JP5523136B2 - Polyester film for laminated glass - Google Patents

Description

  The present invention relates to a polyester film for laminated glass, and more particularly to a polyester film for laminated glass using glass having a large curvature.

  Efforts have been made to impart a heat ray blocking function to window glass, particularly window glass of vehicles such as automobiles, in order to prevent the temperature inside the vehicle from rising. In the laminated glass, a soft resin such as polyvinyl butyral (hereinafter sometimes abbreviated as PVB) is used as an intermediate film in order to improve the scattering prevention effect and penetration resistance. There are known methods of blending inorganic oxides to absorb heat rays, and methods of newly adding an intermediate film obtained by laminating a heat ray blocking layer on a plastic film such as polyester by a vacuum deposition method or a sputtering method.

  In the method of blending an organic dye with a soft resin and absorbing heat rays, the soft resin has excellent followability to curved glass, so there is no optical distortion in the laminated glass, but the soft resin becomes a colored film, and the visible light region It cannot be used for applications that require high transmittance. Although the method of blending an inorganic oxide with a soft resin is excellent in followability to glass with a curved surface, the method may absorb heat rays and break the glass.

  The method of adding a heat ray blocking layer laminated on a plastic film such as polyester by vacuum deposition or sputtering as a new intermediate film has high transmittance in the visible region and is excellent as a laminated glass having a heat ray blocking function. However, when glass with a curved surface is used, the plastic film does not follow the curved surface of the glass, and optical distortion may occur.

  In addition, it is necessary to bond a soft resin such as PVB and a plastic film, but PVB is excellent in adhesiveness with glass, but is generally inferior in adhesiveness with a plastic film such as polyester, so that some kind of easy adhesion treatment is generally required. The As this method, conventionally, a method of undercoating an amino-functional silane on a plastic film (Patent Document 4), a method of undercoating with a polyallylamine coating (Patent Document 5), an ethylene-vinyl acetate copolymer between PVB and the film A method of providing a layer made of (EVA) (Patent Document 6) has been proposed.

JP-A-56-32352 JP-A-6-191906 JP-A-8-217500 JP-A-2-38432 JP-T-2007-513813 JP 2003-176159 A

  The present invention was made in view of the above-mentioned actual situation, and the solution problem is when the glass having a curved surface is used, the polyester film follows and is laminated so as to follow the curved surface of the glass, An object of the present invention is to provide a polyester film for laminated glass having no optical distortion and high interface adhesion.

  As a result of intensive studies in view of the above problems, the present inventors can easily solve the above problems if a polyester film having a water-based easy-adhesive resin coating layer on both sides and having a specific shrinkage ratio is used as an intermediate film. As a result, the present invention has been completed.

That is, the gist of the present invention is that, in a laminated glass configured by interposing an intermediate film between at least two glass plates, the intermediate film has a heat shrinkage rate at 130 ° C. for 30 minutes of 30 μm. Both are in the range of 5.0 to 10.0%, on one side, an aqueous easy-adhesive resin coating layer having a coating amount after drying of 0.005 to 0.5 g / m ² (however, a coating layer containing a silane coupling agent is applied). A polyester film for laminated glass comprising a composite in which a soft resin layer is laminated on the coating layer of the polyester film having the above.

  According to the present invention, even when a glass having a curved surface is used, the polyester film is laminated so as to follow the curved surface of the glass, and optical distortion does not occur. A film can be provided, and the industrial value of the present invention is high.

Hereinafter, the present invention will be described in detail.
The polyester film referred to in the present invention is a film obtained by stretching a sheet melt-extruded from an extrusion die according to a so-called extrusion method.

The polyester constituting the film refers to a polymer containing an ester group obtained by polycondensation from dicarboxylic acid and diol or from hydroxycarboxylic acid.
Examples of dicarboxylic acids include terephthalic acid, isophthalic acid, adipic acid, azelaic acid, sebacic acid, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and diols include ethylene glycol and 1,4-butane. Examples include diol, diethylene glycol, triethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, polyethylene glycol and the like, and examples of hydroxycarboxylic acid include p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid. be able to. Typical examples of such polymers include polyethylene terephthalate and polyethylene-2, 6 naphthalate.

  In order to facilitate handling, the polyester film in the present invention may contain particles under conditions that do not impair transparency. Examples of particles used in the present invention include inorganic particles such as calcium carbonate, calcium phosphate, silica, kaolin, talc, titanium dioxide, alumina, barium sulfate, calcium fluoride, lithium fluoride, zeolite, molybdenum sulfide, and crosslinked polymers. Examples thereof include organic particles such as particles and calcium oxalate. Examples of the method of adding particles include a method of adding particles in a polyester as a raw material, a method of adding directly to an extruder, and the like. Well, you may use two methods together.

  The particle diameter of the particles used is usually 0.05 to 5.0 μm, preferably 0.1 to 4.0 μm. When the average particle size is larger than 5.0 μm, the haze of the film increases, and the transparency of the film may decrease. If the average particle size is smaller than 0.1 μm, the surface roughness becomes too small, and the film may be difficult to handle. The particle content is usually 0.001 to 30.0% by weight, preferably 0.01 to 10.0% by weight, based on the polyester. If the particle content is high, the haze increases and the transmittance in the visible light region may be reduced. If the particle content is low, the film may be difficult to handle.

  The method of adding particles to the polyester is not particularly limited, and a conventionally known method can be adopted. For example, it can be added at any stage for producing the polyester, but the polycondensation reaction may proceed preferably after the esterification stage or after the transesterification reaction. Also, a method of blending a slurry of particles dispersed in ethylene glycol or water with a vented kneading extruder and a polyester raw material, or a method of blending dried particles and a polyester raw material using a kneading extruder. It is performed by the method of blending.

  In the present invention, additives may be added in addition to the above particles as necessary. Examples of such additives include stabilizers, lubricants, cross-linking agents, anti-blocking agents, antioxidants, dyes, pigments, and ultraviolet absorbers.

  In the present invention, a biaxially oriented polyester film is preferred, but an unstretched or at least one stretched polyester film can be used as long as the obtained film does not depart from the gist of the present invention.

  The polyester film of the present invention needs to have a thermal shrinkage rate in the range of 5.0 to 10.0% at 130 ° C. and 30 minutes in the longitudinal direction and the width direction. When the thermal shrinkage rate at 130 ° C. for 30 minutes in either the longitudinal direction or the width direction is smaller than 5.0%, an optical distortion occurs in the laminated glass due to the elongation of the film during the processing of the laminated glass. When the shrinkage rate is larger than 10.0%, optical distortion occurs in the laminated glass due to shrinkage of the film during processing of the laminated glass, which is not preferable.

  In the present invention, the difference in heat shrinkage between the longitudinal direction and the width direction at 130 ° C. for 30 minutes is preferably 0.3% or less. When the difference in thermal shrinkage between the longitudinal direction and the width direction is larger than 0.3%, the balance between the longitudinal direction and the width direction is lost, the flatness of the polyester film is deteriorated, and optical distortion occurs in the laminated glass. There is.

  In the present invention, the water-based easy-adhesion resin coating layer is provided on at least one surface of the film. On the other surface, a similar water-based easy-adhesive resin coating layer may be provided, or a coating layer imparting other functions (antistatic, heat ray blocking, slipperiness, transparency, etc.) may be provided.

  The component constituting the water-based easy-adhesive resin layer preferably contains at least one of an amide ester bond, a urethane bond, an amide bond, and a urea bond. The method for containing the bond in the water-based easy-adhesion resin layer is not particularly limited. For example, a water-based easy-adhesion resin layer made of a compound having the bond or a resin having a crosslinkable functional group can be used. For example, a method of providing a water-based easy-adhesive resin layer having the bond by a crosslinking reaction by a combination of crosslinking agents or a combination of resins having a crosslinkable functional group can be used. In particular, the method of providing a water-based easy-adhesion resin layer having a bond by a cross-linking reaction by combining a resin having a crosslinkable functional group and a cross-linking reaction improves the strength of the water-based easy-adhesion resin layer by improving the cross-linking density by using a cross-linking agent. Since it is excellent in the point of property and adhesiveness also becomes favorable, it can be used more suitably.

  As a combination of functional groups for obtaining each bond, a reaction of a carboxylic acid group and an oxazoline group can be used to obtain an amide ester bond, and a hydroxyl group and an isocyanate group can be obtained to obtain a urethane bond. In order to obtain an amide bond, a reaction of a carboxylic acid group and an isocyanate group or a reaction of a carboxylic acid and an imino group can be used. To obtain a urea bond, an amino group Reaction of isocyanate groups and the like can be used, but the reaction is not limited to these reactions.

  Crosslinkable functional groups such as carboxylic acid groups, hydroxyl groups, amino groups, oxazoline groups, isocyanate groups, imino groups described above, for example, acrylic resins, polyester resins, urethane resins, polyolefin resins, polycarbonate resins, alkyd resins, epoxy resins, It can be used by introducing it into a resin such as urea resin, phenol resin, vinyl chloride resin, vinyl acetate resin, fluorine resin, silicone resin, rubber resin, wax resin, etc. A method of copolymerizing a monomer having a group with the above-described resin can be suitably used. Furthermore, in this invention, at least 1 sort (s) chosen from the resin mentioned above can be used.

  Among these, it is preferable to use an acrylic resin, a polyester resin, and a urethane resin in terms of adhesion to a base film and adhesion to a soft resin layer, and two different resins, for example, an acrylic resin and a polyester resin. Using an acrylic resin and a urethane resin or a combination of a polyester resin and a urethane resin has the advantages that both characteristics are exhibited and the adhesiveness is further improved.

  In the present invention, the acrylic resin used as a component of the water-based easy-adhesive resin coating layer is a copolymer monomer of an acrylic resin having a crosslinkable functional group such as a carboxylic acid group, a hydroxyl group, an amino group, an oxazoline group, an isocyanate group, or an imino group. It is preferable to contain in.

  Examples of the monomer component constituting the acrylic resin include alkyl acrylate, alkyl methacrylate (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2 -Ethylhexyl group, lauryl group, stearyl group, cyclohexyl group, phenyl group, benzyl group, phenylethyl group, etc.), 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, etc. Hydroxyl group-containing monomer, acrylamide, methacrylamide, N-methyl acrylamide, N-methyl methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N, N-dimethylol Amide group-containing monomers such as acrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N-phenylacrylamide, amino group-containing monomers such as N, N-diethylaminoethyl acrylate, N, N-diethylaminoethyl methacrylate, glycidyl acrylate , An epoxy group-containing monomer such as glycidyl methacrylate, a monomer containing a carboxyl group such as acrylic acid, methacrylic acid and salts thereof (lithium salt, sodium salt, potassium salt, etc.) or a salt thereof. It copolymerizes using 1 type (s) or 2 or more types. Furthermore, these can be used in combination with other types of monomers.

  Examples of other types of monomers include sulfonic acid groups such as epoxy group-containing monomers such as allyl glycidyl ether, styrene sulfonic acid, vinyl sulfonic acid and salts thereof (lithium salt, sodium salt, potassium salt, ammonium salt, etc.) Monomers containing such salts, monomers containing crotonic acid, itaconic acid, maleic acid, fumaric acid and their salts (lithium salts, sodium salts, potassium salts, ammonium salts, etc.) or salts thereof, maleic anhydride Monomers containing acid anhydrides such as acid and itaconic anhydride, vinyl isocyanate, allyl isocyanate, styrene, vinyl methyl ether, vinyl ethyl ether, vinyl trisalkoxysilane, alkyl maleic acid monoester, alkyl fumaric acid mono Ester, acrylonitrile, methacrylonitrile, alkyl itaconic acid monoester, vinylidene chloride, vinyl acetate, etc. can be used vinyl chloride.

  The acrylic resin that can be used in the water-based easy-adhesive resin coating layer of the present invention is also a modified acrylic copolymer, such as a block copolymer modified with polyester, urethane, epoxy, or a graft copolymer. It is.

  Although the glass transition point (Tg) of the acrylic resin used for the water-based easily-adhesive resin coating layer of the present invention is not particularly limited, it is preferably 0 to 90 ° C, more preferably 10 to 80 ° C. When an acrylic resin having a low Tg is used, the adhesiveness under high temperature and high humidity tends to be inferior, and conversely, if it is too high, cracks may be generated during stretching. Further, the molecular weight of the acrylic resin is preferably 100,000 or more, and particularly preferably 300,000 or more from the viewpoint of adhesiveness. Such water-based acrylic resins are copolymerized with monomers having a hydrophilic group (such as acrylic acid, methacrylic acid, acrylamide, vinyl sulfonic acid and salts thereof), emulsion polymerization using reactive emulsifiers and surfactants, and suspension polymerization. It can be prepared by a method such as turbid polymerization or soap-free polymerization.

  The preferred acrylic resin used for the water-based easily adhesive resin coating layer of the present invention is selected from methyl methacrylate, ethyl acrylate, n-butyl acrylate, 2-hydroxyethyl acrylate, acrylamide, N-methylol acrylamide, glycidyl methacrylate, and acrylic acid. Such as a copolymer.

  In the present invention, the polyester resin used as a component of the water-based easy-adhesive resin coating layer has an ester bond in the main chain or side chain, and is obtained by polycondensation from dicarboxylic acid and diol. A crosslinkable functional group such as a group, a hydroxyl group, an amino group, an oxazoline group, an isocyanate group, or an imino group may be contained as a copolymerization component of the polyester resin.

  As the carboxylic acid component constituting the polyester resin, aromatic, aliphatic, and alicyclic dicarboxylic acids and trivalent or higher polyvalent carboxylic acids can be used. As aromatic dicarboxylic acids, terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 2,5-dimethylterephthalic acid, 1,4-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2 -Bisphenoxyethane-p, p'-dicarboxylic acid, phenylindanedicarboxylic acid, etc. can be used. These aromatic dicarboxylic acids are preferably 30 mol% or more, more preferably 35 mol% or more, most preferably 40 mol% or more of the total dicarboxylic acid component, from the viewpoint of strength and heat resistance of the water-based easy-adhesion resin layer. It is better to use something. Aliphatic and alicyclic dicarboxylic acids include succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, dimer acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1, 4-Cyclohexanedicarboxylic acid and the like, and ester-forming derivatives thereof can be used.

  As the glycol component of the polyester resin, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2,4-dimethyl-2-ethylhexane-1,3- Diol, neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2 , 4-Trimethyl-1,6-hexanediol, 1,2-si Rhohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 4,4'-thiodiphenol, bisphenol A 4,4′-methylenediphenol, 4,4 ′-(2-norbornylidene) diphenol, 4,4′-dihydroxybiphenol, o-, m-, and p-dihydroxybenzene, 4,4′-isopropylidene Phenol, 4,4′-isopropylidene bin diol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol and the like can be used.

  In addition, when a polyester resin is used as a coating solution containing a water-based resin, a compound containing a sulfonate group or a carboxylate base is used to improve the adhesion of the polyester resin or to facilitate water-solubilization of the polyester resin. It is preferred to copolymerize the containing compound.

  Examples of the compound containing a carboxylate group include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 4-methylcyclohexene-1,2,3-tricarboxylic acid, trimesic acid, 1,2, 3,4-butanetetracarboxylic acid, 1,2,3,4-pentanetetracarboxylic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 5- (2,5-dioxotetrahydrofurfuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid, 5- (2,5-dioxotetrahydrofurfuryl) -3-cyclohexene-1,2-dicarboxylic acid, cyclopentanetetracarboxylic acid, 2,3 , 6,7-Naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, ethylene glycol bis trimellitate 2,2 ′, 3,3′-diphenyltetracarboxylic acid, thiophene-2,3,4,5-tetracarboxylic acid, ethylenetetracarboxylic acid, etc., or alkali metal salts, alkaline earth metal salts, ammonium salts thereof However, it is not limited to these.

  Examples of the compound containing a sulfonate group include sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfoisophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, sulfo-p-xylylene glycol, 2-sulfo -1,4-bis (hydroxyethoxy) benzene or the like, or alkali metal salts, alkaline earth metal salts, and ammonium salts thereof can be used, but are not limited thereto.

  The polyester resin used in the aqueous easy-adhesive resin coating layer of the present invention can be a modified polyester copolymer, for example, a block copolymer modified with acrylic, urethane, epoxy or the like, a graft copolymer, and the like.

  Preferred polyester resins include terephthalic acid, isophthalic acid, sebacic acid, 5-sodiumsulfoisophthalic acid, trimellitic acid, pyromellitic acid, 5- (2,5-dioxotetrahydrofurfuryl) -3- Examples include methyl-3-cyclohexene-1,2-dicarboxylic acid, a copolymer selected from ethylene glycol, diethylene glycol, 1,4-butanediol, and neopentyl glycol as a glycol component.

  In the present invention, the polyester resin used for the water-based easy-adhesive resin coating layer can be produced by the following production method. For example, a polyester resin composed of terephthalic acid, isophthalic acid, 5-sodiumsulfoisophthalic acid as the dicarboxylic acid component, and ethylene glycol and 1,4 butanediol as the glycol component will be described as follows: terephthalic acid, isophthalic acid, 5-sodium sulfone A first esterification reaction of isophthalic acid with ethylene glycol and 1,4 butanediol, or a transesterification reaction of terephthalic acid, isophthalic acid, 5-sodiumsulfoisophthalic acid and ethylene glycol, 1,4 butanediol It can be produced by a method of producing by a stage and a second stage in which the reaction product of the first stage is subjected to a polycondensation reaction.

  At this time, as the reaction catalyst, for example, alkali metal, alkaline earth metal, manganese, cobalt, zinc, antimony, germanium, titanium compound, or the like can be used.

  In the present invention, the intrinsic viscosity of the polyester resin used in the water-based easy-adhesive resin coating layer is not particularly limited, but is preferably 0.3 dl / g or more, more preferably 0.35 dl / g in terms of adhesiveness. g or more, most preferably 0.4 dl / g or more. The glass transition point (hereinafter abbreviated as “Tg”) of the water-based polyester resin is preferably 0 to 90 ° C., more preferably 10 to 80 ° C. When Tg is less than 0 ° C., the moisture-resistant adhesion is poor, and conversely when it exceeds 90 ° C., the resin film-forming property tends to be inferior.

  The acid value of the water-based polyester resin is preferably 20 mgKOH / g or more, more preferably 30 mgKOH / g or more. The higher the acid value, the better the adhesiveness, particularly the moisture-resistant adhesion.

  In the present invention, it is preferable that 1,4-butanediol, neopentyl glycol, and polyethylene glycol are copolymerized as the diol component of the polyester resin used in the aqueous easy-adhesive resin coating layer. Moreover, it is preferable from the point of adhesiveness that sebacic acid, adipic acid, and azelaic acid are copolymerized as a dicarboxylic acid component.

  In addition, the copolymerization of polyethylene glycol is effective for water-solubilizing the polyester resin. Among them, those having a molecular weight of 600-20000 are preferable, more preferably 1000-6000, and the copolymerization ratio is diol. In a component, 0.2-10 mol% is preferable, More preferably, it is 0.4-5 mol%. Furthermore, since the copolymerization ratio described above varies greatly depending on the molecular weight of polyethylene glycol even if the copolymerization ratio is the same, the copolymerization amount of polyethylene glycol is preferably 1 to 20% by weight in terms of weight% in the polyester resin. More preferably, it is 2 to 15% by weight.

  In the present invention, the urethane resin used as a constituent component of the water-based easy-adhesive resin coating layer is not particularly limited as long as it is a water-soluble or water-dispersible urethane resin having an anionic group. , Polyol and polyisocyanate are copolymerized. The urethane resin has a urethane bond. In the present invention, a crosslinkable functional group such as a carboxylic acid group, a hydroxyl group, an amino group, an oxazoline group, an isocyanate group, or an imino group is contained in the copolymer monomer of the urethane resin. It is preferable that it is contained in this because the adhesiveness is further improved.

  As the urethane resin, a resin whose affinity for water is enhanced by a carboxylate group, a sulfonate group, or a sulfuric acid half ester base can be used. The content of carboxylate group, sulfonate group, or sulfuric acid half ester base is preferably 0.5 to 15% by weight.

  Examples of the polyol compound include polyethylene glycol, polypropylene glycol, polyethylene / propylene glycol, polytetramethylene glycol, hexamethylene glycol, hexamethylene glycol, tetramethylene glycol, 1,5-pentanediol, diethylene glycol, triethylene glycol, polycaprolactone. Polyhexamethylene adipate, polytetramethylene adipate, trimethylolpropane, trimethylolethane, glycerin, acrylic polyol, polycarbonate polyol and the like can be used.

  Examples of the polyisocyanate compound include tolylene diisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, an adduct of tolylene diisocyanate and trimethylolpropane, an adduct of hexamethylene diisocyanate and trimethylolethane, and the like.

  Here, main components of the urethane resin may contain a chain extender, a crosslinking agent, and the like in addition to the polyol compound and the polyisocyanate compound.

  As the chain extender or crosslinking agent, ethylene glycol, propylene glycol, butanediol, diethylene glycol, ethylenediamine, diethylenetriamine, or the like can be used.

  The urethane resin having an anionic group is, for example, a method of using a compound having an anionic group for polyol, polyisocyanate, chain extender, etc., and reacting a compound having an anionic group with an unreacted isocyanate group of the produced urethane resin. Can be produced using a method of reacting a group having active hydrogen of a urethane resin with a specific compound, but is not particularly limited.

  Further, a resin comprising a polyol having a molecular weight of 300 to 20,000, a polyisocyanate, a chain extender having a reactive hydrogen atom, a group that reacts with an isocyanate group, and a compound having at least one anionic group is preferable.

  The anionic group in the urethane resin is preferably used as a sulfonic acid group, a carboxylic acid group, or an ammonium salt, lithium salt, sodium salt, potassium salt or magnesium salt thereof, and particularly preferably a sulfonic acid group.

  The amount of the anionic group in the polyurethane resin is preferably in the range of 0.05 to 8% by weight. If it is less than 0.05% by weight, the water dispersibility of the urethane resin tends to be poor, and if it exceeds 8% by weight, the water resistance and blocking resistance of the resin tend to be poor.

  In the present invention, the water-based easy-adhesion resin coating layer is made of at least one resin selected from the group consisting of vinyl resins, polyether resins, cellulose resins, epoxy resins, nylon resins, gelatins and the like in addition to the above resins. Can be included.

  Vinyl resin has a styrene, α-methyl styrene, sodium styrene sulfonate, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl ether, sodium vinyl sulfonate, sodium methallylate, polyvinyl alcohol, polyvinyl butyral, etc. A polymer or copolymer obtained from a monomer having an unsaturated double bond, preferably having a number average molecular weight of 5,000 to 250,000.

  Examples of the polyether resin include polyethylene oxide, polypropylene oxide, phenoxy resin, and the like, and those having a number average molecular weight of 800 to 400,000 are preferable.

  Cellulosic resins are resins having a cellulose structure in the molecule, such as methylcellulose and nitrocellulose.

  The epoxy resin is a polymer or copolymer obtained from a compound having a bifunctional or higher functional glycidyl group in the molecule, and preferably has a number average molecular weight of 150 to 30,000. Examples of the compound include bisphenol glycidyl ether, glycerin polyglycidyl ether, and aminoglycidyl ether.

  Examples of the nylon resin include 6 nylon, 6 and 6 nylon, methoxymethylated resins, and copolymers such as acrylic acid.

  Gelatin is a high-molecular-weight polypeptide, and those obtained from protein raw materials such as collagen can be used.

  In the water-based easy-adhesive resin coating layer of the present invention, it has been found that the adhesiveness under high temperature and high humidity is improved by using the above-mentioned resin having a crosslinkable functional group together with a crosslinking agent that undergoes a crosslinking reaction. In particular, it is preferable to use a crosslinking agent in combination with a resin selected from at least one of an acrylic resin, a polyester resin, and a urethane resin as a resin used for the water-based easily adhesive resin layer.

The crosslinking agent to be used is not particularly limited as long as it can undergo a crosslinking reaction with a functional group present in the above-described resin, for example, a hydroxyl group, a carboxyl group, a methylol group, an amide group, and the like. Cross-linking agent, oxazoline-based cross-linking agent, (block) isocyanate-based cross-linking agent, aziridine-based cross-linking agent, epoxy-based cross-linking agent, methylolized or alkylolized urea-based, acrylamide-based, polyamide-based resin, carbodiimide resin, various silane couplings Agents, various titanate coupling agents and the like can be used.
In particular, those that generate an amide ester bond, a urethane bond, an amide bond, or a urea bond by a crosslinking reaction are suitable in the present invention.

  Among the crosslinking agents used, oxazoline-based crosslinking agents, melamine-based crosslinking agents, epoxy-based crosslinking agents, isocyanate-based crosslinking agents, carbodiimide-based crosslinking agents, and aziridine-based crosslinking agents are preferable from the viewpoint of crosslinkability and adhesiveness, and in particular, oxazoline. By using a system cross-linking agent and another cross-linking agent in combination, adhesion under normal conditions is improved, and at the same time, adhesion under high temperature and high humidity is dramatically improved.

  In the present invention, the melamine-based crosslinking agent used in the water-based easy-adhesive resin coating layer is not particularly limited, but melamine, a methylolated melamine derivative obtained by condensing melamine and formaldehyde, and a methylolated melamine are reacted with a lower alcohol. A partially or completely etherified compound or a mixture thereof can be used. Moreover, as a melamine type crosslinking agent, a monomer, the condensate which consists of a multimer more than a dimer, or a mixture thereof can be used. As the lower alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like can be used. The functional group has an imino group, a methylol group, or an alkoxymethyl group such as a methoxymethyl group or a butoxymethyl group in one molecule, and an imino group type methylated melamine resin, a methylol group type melamine resin, or a methylol group type. Examples include methylated melamine resins and fully alkyl type methylated melamine resins. Among these, an imino group type melamine resin and a methylolated melamine resin are preferable, and an imino group type melamine resin is most preferable. Furthermore, in order to accelerate | stimulate the thermosetting of a melamine type crosslinking agent, you may use acidic catalysts, such as p-toluenesulfonic acid, for example.

  In the present invention, the oxazoline-based crosslinking agent used for the water-based easy-adhesive resin coating layer is not particularly limited as long as it has an oxazoline group as a functional group in the compound, but a monomer containing an oxazoline group is used. What consists of an oxazoline group containing copolymer containing at least 1 sort (s) or more is preferable.

  Examples of such oxazoline-based crosslinking agents include copolymers and derivatives thereof described in JP-A-2-60941, JP-A-2-99537, JP-A-2-115238, JP-B63-48884, and the like. Can be used.

  Examples of the oxazoline compound include 2-oxazoline, 3-oxazoline, and 4-oxazoline compound, and any of them may be used. In particular, the 2-oxazoline compound is rich in reactivity and has been industrially put into practical use.

  For example, 2-vinyl-2-oxazoline (VOZO), 5-methyl-2-vinyl-2-oxazoline (MVOZO), 4,4-dimethyl-2-vinyl-2-oxazoline (DMVOZO), 4,4-dimethyl -2-vinyl-5,6-dihydro-4H-1, -oxazine (DMVOZI), 4,4,6-trimethyl-2-vinyl-5,6-dihydro-4H-1,3-oxazine (TMVOZI), 2 -Isopropenyl-2-oxazoline (IPOZO), 4,4-dimethyl-2-isopropenyl-2-oxazoline (DMIPOZO), 4-acryloyl-oxymethyl-2,4-dimethyl-2-oxazoline (AOZO), 4 -Methacryloyl-oxymethyl-2,4-dimethyl-2-oxazoline (MAOZO), 4-methacryloyl-o Methyl-2-phenyl-4-methyl-2-oxazoline (MAPOZO), 2- (4-vinylphenyl) -4,4-dimethyl-2-oxazoline (VPMOZO), 4-ethyl-4-hydroxymethyl-2- Examples thereof include, but are not limited to, isopropenyl-2-oxazoline (EHMIPOZO) and 4-ethyl-4-carboethoxymethyl-2-isopropenyl-2-oxazoline (EEMIPOZO).

  Vinyl oxazolines easily undergo radical polymerization with azobisisobutyronitrile (AIBN) or benzoyl peroxide (BPO) to produce a polymer having an oxazoline ring in the side chain. Vinyl oxazolines generate similar poly (vinyl oxazolines) by anionic polymerization using n-butyllithium as a catalyst. In addition, there is a method not using a monomer having an oxazoline ring for the synthesis of poly (vinyloxazoline) s. For example, a method by an isomerization reaction of poly (methacryloylaziridine) can be mentioned.

  The oxazoline-based crosslinking agent used in the present invention may be copolymerized with any other copolymerizable monomer. It is preferably copolymerized with an alkyl (meth) acrylate, and more preferably copolymerized with one or more of methyl (meth) acrylate and ethyl (meth) acrylate.

  The density of the oxazoline group is preferably high, and the oxazoline value is preferably less than 300 g (solid content) / equivalent, and more preferably less than 180 g (solid content) / equivalent.

  In the present invention, the water-based easy-adhesion resin coating layer can be used by mixing the resin and the crosslinking agent in an arbitrary ratio. To make the effects of the present invention more prominently, the entire coating layer is 100 wt. In terms of the active ingredient ratio in parts, the crosslinking agent is preferably added in an amount of 0.2 to 20 parts by weight with respect to 10 to 80 resin in the coating layer in terms of improving adhesiveness under normal conditions, more preferably Addition of 20-800.5-15 parts by weight, most preferably 40-701-10 parts by weight. When the addition amount of the cross-linking agent is less than 100.2 parts by weight, the effect of addition tends to be small, and when it exceeds 8020 parts by weight, the adhesion tends to decrease.

  Further, in the present invention, it should be noted that the oxazoline-based crosslinking agent comprising the oxazoline group-containing copolymer is in the above range, and the second crosslinking agent (a low molecular weight polyfunctional crosslinking agent such as a melamine-based crosslinking agent or an epoxy crosslinking agent). ) And the addition weight ratio ([oxazoline-based cross-linking agent] / [second cross-linking agent], parentheses indicate the addition weight of each cross-linking agent) in the range of 0.1 to 10, a significant effect on adhesiveness There is. According to the knowledge of the present inventors, when the addition weight ratio is 0.5 to 5, the adhesiveness is particularly excellent.

  Further, in the present invention, various additives such as a surfactant, an antifoaming agent, a coating property improving agent, and a thickening agent are included in the aqueous easy-adhesive resin coating layer within a range not impairing the effects of the present invention. , Antioxidants, heat stabilizers, weather stabilizers, UV absorbers, organic lubricants, pigments, dyes, organic or inorganic fine particles, fillers, antistatic agents, organic lubricants, nucleating agents, etc. It may be. These additives may be used alone or in combination of two or more as necessary.

  In particular, those obtained by adding inorganic particles to the water-based easy-adhesive resin layer are more preferable because the slipperiness and blocking resistance are improved. In this case, silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate, or the like can be used as the inorganic particles to be added. The inorganic particles used preferably have an average particle size of 0.01 to 5 μm, more preferably 0.05 to 3 μm, most preferably 0.08 to 2 μm, and the mixing ratio with respect to the resin in the water-based easy-adhesion resin layer is particularly high Although not limited, 0.05-8 weight part is preferable by solid content weight ratio, More preferably, it is 0.1-3 weight part.

  As a method of applying a coating solution to a polyester film, for example, a coating technique as shown in “Coating Method” published by Yuji Harasaki, Tsuji Shoten, 1979, can be used. Specifically, air doctor coater, blade coater, rod coater, knife coater, squeeze coater, impregnation coater, reverse roll coater, transfer roll coater, gravure coater, kiss roll coater, cast coater, spray coater, curtain coater, calendar coater, Techniques such as an extrusion coater can be used, and coating devices other than these can also be used.

  When providing a coating layer on a polyester film, a method of applying a coating solution in the process of producing a polyester film, that is, in-line coating is suitably employed. For example, there are a method of stretching after coating on an unstretched film, a method of stretching after coating on a uniaxially stretched film, a method of stretching after coating on a biaxially stretched film, and the like. In particular, it is economical to apply a coating solution to an unstretched or uniaxially stretched film and then perform drying and stretching simultaneously in a tenter. In particular, by applying a water-based easy-adhesive resin to the polyester film before completion of crystal orientation, and by completing the crystal orientation by stretching and heat treatment, heat treatment at high temperature is possible, and more uniform and thin film A water-based easy-adhesion resin layer can be obtained, which is particularly preferable. In addition, you may process by the method called the offline coat | court applied after manufacture of a film as needed.

  When the aqueous easy-adhesive resin coating layer is formed by the in-line coating method, the coating liquid in the aqueous easy-adhesive resin coating layer of the present invention is an aqueous solution or an aqueous dispersion (emulsification / suspension). However, the organic solvent may be contained as long as water is the main medium. In the case of off-line coating, either water-based and / or solvent-based may be used.

In the present invention, the solid content concentration of the coating solution for forming the water-based easy-adhesive resin coating layer is not particularly limited, but is usually 0.3 to 65% by weight, preferably 0.5 to 30% by weight, and more preferably. 1 to 20% by weight. Further, the amount of coating after drying, usually 0.003~1.5g / ^{m 2,} preferably not 0.005 to 0.5 / ^{m 2,} more preferably at 0.01 to 0.3 g / ^{m 2.} If the coating amount is less than 0.003 g / m ^2, sufficient adhesion performance may not be obtained, and if it exceeds 1.5 g / m ² , blocking between the films is likely to occur, and particularly the strength of the film is increased. For this reason, when the coated film is re-stretched, it tends to stick to the roll in the process. The above problem of sticking appears particularly when the same coating layer is formed on both sides of the film.

  In addition, in order to improve the applicability | paintability and adhesiveness to the film of a coating agent, you may give a chemical process and an electrical discharge process to a film before application | coating. Further, in order to further improve the surface characteristics, a discharge treatment may be performed after the coating layer is formed.

  As the soft resin used for the laminated glass, polyvinyl butyral (PVB) or ethylene-vinyl acetate copolymer (EVA) is preferably used.

  As the glass used for the laminated glass, any glass can be used as long as it is used for buildings or automobiles.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded. Various physical properties and characteristics are measured or defined as follows. In the examples, “%” means “% by weight”.

(1) Measurement of thermal shrinkage rate A sample is cut out into a strip shape having a size of 15 mm wide × 150 mm long from a position corresponding to 10, 50, 90% with respect to the longitudinal direction of the film and the width direction of the film. Then, heat treatment for 30 minutes was performed in an oven set at 150 ° C., the length before and after the heat treatment was measured with a micrometer, and the heat shrinkage rate was obtained by the following formula.
Thermal contraction rate (%) = [(ab) / a] × 100
(Where a and b are the film lengths before and after heating (mm))

(2) Optical distortion in laminated glass A polyvinyl butyral film and a polyester film are sandwiched between two glass plates having curved surfaces, pre-pressed at a glass temperature of 80 to 100 ° C. and a degree of vacuum of 650 mmHg or more, and then a temperature of 120 to 150 ° C. Laminated glass was obtained by performing main bonding for 20 to 40 minutes in an autoclave at a pressure of 10 to 15 kg / cm ² . The appearance of the prepared laminated glass was observed, and optical distortion in the laminated glass was evaluated according to the following criteria.
○: Wrinkled due to the polyester film in the laminated glass and excellent appearance without any optical distortion ×: Wrinkled due to the polyester film in the laminated glass, transparency is lowered and there is a problem in practical use

(3) Preparation of PVB Sheet for Adhesion and Evaluation with PVB Powdered PVB (molecular weight about 110,000, butyralization degree 65 mol%, hydroxyl group amount about 34 mol%) 6 parts by weight, tri (ethylene glycol) bis (2- 4 parts by weight of ethylhexanoate (plasticizer) was mixed with 45 parts by weight of toluene and swollen, and then 45 parts by weight of ethanol was added and dissolved. This solution was put in a Teflon (registered trademark) petri dish so as to have a depth of 4 mm and dried in a hot air oven at 100 ° C. for 1 hour to prepare a PVB sheet having a thickness of about 0.4 mm.

-Adhesive evaluation The PVB sheet was cut into a width of 1 cm and a length of 10 cm, and sandwiched between two test films so that the easy-adhesion surface would face the sheet, a heat seal tester (TP-701, manufactured by Tester Sangyo Co., Ltd.) Thermocompression with. The conditions are as follows.
Load: 1000 N (approx. 1 MPa pressure is applied to the bonding surface); temperature: 140 ° C .; time: 1 minute

After allowing to cool, the pressure-bonded part was peeled off by hand, and the adhesiveness was determined according to the following criteria.
A: Extremely good (adhesive enough to cause damage to the test film or PVB sheet)
○: Good (peeling at the bonding interface but requires strong force)
Δ: Normal (peeling at the bonding interface but light response)
X: Defect (There is almost no response at the bonding interface and easily peels off)

In the examples and comparative examples, the compounds used as components constituting the aqueous easy-adhesive resin coating liquid are as follows.
・ Polyester resin: A1
An aqueous dispersion of polyester comprising 56 mol% terephthalic acid, 40 mol% isophthalic acid, 4 mol% 5-sodiumsulfoisophthalic acid, 70 mol% ethylene glycol, 17 mol% 1,4 butanediol and 13 mol% diethylene glycol

・ Polyester resin: A2
A polyester composed of 50 mol% terephthalic acid, 50 mol% isophthalic acid, 73 mol% ethylene glycol and 27 mol% diethylene glycol was reacted with pyromellitic anhydride to obtain a polyester having a molecular weight of 15000 and a carboxylic acid group content of 87 mgKOH / g. . The polyester was neutralized with ammonia to be dispersed in water. MMA was emulsion-polymerized in this aqueous dispersion to obtain an acrylic graft polyester (aqueous dispersion). The charge ratio of polyester and MMA was 50/50% by weight.

-Oxazoline group-containing polymer: B1
Copolymerization type with (meth) acrylic monomer. Oxazoline value 220 g (solid content) / equivalent (Epocross WS-700, manufactured by Nippon Shokubai Co., Ltd.)

・ Oxazoline group-containing polymer: B2
Copolymerization type with (meth) acrylic acid alkyl ester. Oxazoline value 130g (solid content) / equivalent (Epocross WS-300, manufactured by Nippon Shokubai Co., Ltd.)

・ Melamine compounds: C1
Alkyrol Melamine (DIC Corporation, Becamine J101)
・ Inert particles: D1
Silica sol with an average particle size of 0.05μm (Snowtex manufactured by Nissan Chemical Industries, Ltd.)
・ Polyacrylate polymer: E1
An aqueous dispersion of acrylate comprising 41 mol% methyl methacrylate, 46 mol% ethyl acrylate, 7 mol% acrylonitrile, 5 mol% N-methylolacrylamide, and 1 mol% methacrylic acid.

Example 1:
(Polyester chip manufacturing method)
Take 100 parts of dimethyl terephthalate, 70 parts of ethylene glycol, and 0.07 part of calcium acetate monohydrate in a reactor, heat up and evaporate methanol to conduct transesterification, and take about 4 and a half hours after starting the reaction. The temperature was raised to 230 ° C. to substantially complete the transesterification reaction. Next, 0.04 part of phosphoric acid and 0.035 part of antimony trioxide were added and polymerized in accordance with a conventional method. That is, the reaction temperature was gradually raised to finally 280 ° C., while the pressure was gradually reduced to finally 0.05 mmHg. After 4 hours, the reaction was completed, and chipped into a polyester (A) according to a conventional method. The solution viscosity IV of the obtained polyester chip was 0.66. Moreover, when manufacturing the said polyester (A), 1000 ppm of amorphous silica with an average particle diameter of 2 micrometers was added, and polyester (B) was created.

(Manufacture of polyester film)
The polyester (A) is a raw material for the B layer, the polyester (B) is the raw material for the A layer, and the raw materials for the A layer and the B layer are melt-extruded by separate melt extruders (A / B / A) An amorphous sheet having two layers and three layers was obtained. Subsequently, the sheet was coextruded on a cooled casting drum and solidified by cooling to obtain a non-oriented sheet. Next, the film was stretched 3.6 times in the longitudinal direction at 90 ° C., and then an aqueous easy-adhesive coating solution 1 was applied to both sides at a coating amount of 5 g / m 2 on each side, followed by a preheating step in a tenter and 90 ° C. Then, a polyester film having a water-based easy-adhesive resin coating layer on both surfaces of 125 μm was obtained. A laminated glass was prepared using the obtained polyester film, polyvinyl butyral, and two pieces of glass having a curved surface, and the appearance of the laminated glass was confirmed. The laminated glass had no optical distortion and a good appearance.

Example 2:
A laminated glass was obtained in the same manner as in Example 1 except that the heat treatment temperature for forming the polyester film was 150 ° C. The obtained laminated glass had no optical distortion and a good appearance.

Example 3:
A laminated glass was obtained in the same manner as in Example 1 except that the water-based easy-adhesive coating liquid 1 for the polyester film was changed to the water-based easy-adhesive coating liquid 2. The obtained laminated glass had no optical distortion and a good appearance.

Example 4:
A laminated glass was obtained in the same manner as in Example 1 except that the water-based easy-adhesion coating solution 1 for the polyester film was changed to the water-based easy-adhesion coating solution 3. The obtained laminated glass had no optical distortion and a good appearance.

Example 5:
A laminated glass was obtained in the same manner as in Example 1 except that the water-based easy-adhesive coating liquid 1 for the polyester film was changed to the water-based easy-adhesive coating liquid 4. The obtained laminated glass had no optical distortion and a good appearance.

Example 6:
A laminated glass was obtained in the same manner as in Example 1 except that the water-based easy-adhesive coating solution 1 for the polyester film was changed to the water-based easy-adhesive coating solution 5. The obtained laminated glass had no optical distortion and a good appearance.

Comparative Example 1:
A laminated glass was obtained in the same manner as in Example 1 except that the heat treatment temperature when forming the polyester film was 200 ° C. The obtained laminated glass had wrinkles due to the polyester film, and had a problem in practical use due to a decrease in transparency.

Comparative Example 2:
A laminated glass was obtained in the same manner as in Example 1 except that the heat treatment temperature when forming the polyester film was 130 ° C. The obtained laminated glass had wrinkles due to the polyester film, and had a problem in practical use due to a decrease in transparency.

Comparative Example 3:
Laminated glass was obtained by the same method as in Example 1 except that the coating layer was not provided after stretching in the longitudinal direction when forming the polyester film. In the obtained laminated glass, the adhesion between the polyester film and PVB was insufficient.

  The film of the present invention can be suitably used as, for example, a laminated glass film for windows of building materials and automobiles.

Claims (1)

In the laminated glass constituted by interposing an intermediate film between at least two glass plates, the intermediate film has a thermal shrinkage rate at 130 ° C. for 30 minutes of 5.0 to 10.0 in both the longitudinal direction and the width direction of the film. % Of the polyester film having a water-based easy-adhesive resin coating layer (excluding a coating layer containing a silane coupling agent) having a coating amount after drying of 0.005 to 0.5 g / m ^{2 on} one side. A polyester film for laminated glass comprising a composite in which a soft resin layer is laminated on a coating layer.