JP5417259B2 - LAMINATE, RESIN SHEET USED FOR THE SAME, AND USE OF THE LAMINATE - Google Patents

Description

  The present invention relates to a laminate, a resin sheet used for the laminate, and uses of the laminate. In more detail, by laminating two hard flat plates (one flat plate has a step inside) in two specific directions through two resin sheets having a specific shape, Used for internal members used in portable information terminal devices such as mobile phones and mobile devices, and screen displays of televisions, which can effectively reduce bubbles depending on the directionality of the film and reduce the thickness of the resin sheet. The present invention relates to a laminate that can be used, the resin sheet used in the laminate, and a portable information terminal device and a capacitive touch panel device using the laminate as members.

Conventionally, in order to join a display device of a mobile device or a display and a protective plate, frame-shaped bonding using a double-sided tape has been common. However, this method has a problem that the image quality deteriorates due to internal scattering derived from the air gap layer between the display and the protective plate. As a solution to this problem, a method has been proposed in which the internal gap is reduced and the image quality is improved by filling the air gap layer with an adhesive or acrylic resin.
In recent years, a “design” in which the bezel for concealing the internal electrode from the outside is eliminated and the surface of the display body is flattened is preferred. In this case, a technique of sticking a film with black decorative printing on the surface is taken, but a technique of sticking frame-printed glass to a display body has been proposed in order to make a design that takes advantage of the texture of glass.

However, when a flat plate with high rigidity such as glass and a flat surface such as an LCD or PDP module are bonded together, it is difficult to bond without bubbles if there is black frame printing that is only partially different in height. Become.
It can also be pasted simply by using a thick adhesive (resin layer) compared to the height of the step, but the punching accuracy is reduced and the adhesive oozes out from the edge. However, there is a concern about the yield drop. Therefore, a method of bonding a flat plate having a step with a pressure-sensitive adhesive film thickness of 200 μm or less is desired.
On the other hand, when laminating a plane plate and a plane plate, a method of laminating by holding two plates at intervals of several mm and running a laminating roller from one short side toward the long side. Is common. However, in this method, it is easy to follow the step on the long side, but it is difficult to follow the short side, and it was possible to cope only with a method of thickening the adhesive.

  On the other hand, many portable information terminal devices equipped with a resistive film type, a capacitive type, an electromagnetic induction type, an infrared type touch panel, etc. are already on the market. (Multi-touch) is possible, which is effective for recent mobile product applications. Since the capacitive touch panel is a system that detects a change in electrostatic capacitance on the surface, a uniform electric field is required. Usually, a film method is effective for reducing the thickness, reducing the weight, and mixing bubbles, but a smooth surface such as glass is effective for forming a uniform electric field. Therefore, the capacitive touch panel requires bonding between flat plates.

As a method for bonding internal members of a conventional portable information terminal device, Patent Document 1 proposes a double-sided pressure-sensitive adhesive tape using an adhesive on both surfaces of a core material made of a polyurethane film.
However, in the double-sided pressure-sensitive adhesive tape of Patent Document 1, when a flat plate and a deformable film are bonded, even if there are some steps, it can be applied without leaving bubbles. In the case of bonding between non-deformable surfaces, it is impossible to bond while expelling air bubbles, so it is difficult for air bubbles to enter the bonding surface and to follow the steps completely.

On the other hand, Patent Document 2 discloses an adhesive layer having a loss tangent of a dynamic viscoelastic spectrum of 0.6 to 1.5 and a storage elastic modulus at 80 ° C. of 1.0 × 10 ⁵ Pa or more. A double-sided PSA sheet has been proposed.
The double-sided pressure-sensitive adhesive sheet of Patent Document 2 can remove air bubbles mixed when the surface protection panel is attached to the image display panel by autoclaving, and the air bubbles are not restored even if heating is promoted thereafter. No new bubbles are generated.
Patent Document 3 discloses that a first layer having a tan δ at 25 ° C. of 0.5 or more, a second layer having a tan δ at 25 ° C. of less than 0.5, and a tan δ at 25 ° C. of 0.5 or more. A three-layer impact-resistant film for display has been proposed.
Also in the impact-resistant film for display of Patent Document 3, bubbles generated at the time of bonding can be removed by heat and pressure treatment, and the bubbles do not recur with time.

JP-A-6-346032 JP 2008-231358 A JP 2009-300506 A

However, when the double-sided pressure-sensitive adhesive sheet described in Patent Document 2 or the impact-resistant film for display described in Patent Document 3 is attached to a surface having a step rather than a flat glass panel, the autoclave treatment is performed over time. It has been confirmed by the present inventors that bubbles are generated.
The present invention has been made under such circumstances, and is a laminate formed by bonding two hard flat plates (one flat plate has a step inside) via a resin sheet. To provide a laminate capable of effectively reducing bubbles depending on the directionality of a laminar roller and reducing the thickness of the resin sheet, a resin sheet used for forming the laminate, and use of the laminate It is intended.

As a result of intensive studies to achieve the above object, the present inventors used two resin sheets, a resin sheet (1) having a specific shape and a resin sheet (2), as the resin sheet, First, after laminating the resin sheet (1) directly on the surface having the frame-shaped convex step difference, the resin sheet (2) is directly laminated in the direction orthogonal to the laminating direction of the resin sheet (1) surface, thereby It has been found that a laminate having characteristics can be easily obtained, and that this laminate is useful as a member of a portable information terminal device and a capacitive touch panel device.
The present invention has been completed based on such findings.

That is, the present invention
[1] A laminate in which hard flat plates are bonded together via two resin sheets, and one of the hard flat plates has a rectangular shape with a height of 0.003 to 0.050 mm inside. It has a frame-shaped convex step, and the length of one side of the outer periphery of the frame-shaped convex step (hereinafter, the direction parallel to one side is taken as the X direction) is A (mm), and one side B (mm) is the length of the other side orthogonal to (the direction parallel to the other side is the Y direction), and the length in the X direction of the inner periphery of the frame-shaped convex step is a (mm). When the length in the Y direction is b (mm) and the height of the frame-shaped convex step is c (mm), the length x1 (mm) in the X direction of one of the resin sheets (1) ), Y-direction length y1 (mm) and film thickness z1 (mm) are 0.95 × a ≦ x1 <1.05 × a (mm), b ≦ y1 ≦ B (mm), and c ≦ z1 < 00 satisfy the relationship of (mm),
The length x2 (mm) in the X direction, the length y2 (mm) in the Y direction, and the film thickness z2 (mm) of the other resin sheet (2) are a ≦ x2 ≦ A (mm) and b− (2 × z1) ≦ y2 <1.05 × {b− (2 × z1)} (mm) and c ≦ z2 (mm)
The total thickness z _{1 + 2} when the resin sheet (1) and the resin sheet (2) are laminated satisfies the relationship of 2 × c ≦ z _{1 + 2} ≦ 200 (mm), and the resin sheet (1) has a frame shape. A laminate characterized by laminating the resin sheet (2) directly on the surface of the resin sheet (1) directly in the X direction after laminating directly on the surface of the convex step.
[2] The laminate according to the above item [1], wherein the step of the hard flat plate is a step due to the printed layer.
[3] The laminate according to [1] or [2], which is used for screen display of a portable information terminal device,
[4] A resin sheet used for the laminate according to any one of [1] to [3] above,
[5] A portable information terminal device using the laminate according to any one of [1] to [3] as a member, and [6] any one of [1] to [3] A capacitive touch panel device characterized by using the laminate according to claim 1 as a member;
Is to provide.

  According to the present invention, two hard flat plates (one flat plate has a step inside) are bonded to each other via a resin sheet having a specific shape, thereby depending on the directionality of the lami roller. Laminate that can effectively reduce bubbles and reduce the thickness of the resin sheet, especially a laminate that can be used for portable information terminal devices such as mobile phones and mobile devices and internal members used for TV screen display Body, the resin sheet used for the laminate, and a portable information terminal device and a capacitive touch panel device using the laminate as members.

It is explanatory drawing which shows the dimension of each member which comprises the laminated body of this invention, and the lamination direction of resin sheet (1) and (2). In the laminated body of this invention, it is explanatory drawing which shows the relationship between the printing level | step difference, the resin sheet (1), and the resin sheet (2) when it sees from the edge | side side of the Y direction of a printing level | step difference.

First, the laminated body of this invention is demonstrated.
The laminate of the present invention is a laminate in which hard flat plates are bonded to each other via two resin sheets, and one of the hard flat plates has a height of 0.003 to 0.00 on the inside. It has a rectangular frame-shaped convex step difference of 050 mm, and the length of one side of the outer periphery of the frame-shaped convex step difference (hereinafter, the direction parallel to one side is taken as the X direction) is A (mm) The length of the other side orthogonal to one side (hereinafter, the direction parallel to the other side is defined as the Y direction) is B (mm), and the length in the X direction of the inner periphery of the frame-shaped convex step is When a (mm), the length in the Y direction is b (mm), and the height of the frame-shaped convex step is c (mm), the resin sheet (1) and the resin sheet (2) are as follows. And the total thickness when the resin sheet (1) and the resin sheet (2) are laminated satisfies the following relational expression, and the resin sheet 1) directly to the surface having the frame-like protrusion step, was laminated to the Y-direction, a resin sheet (2) directly to the resin sheet (1) surface, characterized by being laminated in the X direction.

[Rigid flat plate]
In the laminate of the present invention, hard flat plates are bonded together via two resin sheets described later, and one of the hard flat plates has a height of 0.003 to 0.050 mm inside. , Preferably 0.005 to 0.035 mm, more preferably 0.007 to 0.025 mm.
As a material for the hard flat plate, a transparent glass plate is usually used. As this glass plate, for example, soda lime glass, barium / strontium-containing glass, aluminosilicate glass, lead glass, borosilicate glass, barium borosilicate glass, quartz or the like can be used.
Although the thickness of the said hard plane board is based also on the use of the said laminated body, it is about 0.08-5 mm normally, Preferably it is about 0.2-4 mm, Most preferably, it is 0.4-3 mm.
The level difference in the hard flat plate is usually formed by providing a decorative print layer in a frame shape using ultraviolet curable ink or the like with respect to the flat plate.
FIG. 1 is a perspective view of an example of a hard flat plate having a rectangular frame-shaped convex step (hereinafter sometimes referred to as a printing step) provided by decorative printing.
As shown in this perspective view, the X direction of the outer periphery of the printing step is A (mm), the length in the Y direction is B (mm), the length of the inner periphery of the printing step in the X direction is a (mm), The length in the Y direction is b (mm) and the height of the step is c (mm).
In addition, although the shape of the frame-shaped convex part level | step difference is described with the rectangle, the rectangle in this application is a concept also including a square.

[Resin sheet (1)]
When the resin sheet (1) used in the laminate of the present invention is bonded to two hard flat plates (one flat plate has the above step inside) to produce a laminate, It is a member that is directly laminated on the surface having
When the length in the X direction of the resin sheet (1) is x1 (mm), the length in the Y direction is y1 (mm), and the film thickness is z1 (mm), the above-described effects of the present invention are exhibited. Are the following relational expressions (a), (b) and (c)
0.95 × a ≦ x1 <1.05 × a (mm) (a)
b ≦ y1 ≦ B (mm) (b)
c ≦ z1 <100 (mm) (c)
It is necessary to satisfy both.
In the relational expression (a), it is preferable that a ≦ x1 ≦ 1.02 × a (mm). Since there is an error in the accuracy of the bonding machine, it is better that x1 is larger than a than x1 and a have the same length. However, when pasting, if both sides of the frame are combined and exceed 1.05 times, bubbles will be mixed.
In the relational expression (b), when y1 <b, a gap is generated between the printing step and the resin sheet, and thus good visibility cannot be obtained. Moreover, in the case of B <y1, the resin sheet protrudes from the frame, resulting in trouble in the subsequent process of using the laminate.
In the relational expression (c), it is preferable that 1.1 × c ≦ z1 ≦ 80 (mm). When z1 is lower than c, the thickness of the portion surrounded by the frame is eventually thinner than the frame, and bubbles are mixed during lamination. Further, when z1 is 100 mm or more, there are problems of a decrease in punching accuracy and bleeding of the adhesive from the end.

[Resin sheet (2)]
When the resin sheet (2) used in the laminate of the present invention is prepared by laminating two hard flat plates (one flat plate has the above-mentioned steps on the inside) to produce a laminate. It is a member that is directly laminated on the surface of the resin sheet (1) laminated on the surface having a step.
When the X direction length of the resin sheet (2) is x2 (mm), the Y direction length is y2 (mm), and the film thickness is z2 (mm), the following relational expressions (d), (e) and (F)
a ≦ x2 ≦ A (mm) (d)
b− (2 × z1) ≦ y2 <1.05y × {b− (2 × z1)} (mm) (e)
c ≦ z2 (mm) (f)
It is necessary to satisfy both.
In the relational expression (d), when x2 <a, the view area of the display cannot be filled with the resin layer, and the visibility is remarkably lowered.
In the relational expression (e), if y2 is narrower than b− (2 × z1), the printing step cannot be completely filled, and is 1.05 × {b− (2 × z1)} or more. Since the bubbles are taken in when the display is bonded, a sufficient effect cannot be obtained.
In the relational expression (f), if z2 <c, the printing step cannot be completely filled.

In the laminate of the present invention, when the hard flat plates are bonded together via the resin sheet (1) and the resin sheet (2), first, the resin sheet (1) is placed on the surface having the frame-shaped convex step. After laminating directly in the Y direction of frame-like printing, it is necessary to laminate the resin sheet (2) directly on the surface of the resin sheet (1) in the X direction of frame-like printing. Thereby, the deformation | transformation of a resin sheet can be canceled and it can bond simply without a bubble.
The total thickness of the resin sheet: z _{1 + 2} must be 2 × c ≦ z _{1 + 2} ≦ 200 (mm), and preferably 3 × c ≦ z _{1 + 2} ≦ 150 (mm). When it is less than 2 × c (mm), the bonding suitability between the flat plates is lowered. On the other hand, if it exceeds 200 mm, the punching accuracy decreases, the adhesive oozes out from the end, and the yield may be lowered.
The two resin sheets may be colored. The two sheets may be the same color or different colors. When different colors are used, the combination can control the wavelength (for example, near infrared rays) and the color of light transmitted through the laminate, and is particularly useful for PDP applications.

The material of the resin sheets (1) and (2) in the laminate of the present invention is not particularly limited, and examples thereof include acrylic resins, rubber resins, silicone resins, and fluorine resins. Among them, an acrylic resin that is excellent in weather resistance and that can easily control the storage elastic modulus and the adhesive force to a flat plate is particularly preferable.
(Acrylic resin)
The acrylic resin is not particularly limited, but a (meth) acrylic ester copolymer is preferable.
This (meth) acrylic acid ester-based copolymer includes (meth) acrylic acid alkyl ester having 1 to 18 carbon atoms in the alkyl moiety of the ester portion and a crosslinkable functional group-containing ethylenic monomer used as necessary. Preferred examples include monomers and copolymers with other monomers.

<(Meth) acrylic acid alkyl ester>
Examples of (meth) acrylic acid alkyl esters having 1 to 18 carbon atoms in the alkyl moiety of the ester moiety include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, and n-butyl. Examples include acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, n-hexyl acrylate, n-hexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, and lauryl methacrylate. These may be used individually by 1 type and may be used in combination of 2 or more type.

<Crosslinkable functional group-containing ethylene monomer>
Examples of the crosslinkable functional group-containing ethylenic monomer used as necessary include ethylenic monomers having functional groups such as hydroxyl group, carboxyl group, amino group, substituted amino group, and epoxy group in the molecule. Yes, preferably a hydroxy group-containing ethylenically unsaturated compound or a carboxyl group-containing ethylenically unsaturated compound is used. Specific examples of such a crosslinkable functional group-containing ethylenic monomer include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate. Hydroxy group-containing acrylates such as 2-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, carboxyl group-containing ethylenic groups such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, citraconic acid Saturated compounds are mentioned. The crosslinkable functional group-containing ethylenic monomer may be used alone or in combination of two or more.

<Other monomers>
Other monomers used as needed include alicyclic group-containing acrylic acid esters such as cyclohexyl acrylate and isobornyl acrylate; vinyl esters such as vinyl formate, vinyl acetate, and vinyl propionate; ethylene, propylene Olefins such as styrene, isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; styrene monomers such as styrene and α-methylstyrene; diene monomers such as butadiene, isoprene and chloroprene; acrylonitrile and methacrylo Nitrile monomers such as nitriles; N, N-dialkyl-substituted acrylamides such as N, N-dimethylacrylamide, N, N-dimethylmethacrylamide and the like. These may be used individually by 1 type and may be used in combination of 2 or more type.

(Production of acrylic resin sheet)
First, the (meth) acrylic acid ester described above, and the crosslinkable functional group-containing ethylenic monomer and other monomers used as necessary are used in a predetermined ratio, respectively, and copolymerized according to a conventionally known method. To produce a (meth) acrylic acid ester-based polymer having a weight average molecular weight of preferably about 500,000 to 1,500,000, more preferably about 600,000 to 1,300,000.
In addition, the said weight average molecular weight is the value of standard polystyrene conversion measured by the gel permeation chromatography (GPC) method.
Next, resin composition solutions (A) and (B) for preparing the resin layer (A) and the resin layer (B) are prepared. The resin composition solutions (A) and (B) may be the same or different. The resin composition solutions (A) and (B) include the (meth) acrylic acid ester polymer obtained above, and a crosslinking agent and other additives used as necessary, such as a tackifier and a pigment. It can be prepared by adding an appropriate solvent to a mixture with a dye, a filler, an antioxidant, an ultraviolet absorber and the like to obtain a concentration suitable for coating.

<Crosslinking agent>
As a crosslinking agent used as needed, arbitrary things can be suitably selected from what was conventionally used as a crosslinking agent in acrylic resin. Examples of such a cross-linking agent include polyisocyanate compounds, epoxy resins, melamine resins, urea resins, dialdehydes, methylol polymers, aziridine compounds, metal chelate compounds, metal alkoxides, and metal salts. When the (meth) acrylic acid ester copolymer has a hydroxyl group as a crosslinkable functional group, a polyisocyanate compound is preferable, and when it has a carboxyl group, a metal chelate compound is preferable.

≪Polyisocyanate compound≫
Examples of polyisocyanate compounds include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, etc. , And their biuret bodies, isocyanurate bodies, and adduct bodies that are a reaction product with low molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylol propane, castor oil, etc. it can. The said polyisocyanate compound may be used individually by 1 type, and may be used in combination of 2 or more type.

≪Metal chelate compound≫
The metal chelate compound used as the cross-linking agent includes chelate compounds whose metal atoms are aluminum, zirconium, titanium, zinc, iron, tin, etc., but aluminum chelate compounds are preferable from the viewpoint of performance.
Examples of the aluminum chelate compound include diisopropoxy aluminum monooleyl acetoacetate, monoisopropoxy aluminum bis oleyl acetoacetate, monoisopropoxy aluminum monooleate monoethyl acetoacetate, diisopropoxy aluminum monolauryl acetoacetate, diisopropoxy aluminum Monostearyl acetoacetate, diisopropoxyaluminum monoisostearyl acetoacetate, monoisopropoxyaluminum mono-N-lauroyl-β-alanate monolauryl acetoacetate, aluminum trisacetylacetonate, monoacetylacetonate aluminum bis (isobutylacetoacetate ) Chelate, monoacetylacetonate aluminum bis (2-ethylhexyl acetoacetate) chelate, monoacetylacetonate aluminum bis (dodecyl acetoacetate) chelate, monoacetylacetonate aluminum bis (oleyl acetoacetate) chelate and the like. The said metal chelate compound may be used individually by 1 type, and may be used in combination of 2 or more type.

  The laminate of the present invention is a laminate obtained by laminating two hard flat plates (one flat plate has a step inside) via two resin sheets, Air bubbles depending on the directionality of the laminating roller generated when the hard flat plate is bonded through two resin sheets can be effectively reduced, and the thickness of the resin sheet can be reduced. It is suitably used as an internal member used for terminal device screen display, television screen display, and the like.

The present invention also provides a resin sheet used in the above-described laminate of the present invention and a resin sheet with a release film formed by sandwiching the resin sheet between two release films.
The present invention further provides a portable information terminal device and a capacitive touch panel device using the laminate as a member.
Examples of portable information terminal devices include devices equipped with a touch panel such as a resistive film method, a capacitance method, an electromagnetic induction method, and an infrared method.
In addition, since the capacitive touch panel is a system that detects a change in electrostatic capacitance on the surface, a uniform electric field is required. In order to form a uniform electric field, a smooth surface such as glass is effective. Therefore, in a capacitive touch panel, the laminate is effective because bonding between hard flat plates is required.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
The presence / absence of bubbles and the visibility in each example were evaluated according to the following methods.
<Thickness of resin sheet>
The release film of the obtained resin sheet was removed, and the measurement was performed with a constant pressure thickness measuring instrument [manufactured by Tecrock, product name “PG-02”] according to JIS K 7130.
<Presence of bubbles>
On the surface of a glass plate [manufactured by NSG Precision, product name “Corning Glass Eagle XG”, length 90 mm × width 50 mm × thickness 0.5 mm], UV curable ink [product name “POS-911 ink”, manufactured by Teikoku Ink Co., Ltd.] ], A frame-shaped (outer shape, vertical 90 mm × width 50 mm, width 10 mm) is printed by screen printing so that the coating thickness is 15 μm, and irradiated with ultraviolet rays (two 80 W / cm metal halide lamps, lamp height 15 cm, A glass plate having a step due to printing was produced by curing at a belt speed of 10 to 15 m / min.
A laminator was used to laminate and affix the resin sheet (1) in the Y direction on the glass with a printed step, and after peeling the heavy release film, the resin sheet (2) was laminated and affixed in the X direction. Next, after pasting the glass plates, an autoclave treatment (50 ° C., 0.5 MPa, 30 minutes) was performed. The inside of the frame printing was visually observed.
The glass with printing steps is set to A = 90 mm on the outer periphery of the printing steps, B = 50 mm on the Y direction, a = 70 mm on the X direction on the inner periphery of the printing steps, and b = 42 mm on the Y direction. What changed (mm) was used.
<Visibility>
In the sample where the presence or absence of air bubbles was confirmed, the inside of the frame printing was visually observed, and if the inside area of the printing step could be completely covered with the resin sheet, the inside area of the printing step was completely covered with the resin sheet. When it was not able to be answered, it was set as x.

Preparation Example 1 Preparation of Resin Composition Solution 1 Acrylic copolymer (79% by mass of butyl acrylate unit, 20% by mass of methyl acrylate unit, 1% by mass of 4-hydroxybutyl acrylate unit, weight average molecular weight 900,000, solid content 30 (Mass%) to 100 parts by mass of an ethyl acetate solution, 0.05 parts by mass of an isocyanate-based crosslinking agent [manufactured by Soken Chemical Co., Ltd., product name “TD-75”, solid content concentration: 75% by mass] is diluted with methyl ethyl ketone. Then, a resin composition solution 1 having a solid content concentration of 30% by mass was prepared.

Examples 1-5 and Comparative Examples 1-7
The release film [manufactured by Lintec Corporation, “SP-PET38T103-1”] was coated such that the film thickness after drying the resin composition solution 1 was z1 (mm) and z2 (mm) in Table 1. Then, after drying at 100 ° C. for 1 minute, a release film [manufactured by Lintec Corporation, “SP-PET381031H”] is laminated, and a roll sample of the resin sheet (1) having a film thickness of z1 (mm) and a film thickness of z2 A roll sample of the resin sheet (2) of (mm) was obtained. Thereafter, the length in the X direction and the length in the Y direction are respectively cut so as to be x1 (mm) and y1 (mm), x2 (mm) and y2 (mm) in Table 1, and the resin sheet (1) And a resin sheet (2) were obtained.
The presence / absence of bubbles and the evaluation results of visibility are shown in Table 1.

  In the laminate of the present invention, two hard flat plates (one flat plate has a step inside) are bonded in specific directions through two resin sheets having specific shapes. Is a laminate that can effectively reduce bubbles depending on the direction of the laminar roller and can also reduce the thickness of the resin sheet, and has excellent visibility, especially morphological information terminals such as mobile phones and mobile devices It can be used as an internal member used for screen display of equipment and television.

Claims (6)

A laminate in which hard flat plates are bonded together via two resin sheets, and one of the hard flat plates has a rectangular frame shape with a height of 0.003 to 0.050 mm inside. The length of one side of the outer periphery of the frame-like convex step (hereinafter, the direction parallel to one side is taken as the X direction) is A (mm), and is orthogonal to one side. The length of the other side (hereinafter, the direction parallel to the other side is defined as the Y direction) is B (mm), the length in the X direction of the inner periphery of the frame-shaped convex step is a (mm), the Y direction Is the length x1 (mm) in the X direction of one of the resin sheets (1) and Y The length y1 (mm) in the direction and the film thickness z1 (mm) are 0.95 × a ≦ x1 <1.05 × a (mm), b ≦ y1 ≦ B (mm), and c ≦ z1 <100. Satisfy the relationship of mm),
The length x2 (mm) in the X direction, the length y2 (mm) in the Y direction, and the film thickness z2 (mm) of the other resin sheet (2) are a ≦ x2 ≦ A (mm) and b− (2 × z1) ≦ y2 <1.05 × {b− (2 × z1)} (mm) and c ≦ z2 (mm)
The total thickness z _{1 + 2} when the resin sheet (1) and the resin sheet (2) are laminated satisfies the relationship of 2 × c ≦ z _{1 + 2} ≦ 200 (mm), and the resin sheet (1) has a frame shape. A laminate comprising the resin sheet (2) laminated directly on the surface of the resin sheet (1) in the X direction after laminating directly on the surface of the convex step.   The laminate according to claim 1, wherein the step of the hard flat plate is a step due to a printed layer.   The laminated body of Claim 1 or 2 used for the screen display of a portable information terminal device.   A resin sheet used for the laminate according to any one of claims 1 to 3.   A portable information terminal device using the laminate according to any one of claims 1 to 3 as a member.   A capacitive touch panel device using the laminate according to claim 1 as a member.

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