JP2009221316A - Polyester resin aqueous dispersion, film prepared therefrom, and packaging bag using the film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin aqueous dispersion having excellent adhesiveness to a base material having a low glass transition temperature even when formed into a film at low temperatures, and can form a resin film having excellent blocking resistance, to provide the film obtained therefrom, and to provide a packaging bag utilizing the film. <P>SOLUTION: The polyester resin aqueous dispersion is composed of a polyester resin (A) having &ge;5,000 number-average molecular weight and &ge;50&deg;C glass transition temperature, and a polyester resin (B) having &ge;9,000 number-average molecular weight, and &le;30&deg;C glass transition temperature. In the polyester resin aqueous dispersion, the polyester resin (A) is finely dispersed with an alcohol (i), and the polyester resin (B) is finely dispersed with a solvent (ii). Mixing is carried out in (A)/(B) (mass ratio) of (80/20)-(50/50) in terms of polyester resin solids, and the resin film can be formed at &ge;40&deg;C and &lt;100&deg;C film-forming temperature. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an aqueous polyester resin dispersion containing two kinds of polyester resins in a specific ratio and forming a film at a low film-forming temperature, a film obtained therefrom, and a packaging bag using the film. is there.

  Conventionally, polyester resins have been excellent in film processability, resistance to organic solvents (solvent resistance), and weather resistance as resin for film formation, and molded articles and films of PET, PBT, vinyl chloride, various metals, etc. Because of its excellent adhesion to the resin, it is used in large quantities as a resin used in paints, inks, adhesives, coating agents and the like.

  On the other hand, in recent years, there is a tendency to suppress the use of organic solvents for reasons such as environmental protection, regulation of dangerous goods under the Fire Service Act, and improvement of the workplace environment. There is a demand for supplying an aqueous polyester resin dispersion, which has been actively developed.

  For example, Patent Document 1 proposes an aqueous polyester resin dispersion in which a high-molecular-weight polyester resin having a relatively low acid value is dispersed in an aqueous medium. When such an aqueous dispersion is used, adhesion to a substrate is improved. It is described that a film excellent in performance such as water resistance can be formed. However, the aqueous polyester resin dispersion described in this document is a so-called self-emulsifying polyester resin aqueous dispersion in which the carboxyl group of the polyester resin is dispersed in an aqueous medium by neutralizing with a basic compound. In order to stably disperse the polyester resin in the aqueous medium, the polyester resin to be used needs to have a terminal carboxyl group corresponding to an acid value of 8 mgKOH / g or more. As a result, the molecular weight of the polyester resin is limited, the film strength is insufficient, and the adhesiveness may be insufficient.

  Patent Document 2 proposes an aqueous polyester resin dispersion in which a polyester resin having a lower acid value and a higher molecular weight is dispersed in an aqueous medium. Although this proposal has sufficient film strength and can form a film with excellent adhesion, another new problem relating to low-temperature film-forming properties, blocking resistance and low-temperature heat-sealing properties has arisen. That is, when a film is formed on the surface of the base material, it is necessary to form a film at a low temperature depending on the base material, but when a polyester resin aqueous dispersion that forms a film at a low temperature is selected, the dispersion is necessarily made of glass. Since it consists of a polyester resin with a low transition temperature, it becomes a film inferior in blocking resistance. For these reasons, it has been difficult to achieve both low-temperature film-forming properties and blocking resistance.

For example, Patent Document 3 proposes an aqueous polyester resin dispersion capable of forming a film excellent in low-temperature film-forming properties, blocking resistance, and low-temperature heat sealability. However, the aqueous polyester resin dispersion at 100 ° C. Only film formation has been studied. Amorphous PET (A-PET), acrylic, polylactic acid (PLA), etc. have a glass transition temperature as low as around 70 ° C., and when these are used as a substrate for coating or coating, they are higher than the glass transition temperature. If a polyester resin is formed at a temperature, for example, 100 ° C., the base material is deformed, contracted or damaged.
JP 2002-173582 A International Publication No. 2004/037924 Pamphlet International Publication No. 2007/029728 Pamphlet

  The present invention has been made in view of the above circumstances, and has excellent low-temperature film-forming properties, blocking resistance, and low-temperature heat sealability, without damaging the base material, even for a base material having a low glass transition temperature. It is an object of the present invention to provide an aqueous polyester resin dispersion capable of forming a film, a film obtained therefrom, and a packaging bag using the film.

  In particular, the present invention is capable of forming a resin film having no cracks in the film, excellent adhesion to the base material and excellent blocking resistance even when the film is formed at a low temperature, and even when heat-sealed at a low temperature. It aims at providing the polyester resin aqueous dispersion which can form the resin film which is excellent in the property, the film obtained from it, and the packaging bag using this film.

  In the present specification, the adhesion means a characteristic that the resin film itself formed on the substrate can be firmly attached to and bonded to the substrate. In addition, the adhesive property means that when two substrates having a resin coating formed on the surface of at least one substrate are heat-sealed so that the coating-forming surface is in contact, the two resin coatings are formed. Is a property that can be firmly connected and bonded.

  In order to solve the above-mentioned problems, the present inventors have intensively studied, and as a result, the present invention has been completed.

  That is, the gist of the present invention is as follows.

(1) A polyester resin (A) having a number average molecular weight of 5000 or more and a glass transition temperature of 50 ° C. or more, and a polyester resin (B) having a number average molecular weight of 9000 or more and a glass transition temperature of 30 ° C. or less. Polyester resin aqueous dispersion, polyester resin (A) is finely dispersed using the following alcohol (A), polyester resin (B) is finely dispersed using the following solvent (B), polyester It is characterized by being capable of forming a resin film at a film forming temperature of 40 ° C. or higher and lower than 100 ° C. by mixing at (A) / (B) = 80/20 to 50/50 (mass ratio) in terms of resin solid content. Polyester resin aqueous dispersion.
(A) A mixture of one or more alcohols having a boiling point of 150 ° C. or lower and a water solubility of 5 g / L (20 ° C.) or higher.
(B) The polyester resin (B) can be dissolved in an amount of 10% by mass or more with the temperature kept at 40 ° C. or less, the boiling point is 150 ° C. or less, and the solubility in water is 5 g / L (20 ° C.) or more. A mixture of one or more organic solvents (2) The polyester resin (A) and / or the polyester resin (B) has a carboxyl group at its terminal, and part of the carboxyl group Alternatively, the aqueous polyester resin dispersion according to (1), wherein the whole is neutralized with a basic compound.
(3) The polyester resin aqueous dispersion according to (1) or (2), wherein the acid value of the polyester resin (A) is 4 to 40 mgKOH / g.
(4) The polyester resin aqueous dispersion according to (1) or (2), wherein the acid value of the polyester resin (B) is 2 to 10 mgKOH / g.
(5) A film formed by removing an aqueous medium from the aqueous polyester resin dispersion of (1) to (4).
(6) A packaging bag obtained by heat-sealing the film of (5).

  The aqueous polyester resin dispersion of the present invention can form a resin film having excellent low-temperature film-forming properties, blocking resistance and low-temperature heat-sealing properties. It is suitable as a binder component of a sealant, and the film-formed product is suitable for packaging bags and has a very high industrial utility value.

  The aqueous polyester resin dispersion of the present invention is a liquid material in which at least a polyester resin (A) and a polyester resin (B) are contained in an aqueous medium at a specific ratio.

  In the present invention, the glass transition temperature of the polyester resin (A) is 50 ° C or higher, particularly 50 ° C or higher and 80 ° C or lower, and more preferably 60 ° C or higher and 75 ° C or lower. The polyester resin (A) is a component mainly acting to improve the blocking resistance in the coating obtained from the aqueous polyester resin dispersion of the present invention. When the Tg is less than 50 ° C., the blocking resistance is lowered. .

  The number average molecular weight determined by GPC (gel permeation chromatography) analysis of the polyester resin (A) needs to be 5000 or more, and preferably 6000 or more. If the number average molecular weight is less than 5,000, the resin film is brittle, so that the low-temperature film-forming property (adhesiveness) and adhesiveness are insufficient. Further, from the viewpoint of the stability of the aqueous dispersion, the number average molecular weight is usually preferably 10,000 or less.

  Such a polyester resin (A) usually has an acid value of 4 to 40 mgKOH / g, and particularly preferably 10 to 30 mgKOH / g.

  The glass transition temperature of the polyester resin (B) is 30 ° C. or lower, particularly −30 ° C. or higher and 30 ° C. or lower, and more preferably −25 ° C. or higher and 25 ° C. or lower. The polyester resin (B) is a component mainly acting to improve the low temperature film-forming property and the low temperature heat sealability in the coating obtained from the aqueous polyester resin dispersion of the present invention, and the glass transition temperature is 30 ° C. When it exceeds, low-temperature film-forming property and / or low-temperature heat-sealing property will deteriorate.

  The number average molecular weight by GPC of the polyester resin (B) is required to be 9000 or more, and preferably 10,000 or more. When the number average molecular weight is less than 9000, the heat sealability (adhesiveness) of the resin film is insufficient. Also, from the viewpoint of dispersion stability of the aqueous dispersion, the number average molecular weight is usually preferably 25000 or less.

  Such a polyester resin (B) usually has an acid value of 2 to 10 mgKOH / g, and particularly preferably 4 to 8 mgKOH / g.

  The film forming temperature of the resin coating in the present invention needs to be 40 ° C. or higher and lower than 100 ° C., and 50 ° C. to 80 ° C. is particularly preferable. When the film forming temperature exceeds 100 ° C., the base material is remarkably deformed, contracted, or broken, and thus a base material having a low glass transition temperature cannot be used. On the other hand, when the film forming temperature is lower than 40 ° C., the aqueous medium is not sufficiently removed, and a resin film cannot be obtained.

  The mass ratio of the polyester resin (A) and the polyester resin (B) contained in the aqueous polyester resin dispersion of the present invention is such that the ratio (A) / (B) is in the range of 80/20 to 50/50. It is necessary, and it is preferable that it is the range of 75 / 25-55 / 45, and it is more preferable that it is the range of 70 / 30-60 / 40. When the polyester resin (A) exceeds 80% by mass, the low-temperature film-forming property and / or the low-temperature heat sealability is deteriorated. Conversely, when the polyester resin (A) is less than 50% by mass, The blocking resistance of the resulting resin coating is reduced.

  Polyester resins (A) and (B) are both polycondensed with one or more polybasic acid components and one or more polyhydric alcohol components, or depolymerized with polybasic acid components after polycondensation. In addition, it can be produced by a known method such as addition of an acid anhydride after polycondensation. At this time, by adjusting various conditions, the glass transition temperature, number average molecular weight, acid value and the like of the resin can be controlled, and as a result, the polyester resins (A) and (B) can be distinguished and manufactured.

  For example, aromatic dicarboxylic acid, aliphatic dicarboxylic acid, etc. are mentioned as a polybasic acid component, However, If the ratio of the aliphatic dicarboxylic acid in a polybasic acid component is increased, the glass transition temperature of resin will fall. On the other hand, reducing the proportion of aliphatic dicarboxylic acid increases the glass transition temperature of the resin.

  Examples of the polyhydric alcohol component include aliphatic glycols, alicyclic glycols, ether bond-containing glycols, and the like. When the proportion of the long-chain ether bond-containing glycol in the polyhydric alcohol component is increased, the glass transition of the resin The temperature drops. On the other hand, if the proportion of the long-chain ether bond-containing glycol is decreased, the glass transition temperature of the resin increases.

  On the other hand, for example, when the amount of the polybasic acid component used for depolymerization is increased, the number average molecular weight of the resin decreases and the acid value increases. On the other hand, when the usage-amount of the said polybasic acid component is decreased, the number average molecular weight of resin will increase and an acid value will fall. At this time, when a polybasic acid component having three or more functional groups is used, the increase in acid value becomes more significant than when a bifunctional one is used.

  The polybasic acid component, polyhydric alcohol component, and preferred components and resin composition that can be used in the production of the polyester resins (A) and (B) will be described below. In addition, those descriptions are applicable as a common description of the polyester resins (A) and (B) unless otherwise specified.

  Specific examples of the polybasic acid component include, for example, terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, naphthalene dicarboxylic acid, biphenyldicarboxylic acid and other aromatic dicarboxylic acids, oxalic acid, succinic acid, succinic anhydride, adipine Saturated or unsaturated such as acid, azelaic acid, sebacic acid, dodecanedioic acid, hydrogenated dimer acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, dimer acid, etc. Aliphatic dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 2,5-norbornene dicarboxylic acid, 2,5-norbornene dicarboxylic acid anhydride, tetrahydrophthalic acid , Alicyclic dicarboxylic acids such as tetrahydrophthalic anhydride, etc. And the like. A small amount of 5-sodium sulfoisophthalic acid or 5-hydroxyisophthalic acid can be used as necessary.

  A tribasic or higher polybasic acid can also be used. For example, trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, trimesic acid, ethylene glycol bis ( Anhydro trimellitate), glycerol tris (anhydro trimellitate), 1,2,3,4-butanetetracarboxylic acid and the like may be contained. Such a trifunctional or higher polybasic acid is usually 10 mol% or less in the polybasic acid component, and more preferably 5 mol% or less, from the viewpoint of maintaining good processability of the resin film.

  Among the polybasic acid components described above, an aromatic polybasic acid is preferably used, and the content of the polyester resin in the polybasic acid component is preferably 50 mol% or more, and more preferably 60 mol% or more. By increasing the proportion of the aromatic polybasic acid component, the processability, water resistance, solvent resistance, etc. of the resin film formed from the aqueous dispersion are improved. As the aromatic polybasic acid, terephthalic acid and isophthalic acid are preferred because they are industrially produced in large quantities and are inexpensive.

  Examples of the polyhydric alcohol component include aliphatic glycol, alicyclic glycol, ether bond-containing glycol and the like. Specific examples of the aliphatic glycol include, for example, ethylene glycol, 1,2-propanediol, 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. Specific examples of the alicyclic glycol include 1,4-cyclohexanedimethanol and the like. Specific examples of the glycol containing an ether bond include, for example, diethylene glycol, triethylene glycol, dipropylene glycol, and bisphenols (bisphenol A) such as 2,2-bis [4- (hydroxyethoxy) phenyl] propane. Examples include ethylene oxide adducts, ethylene oxide adducts of bisphenols (bisphenol S) such as bis [4- (hydroxyethoxy) phenyl] sulfone, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Among these, examples of the long-chain ether bond-containing glycol include polyethylene glycol having a molecular weight of 500 or more, polypropylene glycol, polytetramethylene glycol, and the like.

  Examples of the trifunctional or higher polyhydric alcohol may include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and the like.

  Among the polyhydric alcohol components described above, ethylene glycol or neopentyl glycol is particularly preferable, and the total proportion of ethylene glycol and neopentyl glycol in the alcohol component of the polyester resin is preferably 50 mol% or more, and 60 mol% or more. Is more preferable. Since ethylene glycol and neopentyl glycol are industrially mass-produced, they are inexpensive and well balanced with various performances of the resin coating. Ethylene glycol particularly improves the solvent resistance of the resin film, and neopentyl glycol particularly improves the weather resistance of the resin film. The individual proportions of ethylene glycol and neopentyl glycol are preferably 20 to 80 mol%, more preferably 30 to 70 mol% in the alcohol component.

  Polyester resins include fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, and ester-forming derivatives thereof, benzoic acid, and p-tert-butylbenzoic acid as necessary. Monocarboxylic acids such as cyclohexane acid and 4-hydroxyphenyl stearic acid, monoalcohols such as stearyl alcohol and 2-phenoxyethanol, hydroxycarboxylic acids such as ε-caprolactone, lactic acid, β-hydroxybutyric acid, p-hydroxybenzoic acid and the like An ester-forming derivative may be copolymerized.

Examples of a preferable combination of the polyester resin (A) and the polyester resin (B) include the following combinations.
[Combination 1]
Polyester resin (A) (aromatic dicarboxylic acid, aromatic tricarboxylic acid, aliphatic glycol);
Polyester resin (B) (aromatic dicarboxylic acid, aliphatic dicarboxylic acid, aromatic tricarboxylic acid, aliphatic glycol).
[Combination 2]
Polyester resin (A) (aromatic dicarboxylic acid, aromatic tricarboxylic acid, aliphatic glycol);
Polyester resin (B) (aromatic dicarboxylic acid, aromatic tricarboxylic acid, aliphatic glycol, long-chain ether bond-containing glycol).
[Combination 3]
Polyester resin (A) (aromatic dicarboxylic acid, aliphatic dicarboxylic acid, aromatic tricarboxylic acid, aliphatic glycol);
Polyester resin (B) (aromatic dicarboxylic acid, aliphatic dicarboxylic acid, aromatic tricarboxylic acid, aliphatic glycol).
[Combination 4]
Polyester resin (A) (aromatic dicarboxylic acid, aliphatic glycol);
Polyester resin (B) (aromatic dicarboxylic acid, aliphatic dicarboxylic acid, aromatic tricarboxylic acid, aliphatic glycol).
[Combination 5]
Polyester resin (A) (aromatic dicarboxylic acid, aliphatic glycol);
Polyester resin (B) (aromatic dicarboxylic acid, aromatic tricarboxylic acid, aliphatic glycol, long-chain ether bond-containing glycol).

Among the above combinations, combinations 1 to 3 are preferable.

  The polyester resin (A) and / or the polyester resin (B) preferably has a carboxyl group at the terminal. In the case of a polyester resin having a carboxyl group at the terminal, at the time of manufacturing an aqueous dispersion, by adding a basic compound, at least a part or all of the carboxyl group is neutralized to generate a carboxyl anion. However, since the polyester resin fine particles are not aggregated and stably dispersed by the electric repulsion between the anions, an aqueous polyester resin dispersion having good dispersion stability can be obtained without using a surfactant. A film made of an aqueous dispersion using a surfactant tends to be inferior in water resistance.

  The polyester resin (A) and the polyester resin (B) are dispersed in an aqueous medium. Here, the aqueous medium is a medium composed of a liquid containing water as a main component, and may contain a basic compound or an organic solvent described later. Further, the boiling point of the aqueous medium is preferably 150 ° C. or lower, more preferably 120 ° C. or lower, since the aqueous medium can be easily volatilized from the resin film even at a low film-forming temperature. It is particularly preferable that the temperature is 100 ° C. or lower.

  The organic solvent used in producing the aqueous dispersion using the polyester resin (A) is an alcohol having a boiling point of 150 ° C. or lower and a water solubility of 5 g / L (20 ° C.) or higher (hereinafter referred to as alcohol ( B)). When the boiling point is higher than 150 ° C., the organic solvent is not completely volatilized from the resin coating, and the resulting coating is brittle and has poor adhesion and adhesion. If the solubility in water is less than 5 g / L (20 ° C.), a uniform aqueous dispersion cannot be obtained. If the alcohol is not used, a stable aqueous dispersion cannot be obtained. For satisfying these conditions, for example, methanol, ethanol, isopropanol and the like are preferable. In addition, you may use this organic solvent in mixture of 2 or more types. In addition, the alcohol to be used may be one that swells without dissolving the polyester resin (A).

The organic solvent used when manufacturing the aqueous dispersion using the polyester resin (B) is:
An organic solvent capable of dissolving 10% by mass or more of the polyester resin (B) while maintaining the temperature at 40 ° C. or lower, having a boiling point of 150 ° C. or lower and a solubility in water of 5 g / L (20 ° C.) or higher. (Hereinafter referred to as organic solvent (b)). When the boiling point exceeds 150 ° C., it becomes very difficult to completely remove the organic solvent in the polyester resin (B) aqueous dispersion production method described later, and a stable aqueous dispersion cannot be obtained. If the solubility in water is less than 5 g / L (20 ° C.), a uniform aqueous dispersion cannot be obtained. Further, if the polyester resin (B) can be dissolved only in an amount of less than 10% by mass while maintaining the temperature at 40 ° C. or lower, it becomes difficult to increase the solid content concentration of the completed aqueous dispersion, which is extremely non-existent. It becomes practical and uneconomical. As satisfying these conditions, for example, methyl ethyl ketone (hereinafter referred to as MEK), tetrahydrofuran (hereinafter referred to as THF) and the like are preferable. In addition, you may use this organic solvent in mixture of 2 or more types. The boiling point of MEK is 80 ° C., and the boiling point of THF is 65 ° C.

  In the polyester resin aqueous dispersion of the present invention, the polyester resin (A) and the content of the polyester resin containing the polyester resin (B) include the film formation method, the type of the object to be coated, the thickness of the target resin film, Although it can select suitably by performance etc. and is not specifically limited, 1-50 mass% with respect to the aqueous dispersion whole quantity is a point which maintains moderate viscosity in the case of coating, and expresses favorable film formation ability. Preferably, 5-45 mass% is more preferable, and 10-40 mass% is especially preferable.

  The particle diameter of the polyester resin in the aqueous dispersion is not particularly limited, but from the viewpoint of maintaining good storage stability, each volume average particle diameter is preferably 500 nm or less, more preferably 300 nm or less. , 200 nm or less is particularly preferable.

  Next, the manufacturing method of the polyester resin aqueous dispersion of this invention is demonstrated.

  As long as it can stir in a solvent, what kind of shape may be used for the polyester resin to be used, the shape of a pellet may be sufficient, and the thing cut | disconnected in the sheet form, the granular form, the lump form, and the dice form But you can.

  First, as a method for producing a polyester resin (A) aqueous dispersion, a polyester resin (A) having an acid value of 4 to 40 mgKOH / g, alcohol (I), water, and a basic compound are heated and stirred at 40 to 100 ° C. Can be manufactured. Specifically, when the polyester resin (A) and the alcohol (I) are mixed, the polyester resin (A) becomes swollen in the alcohol (I), water and a basic compound are added, and the mixture is heated and stirred at 40 ° C to 100 ° C. By doing so, the particle diameter gradually becomes finer, and it can be finely dispersed by continuing stirring. If necessary, by removing undispersed matter and aggregates by filtration, a uniform polyester resin (A) aqueous dispersion in which no precipitates or phase separation is observed can be obtained.

  The polyester resin (B) aqueous dispersion is produced by using a polyester resin (B) having an acid value of 2 to 10 mgKOH / g, dissolving the polyester resin in an organic solvent (b) (dissolution step), organic 3 of the step of dispersing the polyester resin solution dissolved in the solvent (b) in water together with the basic compound (phase inversion emulsification step), and the step of removing the organic solvent (b) from the resulting dispersion (solvent removal step). It can manufacture by manufacturing in a process. If necessary, by removing undispersed matter and aggregates by filtration, a uniform polyester resin (B) aqueous dispersion in which no precipitates or phase separation is observed can be obtained.

  In the present invention, phase inversion emulsification means that the amount of water exceeding the amount of the organic solvent contained in this solution is added to the organic solvent solution of the polyester resin to change the system from the organic solvent phase to the O / W emulsion dispersion system. It means that it can be made.

  The phase inversion emulsification step is performed at 40 ° C. or less, preferably 30 ° C. or less, more preferably 20 ° C. or less, and particularly preferably 15 ° C. By performing the phase inversion emulsification step at 40 ° C. or less, the volume average particle size of the obtained aqueous dispersion becomes small, and an aqueous dispersion excellent in storage stability can be obtained. In addition, in the solvent removal step, it is possible to suppress the formation of a polyester resin precipitate caused by the aggregation of the aqueous dispersion, and as a result, the yield is improved and it is economical.

  The aqueous polyester resin dispersion of the present invention can be produced by using an aqueous polyester resin (A) dispersion and an aqueous polyester resin (B) dispersion and stirring and mixing them at a predetermined ratio. Mixing can be easily performed using a general stirring device.

  In both the polyester resin (A) aqueous dispersion and the polyester resin (B) aqueous dispersion, the basic compound used can easily volatilize the aqueous medium from the resin film even at a low film forming temperature. Therefore, an organic amine having a boiling point of 150 ° C. or lower, more preferably 100 ° C. or lower, or ammonia is preferable. Of these, ammonia, triethylamine and the like are most preferable. The amount of the basic compound used is preferably an amount that can at least partially neutralize the carboxyl group, depending on the amount of the carboxyl group contained in the polyester resin, that is, 0.4 to 20 times equivalent to the carboxyl group, 0.6-15 times equivalent is more preferable and 0.8-10 times equivalent is especially preferable. By making the usage-amount of a basic compound into the said range, the polyester resin aqueous dispersion whose storage stability is especially favorable can be obtained.

  In the polyester resin aqueous dispersion of the present invention, various agents such as a leveling agent, an antifoaming agent, an anti-waxing agent, a pigment dispersing agent, an ultraviolet absorber, an antifungal agent, an antiseptic agent, titanium oxide, and zinc are optionally added. A pigment or dye such as flower or carbon black, or a water-soluble polymer such as polyvinyl alcohol or polyethylene oxide may be added. Further, by adding water or an organic solvent, it is possible to adjust viscosity, adjust wettability to the substrate, and the like.

Next, the usage method of the polyester resin aqueous dispersion of this invention is demonstrated.
Since the aqueous resin dispersion of the present invention is excellent in film forming ability, it can be uniformly coated on various substrate surfaces by known film forming methods such as dipping method, brush coating method, spray coating method, curtain flow coating method and the like. The aqueous medium can be removed by subjecting it to a heat treatment, and a uniform resin film can be formed in close contact with the surfaces of various substrates. As a heating device at this time, a normal hot air circulation type oven, an infrared heater, or the like may be used. In addition, the thickness of the resin coating is appropriately selected depending on its use and purpose, but is preferably 0.1 to 30 μm, and more preferably 0.3 to 10 μm.

  Examples of the base material for the film-formed product include a thermoplastic resin film, an aluminum foil, and a laminate thereof. The present invention is particularly useful for substrates having a low glass transition temperature, such as A-PET, acrylic, and PLA, but is not limited to these substrates.

  A film comprising the aqueous polyester resin dispersion of the present invention is formed on a base material, and the two obtained film-formed products are stacked so that the film-forming surfaces are in contact with each other and heat-sealed (heat-sealed) by a known method ), A packaging bag having excellent adhesiveness can be obtained even when heat-sealing at a low temperature.

Hereinafter, the present invention will be described specifically by way of examples.
(1) Structure of polyester resin It calculated | required from the 1H-NMR analysis (The product made by a Varian, 300MHz). In addition, for resins containing constituent monomers that do not have identifiable and quantifiable peaks on the 1H-NMR spectrum, they were subjected to methanol decomposition at 230 ° C. for 3 hours in a sealed tube and then subjected to gas chromatogram analysis for quantitative analysis. I did it.
(2) Number average molecular weight of polyester resin The number average molecular weight is determined by GPC analysis (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).
(3) Glass transition temperature of the 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 PerkinElmer Co., Ltd.) at a temperature rising rate of 10 ° C./min. An intermediate value of two bending point temperatures derived from the glass transition in the temperature rising curve was determined, and this was taken as the glass transition temperature.
(4) Acid value of polyester resin 0.5 g of polyester resin was dissolved in 50 ml of water / dioxane = 1/9 (volume ratio), titrated with KOH using cresol red as an indicator, and KOH consumed for neutralization. The value obtained by converting the number of mg per 1 g of polyester resin was determined as the acid value.
(5) Solid Content Concentration of Aqueous Dispersion About 1 g of the aqueous dispersion was weighed (Xg), and the mass of the residue (solid content) after drying at 150 ° C. for 2 hours was weighed (Yg) ), And the solid content concentration was determined by the following formula.
Solid content concentration (% by mass) = Y / X × 100
(6) Volume average particle diameter of aqueous dispersion The aqueous dispersion was diluted to 0.1% with water, and the volume average particle diameter was measured using MICROTRAC UPA (model 9340-UPA) manufactured by Nikkiso.
(7) Content of organic solvent in aqueous dispersion Shimadzu Corporation gas chromatograph GC-8A [using FID detector, 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, material input temperature (injection temperature): 150 ° C., column temperature: 60 ° C., internal standard substance: n-butanol], aqueous dispersion Was directly put into the apparatus, and the content of the organic solvent was determined. The detection limit was 0.01% by mass.
(8) Stability of aqueous dispersion In a 50 ml glass sample bottle, 30 ml of the aqueous dispersion was placed and allowed to stand at 25 ° C. for 2 days. The stability of the aqueous dispersion was evaluated on the basis.
○: No change in appearance and state.
X: Phase separation, precipitation, and gel state are observed.
(9) Thickness of resin film After measuring the thickness of the base material in advance using a thickness meter (manufactured by Union Tool, MICROFINE) and forming the resin film on the base material using an aqueous dispersion, The thickness of the substrate having this resin coating was measured by the same method, and the difference was taken as the thickness of the resin coating.
(10) Low temperature film-forming property (appearance)
The aqueous dispersion is placed on an A-PET sheet (Mineron Kasei Kogyo Co., Ltd., Mineron A-PET, glass transition temperature 73 ° C., thickness 0.3 mm) on a desktop coating apparatus (Yasuda Seiki, film applicator No. 542). -After coating with AB type and bar coater), the film thickness is 1 μm by drying for 1 minute in a hot air drier set at 30 ° C, 40 ° C, 60 ° C, 80 ° C, 120 ° C. The resin film was formed. The resin film was visually observed, and cracks were not observed. The resin film was classified as follows depending on whether or not a transparent resin film was formed.
○: No crack or the like is observed and transparent ×: Crack or the like is observed and / or opaque (11) Low-temperature film-forming property (adhesion)
A film was formed in the same manner as in (10) above. Next, the adhesive tape (width 18 mm) specified in JIS Z1522 is attached to the resin film leaving the end, and then rubbed with an eraser from the top to fully adhere it, and then the end of the adhesive tape is attached to the film. I peeled it momentarily after making it right angle. By analyzing the peeled adhesive tape surface with a surface infrared spectrometer (using a Perkin-Elmer SYSTEM2000, Ge60 ° 50 × 20 × 2 mm prism), it is determined whether or not a resin film is attached to the adhesive tape surface. Was classified as follows, and ○ was determined to be acceptable.
○: No peak derived from the resin film is observed on the adhesive tape surface.
X: A peak derived from the resin film is observed on the adhesive tape surface.
(12) Blocking resistance of resin film In the same manner as (10) above, after forming a resin film having a film thickness of 1 μm on the A-PET sheet, another A-PET sheet was overlaid on the film-forming surface. Whether or not the A-PET sheet can be easily peeled off by hand after peeling off the two A-PET sheets by hand after applying a load of 500 Pa and leaving it in an atmosphere of 38 ° C. for 24 hours and then cooling to 25 ° C. Depending on whether or not, it was classified as follows, and ○ was determined to be acceptable.
○: Can be easily peeled off, and no fusion mark is observed.
Δ: There is some resistance when peeling, but no fusion marks are observed.
X: There is considerable resistance when peeling, and a fusion mark is recognized.
(13) Low temperature heat sealability In the same manner as in (10) above, after forming a resin film having a film thickness of 1 μm on the A-PET sheet, two resin film-formed A-PET sheets are coated with each other. Was pressed at 65 ° C. with a heat press (sealing pressure of 0.2 MPa for 30 seconds). This sample is cut out with a width of 25 mm, and one day later, the peel strength of the film is measured at a tensile speed of 200 mm / min and a tensile angle of 180 degrees using a tensile tester (Intesco Precision Universal Material Tester Model 2020 manufactured by Intesco Corporation). The heat sealability was evaluated. A peel strength of 0.03 N / 25 mm or more is a practical strength.

  The polyester resin used in Examples and Comparative Examples was obtained as follows.

[Production Example of Polyester Resin P-1]
A mixture comprising 2907 g of terephthalic acid, 1246 g of isophthalic acid, 1133 g of ethylene glycol and 1614 g of neopentyl glycol was heated in an autoclave at 260 ° C. for 4 hours to carry out an esterification reaction. Next, 1.8 g of antimony trioxide was added as a catalyst, the temperature of the system was raised to 280 ° C., and the pressure of the system was gradually reduced to 13 Pa after 1.5 hours. Under this condition, the polycondensation reaction was continued, and after 6 hours, the system was brought to atmospheric pressure with nitrogen gas, and the temperature of the system was lowered. The depolymerization reaction was performed. Thereafter, the system was pressurized with nitrogen gas, and the resin was discharged in a sheet form. This was sufficiently cooled to room temperature, then crushed with a crusher, and a fraction having an opening of 1 to 6 mm was collected using a sieve to obtain a granular polyester resin P-1. The obtained polyester resin P-1 had a number average molecular weight of 9000, a glass transition temperature of 68 ° C., and an acid value of 16 mgKOH / g. The results are shown in Table 1.

[Production Example of Polyester Resin P-2]
A mixture consisting of 4153 g of terephthalic acid, 388 g of ethylene glycol and 2568 g of 1,2-propanediol was heated in an autoclave at 240 ° C. for 4 hours to carry out an esterification reaction. Next, 3.4 g of tetra-n-butyl titanate was added as a catalyst, the temperature of the system was lowered to 230 ° C., and 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, and 144 g of trimellitic anhydride is added while keeping the temperature of the system at 230 ° C. The depolymerization reaction was performed. Thereafter, the system was pressurized with nitrogen gas, and the resin was discharged in a sheet form. After sufficiently cooling this to room temperature, it was pulverized by a crusher, and a fraction having an opening of 1 to 6 mm was collected using a sieve to obtain a granular polyester resin P-2. The obtained polyester resin P-2 had a number average molecular weight of 7000, a glass transition temperature of 83 ° C., and an acid value of 23 mgKOH / g. The results are shown in Table 1.

[Production Example of Polyester Resin P-3]
A mixture consisting of 2492 g of terephthalic acid, 623 g of isophthalic acid, 1263 g of sebacic acid, 1311 g of ethylene glycol, and 1315 g of neopentyl glycol was heated at 250 ° C. for 4 hours in an autoclave to carry out an esterification reaction. Subsequently, after adding 3.3 g of zinc acetate dihydrate as a catalyst, the temperature of the system was raised to 270 ° C., and the pressure of the system was gradually reduced to 13 Pa after 1.5 hours. Under this condition, the polycondensation reaction was continued, and after 4 hours, the system was brought to atmospheric pressure with nitrogen gas, the temperature of the system was lowered, and when it reached 265 ° C., 38 g of trimellitic anhydride was added and stirred at 265 ° C. for 2 hours. The depolymerization reaction was performed. Thereafter, the system was pressurized with nitrogen gas and the resin was dispensed into a sheet. This was cooled to room temperature to obtain a sheet-like polyester resin P-3. The number average molecular weight of the obtained polyester resin P-3 was 18000, the glass transition temperature was 19 ° C., and the acid value was 6 mgKOH / g. The results are shown in Table 1.

[Production Example of Polyester Resin P-4]
A mixture of 1163 g of terephthalic acid, 1412 g of isophthalic acid, 1920 g of sebacic acid, and 2740 g of 1,4-butanediol was heated in an autoclave at 220 ° C. for 4 hours to carry out an esterification reaction. Next, after adding 2.6 g of tetra-n-butyl titanate as a catalyst, the temperature of the system was raised to 230 ° C., and the pressure of the system was gradually reduced to 13 Pa after 1 hour. Under this condition, the polycondensation reaction is continued, and after 4 hours, the system is brought to atmospheric pressure with nitrogen gas, 47 g of trimellitic acid is added while keeping the temperature of the system at 230 ° C., and the mixture is stirred at 230 ° C. for 2 hours. A polymerization reaction was performed. Thereafter, the system was pressurized with nitrogen gas, and the resin was discharged in a sheet form. This was cooled to room temperature to obtain a sheet-like polyester resin P-4. The obtained polyester resin P-4 had a number average molecular weight of 17,000, a glass transition temperature of −25 ° C., and an acid value of 6 mgKOH / g. The results are shown in Table 1.

[Production Example of Polyester Resin P-5]
A mixture of 2077 g of terephthalic acid, 2077 g of isophthalic acid, 1358 g of ethylene glycol, 1510 g of neopentyl glycol and 1125 g of polytetrafuran 1000 was heated in an autoclave at 240 ° C. for 4 hours to carry out an esterification reaction. Next, after adding 12.8 g of tetra-n-butyl titanate as a catalyst, the temperature of the system was raised to 250 ° C., and the pressure of the system was gradually reduced to 13 Pa after 1.5 hours. The polycondensation reaction was further continued under these conditions, and after 4 hours, the system was brought to atmospheric pressure with nitrogen gas, 32 g of trimellitic acid was added, and the mixture was stirred at 250 ° C. for 2 hours to perform a depolymerization reaction. Thereafter, the system was pressurized with nitrogen gas, and the resin was discharged in a sheet form. This was cooled to room temperature to obtain a sheet-like polyester resin P-5. The obtained polyester resin P-5 had a number average molecular weight of 11,000, a glass transition temperature of 14 ° C., and an acid value of 6 mgKOH / g. The results are shown in Table 1.

[Production Example of Polyester Resin P-6]
A mixture comprising 2907 g of terephthalic acid, 1246 g of isophthalic acid, 1133 g of ethylene glycol and 1614 g of neopentyl glycol was heated in an autoclave at 260 ° C. for 4 hours to carry out an esterification reaction. Next, 1.8 g of antimony trioxide was added as a catalyst, the temperature of the system was raised to 280 ° C., and 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 6 hours, the system is brought to atmospheric pressure with nitrogen gas, the temperature of the system is lowered, and when 270 ° C. is reached, 125 g of isophthalic acid and 105 g of trimellitic acid are added. The depolymerization reaction was performed by stirring for 2 hours. Thereafter, the system was pressurized with nitrogen gas, and the resin was discharged in a sheet form. After sufficiently cooling this to room temperature, the mixture was pulverized with a crusher, and a fraction having an opening of 1 to 6 mm was collected using a sieve to obtain a granular polyester resin P-6. The number average molecular weight of the obtained polyester resin P-6 was 3000, the glass transition temperature was 65 ° C., and the acid value was 32 mgKOH / g. The results are shown in Table 1.

[Production Example of Polyester Resin P-7]
A mixture consisting of 2492 g of terephthalic acid, 623 g of isophthalic acid, 1263 g of sebacic acid, 1311 g of ethylene glycol, and 1315 g of neopentyl glycol was heated at 250 ° C. for 4 hours in an autoclave to carry out an esterification reaction. Subsequently, after adding 3.3 g of zinc acetate dihydrate as a catalyst, the temperature of the system was raised to 270 ° C., and the pressure of the system was gradually reduced to 13 Pa after 1.5 hours. Under this condition, the polycondensation reaction was further continued. After 4 hours, the system was brought to atmospheric pressure with nitrogen gas, the temperature of the system was lowered, and when it reached 265 ° C., 125 g of isophthalic acid and 38 g of trimellitic anhydride were added, and 265 ° C. The mixture was stirred for 2 hours to carry out a depolymerization reaction. Thereafter, the system was pressurized with nitrogen gas, and the resin was discharged in a sheet form. This was cooled to room temperature to obtain a sheet-like polyester resin P-7. The number average molecular weight of the obtained polyester resin P-7 was 5000, the glass transition temperature was 17 ° C., and the acid value was 22 mgKOH / g. The results are shown in Table 1.

[Production Example of Polyester Resin P-8]
A mixture consisting of 2907 g of terephthalic acid, 664 g of isophthalic acid, 707 g of sebacic acid, 1133 g of ethylene glycol and 1614 g of neopentyl glycol was heated at 260 ° C. for 4 hours in an autoclave to carry out an esterification reaction. Next, 1.8 g of antimony trioxide was added as a catalyst, the temperature of the system was raised to 280 ° C., and the pressure of the system was gradually reduced to 13 Pa after 1.5 hours. Under this condition, the polycondensation reaction was continued, and after 6 hours, the system was brought to atmospheric pressure with nitrogen gas, and the temperature of the system was lowered. The depolymerization reaction was performed. Thereafter, the system was pressurized with nitrogen gas, and the resin was discharged in a sheet form. After sufficiently cooling this to room temperature, it was pulverized with a crusher, and a fraction having an opening of 1 to 6 mm was collected using a sieve to obtain a granular polyester resin P-8. The obtained polyester resin P-8 had a number average molecular weight of 8,000, a glass transition temperature of 40 ° C., and an acid value of 15 mgKOH / g. The results are shown in Table 1.

[Production Example of Polyester Resin P-9]
A mixture of 1744 g of terephthalic acid, 1744 g of isophthalic acid, 584 g of adipic acid, 1210 g of ethylene glycol, and 1484 g of neopentyl glycol was heated in an autoclave at 240 ° C. for 4 hours to carry out an esterification reaction. Next, after adding 3.3 g of zinc acetate dihydrate as a catalyst, the temperature of the system was raised to 265 ° C., and the pressure of the system was gradually reduced to 13 Pa after 1.5 hours. Under this condition, the polycondensation reaction was continued, and after 4 hours, the system was brought to atmospheric pressure with nitrogen gas. The temperature of the system was lowered, and when it reached 260 ° C., 38 g of trimellitic anhydride was added and stirred at 260 ° C. for 2 hours. Then, a depolymerization reaction was performed. Thereafter, the pressure of the system was gradually reduced to 13 Pa after 30 minutes, and then defoaming was performed for 1 hour. Next, the system was pressurized with nitrogen gas and discharged into a strand. After cooling with water, cutting was performed to obtain a polyester resin P-9 in a pellet form (diameter: about 3 mm, length: about 3 mm). The obtained polyester resin P-9 had a number average molecular weight of 15,000, a glass transition temperature of 41 ° C., and an acid value of 6 mgKOH / g. The results are shown in Table 1.

[Production Example of Polyester Resin Aqueous Dispersion E-1]
Using a jacketed glass container (2 liters in volume) and a stirrer (Mazela NZ-1200, manufactured by Tokyo Rika Kikai Co., Ltd.), 300 g of polyester resin P-1, 180 g of isopropyl alcohol, and 10 g of triethylamine Then, 510 g of distilled water was charged into a glass container, and heated with hot water through the jacket while stirring while maintaining the rotation speed of the stirring blade (three propellers) at 300 rpm. Subsequently, the dispersion | distribution process was further performed for 1 hour, keeping system temperature at 71-75 degreeC. Thereafter, cold water was passed through the jacket, and the temperature was lowered to 25 ° C. while stirring at a rotational speed of 200 rpm. The obtained aqueous dispersion was filtered through a 1000 mesh stainless steel filter to obtain an aqueous polyester resin dispersion E-1. Solid content concentration of obtained polyester resin aqueous dispersion E-1 was 30 mass%, the volume average particle diameter was 150 nm, and the content rate of the organic solvent was 18 mass%. Moreover, when the polyester resin aqueous dispersion E-1 was allowed to stand at 25 ° C. for 2 days, the stability of the aqueous dispersion was good. The results are shown in Table 2.

[Production Example of Aqueous Polyester Resin Dispersion E-2]
A polyester resin aqueous dispersion E-2 was obtained in the same manner as E-1, except that the polyester resin was changed to P-2, isopropyl alcohol was changed to 220 g, triethylamine was changed to 12 g, and distilled water was changed to 468 g. . Solid content concentration of obtained polyester resin aqueous dispersion E-2 was 30 mass%, the volume average particle diameter was 21 nm, and the content rate of the organic solvent was 22 mass%. Moreover, when the polyester resin aqueous dispersion E-2 was allowed to stand at 25 ° C. for 2 days, the stability of the aqueous dispersion was good. The results are shown in Table 2.

[Production Example of Aqueous Polyester Resin Dispersion E-3]
400 g of polyester resin P-3 and 600 g of MEK are put into a jacketed glass container (contents 2 l), and stirred using a stirrer (Mazela 1000, manufactured by Tokyo Rika Kikai Co., Ltd.) while heating the jacket through warm water of 60 ° C. Thus, the polyester resin was completely dissolved to obtain 1000 g of a polyester resin solution having a solid concentration of 40% by mass. Next, cool water is passed through the jacket to keep the system temperature at 13 ° C., and while stirring at a rotational speed of 600 rpm, 24 g of triethylamine is added as a basic compound, followed by 1106 g of distilled water at 13 ° C. at a rate of 100 g / min. Then, phase inversion emulsification was performed. Next, 1600 g of the obtained aqueous dispersion was put into a 2 l flask, and the organic solvent was distilled off by distillation under normal pressure. Distillation ended when the amount of distillation reached 630 g. After cooling to room temperature, 1.3 g of 28% by mass ammonia water was added while stirring the aqueous polyester resin dispersion. Then, it filtered with the 1000 mesh stainless steel filter, and it was 31.0 mass% when solid content concentration of the filtrate was measured. While stirring the filtrate, distilled water was added to adjust the solid content concentration to obtain an aqueous polyester resin dispersion E-3. Polyester resin aqueous dispersion E-3 obtained had a solid content concentration of 30% by mass, a volume average particle size of 147 nm, and a content of organic solvent of 0.03% by mass. Moreover, when the polyester resin aqueous dispersion E-3 was allowed to stand at 25 ° C. for 2 days, the stability of the aqueous dispersion was good. The results are shown in Table 2.

[Production Example of Polyester Resin Aqueous Dispersion E-4]
A polyester resin aqueous dispersion E-4 was obtained in the same manner as in E-3 except that the polyester resin was changed to P-4, triethylamine was changed to 64 g, and distilled water was changed to 1066 g. Polyester resin aqueous dispersion E-4 obtained had a solid content concentration of 30% by mass, a volume average particle size of 97 nm, and an organic solvent content of 0.04% by mass. Moreover, when the polyester resin aqueous dispersion E-4 was allowed to stand at 25 ° C. for 2 days, the stability of the aqueous dispersion was good. The results are shown in Table 2.

[Production Example of Polyester Resin Aqueous Dispersion E-5]
The polyester resin is the same as E-3 except that the polyester resin is changed to P-5, the basic compound to be added at the time of phase inversion emulsification is changed to 7.0 g of 28% by mass ammonia water and 1123 g of distilled water. An aqueous dispersion E-5 was obtained. The obtained polyester resin aqueous dispersion E-5 had a solid content concentration of 30% by mass, a volume average particle size of 101 nm, and an organic solvent content of 0.03% by mass. Moreover, when the polyester resin aqueous dispersion E-5 was allowed to stand at 25 ° C. for 2 days, the stability of the aqueous dispersion was good. The results are shown in Table 2.

[Production Example of Polyester Resin Aqueous Dispersion E-6]
A polyester resin aqueous dispersion E-6 was obtained in the same manner as in E-1, except that the polyester resin was changed to P-6, triethylamine was changed to 21 g, and distilled water was changed to 499 g. The obtained polyester resin aqueous dispersion E-6 had a solid content concentration of 30% by mass, a volume average particle size of 50 nm, and an organic solvent content of 18% by mass. Moreover, when the polyester resin aqueous dispersion E-6 was allowed to stand at 25 ° C. for 2 days, the stability of the aqueous dispersion was good. The results are shown in Table 2.

[Production Example of Polyester Resin Aqueous Dispersion E-7]
A polyester resin aqueous dispersion E-7 was obtained in the same manner as in E-3 except that the polyester resin was changed to P-7, triethylamine was changed to 32 g, and distilled water was changed to 1099 g. Polyester resin aqueous dispersion E-7 obtained had a solid content concentration of 30% by mass, a volume average particle size of 60 nm, and a content of organic solvent of 0.01% by mass or less. Moreover, when the polyester resin aqueous dispersion E-7 was allowed to stand at 25 ° C. for 2 days, the stability of the aqueous dispersion was good. The results are shown in Table 2.

[Production Example of Polyester Resin Aqueous Dispersion E-8]
A polyester resin aqueous dispersion E-8 was obtained in the same manner as in E-1, except that the polyester resin was changed to P-8. The obtained polyester resin aqueous dispersion E-8 had a solid content concentration of 30% by mass, a volume average particle size of 150 nm, and an organic solvent content of 18% by mass. Moreover, when the polyester resin aqueous dispersion E-8 was allowed to stand at 25 ° C. for 2 days, the stability of the aqueous dispersion was good. The results are shown in Table 2.

[Production Example of Polyester Resin Aqueous Dispersion E-9]
A polyester resin aqueous dispersion E-9 was obtained in the same manner as in E-3 except that the polyester resin was changed to P-9, triethylamine was changed to 13 g, and distilled water was changed to 1117 g. Polyester resin aqueous dispersion E-9 obtained had a solid content concentration of 30% by mass, a volume average particle size of 144 nm, and a content of organic solvent of 0.01% by mass or less. Further, the stability of the aqueous dispersion when the polyester resin aqueous dispersion E-9 was allowed to stand at 25 ° C. for 2 days was good. The results are shown in Table 2.

[Production Example of Polyester Resin Aqueous Dispersion E-10]
A polyester resin aqueous dispersion E-10 was obtained in the same manner as in E-1, except that the organic solvent to be charged was changed from isopropyl alcohol to 1-hexanol. Polyester resin aqueous dispersion E-10 obtained had a solid content concentration of 30% by mass, a volume average particle size of 135 nm, and an organic solvent content of 18% by mass. Moreover, when the polyester resin aqueous dispersion E-10 was allowed to stand at 25 ° C. for 2 days, the stability of the aqueous dispersion was good. The results are shown in Table 2.

[Production Example of Polyester Resin Aqueous Dispersion E-11]
The dispersion process was performed in the same manner as E-1, except that the organic solvent to be charged was changed from isopropyl alcohol to 1-octanol, but the polyester resin was not dispersed. That is, E-11 is 1-octanol (solubility in water: 0.5 g / L (20 ° C.) or less, which is less than 5 g / L (20 ° C.) in water as the organic solvent (a). ) Was used, a uniform aqueous dispersion could not be obtained.

[Production Example of Polyester Resin Aqueous Dispersion E-12]
A polyester resin aqueous dispersion E-12 was obtained in the same manner as in E-1, except that the organic solvent to be charged was changed from isopropyl alcohol to dichloromethane. The obtained polyester resin aqueous dispersion E-12 had a solid content concentration of 30% by mass, a volume average particle size of 600 nm, and an organic solvent content of 18% by mass. However, since E-12 used dichloromethane (halogenated hydrocarbon) which is not an alcohol as the organic solvent (a), when it is allowed to stand at 25 ° C. for 2 days, it becomes a gel state and a stable aqueous dispersion can be obtained. could not. The results are shown in Table 2.

[Production Example of Polyester Resin Aqueous Dispersion E-13]
A polyester resin aqueous dispersion E-13 was obtained in the same manner as in E-3 except that the organic solvent to be charged was changed from MEK to N-methylpyrrolidone. Polyester resin aqueous dispersion E-13 obtained had a solid content concentration of 30% by mass, a volume average particle size of 1100 nm, and a content of organic solvent of 15% by mass. However, since E-13 used N-methylpyrrolidone (boiling point: 202 ° C.) having a boiling point higher than 150 ° C. as the organic solvent (b), in the solvent removal step of the aqueous dispersion production process, Complete removal could not be performed, and when the mixture was allowed to stand at 25 ° C. for 2 days, it was in a gel state and a stable aqueous dispersion could not be obtained. The results are shown in Table 2.

[Production Example of Aqueous Polyester Resin Dispersion E-14]
The phase inversion emulsification step was performed in the same manner as E-3 except that the organic solvent to be charged was changed from MEK to toluene, but the polyester resin was not dispersed. That is, E-14 uses toluene (solubility in water: 4.5 g / L (20 ° C.)) that is less than 5 g / L (20 ° C.) as an organic solvent (b). Therefore, a uniform aqueous dispersion could not be obtained. The results are shown in Table 2.

[Production Example of Polyester Resin Aqueous Dispersion E-15]
The organic solvent to be charged was changed from MEK to isopropyl alcohol and the dissolution step was performed in the same manner as in E-3, but the polyester resin was hardly dissolved. That is, E-15 uses isopropyl alcohol (polyester resin solubility: 1% by mass or less), which can dissolve the polyester resin in less than 10% by mass as the organic solvent (b), and therefore, uniform aqueous dispersion I couldn't get a body. The results are shown in Table 2.

Example 1
Using E-1 as an aqueous dispersion of the polyester resin (A) and E-3 as an aqueous dispersion of the polyester resin (B), 30 g of E-3 is added to 70 g of E-1, and stirred at room temperature for about 5 minutes. By mixing, an aqueous polyester resin dispersion mixture M-1 was obtained.
About the obtained polyester resin aqueous dispersion mixture M-1, on a 0.3 mm-thick A-PET sheet (Mineron Kasei Kogyo Co., Ltd., Mineron A-PET, glass transition temperature 73 ° C.), a desktop coating apparatus (Coated with Yasuda Seiki, film applicator No. 542-AB type, bar coater mounted), and then dried for 1 minute in a hot air dryer set at 60 ° C. to form a resin film having a thickness of 1 μm Formed. Table 3 shows the results of various characteristic evaluations.

Example 2 to Example 6
Various characteristics were evaluated in the same manner as in Example 1 except that the polyester resin (A) aqueous dispersion and the polyester resin (B) aqueous dispersion shown in Table 3 were used. The results are shown in Table 3.

Example 7 and Example 8
Various characteristics were evaluated in the same manner as in Example 1 except that the drying temperature after coating on the A-PET sheet was 40 ° C. and 80 ° C., respectively. The results are shown in Table 3.

Comparative Examples 1 to 8
Various characteristics were evaluated in the same manner as in Example 1 except that the polyester resin (A) aqueous dispersion and the polyester resin (B) aqueous dispersion shown in Table 3 were used. The results are shown in Table 3.

Comparative Example 9 and Comparative Example 10
Various characteristics were evaluated in the same manner as in Example 1 except that the drying temperatures after coating on the A-PET sheet were 30 ° C. and 120 ° C., respectively. The results are shown in Table 3.

  In Examples, the aqueous polyester resin dispersion of the present invention has sufficient storage stability at room temperature, and is manufactured at a low temperature for a substrate having a low glass transition temperature (A-PET sheet; glass transition temperature 73 ° C.). It can be seen that the resin film excellent in film properties and obtained from the aqueous dispersion is excellent in blocking resistance and low temperature heat sealability.

  Since the number average molecular weight of the polyester resin (B) was less than the range of this invention, the comparative example 1 was a film inferior to low temperature film forming property or low temperature heat seal property.

  Since the glass transition temperature of the polyester resin (B) exceeded the range of this invention, the comparative example 2 was a film inferior to low temperature film forming property and low temperature heat seal property.

  Since the number average molecular weight of the polyester resin (A) was less than the range of this invention, the comparative example 3 was a film inferior to low temperature film forming property and low temperature heat seal property.

  Since the glass transition temperature of the polyester resin (A) was less than the range of this invention, the comparative example 4 was a film inferior to blocking resistance.

  In Comparative Example 5, 1-hexanol (boiling point: 157 ° C.) having a boiling point higher than 150 ° C. was used as the organic solvent (I) during the production of the polyester resin aqueous dispersion E-10, and thus the aqueous medium was not sufficiently removed. Thus, a good resin film could not be obtained.

  Since the content rate of the polyester resin (A) exceeded the range of this invention, the comparative example 6 was a film inferior to low-temperature film-forming property or low-temperature heat-sealability.

  Since the content rate of the polyester resin (B) exceeded the range of this invention, the comparative example 7 and the comparative example 8 were the films inferior to blocking resistance.

  In Comparative Example 9, since the drying temperature after coating on the A-PET sheet was too low, the removal of the aqueous medium was insufficient, and a good resin film could not be obtained.

In Comparative Example 10, since the drying temperature after coating on the A-PET sheet was too high, A-PET as the base material was significantly deformed and contracted, and a good resin film could not be obtained.

Claims (6)

A polyester resin aqueous solution comprising a polyester resin (A) having a number average molecular weight of 5000 or more and a glass transition temperature of 50 ° C. or more, and a polyester resin (B) having a number average molecular weight of 9000 or more and a glass transition temperature of 30 ° C. or less. The polyester resin (A) is finely dispersed using the following alcohol (I), the polyester resin (B) is finely dispersed using the following solvent (b), and the polyester resin solid content (A) / (B) = 80/20 to 50/50 (mass ratio) in terms of conversion, and a polyester resin can be formed at a film forming temperature of 40 ° C. or higher and lower than 100 ° C. Aqueous dispersion.
(A) A mixture of one or more alcohols having a boiling point of 150 ° C. or lower and a water solubility of 5 g / L (20 ° C.) or higher.
(B) The polyester resin (B) can be dissolved in an amount of 10% by mass or more with the temperature kept at 40 ° C. or less, the boiling point is 150 ° C. or less, and the solubility in water is 5 g / L (20 ° C.) or more. A mixture of one or more organic solvents   The polyester resin (A) and / or the polyester resin (B) has a carboxyl group at the end, and part or all of the carboxyl group is neutralized with a basic compound. The aqueous polyester resin dispersion according to claim 1, wherein   The polyester resin aqueous dispersion according to claim 1 or 2, wherein the acid value of the polyester resin (A) is 4 to 40 mgKOH / g.   The polyester resin aqueous dispersion according to claim 1 or 2, wherein the polyester resin (B) has an acid value of 2 to 10 mgKOH / g.   A film formed by removing an aqueous medium from the aqueous polyester resin dispersion according to claim 1. A packaging bag formed by heat-sealing the coating film according to claim 5.