable groups in one molecule, a hydroxyphenyl triazine compound, and a solvent, wherein the hydroxyphenyl triazine compound is 100 parts by mass of the silica particles. Preparing a photocurable resin composition for a hard coat layer containing 1.9 to 20.0 parts by mass with respect to
A step of forming a coating film by applying the photocurable resin composition for a hard coat layer to at least one surface side of a translucent substrate;
In the coating film, by removing the solvent in the photocurable resin composition for the hard coat layer, a step of forming a photocurable film for the hard coat layer, and
After heating the photocurable film for hard coat layer at 50 ° C. to 110 ° C. so that the increase in haze due to the photocurable film for hard coat layer is 0.5 or less at the start of ultraviolet irradiation, the heating temperature is maintained. Thus, the manufacturing method of the translucent hard coat laminated body which has the process of forming a hard-coat layer by irradiating and hardening | curing the said photocurable film | membrane for hard-coat layers by ultraviolet irradiation.