JP2013154546A - Laminate and protective material provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate controlled in poor appearance caused by thermal decomposition products manufactured during extrusion molding and having excellent transparency.SOLUTION: A laminate includes a first layer and a second layer formed on at least one side of the first layer. The first layer contains a thermoplastic resin (A) having a total light transmittance of ≥90.5%, a haze of ≤0.95% and a yellowness of ≤0.95 as an injection molding piece of a type D13 specified in JIS K 7139. The second layer contains at least one thermoplastic resin (B) selected from methyl methacrylate resins and methyl methacrylate-styrene copolymer resins and a hindered phenolic compound (C) in a mass ratio of 0.001-1.0% with respect to the thermoplastic resin (B). The thickness of the second layer is ≥10 μm and ≤20% of the total thickness of the laminate.

Description

Background of the Invention

FIELD OF THE INVENTION The present invention relates to a laminate, and more particularly to a laminate having excellent transparency in which poor appearance due to a thermal decomposition product during extrusion molding is suppressed, and a protective member provided with the laminate.

Background Art Transparent plates made of resin, including soundproof partitions, carports, signboards, front plates that protect the display parts of liquid crystal display devices for office automation equipment and portable electronic devices, light guide plates for liquid crystal backlight units, and prism sheets Applied to optical sheets. In particular, as electronic devices have become smaller and more portable in recent years, the user has come closer to the liquid crystal panel attached to the electronic device to watch the display. The resin transparent plate is required to have very high appearance quality and transparency. As the resin used for the display unit front plate, acrylic resins such as methacrylic resin and methyl methacrylate-styrene copolymer resin are widely used. The display unit front plate is generally manufactured industrially by forming the above acrylic resin into a film or sheet by a molding method such as T-die extrusion.

  When the acrylic resin is molded into a film or sheet, extrusion molding is usually performed at a molding temperature of 220 to 250 ° C. However, depending on the shape of the flow path of the feed block and T-die, the viscosity of the molten resin may be higher than the flow path design in the above temperature range, which may cause problems such as vent-up and uneven discharge in the width direction. May cause problems. In this case, by performing extrusion molding at a higher molding temperature, for example, in a temperature range of 260 to 270 ° C., it is possible to optimize the viscosity of the molten resin and solve problems such as vent-up and discharge unevenness.

  On the other hand, since the thermal decomposition start temperature of the acrylic resin is 260 to 270 ° C., when the molding temperature is increased, the viscosity of the molten resin can be reduced, but the thermal decomposition of the resin proceeds. Due to the decomposed product generated by the thermal decomposition, the appearance of the surface of the film or sheet obtained by extrusion may be poor. In particular, as described above, a film or sheet used for applications such as a display unit front plate is required to have very high appearance quality and transparency. Become.

  In order to solve the above problems, a method for improving the appearance quality by suppressing thermal decomposition during the extrusion molding of an acrylic resin has been proposed. For example, Japanese Patent Publication No. 7-25971 proposes that thermal decomposition during molding can be suppressed by adding a specific hindered phenol compound and a phosphite compound to a methacrylic resin.

Japanese Patent Publication No. 7-25971

  Although the present inventors can suppress the thermal decomposition of the resin by adding a hindered phenol compound or the like to the acrylic resin, the present inventors have noticed that the resin is colored and the transparency is lowered. And, by providing a layer made of an acrylic resin containing a predetermined amount of a hindered phenol compound on at least one surface of the transparent resin layer having a predetermined transparency, the thickness is set to a predetermined thickness. We obtained knowledge that a film or sheet having excellent transparency can be realized. The present invention is based on this finding.

  Accordingly, an object of the present invention is to provide a laminate in which appearance defects due to thermal decomposition products during extrusion molding are suppressed and excellent in transparency.

  Another object of the present invention is to provide a surface protection member provided with a laminate having excellent transparency as described above.

And the laminate according to the present invention is a laminate comprising a first layer and a second layer provided on at least one surface of the first layer,
When the first layer is an injection-molded piece of type D13 defined by JIS K 7139, the total light transmittance is 90.5% or more, the haze is 0.95% or less, and the yellowness is 0.95 or less. Comprising a thermoplastic resin (A),
The second layer has a mass with respect to at least one thermoplastic resin (B) selected from the group consisting of a methyl methacrylate resin and a methyl methacrylate-styrene copolymer resin, and the thermoplastic resin (B). 0.001 to 1.0% of a hindered phenol compound (C) on a basis,
The thickness of the second layer is 10 μm or more and 20% or less of the total thickness of the laminate.

  According to an embodiment of the present invention, the second layer further comprises 1.0% or less of a phosphite compound (D) on a mass basis with respect to the thermoplastic resin (B). preferable.

  Moreover, according to the embodiment of the present invention, it is preferable that the thermoplastic resin (A) comprises a (meth) acrylic acid ester resin or a copolymer resin thereof.

  According to an embodiment of the present invention, the hindered phenol compound (C) is octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, pentaerythritol-tetrakis [3 -(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and 1,1,3-tris [5-tert-butyl-4-hydroxy-2-methylphenyl] butane It is preferable that it is at least one kind.

  According to an embodiment of the present invention, the phosphite compound (D) is bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, tris (2,4- It is preferably at least one selected from the group consisting of di-t-butylphenyl) phosphite and pentaerythritol-bis (2,4-di-t-butyl) phosphite.

  According to an embodiment of the present invention, it is preferable that the second layer is provided on both surfaces of the first layer.

  According to an embodiment of the present invention, the surface of the laminate is selected from the group consisting of scratch resistance treatment, antireflection treatment, antifouling treatment, antistatic treatment, weather resistance treatment, and antiglare treatment. It is preferable that at least one surface treatment is performed.

  According to another aspect of the present invention, a transparent substrate provided with a laminate and a surface protection member provided with the transparent substrate are also provided.

  The laminate according to the present invention is provided with a layer made of an acrylic resin containing a predetermined amount of a hindered phenol compound on at least one surface of a transparent resin layer having a certain level of transparency, and the thickness is Since it has a predetermined thickness, it is possible to realize a laminated body that is free from poor appearance due to a thermal decomposition product during extrusion molding and that is excellent in transparency. The laminate according to the present invention is used as a transparent substrate for an optical sheet or a surface protection member as a surface protection sheet of a display unit, and can be suitably used particularly for a display unit front plate of a display device.

It is the cross-sectional schematic by one embodiment of the laminated body by this invention. It is the cross-sectional schematic by another embodiment of the laminated body by this invention. It is the cross-sectional schematic by another embodiment of the laminated body by this invention. It is the cross-sectional schematic by another embodiment of the laminated body by this invention.

Detailed description of the invention

<Definition>
In this specification, the “transparent” resin means a total light transmittance of 90.5% or more and a haze of 0.95% or less when it is an injection-molded piece of type D13 defined by JIS K 7139. And a resin having a yellowness of 0.95 or less.

  In this specification, “(meth) acrylic acid” means acrylic acid or methacrylic acid.

<Laminated body>
The laminate according to the present invention will be described with reference to the drawings. 1 to 4 are schematic cross-sectional views showing an embodiment of a laminate according to the present invention. The laminate 1 according to the present invention includes a first layer 11 and a second layer 12 provided on at least one surface of the first layer 11 as essential constituent layers. The second layer 12 may be provided on only one side of the first layer 11 as shown in FIG. 1, or provided on both sides of the first layer 11 as shown in FIG. It may be done. When the second layer 12 is provided only on one surface side of the first layer 11, the thermal decomposition product of the thermoplastic resin (A) is formed on the surface of the first layer 11 where the second layer 12 is not provided. The resulting appearance defect may occur on the surface. As described above, by providing the second layer 12 on both surfaces of the first layer 11, it is possible to obtain a laminate having further excellent transparency.

  Furthermore, as shown in FIGS. 3 and 4, the laminate 1 according to the present invention is a surface between the first layer 11 and the second layer 12 or the surface of the first layer 11 on which the second layer 12 is not provided. An optional third layer 13 may be provided on the side, but from the viewpoint of transparency, the two-layer structure in which the second layer 12 is provided only on one side of the first layer 11 or both sides It is preferable that the three-layer structure is provided. Hereinafter, the layer which comprises the laminated body by this invention is demonstrated.

  The first layer 11 comprises a thermoplastic resin (A). As the thermoplastic resin (A), the total light transmittance is 90.5% or more, the haze is 0.95% or less, and the yellowness is 0 when an injection-molded piece of type D13 defined by JIS K 7139 is used. A highly transparent resin such as .95 or less is used, but a more transparent resin, for example, a total light transmittance of 91.0% or more, a haze of less than 0.90%, and a yellowness of 0.8. It is preferable to use a thermoplastic resin that is less than 90, and further, transparency such that the total light transmittance is 92.0% or more, the haze is less than 0.80%, and the yellowness is less than 0.80. It is preferable to use a high resin.

  The above-described highly transparent thermoplastic resin (A) is not particularly limited, but from the viewpoint of adhesion between the second layer made of the thermoplastic resin (B) described later, A (meth) acrylic ester resin or a copolymer resin thereof can be preferably used. Among (meth) acrylic ester resins or copolymer resins thereof, from the viewpoint of transparency, methyl methacrylate resin, methyl methacrylate-styrene copolymer resin and the like are preferable, and adhesion between layers with the second layer From the viewpoint of balance with transparency, methyl methacrylate-styrene copolymer resin is more preferable.

  The above (meth) acrylic ester resin or copolymer resin thereof can be produced by a known method, and can be produced by a bulk polymerization method or a solution polymerization method. For example, in the solution polymerization method, a monomer composition containing a monomer, a chain transfer agent, and a polymerization initiator is continuously supplied to a complete mixing tank and continuously polymerized at 100 to 180 ° C.

  Examples of the solvent used in this case include hydrocarbon solvents such as toluene, xylene, cyclohexane and methylcyclohexane, ester solvents such as ethyl acetate and methyl isobutyrate, ketone solvents such as acetone and methyl ethyl ketone, tetrahydrofuran and dioxane. And ether solvents such as methanol, and alcohol solvents such as methanol and isopropanol.

  The first layer constituting the laminate may contain other resins as long as the above optical properties are satisfied. Examples of such a resin include highly transparent resins such as polystyrene and polycarbonate.

  The first layer may contain conventionally known additives as long as the above optical properties are satisfied. Examples of such additives include ultraviolet absorbers, anticolorants, antistatic agents, mold release agents, lubricants, dyes, pigments, inorganic fillers, resin fillers, and the like. The method of mixing the additive with the thermoplastic resin (A) is not particularly limited, and examples thereof include a method of compounding the entire amount, a method of dry blending the masterbatch, and a method of dry blending the entire amount.

  The thickness of the first layer 11 is not particularly limited, but is adjusted so that the total thickness is 0.1 to 10.0 mm when a laminated body in which other layers to be described later are laminated. It is preferable. When the thickness of the entire laminate is in the above range, transfer failure and thickness accuracy failure are less likely to occur during roll rolling, and thickness accuracy failure and appearance failure due to cooling unevenness after molding are less likely to occur. A more preferable range of the thickness of the entire laminate is 0.3 to 5.0 mm, and a more preferable range is 0.5 to 3.0 mm.

  The second layer constituting the laminate according to the present invention includes a thermoplastic resin (B) selected from the group consisting of methyl methacrylate resin and methyl methacrylate-styrene copolymer resin, and the thermoplastic resin (B). On the other hand, it contains 0.001 to 1.0% of a hindered phenol compound (C) on a mass basis. Such a methyl methacrylate resin or a methyl methacrylate-styrene copolymer resin to which a predetermined amount of a hindered phenol compound is added has a resin melting temperature of 260 ° C. or higher when the second layer is formed by extrusion molding. However, since the thermal decomposition of the resin is suppressed, it is difficult for the appearance defect due to the thermal decomposition product to occur on the surface of the second layer, and the transparency of the laminate can be maintained. It is preferable that content of the preferable hindered phenol type compound (C) is 0.01 to 1.0% on a mass basis with respect to an above-described thermoplastic resin (B), More preferably, it is 0.01 to 0 0.5%, more preferably 0.05 to 0.3%.

  The second layer is formed to have a thickness of 10 μm or more and 20% or less of the total thickness of the laminate. As described above, when extrusion molding is performed using an acrylic resin containing a hindered phenol-based compound, the resin is yellowed although thermal decomposition of the resin is suppressed. In the present invention, by laminating the second layer having the thickness as described above with the first layer, the entire laminated body is suppressed in appearance defects due to the thermal decomposition product of the resin while maintaining high transparency. be able to. The preferred range of the thickness of the second layer is 10 μm or more and 15% or less of the total thickness of the laminate, and the more preferred range is 20 μm or more and 10% or less of the total thickness of the laminate, most preferably the entire laminate. It is 5% or less of the thickness.

  The methyl methacrylate resin is methyl methacrylate as a monomer, and the methyl methacrylate-styrene copolymer resin is methyl methacrylate and styrene as monomers. The polymerization method can be used.

  Examples of the hindered phenol compound (C) include octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, pentaerythritol-tetrakis [3- (3,5-di-t -Butyl-4-hydroxyphenyl) propionate] or 1,1,3-tris [5-t-butyl-4-hydroxy-2-methylphenyl] butane.

  The second layer constituting the laminate may contain a phosphite compound (D) in addition to the hindered phenol compound (C) described above. Phosphite compounds, when used alone, have little effect of suppressing poor appearance due to resin thermal decomposition products, but when used in combination with hindered phenol compounds, poor appearance due to thermal decomposition products Can be significantly improved.

  As the phosphite compound (D), bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, tris (2,4-di-t-butylphenyl) phosphite, or And pentaerythritol-bis (2,4-di-t-butyl) phosphite.

  Content of a phosphite type compound (D) is 1.0% or less by mass reference | standard with respect to a thermoplastic resin (B), More preferably, it is 0.1-0.5%. If the content of the phosphite compound (D) exceeds 1.0%, the transparency of the laminate may be deteriorated.

  The method for adding the hindered phenolic compound (C) and the phosphite compound (D) to the thermoplastic resin (B) is not particularly limited. For example, the method of compounding the whole amount, the masterbatch is dried. The method of blending, the method of dry blending all, etc. are mentioned.

  In addition, when the hindered phenol compound (C) or phosphite compound (D) in the present invention is added to the second layer, an ultraviolet absorber, a flame retardant, an antistatic agent, etc. are added as necessary. You may use together.

  The laminated body by this invention can be manufactured by laminating | stacking a 1st layer and a 2nd layer by coextrusion molding. The coextrusion molding method is not particularly limited, and a conventionally known method can be used. For example, in the feed block method, a second layer is laminated on at least one surface of the first layer with a feed block, extruded into a sheet shape with a T-die, and then cooled while passing through a forming roll to obtain a desired laminate. Can be obtained. In the multi-manifold system, the second layer is laminated on both sides of the first layer in the multi-manifold die, extruded into a sheet, and then cooled while being clamped by passing through a forming roll to obtain a desired lamination. The body can be formed.

  Although this shaping | molding roll is not specifically limited, The method of pinching and cooling with a some metal roll and the method of pinching and cooling with a metal roll, a nonmetal roll, or a metal belt can be illustrated.

  The laminate according to the present invention may be stretched during extrusion molding or after the laminate is produced. The stretching may be uniaxial stretching that extends only in the longitudinal direction (MD direction) of the laminate, or may be biaxial stretching that extends in the direction perpendicular to the longitudinal direction (TD direction). . A draw ratio can be suitably adjusted with the use which uses a laminated body.

  The laminate according to the present invention may be subjected to surface treatment such as scratch resistance treatment, antireflection treatment, antifouling treatment, antistatic treatment, weather resistance treatment, and antiglare treatment on one side or both sides thereof. The methods of scratch resistance treatment, antireflection treatment, antifouling treatment, antistatic treatment, weather resistance treatment and antiglare treatment are not particularly limited, and conventionally known methods can be used. For example, a method of applying a scratch-resistant coating, a method of applying a reflection reducing coating, a method of depositing a dielectric thin film, a method of applying an antistatic coating, and the like can be mentioned.

  The laminate according to the present invention has no appearance defect due to a thermal decomposition product at the time of extrusion molding, and is excellent in transparency. Therefore, as a transparent substrate for an optical sheet and a surface protection sheet for a display unit It is used as a surface protection member and can be suitably used particularly for a display unit front plate of a display device.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not particularly limited to the following examples.

<Preparation of first layer forming resin>
Five types of resins shown in Table 1 below were prepared. In addition, the total light transmittance, haze, and yellowness of each resin were measured using a color difference meter (COH-400) in accordance with JIS K 7105 after forming an injection molded piece of type D13 described in JIS K 7139 with an injection molding machine. , Nippon Denshoku Industries Co., Ltd .: transmission method).

<Preparation of second layer forming resin>
A mixture obtained by dry blending a hindered phenol compound and / or a phosphite compound with the above resin in accordance with the composition shown in Table 2 below was continuously fed to a twin screw extruder having a shaft diameter of 37 mm with a strand die attached to the tip. It was introduced, extruded at a cylinder temperature of 250 ° C., a screw rotation speed of 100 rpm, and a discharge speed of 10 kg / h, the strand was cooled, and pelletized to obtain a resin.

  As hindered phenol compounds, pentaerythritol-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (AO-60) and octadecyl-3- (3,5- Two kinds of di-t-butyl-4-hydroxyphenyl) propionate (AO-50, both manufactured by ADEKA) were used as phosphite compounds, and bis (2,6-di-t-butyl-4-methylphenyl) ) Two types of pentaerythritol diphosphite (PEP-36) and tris (2,4-di-t-butylphenyl) phosphite (Adeka Stub 2112, both manufactured by ADEKA) were used. Moreover, the numerical value of Table 2 means the addition amount (mass part) with respect to 100 mass parts of resin.

<Production of laminate>
First, the resins A1 to A5 and the resins B1 to B10 obtained as described above were dried for 16 hours or more in a hot air drier set at 80 ° C. before molding, and taken out from the dryer. Introduced into each extruder within hours.

Example 1
Resin lamination using a multilayer extruder having a single screw extruder with a shaft diameter of 32 mm, a single screw extruder with a shaft diameter of 65 mm, a feed block connected to all the extruders, and a T-die connected to the feed block A plate was formed. Resin B1 was continuously introduced into a single screw extruder having a shaft diameter of 32 mm and extruded under conditions of a cylinder temperature of 260 ° C. and a discharge speed of 3 kg / h. Resin A3 was continuously introduced into a single screw extruder having a shaft diameter of 65 mm and extruded at a cylinder temperature of 260 ° C. and a discharge speed of 45 kg / h. The feed block connected to the entire extruder was provided with 2 types and 3 layers of distribution pins, and the temperature was set to 260 ° C., and the (resin B1) layer was introduced and laminated on both sides of the (resin A3) layer. Extruded into a sheet shape with a T-die at a temperature of 270 ° C connected to the tip, cooled while transferring the mirror surface with three mirror-finishing rolls with a spacing of 3.0 mm between each roll, and resin on both sides of the resin A3 A laminate in which B1 was laminated was obtained. At this time, the set temperature of the roll was 80 ° C., 80 ° C., and 90 ° C. in order from the upstream side. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin B1 layer was 100 μm near the center.

Example 2
A laminated body in which the resin B2 was laminated on both surfaces of the resin A3 was obtained in the same manner as in the example 1 except that the resin B2 was used instead of the resin B1 used in the example 1. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin B2 layer was 100 μm near the center.

Example 3
A laminated body in which the resin B3 was laminated on both surfaces of the resin A3 was obtained in the same manner as in the example 1 except that the resin B3 was used instead of the resin B1 used in the example 1. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin B3 layer was 110 μm near the center.

Example 4
A laminate in which the resin B4 was laminated on both surfaces of the resin A3 was obtained in the same manner as in Example 1 except that the resin B4 was used instead of the resin B1 used in Example 1. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin B4 layer was 120 μm near the center.

Example 5
A laminate in which the resin B5 was laminated on both surfaces of the resin A3 was obtained in the same manner as in Example 1 except that the resin B5 was used instead of the resin B1 used in Example 1. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin B5 layer was 110 μm near the center.

Example 6
A laminated body in which the resin B6 was laminated on both surfaces of the resin A3 was obtained in the same manner as in the example 1 except that the resin B6 was used instead of the resin B1 used in the example 1. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin B6 layer was 110 μm near the center.

Example 7
A laminate in which the resin B7 was laminated on both surfaces of the resin A3 was obtained in the same manner as in Example 1 except that the resin B7 was used instead of the resin B1 used in Example 1. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin B7 layer was 90 μm near the center.

Example 8
A laminated body in which the resin B8 was laminated on both surfaces of the resin A3 was obtained in the same manner as in the example 1 except that the resin B8 was used instead of the resin B1 used in the example 1. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin B8 layer was 90 μm near the center.

Example 9
A laminated body in which the resin B9 was laminated on both surfaces of the resin A3 was obtained in the same manner as in the example 1 except that the resin B9 was used instead of the resin B1 used in the example 1. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin B9 layer was 90 μm near the center.

Example 10
Lamination in which resin B2 was laminated on both surfaces of resin A4 in the same manner as in Example 1 except that resin B2 was used instead of resin B1 used in Example 1 and resin A4 was used instead of resin A3 Got the body. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin B2 layer was 100 μm near the center.

Example 11
Resin lamination using a multilayer extruder having a single screw extruder with a shaft diameter of 32 mm, a single screw extruder with a shaft diameter of 65 mm, a feed block connected to all the extruders, and a T-die connected to the feed block A plate was formed. Resin B2 produced in Production Example 2 was continuously introduced into a single-screw extruder having a shaft diameter of 32 mm and extruded under conditions of a cylinder temperature of 260 ° C. and a discharge speed of 12 kg / h. Resin A4 was continuously introduced into a single screw extruder having a shaft diameter of 65 mm and extruded at a cylinder temperature of 260 ° C. and a discharge speed of 33 kg / h. The feed block connected to the entire extruder was provided with two types and three layers of distribution pins, and the temperature was set to 260 ° C., and the (resin B2) layer was introduced and laminated on both sides of the (resin A4) layer. Extruded into a sheet form with a T-die at a temperature of 270 ° C. connected to the tip, cooled while transferring the mirror surface with three mirror-finishing rolls with a gap of 3.0 mm between each roll, and resin on both sides of the resin A4 A laminate in which B2 was laminated was obtained. At this time, the set temperature of the roll was 80 ° C., 80 ° C., and 90 ° C. in order from the upstream side. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin B2 layer was 550 μm near the center.

Example 12
Resin lamination using a multi-layer extrusion apparatus having a single-screw extruder with a shaft diameter of 25 mm, a single-screw extruder with a shaft diameter of 65 mm, a feed block connected to all the extruders, and a T-die connected to the feed block A plate was formed. Resin B2 produced in Production Example 2 was continuously introduced into a single-screw extruder having a shaft diameter of 25 mm and extruded under conditions of a cylinder temperature of 260 ° C. and a discharge speed of 3 kg / h. Resin A4 was continuously introduced into a single screw extruder having a shaft diameter of 65 mm and extruded at a cylinder temperature of 260 ° C. and a discharge speed of 45 kg / h. The feed block connected to the entire extruder was provided with two types and three layers of distribution pins, and the temperature was set to 260 ° C., and the (resin B2) layer was introduced and laminated on both sides of the (resin A4) layer. Extruded into a sheet form with a T-die at a temperature of 270 ° C connected to the tip, cooled while transferring the mirror surface with three mirror-finishing rolls with a gap between each roll of 1.0 mm, and resin on both sides of the resin A4 A laminate in which B2 was laminated was obtained. At this time, the set temperature of the roll was 80 ° C., 80 ° C., and 90 ° C. in order from the upstream side. The thickness of the obtained laminate was 1.0 mm, and the thickness (one side) of the resin B2 layer was 25 μm near the center.

Example 13
Resin lamination using a multilayer extruder having a single screw extruder with a shaft diameter of 32 mm, a single screw extruder with a shaft diameter of 65 mm, a feed block connected to all the extruders, and a T-die connected to the feed block A plate was formed. Resin B1 was continuously introduced into a single screw extruder having a shaft diameter of 32 mm and extruded under conditions of a cylinder temperature of 260 ° C. and a discharge speed of 1.5 kg / h. Resin A3 was continuously introduced into a single screw extruder having a shaft diameter of 65 mm and extruded at a cylinder temperature of 260 ° C. and a discharge speed of 45 kg / h. The feed block connected to the entire extruder was provided with two types and two layers of distribution pins, and the temperature was set at 260 ° C., and the (resin A3) layer was introduced and laminated on one side of the (resin A3) layer. Extruded into a sheet shape with a T-die at a temperature of 270 ° C connected to the tip, cooled while transferring the mirror surface with three mirror-finishing rolls with a spacing of 3.0 mm between each roll, and resin on both sides of the resin A3 A laminate in which B1 was laminated was obtained. At this time, the set temperature of the roll was 80 ° C., 80 ° C., and 90 ° C. in order from the upstream side. The thickness of the obtained laminate was 3.0 mm, and the thickness of the resin B1 layer was 100 μm near the center.

Comparative Example 1
A laminated body in which the resin B1 was laminated on both surfaces of the resin A5 was obtained in the same manner as in Example 1 except that the resin A5 was used instead of the resin A1 used in Example 1. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin B2 layer was 100 μm near the center.

Comparative Example 2
Resin lamination using a multilayer extruder having a single screw extruder with a shaft diameter of 32 mm, a single screw extruder with a shaft diameter of 65 mm, a feed block connected to all the extruders, and a T-die connected to the feed block A plate was formed. Resin B8 was continuously introduced into a single-screw extruder having a shaft diameter of 32 mm and extruded under conditions of a cylinder temperature of 260 ° C. and a discharge speed of 18 kg / h. Resin A3 was continuously introduced into a single screw extruder having a shaft diameter of 65 mm and extruded at a cylinder temperature of 260 ° C. and a discharge speed of 30 kg / h. The feed block connected to the entire extruder was provided with 2 types and 3 layers of distribution pins, and the temperature was set to 260 ° C., and (Resin B8) layers were introduced and laminated on both sides of the (Resin A3) layer. Extruded into a sheet shape with a T-die at a temperature of 270 ° C connected to the tip, cooled while transferring the mirror surface with three mirror-finishing rolls with a spacing of 3.0 mm between each roll, and resin on both sides of the resin A3 A laminate in which B8 was laminated was obtained. At this time, the set temperature of the roll was 80 ° C., 80 ° C., and 90 ° C. in order from the upstream side. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin B1 layer was 700 μm near the center.

Comparative Example 3
Resin lamination using a multi-layer extrusion apparatus having a single-screw extruder with a shaft diameter of 25 mm, a single-screw extruder with a shaft diameter of 65 mm, a feed block connected to all the extruders, and a T-die connected to the feed block A plate was formed. Resin B2 produced in Production Example 1 was continuously introduced into a single-screw extruder having a shaft diameter of 25 mm and extruded under conditions of a cylinder temperature of 260 ° C. and a discharge speed of 1.0 kg / h. Resin A4 was continuously introduced into a single screw extruder having a shaft diameter of 65 mm and extruded at a cylinder temperature of 260 ° C. and a discharge speed of 45 kg / h. The feed block connected to the entire extruder was provided with two types and three layers of distribution pins, and the temperature was set to 260 ° C., and the (resin B2) layer was introduced and laminated on both sides of the (resin A4) layer. Extruded into a sheet form with a T-die at a temperature of 270 ° C connected to the tip, cooled while transferring the mirror surface with three mirror-finishing rolls with a gap between each roll of 1.0 mm, and resin on both sides of the resin A4 A laminate in which B2 was laminated was obtained. At this time, the set temperature of the roll was 80 ° C., 80 ° C., and 90 ° C. in order from the upstream side. The thickness of the obtained laminate was 1.0 mm, and the thickness (one side) of the resin B2 layer was 8 μm near the center.

Comparative Example 4
A laminated body in which the resin B10 was laminated on both surfaces of the resin A3 was obtained in the same manner as in the example 1 except that the resin B10 was used instead of the resin B1 used in the example 1. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin B10 layer was 100 μm near the center.

Comparative Example 5
In Comparative Example 4, a laminate in which the resin A1 was laminated on both surfaces of the resin A3 was obtained in the same manner as in the comparative example 4 except that the resin A1 was used instead of the resin B10. The thickness of the obtained laminate was 3.0 mm, and the thickness (one side) of the resin A1 layer was 100 μm near the center.

Comparative Example 6
A resin plate was formed using a single-layer extruder having a shaft diameter of 65 mm and a T-die. Resin A1 was continuously introduced into a single-screw extruder having a shaft diameter of 65 mm and extruded at a cylinder temperature of 260 ° C. and a discharge speed of 50 kg / h. It was extruded in a sheet form with a T-die having a temperature of 270 ° C. connected to the tip, and cooled while transferring the mirror surface with three mirror finish rolls, to obtain a resin plate made of resin A1. At this time, the temperature of the roll was set to 80 ° C., 80 ° C., and 90 ° C. from the upstream side. The thickness of the obtained resin plate was 3.0 mm.

Comparative Example 7
A resin plate made of the resin A2 was obtained in the same manner as in the comparative example 6 except that the resin A2 was used instead of the resin A1 used in the comparative example 6. The thickness of the obtained resin plate was 3.0 mm.

Comparative Example 8
A resin plate made of the resin A3 was obtained in the same manner as in the comparative example 6 except that the resin A3 was used instead of the resin A1 used in the comparative example 6. The thickness of the obtained resin plate was 3.0 mm.

Comparative Example 9
A resin plate made of resin A4 was obtained in the same manner as in comparative example 6 except that resin A4 was used instead of resin A1 used in comparative example 6. The thickness of the obtained resin plate was 3.0 mm.

Comparative Example 10
A resin plate made of the resin B1 was obtained in the same manner as in the comparative example 6 except that the resin B1 was used instead of the resin A1 used in the comparative example 6. The thickness of the obtained resin plate was 3.0 mm.

Comparative Example 11
A resin plate made of the resin B2 was obtained in the same manner as in the comparative example 6 except that the resin B2 was used instead of the resin A1 used in the comparative example 6. The thickness of the obtained resin plate was 3.0 mm.

Comparative Example 12
A resin plate made of the resin B4 was obtained in the same manner as in the comparative example 6 except that the resin B4 was used instead of the resin A1 used in the comparative example 6. The thickness of the obtained resin plate was 3.0 mm.

Comparative Example 13
A resin plate made of the resin B8 was obtained in the same manner as in the comparative example 6 except that the resin B8 was used instead of the resin A1 used in the comparative example 6. The thickness of the obtained resin plate was 3.0 mm.

<Transparency evaluation 1: total light transmittance>
Regarding the laminate and the resin plate obtained as described above, the total light transmittance was measured with a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd .: COH-400, transmission method) in accordance with JIS K 7105.

<Transparency evaluation 2: haze>
About the laminated body and resin board which were obtained as mentioned above, based on JISK7105, the haze was measured with the color difference meter (Nippon Denshoku Industries Co., Ltd. product: COH-400, the transmission method).

<Transparency evaluation 3: Yellowness>
Regarding the laminate and the resin plate obtained as described above, yellowness was measured with a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd .: COH-400, transmission method) in accordance with JIS K 7105.

<Appearance evaluation>
The laminate and the resin plate obtained as described above were cut at 450 mm square from the center of the sheet, and the surface condition of both surfaces was visually inspected, and the major axis length was 0.3 mm or more. The number of was calculated. Measurement of the length of the major axis of the appearance defect was performed by microscopic observation.

<Comprehensive judgment>
In the above-described transparency evaluation 1, a sample having a total light transmittance of 90% or more is regarded as acceptable, a sample having a haze of less than 1.0 is regarded as acceptable in transparency evaluation 2, and a yellowness is less than 1.0 in transparency evaluation 3. When a product was accepted and a product with less than 10 appearance defects was accepted in the appearance evaluation, a product that passed in all evaluations was evaluated as ◯. The evaluation results were as shown in Table 3 below.

1 Laminate 11 First layer 12 Second layer 13 Other layers

Claims (9)

A laminated body comprising a first layer and a second layer provided on at least one surface of the first layer,
When the first layer is an injection-molded piece of type D13 defined by JIS K 7139, the total light transmittance is 90.5% or more, the haze is 0.95% or less, and the yellowness is 0.95 or less. Comprising a thermoplastic resin (A),
The second layer has a mass with respect to at least one thermoplastic resin (B) selected from the group consisting of a methyl methacrylate resin and a methyl methacrylate-styrene copolymer resin, and the thermoplastic resin (B). 0.001 to 1.0% of a hindered phenol compound (C) on a basis,
The thickness of said 2nd layer is 10 micrometers or more and 20% or less of the thickness of the whole laminated body, The laminated body characterized by the above-mentioned.   The laminate according to claim 1, wherein the second layer further comprises 1.0% or less of a phosphite compound (D) on a mass basis with respect to the thermoplastic resin (B).   The laminate according to claim 1 or 2, wherein the thermoplastic resin (A) comprises a (meth) acrylic ester resin or a copolymer resin thereof.   The hindered phenol compound (C) is octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, pentaerythritol-tetrakis [3- (3,5-di-t-butyl). -4-hydroxyphenyl) propionate], and 1,1,3-tris [5-t-butyl-4-hydroxy-2-methylphenyl] butane. The laminated body as described in any one of -3.   The phosphite compound (D) is bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, tris (2,4-di-t-butylphenyl) phosphite, and The laminate according to any one of claims 2 to 4, which is at least one selected from the group consisting of pentaerythritol-bis (2,4-di-t-butyl) phosphite.   The surface is subjected to at least one treatment selected from the group consisting of an abrasion resistance treatment, an antireflection treatment, an antifouling treatment, an antistatic treatment, a weather resistance treatment, and an antiglare treatment. The laminate according to any one of the above.   The laminate according to any one of claims 1 to 6, wherein the second layer is provided on both surfaces of the first layer.   The transparency board | substrate provided with the laminated body as described in any one of Claims 1-7.   A surface protection member comprising the transparent substrate according to claim 8.

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