CN110901198A

CN110901198A - Glass laminate

Info

Publication number: CN110901198A
Application number: CN201910859245.2A
Authority: CN
Inventors: 松本正宪; 西森才将; 梨木智刚; 小川圭太
Original assignee: Nitto Denko Corp
Current assignee: Nitto Denko Corp
Priority date: 2018-09-14
Filing date: 2019-09-11
Publication date: 2020-03-24
Also published as: KR20200031521A; TW202021800A; JP7171330B2; JP2020044651A

Abstract

The invention provides a glass laminate which can inhibit the generation of curl and inhibit the breakage of a glass substrate. The glass laminate (1) is provided with a carrier film (2) and a glass substrate (3) which is arranged on the upper side of the carrier film and has a thickness of 150 [ mu ] m or less, wherein the carrier film (2) is provided with a plastic substrate (4) having a thickness of 100 [ mu ] m or less and an adhesive layer (5) arranged on the upper side of the carrier film, and the peeling force between the carrier film (2) and the glass substrate (3) is 0.1N/50mm or more and 2.0N/50mm or less when the glass laminate (1) is heated at 140 ℃ for 60 minutes.

Description

Glass laminate

Technical Field

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

Background

In recent years, a thin glass substrate has been used as a flexible substrate of an optical film provided in an image display device such as a liquid crystal display or an organic EL display, 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.

In order to mass-produce such an optical film, a roll-to-roll (roll-to-roll) method is used. That is, a long thin glass substrate is prepared, functional layers such as a transparent conductive layer are sequentially formed on the thin glass substrate, and finally wound into a roll.

However, when an optical film including thin glass substrates is wound, the thin glass substrates stacked in the thickness direction are damaged by stress between the thin glass substrates. 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).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-39227

Disclosure of Invention

Problems to be solved by the invention

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 peeled off from the thin glass substrate. Therefore, the resin layer remains as a final product (optical film), and thus the optical film cannot be made thin, and optical characteristics (light transmittance and color tone) may be reduced.

Therefore, a method of laminating a support film including an adhesive layer and a plastic film on a thin glass substrate of an optical film has been studied. Since the carrier film is laminated on the thin glass substrate via the adhesive layer, the carrier film can be easily removed (peeled off) from the adhesive layer after the production of the optical film and before the assembly of the optical film into an image display device.

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

Thus, curling occurs due to the difference in thermal expansion rates between the thin glass substrate and the carrier film. Therefore, it is also studied to reduce curling by thinning the carrier film.

However, when a laminate of the carrier film and the thin glass substrate is heated, the carrier film is not smoothly peeled off from the thin glass substrate when the carrier film is removed, and the thin glass substrate is damaged.

The purpose of the present invention is to provide a glass laminate that can suppress the occurrence of curl and can suppress breakage of a glass substrate.

Means for solving the problems

The present invention [1] includes a glass laminate comprising: a carrier film and a glass substrate disposed on one side of the carrier film in a thickness direction and having a thickness of 150 μm or less, the carrier film comprising: a plastic substrate having a thickness of 100 [ mu ] m or less, and an adhesive layer disposed on one side of the plastic substrate in the thickness direction, wherein when the glass laminate is heated at 140 ℃ for 60 minutes, the peeling force between the carrier film and the glass substrate is 0.1N/50mm or more and 2.0N/50mm or less.

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

The invention [3] comprises the glass laminate according to [1] or [2], which is wound in a roll form.

ADVANTAGEOUS EFFECTS OF INVENTION

The glass laminate of the present invention has a glass substrate having a thickness of 150 μm or less, and therefore can be formed into a roll shape, and can be industrially produced (mass-produced) by a roll-to-roll method.

Further, the glass laminate of the present invention includes the carrier film and the glass substrate, and therefore, breakage of the glass substrate can be suppressed when the glass laminate is formed into a roll.

Further, since the carrier film includes the plastic base material having a thickness of 100 μm or less and the pressure-sensitive adhesive layer, curling during the heating treatment can be suppressed.

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

Drawings

FIG. 1 is a cross-sectional view of one embodiment of a glass laminate according to the present invention.

Fig. 2 is a cross-sectional view of a transparent conductive glass laminate including the glass laminate shown in fig. 1.

Fig. 3 is a perspective view of the roll of the transparent conductive glass laminate shown in fig. 2.

FIG. 4 is a schematic view of a test for measuring the peel force of the glass laminate in the examples.

FIG. 5 is a schematic view of a test for measuring the curl of a glass laminate in examples.

Description of the reference numerals

1 glass laminate

2 Carrier film

3 glass substrate

4 Plastic base Material

5 adhesive layer

7 transparent conductive layer

Detailed Description

< one embodiment >

A glass laminate 1 according to an embodiment of the present invention will be described with reference to fig. 1 to 4.

In fig. 1, the vertical direction on the paper surface is the vertical direction (thickness direction), the upper side on the paper surface is the upper side (thickness direction side), and the lower side on the paper surface is the lower side (thickness direction side). In fig. 1, the horizontal direction and the depth direction of the drawing sheet are plane directions orthogonal to the vertical direction. Specifically, directional arrows in the drawings are used as references.

1. Glass laminate

As shown in fig. 1, the glass laminate 1 has flexibility and is in the form of a thin film (including a sheet) having a predetermined thickness. The glass laminate 1 extends in a plane direction orthogonal 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, a member for producing a substrate for a touch panel or the like included in an image display device, that is, 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, and is distributed by itself as a component and industrially available.

Specifically, the glass laminate 1 includes: a carrier film 2, and a glass substrate 3 disposed 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 below. Preferably, the glass laminate 1 is formed of a support film 2 and a glass substrate 3. Hereinafter, each member will be described in detail.

2. Carrier film

The carrier film 2 is a protective member provided on the lower surface of the glass substrate 3 in order to prevent the glass substrate 3 from being damaged when the glass substrate 3 and the transparent conductive glass 6, which will be described later, are conveyed, heated, and/or stored. The carrier film 2 supports the glass substrate 3 from the lower side.

The carrier film 2 has a film shape having a predetermined thickness, extends in the planar direction, and has a flat upper surface and a flat lower surface. The carrier film 2 is disposed below the glass laminate 1, and specifically, is disposed over 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 a pressure-sensitive adhesive layer 5 disposed on the upper surface of the plastic substrate 4. That is, the carrier film 2 includes the plastic base 4 and the pressure-sensitive adhesive layer 5 in this order from below. The carrier film 2 is preferably formed of a plastic substrate 4 and an adhesive layer 5.

(Plastic substrate)

The plastic substrate 4 is a support substrate for securing the mechanical strength of the carrier film 2 and protecting the glass substrate 3 from damage during transportation, heating, storage, and the like.

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

The plastic substrate 4 is, for example, a flexible polymer film. Examples of the material of the plastic substrate 4 include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate, (meth) acrylic resins such as polymethacrylate (acrylic resins and/or methacrylic resins), olefin resins such as polyethylene, polypropylene, and cycloolefin polymers (for example, norbornene-based and cyclopentadiene-based), polycarbonate resins, polyether sulfone resins, polyarylate resins, melamine resins, polyamide resins, polyimide resins, cellulose resins, and polystyrene resins. These materials may be used alone or in combination of 2 or more.

From the viewpoint of transparency, heat resistance, mechanical strength, and the like, a polyester resin is preferably used, and PET is more preferably used.

The thickness of the plastic substrate 4 is 100 μm or less, preferably 60 μm or less, and more preferably 35 μm or less. The thickness is, for example, 5 μm or more, preferably 10 μm or more. When the thickness of the plastic substrate 4 is not more than the upper limit, the occurrence of curling when heating the glass laminate 1 can be suppressed. On the other hand, when the thickness of the plastic substrate 4 is not less than the 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 by using a direct reading thickness meter (manufactured by PEACOCK, "DG-205").

(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 a layer (easy-to-peel layer) that is easily peeled from the glass substrate 3 after adhesion.

The pressure-sensitive adhesive layer 5 has a film shape and is disposed 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 pressure-sensitive adhesive layer 5 is disposed between the plastic substrate 4 and the glass substrate 3 so as to be in contact with the upper surface of the plastic substrate 4 and the lower surface of the glass substrate 3. In detail, the adhesive layer 5 pressure-sensitive bonds glass to the lower surface of the base material 3.

The adhesive layer 5 is formed of an adhesive composition.

Examples of the adhesive composition include an acrylic adhesive composition, a rubber adhesive composition, a silicone adhesive composition, a polyester adhesive composition, a polyurethane adhesive composition, a polyamide adhesive composition, an epoxy adhesive composition, a vinyl alkyl ether adhesive composition, and a fluorine adhesive composition. These adhesive compositions may be used alone or in combination of 2 or more.

The pressure-sensitive adhesive composition is preferably an acrylic pressure-sensitive adhesive composition from the viewpoints of adhesiveness before heating, releasability after heating, and the like.

The acrylic adhesive composition contains, as a polymer component, an acrylic polymer obtained by polymerizing a monomer component containing an alkyl (meth) acrylate.

The alkyl (meth) acrylate is an alkyl acrylate and/or an alkyl methacrylate, and specific examples thereof include alkyl (meth) acrylates having a linear or branched alkyl moiety having 4 to 14 carbon atoms such as butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, neopentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, and tetradecyl (meth) acrylate. The alkyl (meth) acrylate may be used singly or in combination of 2 or more.

The alkyl (meth) acrylate preferably includes an alkyl (meth) acrylate having an alkyl moiety of 4 to 12 carbon atoms, more preferably includes an alkyl (meth) acrylate having an alkyl moiety of 6 to 10 carbon atoms, and still more preferably includes 2-ethylhexyl (meth) acrylate.

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

The monomer component may contain a functional group-containing monomer in addition to the alkyl methacrylate.

Examples of the functional group-containing monomer include 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 may be used singly or in combination of 2 or more.

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

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 or less, per 100 parts by mass of the total amount of the monomer components.

The weight average molecular weight of the acrylic polymer is, for example, 10 ten thousand or more, preferably 30 ten thousand or more, and, for example, 200 ten thousand or less, preferably 100 ten thousand or less. The weight average molecular weight can be determined by gel permeation chromatography based on standard polystyrene conversion values.

The acrylic pressure-sensitive adhesive composition can be obtained by a known method such as solution polymerization, bulk polymerization, or photopolymerization.

The adhesive composition preferably contains a crosslinking agent. Examples of the crosslinking agent include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, melamine-based resins, aziridine derivatives, and metal chelate compounds. These crosslinking agents may be used alone or in combination of 2 or more.

The crosslinking agent is preferably an isocyanate crosslinking agent or an epoxy crosslinking agent, and more preferably an isocyanate crosslinking agent.

Examples of the isocyanate-based crosslinking agent include aromatic isocyanates such as tolylene diisocyanate and xylylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate and cyclohexylene diisocyanate, aliphatic isocyanates such as butylene diisocyanate and hexamethylene diisocyanate, isocyanate adducts such as trimethylolpropane/tolylene diisocyanate trimer adduct, trimethylolpropane/hexamethylene diisocyanate trimer adduct and isocyanurate of hexamethylene diisocyanate, polyol adducts such as polyether polyisocyanate and polyester polyisocyanate, isocyanurate, biuret and allophanate.

The epoxy-based crosslinking agent preferably includes a polyfunctional epoxy compound, and specifically includes, for example, N' -tetraglycidyl m-xylylenediamine, 1, 3-bis (N, N-diglycidylaminomethyl) cyclohexane (trade name "TETRAD C", manufactured by mitsubishi gas chemical corporation), and the like.

The blending ratio of the crosslinking agent is, for example, 1 part by mass or more, preferably 2 parts by mass or more, and is, for example, 15 parts by mass or less, preferably 5 parts by mass or less, relative to 100 parts by mass of the polymer component. The peeling force of the pressure-sensitive adhesive layer 5 can be adjusted by adjusting the blending ratio of the crosslinking agent.

When the crosslinking agent is contained, it is more preferable to use a crosslinking catalyst as well. Examples of the crosslinking catalyst include tin catalysts such as tin octylate, dioctyltin dilaurate, dibutyltin bis (acetylacetonate), and tin chelate compounds, and iron catalysts such as iron tris (acetylacetonate), iron trimethoxy, iron triisopropyloxide, and iron chloride. These crosslinking catalysts may be used alone or in combination of 2 or more. Preferably, a tin-based catalyst is used.

The blending ratio of the crosslinking catalyst is, for example, 0.1 part by mass or more, preferably 0.2 part by mass or more, and is, for example, 5 parts by mass or less, preferably 3 parts by mass or less, relative to 100 parts by mass of the crosslinking agent. The peeling force of the pressure-sensitive adhesive layer 5 can be adjusted by adjusting the blending ratio of the crosslinking catalyst.

The pressure-sensitive adhesive composition may further contain known additives such as a tackifier resin, a processing aid, a pigment, a flame retardant, a filler, a softener, and an antioxidant.

The thickness of the pressure-sensitive 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 by using a direct reading thickness meter (manufactured by PEACOCK, "DG-205").

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, and still more preferably 25 μm or less. When the thickness of the carrier film 2 is not more than the upper limit, the occurrence of curling when heating the glass laminate 1 can be suppressed. On the other hand, when the thickness of the carrier film 2 is not less than the lower limit, the mechanical strength is excellent, and breakage of the glass substrate 3 can be suppressed.

3. Glass substrate

The glass substrate 3 is a support member for supporting a functional layer such as a transparent conductive layer (described later) while ensuring mechanical strength of an optical member such as transparent conductive glass (described later).

The glass substrate 3 has a film shape and is disposed 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. In detail, the glass substrate 3 is pressure-sensitive bonded to the upper surface of the adhesive layer 5.

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

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

The upper surface or the lower surface of the glass substrate 3 may be subjected to a known primer treatment. That is, the glass substrate 3 may be provided with a primer layer on the upper surface or the lower surface thereof.

The thickness of the glass substrate 3 is 150 μm or less, preferably 120 μm or less, and more preferably 100 μm or less. The thickness is, for example, 10 μm or more, preferably 50 μm or more. When the thickness of the glass substrate 3 is not more than the upper limit, the flexibility is excellent and the glass substrate can be wound in a roll shape. When the thickness of the glass substrate 3 is not less than the lower limit, the mechanical strength is excellent, and breakage during conveyance can be suppressed.

The thickness of the glass substrate 3 can be measured by using a direct reading thickness meter (manufactured by PEACOCK, "DG-205").

4. Method for producing glass laminate

A method for producing the glass laminate 1 will be described. The method for manufacturing the glass laminate 1 includes, for example, a preparation step and a bonding step in this order. The glass laminate 1 can be manufactured, for example, by a roll-to-roll method.

(preparation Process)

In the preparation step, the carrier film 2 is prepared.

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

Examples of the solvent include an organic solvent and an aqueous solvent (specifically, water), and preferably an organic solvent. Examples of the organic solvent include alcohol compounds such as methanol, ethanol, and isopropanol, ketone compounds such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, ester compounds such as ethyl acetate and butyl acetate, ether compounds such as propylene glycol monomethyl ether, and aromatic compounds such as toluene and xylene. These solvents may be used alone or in combination of 2 or more. Ester compounds are preferably mentioned.

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

The coating method can be appropriately selected depending on the coating liquid and the plastic substrate 4. Examples thereof include a dip coating method, an air knife coating method, a curtain coating method, a roll coating method, a wire bar coating method, a gravure coating method, and an ink jet method.

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

The drying time is, for example, 0.5 minutes or more, preferably 1 minute or more, for example, 30 minutes or less, preferably 10 minutes or less.

(bonding step)

In the bonding step, the carrier film 2 is bonded 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.

As the glass substrate 3, a known or commercially available one can be used. The long glass substrate 3 generally includes a glass substrate 3 and a spacer (interleaving paper or the like) disposed on one surface thereof, and these are wound in a roll shape. The spacer is removed from the glass substrate 3 before the attachment process.

If necessary, the lower surface or the upper surface of the glass substrate 3 may be subjected to etching treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, or oxidation, from the viewpoint of adhesion between the glass substrate 3 and a transparent conductive layer (described later). The glass substrate 3 may be cleaned or dedusted by solvent cleaning, ultrasonic cleaning, or the like.

In this way, a glass laminate 1 including the carrier film 2 and the glass substrate 3 disposed on the upper surface thereof was 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.

The peeling force between the carrier film 2 and the glass substrate 3 of the glass laminate 1 before heating, i.e., the initial glass laminate 1, is, for example, 0.05N/50mm or more, preferably 0.1N/50mm or more, and is, for example, 1.5N/50mm or less, preferably 1.0N/50mm or less, and more preferably 0.5N/50mm or less. When the peeling force is not less than the lower limit, peeling or detachment of the carrier film 2 from the glass substrate 3 during conveyance can be suppressed. When the peeling force is not more than the upper limit, excessive increase in the peeling 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.

Specifically, in the glass laminate 1 after heating, the peeling force between the carrier film 2 and the glass substrate 3 is 0.1N/50mm or more and 2.0N/50mm or less in the glass laminate 1 heated at 140 ℃ for 60 minutes. Preferably 0.5N/50mm or more, more preferably 1.0N/50mm or more, and further preferably 1.8N/50mm or less. That is, after the glass laminate 1 was heated at 140 ℃ for 60 minutes, the peeling force between the carrier film 2 and the glass substrate 3 was within the above range. When the peeling force is not less than the lower limit, the generation of bubbles between the carrier film 2 and the glass laminate 1 can be suppressed. When the peeling force is not more than the upper limit, the carrier film 2 can be smoothly removed from the glass laminate 1, and damage to the glass substrate 3 can be suppressed.

The peeling force can be measured using a sample obtained by cutting the glass laminate 1 into pieces having a width of 50mm at a drawing speed of 300 mm/min and a peeling angle of 180 °. More specifically, the details are described in examples.

5. Use of glass laminate

The glass laminate 1 can be used for a method for manufacturing an optical member, for example. Hereinafter, a method for producing the transparent conductive glass 6 shown in fig. 2 by using the glass laminate 1 will be described as an embodiment of a method for producing an optical member.

The method for manufacturing the transparent conductive glass 6 includes, for example, a conductive layer disposing 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 disposing Process)

In the conductive layer disposing step, the transparent conductive layer 7 is disposed on the upper 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.

Examples of the dry method include a vacuum deposition method, a sputtering method, and an ion plating method. A sputtering method is preferably used. This method can form the transparent conductive layer 7 in a thin film and uniform in thickness.

In the case of the sputtering method, the target material may be a metal oxide described later which constitutes the transparent conductive layer 7, and preferably ITO. The tin oxide concentration of the ITO is, for example, 0.5 mass% or more, preferably 3 mass% or more, and, for example, 15 mass% or less, preferably 13 mass% or less, from the viewpoint of durability, crystallization, and the like of the ITO layer.

Examples of the gas include inert gases such as Ar. Further, reactive gases such as oxygen may be used in combination as necessary. When the reactive gases are used in combination, the flow rate ratio (sccm) of the reactive gases is not particularly limited, and is, for example, 0.1 to 5% by flow rate relative to the total flow rate ratio of the sputtering gas and the reactive gases.

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

The power source may be any of a DC power source, an AC power source, an MF power source, and an RF power source, for example, or a combination thereof.

As a result, a transparent conductive glass laminate 8 including the carrier film 2 and the transparent conductive glass 6 disposed on the upper surface thereof was obtained as shown in fig. 2.

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

(heating step)

In the heating step, the transparent conductive glass laminate 8 is subjected to a heating step.

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

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

The heating temperature is, for example, 100 ℃ or higher, preferably 120 ℃ or higher, and is, for example, 200 ℃ or lower, preferably 160 ℃ or lower. When the heating temperature is within the above range, the crystal transformation can be reliably performed while suppressing thermal damage to the plastic base material 4 and impurities generated therefrom.

The heating time is suitably determined depending on the heating temperature, and is, for example, 10 minutes or more, preferably 30 minutes or more, and is, for example, 5 hours or less, preferably 2 hours or less.

Accordingly, when the transparent conductive layer 7 is 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 including the glass substrate 3 and the heated transparent conductive layer 7 disposed on the upper surface thereof was obtained.

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

Then, the sheet was wound into a roll. Thus, the long transparent conductive glass laminate 8 is obtained as a roll 9 wound in a roll shape as shown in fig. 3.

Thereafter, the transparent conductive layer 7 is patterned by known etching as needed. The etching may be performed before the transparent conductive glass laminate 8 is wound into a roll 9. Alternatively, the transparent conductive glass laminate 8 may be unwound from the roll 9 in a roll-to-roll manner, etched, and wound into a roll again.

The pattern of the transparent conductive layer 7 is suitably determined according to the application of the transparent conductive glass 6, and examples thereof include an electrode pattern such as a stripe pattern and a wiring pattern.

6. Transparent conductive glass laminate

The transparent conductive glass laminate 8 includes a carrier film 2 and a transparent conductive glass 6 disposed on the upper surface thereof. The transparent conductive glass 6 includes a glass substrate 3 and a transparent conductive layer 7 disposed on the upper surface thereof. 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 a desired transparent pattern such as an electrode pattern or a wiring pattern.

The transparent conductive layer 7 is the uppermost layer of the transparent conductive glass laminate 8 and has a thin film shape. The transparent conductive layer 7 is disposed 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.

As the material of the transparent conductive layer 7, for example, a metal oxide containing at least 1 metal selected from the group consisting of In, Sn, Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, and W is cited. The metal oxide may further be doped with a metal atom shown in the above group as necessary.

Specific examples of the transparent conductive layer 7 include indium-containing oxides such as Indium Tin Oxide (ITO) and antimony-containing oxides such as Antimony Tin Oxide (ATO), and preferably indium-containing oxides, and more preferably ITO.

When the transparent conductive layer 7 contains ITO, tin oxide (SnO)₂) The content of tin oxide and indium oxide (In)₂O₃) The total amount of (b) 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. When the content of tin oxide is not less than the lower limit, the durability of the transparent conductive layer 7 can be further improved. When the content of tin oxide is not more than the upper limit, the crystal transformation of the transparent conductive layer 7 is facilitated, and the stability of transparency and resistivity can be improved.

The "ITO" In the present specification may contain an additional component other than the compound oxide containing at least indium (In) and tin (Sn). Examples of the additional component include metal elements other than In and Sn, and specifically include Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, W, Fe, Pb, Ni, Nb, Cr, Ga, and the like.

The resistivity of the transparent conductive layer 7 is, for example, 5.0 × 10^-4Omega. cm or less, preferably 2.0X 10^-4Ω·cmThe following. The resistivity can be measured by the 4-terminal method.

The thickness of the transparent conductive layer 7 is, for example, 10nm or more, preferably 30nm or more, and is, for example, 300nm or less, preferably 100nm or less. When the thickness of the transparent conductive layer 7 is not less than the lower limit, the conductivity is excellent. On the other hand, when the thickness of the transparent conductive layer 7 is not more than the upper limit, the transparent conductive glass 6 can be made thin. 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, and when the heating step is performed, it is preferably crystalline. When the transparent conductive layer 7 is crystalline, the conductivity is excellent.

Whether the transparent conductive layer is amorphous or crystalline can be determined, for example, as follows: when the transparent conductive layer is an ITO layer, it is immersed in hydrochloric acid (concentration 5 mass%) at 20 ℃ for 15 minutes, washed with water, dried, and measured for the resistance between terminals between about 15 mm. In the present specification, after immersion in hydrochloric acid (20 ℃ C., concentration 5% by mass), washing with water and drying, the ITO layer is amorphous when the inter-terminal resistance between 15mm exceeds 10 k.OMEGA.and crystalline when the inter-terminal resistance between 15mm is 10 k.OMEGA.or less.

The transparent conductive glass laminate 8 is used for an optical device such as an image display device, for example. More specifically, the transparent conductive glass 6 is used as a member of the image display device by removing (peeling) the carrier film 2 from the transparent conductive glass laminate 8.

Specifically, when the image display device (for example, an image display device having an image display element such as an LCD module or an organic EL module) includes the transparent conductive glass 6, the transparent conductive glass 6 is used as, for example, a substrate for a touch panel. Examples of the form of the touch panel include various forms such as an optical form, an ultrasonic form, a capacitance form, and a resistance film form, and particularly, the touch panel is suitably used for a capacitance form.

The transparent conductive glass 6 is, for example, a member included in an image display device, such as a touch panel substrate, that is, is not an image display device. That is, the transparent conductive glass 6 is a member used for manufacturing an image display device or the like, and is an industrially applicable device that includes the glass substrate 3 and the transparent conductive layer 7 and circulates as a member itself, without including an image display element such as an LCD module.

Further, since the glass laminate 1 and the transparent conductive glass laminate 8 include the carrier film 2 and the glass substrate 3 having a thickness of 150 μm or less, the roll 9 can be formed, and industrial production by the roll-to-roll method can be realized.

Further, since the carrier film 2 includes the plastic substrate 4 and the pressure-sensitive adhesive layer 5 having a thickness of 100 μm or less, when wound up in a roll-to-roll manner, stress between the glass substrates 3 laminated on each other in the roll 9 can be relaxed, and breakage due to the stress can be suppressed.

Further, since the carrier film 2 includes the plastic base 4 having a thickness of 100 μm or less and the pressure-sensitive adhesive layer 5, the heat shrinkage of the plastic base 4 can be reduced and the curling after heating can be suppressed. Therefore, the heated glass laminate 1 can be easily formed into a roll shape.

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

In particular, the optical member (for example, the transparent conductive glass 6) having the flexible glass substrate 3 as a support substrate in the present invention is mass-produced by a roll-to-roll method.

Specifically, when an optical film is produced by a roll-to-roll method using a flexible glass substrate 3, the glass substrate 3 may be damaged by stress of the glass substrates 3 stacked on each other in the rolled optical film.

Therefore, if the carrier film 2 is disposed on the lower surface of the glass substrate 3 in order to suppress breakage of the glass substrate 3, a large curl is generated due to a difference in thermal expansion coefficient between the carrier film 2 and the glass substrate 3 at the time of heating, and as a result, it is difficult to wind the film in a roll shape.

Thus, the following insight is obtained: if the thickness of the plastic substrate 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 peeled off from the glass substrate 3, and the glass substrate 3 is damaged. As a result of further studies, it was found that the peeling force of the pressure-sensitive adhesive layer 5 greatly increased with the thinning of the plastic substrate 4.

Based on this finding, the present inventors have focused on the peeling force of the heated pressure-sensitive adhesive layer 5, and as a result, the above-described problems have been solved by setting the peeling force between the heated carrier film 2 and the glass substrate 3 within a predetermined range in addition to the structure of the carrier film. That is, the problems of occurrence 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 are solved. Therefore, the roll-to-roll system can be realized in a practical mass production.

< modification example >

A modification of the embodiment shown in fig. 1 to 2 will be described below. These modifications also exhibit the same operational effects as those of the above-described embodiment.

(1) In fig. 1 to 2, a method for producing the transparent conductive glass laminate 8 is exemplified as an application of the glass laminate 1, and for example, although not shown, a method for producing an antireflection glass laminate may be exemplified as an application of the glass laminate 1.

The antireflection glass laminate comprises a support film 2 and antireflection glass disposed on the upper surface thereof. The antireflection glass includes a glass substrate 3 and an antireflection layer disposed on the upper surface thereof. That is, the antireflection glass and the antireflection glass laminate include an antireflection layer instead of the transparent conductive layer 7.

The antireflection layer includes a low refractive index layer and a high refractive index layer, and is preferably an alternating stack of the low refractive index layer and the high refractive index layer.

The refractive index of the low refractive layer is, for example, 1.35 or more and 1.55 or less. Examples of the material of 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. Examples of the material of the high refractive layer include titanium oxide, niobium oxide, zirconium oxide, ITO, ATO, and the like.

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

Such an antireflection layer is described in, for example, japanese patent laid-open No. 2017-227898.

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

In the antireflection layer disposing step, an antireflection layer is formed on the upper surface of the glass substrate 3 by a dry method. The dry method may be exemplified by the above-mentioned examples, and preferably, a sputtering method is exemplified.

In the case of the sputtering method, the material constituting the antireflection layer is used as the target material. That is, a target formed of a material of the high refractive layer and a target formed of a material of the low refractive layer are used.

(2) As an application of the glass laminate 1, for example, although not shown, a glass laminate having a desired functional layer (for example, an optical adjustment layer) may be manufactured by disposing functional layers other than the transparent conductive layer 7 and the antireflection layer on the glass substrate 3 of the glass laminate 1.

[ examples ]

The present invention will be described more specifically below with reference to examples and comparative examples. The present invention is not limited to the examples and comparative examples. Specific numerical values such as the blending ratio (content ratio), the physical property value, and the parameter used in the following description may be replaced with the upper limit value (defined as "lower" or "less" numerical value) or the lower limit value (defined as "upper" or "more" numerical value) described in the above-mentioned "specific embodiment" in accordance with the blending ratio (content ratio), the physical property value, and the parameter described therein.

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 0.2 part by mass of 2, 2' -Azobisisobutyronitrile (AIBN) as a polymerization initiator were mixed together with 150 parts by mass of ethyl acetate, and nitrogen gas was introduced while stirring at 23 ℃. Thereafter, the polymerization reaction was carried out for 6 hours while keeping the liquid temperature at about 65 ℃ to prepare a solution (concentration: 40 mass%) of the acrylic polymer A. The weight average molecular weight of the acrylic polymer A was 54 ten thousand.

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

An acrylic adhesive solution was applied to one surface of a long polyester film (plastic substrate, "polyester film lumiror 25R 75", manufactured by toyo corporation, thickness 25 μm) in a roll-to-roll manner, and heated at 130 ℃ for 2 minutes to form an adhesive layer having a thickness of 23 μm. Thus, a carrier film was produced.

(production of glass laminate)

A long glass substrate (100 μm thick, manufactured by Nippon Denko K.K.; "G-Leaf") was prepared. The adhesive layer of the carrier film and the glass substrate were bonded in a roll-to-roll manner, and wound up on a take-up roll.

Thus, a glass laminate comprising a carrier film and a glass substrate and wound into a roll was produced.

Examples 2 to 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 described in table 1.

Example 4

In the preparation of the acrylic adhesive solution, 4 parts by mass of an isocyanate-based crosslinking agent "CoronateHX" (C-HX) was used as a crosslinking agent, and the amount of dibutyltin dilaurate was changed to 0.015 part by mass. The thicknesses of the polyester film and the pressure-sensitive adhesive layer were changed to those shown in table 1. Except for this, a glass laminate was produced in the same manner as in example 1.

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 part by mass of AIBN as a polymerization initiator were mixed with 186 parts by mass of ethyl acetate, and nitrogen gas was introduced while stirring at 23 ℃ to replace nitrogen gas. Thereafter, the polymerization reaction was carried out for 10 hours while maintaining the liquid temperature at about 63 ℃ to prepare a solution (concentration: 35% by mass) of the acrylic polymer B. The weight average molecular weight of the acrylic polymer B was 50 ten thousand.

Ethyl acetate was added to the solution of the acrylic polymer B to dilute the solution to a concentration of 20 mass%. To 500 parts by mass of the diluted solution (100 parts by mass of the solid content) was added 11 parts by mass of a 4-functional epoxy compound (made by Mitsubishi gas chemical corporation, "TETRAD C" (T-C)) as a crosslinking agent, and the mixture was stirred to prepare an acrylic adhesive solution.

An acrylic pressure-sensitive adhesive solution was applied to one surface of a long polyester film (the same as described above) in a roll-to-roll manner, and heated at 130 ℃ for 2 minutes to form a pressure-sensitive adhesive layer having a thickness of 20 μm. 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 described 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 crosslinking 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 described in table 1.

Comparative example 4

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 described in table 1.

Comparative example 6

The amounts of the monomer components and the amount of the crosslinking agent in the adhesive layer were changed to the amounts shown in table 1. The thicknesses of the polyester film and the pressure-sensitive adhesive layer were changed to the amounts shown in table 1. Except for this, a glass laminate was produced in the same manner as in example 5.

(thickness of each layer)

The thickness of the plastic film, the adhesive layer, and the glass substrate was measured by a direct reading thickness meter (manufactured by PEACOCK, DG-205).

(initial peeling force)

The glass laminate was cut into a width of 50mm and a length of 200mm, and the glass substrate 3 side of the cut glass laminate was fixed to a sample stage 11 of a peeling force measuring apparatus (product of the apparatus name "TCM-1 kNB", manufactured by minebemitsuminc.) via an adhesive tape (fixing member) 12. Next, one end of the carrier film 2 in the glass laminate in the longitudinal direction was held by the traveling table 13 and stretched in the longitudinal direction at a stretching speed of 300 mm/min, thereby measuring the peeling force (N/50mm) at a peeling angle of 180 ° (see fig. 4). The results are shown in Table 1.

(peeling force after heating)

The glass laminate was heated at 140 ℃ for 60 minutes. The glass laminate after heating was subjected to the test for initial peel force as described above, and the peel force (N/50mm) at a peel angle of 180 ° was measured at a tensile rate of 300 mm/min. The results are shown in Table 1.

(crimp test)

The glass laminates of the examples and comparative examples were cut into a square shape of 20cm × 20cm in a plan view, and test pieces were produced. The test piece was placed on a horizontal table in an oven with the polyester film on the top, and heated at 140 ℃ for 60 minutes. Thereafter, the sample was left to cool at room temperature (23 ℃) for 1 hour to prepare a heated test piece.

The average height H of the four corners from the horizontal table was measured for the heated test piece (see fig. 5). The results are shown in Table 1.

(releasability)

The glass substrate peeled off with the peeling force after heating was confirmed.

The glass substrate was evaluated as good, and the glass substrate was evaluated as poor in breakage, such as chipping, in a portion of the glass substrate. The results are shown in Table 1.

(confirmation of bubble)

The heated test piece in the above-described curl test was visually observed.

The adhesive layer was evaluated as good, and the adhesive layer was evaluated as poor. The results are shown in Table 1.

[ Table 1]

Claims

1. A glass laminate comprising:

a carrier film, and

a glass substrate disposed on one side of the carrier film in the thickness direction and having a thickness of 150 μm or less,

the carrier film is provided with:

a plastic base material having a thickness of 100 μm or less, and

an adhesive layer disposed on one side of the plastic base material in the thickness direction,

when the glass laminate is heated at 140 ℃ for 60 minutes, the peeling force between the carrier film and the glass substrate is 0.1N/50mm or more and 2.0N/50mm or less.

2. The glass laminate according to claim 1, further comprising a transparent conductive layer disposed on one side of the glass substrate in the thickness direction.

3. The glass laminate according to claim 1 or 2, which is wound in a roll shape.