WO2011068112A1

WO2011068112A1 - Highly adhesive thermoplastic resin film

Info

Publication number: WO2011068112A1
Application number: PCT/JP2010/071434
Authority: WO
Inventors: 晃侍伊藤; 淳史山崎; 寛子矢吹; 薫澤田; 水野　直樹; 東浦　真哉
Original assignee: 東洋紡績株式会社
Priority date: 2009-12-04
Filing date: 2010-12-01
Publication date: 2011-06-09
Also published as: CN102648094B; KR101404875B1; KR20120091370A; CN102648094A

Abstract

Disclosed is a highly adhesive thermoplastic resin film which is substantially free from decrease in adhesion under high temperature high humidity conditions. Specifically disclosed is a highly adhesive thermoplastic resin film which comprises a coating layer on at least one surface of a base film. The highly adhesive thermoplastic resin film is characterized in that the coating layer contains (a) a urethane resin that contains a polycarbonate polyol as a component, and/or a polyester resin that does not substantially contain a carboxylic acid group and has a number average molecular weight of not less than 15,000, and (b) a carbodiimide compound.

Description

Easy-adhesive thermoplastic film

The present invention relates to an easily-adhesive thermoplastic resin film excellent in adhesion and heat and moisture resistance. Specifically, it is suitable as a base material for functional films such as hard coat films, antireflection films, light diffusion sheets, prismatic lens sheets, near-infrared shielding films, transparent conductive films, and antiglare films, which are mainly used for displays and the like. The present invention relates to an easily adhesive thermoplastic film.

In general, a transparent thermoplastic resin made of polyethylene terephthalate (PET), acrylic, polycarbonate (PC), triacetyl cellulose (TAC), polyolefin or the like is used as a base material for a functional film used as a liquid crystal display (LCD) member. A film is used.

When using the thermoplastic resin film as a base material for various functional films, functional layers corresponding to various uses are laminated. For example, in a liquid crystal display (LCD), a protective film (hard coat layer) that prevents scratches on the surface, an antireflection layer (AR layer) that prevents reflection of external light, and a prism layer that is used to collect and diffuse light And a functional layer such as a light diffusion layer for improving luminance. Among such substrates, particularly polyester films are widely used as substrates for various functional films because they are excellent in transparency, dimensional stability and chemical resistance and are relatively inexpensive.

In general, in the case of a biaxially oriented thermoplastic film such as a biaxially oriented polyester film or a biaxially oriented polyamide film, the film surface is highly crystallized, so it has good adhesion to various paints, adhesives, inks, etc. There is a disadvantage of being scarce. For this reason, methods for imparting easy adhesion to the biaxially oriented thermoplastic resin film surface by various methods have been proposed.

For example, a method of imparting easy adhesion to a base film by providing a coating layer mainly composed of various resins such as polyester, acrylic, polyurethane, and acrylic graft polyester on the surface of the thermoplastic resin film of the base Is generally known. Among these coating methods, an aqueous coating solution containing the resin solution or a dispersion obtained by dispersing the resin in a dispersion medium is coated on a thermoplastic resin film before completion of crystal orientation, and dried. Thereafter, the film is stretched at least in a uniaxial direction and then subjected to heat treatment to complete the orientation of the thermoplastic resin film (so-called in-line coating method), or after the production of the thermoplastic resin film, the film is water-based or solvent-based. A method of drying after applying a coating solution (so-called off-line coating method) has been industrially implemented.

LCDs, displays such as PDPs, and portable devices using hard coat films as members are used in various environments, both indoors and outdoors. In particular, portable devices may require moisture and heat resistance that can withstand a bathroom, a hot and humid area, and the like. The optical functional film used for such applications is required to have high adhesion such that delamination does not occur even under high temperature and high humidity. Therefore, in the following patent document, an easy-adhesive thermoplastic resin film imparted with moisture and heat resistance is disclosed by adding a crosslinking agent to the coating solution and forming a crosslinked structure in the coating layer resin when forming the coating layer by the in-line coating method. Has been.

JP 2000-141574 A Japanese Patent No. 3900191 Japanese Patent No. 3773738 JP 2007-253512 A JP 2000-355086 A Japanese Patent No. 2544792

Longer life expectancy is expected for home appliances with a display to reduce global environmental impact. Therefore, it was considered that the functional film used as a member also needs to maintain adhesion for a long time even under high temperature and high humidity. However, the easy-adhesion film as disclosed in the above-mentioned patent document shows good adhesion at first, but a decrease in adhesion strength is inevitable in long-term use under high temperature and high humidity. . Due to such a decrease in adhesion, there is a problem that the initial performance is not maintained for a long time.

In view of the above problems, the present invention provides an easily-adhesive thermoplastic resin film that hardly causes deterioration of a coating layer under high temperature and high humidity, which has been conventionally considered to be unavoidable, that is, hardly causes a decrease in adhesion under high temperature and high humidity. To do.

In addition, the adhesiveness under high temperature and high humidity referred to in the present invention is a layer of a photocurable acrylic layer, placed in an environment of 80 ° C., 95% RH, 48 hours, and using a cutter guide with a gap interval of 2 mm, Apply 100 cell-shaped cuts that penetrate the photocurable acrylic layer to the base film on the surface of the photocurable acrylic layer, and then apply cellophane adhesive tape to the cell-shaped cut surface and rub it with an eraser to complete Means the adhesiveness when the same part is peeled off 5 times vigorously, and the adhesiveness is based on stricter criteria than the evaluation method described in JIS K5600-5-6, which is generally used. Therefore, it is a problem that the adhesiveness under such high temperature and high humidity shows the adhesiveness equal to or higher than the initial adhesiveness.

As a result of intensive studies to solve the above problems, the present inventor improves adhesion under high temperature and high humidity by using a coating layer containing a specific urethane resin and / or a specific polyester resin and a carbodiimide compound. Thus, the present inventors have found the fact that overturns the conventional technical common sense, and have arrived at the present invention. As described in the above-mentioned patent document, in order to improve the adhesion of the coating layer in the conventional technical common sense, it is mixed with a crosslinking agent and a resin having a functional group capable of reacting with it, and a highly crosslinked structure is formed when the coating layer is formed. It has been considered desirable to form. However, the present invention uses a urethane resin and / or polyester resin that does not substantially have a carboxylic acid group that is a functional group that reacts with a carbodiimide group, and has substantially no crosslinked structure or a low degree of crosslinking. The present inventors have found a fact contrary to the prior art to maintain high adhesion even under high temperature and high humidity by leaving the carbodiimide group in the coating layer in the state, and have reached the present invention.

The above-described problem can be achieved by the following solution means.
(1) An easy-adhesive thermoplastic resin film having a coating layer on at least one side of a base film, and the coating layer is (a) a urethane resin containing polycarbonate polyol as a constituent component and / or a number average molecular weight of 15000 or more. An easily adhesive thermoplastic resin film comprising a polyester resin substantially free of carboxylic acid groups and (b) a carbodiimide compound.
(2) The easily adhesive thermoplastic resin film, wherein the urethane resin has a polyoxyalkylene group.
(3) The said easily-adhesive thermoplastic resin film in which the said polyester resin contains the dicarboxylic acid component represented by following formula (1) and / or the diol component represented by following formula (2).
(1) HOOC— (CH ₂ ) _n —COOH (where n is an integer satisfying 4 ≦ n ≦ 10)
(2) HO— (CH ₂ ) _n —OH (where n is an integer satisfying 4 ≦ n ≦ 10)
(3) The said easily adhesive thermoplastic resin film in which the said polyester resin contains naphthalene dicarboxylic acid as an acid component.
(5) The above easy-adhesive heat, wherein the coating layer comprises a urethane resin having a polycarbonate polyol as a constituent component and a carbodiimide compound as main components, and the coating layer contains 0.5 to 3.5 mmol / g of carbodiimide groups. Plastic resin film.
(6) The coating layer is mainly composed of a polyester resin having a number average molecular weight of 15000 or more and substantially having no carboxylic acid group and a carbodiimito compound, and carbodiimide groups are contained in the coating layer in an amount of 0.3 to 3. The said easily-adhesive thermoplastic resin film containing 3 mmol / g.
(7) The coating layer is mainly composed of a urethane resin having a polycarbonate polyol as a constituent component, a polyester resin having a number average molecular weight of 15000 or more and substantially having no carboxylic acid group, and a carbodiimide compound. The above-mentioned easily-adhesive thermoplastic resin film containing 0.1 to 2.0 mmol / g of carbodiimide group.
(8) The said easily adhesive polyester film whose said carbodiimide compound is water-soluble and whose haze is 2.5% or less.
(9) At least one layer selected from a hard coat layer, a light diffusion layer, a prismatic lens layer, an electromagnetic wave absorption layer, a near infrared ray blocking layer, and a transparent conductive layer is formed on the coating layer of the easily adhesive thermoplastic resin film. A laminated thermoplastic resin film formed by laminating functional layers.

The first effect of the easy-adhesive thermoplastic resin film of the present invention is excellent in adhesiveness (wet heat resistance) with the optical functional layer under high temperature and high humidity. Therefore, as a preferred embodiment, the adhesion at the high temperature and high humidity treatment is equal to or improved from the initial adhesion. As a preferred embodiment of the present invention, when the easily adhesive polyester film of the present invention is used as a substrate for a lens sheet, the adhesion with the lens layer under high temperature and high humidity is good.
Furthermore, in a preferred embodiment of the present invention, in addition to the first effect, even when the hard coat layer is laminated, the light interference fringes are suppressed and the visibility is excellent.
Furthermore, in a preferred embodiment of the present invention, in addition to the first effect, the blocking resistance is excellent.

(Thermoplastic resin film)
The thermoplastic resin constituting the thermoplastic resin film used as a base material in the present invention includes polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon 6 and nylon 66, polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6- Naphthalate, polymethylene terephthalate, and copolymer components such as diol components such as diethylene glycol, neopentyl glycol, polyalkylene glycol, adipic acid, sebacic acid, phthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, etc. A polyester resin copolymerized with a dicarboxylic acid component or the like can be used. Of these, polyester resins are preferred from the viewpoint of mechanical strength and chemical resistance.

Polyester resins preferably used in the present invention include polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, polymethylene terephthalate, and copolymer components such as diols such as diethylene glycol, neopentyl glycol, and polyalkylene glycol. A polyester resin obtained by copolymerizing a component, a dicarboxylic acid component such as adipic acid, sebacic acid, phthalic acid, isophthalic acid, or 2,6-naphthalenedicarboxylic acid can be used.

The polyester resin suitably used in the present invention mainly contains at least one of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate as a constituent component. Among these polyester resins, polyethylene terephthalate is most preferable from the balance between physical properties and cost. Moreover, these polyester films can improve chemical resistance, heat resistance, mechanical strength, etc. by biaxially stretching.

The biaxially stretched polyester film may be a single layer or a multilayer. Moreover, as long as it exists in the range with the effect of this invention, each of these layers can contain various additives in a polyester resin as needed. Examples of the additive include an antioxidant, a light resistance agent, an antigelling agent, an organic wetting agent, an antistatic agent, an ultraviolet absorber, and a surfactant.

In addition, in order to improve handling characteristics such as film slipperiness, rollability and blocking resistance, and wear characteristics such as wear resistance and scratch resistance, inert particles may be included in the polyester film. However, when used for a base film of an optical member, it is required to have excellent handling properties while maintaining high transparency. Specifically, when used as a substrate film for an optical member, the total light transmittance of the easily adhesive polyester film is preferably 85% or more, more preferably 87% or more, and even more preferably 88% or more. 89% or more is more preferable, and 90% or more is particularly preferable.

For high definition, it is preferable that the content of inert particles in the base film is as small as possible. Therefore, it is preferable to make a multilayer structure in which particles are contained only in the surface layer of the film, or to contain fine particles only in the coating layer without substantially containing particles in the film.

In particular, from the viewpoint of transparency, when an inert particle is practically not contained in the polyester film, an inorganic and / or heat-resistant polymer particle is contained in the aqueous coating solution in order to improve the handleability of the film. It is also preferable to form irregularities on the surface of the coating layer.

Note that “substantially no inert particles” means, for example, in the case of inorganic particles, when the element derived from the particles is quantitatively analyzed by fluorescent X-ray analysis, 50 ppm or less, preferably 10 ppm or less, Preferably, the content is below the detection limit. This means that even if particles are not actively added to the base film, contaminants derived from foreign substances and raw material resin or dirt adhering to the line or equipment in the film manufacturing process will be peeled off and mixed into the film. It is because there is a case to do.

In addition, it is also a preferable aspect to add inert particles only to the surface layer from the viewpoint of achieving both high transparency and handling properties. For example, in the case of a three-layer structure, it is preferable that particles are contained in the outermost layer (A layer in the case of A layer / B layer / A layer), and the center layer (B layer) is substantially free of particles. .

The type and content of the particles contained in the outermost layer may be inorganic particles or organic particles, and are not particularly limited, but include metal oxidation such as silica, titanium dioxide, talc, and kaolinite. Examples thereof include inorganic particles that are inert to polyesters such as products, calcium carbonate, calcium phosphate, and barium sulfate. Any one of these inert inorganic particles may be used alone, or two or more thereof may be used in combination.

The above particles preferably have an average particle size of 0.1 to 3.5 μm. If the average particle size is less than the lower limit, sufficient handling properties may not be obtained. If the upper limit is exceeded, the transparency may decrease. The content of inorganic particles in the outermost layer is preferably 0.01 to 0.20% by mass with respect to the polyester constituting the outermost layer. If it is less than the lower limit, sufficient handling properties cannot be obtained. When the upper limit is exceeded, the transparency decreases.

Furthermore, when reflectivity and high concealability are required, a whitening film having a high void content may be used by adding a cavity developer in the base film. In applications where moldability is required, a molding film imparted with moldability by adding a copolymer component as a polyester resin may be used.

The thickness of the base film used in the present invention is not particularly limited, but can be arbitrarily determined in the range of 30 to 500 μm according to the standard to be used. The upper limit of the thickness of the base film is preferably 350 μm, particularly preferably 250 μm. On the other hand, the lower limit of the film thickness is preferably 50 μm, more preferably 75 μm, and particularly preferably 100 μm. When the film thickness is less than the lower limit, rigidity and mechanical strength tend to be insufficient. On the other hand, when the film thickness exceeds the upper limit, the cost may increase.

(Coating layer)
The easy-adhesive thermoplastic resin film of the present invention includes (a) a urethane resin having a polycarbonate polyol as a constituent component and / or a polyester resin having a number average molecular weight of 15000 or more and having substantially no carboxylic acid group, (B) It is important to provide a coating layer containing a carbodiimide compound. Among these, a coating layer mainly composed of the above (a) and (b) is preferable. Here, the “main component” means that 50% by mass or more is contained in the total solid component contained in the coating layer.

Conventionally, it was considered desirable to positively introduce a crosslinked structure from the viewpoint of improving the heat and moisture resistance of the coating layer. However, in this invention, it discovered that heat-and-moisture resistance improved by making a coating layer into the above structures. Although the mechanism by which the adhesiveness under high temperature and high humidity is improved by such a configuration is not well understood, the present inventor thinks as follows. Since the coating layer of the present invention is substantially free of carboxylic acid groups that are functional groups that react with carbodiimide groups, unreacted carbodiimide groups remain in the coating layer when the coating layer is formed. On the other hand, under high temperature and high humidity, the polyester resin in the coating layer undergoes hydrolysis, the ester bond is broken, and carboxylic acid group terminals are generated. Here, the unreacted carbodiimide group reacts with the generated carboxylic acid terminal to form a crosslink. In other words, it is considered that the deterioration of the coating film strength under high temperature and high humidity can be prevented by self-healing the deterioration of the coating film strength due to hydrolysis.

In other words, the coating layer of the present invention does not contain a carboxyl group or a salt thereof, which is a functional group having high reactivity with the carbodiimide group, or its salt is very small, and therefore there are many unreacted carbodiimide groups in the coating layer. Exists. On the other hand, a functional group such as a carboxyl group is present in a resin used for a functional layer to be laminated, such as a photocurable acrylic resin and an unreacted product. Furthermore, a functional group exists also in the thermoplastic resin which is a base film. It is presumed that in a high-temperature and high-humidity environment, the interaction between the functional group and / or the carbodiimide group present in these functional layers and / or base film proceeds, and strong adhesion can be obtained.

The present invention can improve the adhesion (humidity heat resistance) to the lens layer and other functional layers under high temperature and high humidity according to the above embodiment. Further, the configuration of the present invention will be described in detail below.

(Urethane resin)
The urethane resin used in the present invention contains at least a polyol component and a polyisocyanate component as constituent components, and further contains a chain extender as necessary. The urethane resin of the present invention is a polymer compound in which these constituent components are mainly copolymerized by urethane bonds. In this invention, it has the polycarbonate polyol as a structural component of a urethane resin, It is characterized by the above-mentioned. Moisture heat resistance can be improved by including a urethane resin containing polycarbonate as a constituent component in the coating layer of the present invention. The components of these urethane resins can be specified by nuclear magnetic resonance analysis or the like.

Examples of the polycarbonate polyol which is a constituent component of the urethane resin of the present invention include polycarbonate diol, polycarbonate triol and the like, and polycarbonate diol can be preferably used. Examples of the polycarbonate diol that is a constituent of the urethane resin of the present invention include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 3-methyl-1,5. -Pentanediol, 1,6-hexanediol, 1,9-nonanediol, 1,8-nonanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, A polycarbonate diol obtained by reacting one or more diols such as bisphenol-A with carbonates such as dimethyl carbonate, diphenyl carbonate, ethylene carbonate, and phosgene. And the like. The number average molecular weight of the polycarbonate diol is preferably 300 to 5000, and more preferably 500 to 3000.

In the present invention, the composition molar ratio of the polycarbonate polyol, which is a constituent component of the urethane resin, is preferably 3 to 100 mol% when the total polyisocyanate component of the urethane resin is 100 mol%, preferably 5 to 50 mol%. More preferably, it is 6 to 20 mol%. When the composition molar ratio is low, the durability effect by the polycarbonate polyol may not be obtained. Moreover, when the said composition molar ratio is high, initial adhesiveness may fall.

Examples of the polyisocyanate that is a constituent of the urethane resin of the present invention include isomers of toluylene diisocyanate, aromatic diisocyanates such as 4,4-diphenylmethane diisocyanate, aromatic aliphatic diisocyanates such as xylylene diisocyanate, Aliphatic diisocyanates such as isophorone diisocyanate and 4,4-dicyclohexylmethane diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, hexamethylene diisocyanate, and aliphatic diisocyanates such as 2,2,4-trimethylhexamethylene diisocyanate Or polyisocyanates obtained by adding these compounds in advance with trimethylolpropane or the like alone or in plural.

Chain extenders include glycols such as ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol and 1,6-hexanediol, polyhydric alcohols such as glycerin, trimethylolpropane, and pentaerythritol, ethylenediamine Diamines such as hexamethylenediamine and piperazine, aminoalcohols such as monoethanolamine and diethanolamine, thiodiglycols such as thiodiethylene glycol, and water.

The coating layer of the present invention is preferably provided by an in-line coating method described later using an aqueous coating solution. Therefore, it is desirable that the urethane resin of the present invention is water-soluble. When a water-soluble urethane resin is used, compatibility with a carbodiimide compound increases, and transparency can be improved. The “water-soluble” means that it dissolves in water or an aqueous solution containing less than 50% by mass of a water-soluble organic solvent.

In order to impart water solubility to the urethane resin, a sulfonic acid (salt) group or a carboxylic acid (salt) group can be introduced (copolymerized) into the urethane molecular skeleton. Since the sulfonic acid (salt) group is strongly acidic and it may be difficult to maintain moisture resistance due to its hygroscopic performance, it is preferable to introduce a weakly acidic carboxylic acid (salt) group.

In order to introduce a carboxylic acid (salt) group into a urethane resin, for example, as a polyol component, a polyol compound having a carboxylic acid group such as dimethylolpropionic acid or dimethylolbutanoic acid is introduced as a copolymer component to form a salt. Neutralize with an agent. Specific examples of the salt forming agent include trialkylamines such as ammonia, trimethylamine, triethylamine, triisopropylamine, tri-n-propylamine, and tri-n-butylamine, N such as N-methylmorpholine and N-ethylmorpholine. -N-dialkylalkanolamines such as alkylmorpholines, N-dimethylethanolamine and N-diethylethanolamine. These can be used alone or in combination of two or more.

In order to impart water solubility, when a polyol compound having a carboxylic acid (salt) group is used as a copolymerization component, the composition molar ratio of the polyol compound having a carboxylic acid (salt) group in the urethane resin is the same as that of the urethane resin. When the total polyisocyanate component is 100 mol%, it is preferably 3 to 60 mol%, and more preferably 10 to 40 mol%. If the composition molar ratio is less than 3 mol%, water dispersibility may be difficult. Moreover, when the said composition molar ratio exceeds 60 mol%, since the residual carbodiimide group at the time of coating layer formation reduces, heat-and-moisture resistance may fall.

However, when a urethane resin into which a carboxylic acid is introduced is used as the urethane resin as described above, the carbodiimide group may react with the carbodiimide group in the coating solution, and the unreacted carbodiimide group may be reduced when the coating layer is formed. Therefore, it is desirable that the coating layer has substantially no carboxylic acid (salt) group. Therefore, in order to impart water solubility to the urethane resin, it is a preferred embodiment of the present invention to introduce a polyoxyalkylene group instead of the carboxylate group. When using the urethane resin which introduce | transduced the polyoxyalkylene group as a urethane resin, a coating layer does not have a carboxyl group substantially. Therefore, an unreacted carbodiimide group remains stably and can exhibit more excellent moisture and heat resistance.

Examples of the polyoxyalkylene group introduced into the urethane resin include a polyoxyethylene group, a polyoxypropylene group, and a polytetramethylene glycol chain, and these can be used alone or in combination of two or more. Among these, a polyoxyethylene group can be preferably used.

In order to introduce a polyoxyethylene group into a urethane resin, for example, polyisocyanate and one-end blocked polyoxyethylene glycol (alkoxyethylene glycol whose one end is blocked with an alkyl group having 1 to 20 carbon atoms) are blocked at one end. After the urethanation reaction in an excess ratio of the isocyanate group of the diisocyanate with respect to the hydroxyl group of the polyoxyethylene glycol, the polyoxyethylene chain-containing monoisocyanate was obtained by removing the unreacted polyisocyanate if necessary. Then, the obtained polyoxyethylene chain-containing monoisocyanate and diisocyanate can be obtained by an allophanatization reaction.

In order to impart water solubility, when introducing polyoxyethylene groups into the urethane resin, the composition molar ratio of the polyoxyethylene groups in the urethane resin is 100 mol% of the total polyisocyanate component of the urethane resin. It is preferably 3 mol% or more, more preferably 10 mol% or more, and further preferably 20 mol% or more. If the composition molar ratio is less than 3 mol%, water dispersibility may be difficult.

When using only the urethane resin as the component (a), the urethane resin is preferably contained in the coating layer in an amount of 10% by mass to 90% by mass. In particular, when high adhesion is required as in a lens layer, it is more preferably 20% by mass or more and 80% by mass or less. When the content of the urethane resin is large, the adhesiveness under high temperature and high humidity is lowered, and conversely, when the content is small, the initial adhesiveness is lowered.

When only the urethane resin is used as the component (a), the lower limit of the carbodiimide group concentration in the coating layer is 0.5 mmol / g, preferably 0.7 mmol / g, more preferably 1.0 mmol / g, and the upper limit. Is 3.5 mmol / g, preferably 3.3 mmol / g, more preferably 3.0 mmol / g. If the amount is less than the above lower limit, sufficient adhesiveness at high temperature and high humidity may not be obtained. When the above upper limit is exceeded, the ratio of the polycarbonate-based urethane resin becomes relatively small, and the adhesiveness, particularly the initial adhesiveness, may be lowered.

(Polyester resin)
The polyester resin used in the present invention preferably has fewer carboxylic acid groups which are reactive groups with carbodiimide groups. More preferably, it has substantially no carboxylic acid group. Here, having substantially no carboxylic group means that it contains no carboxylic acid group other than the terminal group. As a method for defining a carboxylic acid group, an acid value can be measured. However, the polyester resin having substantially no carboxylic acid group has an acid value of 3 KOHmg / g or less, more preferably 2 KOHmg / g or less. More preferably, it is a polyester resin of 1 KOHmg / g or less.

The number average molecular weight of the polyester resin needs to be 15000 or more. When the number average molecular weight is low, the terminal carboxylic acid group increases, which may cause a reaction with a carbodiimide group. In addition, the hydrolysis is accelerated, the coating film is not sufficiently repaired, and not only the adhesiveness under high temperature and high humidity is not obtained, but also the adhesiveness with the substrate film is lowered. Further, the number average molecular weight is more preferably 20000 or more, and it is preferably higher as long as it can be produced. However, the number average molecular weight is preferably 60000 or less because the solubility in the coating solution may be reduced as the number average molecular weight increases.

Polyester resin has acid components such as terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, pyromellitic acid, Examples include dimer acid, 5-sodium sulfoisophthalic acid, 4-sodium sulfonaphthalene-2,7-dicarboxylic acid, and the like. Diol components include ethylene glycol, propane glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylene glycol, ethylene oxide adducts of bisphenol A, etc. Is mentioned. When a hard coat layer mainly made of an acrylic resin is provided on the film of the present invention, interference fringes are generated due to the difference in refractive index between the coating layer and the other layer, which may cause a problem in terms of visibility. For this reason, it is preferable to contain naphthalenedicarboxylic acid capable of obtaining a higher refractive index as an acid component because it improves the heat and moisture resistance and the effect of suppressing iris-like colors.

Moreover, from the point of suppression of the iris-like color at the time of providing a hard-coat layer, it may contain the dicarboxylic acid component of following formula (1) and / or the diol component of following formula (2) as a component of a polyester resin. preferable. The dicarboxylic acid component of the following formula (1) and / or the diol component of the following formula (2) in the polyester resin is preferably 10% or more, more preferably 15% or more, and further preferably 20% or more. Further, the dicarboxylic acid component of the following formula (1) and / or the diol component of the following formula (2) in the polyester resin is preferably 70% or less, more preferably 60% or less, and further preferably 50% or less. When exceeding the said upper limit, a coating film may become soft too much and heat-and-moisture resistance may fall. When it is less than the above lower limit, the flexibility of the polyester resin is lowered, the coating film becomes too hard, and the adhesion may be lowered.
(1) HOOC— (CH ₂ ) _n —COOH (where n is an integer satisfying 4 ≦ n ≦ 10)
(2) HO— (CH ₂ ) _n —OH (where n is an integer satisfying 4 ≦ n ≦ 10)

The polyester resin is based on water or a water-soluble organic solvent (for example, an aqueous solution containing less than 50% by weight of alcohol, alkyl cellosolve, ketone, or ether) or an organic solvent (for example, toluene, ethyl acetate, etc.). Those dissolved or dispersed can be used.

When the polyester resin is used as an aqueous coating liquid, a water-soluble or water-dispersible polyester resin is used. For such water-solubilization or water-dispersion, a compound containing a sulfonate group or a carboxyl group is used. It is preferable to copolymerize a compound containing an acid base. Therefore, in addition to the dicarboxylic acid component described above, in order to impart water dispersibility to the polyester, it is preferable to use 5-sulfoisophthalic acid or an alkali metal salt thereof in the range of 1 to 10 mol%. Mention may be made of acids, 5-sulfoisophthalic acid, 4-sulfonaphthaleneisophthalic acid-2,7-dicarboxylic acid and 5- (4-sulfophenoxy) isophthalic acid or alkali metal salts thereof.

In order to set the number average molecular weight of the polyester resin to 15000 or more and to have a glass transition temperature enough to suppress blocking, it is preferable to introduce a branched structure into the polyester resin. However, as the number of branched structures increases, the acid value tends to increase. Therefore, in the polyester resin of the present invention, the molar ratio of the third component having three or more carboxyl groups / one molecule or three or more hydroxyl groups / one molecule is 5.0 mol% or less in the total dicarboxylic acid component. Preferably, it is 1.0 mol% or less more preferably.

When only the polyester resin is used as the component (a), the polyester resin is preferably contained in the coating layer in an amount of 10% by mass to 85% by mass. When high adhesiveness is required, it is more preferably 20% by mass or more and 80% by mass or less. When the content of the polyester resin is large, the adhesiveness under high temperature and high humidity decreases, and conversely, when the content is small, the adhesiveness with the base film decreases.

When only the polyester resin is used as the component (a), the lower limit of the carbodiimide group concentration in the coating layer is 0.3 mmol / g, preferably 0.5 mmol / g, more preferably 0.8 mmol / g, and the upper limit. Is 3.3 mmol / g, preferably 3.0 mmol / g, more preferably 2.8 mmol / g. If the amount is less than the above lower limit, sufficient adhesiveness at high temperature and high humidity may not be obtained. When the upper limit is exceeded, the ratio of the polyester resin becomes relatively small, and the adhesion, particularly the initial adhesion, may be lowered.

(Polyurethane resin and polyester resin)
In the present invention, as the component (a), the polycarbonate-based urethane resin having excellent durability and the polyester resin are used to improve the coating film hardness and exhibit excellent blocking resistance as well as adhesion. Can do.

The polyester resin preferably has a low glass transition temperature from the viewpoint of adhesion, but preferably has a high glass transition temperature from the viewpoint of blocking resistance. Therefore, the glass transition temperature of the polyester resin is preferably 10 to 100 ° C., and more preferably 30 to 70 ° C. When the glass transition temperature is higher than 100 ° C., the melt viscosity becomes high, and it is difficult to obtain a product having a sufficient molecular weight, so that the adhesiveness is lowered. When the glass transition temperature is lower than 10 ° C., the blocking resistance of the film is lowered.

In order to set the number average molecular weight of the polyester resin to 15000 or more and make the glass transition temperature in the above range, it is preferable to introduce a branched structure into the polyester resin. However, as the number of branched structures increases, the acid value tends to increase. Therefore, in the polyester resin of the present invention, the molar ratio of the third component having three or more carboxyl groups / one molecule or three or more hydroxyl groups / one molecule is 5.0 mol% or less in the total dicarboxylic acid component. Preferably, it is 1.0 mol% or less more preferably.

When the polyurethane resin and the polyester resin are used as the component (a), the concentration of the polyurethane resin and the polyester resin is preferably 10% by mass to 80% by mass in the coating layer. When high adhesiveness is required, it is more preferably 20% by mass or more and 70% by mass or less. When the content of the urethane resin is large, the adhesiveness under high temperature and high humidity is lowered, and conversely, when the content is small, the initial adhesiveness is lowered. Moreover, when there is much content of a polyester resin, the adhesiveness under high temperature, high humidity falls, and conversely, when there is little content, adhesiveness with a base film and blocking resistance fall.

When the polyurethane resin and the polyester resin are used as the component (a), the lower limit of the carbodiimide group concentration in the coating layer is 0.1 mmol / g, preferably 0.2 mmol / g, more preferably 0.4 mmol / g. Yes, the upper limit is 2.0 mmol / g, preferably 1.8 mmol / g, more preferably 1.5 mmol / g. If the amount is less than the above lower limit, sufficient adhesiveness at high temperature and high humidity may not be obtained. When the above upper limit is exceeded, the ratio of the urethane resin and the polyester resin becomes relatively small, and the adhesiveness, particularly the initial adhesiveness, may be lowered.

In the present invention, a resin other than the urethane resin and / or the polyester resin may be contained in order to improve adhesion. For example, an acrylic resin, a polyester resin, etc. are mentioned. Preferably, the carboxylic acid group content is low. More preferably, it does not contain a carboxylic acid group. When there are many carboxylic acid groups, it will react with a carbodiimide group, and the carbodiimide group which reacts with the carboxylic acid group generated from a urethane resin under high temperature and high humidity will decrease.

(Carbodiimide compound)
In the present invention, it is necessary to contain a carbodiimide compound. Examples of the carbodiimide compound include a monocarbodiimide compound and a polycarbodiimide compound.

Examples of monocarbodiimide compounds include dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, t − butylisopropylcarbodiimide, diphenylcarbodiimide, di − t − butylcarbodiimide, di − β − naphthylcarbodiimide and the like.

As the polycarbodiimide compound, those produced by a conventionally known method can be used. For example, it can be produced by synthesizing an isocyanate-terminated polycarbodiimide by a condensation reaction involving decarbonization of diisocyanate.

Examples of the diisocyanate that is a raw material for synthesizing a polycarbodiimide compound include isomers of toluylene diisocyanate, aromatic diisocyanates such as 4,4-diphenylmethane diisocyanate, aromatic aliphatic diisocyanates such as xylylene diisocyanate, isophorone diisocyanate and 4 Alicyclic diisocyanates such as 1,4-dicyclohexylmethane diisocyanate and 1,3-bis (isocyanatemethyl) cyclohexane, and aliphatic diisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate. From the problem of yellowing, aromatic aliphatic diisocyanates, alicyclic diisocyanates, and aliphatic diisocyanates are preferred.

The diisocyanate may be used with a molecule controlled to an appropriate degree of polymerization using a compound that reacts with a terminal isocyanate such as monoisocyanate. Examples of monoisocyanates for sealing the ends of polycarbodiimide and controlling the degree of polymerization thereof include phenyl isocyanate, toluylene isocyanate, dimethylphenyl isocyanate, cyclohexyl isocyanate, butyl isocyanate, and naphthyl isocyanate. In addition, a compound having an —OH group, —NH ₂ group, —COOH group, or —SO ₂ H group can be used as a terminal blocking agent.

The condensation reaction accompanied by decarbonization of diisocyanate proceeds in the presence of a carbodiimidization catalyst. Examples of the catalyst include 1 − phenyl − 2 − phospholene − 1 − oxide, 3 − methyl − 2 − phospholene − 1 − Oxide, 1 − ethyl − 2 − phospholene − 1 − oxide, 3 − methyl − 1 − phenyl − 2 − phospholene − 1 − Oxides and phospholene isomers such as these 3 − phospholene isomers, etc., and 3 − Methyl − 1 − Phenyl − 2 − phospholene − 1 − oxide is preferred. The amount of the catalyst used can be a catalyst amount.

The mono- or polycarbodiimide compound described above is desirably kept in a uniform dispersed state when blended with an aqueous coating material. For this purpose, it is emulsified with an appropriate emulsifier and used as an emulsion, or a polycarbodiimide compound. It is preferable to add a hydrophilic segment in the molecular structure of the compound and mix it with the paint in the form of a self-emulsified product or in the form of a self-dissolved product.

The carbodiimide compound used in the present invention includes water dispersibility and water solubility. Water solubility is preferred because it is highly compatible with other water-soluble resins and improves the transparency of the coating layer and the crosslinking reaction efficiency.

The degree of polymerization (n) of the polycarbodiimide compound is preferably 2 to 10, more preferably 3 to 7. When the degree of polymerization is small, the crosslinking reaction rate is deteriorated and the adhesion with the functional layer is lowered. When the degree of polymerization is large, the compatibility with the resin is deteriorated and haze may be increased.

In order to make a carbodiimide compound water-soluble, an isocyanate-terminated polycarbodiimide is synthesized by a condensation reaction involving decarbonization of isocyanate, and then a hydrophilic part having a functional group having reactivity with an isocyanate group is added. Can be manufactured.

Examples of hydrophilic sites include (1) quaternary ammonium salts of dialkylamino alcohols and quaternary ammonium salts of dialkylaminoalkylamines, (2) alkyl sulfonates having at least one reactive hydroxyl group, and the like (3) Examples thereof include poly (ethylene oxide) end-capped with an alkoxy group, poly (propylene oxide), a mixture of poly (ethylene oxide) and poly (propylene oxide), and the like. The repeating unit of ethylene oxide and / or propylene oxide is preferably 3 to 50, more preferably 5 to 35. When the repeating unit is small, the compatibility with the resin is deteriorated and the haze is increased. When the repeating unit is large, the adhesiveness under high temperature and high humidity may be decreased. The carbodiimide compound is (1) cationic, (2) anionic, and (3) nonionic when the above hydrophilic moiety is introduced. Especially, the nonionic property which can be compatible regardless of the ionicity of other water-soluble resin is preferable. Moreover, in order to improve heat-and-moisture resistance, the nonionic property which does not need to introduce | transduce an ionic hydrophilic group is preferable.

The carbodiimide equivalent of the carbodiimide compound used in the present invention is not particularly limited, but specifically, for example, it is preferably 1000 or less, more preferably 500 or less, and even more preferably 300 or less. is there. When the said carbodiimide equivalent exceeds an upper limit, sufficient interaction with a carboxyl group etc. contained in a base film or a functional layer is not expressed, but durability and water resistance may not be obtained satisfactorily. In addition, the said carbodiimide equivalent shall be a chemical formula amount per 1 mol of carbodiimide groups. Therefore, the smaller the carbodiimide equivalent value, the larger the amount of carbodiimide groups in the polymer, and the larger the value, the smaller the amount of carbodiimide groups in the polymer.

The carbodiimide compound is preferably contained in the coating layer in an amount of 5% by mass to 90% by mass. More preferably, it is 10% by mass or more and 70% by mass or less. When the content of the carbodiimide compound is large, the adhesion with the functional layer is lowered, and conversely, when the content is small, the adhesion under high temperature and high humidity may be lowered.

In the present invention, in order to improve the coating film strength, the coating layer may contain a crosslinking agent different from the carbodiimide compound or a resin having a crosslinking group. Examples of the crosslinking agent include urea, epoxy, melamine, isocyanate, oxazoline, silanol and the like. Moreover, in order to promote a crosslinking reaction, a catalyst etc. are used suitably as needed.

In the present invention, particles may be contained in the coating layer. Particles are (1) silica, kaolinite, talc, light calcium carbonate, heavy calcium carbonate, zeolite, alumina, barium sulfate, carbon black, zinc oxide, zinc sulfate, zinc carbonate, titanium dioxide, zirconium dioxide, tin oxide, satin White, titanium black, aluminum silicate, diatomaceous earth, calcium silicate, aluminum hydroxide, hydrous halloysite, magnesium carbonate, magnesium hydroxide, inorganic particles, (2) acrylic or methacrylic, vinyl chloride, vinyl acetate, Nylon, styrene / acrylic, styrene / butadiene, polystyrene / acrylic, polystyrene / isoprene, polystyrene / isoprene, methyl methacrylate / butyl methacrylate, melamine, polycarbonate, urea , Epoxy, urethane, phenolic, diallyl phthalate, and organic particles of a polyester or the like.

The particles preferably have an average particle diameter of 1 to 500 nm. The average particle size is not particularly limited, but is preferably 1 to 100 nm from the viewpoint of maintaining the transparency of the film.

The particles may contain two or more kinds of particles having different average particle diameters.

In addition, said average particle diameter measures the maximum diameter of the 10 or more particle | grains which exist in the cross section of a coating layer by image | photographing the cross section of a laminated film at a magnification of 120,000 times using a transmission electron microscope (TEM). And can be obtained as an average value of them. Moreover, you may obtain | require by the Coulter counter method.

The particle content is preferably 0.5% by mass or more and 20% by mass or less. When the amount is small, sufficient blocking resistance cannot be obtained. Further, scratch resistance is deteriorated. When the amount is large, not only the transparency of the coating layer is deteriorated, but also the coating strength is lowered.

The coating layer may contain a surfactant for the purpose of improving leveling properties during coating and defoaming the coating solution. The surfactant may be any of cationic, anionic and nonionic surfactants, but is preferably a silicon-based, acetylene glycol-based or fluorine-based surfactant. These surfactants are preferably contained in a range that does not impair the adhesion to the functional layer, for example, 0.005 to 0.5% by mass in the coating solution.

The easily adhesive polyester film of the present invention preferably has a haze value of 2.5% or less, more preferably 2.0% or less, and even more preferably 1.5% or less. Such an easily adhesive thermoplastic resin film can be improved in compatibility with other resins by making the carbodiimide compound contained in the coating layer described above water-soluble.

In order to impart other functionality to the coating layer, various additives may be contained within a range that does not impair the adhesion to the functional layer. Examples of the additive include fluorescent dyes, fluorescent brighteners, plasticizers, ultraviolet absorbers, pigment dispersants, foam suppressors, antifoaming agents, preservatives, and antistatic agents.

In the present invention, as a method of providing a coating layer on a thermoplastic resin film, a method of applying a coating solution containing a solvent, particles, and a resin to a polyester film and drying may be mentioned. Examples of the solvent include organic solvents such as toluene, water, or a mixed system of water and a water-soluble organic solvent. Preferably, water alone or a mixture of a water-soluble organic solvent and water is used from the viewpoint of environmental problems. preferable.

The laminated thermoplastic resin film of the present invention comprises a hard coat layer, a light diffusion layer, a prismatic lens layer, an electromagnetic wave absorption layer, a near-infrared shielding layer, and a transparent conductive layer on at least one surface of the above-mentioned thermoplastic resin film coating layer. It is obtained by at least one optical functional layer selected.

The material used for the optical functional layer is not particularly limited.

(Manufacture of easy-adhesive thermoplastic resin film)
Although the production method of the easily adhesive thermoplastic resin film of the present invention will be described by taking a polyethylene terephthalate (hereinafter abbreviated as PET) film as an example, it is naturally not limited thereto.

After sufficiently drying the PET resin in a vacuum, it is supplied to an extruder, melted and extruded at about 280 ° C. from a T-die into a rotating cooling roll into a sheet, cooled and solidified by an electrostatic application method, and unstretched PET. Get a sheet. The unstretched PET sheet may have a single layer structure or a multilayer structure by a coextrusion method. Moreover, it is preferable not to contain an inert particle substantially in PET resin.

The obtained unstretched PET sheet is stretched 2.5 to 5.0 times in the longitudinal direction with a roll heated to 80 to 120 ° C. to obtain a uniaxially stretched PET film. Further, the end of the film is gripped with a clip, led to a hot air zone heated to 70 to 140 ° C., and stretched 2.5 to 5.0 times in the width direction. Subsequently, the film is guided to a heat treatment zone of 160 to 240 ° C., and heat treatment is performed for 1 to 60 seconds to complete crystal orientation.

In any stage of the film manufacturing process, a coating solution is applied to at least one surface of the PET film to form the coating layer. There is no particular problem even if the coating layer is formed on both sides of the PET film. The solid concentration of the resin composition in the coating solution is preferably 2 to 35% by weight, particularly preferably 4 to 15% by weight.

Any known method can be used as a method for applying this coating solution to the PET film. For example, reverse roll coating method, gravure coating method, kiss coating method, die coater method, roll brush method, spray coating method, air knife coating method, wire bar coating method, pipe doctor method, impregnation coating method, curtain coating method, etc. It is done. These methods are applied alone or in combination.

In the present invention, the coating layer is formed by applying the coating solution to an unstretched or uniaxially stretched PET film, drying it, stretching it at least in a uniaxial direction, and then performing a heat treatment.

In the present invention, the thickness of the finally obtained coating layer is preferably 20 to 350 nm, and the coating amount after drying is preferably 0.02 to 0.5 g / m ² . When the coating amount of the coating layer is less than 0.02 g / m ² , the effect on adhesiveness is almost lost. On the other hand, when the coating amount exceeds 0.5 g / m ² , haze increases.

The coating layer of the easy-adhesive thermoplastic resin film obtained in the present invention has good adhesion to a hard coat layer, a light diffusion layer, a prismatic lens layer, an electromagnetic wave absorption layer, a near-infrared shielding layer, and a transparent conductive layer. Have By laminating these optical functional layers, it is possible to provide an optical laminated thermoplastic resin film that can maintain an initial function for a long period of time even in a moisture and heat resistant environment. Also, good adhesive strength can be obtained even for applications other than optical applications. Specifically, adhesion such as photographic photosensitive layer, diazo photosensitive layer, matte layer, magnetic layer, inkjet ink receiving layer, hard coat layer, UV curable resin, thermosetting resin, printing ink and UV ink, dry laminate, extrusion laminate, etc. Examples thereof include vacuum deposition, electron beam deposition, sputtering, ion plating, CVD, plasma polymerization and the like of an agent, a metal or an inorganic substance, or an oxide thereof, and an organic barrier layer.

Next, the present invention will be described in detail using examples and comparative examples, but the present invention is not limited to the following examples. The evaluation method used in the present invention is as follows.

(1) Intrinsic viscosity Based on JIS K 7367-5, a mixed solvent of phenol (60% by mass) and 1,1,2,2-tetrachloroethane (40% by mass) was used as a solvent and measured at 30 ° C.

(2) Reduced viscosity Measured at 30 ° C. using 25 mL of a mixed solvent of phenol (60 mass%) and 1,1,2,2-tetrachloroethane (40 mass%) as a solvent with respect to 0.1 g of resin.

(3) Glass transition temperature In accordance with JIS K7121, using a differential scanning calorimeter (Seiko Instruments, DSC6200), 10 mg of a resin sample was heated at a rate of 20 ° C / min over a temperature range of 25 to 300 ° C. The extrapolated glass transition start temperature obtained from the curve was defined as the glass transition temperature.

(4) Resin composition The resin was dissolved in deuterated chloroform and subjected to ¹ H-NMR analysis using a nuclear magnetic resonance analyzer (NMR) Gemini-200 manufactured by Varian, Inc. From the integration ratio, 100 moles of all isocyanate components were obtained. The mole% ratio of each composition was determined.

(5) Number average molecular weight 0.03 g of a resin was dissolved in 10 ml of tetrahydrofuran, and a GPC-LALLS apparatus low angle light scattering photometer LS-8000 (manufactured by Tosoh Corporation, tetrahydrofuran solvent, reference: polystyrene) was used. The number average molecular weight was measured using a column (showex KF-802, 804, 806 manufactured by Showa Denko KK) at a flow rate of 1 ml / min.

(6) Acid value 1 g (solid content) of a sample was dissolved in 30 ml of chloroform or dimethylformamide, and titrated with 0.1 N potassium hydroxide ethanol solution using phenolphthalein as an indicator to determine the carboxyl groups per gram of the sample. The amount (mg) of KOH required for neutralization was determined.

(7) Carbodiimide value The carbodiimide compound was freeze-dried and analyzed by ¹ H-NMR, and the carbodiimide value was calculated from the absorption peak intensity derived from the carbodiimide group and the absorption peak intensity derived from other monomers.

(8) Total light transmittance of easy-adhesive polyester film The total light transmittance of the obtained easily-adhesive polyester film was measured using a turbidimeter (Nippon Denshoku, NDH2000) in accordance with JIS K 7105. .

(9) Haze of easy-adhesive polyester film The haze of the obtained easy-adhesive polyester film was measured using a turbidimeter (Nippon Denshoku, NDH2000) in accordance with JIS K7136.

(10) Determination of carbodiimide group concentration in the coating layer The coating layer surfaces of the films obtained in Examples and Comparative Examples were measured by total reflection absorption infrared spectroscopy, and the absorbance specifically obtained from the base film was controlled. As a result, the carbodiimide group concentration in the coating layer was determined.
That is, it is measured by total reflection absorption infrared spectroscopy under the conditions shown below to obtain an infrared absorption spectrum, and the ratio of the absorbance derived from carbodiimide to the absorbance of the substrate film (ethylene glycol in the case of PET film) (infrared absorbance) The ratio _A2120 / _A1340 ) was determined. The absorbance derived from the carbodiimide group is the height of the absorption peak having an absorption maximum in the region of 2120 ± 10 cm ⁻¹ (A ₂₁₂₀ ), and the absorbance derived from PET has the absorption maximum in the region of 1340 ± 10 cm ^−1. The height of the absorption peak (A ₁₃₄₀ ) was used. The base line was a line connecting the sleeves on both sides of each maximum absorption peak.
The thickness of the coating layer was determined with a transmission electron microscope. A sample of the laminated film was embedded in a visible light curable resin (D-800 manufactured by Nippon Shin-EM Co., Ltd.) and cured by exposure to visible light at room temperature. From the obtained embedding block, an ultrathin section having a thickness of about 70 to 100 nm was prepared using an ultramicrotome equipped with a diamond knife, and stained in ruthenium tetroxide vapor for 30 minutes. Furthermore, after performing carbon vapor deposition, the cross section was observed using the transmission electron microscope (the JEOL Co., Ltd. make, TEM2010), the photograph was image | photographed, and the thickness of the coating layer was measured from this. The photographing was appropriately set in the range of 10,000 to 100,000 times.
Based on the obtained infrared absorbance ratio A ₂₁₂₀ / A ₁₃₄₀ and the thickness of the coating layer, the carbodiimide group concentration in the coating layer was determined using a calibration curve prepared from a standard sample that had been coated in advance with a coating solution with a known carbodiimide concentration and air-dried. Asked.
In preparing the calibration curve, the coating solution with a carbodiimide group concentration of 0.5, 1.4, 2.7, 4.5 mmol / g (solvent: water / isopropyl alcohol = 1/1, with acrylic resin) The mixture was adjusted so that the fixed component concentration was 30% by mass), and the coating layer after drying was applied so that the thickness of the coating layer was 50 nm, 100 nm, and 200 nm. The infrared absorbance ratio A ₂₁₂₀ / A ₁₃₄₀ was measured by external spectroscopy, and the following primary formula consisting of three variables of oxazoline group concentration, coating layer thickness, infrared absorbance ratio A ₂₁₂₀ / A ₁₃₄₀ was obtained from the obtained results. This was used as a calibration curve.
(Carbodiimide concentration) = A × (infrared absorbance ratio A ₂₁₂₀ / A ₁₃₄₀ ) / (coating layer thickness) + B
(Here, A and B are constants obtained from the data obtained by creating the calibration curve)

(Measurement condition)
Apparatus: FTS-60A / 896 manufactured by Varian
Single reflection ATR attachment: Silver Gate manufactured by SPECTRA TECH
Optical crystal: Ge
Incident angle: 45 °
Resolution: 4cm ^-1
Cumulative number: 128 times If the coating layer is thin and sufficient sensitivity cannot be obtained, use a one-time reflection attachment with a larger incident angle (65 degrees) (for example, ST Japan Instead of VeeMax), the measurement may be performed.

(11) Adhesiveness 100 square grids that reach the base film through the photocurable acrylic layer on the photocurable acrylic layer surface of the obtained laminated polyester film using a cutter guide with a gap interval of 2 mm Make a cut. Next, a cellophane adhesive tape (manufactured by Nichiban Co., Ltd., No. 405; 24 mm width) was attached to the cut surface of the grid and rubbed with an eraser for complete adhesion. Then, after performing the work of peeling the cellophane adhesive tape vertically from the photocurable acrylic layer surface of the laminated polyester film 5 times, the number of squares peeled off from the photocurable acrylic layer surface of the laminated polyester film was visually counted, From the formula, the adhesion between the photocurable acrylic layer and the substrate film was determined. In addition, what peeled partially among squares was also counted as the square which peeled, and was ranked according to the following references | standards.
Adhesiveness (%) = (1−number of peeled squares / 100) × 100
◎: 100% or photocuring acrylic layer material failure ○: 99-90%
Δ: 89-70%
×: 69 to 0%

(12) Heat-and-moisture resistance The obtained laminated polyester film was allowed to stand in an environment of 80 ° C. and 95% RH for 48 hours in a high-temperature and high-humidity tank. Next, the laminated polyester film was taken out and allowed to stand at room temperature and humidity for 12 hours. Thereafter, the adhesiveness between the photocurable acrylic layer and the substrate film is the same as the above (11) except that the cellophane adhesive tape is peeled off from the photocurable acrylic layer surface of the laminated polyester film five times. Was ranked according to the following criteria.
◎: 100% or photocuring acrylic layer material failure ○: 99-90%
Δ: 89-70%
×: 69 to 0%

(13) Interference plaque improvement (iris color)
The obtained laminated polyester film was cut into an area of 10 cm (film width direction) × 15 cm (film longitudinal direction) to prepare a sample film. A black glossy tape (manufactured by Nitto Denko, vinyl tape No. 21; black) was attached to the surface of the obtained sample film opposite to the hard coat layer. Three-wavelength daylight white (National Parrook, FL)
15EX-N 15W) was used as a light source, and was observed in a positional relationship (distance 40 to 60 cm from the light source and an angle of 15 to 45 ° with respect to the perpendicular to the film surface) where reflection was most intense visually from above.

The results of visual observation are ranked according to the following criteria. The observation is performed by five people who are familiar with the evaluation, and the highest rank is the evaluation rank. If two ranks have the same number, the center of the rank divided into three is adopted.
○: Almost no iris color is seen △: Slightly iris color is observed ×: Clear iris color is observed

(Polyester resin polymerization)
In a stainless steel autoclave equipped with a stirrer, a thermometer, and a partial reflux condenser, 194.2 parts by weight of dimethyl terephthalate, 184.5 parts by weight of dimethyl isophthalate, 14.8 parts by weight of dimethyl-5-sodium sulfoisophthalate, 233.5 parts by mass of diethylene glycol, 136.6 parts by mass of ethylene glycol, and 0.2 parts by mass of tetra-n-butyl titanate were charged, and a transesterification reaction was performed from 160 ° C. to 220 ° C. over 4 hours. Next, the temperature was raised to 255 ° C., and the pressure of the reaction system was gradually reduced, followed by reaction for 1 hour 30 minutes under a reduced pressure of 30 Pa to obtain a copolyester resin (A-1). The obtained copolyester resin (A-1) was light yellow and transparent. The reduced viscosity of the obtained copolyester resin (A-1) was measured and found to be 0.70 dl / g. The glass transition temperature by DSC was 40 ° C.

In the same manner, copolymer polyester resins (A-2) to (A-7) having different compositions were obtained. Table 1 shows the composition (mole% ratio) and other characteristics of these copolyester resins measured by ¹ H-NMR.

(Adjustment of polyester aqueous dispersion)
In a reactor equipped with a stirrer, a thermometer, and a reflux device, 30 parts by mass of polyester resin (A-1) and 15 parts by mass of ethylene glycol n-butyl ether were added and heated at 110 ° C. and stirred to dissolve the resin. After the resin was completely dissolved, 55 parts by mass of water was gradually added to the polyester solution while stirring. After the addition, the liquid was cooled to room temperature while stirring to prepare a milky white polyester aqueous dispersion (B-1) having a solid content of 30% by mass. Similarly, by using polyester resins (A-2) to (A-7) instead of polyester resin (A-1), water dispersions were prepared, and water dispersions (B-2) to (B- 7).

(Polymerization of water-soluble carbodiimide compounds)
A flask equipped with a thermometer, a nitrogen gas introduction tube, a reflux condenser, a dropping funnel, and a stirrer was mixed with 200 parts by mass of tetramethylxylylene diisocyanate and carbodiimidization catalyst 3-methyl-1-phenyl-2-phospholene-1-oxide 4 parts by mass was added and stirred at 180 ° C. for 40 hours under a nitrogen atmosphere to obtain isocyanate-terminated tetramethylxylylene carbodiimide (degree of polymerization = 5). Next, 94.5 g of the obtained carbodiimide and 40.0 g of polyethylene glycol monomethyl ether (molecular weight 220) were reacted at 100 ° C. for 24 hours. Water was gradually added thereto at 50 ° C. to obtain a yellow transparent water-soluble carbodiimide compound (C-1) having a solid content of 40% by mass. The carbodiimide equivalent was 246.

(Polymerization of water-soluble carbodiimide compounds)
In a flask equipped with a thermometer, a nitrogen gas inlet tube, a reflux condenser, a dropping funnel, and a stirrer, 200 parts by mass of isophorone diisocyanate and 4 parts by mass of 3-methyl-1-phenyl-2-phospholene-1-oxide as a carbodiimidization catalyst And stirred at 180 ° C. for 12 hours under a nitrogen atmosphere to obtain an isocyanate-terminated isophorone carbodiimide (degree of polymerization = 6). Next, 129.2 g of the obtained carbodiimide and 80 g of polyethylene glycol monomethyl ether (molecular weight 400) were reacted at 100 ° C. for 24 hours. Water was gradually added thereto at 50 ° C. to obtain a yellow transparent water-soluble carbodiimide compound (C-2) having a solid content of 40% by mass. The carbodiimide equivalent was 349.

(Polymerization of water-soluble carbodiimide compounds)
In a flask equipped with a thermometer, a nitrogen gas inlet tube, a reflux condenser, a dropping funnel, and a stirrer, 200 parts by mass of 4,4-dicyclohexylmethane diisocyanate, 3-methyl-1-phenyl-2-phospholene-1 as a carbodiimidization catalyst -4 parts by mass of oxide was added and stirred at 180 ° C for 10 hours in a nitrogen atmosphere to obtain isocyanate-terminated 4,4-dicyclohexylmethane (degree of polymerization = 4). Next, 113.6 g of the obtained carbodiimide and 80 g of polyethylene glycol monomethyl ether (molecular weight 400) were reacted at 100 ° C. for 24 hours. Water was gradually added thereto at 50 ° C. to obtain a yellow transparent water-soluble carbodiimide compound (C-3) having a solid content of 40% by mass. The carbodiimide equivalent was 484.

(Polymerization of water-dispersible carbodiimide compound)
A flask equipped with a thermometer, a nitrogen gas introduction tube, a reflux condenser, a dropping funnel, and a stirrer was mixed with 200 parts by mass of tetramethylxylylene diisocyanate and carbodiimidization catalyst 3-methyl-1-phenyl-2-phospholene-1-oxide 4 parts by mass was added and stirred at 180 ° C. for 40 hours in a nitrogen atmosphere to obtain isocyanate-terminated tetramethylxylylene carbodiimide (degree of polymerization = 10). Next, 169.7 g of the obtained carbodiimide and 80 g of polyethylene glycol monomethyl ether (molecular weight 400) were reacted at 100 ° C. for 24 hours. Water was gradually added thereto at 50 ° C. to obtain a water-dispersible carbodiimide compound (C-4) having a solid content of 40% by mass. The carbodiimide equivalent was 250.

(Polymerization of polycarbonate resin and polyoxyethylene group urethane resin)
In a reactor equipped with a thermometer, a nitrogen gas inlet tube and a stirrer, while introducing nitrogen gas, 627.1 parts by mass of hexamethylene diisocyanate and methoxypolyethylene glycol 372.9 having a number average molecular weight of 1000 heated to 50 ° C. A mass part was charged and reacted at 80 ° C. for 6 hours. After reaching a predetermined isocyanate group content, unreacted hexamethylene diisocyanate was removed with a Smith-type thin film distiller to obtain a polyoxyethylene group-containing monoisocyanate (D). The calculated number average molecular weight of this polyoxyethylene chain-containing monoisocyanate (D) was 1168 g / mol.

Next, 83.9 parts by mass of diethanolamine was charged while introducing nitrogen gas at room temperature in a reactor equipped with a thermometer, a nitrogen gas introduction tube, and a stirrer. While cooling, 916.1 parts by mass of polyoxyethylene chain-containing monoisocyanate (D) was added and reacted at 60 ° C. for 3 hours. Formation of urea bonds was confirmed by infrared spectrum, and a polyoxyethylene group-containing polyol (D) was obtained.

In a four-necked flask equipped with a reflux condenser, a nitrogen inlet tube, a thermometer, and a stirrer, 53.69 parts by mass of 1,3-cyclohexanebis (methylisocyanate) as a polyisocyanate and several as a hydrophobic macropolyol Polycarbonate diol having an average molecular weight of 2000, 88.6 parts by mass, neopentyl glycol 14.97 parts by mass, the above polyoxyethylene group-containing polyol (D) 52.87 parts by mass, an organic solvent, 60 parts by mass of acetonitrile, N -30 parts by mass of methylpyrrolidone was charged, the reaction solution temperature was adjusted to 75 to 78 ° C under a nitrogen atmosphere, 0.06 parts by mass of stannous octylate was added as a reaction catalyst, and the reaction rate was 99 in 7 hours. It was made to react to above%. Subsequently, this was cooled to 30 degreeC and the isocyanate group terminal prepolymer was obtained. Next, 450 g of water was added to a reaction vessel equipped with a homodisper capable of high-speed stirring, adjusted to 25 ° C., and mixed with stirring at 2000 min −1 while adding an isocyanate group-terminated prepolymer to disperse in water. did. Thereafter, acetonitrile and a part of water were removed under reduced pressure to prepare a water-soluble polyurethane resin (D-1) having a solid content of 35%.

(Polymerization of urethane resin containing polycarbonate polyol)
In a four-necked flask equipped with a stirrer, a Dimroth condenser, a nitrogen inlet tube, a silica gel drying tube, and a thermometer, 72.96 parts by mass of 1,3-bis (isocyanatomethyl) cyclohexane, 12.60 dimethylolpropionic acid A nitrogen atmosphere was charged with 11 parts by weight of neopentyl glycol, 112.70 parts by weight of polycarbonate diol having a number average molecular weight of 2000, 85.00 parts by weight of acetonitrile and 5.00 parts by weight of N-methylpyrrolidone as a solvent. Under stirring at 75 ° C. for 3 hours, it was confirmed that the reaction solution reached a predetermined amine equivalent. Next, after lowering the temperature of the reaction solution to 40 ° C., 9.03 parts by mass of triethylamine was added to obtain a polyurethane prepolymer D solution. Next, 450 g of water was added to a reaction vessel equipped with a homodisper capable of high-speed stirring, adjusted to 25 ° C., and mixed with stirring at 2000 min −1 while adding an isocyanate group-terminated prepolymer to disperse in water. did. Thereafter, acetonitrile and a part of water were removed under reduced pressure to prepare a water-soluble polyurethane resin (D-2) having a solid content of 35%.

In the same manner, water-soluble polyurethane resins (D-3) to (D-4) having different compositions were obtained. Table 2 shows the composition (mole% ratio) and other characteristics measured by ¹ H-NMR for these water-soluble polyurethane resins.

Example 1
(1) Adjustment of coating liquid The following coating agent was mixed and the coating liquid was created. The polyester resin has a number average molecular weight of 20000.
Water 51.78% by mass
Isopropanol 30.00% by mass
Polyester aqueous dispersion (B-1) 13.16% by mass
Water-soluble carbodiimide compound (C-1)
4.23% by mass
Particles 0.71% by mass
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
0.07% by mass of particles
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)
Surfactant 0.05% by mass
(Silicon, solid content concentration of 100% by mass)

(2) Production of easy-adhesive polyester film PET film pellets having an intrinsic viscosity of 0.62 dl / g and substantially free of particles as a film raw material polymer are dried at 135 ° C. for 6 hours under a reduced pressure of 133 Pa. did. Thereafter, the sheet was supplied to an extruder, melted and extruded into a sheet at about 280 ° C., and rapidly cooled and solidified on a rotating cooling metal roll maintained at a surface temperature of 20 ° C. to obtain an unstretched PET sheet.

The unstretched PET sheet was heated to 100 ° C. with a heated roll group and an infrared heater, and then stretched 3.5 times in the longitudinal direction with a roll group having a difference in peripheral speed to obtain a uniaxially stretched PET film.

Subsequently, after apply | coating the said coating liquid on the single side | surface of PET film by the roll coat method, it dried at 80 degreeC for 20 second. The final coating amount (after biaxial stretching) was adjusted so that the coating amount after drying was 0.15 g / m ² . Subsequently, the film was stretched 4.0 times in the width direction at 120 ° C. with a tenter, and heated at 230 ° C. for 0.5 seconds with the length in the width direction fixed, and further at 230 ° C. for 10 seconds. % Relaxation treatment in the width direction was performed to obtain an easily adhesive polyester film having a thickness of 100 μm. The evaluation results are shown in Table 3.

(3) Manufacture of laminated polyester film A coating liquid for forming a hard coat layer (C-1) having the following composition was applied to the coating layer surface of the above-mentioned easy-adhesive polyester film using a # 10 wire bar. Dry for minutes to remove the solvent. Next, the film coated with the hard coat layer was irradiated with 300 mJ / cm ² ultraviolet rays using a high-pressure mercury lamp to obtain a laminated polyester film having a hard coat layer with a thickness of 5 μm.
Hard coat layer forming coating liquid methyl ethyl ketone 39.00% by mass
Toluene 26.00% by mass
Dipentaerythritol hexaacrylate 22.83 mass%
(Shin-Nakamura Chemical A-DPH)
Polyethylene diacrylate 11.17% by mass
(Shin-Nakamura Chemical A-400)
Photopolymerization initiator 1.00% by mass
(Irgacure 184 manufactured by Ciba Specialty Chemicals)

Comparative Example 1
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to a polyester water dispersion (B-6) having a molecular weight of 8000.

Comparative Example 2
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to a polyester aqueous dispersion (B-7) having an acid value of 50 KOHmg / g.

Comparative Example 3
An easy-adhesive polyester film and a laminated polyester film were prepared in the same manner as in Example 1 except that the water-soluble carbodiimide compound (C-1) was changed to an epoxy compound (Denacol EX-521, solid content concentration: 100%, manufactured by Nagase ChemteX Corporation). Obtained.

Comparative Example 4
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 1 except that the water-soluble carbodiimide compound (C-1) was changed to a melamine compound (Becamine M-3 solid content concentration: 60%, manufactured by DIC). .

Example 2
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 1 except that the coating solution was changed to the following.
Water 51.31% by mass
Isopropanol 30.00% by mass
Polyester water dispersion (B-1) 15.04 mass%
Water-soluble carbodiimide compound (C-1) 2.82% by mass
Particles 0.71% by mass
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
0.07% by mass of particles
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)
Surfactant 0.05% by mass
(Silicon, solid content concentration of 100% by mass)

Example 3
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 1 except that the coating solution was changed to the following.
Water 53.19% by mass
Isopropanol 30.00% by mass
Polyester water dispersion (B-1) 7.52% by mass
Water-soluble carbodiimide compound (C-1) 8.46% by mass
Particles 0.71% by mass
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
0.07% by mass of particles
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)
Surfactant 0.05% by mass
(Silicon, solid content concentration of 100% by mass)

Example 4
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 1 except that the coating solution was changed to the following.
Water 53.66% by mass
Isopropanol 30.00% by mass
Polyester aqueous dispersion (B-1) 5.64% by mass
Water-soluble carbodiimide compound (C-1) 9.87% by mass
Particles 0.71% by mass
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
0.07% by mass of particles
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)
Surfactant 0.05% by mass
(Silicon, solid content concentration of 100% by mass)

Example 5
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 1 except that the water-soluble carbodiimide compound (C-1) was changed to the water-soluble carbodiimide compound (C-2).

Example 6
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 1 except that the water-soluble carbodiimide compound (C-1) was changed to the water-soluble carbodiimide compound (C-3).

Example 7
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to a polyester aqueous dispersion (B-2) having a molecular weight of 15000.

Example 8
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to a polyester aqueous dispersion (B-3) having a molecular weight of 23,000.

Example 9
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 1 except that the polyester water dispersion was changed to a polyester water dispersion (B-4) having a molecular weight of 46000.

Example 10
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 1 except that the polyester aqueous dispersion was changed to a polyester aqueous dispersion (B-5) having a molecular weight of 50000.

Example 11
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 1 except that the water-soluble carbodiimide compound (C-1) was changed to the water-dispersible carbodiimide compound (C-4).

Example 12
(1) Adjustment of coating liquid The following coating agent was mixed and the coating liquid was created.
Water 53.66% by mass
Isopropanol 30.00% by mass
Polyurethane resin (D-1) 11.28% by mass
Water-soluble carbodiimide compound (C-1) 4.23 mass%
Particles 0.71% by mass
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
0.07% by mass of particles
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)
Surfactant 0.05% by mass
(Silicon, solid content concentration of 100% by mass)

Subsequently, after apply | coating the said coating liquid on the single side | surface of PET film by the roll coat method, it dried at 80 degreeC for 20 second. The final coating amount (after biaxial stretching) was adjusted so that the coating amount after drying was 0.15 g / m ² . Subsequently, the film was stretched 4.0 times in the width direction at 120 ° C. with a tenter, and heated at 230 ° C. for 0.5 seconds with the length in the width direction fixed, and further at 230 ° C. for 10 seconds. % Relaxation treatment in the width direction was performed to obtain an easily adhesive thermoplastic resin film having a thickness of 100 μm. The evaluation results are shown in Table 4.

Comparative Example 5
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 12 except that the polyurethane resin was changed to a polyurethane resin (D-5) containing polyester polyol as a constituent component.

Comparative Example 6
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 12 except that the polyurethane resin was changed to a polyurethane resin (D-6) containing polyether polyol as a constituent component.

Comparative Example 7
An easily adhesive polyester film and a laminated polyester film were prepared in the same manner as in Example 12 except that the water-soluble carbodiimide compound (C-1) was changed to an epoxy compound (Denacol EX-521, solid content concentration 100%, manufactured by Nagase ChemteX Corporation). Obtained.

Comparative Example 8
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 12 except that the water-soluble carbodiimide compound (C-1) was changed to a melamine compound (Becamine M-3 solid content concentration: 60% by DIC). .

Example 13
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 12 except that the coating solution was changed to the following.
Water 53.46% by mass
Isopropanol 30.00% by mass
Polyurethane resin (D-1) 12.89% by mass
Water-soluble carbodiimide compound (C-1) 2.82% by mass
Particles 0.71% by mass
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
0.07% by mass of particles
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)
Surfactant 0.05% by mass
(Silicon, solid content concentration of 100% by mass)

Example 14
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 12 except that the coating solution was changed to the following.
Water 54.26% by mass
Isopropanol 30.00% by mass
Polyurethane resin (D-1) 6.45% by mass
Water-soluble carbodiimide compound (C-1) 8.46% by mass
Particles 0.71% by mass
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
0.07% by mass of particles
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)
Surfactant 0.05% by mass
(Silicon, solid content concentration of 100% by mass)

Example 15
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 12 except that the coating solution was changed to the following.
Water 54.47% by mass
Isopropanol 30.00% by mass
Polyurethane resin (D-1) 4.83% by mass
Water-soluble carbodiimide compound (C-1) 9.87% by mass
Particles 0.71% by mass
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
0.07% by mass of particles
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)
Surfactant 0.05% by mass
(Silicon, solid content concentration of 100% by mass)

Example 16
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 12 except that the water-soluble carbodiimide compound (C-1) was changed to the water-soluble carbodiimide compound (C-2).

Example 17
An easy-adhesive polyester film and a laminated polyether film were obtained in the same manner as in Example 12 except that the water-soluble carbodiimide compound (C-1) was changed to the water-soluble carbodiimide compound (C-3).

Example 18
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 12 except that the polyurethane resin (D-1) was changed to the polyurethane resin (D-2).

Example 19
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 12 except that the polyurethane resin (D-1) was changed to the polyurethane resin (D-3).

Example 20
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 12 except that the polyurethane resin (D-1) was changed to the polyurethane resin (D-4).

Example 21
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 12 except that the water-soluble carbodiimide compound (C-1) was changed to the water-dispersible carbodiimide compound (C-4).

Example 22
(1) Adjustment of coating liquid The following coating agent was mixed and the coating liquid was created.
Water 52.65% by mass
Isopropanol 30.00% by mass
Polyester resin (B-2) 7.15% by mass
Polyurethane resin (D-1) 6.95% by mass
Water-soluble carbodiimide compound (C-1) 1.35% by mass
1.35% by mass of particles
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
0.54% by mass of particles
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)

Subsequently, after apply | coating the said coating liquid on the single side | surface of PET film by the roll coat method, it dried at 80 degreeC for 20 second. The final coating amount (after biaxial stretching) was adjusted so that the coating amount after drying was 0.15 g / m ² . Subsequently, the film was stretched 4.0 times in the width direction at 120 ° C. with a tenter, and heated at 230 ° C. for 0.5 seconds with the length in the width direction fixed, and further at 230 ° C. for 10 seconds. % Relaxation treatment in the width direction was performed to obtain an easily adhesive polyester film having a thickness of 100 μm. The evaluation results are shown in Table 5.

(3) Manufacture of a laminated polyester film About 5 g of the following photocurable acrylic coating solution is placed on a 1 mm thick SUS plate (SUS304) kept clean, and the coating layer surface of the film sample and the photocurable acrylic coating solution And a pressure-sensitive acrylic coating liquid was stretched by a manually loaded rubber roller having a width of 10 cm and a diameter of 4 cm from above the film sample. Subsequently, 800 mJ / cm < ² > of ultraviolet rays were irradiated from the film surface side using the high pressure mercury lamp, and the photocurable acrylic resin was hardened. A film sample having a photocurable acrylic layer having a thickness of 20 μm was peeled from the SUS plate to obtain a laminated polyester film.
Photo-curing acrylic coating solution Photo-curing acrylic resin 60.00% by mass
(Shin Nakamura Chemical 4G)
Photo-curing acrylic resin 20.00% by mass
(Shin Nakamura Chemical A-TMMT)
Photo-curing acrylic resin 10.00% by mass
(Shin-Nakamura Chemical A-BPE-4)
Photo-curing acrylic resin 8.00% by mass
(Shin Nakamura Chemical U-6HA)
Photopolymerization initiator 2.00% by mass
(Irgacure 184 manufactured by Ciba Specialty Chemicals)

Example 23
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 22 except that the polyester water dispersion was changed to a polyester water dispersion (B-1) having a molecular weight of 20000.

Example 24
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 22 except that the polyester water dispersion was changed to a polyester water dispersion (B-3) having a molecular weight of 23000.

Example 25
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 22 except that the coating solution was changed to the following.
52.54% by mass of water
Isopropanol 30.00% by mass
Polyester resin (B-2) 7.55 mass%
Polyurethane resin (D-1) 7.34% by mass
Water-soluble carbodiimide compound (C-1) 0.68% by mass
1.35% by mass of particles
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
0.54% by mass of particles
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)

Example 26
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 22 except that the coating solution was changed to the following.
Water 52.87% by mass
Isopropanol 30.00% by mass
Polyester resin (B-2) 6.36 mass%
Polyurethane resin (D-1) 6.18% by mass
Water-soluble carbodiimide compound (C-1) 2.70% by mass
1.35% by mass of particles
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
0.54% by mass of particles
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)

Example 27
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 22 except that the coating solution was changed to the following.
Water 53.08 mass%
Isopropanol 30.00% by mass
Polyester resin (B-2) 5.56 mass%
Polyurethane resin (D-1) 5.41% by mass
Water-soluble carbodiimide compound (C-1) 4.05 mass%
1.35% by mass of particles
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
0.54% by mass of particles
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)

Example 28
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 22 except that the coating solution was changed to the following.
52.56% by mass of water
Isopropanol 30.00% by mass
Polyester resin (B-2) 10.33% by mass
Polyurethane resin (D-1) 3.86% by mass
Water-soluble carbodiimide compound (C-1) 1.35% by mass
1.35% by mass of particles
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
0.54% by mass of particles
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)

Example 29
An easy-adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 22 except that the coating solution was changed to the following.
Water 52.74% by mass
Isopropanol 30.00% by mass
Polyester resin (B-2) 3.97 mass%
Polyurethane resin (D-1) 10.04% by mass
Water-soluble carbodiimide compound (C-1) 1.35% by mass
1.35% by mass of particles
(Silica sol with an average particle size of 40 nm, solid content concentration of 40% by mass)
0.54% by mass of particles
(Silica sol with an average particle size of 450 nm, solid content concentration of 40% by mass)

Example 30
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 22 except that the water-soluble carbodiimide compound (C-1) was changed to the water-soluble carbodiimide compound (C-3).

Example 31
An easily adhesive polyester film and a laminated polyester film were obtained in the same manner as in Example 22 except that the water-soluble carbodiimide compound (C-1) was changed to the water-dispersible carbodiimide compound (C-4).

The easily adhesive polyester film of the present invention is excellent in adhesion with an optical functional layer and adhesion under high temperature and high humidity (moisture and heat resistance), so that it is mainly used for displays and the like, and a reflection using the film. It is suitable as a base film for optical functional films such as prevention films, light diffusion sheets, prismatic lens sheets, near-infrared shielding films, transparent conductive films, and antiglare films.

Claims

It is an easy-adhesive thermoplastic resin film having a coating layer on at least one side of the base film,
The coating layer is
(A) a urethane resin having a polycarbonate polyol as a constituent component and / or a polyester resin having a number average molecular weight of 15000 or more and having substantially no carboxylic acid group;
(B) containing a carbodiimide compound,
Easy-adhesive thermoplastic film.
The easily adhesive thermoplastic resin film according to claim 1, wherein the urethane resin has a polyoxyalkylene group.
The easily adhesive thermoplastic resin film of Claim 1 in which the said polyester resin contains the dicarboxylic acid component represented by following formula (1) and / or the diol component represented by following formula (2).
(1) HOOC— (CH 2 ) n —COOH (where n is an integer satisfying 4 ≦ n ≦ 10)
(2) HO— (CH 2 ) n —OH (where n is an integer satisfying 4 ≦ n ≦ 10)
The easily adhesive thermoplastic resin film according to claim 1, wherein the polyester resin contains naphthalenedicarboxylic acid as an acid component.
The easy adhesion according to claim 1, wherein the coating layer contains a urethane resin having a polycarbonate polyol as a constituent component and a carbodiimide compound as main components, and the coating layer contains a carbodiimide group of 0.5 to 3.5 mmol / g. Thermoplastic resin film.
The coating layer is composed mainly of a polyester resin having a number average molecular weight of 15000 or more and substantially having no carboxylic acid group and a carbodiimito compound, and carbodiimide groups are contained in the coating layer in an amount of 0.3 to 3.3 mmol / g. The easy-adhesive thermoplastic resin film according to claim 1.
The coating layer is mainly composed of a urethane resin containing polycarbonate polyol as a constituent component, a polyester resin having a number average molecular weight of 15000 or more and substantially having no carboxylic acid group, and a carbodiimide group in the coating layer. The easy-adhesive thermoplastic resin film according to claim 1, comprising 0.1 to 2.0 mmol / g.
The easily adhesive polyester film according to claim 1, wherein the carbodiimide compound is water-soluble and has a haze of 2.5% or less.
A hard coat layer, a light diffusion layer, a prismatic lens layer, an electromagnetic wave absorption layer, a near-infrared shielding layer, and a transparent conductive layer are applied to the coating layer of the easily adhesive thermoplastic resin film according to any one of claims 1 to 8. A laminated thermoplastic resin film obtained by laminating at least one selected functional layer.