KR20120051043A - Highly adhesive polyester film - Google Patents

Abstract

This invention makes it a subject to provide the easily-adhesive polyester film excellent in adhesiveness under high temperature, high humidity with an optical function layer.
In order to solve the said subject, the easily-adhesive polyester film of this invention has the coating layer which has a urethane resin and crosslinking agent as a main component which consists of an aliphatic polycarbonate polyol on at least one side of a polyester film, and is infrared In the measurement by a spectroscopic method, the ratio of the absorbance in the vicinity of 1460 cm <^-1> derived from an aliphatic polycarbonate component / around 1530 cm <^-1> derived from a urethane component is 0.40-1.55, It is characterized by the above-mentioned.

Description

Easily adhesive polyester film {Highly adhesive polyester film}

This invention relates to the easily adhesive polyester film excellent in adhesiveness and moisture-heat resistance. Specifically, these materials are very suitable as substrates of optical functional films such as hard coat films, antireflection films, light diffusion sheets, lens sheets, near infrared ray blocking films, transparent conductive films, and antiglare films, which are mainly used in displays and the like. It relates to an adhesive polyester film.

Generally, the transparent thermoplastic resin film which consists of a polyethylene terephthalate (PET), an acryl, a polycarbonate (PC), a triacetyl cellulose (TAC), a polyolefin etc. in the base material of the optical functional film used as a member of a liquid crystal display (LCD). Is being used.

When using the said thermoplastic resin film as a base material of various optical functional films, the functional layer according to various uses is laminated | stacked. For example, in the case of a liquid crystal display (LCD), a protective layer (hard coat layer) that prevents scratches on the surface, an antireflection layer (AR layer) that prevents external light from shining, and a prism used for collecting or diffusing light Functional layers, such as a layer and the light-diffusion layer which improves a brightness | luminance, are mentioned. Among these substrates, in particular, polyester films are widely used as substrates for various optical functional films because they are excellent in excellent transparency, dimensional stability, chemical resistance, and 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, since the surface of the film is highly crystallized, there is a disadvantage that the adhesion to various paints, adhesives, inks and the like is insufficient. For this reason, the method of providing the easily adhesive property to the biaxially-oriented polyester film surface by various methods conventionally has been proposed.

For example, by providing the coating layer which consists of various resins, such as polyester, an acryl, a polyurethane, an acrylic graft polyester, as a main structural component on the surface of the polyester film of a base material, it provides an easily adhesive property to a base film. Methods are generally known. Also in this coating method, the aqueous coating liquid containing the dispersion which disperse | distributed the solution of the said resin or resin in the dispersion medium to the polyester film before crystal orientation is completed is coated on a base film, and it extends | stretches at least uniaxially after drying. And then performing a heat treatment to complete the orientation of the polyester film (so-called in-line coating method) or after the production of the polyester film, and then applying the aqueous or solvent-based coating liquid to the film, and then drying ( The so-called offline coat method) is industrially implemented.

Displays such as LCDs and PDPs, and portable devices including hard coat films are used in various environments regardless of indoors or outdoors. In particular, in the case of a portable device, moisture and heat resistance that can withstand a bathroom, a high temperature and high humidity region, etc. may be required. In the case of the optical functional film used for such a use, the high adhesiveness which does not produce delamination even in high temperature, high humidity is calculated | required. For this reason, in the following patent document, the easily-adhesive which provided moisture-heat resistance by adding a resin with a high glass transition temperature or a crosslinking agent to a coating liquid, and forming a rigid coating layer in coating layer resin at the time of forming an application layer by the inline coat method. A sex polyester film is disclosed.

Japanese Patent Publication No. 2000-141574 Japanese Patent No. 3900191 Japanese Patent Publication No. 2007-253512

In order to reduce the global environmental load, life expectancy longer than conventional is expected in home appliances having a display. For this reason, also in the optical functional film used as a member, it was thought that it is necessary to maintain adhesiveness for a long time under high temperature, high humidity. However, although the easily-adhesive film as disclosed in the said patent document initially shows favorable adhesiveness, the fall of adhesive strength was inevitable in the long term use under high temperature, high humidity. Because of this deterioration of adhesiveness, there was a problem that initial performance was not maintained for a long time.

In addition, with the refinement of an optical design, various resin composition types from which refractive index and intensity differ as a photocurable resin which comprises an optical functional layer are used. However, although the said easily-adhesive film has high adhesiveness with respect to specific resin composition species, the highly versatile easily adhesive film which shows the same degree of adhesiveness with respect to various photocurable resins is calculated | required.

This invention provides the easily adhesive polyester film which has favorable adhesiveness with respect to various optical resin compositions, hardly causing the fall of the adhesiveness under the high temperature, high humidity, which was considered to be avoidable conventionally in view of the said subject.

In addition, the adhesiveness under the high temperature, high humidity as used in this invention means after laminating | stacking a photocurable resin layer etc., it puts it in the environment of 80 degreeC, 95% RH, and 48 hours, and uses the cutter guide of 2 mm gap space | intervals, and uses a photocurable resin layer The 100 grid-shaped cutlines that penetrate and reach the base film are drawn on the photocurable resin layer surface, and then the cellophane adhesive tape is attached to the grid-shaped cutline surface, rubbed with an eraser, and completely adhered to each other. It means the adhesiveness when tearing off five times hardly, and is adhesiveness in the criterion which is stricter than the evaluation method of JISK5600-5-6 which is generally used, and this invention is the adhesiveness which the adhesiveness under such high temperature, high humidity initially shows. It is a subject to show adhesiveness equivalent to.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve the said subject, as a polyester film which has an application layer on at least one side, it has a urethane resin and a crosslinking agent which comprise an aliphatic polycarbonate polyol as a main component, The ratio (A ₁₄₆₀ / A ₁₅₃₀ ) of the absorbance (A ₁₄₆₀ ) at around 1460 cm ^-1 derived from the aliphatic polycarbonate component and the absorbance (A ₁₅₃₀ ) at around 1530 cm ^-1 derived from the urethane component is 0.40 to 1.55. By using a layer, it discovered that adhesiveness under high temperature, high humidity improves, and reached this invention.

That is, the said subject can be achieved by the following solutions.

(1) A polyester film having a coating layer on at least one side, wherein the coating layer is composed of a urethane resin and a crosslinking agent composed of aliphatic polycarbonate polyols as constituents and an aliphatic system in the infrared spectral spectrum of the coating layer. The ratio (A ₁₄₆₀ / A ₁₅₃₀ ) of the absorbance (A ₁₄₆₀ ) around 1460 cm ^-1 derived from the polycarbonate component and the absorbance (A ₁₅₃₀ ) near 1530 cm ^-1 derived from the urethane component is 0.40 to 1.55, characterized in that Easily adhesive polyester film.

(2) The said easily-adhesive polyester film whose said crosslinking agent is 1 or more types of crosslinking agents chosen from a melamine type crosslinking agent, an isocyanate type crosslinking agent, a carbodiimide type crosslinking agent, and an oxazoline type crosslinking agent.

(3) The said easily-adhesive polyester film whose mass ratio (urethane resin / crosslinking agent) of the urethane resin and crosslinking agent which make an aliphatic polycarbonate polyol in the said application layer are 1/9-9/1.

(5) A laminated poly formed by laminating one or more optical functional layers selected from a hard coat layer, a light diffusing layer, a lens layer, an electromagnetic wave absorbing layer, a near infrared ray shielding layer and a transparent conductive layer to the coating layer of the easily adhesive polyester film. Ester film.

(6) The easily-adhesive polyester film roll obtained by winding up the said easily-adhesive polyester film for optics.

The easily adhesive polyester film of this invention is excellent in adhesiveness (heat-and-moisture resistance) under high temperature, high humidity with various optical functional layers. For this reason, as a preferable embodiment, the adhesiveness in the said high temperature and high humidity process is maintained equal to original adhesiveness.

(Polyester film)

The polyester resin which comprises a base material in this invention is polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, a polymethylene terephthalate, and a copolymerization component, For example, diethylene glycol, neo Polyester resins obtained by copolymerizing diol components such as pentyl glycol and polyalkylene glycol, and dicarboxylic acid components such as adipic acid, sebacic acid, phthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid. Can be used.

The polyester resin used very suitably in the present invention mainly contains one or more of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate and polyethylene naphthalate as constituents. Among these polyester resins, polyethylene terephthalate is most preferred in terms of balance between physical properties and cost. Moreover, these polyester films can improve chemical resistance, heat resistance, mechanical strength, etc. by biaxially stretching.

In addition, the biaxially stretched polyester film may be a single layer or a multilayer. Moreover, as long as it is in the range which shows the effect of this invention, each of these layers can be made to contain various additives in a polyester resin as needed. As an additive, antioxidant, a light resistant agent, an antigelling agent, an organic wetting agent, an antistatic agent, a ultraviolet absorber, surfactant, etc. are mentioned, for example.

Moreover, in order to improve the handling characteristics, such as activity, winding property, and blocking resistance of a film, and abrasion characteristics, such as abrasion resistance and scratch resistance, it is made to contain inert particle in the polyester film which is a base material. There is a case. However, since the film of this invention is used as a base film of an optical member, what is excellent in handling property is calculated | required, maintaining a high transparency. Specifically, when used as an optical member, the total light transmittance of the optically easy-adhesive polyester film is preferably 85% or more, more preferably 87% or more, still more preferably 88% or more, and 89% or more. Even more preferred is this, with 90% or more being particularly preferred.

In addition, it is preferable that content of the inert particle in a base film is as small as possible for a high definition. Therefore, it is a preferable embodiment to set it as the multilayer structure which contained particle only in the surface layer of a film, or to contain microparticles only in a coating layer, without particle | grains contained substantially in a film.

In particular, from the viewpoint of transparency, when the inert particles are not substantially contained in the polyester film, in order to improve the handling properties of the film, inorganic and / or heat resistant polymer particles are contained in the aqueous coating liquid, and the unevenness is formed on the surface of the coating layer. It is also preferable to form

In addition, "the inert particle does not contain substantially", for example, in the case of an inorganic particle, 50 ppm or less, Preferably it is 10 ppm, when the element derived from a particle is quantitatively analyzed by fluorescence X-ray analysis. Hereinafter, most preferably, the content falls below the detection limit. This is because, even if the particles are not actively added to the base film, the contaminant derived from foreign foreign matter, the raw material resin or the contamination adhered to the line or the device in the manufacturing process of the film may peel off and be mixed in the film. .

(Coating layer)

In the easily-adhesive polyester film of the present invention, a coating layer composed mainly of a urethane resin containing a aliphatic polycarbonate polyol and a crosslinking agent is formed, and the aliphatic polycarbonate of the coating layer is measured by infrared spectroscopy. It is important that the ratio (A ₁₄₆₀ / A ₁₅₃₀ ) of the absorbance (A ₁₄₆₀ ) around 1460 cm ^-1 derived from the component and the absorbance (A ₁₅₃₀ ) near 1530 cm ^-1 derived from the urethane component is 0.40 to 1.55. Here, a "main component" means containing 50 mass% or more, more preferably 70 mass% or more among all the solid components contained in an application layer.

As in Patent Literatures 1 to 3 above, in view of improving the moisture and heat resistance of the coating layer in the conventional technical knowledge, a resin or a crosslinked structure having a high glass transition temperature is actively introduced in forming the coating layer, and a rigid coating layer is obtained. It was thought to be desirable. However, in the present invention, by combining the polyurethane resin and the crosslinking agent and controlling the absorbance by infrared spectroscopy to a certain range, a remarkable effect of improving the adhesiveness under high temperature and high humidity heat was found and the present invention was reached. By this structure, although the mechanism of improving adhesiveness under high temperature, high humidity is not well understood, this inventor thinks as follows.

When the optical functional layer is laminated on the base film, a strong stress is generated between the optical functional layer and the coating layer due to shrinkage during curing of the photocurable resin constituting the optical functional layer and swelling during high temperature and high humidity treatment. When this laminated | multilayer film is placed under high temperature, high humidity, deterioration of a coating layer advances by dissolution, swelling, or hydrolysis by the solvent contained in photocurable resin. As a result, it was considered that the optical function layer could not be tolerated and the adhesiveness fell. For this reason, in order to maintain high adhesiveness under high temperature, high humidity, it is thought that it is preferable to provide the flexibility which can not only crosslink | strengthen firmly, impart hydrolysis resistance, but also bear the said stress. However, merely having flexibility has problems in terms of solvent resistance and strength. For this reason, it is most preferable to make these opposite characteristics compatible.

In this invention, the absorbance (A ₁₄₆₀ ) of 1460 cm <^-1> vicinity derived from the aliphatic polycarbonate component measured by infrared spectroscopy as an application layer which consists mainly of the urethane resin and crosslinking agent which make an aliphatic polycarbonate polyol a structural component. And the said characteristic are made compatible by making the ratio (A ₁₄₆₀ / A ₁₅₃₀ ) of the absorbance (A ₁₅₃₀ ) of 1530 cm <^-1> derived from a urethane component into 0.40-1.55. That is, while providing solvent resistance with a crosslinking agent, the aliphatic polycarbonate component which has hydrolysis resistance and flexibility, and the urethane component which shows rigidity coexist at a predetermined ratio, and aims at the compatibility of the said characteristic. As a result, the stress due to the shrinkage during curing of the photocurable resin and the swelling during the high temperature and high humidity treatment can be alleviated, so that good adhesion can be obtained with various photocurable resins and the like, even in an environment of subsequent high temperature and high humidity. It is thought that deterioration of the coating layer such as dissolution, swelling or hydrolysis by the solvent or the diluent monomer remaining in the coating layer can be prevented.

Here, the absorbance (A ₁₄₆₀ ) of 1460 cm <^-1> originates in the variable oscillation peculiar to CH bond of the methylene group contained in an aliphatic polycarbonate component. Therefore, the magnitude of the absorbance (A ₁₄₆₀ ) around 1460 cm ⁻¹ depends on the amount of aliphatic polycarbonate polyol component constituting the urethane resin present in the coating layer. On the other hand, the absorbance (A ₁₅₃₀ ) of 1530 cm <^-1> originates in the variable oscillation peculiar to NH bond contained in a urethane component. Therefore, the magnitude of the absorbance A ₁₅₃₀ around 1530 cm ⁻¹ depends on the amount of urethane component (the number of urethane bonds) constituting the urethane resin present in the coating layer. In addition, when using an isocyanate-based crosslinking agent as the crosslinking agent, the size of the absorbance (A ₁₅₃₀ ) around 1530 cm ⁻¹ depends on the amount of urethane component (the number of urethane bonds) as the sum of the amount of the urethane resin and the crosslinking agent present in the coating layer. For this reason, these absorbance ratios (A ₁₄₆₀ / A ₁₅₃₀ ) indicate that both components having different characteristics coexist in a specific ratio. In the present invention, the ratio A ₁₄₆₀ / A ₁₅₃₀ is 0.40 to 1.55, and the lower limit of the ratio A ₁₄₆₀ / A ₁₅₃₀ is preferably 0.45, and more preferably 0.50. The upper limit of the ratio (A ₁₄₆₀ / A ₁₅₃₀ ) is preferably 1.50, more preferably 1.40, still more preferably 1.30, still more preferably 1.20. When the ratio (A ₁₄₆₀ / A ₁₅₃₀ ) is less than 0.40, the rigid urethane component is too large, and the stress relaxation of the coating layer is lowered, so that the heat and humidity resistance is lowered. Moreover, when the said ratio (A ₁₄₆₀ / A ₁₅₃₀ ) exceeds 1.55, the aliphatic component of a flexible aliphatic polycarbonate becomes too large, and the solvent resistance of a coating layer falls, and moisture heat resistance falls.

This invention can improve adhesiveness (heat-and-moisture resistance) under high temperature, high humidity with a lens layer and another optical function layer by the said aspect. In addition, the structure of this invention is described in detail below.

(Urethane resin)

The urethane resin of this invention contains a polyol component and a polyisocyanate component at least as a structural component, and also contains a chain extender as needed. The urethane resin of this invention is a high molecular compound in which these structural components were copolymerized mainly by the urethane bond. In this invention, it has an aliphatic polycarbonate polyol as a structural component of a urethane resin, It is characterized by the above-mentioned. Moist heat resistance can be improved by containing the urethane resin which uses an aliphatic polycarbonate as a structural component in the coating layer of this invention. In addition, the component of these urethane resin can be specified by nuclear magnetic resonance analysis.

It is necessary to contain the aliphatic polycarbonate polyol excellent in heat resistance and hydrolysis resistance in the diol component which is a structural component of the urethane resin of this invention. In the optical use of this invention, it is preferable to use an aliphatic polycarbonate polyol also from the yellowing prevention side.

Examples of the aliphatic polycarbonate polyols include aliphatic polycarbonate diols and aliphatic polycarbonate triols. Aliphatic polycarbonate diols can be preferably used. As aliphatic polycarbonate diol which is a structural component of the urethane resin of this invention, ethylene glycol, propylene glycol, 1, 3- propanediol, 1, 4- butanediol, 1, 5- pentanediol, 3-methyl- 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 1,8-nonanediol, neopentylglycol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanediol, 1, Aliphatic polycarbonate diol etc. which are obtained by making 1 type (s) or 2 or more types of diols, such as 4-cyclohexane dimethanol, and carbonates, such as dimethyl carbonate, a diphenyl carbonate, ethylene carbonate, and phosgene, react, etc. are mentioned, for example. Can be. As the number average molecular weight of aliphatic polycarbonate diol, Preferably it is 1500-4000, More preferably, it is 2000-3000. When the number average molecular weight of aliphatic polycarbonate diol is small, the ratio of the aliphatic polycarbonate component which comprises a urethane resin relatively becomes small. For this reason, in order to make the said ratio (A ₁₄₆₀ / A ₁₅₃₀ ) into the range mentioned above, it is preferable to control the number average molecular weight of aliphatic polycarbonate diol in the said range. When the number average molecular weight of the aliphatic polycarbonate diol is large, the absorbance (A ₁₄₆₀ ) around 1460 cm ⁻¹ derived from the aliphatic polycarbonate component is increased, and the aliphatic component is increased. It may fall. When the number average molecular weight of aliphatic polycarbonate diol is small, a rigid urethane component will increase, and the stress by shrinkage and swelling of a photocurable resin etc. cannot be alleviated, and adhesiveness may fall.

As polyisocyanate which is a structural component of the urethane resin of this invention, aromatic aliphatic diisocyanates, such as xylylene diisocyanate, isophorone diisocyanate, 4, 4- dicyclohexyl methane diisocyanate, 1, 3-bis Alicyclic diisocyanates such as (isocyanate methyl) cyclohexane, hexamethylene diisocyanate, and aliphatic diisocyanates such as 2,2,4-trimethylhexamethylene diisocyanate, or these compounds in a single or plural form, such as trimethylolpropane; The polyisocyanate added previously is mentioned. When aromatic isocyanate is used, there exists a problem of yellowing, and it is not preferable as the optical use for which high transparency is calculated | required. Moreover, since it becomes a rigid coating film compared with an aliphatic system, the stress by shrinkage | shrinkage and swelling of a photocurable resin etc. cannot be alleviated, and adhesiveness may fall.

The said ratio A ₁₄₆₀ / A ₁₅₃₀ can also be adjusted with a chain extender. Examples of the chain extender that can be used in the present invention include glycols such as ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, and 1,6-hexanediol, glycerin, trimethylolpropane, pentaerythritol, and the like. Polyhydric alcohols, diamines such as ethylenediamine, hexamethylenediamine and piperazine, amino alcohols such as monoethanolamine and diethanolamine, thiodiglycols such as thiodiethylene glycol, and water. However, when the chain extender with a short main chain is used, the absorbance (A ₁₅₃₀ ) of 1530 cm <^-1> vicinity derived from a urethane component may increase, and the softness of an application layer may fall. Therefore, as the chain extender, one having a long main chain is preferable. Moreover, in the point which gives the softness of an application layer, the chain extender of diol and diamine of aliphatic type and length of 4-10 carbon atoms of a main chain is preferable. From these viewpoints, 1,4-butanediol, 1,6-hexanediol, hexamethylenediamine, etc. are very suitable as a chain extender used for this invention.

The coating layer of the present invention is preferably formed by an in-line coating method described below using an aqueous coating liquid. For this reason, it is preferable that the urethane resin of this invention is water-soluble. In addition, said "water-soluble" means melt | dissolving with respect to the aqueous solution containing water or less than 50 mass% of water-soluble organic solvents.

In order to provide water solubility to a urethane resin, a sulfonic acid (salt) group or a carboxylic acid (salt) group can be introduce | transduced (copolymerized) in a urethane molecular skeleton. Since the sulfonic acid (salt) group is strongly acidic and it may be difficult to maintain moisture resistance due to its moisture absorption performance, it is very suitable to introduce a weakly acidic carboxylic acid (salt) group. It is also possible to introduce nonionic groups such as polyoxyalkylene groups.

In order to introduce a carboxylic acid (salt) group into the urethane resin, for example, a polyol compound having a carboxylic acid group such as dimethylolpropionic acid, dimethylolbutanoic acid as a polyol component is introduced as a copolymerization component, and a salt forming agent is used. Neutralize. Specific examples of the salt forming agent include trialkylamines such as ammonia, trimethylamine, triethylamine, triisopropylamine, tri-n-propylamine, and tri-n-butylamine, N-methylmorpholine, and N-ethylmorph N-dialkyl alkanolamines, such as N-alkyl morpholines, such as Pauline, N-dimethylethanolamine, and N-diethylethanolamine. These can be used independently and can also be used together 2 or more types.

When using the polyol compound which has a carboxylic acid (salt) group as a copolymerization component in order to provide water solubility, the composition molar ratio of the polyol compound which has a carboxylic acid (salt) group in a urethane resin is the total polyisocyanate component of a urethane resin. When making it 100 mol%, it is preferable that it is 3-60 mol%, and it is preferable that it is 5-40 mol%. When the said composition molar ratio is less than 3 mol%, water dispersibility may become difficult. In addition, when the said composition molar ratio exceeds 60 mol%, since water resistance falls, the moist heat resistance may fall.

The glass transition point temperature of the urethane resin of the present invention is preferably less than 0 ° C, more preferably less than -5 ° C. When glass transition point temperature is less than 0 degreeC, since it is easy to show the suitable flexibility from the viewpoint of the stress relaxation of an application layer, it is preferable.

It is preferable that the said urethane resin contains 10 mass% or more and 90 mass% or less with respect to a crosslinking agent. Especially when high adhesiveness is requested | required like a lens layer, More preferably, they are 20 mass% or more and 80 mass% or less. When there is much content of a urethane resin, adhesiveness under high temperature, high humidity falls, On the contrary, when there is little content, adhesiveness in an initial stage falls.

In order to improve solvent resistance, the urethane resin of this invention may introduce a self-crosslinking group into urethane resin itself in addition to addition of a crosslinking agent. Thereby, the crosslinking degree of resin increases and solvent resistance improves. Although it does not specifically limit as a magnetic crosslinking group used for this invention, The silanol group of comparatively stable can be used suitably also in an aqueous coating liquid.

In the case of resins other than the urethane resin of this invention, you may contain in order to improve adhesiveness. For example, a urethane resin, an acrylic resin, a polyester resin etc. which have polyester as a structural component is mentioned.

(Bridge)

In this invention, it is necessary to contain a crosslinking agent in an application layer. By containing a crosslinking agent, it becomes possible to further improve adhesiveness under high temperature, high humidity. As a crosslinking agent, it is preferable to react with a carboxylic acid group, a hydroxyl group, an amino group, etc., and to form an amide bond, a urethane bond, and a urea bond because it is hard to deteriorate by high temperature, high humidity treatment. On the contrary, when it carries ester bond and ether bond, it may have hydrolyzability and is not preferable. As a crosslinking agent used suitably in this invention, a melamine type, an isocyanate type, a carbodiimide type, an oxazoline type, etc. are mentioned. Among these, an isocyanate type and a carbodiimide type are preferable from the stability of a coating solution with time, and the adhesive improvement effect under high temperature, high humidity treatment. Moreover, it is especially preferable to use an isocyanate type crosslinking agent from a viewpoint of showing suitable softness to a coating layer and giving the stress relaxation effect of a coating layer very suitably. In addition, in order to accelerate the crosslinking reaction, a catalyst or the like is suitably used as necessary.

As content of a crosslinking agent, 10 mass% or more and 90 mass% or less are preferable with respect to a urethane resin. More preferably, they are 20 mass% or more and 80 mass% or less. When there is little, the solvent resistance of a coating layer falls, adhesiveness under high temperature, high humidity falls, and in many cases, the flexibility of coating layer resin falls, and adhesiveness under normal temperature and high temperature high humidity falls.

In the present invention, two kinds of crosslinking agents may be mixed in order to improve the coating film strength. In addition, in order to accelerate the crosslinking reaction, a catalyst or the like is suitably used as necessary.

(additive)

In this invention, it is also possible to contain particle | grains in an application layer. The particles are (1) silica, kaolinite, talc, hard calcium carbonate, heavy calcium carbonate, zeolite, alumina, barium sulfate, carbon black, zinc oxide, zinc sulfate, zinc carbonate, titanium dioxide, satin white, aluminum silicate, diatomaceous earth, silicic acid Inorganic particles such as calcium, aluminum hydroxide, hydrolyzate, magnesium carbonate and magnesium hydroxide, (2) acrylic or methacryl, vinyl chloride, vinyl acetate, nylon, styrene / acrylic, styrene / butadiene, polystyrene / acrylic, Organic such as polystyrene / isoprene-based, polystyrene / isoprene-based, methyl methacrylate / butyl methacrylate-based, melamine-based, polycarbonate-based, urea-based, epoxy-based, urethane-based, phenol-based, diallyl phthalate-based and polyester-based And particles.

As for the said particle | grain, it is very suitable that the average particle diameter is 1-500 nm. The average particle diameter is not particularly limited, but is preferably 1 to 100 nm from the viewpoint of maintaining the transparency of the film.

The said particle | grain may contain two or more types of particle | grains from which an average particle diameter differs.

In addition, the said average particle diameter photographs the cross section of a laminated | multilayer film at 120,000 times magnification using a transmission electron microscope (TEM), measures the maximum diameter of ten or more particle | grains which exist in the cross section of an application layer, and averages these values It can be obtained as

As content of particle | grains, 0.5 mass% or more and 20 mass% or less are preferable. In a small case, sufficient blocking resistance cannot be obtained. In addition, scratch resistance deteriorates. In many cases, not only the transparency of a coating layer worsens, but coating film strength falls.

It is also possible to make a coating layer contain surfactant for the purpose of the improvement of the leveling property at the time of coating, and the defoaming of a coating liquid. The surfactant may be any one of cationic, anionic and nonionic, but a silicone, acetylene glycol or fluorine-based surfactant is preferable. It is also preferable to contain these surfactant in the range which does not impair adhesiveness with an optical function layer, for example in 0.005 to 0.5 mass% in a coating liquid.

It is preferable that haze value is 2.5% or less of the easily adhesive polyester film of this invention, More preferably, it is 2.0% or less, More preferably, it is 1.5% or less. In addition, in order to obtain high transparency, it is preferable to make the average particle diameter of the said urethane resin small. Thereby, dispersibility and compatibility of resin improve and high transparency is obtained. From the viewpoint of transparency, the average particle diameter of the urethane resin used for the coating layer is preferably 150 nm or less, and more preferably 100 nm or less.

In order to provide another functionality to an application layer, you may contain various additives in the range which does not impair the adhesiveness with a sealing material. Examples of the additives include fluorescent dyes, fluorescent brighteners, plasticizers, ultraviolet absorbers, pigment dispersants, suppressors, antifoaming agents, preservatives, antistatic agents and the like.

In this invention, the method of apply | coating and drying the coating liquid containing a solvent, particle | grain, and resin to a polyester film as a method of providing a coating layer on a polyester film is mentioned. Examples of the solvent include an organic solvent such as toluene, water, or a mixed system of water and a water-soluble organic solvent. Preferably, a water-soluble organic solvent is mixed with water alone or water from the viewpoint of environmental problems.

(Manufacture of easily adhesive polyester film)

Although the polyethylene terephthalate (it abbreviates as PET) film is demonstrated to an example about the manufacturing method of the easily adhesive polyester film of this invention, it is not limited to this naturally.

After sufficiently drying the PET resin in vacuum, the extruder is supplied to an extruder, and the melted PET resin at about 280 ° C. is melt-extruded in a sheet form on a rotary cooling roll from a T die, and cooled and solidified by electrostatic application to obtain an unstretched PET sheet. A single layer structure may be sufficient as the said unstretched PET sheet, and the multilayer structure by a coextrusion method may be sufficient as it. Moreover, it is preferable not to contain inert particle substantially in PET resin.

The obtained unstretched PET sheet is stretched at 2.5 to 5.0 times in the longitudinal direction with a roll heated at 80 to 120 ° C to obtain a uniaxially stretched PET film. Moreover, the edge part of a film is gripped with a clip, it guides to the hot air zone heated at 70-140 degreeC, and it extends | stretches 2.5-5.0 times in the width direction. Subsequently, it is led to a heat treatment zone of 160 to 240 ° C, heat treatment is performed for 1 to 60 seconds, and crystal orientation is completed.

In any step of this film manufacturing process, a coating liquid is applied to at least one side of the PET film to form the coating layer. Even if it forms in an application layer on both surfaces of a PET film, there is no problem in particular. It is preferable that solid content concentration of the resin composition in a coating liquid is 2 to 35 weight%, Especially preferably, it is 4 to 15 weight%.

The method for apply | coating this coating liquid to PET film can use a well-known arbitrary method. 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. can be mentioned. These methods are coated alone or in combination.

In this invention, after apply | coating and drying the said coating liquid to the PET film after unstretched or uniaxial stretching, it is extended | stretched in at least one axial direction, and is formed by performing heat processing subsequently.

In this invention, it is preferable that the thickness of the coating layer finally obtained is 20-350 nm, and the application amount after drying is 0.02-0.5 g / m <2>. If the coating amount of the coating layer is less than 0.02 g / m 2, the effect on adhesion is almost eliminated, while if the coating amount is more than 0.5 g / m 2, the haze increases.

The easily adhesive polyester film roll obtained by winding up the easily adhesive polyester film of this invention is also a very suitable aspect of this invention. Since the blocking resistance is favorable by addition of a crosslinking agent, the coating layer of this invention can be used suitably also when it is set as a roll body for productivity improvement.

Although the thickness of the easily adhesive polyester film of this invention is not specifically limited, It can determine arbitrarily according to the specification of the use to be used in the range of 25-500 micrometers. 400 micrometers is preferable and, as for the upper limit of the thickness of an easily adhesive polyester film, 350 micrometers is especially preferable. On the other hand, as for the minimum of film thickness, 50 micrometers is preferable, Especially preferably, it is 75 micrometers. If the film thickness is less than 25 µm, the mechanical strength is likely to be insufficient. On the other hand, when a film thickness exceeds 500 micrometers, it will become difficult to wind up in roll shape.

When using the easily adhesive polyester film of this invention as a roll, the roll length and width are suitably determined according to the use of the said film roll. 1500 m or more is preferable and, as for the length of a film roll, 1800 m or more is more preferable. Moreover, as an upper limit of roll length, 5000 m is preferable. Moreover, it is preferable that the width of a film roll is 500 mm or more, More preferably, it is 800 mm. Moreover, as an upper limit of the width of a film roll, 2000 mm is preferable.

(Laminated Film for Optics)

The optical laminated polyester film of this invention is one or more layers chosen from the hard coat layer, the light-diffusion layer, the lens layer, the electromagnetic wave absorption layer, the near-infrared cut off layer, and the transparent conductive layer on at least one surface of the application layer of the polyester film mentioned above. It is obtained by laminating an optical function layer. In addition, the shape of the lens layer is not particularly limited, and for example, a prism-shaped lens, a Fresnel-shaped lens, a micro lens, and the like can be suitably applied.

The material used for the said optical function layer is not specifically limited, The resin compound which superposes | polymerizes and / or reacts by irradiating any one of drying, a heat | fever, a chemical reaction, or an electron beam, radiation, and an ultraviolet-ray can be used. Examples of such curable resins include melamine-based, acrylic-based, silicone-based, and polyvinyl alcohol-based curable resins. Photocurable acrylic curable resins are preferred from the viewpoint of obtaining high surface hardness or optical design. As such acryl-type curable resin, a polyfunctional (meth) acrylate type monomer and an acrylate oligomer can be used, As an example of an acrylate oligomer, it is a polyester acrylate type, an epoxy acrylate type, a urethane acrylate type, a polyether Acrylate type, polybutadiene acrylate type, silicone acrylate type and the like. By mixing a reaction diluent, a photoinitiator, a sensitizer, etc. with these acrylic curable resins, the coating composition for forming the said optical function layer can be obtained.

Further, in the polyester film of the present invention, good adhesive strength can be obtained in addition to the above-described optical use. Specifically, an adhesive such as a photosensitive layer, a diazo photosensitive layer, a mat layer, a magnetic layer, an inkjet ink receiving layer, a hard coat layer, an ultraviolet curable resin, a thermosetting resin, a printing ink or a UV ink, a dry laminate or an extrusion laminate, a metal or The thin film layer obtained by vacuum deposition of an inorganic substance or these oxides, electron beam deposition, sputtering, ion plating, CVD, plasma polymerization, etc., an organic barrier layer, etc. are mentioned.

Example

Next, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited to a following example naturally. In addition, the evaluation method used by this invention is as follows.

(1) intrinsic viscosity

According to JIS K 7367-5, it measured at 30 degreeC using the mixed solvent of phenol (60 mass%) and 1,1,2,2- tetrachloroethane (40 mass%) as a solvent.

(2) glass transition point temperature

In accordance with JIS K7121, the glass transition start temperature was calculated | required from a DSC curve using a differential scanning calorimeter (Seiko Instruments Co., Ltd. make, DSC6200).

(3) absorbance measurement by infrared spectroscopy

About the obtained easily-adhesive polyester film, the coating layer was carved and the sample of about 1 mg was collected. A pressure was applied to the collected sample to prepare an application layer sample piece (size: about 50 μm × about 50 μm) formed into a film shape having a thickness of about 1 μm. Moreover, the sample piece (blank sample piece) was produced similarly to the said procedure about the PET resin of the same quality as a base film as a blank sample.

The produced sample piece was put on the KBr plate, and the infrared absorption spectrum was measured by the microscopic permeation method of the following conditions. The infrared spectral spectrum of the coating layer was obtained as a difference spectrum between the infrared spectral spectrum obtained from the coating layer sample piece and the spectrum of the blank sample piece.

Absorbance in the vicinity of 1460 ㎝ ^-1-derived aliphatic polycarbonate component (A ₁₄₆₀₎ is in the vicinity of the region of 1460 ± 10㎝ ^-1 to the value of the absorption peak heights and having a peak absorption, 1530 ㎝ derived urethane component ^-1 The absorbance (A ₁₅₃₀ ) was taken as the value of the absorption peak height which has an absorption maximum in the area | region of 1530 +/- 10 cm <^-1> . In addition, the base line was made into the line which connects the base of both sides of the peak of each maximum absorption. From the obtained absorbance, the absorbance ratio was calculated | required by the following formula.

Absorbance Ratio = A ₁₄₆₀ / A ₁₅₃₀

(Measuring conditions)

Device: FT-IR Analyzer SPECTRA

TECH Co., Ltd. IRμs / SIRM

Detector: MCT

Resolution: 4 cm ^-1

Total count: 128 times

(4) Total light transmittance of the easily adhesive polyester film

The total light transmittance of the obtained easily-adhesive polyester film was measured using the turbidimeter (Nippon Denshoku make, NDH2000) based on JISK7105.

(5) Haze of easily adhesive polyester film

The haze of the obtained easily-adhesive polyester film was measured using the turbidimeter (Nippon Denshoku make, NDH2000) based on JISK7136.

(6) adhesive

Penetrate the hard coat layer using a cutter guide with a gap of 2 mm between the photocurable hard coat layer or the photocurable acrylic layer or the photocurable urethane / acrylic layer surface (hereinafter optical functional layer) of the obtained optically laminated polyester film. To cut 100 grid-shaped cut lines reaching the base film. Subsequently, a cellophane adhesive tape (Nichiban Co., Ltd. No. 405; 24 mm width) was affixed on the grid-shaped cut line surface, and it rubbed with an eraser and was made to adhere completely. Thereafter, after performing the operation of peeling the cellophane adhesive tape from the optically functional layer surface of the optically laminated polyester film vertically five times, the number of grids peeled from the optically functional layer surface of the optically laminated polyester film is visually counted, The adhesiveness of an optical function layer and a base film was calculated | required from the following formula. In addition, the part which peeled partially in the grid was also counted as the peeled grid, and the rank was divided according to the following reference | standard.

Adhesion (%) = (1-number of stripped grids / 100) × 100

(Double-circle): 100% or re-wave of an optical function layer

○: 99-90%

△: 89-70%

×: 69 ~ 0%

(7) heat and moisture resistance

The obtained laminated polyester film for optics was left to stand in 80 degreeC and 95 RH% of environment for 48 hours in high temperature, high humidity bath. Next, the optically laminated polyester film was taken out and left to stand at room temperature normal humidity for 12 hours. Then, the adhesiveness of an optical function layer and a base film was calculated | required in the same way as said (6), and rank division was performed based on the following reference | standard.

◎: 100% or re-wave of optical function layer

○: 99-90%

△: 89-70%

×: 69 ~ 0%

(Polymerization of Urethane Resin A-1 Using Aliphatic Polycarbonate Polyol as a Component)

In a four-necked flask equipped with a stirrer, a dimross cooler, a nitrogen introduction tube, a silica gel drying tube, and a thermometer, 43.75 parts by mass of 4,4-diphenylmethane diisocyanate, 12.85 parts by mass of dimethylolbutanoic acid, and a polyamide having a number average molecular weight of 2000 153.41 parts by mass of hexamethylene carbonate diol, 0.03 parts by mass of dibutyltin dilaurate, and 84.00 parts by mass of acetone as a solvent were added, and the mixture was stirred for 3 hours at 75 ° C. under a nitrogen atmosphere to reach a predetermined amine equivalent. It confirmed that it did. Next, after cooling this reaction liquid to 40 degreeC, 8.77 mass parts of triethylamines were added and the polyurethane prepolymer solution was obtained. Next, 450 g of water was added to the reaction vessel equipped with a homodisper capable of high speed stirring, adjusted to 25 ° C., and stirred and mixed at 2000 min ⁻¹ to add and disperse the polyurethane prepolymer solution. Then, the polyurethane resin (A-1) of 35% of solid content was prepared by removing a part of acetone and water under reduced pressure. The glass transition point temperature of the obtained polyurethane resin (A-1) was -30 degreeC.

(Polymerization of Urethane Resin A-2 with Aliphatic Polycarbonate Polyol as a Component)

In a four-necked flask equipped with a stirrer, a dimross cooler, a nitrogen introduction tube, a silica gel drying tube, and a thermometer, 29.14 parts by mass of 4,4-diphenylmethane diisocyanate, 7.57 parts by mass of dimethylolbutanoic acid, and a poly of number average molecular weight 3000 173.29 parts by mass of hexamethylene carbonate diol, 0.03 parts by mass of dibutyltin dilaurate, and 84.00 parts by mass of acetone as a solvent were added, and the mixture was stirred at 75 ° C for 3 hours under a nitrogen atmosphere to reach a predetermined amine equivalent. It confirmed that it did. Next, after cooling this reaction liquid to 40 degreeC, 5.17 mass parts of triethylamines were added and the polyurethane prepolymer solution was obtained. Next, 450 g of water was added to the reaction vessel equipped with a homodisper capable of high speed stirring, adjusted to 25 ° C., and stirred and mixed at 2000 min ⁻¹ to add and disperse the polyurethane prepolymer solution. Thereafter, a part of acetone and water was removed under reduced pressure to prepare a water-soluble polyurethane resin (A-2) having a solid content of 35%.

(Polymerization of Urethane Resin A-3 Having Aliphatic Polycarbonate Polyol as a Component)

In a four-necked flask equipped with a stirrer, a dimross cooler, a nitrogen introduction tube, a silica gel drying tube, and a thermometer, 43.75 parts by mass of 4,4-diphenylmethane diisocyanate, 11.12 parts by mass of dimethylolbutanoic acid, 1.97 parts by mass of hexanediol, 143.40 parts by mass of polyhexamethylene carbonate diol having a number average molecular weight of 2000, 0.03 parts by mass of dibutyltin dilaurate, and 84.00 parts by mass of acetone as a solvent were added and stirred at 75 ° C. under a nitrogen atmosphere for 3 hours. It was confirmed that a predetermined amine equivalent was reached. Next, after cooling this reaction liquid to 40 degreeC, 8.77 mass parts of triethylamines were added and the polyurethane prepolymer solution was obtained. Next, 450 g of water was added to the reaction vessel equipped with a homodisper capable of high speed stirring, adjusted to 25 ° C., and stirred and mixed at 2000 min ⁻¹ to add and disperse the polyurethane prepolymer solution. Thereafter, a part of acetone and water was removed under reduced pressure to prepare a water-soluble polyurethane resin (A-3) having a solid content of 35%.

(Polymerization of silanol group-containing urethane resin A-4 having aliphatic polycarbonate polyol as a component)

In a four-necked flask equipped with a stirrer, a dimross cooler, a nitrogen introduction tube, a silica gel drying tube, and a thermometer, 38.41 parts by mass of isophorone diisocyanate, 6.95 parts by mass of dimethylolpropanoic acid, and a polyhexamethylenecarbonate diol having a number average molecular weight of 2000 158.99 parts by mass, dibutyltin dilaurate 0.03 parts by mass, and 84.00 parts by mass of acetone as a solvent were added thereto, and the mixture was stirred at 75 ° C for 3 hours under a nitrogen atmosphere to confirm that the reaction solution reached a predetermined amine equivalent. . Next, after cooling this reaction liquid to 40 degreeC, 4.37 mass parts of triethylamines were added and the polyurethane prepolymer solution was obtained. Next, 3.84 parts by mass of γ- (aminoethyl) aminopropyltriethoxysilane, 1.80 parts by mass of 2-[(2-aminoethyl) amino] ethanol, and 450 g of water were added, and a polyurethane prepolymer solution was added dropwise to disperse the water. It was. Thereafter, a part of acetone and water was removed under reduced pressure to prepare a water-soluble silanol group-containing polyurethane resin (A-4) having a solid content of 30%.

(Polymerization of Urethane Resin A-5 with Aliphatic Polycarbonate Polyol as a Component)

A water-soluble polyurethane resin (A) having a solid content of 35% by the same method, except that the polyhexamethylene carbonate diol having a number average molecular weight of 2000 of the water-soluble polyurethane resin (A-1) was changed to a polyhexamethylene carbonate diol having a number average molecular weight of 1000 (A-1). -5) was obtained.

(Polymerization of Urethane Resin A-6 with Aliphatic Polycarbonate Polyol as a Component)

Water-soluble polyurethane resin (A) of 35% of solid content by the same method except having changed the polyhexamethylene carbonate diol of the number average molecular weight 2000 of the water-soluble polyurethane resin (A-1) into the polyhexamethylene carbonate diol of the number average molecular weight 5000. -6) was obtained.

(Polymerization of Urethane Resin A-7 Containing Polyester Polyol)

Water-soluble polyurethane resin (A-7) of 35% of solid content by the same method except the polyhexamethylene carbonate diol of the number average molecular weight 2000 of water-soluble polyurethane resin (A-1) was changed to the polyester diol of the number average molecular weight 2000. )

(Polymerization of Urethane Resin A-8 with Polyether Polyol as a Component)

Water-soluble polyurethane resin (A-8) of 35% of solid content by the same method except the polyhexamethylene carbonate diol of the number average molecular weight 2000 of water-soluble polyurethane resin (A-1) was changed to the polyetherdiol of the number average molecular weight 2000. )

(Polymerization of Block Polyisocyanate Crosslinking Agent)

100 parts by mass of a polyisocyanate compound (Asahi Kasei Chemicals, Duranate TPA) having an isocyanurate structure using hexamethylene diisocyanate as a raw material in a flask equipped with a stirrer, a thermometer and a reflux condenser, propylene glycol monomethyl ether 55 parts by mass of acetate and 30 parts by mass of polyethylene glycol monomethyl ether (average molecular weight 750) were added, and the mixture was maintained at 70 ° C. for 4 hours under a nitrogen atmosphere. Thereafter, the reaction solution temperature was lowered to 50 ° C, and 47 parts by mass of methyl ethyl ketooxime was added dropwise. The infrared spectrum of the reaction solution was measured to confirm that absorption of the isocyanate group was lost, thereby obtaining a blocked polyisocyanate aqueous dispersion (B) having a solid content of 75% by mass.

(Polymerization of oxazoline-based crosslinking agent)

In a flask equipped with a thermometer, a nitrogen gas introduction tube, a reflux cooler, a dropping funnel, and a stirrer, a mixture of 58 parts by mass of ion-exchanged water as an aqueous medium and 58 parts by mass of isopropanol, and a polymerization initiator (2,2'-azobis (2- 4 parts by mass of amidinopropane) -dihydrochloride) was added. On the other hand, 16 mass parts of 2-isopropenyl 2-oxazoline as a polymerizable unsaturated monomer which has an oxazoline group in a dropping funnel, methoxy polyethyleneglycol acrylate (average number of moles of ethylene glycol-9 mol, Shinnakamura chemical | chemistry) Manufacture) 32 mass parts and the mixture of 32 mass parts of methyl methacrylates were thrown in, and it dripped at 70 degreeC under nitrogen atmosphere over 1 hour. After completion of the dropwise addition, the reaction solution was stirred for 9 hours and cooled to obtain a water-soluble resin (C) having an oxazoline group having a solid content concentration of 40% by mass.

(Polymerization of Carbodiimide-Based Crosslinking Agent)

168 parts by mass of hexamethylene diisocyanate and 220 parts by mass of polyethylene glycol monomethyl ether (M400, average molecular weight 400) were added to a flask equipped with a stirrer, a thermometer, and a reflux condenser, followed by stirring at 120 ° C for 1 hour. 26 parts by mass of 4'-dicyclohexylmethane diisocyanate and 3.8 parts by mass of 2-methyl-1-phenyl-2-phosphorene-1-oxide (2% by weight based on total isocyanate) as a carbodiimidization catalyst And it stirred at 185 degreeC under nitrogen stream further for 5 hours. The infrared spectrum of the reaction solution was measured to confirm that absorption at wavelengths 2200 to 2300 cm ^-1 was lost. It cooled to 60 degreeC, 567 mass parts of ion-exchange water was added, and the carbodiimide water-soluble resin (D) of 40 mass% of solid content was obtained.

Example 1

(1) Preparation of coating liquid

The following ceramics were mixed to prepare a coating liquid.

55.62 mass% of water

Isopropanol 30.00 mass%

Polyurethane resin (A-1) 11.29 mass%

Block polyisocyanate aqueous dispersion (B) 2.26 mass%

0.71 mass% of particles

(Silica sol with an average particle diameter of 40 nm, solid content concentration 40 mass%)

0.07 mass% of particles

(Silica sol with an average particle diameter of 450 nm, solid content concentration 40 mass%)

0.05 mass% of surfactant

(Silicone, solid content 100%)

(2) Preparation of easily adhesive polyester film

As a film raw material polymer, PET resin pellet which has an intrinsic viscosity of 0.62 dl / g and does not contain particle | grains substantially was dried at 135 degreeC under reduced pressure of 133 Pa for 6 hours. Then, it supplied to the extruder, melt-extruded in the sheet form at about 280 degreeC, and rapidly quenched and solidified on the rotating cooling metal roll maintained at the surface temperature of 20 degreeC, and obtained the 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 circumferential speed difference to obtain a uniaxially stretched PET film.

Subsequently, after apply | coating the said coating liquid to the single side | surface of PET film by the roll coat method, it dried at 80 degreeC for 20 second. In addition, it adjusted so that the application amount after final (after biaxial stretching) drying might be 0.15 g / m <2>. Subsequently, with a tenter, it extended | stretched 4.0 times in the width direction at 120 degreeC, heated for 0.5 second at 230 degreeC in the state which fixed the length of the width direction of the film, and further relaxed | treated in the width direction of 3% for 10 second at 230 degreeC. Was performed. Both ends were trimmed and wound up by the winding device, and this was further divided into two in the width direction and slitted to obtain a film roll having a width of 1300 mm, a film length of 3000 m, and a film thickness of 100 m. Table 1 shows the evaluation results for the obtained easy-adhesive polyester film.

(3) Production of optically laminated polyester film

(Laminated polyester film for optics having a hard coat layer)

The coating liquid (E) for hard-coat layer formation of the following composition was apply | coated to the application layer surface of the said easily adhesive polyester film using # 10 wire bar, and it dried at 70 degreeC for 1 minute, and removed the solvent. Subsequently, 300 mJ / cm <2> of ultraviolet-rays were irradiated to the film which apply | coated the hard-coat layer using the high pressure mercury lamp, and the optical laminated polyester film which has a hard-coat layer of thickness 5micrometer was obtained.

Coating liquid for hard coat layer formation (E)

Methyl ethyl ketone 65.00 mass%

Dipentaerythritol hexaacrylate 27.20 mass%

(Shin-Nakamura Chemical A-DPH)

Polyethylene diacrylate 6.80 mass%

(Shin-Nakamura Chemical A-400)

1.00 mass% of photopolymerization initiator

(Irucure 184 made by Ciba specialty chemicals company)

(Optical laminated polyester film having photocurable urethane / acryl layer)

On a SUS plate (SUS304) having a thickness of 1 mm kept clean, about 5 g of the following photocurable acrylic coating liquid was placed on the film sample. The photocurable urethane / acrylic coating liquid (F) was stretched and crimped with a manual load rubber roller having a width of 10 cm and a diameter of 4 cm. Subsequently, 500 mJ / cm <2> ultraviolet-rays were irradiated from the film surface side using the high pressure mercury lamp, and the photocurable urethane / acrylic resin was hardened. The film sample which has a 20 micrometers-thick photocurable urethane / acryl layer was peeled from the SUS board, and the laminated polyester film for optics was obtained.

Photocurable Urethane / Acrylic Coating Solution (F)

Photocurable acrylic resin 67.00 mass%

(Shin-Nakamura Chemical A-BPE-4)

Photocurable Acrylic Resin 15.00 Mass%

(Shin-Nakamura Chemical Co., Ltd. AMP-10G)

Photocurable Urethane / Acrylic Resin 15.00 Mass%

(Shinakamura Chemical Co., Ltd. U-6HA)

Photopolymerization Initiator 3.00 Mass%

(Irucure 184 made by Ciba specialty chemicals company)

(Laminated polyester film for optics having a photocurable acrylic layer)

The optical laminated polyester film was made the same except having changed the photocurable urethane / acrylic-type coating liquid (F) of the optical laminated polyester film which has a photocurable urethane / acryl layer into the photocurable acrylic coating liquid (G). Got it.

Photocurable Acrylic Coating Liquid (G)

Photocurable acrylic resin 67.00 mass%

(Shin-Nakamura Chemical A-BPE-4)

Photocurable acrylic resin 30.00 mass%

(Shin-Nakamura Chemical Co., Ltd. AMP-10G)

Photopolymerization Initiator 3.00 Mass%

(Irucure 184 made by Ciba specialty chemicals company)

Comparative Example 1

The easily-adhesive polyester film and the optical laminated polyester film were obtained like Example 1 except having changed the polyurethane resin into the polyurethane resin (A-5).

Comparative Example 2

The easily-adhesive polyester film and the optical laminated polyester film were obtained like Example 1 except having changed the polyurethane resin into the polyurethane resin (A-6).

Comparative Example 3

The easily-adhesive polyester film and the optical laminated polyester film were obtained like Example 1 except having changed the polyurethane resin into the polyurethane resin (A-7).

Comparative Example 4

The easily-adhesive polyester film and the optical laminated polyester film were obtained like Example 1 except having changed the polyurethane resin into the polyurethane resin (A-8).

Comparative Example 5

The easily-adhesive polyester film and the optical laminated polyester film were obtained like Example 1 except having changed the coating liquid below.

53.04 mass% of water

Isopropanol 30.00 mass%

Polyurethane resin (A-1) 16.13 mass%

0.71 mass% of particles

(Silica sol with an average particle diameter of 40 nm, solid content concentration 40 mass%)

0.07 mass% of particles

(Silica sol with an average particle diameter of 450 nm, solid content concentration 40 mass%)

0.05 mass% of surfactant

(Silicone system, solid content concentration 100% by mass)

Example 2

The easily-adhesive polyester film and the optical laminated polyester film were obtained like Example 1 except having changed the coating liquid below.

53.91 mass% of water

Isopropanol 30.00 mass%

Polyurethane resin (A-1) 14.51 mass%

Block polyisocyanate aqueous dispersion (B) 0.75 mass%

0.71 mass% of particles

(Silica sol with an average particle diameter of 40 nm, solid content concentration 40 mass%)

0.07 mass% of particles

(Silica sol with an average particle diameter of 450 nm, solid content concentration 40 mass%)

0.05 mass% of surfactant

(Silicone system, solid content concentration 100% by mass)

Example 3

The easily-adhesive polyester film and the optical laminated polyester film were obtained like Example 1 except having changed the coating liquid below.

54.76 mass% of water

Isopropanol 30.00 mass%

12.90 mass% of polyurethane resin (A-1)

Block polyisocyanate aqueous dispersion (B) 1.51 mass%

0.71 mass% of particles

(Silica sol with an average particle diameter of 40 nm, solid content concentration 40 mass%)

0.07 mass% of particles

(Silica sol with an average particle diameter of 450 nm, solid content concentration 40 mass%)

0.05 mass% of surfactant

(Silicone system, solid content concentration 100% by mass)

Example 4

The easily-adhesive polyester film and the optical laminated polyester film were obtained like Example 1 except having changed the coating liquid below.

57.35 mass% of water

Isopropanol 30.00 mass%

8.06% by mass of polyurethane resin (A-1)

Block polyisocyanate aqueous dispersion (B) 3.76 mass%

0.71 mass% of particles

(Silica sol with an average particle diameter of 40 nm, solid content concentration 40 mass%)

0.07 mass% of particles

(Silica sol with an average particle diameter of 450 nm, solid content concentration 40 mass%)

0.05 mass% of surfactant

(Silicone system, solid content concentration 100% by mass)

Example 5

The easily-adhesive polyester film and the optical laminated polyester film were obtained like Example 1 except having changed the coating liquid below.

59.92 mass% of water

Isopropanol 30.00 mass%

3.23% by mass of polyurethane resin (A-1)

Block polyisocyanate aqueous dispersion (B) 6.02 mass%

0.71 mass% of particles

(Silica sol with an average particle diameter of 40 nm, solid content concentration 40 mass%)

0.07 mass% of particles

(Silica sol with an average particle diameter of 450 nm, solid content concentration 40 mass%)

0.05 mass% of surfactant

(Silicone system, solid content concentration 100% by mass)

Example 6

The easily-adhesive polyester film and the optical laminated polyester film were obtained like Example 1 except having changed the coating liquid below.

60.79 mass% of water

Isopropanol 30.00 mass%

Polyurethane resin (A-1) 1.61 mass%

Block polyisocyanate aqueous dispersion (B) 6.77 mass%

0.71 mass% of particles

(Silica sol with an average particle diameter of 40 nm, solid content concentration 40 mass%)

0.07 mass% of particles

(Silica sol with an average particle diameter of 450 nm, solid content concentration 40 mass%)

0.05 mass% of surfactant

(Silicone system, solid content concentration 100% by mass)

Example 7

The easily-adhesive polyester film and the optical laminated polyester film were obtained like Example 1 except having changed the polyurethane resin into the polyurethane resin (A-2).

Example 8

Except having changed the polyurethane resin into the polyurethane resin (A-3), it carried out similarly to Example 1, and obtained the easily-adhesive polyester film and the optical laminated polyester film.

Example 9

The easily-adhesive polyester film and the optical laminated polyester film were obtained like Example 1 except having changed the polyurethane resin into the silanol-group containing polyurethane resin (A-4).

Example 10

The laminated polyester film for optics was obtained like Example 1 except having changed the block polyisocyanate aqueous dispersion (B) into the water-soluble resin (C) which has an oxazoline group.

Example 11

The laminated polyester film for optics was obtained like Example 1 except having changed the block polyisocyanate aqueous dispersion (C) into carbodiimide water-soluble resin (D).

Example 12

The laminated polyester film for optics was obtained like Example 1 except having changed the block polyisocyanate aqueous dispersion (C) into imino methylol melamine (solid content concentration 70 mass%).

Example 13

The easily-adhesive polyester film and the optical laminated polyester film were obtained like Example 1 except having changed the coating liquid below.

62.82 mass% of water

Isopropanol 30.00 mass%

5.64 mass% of polyurethane resins (A-1)

Block polyisocyanate aqueous dispersion (B) 1.13 mass%

0.35 mass% of particles

(Silica sol with an average particle diameter of 40 nm, solid content concentration 40 mass%)

0.04 mass% of particles

(Silica sol with an average particle diameter of 450 nm, solid content concentration 40 mass%)

0.02 mass% of surfactant

(Silicone system, solid content concentration 100% by mass)

Since the easily adhesive polyester film of this invention is excellent in adhesiveness with an optical function layer, and adhesiveness (heat-and-moisture resistance) under high temperature, high humidity, it is especially suitable for optical use, and a hard coat film mainly used for a display etc. and this film It is very suitable as a base film of optical functional films, such as an antireflection film, a light-diffusion sheet, a lens sheet, a near-infrared cut off film, a transparent conductive film, and an anti-glare film using this.

Claims (6)

As a polyester film which has an application layer on at least one side,
The said application layer has urethane resin and a crosslinking agent which make an aliphatic polycarbonate polyol a structural component as a main component,
In the infrared spectral spectrum of the coating layer, the ratio of absorbance (A ₁₄₆₀ ) at around 1460 cm ⁻¹ derived from aliphatic polycarbonate component and absorbance (A ₁₅₃₀ ) at around 1530 cm ⁻¹ derived from urethane component (A ₁₄₆₀ / A ₁₅₃₀ ) is 0.40 to 1.55. The method of claim 1,
The crosslinking agent is at least one crosslinking agent selected from a melamine crosslinking agent, an isocyanate crosslinking agent, a carbodiimide crosslinking agent, and an oxazoline crosslinking agent. The method according to claim 1 or 2,
The easily-adhesive polyester film whose mass ratio (urethane resin / crosslinking agent) of the urethane resin and crosslinking agent which make an aliphatic polycarbonate polyol in the said application layer as a component is 1/9-9/1. 4. The method according to any one of claims 1 to 3,
The easily adhesive polyester film whose haze of a polyester film is 2.5% or less. 1 layer selected from the said coating layer of the easily-adhesive polyester film as described in any one of Claims 1-3 from a hard-coat layer, a light-diffusion layer, a lens layer, an electromagnetic wave absorption layer, a near-infrared shielding layer, and a transparent conductive layer. The laminated polyester film formed by laminating | stacking the above optical function layer. The easily-adhesive polyester film roll for optics which winds up the easily-adhesive polyester film in any one of Claims 1-4.