WO2013099684A1 - 光学部材用粘着剤組成物並びにそれを使用した粘着シート、粘着剤層付き光学部材及びフラットパネルディスプレイ - Google Patents
光学部材用粘着剤組成物並びにそれを使用した粘着シート、粘着剤層付き光学部材及びフラットパネルディスプレイ Download PDFInfo
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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
- C09J133/00—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 only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
- C09J133/04—Homopolymers or copolymers of esters
- C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
- C09J133/062—Copolymers with monomers not covered by C09J133/06
- C09J133/066—Copolymers with monomers not covered by C09J133/06 containing -OH groups
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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
- C09J133/00—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 only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
- C09J133/04—Homopolymers or copolymers of esters
- C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
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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
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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
- C09J7/00—Adhesives in the form of films or foils
- C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
- C09J7/38—Pressure-sensitive adhesives [PSA]
- C09J7/381—Pressure-sensitive adhesives [PSA] based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
- C09J7/385—Acrylic polymers
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/30—Polarising elements
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2312/00—Crosslinking
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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
- C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
- C09J2203/318—Applications of adhesives in processes or use of adhesives in the form of films or foils for the production of liquid crystal displays
Definitions
- the present invention provides an adhesive composition for optical members which is excellent in dimensional stability and wet heat durability and can effectively prevent light leakage and peeling in a high temperature and high humidity environment, and an adhesive sheet and an adhesive layer using the same.
- the present invention relates to an attached optical member and a flat panel display.
- a liquid crystal display classified as FPD is formed of a liquid crystal panel, a backlight, and peripheral circuits.
- This liquid crystal panel is typically composed of layers such as a polarizing plate, a glass substrate having a transparent electrode, and a color filter, and the glass substrate sandwiches the liquid crystal.
- the polarizing plate has a multilayer structure of different materials, and each material has different physical and chemical characteristics. For this reason, in particular, there is a process performed in an environment of high temperature and high humidity in the manufacture of FPD. However, in such an environment, the degree of dimensional change of each layer due to shrinkage and swelling is different, and the degree of the difference is large. For this reason, the polarizing plate as a whole has poor dimensional stability.
- pressure sensitive adhesives that focus on hard characteristics are not easily deformed even in a humid heat environment, and foaming is not likely to occur. Therefore, they have excellent stress resistance and durability when contracting the polarizing plate, and relatively good light leakage characteristics and durability. It was easy to get. However, when the FPD is increased in size, light leakage and slight foaming, which were not a problem in the previous size, become more noticeable, which is a problem. For this reason, conventional pressure-sensitive adhesives cannot sufficiently cope with the sophistication of required characteristics.
- the bending of the thin glass substrate used in the liquid crystal cell occurs with the dimensional change at the time of contraction of the polarizing plate in a humid heat environment.
- the occurrence of light leakage due to the warpage of the glass substrate and the distortion of the screen are also taken up as problems in making the display thinner.
- Patent Document 1 discloses a monomer having an alkyl group of 1 to 16 carbon atoms of 96.5 to 99.9 parts by mass as an adhesive used for bonding a polarizing plate, a retardation plate, an antireflection film, and the like.
- a copolymer polymer obtained by copolymerizing at least 0.1 to 1 part by mass of a monomer having a carboxyl group, and 0.05 to 1 part by mass of metal with respect to 100 parts by mass of the copolymer polymer.
- a pressure-sensitive adhesive composition comprising at least a chelate-based curing agent and 0.05 to 1 part by mass of an isocyanate-based curing agent with respect to 100 parts by mass of the copolymer polymer. Yes.
- Patent Document 1 discloses 2 parts by mass as a constituent monomer of the copolymer polymer. There is a description that the following monomer having a hydroxyl group (for example, 2-hydroxyethyl (meth) acrylate) may be used.
- the present invention is superior in dimensional stability, exhibits excellent light leakage prevention performance and durability even in a humid heat environment, and satisfies the required physical properties particularly in thinning of a display to bend the glass substrate. It aims at providing the adhesive composition for optical members which can prevent effectively.
- the inventors of the present invention have studied by paying attention to the hard characteristics and the like of the polymer.
- specific (meth) acrylic acid ester, t-butyl (meth) acrylate and (meth) acrylic monomer having a hydroxyl group are contained in a predetermined ratio.
- the (meth) acrylic copolymer obtained by copolymerizing the monomer mixture contained in the above is cross-linked with a predetermined combination of cross-linking agents to simultaneously achieve excellent hard properties and slight stress relaxation in the pressure-sensitive adhesive composition.
- this composition for laminating polarizing plates, it is possible to effectively suppress the warpage of the glass substrate accompanying the contraction of the polarizing plate in a humid heat environment, and to obtain good light leakage prevention characteristics and durability.
- the headline and the present invention were completed.
- the present invention relates to (A): a (meth) acrylic copolymer obtained by copolymerizing a monomer mixture containing the following (a-1) to (a-3) in the following proportions; (A-1) (meth) acrylic acid ester having no functional group (excluding t-butyl (meth) acrylate) 55 to 94 parts by weight (a-2) t-butyl (meth) acrylate 5 to 40 Parts by weight (a-3) 1 to 5 parts by weight of a (meth) acrylic monomer having a hydroxyl group (however, the total of (a-1) to (a-3) is 100 parts by weight) (B): A pressure-sensitive adhesive composition for an optical member comprising an isocyanate-based crosslinking agent and a combination of crosslinking agents other than the isocyanate-based crosslinking agent.
- the content of the structural unit derived from the monomer having a carboxyl group is preferably less than 1% by weight, more preferably less than 0.1% by weight.
- the (meth) acrylic copolymer (A) contains substantially no functional group other than the hydroxyl group.
- the (B) preferably contains a metal chelate crosslinking agent, and more preferably (B) contains a xylylene diisocyanate compound and an aluminum chelate compound.
- the (B) is usually contained in an amount of 0.05 to 0.5 parts by weight with respect to 100 parts by weight of the (meth) acrylic copolymer (A) in the pressure-sensitive adhesive composition for optical members of the present invention.
- the pressure-sensitive adhesive composition for optical members of the present invention preferably further contains 0.01 to 0.3 parts by weight of a silane coupling agent with respect to 100 parts by weight of the (meth) acrylic copolymer (A).
- a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed on a substrate film can be obtained.
- optical member with an adhesive layer in which an adhesive layer is formed on at least one surface of the optical member, wherein the adhesive layer contains the adhesive composition for optical members of the present invention.
- the attached optical member is also included in the scope of the present invention.
- the flat panel display of the present invention is characterized by having the optical member with the pressure-sensitive adhesive layer.
- the present invention has excellent dimensional stability, exhibits excellent light leakage prevention performance and durability even in a humid heat environment, and particularly satisfies these required physical properties in thinning the display, and warps the glass substrate (A pressure-sensitive adhesive composition for an optical member that can effectively prevent bending is provided.
- the pressure-sensitive adhesive composition for optical members of the present invention (hereinafter also simply referred to as “the composition of the present invention”), the pressure-sensitive adhesive sheet using the same, the optical member with a pressure-sensitive adhesive layer, and a flat panel display will be described in detail in order.
- (meth) acryl means methacryl or acryl
- (meth) acrylate means methacrylate or acrylate.
- the (meth) acrylic acid ester (a-1) used in the present invention is a (meth) acrylic acid ester other than t-butyl (meth) acrylate and has no functional group.
- the functional group is a group having reactivity with the crosslinking agent in the combination (B) of the crosslinking agent described later, and examples thereof include a hydroxyl group, a carboxyl group, an epoxy group, an amino group, and an amide group. A tertiary amino group and the like can be mentioned.
- the (meth) acrylic acid ester (a-1) is designed so as not to cause a crosslinking reaction with the combination (B) of the crosslinking agent as described above, and the crosslinking point of the (meth) acrylic copolymer (A) will be described later in principle.
- the structural unit derived from the (meth) acrylic monomer (a-3) it is possible to prevent an excessive crosslinking reaction from occurring, whereby the composition of the present invention has a slight stress relaxation property as well as a hard property. Is granted.
- the glass transition temperature of the homopolymer (hereinafter sometimes referred to as Tg) is ⁇ 60 ° C. or higher.
- the Tg is measured by heating a test piece (homopolymer) for measuring Tg at a rate of 10 ° C./min in a range of ⁇ 60 ° C. to 180 ° C. in an N 2 atmosphere.
- DSC differential scanning calorimeter DSC8230
- JIS K7121 plastic transition temperature measurement method
- glass transition temperature (Tg (° C.)) of the homopolymer the glass transition temperatures (homopolymers) of various homopolymers described in “POLYMERHANDBOOK Third Edition” (John Wiley & Sons, Inc.) Tg (K)) may be referred to.
- (meth) acrylic copolymer (A) is obtained by using a combination of (meth) acrylic acid ester (a-1) having a Tg of a certain temperature or more and t-butyl (meth) acrylate described later, a copolymer is obtained.
- (A) is preferable because good hard properties are imparted. This contributes to excellent dimensional stability and wet heat durability in the composition of the present invention.
- (meth) acrylic acid ester (a-1) Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, (meth) acrylic acid alkyl ester having a linear alkyl group such as n-decyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate; (Meth) acrylic acid alkyl ester having a branched alkyl group such as isobutyl (meth) acrylate, sec-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate;
- a-1 Me
- (Meth) acrylic acid ester having an alicyclic group Phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenol ethylene oxide modified (meth) acrylate, phenoxypropyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, 2-naphthoethyl (meth) acrylate, (Meth) acrylic acid ester having an aromatic ring group such as 2- (4-methoxy-1-naphthoxy) ethyl (meth) acrylate; (Meth) acrylic acid alkoxyesters such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, methoxyethylene oxide modified (meth) acrylate, ethoxyethylene oxide modified (meth) acrylate, ethoxyethoxyethyl (meth) acrylate; Can
- (meth) acrylic acid alkyl ester having a linear alkyl group (meth) acrylic acid alkyl ester having a branched alkyl group, and (meth) acrylic acid having an aromatic ring group Esters are preferred, with n-butyl (meth) acrylate and 2-ethylhexyl acrylate being particularly preferred.
- the (meth) acrylic acid ester (a-1) described above can be used alone or in combination of two or more.
- t-butyl acrylate or t-butyl methacrylate may be used, or both may be used.
- the (meth) acrylic monomer (a-3) used in the present invention has one or more hydroxyl groups and usually does not have other functional groups.
- the copolymer (A) has a hydroxyl group, and this hydroxyl group is crosslinked with a combination of crosslinking agents (B) described later.
- the hard characteristics are further enhanced and a slight stress relaxation property is expected to be imparted.
- excellent dimensional stability, wet heat durability and stress resistance are realized for the composition of the present invention.
- Examples of such a (meth) acrylic monomer (a-3) include compounds represented by the following general formula (1).
- R 0 is hydrogen or a methyl group
- R 1 is a linear or branched alkyl group having 1 to 14 carbon atoms which may have a hydroxyl group, (CH 2 CH 2 O) m (M is an integer of 1 or more), (CH 2 CH (CH 3 ) O) n (n is an integer of 1 or more) or a cyclohexylene group.
- (meth) acrylic monomer (a-3) represented by the general formula (1) examples include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl.
- (Meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 1,4-cyclohexanedimethanol (meth) acrylate, glycerin mono (meth) acrylate, (poly) ethylene glycol mono (meth) acrylate, (poly) propylene glycol mono (Meth) acrylate etc. are mentioned.
- 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are used from the viewpoint of achieving excellent dimensional stability, wet heat durability and stress resistance. Is preferred.
- the (meth) acrylic monomer (a-3) described above can be used alone or in combination of two or more.
- Examples of such other monomer (a-4) include (meth) acrylic acid, (meth) acrylic monomer having a carboxyl group such as ⁇ -carboxylethyl (meth) acrylate; aminoethyl (meth) acrylate, (Meth) acrylic monomers having an amino group such as N, N-dimethylaminoethyl (meth) acrylate and t-butylaminoethyl (meth) acrylate; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N -(Meth) acrylic monomers having amide groups such as butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide; glycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate Glycidyl ether Having the epoxy group-containing (meth) acrylic monomer; Examples thereof include sty
- a monomer having no functional group is preferable from the viewpoint of achieving excellent dimensional stability and wet heat durability.
- the (meth) acrylic copolymer (A) which is a constituent component of the pressure-sensitive adhesive composition for optical members of the present invention, includes the monomer components (a-1) to (a-3) described above, and other components as necessary. It is obtained by copolymerizing a monomer mixture containing the monomer (a-4) at a specific ratio described below.
- the “copolymerizing the monomer mixture” means, for example, that each of the mixture containing the monomer components (a-1) to (a-3) and optionally other monomers (a-4) is reacted in an appropriate reaction system.
- the copolymerization reaction of the monomer component is carried out in a state where the monomer component coexists in the reaction system by subjecting the monomer component to conditions for copolymerization or by appropriately adding these monomer components in the reaction system. Means.
- the proportion of the (meth) acrylic acid ester (a-1) in the monomer mixture is 55 to 94 parts by weight from the viewpoint of hard characteristics and wet heat durability.
- the amount is preferably 60 to 90 parts by weight.
- the proportion of the t-butyl (meth) acrylate (a-2) in the monomer mixture is 5 to 40 parts by weight from the viewpoint of hard characteristics and wet heat durability. Yes, preferably 8 to 37 parts by weight.
- the ratio of the (meth) acrylic monomer (a-3) in the monomer mixture is achieved by the crosslinkability with the combination (B) of the crosslinking agent and thereby. From the viewpoint of hard characteristics and stress relaxation properties, it is 1 to 5 parts by weight, preferably 1.5 to 4.5 parts by weight.
- the total ratio of the monomer components (a-1) to (a-3) is 100 parts by weight.
- the ratio of the other monomer (a-4) is usually 0 to 5 parts by weight with respect to 100 parts by weight as a total of the monomers (a-1) to (a-3).
- the monomer components (a-1) to (a-3) and, if necessary, other monomers (a-4) are mixed by a solution polymerization method, a bulk polymerization method, an emulsification method. It can be produced by polymerizing by a conventionally known polymerization method such as a polymerization method or a suspension polymerization method. Among these methods, it is preferable to employ a solution polymerization method because the molecular weight of the polymer can be easily adjusted and impurities are hardly mixed into the reaction system.
- an organic solvent is used as a reaction solvent, and a mixture of monomer components forming the (meth) acrylic copolymer (A) is dissolved or dispersed in the reaction solvent, and a polymerization initiator is added under stirring. By adding, a copolymerization reaction is carried out.
- organic solvent examples include ester solvents such as ethyl acetate; ketone solvents such as methyl ethyl ketone, formaldehyde and acetaldehyde; ether solvents such as dimethyl ether; aromatic solvents such as toluene and xylene; and alicyclic systems such as cyclohexane. Solvents; and aliphatic solvents such as hexane and octane. These solvents may be used alone or as a mixed solvent of two or more.
- polymerization initiator examples include 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis.
- Azo compounds such as -2,4-dimethylvaleronitrile and 1,1'-azobiscyclohexane-1-carbonitrile; isobutyryl peroxide, ⁇ , ⁇ '-bis (neodecanoylperoxy) diisopropylbenzene, cumylper Oxyneodecanoate, di-n-propylperoxydicarbonate, diisopropylperoxydicarbonate, di-sec-butylperoxydicarbonate, 1,1,3,3-tetramethylbutylperoxyneodecanoate Bis (4-butylcyclohexyl) peroxydicarbonate, benzoyl peroxide, di- ert- butyl peroxide, lauroyl
- the reaction temperature of the copolymerization reaction using these reaction solvent and polymerization initiator is usually in the range of 50 to 90 ° C., preferably 60 to 85 ° C.
- the reaction time is usually 1 to It is 10 hours, preferably 2 to 8 hours
- the reaction pressure is usually atmospheric pressure to 0.1 MPa.
- the (meth) acrylic copolymer (A) is considered to form a crosslinked body having excellent hard properties and having a certain stress relaxation property by crosslinking using a combination of crosslinking agents (B) described later.
- the pressure-sensitive adhesive composition for an optical member of the invention is used, light leakage prevention performance based on durability in an excellent wet heat environment and excellent bending prevention performance can be achieved.
- Such excellent properties are achieved by crosslinking of the hydroxyl group in the (meth) acrylic copolymer (A) and the combination (B) of the crosslinking agent described later, and other functional groups and the component (B). Depending on the crosslinking reaction, the above properties tend not to be achieved.
- the content of the structural unit derived from the monomer having a carboxyl group is less than 1% by weight in 100% by weight of the copolymer (A), and more preferably 0.8%. Less than 1% by weight.
- content of the monomer which has a carboxyl group is small, it can achieve Bending prevention performance, light leakage prevention performance, and wet heat durability at a higher level.
- the (meth) acrylic copolymer (A) is substantially free of functional groups other than hydroxyl groups.
- substantially free means that a monomer having a functional group other than a hydroxyl group is not intentionally added to the monomer mixture in the production of the (meth) acrylic copolymer (A).
- the content of the structural unit derived from the monomer component having a functional group other than the hydroxyl group in the (meth) acrylic copolymer (A) is 1% by weight with respect to 100% by weight of the total monomer components. Less than, preferably less than 0.1% by weight, more preferably less than 0.01% by weight.
- the copolymer (A) contains a monomer having a functional group other than a hydroxyl group, for example, a structural unit derived from a carboxyl group-containing monomer, the carboxyl group itself becomes a crosslinking point of the (meth) acrylic copolymer (A). And the cross-linking reaction promoting effect, the degree of cross-linking tends to be high, and the anti-bending performance of the composition of the present invention is lowered, resulting in a decrease in light leakage performance and durability. There is a case.
- the degree of crosslinking tends to increase due to the crosslinking reaction promoting effect peculiar to amino groups and amide groups.
- the bending prevention performance of the composition is lowered, that is, the light leakage performance is lowered, and the durability is easily deteriorated.
- the site that reacts with the component (B) in the (meth) acrylic copolymer (A) is substantially limited to only hydroxyl groups, thereby further improving the anti-bending performance, the light leakage prevention performance, and the wet heat durability.
- An adhesive composition for optical members can be obtained.
- the weight average molecular weight (Mw) of the (meth) acrylic copolymer (A) measured by gel permeation chromatography (GPC) is usually 500,000 to 2,000,000, preferably 800,000 to 1,800,000. Excellent adhesive performance can be expressed.
- the polydispersity index (PDI) is usually 5-15.
- the Tg of the (meth) acrylic copolymer (A) is preferably in the range of ⁇ 70 to 15 ° C., more preferably in the range of ⁇ 70 to 0 ° C., and ⁇ 50 to ⁇ 5 ° C. Within the range is particularly preferred. If the Tg of the (meth) acrylic copolymer (A) is lower than ⁇ 70 ° C., the hard properties of the (meth) acrylic copolymer (A) will deteriorate, causing light leakage or peeling in wet heat durability tests, etc.
- Tg of the (meth) acrylic copolymer (A) is a value calculated by the following FOX formula.
- the (meth) acrylic copolymer (A) may be a random copolymer of the above monomer components or a block copolymer.
- the (meth) acrylic copolymer (A) may be used alone or in combination of two or more.
- the pressure-sensitive adhesive composition for an optical member of the present invention contains an isocyanate-based crosslinking agent and a combination (B) of a crosslinking agent other than the isocyanate-based crosslinking agent together with the (meth) acrylic copolymer (A) described above.
- crosslinking agent other than the isocyanate crosslinking agent for example, a metal chelate crosslinking agent and an epoxy crosslinking agent can be used. From the viewpoint of bending prevention performance, light leakage prevention performance, and wet heat durability, metal chelate crosslinking agents are preferred.
- a covalent bond is formed by the reaction between the isocyanate-based crosslinking agent and the hydroxyl group, and a covalent bond and a coordination bond are formed by the reaction between the metal chelate-based crosslinking agent and the hydroxyl group. The latter reaction gives some stress relaxation.
- isocyanate crosslinking agent examples include xylylene diisocyanate compounds such as xylylene diisocyanate; tolylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate.
- xylylene diisocyanate compounds such as xylylene diisocyanate; tolylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate.
- Isocyanate monomers such as isocyanate compounds obtained by adding these isocyanate monomers to trimethylolpropane, etc .; isocyanurates; burette type compounds; and addition with known polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, etc. Reacted urethane prepo It can be mentioned mer type of isocyanate.
- isopropyl alcohol, acetylacetone, ethyl acetoacetate or the like is arranged on a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium or zirconium. And the like.
- aluminum chelate compounds such as aluminum isopropylate and aluminum triethylacetoacetate, and diisopropoxybisacetylacetone titanate.
- epoxy-based crosslinking agent examples include ethylene glycol glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N , N, N ′, N′-tetraglycidyl-m-xylylenediamine, N, N, N ′, N′-tetraglycidylaminophenylmethane, triglycidyl isocyanurate, mN, N-diglycidylaminophenyl Mention may be made of glycidyl ether, N, N-diglycidyltoluidine and N, N-diglycidylaniline.
- cross-linking agent combination (B) described above is not particularly limited as long as it is used in combination with an isocyanate cross-linking agent and a cross-linking agent other than the cross-linking agent, but a combination of a xylylene diisocyanate compound and an aluminum chelate compound is used. It is preferable.
- Such a combination of crosslinking agents (B) is usually contained in an amount of 0.05 to 0.5 parts by weight per 100 parts by weight of the (meth) acrylic copolymer (A) in the pressure-sensitive adhesive composition for optical members of the present invention. ing.
- the content of the crosslinking agent (B) is preferably 0.05 to 0.35 parts by weight with respect to 100 parts by weight of the (meth) acrylic copolymer (A).
- a silane coupling agent In the pressure-sensitive adhesive composition for an optical member of the present invention, a silane coupling agent, an antistatic agent, an antioxidant, an ultraviolet absorber, a colorant, a pigment, a dye, a tackifying resin, a surface lubricant, and a leveling as necessary.
- Other components such as an agent, a softening agent, an anti-aging agent, a light stabilizer, a photoinitiator, a polymerization inhibitor, a filler, organic particles, inorganic particles, or a plasticizer may be contained.
- the composition of the present invention may contain the solvent or other solvent used in the production of the (meth) acrylic copolymer (A).
- the silane coupling agent will be described.
- silane coupling agent examples include polymerizable unsaturated group-containing silicon compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, and methacryloxypropyltrimethoxysilane; 3-glycidoxypropyltrimethoxysilane, 3-glycidoxy Silicon compounds having an epoxy structure such as propylmethyldimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxy Examples thereof include amino group-containing silicon compounds such as silane and N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane; and 3-chloropropyltrimethoxysilane; oligomer type silane coupling agent.
- silane coupling agent examples include polymerizable unsaturated group-containing silicon compounds
- the use of a silane coupling agent having a functional group that reacts with a functional group contained in the (meth) acrylic copolymer (A) is preferable in that it is difficult to cause peeling in a humid heat environment. .
- the compounding amount of the silane coupling agent in the pressure-sensitive adhesive composition for optical members of the present invention is usually 0.01 to 0.3 parts by weight, preferably 100 parts by weight of the (meth) acrylic copolymer (A). Is 0.05 to 0.25 parts by weight.
- a silane coupling agent may be used individually by 1 type, or may be used in combination of 2 or more type.
- the pressure-sensitive adhesive composition for an optical member of the present invention comprises the combination (B) of the (meth) acrylic copolymer (A) and the crosslinking agent described above as essential components, and may optionally contain the above other components.
- the specific monomer components (a-1) and (a-2) are copolymerized at a specific ratio, so that the hard characteristics are increased and the crosslinking is performed. Since the (meth) acrylic monomer (a-3) having a specific functional group that causes a cross-linking reaction with the combination of agents (B) is also copolymerized, this not only enhances the hard properties, but at the same time stresses Relaxation is also expected to be imparted, and excellent dimensional stability and stress resistance in a wet heat environment are achieved.
- composition of the present invention is excellent in dimensional stability and durability in a humid heat environment, it is very unlikely to deform even in a humid heat environment, and therefore is less likely to cause light leakage, and has a product value such as foaming. The phenomenon that drops is very unlikely.
- the adhesive layer follows the deformation of the polarizing plate during the thermal contraction of the polarizing plate. At this time, the adhesive layer is deformed. And non-deformation action (stress resistance) based on its own hard characteristics. Although depending on the properties of the adhesive layer, in general, the deformation action is stronger than the non-deformation action, and as the polarizing plate shrinks and deforms, the adhesive layer also deforms, and the adherend glass The deformation action of the polarizing plate is transmitted to the substrate through the pressure-sensitive adhesive layer, and the glass substrate is pulled and deformed by the contraction of the polarizing plate. As a result, light leakage occurs.
- the composition of the present invention is excellent in dimensional stability due to excellent hard characteristics and stress relaxation properties, it exhibits a high non-deformation action during thermal contraction of the polarizing plate. As a result, the stress resistance against the deformation of the polarizing plate is enhanced, the deformation action of the polarizing plate is hardly transmitted to the glass substrate, the amount of bending of the glass substrate is minimized, and bending is effectively prevented.
- the composition of the present invention is applied to a glass substrate having a thickness of 500 ⁇ m or less (particularly 300 ⁇ m or less) and then the polarizing plate is thermally shrunk, compared to the case where a known pressure-sensitive adhesive composition for optical members is used. The difference in the bending amount of the glass substrate appears remarkably.
- the composition of the present invention contains an isocyanate-based crosslinking agent and a metal chelate-based crosslinking agent as the combination (B) of the crosslinking agent
- the composition has a good balance of hard properties and stress relaxation properties. It is presumed that floating and peeling are effectively prevented in the pressure-sensitive adhesive layer obtained from the product, and light leakage in a wet heat environment is also effectively prevented.
- a polarizing plate that can be used for the bonding application of such a composition of the present invention
- a polarizing plate having a layer structure such as TAC (triacetyl cellulose) -PVA (polyvinyl alcohol) -TAC is typically used.
- TAC triacetyl cellulose
- PVA polyvinyl alcohol
- TAC triacetyl cellulose
- COP cycloolefin polymer
- the base film is preferably a release film in consideration of handling properties such as when the pressure-sensitive adhesive sheet is used in the production process of a flat panel display.
- the material include polyester, polyolefin, and polyether. Can be mentioned.
- the pressure-sensitive adhesive sheet of the present invention has a desired thickness, for example, by applying and drying a coating liquid containing the pressure-sensitive adhesive composition for optical members of the present invention on a substrate film to evaporate the solvent contained in the coating liquid. It can be produced by forming an adhesive layer.
- the thickness of the pressure-sensitive adhesive layer is not particularly limited, but is preferably in the range of 5 to 100 ⁇ m, more preferably in the range of 10 to 50 ⁇ m. If the thickness of this pressure-sensitive adhesive layer is less than 5 ⁇ m, it may not be possible to exhibit the prescribed performance (wet heat durability, etc.). If it exceeds 100 ⁇ m, the adhesive sheet tends to protrude when the pressure-sensitive adhesive sheet is cut. May decrease.
- the surface of the pressure-sensitive adhesive layer that is not in contact with the base film surface may be covered with a release film, and the release film may be peeled off during use.
- Optical member with adhesive layer By forming the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition for optical members of the present invention on at least one surface of the optical member, the pressure-sensitive adhesive that has achieved excellent light leakage prevention performance and durability even in a humid heat environment as described above. An optical member with an agent layer is obtained.
- the optical member in the present invention is not particularly limited, and is an optical film suitably used for a flat panel display, for example, a polarizing plate, a retardation plate, an elliptical polarizing plate, an optical compensation film, a brightness enhancement film, an infrared / electromagnetic wave.
- a polarizing plate for example, a polarizing plate, a retardation plate, an elliptical polarizing plate, an optical compensation film, a brightness enhancement film, an infrared / electromagnetic wave.
- Examples thereof include a cut film, an antireflection film for the front surface, a surface protective film, and those in which these are laminated.
- the polarizing plate in particular, has a different degree of deformation of the constituent layers in a humid heat environment, and thus birefringence occurs due to optical distortion and physical distortion. This birefringence causes light leakage and becomes a serious problem.
- composition of the present invention suppresses deformation of the polarizing plate with hard characteristics, can suppress optical distortion, that is, light leakage, and has excellent durability such as peeling.
- the optical member with an adhesive layer of the present invention is produced, for example, by the following methods (1) to (3).
- a coating solution containing the pressure-sensitive adhesive composition for an optical member of the present invention is applied to a release layer of a release film by a known method (die coating method, knife coating method, etc.), and contained in the coating solution by heat drying.
- a pressure-sensitive adhesive layer having a desired thickness is formed by evaporating a solvent or the like, and this pressure-sensitive adhesive layer is bonded to the optical member.
- a coating solution containing the pressure-sensitive adhesive composition for an optical member of the present invention is applied to the optical member by a known method (die coating method, knife coating method, etc.), and a solvent contained in the coating solution is dried by heat drying. Vaporization is performed to form a pressure-sensitive adhesive layer having a desired thickness, and this pressure-sensitive adhesive layer is bonded to the release layer of the release film.
- a coating solution containing the pressure-sensitive adhesive composition for optical members of the present invention is applied to the release layer of the first release film by a known method (die coating method, knife coating method, etc.), and the coating solution is dried by heat drying.
- the solvent contained in is vaporized to form a pressure-sensitive adhesive layer having a desired thickness, and this pressure-sensitive adhesive layer is separated from the release layer of the second release film (usually, the release force is lower than that of the first release film).
- a non-carrier adhesive film is produced by laminating. Thereafter, the second release film is peeled off, and the pressure-sensitive adhesive layer is bonded to the optical member.
- the pressure-sensitive adhesive composition for an optical member of the present invention comprises 3 to 7 days at room temperature (23 ° C. and 50% RH) after formation of the pressure-sensitive adhesive layer, and 2 to 5 under accelerated heating (40 ° C. and 90% RH). Crosslinking is made in about a day, and it can be attached to a flat panel display described later.
- the thickness of the pressure-sensitive adhesive layer in the obtained optical member with the pressure-sensitive adhesive layer is not particularly limited, but is preferably in the range of 5 to 100 ⁇ m, more preferably in the range of 10 to 50 ⁇ m. If the thickness of the pressure-sensitive adhesive layer is less than 5 ⁇ m, the prescribed performance (wet heat durability, etc.) may not be exhibited. If the thickness exceeds 100 ⁇ m, the adhesive sticks out when the optical member with the pressure-sensitive adhesive layer is cut. It becomes easy and processing suitability may fall.
- FPD field emission display
- the liquid crystal layer is generally sandwiched between glass substrates having transparent electrodes, an alignment film or a color filter is provided between the glass substrate and the liquid crystal layer, and the surface opposite to the surface of the glass substrate close to the liquid crystal layer. It has the structure which has the laminated body structure in which the polarizing plate was provided on the surface.
- a PDP is a laminate in which a phosphor layer exists between opposing glass substrates, and various dielectric layers, electrodes, and other functional layers are provided on the surface of the glass substrate close to the phosphor layer. It has a configuration having a body structure.
- the FED generally has a glass substrate, an anode electrode (anode) formed on the substrate, a phosphor layer formed on the electrode, a vacuum space, and a phosphor layer across the space.
- the glass substrate has a laminated structure in which a cathode electrode (cathode) is provided.
- the optical member with an adhesive layer of the present invention constitutes a part of the constituent layers of these FPDs. Moreover, it is also possible to laminate
- Tg measurement The Tg of the homopolymers of (meth) acrylic monomers (a-1) to (a-4) shown in Tables 1 to 4 was measured as follows.
- Homopolymers shown in Table 5 below were prepared by solution polymerization and used as test pieces.
- the test piece was heated at a rate of 10 ° C./min in the range of ⁇ 60 ° C. to 180 ° C. in an N 2 atmosphere, and calorimetrically measured with DSC (differential scanning calorimeter DSC 8283).
- the measurement was performed according to JISK7121 (plastic transition temperature measurement method).
- Measuring device HLC-8120GPC (manufactured by Tosoh Corporation)
- GPC column configuration The following five columns (all manufactured by Tosoh Corporation) (1) TSK-GEL HXL-H (guard column) (2) TSK-GEL G7000HXL (3) TSK-GEL GMHXL (4) TSK-GEL GMHXL (5) TSK-GEL G2500HXL Diluted with tetrahydrofuran so that the sample concentration is 1.0 mg / cm 3
- Mobile phase solvent Tetrahydrofuran Flow rate: 1 ml / min Column temperature: 40 ° C
- ⁇ 0.3 mm or less ⁇ : Greater than 0.3 mm, 0.6 mm or less ⁇ : Greater than 0.6 mm, 1.2 mm or less ⁇ : Over 1.2 mm
- the liquid crystal panel on which the polarizing plate was bonded was connected to a personal computer in a dark room to display a full screen black.
- the luminance (La, Lb, Lc, Ld) in the 1 cm diameter region near each corner and the luminance (Lcenter) in the 1 cm diameter region in the center of the monitor are measured with a luminance meter (Highland Corporation). Measurement was performed using RISA-COLOR / CD8), and light leakage ( ⁇ L) was determined by the following formula. Smaller ⁇ L means less light leakage (from the backlight), and if it is less than 2.0, it can be used as a liquid crystal display panel.
- the portion where light leakage occurred was visually confirmed in the above-described black display on the entire screen, and the distance d from the corner of the light leakage occurrence portion was measured as shown in FIG. If the distance is 30 mm or less, it can be used as a liquid crystal display panel.
- the evaluation-adhesive polarizing plate from which the peeled polyester film was peeled off was cut into a 15-inch size (233 mm ⁇ 309 mm), and a pressure-sensitive adhesive layer was applied to the glass plate on one surface of a 0.5 mm-thick alkali-free glass plate. It stuck using the laminator roll so that it might contact
- the test plate thus obtained was left under conditions of 60 ° C./90% RH for 500 hours. After completion of the test, it was taken out from the test environment and allowed to stand in a 23 ° C./50% RH atmosphere for 2 hours, and then peeled off and floated on the pressure-sensitive adhesive layer was visually observed and evaluated according to the following evaluation criteria.
- Foam-size ⁇ No foaming is observed ⁇ : Foam diameter is 1 mm or less ⁇ : Foam diameter is greater than 1 mm
- Peeling-size ⁇ No peeling at all ⁇ : Peeling area is 5% or less with respect to the whole bonded portion (100%) in the test plate x: Peeling area is the whole bonded portion in the test plate ( 100%) over 5%
- Peeling-Position No defect (peeling) ⁇ : Defect only at a position less than 0.5 mm from the end X: Defect at a position of 0.5 mm or more from the end
- the “edge” in the evaluation of peeling-position refers to the intersection of the shortest perpendicular line and the side of the test plate when a perpendicular line is dropped from the position where peeling occurred to each side of the test plate. .
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Abstract
Description
(a-1)官能基を有さない(メタ)アクリル酸エステル(ただし、t-ブチル(メタ)アクリレートを除く)55~94重量部
(a-2)t-ブチル(メタ)アクリレート5~40重量部
(a-3)ヒドロキシル基を有する(メタ)アクリル系モノマー1~5重量部
(ただし、(a-1)~(a-3)の合計は100重量部である)
(B):イソシアネート系架橋剤、及びイソシアネート系架橋剤以外の架橋剤の組み合わせとを含むことを特徴とする光学部材用粘着剤組成物である。
〔(A)(メタ)アクリル系コポリマー〕
本発明の組成物の構成成分である(メタ)アクリル系コポリマー(A)は、前述の通り特定のモノマー成分(a-1)~(a-3)を特定の割合で含むモノマー混合物を共重合することによって得られる。以下、これら各モノマーについて説明する。
本発明に使用される(メタ)アクリル酸エステル(a-1)は、t-ブチル(メタ)アクリレート以外の(メタ)アクリル酸エステルであって、官能基を有していない。本明細書において官能基とは、後述する架橋剤の組み合わせ(B)における架橋剤と反応性を有する基であって、その例としては、ヒドロキシル基、カルボキシル基、エポキシ基、アミノ基、アミド基、3級アミノ基等が挙げられる。
メチル(メタ)アクリレート、エチル(メタ)アクリレート、プロピル(メタ)アクリレート、n-ブチル(メタ)アクリレート、n-ヘキシル(メタ)アクリレート、n-オクチル(メタ)アクリレート、n-ノニル(メタ)アクリレート、n-デシル(メタ)アクリレート、ラウリル(メタ)アクリレート、ステアリル(メタ)アクリレートなどの直鎖アルキル基を有する(メタ)アクリル酸アルキルエステル;
イソブチル(メタ)アクリレート、sec-ブチル(メタ)アクリレート、2-エチルヘキシル(メタ)アクリレート、イソオクチル(メタ)アクリレートなどの分枝アルキル基を有する(メタ)アクリル酸アルキルエステル;
シクロヘキシル(メタ)アクリレート、イソボルニル(メタ)アクリレート、ジシクロペンタニル(メタ)アクリレート、ジシクロペンタニルオキシエチル(メタ)アクリレート、トリシクロペンタニル(メタ)アクリレート、1-アダマンチル(メタ)アクリレートなどの脂環基を有する(メタ)アクリル酸エステル;
フェニル(メタ)アクリレート、ベンジル(メタ)アクリレート、フェノキシエチル(メタ)アクリレート、フェノールエチレンオキサイド変性(メタ)アクリレート、フェノキシプロピル(メタ)アクリレート、フェノキシジエチレングリコール(メタ)アクリレート、2-ナフトエチル(メタ)アクリレート、2-(4-メトキシ-1-ナフトキシ)エチル(メタ)アクリレートなどの芳香族環基を有する(メタ)アクリル酸エステル;
メトキシエチル(メタ)アクリレート、エトキシエチル(メタ)アクリレート、メトキシエチレンオキサイド変性(メタ)アクリレート、エトキシエチレンオキサイド変性(メタ)アクリレート、エトキシエトキシエチル(メタ)アクリレートなどの(メタ)アクリル酸アルコキシエステル;
を使用することができる。
t-ブチル(メタ)アクリレート(a-2)及び前述の(メタ)アクリル酸エステル(a-1)を共重合モノマーとして組み合わせて使用して(メタ)アクリル系コポリマー(A)の構造単位とすることによって、コポリマー(A)に良好なハード特性が付与される。これが本発明の組成物における優れた寸法安定性及び湿熱耐久性に寄与する。
本発明において使用される(メタ)アクリル系モノマー(a-3)はヒドロキシル基を一つないし複数有し、通常その他の官能基を有していない。
本発明においては、本発明の効果を損なわない範囲で、種々の特性の調整のために、上記モノマー成分(a-1)~(a-3)以外のその他のモノマー(a-4)に由来する構造単位を、(メタ)アクリル系コポリマー(A)に含ませることができる。
スチレン、α-メチルスチレン、酢酸ビニル、プロピオン酸ビニル等が挙げられる。
(モノマー混合物における割合)
本発明の光学部材用粘着剤組成物の構成成分である(メタ)アクリル系コポリマー(A)は、以上説明した各モノマー成分(a-1)~(a-3)、及び必要に応じてその他のモノマー(a-4)を以下に説明する特定の割合で含むモノマー混合物を共重合することによって得られる。
(メタ)アクリル系コポリマー(A)は、各モノマー成分(a-1)~(a-3)、及び必要に応じてその他のモノマー(a-4)を、溶液重合法、塊状重合法、乳化重合法、懸濁重合法等の従来公知の重合法により重合させることで製造することができる。これらの方法の中でも、ポリマーの分子量の調整が容易であり、反応系への不純物の混入が少ないため、溶液重合法を採用することが好ましい。
これらの溶媒は1種単独で用いても、2種以上の混合溶媒としてもよい。
(メタ)アクリル系コポリマー(A)は、後述する架橋剤の組み合わせ(B)を使用して架橋させることによって、ハード特性に優れ、一定の応力緩和性を有する架橋体を形成すると考えられ、本発明の光学部材用粘着剤組成物を使用すると、優れた湿熱環境下における耐久性及び優れたBending防止性能に基づく光漏れ防止性能を達成することができる。
また、その多分散性指数(PDI)は通常5~15である。
1/Tg=Wa/Tga+Wb/Tgb+・・・
Tg:(メタ)アクリル系コポリマー(A)のガラス転移温度
Tga,Tgb,・・:単量体a,単量体b,・・・のそれぞれのホモポリマーのガラス転移温度
Wa,Wb,・・・・:単量体a,単量体b,・・・のそれぞれに由来する構造単位の(メタ)アクリル系コポリマー(A)における重量分率
*(メタ)アクリル系モノマー(a-1)~(a-3)及びその他のモノマー(a-4)は、単量体a,単量体b,・・・に任意に割り当てることができる。
本発明の光学部材用粘着剤組成物は、以上説明した(メタ)アクリル系コポリマー(A)とともに、イソシアネート系架橋剤、及びイソシアネート系架橋剤以外の架橋剤の組み合わせ(B)を含んでいる。
本発明の光学部材用粘着剤組成物には、必要に応じてシランカップリング剤、帯電防止剤、酸化防止剤、紫外線吸収剤、着色剤、顔料、染料、粘着付与樹脂、表面潤滑剤、レベリング剤、軟化剤、老化防止剤、光安定剤、光開始剤、重合禁止剤、充填剤、有機粒子、無機粒子又は可塑剤などのその他の成分を含有させてもよい。さらに本発明の組成物は、(メタ)アクリル系コポリマー(A)の製造に使用した溶媒その他の溶媒を含有してもよい。以下においては、前記シランカップリング剤について説明する。
前記シランカップリング剤としては、ビニルトリメトキシシラン,ビニルトリエトキシシラン及びメタクリロキシプロピルトリメトキシシラン等の重合性不飽和基含有ケイ素化合物;3-グリシドキシプロピルトリメトキシシラン,3-グリシドキシプロピルメチルジメトキシシラン及び2-(3,4-エポキシシクロヘキシル)エチルトリメトキシシラン等のエポキシ構造を有するケイ素化合物;3-アミノプロピルトリメトキシシラン,N-(2-アミノエチル)3-アミノプロピルトリメトキシシラン及びN-(2-アミノエチル)-3-アミノプロピルメチルジメトキシシラン等のアミノ基含有ケイ素化合物;並びに3-クロロプロピルトリメトキシシラン;オリゴマー型シランカップリング剤等が挙げられる。
本発明の光学部材用粘着剤組成物は、以上説明した(メタ)アクリル系コポリマー(A)及び架橋剤の組み合わせ(B)を必須成分とし、任意に上記その他の成分を含んでもよい。
本発明の光学部材用粘着剤組成物を粘着剤として使用する場合、基材フィルム上に粘着剤層を形成して粘着シートとすると、取り扱いが簡便で便利である。
本発明の光学部材用粘着剤組成物を含有する粘着剤層を光学部材の少なくとも片面に形成することにより、前述のように湿熱環境下においても優れた光漏れ防止性能及び耐久性を達成した粘着剤層付き光学部材が得られる。
本発明の粘着剤層付き光学部材は、たとえば、以下の(1)~(3)の方法により作製される。
例えば本発明の光学部材用粘着剤組成物を使用して偏光板とガラス基板等とを貼り合わせることで、前述のように湿熱環境下においても優れたBending防止性能に基づく光漏れ防止性能及び耐久性が達成される。
<実施例1~7及び比較例1~10に使用した(メタ)アクリル系コポリマーの製造例>
撹拌機、還流冷却器、温度計及び窒素導入管を備えた反応装置に、下記表1~4に示す(メタ)アクリル系モノマー(a-1)~(a-3)及びその他のモノマー(a-4)を、表1~4に示された配合比率(重量部)に従って仕込み、次に酢酸エチルをモノマー濃度が50wt%になる配合量にて仕込んだ。
製造例により得られた(メタ)アクリル系コポリマー溶液を用いて、下記表1~4の配合にて各成分を添加して粘着剤組成物の溶液を得た。この粘着剤組成物の溶液を剥離処理したポリエステルフィルムの表面に塗布して乾燥させることにより、厚さ25μmの粘着剤層を有する粘着シートを得た。この粘着シートを、TAC-PVA-TACの層構成の偏光フィルムの片面に貼り付けた後に23℃/50%RH暗所の条件で7日間熟成させて、評価用粘着加工偏光板を得た。
BA:n-ブチルアクリレート
t-BA:t-ブチルアクリレート
2-HEA:2-ヒドロキシエチルアクリレート
iBOA:イソボルニルアクリレート
iBMA:イソブチルメタクリレート
LA: ラウリルアクリレート
AA:アクリル酸
AM:アクリルアミド
XDI:キシリレンジイソシアネート化合物
Alキレート:アルミニウムトリス(アセチルアセトネート)
Epoxy:N,N,N‘,N’-テトラグリシジルm-キシレンジアミン
KBM-403:3-グリシドキプロピルトリメトキシシラン(信越化学工業社製)
測定不可:光漏れ評価の際の熱環境下にて粘着剤層から剥がれや発泡等の不具合が発生したため、光漏れの評価を実施することが不可能であったことを示す。
表1~4に示された(メタ)アクリル系モノマー(a-1)~(a-4)のホモポリマーのTgの測定を、以下の通り行った。
試験片をN2雰囲気下、-60℃から180℃の範囲にて、10℃/分の割合で昇温させ、DSC(示差走査熱量計DSC8283)にて熱量測定した。測定はJISK7121(プラスチックの転移温度測定方法)に準拠して行った。
製造例で調製した(メタ)アクリル系コポリマーについて、重量平均分子量(Mw)、数平均分子量(Mn)を下記GPC測定条件に従って測定し、多分散性指数(PDI=Mw/Mn)を求めた。
測定装置:HLC-8120GPC(東ソー社製)
GPCカラム構成:以下の5連カラム(すべて東ソー社製)
(1)TSK-GEL HXL-H (ガードカラム)
(2)TSK-GEL G7000HXL
(3)TSK-GEL GMHXL
(4)TSK-GEL GMHXL
(5)TSK-GEL G2500HXL
サンプル濃度:1.0mg/cm3となるように、テトラヒドロフランで希釈
移動相溶媒:テトラヒドロフラン
流量: 1ml/min
カラム温度:40℃
表1~4に示された各種評価は、以下に示す方法によって行った。
厚さ0.3mm、Size150mm×220mmのホウケイ酸塩系ガラス基板に、Size140mm×210mmにカットし、剥離処理されたポリエステルフィルムを剥がした評価用粘着加工偏光板を、粘着剤層が前記ガラス基板に接し、かつ前記偏光板とガラス基板とがクロスニコルになるように貼り合わせて、オートクレーブ処理(50℃、5atm)を行った。
○:0.3mmより大きく、0.6mm以下
△:0.6mmより大きく、1.2mm以下
×:1.2mmを超えている
19インチサイズの液晶パネルに、剥離処理されたポリエステルフィルムを剥がした評価用粘着加工偏光板を、粘着剤層が前記ガラス基板に接し、かつ前記偏光板と液晶パネルとがクロスニコルになるように貼り合わせて、80℃雰囲気下240時間放置した後、23℃/50%RH雰囲気下で2時間放置した。
剥離処理されたポリエステルフィルムを剥がした評価用粘着加工偏光板を15インチサイズ(233mm×309mm)に裁断し、厚さ0.5mmの無アルカリガラス板の片面に、粘着剤層が前記ガラス板に接するようにして、ラミネータロールを用いて貼り付けた。貼付後、オートクレーブ(栗原製作所製)にて0.5MPa、50℃、20分の条件で加圧処理して試験用プレートを得た。
○:発泡が全く見られない
△:発泡の直径が1mm以下
×:発泡の直径が1mmより大きい
○:発泡が全く見られない
△:発泡の個数が10コ以下
×:発泡の個数が10コより多い
○:剥がれが全く見られない
△:剥がれの面積が試験用プレートにおける貼り合わせ部分全体(100%)に対して5%以下
×:剥がれの面積が試験用プレートにおける貼り合わせ部分全体(100%)に対して5%以上
○:欠点(剥がれ)が全くない
△:端部から0.5mm未満の位置のみに欠点がある
×:端部から0.5mm以上の位置に欠点がある。
Claims (11)
- (A):下記(a-1)~(a-3)を下記割合で含むモノマー混合物を共重合して得られる(メタ)アクリル系コポリマーと;
(a-1)官能基を有さない(メタ)アクリル酸エステル(ただし、t-ブチル(メタ)アクリレートを除く)55~94重量部
(a-2)t-ブチル(メタ)アクリレート5~40重量部
(a-3)ヒドロキシル基を有する(メタ)アクリル系モノマー1~5重量部
(ただし、(a-1)~(a-3)の合計は100重量部である)
(B):イソシアネート系架橋剤、及びイソシアネート系架橋剤以外の架橋剤の組み合わせと
を含むことを特徴とする光学部材用粘着剤組成物。 - 前記(メタ)アクリル系コポリマー(A)において、カルボキシル基を有するモノマーに由来する構造単位の含有量が1重量%未満であることを特徴とする請求項1に記載の光学部材用粘着剤組成物。
- 前記(B)が、金属キレート系架橋剤を含む、請求項1又は2に記載の光学部材用粘着剤組成物。
- 前記(メタ)アクリル系コポリマー(A)において、カルボキシル基を有するモノマーに由来する構造単位の含有量が0.1重量%未満であることを特徴とする請求項1~3のいずれかに記載の光学部材用粘着剤組成物。
- 前記(メタ)アクリル系コポリマー(A)が、ヒドロキシル基以外には実質的に官能基を含まないことを特徴とする請求項1~4のいずれかに記載の光学部材用粘着剤組成物。
- 前記(B)が、前記(メタ)アクリル系コポリマー(A)100重量部に対して0.05~0.5重量部含まれていることを特徴とする請求項1~5のいずれかに記載の光学部材用粘着剤組成物。
- 前記(B)として、キシリレンジイソシアネート系化合物及びアルミニウムキレート系化合物を含むことを特徴とする請求項1~6のいずれかに記載の光学部材用粘着剤組成物。
- さらにシランカップリング剤を、前記(メタ)アクリル系コポリマー(A)100重量部に対して0.01~0.3重量部含むことを特徴とする請求項1~7のいずれかに記載の光学部材用粘着剤組成物。
- 基材フィルム上に請求項1~8のいずれかに記載の光学部材用粘着剤組成物を含む粘着剤層が形成されてなる粘着シート。
- 光学部材の少なくとも片面に粘着剤層が形成された粘着剤層付き光学部材であって、前記粘着剤層が請求項1~8のいずれかに記載の光学部材用粘着剤組成物を含むことを特徴とする粘着剤層付き光学部材。
- 請求項10に記載の粘着剤層付き光学部材を有することを特徴とするフラットパネルディスプレイ。
Priority Applications (3)
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JP2013551624A JP5793783B2 (ja) | 2011-12-28 | 2012-12-18 | 光学部材用粘着剤組成物並びにそれを使用した粘着シート、粘着剤層付き光学部材及びフラットパネルディスプレイ |
CN201280065214.6A CN104024362B (zh) | 2011-12-28 | 2012-12-18 | 光学部件用粘结剂组合物、粘结片、光学部件及显示器 |
KR1020147020652A KR20140107593A (ko) | 2011-12-28 | 2012-12-18 | 광학 부재용 점착제 조성물 그리고 그것을 사용한 점착 시트, 점착제층 부착 광학 부재 및 플랫 패널 디스플레이 |
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JP2011288779 | 2011-12-28 |
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JP (1) | JP5793783B2 (ja) |
KR (1) | KR20140107593A (ja) |
CN (1) | CN104024362B (ja) |
WO (1) | WO2013099684A1 (ja) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2014162835A (ja) * | 2013-02-25 | 2014-09-08 | Lintec Corp | 粘着性組成物、粘着剤および粘着シート |
JP2015105299A (ja) * | 2013-11-29 | 2015-06-08 | 藤森工業株式会社 | 粘着剤組成物及び表面保護フィルム |
CN105992803A (zh) * | 2014-03-17 | 2016-10-05 | 琳得科株式会社 | 粘着片及层叠体 |
JP2016183350A (ja) * | 2016-06-10 | 2016-10-20 | 藤森工業株式会社 | 粘着剤組成物及び表面保護フィルム |
JP2018076539A (ja) * | 2018-02-02 | 2018-05-17 | 藤森工業株式会社 | 表面保護フィルム |
JP2018115336A (ja) * | 2018-03-27 | 2018-07-26 | 藤森工業株式会社 | 粘着剤組成物及び表面保護フィルム |
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JP2009084400A (ja) * | 2007-09-28 | 2009-04-23 | Gunze Ltd | 近赤外線吸収性粘着剤組成物及び多層光学フィルム |
JP2009132752A (ja) * | 2007-11-28 | 2009-06-18 | Cheil Industries Inc | 粘着剤組成物及び光学部材 |
WO2010110254A1 (ja) * | 2009-03-24 | 2010-09-30 | 日本カーバイド工業株式会社 | 粘着剤組成物 |
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JP5231774B2 (ja) * | 2007-09-07 | 2013-07-10 | リンテック株式会社 | 両面粘着シート |
JP5212688B2 (ja) * | 2007-10-26 | 2013-06-19 | サイデン化学株式会社 | 光学用粘着剤組成物および光学機能性フィルム |
JP4800363B2 (ja) * | 2008-09-26 | 2011-10-26 | 日東電工株式会社 | 光学部材貼り合わせ用粘着シート |
JP5702912B2 (ja) * | 2008-11-21 | 2015-04-15 | 積水化学工業株式会社 | 粘着剤及び研磨布固定用両面粘着テープ |
-
2012
- 2012-12-18 JP JP2013551624A patent/JP5793783B2/ja not_active Expired - Fee Related
- 2012-12-18 CN CN201280065214.6A patent/CN104024362B/zh not_active Expired - Fee Related
- 2012-12-18 WO PCT/JP2012/082714 patent/WO2013099684A1/ja active Application Filing
- 2012-12-18 KR KR1020147020652A patent/KR20140107593A/ko not_active Application Discontinuation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2009084400A (ja) * | 2007-09-28 | 2009-04-23 | Gunze Ltd | 近赤外線吸収性粘着剤組成物及び多層光学フィルム |
JP2009132752A (ja) * | 2007-11-28 | 2009-06-18 | Cheil Industries Inc | 粘着剤組成物及び光学部材 |
WO2010110254A1 (ja) * | 2009-03-24 | 2010-09-30 | 日本カーバイド工業株式会社 | 粘着剤組成物 |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2014162835A (ja) * | 2013-02-25 | 2014-09-08 | Lintec Corp | 粘着性組成物、粘着剤および粘着シート |
JP2015105299A (ja) * | 2013-11-29 | 2015-06-08 | 藤森工業株式会社 | 粘着剤組成物及び表面保護フィルム |
CN105992803A (zh) * | 2014-03-17 | 2016-10-05 | 琳得科株式会社 | 粘着片及层叠体 |
JP2016183350A (ja) * | 2016-06-10 | 2016-10-20 | 藤森工業株式会社 | 粘着剤組成物及び表面保護フィルム |
JP2018076539A (ja) * | 2018-02-02 | 2018-05-17 | 藤森工業株式会社 | 表面保護フィルム |
JP2018115336A (ja) * | 2018-03-27 | 2018-07-26 | 藤森工業株式会社 | 粘着剤組成物及び表面保護フィルム |
Also Published As
Publication number | Publication date |
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JPWO2013099684A1 (ja) | 2015-05-07 |
CN104024362B (zh) | 2016-08-31 |
JP5793783B2 (ja) | 2015-10-14 |
KR20140107593A (ko) | 2014-09-04 |
CN104024362A (zh) | 2014-09-03 |
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