JP2008007727A - Antistatic film and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an antistatic film having high transparency, high adhesivity between an antistatic layer and an organic substrate, excellent antistatic property (surface stain resistance) and its durability and to provide a method for producing the same. <P>SOLUTION: The antistatic film comprises an antistatic layer composed of an organic-inorganic composite material comprising an inorganic component having a crosslinking structure formed by hydrolysis and condensation polymerization of an alkoxide of an element selected from Si, Ti, Zr and Al and a conductive colloid in a graft polymer layer containing a graft polymer chain directly bonded to a substrate surface and is obtained by subjecting the surface of the antistatic layer to water-repellent and oil-repellent treatment. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an antistatic film using an organic-inorganic composite layer excellent in antistatic ability and its durability and a method for producing the same, and more particularly to an antistatic film having surface antifouling properties and a method for producing the same.

Conventionally, various transparent coatings having such functions have been developed for the purpose of imparting an antistatic function and an antireflection function to the surface of a transparent substrate used in display panels of cathode ray tubes, fluorescent display tubes, and liquid crystal display panels. Yes.
The influence of electromagnetic waves emitted from cathode ray tubes and the like on the human body has recently become a problem, not only with conventional antistatic ability, but also with the function of shielding electromagnetic fields formed with the emission of electromagnetic waves and electromagnetic waves. A coating having is desired.

One method for shielding electromagnetic waves is to form a conductive film for shielding electromagnetic waves on the surface of a display panel such as a cathode ray tube. However, a conductive film for shielding electromagnetic waves requires a film having a lower surface resistance than a conventional antistatic conductive film, specifically, a low surface resistance of about 10 ² to 10 ⁴ Ω / □. ing.
When a conductive film having a low surface resistance is formed using a coating solution containing a conventionally known conductive oxide such as Sb-doped tin oxide or Sn-doped indium oxide, It is necessary to make the film thickness thicker than in the case, and there arises a problem that transparency and antireflection ability are lowered. Conventionally, when a conductive oxide such as Sb-doped tin oxide or Sn-doped indium oxide is used, electrons are It has been difficult to obtain a conductive film satisfying a sufficiently low surface resistance for blocking and antireflection ability.

  As another method of forming a low surface resistance conductive film, a coating film for forming a conductive film containing a dispersion in which metal fine particles such as Ag are colloidally dispersed in a polar solvent is used. There is a method of forming a coating containing metal fine particles. In the coating solution used in this method, the surface of the fine particles is surface-treated with a polymer compound such as polyvinyl alcohol, polyvinyl pyrrolidone or gelatin for the purpose of improving the dispersibility of the colloidal metal fine particles. In the conductive coating, the metal fine particles are in contact with each other through the stabilizer in the coating, and therefore there is a concern that the grain boundary resistance becomes large and the intended low surface resistance cannot be achieved. For this reason, there is also a method of performing a step of decomposing and removing the stabilizer by baking at a high temperature, but under the high temperature conditions necessary for decomposing and removing the polymer compound used as the stabilizer, undesired fusion of the metal fine particles to each other There is a problem that aggregation and the like occur and the transparency and haze value of the obtained conductive film are lowered. In addition, when such a coating is used for a cathode ray tube, there is a problem that the cathode ray tube itself deteriorates due to high-temperature firing, and the use mode is extremely limited.

Further, in such a transparent conductive film containing metal fine particles, the metal oxidizes and deteriorates over time, the particles grow due to ionization, and depending on the metal material used, phenomena such as the occurrence of corrosion occur. There is a problem that the conductivity and light transmittance of the film fluctuate with time and the display device lacks reliability.
In addition, there is a problem in adhesion and durability between a transparent conductive film using inorganic fine particles, Sb-doped tin oxide, and the like, and a base material, particularly an organic material base material. Improving the strength of the transparent conductive film and the substrate is also a major issue.

In order to achieve transparency and low surface resistance, a technology has been proposed in which a conductive coating film is formed using a transparent conductive fine particle coating solution containing silica particles and metal fine particles, using a hydrolyzed polycondensate of alkoxysilane as a binder. (For example, refer to Patent Document 1). According to this method, it is disclosed that a transparent conductive film having a low surface resistance is provided. However, when an antistatic layer is formed on an organic substrate using the coating solution, an organic-inorganic interface is used. Therefore, it has been desired to improve the adhesion and durability of the antistatic layer.
Japanese Patent Laid-Open No. 2004-55298

  The object of the present invention in consideration of the above-mentioned problems of the prior art is high transparency, high adhesion between the antistatic layer and the organic substrate, antistatic property (surface antifouling property) and durability thereof. The object is to provide an excellent antistatic film.

The inventors of the present invention focused on the possibility that a graft polymer chain directly bonded to the surface of a base material gives a strong functional thin film that is excellent in adhesion to a substrate and can be expected to develop various applications. The present inventors have found that the organic-inorganic composite material of the graft polymer and the inorganic compound has a dense network structure and excellent adhesion to the substrate.
That is, the antistatic film according to claim 1 of the present invention is an element selected from Si, Ti, Zr, and Al in a support and a graft polymer layer having a graft polymer chain directly bonded to the surface of the support. An antistatic layer comprising an organic-inorganic composite film containing a crosslinked structure and a conductive colloid formed by hydrolysis and condensation polymerization of the alkoxide, and the surface of the antistatic layer is subjected to a water / oil repellent treatment. It is characterized by becoming.
The antistatic film of the present invention preferably has a haze of 2% or less.

  According to a third aspect of the present invention, there is provided a method for producing an antistatic film, wherein a graft polymer layer is formed by forming a graft polymer chain directly bonded to a support surface to form a graft polymer layer comprising the graft polymer chain. Addition of conductive colloid to the formation process and the graft polymer layer, followed by hydrolysis and polycondensation reaction of alkoxides of elements selected from Si, Ti, Zr, and Al to form a crosslinked structure to prevent antistatic An antistatic layer forming step for forming an organic-inorganic composite film having a function, and a water / oil repellent treatment step for subjecting the surface of the antistatic layer to a water / oil repellent treatment.

Such a graft polymer chain is preferably formed by a polymerization reaction starting from the starting species generated on the surface of the support. Here, the support surface may be either the surface of the base material constituting the support or the surface of the polymerization initiation layer provided for efficiently generating active species on the base material surface.
The graft polymer chain preferably has an alkoxide group and / or an amide group of an element selected from Si, Ti, Zr, and Al in the chain.
Furthermore, the graft polymer chain is a co-polymer of a structural unit having a polar group, preferably an amide group, and a structural unit having an alkoxide group of an element selected from Si, Ti, Zr and Al such as a silane coupling group. It is a preferred embodiment that it is a coalescence.
This antistatic layer is a layer made of an organic-inorganic hybrid material (organic-inorganic composite film) having a crosslinked structure formed by hydrolysis and condensation polymerization of an alkoxide of an element selected from Si, Ti, Zr, and Al. The graft polymer chain forming the antistatic layer is preferably a copolymer of a structural unit having a hydrophilic functional group and a structural unit having a silane coupling group.
Further, the surface of the obtained antistatic layer is treated with water and oil repellency to give an antifouling antistatic film excellent in antifouling property and its durability.

Although the operation of the present invention is not clear, it is estimated as follows.
In the present invention, a hydrophilic graft polymer chain (organic component) directly bonded to the support surface and an alkoxide of an element selected from Si, Ti, Zr and Al in the graft polymer layer comprising the graft polymer chain. An organic-inorganic composite layer (organic-inorganic hybrid material) having a crosslinked structure (inorganic component) formed by hydrolysis and condensation polymerization is formed. In particular, when a polar group is present in the graft polymer chain, a polar interaction is formed with the crosslinked structure obtained by hydrolysis and polycondensation of the alkoxide compound due to the function of the polar group. Due to the function of the interaction, a high-density crosslinked structure with higher strength is obtained. By making a conductive colloid coexist in such a layer having a high density cross-linked structure, the conductive colloid is stably held in the cross-linked structure. Therefore, even if it is a thin layer, the wear resistance is increased, and an organic-inorganic composite film having high durability is formed. In addition, the conductive colloid having antistatic ability is strong and stable in the film. Therefore, even if the formed antistatic layer is a thin layer that does not impair the transparency of the coating, it is presumed that high antistatic ability and durability are realized. In addition, the adhesion between the two results from the fact that an organic-inorganic composite thin film (organic-inorganic hybrid material) is formed by the function of the graft polymer chain in which the support surface and the antistatic layer are directly bonded to the support surface. Therefore, high adhesion is maintained without providing an intermediate layer such as a binder. Furthermore, in the present invention, the surface of the organic-inorganic composite layer is treated with water and oil repellency, so that the surface of the antistatic layer has super water repellency and exhibits a function of preventing dirt.

  According to the present invention, the transparency is high, the adhesion between the substrate and the antistatic layer and its durability, the antifouling property of the surface and its durability are also good, the surface is water repellent, and the surface energy is To provide an antistatic film that is small and can be easily wiped off even if dirt is attached, has high antifouling properties, and can impart high antistatic ability and antifouling performance to the surface of a substrate. Can do.

Hereinafter, the present invention will be described in detail.
The antistatic film of the present invention comprises hydrolysis of an alkoxide of an element selected from Si, Ti, Zr, and Al in a support and a graft polymer layer having a graft polymer chain directly bonded to the surface of the support. An antistatic layer comprising an organic-inorganic composite film containing a crosslinked structure and a conductive colloid formed by condensation polymerization, and the surface of the antistatic layer is subjected to a water / oil repellent treatment. .

In the antistatic film of the present invention, the organic-inorganic hybrid material constituting the antistatic layer is an element selected from Si, Ti, Zr, and Al in the graft polymer layer having a graft polymer chain directly bonded to the support surface. It contains a cross-linked structure formed by hydrolysis and condensation polymerization of alkoxide, and a conductive colloid which is a conductive material described later is held in this cross-linked structure.
Of the alkoxide compounds, Si alkoxides are preferred because of their reactivity and availability.
In the present invention, the above-described crosslinked structure formed by hydrolysis and polycondensation of the metal alkoxide is hereinafter appropriately referred to as a sol-gel crosslinked structure.

The method for producing such an antistatic film is not particularly limited, but (1) a graft polymer that forms a graft polymer layer composed of the graft polymer chain by directly forming a graft polymer chain bonded to the surface of the support. (2) Addition of conductive colloid to the graft polymer layer, followed by hydrolysis and condensation polymerization of an alkoxide of an element selected from Si, Ti, Zr, and Al to form a crosslinked structure An antistatic layer forming step for forming an organic-inorganic composite film having antistatic ability, and (3) a water / oil repellent treatment step for subjecting the surface of the antistatic layer to water / oil repellent treatment. preferable.
(1) In the graft polymer layer forming step, (1-1) active species are generated by irradiating the substrate surface constituting the support with radiation, and polymerization is possible before or after the radiation irradiation. A method may be used in which a compound having a functional group is brought into contact and the compound is bonded to the surface of the polymerization initiation layer by graft polymerization to form a graft polymer chain. (1-2) Polymerization on the surface of the support substrate A polymerization initiating layer containing an initiator, preferably a polymerization initiating layer formed by immobilizing the polymerization initiator by a crosslinking reaction, is provided on the polymerization initiating layer (in this embodiment, the surface is the surface of the support). To generate active species, contact a compound having a polymerizable functional group before or after irradiation with radiation, and bond the compound to the surface of the polymerization initiation layer by graft polymerization. It may be adopted a method of generating a shift polymer chain.

<Support with graft polymer chain>
The support for forming the antistatic layer having a crosslinked structure according to the present invention is generally prepared by preparing a graft polymer having a polar group such as a hydrophilic group by using a known method as a method for synthesizing a graft polymer. It can be produced by cross-linking using a sol-gel cross-linking structure forming step described in detail below. Specifically, the synthesis of the graft polymer is “graft polymerization and its application” by Fumio Ide, published in 1977, Polymer Publishing Society, and “New Polymer Experimental Studies 2, Synthesis and Reaction of Polymers” edited by the Society of Polymer Science. Kyoritsu Publishing Co., Ltd. 1995.

  The graft polymer layer in the present invention refers to a layer composed of a graft polymer chain having a polar group, which is directly bonded to the support surface. In order to form such a structure, the starting species generated on the surface of the support substrate or the surface of the polymerization initiation layer provided on the substrate surface is the starting point, and a compound that can react with such starting species. A graft polymer chain may be formed on the support by bonding. By setting it as such a structure, the formed hydrophilic graft polymer chain couple | bonds with a support body or its surface layer directly. Here, as the support capable of generating the starting species, a support capable of generating active species within the structure of the support may be used, and a polymerization initiating layer or the like in which the graft polymer is easily bonded to the substrate surface. A support provided with a surface layer may be used to form a hydrophilic graft polymer chain directly bonded to the surface of the support.

<Support with graft polymer chain>
The graft polymer layer formed on the surface of the support of the present invention preferably refers to a layer formed by a graft polymer chain having a polar group. This may be one in which the graft polymer chain is directly bonded to the surface of the support, or a polymerization initiating layer is provided on the surface of the support where the graft polymer is easy to bond (easily generate active species). The polymer chain may be grafted on the surface.

  Furthermore, the hydrophilic surface in the present invention has a polymer in which a hydrophilic graft polymer chain is bonded to a trunk polymer compound, or a functional group in which a hydrophilic graft polymer chain is bonded to a trunk polymer compound and can be crosslinked. Using the introduced polymer, coating or coating using a composition containing a hydrophilic polymer having a crosslinkable group at the polymer terminal and a crosslinking agent, which is disposed on the support surface by coating or coating crosslinking. Those arranged on the surface of the support by crosslinking are also included.

The feature of the graft polymer chain directly bonded to the support surface in the present invention is that one end of the polymer is bonded to the support surface or the support surface layer, and the graft portion having a polar group is not substantially crosslinked. It has a structure. This structure has the characteristics that the high mobility can be maintained without restricting the mobility of the polymer part capable of forming a polar interaction or being buried in a strong crosslinked structure. For this reason, compared with the polymer which has a polar group which has a normal crosslinked structure, it is thought that higher affinity is expressed with respect to a conductive colloid etc., for example.
The molecular weight of such a graft polymer chain is in the range of Mw 500 to 5,000,000, the preferred molecular weight is in the range of Mw 1000 to 1,000,000, and more preferably in the range of Mw 2000 to 500,000.
The contact angle with respect to water of the surface of the graft polymer layer before forming the organic-inorganic composite film, which will be described later, and before the antistatic layer forming step is preferably 90 ° or less, and 80 ° or less. It is more preferable. In addition, the contact angle of water in the present invention is a value obtained by a method of measuring an angle 20 seconds after dropping of pure water using CA-Z manufactured by Kyowa Interface Chemical Co., Ltd.

  In the present invention, a graft polymer chain bonded directly on a support surface or a polymerization initiation layer provided on the support surface is referred to as “surface graft”. In the present invention, both the substrate itself constituting the support and the substrate provided with a polymerization initiating layer are referred to as “support”.

[Method for producing surface graft]
As a method for producing a surface having a hydrophilic group made of a graft polymer on the surface of the support, (1) a method of attaching the support surface and the graft polymer by chemical bonding, and (2) using the support surface as a base point There are two methods in which a compound having a polymerizable double bond is polymerized into a graft polymer.

(1) Method of attaching graft polymer to chemical bond on support surface First, a method of attaching a graft polymer to a support surface by chemical bond will be described.
In this method, a polymer having a functional group that reacts with the substrate at the terminal or side chain of the polymer is used, and this functional group is grafted by chemically reacting with the functional group on the surface of the substrate. The polymer and the substrate can be bonded by a chemical reaction. The functional group that reacts with the substrate is not particularly limited as long as it can react with the functional group on the substrate surface. For example, a silane coupling group such as alkoxysilane, an isocyanate group, an amino group, a hydroxyl group, Examples thereof include a carboxyl group, a sulfonic acid group, a phosphoric acid group, an epoxy group, an allyl group, a methacryloyl group, and an acryloyl group. Particularly useful compounds as a polymer having a reactive functional group at the terminal or side chain of the polymer include a polymer having a trialkoxysilyl group at the terminal, a polymer having an amino group at the terminal, a polymer having a carboxyl group at the terminal, and an epoxy group. A polymer having a terminal and a polymer having an isocyanate group at a terminal.
In addition, the polymer having a polar group used at this time is not particularly limited. Specifically, polyacrylic acid, polymethacrylic acid, polystyrene sulfonic acid, poly-2-acrylamido-2-methylpropane sulfonic acid and Examples thereof include salts thereof, polyacrylamide, and polyvinyl acetamide. In addition, a hydrophilic monomer polymer used in the following surface graft polymerization or a copolymer containing a hydrophilic monomer can be advantageously used.

(2) A method of polymerizing a compound having a double bond that can be polymerized from a base material to form a graft polymer. Using a support (support base material or a support having a polymerization initiation layer on the substrate surface) as a base point A method of polymerizing a compound having a polymerizable double bond to form a graft polymer is generally called surface graft polymerization. The surface graft polymerization method is a method in which an active species is given to the surface of a support by a method such as plasma irradiation, light irradiation, and heating, and a compound having a polymerizable double bond disposed so as to be in contact with the substrate is polymerized by the substrate. Refers to the method of combining with. According to this method, the terminal of the resulting graft polymer is fixed to the substrate surface.

Any known method described in the literature can be used as the surface graft polymerization method for carrying out the present invention. For example, New Polymer Experiment 10, edited by Polymer Society, 1994, published by Kyoritsu Shuppan Co., Ltd., P135 describes a photograft polymerization method and a plasma irradiation graft polymerization method as surface graft polymerization methods. In addition, the adsorption technique handbook, NTS Co., Ltd., supervised by Takeuchi, 1999.2, p203, p695 describes radiation-induced graft polymerization methods such as γ rays and electron beams. As a specific method of the photograft polymerization method, the methods described in JP-A-63-92658, JP-A-10-296895, and JP-A-11-119413 can be used. In the plasma irradiation graft polymerization method and the radiation irradiation graft polymerization method, the literatures described above and Y.C. Ikada et al, Macromolecules vol. 19, page 1804 (1986), and the like can be applied.
Specifically, a polymer surface such as PET is treated with plasma or electron beam to generate radicals on the surface, and then the active surface is reacted with a monomer having a hydrophilic functional group. A graft polymer surface layer, that is, a surface layer having a hydrophilic group (hydrophilic surface) can be obtained.
In addition to the above-mentioned documents, photograft polymerization can be carried out as described in JP-A No. 53-17407 (Kansai Paint) and JP-A No. 2000-212313 (Dainippon Ink). It can also be carried out by irradiating the base material obtained by applying the photopolymerizable composition on the surface with an aqueous radical polymerization compound in contact with light.

A compound useful for forming a graft polymer chain must have a polymerizable double bond and have a polar group in the molecule. Any of these compounds can be used as the compound, as long as it has a double bond in the molecule. Particularly useful compounds are monomers.
The monomer having a polar group useful in the present invention is a monomer having a positive charge such as ammonium or phosphonium, or a negative charge such as a sulfonic acid group, a carboxyl group, a phosphoric acid group or a phosphonic acid group. Monomers having an acidic group that can be dissociated into a negative charge can be mentioned, but other monomers having a nonionic group such as a hydroxyl group, an amide group, a sulfonamide group, an alkoxy group, and a cyano group are also used. You can also

  In the present invention, specific examples of particularly useful monomers include the following monomers. For example, (meth) acrylic acid or its alkali metal salt and amine salt, itaconic acid or its alkali metal salt and amine salt, allylamine or its hydrohalide salt, 3-vinylpropionic acid or its alkali metal salt and amine salt Vinyl sulfonic acid or its alkali metal salt and amine salt, styrene sulfonic acid or its alkali metal salt and amine salt, 2-sulfoethylene (meth) acrylate, 3-sulfopropylene (meth) acrylate or its alkali metal salt and amine salt 2-acrylamido-2-methylpropanesulfonic acid or its alkali metal salts and amine salts, acid phosphooxypolyoxyethylene glycol mono (meth) acrylate or their salts, 2-dimethylaminoethyl (meth) ) Acrylate or its hydrohalide, 3-trimethylammoniumpropyl (meth) acrylate, 3-trimethylammoniumpropyl (meth) acrylamide, N, N, N-trimethyl-N- (2-hydroxy-3-methacryloyloxypropyl) ) Ammonium chloride, etc. can be used. In addition, 2-hydroxyethyl (meth) acrylate, (meth) acrylamide, N-monomethylol (meth) acrylamide, N-dimethylol (meth) acrylamide, N-vinylpyrrolidone, N-vinylacetamide, polyoxyethylene glycol mono (meth) ) Acrylate is also useful.

The synthesis of a graft polymer using a macromer is described in the above-mentioned “New Polymer Experiments 2, Polymer Synthesis and Reaction” edited by Polymer Society, Kyoritsu Shuppan Co., Ltd. 1995. It is also described in detail in Yamashita Yu et al., “Chemical Monomer Chemistry and Industry”, IPC, 1989.
Specifically, macromers having polar groups according to the methods described in the literature using the hydrophilic monomers specifically described above, such as acrylic acid, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylacetamide and the like. Can be synthesized.

Among the macromers used for the formation of the graft polymer chain in the present invention, particularly useful are macromers derived from carboxyl group-containing monomers such as acrylic acid and methacrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, Derived from sulfonic acid macromers derived from monomers of styrenesulfonic acid and its salts, amide macromers such as acrylamide and methacrylamide, N-vinylcarboxylic acid amide monomers such as N-vinylacetamide and N-vinylformamide Amide-based macromers, macromers derived from hydroxyl-containing monomers such as hydroxyethyl methacrylate, hydroxyethyl acrylate, glycerol monomethacrylate, methoxyethyl acrylate, methoxypolyethylene glycol acrylic Over bets, macromers derived from alkoxy group or ethylene oxide group-containing monomers such as polyethylene glycol acrylate. A monomer having a polyethylene glycol chain or a polypropylene glycol chain can also be usefully used as the macromer of the present invention.
Among these macromers, the useful molecular weight is in the range of 400 to 100,000, the preferred range is 1000 to 50,000, and the particularly preferred range is 1500 to 20,000. When the molecular weight is 400 or less, the effect cannot be exhibited, and when it is 100,000 or more, the polymerizability with the copolymerization monomer forming the main chain is deteriorated.

  After synthesizing these macromers, the above macromers may be copolymerized with other monomers having a reactive functional group. In addition, as another method, a method of synthesizing a macromer and a graft polymer having a photocrosslinkable group or a polymerizable group, coating it on a support, reacting it by light irradiation, and crosslinking it can be mentioned. .

In addition, as described above, the graft polymer chain in the present invention is represented by “an alkoxide group of an element selected from Si, Ti, Zr, and Al (hereinafter appropriately referred to as a specific element alkoxide group”). It is preferable to have a “substituent capable of forming a covalent bond via a hydrolysis reaction with a metal alkoxide”. Hereinafter, this embodiment will be described by taking a silane coupling group as an example. Such a graft polymer can be obtained by copolymerizing a structural unit having a specific element alkoxide group and a monomer or macromer having the polar group. Examples of the structural unit having a specific element alkoxide group include monomers and macromers having a specific element alkoxide group at the side chain or terminal.
The introduction of such a specific element alkoxide group will be specifically described by taking a typical specific element alkoxide group as an example. Examples of silane coupling groups that can be introduced here include functional groups as shown in the following general formula (I).

In the general formula (I), R 1 ^and,, R ² each independently represent a hydrogen atom or a hydrocarbon group having 8 or less carbon atoms, m represents an integer of 0 to 2.
Examples of the hydrocarbon group when R ¹ and R ² represent a hydrocarbon group include an alkyl group and an aryl group, and a linear, branched or cyclic alkyl group having 8 or less carbon atoms is preferable. Specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclopentyl group and the like.
R ¹ and R ² are preferably a hydrogen atom, a methyl group or an ethyl group from the viewpoints of effects and availability.

  Examples of the monomer having a functional group represented by the general formula (I) include (3-acryloxypropyl) trimethoxysilane, (3-acryloxypropyl) dimethylmethoxysilane, and (3-acryloxypropyl) methyldimethoxysilane. , (Methacryloxymethyl) dimethylethoxysilane, (methacryloxymethyl) triethoxysilane, (methacryloxymethyl) trimethoxysilane, (methacryloxypropyl) dimethylethoxysilane, (methacryloxypropyl) dimethylmethoxysilane, (methacryloxypropyl) ) Methyldiethoxysilane, (methacryloxypropyl) triethoxysilane, (methacryloxypropyl) triisopropylsilane, methacryloxypropyl (trismethoxyethoxy) silane, and the like.

  The graft polymer according to the present invention includes the above-described two structural units, that is, a macromer having a polar group and a structural unit having an alkoxide group of a specific element such as a silane coupling group, as well as a monomer having another polar group. Can be copolymerized. It is also a preferred embodiment to copolymerize a structural unit having an amide group that can form a polar interaction. As the copolymerizable monomer, the monomers exemplified above as useful for the formation of the macromer can be exemplified.

  After synthesizing these macromers, one method for preparing the surface graft according to the present invention is to combine the macromer having the above polar group with the specific element alkoxide group, and preferably another structural unit having an amide group. The method of polymerizing is mentioned.

The graft polymer, which is a copolymer of the macromer having a polar group and the structural unit having a specific element alkoxide group, obtained here is a reaction site that interacts with a graft polymer chain having excellent mobility and a sol-gel crosslinked layer. Since it has a plurality of specific element alkoxide groups in the molecule, it is useful for forming the antistatic layer according to the present invention.
The preferable introduction amount of the specific element alkoxide group to be introduced into the graft polymer chain used in the present invention is in the range of 10 to 100% by weight, and the preferable introduction amount in the case of having an amide group is in the range of 10 to 100% by weight. There are some.

  The graft polymer layer having a graft chain having a polar group and a silane coupling group and a sol-gel crosslinked structure as described above is, for example, a macromer having a polar group as described above and a structural unit having a specific element alkoxide group. A coating liquid composition containing a graft polymer, preferably a hydrolyzable compound represented by the following general formula (II), is prepared, coated and dried to form a film. Can be formed more easily.

In general formula (II), R ⁶ and R ⁷ each independently represents an alkyl group or an aryl group, X represents Si, Al, Ti or Zr, and m represents an integer of 0 to 2.
When the graft polymer chain has a specific element alkoxide group, the hydrolyzable compound represented by the general formula (II) (hereinafter, simply referred to as a hydrolyzable compound as appropriate) is hydrolyzed with the specific element alkoxide group. By condensation polymerization, a covalent bond can be formed between the graft polymer chain and the sol-gel crosslinked structure. Thereby, a strong organic-inorganic composite layer can be formed.
In the general formula (II), R ⁶ represents a hydrogen atom, an alkyl group or an aryl group, R ⁷ represents an alkyl group or an aryl group, X represents Si, Al, Ti or Zr, and m is 0 to 2 Represents an integer.
The number of carbon atoms when R ⁶ and R ⁷ represent an alkyl group is preferably 1 to 4. The alkyl group or aryl group may have a substituent, and examples of the substituent that can be introduced include a halogen atom, an amino group, and a mercapto group.
This compound is a low molecular compound and preferably has a molecular weight of 1000 or less.

Specific examples of the hydrolyzable compound represented by the general formula (II) will be given below, but the present invention is not limited thereto.
In the case where X is Si, that is, those containing silicon in the hydrolyzable compound include, for example, trimethoxysilane, triethoxysilane, tripropoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, methyltrimethoxy Silane, ethyltriethoxysilane, propyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, γ-chloropropyltriethoxysilane, γ-mercaptopropyltri Methoxysilane, γ-mercaptopropyltriethoxysilane, γ-aminopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, diph Alkenyl dimethoxysilane, mention may be made of diphenyl diethoxy silane.
Among these, tetramethoxysilane, tetraethoxysilane, methyltolumethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxy are particularly preferable. Examples include silane, diphenyldimethoxysilane, diphenyldiethoxysilane, and the like.

In addition, when X is Al, that is, examples of the hydrolyzable compound containing aluminum include, for example, trimethoxy aluminate, triethoxy aluminate, tripropoxy aluminate, tetraethoxy aluminate and the like. it can.
When X is Ti, i.e., those containing titanium include, for example, trimethoxy titanate, tetramethoxy titanate, triethoxy titanate, tetraethoxy titanate, tetrapropoxy titanate, chlorotrimethoxy titanate, chlorotriethoxy titanate, ethyl triethoxy titanate. Examples thereof include methoxy titanate, methyl triethoxy titanate, ethyl triethoxy titanate, diethyl diethoxy titanate, phenyl trimethoxy titanate, and phenyl triethoxy titanate.
In the case where X is Zr, that is, those containing zirconium include, for example, zirconates corresponding to the compounds exemplified as those containing titanium.

[Preparation of coating solution for forming a crosslinked film]
When preparing the said hydrophilic coating liquid composition, the polymer which has a polar group may be included separately. Such a polymer can be obtained by polymerizing a hydrophilic monomer having a polar group useful for forming the graft polymer chain mentioned above. The content of the polymer is preferably 10% by weight or more and less than 50% by weight in terms of solid content. When the content is 50% by weight or more, the film strength tends to decrease. When the content is less than 10% by weight, the film properties are decreased, and the possibility of cracks in the film increases. Absent.

In addition, when a hydrolyzable compound is added to the preparation of the coating liquid composition for forming a crosslinked film which is a preferred embodiment, the amount of the hydrolyzable compound added is hydrolyzable with respect to the specific element alkoxide group in the graft polymer. The amount of the polymerizable group in the compound is preferably 5 mol% or more, more preferably 10 mol% or more. The upper limit of the addition amount of the crosslinking agent is not particularly limited as long as it can be sufficiently crosslinked with the polymer having a polar group, but when added excessively, the surface of the antistatic layer produced becomes sticky due to the crosslinking agent not involved in crosslinking. May cause problems.
From such a viewpoint, generally, the addition amount in the coating liquid composition is preferably in the range of 5 to 50% by mass, and more preferably in the range of 10 to 40% by mass.

  A hydrolyzable compound (crosslinking agent), preferably a solution obtained by further dissolving a polymer having a polar group in a solvent becomes a coating solution for forming a crosslinked film according to the present invention, and Si, Ti, Zr, etc. such as a silane coupling group. After coating on a hydrophilic graft polymer in which an alkoxide group or amide group of an element selected from Al is introduced, these components are hydrolyzed by heating and drying, and polycondensation results in the structure. Thus, an organic-inorganic composite layer having polar groups capable of interacting with each other and having high film strength is formed. In the preparation of the organic-inorganic composite, in order to promote hydrolysis and polycondensation reaction, it is preferable to use an acidic catalyst or a basic catalyst, and when trying to obtain a practically preferable reaction efficiency, the combined use of the catalyst is Particularly preferred.

(catalyst)
As the catalyst, an acid or a basic compound is used as it is, or a catalyst dissolved in a solvent such as water or alcohol (hereinafter referred to as an acidic catalyst and a basic catalyst, respectively). The concentration at the time of dissolving in the solvent is not particularly limited, and may be appropriately selected according to the characteristics of the acid or basic compound used, the desired content of the catalyst, etc. Condensation rate tends to increase. However, if a basic catalyst having a high concentration is used, a precipitate may be generated in the sol solution. Therefore, when a basic catalyst is used, the concentration is preferably 1 N or less in terms of concentration in an aqueous solution.

The type of the acidic catalyst or the basic catalyst is not particularly limited. However, when it is necessary to use a catalyst having a high concentration, a catalyst composed of an element that hardly remains in the coating film after drying is preferable.
Specifically, the acid catalyst is represented by hydrogen halide such as hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, hydrogen sulfide, perchloric acid, hydrogen peroxide, carbonic acid, carboxylic acid such as formic acid or acetic acid, and its RCOOH. Examples thereof include substituted carboxylic acids in which R in the structural formula is substituted with other elements or substituents, sulfonic acids such as benzene sulfonic acid, etc., and basic catalysts include ammonia bases such as aqueous ammonia and amines such as ethylamine and aniline Etc.

  The coating solution for forming a crosslinked film can be prepared by dissolving the hydrolyzable compound and the polymer having a polar group in a solvent such as ethanol, and then adding the catalyst and stirring. The reaction temperature is from room temperature to 80 ° C., and the reaction time, that is, the time for which stirring is continued is preferably in the range of 1 to 72 hours. By this stirring, hydrolysis and polycondensation of both components are advanced, and organic inorganic A composite sol solution can be obtained.

  As the solvent used in preparing the coating solution composition for forming a crosslinked film containing the hydrolyzable compound and preferably a polymer having a polar group, any solvent that can uniformly dissolve and disperse these can be used. Although there is no restriction | limiting, For example, aqueous solvents, such as methanol, ethanol, water, are preferable.

  Various additives can be used in the coating liquid composition for forming a crosslinked film according to the present invention depending on the purpose as long as the effects of the present invention are not impaired. For example, a surfactant or the like can be added to improve the uniformity of the coating solution.

In the present invention, the graft polymer layer and the organic-inorganic composite layer may be formed by the following method.
That is, for example, a coating liquid composition containing a graft polymer, a crosslinking agent, and a catalyst, which is a copolymer of a macromer having a polar group as described above and a structural unit having a specific element alkoxide group, is prepared. The method of apply | coating on the support body which generate | occur | produced the radical which is an active species on the surface by processing with plasma or an electron beam, and heating and drying is mentioned.
In this method, a polymerizable double bond in the macromer reacts with a radical on the support to produce a graft polymer directly bonded to the support, thereby forming a graft polymer layer. Further, when the coating composition is heated and dried, hydrolysis and condensation polymerization reaction of the crosslinking agent occurs, and a crosslinked structure can be formed in the graft polymer layer.
That is, according to such a method, the graft polymer layer and the organic-inorganic composite layer can be formed at a time by a series of steps of adjusting the coating liquid composition, coating, heating, and drying. .

  As described above, the formation of the organic-inorganic composite layer according to the present invention uses the sol-gel method. Regarding the sol-gel method, Sakuo Sakuo, “Science of Sol-Gel Method”, Agne Jofusha (published) (1988), Satoshi Hirashima, “Technology Center for Functional Thin Films Using the Latest Sol-Gel Method” General Technology Center (Published) (1992) and the like, and the methods described therein can be applied to the formation of the surface hydrophilic layer (organic-inorganic composite) according to the present invention.

The antistatic film of the present invention is an organic-inorganic composite having a crosslinked structure in which the coating liquid composition for forming a crosslinked film is coated on a suitable substrate formed with the graft polymer layer, and heated and dried. It can be obtained by forming a layer. By this method, a sol-gel crosslinked structure is formed by hydrolysis and polycondensation of the crosslinking agent.
The heating temperature and heating time for forming the organic-inorganic composite layer are not particularly limited as long as the solvent in the coating solution is removed and a strong film can be formed. The temperature is preferably 200 ° C. or less, and the heating time (crosslinking time) is preferably within 1 hour.

  In this way, an antistatic layer having an organic-inorganic composite can be provided on the support surface. Although the film thickness of the antistatic layer can be selected depending on the purpose, it is generally preferably in the range of 0.1 μm to 10 μm, and more preferably in the range of 0.5 μm to 10 μm. In this film thickness range, preferable antistatic performance and durability can be obtained, and curling in the film, and flexibility and bending resistance are unlikely to occur.

〔Base material〕
As the substrate constituting the support, any material having mechanical strength and dimensional stability can be used. However, when the antistatic film requires visibility, a transparent film is used. Preferably used.
Specific examples of the film used as a substrate include polyester films such as polyethylene terephthalate film, polyethylene terephthalate copolymer polyester film, and polyethylene naphthalate film; nylon 66 film, nylon 6 film, and metaxylidenediamine copolymer. Polyamide film such as polyamide film; Polyolefin film such as polypropylene film, polyethylene film and ethylene-propylene copolymer film; Polyimide film; Polyamideimide film; Polyvinyl alcohol film; Ethylene-vinyl alcohol copolymer film; Polyphenylene film; Film; polyphenylene sulfide film; and the like. Among these, polyester films such as polyethylene terephthalate film and polyolefin films such as polyethylene film and polypropylene film are preferable from the viewpoint of cost performance, transparency, gas barrier property, and the like. These films may be either stretched or unstretched, and may be used alone or may be used by laminating films having different properties.

  Moreover, unless the effect of this invention is impaired, the film used as a base material may contain various additives and stabilizers, or may be applied. Examples of the additive that can be used include an antioxidant, an antistatic agent, an ultraviolet ray inhibitor, a plasticizer, a lubricant, and a heat stabilizer. Further, surface treatment such as corona treatment, plasma treatment, glow discharge treatment, ion bombardment treatment, chemical treatment, solvent treatment, and roughening treatment may be performed.

  The thickness of the substrate is not particularly limited because it can be appropriately set in consideration of suitability for the purpose of use, such as packaging material, but is in the range of 3 μm to 1 mm from a general practical viewpoint. From the viewpoint of flexibility and workability for forming an inorganic thin film, it is more preferably in the range of 10 to 300 μm.

As long as such a support substrate itself can generate active species by energy application, the substrate may be used as a support as it is, but generation of a starting species that forms a graft polymer chain. For the purpose of more efficiently, it is preferable to provide a support by providing a surface layer containing a polymerization initiator on the substrate surface (hereinafter referred to as a polymerization initiation layer as appropriate), and in particular, stability and durability. From this point of view, it is preferable to provide a polymerization initiation layer obtained by immobilizing a polymerization initiator by a crosslinking reaction to provide a support. In the present invention, as described above, both the surface of the support substrate itself capable of generating active species and the substrate surface formed with the polymerization initiation layer are referred to as “support surface”.
(Polymerization initiation layer)
Such a polymerization initiating layer is not particularly limited as long as it contains a polymerization initiator in its structure, but from the viewpoint of stabilizing the polymerization initiator, the polymerization starts in the side chain described in detail below. What is obtained by immobilizing a polymer having a functional group having a function and a crosslinkable group by a crosslinking reaction is preferred.
The formation of the polymerization initiating layer is described in detail in paragraph Nos. [0009] to [0052] of Japanese Patent Application No. 2004-98620 previously filed by the applicant of the present application, and these techniques can be applied to the present invention. it can.

These details are described below.
The polymer having a polymerization initiating group (hereinafter referred to as a specific polymerization initiating polymer as appropriate) used for forming this polymerization initiating layer will be described.
This specific polymerization initiating polymer is essential to have a polymerization initiating group in the polymer structure, and is preferably obtained by polymerizing a monomer having a polymerization initiating group.

(Monomer having a polymerization initiating group)
The monomer having a polymerization initiating group constituting the specific polymerization initiating polymer is preferably composed of a monomer having a radical, anionic, or cationic polymerizable group capable of being polymerized with a pendant structure having the following polymerization initiating ability. That is, this monomer has a structure in which a polymerizable group and a polymerization initiating group are both present in the molecule.
The structure having the ability to initiate polymerization includes (a) aromatic ketones, (b) onium salt compounds, (c) organic peroxides, (d) thio compounds, (e) hexaarylbiimidazole compounds, (f) Examples thereof include ketoxime ester compounds, (g) borate compounds, (h) azinium compounds, (i) active ester compounds, (j) compounds having a carbon halogen bond, and (k) pyridinium compounds. From the viewpoint of polymerization initiating ability, (a), (c) and (j) are preferred. Any of these compounds can be used in the above (a) to (k).

  The specific polymerization initiating polymer in the present invention can be synthesized by polymerizing these monomers. In addition, any polymerization method can be used for the synthesis, but it is preferable to use a radical polymerization reaction from the viewpoint of simplicity of the polymerization reaction. In this case, the radical generator for causing radical polymerization reaction is preferably a compound that generates a radical by heat.

The weight average molecular weight of the specific polymerization initiating polymer in the present invention is preferably 10,000 to 10,000,000, more preferably 10,000 to 5,000,000, and further preferably 100,000 to 1,000,000. When the weight average molecular weight of the specific polymerization initiating polymer in the present invention is less than 10,000, the polymerization initiating layer may be easily dissolved in the monomer solution.
In addition, the preferable range of this weight average molecular weight is the case where the specific polymerization initiating polymer in the present invention is a copolymer with a monomer having a crosslinkable group or other third copolymerization component (monomer) described later. Is the same.

  Further, the specific polymerization initiating polymer in the present invention is preferably a polymer having a crosslinkable group in addition to the above-mentioned polymerization initiating group. Thus, because the specific polymerization initiating polymer has a crosslinkable group, the specific polymerization initiating polymer has the polymerization initiating group bonded to the polymer chain, and the polymer chain is immobilized by a cross-linking reaction. It is possible to form a specific polymerization initiation layer that is strong and in which elution of the initiator component is effectively suppressed.

  In the present invention, the above-described graft polymer is generated on the surface of such a polymerization initiating layer. By providing the specific polymerization initiating layer as described above, the polymerizability that is a material for forming the graft polymer. When the solution containing the compound is contacted or applied, it can be prevented from penetrating into the polymerization initiating layer. In addition, when forming a specific polymerization initiating layer, by using a specific polymerization initiating polymer having a crosslinkable group, it is possible to use not only a normal radical crosslinking reaction but also a condensation reaction or addition reaction between polar groups. Therefore, a stronger cross-linked structure can be obtained. As a result, it is possible to more efficiently prevent the initiator component in the polymerization initiation layer from being eluted, and to prevent the polymerizable compound from penetrating into the polymerization initiation layer.

The specific polymerization initiating polymer having a crosslinkable group can be obtained by copolymerizing the above-described monomer having a polymerization initiating group and a monomer having a crosslinkable group.
(Monomer having a crosslinkable group)
As the monomer having a crosslinkable group constituting the specific polymerization initiating polymer in the present invention, for example, a conventionally known crosslinkable group (structure used for the crosslink reaction as described in Shinji Yamashita “Crosslinker Handbook”). It is preferably a monomer comprising a radical, anion, or cationic polymerizable group having a pendant functional group). That is, this monomer has a structure in which a polymerizable group and a crosslinkable group are both present in the molecule.

Among these conventionally known crosslinkable groups, a carboxylic acid group (—COOH), a hydroxyl group (—OH), an amino group (—NH ₂ ), and an isocyanate group (—NCO) are preferably pendant to the polymerizable group. .
Moreover, as for such a crosslinkable group, only 1 type may be pendant by the polymeric group, and 2 or more types may be pendant.

  Examples of the polymerizable group pendant with these crosslinkable groups include polymerizable groups capable of polymerizing radicals, anions, and cationic groups such as acrylic groups, methacrylic groups, acrylamide groups, methacrylamide groups, and vinyl groups. Among these, an acrylic group and a methacryl group are particularly preferable from the viewpoint of ease of synthesis.

In the specific polymerization initiating polymer in the present invention, the copolymerization molar ratio of the copolymerization component (A) having a polymerization initiating group and the copolymerization component (B) having a crosslinkable group is (A) 1-40. It is preferable that the mol% and (B) is 20 to 70 mol%. From the viewpoint of the film properties of the polymerization initiation layer after the graft polymerization reaction or the crosslinking reaction, it is more preferable that (A) is 5 to 30 mol% and (B) is 30 to 60 mol%.
For the specific polymerization initiating polymer in the present invention, a copolymerization component (monomer) other than these may be used in order to adjust film forming property, hydrophilicity / hydrophobicity, solvent solubility, polymerization initiating property and the like.

[Polymerization initiation layer formed by immobilizing a specific polymerization initiation polymer by a crosslinking reaction]
In the polymerization initiation layer forming step, as a method for fixing the specific polymerization initiating polymer by a crosslinking reaction, there are a method using a self-condensation reaction of the specific polymerization initiating polymer and a method using a crosslinking agent in combination, and a crosslinking agent is used. Is preferred. As a method of using the self-condensation reaction of the specific polymerization initiating polymer, for example, when the crosslinkable group is —NCO, the method uses the property that the self-condensation reaction proceeds by applying heat. As this self-condensation reaction proceeds, a crosslinked structure can be formed.

[Deposition of polymerization initiation layer]
In this step, the above-mentioned specific polymerization initiating polymer is dissolved in a suitable solvent, a coating solution is prepared, the coating solution is placed on the substrate by coating, the solvent is removed, and the crosslinking reaction proceeds. The film is formed by
In addition, when a specific polymerization initiating polymer synthesized only from a monomer having a polymerization initiating group is used when forming the polymerization initiating layer, it is not necessary for the crosslinking reaction to proceed. After the preparation, the coating solution may be disposed on the substrate by coating or the like, and the solvent may be removed (dried).

(solvent)
The solvent used when applying the polymerization initiation layer is not particularly limited as long as the above-mentioned specific polymerization initiation polymer is dissolved. From the viewpoint of easy drying and workability, a solvent having a boiling point that is not too high is preferable. Specifically, a solvent having a boiling point of about 40 ° C to 150 ° C may be selected.
These solvents can be used alone or in combination. The concentration of the solid content in the coating solution is suitably 2 to 50% by mass.
The coating amount of the polymerization initiation layer is preferably 0.1 to 20 g / m ² in terms of weight after drying from the viewpoint of achieving sufficient expression of polymerization initiation ability and excellent film properties. 1-15 g / m < ² > is preferable.

(Conductive colloid)
Examples of the conductive colloid usable in the present invention include metal oxides of ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , InO ₃ , SiO ₂ , MgO, BaO, and MoO ₃ . Furthermore, these complex oxides can also be mentioned.
As the metal oxide, ZnO, TiO ₂ and SnO ₂ are preferable. In addition, as the composite oxide, Sb with respect to SnO ₂ , Sn with respect to In ₂ O ₃ , Al or In with respect to ZnO, and Sb, Nb or halogen elements such as halogen elements with respect to TiO ² of 0. The content is preferably from 01 to 30 mol%, particularly preferably from 0.1 to 10 mol%.
Furthermore, a core-shell type conductive metal oxide in which different conductive metal oxides form a core-shell structure may be used. The components constituting the core particle and the shell layer are the same as those of the metal oxide, and preferred examples are also the same. The composite oxide may have a core-shell structure.
The volume-specific low efficiency of the conductive metal oxide is preferably 10 ⁷ Ω · cm or less, particularly preferably 10 ⁵ Ω · cm or less. A metal oxide crystal having an oxygen defect or a metal oxide containing a small amount of a heterogeneous element serving as a so-called donor to the metal oxide is preferable because of high conductivity.
The conductive metal oxide preferably has a particle size of 0.5 μm or less, and more preferably 0.2 μm or less.

(Antistatic layer forming method)
The antistatic layer is formed by adding a conductive colloid such as a conductive metal oxide to the sol-gel solution described in detail above, and then applying or suspension (adding water or an organic solvent as required). Can be prepared, applied onto a suitable substrate such as a transparent film, and dried by heating. Moreover, after forming a graft polymer layer using the polymer which has an alkoxide group, the method of apply | coating the coating liquid containing a conductive colloid on the surface can also be taken.
The coating can be performed by a known coating method such as a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire barcode method, a graph via coating method, or an extrusion method using a hopper. .
When the conductive metal oxide is used as an antistatic agent, in order to increase the transmittance of the antistatic layer, in order to prevent the difference in refractive index between the metal oxide and the binder from increasing, It is desirable to have the same level. This adjustment can be performed by adjusting the particle diameter of the metal oxide. The diameter of the conductive metal oxide particles is preferably 0.5 μm or less, and in particular, by using a metal oxide of 0.2 μm or less, the light scattering efficiency can be reduced to 10% or less.

The volume resistivity of the antistatic layer is generally 10 ¹ Ω · cm to 10 ¹⁰ Ω · cm, preferably 10 ¹ to 10 ⁹ Ω · cm, more preferably 10 ¹ to 10 ⁸ Ω · cm. Such resistance can be obtained by adjusting the volume content of the conductive metal oxide in the layer.
In general, when forming the antistatic layer, the amount of conductive colloid added is preferably 5 to 90% by mass with respect to the total solid content of the coating solution for forming an antistatic layer containing the sol-gel solution. More preferably, it is in the range of 80% by mass.
The thickness of the antistatic layer is preferably from 0.01 to 10 μm, preferably from 0.05 to 2.0 μm, particularly preferably from 0.05 to 2.0 μm.

(Water and oil repellent treatment)
In order to impart water repellency to the surface of the antistatic layer composed of the organic-inorganic composite coating thus obtained, a water / oil repellent treatment step for performing a surface treatment can be carried out. Although there is no special restriction | limiting in the compound (water repellent) used when performing a surface treatment, and a processing method, It is preferable that a fluorine or an alkyl group is provided to the surface. Examples thereof include organometallic compounds such as silylating agents, titanate coupling agents, and alkylaluminums.
A silylating agent is a compound in which an alkyl group, an aryl group, a fluoroalkyl group containing fluorine, or the like is bonded to a hydrolyzable silyl group that has affinity or reactivity with inorganic materials, and is bonded to silicon. Examples of the functional group include an alkoxy group, a halogen, an acetoxy group, and a silazane.
Furthermore, in order to reduce the critical inclination angle of the water-repellent film (that is, the inclination angle of the plate where a certain amount of water droplets placed on the surface of the water-repellent film-coated substrate starts to roll) so that the water drops can easily fall down. Polydimethylsiloxane compounds may be used as water repellents. The water repellent is hydrolyzed as necessary and then used for coating the water repellent layer.

  The surface treatment with the water repellent is coating by a spray method, a flow coating method, a spin coating method, a dip pulling method, etc., and a surface adsorption by a liquid phase adsorption method or the like. The substrate treated with the water repellent is dried and then heat-treated at a temperature of 300 ° C. or lower, preferably 100 ° C. to 250 ° C. for 10 minutes to 1 hour. If the water-repellent agent forms a monomolecular layer on the surface of the organic-inorganic composite layer, it exhibits water-repellent performance, and even if the thickness of the water-repellent agent exceeds 10 nm, the effect does not increase any more. A preferred thickness is 1 to 10 nm.

The antistatic film of the present invention has good adhesion to the support surface due to the graft polymer chain introduced on the support surface and the high-density cross-linked structure formed between the graft polymer chains, Excellent solvent resistance and has the effect of being difficult to block.
In addition, the antistatic film of the present invention can be produced by a relatively simple process. Particularly, the anti-static film is suitable as a normal antistatic plastic film because it is excellent in blocking under high humidity. In addition, it is particularly suitable for use as a sheet for pasting in the plate making process of photoengraving.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.
(Example 1)
(Production of support)
A biaxially stretched polyethylene terephthalate film (A4100, manufactured by Toyobo Co., Ltd.) having a film thickness of 188 μm was used as a substrate, and a lithographic magnetron sputtering apparatus (CFS-10-EP70 manufactured by Shibaura Eletech) was used as a glow treatment. The base material A was obtained by performing oxygen glow treatment under the conditions.
(Oxygen glow treatment conditions)
Initial vacuum: 1.2 × 10 ⁻³ Pa
Oxygen pressure: 0.9 Pa
RF glow: 1.5 kW
Processing time: 60 sec

(Introduction of graft polymer)
Next, N, N-dimethylacrylamide, methacryloxypropyltriethoxysilane, and ethanol mixed solution (concentration: 50 wt%) were bubbled with nitrogen. The substrate A was immersed in this mixed solution at 70 ° C. for 7 hours. The soaked membrane was sufficiently washed with ethanol to prepare a support B in which a hydrophilic graft polymer chain having an alkoxysilyl group in the molecule was bonded to the substrate A.

[Formation of antistatic layer]
A conductive colloid-containing liquid (ELCOM P-35, manufactured by Catalyst Chemical Industry Co., Ltd.) having a silica oligomer (an alkoxysilane hydrolyzate) as a binder is added to the obtained support B, and the film thickness of the dried coating film By coating with a bar coater so that the thickness becomes 1 μm and heating at 120 ° C. for 10 minutes, a crosslinked structure is formed in the coating, and an antistatic layer made of an organic-inorganic composite film containing a conductive colloid is formed. Organic-inorganic hybrid film 1 was obtained.
(Water and oil repellent treatment)
The obtained organic-inorganic hybrid film 1 is dipped in a 0.1 wt% 1H, 1H, 2H, 2H perfluorodecyltrichlorosilane hexane solution, pulled up, and then heated and dried (100 ° C., 10 min) to repel the surface. An antistatic film 1 having an antifouling surface provided with a water / oil repellent antistatic layer was obtained.
The thickness of the antistatic layer subjected to the water / oil repellent treatment was 600 nm.

(Example 2)
In Example 1, the coating solution used for forming the antistatic layer (organic-inorganic composite film) was replaced with the coating solution composition 1 described below, and the antifouling surface was obtained in the same manner as in Example 1. An antistatic film 2 was obtained.
[Formation of organic-inorganic composite (antistatic layer)]
After the coating liquid composition 1 containing 2-propanol, water, tetraethoxysilane, and phosphoric acid in the following amounts in the obtained support B was stirred at room temperature for 5 hours, the silica oligomer used in Example 1 was used as a binder. A coating containing 2.0 g of a conductive colloid-containing liquid (ELCOM P-35, manufactured by Catalyst Kasei Kogyo Co., Ltd.) is applied, and the mixture is heated and dried at 100 ° C. for 10 minutes to form an anti-static material comprising an organic-inorganic composite. A layer was formed, and then water and oil repellent treatment was performed in the same manner as in Example 1 to obtain an antistatic film 2.
The thickness of the antistatic layer subjected to the water / oil repellent treatment was 520 nm.
(Coating composition 1)
・ 8g 2-propanol
Tetraethoxy titanate [Crosslinking component] 1.0 g
・ Water 1.0g
・ Phosphoric acid aqueous solution (0.85% aqueous solution) 1.0 g

(Example 3)
Example 1 except that 1.0 g of tetraethoxytitanate contained in the coating liquid composition 1 used for forming the antistatic layer (organic-inorganic composite film) in Example 2 was replaced with 1.0 g of tetramethoxyzirconate. The antifouling antistatic film 3 was obtained in the same manner as above.
The thickness of the antistatic layer subjected to the water / oil repellent treatment was 550 nm.
Example 4
Example 1 except that 1.0 g of tetraethoxytitanate contained in the coating liquid composition 1 used for forming the antistatic layer (organic-inorganic composite film) in Example 5 was changed to 1.0 g of trimethoxyaluminate. The antifouling antistatic film 4 was obtained in the same manner as above.
The thickness of the antistatic layer subjected to the water / oil repellent treatment was 880 nm.

(Example 5)
An aqueous acrylamide solution (concentration: 50 wt%) was bubbled with nitrogen. The substrate A described in Example 1 was immersed in this solution at 70 ° C. for 7 hours. The immersed membrane was sufficiently washed with water to prepare a support C having a hydrophilic graft polymer chain.
An antistatic film 5 was obtained in the same manner as in Example 1 except that the support B used in Example 1 was replaced with the support C.
The thickness of the antistatic layer subjected to the water / oil repellent treatment was 650 nm.

(Example 6)
(Introduction of graft polymer 2)
A methacryloxypropyltriethoxysilane / ethanol solution (concentration: 50 wt%) was bubbled with nitrogen. The substrate A was immersed in this mixed solution at 70 ° C. for 7 hours. The immersed membrane was sufficiently washed with distilled water to prepare a support D having a hydrophilic graft polymer chain.
An antifouling antistatic film 6 was obtained in the same manner as in Example 1 except that the support B used in Example 1 was replaced with the support D.
The thickness of the antistatic layer subjected to the water / oil repellent treatment was 730 nm.

(Comparative Example 1)
A styrene / methyl ethyl ketone solution (concentration: 10 wt%) was bubbled with nitrogen. The substrate A described in Example 1 was immersed in this solution at 70 ° C. for 7 hours. The immersed film was sufficiently washed with methyl ethyl ketone, and a surface graft film in which styrene was grafted on the surface was obtained as a support E.
An antifouling antistatic film 7 was obtained in the same manner as in Example 1 except that the support B used in Example 1 was replaced with the support E.
The thickness of the antistatic layer subjected to the water / oil repellent treatment was 850 nm.

(Comparative Example 2)
An antifouling antistatic film 8 was obtained in the same manner as in Example 1 except that the support B used in Example 1 was replaced with polyethylene terephthalate having no graft polymer layer.
The thickness of the antistatic layer subjected to the water / oil repellent treatment was 740 nm.

[Performance evaluation]
The obtained antistatic film was evaluated for performance by the following method. The results are shown in Table 1.
(Water repellency evaluation)
Using Kyowa Interface Science Co., Ltd., CA-Z, the angle after 20 seconds was measured after dropping pure water. A water droplet contact angle of 150 ° or more was evaluated as “◯”.
(Adhesion test)
In accordance with JISK5400, 100 mm squares of 1 mm square were attached with a rotary cutter, and a cello tape (manufactured by Nichiban, registered trademark) was pressure-bonded, and then a 90 ° peel test was performed three times at a speed of 30000 mm / min.

(Initial antifouling property)
Characters were written on the surface of the fluorine-containing polymer film of the antifouling surface material using a quick-drying oil-based ink (Zebra, “Mackey” (registered trademark)). Next, the number of times until the character was wiped clean was measured using “Bem Cotton” (registered trademark) manufactured by Asahi Kasei Corporation.
(Repeated antifouling property)
After rubbing the surface of the antifouling hard coat film 500 times using “Bem Cotton” (registered trademark) manufactured by Asahi Kasei Co., Ltd., the film surface was quickly dried with oil-based ink (Zebra, “Mackey” (registered trademark)). The number of times to write a letter and wipe it off is shown.

(Antistatic property)
The surface resistivity was measured using an insulation resistance measuring instrument (VH-30 type; manufactured by Kawaguchi Electric Co., Ltd.) in an atmosphere of 25 ° C. and 10% RH. A surface resistivity of 10 ¹⁰ Ω or less was evaluated as ◯.
(Haze)
The obtained antistatic plastic film was measured using an integrating sphere haze meter (SEP-HS type; manufactured by Japan Precision Engineering Co., Ltd.). A value of 2% or less was rated as ◯.

  As is apparent from Table 1, the antistatic film of the present invention is excellent in transparency, antistatic properties, surface antifouling properties and durability thereof, and has strong adhesion between the substrate and the antistatic layer. Recognize. On the other hand, in the antistatic film of Comparative Example 1 in which an antistatic layer was formed through a styrene graft polymer layer having no cross-linked structure in the coating, and in Comparative Example 2 in which an antistatic layer was formed without using a graft polymer layer, It can be seen that the adhesion between the body and the antistatic layer is inferior, and peeled off by rubbing or the like, resulting in inferior surface water / oil repellency and antistatic properties.

Claims (3)

  A crosslinked structure formed by hydrolysis and condensation polymerization of an alkoxide of an element selected from Si, Ti, Zr, and Al in a graft polymer layer having a graft polymer chain directly bonded to the support and the support surface; And an antistatic layer comprising an organic-inorganic composite film containing a conductive colloid, and the surface of the antistatic layer is subjected to a water / oil repellent treatment.   The antistatic film according to claim 1, wherein the haze is 2% or less.   A graft polymer layer forming step of forming a graft polymer chain directly bonded to the surface of the support to form a graft polymer layer composed of the graft polymer chain, and adding a conductive colloid to the graft polymer layer, and then Si An antistatic layer forming step of forming an organic-inorganic composite film having an antistatic ability by hydrolyzing an alkoxide of an element selected from Ti, Zr, and Al, and performing a condensation polymerization reaction to form a crosslinked structure; And a water / oil repellent treatment step for subjecting the surface of the antistatic layer to a water / oil repellent treatment.