WO2024034575A1 - Interlayer adhesive, interlayer adhesive for touch panel, and touch panel - Google Patents

Interlayer adhesive, interlayer adhesive for touch panel, and touch panel Download PDF

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Publication number
WO2024034575A1
WO2024034575A1 PCT/JP2023/028773 JP2023028773W WO2024034575A1 WO 2024034575 A1 WO2024034575 A1 WO 2024034575A1 JP 2023028773 W JP2023028773 W JP 2023028773W WO 2024034575 A1 WO2024034575 A1 WO 2024034575A1
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Prior art keywords
interlayer adhesive
group
touch panel
adhesive according
resin
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PCT/JP2023/028773
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French (fr)
Japanese (ja)
Inventor
伸吾 岡沢
敦 野原
裕介 萩原
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積水化学工業株式会社
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Publication of WO2024034575A1 publication Critical patent/WO2024034575A1/en

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/06—Non-macromolecular additives organic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J129/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal, or ketal radical; Adhesives based on hydrolysed polymers of esters of unsaturated alcohols with saturated carboxylic acids; Adhesives based on derivatives of such polymers
    • C09J129/14—Homopolymers or copolymers of acetals or ketals obtained by polymerisation of unsaturated acetals or ketals or by after-treatment of polymers of unsaturated alcohols
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means

Definitions

  • the present invention relates to an interlayer adhesive, an interlayer adhesive for touch panels, and a touch panel.
  • a touch panel has a multilayer structure formed by members such as a cover glass, a sensor glass, and a liquid crystal panel. By filling the spaces between the layers of each member with a filler material, transparency, brightness, contrast, etc. of the display screen are improved, and visibility is improved.
  • Patent Document 1 discloses an invention related to an interlayer filling material for touch panels that is characterized by containing polyvinyl acetal, a reactive diluent, and a photopolymerization initiator, and has excellent followability to steps. It is described that a touch panel laminate that is less susceptible to cracking or damage can be obtained.
  • an object of the present invention is to provide an interlayer adhesive containing a polyvinyl acetal resin and capable of suppressing whitening, and a touch panel equipped with the interlayer adhesive.
  • an interlayer adhesive consisting of a resin layer containing a polyvinyl acetal resin and containing a phosphate ester in the resin layer, and have completed the present invention.
  • the gist of the present invention is as follows.
  • An interlayer adhesive comprising a resin layer containing a polyvinyl acetal resin, and containing a phosphate ester in the resin layer.
  • an interlayer adhesive that includes a polyvinyl acetal resin and is capable of suppressing whitening, and a touch panel equipped with the interlayer adhesive.
  • FIG. 1 is a schematic cross-sectional view showing an embodiment of a touch panel of the present invention. It is a typical sectional view showing other embodiments of the touch panel of the present invention.
  • the interlayer adhesive of the present invention is composed of a resin layer containing a polyvinyl acetal resin, and the resin layer contains a phosphoric acid ester.
  • the resin layer of the present invention contains a phosphoric acid ester.
  • a phosphate ester in the resin layer, whitening of the peripheral edge can be suppressed when used for bonding a touch panel. The reason for this is not clear, but it is thought that the inclusion of phosphoric acid ester can effectively suppress water aggregation, which causes whitening.
  • the HLB (Hydrophilic-Lipophilic Balance) of the phosphoric acid ester in the present invention is preferably 13 or less, more preferably 11 or less, still more preferably 10 or less, and preferably It is 4 or more, more preferably 6 or more.
  • the phosphoric acid ester in the present invention preferably has a polyoxyalkylene alkyl ether group, from the viewpoint of setting the above-mentioned HLB to a desired value and suppressing whitening more effectively.
  • a compound having an ether group and a phosphoric acid skeleton is preferable.
  • a polyoxyalkylene alkyl ether group is a group in which a polyoxyalkylene and an alkyl group are connected through an ether bond (-O-), and has a structure represented by formula (1).
  • R 1 is an alkyl group
  • R 2 is an alkylene group
  • n is 1 to 50
  • * represents a bond
  • R 1 is preferably an alkyl group having 6 to 20 carbon atoms, more preferably an alkyl group having 8 to 18 carbon atoms, and even more preferably an alkyl group having 10 to 14 carbon atoms. Although R 1 may be a linear alkyl group or a branched alkyl group, a linear alkyl group is preferable from the viewpoint of further suppressing whitening.
  • R 1 is, for example, a hexyl group, isohexyl group, heptyl group, isoheptyl group, octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, undecyl group, isoundecyl group, dodecyl group, Isododecyl group, tridecyl group, isotridecyl group, tetradecyl group, isotetradecyl group, pentadecyl group, isopentadecyl group, hexadecyl group, isohexadecyl group, 2-hexyldecyl group, heptadecyl group, isoheptadecyl group, octadecyl group, isooctadecyl
  • R 1 is preferably a dodecyl group or an isotridecyl group, and more preferably a dodecyl group. That is, from the viewpoint of adjusting the HLB to a desired range and further suppressing whitening, the phosphoric acid ester preferably has a dodecyl group or an isotridecyl group, and more preferably has a dodecyl group.
  • R 2 is an alkylene group, preferably an alkylene group having 2 to 6 carbon atoms, more preferably an alkylene group having 2 to 3 carbon atoms, and even more preferably an alkylene group having 2 carbon atoms (i.e., an ethylene group). ). Moreover, in the case where n is 2 or more, a plurality of R 2 may be the same or different. n is 1 to 50, preferably 1 to 30, more preferably 1 to 10. Further, in formula (1), * represents a bond, and * is preferably a bond bonded to a phosphorus atom of a phosphoric acid skeleton.
  • the phosphoric acid ester is preferably a compound represented by the following formula (2) or formula (3), more preferably a compound represented by formula (2). Further, the phosphoric acid ester in the present invention may be a mixture of compounds represented by formula (2) and formula (3).
  • R 1 and n have the same meanings as in formula (1).
  • the content of phosphate ester in the resin layer is preferably 0.04% by mass or more, more preferably 0.1% by mass or more, from the viewpoint of further suppressing whitening, and from the viewpoint of heat resistance to yellowing. , preferably 0.5% by mass or less, more preferably 0.3% by mass or less.
  • the resin layer of the present invention contains polyvinyl acetal resin.
  • polyvinyl acetal resin By containing polyvinyl acetal resin, it is possible to improve the adhesion between each member constituting the touch panel, such as the cover glass and the sensor glass, and the shock absorption property is increased, making it difficult for cracks and breakage to occur.
  • Polyvinyl acetal resin is obtained by acetalizing polyvinyl alcohol (PVA) with aldehyde. That is, the polyvinyl acetal resin is preferably an acetalized product of polyvinyl alcohol (PVA).
  • Polyvinyl alcohol (PVA) is obtained, for example, by saponifying a polyvinyl ester such as polyvinyl acetate. The saponification degree of polyvinyl alcohol is generally 70 to 99.9 mol%.
  • One type of polyvinyl acetal resin may be used alone, or two or more types may be used in combination.
  • the average degree of polymerization of the polyvinyl acetal resin is preferably 200 or more, more preferably 500 or more, still more preferably 1000 or more, even more preferably 1500 or more. Further, the average degree of polymerization of the polyvinyl acetal resin is preferably 5,000 or less, more preferably 4,000 or less, and even more preferably 3,500 or less.
  • the average degree of polymerization of polyvinyl acetal resin is the same as the average degree of polymerization of PVA, which is the raw material for polyvinyl acetal resin, and the average degree of polymerization of PVA is determined by a method based on JIS K6726 "Polyvinyl alcohol test method". .
  • aldehyde used for acetalization is not particularly limited, but aldehydes having 1 to 10 carbon atoms are preferably used, more preferably aldehydes having 3 to 5 carbon atoms, still more preferably aldehydes having 4 or 5 carbon atoms, Particularly preferred are aldehydes having 4 carbon atoms.
  • aldehydes having 1 to 10 carbon atoms are not particularly limited, and examples thereof include formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde, n-hexylaldehyde, n- Examples include octylaldehyde, n-nonylaldehyde, n-decylaldehyde, and benzaldehyde.
  • acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-hexylaldehyde or n-valeraldehyde are preferred, propionaldehyde, n-butyraldehyde, isobutyraldehyde or n-valeraldehyde is more preferred, and n-butyl Aldehydes or n-valeraldehyde are more preferred, and n-butyraldehyde is most preferred.
  • the above aldehydes may be used alone or in combination of two or more.
  • the number of carbon atoms in the acetal group contained in the polyvinyl acetal resin is not particularly limited, but it is preferably 1 to 10, more preferably 3 to 5, still more preferably 4 or 5, particularly preferably 4.
  • a butyral group is particularly preferable as the acetal group, and therefore, a polyvinyl butyral resin is preferable as the polyvinyl acetal resin.
  • the amount of hydroxyl groups in the polyvinyl acetal resin is preferably 15 mol% or more, and preferably 38 mol% or less. By setting the amount of hydroxyl groups to 15 mol% or more, the adhesiveness tends to be good. Further, by controlling the amount of hydroxyl groups to 38 mol% or less, the resin layer is prevented from becoming too hard.
  • the amount of hydroxyl groups is more preferably 20 mol% or more, still more preferably 25 mol% or more, from the viewpoint of adhesion. Further, the amount of hydroxyl groups is more preferably 35% or less, still more preferably 33 mol% or less.
  • the amount of hydroxyl groups is 15 mol% or more, preferably 38 mol% or less, more preferably 20 mol% or more, even more preferably 25 mol% or more. It is mol% or more, more preferably 35% mol or less, still more preferably 33 mol% or less.
  • the amount of hydroxyl groups in the polyvinyl acetal resin is a value expressed as a percentage of the molar fraction obtained by dividing the amount of ethylene groups to which hydroxyl groups are bonded by the total amount of ethylene groups in the main chain.
  • the amount of ethylene groups to which the hydroxyl groups are bonded can be measured, for example, in accordance with JIS K6728 "Polyvinyl Butyral Test Method.”
  • the degree of acetalization of the polyvinyl acetal resin is preferably 47 mol% or more, and preferably 85 mol% or less.
  • the degree of acetalization is more preferably 55 mol% or more, still more preferably 60 mol% or more, and more preferably 80 mol% or less, still more preferably 75 mol% or less.
  • the degree of acetalization means the degree of butyralization when the acetal group is a butyral group and the polyvinyl acetal resin is a polyvinyl butyral resin.
  • the above degree of acetalization is calculated by subtracting the amount of ethylene groups to which hydroxyl groups are bonded and the amount of ethylene groups to which acetyl groups are bonded from the total amount of ethylene groups in the main chain. This is the value expressed as a percentage of the mole fraction obtained by dividing by .
  • the degree of acetalization (degree of butyralization) may be calculated from the results measured by a method based on, for example, JIS K6728 "Polyvinyl butyral test method.”
  • the degree of acetylation of the polyvinyl acetal resin is preferably 30 mol% or less, more preferably 20 mol% or less, still more preferably 10 mol% or less, even more preferably 2 mol% or less. When the degree of acetylation is below the upper limit, the moisture resistance of the resin layer becomes high. Further, the degree of acetylation is not particularly limited, but is preferably 0.01 mol% or more, more preferably 0.1 mol% or more.
  • the above-mentioned degree of acetylation is a value expressed as a percentage of the molar fraction obtained by dividing the amount of ethylene groups to which acetyl groups are bonded by the total amount of ethylene groups in the main chain. The amount of ethylene groups to which the acetyl groups are bonded can be measured, for example, in accordance with JIS K6728 "Test Method for Polyvinyl Butyral.”
  • the resin layer may contain resins other than polyvinyl acetal resin as long as the effects of the present invention are not impaired.
  • resins other than polyvinyl acetal resin include ethylene-vinyl acetate copolymer resin, ionomer resin, polyurethane resin, thermoplastic elastomer, and acrylic resin.
  • the content of the polyvinyl acetal resin is preferably 50% by mass or more, more preferably 80% by mass or more, and even more preferably 100% by mass.
  • the resin layer of the present invention preferably contains a plasticizer.
  • a plasticizer in the resin layer together with the above-mentioned polyvinyl acetal resin, the impact absorption property can be further improved. Further, by containing a plasticizer, the resin layer becomes more flexible and can be easily adjusted to a predetermined shape.
  • plasticizer examples include organic phosphorus plasticizers such as organic ester plasticizers, organic phosphate ester plasticizers, and organic phosphite plasticizers, polyalkylene glycol plasticizers, and polyoxyalkylene ether plasticizers.
  • organic ether plasticizers and alcohol plasticizers examples include organic ether plasticizers and alcohol plasticizers.
  • One type of plasticizer may be used alone, or two or more types may be used in combination. Among the above, organic ester plasticizers and polyalkylene glycol plasticizers are preferred, and organic ester plasticizers are particularly preferred.
  • Preferred organic ester plasticizers include monobasic organic acid esters and polybasic organic acid esters.
  • Examples of monobasic organic acid esters include esters of glycol and monobasic organic acids.
  • Examples of the glycol include polyalkylene glycols in which each alkylene unit has 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms, and the number of repeating alkylene units is 2 to 10, preferably 2 to 4. Further, the glycol may be a monoalkylene glycol having 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms (ie, 1 repeating unit). Specific examples of the glycol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, butylene glycol, and the like.
  • Examples of monobasic organic acids include organic acids having 3 to 10 carbon atoms, specifically butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptylic acid, n-octylic acid, and 2-ethylhexylic acid. , n-nonylic acid and decyl acid.
  • Specific monobasic organic acid esters include triethylene glycol di-2-ethyl butyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, and triethylene glycol di-n-octanoate.
  • polybasic organic acid esters examples include ester compounds of dibasic organic acids having 4 to 12 carbon atoms, such as adipic acid, sebacic acid, azelaic acid, and phthalic acid, and alcohols having 4 to 10 carbon atoms. can be mentioned.
  • the alcohol having 4 to 10 carbon atoms may have a straight chain, a branched structure, or a cyclic structure.
  • the organic ester plasticizer is not limited to the complete esters of the above-mentioned esters, but may also be partial esters.
  • it may be a partial ester of a glycol and a monobasic organic acid, or a partial ester of a dibasic organic acid and an alcohol.
  • Specific examples include triethylene glycol-mono-2-ethylhexanoate.
  • it may be a partial ester of a trihydric or higher alcohol such as glycerin and a monobasic organic acid.
  • the monobasic organic acid include monobasic organic acids having 3 to 24 carbon atoms, preferably 6 to 18 carbon atoms.
  • partial esters of trihydric or higher alcohols and monobasic organic acids include mono- or diesters of glycerin and stearic acid, mono- or diesters of glycerin and 2-ethylhexylic acid, and the like.
  • organic ester plasticizers mentioned above triethylene glycol-di-2-ethylhexanoate (3GO) and dioctyl adipate (DOA) are particularly preferably used.
  • organic phosphorus plasticizer examples include phosphate esters such as tributoxyethyl phosphate, isodecyl diphenyl phosphate, and triisopropyl phosphate.
  • polyalkylene glycol plasticizers examples include polyethylene glycol, polypropylene glycol, poly(ethylene oxide/propylene oxide) block copolymer, poly(ethylene oxide/propylene oxide) random copolymer, polytetramethylene glycol, etc. Among them, polypropylene glycol is preferred.
  • the polyoxyalkylene ether plasticizer is an ether compound of monohydric or polyhydric alcohol and polyoxyalkylene.
  • Specific polyoxyalkylene ether plasticizers include, for example, polyoxyethylene hexyl ether, polyoxyethylene heptyl ether, polyoxyethylene octyl ether, polyoxyethylene-2-ethylhexyl ether, polyoxyethylene nonyl ether, polyoxy Ethylene decyl ether, polyoxyethylene allyl ether, polyoxypropylene allyl ether, polyoxyethylene glyceryl ether, polyoxypropylene glyceryl ether, polyoxyethylene diglyceryl ether, polyoxypropylene diglyceryl ether, polyoxyalkylene pentaerythritol ether, poly Examples include caprolactone triol.
  • the polyoxyalkylene ether plasticizer is preferably an ether compound of polyhydric alcohol and polyoxyalkylene, more preferably an ether compound of glycerin or diglycerin and polyoxyalkylene, still more preferably glycerin or diglycerin. It is an ether compound of polyoxypropylene and polyoxypropylene.
  • alcohol plasticizers include alcohols other than polyalkylene glycol plasticizers and polyoxyalkylene ether plasticizers. Specific examples include various polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, hexanediol, trimethylolpropane, pentaerythritol, glycerin, and diglycerin. Among these, ethylene glycol is preferred.
  • the content of the plasticizer in the resin layer is preferably 5 parts by mass or more, more preferably 15 parts by mass or more, even more preferably 30 parts by mass or more, and preferably 100 parts by mass or more, based on 100 parts by mass of the polyacetal resin. It is not more than 60 parts by mass, more preferably not more than 50 parts by mass.
  • the resin layer of the present invention may contain a tackifying resin, an adhesive force regulator, an emulsifier, a softener, a fine particle, a filler, a pigment, a dye, a silane coupling agent, an antioxidant, a surfactant, and a wax, as necessary. It may also contain known additives such as.
  • the interlayer adhesive of the present invention is preferably in the form of a film from the viewpoint that it can be easily attached to a substrate.
  • the interlayer adhesive of the present invention can be formed by, for example, mixing a resin, a phosphate ester, and various additives blended as necessary, and extruding or press-molding the obtained resin composition. All you have to do is get it.
  • the thickness of the interlayer adhesive of the present invention is not particularly limited, and may be adjusted as appropriate depending on the size and type of the touch panel to be used.
  • the thickness of the interlayer adhesive is preferably 0.05 mm or more, more preferably 0.1 mm or more, even more preferably 0.15 mm or more, and preferably 5 mm or less, more preferably 3 mm or less, More preferably, it is 1 mm or less.
  • the interlayer adhesive of the present invention can be suitably used for adhering members constituting a touch panel. Moreover, in the present invention, a touch panel including an interlayer adhesive can be provided. An interlayer adhesive for a touch panel using such an interlayer adhesive of the present invention is also one of the present invention.
  • FIG. 1 shows an embodiment of the touch panel of the present invention. Note that the present invention is not limited to the contents of the drawings.
  • the touch panel 10 shown in FIG. 1 includes a cover glass 11, a sensor glass 12, and a liquid crystal panel 13 in this order.
  • the cover glass 11 is a light-transmitting member, and its surface serves as an operation surface that the user's fingers and the like come into contact with during touch operations.
  • the sensor glass 12 has an ITO pattern (not shown) formed on its surface, thereby enabling detection of a touch operation by a user's finger (detection target). Note that the sensor glass 12 may have a single layer structure or a multilayer structure. Furthermore, a predetermined image can be displayed on the liquid crystal panel 13. Note that an organic EL panel can also be used instead of the liquid crystal panel 13.
  • An interlayer adhesive 14 of the present invention is provided between the cover glass 11 and the sensor glass 12 to bond and fix the cover glass 11 and the sensor glass 12. Since polyvinyl acetal resin is used as the interlayer adhesive 14, the adhesion between the cover glass 11 and the sensor glass 12 is good, and the impact absorption property is increased, making it difficult for cracks and breakage to occur. In addition, since the resin layer constituting the interlayer adhesive 14 contains phosphoric acid ester, it can suppress whitening even when the temperature and humidity are high under the operating conditions of the touch panel (when voltage is applied). Can be done.
  • the interlayer adhesive 14 of the present invention can be used between the sensor glass 12 and the liquid crystal panel 13 if necessary, but a commonly used optical adhesive ( OCA) etc. may also be used.
  • OCA optical adhesive
  • FIG. 1 shows a touch panel that includes a cover glass 11, a sensor glass 12, a liquid crystal panel 13, and an interlayer adhesive 14, the touch panel may further include a configuration other than these.
  • the touch panel 2 may include a touch panel main body 100 and a cover member 151.
  • the cover member 151 includes a first member 61 made of a glass plate, an interlayer adhesive 65, and a second member 160.
  • the interlayer adhesive 65 is disposed in close contact with the second surface 61B with a substantially uniform thickness.
  • the second member 160 is disposed along the outer surface of the interlayer adhesive 65 in close contact with the interlayer adhesive 65.
  • the second member 160 is arranged to follow the outer surface of the interlayer adhesive 65.
  • the first member 61 has a first surface 61A and a second surface 61B opposite to the first surface 61A.
  • the so-called operation surface is the first surface 61A.
  • a transparent interlayer adhesive 65 is arranged on the entire surface of the second surface 61B.
  • the material of the first member 61 is, for example, a glass plate, and may be a thin sheet of flexible glass. From the viewpoint of weight reduction, etc., it is preferable to use a glass plate having a thickness of 0.01 mm or more and 0.55 mm or less as the first member 61. When constructing the cover member 151 having a size of 25 inches or more, it is preferable to use a glass plate having a thickness of 0.01 mm or more and 1.85 mm or less. Further, by using a glass plate having a thickness of 0.7 mm or less, it is possible to construct the cover member 151 with a thin thickness.
  • the cover member 151 corresponding to the touch panel main body 100 compatible with a large screen of 25 inches or more it is desirable to use a thick glass plate as the first member 61 so as not to cause large deflection, but from the viewpoint of the overall thickness.
  • the thickness of the first member 61 is preferably 2.5 mm or less.
  • the material of the second member 160 is, for example, a glass plate, and may be a flexible thin glass plate. From the viewpoint of weight reduction, it is preferable to use a glass plate having a thickness of 0.01 mm or more and 0.55 mm or less as the second member 160. When constructing the cover member 151 having a size of 25 inches or more, it is preferable to use a glass plate having a thickness of 0.01 mm or more and 1.85 mm or less. A glass plate having this thickness can be easily disposed as the second member 160, following the outer surface of the interlayer adhesive 65, and can also prevent air bubbles from being trapped.
  • the cover member 151 is constructed by arranging a first member 61 made of a glass plate and a second member 160 made of a glass plate so as to sandwich an interlayer adhesive 65 therebetween.
  • the touch panel main body 100 is attached to the outer surface of the second member 160.
  • FIG. 2 shows a touch panel main body 100 having a structure in which two substrates are laminated.
  • the touch panel main body 100 has a first substrate 111 and a second substrate 112.
  • the first substrate 111 and the second substrate 112 have transparency, and are made of, for example, a resin film or a glass plate.
  • a transmitting electrode of the sensor electrode is arranged on the first substrate 111, and a receiving electrode of the sensor electrode is arranged on the second substrate 112.
  • the first substrate 111 and the second substrate 112 are bonded together using a transparent adhesive 115.
  • the second substrate 112 is provided with a transparent adhesive 116 that is used when attaching it to the cover member 151.
  • the touch panel main body 100 is attached to the outer surface of the second member 160 via an adhesive 116.
  • the interlayer adhesive according to the present invention can be used as the adhesive 115 and the adhesive 116, but a commonly used optical adhesive (OCA) or the like may also be used.
  • the method for manufacturing the touch panel of the present invention is not particularly limited, but it is preferably manufactured using a vacuum packing method.
  • an interlayer adhesive is introduced between some or all of the members constituting the touch panel, placed in a vacuum pack, vacuumed, and preliminarily bonded at about 70 to 110° C. to obtain a laminate.
  • the laminate is placed in an autoclave or pressed to bond at about 120 to 150° C. and a pressure of 1 to 1.5 MPa. In this way, a touch panel can be obtained.
  • plasticizers and phosphate esters used in Examples and Comparative Examples are as follows.
  • ⁇ Plasticizer> 3GO Triethylene glycol-di-2-ethylhexanoate ⁇ phosphate ester> - "Plysurf A208B” manufactured by Daiichi Kogyo Seiyaku Co., Ltd., a compound in which R1 is a dodecyl group and n is 2 in formula (2).
  • HLB 8.
  • DISPERBYK-102 manufactured by BYK Chemie, a phosphoric acid ester having a polyoxyalkylene alkyl ether group.
  • Example 1 Production of polyvinyl butyral resin
  • a reactor equipped with a stirring device 1800 g of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, degree of saponification 99 mol %) were placed, and heated and dissolved while stirring to obtain a polyvinyl alcohol solution.
  • 25% hydrochloric acid was added as a catalyst to this solution so that the hydrochloric acid concentration was 0.2% by weight, and after adjusting the temperature to 15° C., 16 g of n-butyraldehyde was added with stirring.
  • the amount of hydroxyl groups in the obtained polyvinyl butyral resin was 30.6 mol%, the degree of acetalization was 68.7 mol%, and the degree of acetylation was 0.7 mol%.
  • Manufacture of interlayer adhesive After mixing 100 parts by mass of the above polyvinyl butyral resin, 35 parts by mass of 3GO as a plasticizer, and 0.14 parts by mass of Plysurf A208B as a phosphoric acid ester, and thoroughly melting and kneading this with a mixing roll, Press molding was performed using a press molding machine at 150° C. for 10 minutes to obtain an interlayer adhesive having a thickness of 0.4 mm.
  • a cover glass (soda glass manufactured by Nippon Sheet Glass Co., Ltd.) and a sensor glass on which an ITO pattern was formed (manufactured by Techno Print Co., Ltd., ITO thickness 150 nm, resistance value around 10 ⁇ / ⁇ ) were prepared.
  • the interlayer adhesive produced as described above was sandwiched between a sensor glass and a cover glass to obtain a laminate.
  • This laminate was placed in a rubber bag and degassed for 10 minutes at a vacuum level of 1.0 MPa, then transferred to an oven heated to 100°C while still being degassed, and the laminate was kept temporarily until the temperature reached 85°C. It was crimped.
  • the temporarily pressed laminate was pressed in an autoclave at 140°C and a pressure of 1.3 MPa for 20 minutes to form a cover glass laminate in which the cover glass, resin layer (interlayer adhesive), and sensor glass were laminated in this order. Obtained.
  • the whitening distance of the cover glass laminate was measured as described above. The results are shown in Table 1.
  • Example 2 In the production of the interlayer adhesive of Example 1, the amount of Plysurf A208B was doubled to an equivalent amount (0.28 parts by mass), and the same procedure as in Example 1 was carried out except for that.
  • Example 3 In the production of the interlayer adhesive of Example 1, the amount of Plysurf A208B was changed to 4/10 times the equivalent amount (0.056 parts by mass), and the same procedure as in Example 1 was carried out except for that.
  • Example 4 In producing the interlayer adhesive of Example 1, the same procedure as in Example 1 was carried out except that the type of phosphate ester was changed from Plysurf A208B to DISPERBYK-102.
  • Example 1 The interlayer adhesive of Example 1 was produced in the same manner as in Example 1, except that phosphoric acid ester was not added.
  • the interlayer adhesive of each example containing a phosphate ester As described above, by using the interlayer adhesive of each example containing a phosphate ester, it was possible to suppress whitening of the touch panel in the heat and humidity test. On the other hand, the interlayer adhesives of each comparative example did not contain phosphate ester and were unable to suppress whitening of the touch panel in the heat and humidity test.

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Abstract

An interlayer adhesive according to the present invention comprises a resin layer that includes a polyvinyl acetal resin, and the resin layer contains a phosphate ester.　The present invention can provide an interlayer adhesive which includes a polyvinyl acetal resin and is capable of suppressing whitening.

Description

層間接着剤、タッチパネル用層間接着剤、及びタッチパネルInterlayer adhesive, interlayer adhesive for touch panels, and touch panels
　本発明は、層間接着剤、タッチパネル用層間接着剤、及びタッチパネルに関する。 The present invention relates to an interlayer adhesive, an interlayer adhesive for touch panels, and a touch panel.
　近年、スマートフォン、タブレット等の携帯情報端末、車載用ディスプレイなどに、指で触れることにより情報を入力することが可能なタッチパネルが配置されることがある。
　タッチパネルは、カバーガラス、センサーガラス、液晶パネルなどの部材により多層構造が形成されている。そして、各部材の層間を充填材料で埋めることにより、表示画面の透明性、輝度、コントラスト等を改善して、視認性を向上させることが行われている。
　例えば、特許文献１には、ポリビニルアセタール、反応性希釈剤、及び、光重合開始剤を含有することを特徴とするタッチパネル用層間充填材料に関する発明が開示されており、段差への追従性に優れ、かつ割れや破損が生じにくいタッチパネル積層体が得られることが記載されている。 2. Description of the Related Art In recent years, touch panels that allow information to be input by touching with a finger are sometimes installed in mobile information terminals such as smartphones and tablets, and in-vehicle displays.
A touch panel has a multilayer structure formed by members such as a cover glass, a sensor glass, and a liquid crystal panel. By filling the spaces between the layers of each member with a filler material, transparency, brightness, contrast, etc. of the display screen are improved, and visibility is improved.
For example, Patent Document 1 discloses an invention related to an interlayer filling material for touch panels that is characterized by containing polyvinyl acetal, a reactive diluent, and a photopolymerization initiator, and has excellent followability to steps. It is described that a touch panel laminate that is less susceptible to cracking or damage can be obtained.
国際公開第２０１６／１８６０２９号International Publication No. 2016/186029
　特許文献１に記載のように、タッチパネルの層間を接着する材料として、ポリビニルアセタール樹脂を用いると、衝撃吸収性が高まり、割れや破損が生じ難くなる。しかしながら、本発明者らの検討によると、センサーガラスを備えるタッチパネルの層間接着剤として、ポリビニルアセタール樹脂を用いると、タッチパネルの作動条件下（電圧印加時）において、特に温度や湿度が高い場合には、タッチパネルの周縁部に白化が生じやすいこと分かった。白化が生じると、タッチパネルの視認性が低下してしまうため、改善が求められる。 As described in Patent Document 1, when polyvinyl acetal resin is used as a material for bonding between layers of a touch panel, the impact absorption property is increased and cracking and damage are less likely to occur. However, according to studies conducted by the present inventors, when polyvinyl acetal resin is used as an interlayer adhesive for a touch panel equipped with sensor glass, under the operating conditions of the touch panel (when voltage is applied), especially when the temperature and humidity are high, It was found that whitening was more likely to occur on the periphery of the touch panel. When whitening occurs, the visibility of the touch panel decreases, so improvements are required.
　そこで、本発明は、ポリビニルアセタール樹脂を含む層間接着剤であって、白化を抑制することが可能な層間接着剤、及び該層間接着剤を備えるタッチパネルを提供することを目的とする。 Therefore, an object of the present invention is to provide an interlayer adhesive containing a polyvinyl acetal resin and capable of suppressing whitening, and a touch panel equipped with the interlayer adhesive.
　本発明者らは、鋭意検討の結果、ポリビニルアセタール樹脂を含む樹脂層からなり、前記樹脂層にリン酸エステルを含有する層間接着剤により上記課題を解決できることを見出し、本発明を完成させた。
　本発明の要旨は、以下のとおりである。 As a result of extensive studies, the present inventors have found that the above-mentioned problems can be solved by an interlayer adhesive consisting of a resin layer containing a polyvinyl acetal resin and containing a phosphate ester in the resin layer, and have completed the present invention.
The gist of the present invention is as follows.
［１］ポリビニルアセタール樹脂を含む樹脂層からなり、前記樹脂層にリン酸エステルを含有する、層間接着剤。
［２］前記樹脂層における前記リン酸エステルの濃度が０．１質量％以上である、上記［１］に記載の層間接着剤。
［３］前記樹脂層における前記リン酸エステルの濃度が０．５質量％以下である、上記［２］に記載の層間接着剤。
［４］前記リン酸エステルのＨＬＢが１０以下である、上記［１］～［３］いずれかに記載の層間接着剤。
［５］前記リン酸エステルが、ポリオキシアルキレンアルキルエーテル基を有する、上記［１］～［４］いずれかに記載の層間接着剤。
［６］前記ポリオキシアルキレンアルキルエーテル基が、式（１）で表される化合物である、上記［５］に記載の層間接着剤。
Figure JPOXMLDOC01-appb-C000003
 （Ｒ１は炭素数８～１８のアルキル基であり、Ｒ２は炭素数２～６のアルキレン基であり、ｎは１～１０であり、＊は結合手を表す）
［７］前記リン酸エステルは、式（２）又は式（３）で表される化合物である、上記［１］～［６］のいずれか記載の層間接着剤。
Figure JPOXMLDOC01-appb-C000004
 （Ｒ１は炭素数８～１８のアルキル基であり、ｎは１～１０である）
［８］前記リン酸エステルが、ドデシル基を有する、上記［１］～［７］のいずれかに記載の層間接着剤。
［９］前記ポリビニルアセタール樹脂がポリビニルブチラール樹脂である、上記［１］～［８］のいずれかに記載の層間接着剤。
［１０］前記樹脂層が可塑剤を含有する、上記［１］～［９］のいずれかに記載の層間接着剤。
［１１］上記［１］～［１０］のいずれか記載の層間接着剤からなる、タッチパネル用層間接着剤。
［１２］上記［１］～［１０］のいずれかに記載の層間接着剤を備えるタッチパネル。 [1] An interlayer adhesive comprising a resin layer containing a polyvinyl acetal resin, and containing a phosphate ester in the resin layer.
[2] The interlayer adhesive according to [1] above, wherein the concentration of the phosphate ester in the resin layer is 0.1% by mass or more.
[3] The interlayer adhesive according to [2] above, wherein the concentration of the phosphate ester in the resin layer is 0.5% by mass or less.
[4] The interlayer adhesive according to any one of [1] to [3] above, wherein the phosphoric acid ester has an HLB of 10 or less.
[5] The interlayer adhesive according to any one of [1] to [4] above, wherein the phosphoric acid ester has a polyoxyalkylene alkyl ether group.
[6] The interlayer adhesive according to [5] above, wherein the polyoxyalkylene alkyl ether group is a compound represented by formula (1).
Figure JPOXMLDOC01-appb-C000003
 (R 1 is an alkyl group having 8 to 18 carbon atoms, R 2 is an alkylene group having 2 to 6 carbon atoms, n is 1 to 10, and * represents a bond)
[7] The interlayer adhesive according to any one of [1] to [6] above, wherein the phosphoric acid ester is a compound represented by formula (2) or formula (3).
Figure JPOXMLDOC01-appb-C000004
 (R 1 is an alkyl group having 8 to 18 carbon atoms, and n is 1 to 10)
[8] The interlayer adhesive according to any one of [1] to [7] above, wherein the phosphoric acid ester has a dodecyl group.
[9] The interlayer adhesive according to any one of [1] to [8] above, wherein the polyvinyl acetal resin is a polyvinyl butyral resin.
[10] The interlayer adhesive according to any one of [1] to [9] above, wherein the resin layer contains a plasticizer.
[11] An interlayer adhesive for touch panels, comprising the interlayer adhesive according to any one of [1] to [10] above.
[12] A touch panel comprising the interlayer adhesive according to any one of [1] to [10] above.
　本発明によれば、ポリビニルアセタール樹脂を含む層間接着剤であって、白化を抑制することが可能な層間接着剤、及び該層間接着剤を備えるタッチパネルを提供できる。 According to the present invention, it is possible to provide an interlayer adhesive that includes a polyvinyl acetal resin and is capable of suppressing whitening, and a touch panel equipped with the interlayer adhesive.
本発明のタッチパネルの一実施形態を示す模式的な断面図である。FIG. 1 is a schematic cross-sectional view showing an embodiment of a touch panel of the present invention. 本発明のタッチパネルの他の実施形態を示す模式的な断面図である。It is a typical sectional view showing other embodiments of the touch panel of the present invention.
＜層間接着剤＞
　本発明の層間接着剤は、ポリビニルアセタール樹脂を含む樹脂層からなり、前記樹脂層にリン酸エステルを含有する。 <Interlayer adhesive>
The interlayer adhesive of the present invention is composed of a resin layer containing a polyvinyl acetal resin, and the resin layer contains a phosphoric acid ester.
［リン酸エステル］
　本発明の樹脂層は、リン酸エステルを含有する。樹脂層にリン酸エステルを含有させることで、タッチパネルの貼り合せに用いた際には周縁部の白化を抑制することができる。この理由は定かではないが、リン酸エステルを含有させることで、白化の原因となる水の凝集を効果的に抑制できるからと考えられる。 [Phosphate ester]
The resin layer of the present invention contains a phosphoric acid ester. By containing a phosphate ester in the resin layer, whitening of the peripheral edge can be suppressed when used for bonding a touch panel. The reason for this is not clear, but it is thought that the inclusion of phosphoric acid ester can effectively suppress water aggregation, which causes whitening.
　リン酸エステルは、リン酸モノエステル、リン酸ジエステル、リン酸トリエステルなど、リン酸（Ｏ＝Ｐ（ＯＨ）３）が持つ３個の水素の全てまたは一部が有機基で置き換わった構造であるリン酸エステル構造を有する化合物である。なかでも親水部分と親油部分を有する界面活性剤の機能を有する化合物であることが好ましく、リン酸モノエステル、リン酸ジエステルが好ましい。
　本発明におけるリン酸エステルのＨＬＢ（Ｈｙｄｒｏｐｈｉｌｉｃ－Ｌｉｐｏｐｈｉｌｉｃ　Ｂａｌａｎｃｅ）は、白化をより抑制する観点から、好ましくは１３以下であり、より好ましくは１１以下であり、さらに好ましくは１０以下であり、そして好ましくは４以上であり、より好ましくは６以上である。
　なお、本発明における「ＨＬＢ」は、グリフィン法〔ＨＬＢ＝２０×（ＭＷ／ＭＯ）、ＭＷ：親水部分の式量の総和、ＭＯ：分子量〕から算出することができる。 Phosphate esters have a structure in which all or part of the three hydrogens of phosphoric acid (O=P(OH) 3 ) are replaced with organic groups, such as phosphoric acid monoester, phosphoric acid diester, and phosphoric acid triester. It is a compound that has a certain phosphate ester structure. Among these, compounds having a surfactant function and having a hydrophilic part and a lipophilic part are preferable, and phosphoric acid monoesters and phosphoric acid diesters are preferable.
The HLB (Hydrophilic-Lipophilic Balance) of the phosphoric acid ester in the present invention is preferably 13 or less, more preferably 11 or less, still more preferably 10 or less, and preferably It is 4 or more, more preferably 6 or more.
In addition, "HLB" in the present invention can be calculated from the Griffin method [HLB=20×(MW/MO), MW: sum of formula weights of hydrophilic moieties, MO: molecular weight].
　本発明におけるリン酸エステルは、上記したＨＬＢを所望の値とし、白化をより効果的に抑制する観点から、ポリオキシアルキレンアルキルエーテル基を有することが好ましく、より具体的には、ポリオキシアルキレンアルキルエーテル基とリン酸骨格とを備える化合物であることが好ましい。
　ポリオキシアルキレンアルキルエーテル基は、ポリオキシアルキレンとアルキル基がエーテル結合（－Ｏ－）で連結された基であり、式（１）で表される構造を有している。 The phosphoric acid ester in the present invention preferably has a polyoxyalkylene alkyl ether group, from the viewpoint of setting the above-mentioned HLB to a desired value and suppressing whitening more effectively. A compound having an ether group and a phosphoric acid skeleton is preferable.
A polyoxyalkylene alkyl ether group is a group in which a polyoxyalkylene and an alkyl group are connected through an ether bond (-O-), and has a structure represented by formula (1).
Figure JPOXMLDOC01-appb-C000005
 （Ｒ１はアルキル基であり、Ｒ２はアルキレン基であり、ｎは１～５０であり、＊は結合手を表す）
Figure JPOXMLDOC01-appb-C000005
 (R 1 is an alkyl group, R 2 is an alkylene group, n is 1 to 50, * represents a bond)
　Ｒ１は、炭素数６～２０のアルキル基であることが好ましく、炭素数８～１８のアルキル基であることがより好ましく、炭素数１０～１４のアルキル基であることがさらに好ましい。Ｒ１は、直鎖状のアルキル基であってもよいし、分岐状のアルキル基であってもよいが、白化をより抑制する観点から、直鎖状のアルキル基が好ましい。 R 1 is preferably an alkyl group having 6 to 20 carbon atoms, more preferably an alkyl group having 8 to 18 carbon atoms, and even more preferably an alkyl group having 10 to 14 carbon atoms. Although R 1 may be a linear alkyl group or a branched alkyl group, a linear alkyl group is preferable from the viewpoint of further suppressing whitening.
　Ｒ１は、例えば、ヘキシル基、イソヘキシル基、ヘプチル基、イソヘプチル基、オクチル基、２－エチルヘキシル基、イソオクチル基、ノニル基、イソノニル基、デシル基、イソデシル基、ウンデシル基、イソウンデシル基、ドデシル基、イソドデシル基、トリデシル基、イソトリデシル基、テトラデシル基、イソテトラデシル基、ペンタデシル基、イソペンタデシル基、ヘキサデシル基、イソヘキサデシル基、２－ヘキシルデシル基、ヘプタデシル基、イソヘプタデシル基、オクタデシル基、イソオクタデシル基、２－オクチルデシル基、２－ヘキシルドデシル基、ノナデシル基、イソノナデシル基、エイコシル基、イソエイコシル基などが挙げられる。
　これらの中でも、Ｒ１は、ドデシル基又はイソトリデシル基が好ましく、ドデシル基がより好ましい。すなわち、リン酸エステルとしては、ＨＬＢを所望の範囲に調整して、白化をより抑制する観点から、ドデシル基又はイソトリデシル基を有するものが好ましく、ドデシル基を有するものがより好ましい。 R 1 is, for example, a hexyl group, isohexyl group, heptyl group, isoheptyl group, octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, undecyl group, isoundecyl group, dodecyl group, Isododecyl group, tridecyl group, isotridecyl group, tetradecyl group, isotetradecyl group, pentadecyl group, isopentadecyl group, hexadecyl group, isohexadecyl group, 2-hexyldecyl group, heptadecyl group, isoheptadecyl group, octadecyl group, isooctadecyl group group, 2-octyldecyl group, 2-hexyldodecyl group, nonadecyl group, isononadecyl group, eicosyl group, isoeicosyl group, and the like.
Among these, R 1 is preferably a dodecyl group or an isotridecyl group, and more preferably a dodecyl group. That is, from the viewpoint of adjusting the HLB to a desired range and further suppressing whitening, the phosphoric acid ester preferably has a dodecyl group or an isotridecyl group, and more preferably has a dodecyl group.
　上記式（１）において、Ｒ２はアルキレン基であり、好ましくは炭素数２～６、より好ましくは炭素数２～３のアルキレン基であり、さらに好ましくは炭素数２のアルキレン基（すなわちエチレン基）である。また、ｎが２以上の場合において、複数のＲ２は同一であっても異なっていてもよい。
　ｎは１～５０であり、好ましくは１～３０であり、より好ましくは１～１０である。
　また、式（１）において＊は結合手を表し、＊は好ましくはリン酸骨格のリン原子と結合する結合手である。 In the above formula (1), R 2 is an alkylene group, preferably an alkylene group having 2 to 6 carbon atoms, more preferably an alkylene group having 2 to 3 carbon atoms, and even more preferably an alkylene group having 2 carbon atoms (i.e., an ethylene group). ). Moreover, in the case where n is 2 or more, a plurality of R 2 may be the same or different.
n is 1 to 50, preferably 1 to 30, more preferably 1 to 10.
Further, in formula (1), * represents a bond, and * is preferably a bond bonded to a phosphorus atom of a phosphoric acid skeleton.
　本発明において、リン酸エステルは、好ましくは以下の式（２）、又は式（３）で表される化合物であり、より好ましくは式（２）で表される化合物である。また本発明におけるリン酸エステルは、式（２）及び式（３）で表される化合物の混合物であってもよい。
Figure JPOXMLDOC01-appb-C000006
 　式（２）及び式（３）において、Ｒ１及びｎは式（１）のものと同義である。 In the present invention, the phosphoric acid ester is preferably a compound represented by the following formula (2) or formula (3), more preferably a compound represented by formula (2). Further, the phosphoric acid ester in the present invention may be a mixture of compounds represented by formula (2) and formula (3).
Figure JPOXMLDOC01-appb-C000006
 In formula (2) and formula (3), R 1 and n have the same meanings as in formula (1).
　樹脂層におけるリン酸エステルの含有量は、白化をより抑制する観点から、好ましくは０．０４質量％以上であり、より好ましくは０．１質量％以上であり、そして、耐熱黄変の観点から、好ましくは０．５質量％以下であり、より好ましくは０．３質量％以下である。 The content of phosphate ester in the resin layer is preferably 0.04% by mass or more, more preferably 0.1% by mass or more, from the viewpoint of further suppressing whitening, and from the viewpoint of heat resistance to yellowing. , preferably 0.5% by mass or less, more preferably 0.3% by mass or less.
［ポリビニルアセタール樹脂］
　本発明の樹脂層は、ポリビニルアセタール樹脂を含有する。ポリビニルアセタール樹脂を含有することにより、カバーガラスやセンサーガラスなどのタッチパネルを構成する各部材間の接着性を高めることができ、かつ衝撃吸収性が高まり、割れや破損が生じ難くなる。 [Polyvinyl acetal resin]
The resin layer of the present invention contains polyvinyl acetal resin. By containing polyvinyl acetal resin, it is possible to improve the adhesion between each member constituting the touch panel, such as the cover glass and the sensor glass, and the shock absorption property is increased, making it difficult for cracks and breakage to occur.
　ポリビニルアセタール樹脂は、ポリビニルアルコール（ＰＶＡ）をアルデヒドでアセタール化して得られる。すなわち、ポリビニルアセタール樹脂は、ポリビニルアルコール（ＰＶＡ）のアセタール化物であることが好ましい。ポリビニルアルコール（ＰＶＡ）は、例えば、ポリ酢酸ビニルなどのポリビニルエステルをけん化することにより得られる。ポリビニルアルコールのけん化度は、一般に７０～９９．９モル％である。ポリビニルアセタール樹脂は、１種単独で使用してもよいし、２種以上を併用してもよい。 Polyvinyl acetal resin is obtained by acetalizing polyvinyl alcohol (PVA) with aldehyde. That is, the polyvinyl acetal resin is preferably an acetalized product of polyvinyl alcohol (PVA). Polyvinyl alcohol (PVA) is obtained, for example, by saponifying a polyvinyl ester such as polyvinyl acetate. The saponification degree of polyvinyl alcohol is generally 70 to 99.9 mol%. One type of polyvinyl acetal resin may be used alone, or two or more types may be used in combination.
　ポリビニルアセタール樹脂の平均重合度は、好ましくは２００以上、より好ましくは５００以上、さらに好ましくは１０００以上、よりさらに好ましくは１５００以上である。また、ポリビニルアセタール樹脂の平均重合度は、好ましくは５０００以下、より好ましくは４０００以下、更に好ましくは３５００以下である。
　なお、ポリビニルアセタール樹脂の平均重合度は、ポリビニルアセタール樹脂の原料となるＰＶＡの平均重合度と同じであり、ＰＶＡの平均重合度は、ＪＩＳ  Ｋ６７２６「ポリビニルアルコール試験方法」に準拠した方法により求められる。 The average degree of polymerization of the polyvinyl acetal resin is preferably 200 or more, more preferably 500 or more, still more preferably 1000 or more, even more preferably 1500 or more. Further, the average degree of polymerization of the polyvinyl acetal resin is preferably 5,000 or less, more preferably 4,000 or less, and even more preferably 3,500 or less.
The average degree of polymerization of polyvinyl acetal resin is the same as the average degree of polymerization of PVA, which is the raw material for polyvinyl acetal resin, and the average degree of polymerization of PVA is determined by a method based on JIS K6726 "Polyvinyl alcohol test method". .
　アセタール化に使用するアルデヒドは特に限定されないが、炭素数が１～１０のアルデヒドが好適に用いられ、より好ましくは炭素数が３～５のアルデヒド、さらに好ましくは炭素数が４又は５のアルデヒド、特に好ましくは炭素数４のアルデヒドである。
　上記炭素数が１～１０のアルデヒドは特に限定されず、例えば、ホルムアルデヒド、アセトアルデヒド、プロピオンアルデヒド、ｎ－ブチルアルデヒド、イソブチルアルデヒド、ｎ－バレルアルデヒド、２－エチルブチルアルデヒド、ｎ－ヘキシルアルデヒド、ｎ－オクチルアルデヒド、ｎ－ノニルアルデヒド、ｎ－デシルアルデヒド、ベンズアルデヒド等が挙げられる。なかでも、アセトアルデヒド、プロピオンアルデヒド、ｎ－ブチルアルデヒド、イソブチルアルデヒド、ｎ－ヘキシルアルデヒド又はｎ－バレルアルデヒドが好ましく、プロピオンアルデヒド、ｎ－ブチルアルデヒド、イソブチルアルデヒド又はｎ－バレルアルデヒドがより好ましく、ｎ－ブチルアルデヒド又はｎ－バレルアルデヒドが更に好ましく、ｎ－ブチルアルデヒドが最も好ましい。上記アルデヒドは、１種のみが用いられてもよく、２種以上が併用されてもよい。 The aldehyde used for acetalization is not particularly limited, but aldehydes having 1 to 10 carbon atoms are preferably used, more preferably aldehydes having 3 to 5 carbon atoms, still more preferably aldehydes having 4 or 5 carbon atoms, Particularly preferred are aldehydes having 4 carbon atoms.
The above aldehydes having 1 to 10 carbon atoms are not particularly limited, and examples thereof include formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde, n-hexylaldehyde, n- Examples include octylaldehyde, n-nonylaldehyde, n-decylaldehyde, and benzaldehyde. Among them, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-hexylaldehyde or n-valeraldehyde are preferred, propionaldehyde, n-butyraldehyde, isobutyraldehyde or n-valeraldehyde is more preferred, and n-butyl Aldehydes or n-valeraldehyde are more preferred, and n-butyraldehyde is most preferred. The above aldehydes may be used alone or in combination of two or more.
　ポリビニルアセタール樹脂に含まれているアセタール基の炭素数は特に限定されないが、１～１０であることが好ましく、より好ましくは３～５、さらに好ましくは４又は５、特に好ましくは４である。アセタール基としては、具体的にはブチラール基が特に好ましく、したがって、ポリビニルアセタール樹脂としては、ポリビニルブチラール樹脂が好ましい。 The number of carbon atoms in the acetal group contained in the polyvinyl acetal resin is not particularly limited, but it is preferably 1 to 10, more preferably 3 to 5, still more preferably 4 or 5, particularly preferably 4. Specifically, a butyral group is particularly preferable as the acetal group, and therefore, a polyvinyl butyral resin is preferable as the polyvinyl acetal resin.
　ポリビニルアセタール樹脂の水酸基量は、好ましくは１５モル％以上であり、また、好ましくは３８モル％以下である。水酸基量を１５モル％以上とすることで、接着性が良好になりやすくなる。また、水酸基量を３８モル％以下とすることで、樹脂層が硬くなり過ぎたりすることを防止する。上記水酸基量は接着性などの観点から、より好ましくは２０モル％以上であり、さらに好ましくは２５モル％以上である。また、上記水酸基量は、より好ましくは３５％以下、さらに好ましくは３３モル％以下である。
　ポリビニルアセタール樹脂としてポリビニルブチラール樹脂を用いる場合も、同様の観点から、水酸基量は１５モル％以上であり、また、好ましくは３８モル％以下であり、より好ましくは２０モル％以上、さらに好ましくは２５モル％以上であり、より好ましくは３５％モル以下、さらに好ましくは３３モル％以下である。
　ポリビニルアセタール樹脂の水酸基量は、水酸基が結合しているエチレン基量を、主鎖の全エチレン基量で除算して求めたモル分率を百分率で示した値である。上記水酸基が結合しているエチレン基量は、例えば、ＪＩＳ  Ｋ６７２８「ポリビニルブチラール試験方法」に準拠して測定できる。 The amount of hydroxyl groups in the polyvinyl acetal resin is preferably 15 mol% or more, and preferably 38 mol% or less. By setting the amount of hydroxyl groups to 15 mol% or more, the adhesiveness tends to be good. Further, by controlling the amount of hydroxyl groups to 38 mol% or less, the resin layer is prevented from becoming too hard. The amount of hydroxyl groups is more preferably 20 mol% or more, still more preferably 25 mol% or more, from the viewpoint of adhesion. Further, the amount of hydroxyl groups is more preferably 35% or less, still more preferably 33 mol% or less.
When polyvinyl butyral resin is used as the polyvinyl acetal resin, from the same viewpoint, the amount of hydroxyl groups is 15 mol% or more, preferably 38 mol% or less, more preferably 20 mol% or more, even more preferably 25 mol% or more. It is mol% or more, more preferably 35% mol or less, still more preferably 33 mol% or less.
The amount of hydroxyl groups in the polyvinyl acetal resin is a value expressed as a percentage of the molar fraction obtained by dividing the amount of ethylene groups to which hydroxyl groups are bonded by the total amount of ethylene groups in the main chain. The amount of ethylene groups to which the hydroxyl groups are bonded can be measured, for example, in accordance with JIS K6728 "Polyvinyl Butyral Test Method."
　上記ポリビニルアセタール樹脂のアセタール化度は、好ましくは４７モル％以上、また好ましくは８５モル％以下である。上記アセタール化度は、より好ましくは５５モル％以上、さらに好ましくは６０モル％以上であり、また、より好ましくは８０モル％以下、さらに好ましくは７５モル％以下である。
　なお、アセタール化度とは、アセタール基がブチラール基であり、ポリビニルアセタール樹脂がポリビニルブチラール樹脂の場合には、ブチラール化度を意味する。 The degree of acetalization of the polyvinyl acetal resin is preferably 47 mol% or more, and preferably 85 mol% or less. The degree of acetalization is more preferably 55 mol% or more, still more preferably 60 mol% or more, and more preferably 80 mol% or less, still more preferably 75 mol% or less.
In addition, the degree of acetalization means the degree of butyralization when the acetal group is a butyral group and the polyvinyl acetal resin is a polyvinyl butyral resin.
　上記アセタール化度は、主鎖の全エチレン基量から、水酸基が結合しているエチレン基量と、アセチル基が結合しているエチレン基量とを差し引いた値を、主鎖の全エチレン基量で除算して求めたモル分率を百分率で示した値である。アセタール化度（ブチラール化度）は、例えばＪＩＳ  Ｋ６７２８「ポリビニルブチラール試験方法」に準拠した方法により測定された結果から算出するとよい。 The above degree of acetalization is calculated by subtracting the amount of ethylene groups to which hydroxyl groups are bonded and the amount of ethylene groups to which acetyl groups are bonded from the total amount of ethylene groups in the main chain. This is the value expressed as a percentage of the mole fraction obtained by dividing by . The degree of acetalization (degree of butyralization) may be calculated from the results measured by a method based on, for example, JIS K6728 "Polyvinyl butyral test method."
　ポリビニルアセタール樹脂のアセチル化度は、好ましくは３０モル％以下、より好ましくは２０モル％以下、さらに好ましくは１０モル％以下、よりさらに好ましくは２モル％以下である。上記アセチル化度が上記上限以下であると、樹脂層の耐湿性が高くなる。また、上記アセチル化度は、特に限定されないが、好ましくは０．０１モル％以上であり、より好ましくは０．１モル％以上である。
　上記アセチル化度は、アセチル基が結合しているエチレン基量を、主鎖の全エチレン基量で除算して求めたモル分率を百分率で示した値である。上記アセチル基が結合しているエチレン基量は、例えば、ＪＩＳ  Ｋ６７２８「ポリビニルブチラール試験方法」に準拠して測定できる。 The degree of acetylation of the polyvinyl acetal resin is preferably 30 mol% or less, more preferably 20 mol% or less, still more preferably 10 mol% or less, even more preferably 2 mol% or less. When the degree of acetylation is below the upper limit, the moisture resistance of the resin layer becomes high. Further, the degree of acetylation is not particularly limited, but is preferably 0.01 mol% or more, more preferably 0.1 mol% or more.
The above-mentioned degree of acetylation is a value expressed as a percentage of the molar fraction obtained by dividing the amount of ethylene groups to which acetyl groups are bonded by the total amount of ethylene groups in the main chain. The amount of ethylene groups to which the acetyl groups are bonded can be measured, for example, in accordance with JIS K6728 "Test Method for Polyvinyl Butyral."
［他の樹脂］
　樹脂層は、本発明の効果を阻害しない範囲で、ポリビニルアセタール樹脂以外の樹脂を含有してもよい。ポリビニルアセタール樹脂以外の樹脂としては、例えば、エチレン－酢酸ビニル共重合体樹脂、アイオノマー樹脂、ポリウレタン樹脂、熱可塑性エラストマー、アクリル樹脂などが挙げられる。樹脂層に含まれる樹脂全量基準で、ポリビニルアセタール樹脂の含有量は、好ましくは５０質量％以上、より好ましくは８０質量％以上、さらに好ましくは１００質量％である。 [Other resins]
The resin layer may contain resins other than polyvinyl acetal resin as long as the effects of the present invention are not impaired. Examples of resins other than polyvinyl acetal resin include ethylene-vinyl acetate copolymer resin, ionomer resin, polyurethane resin, thermoplastic elastomer, and acrylic resin. Based on the total amount of resin contained in the resin layer, the content of the polyvinyl acetal resin is preferably 50% by mass or more, more preferably 80% by mass or more, and even more preferably 100% by mass.
［可塑剤］
　本発明の樹脂層は、可塑剤を含有することが好ましい。樹脂層に上記したポリビニルアセタール樹脂と共に可塑剤を含有させることで、衝撃吸収性をより向上させることができる。また樹脂層は可塑剤を含有することで、より柔軟となり、所定の形状に調整しやすくなる。 [Plasticizer]
The resin layer of the present invention preferably contains a plasticizer. By including a plasticizer in the resin layer together with the above-mentioned polyvinyl acetal resin, the impact absorption property can be further improved. Further, by containing a plasticizer, the resin layer becomes more flexible and can be easily adjusted to a predetermined shape.
　可塑剤としては、例えば、有機エステル可塑剤、有機リン酸エステル可塑剤及び有機亜リン酸エステル可塑剤などの有機リン系可塑剤、ポリアルキレングリコール系可塑剤、ポリオキシアルキレンエーテル系可塑剤などの有機エーテル系可塑剤、アルコール系可塑剤などが挙げられる。可塑剤は１種単独で使用してもよいし、２種以上を併用してもよい。上記したなかでも、有機エステル可塑剤、ポリアルキレングリコール系可塑剤が好ましく、中でも有機エステル可塑剤がより好ましい。好ましい有機エステル可塑剤としては、一塩基性有機酸エステル及び多塩基性有機酸エステル等が挙げられる。 Examples of the plasticizer include organic phosphorus plasticizers such as organic ester plasticizers, organic phosphate ester plasticizers, and organic phosphite plasticizers, polyalkylene glycol plasticizers, and polyoxyalkylene ether plasticizers. Examples include organic ether plasticizers and alcohol plasticizers. One type of plasticizer may be used alone, or two or more types may be used in combination. Among the above, organic ester plasticizers and polyalkylene glycol plasticizers are preferred, and organic ester plasticizers are particularly preferred. Preferred organic ester plasticizers include monobasic organic acid esters and polybasic organic acid esters.
　一塩基性有機酸エステルとしては、グリコールと、一塩基性有機酸とのエステルが挙げられる。グリコールとしては、各アルキレン単位が炭素数２～４、好ましくは炭素数２又は３であり、アルキレン単位の繰り返し数が２～１０、好ましくは２～４であるポリアルキレングリコールが挙げられる。また、グリコールとしては、炭素数２～４、好ましくは炭素数２又は３のモノアルキレングリコール（すなわち、繰り返し単位が１）でもよい。
　グリコールとしては、具体的には、エチレングリコール、ジエチレングリコール、トリエチレングリコール、テトラエチレングリコール、プロピレングリコール、ジプロピレングリコール、トリプロピレングリコール、テトラプロピレングリコール、ブチレングリコールなどが挙げられる。
　一塩基性有機酸としては、炭素数３～１０の有機酸が挙げられ、具体的には、酪酸、イソ酪酸、カプロン酸、２－エチル酪酸、ヘプチル酸、ｎ－オクチル酸、２－エチルヘキシル酸、ｎ－ノニル酸及びデシル酸などが挙げられる。 Examples of monobasic organic acid esters include esters of glycol and monobasic organic acids. Examples of the glycol include polyalkylene glycols in which each alkylene unit has 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms, and the number of repeating alkylene units is 2 to 10, preferably 2 to 4. Further, the glycol may be a monoalkylene glycol having 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms (ie, 1 repeating unit).
Specific examples of the glycol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, butylene glycol, and the like.
Examples of monobasic organic acids include organic acids having 3 to 10 carbon atoms, specifically butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptylic acid, n-octylic acid, and 2-ethylhexylic acid. , n-nonylic acid and decyl acid.
　具体的な一塩基性有機酸エステルとしては、トリエチレングリコールジ－２－エチルブチレート、トリエチレングリコールジ－２－エチルヘキサノエート、トリエチレングリコールジカプリレート、トリエチレングリコールジ－ｎ－オクタノエート、トリエチレングリコールジ－ｎ－ヘプタノエート、テトラエチレングリコールジ－ｎ－ヘプタノエート、テトラエチレングリコールジ－２－エチルヘキサノエート、ジエチレングリコールジ－２－エチルブチレート、ジエチレングリコールジ－２－エチルヘキサノエート、ジプロピレングリコールジ－２－エチルブチレート、トリエチレングリコールジ－２－エチルペンタノエート、テトラエチレングリコールジ－２－エチルブチレート、ジエチレングリコールジカプリエート、トリエチレングリコールジ－ｎ－ヘプタノエート、テトラエチレングリコールジ－ｎ－ヘプタノエート、トリエチレングリコールジ－２－エチルブチレート、エチレングリコールジ－２－エチルブチレート、１，２－プロピレングリコールジ－２－エチルブチレート、１，３－プロピレングリコールジ－２－エチルブチレート、１，４－ブチレングリコールジ－２－エチルブチレート、１，２－ブチレングリコールジ－２－エチルブチレートなどが挙げられる。 Specific monobasic organic acid esters include triethylene glycol di-2-ethyl butyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, and triethylene glycol di-n-octanoate. , triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, tetraethylene glycol di-2-ethylhexanoate, diethylene glycol di-2-ethyl butyrate, diethylene glycol di-2-ethylhexanoate, Dipropylene glycol di-2-ethyl butyrate, triethylene glycol di-2-ethyl pentanoate, tetraethylene glycol di-2-ethyl butyrate, diethylene glycol dicapryate, triethylene glycol di-n-heptanoate, tetraethylene Glycol di-n-heptanoate, triethylene glycol di-2-ethyl butyrate, ethylene glycol di-2-ethyl butyrate, 1,2-propylene glycol di-2-ethyl butyrate, 1,3-propylene glycol di- Examples include 2-ethyl butyrate, 1,4-butylene glycol di-2-ethyl butyrate, and 1,2-butylene glycol di-2-ethyl butyrate.
　また、多塩基性有機酸エステルとしては、例えば、アジピン酸、セバシン酸、アゼライン酸、フタル酸等の炭素数４～１２の二塩基性有機酸と、炭素数４～１０のアルコールとのエステル化合物が挙げられる。炭素数４～１０のアルコールは、直鎖でもよいし、分岐構造を有していてもよいし、環状構造を有してもよい。
　具体的には、セバシン酸ジブチル、アゼライン酸ジオクチル、アジピン酸ジヘキシル、アジピン酸ジオクチル、アジピン酸ヘキシルシクロヘキシル、アジピン酸ヘキシルシクロヘキシル、アジピン酸ジイソノニル、アジピン酸ヘプチルノニル、ジブチルカルビトールアジペート、混合型アジピン酸エステル、フタル酸ジオクチル、フタル酸ジブチルなどが挙げられる。また、油変性セバシン酸アルキドなどでもよい。混合型アジピン酸エステルとしては、炭素数４～９のアルキルアルコール及び炭素数４～９の環状アルコールから選択される２種以上のアルコールから作製されたアジピン酸エステルが挙げられる。 Examples of polybasic organic acid esters include ester compounds of dibasic organic acids having 4 to 12 carbon atoms, such as adipic acid, sebacic acid, azelaic acid, and phthalic acid, and alcohols having 4 to 10 carbon atoms. can be mentioned. The alcohol having 4 to 10 carbon atoms may have a straight chain, a branched structure, or a cyclic structure.
Specifically, dibutyl sebacate, dioctyl azelate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, dibutyl carbitol adipate, mixed adipate ester, Examples include dioctyl phthalate and dibutyl phthalate. Alternatively, oil-modified sebacic acid alkyd or the like may be used. Examples of mixed adipate esters include adipate esters prepared from two or more alcohols selected from alkyl alcohols having 4 to 9 carbon atoms and cyclic alcohols having 4 to 9 carbon atoms.
　有機エステル可塑剤としては、上記した各エステルの完全エステルに限定されず、部分エステルであってもよい。例えば、グリコールと、一塩基性有機酸との部分エステルであってもよいし、二塩基性有機酸と、アルコールとの部分エステルであってもよい。具体的には、トリエチレングリコール－モノ－２－エチルヘキサノエートなどが挙げられる。
　さらに、グリセリンなどの３価以上のアルコールと、一塩基性有機酸の部分エステルなどであってよい。一塩基性有機酸としては、炭素数３～２４、好ましくは炭素数６～１８の一塩基性有機酸が挙げられる。３価以上のアルコールと、一塩基性有機酸の部分エステルの具体例としては、グリセリンとステアリン酸のモノ又はジエステル、グリセリンと２－エチルヘキシル酸とのモノ又はジエステルなどが挙げられる。
　有機エステル可塑剤としては、上記したなかでも、トリエチレングリコール－ジ－２－エチルヘキサノエート（３ＧＯ）、アジピン酸ジオクチル（ＤＯＡ）が特に好適に用いられる。 The organic ester plasticizer is not limited to the complete esters of the above-mentioned esters, but may also be partial esters. For example, it may be a partial ester of a glycol and a monobasic organic acid, or a partial ester of a dibasic organic acid and an alcohol. Specific examples include triethylene glycol-mono-2-ethylhexanoate.
Further, it may be a partial ester of a trihydric or higher alcohol such as glycerin and a monobasic organic acid. Examples of the monobasic organic acid include monobasic organic acids having 3 to 24 carbon atoms, preferably 6 to 18 carbon atoms. Specific examples of partial esters of trihydric or higher alcohols and monobasic organic acids include mono- or diesters of glycerin and stearic acid, mono- or diesters of glycerin and 2-ethylhexylic acid, and the like.
Among the organic ester plasticizers mentioned above, triethylene glycol-di-2-ethylhexanoate (3GO) and dioctyl adipate (DOA) are particularly preferably used.
　上記有機リン系可塑剤としては、トリブトキシエチルホスフェート、イソデシルジフェニルホスフェート及びトリイソプロピルホスフェート等のリン酸エステルなどが挙げられる。 Examples of the organic phosphorus plasticizer include phosphate esters such as tributoxyethyl phosphate, isodecyl diphenyl phosphate, and triisopropyl phosphate.
　ポリアルキレングリコール系可塑剤としては、ポリエチレングリコール、ポリプロピレングリコール、ポリ（エチレンオキシド／プロピレンオキシド）ブロック共重合体、ポリ（エチレンオキシド／プロピレンオキシド）ランダム共重合体、ポリテトラメチレングリコールなどが挙げられ、これらの中では、ポリプロピレングリコール、が好ましい。 Examples of polyalkylene glycol plasticizers include polyethylene glycol, polypropylene glycol, poly(ethylene oxide/propylene oxide) block copolymer, poly(ethylene oxide/propylene oxide) random copolymer, polytetramethylene glycol, etc. Among them, polypropylene glycol is preferred.
　ポリオキシアルキレンエーテル系可塑剤は、１価又は多価アルコールとポリオキシアルキレンとのエーテル化合物である。
　具体的なポリオキシアルキレンエーテル系可塑剤としては、例えば、ポリオキシエチレンヘキシルエーテル、ポリオキシエチレンヘプチルエーテル、ポリオキシエチレンオクチルエーテル、ポリオキシエチレン－２－エチルヘキシルエーテル、ポリオキシエチレンノニルエーテル、ポリオキシエチレンデシルエーテル、ポリオキシエチレンアリルエーテル、ポリオキシプロピレンアリルエーテル、ポリオキシエチレングリセリルエーテル、ポリオキシプロピレングリセリルエーテル、ポリオキシエチレンジグリセリルエーテル、ポリオキシプロピレンジグリセリルエーテル、ポリオキシアルキレンペンタエリスリトールエーテル、ポリカプロラクトントリオールなどが挙げられる。
　ポリオキシアルキレンエーテル系可塑剤は、好ましくは多価アルコールとポリオキシアルキレンとのエーテル化合物であり、より好ましくはグリセリン又はジグリセリンとポリオキシアルキレンとのエーテル化合物であり、更に好ましくはグリセリン又はジグリセリンとポリオキシプロピレンとのエーテル化合物である。
　アルコール系可塑剤としては、ポリアルキレングリコール可塑剤、ポリオキシアルキレンエーテル可塑剤以外のアルコールが挙げられる。具体的には、エチレングリコール、プロピレングリコール、ブタンジオール、ヘキサンジオール、トリメチロールプロパン、ペンタエリスリトール、グリセリン、ジグリセリンなどの各種の多価アルコールが挙げられる。これらの中では、エチレングリコールが好ましい。 The polyoxyalkylene ether plasticizer is an ether compound of monohydric or polyhydric alcohol and polyoxyalkylene.
Specific polyoxyalkylene ether plasticizers include, for example, polyoxyethylene hexyl ether, polyoxyethylene heptyl ether, polyoxyethylene octyl ether, polyoxyethylene-2-ethylhexyl ether, polyoxyethylene nonyl ether, polyoxy Ethylene decyl ether, polyoxyethylene allyl ether, polyoxypropylene allyl ether, polyoxyethylene glyceryl ether, polyoxypropylene glyceryl ether, polyoxyethylene diglyceryl ether, polyoxypropylene diglyceryl ether, polyoxyalkylene pentaerythritol ether, poly Examples include caprolactone triol.
The polyoxyalkylene ether plasticizer is preferably an ether compound of polyhydric alcohol and polyoxyalkylene, more preferably an ether compound of glycerin or diglycerin and polyoxyalkylene, still more preferably glycerin or diglycerin. It is an ether compound of polyoxypropylene and polyoxypropylene.
Examples of alcohol plasticizers include alcohols other than polyalkylene glycol plasticizers and polyoxyalkylene ether plasticizers. Specific examples include various polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, hexanediol, trimethylolpropane, pentaerythritol, glycerin, and diglycerin. Among these, ethylene glycol is preferred.
　樹脂層における可塑剤の含有量は、好ましくはポリアセタール樹脂１００質量部に対して、好ましくは５質量部以上、より好ましくは１５質量部以上、さらに好ましくは３０質量部以上であり、そして好ましくは１００質量部以下、より好ましくは６０質量部以下であり、さらに好ましくは５０質量部以下である。 The content of the plasticizer in the resin layer is preferably 5 parts by mass or more, more preferably 15 parts by mass or more, even more preferably 30 parts by mass or more, and preferably 100 parts by mass or more, based on 100 parts by mass of the polyacetal resin. It is not more than 60 parts by mass, more preferably not more than 50 parts by mass.
［その他の添加剤］
　本発明の樹脂層には、必要に応じて、粘着付与樹脂、接着力調整剤、乳化剤、軟化剤、微粒子、充填材、顔料、染料、シランカップリング剤、酸化防止剤、界面活性剤、ワックスなどの公知の添加剤を含有してもよい。 [Other additives]
The resin layer of the present invention may contain a tackifying resin, an adhesive force regulator, an emulsifier, a softener, a fine particle, a filler, a pigment, a dye, a silane coupling agent, an antioxidant, a surfactant, and a wax, as necessary. It may also contain known additives such as.
（フィルム形状）
　基材に容易に貼り付けることができるという観点から、本発明の層間接着剤はフィルム形状であることが好ましい。この場合、本発明の層間接着剤は、例えば、樹脂、リン酸エステル及び、必要に応じて配合される各種添加剤を混合し、得られた樹脂組成物を押出成形、プレス成形などして成形して得ればよい。 (Film shape)
The interlayer adhesive of the present invention is preferably in the form of a film from the viewpoint that it can be easily attached to a substrate. In this case, the interlayer adhesive of the present invention can be formed by, for example, mixing a resin, a phosphate ester, and various additives blended as necessary, and extruding or press-molding the obtained resin composition. All you have to do is get it.
［厚み］
　本発明の層間接着剤の厚みは、特に限定されず、使用するタッチパネルのサイズや種類に応じて適宜調整するとよい。層間接着剤の厚みは、好ましくは０．０５ｍｍ以上であり、より好ましくは０．１ｍｍ以上であり、さらに好ましくは０．１５ｍｍ以上であり、そして好ましくは５ｍｍ以下であり、より好ましくは３ｍｍ以下、さらに好ましくは１ｍｍ以下である。 [Thickness]
The thickness of the interlayer adhesive of the present invention is not particularly limited, and may be adjusted as appropriate depending on the size and type of the touch panel to be used. The thickness of the interlayer adhesive is preferably 0.05 mm or more, more preferably 0.1 mm or more, even more preferably 0.15 mm or more, and preferably 5 mm or less, more preferably 3 mm or less, More preferably, it is 1 mm or less.
［タッチパネル］
　本発明の層間接着剤は、タッチパネルを構成する各部材同士を接着する用途に好適に使用することができる。また、本発明においては、層間接着剤を備えるタッチパネルを提供することができる。
　このような本発明の層間接着剤を用いた、タッチパネル用層間接着剤もまた、本発明の一つである。 [Touch panel]
The interlayer adhesive of the present invention can be suitably used for adhering members constituting a touch panel. Moreover, in the present invention, a touch panel including an interlayer adhesive can be provided.
An interlayer adhesive for a touch panel using such an interlayer adhesive of the present invention is also one of the present invention.
　図１に本発明のタッチパネルの一実施形態を示す。なお、本発明は図面の内容に限定されるものではない。
　図１に示すタッチパネル１０は、カバーガラス１１、センサーガラス１２、及び液晶パネル１３をこの順に備える。カバーガラス１１は光透過性を有する部材であり、その表面は、タッチ操作に伴い使用者の手指などが接触する操作面となる。センサーガラス１２は、その表面にＩＴＯパターン（図示せず）が形成されており、これにより、使用者の手指（検知対象物）によるタッチ操作の検知を可能としている。なお、センサーガラス１２は単層構造であっても多層構造であってもよい。また、液晶パネル１３により所定の画像を表示されることができる。なお、液晶パネル１３の代わりに、有機ＥＬパネルを用いることもできる。 FIG. 1 shows an embodiment of the touch panel of the present invention. Note that the present invention is not limited to the contents of the drawings.
The touch panel 10 shown in FIG. 1 includes a cover glass 11, a sensor glass 12, and a liquid crystal panel 13 in this order. The cover glass 11 is a light-transmitting member, and its surface serves as an operation surface that the user's fingers and the like come into contact with during touch operations. The sensor glass 12 has an ITO pattern (not shown) formed on its surface, thereby enabling detection of a touch operation by a user's finger (detection target). Note that the sensor glass 12 may have a single layer structure or a multilayer structure. Furthermore, a predetermined image can be displayed on the liquid crystal panel 13. Note that an organic EL panel can also be used instead of the liquid crystal panel 13.
　カバーガラス１１とセンサーガラス１２との間には、本発明の層間接着剤１４が備えられており、カバーガラス１１とセンサーガラス１２とを接着し、固定化している。層間接着剤１４には、ポリビニルアセタール樹脂が使用されているため、カバーガラス１１とセンサーガラス１２との接着性が良好であり、かつ、衝撃吸収性が高まり、割れや破損が生じ難くなる。
　また、層間接着剤１４を構成する樹脂層は、リン酸エステルを含有していることより、タッチパネルの作動条件下（電圧印加時）において、温度や湿度が高い場合においても、白化を抑制することができる。 An interlayer adhesive 14 of the present invention is provided between the cover glass 11 and the sensor glass 12 to bond and fix the cover glass 11 and the sensor glass 12. Since polyvinyl acetal resin is used as the interlayer adhesive 14, the adhesion between the cover glass 11 and the sensor glass 12 is good, and the impact absorption property is increased, making it difficult for cracks and breakage to occur.
In addition, since the resin layer constituting the interlayer adhesive 14 contains phosphoric acid ester, it can suppress whitening even when the temperature and humidity are high under the operating conditions of the touch panel (when voltage is applied). Can be done.
　また、図１に示すように、センサーガラス１２と液晶パネル１３との間にも、必要に応じて本発明の層間接着剤１４を用いることができるが、一般に使用されている光学用粘着剤（ＯＣＡ）などを用いてもよい。
　なお、図１には、カバーガラス１１、センサーガラス１２、液晶パネル１３、及び層間接着剤１４から構成されるタッチパネルを示したが、これら以外の構成をさらに備えるタッチパネルであってもよい。 In addition, as shown in FIG. 1, the interlayer adhesive 14 of the present invention can be used between the sensor glass 12 and the liquid crystal panel 13 if necessary, but a commonly used optical adhesive ( OCA) etc. may also be used.
Note that although FIG. 1 shows a touch panel that includes a cover glass 11, a sensor glass 12, a liquid crystal panel 13, and an interlayer adhesive 14, the touch panel may further include a configuration other than these.
　また、図２に示すように、タッチパネル２は、タッチパネル本体１００と、カバー部材１５１とを有してもよい。
　カバー部材１５１は、ガラス板製の第一部材６１と層間接着剤６５と第二部材１６０とを有する。層間接着剤６５は第二面６１Ｂに略一様な厚みで密着して配置されている。第二部材１６０は、層間接着剤６５の外面に沿って層間接着剤６５に密着して配置されている。第二部材１６０は層間接着剤６５の外面に追従して配置されている。 Further, as shown in FIG. 2, the touch panel 2 may include a touch panel main body 100 and a cover member 151.
The cover member 151 includes a first member 61 made of a glass plate, an interlayer adhesive 65, and a second member 160. The interlayer adhesive 65 is disposed in close contact with the second surface 61B with a substantially uniform thickness. The second member 160 is disposed along the outer surface of the interlayer adhesive 65 in close contact with the interlayer adhesive 65. The second member 160 is arranged to follow the outer surface of the interlayer adhesive 65.
　第一部材６１は第一面６１Ａと第一面６１Ａとは反対の第二面６１Ｂを有する。所謂操作面は、第一面６１Ａである。第二面６１Ｂの全面には、透明性を有する層間接着剤６５が配置されている。 The first member 61 has a first surface 61A and a second surface 61B opposite to the first surface 61A. The so-called operation surface is the first surface 61A. A transparent interlayer adhesive 65 is arranged on the entire surface of the second surface 61B.
　第一部材６１の材質は、例えばガラス板であり、可撓性を有する薄板ガラスであってもよい。第一部材６１として、軽量化などの観点からすれば、０．０１ｍｍ以上０．５５ｍｍ以下の厚みのガラス板を用いることが好ましい。２５インチサイズ以上のカバー部材１５１を構成する際には、０．０１ｍｍ以上で１．８５ｍｍ以下の厚みのガラス板を用いることが好ましい。
　また、０．７ｍｍ以下の厚みのガラス板を用いると、薄い厚みのカバー部材１５１を構成可能である。２５インチサイズ以上の大画面対応のタッチパネル本体１００に対応するカバー部材１５１では、撓みが大きく生じないように、第一部材６１として厚目のガラス板を用いると望ましいが、全体の厚みの観点から、第一部材６１の厚みは２．５ｍｍ以下の厚みが望ましい。 The material of the first member 61 is, for example, a glass plate, and may be a thin sheet of flexible glass. From the viewpoint of weight reduction, etc., it is preferable to use a glass plate having a thickness of 0.01 mm or more and 0.55 mm or less as the first member 61. When constructing the cover member 151 having a size of 25 inches or more, it is preferable to use a glass plate having a thickness of 0.01 mm or more and 1.85 mm or less.
Further, by using a glass plate having a thickness of 0.7 mm or less, it is possible to construct the cover member 151 with a thin thickness. In the cover member 151 corresponding to the touch panel main body 100 compatible with a large screen of 25 inches or more, it is desirable to use a thick glass plate as the first member 61 so as not to cause large deflection, but from the viewpoint of the overall thickness. The thickness of the first member 61 is preferably 2.5 mm or less.
　第二部材１６０の材質は、例えばガラス板であり、可撓性を有する薄板ガラスであってもよい。軽量化などの観点からすれば、第二部材１６０として０．０１ｍｍ以上０．５５ｍｍ以下の厚みのガラス板を用いることが好ましい。２５インチサイズ以上のカバー部材１５１を構成する際には、０．０１ｍｍ以上で１．８５ｍｍ以下の厚みのガラス板を用いることが好ましい。この厚みのガラス板であれば、第二部材１６０として、層間接着剤６５の外面に追従して容易に配置でき、しかも気泡などの噛み込みも抑えられる。 The material of the second member 160 is, for example, a glass plate, and may be a flexible thin glass plate. From the viewpoint of weight reduction, it is preferable to use a glass plate having a thickness of 0.01 mm or more and 0.55 mm or less as the second member 160. When constructing the cover member 151 having a size of 25 inches or more, it is preferable to use a glass plate having a thickness of 0.01 mm or more and 1.85 mm or less. A glass plate having this thickness can be easily disposed as the second member 160, following the outer surface of the interlayer adhesive 65, and can also prevent air bubbles from being trapped.
　カバー部材１５１は、層間接着剤６５を挟むようにガラス板製の第一部材６１とガラス板製の第二部材１６０とを配置して構成している。 The cover member 151 is constructed by arranging a first member 61 made of a glass plate and a second member 160 made of a glass plate so as to sandwich an interlayer adhesive 65 therebetween.
　第二部材１６０の外面に、タッチパネル本体１００が装着されている。図２では、二枚の基板を積層した構成のタッチパネル本体１００を図示している。タッチパネル本体１００について簡単に説明すると、タッチパネル本体１００は第一基板１１１と第二基板１１２とを有する。第一基板１１１と第二基板１１２は透明性を有し、例えば樹脂フィルム製やガラス板製である。第一基板１１１にはセンサ電極の送信電極が配置され、第二基板１１２にはセンサ電極の受信電極が配置されている。第一基板１１１と第二基板１１２とは透明な粘着剤１１５によって貼り合せられている。そして、第二基板１１２には、カバー部材１５１への被着時に用いる透明な粘着剤１１６が設けられている。タッチパネル本体１００は、粘着剤１１６を介して第二部材１６０の外面に装着されている。粘着剤１１５および粘着剤１１６を、本発明にかかる層間接着剤を用いることができるが、一般に使用されている光学用粘着剤（ＯＣＡ）などを用いてもよい。 The touch panel main body 100 is attached to the outer surface of the second member 160. FIG. 2 shows a touch panel main body 100 having a structure in which two substrates are laminated. To briefly explain the touch panel main body 100, the touch panel main body 100 has a first substrate 111 and a second substrate 112. The first substrate 111 and the second substrate 112 have transparency, and are made of, for example, a resin film or a glass plate. A transmitting electrode of the sensor electrode is arranged on the first substrate 111, and a receiving electrode of the sensor electrode is arranged on the second substrate 112. The first substrate 111 and the second substrate 112 are bonded together using a transparent adhesive 115. The second substrate 112 is provided with a transparent adhesive 116 that is used when attaching it to the cover member 151. The touch panel main body 100 is attached to the outer surface of the second member 160 via an adhesive 116. The interlayer adhesive according to the present invention can be used as the adhesive 115 and the adhesive 116, but a commonly used optical adhesive (OCA) or the like may also be used.
　本発明のタッチパネルの製造方法は特に限定されないが、真空パック方式により製造することが好ましい。例えば、タッチパネルを構成する各部材の間の一部又は全てに層間接着剤を導入し、真空パックに入れて、減圧吸引した後、約７０～１１０℃で予備接着して積層体を得る。次に、積層体をオートクレーブに入れたり、又はプレスしたりして、約１２０～１５０℃及び１～１．５ＭＰａの圧力で圧着する。このようにして、タッチパネルを得ることができる。 The method for manufacturing the touch panel of the present invention is not particularly limited, but it is preferably manufactured using a vacuum packing method. For example, an interlayer adhesive is introduced between some or all of the members constituting the touch panel, placed in a vacuum pack, vacuumed, and preliminarily bonded at about 70 to 110° C. to obtain a laminate. Next, the laminate is placed in an autoclave or pressed to bond at about 120 to 150° C. and a pressure of 1 to 1.5 MPa. In this way, a touch panel can be obtained.
　本発明を実施例によりさらに詳細に説明するが、本発明はこれらの例によってなんら限定されるものではない。 The present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples in any way.
　なお、各種物性の測定及び評価は、以下のように行った。 Note that various physical properties were measured and evaluated as follows.
［耐湿熱試験による白化距離］
　各実施例及び比較例で作製したカバーガラス積層体に、ファンクションジェネレータにより電圧（５Ｖ）を印加しながら、温度６０℃、相対湿度９０％に維持して、１０００時間経過した後の白化距離を測定した。白化距離は、カバーガラス積層体のエッジから白化している部分の距離を測定して求め、以下の基準で評価した。
（評価基準）
　Ａ：白化距離が３ｍｍ以下
　Ｂ：白化距離が３ｍｍ超５ｍｍ以下
　Ｃ：白化距離が５ｍｍ超 [Whitening distance by heat and humidity test]
While applying a voltage (5V) using a function generator to the cover glass laminates produced in each example and comparative example, the temperature was maintained at 60°C and relative humidity 90%, and the whitening distance was measured after 1000 hours had passed. did. The whitening distance was determined by measuring the distance from the edge of the cover glass laminate to the whitened portion, and was evaluated based on the following criteria.
(Evaluation criteria)
A: Whitening distance is 3 mm or less B: Whitening distance is more than 3 mm and less than 5 mm C: Whitening distance is more than 5 mm
　実施例及び比較例で使用した可塑剤、リン酸エステルは以下のとおりである。 The plasticizers and phosphate esters used in Examples and Comparative Examples are as follows.
＜可塑剤＞
３ＧＯ：トリエチレングリコール－ジ－２－エチルヘキサノエート
＜リン酸エステル＞
・第一工業製薬株式会社製「プライサーフＡ２０８Ｂ」、式（２）において、Ｒ１がドデシル基、ｎが２の化合物。ＨＬＢ＝８。
・ビックケミー社製「ＤＩＳＰＥＲＢＹＫ－１０２」、ポリオキシアルキレンアルキルエーテル基を有するリン酸エステル。 <Plasticizer>
3GO: Triethylene glycol-di-2-ethylhexanoate <phosphate ester>
- "Plysurf A208B" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., a compound in which R1 is a dodecyl group and n is 2 in formula (2). HLB=8.
- "DISPERBYK-102" manufactured by BYK Chemie, a phosphoric acid ester having a polyoxyalkylene alkyl ether group.
［実施例１］
（ポリビニルブチラール樹脂の製造）
　攪拌装置を備えた反応器に、イオン交換水１８００ｇと、ポリビニルアルコールＡ（平均重合度１７００、けん化度９９モル％）２００ｇとを入れ、攪拌しながら加熱溶解し、ポリビニルアルコール溶液を得た。次にこの溶液に、触媒として２５％塩酸を、塩酸濃度が０．２重量％となるように添加し、温度を１５℃に調整したのち、攪拌しながらｎ－ブチルアルデヒド１６ｇを添加した。そのあと、ｎ－ブチルアルデヒド９５ｇを添加したところ、白色粒子状のポリビニルブチラール樹脂が析出した。析出後１０分後に２５％塩酸を１．８重量％になるように添加し、６３℃に加熱し２時間保持した。その後、溶液を冷却し、過剰の水で洗浄して未反応のブチルアルデヒドで洗い流し、塩酸触媒を汎用な中和剤である炭酸水素ナトリウムで中和し、更に過剰の水で洗浄し、乾燥させることによりポリビニルブチラール樹脂を得た。得られたポリビニルブチラール樹脂の水酸基量は３０．６モル％、アセタール化度は６８．７モル％、アセチル化度は０．７モル％であった。
（層間接着剤の製造）
　上記ポリビニルブチラール樹脂１００質量部と、可塑剤として３ＧＯを３５質量部、リン酸エステルとして、プライサーフＡ２０８Ｂを０．１４質量部とを混合し、これをミキシングロールで十分に溶融混錬したあと、プレス成形機で１５０℃、１０分間プレス成形して、厚さ０．４ｍｍの層間接着剤を得た。
（評価）
　カバーガラス（日本板硝子社製ソーダガラス）、ＩＴＯパターンが形成されたセンサーガラス（テクノプリント社製、ＩＴＯ厚み１５０ｎｍ、抵抗値１０Ω／□前後）を準備した。
　上記のとおり作製した層間接着剤を、センサーガラスとカバーガラスにより挟み込み積層体を得た。この積層体をゴムバッグ内に入れ、１．０ＭＰａの真空度で１０分間脱気した後、脱気したまま温度１００℃にしたオーブン内に移し、更に８５℃に到達するまで、積層体を仮圧着した。オートクレーブ中で１４０℃及び圧力１．３ＭＰａの条件で、仮圧着された積層体を２０分間圧着し、カバーガラス、樹脂層（層間接着剤）、センサーガラスがこの順に積層されたカバーガラス積層体を得た。
　該カバーガラス積層体の白化距離を上記のとおり測定した。結果を表１に示した。 [Example 1]
(Production of polyvinyl butyral resin)
In a reactor equipped with a stirring device, 1800 g of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, degree of saponification 99 mol %) were placed, and heated and dissolved while stirring to obtain a polyvinyl alcohol solution. Next, 25% hydrochloric acid was added as a catalyst to this solution so that the hydrochloric acid concentration was 0.2% by weight, and after adjusting the temperature to 15° C., 16 g of n-butyraldehyde was added with stirring. Thereafter, when 95 g of n-butyraldehyde was added, white particulate polyvinyl butyral resin was precipitated. Ten minutes after the precipitation, 25% hydrochloric acid was added to give a concentration of 1.8% by weight, and the mixture was heated to 63°C and held for 2 hours. The solution is then cooled, washed with excess water and unreacted butyraldehyde, the hydrochloric acid catalyst is neutralized with sodium bicarbonate, a common neutralizing agent, washed with excess water, and dried. A polyvinyl butyral resin was thus obtained. The amount of hydroxyl groups in the obtained polyvinyl butyral resin was 30.6 mol%, the degree of acetalization was 68.7 mol%, and the degree of acetylation was 0.7 mol%.
(Manufacture of interlayer adhesive)
After mixing 100 parts by mass of the above polyvinyl butyral resin, 35 parts by mass of 3GO as a plasticizer, and 0.14 parts by mass of Plysurf A208B as a phosphoric acid ester, and thoroughly melting and kneading this with a mixing roll, Press molding was performed using a press molding machine at 150° C. for 10 minutes to obtain an interlayer adhesive having a thickness of 0.4 mm.
(evaluation)
A cover glass (soda glass manufactured by Nippon Sheet Glass Co., Ltd.) and a sensor glass on which an ITO pattern was formed (manufactured by Techno Print Co., Ltd., ITO thickness 150 nm, resistance value around 10 Ω/□) were prepared.
The interlayer adhesive produced as described above was sandwiched between a sensor glass and a cover glass to obtain a laminate. This laminate was placed in a rubber bag and degassed for 10 minutes at a vacuum level of 1.0 MPa, then transferred to an oven heated to 100°C while still being degassed, and the laminate was kept temporarily until the temperature reached 85°C. It was crimped. The temporarily pressed laminate was pressed in an autoclave at 140°C and a pressure of 1.3 MPa for 20 minutes to form a cover glass laminate in which the cover glass, resin layer (interlayer adhesive), and sensor glass were laminated in this order. Obtained.
The whitening distance of the cover glass laminate was measured as described above. The results are shown in Table 1.
［実施例２］
　実施例１の層間接着剤の製造において、プライサーフＡ２０８Ｂの量を２倍等量（０．２８質量部）とし、それ以外は実施例１と同様に行った。 [Example 2]
In the production of the interlayer adhesive of Example 1, the amount of Plysurf A208B was doubled to an equivalent amount (0.28 parts by mass), and the same procedure as in Example 1 was carried out except for that.
［実施例３］
　実施例１の層間接着剤の製造において、プライサーフＡ２０８Ｂの量を４／１０倍等量（０．０５６質量部）とし、それ以外は実施例１と同様に行った。 [Example 3]
In the production of the interlayer adhesive of Example 1, the amount of Plysurf A208B was changed to 4/10 times the equivalent amount (0.056 parts by mass), and the same procedure as in Example 1 was carried out except for that.
［実施例４］
　実施例１の層間接着剤の製造において、リン酸エステルの種類をプライサーフＡ２０８ＢからＤＩＳＰＥＲＢＹＫ－１０２に変更して、それ以外は実施例１と同様に行った。 [Example 4]
In producing the interlayer adhesive of Example 1, the same procedure as in Example 1 was carried out except that the type of phosphate ester was changed from Plysurf A208B to DISPERBYK-102.
［比較例１］
　実施例１の層間接着剤の製造において、リン酸エステルの添加を行わなかった以外は、実施例１と同様に行った。 [Comparative example 1]
The interlayer adhesive of Example 1 was produced in the same manner as in Example 1, except that phosphoric acid ester was not added.
Figure JPOXMLDOC01-appb-T000007
 ※表１におけるＰＶＢ及び可塑剤は質量部数を表す。リン酸エステルの含有量は樹脂層中の質量％を表す。
Figure JPOXMLDOC01-appb-T000007
 *PVB and plasticizer in Table 1 represent parts by mass. The content of phosphoric acid ester represents mass % in the resin layer.
　以上のように、リン酸エステルを含有する各実施例の層間接着剤を用いることで、耐湿熱試験におけるタッチパネルの白化を抑制することができた。
　それに対して、各比較例の層間接着剤は、リン酸エステルを含有しておらず、耐湿熱試験におけるタッチパネルの白化を抑制することができなかった。 As described above, by using the interlayer adhesive of each example containing a phosphate ester, it was possible to suppress whitening of the touch panel in the heat and humidity test.
On the other hand, the interlayer adhesives of each comparative example did not contain phosphate ester and were unable to suppress whitening of the touch panel in the heat and humidity test.
　２、１０　タッチパネル
　１１　カバーガラス
　１２　センサーガラス
　１３　液晶パネル
　１４　層間接着剤
　６１　第一部材
　６５　層間接着剤
　１００　タッチパネル本体
　１１１　第一基板
　１１２　第二基板
　１１５、１１６　粘着剤
　１５１　カバー部材
　１６０　第二部材 2, 10 touch panel 11 cover glass 12 sensor glass 13 liquid crystal panel 14 interlayer adhesive 61 first member 65 interlayer adhesive 100 touch panel body 111 first substrate 112 second substrate 115, 116 adhesive 151 cover member 160 second member

Claims (12)

  1. 　ポリビニルアセタール樹脂を含む樹脂層からなり、前記樹脂層にリン酸エステルを含有する、層間接着剤。 An interlayer adhesive consisting of a resin layer containing polyvinyl acetal resin, and containing a phosphate ester in the resin layer.
  2. 　前記樹脂層における前記リン酸エステルの濃度が０．１質量％以上である、請求項１に記載の層間接着剤。 The interlayer adhesive according to claim 1, wherein the concentration of the phosphate ester in the resin layer is 0.1% by mass or more.
  3. 　前記樹脂層における前記リン酸エステルの濃度が０．５質量％以下である、請求項２に記載の層間接着剤。 The interlayer adhesive according to claim 2, wherein the concentration of the phosphate ester in the resin layer is 0.5% by mass or less.
  4. 　前記リン酸エステルのＨＬＢが１０以下である、請求項１～３のいずれかに記載の層間接着剤。 The interlayer adhesive according to any one of claims 1 to 3, wherein the phosphoric acid ester has an HLB of 10 or less.
  5. 　前記リン酸エステルが、ポリオキシアルキレンアルキルエーテル基を有する、請求項１～４のいずれかに記載の層間接着剤。 The interlayer adhesive according to any one of claims 1 to 4, wherein the phosphoric acid ester has a polyoxyalkylene alkyl ether group.
  6. 　前記ポリオキシアルキレンアルキルエーテル基が、式（１）で表される化合物である、請求項５に記載の層間接着剤。
    Figure JPOXMLDOC01-appb-C000001
     （Ｒ１は炭素数８～１８のアルキル基であり、Ｒ２は炭素数２～６のアルキレン基であり、ｎは１～１０であり、＊は結合手を表す）     The interlayer adhesive according to claim 5, wherein the polyoxyalkylene alkyl ether group is a compound represented by formula (1).
    Figure JPOXMLDOC01-appb-C000001
     (R 1 is an alkyl group having 8 to 18 carbon atoms, R 2 is an alkylene group having 2 to 6 carbon atoms, n is 1 to 10, and * represents a bond)
  7. 　前記リン酸エステルは、式（２）又は式（３）で表される化合物である、請求項１～６のいずれか記載の層間接着剤。
    Figure JPOXMLDOC01-appb-C000002
     （Ｒ１は炭素数８～１８のアルキル基であり、ｎは１～１０である）     The interlayer adhesive according to any one of claims 1 to 6, wherein the phosphoric acid ester is a compound represented by formula (2) or formula (3).
    Figure JPOXMLDOC01-appb-C000002
     (R 1 is an alkyl group having 8 to 18 carbon atoms, and n is 1 to 10)
  8. 　前記リン酸エステルが、ドデシル基を有する、請求項１～７のいずれかに記載の層間接着剤。 The interlayer adhesive according to any one of claims 1 to 7, wherein the phosphoric acid ester has a dodecyl group.
  9. 　前記ポリビニルアセタール樹脂がポリビニルブチラール樹脂である、請求項１～８のいずれかに記載の層間接着剤。 The interlayer adhesive according to any one of claims 1 to 8, wherein the polyvinyl acetal resin is a polyvinyl butyral resin.
  10. 　前記樹脂層が可塑剤を含有する、請求項１～９のいずれかに記載の層間接着剤。 The interlayer adhesive according to any one of claims 1 to 9, wherein the resin layer contains a plasticizer.
  11. 　請求項１～１０のいずれか記載の層間接着剤からなる、タッチパネル用層間接着剤。 An interlayer adhesive for touch panels, comprising the interlayer adhesive according to any one of claims 1 to 10.
  12. 　請求項１～１０のいずれかに記載の層間接着剤を備えるタッチパネル。

          A touch panel comprising the interlayer adhesive according to any one of claims 1 to 10.
PCT/JP2023/028773 2022-08-08 2023-08-07 Interlayer adhesive, interlayer adhesive for touch panel, and touch panel WO2024034575A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0570751A (en) * 1991-09-10 1993-03-23 Toshiba Chem Corp Adhesive for copper foil
WO1999026952A1 (en) * 1997-11-21 1999-06-03 Kureha Kagaku Kogyo Kabushiki Kaisha Phosphate compounds and process for producing the same, phosphate/copper compounds and process for producing the same, substance absorbing near infrared and composition absorbing near infrared, and application product thereof
JP2000234083A (en) * 1998-10-13 2000-08-29 Sumitomo Bakelite Co Ltd Preparation of anisotropically conductive adhesive, and electronic apparatus made by using adhesive prepared thereby
JP2015040167A (en) * 2013-08-23 2015-03-02 積水化学工業株式会社 Intermediate film for laminated glass, and laminated glass
WO2016186029A1 (en) * 2015-05-15 2016-11-24 積水化学工業株式会社 Interlayer filling material for touch panels, and touch panel laminate

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0570751A (en) * 1991-09-10 1993-03-23 Toshiba Chem Corp Adhesive for copper foil
WO1999026952A1 (en) * 1997-11-21 1999-06-03 Kureha Kagaku Kogyo Kabushiki Kaisha Phosphate compounds and process for producing the same, phosphate/copper compounds and process for producing the same, substance absorbing near infrared and composition absorbing near infrared, and application product thereof
JP2000234083A (en) * 1998-10-13 2000-08-29 Sumitomo Bakelite Co Ltd Preparation of anisotropically conductive adhesive, and electronic apparatus made by using adhesive prepared thereby
JP2015040167A (en) * 2013-08-23 2015-03-02 積水化学工業株式会社 Intermediate film for laminated glass, and laminated glass
WO2016186029A1 (en) * 2015-05-15 2016-11-24 積水化学工業株式会社 Interlayer filling material for touch panels, and touch panel laminate

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