JP7456093B2 - Organic glass with hard coat layer and method for producing organic glass molded product with hard coat layer - Google Patents

Description

The present invention relates to organic glass with a hard coat layer, which is formed by laminating a hard coat layer on organic glass, and a method for manufacturing an organic glass molded article with a hard coat layer using the same. More specifically, the present invention relates to organic glass with a hard coat layer that is particularly suitable for heat bending processing, and a method for manufacturing an organic glass molded article with a hard coat layer that involves heat bending processing.

In order to impart scratch resistance to the surface of organic glass, a hard coat layer is formed on the surface. In addition to scratch resistance, in particular, when the above-mentioned organic glass is a highly transparent base material such as a polycarbonate plate, in order to take advantage of the high transparency of the base material itself, transparent organic glass molded products with a hard coat layer are also required. sexuality is required.

For example, Patent Document 1 listed below discloses a structure in which a primer layer and a hard coat layer are laminated on a polycarbonate plate by extruding the polycarbonate plate and transferring it using a thermal transfer film. There is.

The problem that Patent Document 1 aims to solve is to reduce the occurrence of cracks on the surface of organic glass with a hard coat layer when it is heated and bent, that is, on the hard coat layer. Crack resistance is imparted by incorporating particles into the primer layer. Addition of particles to the primer layer is also useful for preventing blocking between the primer layer and other layers during the manufacturing process and maintaining good manufacturing efficiency.

Here, when bending the organic glass with a hard coat layer by heating it at a high temperature exceeding 160°C, the mapping ratio of the molded product after the bending process is determined at the material stage, that is, when the organic glass with a hard coat layer is bent. A problem has been that the imaging ratio may be lower than that of glass.

Furthermore, the above-mentioned problem related to the reduction in image contrast due to heat processing at high temperatures may occur, for example, when it is necessary to form a shape with a large curvature (small bending radius), or when it is necessary to shorten the pressing time. This was particularly likely to occur when processing at a high temperature of about 160° C. or higher was required.

The inventors of the present invention have conducted extensive research and have found that the particles (antiblocking agent) contained in the primer layer are one of the causes of the decrease in image contrast. However, as mentioned above, in order to maintain good quality stability and productivity of the organic glass with a hard coat layer, addition of particles to the primer layer is an essential requirement.

Japanese Patent Application Publication No. 2005-178035

The present invention is capable of maintaining high transparency even after bending, which involves heating at high temperatures, while enjoying the effect of improving productivity due to the particles present in the primer layer during manufacturing. The purpose of the present invention is to provide an organic glass with a hard coat layer that is suitable for processing purposes.

As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention found that, as an example, by transferring the thermal transfer film forming the hard coat layer while applying sufficiently high pressure, the By using such an organic glass with a hard coat layer, it was discovered that the decrease in image contrast during heating at high temperatures can be reduced compared to the organic glass with a hard coat layer. The inventors have discovered that the above problems can be solved, and have completed the present invention.

(1) An organic glass with a hard coat layer for bending, in which a hard coat layer is laminated on the surface of an organic glass substrate via a heat seal layer and a primer layer, and the primer layer contains particulates. An organic glass with a hard coat layer, which contains an anti-blocking agent, and has a difference of 10% or less in the image mapping ratio (%) before and after the heating test described below, as measured by the image mapping method described below.
(Method for measuring imaging ratio)
Using a mapping ratio measuring device compliant with JIS K7374:2007, the hard coat layer of organic glass with a hard coat layer was placed on a sample stand with the hard coat layer facing the light source, and the measurement was performed at a reflection angle of 60° and a comb width of 2 mm.
(Heating test)
It is heated by placing it in a hot air oven with a stable atmosphere temperature of 165° C. for 5 minutes.

(2) The organic glass with a hard coat layer according to (1), in which the image ratio after the heating test is 90% or more.

(3) The hard coat layer according to (1) or (2), wherein the particle size of at least some of the particles of the inorganic filler contained in the primer layer exceeds the thickness of the primer layer. organic glass.

(4) A heating step of heating the organic glass with a hard coat layer according to any one of (1) to (3) at a predetermined heating temperature, and a bending step of bending the organic glass with a hard coat layer after the heating. A method for manufacturing an organic glass molded article with a hard coat layer, comprising: heating the organic glass with a hard coat layer at a heating temperature such that the surface temperature of the organic glass substrate is 160° C. or higher; A method for producing an organic glass molded product with a hard coat layer by heating.

While enjoying the productivity improvement effect of the particles present in the primer layer during manufacturing, it is possible to maintain high transparency even in molded products after bending that involves heating at high temperatures, making it especially suitable for bending applications. It is possible to provide an organic glass with a hard coat layer.

1 is a schematic diagram showing an example of a manufacturing method for manufacturing an organic glass with a hard coat layer according to the present invention. FIG. 1 is a schematic cross-sectional view showing the layer structure of the organic glass with a hard coat layer of the present invention. FIG. 1 is a schematic cross-sectional view showing the layer structure of an organic glass molded article with a hard coat layer that can be obtained by heating and bending the organic glass with a hard coat layer of the present invention.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and may be implemented with appropriate modifications within the scope of the purpose of the present invention. can.

<Organic glass molded product with hard coat layer>
The organic glass molded article 100 with a hard coat layer (see FIG. 3) according to the present invention has a hard coat layer 12b formed on the surface of the organic glass substrate 11 (see FIG. 2). ) is a molded product made by bending.

This hard coat layer-equipped organic glass molded article 100 is manufactured by the "hard coat layer-equipped organic glass molded article 100" of the present invention, which includes a heating process of heating the hard coat layer-equipped organic glass 10 and a bending process of the heated organic glass layer-equipped organic glass 10. It can be manufactured by the method for manufacturing an organic glass molded article with a coat layer. The details of this "method for producing an organic glass molded article with a hard coat layer" will be described in detail following the description of the organic glass 10 with a hard coat layer used therein.

<Organic glass with hard coat layer>
The organic glass with a hard coat layer 10 is a laminate in which a hard coat layer 12b is formed on at least one surface of an organic glass substrate 11. By using this organic glass 10 with a hard coat layer as a material base and subjecting it to a manufacturing method involving heating and bending, an organic glass molded article 100 with a hard coat layer can be obtained.

[Basic configuration and effects]
In the hard coat layer-equipped organic glass 10, the hard coat layer 12b is bonded to the organic glass substrate 11 via two adhesive layers (see FIG. 2). The two adhesive layers are a heat seal layer 12d formed on the surface of the organic glass substrate 11, and a primer layer 12c formed between the heat seal layer 12d and the hard coat layer 12b.

In the hard coat layer-equipped organic glass 10 having the layer structure described above, the primer layer 12c contains a particulate antiblocking agent. In the primer layer 12c, the particle size (secondary particle size after aggregation) of the particulate antiblocking agent contained in the same layer is larger than the thickness of the primer layer 12c itself, at least in part thereof. Due to the existence of the portion where the hard coat layer is attached, blocking of the primer layer 12c during the manufacturing process of the hard coat layer-equipped organic glass 10 can be sufficiently avoided. In the organic glass with a hard coat layer of the present invention, the secondary particle size of at least some of the inorganic fillers contained as an antiblocking agent in the primer layer 12c exceeds the thickness of the primer layer 12c. This method is particularly effective in cases where the productivity at the material manufacturing stage and the quality stability of the final product can both be maintained at a high level.

Moreover, the organic glass molded article 100 with a hard coat layer not only has excellent productivity in the manufacturing stage by being provided with a primer layer containing an anti-blocking agent as described above, but also has high resistance to bending at high temperatures. It is also a base material for organic glass molded products with extremely good processing suitability. In order to ensure suitability for bending at high temperatures, the organic glass 10 with a hard coat layer has a reduction in image clarity after a predetermined high-temperature heat treatment, which is suppressed to an extremely small variation range.

In order to ensure the suitability for the above-mentioned bending process at high temperatures, the hard coat layer-equipped organic glass 10 was specifically tested to determine the difference in the mapping ratio before and after the heating test described below using the mapping ratio measurement method described below. It is said to be kept at 10% or less, preferably 5% or less.
(Method for measuring imaging ratio)
Using a mapping ratio measuring device compliant with JIS K7374:2007, the hard coat layer of organic glass with a hard coat layer was placed on a sample stand with the hard coat layer facing the light source, and the measurement was performed at a reflection angle of 60° and a comb width of 2 mm.
(Heating test)
It is heated by placing it in a hot air oven with a stable atmosphere temperature of 165° C. for 5 minutes.

Many conventional organic glasses with a hard coat layer, in which the primer layer 12c contains an antiblocking agent, have a large difference in image contrast of more than 10% in the molded product stage after bending, which involves heating to about 160°C. There were many cases where it decreased.

On the other hand, in the organic glass 10 with a hard coat layer of the present invention, the image mapping ratio does not decrease by more than 10% even when heated to about 160°C, so the antiblocking agent is included in the primer layer 12c. While enjoying the above-mentioned benefits, an excellent image mapping ratio can be maintained even at the stage of the molded product after bending.

It is preferable that the hard coat layer-equipped organic glass 10 has a hard-coat layer-equipped organic glass 10 with a small decrease in image resolution after heating, and the image image ratio after the above heating test is preferably 90% or more, and more preferably 95% or more. .

The organic glass 10 with a hard coat layer, the basic structure and effects of which have been explained above, is manufactured by a method of thermally transferring the "transfer sheet 12 with a hard coat layer", which will be explained in detail below, onto the surface of the organic glass substrate 11. can do.

[Organic glass substrate]
Regarding the organic glass substrate 11 constituting the organic glass with hard coat layer 10, various organic glasses can be appropriately selected depending on the desired molded product. However, as described above, the hard coat layer-equipped organic glass 10 is characterized by a small decrease in image mapping after bending processing that involves heating at high temperatures. From the viewpoint of taking advantage of this excellent feature, it is preferable to use an organic glass plate having excellent transparency as the organic glass substrate 11. Specifically, an organic glass plate made of polycarbonate resin, ABS resin, acrylic resin, or the like can be cited as a specific example of a preferable organic glass plate.

The thickness of the organic glass substrate 11 plate made of polycarbonate resin or the like is not particularly limited. However, this thickness is preferably 1 mm or more and 20 mm or less, and more preferably 1.5 mm or more and 15 mm or less.

(Hard coat layer)
The hard coat layer 12b is a layer that has the function of imparting scratch resistance to the surfaces of the hard coat layer-equipped organic glass 10 and the hard coat layer-equipped organic glass molded product 100.

The hard coat layer 12b is a layer made of a cured product of a curable resin composition. The main resin of the curable resin composition forming the hard coat layer 12b is not particularly limited. However, for example, polyester resin, epoxy resin, polyurethane resin, aminoalkyd resin, melamine resin, guanamine resin, urea resin, thermosetting acrylic resin, ionizing radiation curable resin, etc. are preferred resins for forming the hard coat layer 12b. This can be mentioned as a specific example. From the viewpoint of imparting higher levels of weather resistance and scratch resistance, among the above, it is preferable that the resin forming the hard coat layer 12b be an ionizing radiation curable resin.

The ionizing radiation curable resin is a curable resin that is cured by irradiation with ionizing radiation, and examples of ionizing radiation include electromagnetic waves or charged particle beams that have energy quantum capable of polymerizing or crosslinking molecules, such as: In addition to ultraviolet light (UV) or electron beams (EB), electromagnetic waves such as X-rays and γ-rays, and charged particle beams such as α-rays and ion beams are also used.

The ionizing radiation-curable resin that can be used for the hard coat layer 12b can be appropriately selected from polymerizable oligomers (prepolymers) and polymerizable polymers that have been conventionally used as resins that have ionizing radiation-curable properties. From the viewpoint of obtaining good curing properties, it is difficult to bleed out, has coating properties even when the solid content is about 95 to 100%, and causes curing shrinkage when curing to form the hard coat layer 12b. Preferably something that is difficult.

The thickness of the hard coat layer 12b is not particularly limited. However, the thickness is usually about 1 μm or more and 20 μm or less. The thickness of the hard coat layer 12b is preferably 2 μm or more and 20 μm or less, and 2 μm or more, from the viewpoint of obtaining excellent weather resistance and its sustainability, and from the viewpoint of maintaining the transparency of the hard coat layer-equipped organic glass 10. More preferably, it is 10 μm or less.

The uncured resin layer formed by applying the above-mentioned resin composition is cured by heat treatment or by irradiation with ionizing radiation such as an electron beam, to form the hard coat layer 12b. When an electron beam is used as the ionizing radiation, the acceleration voltage can be appropriately selected depending on the resin used and the thickness of the layer, but it is usually preferable to cure the uncured resin layer with an acceleration voltage of 70 kV or more and 300 kV or less and an exposure dose of about 5 Mrad or more and 10 Mrad or less.

(Primer layer)
The primer layer 12c is disposed between the hard coat layer 12b and the heat seal layer 12d in the hard coat layer-provided organic glass 10, and functions as a stress relaxation layer for the hard coat layer 12b in the hard coat layer-provided organic glass 10 and the hard coat layer-provided organic glass molded product 100, and has the function of improving the adhesion of the hard coat layer 12b to the organic glass substrate 11.

The primer layer of the transfer sheet 12 with a hard coat layer, that is, the primer layer 12c of the organic glass 10 with a hard coat layer, is formed using a composition for forming a primer layer containing a binder resin. The binder resin contained in the composition for forming a primer layer is not particularly limited, but preferably contains a two-part curable resin consisting of a main resin and a curing agent.

As the above-mentioned main material used to form the primer layer 12c, for example, polyurethane resin, (meth)acrylic resin, vinyl chloride/vinyl acetate copolymer, polyester resin, petitral resin, chlorinated polypropylene, chlorinated polyethylene, etc. can be used. I can do it. These binder resins may be used alone or in combination of two or more. Among these binder resins, polyurethane resins are preferably used from the viewpoint of adhesiveness and weather resistance.

Examples of the curing agent that accelerates the curing of each of the above main ingredients used in forming the primer layer 12c include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, cyclohexanephenylene diisocyanate, naphthalene-1,5-diisocyanate, and the like. Isocyanate curing agents and the like can be used.

The thickness of the primer layer 12c is not particularly limited, but is preferably, for example, 0.1 μm or more and 5 μm or less, more preferably 1 μm or more and 4 μm or less.

The primer layer 12c having such a thickness contains a particulate antiblocking agent. This antiblocking agent can be appropriately selected from known antiblocking agents made of inorganic particles and the like that have been conventionally used in various resin laminate molded products.

As described above, the particle size of at least some of the particles of the inorganic filler, which is an anti-blocking agent, contained in the primer layer 12c of the organic glass 10 with a hard coat layer depends on the thickness of the primer layer. The present invention is particularly effective when the Here, the above-mentioned "particle size of the antiblocking agent (particles)" refers to the particle size of the secondary particles after the aggregation when the primary particles are aggregated within the primer layer 12c.

Inorganic particles such as silica, alumina, aluminum hydroxide, barium sulfate, talc, and calcium carbonate can be preferably used as particulate antiblocking agents to be included in the primer layer 12c of organic glass with a hard coat layer. This can be mentioned as a specific example. These inorganic particles can not only sufficiently suppress the occurrence of blocking phenomena during the manufacturing stage, but also have high transparency, so they can be used to form organic glass with hard coat layer 10 and organic glass with hard coat layer 10. It is easy to maintain a high level of transparency.

From the viewpoint of suppressing blocking while maintaining transparency, the average particle size of the antiblocking agent is preferably about 0.1 to 10 μm. It is preferable that at least a part of the particles, preferably more than half of all the particles, actually exceed the thickness of the primer layer described above (preferably 0.1 μm or more and 5 μm or less). Incidentally, the particle size of the antiblocking agent can be measured using a laser diffraction type particle size distribution analyzer.

Further, the content of the antiblocking agent is preferably 0.1 parts by mass or more and 30 parts by mass or less, more preferably 3 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the above binder resin. preferable.

In addition, the primer layer 12c may contain various additives other than those mentioned above, as necessary, within a range that does not impair the effects of the present invention. Examples of such additives include ultraviolet absorbers, light stabilizers, wear resistance improvers, infrared absorbers, antistatic agents, adhesion improvers, leveling agents, thixotropic agents, coupling agents, and plasticizers. agent, antifoaming agent, filler, solvent, coloring agent, etc. These additives can be appropriately selected from commonly used additives.

(heat seal layer)
The heat seal layer 12d is a layer provided to bond the hard coat layer 12b to the organic glass substrate 11 in order to form the hard coat layer 12b on the surface of the transfer body. It has a function of adhering to the base 11.

Resins with thermal fusibility that can be used for the heat-sealing layer 12d are determined depending on the material of the organic glass substrate 11 and the transfer temperature and pressure during thermal transfer, but generally acrylic resins, Resins such as vinyl chloride-vinyl acetate copolymer, polyamide resin, polyester resin, chlorinated polypropylene, chlorinated rubber, urethane resin, epoxy resin, and styrene resin are preferable, depending on the material of the organic glass substrate 11 and the use of the transfer product. One or more resins are selected from among the above resins. Among the above-mentioned resins, it is particularly preferable to use an acrylic resin alone, since it has a small refractive index difference with the particles contained in the primer layer 12c and has excellent transparency, and improves transparency and weather resistance.

Like the hard coat layer 12b and primer layer 12c, the heat seal layer 12d can also contain a weather resistance improving agent such as an ultraviolet absorber or a light stabilizer in order to further improve weather resistance. As the ultraviolet absorber and light stabilizer that can be used, various resins and additives similar to those described in the primer layer 12c can be used as appropriate.

The thickness of the heat seal layer 12d is preferably 1 μm or more and 7 μm or less, and 1 μm or more and 6 μm or less, from the viewpoint of adhering the hard coat layer 12b to the organic glass substrate 11 and ensuring excellent transparency. It is more preferable that it is below.

[Transfer sheet with hard coat layer]
There is no particular limitation on the method of laminating and integrating the laminate including the hard coat layer 12b, primer layer 12c, and heat seal layer 12d described above on the surface of the organic glass substrate 11, but transfer sheets with hard coat layers may be used. It is preferable to use

In the hard coat layer-equipped transfer sheet, for example, each resin layer that will constitute the hard coat layer, primer layer, and heat seal layer of the hard coat layer-equipped organic glass 10 is placed on a base film such as a polyester film. This is a laminate of materials that are laminated in this order.

When producing organic glass 10 with a hard coat layer using a transfer sheet with a hard coat layer, the transfer sheet 12 with a hard coat layer is laminated with the heat seal layer facing the surface of the organic glass substrate 11 and bonded under heat and pressure. By doing so, the transfer sheet 12 with a hard coat layer is transferred onto the surface of the organic glass substrate 11. Through this transfer process, a heat seal layer 12d, a primer layer 12c, and a hard coat layer 12b are laminated in this order on the surface of the organic glass substrate 11 (see FIG. 2). can be obtained.

The material of the base film constituting the hard coat layer-equipped transfer sheet 12 is not particularly limited. However, the material of the base film is preferably a polyester resin film or a polyolefin resin film. Moreover, among the above films, a stretched film is more preferable. When the base film is one of these resin films, the hard coat layer can be easily formed. Note that this base film is not an essential component of the hard coat layer-equipped organic glass 10, and is usually peeled off after the above thermal transfer is completed.

Examples of polyester resin films that can be preferably used as the above-mentioned base film include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, polyarylate, polycarbonate, and ethylene terephthalate-isophthalate copolymer. Various resin films can be mentioned.

<Method for manufacturing organic glass with hard coat layer>
Hereinafter, a manufacturing method for manufacturing the organic glass 10 with a hard coat layer will be described. In the following, embodiments of this manufacturing method will be described, taking as an example the step of forming hard coat layers on both sides of the organic glass substrate 11. However, the method for manufacturing the organic glass 10 with a hard coat layer of the present invention is not limited to the manufacturing method described below.

As shown in FIG. 1, the method for producing organic glass with a hard coat layer includes (a) a step of obtaining an organic glass substrate 11 by extrusion molding, and (c) a step of transferring the hard coat layer onto the organic glass substrate 11. This is a manufacturing method in which at least the following two steps are performed. Further, as necessary, before performing the above step (c), a step (b) of heating the organic glass substrate 11 may be further performed.

Note that the manufacturing method for manufacturing the hard coat layer-equipped organic glass 10 of the present invention is not limited to the in-line continuous process as shown in FIG. 1, but may be a manufacturing method in which each process is performed independently off-line. Each step of (a), (b), and (c) will be explained below.

[(a) Step of obtaining organic glass substrate by extrusion molding]
Extrusion molding can be performed by a conventionally known method. For example, the material resin (polycarbonate resin) of the organic glass substrate 11 (polycarbonate plate) is heated and melted, extruded from the die of the extruder 20, rolled with a cooling roll, passed through a guide roll, and taken up with a take-up roll. The organic glass substrate 11 (polycarbonate plate) can be obtained by cooling and solidifying.

[(b) Step of heating the organic glass substrate]
Next, the extruded organic glass substrate 11 is heated using heaters 30a and 30b. Although heating is performed from both sides in FIG. 1(b), heating may be performed from one side of the organic glass substrate 11. Note that, as described above, this step is not necessarily an essential step in manufacturing the hard coat layer-equipped organic glass 10 of the present invention.

[(c) Step of transferring the hard coat layer onto the organic glass substrate]
In order to transfer the laminate including the hard coat layer 12b, primer layer 12c, and heat seal layer 12d (hereinafter also referred to as "transfer layer") to the organic glass substrate 11, as shown in FIG. The transfer sheet 12 with a hard coat layer was unwound from the rolls of paper feed rolls 41a and 41b, and the surface of the organic glass substrate 11 such as a polycarbonate plate was made to face the heat seal layer 12d of the transfer sheet 12 with a hard coat layer. In this state, the base film 12a is bonded by heating and pressurizing with the nip rolls 42a and 42b, and then the base film 12a is peeled off. Thereby, the organic glass 10 with a hard coat layer can be obtained.

Although the base film can be peeled off after the subsequent "bending process," it is preferable to peel it off before the bending process for ease of peeling. The method of peeling the base film 12a from the laminate of the transfer sheet 12 with a hard coat layer and the organic glass substrate 11 is not particularly limited, but for example, the base film is peeled off from the laminate of the transfer sheet 12 with a hard coat layer 12 and the organic glass substrate 11 to the discharge rolls 44a and 44b via the peeling rolls 43a and 43b. By winding up the film 12a, the base film 12a can be continuously peeled off from the laminate.

[Pressure and heating conditions]
In the above manufacturing method, the pressure and heating temperature when transferring the hard coat layer are not limited to a specific range, but based on the inventors' accumulated experiments, as an example, the pressure and heating temperature when transferring the hard coat layer were ) It has been confirmed that by omitting the process and significantly increasing the pressure during transfer, it is possible to significantly reduce the decrease in image clarity of the hard coat layer-equipped organic glass 10 "before and after the heating test". . Specific examples of preferred manufacturing conditions are shown in Examples. In any case, the above-mentioned simple heating test is conducted on the prototype obtained through experimental manufacturing, and if it is confirmed that it shows good results in this test, the manufacturing conditions (heating temperature and pressure The effects of the present invention can be enjoyed by manufacturing a product using the above combination.

<Method for producing organic glass molded product with hard coat layer>
Hereinafter, a manufacturing method for manufacturing the organic glass molded product 100 with a hard coat layer will be described. In the following, the organic glass with a hard coat layer 10 obtained by the above-mentioned "method for producing organic glass with a hard coat layer" is used to form an organic glass with a hard coat layer having a shape including a curved surface part and a bent part. An embodiment in which the product 100 is manufactured will be described as a specific example.

[(d) Heating process]
This step is a step of heating the hard coat layer-equipped organic glass 10 obtained in the previous step, prior to the subsequent bending step. This heating can be performed by various conventionally known heating means. For example, partial heating can be performed using a pipe heater or an infrared heater, or whole heating can be performed using an electric furnace.

The heating temperature may be set as long as the surface temperature of the organic glass substrate 11 constituting the hard coat layer-equipped organic glass 10 is equal to or higher than the glass transition temperature (Tg), for example, even when the organic glass substrate 11 is a polycarbonate plate. For example, the temperature is preferably 160°C or higher.

[(e) Bending process]
This step is a step of bending and deforming the heated organic glass 10 with a hard coat layer into a desired shape. The bending method is not particularly limited, but one example is a manufacturing method in which a mold is applied to a portion softened by heating and the shape is created by bending it along the mold.

In this manufacturing method, by using the organic glass 10 with a hard coat layer of the present invention, even when bending is performed after heating at a high temperature of about 160°C as described above, the hard coat layer after bending Decrease in the mapping ratio in the layered organic glass molded product 100 can be sufficiently suppressed.

[1. Creation of transfer sheet with hard coat layer]
A coating film was formed by applying the following "composition for forming a hard coat layer" to a coating thickness of 3 micrometers on a base film (thickness 50 micrometers) made of polyethylene terephthalate, and this coating film was irradiated with an electron beam at 10 Mrad. A hard coat layer having a thickness of 3 μm was formed on the base film.

(Resin composition for forming hard coat layer)
60 parts by mass of polyfunctional urethane acrylate (molecular weight approximately 1,000) 40 parts by mass of polyfunctional caprolactone-modified urethane acrylate (molecular weight approximately several thousand) Hydroxyphenyltriazine ultraviolet absorber: 0.7 parts by mass Hindered amine light stabilizer: 4.2 parts by weight Non-reactive silicone compound: 0.3 parts by weight Scratch-resistant inorganic particles: 2 parts by weight

Next, the surface of this hard coat layer was subjected to a corona discharge treatment, and the following "resin composition for forming a primer layer" was applied by a gravure reverse method to form a 2 μm thick primer layer.

(Resin composition for forming primer layer)
Polycarbonate-based urethane acrylic copolymer: 100 parts by mass Benzotriazole-based UV absorber: 17 parts by mass Hydroxyphenyltriazine-based UV absorber: 13 parts by mass Light stabilizer: 8 parts by mass Particles (silica particles, average particle size: 3 μm) : 9 parts by mass Curing agent (hexamethylene diisocyanate): 25 parts by mass

Thereafter, a heat-sealing resin (acrylic resin) was applied on the formed primer layer by a gravure reverse method to form a heat-sealing layer with a thickness of 4 μm.

Through the above steps, a "transfer sheet with hard coat layer" for Examples and Comparative Examples in which a hard coat layer, a primer layer, and a heat seal layer were laminated in this order on a base film was obtained. In each manufacturing and testing described below, the above-mentioned "transfer sheet with hard coat layer" was used in both the manufacturing and testing of Examples and Comparative Examples.

[2. Production of organic glass with hard coat layer]
Using the following organic glass substrate and the above-mentioned "transfer sheet with hard coat layer", "organic glasses with hard coat layer" of Examples and Comparative Examples were manufactured. The "organic glasses with a hard coat layer" in each of the examples and comparative examples were made using the same materials and only the manufacturing conditions were changed. We made different types of glass. The size of the "organic glass with hard coat layer" in both Examples and Comparative Examples was 300 mm x 300 mm. Two pieces of organic glass with a hard coat layer were produced under the same conditions for Examples, and two pieces of organic glass with a hard coat layer were produced under the same conditions for Comparative Examples, and these are shown as Samples 1 and 2 in Table 1, respectively.

(Organic glass substrate)
In both Examples and Comparative Examples, polycarbonate plates of the same type having a size of 300 mm x 300 mm and a thickness of 4.0 mm were used as "organic glass substrates".

(Production method)
Among the steps constituting the above-mentioned "method for producing organic glass with a hard coat layer", the above "organic glass substrate" is introduced into "step of transferring a hard coat layer onto an organic glass substrate" (c). , each "organic glass with hard coat layer" of Examples and Comparative Examples were manufactured.

The "step of heating the organic glass substrate" (b) was carried out under the following conditions in the production of the "organic glass with a hard coat layer" of the comparative example, but the "step of heating the organic glass substrate with a hard coat layer" of the example was carried out under the following conditions. In the production of , the organic glass substrate was put into the above step (c) at room temperature (20 to 25° C.) without performing step (b).

(Manufacturing conditions: heating conditions in step (b))
As shown in Table 1 below, only in the production of the comparative example, a heater was used to heat the organic glass substrate (polycarbonate plate) to a surface temperature of 120° C. immediately before inputting it to step (c).

(Manufacturing conditions: transfer conditions in step (c))
The transfer conditions (heating and pressing conditions using nip rolls) for manufacturing each of the "organic glass with hard coat layer" of Examples and Comparative Examples in the "step of transferring the hard coat layer onto the organic glass substrate" (c) are as follows. The procedure was as shown in Table 2.

[Test Example 1: Measurement of imaging ratio before and after heating test]
The "organic glass with hard coat layer" of each sample of Examples and Comparative Examples was cut into 100 mm x 50 mm, and the following "heating test" was conducted, and the mapping ratio before and after the "heating test" was calculated as follows. Measurement was carried out using the "image rate measurement method". The results were as shown in Table 3.
(Heating test)
It is heated by placing it in a hot air oven with a stable atmosphere temperature of 165° C. for 5 minutes.
(Method for measuring imaging ratio)
Measured using a mapping ratio measuring device "ICM-1T (manufactured by Suga Test Instruments Co., Ltd.)" (based on JIS K7374:2007). The hard coat layer of each "organic glass with hard coat layer" of Examples and Comparative Examples was placed on a sample stand facing the light source, and measurements were taken at a reflection angle of 60° and a comb width of 2 mm. Regarding the measurement after heating, the mapping ratio was measured after each "organic glass with hard coat layer" was naturally cooled to room temperature. The results were as shown in Table 3.

[Test Example 2: Transparency evaluation before and after heating test (visual confirmation)]
Transparency of each sample produced in Test Example 1 was confirmed by the "visual evaluation method" below, and evaluated based on the "evaluation criteria" below. The results were as shown in Table 3.
(Visual evaluation method)
Apply black vinyl tape to the opposite side of the hard coat layer to be evaluated. At that time, use a lami roll to avoid biting the air bubbles. Hold the object at a height below eye level with the surface of the hard coat layer to be evaluated facing upward, reflect the fluorescent light on the ceiling, and evaluate the clarity of the image based on the evaluation criteria below.
(Evaluation criteria)
A: The entire reflected image has a sense of transparency, and the outline of the fluorescent light is clear.
B: The overall transparency of the reflected image is low, but the outline of the fluorescent light is clear.
C: The entire reflected image has a cloudy appearance, and the outline of the fluorescent light is clear.
D: The entire reflected image has a strong whitish appearance, and blurring occurs on the outline of the fluorescent light.

As shown in Table 3, by adjusting the manufacturing conditions, for example, increasing the pressure during hard coat layer transfer more than usual while maintaining the surface temperature of the organic glass substrate before transfer at room temperature, the image contrast after heating can be improved. It was confirmed that it is possible to reduce the image density, and that high transparency can be maintained by using "organic glass with a hard coat layer" in which the reduction in image clarity after heating is suppressed to a small extent. This shows that the "organic glass with hard coat layer" of the present invention is suitable for bending applications that involve heating at high temperatures.

10 Organic glass with hard coat layer 11 Organic glass substrate 12 Transfer sheet with hard coat layer 12a Base film 12b Hard coat layer 12c Primer layer 12d Heat seal layer 20 Extruder 30a, 30b Heater 41a, 41b Paper feed roll 42a, 42b Nip roll 43a, 43b Peeling roll 44a, 44b Paper discharge roll 100 Organic glass molded product with hard coat layer

Claims (5)

An organic glass with a hard coat layer for bending, in which a hard coat layer is laminated on the surface of an organic glass substrate via a heat seal layer and a primer layer,
The primer layer contains a particulate antiblocking agent,
The average particle size of the antiblocking agent is 0.1 μm or more and 10 μm or less and exceeds the thickness of the primer layer, and the thickness of the primer layer is 0.1 μm or more and 5 μm or less,
An organic glass with a hard coat layer, in which the difference in the image mapping ratio (%) before and after the heating test described below is 10% or less as measured by the image mapping method described below.
(Method for measuring imaging ratio)
Using a mapping ratio measuring device compliant with JIS K7374:2007, the hard coat layer of organic glass with a hard coat layer is placed on a sample stand with the hard coat layer facing the light source, and measurement is performed at a reflection angle of 60° and a comb width of 2 mm.
(Heating test)
It is heated by placing it in a hot air oven with a stable atmosphere temperature of 165° C. for 5 minutes. The organic glass with a hard coat layer according to claim 1, wherein the image mapping ratio after the heating test is 90% or more. The organic glass with a hard coat layer according to claim 1 or 2, wherein the particle size of at least some of the particles of the antiblocking agent contained in the primer layer exceeds the thickness of the primer layer. A method for producing an organic glass with a hard coat layer according to any one of claims 1 to 3 , comprising:
Transferring the hard coat layer to the organic glass substrate using a transfer sheet with a hard coat layer in which the hard coat layer, the primer layer, and the heat seal layer are laminated in this order on the base film. It includes a process,
In the transfer step, the hard coat layer-equipped transfer sheet is placed on the surface of the organic glass substrate whose surface temperature is maintained at 20°C or higher and 25°C or lower while being heated at a temperature of 220°C or higher while applying a surface pressure of 8 MPa or higher. Crimp with
A method for producing organic glass with a hard coat layer. A hard coat layer comprising: a heating step of heating the organic glass with a hard coat layer according to any one of claims 1 to 3 at a predetermined heating temperature; and a bending step of bending the heated organic glass with a hard coat layer. A method for producing an organic glass molded article with a coating layer, the method comprising:
In the heating step, the organic glass with a hard coat layer is heated at a heating temperature such that the surface temperature of the organic glass substrate is 160° C. or higher.

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