JP7171330B2 - glass laminate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a glass laminate, and more particularly to a glass laminate suitable for optical applications.

In recent years, thin glass substrates have been used as flexible substrates for optical films provided in image display devices such as liquid crystal displays and organic EL displays from the viewpoint of heat resistance and the like. Specifically, a transparent conductive film in which a transparent conductive layer such as indium tin oxide (ITO) is formed on a thin glass substrate is used as a touch panel film.

A roll-to-roll method is employed for mass production of such optical films. That is, a long thin glass base material is prepared, functional layers such as a transparent conductive layer are sequentially formed on the thin glass base material, and finally, the thin glass base material is wound into a roll.

However, when the optical film including the thin glass substrate is wound, the thin glass substrate is damaged due to the stress between the thin glass substrates laminated in the thickness direction. Therefore, a glass laminate with a resin layer, in which an adhesive layer and a resin layer are laminated on a thin glass substrate, has been proposed (see Patent Document 1).

JP 2017-39227 A

However, in Patent Document 1, since the resin layer is laminated on the thin glass substrate via the adhesive layer, the resin layer cannot be separated from the thin glass substrate. Therefore, since the resin layer remains as the final product (optical film), it is not possible to reduce the thickness of the optical film, and the optical properties (light transmittance and color) may deteriorate.

Therefore, a method of laminating a carrier film composed of an adhesive layer and a plastic film on a thin glass substrate of an optical film is being studied. Since this carrier film is laminated on the thin glass base material via the adhesive layer, it can be easily removed (peeled off) with the adhesive layer as the boundary after the optical film is produced and before it is incorporated into the image display device. be able to.

By the way, depending on the type of optical film, heat treatment may be performed during the production of the optical film. For example, an optical film in which a transparent conductive layer such as ITO is formed on a thin glass substrate is subjected to heat treatment for crystallization (reduction of resistance).

As a result, curling occurs due to the difference in coefficient of thermal expansion between the thin glass substrate and the carrier film. Therefore, thinning the carrier film to reduce curling is also being considered.

However, when the laminate of the thin film carrier film and the thin glass substrate is heated, the carrier film does not peel off smoothly from the thin glass substrate when the carrier film is removed, resulting in damage to the thin glass substrate. occur.

An object of the present invention is to provide a glass laminate capable of suppressing the occurrence of curling and suppressing breakage of the glass substrate.

The present invention [1] is a glass laminate comprising a carrier film and a glass substrate having a thickness of 150 μm or less disposed on one side in the thickness direction of the carrier film, wherein the carrier film has a thickness of 100 μm. and a pressure-sensitive adhesive layer disposed on one side in the thickness direction of the plastic substrate, and when the glass laminate is heated at 140 ° C. for 60 minutes, the carrier film and the glass substrate A glass laminate having a peeling force of 0.1 N/50 mm or more and 2.0 N/50 mm or less.

The present invention [2] includes the glass laminate according to [1], further comprising a transparent conductive layer arranged on one side in the thickness direction of the glass substrate.

The present invention [3] includes the glass laminate according to [1] or [2], which is wound into a roll.

Since the glass laminate of the present invention includes a glass base material having a thickness of 150 μm or less, it can be made into a roll, and industrial production (mass production) by a roll-to-roll method is possible.

Moreover, since the glass laminate of the present invention includes a carrier film and a glass base material, it is possible to suppress breakage of the glass base material when the glass laminate is rolled.

In addition, since the carrier film includes a plastic substrate having a thickness of 100 μm or less and an adhesive layer, curling during heat treatment can be suppressed.

Further, when the glass laminate of the present invention is heated at 140° C. for 60 minutes, the peeling force between the carrier film and the glass substrate is 0.1 N/50 mm or more and 2.0 N/50 mm or less. Also, the carrier film can be smoothly peeled off from the glass substrate. Therefore, breakage of the glass substrate can be suppressed when the carrier film is peeled off.

FIG. 1 shows a cross-sectional view of one embodiment of the glass laminate of the present invention. FIG. 2 shows a cross-sectional view of a transparent conductive glass laminate comprising the glass laminate shown in FIG. FIG. 3 shows a perspective view of the roll body of the transparent conductive glass laminate shown in FIG. FIG. 4 shows a schematic diagram of a test for measuring the peel force of the glass laminate in the example. FIG. 5 shows a schematic diagram of a test for measuring the curl of a glass laminate in Examples.

<One embodiment>
A glass laminate 1 that is an embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG.

In FIG. 1, the vertical direction on the page is the vertical direction (thickness direction), the upper side on the page is the upper side (one side in the thickness direction), and the lower side on the page is the lower side (the other side in the thickness direction). In addition, in FIG. 1, the left-right direction and the depth direction of the paper surface are plane directions orthogonal to the up-down direction. Specifically, it conforms to the directional arrows in each figure.

1. Glass Laminate As shown in FIG. 1, the glass laminate 1 is flexible and has a film shape (including a sheet shape) having a predetermined thickness. The glass laminate 1 extends in a plane direction perpendicular to the vertical direction (thickness direction) and has a flat upper surface (surface on one side in the thickness direction) and a flat lower surface (surface on the other side in the thickness direction). The glass laminate 1 is, for example, one component for producing a base material for a touch panel provided in an image display device, and is not an image display device. That is, the glass laminate 1 is a device that does not include an image display element such as an LCD module, is distributed as a component alone, and can be used industrially.

Specifically, the glass laminate 1 includes a carrier film 2 and a glass substrate 3 arranged on the upper surface thereof. That is, the glass laminate 1 includes the carrier film 2 and the glass substrate 3 in this order from the bottom. Preferably, glass laminate 1 consists of carrier film 2 and glass substrate 3 . Each member will be described in detail below.

2. Carrier Film The carrier film 2 serves to prevent the glass substrate 3 from being scratched when the glass substrate 3 or the transparent conductive glass 6, which will be described later, is transported, heated, and/or stored. It is a protective member provided on the lower surface. The carrier film 2 supports the glass substrate 3 from below.

The carrier film 2 has a film shape with a predetermined thickness, extends in the plane direction, and has a flat upper surface and a flat lower surface. The carrier film 2 is arranged on the lower side of the glass laminate 1 , and more specifically, is arranged on the entire lower surface of the glass substrate 3 so as to be in contact with the lower surface of the glass substrate 3 .

Specifically, the carrier film 2 includes a plastic substrate 4 and an adhesive layer 5 placed on the upper surface of the plastic substrate 4 . That is, the carrier film 2 has a plastic substrate 4 and an adhesive layer 5 in order from the bottom. Preferably, carrier film 2 consists of plastic substrate 4 and adhesive layer 5 .

(Plastic substrate)
The plastic substrate 4 is a supporting substrate that secures the mechanical strength of the carrier film 2 and protects the glass substrate 3 from scratches that may occur during transportation, heating and/or storage.

The plastic substrate 4 has a film shape and is provided as the bottom layer of the glass laminate 1 .

The plastic substrate 4 is, for example, a polymer film having flexibility. Examples of materials for the plastic base material 4 include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate; (meth)acrylic resins such as polymethacrylate (acrylic resin and/or methacrylic resin); For example, polyethylene, polypropylene, olefin resins such as cycloolefin polymers (e.g., norbornene-based, cyclopentadiene-based), e.g., polycarbonate resins, polyethersulfone resins, polyarylate resins, melamine resins, polyamide resins, polyimide resins, cellulose resins, polystyrene resin and the like. These materials can be used singly or in combination of two or more.

From the viewpoint of transparency, heat resistance, mechanical strength, etc., polyester resins are preferred, and PET is more preferred.

The thickness of the plastic substrate 4 is 100 μm or less, preferably 60 μm or less, more preferably 35 μm or less. Also, for example, it is 5 μm or more, preferably 10 μm or more. If the thickness of the plastic substrate 4 is equal to or less than the above upper limit, curling can be suppressed when the glass laminate 1 is heated. On the other hand, if the thickness of the plastic substrate 4 is at least the above lower limit, the mechanical strength is excellent, and breakage of the glass substrate 3 can be suppressed.

The thickness of the plastic substrate 4 can be measured using a dial gauge (“DG-205” manufactured by PEACOCK).

(Adhesive layer)
The pressure-sensitive adhesive layer 5 is a layer (pressure-sensitive adhesive layer) for adhering the plastic substrate 4 to the glass substrate 3, and is easy to peel off from the glass substrate 3 after being adhered. It is a layer (easy peeling layer).

The pressure-sensitive adhesive layer 5 has a film shape and is arranged on the entire upper surface of the plastic substrate 4 so as to be in contact with the upper surface of the plastic substrate 4 . Specifically, the adhesive layer 5 is arranged between the plastic substrate 4 and the glass substrate 3 so as to contact the upper surface of the plastic substrate 4 and the lower surface of the glass substrate 3 . Specifically, the adhesive layer 5 is pressure-sensitively adhered to the lower surface of the glass substrate 3 .

The adhesive layer 5 is formed from an adhesive composition.

Examples of adhesive compositions include acrylic adhesive compositions, rubber adhesive compositions, silicone adhesive compositions, polyester adhesive compositions, polyurethane adhesive compositions, and polyamide adhesive compositions. , epoxy-based adhesive compositions, vinyl alkyl ether-based adhesive compositions, fluorine-based adhesive compositions, and the like. These adhesive compositions can be used alone or in combination of two or more.

The adhesive composition is preferably an acrylic adhesive composition from the viewpoint of adhesiveness before heating, releasability after heating, and the like.

The acrylic pressure-sensitive adhesive composition contains, as a polymer component, for example, an acrylic polymer obtained by polymerizing a monomer component containing a (meth)acrylic acid alkyl ester.

(Meth)acrylic acid alkyl ester is acrylic acid alkyl ester and/or methacrylic acid alkyl ester, specifically, for example, butyl (meth)acrylate, isobutyl (meth)acrylate, sec (meth)acrylate -butyl, t-butyl (meth)acrylate, pentyl (meth)acrylate, neopentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, (meth)acrylate 2-ethylhexyl acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, tetradecyl (meth)acrylate, etc., linear or branched, having 4 to 4 carbon atoms Examples include (meth)acrylic acid alkyl esters having 14 alkyl moieties. The (meth)acrylic acid alkyl esters may be used alone or in combination of two or more.

The (meth)acrylic acid alkyl ester preferably includes a (meth)acrylic acid alkyl ester having an alkyl moiety having 4 to 12 carbon atoms, more preferably having an alkyl moiety having 6 to 10 carbon atoms. Examples include (meth)acrylic acid alkyl esters, more preferably 2-ethylhexyl (meth)acrylate.

The mixing ratio of the (meth)acrylic acid alkyl ester is, for example, 90 parts by mass or more, preferably 95 parts by mass or more, and for example, 99 parts by mass or less, preferably, with respect to 100 parts by mass of the total amount of the monomer components. is 98 parts by mass or less. The release force of the pressure-sensitive adhesive layer 5 can be adjusted by adjusting the blending ratio of the (meth)acrylic acid alkyl ester.

The monomer component can contain a functional group-containing monomer in addition to the (meth)acrylic acid alkyl ester.

Functional group-containing monomers include, for example, carboxyl group-containing monomers such as acrylic acid and methacrylic acid, and hydroxyl group-containing monomers such as 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate. The functional group-containing monomers can be used singly or in combination of two or more.

The functional group-containing monomer is preferably a hydroxyl group-containing monomer, more preferably 2-hydroxyethyl acrylate, from the viewpoint of adhesion before heating and peelability after heating.

The blending ratio of the functional group-containing monomer is, for example, 1 part by mass or more, preferably 2 parts by mass or more, and for example, 10 parts by mass or less, preferably 5 parts by mass, per 100 parts by mass of the total amount of the monomer components. It is below.

The weight average molecular weight of the acrylic polymer is, for example, 100,000 or more, preferably 300,000 or more, and is, for example, 2,000,000 or less, preferably 1,000,000 or less. The weight average molecular weight can be measured by gel permeation chromatography based on standard polystyrene conversion values.

The acrylic pressure-sensitive adhesive composition can be obtained, for example, by known methods such as solution polymerization, bulk polymerization, and photopolymerization.

The adhesive composition preferably contains a cross-linking agent. Examples of cross-linking agents include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, melamine-based resins, aziridine derivatives, and metal chelate compounds. These cross-linking agents can be used alone or in combination of two or more.

The cross-linking agent preferably includes an isocyanate-based cross-linking agent and an epoxy-based cross-linking agent, more preferably an isocyanate-based cross-linking agent.

Examples of isocyanate-based cross-linking agents include aromatic isocyanates such as toluene diisocyanate and xylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate and cyclohexylene diisocyanate, and aliphatic isocyanates such as butylene diisocyanate and hexamethylene diisocyanate. , For example, trimethylolpropane/tolylene diisocyanate trimer adduct, trimethylolpropane/hexamethylene diisocyanate trimer adduct, isocyanate adduct such as isocyanurate of hexamethylene diisocyanate, e.g., polyether polyisocyanate, polyester Polyol adducts such as polyisocyanates, such as isocyanurate, biuret, and allophanate.

The epoxy-based cross-linking agent preferably includes polyfunctional epoxy-based compounds. Specifically, examples include N,N,N',N'-tetraglycidyl-m-xylenediamine, 1,3-bis( N,N-diglycidylaminomethyl)cyclohexane (trade name “Tetrad C”, manufactured by Mitsubishi Gas Chemical Company) and the like.

The mixing ratio of the cross-linking agent is, for example, 1 part by mass or more, preferably 2 parts by mass or more, and for example, 15 parts by mass or less, preferably 5 parts by mass or less with respect to 100 parts by mass of the polymer component. be. By adjusting the mixing ratio of the cross-linking agent, the peel strength of the pressure-sensitive adhesive layer 5 can be adjusted.

When a cross-linking agent is contained, a cross-linking catalyst is more preferably included. Cross-linking catalysts include, for example, tin octanoate, dioctyltin dilaurate, dibutyltin bis(acetylacetonate), tin-based catalysts such as tin-based chelate compounds, tris(acetylacetonate)iron, trimethoxyiron, triiso iron-based catalysts such as propoxy iron and ferric chloride; These crosslinking catalysts can be used alone or in combination of two or more. Tin-based catalysts are preferred.

The mixing ratio of the cross-linking catalyst is, for example, 0.1 parts by mass or more, preferably 0.2 parts by mass or more, and for example, 5 parts by mass or less, preferably 3 parts by mass, with respect to 100 parts by mass of the cross-linking agent. Part by mass or less. The release force of the adhesive layer 5 can be adjusted by adjusting the mixing ratio of the cross-linking catalyst.

The pressure-sensitive adhesive composition may further contain known additives such as tackifying resins, processing aids, pigments, flame retardants, fillers, softeners and anti-aging agents as appropriate.

The thickness of the adhesive layer 5 is, for example, 5 μm or more, preferably 10 μm or more, and is, for example, 100 μm or less, preferably 50 μm or less.

The thickness of the adhesive layer 5 can be measured using a dial gauge (“DG-205” manufactured by PEACOCK).

The thickness of the carrier film 2 is, for example, 10 μm or more, preferably 20 μm or more, and is, for example, 100 μm or less, preferably 75 μm or less, more preferably 50 μm or less, still more preferably 25 μm or less. If the thickness of the carrier film 2 is equal to or less than the above upper limit, curling can be suppressed when the glass laminate 1 is heated. On the other hand, when the thickness of the carrier film 2 is at least the above lower limit, the mechanical strength is excellent and breakage of the glass substrate 3 can be suppressed.

3. Glass Base Material The glass base material 3 is a supporting member that secures the mechanical strength of an optical member such as a transparent conductive glass (described later) and supports a functional layer such as a transparent conductive layer (described later).

The glass substrate 3 has a film shape and is arranged on the entire upper surface of the carrier film 2 so as to be in contact with the upper surface of the carrier film 2 . Specifically, the glass substrate 3 is pressure-sensitively adhered to the upper surface of the adhesive layer 5 .

The glass substrate 3 is made of flexible and transparent glass.

Examples of glass include alkali-free glass, soda glass, borosilicate glass, and aluminosilicate glass.

The upper surface or the lower surface of the glass substrate 3 may be subjected to a known base treatment (primer treatment). That is, the glass substrate 3 may have a primer layer on its upper or lower surface.

The thickness of the glass substrate 3 is 150 μm or less, preferably 120 μm or less, more preferably 100 μm or less. Also, for example, it is 10 μm or more, preferably 50 μm or more. When the thickness of the glass substrate 3 is equal to or less than the above upper limit, it is excellent in flexibility and can be wound into a roll. Moreover, if the thickness of the glass base material 3 is more than the said minimum, it will be excellent in mechanical strength, and it can suppress the breakage at the time of conveyance.

The thickness of the glass substrate 3 can be measured using a dial gauge ("DG-205" manufactured by PEACOCK).

4. Method for Manufacturing Glass Laminate A method for manufacturing the glass laminate 1 will be described. The manufacturing method of the glass laminate 1 includes, for example, a preparing step and an adhering step in order. The glass laminated body 1 is manufactured by a roll-to-roll method, for example.

(Preparation process)
In the preparing step, the carrier film 2 is prepared.

The carrier film 2 can be obtained by applying a diluted solution of an adhesive composition diluted with a solvent to the upper surface of a long plastic substrate 4 and drying it.

Examples of the solvent include organic solvents and aqueous solvents (specifically, water), and organic solvents are preferred. Examples of organic solvents include alcohol compounds such as methanol, ethanol and isopropyl alcohol; ketone compounds such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ester compounds such as ethyl acetate and butyl acetate; Ether compounds, for example, aromatic compounds such as toluene and xylene. These solvents can be used alone or in combination of two or more. Ester compounds are preferred.

The solid content concentration in the diluent is, for example, 1% by mass or more, preferably 10% by mass or more, and is, for example, 40% by mass or less, preferably 30% by mass or less.

The coating method can be appropriately selected according to the coating liquid and the plastic substrate 4 . For example, a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method, an inkjet method and the like can be mentioned.

The drying temperature is, for example, 50° C. or higher, preferably 100° C. or higher, and for example, 200° C. or lower, preferably 150° C. or lower.

The drying time is, for example, 0.5 minutes or longer, preferably 1 minute or longer, and for example, 30 minutes or shorter, preferably 10 minutes or shorter.

(Affixing process)
In the adhering step, the carrier film 2 is adhered to the glass substrate 3 .

Specifically, the lower surface of the long glass substrate 3 is brought into contact with the adhesive layer 5 of the carrier film 2 .

A known or commercially available glass substrate 3 can be used. The elongated glass base material 3 generally includes the glass base material 3 and a spacer (interleaving paper or the like) arranged on one side thereof, which are wound into a roll. This spacer is removed from the glass substrate 3 before the bonding process.

From the viewpoint of adhesion between the glass substrate 3 and a transparent conductive layer (described later), if necessary, the lower surface or upper surface of the glass substrate 3 may be coated with, for example, sputtering, corona discharge, flame, ultraviolet irradiation, or an electron beam. Etching processes such as irradiation, conversion, oxidation, etc. can be performed. Further, the glass substrate 3 can be dust-removed and cleaned by solvent cleaning, ultrasonic cleaning, or the like.

Thereby, the glass laminate 1 including the carrier film 2 and the glass substrate 3 arranged on the upper surface thereof is obtained.

The thickness of the glass laminate 1 is, for example, 50 μm or more, preferably 100 μm or more, and is, for example, 300 μm or less, preferably 200 μm or less.

In the glass laminate 1 before heating, that is, in the initial glass laminate 1, the peeling force between the carrier film 2 and the glass substrate 3 is, for example, 0.05 N/50 mm or more, preferably 0.1 N/ It is 50 mm or more, and is, for example, 1.5 N/50 mm or less, preferably 1.0 N/50 mm or less, more preferably 0.5 N/50 mm or less. When the peeling force is equal to or higher than the lower limit, peeling or detachment between the carrier film 2 and the glass substrate 3 can be suppressed during transportation. Further, if the peel force is equal to or less than the upper limit, excessive increase in the peel force can be suppressed when the glass laminate 1 is heated, and the carrier film 2 can be smoothly removed from the glass laminate 1. can.

In the glass laminate 1 after heating, specifically, in the glass laminate 1 when heated at 140° C. for 60 minutes, the peeling force between the carrier film 2 and the glass substrate 3 is 0.1 N/50 mm or more, It is 2.0 N/50 mm or less. It is preferably 0.5 N/50 mm or more, more preferably 1.0 N/50 mm or more, and preferably 1.8 N/50 mm or less. That is, when the glass laminate 1 is heated at 140° C. for 60 minutes, the peel strength between the carrier film 2 and the glass substrate 3 falls within the above range. When the peeling force is equal to or higher than the lower limit, it is possible to suppress the generation of air bubbles between the carrier film 2 and the glass laminate 1 . Moreover, if the said peel force is below the said upper limit, the carrier film 2 can be removed smoothly from the glass laminated body 1, and the breakage of the glass base material 3 can be suppressed.

These peel forces can be measured using a sample obtained by cutting the glass laminate 1 into a width of 50 mm under the conditions of a tensile speed of 300 mm/min and a peel angle of 180°. More specifically, it will be described in detail in Examples.

5. Use of Glass Laminate The glass laminate 1 can be used, for example, in a method for producing an optical member. A method for manufacturing the transparent conductive glass 6 shown in FIG. 2 using the glass laminate 1 will be described below as an embodiment of the method for manufacturing an optical member.

The method for manufacturing the transparent conductive glass 6 includes, for example, a conductive layer placement step and a heating step in this order. The transparent conductive glass 6 is manufactured, for example, by a roll-to-roll method.

(Conductive layer placement step)
In the conductive layer placement step, the transparent conductive layer 7 is placed on the top surface of the glass laminate 1 .

Specifically, for example, the transparent conductive layer 7 is formed on the upper surface of the glass substrate 3 by a dry method.

Dry methods include, for example, a vacuum deposition method, a sputtering method, an ion plating method, and the like. Sputtering is preferred. By this method, the transparent conductive layer 7 which is a thin film and has a uniform thickness can be formed.

When the sputtering method is employed, the target material includes a metal oxide, which constitutes the transparent conductive layer 7 and will be described later, and preferably ITO. From the viewpoint of the durability and crystallization of the ITO layer, the tin oxide concentration of ITO is, for example, 0.5% by mass or more, preferably 3% by mass or more, and is, for example, 15% by mass or less, preferably , 13% by mass or less.

Examples of gases include inert gases such as Ar. In addition, a reactive gas such as oxygen gas can be used together as necessary. When a reactive gas is used in combination, the flow rate ratio (sccm) of the reactive gas is not particularly limited. is.

The atmospheric pressure during sputtering is, for example, 1 Pa or less, preferably 0.1 Pa or more and 0.7 Pa or less, from the viewpoints of suppressing a decrease in sputtering rate, discharge stability, and the like.

The power supply may be, for example, a DC power supply, an AC power supply, an MF power supply, an RF power supply, or a combination thereof.

As a result, as shown in FIG. 2, a transparent conductive glass laminate 8 including the carrier film 2 and the transparent conductive glass 6 placed thereon is obtained.

The peeling force between the carrier film 2 and the transparent conductive glass 6 at this time is substantially the same as the initial peeling force between the carrier film 2 and the glass substrate 3 described above.

(Heating process)
In the heating step, the transparent conductive glass laminate 8 is subjected to a heating step.

Heat treatment can be performed using, for example, an infrared heater, an oven, or the like.

The heating atmosphere may be either in air or in vacuum, but is preferably in air from the viewpoint of crystallization.

The heating temperature is, for example, 100° C. or higher, preferably 120° C. or higher, and is, for example, 200° C. or lower, preferably 160° C. or lower. If the heating temperature is within the above range, crystal conversion can be ensured while suppressing thermal damage to the plastic substrate 4 and impurities generated therefrom.

The heating time is appropriately determined depending on the heating temperature, and is, for example, 10 minutes or longer, preferably 30 minutes or longer, and is, for example, 5 hours or shorter, preferably 2 hours or shorter.

Thereby, when the transparent conductive layer 7 is made of ITO or the like, the transparent conductive layer 7 is crystallized, and the conductivity of the transparent conductive layer 7 is improved. Specifically, a transparent conductive glass laminate 8 comprising a glass substrate 3 and a heated transparent conductive layer 7 disposed on the upper surface thereof is obtained.

The peeling force between the carrier film 2 and the transparent conductive glass 6 in the transparent conductive glass laminate 8 after heating is the same as the peeling force between the carrier film 2 and the glass substrate 3 in the glass laminate 1 after heating. are substantially identical.

Then, it is wound into a roll. As a result, the long transparent conductive glass laminate 8 is obtained as a roll body 9 wound into a roll shape, as shown in FIG.

If necessary, the transparent conductive layer 7 is then patterned by known etching. Etching may be performed before winding the transparent conductive glass laminate 8 as a roll 9 . Alternatively, after unrolling the transparent conductive glass laminate 8 from the roll body 9 by a roll-to-roll method, the etching may be performed and the roll may be wound again.

The pattern of the transparent conductive layer 7 is appropriately determined according to the application to which the transparent conductive glass 6 is applied, and examples thereof include a striped electrode pattern and a wiring pattern.

6. Transparent Conductive Glass Laminate The transparent conductive glass laminate 8 comprises a carrier film 2 and a transparent conductive glass 6 placed on top thereof. The transparent conductive glass 6 comprises a glass substrate 3 and a transparent conductive layer 7 arranged on its upper surface. In other words, the transparent conductive glass laminate 8 includes the glass laminate 1 and the transparent conductive layer 7 disposed on the upper surface thereof.

(Transparent conductive layer)
The transparent conductive layer 7 is a conductive layer for forming desired transparent patterns such as electrode patterns and wiring patterns.

The transparent conductive layer 7 is the uppermost layer of the transparent conductive glass laminate 8 and has a film shape. The transparent conductive layer 7 is arranged on the entire upper surface of the glass substrate 3 so as to be in contact with the upper surface of the glass substrate 3 .

At least one selected from the group consisting of In, Sn, Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, and W as the material of the transparent conductive layer 7, for example. metal oxides containing metals of The metal oxide may be further doped with a metal atom shown in the above group, if necessary.

Specific examples of the transparent conductive layer 7 include indium-containing oxides such as indium-tin composite oxide (ITO) and antimony-containing oxides such as antimony-tin composite oxide (ATO). Indium-containing oxides are preferred, and ITO is more preferred.

When the transparent conductive layer 7 is made of ITO, the tin oxide (SnO ₂ ) content is, for example, 0.5% by mass or more with respect to the total amount of tin oxide and indium oxide (In ₂ O ₃ ), preferably It is 3% by mass or more and, for example, 15% by mass or less, preferably 13% by mass or less. If the content of tin oxide is at least the above lower limit, the durability of the transparent conductive layer 7 can be further improved. Moreover, if the content of tin oxide is equal to or less than the above upper limit, the crystal conversion of the transparent conductive layer 7 can be facilitated, and the stability of transparency and specific resistance can be improved.

"ITO" in this specification may be a composite oxide containing at least indium (In) and tin (Sn), and may contain additional components other than these. Examples of additional components include metal elements other than In and Sn, and specific examples include Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, W, and Fe. , Pb, Ni, Nb, Cr, Ga, and the like.

The specific resistance of the transparent conductive layer 7 is, for example, 5.0×10 ⁻⁴ Ω·cm or less, preferably 2.0×10 ⁻⁴ Ω·cm or less. A specific resistance can be measured by a four-probe method.

The thickness of the transparent conductive layer 7 is, for example, 10 nm or more, preferably 30 nm or more, and for example, 300 nm or less, preferably 100 nm or less. If the thickness of the transparent conductive layer 7 is equal to or more than the above lower limit, the conductivity is excellent. On the other hand, if the thickness of the transparent conductive layer 7 is equal to or less than the above upper limit, the thickness of the transparent conductive glass 6 can be reduced. The thickness of the transparent conductive layer 7 can be measured using a scanning fluorescent X-ray analyzer.

The transparent conductive layer 7 may be either amorphous or crystalline, but is preferably crystalline when the heating step is performed. If the transparent conductive layer 7 is crystalline, it has excellent conductivity.

Whether the transparent conductive layer is amorphous or crystalline can be determined, for example, when the transparent conductive layer is an ITO layer, it is immersed in hydrochloric acid (concentration: 5% by mass) at 20° C. for 15 minutes, then washed with water and dried to obtain a thickness of about 15 mm. It can be judged by measuring the resistance between the terminals. In this specification, if the resistance between terminals for 15 mm exceeds 10 kΩ after immersion in hydrochloric acid (20 ° C., concentration 5% by mass), washing with water, and drying, the ITO layer is amorphous, and the terminals between 15 mm If the resistance is less than 10 kΩ, the ITO layer is crystalline.

The transparent conductive glass laminate 8 is used, for example, in optical devices such as image display devices. More specifically, the carrier film 2 is removed (peeled off) from the transparent conductive glass laminate 8, and the transparent conductive glass 6 is used as a member of the image display device.

Specifically, when the transparent conductive glass 6 is provided in an image display device (for example, an image display device having an image display element such as an LCD module or an organic EL module), the transparent conductive glass 6 is, for example, a touch panel. used as a base material for Touch panels may be of various types, such as an optical system, an ultrasonic system, a capacitive system, and a resistive film system, and are particularly suitable for capacitive touch panels.

In addition, the transparent conductive glass 6 is, for example, a component such as a base material for a touch panel provided in an image display device, that is, it is not an image display device. That is, the transparent conductive glass 6 is a part for producing an image display device or the like, does not include an image display element such as an LCD module, but includes the glass substrate 3 and the transparent conductive layer 7, and is distributed as a component alone. and is an industrially applicable device.

Since the glass laminate 1 and the transparent conductive glass laminate 8 are provided with the carrier film 2 and the glass substrate 3 having a thickness of 150 μm or less, they can be made into a roll 9, and can be obtained by a roll-to-roll method. Industrial production is possible.

In addition, since the carrier film 2 includes the plastic substrate 4 having a thickness of 100 μm or less and the adhesive layer 5, the glass substrates laminated on each other in the roll body 9 during winding by the roll-to-roll method. It is possible to relax the stress between the members 3 and suppress damage caused by the stress.

In addition, since the carrier film 2 includes the plastic substrate 4 having a thickness of 100 μm or less and the adhesive layer 5, the heat shrinkage of the plastic substrate 4 can be reduced, and curling after heating can be suppressed. . Therefore, the glass laminate 1 after heating can be easily rolled.

Further, when the glass laminate 1 or the transparent conductive glass laminate 8 was heated at 140° C. for 60 minutes, the peeling force between the carrier film 2 and the glass substrate 3 (and thus the transparent conductive glass 6) was 0.1 N. /50 mm or more and 2.0 N/50 mm or less, the carrier film 2 can be smoothly peeled from the glass substrate 3 (or the transparent conductive glass 6) even after heating. Therefore, breakage of the glass substrate 3 can be suppressed when the carrier film 2 is peeled off.

In particular, the present invention achieves mass production by the roll-to-roll system in optical members (for example, transparent conductive glass 6) having a flexible glass substrate 3 as a supporting substrate.

Specifically, when an optical film is produced by a roll-to-roll method using a flexible glass substrate 3, the stress between the glass substrates 3 that are laminated to each other in the roll-shaped optical film causes the glass to crack. Breakage of the substrate 3 occurs.

Therefore, if the carrier film 2 is arranged on the lower surface of the glass substrate 3 in order to suppress breakage of the glass substrate 3, due to the difference in thermal expansion coefficient between the carrier film 2 and the glass substrate 3 during heating, A large amount of curl occurs, and as a result, winding into a roll becomes difficult.

Therefore, if the thickness of the plastic base material 4 of the carrier film 2 is set to 100 μm or less in order to suppress curling, the carrier film 2 cannot be smoothly separated from the glass base material 3, and the glass base material 3 is damaged. There was found. As a result of further research on this point, it was found that the peeling force of the pressure-sensitive adhesive layer 5 significantly increases as the thickness of the plastic substrate 4 is reduced.

Based on this knowledge, the present inventors focused on the peeling force of the adhesive layer 5 after heating, and as a result, in addition to the structure of the carrier film, the separation between the carrier film 2 and the glass substrate 3 after heating The above problem is solved by setting the peeling force within a predetermined range. That is, the problem of curling due to heating, breakage of the glass substrate 3 during winding, and breakage of the glass substrate 3 during peeling of the carrier film has been solved. Therefore, realistic mass production by the roll-to-roll method becomes possible.

<Modification>
Modifications of the embodiment shown in FIGS. 1 and 2 will be described below. Note that these modifications also have the same effects as the above-described embodiment.

(1) FIGS. 1 and 2 exemplify a method for manufacturing a transparent conductive glass laminate 8 as an application of the glass laminate 1. For example, although not shown, as an application of the glass laminate 1, A method for manufacturing an antireflection glass laminate can be exemplified.

The antireflection glass laminate comprises a carrier film 2 and an antireflection glass arranged on top thereof. The antireflection glass comprises a glass substrate 3 and an antireflection layer arranged on the upper surface thereof. That is, the antireflection glass and the antireflection glass laminate have an antireflection layer instead of the transparent conductive layer 7 .

The antireflection layer comprises a low refractive index layer and a high refractive index layer, preferably an alternate laminate of low refractive index layers and high refractive index layers.

The refractive index of the low refractive layer is, for example, 1.35 or more and 1.55 or less. Examples of materials for the low refractive layer include silicon oxide and magnesium fluoride.

The refractive index of the high refractive index layer is, for example, 1.80 or more and 2.40 or less. Materials for the high refractive layer include, for example, titanium oxide, niobium oxide, zirconium oxide, ITO, and ATO.

The total thickness of the antireflection layer is, for example, 100 nm or more, preferably 200 nm or more, and is, for example, 500 nm or less, preferably 300 nm or less.

Such an antireflection layer is described, for example, in JP-A-2017-227898.

The antireflection glass laminate can be produced by performing an antireflection layer arrangement step instead of the conductive layer arrangement step in the method for producing the transparent conductive glass laminate 8 .

In the antireflection layer disposing step, an antireflection layer is formed on the upper surface of the glass substrate 3 by a dry method. Examples of the dry method include those described above, preferably the sputtering method.

When the sputtering method is adopted, the material constituting the above antireflection layer is used as the target material. That is, a target made of the material for the high refractive layer and a target made of the material for the low refractive layer are used.

(2) As an application of the glass laminate 1, for example, although not shown, a functional layer other than the transparent conductive layer 7 and the antireflection layer is arranged on the glass substrate 3 of the glass laminate 1 to form a desired functional layer ( For example, a glass laminate having an optical adjustment layer) can also be produced.

EXAMPLES Examples and comparative examples are shown below to describe the present invention more specifically. In addition, the present invention is not limited to Examples and Comparative Examples. In addition, specific numerical values such as the mixing ratio (content ratio), physical property values, and parameters used in the following description are the corresponding mixing ratios ( Content ratio), physical properties, parameters, etc. be able to.

Example 1
(Preparation of carrier film)
96.2 parts by mass of 2-ethylhexyl acrylate (2EHA) and 3.8 parts by mass of hydroxyethyl acrylate (HEA) as monomer components, and 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator 0.2 part by mass was mixed with 150 parts by mass of ethyl acetate, and nitrogen gas was introduced while stirring at 23° C. to replace with nitrogen. After that, the liquid temperature was kept around 65° C. and the polymerization reaction was carried out for 6 hours to prepare a solution of acrylic polymer A (concentration: 40% by mass). The weight average molecular weight of Acrypolymer A was 540,000.

Ethyl acetate was added to the acrylic polymer A solution to dilute it to a concentration of 20% by mass. To 500 parts by mass of the diluted solution (100 parts by mass of solid content), 4 parts by mass of toluene diisocyanate (manufactured by Tosoh, "Coronate L" (C/L)) as a cross-linking agent, and 0.02 parts by mass of dibutyltin dilaurate as a cross-linking catalyst. was added and stirred to prepare an acrylic adhesive solution.

An acrylic pressure-sensitive adhesive solution is applied to one side of a long polyester film (plastic substrate, manufactured by Toray Industries, Inc., "Polyester Film Lumirror 25R75", thickness 25 μm) by a roll-to-roll method, and is heated at 130° C. for 2 minutes. It was heated to form an adhesive layer with a thickness of 23 μm. Thus, a carrier film was produced.

(Manufacture of glass laminate)
A long glass substrate (thickness 100 μm, “G-Leaf” manufactured by Nippon Electric Glass Co., Ltd.) was prepared. The pressure-sensitive adhesive layer of the carrier film and the glass substrate were bonded together by a roll-to-roll method, and wound around a take-up roll.

In this way, a glass laminate including the carrier film and the glass substrate and wound into a roll was produced.

Examples 2-3
A glass laminate was produced in the same manner as in Example 1, except that the thickness of the polyester film was changed to the thickness shown in Table 1.

Example 4
In the preparation of the acrylic pressure-sensitive adhesive solution, 4 parts by mass of an isocyanate-based cross-linking agent "Coronate HX" (C-HX)) was used as a cross-linking agent, and the amount of dibutyltin dilaurate was changed to 0.015 parts by mass. Moreover, the thicknesses of the polyester film and the pressure-sensitive adhesive layer were changed to the thicknesses described in Example 1. Except these, it carried out similarly to Example 1, and manufactured the glass laminated body.

Example 5
90 parts by mass of butyl acrylate (BA) and 10 parts by mass of acrylic acid (AA) as monomer components, and 0.2 parts by mass of AIBN as a polymerization initiator were mixed with 186 parts by mass of ethyl acetate and stirred at 23°C. Nitrogen substitution was performed by introducing nitrogen gas while After that, the liquid temperature was kept around 63° C. and the polymerization reaction was carried out for 10 hours to prepare a solution of acrylic polymer B (concentration: 35 mass %). The weight average molecular weight of Acrypolymer B was 500,000.

Ethyl acetate was added to the acrylic polymer B solution to dilute it to a concentration of 20% by mass. To 500 parts by mass of the diluted solution (100 parts by mass of solid content), 11 parts by mass of a tetrafunctional epoxy compound (manufactured by Mitsubishi Gas Chemical Co., Ltd., "Tetrad C" (TC)) as a cross-linking agent is added and stirred, and the acrylic An adhesive solution was prepared.

The acrylic adhesive solution was applied to one side of a long polyester film (same as above) by a roll-to-roll method and heated at 130° C. for 2 minutes to form a 20 μm thick adhesive layer. . Thus, a carrier film was produced.

A glass laminate was produced in the same manner as in Example 1, except that this carrier film was used.

Comparative example 1
A glass laminate was produced in the same manner as in Example 5, except that the thickness of the polyester film was changed to the thickness shown in Table 1.

Comparative example 2
A glass laminate was produced in the same manner as in Example 5, except that the amount of the cross-linking agent in the pressure-sensitive adhesive layer was changed to the amount shown in Table 1.

Comparative example 3
A glass laminate was produced in the same manner as in Comparative Example 2, except that the thickness of the polyester film was changed to the thickness shown in Table 1.

Comparative example 4
A glass laminate was produced in the same manner as in Example 5, except that the amount of the cross-linking agent in the pressure-sensitive adhesive layer was changed to the amount shown in Table 1.

Comparative example 5
A glass laminate was produced in the same manner as in Comparative Example 4, except that the thickness of the polyester film was changed to the thickness shown in Table 1.

Comparative example 6
In the pressure-sensitive adhesive layer, the amount of the monomer component and the amount of the cross-linking agent were changed to the amounts shown in Table 1. In addition, the thicknesses of the polyester film and the pressure-sensitive adhesive layer were changed to the amounts shown in Table 1. Except these, it carried out similarly to Example 5, and manufactured the glass laminated body.

(thickness of each layer)
The thicknesses of the plastic film, adhesive layer, and glass substrate were measured using a dial gauge (“DG-205” manufactured by PEACOCK).

(Initial peel strength)
The glass laminate is cut into a width of 50 mm and a length of 200 mm, and the glass substrate 3 side of the cut glass laminate is placed on the sample table 11 of a peel force measurement device (device name “TCM-1kNB”, manufactured by MinebeaMitsumi Co., Ltd.). , and an adhesive tape (fixing member) 12 . Subsequently, one end in the length direction of the carrier film 2 in the glass laminate was gripped by the movable stage 13 and pulled in the length direction at a tensile speed of 300 mm/min to obtain a peel force at a peel angle of 180° (N/ 50 mm) was measured (see FIG. 4). Table 1 shows the results.

(Peel strength after heating)
The glass laminate was heated at 140° C. for 60 minutes. For this glass laminate after heating, the peel strength (N/50 mm) at a peel angle of 180° was measured at a tensile speed of 300 mm/min in the same manner as in the initial peel strength test. Table 1 shows the results.

(Curl test)
The glass laminate of each example and each comparative example was cut into a square shape of 20 cm×20 cm in plan view to prepare a test piece. The test piece was placed on a horizontal table in an oven with the polyester film facing upward, and heated at 140° C. for 60 minutes. Then, it was allowed to cool at room temperature (23° C.) for 1 hour, and this was used as a test piece after heating.

After heating, the average height H of the four corners from the horizontal table was measured (see FIG. 5). Table 1 shows the results.

(Peelability)
The glass base material after peeling was confirmed at the peel strength after heating.

A case in which no breakage was observed in the glass substrate was evaluated as ◯, and a case in which breakage such as chipping was observed in a part of the glass substrate was evaluated as x. Table 1 shows the results.

(Confirmation of air bubbles)
The test piece after heating in the curl test was observed with the naked eye.

A case where no air bubbles were observed in the pressure-sensitive adhesive layer was evaluated as ◯, and a case where air bubbles were observed was evaluated as x. Table 1 shows the results.

1 glass laminate 2 carrier film 3 glass substrate 4 plastic substrate 5 adhesive layer 7 transparent conductive layer

Claims (3)

a carrier film;
A glass laminate comprising a glass substrate arranged on one side in the thickness direction of the carrier film and having a thickness of 150 μm or less,
The carrier film is
a plastic substrate having a thickness of 100 μm or less;
a pressure-sensitive adhesive layer arranged on one side in the thickness direction of the plastic substrate,
When the glass laminate is heated at 140° C. for 60 minutes, the peeling force between the carrier film and the glass substrate is 0.1 N/50 mm or more and 2.0 N/50 mm or less. laminate. The glass laminate according to claim 1, further comprising a transparent conductive layer arranged on one side in the thickness direction of the glass substrate. 3. The glass laminate according to claim 1, wherein the glass laminate is wound into a roll.

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