TW202208184A - Laminated polyester film for optical use - Google Patents

Abstract

The present invention addresses the problem of providing a laminated polyester film for optical use, which is highly transparent, has an antiblocking property, and exhibits excellent adhesion to hard coat layers, light diffusing layers, lens layers, antiglare layers, and transparent conductive layers. The laminated polyester film for optical use according to the present invention includes a readily adhesive polyester film having a coated layer disposed at least on one surface of a polyester film base material, and at least one optical function layer that is laminated on said coated layer and that is selected from among hard coat layers, light diffusing layers, lens layers, antiglare layers, and transparent conductive layers. The coated layer has a specific compositional makeup.

Description

Optical laminated polyester film

The present invention relates to a laminated polyester film for optics excellent in adhesiveness and transparency. In detail, it is about an optical laminate in which an optically functional film such as a hard coat film, a light diffusing sheet, a lens sheet, a transparent conductive film, and an anti-glare film is laminated on the coating layer of the easy-adhesive polyester film. polyester film.

In general, as a base material of an optically functional film used as a member of various displays such as liquid crystal displays, polyethylene terephthalate (PET; polyethylene terephthalate), acrylic, polycarbonate (PC; polycarbonate), Transparent thermoplastic resin film composed of triacetyl cellulose (TAC; triacetyl cellulose), polyolefin, etc.

When using the said thermoplastic resin film as a base material of various optical functional films, the functional layer corresponding to each application is laminated|stacked. For example, in a liquid crystal display, functional layers, such as a protective film (hard coat layer) for preventing surface damage, a fluoride layer for condensing or diffusing light, and a light-diffusion layer for improving brightness are exemplified. Among such substrates, in particular, polyester films are widely used as substrates for various optical functional films because they are excellent in transparency, dimensional stability, and chemical resistance, and are relatively inexpensive.

In general, since the surface of a biaxially oriented polyester film is highly crystalline, there is a disadvantage that adhesion to various paints, adhesives, and the like is lacking. Therefore, a method of imparting easy adhesion to the surface of a biaxially oriented polyester film by various methods has been proposed.

Heretofore, there has been known a technique in which, by using a copolymerized polyester resin and a urethane resin for a coating layer, easy adhesion is imparted to hard coat processing, high lens processing, and the like (for example, refer to Patent Document 1). ). However, this prior art has a problem that the blocking resistance of the easily adhesive polyester film is not excellent.

In addition, there is also known a technique in which, by using a urethane resin and a blocked isocyanate for a coating layer, it is possible to impart easy adhesion to a hard coating process used in the production of a solar cell front sheet in particular (for example, refer to Patent Document 2). However, this prior art has a problem that the transparency of the easily adhesive polyester film is low. Moreover, the technique which improves the adhesiveness with a lens layer by using a urethane resin and a blocked isocyanate for a coating layer is known (for example, refer patent document 3). However, this prior art has a problem that the adhesion with the lens layer is insufficient. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2000-229355. [Patent Document 2] Japanese Patent Laid-Open No. 2016-015491. [Patent Document 3] Japanese Patent Laid-Open No. 2014-221560.

[The problem to be solved by the invention]

The present invention has been made on the background of the above-mentioned problems of the prior art. That is, the object of the present invention is to provide an optical laminated polyester film using an easy-adhesive polyester film, the easy-adhesive polyester film having high transparency and anti-blocking properties, which is suitable for various optical resin compositions. All have good adhesion. [means to solve the problem]

In order to solve the above-mentioned problems, the inventors of the present invention have studied the causes and the like of the above-mentioned problems, and found in the process that a urethane containing a cross-linking agent and having a polycarbonate structure is present on at least one side of a polyester film base material. Resin and a coating layer of polyester resin, and the ratio of nitrogen atoms in the coating layer and the ratio of OCOO bonds on the surface of the coating layer on the opposite side to the polyester film base material satisfy certain conditions, can be The problems of the present invention have been solved, and the present invention has been completed.

The aforementioned problems can be achieved by the following solutions. 1. A laminated polyester film for optics, the above-mentioned coating layer of the easy-adhesive polyester film having a coating layer on at least one side of a polyester film substrate, the laminated layer having a layer selected from the group consisting of a hard coat layer, a light diffusing layer, At least one optical functional layer among the lens layer, the anti-glare layer, and the transparent conductive layer, and the coating layer is composed of a urethane resin having a polycarbonate structure, a crosslinking agent, and a polyester resin In the distribution curve of nitrogen element based on the element distribution in the depth direction measured by X-ray photoelectron spectroscopy on the coating layer, when the surface of the coating layer on the opposite side to the polyester film substrate is The nitrogen atomic ratio is set to A (at%), the maximum value of the nitrogen atomic ratio is set to B (at%), and the etching time of the nitrogen atomic ratio showing the maximum value B (at%) is set to b (seconds), b (seconds) When the etching time when the nitrogen atom ratio becomes 1/2B (at%) is set to c (seconds), the following formulas (i) to (iii) are satisfied, and the values measured by X-ray photoelectron spectroscopy In the surface analysis spectrum, the following formula (iv) is satisfied when the total peak area derived from each bond species in the C1s spectral region is set to 100 (%) and the peak area derived from the OCOO bond is set to X (%). (i)0.5≦B－A(at%)≦3.0 (ii)30≦b(second)≦180 (iii)0≦c－b(second)≦300 (iv)2.0≦X(%)≦10.0 2. The optical laminated polyester film according to the above 1, wherein the easily adhesive polyester film has a haze of 1.5 (%) or less. [Inventive effect]

The easily adhesive polyester film of the present invention has high transparency, has anti-blocking properties, and has good adhesion to various optical resin compositions. Therefore, the laminated polyester film-based coating layer for optics of the present invention using the above-described easily adhesive polyester film is excellent in adhesion between the coating layer and various functional layers, and is suitable as an optical member such as a display.

[Polyester film substrate] In the present invention, the polyester resin constituting the polyester film base material is polyethylene terephthalate, polybutylene terephthalate, polyethylene 2,6-naphthalate, polyethylene terephthalate Propylene diester, etc., and copolymerized polyester resins obtained by substituting a part of the diol component or dicarboxylic acid component of the aforementioned polyester resin with the following copolymerization components, for example, as the copolymerization components, there may be mentioned: Diol components such as ethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, polyalkylene glycol, and adipic acid, sebacic acid, phthalic acid, isophthalic acid, and 5-sodium Dicarboxylic acid components such as isophthalic acid and 2,6-naphthalene dicarboxylic acid, etc.

The polyester resin suitable for use in the present invention is mainly selected from polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene 2,6-naphthalate ester. Among these polyester resins, polyethylene terephthalate is the most optimal in terms of the balance between physical properties and cost. Moreover, it is preferable that the polyester film base material which consists of these polyester resins is a biaxially stretched polyester film, and chemical resistance, heat resistance, mechanical strength, etc. can be improved.

The catalyst for polycondensation used in the production of polyester resin is not particularly limited, but antimony trioxide is suitable because it is inexpensive and has excellent catalytic activity. Moreover, a germanium compound or a titanium compound is also preferable. More preferable polycondensation catalysts include catalysts containing aluminum and/or compounds thereof and phenolic compounds, catalysts containing aluminum and/or compounds thereof and phosphorus compounds, and catalysts containing aluminum salts of phosphorus compounds. In particular, the transparency of the film can be improved by using a catalyst containing aluminum and/or a compound thereof and a phosphorus compound.

In addition, the polyester film base material in the present invention may be a single-layer polyester film, may be composed of two layers with mutually different components, or may be a polyester film having an outer layer and an inner layer and composed of at least three layers substrate.

[Explanation of characteristic values in the present invention] The easily adhesive polyester film in the present invention preferably has a coating layer on at least one side of the polyester film substrate as described above. The aforementioned coating layer is formed by curing a composition containing a urethane resin having a polycarbonate structure, a crosslinking agent, and a polyester resin. Here, the reason why the expression "the composition is cured" is used because it is extremely difficult to accurately express that the urethane resin having a polycarbonate structure, the crosslinking agent, and the polyester resin are crosslinked by the crosslinking agent. The chemical composition of the hardened state. In addition, when the maximum value of the nitrogen element distribution curve measured based on the element distribution in the depth direction of the coating layer exists in the vicinity of the coating layer surface on the opposite side to the polyester film substrate, transparency and blocking resistance can be achieved. It is preferable because of the improvement of the adhesion with the hard coat layer, anti-glare layer, transparent conductive layer, etc. Furthermore, when an appropriate amount of polycarbonate structure exists on the surface of the coating layer on the opposite side to the polyester film substrate, it is possible to improve the adhesion with the lens layer, the light-diffusion layer, and the like, which is preferable.

The characteristics of the coating layer in the above-mentioned easily adhesive polyester film will be described. First, the distribution curve of nitrogen element measured based on the element distribution in the depth direction of the coating layer was drawn by X-ray photoelectron spectroscopy (ESCA; electron spectroscopy chemical analysis). That is, the spectrum collection is performed every 30 seconds until the etching time is 120 seconds, and thereafter every 60 seconds. Then, as shown in FIG. 2, the etching time (unit: second) taken from the surface of the coating layer is the horizontal axis, the ratio of the amount of nitrogen atoms to the total amount of carbon atoms, oxygen atoms, nitrogen atoms, and silicon atoms (Nitrogen atomic ratio, unit: at%) is the vertical axis, the nitrogen atomic ratio on the surface of the coating layer on the opposite side to the polyester film substrate is A (at%), and the maximum value of the nitrogen atomic ratio is B. (at%), the etching time when the nitrogen atom ratio shows the maximum value B (at%) is b (sec), and the etching time when the nitrogen atom ratio becomes 1/2B (at%) after b (sec) is set as c ( Second). Calculate BA (at%) and c-b (second) from the read data. The nitrogen atomic ratio A (at%) of the surface of the coating layer on the opposite side to the polyester film substrate is the nitrogen atomic ratio at the time of etching time 0 (sec).

Furthermore, when each characteristic value read from the distribution curve of nitrogen element measured based on the element distribution in the depth direction of the coating layer is in the following relationship, transparency, anti-blocking property, resistance to hard coat layer, light resistance can be obtained. Easy-adhesive polyester film with excellent adhesion between diffusion layer, lens layer, anti-glare layer, and transparent conductive layer. (i)0.5≦B－A(at%)≦3.0 (ii)30≦b(second)≦180 (iii)30≦c－b(second)≦300

The lower limit of BA is preferably 0.5 at %, more preferably 0.6 at %, still more preferably 0.7 at %, still more preferably 0.8 at %, and most preferably 0.9 at %. If it is 0.5 at% or more, the amount of the urethane resin having toughness is sufficient to obtain blocking resistance, which is preferable. Moreover, since the adhesiveness with a hard-coat layer, an anti-glare layer, and a transparent conductive layer also improves, it is preferable. The upper limit of BA is preferably 3.0 at %, more preferably 2.9 at %, still more preferably 2.8 at %, still more preferably 2.7 at %, and most preferably 2.5 at %. If it is 3.0 at % or less, the haze is low and transparency is obtained, which is preferable.

The lower limit of b is preferably 30 seconds, and if it is 30 seconds or more, the toughness of the surface of the coating layer on the opposite side to the polyester film substrate is maintained and blocking resistance is obtained, which is preferable. The upper limit of b is preferably 180 seconds, more preferably 120 seconds, still more preferably 90 seconds, particularly preferably 60 seconds. If it is 180 seconds or less, the toughness of the surface of the coating layer on the opposite side to the polyester film substrate is maintained, and the blocking resistance becomes good, which is preferable. In addition, the adhesiveness with the hard coat layer, the anti-glare layer, and the transparent conductive layer is improved, so it is preferable.

The upper limit of c-b is preferably 300 seconds, more preferably 240 seconds, and still more preferably 180 seconds. If it is 300 seconds or less, the urethane resin component in the coating layer will not become excessive, the haze will be low and transparency will be obtained, which is preferable. The lower limit of c-b is 30 seconds or more from the relationship that the spectrum collection is performed every 30 seconds from the start of the measurement until the etching time is 120 seconds.

In the present invention, it is preferable that most of the polycarbonate structural moieties in the urethane resin constituting the coating layer of the easily adhesive polyester film are locally present in the coating layer on the opposite side to the polyester film substrate. cloth surface. The reason is that the adhesion to the lens layer and the light diffusion layer is improved by the presence of an appropriate amount of the polycarbonate structure on the surface. On the other hand, it has also been found that the presence of a polycarbonate structure on the surface sometimes results in high flexibility without sufficient blocking resistance. Therefore, as described above, when each characteristic value read from the distribution curve of nitrogen element measured based on the element distribution in the depth direction of the coating layer is in the following relationship, it is possible to obtain the properties of transparency, blocking resistance, and hardness. Easy-adhesive polyester film with excellent adhesion of coating, anti-glare layer and transparent conductive layer. (i)0.5≦B－A(at%)≦3.0 (ii)30≦b(second)≦180 (iii)30≦c－b(second)≦300

Examples of means for making the easily adhesive polyester film of the present invention satisfy the above-mentioned formulas (i) to (iii) include: urethane having a polycarbonate structure that is synthesized and polymerized to form a coating layer In the case of resin, it is synthesized and polymerized including a polycarbonate polyol component and a polyisocyanate component, the mass ratio of the polycarbonate polyol component to the polyisocyanate component is in the range of 0.5 to 2.5, and the molecular weight of the polycarbonate polyol component is 500 To 1800, when the sum of the solid content of the polyester resin, the urethane resin, and the crosslinking agent in the coating liquid is 100% by mass, the content rate of the solid content of the crosslinking agent is 10% by mass to 50% by mass %. In addition, as a crosslinking agent, BA can be efficiently adjusted by using a blocked isocyanate and a trifunctional or more blocked isocyanate having an isocyanate group.

In addition, as described above, it is preferable that most of the polycarbonate structural moieties in the urethane resin in the coating layer in the present invention are present in a certain ratio in the coating layer on the opposite side to the polyester film substrate. cloth surface. In the present invention, in the surface analysis spectrum measured by X-ray photoelectron spectroscopy, the total peak area derived from each bond species in the C1s spectral region is set as 100 (%), and the peak area derived from (as a polycarbonate structure) OCOO The peak area of the bond is set as X (%), expressed as a percentage of the OCOO bond.

The ratio X (%) of OCOO bonds in the surface area (as a polycarbonate structure) here is evaluated by X-ray photoelectron spectroscopy (ESCA). FIGS. 5 and 6 are examples of graphs showing the results of analysis of the C1s spectrum of the surface region of the easily adhesive polyester film of Example 6 and Experimental Example 1 to be described later, respectively. The solid grey line represents the measured data of the C1s spectrum. The peaks of the obtained measured spectrum are separated into a plurality of peaks, and the bond species corresponding to each peak is identified according to the position and shape of each peak. Furthermore, curve fitting can be performed using the peaks derived from each bond species, and the peak area can be calculated. The coating layer in the present invention contains a urethane resin having a polycarbonate structure, a cross-linking agent represented by a blocked isocyanate having an isocyanate group having 3 or more functions, and a polyester resin. In the case of the coating layer , the peaks of the bond species from the peak (1) to the peak (6) in Table 1 can be detected. The bond species from the peak (1) to the peak (6) in Table 1 are not necessarily only the bond species shown in Table 1, and may also contain a small amount of similar bond species. Here, in FIG. 5 concerning Example 6, the C=O bond peak of (3) and the π-π* bond peak of (6) in Table 1 do not appear. In addition, in FIG. 6 concerning Experimental Example 1, the C=O bond peak of (3) and the OCOO bond peak of (5) of Table 1 do not appear. The ratio X (%) of the OCOO bonds in the surface area can be said to represent the area ratio of the peak ( 5 ) when the entire peak area from the peak ( 1 ) to the peak ( 6 ) is set to 100% as a percentage (%).

[Table 1] key species (1) Black two-point chain line CC key (2) Black dotted line CO key, CN key (3) Black three-point chain line C=O key (4) Black single point chain line COO key (5) Black dotted line OCOO key (6) Black solid line π-π* bond

A suitable range of the peak area X (%) derived from the OCOO bond is as follows. The lower limit of X is preferably 2.0%, more preferably 2.5%, still more preferably 3.0%, particularly preferably 3.5%, and most preferably 4.0%. If it is 2.0% or more, since the adhesiveness to the lens layer and the light-diffusion layer can be effectively satisfied, it is preferable. The upper limit of X is preferably 10.0%, more preferably 9.0%, still more preferably 8.0%, particularly preferably 7.5%, and most preferably 7%. If it is 10.0% or less, the flexibility of the surface layer is not excessively high, and blocking resistance is easily obtained, which is preferable.

As the production method of the easily adhesive polyester film in the present invention, since the X characteristic value based on the aforementioned C1s spectral region can be effectively realized in the range of 2.0% to 10.0%, it is preferable to form a coating layer by synthesis and polymerization In the case of a urethane resin having a polycarbonate structure, the mass ratio of the polycarbonate polyol component to the polyisocyanate component is 0.5 or more, and the polyester resin in the coating solution and the urethane having a polycarbonate structure are The urethane resin content rate is 5 to 50 mass % when the sum of the solid content of the acid ester resin and the crosslinking agent is 100 mass %.

[coating layer] In the easy-adhesive polyester film of the present invention, in order to improve the adhesiveness to the hard coat layer, the adhesiveness to the lens layer and the light-diffusion layer, at least one surface layer of the easy-adhesive polyester film preferably has The coating layer is formed from a composition containing a urethane resin having a polycarbonate structure, a crosslinking agent, and a polyester resin. The coating layer can be provided on both sides of the polyester film, or only on one side of the polyester film, and different types of resin coating layers can be provided on the other side.

Hereinafter, each composition of the coating layer will be described in detail. [urethane resin] The urethane resin having a polycarbonate structure in the present invention has at least a urethane bond moiety derived from a polycarbonate polyol component and a polyisocyanate component, and further contains a chain extender if necessary.

Mass ratio of polycarbonate polyol component and polyisocyanate component when synthesizing and polymerizing the urethane resin having a polycarbonate structure in the present invention (mass of polycarbonate polyol component/mass of polyisocyanate component) The lower limit of is preferably 0.5, more preferably 0.6, still more preferably 0.7, particularly preferably 0.8, and most preferably 1.0. If it is 0.5 or more, the ratio X of the OCOO bonds on the surface of the coating layer can be efficiently adjusted to 2% or more, which is preferable. The upper limit of the mass ratio of the polycarbonate polyol component and the polyisocyanate component when synthesizing and polymerizing the urethane resin having a polycarbonate structure in the present invention is preferably 2.5, more preferably 2.2, and still more preferably 2.0, preferably 1.7, and best 1.5. If it is 2.5 or less, the ratio X of the OCOO bonds on the surface of the coating layer can be efficiently adjusted to 10% or less, which is preferable. Furthermore, in the nitrogen distribution curve based on the element distribution measurement in the depth direction by X-ray photoelectron spectroscopy, BA can be effectively adjusted to 0.5 at% or more, and c-b can be effectively adjusted to 300 seconds the following.

Among the polycarbonate polyol components used for synthesizing and polymerizing the urethane resin having a polycarbonate structure in the present invention, it is preferable to contain an aliphatic polycarbonate polyol having excellent heat resistance and hydrolysis resistance . As aliphatic polycarbonate polyol, aliphatic polycarbonate diol, aliphatic polycarbonate triol, etc. are mentioned, and aliphatic polycarbonate diol can be used suitably. The aliphatic polycarbonate diol used for synthesizing and polymerizing the urethane resin having a polycarbonate structure in the present invention includes, for example, ethylene glycol, propylene glycol, and 1,3-propylene glycol. , 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 1,8- One or two or more of glycols such as nonanediol, neopentyl glycol, diethylene glycol, and dipropylene glycol are reacted with carbonates such as dimethyl carbonate, ethylene carbonate, and carboxychloride. Aliphatic polycarbonate diols, etc.

As a number average molecular weight of the said polycarbonate polyol in this invention, 500-1800 are preferable. More preferably, it is 600 to 1700, and most preferably, it is 700 to 1500. When it is 500 or more, the ratio X of the OCOO bonds on the surface of the coating layer can be effectively adjusted to 10% or less. If it is 1800 or less, in the nitrogen distribution curve based on the element distribution measurement in the depth direction by X-ray photoelectron spectroscopy, BA can be effectively adjusted to 0.5 or more, and c-b can be effectively adjusted to 300 seconds or less.

Examples of polyisocyanates used in the synthesis and polymerization of the urethane resin having a polycarbonate structure in the present invention include aromatic aliphatic diisocyanates such as xylylene diisocyanate, and isophorone. Diisocyanates, alicyclic diisocyanates such as 4,4-dicyclohexylmethane diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, hexamethylene diisocyanate, and 2,2, Aliphatic diisocyanates such as 4-trimethylhexamethylene diisocyanate, or polyisocyanates obtained by adding trimethylolpropane or the like to one or more of these compounds in advance. In the case of using the aforementioned aromatic aliphatic diisocyanates, alicyclic diisocyanates, or aliphatic diisocyanates, etc., there is no problem of yellowing, which is preferable. In addition, the coating film does not become too hard, the stress due to the thermal shrinkage of the polyester film base material can be relieved, and the adhesiveness becomes good, which is preferable.

Examples of the chain extender include glycols such as ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, and 1,6-hexanediol, glycerin, trimethylolpropane, and polyols such as neotaerythritol, diamines such as ethylenediamine, hexamethylenediamine, and piperazine, amine alcohols such as monoethanolamine and diethanolamine, thioglycols such as thiodiethanol, or water.

The coating layer in the present invention is preferably provided by an in-line coating method described later using an aqueous coating liquid. Therefore, the urethane resin of the present invention is expected to have water solubility or water dispersibility. In addition, the above-mentioned "water-soluble or water-dispersible" means to be dispersed in an aqueous solution containing less than 50% by mass of water or a water-soluble organic solvent.

In order to impart water dispersibility to the urethane resin, a (copolymerized) sulfonic acid (salt) group or a carboxylic acid (salt) group may be introduced into the urethane molecular skeleton. In order to maintain moisture resistance, it is suitable to introduce a weakly acidic carboxylic acid (salt) group. In addition, a nonionic group such as a polyoxyalkylene group may be introduced.

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 dimethylol propionic acid and dimethylol butyric acid, which are polyol components, is introduced as a copolymerization component, and neutralized with a salt-forming agent. Specific examples of the salt-forming agent include ammonia, trimethylamine, triethylamine, triisopropylamine, tri-n-propylamine, trialkylamines such as tri-n-butylamine, N-methylamine, etc. N-alkylmorphines such as methoxine and N-ethylmorphine, N-dialkyl alkanolamines such as N-dimethylethanolamine and N-diethylethanolamine. These salt-forming agents may be used alone or in combination of two or more.

In the case where a polyol compound having a carboxylic acid (salt) group is used as a copolymerization component for imparting water dispersibility, when the total polyisocyanate component of the urethane resin is 100 mol %, urethane methyl The molar ratio of the polyol compound having a carboxylic acid (salt) group in the acid ester resin is preferably 3 mol % to 60 mol %, more preferably 5 mol % to 40 mol %. When the molar ratio of the aforementioned composition is less than 3 mol %, water dispersibility may become difficult. Moreover, when the said composition molar ratio exceeds 60 mol%, since water resistance falls, moist heat resistance may fall.

In the urethane resin of the present invention, a blocked isocyanate may be bonded to the terminal in order to improve rigidity.

[Crosslinking agent] In the present invention, the crosslinking agent contained in the composition for forming the coating layer is preferably a blocked isocyanate, more preferably a trifunctional or more blocked isocyanate, particularly preferably a tetrafunctional or more blocked isocyanate . With these cross-linking agents, the anti-blocking property is improved, and the adhesion with the hard coat layer, anti-glare layer, and transparent conductive layer is improved. When a blocked isocyanate crosslinking agent is used, BA can be effectively adjusted to 0.5 at% or more in the nitrogen distribution curve based on the element distribution measurement in the depth direction by X-ray photoelectron spectroscopy, which is preferable .

The lower limit of the boiling point of the blocking agent for blocking isocyanate is preferably 150°C, more preferably 160°C, still more preferably 180°C, particularly preferably 200°C, and most preferably 210°C. The higher the boiling point of the end-capping agent, the more the volatilization of the end-capping agent is suppressed by the heat load in the drying step after applying the coating solution or the film production step in the case of the in-line coating method, and the generation of minute particles is suppressed. The unevenness of the coating surface improves the transparency of the film. The upper limit of the boiling point of the terminal blocking agent is not particularly limited, but it is considered that the upper limit is about 300°C in terms of productivity. Since the boiling point is related to the molecular weight, in order to increase the boiling point of the end-capping agent, it is preferable to use an end-capping agent with a large molecular weight.

The upper limit of the dissociation temperature of the capping agent is preferably 200°C, more preferably 180°C, still more preferably 160°C, particularly preferably 150°C, and most preferably 120°C. The terminal blocking agent dissociates from the functional group due to the drying step after applying the coating liquid or the thermal load in the film production step in the case of the in-line coating method, thereby generating a regenerated isocyanate group. Therefore, the crosslinking reaction with the urethane resin or the like progresses, and the adhesiveness improves. When the dissociation temperature of the blocked isocyanate is equal to or lower than the above-mentioned temperature, the dissociation of the blocking agent proceeds sufficiently, and thus the adhesiveness, especially the moist heat resistance, becomes favorable.

As the blocking agent used in the blocked isocyanate of the present invention, the dissociation temperature is 120° C. or lower and the boiling point of the blocking agent is 150° C. or higher. Examples of the blocking agent include: bisulfite-based compounds: sodium bisulfite, etc., pyrazole-based Compounds: 3,5-dimethylpyrazole, 3-methylpyrazole, 4-bromo-3,5-dimethylpyrazole, 4-nitro-3,5-dimethylpyrazole, etc., active Methylene series: malonate diester (dimethyl malonate, diethyl malonate, di-n-butyl malonate, bis(2-ethylhexyl) malonate), methyl ethyl Ketones etc. 1,2,4-triazole etc. are mentioned as a triazole type compound. Among them, pyrazole-based compounds are preferred in terms of moist heat resistance and yellowing.

The polyisocyanate that is a precursor of the blocked isocyanate of the present invention can be obtained by introducing a diisocyanate. For example, a urethane-modified product of diisocyanate, an allophanate-modified product, a urea-modified product, a biuret-modified product, a uretdione-modified product, and a ureaimine-modified product can be mentioned. , isocyanurate modified body, carbodiimide modified body, etc.

As the diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2 '-Diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-naphthalene diisocyanate, phenylene diisocyanate, tetramethyl xylylene diisocyanate, 4,4'-diphenyl ether diisocyanate , 2-nitrobiphenyl-4,4'-diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4 '-diisocyanate, 4,4'-diphenylpropane diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate and other aromatic diisocyanates, xylylene diisocyanate Aromatic aliphatic diisocyanates such as isophorone diisocyanate, alicyclic diisocyanates such as 4,4-dicyclohexylmethane diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, Aliphatic diisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate. In terms of transparency, adhesiveness, and heat and humidity resistance, an aliphatic, alicyclic isocyanate, or a modified product of these is preferable, and it is preferable for optical applications requiring no yellowing and high transparency.

Regarding the blocked isocyanate in the present invention, a hydrophilic group may be introduced into the polyisocyanate as a precursor in order to impart water solubility or water dispersibility. Examples of the hydrophilic group include (1) quaternary ammonium salts of dialkylamino alcohols, quaternary ammonium salts of dialkylamino alkylamines, and the like, (2) sulfonates, carboxylates, and phosphates etc., (3) polyethylene glycol, polypropylene glycol, etc. whose single end is capped with an alkoxy group. When a hydrophilic part is introduced, it becomes (1) cationic, (2) anionic, and (3) nonionic. Among them, since many other water-soluble resins are anionic resins, anionic or nonionic ones that can be easily compatibilized are preferred. In addition, the anionic property is excellent in compatibility with other resins, and the nonionic property does not have an ionic hydrophilic group, so that it also improves the heat-and-moisture resistance, which is preferable.

The anionic hydrophilic group is preferably an anionic hydrophilic group having a hydroxyl group for introduction into polyisocyanate and a carboxylic acid group for imparting hydrophilicity. For example, glycolic acid, lactic acid, tartaric acid, citric acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxytrimethylacetic acid, dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutyric acid, carboxyl Acid-based polycaprolactone. In order to neutralize the carboxylic acid group, an organic amine compound is preferable. For example, ammonia, methylamine, ethylamine, propylamine, isopropylamine, butylamine, 2-ethylhexylamine, cyclohexylamine, dimethylamine, diethylamine, dipropylene Linear, split-chain, fractionated, carbon number from 1 to 20, such as base amine, diisopropylamine, dibutylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, ethylenediamine, etc. Dendritic 1st, 2nd or 3rd amines, cyclic amines such as morpholin, N-alkyl morpholin, pyridine, monoisopropanolamine, methylethanolamine, methylisopropanolamine, dimethyl Ethanolamine, diisopropanolamine, diethanolamine, triethanolamine, diethylethanolamine, triethanolamine and other hydroxyl-containing amines, etc.

As the nonionic hydrophilic group, the number of repeating units of ethylene oxide and/or propylene oxide of polyethylene glycol, polypropylene glycol terminated with an alkoxy group at one end is preferably 3 to 50, more preferably 5 to 50 30. When there are few repeating units, the compatibility with resin may deteriorate, and haze may rise; when there are many repeating units, adhesiveness under high temperature and high humidity may fall. Regarding the blocked isocyanate of the present invention, nonionic, anionic, cationic, and amphoteric surfactants may be added in order to improve water dispersibility. For example, nonionics such as polyethylene glycol and polyhydric alcohol fatty acid esters, anionic systems such as fatty acid salts, alkyl sulfates, alkylbenzenesulfonates, sulfosuccinates, and alkylphosphates, alkyl phosphates, etc. Cationics such as amine salts and alkyl betaines, surfactants such as carboxylic acid amine salts, sulfonic acid amine salts, and sulfate ester salts.

Moreover, in addition to water, a water-soluble organic solvent may be contained. For example, the organic solvent used for the reaction may be used, or the organic solvent may be removed, and another organic solvent may be added.

[polyester resin] The polyester resin used for forming the coating layer in the present invention may be a linear polyester resin, but is more preferably a polyester resin containing a dicarboxylic acid and a branched alkanediol as constituents. Regarding the dicarboxylic acid referred to here, in addition to terephthalic acid, isophthalic acid, or 2,6-naphthalene dicarboxylic acid, the main components thereof include aliphatic dicarboxylic acids such as adipic acid and sebacic acid, para- Aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, phthalic acid, and 2,6-naphthalenedicarboxylic acid. In addition, the so-called branched alkanediol is a diol having a branched alkyl group, for example, 2,2-dimethyl-1,3-propanediol, 2-methyl-2-ethyl-1, 3-Propanediol, 2-Methyl-2-butyl-1,3-propanediol, 2-Methyl-2-propyl-1,3-propanediol, 2-Methyl-2-isopropyl-1,3 -Propanediol, 2-methyl-2-n-hexyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-n-butyl-1,3-propanediol, 2-ethyl-2-n-hexyl-1,3-propanediol, 2,2-di-n-butyl-1,3-propanediol, 2-n-butyl-2-propyl-1,3-propanediol, and 2 , 2-Di-n-hexyl-1,3-propanediol, etc.

Regarding the polyester resin, it is considered that the branched alkanediol component, which is the above-mentioned more preferable form, is preferably contained in a ratio of 10 mol% or more, more preferably 20 mol%, in the total alkanediol component. % or more contained. As an alkanediol component other than the above-mentioned compounds, ethylene glycol is most preferable. If it is a small amount, diethylene glycol, propylene glycol, butanediol, hexanediol, 1, 4- cyclohexane dimethanol, etc. can also be used.

About the dicarboxylic acid which is a constituent component of the said polyester resin, terephthalic acid or isophthalic acid is preferable. If it is a small amount, other dicarboxylic acids, especially aromatic dicarboxylic acids, such as diphenylcarboxylic acid and 2, 6- naphthalene dicarboxylic acid, may be added and copolymerized. In addition to the above-mentioned dicarboxylic acid, in order to impart water dispersibility to the copolymerized polyester resin, it is preferable to copolymerize 5-sulfoisophthalic acid in the range of 1 mol % to 10 mol %, for example, : Sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfonaphthalene isophthalic acid-2,7-dicarboxylic acid, 5-(4-sulfophenoxy)isophthalic acid and its salts.

When the sum of the solid content of the polyester resin, the urethane resin having a polycarbonate structure, and the crosslinking agent in the coating liquid is 100% by mass, the lower limit of the content of the crosslinking agent is preferably 100% by mass. 5 mass %, more preferably 7 mass %, still more preferably 10 mass %, and most preferably 12 mass %. When the lower limit of the content of the crosslinking agent is 5 mass % or more, it is easy to adjust BB to 0.5 at % or more in the nitrogen distribution curve based on the element distribution measurement in the depth direction by X-ray photoelectron spectroscopy. , so it is better. The upper limit of the content rate of the crosslinking agent is preferably 50% by mass, more preferably 40% by mass, still more preferably 35% by mass, and most preferably 30% by mass. If the lower limit of the content of the crosslinking agent is 50 mass % or less, it is easy to adjust c-b to 300 seconds or less in the nitrogen distribution curve based on the element distribution measurement in the depth direction by X-ray photoelectron spectroscopy. Therefore, it is preferable.

When the sum of the solid content of the polyester resin in the coating liquid, the urethane resin having a polycarbonate structure, and the crosslinking agent is 100% by mass, the urethane having a polycarbonate structure The lower limit of the resin content is preferably 5% by mass. When the content rate of the urethane resin having a polycarbonate structure is 5% by mass or more, it is easy to adjust the ratio X of the OCOO bond on the surface of the coating layer to 2.0% or more, which is preferable. The upper limit of the content of the urethane resin having a polycarbonate structure is preferably 50% by mass, more preferably 40% by mass, still more preferably 30% by mass, and most preferably 20% by mass. If the content rate of the urethane resin is 50% by mass or less, it is easy to adjust the ratio X of the OCOO bond on the surface of the coating layer to 10.0% or less, which is preferable.

The lower limit of the polyester resin content is preferably 10% by mass, and more preferably 20 mass %, more preferably 30 mass %, particularly preferably 35 mass %, and most preferably 40 mass %. Since the adhesiveness of a coating layer and a polyester film base material becomes favorable that the content rate of a polyester resin is 10 mass % or more, it is preferable. The upper limit of the content rate of the polyester resin is preferably 70% by mass, more preferably 67% by mass, still more preferably 65% by mass, still more preferably 62% by mass, and most preferably 60% by mass. If the content rate of the polyester resin is 70 mass % or less, the heat and humidity resistance of the hard coat film after the hard coat process becomes favorable, which is preferable.

[additive] In the coating layer of the present invention, known additives such as surfactants, antioxidants, heat-resistant stabilizers, weather-resistant stabilizers, ultraviolet absorbers, and organic lubricants may be added within a range that does not inhibit the effects of the present invention. , pigments, dyes, organic or inorganic particles, antistatic agents, nucleating agents, etc.

In the present invention, in order to improve the blocking resistance of the coating layer, it is also a preferred form to add particles to the coating layer. In the present invention, as particles to be contained in the coating layer, for example, titanium oxide, barium sulfate, calcium carbonate, calcium sulfate, silicon dioxide, aluminum oxide, talc, high soil, clay, etc., or a mixture of these, and further Other general inorganic particles, such as calcium phosphate, mica, lithium bentonite, zirconia, tungsten oxide, lithium fluoride, calcium fluoride and other inorganic particles used in combination, or styrene-based, acrylic-based, melamine-based , benzomelamine, polysiloxane and other organic polymer particles, etc.

The average particle diameter of the particles in the coating layer (the average particle diameter based on the number measured by a scanning electron microscope (SEM). The same applies hereinafter) is preferably 0.04 μm to 2.0 μm, more preferably 0.1 μm to 1.0 μm . When the average particle diameter of the inert particles is 0.04 μm or more, it becomes easy to form unevenness on the film surface, so that the handling properties such as the sliding property and the winding property of the film are improved, and the workability at the time of bonding is good, which is preferable. On the other hand, when the average particle diameter of the inert particles is 2.0 μm or less, the particles are less likely to fall off, which is preferable. The particle concentration in the coating layer is preferably 1% by mass to 20% by mass in the solid content.

The method for measuring the average particle diameter of the particles is carried out by observing the particles in the cross section of the easy-adhesive polyester film with a scanning electron microscope, observing 30 particles, and taking the average value of the particle diameters as the particle diameter. The average particle size.

The shape of the particles is not particularly limited as long as it satisfies the object of the present invention, and spherical particles and non-spherical particles of indeterminate shape can be used. The particle size of the amorphous particles can calculate the equivalent circle diameter. The equivalent circle diameter is a value obtained by dividing the area of the observed particle by π, and multiplying the square root by 2 times.

[Manufacture of easily adhesive polyester film] The production method of the easily adhesive polyester film in the present invention will be described with reference to an example in which a polyethylene terephthalate (hereinafter, abbreviated as PET) film substrate is used, but of course it is not limited to this example. .

After the PET resin is fully vacuum-dried, it is supplied to an extruder, and the molten PET resin at about 280° C. is melted and extruded into a sheet form from a T die on a rotating cooling roll, and is cooled and solidified by applying an electrostatic method to obtain an unstretched material. PET sheet. The aforementioned unstretched PET sheet may have a single-layer structure or a multi-layer structure formed by a co-extrusion method.

The unstretched PET sheet is crystallized and aligned by performing uniaxial stretching or biaxial stretching on the obtained unstretched PET sheet. For example, in the case of biaxial stretching, after the uniaxially stretched PET film is obtained by extending the uniaxially stretched PET film by 2.5 times to 5.0 times in the length direction with a roller heated to 80° C. to 120° C., the end of the film is clamped with a clamp, and Introduce into a hot air zone heated to 80°C to 180°C, and extend 2.5 times to 5.0 times along the width direction. In addition, in the case of using uniaxial stretching, it is stretched to 2.5 times to 5.0 times in the tenter. After the stretching, the crystal orientation is completed by being continuously introduced into the heat treatment zone for heat treatment.

The lower limit of the temperature of the heat treatment zone is preferably 170°C, more preferably 180°C. When the temperature of the heat treatment zone is 170° C. or higher, the curing becomes sufficient, and the adhesion in the presence of liquid water becomes good and preferable, and it is not necessary to set a long drying time. On the other hand, the upper limit of the temperature of the heat treatment zone is preferably 230°C, more preferably 200°C. It is preferable that the temperature of the heat treatment zone is 230° C. or lower, since there is no possibility of lowering the physical properties of the film.

The coating layer can be provided after the film is produced or during the production step. In particular, in terms of productivity, it is preferable to form a coating layer by applying the coating liquid to at least one side of a PET film that is not stretched or uniaxially stretched at any stage of the film production process.

Any known method can be used as a method for applying the coating liquid to a PET film. For example, the reverse roll coating method, the gravure coating method, the light touch coating method, the die coater method, the roll brush coating method, the spray coating method, the air knife coating method, the wire bar coating method, the pipe coating method, the Doctor blade method, dip coating method, curtain coating method, etc. These methods can be applied individually or in combination.

In the present invention, the thickness of the coating layer can be appropriately set in the range of 0.001 μm to 2.00 μm, but in order to achieve both workability and adhesiveness, it is preferably in the range of 0.01 μm to 1.00 μm, more preferably 0.02 μm to 0.80 μm. μm, more preferably 0.05 μm to 0.50 μm. When the thickness of the coating layer is 0.001 μm or more, since the adhesiveness is good, it is preferable. If the thickness of the coating layer is 2.00 μm or less, blocking is less likely to occur, which is preferable.

The upper limit of the haze of the easily adhesive polyester film in the present invention is preferably 1.5%, more preferably 1.3%, still more preferably 1.2%, particularly preferably 1.0%. When the haze is 1.5% or less, it is preferable in terms of transparency, and it can be suitably used for an optical film requiring transparency. The haze is preferably small, and may be 0.1% or more.

[Laminated polyester film for optics] It is a preferable aspect to provide a functional layer on the coating layer of the easily adhesive polyester film in this invention. The functional layer refers to a functional layer such as a hard coat layer, an anti-glare layer, a light diffusion layer, and a transparent conductive layer for the purpose of preventing reflection or suppressing glare, suppressing rainbow unevenness, and suppressing scratches. As the functional layer, various functional layers known in the technical field can be used, and the type of the functional layer is not particularly limited. Hereinafter, each functional layer will be described.

[Hard coat] When forming the hard coat layer, known materials for hard coat layers can be used, but there are no particular limitations, and those that are polymerized and/or reacted by drying, heat, chemical reaction, or irradiation with electron beams, radiation, and ultraviolet rays can be used. resin compound. Examples of such curable resins include melamine-based, acrylic-based, polysiloxane-based, and polyvinyl alcohol-based curable resins, but a photocurable type is preferred in terms of obtaining high surface hardness and optical design. The acrylic curable resin. As such an acrylic curable resin, a polyfunctional (meth)acrylate-based monomer or an acrylate-based oligomer can be used, and examples of the acrylate-based oligomer include polyester acrylate-based, cyclic Oxyacrylate, urethane acrylate, polyether acrylate, polybutadiene acrylate, polysiloxane acrylate, etc. By mixing a reactive diluent, a photopolymerization initiator, a sensitizer, etc. with these acrylic curable resins, a coating composition for forming the aforementioned optical functional layer can be obtained.

The aforementioned hard coat layer preferably contains inorganic particles. Inorganic particles are prepared in order to increase the hardness of the cured film. For example, silica, alumina, zirconia, titania, zinc oxide, tin oxide, etc. are mentioned, and it can be used individually or in combination of 2 or more types. Among these, silicon dioxide and aluminum oxide are preferable in that the influence on optical properties is small. In the case of using silica, in order to improve the dispersibility in the coating, it is preferable to use a silane-based coupling agent, an organic compound having a reactive functional group such as a (meth)acryloyl group, and the like for the second surface treatment. Silicon oxide, but in the case of using aluminum oxide, the presence or absence of surface treatment has little effect on dispersibility, so it can be used without any problem with or without surface treatment.

The average particle diameter of the aforementioned inorganic particles is preferably 5 nm to 200 nm, more preferably 10 nm to 100 nm, and particularly preferably 20 nm to 60 nm. By setting the average particle diameter of the inorganic particles to be 5 nm or more, improvement in the hardness of the film can be expected, and by setting the average particle diameter of the inorganic particles to be 200 nm or less, the influence on optical properties such as haze can be reduced. Moreover, 0.5 weight% - 10 weight% are preferable with respect to the total solid content of an inorganic particle, and, as for the compounding quantity, 1 weight% - 8 weight% are more preferable. By setting it as 0.5 weight% or more, improvement of hardness can be expected, and by setting it as 10 weight% or less, the influence on optical characteristics, such as haze, can be reduced. In addition, regarding the average particle size, in the case of silica, the median particle size (d50) measured by the BET (Brunauer-Emmett-Teller; Beuett) method was used, and the other In this case, the median diameter (d50) was measured by the laser diffraction scattering method according to JISZ8825-1.

The above-mentioned hard coat layer may have an anti-glare function (anti-glare function) for scattering external light. The anti-glare function (anti-glare function) can be obtained by forming unevenness on the surface of the hard coat layer. At this time, the haze of the film is desirably preferably 0% to 50%, more preferably 0% to 40%, still more preferably 0% to 30%, and most preferably 1.5% or less. The lower limit may be 0.1% or more.

[Light Diffusion Layer] The upper limit of the thickness is preferably 250 μm from the viewpoint of practicality as a base film of a light-diffusing sheet. The upper limit of the particularly preferable thickness is 200 μm, which is equivalent to a general TAC film. Preferably, at least one side of the substrate has a bead coating layer mainly composed of acrylic resin beads and a binder, and the haze of the light diffusing sheet is 80% or more. If the haze of the light-diffusion sheet is 80% or more, the brightness improvement effect can be obtained, and color unevenness will not be caused, which is preferable. A better lower limit value is 85%.

Next, the method of forming a bead coating layer on the base polyester film as a light-diffusing sheet will be described, but the present invention is not limited to this. Examples of the binder used in the bead coating layer include acrylic resins such as PMMA (polymethyl methacrylate; polymethyl methacrylate), polyester resins, polyvinyl chloride, polyurethane, and polysiloxane. Various resins such as resins, and acrylic resins are particularly suitable because of their excellent transparency.

As the beads contained in the bead coating layer, it is preferable to use beads of an acrylic resin, and beads of other resins may be used in combination. As other resins, various resins such as polysiloxane resins, nylon resins, urethane resins, styrene resins, polyethylene resins, silica particles, and polyester resins can be exemplified. The particle diameter of such beads is not particularly limited, and beads having an average particle diameter of 1 μm to 50 μm are suitably used. In addition, when spherical beads are used as the above-mentioned beads, the spherical beads function as a kind of lens, and a more effective light-diffusing effect can be provided.

The above-mentioned beads are prepared in the above-mentioned binder in an appropriate proportion to prepare a coating liquid, and the coating liquid is uniformly coated on the surface of the coating layer of the easy-adhesive polyester film produced as described above, and It is dried, thereby forming a bead coating layer in which the beads are uniformly dispersed in the binder. The proportion of the beads to the binder is not particularly limited. Considering the light diffusing performance, it is preferably about 10 to 60 parts by weight relative to 100 parts by weight of the binder. As the coating method, various methods such as a roll coating method, a dipping method, a spray coating method, a spin coating method, a lamination method, and a flow coating method can be used, but are not particularly limited.

The brightness of the backlight of the liquid crystal display device using the light-diffusing sheet of the present invention is good, and the brightness variation according to the angle is small, and the brightness unevenness is also small. Therefore, it can contribute to high brightness, high quality, and cost reduction of the liquid crystal.

[Transparent conductive layer] Examples of the transparent conductive film in the present invention include indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, indium-zinc composite oxide, and the like . Among these, indium-tin composite oxide is suitable from the viewpoint of environmental stability and circuit workability. In the present invention, the transparent conductive thin film layer is laminated, and the surface resistance value of the transparent conductive laminated film is preferably 50Ω/□ to 2000Ω/□, more preferably 100Ω/□ to 1500Ω/□, whereby it is possible to It is used for a touch panel etc. as a transparent conductive laminated film. When the surface resistance value is 50Ω/□ or more and 2000Ω/□ or less, the position recognition accuracy of the touch panel is good, which is preferable.

The thickness of the transparent conductive thin film is preferably in the range of 4 nm to 30 nm, and more preferably in the range of 10 nm to 25 nm. When the film thickness of the transparent conductive thin film is 4 nm or more, it is easy to form a thin film continuously and good conductivity is obtained, which is preferable. On the other hand, when the film thickness of the transparent conductive film is 30 nm or less, when the transparent conductive layer is patterned, the difference between the optical properties of the part having the transparent conductive layer and the part not having the transparent conductive layer is small, so better.

The structure of the transparent conductive layer may be a single-layer structure, or may be a laminated structure of two or more layers. In the case of a transparent conductive thin film having a laminated structure of two or more layers, the aforementioned metal oxides constituting each layer may be the same or different.

As a film forming method of the transparent conductive thin film in the present invention, a vacuum evaporation method, a sputtering method, a CVD (Chemical Vapor Deposition) method, an ion plating method, a spray method, etc. The aforementioned method is suitably used for the desired film thickness. In addition, a transparent conductive layer may be laminated on the coating layer by a method of coating a binder resin containing conductive substances such as aniline-based compounds, thiol-based compounds, pyrrole-based compounds, and carbon nanotubes. For example, in the case of the sputtering method, a normal sputtering method using an oxide target, a reactive sputtering method using a metal target, or the like can be used. At this time, oxygen gas, nitrogen gas, or the like may be introduced as a reactive gas, or means such as ozone addition, plasma irradiation, and ion assist may be used in combination. In addition, bias voltages such as direct current, alternating current, and high frequency may be applied to the substrate within a range that does not impair the object of the present invention.

The optically laminated polyester film having a transparent conductive layer of the present invention is particularly suitable as an electrode film of a resistive film type or an electrostatic capacitance type for a touch panel. In addition, when the above-mentioned hard coat layer is laminated on the coating layer of the easily adhesive polyester film, and the transparent conductive layer is laminated on the hard coat layer, precipitation of the oligomer of the easily adhesive polyester film can be suppressed, so it is particularly preferable. 's appearance.

[lens layer] The light from the backlight in the liquid crystal panel is directed in various directions, and as a preferred aspect, it is known to provide a lens sheet to concentrate the light toward the viewing side to improve the brightness of the display device. As the lens sheet, depending on the shape of the lens processed on the surface, there are 1-axis condensing type, quadrangular pyramid type, or ridge portion long in one direction, such as cylindrical lens, hexagonal lens, biconvex lens, etc. Deformed quadrangular pyramid type, etc., 2-axis concentrating type, 3-axis concentrating type, such as 3-pyramid or 6-pyramid cone, etc., 8-pyramid or more multi-axis type, and smaller hemispherical, semi-spherical type, etc. Any of ellipsoidal microlens type, Fresnel lens type, etc. can be used. The lens sheet can be lens-processed on both sides instead of just one side, and the shape of the lenses can also be different on both sides. The 1-axis condensing lens can also be processed on both sides so that the condensing axes are orthogonal. Among these, the 2-axis type, the 3-axis type, the multi-axis type, and the microlens type have a high light-converging effect, and can be listed as particularly preferable lens shapes.

The lens layer in the present invention can be obtained, for example, by applying, for example, a thermoplastic resin or a reaction-curable resin having moderate hardness and formability on the coating layer of the easy-adhesive polyester film. The composition and the like are shaped. Various materials can be applied to the composition containing the excipient thermoplastic resin or the reaction-curable resin, including various curable resins as described in the description of the hard coat layer, and UV-curable acrylic resins are a typical example. In addition, a composition containing a monomer or an oligomer for forming a UV-curable acrylic resin may be cast into a mold in which the lens pattern is formed, so that the coating surface of the easy-adhesive polyester film is closely attached to the resin side. On this resin, ultraviolet rays are irradiated from the surface side of the easily adhesive polyester film to harden the composition, thereby forming a lens layer.

Regarding the lens sheet, the method of embossing the surface of a transparent base material using a mold with a specific pattern, coating an ultraviolet curable resin such as acrylic on an easy-adhesive polyester film as described above, and contacting one side with a specific pattern can also be used. A method of UV-curing while patterning the mold, etc.

The shape of the lens layer is not particularly limited, and for example, a prismatic lens, a Fresnel-shaped lens, a microlens, and the like can be suitably used.

From the above, the use of the optical laminated polyester film of the present invention is mainly suitable for all optical films, that is, a lens sheet, AR (Anti Reflection; anti-reflection) film, hard coat film, diffuser LCD (Liquid Crystal Display; liquid crystal display), flat-panel TV (television; television), CRT (Cathode Ray Tube; cathode ray tube) and other optical components such as boards, anti-fragment films, etc. Components such as near-infrared absorption filters, touch panels, and transparent conductive films such as electroluminescence. [Example]

Next, the present invention will be described in detail using examples and experimental examples, but the present invention is not limited to the following examples.

[Production of polyester resin pellets P-1] A 2-liter stainless steel autoclave with a stirrer was charged with high-purity terephthalic acid and ethylene glycol in an amount twice the molar amount of the high-purity terephthalic acid, and 0.3 mol % of triethylamine was added relative to the acid component. , while distilling water to the outside of the system at 250 ° C under a pressure of 0.25 MPa, the esterification reaction was carried out to obtain bis(2-hydroxyethyl) terephthalate with an esterification rate of about 95% and A mixture of oligomers (hereinafter referred to as a BHET mixture). Then, while stirring the BHET mixture, an ethylene glycol solution of antimony trioxide as a polymerization catalyst was added in an amount of 0.04 mol % of antimony atoms relative to the acid component in the polyester, and the solution was continued under a nitrogen atmosphere at normal pressure. , and stirred at 250°C for 10 minutes. Then, the temperature was raised to 280° C. over 60 minutes, the pressure of the reaction system was gradually lowered to 13.3 Pa (0.1 Torr), and the polycondensation reaction was carried out at 280° C. and 13.3 Pa. After releasing the pressure, continue to spray the slightly pressurized resin into cold water for quenching in strands, then keep it in cold water for 20 seconds, and cut it to obtain a cylindrical shape with a length of about 3mm and a diameter of about 2mm. particle.

After the polyester pellets obtained by melt polymerization were dried under reduced pressure (13.3Pa or less, 80°C, 12 hours), crystallization treatment was continued (13.3Pa or less, 130°C, 3 hours, and further 13.3Pa or less, 160°C). °C, 3 hours). While keeping the inside of the system below 13.3Pa and 215°C, the polyester particles after being left to cool are subjected to solid-phase polymerization in a solid-phase polymerization reactor to obtain polyester particles (P -1).

[Production of polyester pellets P-2] [Preparation of aluminum compound] A 20 g/l aqueous solution of basic aluminum acetate (aluminum hydroxyacetate; manufactured by Aldrich Co., Ltd.) was put into a flask together with an equivalent amount (volume ratio) of ethylene glycol, and stirred at room temperature for 6 hours. Under pressure (133Pa), stir at 90 ℃ to 110 ℃ for several hours, while distilling water from the system, and prepare 20g/l ethylene glycol solution of aluminum compound, the aforementioned basic aluminum acetate system is heated at 80 ℃ under stirring It was prepared in 2 hours and the chemical shift of the peak position of the 27Al-NMR spectrum toward the low magnetic field side was confirmed.

[Preparation of phosphorus compound] Irganox 1222 (manufactured by Ciba Refinery Co., Ltd.), which is a phosphorus compound, was put into a flask together with ethylene glycol, and heated at a liquid temperature of 160° C. for 25 hours while stirring under nitrogen substitution to prepare 50 g/l of phosphorus compound. Glycol solution. By measuring the 31P-NMR spectrum, it was confirmed that about 60 mol% was converted into a hydroxyl group.

[Preparation of mixture of ethylene glycol solution of aluminum compound/ethylene glycol solution of phosphorus compound] The respective ethylene glycol solutions obtained by the preparation of the above-mentioned aluminum compound and the above-mentioned preparation of the phosphorus compound were put into a flask, and the aluminum atom and the phosphorus atom were mixed at room temperature in a molar ratio of 1:2, and stirred for 1 day. And prepare the catalyst solution. The chemical shift was confirmed in any of the measurement results of the 27Al-NMR spectrum and the 31P-NMR spectrum of the mixed solution.

[Production of Granule P-2] Using the mixture of the ethylene glycol solution of the aluminum compound/phosphorus compound as a polycondensation catalyst, the aluminum atom and the phosphorus atom are respectively 0.014 mol % and 0.028 mol % with respect to the acid component in the polyester. The same operation as in the production of polyester pellet P-1 was performed except that it was added in the same manner. Polyester particles (P-2) with an intrinsic viscosity of 0.65 dl/g were obtained.

[Polymerization of Urethane Resin A-1 Having a Polycarbonate Structure] 1,3-cyclohexyldicarbonate was put into a four-necked flask equipped with a stirrer, a Day's condenser, a nitrogen gas introduction tube, a silica gel drying tube, and a thermometer 32 parts by mass of isocyanate, 7 parts by mass of dimethylolpropionic acid, 58 parts by mass of polyhexamethylene carbonate diol with a number average molecular weight of 800, 3 parts by mass of neopentyl glycol, and 84.00 parts by mass of acetone as a solvent, in The mixture was stirred at 75°C for 3 hours under a nitrogen atmosphere, and it was confirmed that the reaction liquid reached a predetermined amine equivalent. 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 a reaction vessel equipped with a homogenizer capable of high-speed stirring, the temperature was adjusted to 25° C., and the polyurethane prepolymer solution was added and water-dispersed while stirring and mixing for 2000 min ⁻¹ . Then, a part of acetone and water were removed under reduced pressure, whereby a water-dispersible urethane resin solution (A-1) having a solid content of 34% was prepared.

[Polymerization of Urethane Resin A-2 Having a Polycarbonate Structure] 4,4-Dicyclohexyl was put into a four-necked flask equipped with a stirrer, a Day's condenser, a nitrogen gas introduction tube, a silica gel drying tube, and a thermometer 38 parts by mass of methane diisocyanate, 9 parts by mass of dimethylolpropionic acid, 53 parts by mass of polyhexamethylene carbonate diol with a number average molecular weight of 1,000, and 84.00 parts by mass of acetone as a solvent, in a nitrogen atmosphere at 75 parts by mass The mixture was stirred for 3 hours, and it was confirmed that the reaction liquid reached a predetermined amine equivalent. 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 a reaction vessel equipped with a homogenizer capable of high-speed stirring, the temperature was adjusted to 25° C., and the polyurethane prepolymer solution was added and water-dispersed while stirring and mixing for 2000 min ⁻¹ . Then, a part of acetone and water were removed under reduced pressure to prepare a water-dispersible urethane resin solution (A-2) having a solid content of 35% by mass.

[Polymerization of Urethane Resin A-3 Having a Polycarbonate Structure] 4,4-Dicyclohexyl was put into a four-necked flask equipped with a stirrer, a Day's condenser, a nitrogen gas introduction tube, a silica gel drying tube, and a thermometer 30 parts by mass of methane diisocyanate, 16 parts by mass of polyethylene glycol monomethyl ether with a number average molecular weight of 700, 50 parts by mass of polyhexamethylene carbonate glycol with a number average molecular weight of 1200, 4 parts by mass of neopentyl glycol, and 84.00 parts by mass of acetone as a solvent was stirred at 75° C. for 3 hours under a nitrogen atmosphere, and it was confirmed that the reaction liquid reached a predetermined amine equivalent. Next, after cooling this reaction liquid to 40 degreeC, the polyurethane prepolymer solution was obtained. Next, 450 g of water was added to a reaction vessel equipped with a homogenizer capable of high-speed stirring, the temperature was adjusted to 25° C., and the polyurethane prepolymer solution was added and water-dispersed while stirring and mixing for 2000 min ⁻¹ . Then, a part of acetone and water were removed under reduced pressure to prepare a water-dispersible urethane resin solution (A-3) having a solid content of 35% by mass.

[Polymerization of Urethane Resin A-4 Having a Polycarbonate Structure] 4,4-Dicyclohexylmethane was put into a four-necked flask equipped with a stirrer, a Day's condenser, a nitrogen gas introduction tube, a silica gel drying tube, and a thermometer 24 parts by mass of diisocyanate, 4 parts by mass of dimethylolbutyric acid, 71 parts by mass of polyhexamethylene carbonate diol with a number average molecular weight of 2000, 1 part by mass of neopentyl glycol, and 84.00 parts by mass of acetone as a solvent , and stirred at 75° C. for 3 hours under a nitrogen atmosphere, and it was confirmed that the reaction solution reached a predetermined amine equivalent. 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 a reaction vessel equipped with a homogenizer capable of high-speed stirring, the temperature was adjusted to 25° C., and the polyurethane prepolymer solution was added and water-dispersed while stirring and mixing for 2000 min ⁻¹ . Then, a part of acetone and water were removed under reduced pressure to prepare a water-dispersible urethane resin solution (A-4) having a solid content of 34% by mass.

[Polymerization of Urethane Resin A-5 Without Polycarbonate Polyol Component] Using polyether polyol, organic polyisocyanate, and diethylene glycol as a chain extender, the reaction is carried out at a temperature of 70° C. to 120° C. for 2 hours by a multi-stage isocyanate compound addition method. The obtained urethane prepolymer was mixed with an aqueous hydrogen sulfite solution, and the reaction was carried out while sufficiently stirring for about 1 hour, so that the terminal was capped. The reaction temperature is set to 60°C or lower. Then, it diluted with water, and prepared the heat-reactive water-dispersible urethane resin solution (A-5) whose solid content is 20 mass %.

[Polymerization of Urethane Resin A-6 having a Polycarbonate Structure] 4,4-Dicyclohexyl was put into a four-necked flask equipped with a stirrer, a Day's condenser, a nitrogen gas introduction tube, a silica gel drying tube, and a thermometer 54 parts by mass of methane diisocyanate, 16 parts by mass of polyethylene glycol monomethyl ether with a number average molecular weight of 700, 18 parts by mass of polyhexamethylene carbonate diol with a number average molecular weight of 1200, 12 parts by mass of neopentyl glycol and as 84.00 parts by mass of acetone as a solvent was stirred at 75° C. for 3 hours under a nitrogen atmosphere, and it was confirmed that the reaction liquid reached a predetermined amine equivalent. 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 a reaction vessel equipped with a homogenizer capable of high-speed stirring, the temperature was adjusted to 25° C., and the polyurethane prepolymer solution was added and water-dispersed while stirring and mixing for 2000 min ⁻¹ . Then, a part of acetone and water were removed under reduced pressure to prepare a water-dispersible urethane resin solution (A-6) having a solid content of 34% by mass.

The following two items are shown in Table 2. A. Mass ratio of polycarbonate polyol component and polyisocyanate component when synthesizing and polymerizing the urethane resin to form the coating layer (polycarbonate polyol component/polyisocyanate component) B. Molecular weight of polycarbonate polyol components

[Table 2] A. Mass ratio (polycarbonate polyol component/polyisocyanate component) B. Molecular weight of polycarbonate polyol components A-1 1.8 800 A-2 1.4 1000 A-3 1.7 1200 A-4 3 2000 A-5 0 - A-6 0.3 1200

[Polymerization of Blocked Isocyanate Crosslinking Agent B-1] In a flask equipped with a stirrer, a thermometer, and a reflux condenser, 66.04 parts by mass of a polyisocyanate compound having an isocyanurate structure (Duranate TPA, manufactured by Asahi Kasei Chemical Co., Ltd.) using hexamethylene diisocyanate as a raw material, N-methyl To 17.50 parts by mass of pyrrolidone, 25.19 parts by mass of 3,5-dimethylpyrazole (dissociation temperature: 120° C., boiling point: 218° C.) was added dropwise, and the mixture was kept at 70° C. for 1 hour under a nitrogen atmosphere. Then, 5.27 parts by mass of dimethylolpropionic acid was added dropwise. The infrared spectrum of the reaction solution was measured, and after confirming that the absorption of the isocyanate group disappeared, 5.59 parts by mass of N,N-dimethylethanolamine and 132.5 parts by mass of water were added to obtain a blocked polyisocyanate aqueous dispersion having a solid content of 40% by mass ( B-1). The number of functional groups of the blocked isocyanate crosslinking agent is 4.

[Polymerization of Blocked Isocyanate Crosslinking Agent B-2] Into a flask equipped with a stirrer, a thermometer, and a reflux condenser, 100 parts by mass of a polyisocyanate compound having an isocyanurate structure (manufactured by Asahi Kasei Chemical Co., Ltd., Duranate TPA) using hexamethylene diisocyanate as a raw material, propylene glycol monomethyl 55 parts by mass of ether acetate and 30 parts by mass of polyethylene glycol monomethyl ether (average molecular weight: 750) were kept at 70° C. for 4 hours under a nitrogen atmosphere. Then, the temperature of the reaction solution was lowered to 50°C, and 47 parts by mass of methyl ethyl ketoxime was added dropwise. The infrared spectrum of the reaction solution was measured, and it was confirmed that the absorption of the isocyanate group disappeared, and the oxime-blocked isocyanate crosslinking agent (B-2) having a solid content of 40% by mass was obtained. The number of functional groups of the blocked isocyanate crosslinking agent is 3.

[Polymerization of Carbodiimide B-3] Into a flask equipped with a stirrer, a thermometer, and a reflux condenser, 168 parts by mass of hexamethylene diisocyanate and 220 parts by mass of polyethylene glycol monomethyl ether (M400, average molecular weight 400) were charged parts by mass, stirred at 120°C for 1 hour, and further added 26 parts by mass of 4,4'-dicyclohexylmethane diisocyanate and 3-methyl-1-phenyl-2-phosphorus as a carbodiimide catalyst 3.8 parts by mass of cyclopentene-1-oxide (2 mass % with respect to all isocyanates) was further stirred at 185° C. for 5 hours under nitrogen flow. The infrared spectrum of the reaction solution was measured, and it was confirmed that the absorption at wavelengths of 220 cm ^-1 to 2300 cm ^-1 disappeared. It stood to cool to 60 degreeC, and 567 mass parts of ion-exchange water were added, and the carbodiimide aqueous resin liquid (B-3) whose solid content is 40 mass % was obtained.

[Polymerization of polyester resin C-1] 194.2 parts by mass of dimethyl terephthalate, 184.5 parts by mass of dimethyl isophthalate, and dimethyl 5-sulfoisophthalate were charged into a stainless steel autoclave equipped with a stirrer, a thermometer, and a partial reflux condenser. 14.8 parts by mass of sodium ester, 233.5 parts by mass of diethylene glycol, 136.6 parts by mass of ethylene glycol, and 0.2 part by mass of tetra-n-butyl titanate were transesterified at a temperature from 160°C to 220°C for 4 hours. Then, the temperature was raised to 255° C., the reaction system was gradually reduced in pressure, and then the reaction system was reacted under a reduced pressure of 30 Pa for 1 hour and 30 minutes to obtain a copolymerized polyester resin (C-1). The obtained copolymerized polyester resin (C-1) was pale yellow and transparent. The reduced viscosity of the copolymerized polyester resin (C-1) was measured and found to be 0.70 dl/g. The glass transition temperature measured by DSC was 40°C.

[Preparation of Aqueous Polyester Dispersion] 15 parts by mass of polyester resin (C-1) and 15 parts by mass of ethylene glycol n-butyl ether were added to the reactor equipped with a stirrer, a thermometer and a reflux device, and the resin was dissolved by heating and stirring at 110°C. After the resin was completely dissolved, 70 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 (Cw-1) having a solid content of 15% by mass.

[Example 1] (1) Preparation of coating solution The following coating agents were mixed with a mixed solvent of water and isopropyl alcohol to prepare a urethane resin solution (A-1)/crosslinking agent (B-1)/polyester aqueous dispersion (Cw-1). The solid matter mass ratio was a coating liquid of 25/26/49. Urethane resin solution (A-1) 3.55 parts by mass Cross-linking agent (B-1) 3.16 parts by mass Polyester water dispersion (Cw-1) 16.05 parts by mass Particles 0.47 parts by mass (Dry-process silica with an average particle size of 200 nm, solid content concentration 3.5%) Particles 1.85 parts by mass (Silica sol with an average particle diameter of 40 nm to 50 nm, solid content concentration 30% by mass) Surfactant 0.30 parts by mass (polysiloxane-based, solid content concentration 10% by mass)

(2) Manufacture of easily adhesive polyester film The polyester particles (P-1) as the film raw material polymer were dried at 135° C. for 6 hours under a reduced pressure of 133 Pa. Then, it was supplied to an extruder, melt-extruded to a sheet form at about 280 degreeC, and was quenched and solidified on the rotating cooling metal roll whose surface temperature was maintained at 20 degreeC, and the unstretched PET sheet was obtained.

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

Then, after applying the coating liquid left standing at room temperature for 5 hours or more on one side of a PET film by a roll coating method, it was dried at 80° C. for 20 seconds. In addition, it adjusted so that the coating amount after drying in the final (after biaxial stretching) might be 0.15 g/m ² (coating layer thickness after drying: 150 nm). Continue to stretch to 4.0 times in the width direction with a tenter at 120°C, heat the film at 230°C for 5 seconds in a state where the length in the width direction of the film is fixed, and further perform a 3% relaxation treatment in the width direction at 100°C for 10 seconds bell to obtain a 100 μm easy-adhesive polyester film.

(3) Manufacture of laminated polyester film for optics

[Laminated polyester film for optics with hard coat layer (1)] A coating liquid for forming a hard coat layer having the following composition was applied on the coating layer of the easily adhesive polyester film using a #5 wire bar, and then The solvent was removed by drying at 80°C for 1 minute. Next, the film coated with the hard coat layer was irradiated with ultraviolet rays of 300 mJ/cm ² using a high pressure mercury lamp to obtain a laminated polyester film (1) for optics with a hard coat layer. [Coating liquid for forming a hard coat layer] ・39.10 mass % neotaerythritol triacrylate PETA (manufactured by Toagosei Co., Ltd., trifunctional acrylic UV-curable resin, solid content 100%, refractive index 1.49) ・Zirconium oxide particles 3.40 mass % (Nihon Shokubai Co., Ltd., ZP-153, average particle size 11 nm, solid content 70%, refractive index 1.53) ・Photopolymerization initiator 3.50 mass% (Omnirad184 manufactured by IGM Resins BV) ・Photopolymerization initiator 2.00 mass % (Omnirad907 manufactured by IGM Resins BV) ・Solvent 52.00 mass % (methyl ethyl ketone (MEK)/propylene glycol monomethyl ether (PGM))

[Laminated polyester film for optics with hard coat layer (2)] The coating liquid for forming a hard coat layer having the following composition was applied on the coating layer of the easily adhesive polyester film using a #5 wire bar, and then The solvent was removed by drying at 80°C for 1 minute. Then, 300mJ/cm< ² > of ultraviolet rays were irradiated to the film coated with the hard coat layer using a high pressure mercury lamp to obtain a laminated polyester film (2) for optics with a hard coat layer. [Coating liquid for forming a hard coat layer] ・34.2 mass % neotaerythritol triacrylate PETA (manufactured by Toagosei Co., Ltd., trifunctional acrylic UV-curable resin, solid content 100%, refractive index 1.49) ・Nanodi Silica 4.30% by mass (made by Nissan Chemical, average particle system 80nm, MEK-AC-5140Z, solid content 32%) ・Photopolymerization initiator 3.50% by mass (Omnirad184 by IGM Resins BV) ・Photopolymerization initiator 2.00 Mass % (Omnirad 907 manufactured by IGM Resins BV) ・Solvent 56.00 mass % (Propylene Glycol Monomethyl Ether (PGM))

[Laminated polyester film for optics with lens layer of photocurable urethane/acrylic resin] The following photocurable urethane/ About 5g of acrylic coating liquid, superimposed so that the coating layer of the easy-adhesive polyester film is in contact with the photocurable urethane/acrylic coating liquid, using a width of 10 cm from the easy-adhesive polyester film . A manual load-bearing rubber roller with a diameter of 4cm presses the light-hardening urethane/acrylic coating solution in an extended manner. The photocurable urethane/acrylic resin was cured by irradiating ultraviolet rays of 300 mJ/cm ² from the surface side of the easily adhesive polyester film using a high-pressure mercury lamp. The film sample having a photocurable urethane/acrylic layer with a thickness of 50 μm was peeled from the SUS plate to obtain a laminated polyester film for optics with a photocurable urethane/acrylic layer (for shaping processing) previous state). [Photocurable urethane/acrylic coating liquid] 20.00 mass% of photocurable acrylic resin (Blemmer 650, manufactured by Shin-Nakamura Chemical) 40.00 mass% of photocurable methacrylate resin (manufactured by Shin-Nakamura Chemical) BPE-500) Photocurable urethane/acrylic resin 29.00% by mass (U-6HA manufactured by Shin-Nakamura Chemical) 8.00% by mass of photocurable acrylic resin (AMP-10G manufactured by Shin-Nakamura Chemical) Start of photopolymerization Agent 3.00% by mass (Irgacure 184 manufactured by Ciba Refinery Co., Ltd.)

[Laminated polyester film for optics with lens layer of photocurable acrylic resin] An optical laminate having a photocurable acrylic resin lens layer was obtained in the same manner except that the coating liquid was changed to the following photocurable acrylic coating liquid, and the ultraviolet irradiation amount was changed to 100 mJ/cm ² . Polyester film (state before shaping). [Photocurable acrylic coating liquid] 77.00 mass % of photocurable acrylic resin (A-BPE-4 manufactured by Shin-Nakamura Chemical) 22.00 mass % of photocurable acrylic resin (AMP-10G manufactured by Shin-Nakamura Chemical) Photopolymerization Starter 1.00% by mass (Irgacure 184 manufactured by Ciba Refinery Co., Ltd.)

[Laminated polyester film for optics with light diffusing layer] The coating liquid for forming a light-diffusion layer of the following composition was applied on the coating layer of the easily-adhesive polyester film using a wire bar of #5, dried and thermally cured at 160° C. for 60 seconds. Optical laminated polyester film with light diffusing layer. [Coating liquid for forming a light-diffusion layer] Acrylic polyol (solid content 50%) 150 parts by mass (Acrydic A-807: Dainippon Ink Chemical Industry Co., Ltd.) Isocyanate (solid content 60%) 30 parts by mass (Takenate D11N: Takeda Pharmaceutical Co., Ltd.) 200 parts by mass of methyl ethyl ketone Butyl acetate 200 parts by mass 40 parts by mass of acrylic resin particles (MX-1000, average particle size 10.0 μm: Soken Chemical Co., Ltd.)

[Laminated polyester film for optics with anti-glare layer] The coating liquid for forming an anti-glare layer having the following composition was applied on the coating layer of the easily adhesive polyester film using a #5 wire bar, and dried at 70°C 1 minute to remove the solvent. Next, the anti-glare layer-coated film was irradiated with ultraviolet rays of 300 mJ/cm ² using a high-pressure mercury lamp to obtain an optical laminated polyester film having an anti-glare layer with a thickness of 5 μm.・Anti-glare layer forming coating liquid 34 parts by mass of toluene, 50 parts by mass of neotaerythritol triacrylate, 50 parts by mass of silica (average particle size of 1 μm), 12 parts by mass of polysiloxane (leveling agent), 1 part by mass of starting photopolymerization 1 part by mass of agent (Irgacure 184 manufactured by Ciba Refinery Co., Ltd.)

[Example 2] Except having changed the urethane resin to (A-2), it carried out similarly to Example 1, and obtained the easily adhesive polyester film and various optical laminated polyester films.

[Example 3] Except having changed the urethane resin to (A-3), it carried out similarly to Example 1, and obtained the easily adhesive polyester film and various optical laminated polyester films.

[Example 4] Except having changed the crosslinking agent into (B-2), it carried out similarly to Example 1, and obtained the easily adhesive polyester film and various optical laminated polyester films.

[Example 5] To a mixed solvent of water and isopropanol, mix the following coating agent, and use the solid of urethane resin solution (A-1)/crosslinking agent (B-1)/polyester water dispersion (Cw-1) Except having changed so that a substance mass ratio might become 22/10/68, it carried out similarly to Example 1, and obtained the easily adhesive polyester film and various optical laminated polyester films. Urethane resin solution (A-1) 2.71 parts by mass Cross-linking agent (B-1) 1.00 parts by mass Polyester water dispersion (Cw-1) 19.05 parts by mass Particles 0.47 parts by mass (Dry-process silica with an average particle size of 200 nm, solid content concentration 3.5%) Particles 1.85 parts by mass (Silica sol with an average particle diameter of 40 nm to 50 nm, solid content concentration 30% by mass) Surfactant 0.30 parts by mass (polysiloxane-based, solid content concentration 10% by mass)

[Example 6] Except having changed the urethane resin into (A-2), it carried out similarly to Example 5, and obtained the easily adhesive polyester film and various optical laminated polyester films.

As shown in Table 5, in Examples 1 to 6, "B-A", "b", and "c-b" satisfy the ranges of the following formulas, respectively, haze, hard coat adhesion, anti-blocking Sex can meet the requirements. (i)0.5≦B－A(at%)≦3.0 (ii)30≦b(second)≦180 (iii)30≦c－b(second)≦300 In addition, "X" satisfies the following formula, and the adhesiveness with respect to various optical functional layers can satisfy a request|requirement. (iv)2.0≦X(%)≦10.0

[Example 7] Except having changed the polyester pellet into (P-2) as a film raw material polymer, it carried out similarly to Example 1, and obtained the easily adhesive polyester film and various optical laminated polyester films.

As shown in Table 5, in Example 7, "BB", "b", and "c-b" satisfy the ranges of the following formulas, respectively, and the adhesion and blocking resistance to various optical functional layers can be satisfied Require. (i)0.5≦B－A(at%)≦3.0 (ii)30≦b(second)≦180 (iii)30≦c－b(second)≦300 In addition, "X" satisfies the following formula, and the adhesiveness with respect to various optical functional layers can satisfy a request|requirement. (iv)2.0≦X(%)≦10.0 Furthermore, it was confirmed that the haze value was smaller than that of Examples 1 to 6 using the polyester particles P-1, and the transparency of the film was improved.

[Example 8] In order to expose the easily-adhesive polyester film obtained in Example 1 to a vacuum, an unwinding process was performed in a vacuum chamber. The pressure at this time was 0.002 Pa, and the exposure time was 10 minutes. In addition, the temperature of the center roll was made into 40 degreeC. Next, a transparent conductive thin film composed of indium tin oxide is formed on the hard coat layer of the hard coat film. At this time, the pressure before sputtering was set to 0.0007 Pa, indium oxide containing 5 mass % of tin oxide (manufactured by Mitsui Metals & Mining Co., Ltd., density 7.1 g/cm ³ ) was used as a target, and a DC (Direct Current) of 2 W/cm ² was applied. ; DC) electricity. In addition, Ar gas was flowed at a flow rate of 130 sccm, and O ₂ gas was flowed at a flow rate of 10 sccm, and a film was formed in an atmosphere of 0.4 Pa using a DC magnetron sputtering method. In the above manner, a transparent conductive film composed of indium tin oxide with a thickness of 22 nm and having a transparent conductive layer with a surface resistance value of 250Ω can be obtained. The adhesiveness of the transparent conductive layer can satisfy the requirements.

[Example 9] In order to subject the hard coat film (1) obtained in Example 1 to vacuum exposure, unwinding treatment was carried out in a vacuum chamber. Subsequent steps were performed in the same manner as in Example 8, whereby a transparent conductive film composed of indium tin oxide with a thickness of 22 nm and having a transparent conductive layer with a surface resistance value of 250Ω was obtained. The adhesiveness of the transparent conductive layer can satisfy the requirements.

[Experimental Example 1] The following paints were mixed with a mixed solvent of water and isopropyl alcohol, and the solid content ratio of the urethane resin solution (A-5)/polyester aqueous dispersion (Cw-1) was changed to 29/71 , except that, in the same manner as in Example 1, an easily adhesive polyester film and various laminated polyester films for optics were obtained. Urethane resin solution (A-5) 6.25 parts by mass Polyester water dispersion (Cw-1) 20.00 parts by mass Catalyst for Elastron 0.50 parts by mass Particles 1.02 parts by mass (Dry-process silica with an average particle size of 200 nm, solid content concentration 3.5%) Particles 2.15 parts by mass (Silica sol with an average particle size of 40 nm, solid content concentration of 20 mass %) Surfactant 0.30 parts by mass (Fluorine-based, solid content concentration 10% by mass)

As shown in Table 5, in Experimental Example 1, since "X" was less than 2.0%, the adhesiveness to the lens layer could not satisfy the requirement. In addition, "b" exceeds 180 seconds, so the anti-blocking property cannot meet the requirements.

[Experimental example 2] Except having changed the urethane resin to (A-4), it carried out similarly to Example 1, and obtained the easily adhesive polyester film and various optical laminated polyester films.

[Experimental example 3] Except having changed the urethane resin into (A-4) and the crosslinking agent into (B-2), it carried out similarly to Example 1, and obtained the easily adhesive polyester film and various optical laminated layers. polyester film.

As shown in Table 5, in Experimental Example 2 and Experimental Example 3, since "BB" was less than 0.5 at %, the hard coat adhesiveness may not fully satisfy the requirement.

[Experimental Example 4] The following paints were mixed with a mixed solvent of water and isopropyl alcohol, and the solid content ratio of the urethane resin solution (A-4)/crosslinking agent (B-1) was changed to 70/30, except Other than that, it carried out similarly to Example 1, and obtained the easily adhesive polyester film and the laminated polyester film for optics. Urethane resin solution (A-4) 9.03 parts by mass Cross-linking agent (B-1) 3.38 parts by mass Particles 0.52 parts by mass (Dry-process silica with an average particle size of 200 nm, solid content concentration 3.5%) Particles 1.80 parts by mass (Silica sol with an average particle size of 40 nm, solid content concentration of 30 mass %) Surfactant 0.30 parts by mass (polysiloxane-based, solid content concentration 10% by mass)

As shown in Table 5, in Experimental Example 4, since "c-b" exceeded 300 seconds, the haze could not satisfy the requirement.

[Experimental example 5] The following paints were mixed with a mixed solvent of water and isopropyl alcohol, and the solid content ratio of the urethane resin solution (A-4)/crosslinking agent (B-1) was changed to 20/80, except Otherwise, in the same manner as in Example 1, an easily adhesive polyester film and various laminated polyester films for optics were obtained. Urethane resin solution (A-4) 2.58 parts by mass Cross-linking agent (B-1) 9.00 parts by mass Particles 0.52 parts by mass (Dry-process silica with an average particle size of 200 nm, solid content concentration 3.5%) Particles 1.80 parts by mass (Silica sol with an average particle size of 40 nm, solid content concentration of 30 mass %) Surfactant 0.30 parts by mass (polysiloxane-based, solid content concentration 10% by mass)

As shown in Table 5, in Experimental Example 5, since "c-b" exceeded 300 seconds, the haze could not satisfy the requirement.

[Experimental example 6] Except having changed the urethane resin to (A-2) and the crosslinking agent to (B-3), it was carried out in the same manner as in Example 5 to obtain an easily adhesive polyester film and various optical laminates polyester film.

As shown in Table 5, in Experimental Example 6, since "BB" was less than 0.5 at %, the blocking resistance and the hard coat adhesion may not fully satisfy the requirements.

[Experimental example 7] Except having changed the urethane resin to (A-6), it carried out similarly to Example 5, and obtained the easily adhesive polyester film and the laminated polyester film for optics.

As shown in Table 5, in Experimental Example 7, since "X" is less than 2.0%, the adhesiveness to the lens layer may not fully satisfy the requirement.

The evaluation method used in the present invention will be described below.

(1) Haze The haze of the easily adhesive polyester film obtained was measured using a turbidity meter (manufactured by Nippon Denshoku, NDH5000) in accordance with JIS K 7136:2000.

(2) Anti-adhesion Two film samples were superimposed so that the coating layers were opposed to each other, a load of 98 kPa was applied, and the two film samples were allowed to adhere to each other for 24 hours in an atmosphere of 50° C. and left to stand. Then, the film was peeled off, and the peeling state was determined according to the following criteria. ○: The coating layer has no transfer and can be easily peeled off. Δ: The coating layer was maintained, but the surface layer of the coating layer was partially transferred to the opposite side. ×: The two films were fixed and could not be peeled off, or the film substrate was split although peeling was possible.

(3) Adhesion With respect to the optical functional layer of the obtained optical laminated polyester film, 100 square-shaped incisions penetrating the optical functional layer and reaching the base film were formed using a cutter guide with a gap of 2 mm. Next, a cellophane adhesive tape (manufactured by Nichiban Co., Ltd., No. 405; width 24 mm) was attached to the square-shaped cut surface, and the cellophane adhesive tape was completely adhered with an eraser. Then, the cellophane adhesive tape was vertically peeled off from the optically functional layer of the optical laminated polyester film, and after this operation was performed 5 times, the number of squares peeled off from the optically functional layer of the optically laminated polyester film was visually counted. , and the adhesiveness between the optical functional layer and the film substrate was obtained according to the following formula. Furthermore, the partially peeled squares among the squares are also counted as peeled squares. Adhesion was made into pass 95(%). Adhesion (%) = (1 - number of stripped squares/100) × 100

(4) Measurement of Element Distribution in Depth Direction The measurement of element distribution in the depth direction of the coating layer was performed by X-ray photoelectron spectroscopy (ESCA). The ion source for etching uses an Ar cluster that is low in damage to organic materials. In addition, the sample was rotated during etching so as to be able to etch uniformly. In order to minimize the damage caused by X-ray irradiation, the spectrum collection at each etching time was carried out in a snapshot mode which can be evaluated in a short time. In addition, for the convenience of evaluation, the spectrum collection was performed every 30 seconds until the etching time was 120 seconds, and thereafter every 60 seconds. Details of the measurement conditions are shown below. Furthermore, the shirley method is used to remove the background during analysis.・Apparatus: K-Alpha ⁺ (manufactured by Thermo Fisher Scientific) ・Measurement conditions Excitation X-ray: Monochromatic Al Kα-ray X-ray output: 12kV, 2.5mA Photoelectron extraction angle: 90° Spot size: 200μmφ Passing energy: 150 eV (Snapshot mode) Acceleration voltage of ion gun: 6kV Cluster size: Large Etch rate: 10nm/min (polystyrene conversion) ^※ Sample rotation during etching: Yes (When calculating the etching rate, use molecular weight Mn: 91000 (Mw/Mn=1.05) monodisperse polystyrene dissolved in toluene, and then produced by spin coating on a silicon wafer with a film thickness of 155nm)

Based on the data thus evaluated, the etching time taken from the surface of the coating layer is on the horizontal axis, and the ratio of the amount of nitrogen atoms to the total amount of carbon atoms, oxygen atoms, nitrogen atoms, and silicon atoms (nitrogen atom ratio) is on the vertical axis. , depicting the nitrogen distribution curve. The nitrogen distribution curves of the easily adhesive polyester film samples (Example 2, Example 5, and Experimental Example 6) are shown in FIG. 1 , FIG. 3 , and FIG. 4 , respectively. Based on the nitrogen distribution curve of Example 2 shown in FIG. 1 , the method for calculating the characteristic value of the present invention will be described with reference to FIG. 2 . As shown in FIG. 2 , the nitrogen atomic ratio of the surface of the coating layer on the opposite side of the polyester film substrate is A (at%), the maximum nitrogen atomic ratio is B (at%), and the nitrogen atomic ratio is The etching time of the maximum value B (at%) is set to b (seconds), and the etching time when the nitrogen atom ratio becomes 1/2B (at%) after b (seconds) is set to c (seconds), read, and calculate B -A (at%), c-b (seconds) to obtain. The nitrogen atomic ratio on the surface of the coating layer on the opposite side to the polyester film substrate means the nitrogen atomic ratio at the etching time of 0 (sec) in the drawing. (In addition, "s" described as "etching time s" on the horizontal axis in Figs. 1 to 4 means "seconds" in units)

(5) Measurement of the OCOO bond ratio in the surface region The ratio (X) of the OCOO bond in the surface region was evaluated by X-ray photoelectron spectroscopy (ESCA). As the apparatus, K-Alpha ⁺ (manufactured by Thermo Fisher Scientific) was used. Details of the measurement conditions are shown below. Furthermore, the shirley method is used to remove the background during analysis. In addition, the calculation of X is an average value of the measurement results of three or more places.・Measurement conditions Excitation X-ray: Monochromatic Al Kα-ray X-ray output: 12kV, 6mA Photoelectron extraction angle: 90° Spot size: 400μmφ Passing energy: 50eV Step size: 0.1eV Energy decomposition energy: Ag3d(5/2) FWHM of the spectrum=0.75eV FIGS. 5 and 6 are graphs showing the results of analysis of the C1s spectrum of the surface regions of the easily adhesive polyester films of Example 6 and Experimental Example 1, respectively. The solid grey line represents the measured data of the C1s spectrum. The peaks of the obtained measured spectrum are separated into a plurality of peaks, and the bond species corresponding to each peak is identified according to the position and shape of each peak. Furthermore, curve fitting was performed using the peak derived from each bond species, and the peak area was calculated. The bond species of each peak (1) to peak (6) that may appear are shown in Table 3.

[table 3] key species (1) Black two-point chain line CC key (2) Black dotted line CO key, CN key (3) Black three-point chain line C=O key (4) Black single point chain line COO key (5) Black dotted line OCOO key (6) Black solid line π-π* bond

The sum of the peak areas derived from each bond species in the C1s spectral region refers to the sum of the peak areas from peak (1) to peak (6), and the peak area derived from the OCOO bond refers to the peak area of peak (5). When the total of the peak areas derived from each bond species in the C1s spectral region is set to 100%, X (%) represents the ratio (%) of the area of the peak (5) as a percentage.

Table 4 shows the calculation results of the peak area from the peak (1) to the peak (6) in Example 6 and Experimental Example 1. As mentioned above, the percentage data of the peak (5) is the data of X (%). The peaks (3) and (6) of Example 6 and the peaks (3) and (5) of Experimental Example 1 did not appear.

[Table 4] Example 6 Experimental example 1 (1) 63.5% 64.4% (2) 23.1% 20.9% (3) - - (4) 7.5% 12.7% (5) 5.9% - (6) - 2.0%

(6) Determination method of number average molecular weight of polycarbonate polyol When the urethane resin having a polycarbonate structure was measured by proton nuclear magnetic resonance spectroscopy (1H-NMR), a peak derived from the methylene group adjacent to the OCOO bond was observed in the vicinity of 4.1 ppm. In addition, the peak derived from the methylene group adjacent to the urethane bond generated by the reaction of the polyisocyanate and the polycarbonate polyol was observed in a magnetic field about 0.2 ppm higher than the peak. The number average molecular weight of the polycarbonate polyol was calculated from the integrated value of these two types of peaks and the molecular weight of the monomer constituting the polycarbonate polyol.

Table 5 summarizes the evaluation results of the respective examples and experimental examples.

[產業可利用性][table 5]

[Industrial Availability]

The easily adhesive polyester film in the present invention is excellent in adhesion to the hard coat layer, light diffusion layer, lens layer, antiglare layer, and transparent conductive layer, so it is particularly suitable for optical applications, and is suitable for use mainly in displays and the like. A hard coat film and a base film of an optically functional film such as a lens sheet using the film.

1] It is the distribution curve of nitrogen element based on the element distribution measurement of the depth direction by X-ray photoelectron spectroscopy with respect to the easily adhesive polyester film of Example 2. [FIG. 2 is an explanatory diagram for obtaining BB, b, and c-b from the distribution curve of nitrogen element based on the element distribution measurement in the depth direction by X-ray photoelectron spectroscopy. [ Fig. 3] Fig. 3 is a distribution curve of nitrogen based on the element distribution in the depth direction measured by X-ray photoelectron spectroscopy with respect to the easily adhesive polyester film of Example 5. [Fig. 4] It is the distribution curve of nitrogen element based on the element distribution measurement of the depth direction by X-ray photoelectron spectroscopy with respect to the easily adhesive polyester film of Experimental Example 6. [FIG. 5] It is a figure which shows the analysis result of the C1s spectrum of the coating layer surface area|region of the easily adhesive polyester film of Example 6. [FIG. 6] It is a figure which shows the analysis result of the C1s spectrum of the coating layer surface area|region of the easily adhesive polyester film of Experimental Example 1. [FIG.

Claims (2)

A laminated polyester film for optics, the coating layer of the easy-adhesive polyester film having a coating layer on at least one side of a polyester film base material, and the laminated layer is selected from the group consisting of a hard coat layer, a light diffusing layer, and a lens layer. , at least one optical functional layer among the anti-glare layer and the transparent conductive layer, and the above-mentioned coating layer is to harden the composition containing the urethane resin having a polycarbonate structure, the crosslinking agent, and the polyester resin In the distribution curve of nitrogen based on the element distribution in the depth direction measured by X-ray photoelectron spectroscopy on the coating layer, when the nitrogen atoms on the surface of the coating layer on the opposite side to the polyester film substrate are The ratio is set to A (at%), the maximum value of the nitrogen atom ratio is set to B (at%), and the etching time for which the nitrogen atom ratio shows the maximum value B (at%) is set to b (seconds), and nitrogen after b (seconds) When the etching time when the atomic ratio becomes 1/2B (at%) is set to c (seconds), the following formulas (i) to (iii) are satisfied, and surface analysis by X-ray photoelectron spectroscopy In the spectrum, when the total peak area derived from each bond species in the C1s spectral region is set as 100 (%) and the peak area derived from the OCOO bond is set as X (%), the following formula (iv) is satisfied; (i)0.5≦B－A(at%)≦3.0 (ii)30≦b(second)≦180 (iii)30≦c－b(second)≦300 (iv) 2.0≦X(%)≦10.0. The optical laminated polyester film according to claim 1, wherein the easily adhesive polyester film has a haze of 1.5 (%) or less.

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