KR20100014984A - Antistatic film, polyester film for surface-protecting film, and polyester film for protecting surface of optical member - Google Patents

Abstract

An antistatic film excellent in antistatic properties, water resistance, and durability. The antistatic film is characterized by comprising a polyester film and, formed on one side thereof, a coating layer comprising an antistatic polymer having constituent elements represented by the following structural formulae (1) and (2) as repeating units. (In the formula, Rand Reach independently is hydrogen or Calkyl, and Xis a monovalent anion.)

Description

Antistatic Film, Polyester Film For Surface Protection Film And Optical Film Polyester Film For Surface Protection {Antistatic Film, Polyester Film For Surface-Protecting Film, And Polyester Film For Protecting Surface Of Optical Member}

The present invention relates to an antistatic film. More specifically, the present invention relates to an antistatic polyester film having excellent antistatic performance and excellent water resistance of antistatic performance. Moreover, this invention relates to the film suitable for the surface protection film of a polarizing plate, a retardation plate, or a viewing angle expansion film, and is related with the film which is little in the case of friction and peeling, and is excellent in an external appearance.

The polyester film represented by polyethylene terephthalate or polyethylene naphthalate has excellent mechanical strength, dimensional stability, flatness, heat resistance, chemical resistance, optical properties, and the like, and thus has excellent cost performance. It is used as a base material in various uses, including a film for packaging, an optical film.

However, as a common problem of plastic films, there is a drawback that static electricity is generated and easily charged. This causes problems in film processing or poor runability of the processed product, inducing dust and the like.

The protective film which apply | coated the adhesive to the polyester film base material is affixed on the surface of optical members, such as a polarizing plate (or a retardation plate etc.) and the laminated body corresponding to it, for the purpose of protecting a surface from a wound and contamination. When a polyester film is easy to be charged at the time of friction, a peeling from a member, etc., and removes these protective films by peeling after completion | finish of each process used as a protective film of an optical member or an optical member, frictional charging or peeling Charging occurs, and problems such as adhesion of foreign matter and dust, and disturbance of electrostatic discharge occur.

Generally, as an antistatic method of a polyester film, there exists a method of apply | coating antistatic resin to the surface of the film used as a base material, and the method of apply | coating various antistatic compounds (for example, refer patent document 1). ).

In particular, regarding the coating to a polyester film, the method of applying the coating liquid containing the coating composition during the film production process (so-called in-line coating) is widely used because economical efficiency and good characteristics can be obtained. As a typical example, there is a method of applying after longitudinal stretching, then transverse stretching and heat setting.

Moreover, as an antistatic compound, it is known that a high molecular weight cationic compound has a comparatively good characteristic (patent document 2, patent document 3).

However, quaternary ammonium bases attached to the polymer side chains, as shown in Patent Document 2, are generally poor in heat resistance and, when applied to the in-line coating as described above, are liable to cause decomposition and are easily charged because the temperature becomes very high at that time. Worsens the prevention performance.

On the other hand, the compound as shown in Patent Document 3 has excellent heat resistance because its quaternary ammonium base is in the polymer skeleton, and can obtain very good antistatic performance. However, since such a compound itself becomes very high hydrophilicity, the application layer obtained may lack water resistance. Specifically, the antistatic performance is deteriorated through a process such as washing with water. In addition, the surface may become white when placed under high humidity. In the case of an optical member use, the inspection of an optical member is generally performed in the state which stuck the surface protection film. Therefore, since the external appearance which does not inhibit an inspection is calculated | required about a surface protection film, a subject remains even when such a compound is used.

In addition, in the process of processing the optical member, if the protective film surface layer is damaged in contact with a processing machine, a conveying roll, or the like, the inspection may be disturbed, so durability is required. However, in the conventional antistatic resin, such durability was often inadequate.

In addition, with respect to the protective film attached, the surface of the protective film is likely to be contaminated with a pressure-sensitive adhesive or the like that is maintained, exuded, or electrodeposited in a manual process such as a re-peeling work process or an inspection process. In some cases.

Patent Document 1: Japanese Patent Application Laid-open No. Hei 7-26223

Patent Document 2: Japanese Patent Application Publication No. 2004-123932

Patent Document 3: Japanese Patent Application Laid-Open No. 1-146931

Disclosure of Invention

Challenges the invention seeks to solve

The present invention has been made in view of the above circumstances, and its problem is to provide an antistatic film having excellent antistatic property, water resistance and durability. In particular, the present invention provides a coating film that exhibits excellent properties when used as a protective film of an excellent antistatic property and an optical member.

Means to solve the problem

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining the said subject, the present inventors discovered that the said subject could be solved by providing the coating layer containing a specific kind of compound, and came to complete this invention.

That is, the summary of this invention has the coating layer containing the antistatic high molecular compound which has the component represented by following General formula (1) and (2) as a repeating unit on one side of a polyester film, The charging characterized by the above-mentioned It relates to a protective film.

In the above formula, R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and X ⁻ is a monovalent anion.

In the above formula, R ³ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ⁴ is -O- or -NH-, and R ⁵ is an alkylene group having 1 to 6 carbon atoms.

A second aspect of the present invention relates to a surface protective film composed of the antistatic film of the first aspect.

The third aspect of the present invention relates to a polyester film for protecting the surface of an optical member, having a non-adhesive layer on the opposite side of the coating layer of the polyester film according to the first aspect.

Effects of the Invention

According to this invention, the coating film which has the outstanding antistatic property and durability, and shows the outstanding characteristic at the time of using it as an optical part material protective film, especially the protective film for polarizing plates, can provide the industrial value.

Best Mode for Carrying Out the Invention

Hereinafter, the present invention will be described in detail. 'Polyester' which can be used in the polyester film of the present invention is terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, 4,4'-diphenyldicarboxylic acid, 1,4- Prepared by melt polycondensation of dicarboxylic acids or esters thereof such as cyclohexyldicarboxylic acid and glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol and 1.4-cyclohexanedimethanol It is polyester which becomes. The "polyester" which consists of such an acid component and a glycol component can be manufactured using the method currently performed arbitrarily.

For example, the bisglycol ester of an aromatic dicarboxylic acid, or its oligomer is carried out by transesterification reaction between lower alkyl ester of aromatic dicarboxylic acid and glycol, or esterification of aromatic dicarboxylic acid and glycol directly. Is formed and then heated under reduced pressure to polycondense. Depending on the purpose, you may copolymerize an aliphatic dicarboxylic acid.

Representative polyesters of the present invention include polyethylene terephthalate, polyethylene-2,6-naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, and the like. Polyester may be sufficient and may contain another component and an additive as needed.

The polyester film of this invention can be made to contain particle | grains in order to ensure the running property of a film, and to prevent a wound from entering. Examples of such particles include inorganic particles such as silica, calcium carbonate, magnesium carbonate, calcium phosphate, kaolin, talc, aluminum oxide, titanium oxide, alumina, barium sulfate, calcium fluoride, lithium fluoride, zeolite and molybdenum sulfide, Organic particles, such as a crosslinked polymer particle and calcium oxalate, the precipitation particle at the time of a polyester manufacturing process, etc. can be used.

Although the particle diameter and content of the particle | grains used are selected according to the use and the objective of a film, average particle diameter is the range of 0.01-5.0 micrometers normally. The surface roughness of the film whose average particle diameter exceeds 5.0 micrometers may become too rough, and particle | grains may fall easily from the film surface. When the average particle diameter is less than 0.01 µm, the surface roughness may be too low, and sufficient diactivation may not be obtained. About particle content, it is 0.0003 to 1.0 weight% normally with respect to polyester, Preferably it is the range of 0.0005 to 0.5 weight%. When the particle content is less than 0.0003% by weight, the diactivation of the film may be insufficient. On the other hand, when the content is added in excess of 1.0% by weight, the transparency of the film may be insufficient. Moreover, various stabilizers, lubricants, antistatic agents, etc. can also be added suitably in a film.

As a manufacturing method of the film which concerns on this invention, a conventionally well-known manufacturing method can be used and there is no restriction | limiting in particular. For example, first, the sheet obtained by melt extrusion is stretched 2 to 6 times at 70 to 145 ° C. by the roll stretching method to obtain a uniaxially stretched polyester film, and then in a tenter in a direction perpendicular to the previous stretching direction. A film is obtained by extending | stretching 2 to 6 times at 80-160 degreeC, and heat-processing at 150-250 degreeC for 1 to 600 second. At this time, a method of relaxing 0.1 to 20% in the longitudinal direction and / or the transverse direction in the heat treatment region and / or the cooling region of the heat treatment outlet is preferable.

The polyester film in this invention is single layer or multilayered structure. In the case of a multilayered structure, the surface layer and inner layer, or both surface layers and each layer can be made into polyester different according to the objective.

The polyester film of this invention is naturally included in the concept of this invention, even if it provides the antistatic coating layer to the single side | surface of a film, even if it provides on both surfaces, or provides the other coating layer to one side. Moreover, when using the antistatic film of this invention as a polyester film for surface protection of an optical member, it has an antistatic coating layer on one side, and has a non-adhesive layer on the opposite surface.

In the present invention, the antistatic coating layer specifically means a coating layer having a low surface resistivity of the coating layer and having a mechanism for leaking electric charges. The lower the surface resistivity of the coating layer, the better the antistatic property. If surface resistivity is 1 * 10 <^13> or less, it can be said to have antistatic property, and if it is 1 * 10 <^11> or less, it can be said that it is favorable antistatic property.

In this invention, it is necessary to contain the antistatic high molecular compound which has the component shown by following General formula (1) and (2) repeatedly as a unit in an antistatic coating layer.

In the above formula, R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and X ⁻ is a monovalent anion.

Where

R ³ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms,

R ⁴ is -O- or -NH-,

R <^5> is a C1-C6 alkylene group.

X <^-> can be suitably selected from the range which does not deviate from the summary of this invention. As an aspect which is industrially easy to obtain and manufacture, a halogen ion, a nitrate ion, an alkyl sulfonic acid ion, etc. are mentioned.

In the present invention, the ratio of the components represented by the general formulas (1) and (2) is not particularly limited, but the components of the general formula (2) are 1% or more by weight in the polymer compound. Preferably, it is 5% or more more preferably. When the component of Formula (2) is less than this range, there exists a tendency for the durability of an application layer to worsen.

In addition, the ratio which the component of Formula (1) occupies in a high molecular compound is not limited. The smaller the ratio, the worse the antistatic performance of the coated film, but it is because the antistatic performance can be improved by increasing the thickness of the coating layer. However, there is a limit to the thickness of the industrially applicable coating layer, and if the coating layer becomes too thick, it causes blocking, deterioration of appearance, cost increase, etc., and therefore should be appropriately selected as necessary. Specifically, the weight ratio is preferably about 70 to 99%.

In the present invention, the antistatic polymer compound may have components other than the formulas (1) and (2) as constituents within a range not departing from the gist of the present invention. Such component is not particularly limited within the scope not departing from the gist of the present invention, but is preferably a compound having a vinyl group or other carbon-carbon double bond, such as a vinyl compound, in view of ease of polymerization. Examples of such compounds include various carboxyl group-containing monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid and citraconic acid, and salts thereof; Various hydroxyl groups such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, monobutyl hydroxyl fumarate, monobutyl hydroxyitaconate Containing monomers; Various (meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate and lauryl (meth) acrylate; Various nitrogen-containing vinyl monomers, such as (meth) acrylamide, diacetone acrylamide, N-methylol acrylamide, (meth) acrylonitrile, etc. Moreover, in combination with these, the polymerizable monomer as shown below can be copolymerized. Namely, various styrene derivatives such as styrene, α-methylstyrene, divinylbenzene, vinyl toluene, various vinyl esters such as vinyl acetate and vinyl propionate; various silicon-containing polymerizable monomers such as γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane and Chisso Co., Ltd. "Syraprene FM-07" (methacryloylsilicone macroma); Phosphorus-containing vinyl monomers: various vinyl halides such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, trifluorochloroethylene, tetrafluoroethylene, chlorotrifluoroethylene and hexafluoropropylene; And various conjugated dienes such as butadiene.

The molecular weight of the antistatic polymer compound is preferably in the range of a number average molecular weight of 5,000 to 500,000, more preferably of 8,000 to 100,000. If the number average molecular weight is less than 5,000, the antistatic performance of the coating film obtained is likely to be insufficient, and if it exceeds 500,000, the viscosity of the coating liquid rises too much, making it difficult to apply a uniform coating layer.

The high molecular compound which makes such a component a repeating unit is obtained by radical copolymerization of the monomer of Formula (1) and Formula (2) as mentioned above. Such radical copolymerization can use a well-known method. For example, the monomer of each component is used as an aqueous solution, mixed and adjusted so as to have a total concentration of 10 to 50% by weight, and in a nitrogen atmosphere, the mixture is dropped into the reactor simultaneously with the aqueous radical initiator solution, while stirring the inside of the reactor and simultaneously 50 What is necessary is just to superpose | polymerize for 3 to 8 hours, cooling to the temperature rise by heating or reaction heat at ° C-80 ° C. Moreover, also when adding another component, if it is a compound which has a carbon-carbon double bond as mentioned above, it can be radically copolymerized by adjusting a mixed aqueous solution simultaneously. Moreover, the ratio and molecular weight of each monomer component in the obtained copolymerized polymer can be calculated | required by refine | purifying a reaction material and analyzing by ¹ H-NMR, GPC (gel permeation chromatography), etc.

Moreover, it is preferable to contain a thermosetting resin in the antistatic coating layer of this invention. In particular, if it is resin which has reactivity with the compound represented by General formula (2), durability of a coating layer improves and it is preferable. Various well-known things can be used suitably as such resin, For example, an isocyanate type, an oxazoline type, an epoxy type, a glyoxazole type, etc. are mentioned. Also included are polymeric crosslinked reactive compounds which have reactive groups in other polymer backbones. As an especially preferable aspect in this invention, an amino resin type crosslinking agent can be illustrated. Examples of the amino resin crosslinking agent include alkylolated melamine, benzoguanamine, and urea. In particular, the methyl group of an amino group and the methylation of a part of the methylol group are preferably water-soluble, and thus can be preferably used in view of their good handling and high reactivity. Moreover, it is more preferable to use a crosslinking catalyst together.

When such an amino resin crosslinking agent is combined with the antistatic polymer compound of the above-mentioned structure, the antistatic property, durability, etc. of the coating layer obtained are extremely excellent.

In addition, the antistatic coating layer of the present invention may contain at least one compound selected from the group of alkyl compounds, fluorine compounds, and silicone compounds or derivatives thereof. By containing such a component, when the film of this invention is used as a protective film, the surface dirt removal property improves.

 An alkyl compound is a compound having a repeating unit of an olefin represented by the following general formula, such as polyolefin, polyolefin wax, alkyl graft polymer, etc .:

-(CH ₂ -CH ₂ ) _n- (CH ₂ -CHR) _m-

In the above formula, R is hydrogen or an alkyl group having 1 to 6 carbon atoms, n is an integer of 1 or more, and m represents 0 or an integer of 1 or more.

In this invention, a fluorine compound especially shows the compound which has a low polarity fluorine-containing functional group, Specifically, the polymer etc. containing a fluoro olefin or a perfluoro alkyl group are mentioned. In particular, the polymer which made perfluoro alkyl group containing ethylenically unsaturated monomer and another ethylenically unsaturated monomer react is used preferably from a viewpoint of affinity with a polyester film, compatibility with the other component which comprises an application layer, etc. Can be. Although it does not specifically limit as a perfluoro alkyl group containing ethylenically unsaturated monomer, For example, the compound represented by following General formula (3) is mentioned.

Where

R ^l is H or CH ₃ ,

R ² is an alkylene group having 1 to 10 carbon atoms or CON (R ³ ) -R ^4- , S0 ₂ N (R ³ ) -R ^4- ,

Rf is a perfluoro alkyl group having 4 to 20 carbon atoms. R ³ is an alkyl group having 1 to ⁴ carbon atoms, and R ⁴ is an alkylene group having 1 to 10 carbon atoms.

Especially as a silicone type compound of this invention, the compound which has a silicone ring with low polarity is shown, As a specific example, (modified) silicone oil, curable silicone resin, etc. are mentioned. Examples of the (modified) silicone oil include modified silicone oils having reactive organic groups such as methacryl, epoxy and carbinol. In addition, as a specific example of curable silicone resin, the type which has curable silicone resin as a main component may be sufficient, and the modified silicone type etc. by graft polymerization with organic resins, such as an acrylic resin, a urethane resin, an epoxy resin, and an alkyd resin, etc. may be used. In particular, the modified silicone type by graft polymerization with an organic resin or the like can be preferably used in view of affinity with a polyester film or compatibility with other components constituting the coating layer.

In the coating film produced by the present invention, the weight of the antistatic polymer compound in the coating layer is preferably 5 mg / m ² or more, and more preferably 10 mg / m ² or more per area of the coating film. If the amount of the antistatic polymer compound is smaller than this, the antistatic property is often insufficient.

The proportion of the antistatic polymer compound in the coating layer is not limited, but the upper limit is usually 90% by weight, preferably 80%, and more preferably 60%. If the ratio of the antistatic polymer compound is higher than this, the transparency of the coating layer may be insufficient, and the durability of the coating layer is often insufficient. Moreover, a minimum is 10% normally, Preferably it is 20%. If the ratio of the antistatic polymer compound is lower than this, the antistatic performance is insufficient, and the coating film for having sufficient antistatic performance may be very thick. If the coating film becomes thick, the appearance and transparency may be deteriorated, blocking of the film, and an increase in cost are not preferable.

It is preferable that the ratio of an antistatic polymeric compound and a thermosetting resin in a coating layer is the range of 5/1-1/5 normally by weight ratio, More preferably, it is the range of 4/1-1/2. If it is out of this range, there exists a tendency for the antistatic performance, durability of an application layer, and an external appearance to deteriorate easily.

The ratio of the compound selected from the group of the alkyl compound, the fluorine compound and the silicone compound contained in the coating layer or the derivative thereof should be finally determined by the balance with other properties. For example, 30% or less of the entire coating film, more Preferably it is 20% or less, Most preferably, it is 10% or less. When more than this ratio, it will be easy to cause deterioration of an external appearance and a fall of coating film strength. Moreover, it is preferable to contain 1% or more of the whole coating film. In content less than 1% of a coating film, the surface decontamination property does not have a big difference with the case where it does not contain in many cases.

The antistatic coating layer according to the present invention is provided by applying a coating liquid containing a specific compound to a film, and in particular, in the present invention, it is preferable that the antistatic coating layer is provided by an inline coating that performs coating during film forming.

The coating liquid in that case can contain other components mentioned above as needed. Examples thereof include surfactants, binders, antifoaming agents, coatability improving agents, thickeners, organic lubricants, mold release agents, organic particles, inorganic particles, antioxidants, ultraviolet absorbers, foaming agents, dyes, pigments, and the like. Although these components may be used independently, you may use 2 or more types together as needed.

The coating liquid at this time is preferably an aqueous solution or an aqueous dispersion in terms of handling, working environment, and stability of the coating liquid composition. However, the coating liquid mainly contains water as a medium and does not depart from the gist of the present invention. If it contains, it may contain the organic solvent.

In-line coating is a method of coating in the manufacturing process of a polyester film, Specifically, it is a method of coating at arbitrary stages until melt-extruding polyester, biaxial stretching, heat setting, and winding up. Usually, it coats in either the substantially unstretched sheet obtained by melting and quenching, the uniaxial stretched film extended in the longitudinal direction (vertical direction), and the biaxially stretched film before heat setting. In these, after coating to a uniaxial stretched film, it is excellent in the method of extending | stretching in a tenter, drying and a lateral direction, and heat-processing again with a base film. According to this method, since film forming and coating layer coating can be performed simultaneously, there is a merit in manufacturing cost, and since it is extended after coating, thin film coating is easy, and the heat treatment performed after coating is difficult to achieve by other coating methods. Since it is possible to make it high temperature, the film forming property of an application layer improves, and an application layer and a polyester film adhere firmly. Moreover, when a crosslinking reactive compound is contained in an application layer, there exists a merit that it becomes difficult to remain a reaction residue by high temperature heat processing of an inline coating. The presence of a reaction residue in the coating layer may cause blocking or the like when the film is wound onto a roll, which may be undesirable. Especially in this invention, when it contains a thermosetting resin, a crosslinking reaction advances by the high temperature of an inline coating, and the durability of an application layer improves very much.

In addition, if the antistatic compound having poor heat resistance is decomposed by high temperature treatment by this method, the antistatic performance may be insufficient, but this problem is unlikely to occur because the antistatic polymer compound of the present invention has excellent heat resistance. .

As a method of apply | coating a coating liquid to a polyester film, the application | coating technique as shown in Harasaki Yuji Paper Co., Ltd., a bookstore issued in 1979, "coating system" can be used, for example. Specifically, air coater, blade coater, road coater, knife coater, squeeze coater, impregnated coater, reverse roll coater, transfer roll coater, gravure coater, kiss roll coater, cast coater, spray coater, curtain coater, calendar coater, extrusion Techniques such as coaters, bar coaters, and the like.

Moreover, in order to improve the applicability | paintability and adhesiveness of the coating agent to the film, you may perform chemical treatment, a corona discharge treatment, a plasma treatment, etc. to a film before application | coating.

The coating amount of the antistatic coating layer is usually 0.005 to 1.5 g / m ² , preferably 0.01 to 1.0 g / m ² , and more preferably 0.02 to 0.5 g / m ² when viewed as a final coating film. to be. When the coating amount is less than 0.005 g / m ² , there is a possibility that sufficient performance may not be obtained, and an application layer exceeding 1.5 g / m ² is likely to cause deterioration in appearance and transparency, blocking of the film, and an increase in cost.

When using the antistatic film of this invention as an optical member surface protection film, a non-adhesive layer is provided on the opposite surface of an antistatic coating layer.

In this case, a non-adhesion means that the protective film which once bonded was able to peel, without damaging an optical member, and without an adhesive remaining on an optical member. For example, when the layer is bonded to a stainless plate (SUS304) and peeled at an angle of 180 degrees at a rate of 300 mm / min after 6 hours or more at 23 ° C., the peeling force is 2 to 60 g / 25 mm. Say that it is.

Examples of the type of the adhesive include a thermosetting type, a UV curing type, an EB curing type, a high temperature melting type, and the like, and an isocyanate or epoxy crosslinking agent can be appropriately used in order to suppress durability and migration of the adhesive.

As such an unadhesive layer, generally known adhesives can be used as an acrylic adhesive, a silicone adhesive, a rubber adhesive, etc. In these, an acrylic adhesive is preferable from a viewpoint of heat resistance. An acrylic pressure sensitive adhesive has, for example, various acrylic acid esters or methacrylic acid esters as a main component, and copolymerized various monomers are often used, and it can be formed by adding an isocyanate curing agent or the like and curing it.

In this invention, the thickness of a non-adhesive layer is 3-100 micrometers, Preferably it is 5-50 micrometers. When the thickness is less than 3 µm, a sufficient non-adhesive effect is not obtained, and on the contrary, a layer exceeding 100 µm may be said to be excessive quality and uneconomical, which may impair the transparency of the protective film.

The peeling (release) film processed with the mold release agent can be bonded to the non-adhesive layer surface as needed.

Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to a following example, unless the summary is exceeded. Moreover, the evaluation method and the processing method of a sample in an Example and a comparative example are as follows.

(1) Surface Specific Resistance (Ω):

Using a high resistance measuring instrument: HP4339B and a measuring electrode: HP16008B manufactured by Hewlett-Packard Japan, the sample was subjected to humidity for 30 minutes in a measuring atmosphere at 23 ° C. and 50% RH, and then the surface resistivity value was measured.

(2) scratch resistance:

The surface of the antistatic coating layer was reciprocated three times in a rubbing tester and a dedicated felt of Taepyung Chemical Co., Ltd. Then, the rubbed place was visually observed and evaluated according to the following criteria.

(Circle): A change of an appearance is not confirmed by the rubbed point.

△: barely rubbed visible

X: An antistatic coating layer is shaved and it becomes powder

(3) moisture resistance:

 The film was stored for 3 days in a thermostat at 40 ° C. and 90% RH, and the change in appearance of the antistatic coating layer was visually evaluated.

○: no change in appearance

△: appearance change such as whitening is barely seen

X: Appearance changes, such as whitening, are seen

(4) Water resistance of antistatic performance:

After immersing the sample film in hot water at 40 ° C. for 24 hours, the water adhered lightly to qualitative filter paper (“No2” manufactured by TOYO Advantech) was removed, dried at room temperature for one day, and then by the method shown in (1) above. Surface resistivity was measured. The measured value after warm water immersion was divided by the measured value before warm water immersion, and what was multiplied was calculated | required, and the following references | standards evaluated. The less the deterioration after the warm water immersion (the less the change in value before and after the hot water immersion), the better the water resistance.

○: Very good. Deterioration from the value before immersion in hot water within 10 times

(Triangle | delta): Good. Deterioration from the value before hot water immersion is 10-20 times

X: defective. Deterioration from the value before the warm water immersion more than 20 times

The polyester raw material used in the following example and the comparative example is as follows.

(Polyester 1): Polyethylene terephthalate having an ultimate viscosity of 0.66 substantially free of particles.

(Polyester 2): Polyethylene terephthalate having an ultimate viscosity of 0.66 containing 0.6 parts by weight of amorphous silica having an average particle diameter of 2.5 μm.

In addition, the following were used as coating composition.

(Al): A polymer compound having a number average molecular weight of 20,000 in which a structural unit of the following general formula (4) and a structural unit of the following general formula (5) are copolymerized at a weight ratio of 95/5:

(A2): The polymer of the number average molecular weight 33,000 which copolymerized the structural unit of the said General formula (4), the structural unit of the said General formula (5), and the structural unit of the following general formula (6) by the ratio of weight ratio 90/8/2. compound

(A3): A polymer having a number average molecular weight of 21,000 obtained by copolymerizing a structural unit of formula (4), a structural unit of formula (5), and a structural unit of formula (6) at a weight ratio of 80/10/10. compound

(A4): A polymer having a number average molecular weight of 12,000, obtained by copolymerizing a structural unit of formula (4), a structural unit of formula (5), and a structural unit of formula (6) at a weight ratio of 98/1/1. compound

(A5): A polymer having a number average molecular weight of 18,000 in which the structural unit of formula (4), the structural unit of formula (5), and the structural unit of formula (7) are copolymerized at a weight ratio of 85/10/5. compound:

(Bl): A high molecular weight compound having a number average molecular weight of 30,000, consisting of the structural unit of formula (4)

(B2): A polymer compound having a number average molecular weight of 23,000, in which the structural unit of formula (4) and the structural unit of formula (6) are copolymerized at a weight ratio of 95/5.

(Cl): Binikamin J-101 made by Dainipek Ingiga Chemical Co., Ltd. which is a crosslinkable resin of methylated hexamethylol melamine.

(C2): Baccarmine MA-S made by Dainippon Ingiga Chemical Co., Ltd. which is a crosslinkable resin of methoxylated hexamethylolmelamine / urea copolymerization

(Dl): Polyethylene wax water dispersion chain, Toho Gakuku Kogyo high-tech E-8000

(D2): CF ₃ (CF ₂ ) _n CH ₂ CH ₂ 0COCH = CH ₂ (n = 5 to 11, n = 9) 80.Og, acet, in a glass reaction vessel, a perfluoro alkyl group-containing acrylate. 20.0 g of acetoxyethyl methacrylate, 0.8 g of dodecyl mercaptan, 354.7 g of deoxygenated pure water, 40.Og of acetone, 1.0 g of C ₁₆ H ₃₃ N (CH ₃ ) ₃ Cl and C ₈ H ₁₇ C ₆ H ₄ 0 _{(CH 2 CH 2 0) n} H (n = 8) placed 3.Og, azobisisobutyronitrile was added and the Dean amino dihydrochloride 0.5g, fluorine-containing resin obtained by copolymerizing 10 hours reaction at 60 ℃ with stirring in a nitrogen atmosphere Emulsion

(El): Catysto made by Dainippon Ingiga Chemical Co., Ltd. which is a crosslinking catalyst of an amino resin crosslinking agent

(Fl): polyoxyethylene lauryl ether (surfactant: the average degree of polymerization of oxyethylene is 4)

Example 1

The polyester (1) and the polyester (2) are kneaded at a weight ratio of 80/20, sufficiently dried, then heated and melted at 280 to 300 ° C, extruded into a sheet shape from a T-shaped nozzle, and using an electrostatic bonding method. The product was solidified by cooling while being in close contact with a mirror-cooling drum having a surface temperature of 40 to 50 ° C to prepare an unstretched polyethylene terephthalate film. The film was stretched 3.7 times in the longitudinal direction while passing through a 85 ° C. heating roll group to obtain a monoaxially oriented film. The coating composition as shown in following Table 1 was apply | coated to the single side | surface of this uniaxial oriented film. Subsequently, this film is sent to a tenter stretching machine, and it is extended | stretched 4.0 times in the width direction at 100 degreeC, heat-processing at 230 degreeC again, drying a coating composition using the heat, and biaxially-oriented polyethylene terephthalate of 38 micrometers of film thicknesses The coated film which provided the antistatic coating layer in the quantity of 0.03 g / m <^{2> on} the film was obtained. The properties of this film are shown in Table 2 below.

Examples 2-6

In the same process as in Example 1, the coating liquid was changed as shown in Table 1, and a coated film obtained by laminating the antistatic coating layer of the amount shown in Table 1 on a base film having a film thickness of 38 μm. The properties of this film are shown in Table 2.

Comparative Examples 1-3

In the same process as in Example 1, the coating liquid was changed as shown in Table 1, and a coated film obtained by laminating the antistatic coating layer of the amount shown in Table 1 on a base film having a film thickness of 38 μm. The properties of this film are shown in Table 2.

Coating layer composition Solid content weight ratio Coating amount (g / m ² ) Example 1 Al / C1 / El / Fl 60/40/2/5 0.03 Example 2 A3 / Cl / El / Fl 60/40/2/5 0.03 Example 3 A3 / Cl / El / Fl 40/50/2/5 0.05 Example 4 A3 / C2 / El / Fl 40/30/2/5 0.03 Example 5 A4 / C2 / El / Fl 40/30/2/5 0.03 Example 6 A5 / C2 / El / Fl 40/30/2/5 0.03 Comparative Example 1 Bl / Cl / El / Fl 60/40/2/5 0.03 Comparative Example 2 B2 / Cl / El / Fl 60/40/2/5 0.03 Comparative Example 3 B2 / C2 / El / Fl 40/30/2/5 0.03

The coating amount in the said Table 1 means the solid content weight of the coating layer composition per area of the coating film finally obtained.

Surface specific resistance (Ω) Water resistance rating Example 1 2 × 10 ¹⁰ ○ Example 2 5 × 10 ¹⁰ ○ Example 3 5 × 10 ¹⁰ ○ Example 4 4 × 10 ¹⁰ ○ Example 5 2 × 10 ¹⁰ △ Example 6 3 × 10 ¹⁰ ○ Comparative Example 1 1 × 10 ¹⁰ × Comparative Example 2 1 × 10 ¹⁰ × Comparative Example 3 3 × 10 ¹⁰ ×

Example 7

The polyester (1) and the polyester (2) are kneaded at a weight ratio of 80/20, sufficiently dried, then heated and melted at 280 to 300 ° C, extruded into a sheet shape from a T-shaped nozzle, and the surface is subjected to an electrostatic bonding method. Cooling and solidifying while being in close contact with the mirror-cooling drum having a temperature of 40 to 50 ℃ to prepare an unstretched polyethylene terephthalate film. The film was stretched 3.7 times in the longitudinal direction while passing through a 85 ° C. heating roll group to obtain a uniaxially oriented film. The coating composition as shown in following Table 3 was apply | coated to the single side | surface of this uniaxial oriented film. Then, the film was introduced into a tenter stretching machine, the coating composition was dried using the heat, stretched 4.0 times in the width direction at 100 ° C., and then heat treated at 230 ° C. to give a biaxially oriented polyethylene tere having a film thickness of 38 μm. The application film which provided the antistatic coating layer of the quantity of 0.03g / m <^2> on the phthalate film was obtained. The properties of this film are shown in Table 4 below.

Next, an isocyanate hardener (manufactured by Nippon Polyurethane Co., Ltd., Coronate HL) with respect to 100 parts (solid content weight part) of an acrylic adhesive (Imperial Chemical Co., Ltd., SG-800) as an unadhesive layer on the surface opposite the coating layer of this film. The coating liquid to which 10 parts (solid weight part) was added was apply | coated using the bar coater, the coating film was dried and hardened | cured at 100 degreeC for 2 minutes, and the non-adhesive layer of 20 micrometers in thickness was obtained. From above, the release polyester film which coated silicone was coat | covered, and the surface protection film was manufactured. Since the film thus obtained has excellent characteristics as shown in Table 4, when it was actually attached to an optical member and used as a protective film, workability and visibility in inspection were satisfactory, and thus it could be preferably used.

Examples 8-16

In the same process as in Example 1, the coating liquid was changed as shown in Table 1, and a coating film obtained by laminating the antistatic coating layer of the amount shown in Table 3 on a base film having a film thickness of 38 μm was obtained. The properties of this film are shown in Table 4. Moreover, it carried out similarly to Example 7, and set it as the surface protection film which provided the non adhesion layer on the surface opposite to an application layer. Since the obtained film has the outstanding characteristic as shown in Table 4, when it actually attached to an optical member and used as a protective film, workability and visibility in test | inspection were favorable, and it could use it preferably.

Comparative Example 4

In the same process as in Example 7, the coating liquid was changed as shown in Table 3 to obtain a coating film obtained by laminating an antistatic coating layer in an amount of 0.03 g / m ² on a base film having a film thickness of 38 μm. The properties of this film are shown in Table 2.

Moreover, it carried out similarly to Example 7, and set it as the surface protection film which provided the non adhesion layer on the surface opposite to an application layer. Since the obtained film had bad abrasion property, when it actually attached to an optical member and used as a protective film, the wound which was thought to have arisen in the attachment process, a conveyance process, etc. existed on the surface, and it interrupted inspection. Moreover, since moisture resistance was bad, the inspection after putting under high humidity also caused trouble.

Comparative Example 5

In the same process as in Example 7, the coating liquid was changed as shown in Table 3 to obtain a coating film obtained by laminating an antistatic coating layer having a quantity of 0.05 g / m ² on a base film having a film thickness of 38 μm. The properties of this film are shown in Table 4.

Moreover, it carried out similarly to Example 7, and set it as the surface protection film which provided the non adhesion layer on the surface opposite to an application layer. Since the obtained film was bad in moisture resistance, when it actually attached to the optical member and used as a protective film, after being placed under high humidity, the whole surface was clouded white, which hindered inspection.

Comparative Example 6

In the same process as in Example 1, the coating liquid was changed as shown in Table 3 to obtain a coating film obtained by laminating an antistatic coating layer in an amount of 0.05 g / m ² on a base film having a film thickness of 38 μm. The properties of this film are shown in Table 4.

Moreover, it carried out similarly to Example 7, and set it as the surface protection film which provided the non adhesion layer on the surface opposite to an application layer. Since the obtained film was bad in moisture resistance, when it actually attached to the optical member and used as a protective film, after being placed under high humidity, the whole surface became cloudy white, which caused trouble to the inspection.

Comparative Example 7

In the same process as in Example 7, the same operation as in Example 7 was carried out to obtain a polyester film having a film thickness of 38 μm. The properties of this film are shown in Table 4. Further, in the same manner as in Example 7, a surface protection film was prepared in which a non-adhesive layer was provided on one side. Since the obtained film has high surface resistivity and poor antistatic performance, when used as a protective film by actually attaching it to an optical member, it may be wound on the hand during peeling or attracts dirt from the surroundings, thereby greatly deteriorating workability. I was.

Coating layer composition Solid content weight ratio Coating amount (g / m ² ) Example 7 Al / Cl / El / F1 40/30/2/5 0.03 Example 8 Al / C2 / Dl / E1 40/10/10/2 0.03 Example 9 A2 / C2 / Dl / E1 40/50/7/2 0.05 Example 10 A2 / C2 / Dl / E1 40/30/7/2 0.03 Example 11  A2 / C2 / D2 / E1 40/30/5/2 0.03 Example 12 A3 / C2 / El / F1 60/15/2/5 0.03 Example 13 A3 / Cl / Dl / E1 60/15/10/2 0.03 Example 14 A3 / Cl / Dl / E1 40/50/10/2 0.05 Example 15 A4 / Cl / Dl / E1 40/30/10/2 0.03 Example 16 A5 / Cl / Dl / E1 40/30/10/2 0.03 Comparative Example 4 Bl / Cl / El / F1 40/30/2/5 0.03 Comparative Example 5 Bl / Cl / Dl / El / F1 40/50/10/2/5 0.05 Comparative Example 6 B2 / Cl / Dl / El / F1 40/50/10/2/5 0.05 Comparative Example 7 No coating layer provided

The application amount of Table 3 means the solid content weight of an application layer composition per area of the application film finally obtained.

Surface resistivity (Ω) Scratch resistance Moisture resistance The use situation as protection film Example 7 3 × 10 ¹⁰ ○ ○ Good Example 8 9 × 10 ⁹ △ ○ Good Example 9 4 × 10 ¹⁰ ○ ○ Good Example 10 4 × 10 ¹⁰ ○ ○ Good Example 11 4 × 10 ¹⁰ ○ ○ Good Example 12 2 × 10 ¹⁰ △ ○ Good Example 13 2 × 10 ¹⁰ ○ ○ Good Example 14 5 × 10 ¹⁰ ○ ○ Good Example 15 2 × 10 ¹⁰ ○ ○ Good Example 16 3 × 10 ¹⁰ ○ ○ Good Comparative Example 4 9 × 10 ⁹ × × Trouble Comparative Example 5 3 × 10 ¹⁰ △ × Trouble Comparative Example 6 3 × 10 ¹⁰ △ × Trouble Comparative Example 7 6 × 10 ¹⁴ ○ ○ Trouble

As mentioned above, although an Example was given and this invention was demonstrated in more detail, the definition of a numerical range in this invention does not deviate from the summary of this invention, and all the range prescription | regulation which used the numerical value of said arbitrary Example as a threshold is also natural. It is to be considered that it is included, but it is included in this specification.

The film of this invention can be used favorably in various uses for which antistatic performance is calculated | required.

Claims (3)

An antistatic film which has the coating layer containing the antistatic high molecular compound which has the component represented by following General formula (1) and (2) as a repeating unit on one side of a polyester film:

Where R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X ^- is a monovalent anion, R ³ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ⁴ is-○-or -NH-, R <^5> is a C1-C6 alkylene group. The antistatic film according to claim 1, wherein the antistatic film is for a surface protective film. It has a non-adhesive layer on the opposite surface of the application layer of the polyester film of Claim 1, The polyester film for optical member surface protections characterized by the above-mentioned.