JP7671645B2 - Transparent laminated member and face shield using the same - Google Patents

Description

The present invention relates to a transparent laminated member and a face shield using the same.

The novel coronavirus known as COVID-19 is spreading globally, infecting many people. In addition to masks, face shields have been attracting attention as a way to avoid infection. As shown in Figure 1, a face shield is made of a transparent plastic plate with a sponge attached to the edge, and a band is used to hold the sponge part in place against the head. A PET plate is usually used as the transparent plastic plate.

Currently, face shields are inexpensive and can be disposed of after one day of use, but discarding plastic is not good for the environment, so there is a demand for them to be reused. However, face shields made only of PET boards become scratched and white when wiped for repeated use, making them difficult to see. In addition, strict chemical resistance is required because they are wiped with chemicals such as alcohol or sodium hypochlorite, and may be touched when putting on or taking off with hands that have touched these. Furthermore, face shields are required to have anti-fogging properties so that they do not fog up due to exhaled air.

To achieve long-term use of face shields, a film known as a hard coat is formed on a PET plate, and anti-fogging properties can be imparted to the hard coat layer by incorporating a surfactant into the hard coat. However, the surfactant molecules are smaller than the matrix network of the hard coat layer, and the surfactant may bleed out or precipitate on the surface, a phenomenon known as blooming. Therefore, a PET plate with a hard coat that has anti-fogging properties and does not cause surfactant bleed-out or blooming is desired. In addition, if the hard coat layer itself has a certain degree of hydrophilicity, fogging is less likely to occur.

Patent Publication No. 5985100 (Patent Document 1) describes a transparent laminate that has low reflectivity and excellent transparency, visibility, anti-fogging properties, and wipeability, but the low reflectivity is achieved by forming irregularities on the surface. However, the irregularities on the surface are fragile, and scratches can occur when disinfected or rubbed with alcohol.

JP 2010-106282 A (Patent Document 2) discloses a coating composition that has anti-reflection and anti-fogging properties and is made of an inorganic metal oxide and a siloxane polymer. This coating film also does not have sufficient durability against rubbing with alcohol or disinfectants.

Patent No. 5985100 JP 2010-106282 A

The present invention provides a transparent layer member that can impart durability, chemical resistance, and anti-fogging properties to the PET plate used in the face shield. The transparent laminate member of the present invention can also be provided with an anti-reflection layer, enabling the face shield to be used for a long period of time.

（化学式中、Ｒ、Ｒ^１およびＲ^２は、独立して水酸基または－ＯＣＯ－ＣＨ＝ＣＨ_２を表す。）
のいずれか一つを含有することを特徴とする透明積層部材。
［８］上記［３］の透明積層部材であって、その第２層を成す硬化樹脂層に平均粒径３５～７０ｎｍの中空シリカを固形分重量で３５～６５重量％の量で含有することを特徴とする［１］～［７］のいずれかに記載の透明積層部材。
［９］上記［１］～［８］のいずれかに記載の透明積層部材が用いられたフェイスシールド。

That is, the present invention provides the following aspects:
[1] A transparent laminated member having a transparent resin substrate layer and a transparent cured resin layer laminated thereon,
When the total light transmittance of the transparent laminated member is Tt1, the turbidity is Hz1, and the reflectance is R1,
90%<Tt1<98%,
0.01%≦Hz1<2.0%, and 0.5%≦R1<5.0%
and (c) the transparent laminate member does not become cloudy for 3 seconds when distilled water is poured into a glass container having an opening of 5 cm in diameter so that the height of the container surface from the water surface is 5 cm, the temperature is kept at 60° C., and the glass container is covered with a lid so that the cured resin layer side of the transparent laminate member is in contact with water vapor.
The transparent cured resin layer was wiped 100 times with cotton soaked in 6% hypochlorous acid solution under a load of 50 g per unit area. After this, the total light transmittance of the transparent laminate member was Tt2, the turbidity was Hz2, and the reflectance was R2.
0≦|Tt1−Tt2|<1,
0≦|Hz1-Hz2|<2, and 0≦|R1-R2|<0.5
The transparent laminate member satisfies the above relationship, and is characterized in that when distilled water is poured into a glass container having an opening of 5 cm in diameter so that the height of the container surface from the water surface is 5 cm, the temperature is kept at 60°C, and the glass container is covered with a lid so that the cured resin layer side of the transparent laminate member is exposed to water vapor, no fogging occurs for 3 seconds.
[2] The transparent laminate member according to [1] above, which exhibits the same relationship between total light transmittance, turbidity and reflectance even when the 6% hypochlorous acid solution is replaced with a 3% hydrogen peroxide solution, a 70% ethanol solution or an isopropyl alcohol solution.
[3] The transparent cured resin layer comprises two layers,
a first layer laminated on the transparent resin substrate layer has a thickness of 2 to 10 μm and a refractive index of 1.48 to 1.54;
The transparent laminate member according to [1] or [2], wherein the second layer laminated on the first layer has a thickness of 70 to 130 nm and a refractive index of 1.36 to 1.42.
[4] The transparent laminate member according to any one of [1] to [3], wherein the transparent resin substrate is made of a polyester resin and has a thickness of 75 to 250 μm.
[5] The transparent cured resin layer comprises a compound having the chemical formula:
(In the chemical formula, n, m, and o independently represent integers, and n+m+o=12 to 24.)
The transparent laminate member according to any one of [1] to [4], characterized in that it contains an acrylic-modified isocyanurate (I) having the following formula:
[6] The transparent laminate member according to [5], wherein the acrylic-modified isocyanurate (I) is contained in the resin forming the transparent cured resin layer in an amount of 65 to 95% by weight of the resin solid content.
[7] The transparent laminate member according to [5] or [6] above, wherein the cured resin layer contains an unsaturated compound (II) having either a hydroxyl group or an unsaturated double bond group and a difunctional or higher unsaturated double bond group in an amount of 5 to 35% by weight based on the weight of the resin component, and the unsaturated compound (II) is represented by the following chemical formula:

(In the chemical formula, R, ^R1 , and ^R2 independently represent a hydroxyl group or -OCO-CH= _CH2 .)
A transparent laminate member comprising any one of the following:
[8] The transparent laminate member according to [3] above, characterized in that the cured resin layer constituting the second layer contains hollow silica having an average particle size of 35 to 70 nm in an amount of 35 to 65% by solid content weight [1] to [7].
[9] A face shield using the transparent laminate member described in any one of [1] to [8] above.

In the present invention, the transparent laminated member is composed of a transparent resin substrate and a transparent cured resin layer laminated thereon, and the total light transmittance, turbidity, and reflectance of the transparent laminated member are measured by specifying the numerical ranges that each of them satisfies, and the difference between the total light transmittance, turbidity, and reflectance of the transparent laminated member after the transparent cured resin layer is wiped with cotton soaked in a 6% hypochlorous acid solution, a 3% hydrogen peroxide aqueous solution, a 70% ethanol solution, and a 70% IPA solution is specified to be within a specific range. If the transparent laminated member has properties within the above-mentioned specified ranges, the transparent laminated member has transparency, durability, and chemical resistance that can be used for a face shield. Moreover, if the transparent cured resin layer contains a surfactant that imparts anti-fogging properties (hereinafter referred to as an "anti-fogging agent"), the transparent laminated member laminated thereon has anti-fogging properties. If this transparent laminated member is used for a face shield, it can be obtained with satisfactory durability, chemical resistance, and anti-fogging properties.

In order to provide the transparent cured resin layer with an anti-reflection function, it can be made into a two-layer structure, with the layer that comes into contact with the transparent resin substrate as the first layer and the layer that does not come into contact with the transparent resin substrate as the second layer, and the phase difference between the light reflected on the surface of the second layer and the light that passes through the second layer and is reflected on the surface of the first layer can be reversed to cancel each other out, thereby providing an anti-reflection function.

The transparent cured resin layer (or anti-reflective layer) of the present invention, when formed from a crosslinked polymer of isocyanurate of acrylic-modified aliphatic diisocyanate, has a polyethylene glycol chain in itself, and is therefore hydrophilic, and therefore has the function of being less prone to fogging. In addition, the transparent cured resin layer of the present invention has a high ability to retain the anti-fogging agent within the matrix of the transparent cured resin layer (or anti-reflective layer), and does not bleed out or bloom, providing a transparent laminate member that exhibits long-term anti-fogging action and is highly durable.

FIG. 2 is a schematic perspective view of a face shield. FIG. 2 is a schematic cross-sectional view of the transparent laminate member of the present invention having a two-layer structure. FIG. 2 is a schematic cross-sectional view of a transparent laminate member of the present invention having a three-layer structure. FIG. 1 is a diagram showing a five-level evaluation standard for scratch resistance in Examples and Comparative Examples.

The transparent laminate member A of the present invention is of two types: one consisting of two layers, a transparent resin substrate layer 1 and a transparent cured resin layer 2 formed thereon, as shown in FIG. 2, and the other consisting of an anti-reflection layer 3 further formed on the transparent cured resin layer 2, as shown in FIG. 3. The anti-reflection layer 3 is a layer that is provided as needed, but when used as a face shield, for example, it is preferable to provide the anti-reflection layer 3 because a reflected image can cause misalignment of the hand when working with the hands.

In this specification, when a range of numerical values is expressed as "a to b," it means "greater than or equal to a and less than or equal to b," unless otherwise specified. Of course, as will be described later, when expressing a numerical range using ≦ or <, it is treated as the notation generally used in mathematics.

In the transparent laminate member A of the present invention, when the total light transmittance of the transparent laminate member A is Tt1, the turbidity is Hz1, and the reflectance is R1,
90%<Tt1<98%,
0.01%≦Hz1<2.0%, and 0.5%≦R1<5.0%
and the transparent cured resin layer 2 is subjected to a wiping test in which the transparent cured resin layer 2 is wiped 100 times with cotton soaked in 6% sodium hypochlorite solution under a load of 50 g per unit area. After this, the total light transmittance of the transparent laminate member A is Tt2, the turbidity is Hz2, and the reflectance is R2.
0≦|Tt1−Tt2|<2,
0≦|Hz1-Hz2|<2, and 0≦|R1-R2|<0.5
It is necessary to satisfy the relationship:

In this specification, "total light transmittance" refers to the percentage of light transmitted, and "turbidity" refers to an index showing the degree of haze. For the measurement, an NDH4000 manufactured by Nippon Denshoku Industries Co., Ltd. is used, and the light source and method are set to D65 and JIS, and the coating surface is placed on the light receiver side to measure the total light transmittance and parallel light transmittance.
Here, it is calculated by the following equation: diffuse light transmittance=total light transmittance−parallel light transmittance; and turbidity (Hz)=diffuse light transmittance/total light transmittance.

In this specification, "reflectance" refers to the ratio of the reflected light flux from the coating film to the solar radiation incident on the coating film surface, calculated from the spectral reflectance determined in a specified wavelength range. Reflectance is determined in the entire wavelength range (wavelength: 380 nm to 780 nm) in accordance with JIS K 5602. Specifically, reflectance is measured using an SD7000 manufactured by Nippon Denshoku Industries Co., Ltd. under the conditions shown in the examples.

In the present invention, the total light transmittance is expressed as Tt1%, the turbidity is expressed as Hz1%, and the reflectance is expressed as R1%, and the values are 90%<Tt1<98%,
0.01%≦Hz1<2.0%, and 0.5%≦R1<5.0%
The relationship between the above must be satisfied. The higher the total light transmittance, the better the transparency, so a value exceeding 90% is necessary, while the closer to 100%, the better the characteristics, but even if an anti-reflection design is adopted, a design exceeding 98% is not realistic. The lower the turbidity Hz1, the higher the transparency, so it is necessary to be 0.01% or more and less than 2.0%, preferably 0.01 to 1.50%, more preferably 0.01 to 1.00%. The reflectance R1 is preferably not high, and is necessary to be 0.5% or more and less than 5.0%, preferably 0.5 to 3.5%, more preferably 0.5 to 2.5%.

The transparent laminate member A of the present invention further has a total light transmittance of Tt2, a turbidity of Hz2, a contact angle of C2, and a reflectance of R2 after a wiping test in which the transparent cured resin layer 2 is wiped 100 times with cotton soaked in 6% hypochlorous acid solution under a load of 50 g per unit area, where Tt2 is the total light transmittance of the transparent laminate member A, Hz2 is the turbidity, C2 is the contact angle, and R2 is the reflectance.
0%≦|Tt1-Tt2|<1%,
0%≦|Hz1-Hz2|<2%, and 0%≦|R1-R2|<0.5%
It is necessary to satisfy the relationship of. This test is a test for measuring chemical resistance, and can be measured using various chemicals, and a chemical with high usability is selected for testing, but in the present invention, it was determined that sodium hypochlorite is suitable for use as a face shield. A 6% sodium hypochlorite solution is soaked into cotton, and a wiping test is performed 100 times under a load condition of 50 g per unit area to evaluate. When the total light transmittance of the transparent laminated member A after the wiping test with sodium hypochlorite is Tt2, the turbidity is Hz2, and the reflectance is R2, the absolute value of the difference from the value before the wiping test is calculated, and if the value is within the above range, it is determined that the durability and chemical resistance are high.

The absolute value of the difference between the values of total light transmittance Tt before and after the wipe test should be small, and should be higher than 0% and less than 1%, preferably 0-0.6%, and more preferably 0-0.3%. The absolute value of the difference between the values of turbidity Hz before and after the wipe test should be small, and should be higher than 0% and less than 2%, preferably 0-0.8%, and more preferably 0-0.3%. The absolute value of the difference between the values of reflectance R before and after the wipe test should be small, and should be higher than 0% and less than 0.5%, preferably 0-0.4%, and more preferably 0-0.3%.

The transparent laminate member A of the present invention also requires anti-fogging properties. Anti-fogging properties are measured by pouring distilled water into a glass container with an opening of 5 cm in diameter so that the height of the container surface is 5 cm above the water surface, maintaining the temperature at 60°C, and then covering the glass container with a lid so that the transparent cured resin layer 2 side of the transparent laminate member A is in contact with water vapor. The transparent laminate member A of the present invention is required to not fogging for 3 seconds under these conditions. The longer the period during which fogging does not occur, the better the anti-fogging properties, but if no fogging occurs for 3 seconds, it is usually judged to have high rust prevention properties.

In the present invention, it is preferable that the high rust prevention properties described above are maintained even after the wipe test using the above-mentioned 6% hypochlorous acid solution.

In the present invention, the wipe test may be performed by replacing the 6% hypochlorous acid solution with a 70% isopropyl alcohol solution, a 3% aqueous hydrogen peroxide solution, or a 70% ethanol solution. Tests using these solutions must also show relationships between total light transmittance, turbidity, and reflectance within the same ranges as above. Here, the term "solution" refers to all aqueous solutions, and for example, a 3% aqueous hydrogen peroxide solution is an aqueous solution containing 3% by weight of hydrogen peroxide water.

In the present invention, as shown in FIG. 3, an anti-reflection layer 3 may be provided on the transparent cured resin layer 2. The anti-reflection layer 3 is formed by reversing the phase difference between the light reflected on the surface of the second layer and the light reflected on the surface of the first layer after passing through the second layer, so that they cancel each other out, thereby preventing reflection. In short, the anti-reflection function depends on the thickness and refractive index of the transparent cured resin layer 2 (first layer) and the thickness and refractive index of the anti-reflection layer 3 (second layer). In the present invention, the first layer must have a thickness of 2 to 10 μm and a refractive index of 1.48 to 1.54, and the second layer laminated on the first layer must have a thickness of 70 to 130 nm and a refractive index of 1.36 to 1.42.

As described above, the anti-reflection layer 3 is determined by its thickness and refractive index. The refractive index is determined by the resin used, so in order to change the refractive index, a material that changes the refractive index is added without affecting the transparency of the resin layer. In a preferred embodiment of the present invention, the transparent cured resin layer 2 and the anti-reflection layer 3 are formed of the same material, which will be described later, so it is common to blend highly transparent inorganic particles, such as hollow silica with an average particle size of 35 to 70 nm, into the anti-reflection layer 3 to change the refractive index. In the present invention, it is preferable to blend hollow silica with an average particle size of 35 to 70 nm into the anti-reflection layer 3 in an amount of 35 to 65% by weight of solids.

As shown in Figs. 2 and 3, the transparent laminated member of the present invention is composed of a transparent resin substrate 1, a transparent cured resin layer 2, and an anti-reflection layer 3 as required. The transparent resin substrate 1 is generally made of a polyester resin, particularly a so-called PET resin (polyethylene terephthalate resin). Resins other than polyester resins, such as polyolefin resins (e.g., polyethylene resins and polypropylene resins), polyamide resins, etc., may also be used, but polyester resins, particularly PET resins, are preferably used in consideration of transparency and versatility. The transparent resin substrate 1 has a thickness of 75 to 250 μm, preferably 75 to 188 μm, and more preferably 100 to 125 μm. It may be thicker than 250 μm, but if it is too thick, it will not be possible to bend it when used in a face shield that is slightly bent. Conversely, if the thickness is too thin, the strength will be insufficient.

The transparent cured resin layer 2 and anti-reflection layer 3 of the present invention are preferably made of the same material, and resins used in so-called hard coats can be used, but since an anti-fogging agent is added to the resin layer to impart anti-fogging properties, it is preferable to use a polymer material that does not cause bleed-out or blooming, and in the present invention, an isocyanurate of an acrylic-modified aliphatic diisocyanate is used as a monomer to obtain the transparent cured resin layer 2 or the anti-reflection layer 3. Hereinafter, when referring to the transparent cured resin layer, this includes the case where the anti-reflection layer is formed from the same material.

（化学式中、ｎ、ｍおよびｏは独立して整数を表し、ｎ＋ｍ＋ｏ＝１２～２４である。） The chemical formula of the acrylic modified aliphatic diisocyanate isocyanurate can be represented as follows:

(In the chemical formula, n, m, and o independently represent integers, and n+m+o=12 to 24.)

This monomer is formed by reacting one of the isocyanate groups of hexamethylene diisocyanate with ethylene glycol, further capping the end having a hydroxyl group with acrylic acid, and converting the remaining isocyanate group into an isocyanurate. When this monomer is applied to the transparent resin substrate and cured together with a polymerization initiator, particularly a photopolymerization initiator, used in the polymerization of ordinary unsaturated double bonds, a three-dimensionally crosslinked transparent film, particularly a hard coat layer, is formed. This transparent cured resin layer is capable of retaining the antifogging agent described below in the polymer matrix, making it excellent for forming an antifogging material.

In the above chemical formula of acrylic modified isocyanurate (I), n, m, or o means the number of ethylene glycols added, and n+m+o represents an integer of 12 to 24. n+m+o is preferably 16 to 24, and more preferably 18 to 24. If the number of ethylene glycols added is less than 12, it becomes difficult to achieve high anti-fogging properties.

The acrylic modified isocyanurate (I) used in the present invention can be produced by reacting an isocyanurate trimer of hexamethylene diisocyanate with polyethylene glycol mono(meth)acrylate. Polyethylene glycol mono(meth)acrylates come in a variety of molecular weights depending on the number of polyethylene glycol bonds, and various types are commercially available from NOF Corporation under the trademark BLEMMER, so the total number of n, m, and o (n+m+o) of the acrylic modified isocyanurate (I) can be adjusted depending on the type of polyethylene glycol mono(meth)acrylate used.

The transparent cured resin layer of the present invention may be formed by curing only the acrylic modified isocyanurate (I) as a component, but it is preferable that the unsaturated compound (II) having either a hydroxyl group or an unsaturated double bond group and an unsaturated double bond group with two or more functionalities is contained in an amount of 0 to 35% by weight based on the weight of the resin component. This unsaturated compound (II) can be a compound having one hydroxyl group and two or more unsaturated double bond groups, or a compound having three or more unsaturated double bond groups when all are unsaturated double bond groups. A small amount of hydroxyl groups is necessary for the purpose of maintaining hydrophilicity, and unsaturated double bond groups are necessary for crosslinking, so a compound having both, or a compound having three or more functionalities when only unsaturated double bond groups are used. The amount used is 0 to 35% by weight based on the weight of the resin component, but is preferably 5 to 25% by weight, and more preferably 5 to 20% by weight.

（化学式中、Ｒ、Ｒ^１およびＲ^２は、独立して水酸基または－ＯＣＯ－ＣＨ＝ＣＨ_２を表す。）
を有するモノマー化合物（ＩＩ－ａ）～（ＩＩ－ｃ）である。 <Unsaturated compound (II)>
The unsaturated compound (II) has either a hydroxyl group or an unsaturated double bond group, and a bifunctional or higher unsaturated double bond group. Specifically, the unsaturated compound (II) has the following chemical formula:

(In the chemical formula, R, ^R1 , and ^R2 independently represent a hydroxyl group or -OCO-CH= _CH2 .)
The monomer compounds (II-a) to (II-c) have the following formula:

This monomer compound (II-a) is an isocyanurate of ethylene diisocyanate, in which one end of ethylene diisocyanate is completely blocked with acrylic acid, or one of the three OH groups is left as is. Such monomer compounds (II-a) are commercially available and exist as a mixture of those in which R is a hydroxyl group and those in which R is an acrylic end. When this mixture of monomer compounds (II-a) is used, the obtained transparent cured resin layer has appropriate hydrophilicity, durability, chemical resistance, anti-fogging properties, and anti-reflection properties. In the present invention, it is believed that a compound having an isocyanurate ring, such as monomer compound (II-a), is necessary for performance such as durability. Therefore, as an unsaturated compound (II) having either a hydroxyl group or an unsaturated double bond group and an unsaturated double bond group with two or more functionalities, the above-mentioned monomer compound (II-a) is currently the most suitable.

The above monomer compounds (II-b) and (II-c) are also monomers corresponding to the unsaturated compound (II) and are particularly useful. These are polyhydric alcohol compounds in which all alcohol ends are blocked with acrylic acid or one hydroxyl group remains, and R ¹ and R ² represent either a hydroxyl group or -OCO-CH=CH _2. Both monomer compounds (II-b) and (II-c) are commercially available, and both exist as mixtures of those in which R ¹ and R ² are hydroxyl groups and those in which R is an acrylic end. These can also be effectively used.

As described above, the monomer compounds (II-a) to (II-c) used as the unsaturated compound (II) are usually provided as a mixture of two kinds of monomers, and the monomer species include those in which R (including ^R1 and ^R2 ) is a hydroxyl group and those in which R is an acrylic terminal, and the ratio of those in which R is a hydroxyl group is 1 to 50% by weight, preferably 3 to 40% by weight, of the total amount of the monomer compound (II). Those in which R is a hydroxyl group are not necessary, but hydrophilicity tends to be insufficient.

When forming a transparent cured resin layer, it is preferable that the acrylic modified isocyanurate (I) is contained in an amount of 65 to 100% by weight of the solid content weight of all monomers, and the unsaturated compound (II) is contained in an amount of 0 to 35% by weight based on the weight of the resin component in the composition. Preferably, the acrylic modified isocyanurate (I) is 75 to 95% by weight, more preferably 80 to 95% by weight based on the weight of the resin component. The unsaturated compound (II) is blended in an amount obtained by excluding the acrylic modified isocyanurate (I) from 100% by weight. If the acrylic modified isocyanurate (I) is less than 65% by weight based on the weight of the resin component, the anti-fogging properties are insufficient when a cured film is formed. Although the acrylic modified isocyanurate (I) can be used at 100% by weight based on the weight of the resin component, when obtaining better performance such as chemical resistance, it is better to control the performance by including the unsaturated compound (II).

<Photopolymerization initiator>
The combination of the acrylic modified isocyanurate (I) and, if necessary, the unsaturated compound (II) is made UV-curable by combining it with a photopolymerization initiator. The photopolymerization initiator may be any one capable of generating radicals as active species by irradiation with light, and any known radical photopolymerization initiator may be used without any restrictions. Specific examples include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl dimethyl ketal, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone oligomer, 2-hydroxy Acetophenones such as -1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one; oxime esters such as 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime); benzoins such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; Benzophenone, o-benzoyl methyl benzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propenyloxy)ethyl]benzenemethanaminium bromide, (4-benzoylbenzyl)trimethylammonium chloride and other benzophenones; 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4 thioxanthones such as 1-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, and 2-(3-dimethylamino-2-hydroxy)-3,4-dimethyl-9H-thioxanthone-9-one mesochloride; and acylphosphine oxides such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide. In addition, as an auxiliary for the photopolymerization initiator, triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (Michler's ketone), 4,4'-diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, ethyl 4-dimethylaminobenzoate, (n-butoxy)ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, etc. may be used in combination. The above photopolymerization initiators and auxiliary agents can be synthesized by known methods and are also available as commercial products.

The content of the photopolymerization initiator is not particularly limited and may be appropriately adjusted within a range that allows the polymerization reaction (radical polymerization) of the radical polymerizable compound to proceed smoothly. For example, the content is in the range of 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, and more preferably 1 to 10 parts by weight, relative to 100 parts by weight of the polymerizable compound (the acrylic-modified isocyanurate (I) and, if necessary, the unsaturated compound (II)) contained in the composition.

The above-mentioned combination of acrylic modified isocyanurate (I) and, if necessary, unsaturated compound (II) is applied to a substrate together with a solvent, and when irradiated with ultraviolet light, it is cured by ultraviolet light to form a transparent cured resin layer. The thickness is not particularly limited, but can be changed depending on the intended use. In the case of a transparent cured resin layer, the thickness is 2 to 10 μm, preferably 4 to 8 μm, and when used as an anti-reflection layer, the thickness is 70 to 130 nm, preferably 80 to 120 nm.

＜Other＞
The transparent cured resin layer of the present invention may contain an antifogging agent (a surfactant that imparts antifogging properties). When the antifogging agent is contained, the transparent cured resin layer has high antifogging properties. The antifogging agent is usually smaller in molecular weight than the polymer matrix of the transparent cured resin layer, and is prone to the phenomenon of bleed-out and blooming. When the above-mentioned acrylic modified isocyanurate (I) is used, even if the antifogging agent bleeds out or blooms, the base matrix itself has antifogging properties, and the antifogging properties are not lost even after long-term use.

As the anti-fogging agent, anionic, cationic, nonionic, or amphoteric surfactants can be used, for example, sorbitan-based surfactants such as sorbitan monostearate, sorbitan monomyristate, sorbitan monopalmitate, sorbitan monobehenate, and esters of sorbitan and alkylene glycol condensates with fatty acids; glycerin-based surfactants such as glycerin monopalmitate, glycerin monostearate, glycerin monolaurate, diglycerin monopalmitate, glycerin dipalmitate, glycerin distearate, diglycerin monopalmitate/monostearate, triglycerin monostearate, triglycerin distearate, or alkylene oxide adducts thereof; polyethylene glycol monostearate, polyethylene glycol monopalmitate, polyethylene glycol a Examples of suitable surfactants include polyethylene glycol surfactants such as alkylphenyl ether; trimethylolpropane surfactants such as trimethylolpropane monostearate; pentaerythritol surfactants such as pentaerythritol monopalmitate and pentaerythritol monostearate; alkylene oxide adducts of alkylphenols; esters of sorbitan/glycerin condensates and fatty acids, esters of sorbitan/alkylene glycol condensates and fatty acids; sodium diglycerol diolate lauryl sulfate, sodium dodecylbenzenesulfonate, cetyltrimethylammonium chloride, dodecylamine hydrochloride, lauric acid laurylamide ethyl phosphate, triethylcetylammonium iodide, oleylaminodiethylamine hydrochloride, dodecylpyridinium salts, and isomers thereof. The antifogging agent may have a functional group that reacts with a curable monomer or oligomer.

The amount of anti-fog agent added may be, for example, in the range of 0.01 to 20 parts by weight (in some embodiments, 0.1 to 15 parts by weight, or 0.2 to 10 parts by weight) per 100 parts by weight of the photopolymerization initiator and curable monomer (the combination of the acrylic-modified isocyanurate (I) and, if necessary, the unsaturated compound (II)).

The transparent cured resin layer of the present invention may contain additives to complement coating workability. In the present invention, since the layer exhibits not only hydrophilicity but also water absorption, the anti-fogging properties are not impaired even if a silicon-based surface conditioner is included. However, in consideration of bleed-out, etc., it is preferable to select a surface conditioner containing an unsaturated double bond, and it is also preferable to incorporate a small amount of such a surface conditioner. Specifically, by incorporating 0.01 to 0.03 parts by weight of BYK-UV3570 in terms of the resin solid content ratio, it is possible to obtain a cured film that significantly improves coating workability while not affecting the anti-fogging properties or durability.

As described above, the anti-reflection layer (second layer) 3 of the present invention must have a thickness of 70 to 130 nm and a refractive index of 1.36 to 1.42. The anti-reflection layer 3 is formed of the same material as the transparent cured resin layer 2, and contains an anti-fogging agent to impart anti-fogging properties. In this case, the film thickness can be changed during application, but as already mentioned, the refractive index is generally determined by blending highly transparent inorganic particles, such as hollow silica particles with an average particle size of 35 to 70 nm. The average particle size of the hollow silica particles is preferably smaller than the film thickness to be formed, and more preferably 75% or less of the film thickness to be formed. The amount of the compound added to the anti-reflection layer 3 is such that the refractive index decreases and the anti-reflection properties are improved as the amount added increases, but a filling amount of 70% or more is not preferable because it impairs the resin properties.

The transparent laminated member of the present invention may have a two-layer structure as shown in FIG. 2 or a three-layer structure as shown in FIG. 3. However, when the transparent laminated member of the present invention is used as the face shield of FIG. 1, an embodiment in which an anti-reflection layer 3 is provided on the transparent cured resin layer 2 as shown in FIG. 3 is preferable. If the face shield is formed in this embodiment, it can be used repeatedly for a long period of time. In this case, it can be used repeatedly by soaking a cloth in a solvent or chemical and wiping it off, or by removing viruses (sterilizing) with a 6% hypochlorous acid solution or a 3% hydrogen peroxide aqueous solution. It also has a function of maintaining anti-fogging properties for a long period of time, which greatly improves the disadvantages of face shields that are currently discarded after one use. In addition, the anti-reflection layer 3 is highly durable and chemically resistant, so it can be used as a face shield that maintains its anti-reflection function for a long period of time and is easy to handle manually.

The present invention will be described in more detail with reference to examples. The present invention should not be construed as being limited to these examples.

Synthesis Example 1 (24 moles of ethylene glycol unit: using Blenmar PE350)
The following three raw materials are placed in a 3 L separable flask equipped with a stirrer and an air inlet tube.
Isocyanate compound mainly composed of nurate type trimer of hexamethylene diisocyanate [Duranate TPA-100, manufactured by Asahi Kasei Chemicals Corporation, NCO content 23%] 1,369.5 g (NCO 7.5 mol)
2,6-di-tert-butyl-4-methylphenol (hereinafter referred to as "BHT") 2.30 g
Dibutyltin dilaurate (hereinafter referred to as "DBTL") 1.35 g
While stirring at a liquid temperature of 50 to 70° C., 3180 g (7.5 moles) of Blemmer PE-350 was added dropwise. After completion of the dropwise addition, the mixture was stirred at 80° C. for 4 hours, and the reaction was terminated when it was confirmed by IR (infrared absorption) analysis of the reaction product that the isocyanate groups had disappeared, thereby obtaining an isocyanuric ring-containing urethane (meth)acrylate compound (corresponding to the acrylic-modified isocyanurate (I) of the present invention).

Synthesis Example 2 (13 to 14 moles of ethylene glycol unit: using Blenmer PE200)
The following three raw materials are placed in a 3 L separable flask equipped with a stirrer and an air inlet tube.
Isocyanate compound mainly composed of nurate type trimer of hexamethylene diisocyanate [Duranate TPA-100, manufactured by Asahi Kasei Chemicals Corporation, NCO content 23%] 1,369.5 g (NCO 7.5 mol)
・BHT 1.70g
・DBTL 1.03g
While stirring at a liquid temperature of 50 to 70° C., 2025 g (7.5 moles) of Blemmer PE-200 was added dropwise. After the dropwise addition was completed, the mixture was stirred at 80° C. for 4 hours, and the reaction was terminated when it was confirmed by IR (infrared absorption) analysis of the reaction product that the isocyanate groups had disappeared, thereby obtaining an isocyanuric ring-containing urethane (meth)acrylate compound (corresponding to the acrylic-modified isocyanurate (I) of the present invention).

Synthesis Example 3 (6 moles of ethylene glycol unit: Blenmer PE90 used)
The following three raw materials are placed in a 3 L separable flask equipped with a stirrer and an air inlet tube.
Isocyanate compound mainly composed of nurate type trimer of hexamethylene diisocyanate [Duranate TPA-100, manufactured by Asahi Kasei Chemicals Corporation, NCO content 23%] 1,369.5 g (NCO 7.5 mol)
・BHT 1.30g
・DBTL 0.81g
While stirring at a liquid temperature of 50 to 70° C., 1200 g (7.5 moles) of Blemmer PE-90 was added dropwise. After the dropwise addition was completed, the mixture was stirred at 80° C. for 4 hours, and the reaction was terminated when it was confirmed by IR (infrared absorption) analysis of the reaction product that the isocyanate groups had disappeared, thereby obtaining an isocyanuric ring-containing urethane (meth)acrylate compound (not corresponding to the acrylic-modified isocyanurate (I) of the present invention).

Example 1
65 parts by weight of the acrylic modified isocyanurate (I) prepared in Synthesis Example 1, 35 parts by weight of Aronix M-313 (manufactured by Toa Gosei), 4 parts by weight of OMNIRAD 184D as a photopolymerization initiator, and 240 parts by weight of propylene glycol monomethyl ether as a solvent were weighed out and stirred in a container to prepare a hard coat solution 1 with a solid content concentration of about 30%. The hard coat solution 1 was applied to a PET film (125 μm/Toray U-34) using a bar coater #9, and then dried in an oven at 80 ° C. for 1 minute, and then irradiated with 350 mJ with an ultraviolet irradiator (manufactured by Eye Graphics/high pressure mercury lamp), to obtain a hard coat film with a film thickness of 5 μm. Table 1 shows the composition ratio of the resin, the film thickness of the PET film (substrate), the film thickness of the obtained hard coat film, etc. In addition, the product name "Aronix" has been omitted from M-313 in the table, but the chemical formulas of the compounds contained in the M-313 used are listed below.

（上記式中、Ｒは水酸基または－ＯＣＯ－ＣＨ＝ＣＨ_２を表す。）
Ｍ－３１３は、Ｒが水酸基の化合物を３０～４０％含み、Ｒが－ＯＣＯ－ＣＨ＝ＣＨ_２の化合物を６０～７０％含む混合物で提供される。 Chemical formula of M-313

(In the above formula, R represents a hydroxyl group or -OCO-CH= _CH2 .)
M-313 is provided in a mixture containing 30-40% compounds where R is hydroxyl and 60-70% compounds where R is --OCO-- _CH.dbd.CH2 .

（上記式中、Ｒは水酸基または－ＯＣＯ－ＣＨ＝ＣＨ_２を表す。）
Ｍ－３１５は、Ｒが水酸基の化合物を３～１３％含み、Ｒが－ＯＣＯ－ＣＨ＝ＣＨ_２の化合物を８７～９７％含む混合物で提供される。 The types of unsaturated compounds (II) used in other examples and comparative examples are exemplified below.
Chemical formula of M-315

(In the above formula, R represents a hydroxyl group or -OCO-CH= _CH2 .)
M-315 is provided in a mixture containing 3-13% compounds where R is hydroxyl and 87-97% compounds where R is --OCO-- _CH.dbd.CH2 .

（式中、Ｒ^１は水酸基または－ＯＣＯ－ＣＨ＝ＣＨ_２を表す。） Chemical formula of M-402

(In the formula, R ¹ represents a hydroxyl group or -OCO-CH=CH _2. )

（式中、Ｒ^２は水酸基または－ＯＣＯ－ＣＨ＝ＣＨ_２を表す。） Chemical formula of M-305

(In the formula, ^R2 represents a hydroxyl group or -OCO-CH= _CH2 .)

UN3320-HS
Art Resin UN3320-HS (manufactured by Negami Industrial Co., Ltd.)
UN3320-HA
Art Resin UN3320-HA (manufactured by Negami Industrial Co., Ltd.)
M-220
Aronix M-220 (manufactured by Toa Gosei)
M-240
Aronix M-240 (manufactured by Toa Gosei)
M-350
Aronix M-350 (manufactured by Toa Gosei)
M-360
Aronix M-360 (manufactured by Toa Gosei)
M-309
Aronix M-309

The anti-fogging evaluation (3-second fogging evaluation), turbidity (Hz), total light transmittance (Tt), and refractive index and reflectance (R) of the outermost coating layer of the obtained hard coat film were measured by the methods described below, and are listed in Table 3 as initial properties. These correspond to Hz1, Tt1, and R1.

Anti-fogging evaluation (3-second fogging evaluation)
Ion-exchanged water was added to a 10 cm high glass container having an opening with a diameter of 5 mm to a height of 5 cm, and the temperature was maintained at 60° C. while stirring at 100 rpm with a hot magnetic stirrer. The obtained film was covered with a lid so that the hard coat film surface was oriented so as to be placed in the glass container, and 3 seconds after that, the presence or absence of fogging due to steam was observed, and the result was evaluated according to the following criteria.
○: No cloudiness at all.
◯△: Very slight cloudiness is visually observed. △: Slight cloudiness is visually observed.
△×: Cloudiness is visibly observed. ×: Cloudiness is clearly observed.

Measurement of turbidity (Hz) and total light transmittance (Tt) For the measurements, an NDH4000 manufactured by Nippon Denshoku Industries Co., Ltd. was used, and the light source and method were set to D65 and JIS. The hard coat film surface was placed on the light receiver side, and the total light transmittance and parallel light transmittance were measured.
Diffuse light transmittance = Total light transmittance (Tt) - Parallel light transmittance Turbidity (Hz) = Diffuse light transmittance / Total light transmittance
It is calculated as follows.

Refractive index The refractive index at D line 589 nm was measured using an Appe refractometer DR-M2 manufactured by Atago Co., Ltd. The test film was set on the prism surface, and 1-bromonaphthalene was used as the intermediate liquid.

Reflectance evaluation (measurement preparation)
Black ink made by Teikoku Ink Co., Ltd. is applied to the side opposite the hard coat film of the evaluation sample using a bar coater and dried at 80° C. for 30 minutes to provide a 15 μm thick black printed layer.
(Reflectance Measurement)
The reflectance of the evaluation sample was measured from the hard coat film side by the SCI method.
The measurement was performed using SD7000 manufactured by Nippon Denshoku Industries Co., Ltd., with the measurement wavelength region being 380 nm or more and 780 nm or less, and the value at 550 nm was taken as the reflectance.

After durability tests using 6% hypochlorous acid, 3% aqueous hydrogen peroxide solution, 70% ethanol solution, and 70% IPA, the hard coat film obtained in Example 1 was evaluated for the above-mentioned 3-second haze rating, turbidity, total light transmittance, scratch resistance, and reflectance, and the results are shown in Table 3. The durability tests were performed as follows.

Durability evaluation (preparation of disinfectant)
6% hypochlorous acid solution (commercially available),
3% hydrogen peroxide solution (commercial product/oxydol),
70% ethanol solution (ethanol diluted with ion-exchanged water to a concentration of 70%)
70% IPA solution (isopropanol (IPA) diluted with ion-exchanged water to a concentration of 70%)
(Rubbing tester)
Daiei Scientific Precision Machinery Co., Ltd., flat surface abrasion tester PA-300A
(Rubbing test)
Bencotton was placed on the terminal of the abrasion tester so as to have a size of 2 cm square, and 4 ml of disinfectant was soaked into it, and an abrasion test was carried out at a speed of 15 cm/sec. The load was 200 g, and the load per unit area was 50 g.
The Bencotton was replaced every 20 strokes in the abrasion test, and 4 ml of the disinfectant was again soaked in the cotton, and the abrasion test was then repeated. In this manner, a total of 100 strokes in the abrasion test was performed.

(Post-test evaluation)
Scratch resistance: After the test, scratches on the sample were evaluated on a 5-point scale according to the rating scale shown in FIG.
In addition, the antifogging property, reflectance, total light transmittance and turbidity after the rubbing test were measured by the above-mentioned procedures and obtained as Hz2, Tt2 and R2. The differences from the initial properties were calculated and shown in Table 3.

Examples 2 to 9
A hard coat film was obtained in the same manner as in Example 1, except that the acrylic modified isocyanurate (I) and the unsaturated compound (II) shown in Table 1 were used. Thereafter, the above-mentioned evaluations were performed in the same manner as in Example 1, and the results are shown in Table 3.

Example 10
1.80 parts by weight of the acrylic modified isocyanurate (I) prepared in Synthesis Example 1, 0.45 parts by weight of Aronix M-313 (manufactured by Toa Gosei), 0.10 parts by weight of OMNIRAD 184D as a photopolymerization initiator, 13.75 parts by weight of Suluria 4320 (manufactured by JGC Catalysts and Chemicals/solid content concentration 20%) as a refractive index adjuster, and 154 parts by weight of propylene glycol monomethyl ether as a solvent were weighed and stirred in a container to prepare a low-refractive hard coat solution 13 with a solid content concentration of about 3%. The composition of the low-refractive hard coat solution 13 is shown in the column of the second layer of Example 13 in Table 1. At the same time, the refractive index adjuster and the film thickness of the second layer are also shown in Table 1.

Hard coat solution 4 from Example 1 was applied to a PET film (125 μm/Toray U-34) using bar coater #9, then dried in an oven at 80°C for 1 minute, and then irradiated with 200 mJ of ultraviolet light using an ultraviolet irradiator (I-Graphics/high pressure mercury lamp) to obtain hard coat film 4 with a thickness of 5 μm.

The low-refraction hard coat solution 13 was applied onto the hard coat film 4 using a bar coater #4, then dried in an oven at 80°C for 1 minute, and then irradiated with 350 mJ of ultraviolet light using an ultraviolet irradiator (manufactured by Eye Graphics/high-pressure mercury lamp), to obtain a hard coat film 13 in which a low-refraction layer with a thickness of 100 nm was laminated onto a hard coat film with a thickness of 5 μm.

The hard coat film 13 with the obtained low refractive index layer laminated thereon was subjected to various evaluations in the same manner as in Example 1, and the results are shown in Table 3.

Examples 11 to 17
A hard coat film having a low refractive index layer laminated thereon was obtained in the same manner as in Example 10, with the contents shown in Table 1. Each evaluation was carried out in the same manner as in Example 1, and the results are shown in Table 3.

Comparative Examples 1 to 13
A hard coat film was formed in the same manner as in Example 1 using the composition of the first or second layer shown in Table 2. Each evaluation was performed in the same manner as in Example 1, and the results are shown in Table 4.

In Comparative Examples 1 and 2, the amount of acrylic modified isocyanurate (I) used is outside the specified range, and the anti-fogging properties are insufficient. In Comparative Example 3, the amount of polyethylene glycol in the acrylic modified isocyanurate (I) used is insufficient (Synthesis Example 3), so the water absorption is low and the anti-fogging properties are insufficient. In Comparative Examples 4 to 8, an unsaturated compound other than the unsaturated compound (II) is used, and the anti-fogging properties are insufficient. In Comparative Examples 9 to 12, the acrylic modified isocyanurate (I) is not used, and since it does not harden, performance evaluation was not possible. In Comparative Example 13, a combination of a commonly used hard coat layer and an anti-fogging agent, which is not the transparent cured resin layer of the present invention, is used, and the initial properties are satisfactory, but it is not durable for continuous use.

Claims (9)

A transparent laminated member in which a transparent resin substrate layer and a transparent cured resin layer are laminated,
When the total light transmittance of the transparent laminated member is Tt1, the turbidity is Hz1, and the reflectance is R1,
90%<Tt1<98%,
0.01%≦Hz1<2.0%, and 0.5%≦R1<5.0%
and (c) the transparent laminate member does not become cloudy for 3 seconds when distilled water is poured into a glass container having an opening of 5 cm in diameter so that the height of the container surface from the water surface is 5 cm, the temperature is kept at 60° C., and the glass container is covered with a lid so that the cured resin layer side of the transparent laminate member is in contact with water vapor.
The transparent cured resin layer was wiped 100 times with cotton soaked in 6% hypochlorous acid solution under a load of 50 g per unit area. After this, the total light transmittance of the transparent laminate member was Tt2, the turbidity was Hz2, and the reflectance was R2.
0≦|Tt1−Tt2|<1,
0≦|Hz1-Hz2|<2, and 0≦|R1-R2|<0.5
The transparent laminate member satisfies the above relationship, and is characterized in that when distilled water is poured into a glass container having an opening of 5 cm in diameter so that the height of the container surface from the water surface is 5 cm, the temperature is kept at 60°C, and the glass container is covered with a lid so that the cured resin layer side of the transparent laminate member is exposed to water vapor, no fogging occurs for 3 seconds. The transparent laminate member according to claim 1, wherein the relationship between the total light transmittance, turbidity and reflectance is the same even when the 6% hypochlorous acid solution is replaced with a 3% hydrogen peroxide solution, a 70% ethanol solution or an isopropyl alcohol solution. The transparent cured resin layer is composed of two layers,
a first layer laminated on the transparent resin substrate layer has a thickness of 2 to 10 μm and a refractive index of 1.48 to 1.54;
3. The transparent laminate member according to claim 1, wherein the second layer laminated on the first layer has a thickness of 70 to 130 nm and a refractive index of 1.36 to 1.42. The transparent laminate member according to any one of claims 1 to 3, characterized in that the transparent resin substrate is made of a polyester resin and has a thickness of 75 to 250 μm. The transparent cured resin layer is formed of a compound having the chemical formula:
(In the chemical formula, n, m, and o independently represent integers, and n+m+o=12 to 24.)
The transparent laminate member according to any one of claims 1 to 4, characterized in that it contains an acrylic-modified isocyanurate (I) having the formula: The transparent laminate member according to claim 5, wherein the acrylic-modified isocyanurate (I) is contained in the resin forming the transparent cured resin layer in an amount of 65 to 95% by weight of the resin solids. 7. The transparent laminate member according to claim 5 or 6, wherein the cured resin layer contains an unsaturated compound (II) having either a hydroxyl group or an unsaturated double bond group and an unsaturated double bond group having two or more functionalities in an amount of 5 to 35% by weight based on the weight of the resin component, and the unsaturated compound (II) is represented by the following chemical formula:

(In the chemical formula, R, ^R1 , and ^R2 independently represent a hydroxyl group or -OCO-CH= _CH2 .)
A transparent laminate member comprising any one of the following: The transparent laminate member according to claim 3, characterized in that the cured resin layer constituting the second layer contains hollow silica having an average particle size of 35 to 70 nm in an amount of 35 to 65% by solid weight. A face shield using the transparent laminated member according to any one of claims 1 to 8.

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