JP2008024727A - Aqueous dispersion and laminated film using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an aqueous dispersion that suppresses admixture and precipitation of oligomer without impairing the antistatic effect of a coating agent composed of a mixture as a main component comprising specific amounts of a water-dispersible polyester resin, tin oxide ultrafine particles and water and a laminated film obtained by coating with the aqueous dispersion. <P>SOLUTION: The aqueous dispersion comprises a polyester resin and tin oxide ultrafine particles dispersed in an aqueous medium. The polyester resin comprises a polybasic acid component and a polyhydric alcohol component and has the ratio of a 1,2-propanediol component to the total alcohol component of ≥50 mol%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an aqueous dispersion and a laminated film using the aqueous dispersion, and in particular, an aqueous dispersion that is used as an antistatic coating agent and excellent in long-term storage stability, and is used as a transparent antistatic film by coating it. The present invention relates to a laminated film.

  In general, films and sheets are rarely used alone and are subjected to some surface modification treatment. Examples of the surface modification requirements include antistatic properties, blocking resistance, scratch resistance (properties that prevent scratches due to surface rubbing), and slipperiness. In particular, thermoplastic resin films used as general industrial materials and magnetic recording materials have a high surface resistivity, and are easily charged by friction and the like, so that dust, dust, and the like adhere to the film surface. As a result, it is necessary to provide antistatic performance. Therefore, as a method for surface modification that satisfies the above-mentioned essential points including antistatic properties, there is a method in which a coating containing a functional material is applied to form a film.

As an antistatic agent that can be used to form an antistatic coating on the film surface, the present applicant has previously prepared a mixture containing a specific amount of a water-dispersible polyester resin, tin oxide ultrafine particles, and water as a main component. Has been found (Patent Document 1). By using this coating agent, it is possible to obtain a transparent antistatic coating film having high transparency, water resistance, excellent adhesion to a substrate, particularly excellent adhesion to a polyester resin substrate, and aqueous. Since the medium is used, it can contribute to solving environmental problems and improving the working environment.
JP 2002-265860 A

  However, depending on the composition of the polyester resin used, an oligomer may be mixed in the resin, and the oligomer may precipitate when stored for a long time as an antistatic coating agent.

  The present invention relates to transparency, water resistance, adhesion to a substrate and antistatic property of a coating obtained from a coating agent mainly comprising a mixture containing a specific amount of water-dispersible polyester resin, tin oxide ultrafine particles and water. It aims at obtaining the aqueous dispersion which can suppress mixing and sedimentation of an oligomer, without impairing property, and obtaining the laminated film which coated the aqueous dispersion.

  The inventors of the present invention, as a result of further examining the conventional coating agent mainly composed of a mixture containing a specific amount of water-dispersible polyester resin, tin oxide ultrafine particles and water, the composition of the polyester resin In the present invention, it was found that when the ratio of 1,2-propanediol component to the total alcohol component is 50 mol% or more, the generation and mixing of oligomers are suppressed, and as a result, the generation of precipitates can be suppressed when an aqueous dispersion is obtained. The present invention has been reached.

That is, the gist of the present invention is as follows.
(1) 1,2-propane in which a polyester resin and tin oxide ultrafine particles are dispersed in an aqueous medium, and the polyester resin contains a polybasic acid component and a polyhydric alcohol component, and makes all the alcohol components. An aqueous dispersion, wherein the proportion of the diol component is 50 mol% or more.

  (2) The aqueous dispersion according to (1), wherein 30 to 10,000 parts by mass of tin oxide ultrafine particles are contained per 100 parts by mass of the polyester resin.

  (3) The aqueous dispersion of (1) or (2), comprising a basic compound.

  (4) The aqueous dispersion according to any one of (1) to (3), comprising a hydrophilic organic solvent.

  (5) The aqueous dispersion according to any one of (1) to (4), which is substantially free of a non-volatile aqueous solubilizing aid.

  (6) A laminated film in which a coating formed by applying and drying any one of the aqueous dispersions (1) to (5) is laminated on at least one surface of a thermoplastic resin film.

(7) The laminated film according to (6), wherein the surface specific resistance value of the surface on which the coating is laminated is 10 ¹⁰ Ω / □ or less.

  (8) The laminated film according to (6) or (7), wherein the haze is 5% or less.

  (9) The laminated film according to any one of (6) to (8), wherein the thermoplastic resin film is a polyester resin film.

  The aqueous dispersion containing the polyester resin of the specific composition of the present invention and the tin oxide-based ultrafine particles can exhibit the required antistatic effect because of containing the tin oxide-based ultrafine particles, and the polyester resin of the specific composition is Since the ratio of 1,2-propanediol component to all alcohol components is 50 mol% or more, it is possible to suppress the mixture of oligomers that cause precipitation, and to have excellent long-term storage stability. Can do. A laminated film using the same has good quality.

Hereinafter, the present invention will be described in detail.
The aqueous dispersion of the present invention is one in which a polyester resin and tin oxide ultrafine particles are dispersed in an aqueous medium. Here, the aqueous medium is a liquid containing water as a main component and may contain a hydrophilic organic solvent or a basic compound described later.

  The polyester resin used in the present invention needs to contain a polybasic acid component and a polyhydric alcohol component, and the ratio of 1,2-propanediol component to be all alcohol components must be 50 mol% or more. The proportion is preferably 60 mol% or more, more preferably 70 mol% or more, and further preferably 75 mol% or more. If the ratio of the 1,2-propanediol component included in the total alcohol component is less than 50 mol%, it is difficult to suppress the generation of oligomers. On the other hand, the ratio of the 1,2-propanediol component included in all alcohol components is not particularly limited, and the alcohol component may be only 1,2-propanediol.

  The polyester resin, other than 1,2-propanediol, as an alcohol component whose total alcohol component is 50 mol% or less, is an aliphatic glycol having 2 to 10 carbon atoms, an alicyclic glycol having 6 to 12 carbon atoms, An ether bond-containing glycol or the like may be contained. In specific compounds, aliphatic glycols having 2 to 10 carbon atoms include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5- Examples include pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, and 2-ethyl-2-butylpropanediol. Examples of the alicyclic glycol having 6 to 12 carbon atoms include 1,4-cyclohexanedimethanol. Examples of the ether-containing glycol include diethylene glycol, triethylene glycol, dipropylene glycol, and glycols obtained by adding 1 to several moles of ethylene oxide or propylene oxide to two phenolic hydroxyl groups of bisphenols, for example, 2, Examples include 2-bis (4-hydroxyethoxyphenyl) propane. However, since the ether structure decreases the water resistance and weather resistance of the film-formed product, the amount of the ether bond-containing glycol used as the polyhydric alcohol component constituting the polyester resin is 10% by weight or less of the total polyhydric alcohol component. Furthermore, it is preferable to keep it at 5% by weight or less. Polyethylene glycol, polypropylene glycol, and polytetramethylene glycol can also be used as necessary.

  Examples of the polybasic acid include aromatic polybasic acids, aliphatic polybasic acids, and alicyclic polybasic acids. In a specific compound, examples of the aromatic polybasic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, and biphenyldicarboxylic acid. Examples of aliphatic polybasic acids include oxalic acid, (anhydrous) succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, eicosanedioic acid, saturated dicarboxylic acid such as hydrogenated dimer acid, fumaric acid, maleic acid, Examples thereof include unsaturated aliphatic dicarboxylic acids such as maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, and dimer acid. Examples of the alicyclic polybasic acid include 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 2,5-norbornene dicarboxylic acid, 2,5-norbornene dicarboxylic anhydride, And alicyclic dicarboxylic acids such as tetrahydrophthalic acid and tetrahydrophthalic anhydride. In addition, a small amount of 5-sodium sulfoisophthalic acid or 5-hydroxyisophthalic acid can be used as necessary as long as the water resistance of the resin is not impaired.

  Among the polybasic acids described above, it is preferable to use an aromatic polybasic acid, and the ratio of the aromatic polybasic acid component to the total acid components constituting the polyester resin is 50 mol% or more. It is preferable for improving the hardness, chemical resistance and water resistance of the product, and it is more preferably 70 mol% or more for improving the storage stability of the aqueous dispersion by increasing the hydrolysis resistance of the resin. Furthermore, in terms of improving the workability, water resistance, chemical resistance, weather resistance, etc. while balancing with other performances of the film-formed product, among the total acid components constituting the polyester resin, It is particularly preferable that 65 mol% or more is a terephthalic acid component.

  A tribasic or higher polybasic acid or polyhydric alcohol may be used as the polybasic acid or polyhydric alcohol. Examples of such tribasic or more polybasic acids include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, benzophenone tetracarboxylic acid, benzophenone tetracarboxylic anhydride, trimesic acid, ethylene glycol bis (amnes Hydrotrimellitate), glycerol tris (anhydrotrimellitate), 1,2,3,4-butanetetracarboxylic acid and the like. Examples of the trifunctional or higher polyhydric alcohol include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. However, the amount of the tribasic or higher polybasic acid or polyhydric alcohol may be limited to 10 mol% or less, more preferably 5 mol% or less, based on the total acid component or total alcohol component constituting the polyester resin. In order to express the high processability of the film-formed product, it is preferable.

  Examples of the acid component constituting the polyester resin in the present invention include polybasic acids, fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, and ester-forming derivatives thereof; Acids, high-boiling monocarboxylic acids such as p-tert-butylbenzoic acid, cyclohexane acid and 4-hydroxyphenyl stearic acid; hydroxy such as ε-caprolactone, lactic acid, glycolic acid, β-hydroxybutyric acid and p-hydroxybenzoic acid Carboxylic acid and its ester-forming derivatives may be used. Moreover, as an alcohol component which comprises a polyester resin, you may use monoalcohol of high boiling points, such as stearyl alcohol and 2-phenoxyethanol. However, the amount of the monocarboxylic acid component and the monoalcohol component described above is preferably limited to a range in which the ratio of the total acid component and the total alcohol component constituting the polyester resin is 5 mol% or less.

  The acid value range of the polyester resin in the present invention is preferably 8 to 40 mgKOH / g, more preferably 10 to 36 mgKOH / g, and further preferably 10 to 28 mgKOH / g. The polyester resin in the present invention is not originally dispersed or dissolved in water by itself. Therefore, when the acid value is less than 8 mgKOH / g, the amount of carboxyl groups contributing to the aqueous formation described later is not sufficient, and it is difficult to obtain a good aqueous dispersion. On the other hand, when the acid value exceeds 40 mgKOH / g, when the film is formed from the polyester resin aqueous dispersion and dried, water and organic solvent hardly evaporate from the film formation, and the water resistance and resistance of the film formation are reduced. Chemical properties are likely to deteriorate.

  The polyester resin in the present invention has a glass transition temperature measured by DSC (differential scanning calorimetry) of 40 ° C. or higher, or is measured by GPC (gel permeation chromatography, effluent: tetrahydrofuran, polystyrene conversion). It is preferable that the number average molecular weight is 5000 or more and at least one of the conditions is satisfied. When none of these conditions is satisfied, that is, when the number average molecular weight is less than 5000 and the glass transition temperature is less than 40 ° C., not only the water resistance and chemical resistance of the film-formed product are lowered, but also the workability May be inferior. The glass transition temperature is preferably 43 ° C. or higher, particularly preferably 47 ° C. or higher. The number average molecular weight is preferably 5000 to 25000, particularly preferably 6000 to 20000. However, the molecular weight distribution is not limited at all. In addition, when a polyester resin does not melt | dissolve in tetrahydrofuran and said number average molecular weight cannot be measured, it can substitute with a relative viscosity.

  As a method of synthesizing the polyester resin in the present invention, a known method may be applied. For example, (a) esterification reaction is performed by reacting all monomer components and / or a low polymer thereof at 180 to 250 ° C. for about 2.5 to 10 hours under an inert atmosphere, followed by the presence of a transesterification catalyst. Below, a method of obtaining a polyester resin by advancing a polycondensation reaction until reaching a desired molecular weight at a temperature of 220 to 280 ° C. under a reduced pressure of 133 Pa (1 Torr) or less, (b) the polycondensation reaction to a target molecular weight The reaction product is mixed with a chain extender selected from an epoxy compound, an isocyanate compound, a bisoxazoline compound, etc. in the next process and reacted for a short time to increase the molecular weight. Method (c) The polycondensation reaction is advanced to the target molecular weight or higher stage, the monomer component is further added, and the solution is dissolved in an inert atmosphere, normal pressure to pressurized system. It is possible to use a method or the like to obtain a polyester resin having a molecular weight of the target by performing a slip.

  In addition, in the polyester resin, the carboxyl group necessary for the aqueous treatment described later is unevenly distributed at the end of the resin molecular chain rather than being present in the resin skeleton. From the viewpoint of As a method for obtaining such a polyester resin without side reaction or gelation, a tribasic or higher polybasic acid or its ester-forming derivative in the above-described method (a) after the start of the polycondensation reaction is used. Or a method of adding an acid anhydride of a polybasic acid immediately before the end of the polycondensation reaction, in the method (b) described above, a low molecular weight polyester resin in which most of the molecular chain ends are carboxyl groups. A method of increasing the molecular weight with a chain extender, a method of using a polybasic acid or an ester-forming derivative thereof as a depolymerizer in the above-described method (c), and the like can be used.

  The aqueous dispersion of the present invention preferably contains 30 to 10000 parts by mass, more preferably 50 to 5000 parts by mass of tin oxide ultrafine particles with respect to 100 parts by mass of the polyester resin. More preferably, it contains 100 to 1000 parts by mass. If the ratio of the tin oxide ultrafine particles is less than 30 parts by mass, the antistatic property of the film obtained using this aqueous dispersion may be insufficient. On the other hand, if it exceeds 10000 parts by mass, And the adhesion between the substrate and the substrate may be reduced.

  As the tin oxide ultrafine particles, those having a number average particle diameter of 50 nm or less are preferably used. More preferably, it is 20 nm or less, Especially preferably, it is 10 nm or less. If the number average particle diameter of the tin oxide ultrafine particles exceeds 50 nm in the aqueous dispersion, the dispersion stability and the transparency of the coating film may be lowered.

  Specific examples of the tin oxide-based ultrafine particles include tin oxide, antimony-doped tin oxide, indium-doped tin oxide, tin oxide-doped indium, aluminum-doped tin oxide, tungsten-doped tin oxide, titanium oxide-cerium oxide-tin oxide composite. And a composite of titanium oxide and tin oxide, and solvates and coordination compounds thereof can also be used. Of these, tin oxide, antimony-doped tin oxide, tin oxide-doped indium, and their solvates and coordination compounds, which are excellent in performance such as conductivity and well balanced in cost, are preferably used.

  The manufacturing method of said tin oxide type ultrafine particle is not specifically limited. For example, a method of hydrolyzing or thermally hydrolyzing metal tin and tin compounds, a method of alkaline hydrolysis of an acidic solution containing tin ions, a method of ion exchange of a solution containing tin ions with an ion exchange membrane or an ion exchange resin, etc. Either method can be used.

  Commercially available tin oxide ultrafine particles can also be used. For example, there is EPS-6 manufactured by Yamanaka Chemical Co., Ltd. as an aqueous dispersion of tin oxide ultrafine particles, SN100D manufactured by Ishihara Sangyo Co., Ltd. as an antimony-doped tin oxide ultrafine particle aqueous dispersion, and CII Kasei Co., Ltd. as tin oxide-doped indium ultrafine particles. Made of ITO.

  The aqueous dispersion of the present invention preferably contains a basic compound. When a basic compound is used, the carboxyl groups in the polyester resin are neutralized, and the electrostatic repulsion between the carboxyl anions generated by the neutralization prevents aggregation between the polyester resin particles in the aqueous dispersion. Stability is imparted to the aqueous dispersion. Further, when a basic compound is used, dispersion stability in an aqueous dispersion can be imparted to the aforementioned tin oxide ultrafine particles. Therefore, as the basic compound, a compound that can satisfactorily neutralize the carboxyl group in the polyester resin and can satisfactorily disperse and stabilize tin oxide ultrafine particles is preferably used. The amount of basic compound required depends on the type of polyester resin, the type of tin oxide ultrafine particles, the ratio of polyester resin to tin oxide ultrafine particles, the solid content concentration of the aqueous dispersion, etc. The amount that makes the pH of the dispersion 8.0 to 12.0 is preferable, and the amount that makes the pH 9.0 to 11.0 is more preferable. If the pH is less than 8.0, the stability of the aqueous dispersion may be poor. On the other hand, when pH exceeds 12.0, it may cause a cost increase, the drying time at the time of film formation may become long, or an aqueous dispersion may be colored. When the pH deviates from the above range, it becomes difficult to obtain an aqueous dispersion excellent in dispersion stability.

  As the basic compound, a volatile compound is used here. The volatility here means having a boiling point of less than 300 ° C., for example. In particular, a basic compound having a boiling point of 30 to 250 ° C, more preferably 50 to 200 ° C is preferable. When the boiling point is less than 30 ° C., the rate of volatilization when the resin described later becomes aqueous may increase, and the aqueous formation may not proceed completely. On the other hand, when the boiling point is 300 ° C. or higher, it becomes difficult to disperse the basic compound when the film is dried, and the water resistance of the film may deteriorate.

  Specifically, ammonia or an organic amine compound is preferable as the basic compound having the above properties. Specific examples of the organic amine compound include triethylamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine, diethylamine, and 3-ethoxypropylamine. , 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, 3-methoxypropylamine, monoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine and the like. Two or more of these may be mixed and used.

  In the present invention, it is preferable to add a hydrophilic organic solvent in order to improve the coating property of the aqueous dispersion and to accelerate drying after coating. As the hydrophilic organic solvent, it is preferable to use an organic solvent used as a component for promoting the aqueous formation of the polyester resin described later from the viewpoint of stability. Such a hydrophilic organic solvent has one or more atoms (specifically oxygen, nitrogen, fluorine, chlorine) having Pauling electronegativity of 3.0 or more in the molecule. Is preferable from the viewpoint of obtaining a good aqueous dispersion. Furthermore, it is preferable that it itself volatilizes from the film-forming product and has an action of azeotropically with water and promoting the volatilization of water. Specific examples include alcohols, ketones, and glycol derivatives. Among them, an organic solvent having a boiling point of 30 to 250 ° C. is preferable. The boiling point is more preferably 40 to 200 ° C, and still more preferably 50 to 150 ° C. When the one having a boiling point of 250 ° C. or higher is used, repelling or foaming may occur when coating the aqueous dispersion, or the stability of the aqueous dispersion may be impaired. On the other hand, when the boiling point is less than 30 ° C., the rate of volatilization when the resin is made aqueous increases, and the aqueous formation may not proceed completely.

  The content of the organic solvent is preferably 5 to 60% by mass, more preferably 10 to 40% by mass, and particularly preferably 20 to 30% by mass with respect to the aqueous dispersion. When the content of the organic solvent is less than 5% by mass, repelling and foam tend to occur during coating. On the other hand, if the content exceeds 60% by mass, the aqueous dispersion may aggregate depending on the solid content concentration.

  Specific examples of the hydrophilic organic solvent that can be used in the present invention include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n. -Amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, 3-methoxy-3-methylbutanol, 3-methoxybutanol and the like Examples of the ketone include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone, and diethyl ketone. Examples of the glycol derivative include ethylene glycol monomethyl ether, Lenglycol monoethyl ether, ethylene glycol monopropyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether , Dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether and the like. In addition, the organic solvent may be used alone or a plurality of types may be mixed and used.

  It is preferable that the aqueous dispersion of the present invention does not substantially contain a non-volatile aqueous auxiliary agent. The nonvolatile aqueous auxiliary agent remains in the polyester resin even after the film is formed, and may plasticize the film, thereby deteriorating the properties of the polyester resin, such as water resistance.

  Here, the “aqueous additive” refers to a drug or compound added for the purpose of promoting aqueous formation or stabilizing the aqueous dispersion in the production of an aqueous dispersion. “Non-volatile” means having no boiling point at normal pressure or having a high boiling point (eg, 300 ° C. or higher) at normal pressure.

  “Substantially no non-volatile aqueous solubilizing aid” means that no non-volatile aqueous solubilizing aid is actively added to the system, resulting in the absence of these. It is particularly preferable that the content of such a nonvolatile aqueous auxiliary agent is zero, but it may be contained in an amount of about 5% by mass or less based on the polyester resin component as long as the effects of the present invention are not impaired.

  Examples of the non-volatile auxiliary agent used in the present invention include surfactants described later, compounds having a protective colloid effect, modified waxes, high acid value acid-modified compounds, water-soluble polymers, and the like.

  Examples of surfactants include cationic surfactants, anionic surfactants, nonionic (nonionic) surfactants, amphoteric surfactants, fluorosurfactants, and reactive surfactants. In addition to those used for emulsion polymerization, emulsifiers are also included. For example, examples of the cationic surfactant include quaternary ammonium salts and alkylamine oxides. Examples of anionic surfactants include higher alcohol sulfate salts, higher alkyl sulfonic acids and salts thereof, higher carboxylic acids such as oleic acid, stearic acid, and palmitic acid and salts thereof, alkylbenzene sulfonic acids and salts thereof, and polyoxyethylene. Examples thereof include alkyl sulfate salts, polyoxyethylene alkylphenyl ether sulfate salts, and vinyl sulfosuccinates. Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyethylene glycol fatty acid ester, ethylene oxide propylene oxide block copolymer, polyoxyethylene fatty acid amide, ethylene oxide-propylene oxide copolymer, etc. And a sorbitan derivative such as a polyoxyethylene sorbitan fatty acid ester and the like. Examples of amphoteric surfactants include lauryl betaine and lauryl dimethylamine oxide. Examples of the fluorine-based surfactant include perfluorooctanesulfonic acid and its salt, perfluorooctanesulfonamide and its salt, and the like. Examples of reactive surfactants include alkylpropenylphenol polyethylene oxide adducts and their sulfate esters, allyl alkylphenol polyethylene oxide adducts and their sulfate esters, allyl dialkylphenol polyethylene oxide adducts and their sulfate esters, etc. Examples thereof include compounds having a reactive double bond.

  Compounds having protective colloid action, modified waxes, acid-modified compounds with high acid values, water-soluble polymers include polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, modified starch, polyvinyl pyrrolidone Polyacrylic acid and salts thereof, carboxyl group-containing polyethylene wax, carboxyl group-containing polypropylene wax, carboxyl group-containing polyethylene-propylene wax and the like, and acid-modified polyolefin waxes having a weight average molecular weight of usually 5000 or less and salts thereof, acrylic acid- Maleic anhydride copolymer and salts thereof, styrene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid copolymer, isobutylene-maleic anhydride A carboxyl group-containing polymer having an unsaturated carboxylic acid content of 20% by mass or more, such as a mutual copolymer, a (meth) acrylic acid- (meth) acrylic ester copolymer, and a salt thereof, polyitaconic acid and a salt thereof, an amino group Examples thereof include water-soluble acrylic copolymers having gelatin, gelatin, gum arabic, and casein, which are generally used as fine particle dispersion stabilizers.

Next, a method for producing the aqueous dispersion of the present invention will be described.
A method for obtaining an aqueous dispersion containing a polyester resin and tin oxide ultrafine particles is not particularly limited, but from the viewpoint of dispersion stability of the polyester resin particles and tin oxide ultrafine particles, an aqueous dispersion of the polyester resin is provided. It is most preferable to prepare a body and a dispersion of tin oxide-based ultrafine particles separately and mix them. In this way, the excellent storage stability of the aqueous polyester resin dispersion and the excellent dispersibility of the tin oxide ultrafine particles are maintained, and the polyester resin and the tin oxide ultrafine particles exhibit excellent properties of each other. be able to.

Hereinafter, this method will be described in detail.
First, the manufacturing method of the polyester resin aqueous dispersion is demonstrated.
The method for obtaining the aqueous polyester resin dispersion is not particularly limited, and methods widely known to those skilled in the art can be applied. For example, a method in which a solution or melt obtained by dissolving a polyester resin in a general-purpose organic solvent is added little by little to an aqueous medium to which a surfactant is added and stirred at high speed (forced emulsification method) A method (phase inversion emulsification method) or the like of adding an aqueous medium little by little in the solution or melt under stirring to invert the phase to obtain a stable aqueous dispersion can be used. In the phase inversion emulsification method, a surfactant may be added. As the surfactant, those described above can be used, but the addition amount is preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 1% by mass or less, and most preferably zero with respect to the resin component. .

  However, in the present invention, the method described in JP-A-9-296100 is particularly recommended. That is, it is a method of heating and stirring the polyester resin, basic compound, organic solvent and water having the specific composition described above, preferably in a sealable container. This method does not require a surfactant and does not require the resin to be once dissolved in an organic solvent. Moreover, since it is a method that can be produced with a relatively simple process and stable quality without using special equipment, it is suitable as a method for producing an aqueous polyester resin dispersion.

  Specifically, raw materials such as a polyester resin and an aqueous medium are put into the apparatus, and preferably stirred and mixed at a temperature of 40 ° C. or lower. Then, while maintaining the temperature in the tank at a temperature of 60 to 90 ° C., the polyester resin is sufficiently aqueousized by continuing stirring until preferably no coarse particles disappear (for example, for 5 to 120 minutes), and then preferably An aqueous dispersion can be obtained by cooling to 40 ° C. or lower under stirring. When the temperature in the tank is lower than 60 ° C., it becomes difficult to make the polyester resin water-based. When the temperature in a tank exceeds 90 degreeC, there exists a possibility that the molecular weight of a polyester resin may fall.

  The addition amount of the basic compound is an amount capable of at least partially neutralizing the carboxyl group depending on the amount of the carboxyl group contained in the polyester resin, that is, 0.2 to 1.5 times equivalent to the carboxyl group. It is preferably 0.4 to 1.3 times equivalent. When the amount is less than 0.2 times equivalent, the effect of adding a basic compound may not be recognized. On the other hand, when the amount exceeds 1.5 times equivalent, the aqueous polyester resin dispersion may be significantly thickened.

  The addition amount of the organic solvent is preferably 0.5 to 50% by mass, more preferably 5 to 45% by mass, and particularly preferably 10 to 40% by mass with respect to the aqueous polyester resin dispersion. preferable. If the content of the organic solvent is less than 0.5% by mass, it is difficult to make the polyester resin water-based. On the other hand, when the content exceeds 50% by mass, the stability of the dispersion may be impaired.

  A part of the organic solvent used in the production of the aqueous polyester resin dispersion can be distilled out of the system by a solvent removal process generally referred to as “stripping” after making the resin aqueous. The amount of solvent can be reduced. By stripping, the content of the organic solvent in the aqueous dispersion can be set to 10% by mass or less, and if it is set to 5% by mass or less, it is environmentally preferable. In the stripping process, it is necessary to increase the pressure reduction degree of the apparatus or lengthen the operation time. Therefore, considering such productivity, the amount of organic solvent contained in the finally obtained polyester resin aqueous dispersion The lower limit is about 0.01% by mass. However, even if the content is about 0.01% by mass, there is no particular influence on the performance and it can be used satisfactorily.

  Examples of the stripping method include a method in which the aqueous dispersion is heated with stirring at normal pressure or reduced pressure to distill off the organic solvent. When stripping is performed, the aqueous medium is distilled off to increase the solid content concentration. For example, when the viscosity increases and the workability deteriorates, the polyester resin aqueous dispersion is preliminarily mixed with water. May be added.

  The number average particle diameter of the polyester resin particles used in the present invention is preferably 1 μm or less, more preferably 0.5 μm or less, and more preferably 0.3 μm or less from the viewpoint of low-temperature film-forming properties and storage stability. More preferably. When the number average particle diameter exceeds 1 μm, the low-temperature film-forming property is remarkably deteriorated, or the storage stability of the aqueous dispersion is lowered. A polyester resin aqueous dispersion satisfying this condition can be obtained by the method described in JP-A-9-296100 described above.

Here, the number average particle diameter of the polyester resin is measured by a dynamic light scattering method or the like generally used for measuring the particle diameter of the fine particles.
Next, a method for obtaining a dispersion of tin oxide ultrafine particles will be described.

  Although this method is not particularly limited, for example, a method of heating and stirring a tin oxide ultrafine particle, a basic compound, water, and, if necessary, an organic solvent in a container can be employed. The basic compound and organic solvent used at this time can be selected from those described above. The content of the tin oxide ultrafine particles in the aqueous dispersion is not particularly limited, but is preferably 1 to 40% by mass, and 10 to 30% by mass in order to maintain dispersion stability. Is particularly preferred. The amount of basic compound required in this case varies depending on the type of tin oxide ultrafine particles, but is preferably 0.01 to 5.00 mol with respect to 1 mol of tin oxide ultrafine particles. Preferably it is 0.10 to 4.00 mol. At this time, the temperature is preferably 25 ° C. or higher, and more preferably 30 ° C. or higher, in order to promote peptization of the tin oxide ultrafine particles. The stirring method is not particularly limited, and in addition to a general stirring method using a stirring bar or stirring blade, a dispersion method using a homomixer or a homogenizer, a method using a high-pressure disperser, an ultrasonic disperser, or the like is adopted. Is also possible.

  As a dispersion of tin oxide ultrafine particles obtained in this way, a dispersion in which tin oxide ultrafine particles are dispersed while maintaining their primary particle diameter, that is, the number average particle diameter, is preferable. Specifically, as described above, the number average particle diameter is preferably 50 nm or less, more preferably 20 nm or less, and particularly preferably 10 nm or less. If the number average particle diameter of the tin oxide ultrafine particles exceeds 50 nm in the aqueous dispersion, the dispersion stability and the transparency of the coating film may be lowered. Here, the number average particle diameter of the tin oxide-based ultrafine particles is measured by the same dynamic light scattering method as that for the polyester resin fine particles.

  When mixing the polyester resin aqueous dispersion and the tin oxide ultrafine particle dispersion obtained by separate operations in this manner, a predetermined amount of hydrophilicity is added to the tin oxide ultrafine particle dispersion as necessary. The method of adding the said polyester resin aqueous dispersion after adding and stirring an organic solvent is preferable. When an organic solvent is added to the aqueous polyester resin dispersion, aggregates may be generated, but the problem can be suppressed by the above-described procedure. Specifically, when a predetermined amount of a hydrophilic organic solvent is added to the tin oxide ultrafine particle dispersion, agglomerates of tin oxide ultrafine particles are temporarily formed and turbidity is generated, but the turbidity is quickly eliminated by stirring. . It is preferable to add an aqueous polyester resin dispersion after confirming the elimination of this turbidity. At this time, an apparatus widely known as a liquid / liquid stirring apparatus can be used, and since the dispersibility of the mixed liquid is good, it is only necessary to perform a simple mixing operation for a very short time. In order to maintain the dispersion stability of the mixed solution, it is preferable to adjust the pH so that the pH of the mixed solution becomes 8 to 12 as necessary. Examples of the method for adjusting the solid content concentration after mixing include a method in which the aqueous medium is distilled off or diluted with water so as to obtain a desired solid content concentration.

  The solid concentration in the aqueous dispersion of the present invention, that is, the total concentration of the polyester resin and the tin oxide ultrafine particles is preferably 1 to 40% by mass. If the solid content concentration is less than 1% by mass, it tends to be difficult to form a film having a sufficient thickness when applied to a substrate. On the other hand, if it exceeds 40% by mass, the dispersion stability of the particles may decrease. is there.

  By mixing a crosslinking agent with the aqueous dispersion of the present invention, the hardness and chemical resistance of the coating can be improved. As the cross-linking agent, a functional group possessed by the polyester resin, for example, one having reactivity with a carboxyl group is used. For example, a phenol resin, an amino resin, a polyfunctional epoxy resin, a polyfunctional isocyanate compound and various block isocyanate compounds thereof, a polyfunctional aziridine compound, a carbodiimide group-containing compound, an oxazoline group-containing compound, and the like can be given. Only one type of such a crosslinking agent may be used, or two or more types may be used in combination.

  In the aqueous dispersion of the present invention, various agents such as leveling agents, antifoaming agents, anti-waxing agents, pigment dispersants, ultraviolet absorbers, lubricants, titanium oxide, zinc oxide, A pigment or dye such as carbon black can be added. It is also possible to add organic or inorganic compounds other than those described above as long as the stability of the aqueous dispersion is not impaired.

  Since the aqueous dispersion of the present invention is excellent in film forming ability, known film forming methods such as gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, and immersion are used. Various coatings are applied to the surface of various substrates by coating, brushing, etc., set as near room temperature as necessary, and then subjected to heat treatment for drying or drying and baking to produce various uniform films. It can be formed in close contact with the substrate surface. As a heating device at this time, a normal hot air circulation type oven, an infrared heater, or the like may be used. The heating temperature and the heating time are appropriately selected depending on the characteristics of the substrate to be coated, the type of curing agent, the blending amount, etc. In consideration of economy, the heating temperature is 30 to 250 ° C. Is preferable, 60-230 degreeC is more preferable, and 80-210 degreeC is especially preferable. The heating time is preferably 1 second to 20 minutes, more preferably 5 seconds to 15 minutes, and particularly preferably 10 seconds to 10 minutes. When a cross-linking agent is added, it is desirable that the heating temperature and time are appropriately selected depending on the type of the cross-linking agent in order to sufficiently advance the reaction between the carboxyl group in the polyester and the cross-linking agent.

The coating amount of the coating formed using the aqueous dispersion of the present invention is appropriately selected depending on the application, but a coating having a uniform thickness that is difficult to damage and has a uniform thickness is obtained. it is preferably in the range of 3 g / ^{m 2,} more preferably from 0.05 to 2 g / ^{m 2,} further preferably 0.1 to 1 g / ^{m 2.}

  The thermoplastic resin film used as the base material includes polyethylene terephthalate, polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, polylactic acid and other polyester resins, polypropylene, polyethylene, modified polypropylene, and modified polyethylene. And a polyolefin resin such as cyclic polyolefin, a polyamide resin such as nylon 6, nylon 66 and nylon 46, a polyimide resin, a polycarbonate resin, a polyarylate resin, or a mixture thereof, or a laminate of these films. Especially, it is good to use a polyester resin film from the point of adhesiveness with a film. The thermoplastic resin film may be an unstretched film or a stretched film, and its production method is not limited. Although the thickness of a thermoplastic resin film is not specifically limited, Usually, 0.5-2000 micrometers, Preferably it is 1-1000 micrometers, More preferably, it is 1-500 micrometers. The film surface is preferably subjected to physical surface treatment such as corona treatment.

The laminated film obtained by applying the aqueous dispersion of the present invention has a surface resistivity as low as 10 ¹⁰ Ω / □ or less, an excellent antistatic ability, and at the same time, excellent water resistance. Furthermore, the haze is 5% or less. That is, it has very high transparency. The transparency of the coating varies depending on the combination of the polyester resin aqueous dispersion and the tin oxide ultrafine particle dispersion, but as described above, the haze is preferably 5% or less, more preferably 3% or less. preferable.

  The laminated film thus obtained can be used for, for example, packaging materials, magnetic recording materials such as magnetic tapes and magnetic disks, electronic materials, graphic films, plate-making films, OHP films and the like.

Hereinafter, the present invention will be described specifically by way of examples. However, the present invention is not limited to these.
Various characteristics were measured or evaluated by the following methods.

(1) Composition of polyester resin It calculated | required from the < ¹ > H-NMR analysis (300 MHz) using the analyzer by a Varian company. Note that ^one for the H-NMR resin containing a constituent monomer is not observed attributable-quantifiable peaks on the spectrum, after 8 hours methanolysis at 230 ° C. in a sealed tube and subjected to gas chromatography analysis, quantitative Analysis was carried out.

(2) Glass transition temperature of polyester resin 10 mg of the polyester resin was used as a sample, and measurement was performed using a DSC (Differential Scanning Calorimetry) apparatus (DSC7 manufactured by Perkin Elmer Co., Ltd.) at a temperature rising rate of 10 ° C / min. The intermediate value of the temperature of two bending points derived from the glass transition in the obtained temperature rise curve was determined, and this was taken as the glass transition temperature.

(3) Number average molecular weight of polyester resin GPC analysis (using liquid feeding unit LC-10ADvp type and UV-visible spectrophotometer SPD-6AV type manufactured by Shimadzu Corporation, detection wavelength: 254 nm, solvent: tetrahydrofuran, polystyrene conversion) Determined by

(4) Acid value of polyester resin 1 g of polyester resin is completely dissolved in 50 ml of dioxane / water = 9/1 (volume ratio) mixed solvent, titrated with KOH using phenolphthalein as an indicator, and consumed for neutralization. The number of mg of KOH was determined as the acid value.

(5) Organic solvent content of aqueous dispersion Shimadzu Corporation gas chromatograph GC-8A [FID detector used, carrier gas: nitrogen, column packing material (manufactured by GL Sciences): PEG-HT (5%) − Uniport HP (60/80 mesh), column size: diameter 3 mm × 3 m, sample charging temperature (injection temperature): 150 ° C., column temperature: 60 ° C., internal standard substance: n-butanol] A dispersion diluted with water was directly charged into the apparatus, and the content of the organic solvent was determined. The detection limit was 0.01% by mass.

(6) Solid Content Concentration of Aqueous Dispersion An appropriate amount of the aqueous dispersion was weighed and heated at 150 ° C. until the mass of the residue (solid content) reached a constant weight to obtain the solid content concentration.

(7) Average particle diameter of polyester resin fine particles and tin oxide ultrafine particles The number average particle diameter was determined using a Microtrac particle size distribution meter UPA150 (MODEL No. 9340, dynamic light scattering method) manufactured by Nikkiso Co., Ltd. The refractive index of the resin used for particle diameter calculation was 1.57, and the refractive index of tin oxide was 1.99.

(8) Pot Life of Aqueous Dispersion The prepared aqueous dispersion was allowed to stand at 5 ° C. for half a year, and the appearance was evaluated in the following two stages. ○: No change in appearance.

(Triangle | delta): Generation | occurrence | production of agglomeration and precipitation is seen slightly.
X: Generation | occurrence | production of aggregation and precipitation is seen notably.

(9) Coating amount A predetermined amount of the aqueous dispersion of the present invention is applied as a coating liquid to a substrate whose area and mass have been measured in advance, and the mass of the laminate obtained by drying under predetermined conditions is measured. The total coating amount was determined by subtracting the mass of the base material before construction. The coating amount per unit area (g / m ² ) was calculated from the total coating amount and the coating area.

(10) Antistatic property of laminated film Based on JIS-K6911, the surface resistivity of the film of the laminated film was measured under the following three conditions using a digital ultrahigh resistance / microammeter R83340 manufactured by Advantest. Each was evaluated by measuring.

(10-a) Evaluation of standard characteristics Measurement was performed under an atmosphere of a temperature of 23 ° C. and a humidity of 65%.
(10-b) Flow resistance evaluation After the laminated film was exposed to running water for 60 seconds, it was measured under the same conditions as 10-a.

(10-c) Evaluation of hot water resistance The laminated film was immersed in warm water at 40 ° C. for 24 hours and then measured under the same conditions as 10-a.

(11) Solvent resistance The coated surface of the laminated film was rubbed 10 times with a cloth soaked with n-heptane, and the state of the coated surface was evaluated as follows.

○: No change △: Slight whitening ×: Whitening

(12) Haze Based on JIS-K7361-1, the haze of the laminated film was measured using a turbidimeter (Nippon Denshoku Industries Co., Ltd., NDH2000). However, this evaluation value included the turbidity of the base film.

(13) Evaluation of film adhesion After applying an adhesive tape (TF-12 manufactured by Nichiban Co., Ltd.) to the film surface of the laminated film, the tape was peeled off vigorously. And the state of the film surface was observed visually and evaluated as follows.

○: no peeling at all Δ: some peeling occurred ×: all peeling off

(14) Blocking resistance In the state where the coating surface of the laminated film and the base film surface are overlapped, a load of 200 g / cm ² is applied and left standing in an atmosphere of 40 ° C. for 24 hours. Evaluation was made according to the following criteria.

○: Peeling by lightly touching the film △: Peeling by pulling the film ×: Not peeling due to blocking

[Production of polyester resin-1]
1661 g of terephthalic acid is prepared as an acid component constituting the polyester resin, 1026 g of 1,2-propanediol and 155 g of ethylene glycol are prepared as an alcohol component, and the mixture is heated in an autoclave at 240 ° C. for 3 hours to form an ester. The reaction was carried out. Subsequently, the temperature was lowered to 230 ° C., 1.36 g of tetrabutyl titanate was added as a catalyst, and the pressure of the system was gradually reduced to 13 Pa after 1.5 hours. Under these conditions, a polycondensation reaction was performed, and after 2 hours, 60 g of trimellitic anhydride was added and stirred for 1 hour to perform a depolymerization reaction. Thereafter, the system was pressurized with nitrogen gas and dispensed into a sheet. And after fully cooling to room temperature, this was grind | pulverized with the crusher, the fraction of 1-6 mm of openings was extract | collected using the sieve, and the granular polyester resin P-1 was obtained. In the same manner, polyester resins P-2 to P-6 were obtained in such a manner that the constitution of the alcohol component would be the conditions shown in Table 1 below. Table 1 shows the physical properties of the obtained polyester resin.

[Production of polyester resin-2]
1163 g of terephthalic acid and 498 g of isophthalic acid are prepared as acid components constituting the polyester resin, 435 g of ethylene glycol and 625 g of neopentyl glycol are prepared as alcohol components, and the mixture is heated in an autoclave at 260 ° C. for 4 hours. The esterification reaction was performed. Next, 73 g of an ethylene glycol solution containing 1% by mass of antimony trioxide as a catalyst was added, the temperature of the system was raised to 280 ° C., and then the pressure of the system was gradually reduced to 13 Pa after 1.5 hours. . Under this condition, the polycondensation reaction is continued, and after 2 hours, the system is brought to atmospheric pressure with nitrogen gas. The depolymerization reaction was performed. Thereafter, the system was pressurized with nitrogen gas and dispensed into a sheet. And after fully cooling to room temperature, this was grind | pulverized with the crusher and the fraction of 1-6 mm of openings was extract | collected using the sieve, and the granular polyester resin P-7 was obtained. Table 1 shows the physical properties of the obtained polyester resin.

(Preparation of aqueous polyester resin dispersion E-1)
Using a stirrer (Toki Robotics, manufactured by Koki Kogyo Kogyo Co., Ltd.) equipped with a jacketed 2 liter glass container that can be sealed, 300 g of polyester resin P-1 and for promoting aqueous formation 220 g of isopropyl alcohol as a component, 11.4 g of triethylamine as a basic compound to be used for aqueous preparation, and 468.6 g of distilled water are charged in a glass container, and the rotation speed of a stirring blade (homodisper) When the mixture was stirred at 7000 rpm, no precipitation of resin particles was observed at the bottom of the container, and it was confirmed that the container was completely suspended. Thus, while maintaining this state, hot water was passed through the jacket after 10 minutes. Then, the system temperature was kept at 73 to 75 ° C. and further stirred for 1 hour. Thereafter, cold water was allowed to flow through the jacket, and the rotational speed was lowered to 4000 rpm and the mixture was cooled to room temperature (about 25 ° C.) while stirring. Furthermore, pressure filtration (air pressure 196 kPa (2 kg / cm ² )) with a 300-mesh stainless steel filter (wire diameter 0.035 mm, plain weave) was performed to obtain a uniform polyester resin aqueous dispersion E-1. Almost no resin remained on the filtered filter. The number average particle diameter of the obtained dispersion was 0.020 μm.
(Preparation of aqueous polyester resin dispersion E-2)
P-2 was used in place of the polyester resin P-1. Otherwise, an aqueous polyester resin dispersion E-2 was obtained according to the preparation method of E-1. The number average particle diameter of the obtained dispersion was 0.022 μm.

(Preparation of polyester resin aqueous dispersion E-3)
P-3 was used in place of the polyester resin P-1. Otherwise, an aqueous polyester resin dispersion E-3 was obtained according to the preparation method of E-1. The number average particle diameter of the obtained dispersion was 0.024 μm.

(Preparation of aqueous polyester resin dispersion E-4)
P-4 was used in place of the polyester resin P-1. Otherwise, an aqueous polyester resin dispersion E-4 was obtained according to the preparation method of E-1. The number average particle diameter of the obtained dispersion was 0.026 μm.

(Preparation of aqueous polyester resin dispersion E-5)
P-5 was used in place of the polyester resin P-1. Otherwise, an aqueous polyester resin dispersion E-5 was obtained according to the preparation method of E-1. The number average particle diameter of the obtained dispersion was 0.027 μm.

(Preparation of aqueous polyester resin dispersion E-6)
P-6 was used in place of the polyester resin P-1. Otherwise, an aqueous polyester resin dispersion E-6 was obtained according to the preparation method of E-1. The number average particle diameter of the obtained dispersion was 0.030 μm.

(Preparation of aqueous polyester resin dispersion E-7)
P-7 was used in place of the polyester resin P-1. Otherwise, an aqueous polyester resin dispersion E-7 was obtained according to the preparation method of E-1. The number average particle diameter of the obtained dispersion was 0.060 μm.

  The evaluation results of the obtained polyester resin aqueous dispersions E-1 to E-7 are shown in Table 2.

(Preparation of tin oxide sol S-1)
Dissolve 0.1 mol of stannic chloride pentahydrate in 200 ml of water to make a 0.5 M aqueous solution, and add white tin oxide ultrafine particles with pH 1.5 by adding 28% aqueous ammonia with stirring. A slurry was obtained. The obtained tin oxide ultrafine particle-containing slurry is heated to 70 ° C. and then naturally cooled to around 50 ° C., and then pure water is added to obtain a 1 L tin oxide ultrafine particle-containing slurry, which is solid-liquid separated using a centrifuge. Went. After adding 800 ml of pure water to the obtained water-containing solid content and stirring and dispersing with a homogenizer, washing was performed by performing solid-liquid separation using a centrifuge. 75 ml of pure water was added to the water-containing solid content after washing to prepare a tin oxide ultrafine particle-containing slurry. The resulting tin oxide ultrafine particle-containing slurry was added with 3.0 ml of triethylamine and stirred. After the transparency was raised, the temperature was raised to 70 ° C., then the heating was stopped and the mixture was naturally cooled to obtain a solid content concentration of 11.5. A tin oxide sol S-1 having a mass% of organic amine as a dispersion stabilizer was obtained. The number average particle diameter was 0.009 μm.

The base film used below was as follows.
-Biaxially stretched polyethylene terephthalate (hereinafter referred to as "PET") film Unitika's Emblet PET 12, thickness: 12 μm, haze: 2.8%
-Biaxially stretched nylon 6 (hereinafter referred to as “Ny6”) film manufactured by Unitika Ltd. Emblem, thickness: 15 μm, haze: 3.2%
-Stretched polypropylene (hereinafter referred to as “PP”) film manufactured by Tosero Co., Ltd., OP U-1, thickness: 20 μm, haze: 2.4%

(Example 1)
Isopropyl alcohol as a hydrophilic organic solvent was added to tin oxide sol S-1 so that it might become 20 mass% of the obtained aqueous dispersion, and it stirred, and the transparent aqueous dispersion was obtained. The polyester resin aqueous dispersion E-1 (resin P-1) was added to this so that the tin oxide ultrafine particles would be 800 parts by mass with respect to 100 parts by mass of the polyester resin solid content, and stirred to obtain a polyester. An aqueous dispersion containing a resin and tin oxide ultrafine particles was obtained. The solid content concentration was 10.0% by mass.

The obtained aqueous dispersion was applied to the corona-treated surface of the PET film using a film applicator (Yasuda Seiki Seisakusho, 542-AB), and then dried at 130 ° C. for 30 seconds, whereby the film surface was reduced to a surface of 0.001. A laminated film having a 5 g / m ² coating film was obtained.

  Various evaluation was performed about the obtained aqueous dispersion and laminated | multilayer film.

(Example 2)
Compared with Example 1, when mixing a polyester resin aqueous dispersion and a tin oxide sol, it changed so that a tin oxide ultrafine particle might be 400 mass parts with respect to 100 mass parts of polyester resin solid content. Other than that, an aqueous dispersion and a laminated film were obtained in the same manner as in Example 1, and various evaluations were performed.

(Example 3)
Compared to Example 1, when mixing the polyester resin aqueous dispersion and the tin oxide sol, the tin oxide sol was diluted with water to a solid content concentration of 8.5% by mass, and the polyester resin solid content was 100 parts by mass. The ultrafine tin oxide particles were mixed so as to be 6400 parts by mass. Other than that, an aqueous dispersion and a laminated film were obtained in the same manner as in Example 1. In addition, since solid content concentration was made low compared with Example 1, the coating amount became 0.2 g / m < ² > and less than Example 1. FIG. Various evaluation was performed about the obtained aqueous dispersion and laminated | multilayer film.

Example 4
Compared to Example 1, E-2 (resin P-2) was used in place of the polyester resin aqueous dispersion E-1 (resin P-1). Other than that, an aqueous dispersion and a laminated film were obtained in the same manner as in Example 1, and various evaluations were performed.

(Example 5)
Compared to Example 1, E-3 (resin P-3) was used in place of the polyester resin aqueous dispersion E-1 (resin P-1). Other than that, an aqueous dispersion and a laminated film were obtained in the same manner as in Example 1, and various evaluations were performed.

(Example 6)
Compared to Example 1, E-4 (resin P-4) was used instead of the polyester resin aqueous dispersion E-1 (resin P-1). Other than that, an aqueous dispersion and a laminated film were obtained in the same manner as in Example 1, and various evaluations were performed.

(Example 7)
Compared to Example 1, a Ny6 film was used as the base film instead of the PET film. Other than that, an aqueous dispersion and a laminated film were obtained in the same manner as in Example 1, and various evaluations were performed.

(Example 8)
Compared to Example 1, a PP film was used instead of the PET film as the base film, and the drying conditions were changed to 90 ° C. and 1 minute. Other than that, an aqueous dispersion and a laminated film were obtained in the same manner as in Example 1, and various evaluations were performed.

Example 9
Instead of the tin oxide sol S-1 used in Example 1, an antimony-doped tin oxide ultrafine particle aqueous dispersion (manufactured by Ishihara Sangyo Co., Ltd., SN100D, solid content concentration: 30% by mass, number average particle size 0.058 μm), Antimony-doped tin oxide ultrafine particles were mixed at 100 parts by mass with respect to 100 parts by mass of the polyester resin solid content. Other than that, an aqueous dispersion and a laminated film were obtained in the same manner as in Example 1, and various evaluations were performed.

(Comparative Example 1)
Compared with Example 1, it replaced with the polyester resin aqueous dispersion E-1 (resin P-1), and used E-5 (resin P-5). Other than that, an aqueous dispersion and a laminated film were obtained in the same manner as in Example 1, and various evaluations were performed.

(Comparative Example 2)
Compared to Example 1, E-6 (resin P-6) was used instead of the polyester resin aqueous dispersion E-1 (resin P-1). Other than that, an aqueous dispersion and a laminated film were obtained in the same manner as in Example 1, and various evaluations were performed.

(Comparative Example 3)
Compared to Example 1, E-7 (resin P-7) was used instead of the polyester resin aqueous dispersion E-1 (resin P-1). Other than that, an aqueous dispersion and a laminated film were obtained in the same manner as in Example 1, and various evaluations were performed.

  Table 3 shows the evaluation results of the aqueous dispersions and laminated films of Examples 1 to 9 and Comparative Examples 1 to 3.

   No precipitate was confirmed from the aqueous dispersions obtained in Examples 1-9. In addition, as shown in Table 3, the characteristics of the laminated film are all excellent in transparency, exhibit high antistatic properties, and the surface specific resistance value does not change greatly even under running water treatment or hot water treatment, and the solvent resistance is also improved. Excellent, adhesion to each substrate, and excellent blocking resistance. In Example 6, very slight floating was confirmed, but not so much that it was deposited and was within an allowable range.

  On the other hand, in Comparative Examples 1 to 3 in which the composition of the polyester resin is outside the range of the present invention, it was confirmed that a precipitate was generated.

Claims (9)

  A polyester resin and tin oxide-based ultrafine particles are dispersed in an aqueous medium, and the polyester resin contains a polybasic acid component and a polyhydric alcohol component, and is a 1,2-propanediol component that forms a total alcohol component. An aqueous dispersion characterized in that the ratio is 50 mol% or more.   The aqueous dispersion according to claim 1, wherein 30 to 10,000 parts by mass of tin oxide ultrafine particles are contained per 100 parts by mass of the polyester resin.   The aqueous dispersion according to claim 1, comprising a basic compound.   The aqueous dispersion according to any one of claims 1 to 3, further comprising a hydrophilic organic solvent.   The aqueous dispersion according to any one of claims 1 to 4, wherein the aqueous dispersion does not substantially contain a nonvolatile aqueous solubilizing aid.   A laminated film comprising a film formed by applying and drying the aqueous dispersion according to any one of claims 1 to 5 on at least one surface of a thermoplastic resin film. The laminated film according to claim 6, wherein the surface specific resistance value of the surface on which the coating is laminated is 10 ¹⁰ Ω / □ or less.   The laminated film according to claim 6 or 7, wherein the haze is 5% or less.   The laminated film according to any one of claims 6 to 8, wherein the thermoplastic resin film is a polyester resin film.