JP2009242503A - Water-based adhesive and laminate using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a water-based adhesive showing good adhesiveness to an untreated polypropylene resin base material and an untreated polyethylene terephthalate resin base material in comparison with a conventional adhesive. <P>SOLUTION: The water-based adhesive comprises 100 pts.mass of a polyolefin resin containing 0.5-20 mass% of unsaturated carboxylic acid units, 10-60 pts.mass of a polyester resin having an acid value of 2-20 mgKOH/g, and an aqueous medium. The polyolefin resin comprises 50-98 pts.mass of a propylene component and 2-50 pts.mass of an ethylene component when the total of the two components is 100 pts.mass. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a water-based adhesive and a laminate using the same.

  Laminates with a vinyl chloride resin base material and a polyethylene terephthalate base material are easy to construct and have excellent design such as patterns and colors, so they are used for packaging materials and wiring of electronic devices. It has been. However, due to environmental problems in recent years, there has been a movement of the dechlorinated vinyl resin base material, and untreated polypropylene resin material is used as an alternative to the vinyl chloride resin base material. However, the untreated polypropylene resin material and the untreated polyethylene terephthalate resin material are very difficult to bond to each other, which is a problem. For this reason, the bonding technique is being studied.

  As an adhesive for bonding a polypropylene resin base material and a polyethylene terephthalate resin base material, a solvent-based polyester resin adhesive, a solvent-based acrylic resin adhesive, or the like is used.

  On the other hand, recently, water-based adhesives have attracted attention from the viewpoints of environmental problems (indoor pollution and environmental pollution) and safety. For example, Patent Documents 1 and 2 include an unsaturated carboxylic acid content of 5%. An aqueous dispersion in which less than% by mass of a polyolefin resin is dispersed without the addition of a non-volatile aqueous additive, and an adhesive obtained therefrom, which has a water resistance, adhesion to various materials, and a film excellent in heat sealability What can be formed is disclosed.

Patent Document 3 proposes an aqueous dispersion in which a specific amount of a tackifying component having a specific composition is added in order to improve adhesion to polypropylene.
JP 2003-119328 A JP 2003-103734 A JP 2004-051884 A

  In the water-based polyolefin resin adhesives described in Patent Documents 1 and 2, heat that is generally used to bond an untreated polyolefin resin substrate and an untreated polyethylene terephthalate resin substrate using this adhesive. When the sealing method is adopted, there is a problem that sufficient strength (heat seal strength) cannot be obtained.

  Although the thing described in patent document 3 has improved the adhesiveness with an untreated polypropylene resin base material or an untreated polyethylene terephthalate resin base material by adding a tackifying component, sufficient strength is also obtained. There is a problem that can not be.

  As a result of intensive studies to solve the above problems, the present inventors have found that a water-based adhesive containing a specific composition of a polyolefin resin and a specific polyester resin in a specific ratio is an untreated polypropylene resin substrate or untreated It has been found that the adhesiveness with the polyethylene terephthalate substrate is excellent, and the present invention has been achieved.

The gist of the present invention is as follows.
(1) 100 parts by mass of a polyolefin resin containing 0.5 to 20% by mass of an unsaturated carboxylic acid unit, 10 to 60 parts by mass of a polyester resin having an acid value of 2 to 20 mgKOH / g, and an aqueous medium, the polyolefin The resin contains 50 to 98 parts by mass of a propylene component and 2 to 50 parts by mass of an ethylene component when the total of the two components of the propylene component and the ethylene component is 100 parts by mass. Agent.

  (2) 100 parts by mass of a polyolefin resin containing 0.5 to 20% by mass of an unsaturated carboxylic acid unit, 10 to 60 parts by mass of a polyester resin having an acid value of 2 to 20 mgKOH / g, and an aqueous medium, the polyolefin The resin is composed of 8 to 90 parts by mass of propylene component, 8 to 90 parts by mass of butene component, and 2 to 50 parts by mass of ethylene component when the total of the three components of propylene component, butene component and ethylene component is 100 parts by mass. A water-based adhesive characterized by comprising a part.

  (3) The water-based adhesive according to (1) or (2), wherein the polyester resin has a glass transition temperature of 10 ° C. or lower.

  (4) A polypropylene resin base material, an adhesive layer formed by removing the aqueous medium from any of the aqueous adhesives (1) to (3) above, and a polyethylene terephthalate resin base material were laminated in this order. A laminate characterized by being a thing.

  The aqueous adhesive of the present invention exhibits better adhesion to an untreated polypropylene resin substrate and an untreated polyethylene terephthalate resin substrate than a conventional adhesive.

Hereinafter, the present invention will be described in detail.
The polyolefin resin in the present invention needs to contain 0.5 to 20% by mass of an unsaturated carboxylic acid unit in the structure from the viewpoint of dispersibility in an aqueous medium. The content ratio is preferably 0.5 to 15% by mass, more preferably 0.5 to 12% by mass, further preferably 1 to 10% by mass, and particularly preferably 1 to 8% by mass. When the unsaturated carboxylic acid unit is less than 0.5% by mass, it becomes difficult to make the polyolefin resin aqueous. On the other hand, if it exceeds 20% by mass, it becomes easy to make the resin water-based, but the adhesiveness to a polyolefin resin material such as polypropylene is lowered.

  The unsaturated carboxylic acid unit is introduced by an unsaturated carboxylic acid or an anhydride thereof. Specific examples include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, aconitic acid, aconitic anhydride, fumaric acid, crotonic acid, citraconic acid, mesaconic acid, and allyl succinic acid. Examples thereof include compounds having at least one carboxyl group or acid anhydride group in the molecule (in the monomer unit), such as unsaturated dicarboxylic acid half esters and half amides. Among these, maleic anhydride, acrylic acid, and methacrylic acid are preferable, and maleic anhydride is more preferable from the viewpoint of easy introduction into the polyolefin resin. The acid anhydride unit introduced into the polyolefin resin is likely to have an acid anhydride structure in a dry state, and in an aqueous medium containing a basic compound described later, a part or all of the acid anhydride units are opened to form a carboxylic acid or It tends to be the salt structure.

  The polyolefin resin according to the first aspect of the present invention contains a propylene component and an ethylene component. And when the sum total of two components of a propylene component and an ethylene component is 100 mass parts, it is required that they are 50-98 mass parts of propylene components and 2-50 mass parts of ethylene components. In order to develop excellent heat sealability, the propylene component is preferably 55 to 98 parts by mass and the ethylene component is preferably 2 to 45 parts by mass, and the propylene component is 60 to 98 parts by mass and the ethylene component is 2 to 40 parts by mass. It is more preferable that the propylene component is 70 to 98 parts by mass and the ethylene component is 2 to 30 parts by mass.

  Thus, favorable adhesiveness can be exhibited by including a propylene component and an ethylene component. Moreover, adhesiveness with a polypropylene resin base material can be improved because the propylene component is contained in an amount equal to or exceeding the ethylene component. Adhesiveness with a polypropylene resin base material falls that a propylene component is less than 50 mass parts.

  The polyolefin resin of the second aspect in the present invention may further contain a butene component. In that case, when the total of the three components of the propylene component, butene component and ethylene component is 100 parts by mass, the propylene component is 8 to 90 parts by mass, the butene component is 8 to 90 parts by mass, and the ethylene component is 2 to 50 parts by mass. It is necessary. In order to express excellent heat sealability, it is preferably 30 to 90 parts by mass of propylene component, 8 to 70 parts by mass of butene component, and 2 to 40 parts by mass of ethylene component, and 50 to 90 parts by mass of propylene component and butene. It is more preferable that they are 8-50 mass parts of components, and 2-40 mass parts of ethylene components, It is more preferable that they are 60-90 mass parts of propylene components, 8-40 mass parts of butene components, and 2-40 mass parts of ethylene components. .

  Thus, by including a propylene component, a butene component, and an ethylene component, the improvement of adhesiveness can be aimed at similarly.

  In addition to the above components, other components may be contained in an amount of about 20% by mass or less, preferably 2 to 15% by mass based on the whole polyolefin resin. Other components mentioned herein include alkenes and dienes such as 1-pentene, 1-hexene, 1-octene, norbornene, butadiene, chloroprene, cyclopentadiene; methyl (meth) acrylate, (meth) acrylic acid Ethyl, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate (Meth) acrylates such as stearyl (meth) acrylate; maleate esters such as dimethyl maleate, diethyl maleate, dibutyl maleate, dilauryl maleate, dioctyl maleate, didodecyl maleate, distearyl maleate (Meth) acrylic acid amides; Alkyl vinyl ethers such as ruvinyl ether and ethyl vinyl ether; vinyl esters obtained by saponifying vinyl esters such as vinyl formate, vinyl acetate, vinyl propionate, vinyl pivalate, vinyl versatate and vinyl esters with basic compounds, etc. Alcohol; 2-hydroxyethyl acrylate; glycidyl (meth) acrylate; (meth) acrylonitrile; styrene; substituted styrene; halogenated vinyls; halogenated vinylidenes; carbon monoxide; Mixtures of these can also be used. Especially, it is more preferable to contain 0.1-15 mass% of (meth) acrylic acid ester of the whole polyolefin resin from the point of the heat-sealing property of the adhesive bond layer obtained, 0.5-15 mass% It is more preferable to contain, and it is especially preferable to contain 1-10 mass%.

  Each component of the polyolefin resin may be copolymerized in the polyolefin resin. The form of the copolymerization is not limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization.

  The weight average molecular weight of the polyolefin resin is preferably in the range of 10,000 to 150,000, more preferably 20,000 to 120,000 from the viewpoint of heat sealability of the resulting adhesive layer, 20 Is more preferably from 30,000 to 100,000, particularly preferably from 30,000 to 90,000, and most preferably from 40,000 to 80,000. When the weight average molecular weight is less than 10,000, the heat sealability tends to decrease, or the obtained coating film tends to be brittle even if it is hard. When the weight average molecular weight exceeds 150,000, the viscosity of the coating agent becomes high and handling becomes difficult.

  In order to partially neutralize the unsaturated carboxylic acid unit in the polyolefin resin, it is preferable to add a basic compound as an aqueous medium. The carboxyl anion generated by the addition of the basic compound improves the dispersion stability of the resin in the aqueous medium.

  The basic compounds that can be added include ammonia, triethylamine, N, N-dimethylethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, aminoethanolamine, dimethylaminoethanolamine, methylaminopropylamine, Methyliminobispropylamine, diethylaminoethanolamine, iminobispropylamine, ethylamine, diethylamine, isobutylamine, dipropylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, n-butylamine, 2 -Methoxyethylamine, 3-methoxypropylamine, 2,2-dimethoxyethylamine, monoethanolamine, diethanolamine, triethanolamine Min, morpholine, N-methylmorpholine, N-ethylmorpholine and the like can be mentioned.

The polyester resin in the present invention is a polymer mainly composed of a polybasic acid component and a polyhydric alcohol component.
The aqueous dispersion of the present invention can improve adhesion and heat sealability with a polyester resin substrate by blending a polyester resin. If the polyester resin is not blended, such characteristics cannot be obtained.

  Polybasic acid components constituting the polyester resin include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, naphthalenedicarboxylic acid, biphenyldicarboxylic acid; oxalic acid, succinic acid, succinic anhydride, adipine Saturated aliphatic dicarboxylic acids such as acid, azelaic acid, sebacic acid, dodecanedioic acid, eicosane diacid, hydrogenated dimer acid; fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride Unsaturated aliphatic dicarboxylic acids such as acids and dimer acids; 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 2,5-norbornenedicarboxylic acid and anhydrides thereof, tetrahydro Alicyclic dicarboxylic acids such as phthalic acid and its anhydride And the like.

  A small amount of tri- or higher functional acid component may be used for the polyester resin. For example, trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride , Trimesic acid, ethylene glycol bis (anhydrotrimellitate), glycerol tris (anhydrotrimellitate), 1,2,3,4-butanetetracarboxylic acid and the like can be used. However, from the viewpoint of suppressing gelation during the production of the polyester resin, the amount used is preferably limited to 5 mol% or less of the total acid component.

  Of the above acid components, aromatic polybasic acids are preferred. This is because the ratio of aromatic ester bonds that are difficult to hydrolyze to the resin skeleton increases, and the water resistance of the adhesive layer is improved. Specifically, terephthalic acid and isophthalic acid are preferable because they are produced industrially in large quantities and are inexpensive. The aromatic polybasic acid is preferably contained in the total acid component in an amount of 50 mol% or more, particularly preferably 50 to 100%, more preferably 60 to 100 mol%, and more preferably 70 to 100 mol%. It is optimal that

  Polyhydric alcohol components constituting the polyester resin include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5 -Aliphatic glycols such as pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2-butylpropanediol; Alicyclic glycols such as 4-cyclohexanedimethanol; ether-bond-containing glycols such as diethylene glycol, triethylene glycol, dipropylene glycol, polytetramethylene glycol, polyethylene glycol, polypropylene glycol; 2,2-bis [4- (hydroxyethoxy ) Fe Le] bisphenols such as propane (bisphenol A) and its ethylene oxide adduct, bis [4- (hydroxyethoxy) phenyl] bisphenols such as sulfone (bisphenol S, etc.) and its ethylene oxide adduct, and the like. In addition, since the water resistance of a polyester resin, blocking resistance, and heat-sealability may be reduced when an ether bond increases, the ratio of the ether bond containing glycol to the polyhydric alcohol component of a polyester resin is 10 mol% or less. It is preferable that it is 5 mol% or less.

  Specifically, as the polyhydric alcohol, ethylene glycol and neopentyl glycol are preferably used because they are inexpensive because they are industrially produced in large quantities. The total proportion of ethylene glycol and neopentyl glycol in the polyhydric alcohol component of the polyester resin is preferably 50 to 100 mol%, more preferably 60 to 100 mol%, still more preferably 70 to 100 mol%, and more preferably 80 to 100 mol% is most preferred.

Ethylene glycol has the advantage that it improves the heat sealability of the adhesive layer and neopentyl glycol improves its water resistance.
Furthermore, as a polyhydric alcohol component, a trifunctional or higher polyhydric alcohol, for example, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like may be contained. However, in order to suppress gelation during the production of the polyester resin, the proportion of the trifunctional or higher polyhydric alcohol in the polyhydric alcohol component of the polyester resin is preferably limited to 5 mol% or less.

  The polyester resin may be copolymerized with monocarboxylic acid, monoalcohol, or hydroxycarboxylic acid. For example, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, benzoic acid, p-tert-butylbenzoic acid, cyclohexane acid, 4-hydroxyphenyl stearic acid, stearyl alcohol, 2-phenoxyethanol , Ε-caprolactone, lactic acid, β-hydroxybutyric acid, p-hydroxyethoxybenzoic acid and the like may be copolymerized. The proportion of these compounds is preferably 4 mol% or less, particularly preferably 2 mol% or less, based on all monomer components constituting the polyester resin.

  The polyester resin can be produced by polycondensing the above-described components by a known method. For example, all the monomer components and / or low polymers thereof are reacted for about 2.5 to 10 hours under an inert atmosphere at 180 to 260 ° C. to carry out an esterification reaction, followed by a polycondensation catalyst. In the presence of, a polycondensation reaction is allowed to proceed at a temperature of 220 to 280 ° C. under a reduced pressure of 130 Pa or less until a desired molecular weight is reached, thereby obtaining a polyester resin.

  In order to control the acid value and hydroxyl value of the polyester resin, a method in which a polybasic acid component or a polyhydric alcohol component is further added to the polycondensation reaction and depolymerization is performed in an inert atmosphere is adopted. be able to. In particular, when polyfunctional polybasic acids such as trimellitic acid and trimellitic anhydride are used during depolymerization, the adhesive has more excellent heat sealability while suppressing a decrease in the molecular weight of the polyester resin due to depolymerization. An aqueous dispersion capable of forming a layer can be obtained.

  The polyester resin is required to have an acid value of 2 to 20 mgKOH / g. It is preferable that it is 2-15 mgKOH / g, and it is especially preferable that it is 2-10 mgKOH / g. When the acid value exceeds 20 mgKOH / g, the adhesiveness of the adhesive layer becomes insufficient. On the other hand, when the acid value is less than 2 mgKOH / g, it is difficult to obtain an aqueous dispersion having good blocking resistance and adhesiveness.

  The polyester resin may contain a hydroxyl group as long as it does not impair the water resistance of the resulting resin film, that is, the adhesive layer. The hydroxyl value is preferably 15 mgKOH / g or less, more preferably 10 mgKOH / g or less.

  The number average molecular weight of the polyester resin is preferably 4,000 or more, more preferably 10,000 or more, and further preferably 15,000 or more. When the number average molecular weight is less than 4,000, the heat sealability of the resin film, that is, the adhesive layer tends to be insufficient. The upper limit of the number average molecular weight of the polyester resin is not particularly limited, but is preferably 50,000 or less from the viewpoint that an adhesive having good blocking resistance can be easily obtained.

  The glass transition temperature of the polyester resin is not particularly limited, but is preferably −40 to 60 ° C. from the viewpoint of improving the heat sealability of the adhesive, and is 0 to 40 ° C. from the viewpoint of improving blocking resistance. It is more preferable.

  The mass ratio between the polyolefin resin and the polyester resin needs to be (polyolefin resin) / (polyester resin) = 100/10 to 100/60. Furthermore, 100/10 to 100/50 is preferable, 100/15 to 100/40 is more preferable, and 100/20 to 100/40 is more preferable from the viewpoint of blocking resistance, adhesiveness, and heat sealability of the adhesive layer. 100/20 to 100/30 is particularly preferable. When the content of the polyester resin with respect to 100 parts by mass of the polyolefin resin is less than 10 parts by mass, the adhesion with the untreated polyethylene terephthalate resin substrate is lowered. Moreover, when it exceeds 60 mass parts, there exists a tendency for the adhesiveness at the time of bonding of a non-processed polypropylene resin base material and a polyethylene terephthalate resin base material to fall.

  The aqueous medium in the present invention is most preferably essentially all water from the viewpoint of safety to workers and the working environment. However, for the purpose of making the polyolefin resin or polyester resin water-based or reducing the drying load, a hydrophilic organic solvent other than water may be included as long as it does not deviate from the characteristics of “aqueous”. There is no problem. Examples of such an organic solvent include ketones such as methyl ethyl ketone, acetone and diethyl ketone; alcohols such as propanol, butanol, methanol and ethanol; cyclic ethers such as tetrahydrofuran and dioxane; ethylene glycol monobutyl ether and the like. And glycol derivatives. The proportion of these organic solvents in the total amount of the aqueous dispersion is preferably 40% by mass or less, more preferably 20% by mass or less, and particularly preferably 5% by mass or less. The aqueous medium may contain a basic compound that is added when the polyolefin resin is made aqueous, as will be described later.

Next, the manufacturing method of the aqueous adhesive of this invention is demonstrated.
The method for producing the aqueous adhesive of the present invention is not particularly limited as long as the polyolefin resin and the polyester resin are uniformly mixed in an aqueous medium and can be dispersed or dissolved.

The following two examples are given as typical examples.
(A) A method of mixing an aqueous dispersion of a polyolefin resin and an aqueous dispersion of a polyester resin, each prepared in advance.

  (A) A method in which a polyolefin resin and a polyester resin are simultaneously dispersed in water.

  Among these, according to the method (a), an aqueous dispersion composed of a combination of various polyester resins and polyolefin resins can be prepared more easily.

First, the manufacturing method of the aqueous dispersion of polyolefin resin is demonstrated.
The method for obtaining the aqueous dispersion of the polyolefin resin is not particularly limited. For example, a method of heating and stirring the polyolefin resin and the aqueous medium in a sealable container can be employed. At this time, the shape of the resin used for the aqueous treatment is not particularly limited, but from the viewpoint of increasing the aqueousization rate, it is preferably in the form of particles or powder having a particle diameter of 1 cm or less, preferably 0.8 cm or less.

  The container may be any container as long as it has a tank into which a liquid can be charged and can appropriately stir the mixture of the aqueous medium and the resin charged into the tank. As such an apparatus, a known solid / liquid stirring apparatus or emulsifier can be used. An apparatus capable of pressurization of 0.1 MPa or more is preferable. The stirring method and the rotation speed of stirring are not particularly limited.

  After putting each raw material into the tank of this apparatus, it is preferably stirred and mixed at a temperature of 40 ° C. or lower. Next, while maintaining the temperature in the tank at 50 to 200 ° C., preferably 60 to 200 ° C., by continuing stirring for 5 to 120 minutes, the resin is made sufficiently aqueous, and then under stirring, 40 ° C. or less. Aqueous dispersion can be obtained by cooling to. When the temperature in the tank is less than 50 ° C., it becomes difficult to make the resin water-based. When the temperature in a tank exceeds 200 degreeC, there exists a possibility that the molecular weight of resin may fall.

  Since the polyolefin resin contains an unsaturated carboxylic acid component, it is preferable to add the above-mentioned basic compound at the time of aqueous formation. The unsaturated carboxylic acid component is anionized by the basic compound, and electric repulsion prevents aggregation between the fine particles, thereby imparting stability to the aqueous dispersion. The addition amount of the basic compound is preferably 0.5 to 3.0 times equivalent to the carboxyl group in the polyolefin resin (1 mol of acid anhydride group is regarded as 2 mol of carboxyl group), 0.8 -2.5 times equivalent is more preferable and 1.0-2.0 times equivalent is especially preferable. If the amount is less than 0.5 times equivalent, the addition effect of the basic compound is not recognized, and if the amount exceeds 3.0 times equivalent, the drying time during coating film formation may be prolonged or the aqueous dispersion may be colored. is there.

  The basic compound to be added is preferably a compound that volatilizes during formation of the coating film from the viewpoint of water resistance of the coating film, and specifically, ammonia or various organic amine compounds are preferable as described above. The organic amine compound preferably has a boiling point of 250 ° C. or lower. If it exceeds 250 ° C., it becomes difficult to scatter the organic amine compound from the resin coating film by drying, and the water resistance of the coating film may deteriorate.

  In addition, when making the polyolefin resin aqueous, it is preferable to add an organic solvent from the viewpoints of improving the speed of water making and reducing the particle size of the resin particles. The addition amount of the organic solvent is preferably 1 to 40% by mass in the aqueous dispersion of polyolefin resin, more preferably 2 to 30% by mass, and particularly preferably 3 to 20% by mass. The organic solvent can be removed (stripped) partly from the system by heating the aqueous dispersion with stirring under normal pressure or reduced pressure. It can also be present that only 1% by weight or less is present in the dispersion. Specific examples of the organic solvent used include ethanol, n-propanol, isopropanol, n-butanol, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether. . Among these, ethanol, isopropanol, and n-propanol are particularly preferable because they can be dried at a lower temperature.

  The number average particle diameter of the polyolefin resin particles in the aqueous dispersion is the stability of the aqueous dispersion, the surface smoothness when applied, and the transparency and performance of the coating film obtained by mixing with the polyester resin (adhesion, heat From the viewpoint of (sealability), it is preferably 0.5 μm or less, more preferably 0.3 μm or less, further preferably 0.2 μm or less, and particularly preferably 0.15 μm or less. Also about a weight average particle diameter, 0.5 micrometer or less is preferable and 0.3 micrometer or less is more preferable.

  As the aqueous dispersion of polyolefin resin, commercially available products can be used, and examples thereof include “Arrow Base” series manufactured by Unitika, “Super Clon” series manufactured by Nippon Paper Chemicals, and the like.

Next, the manufacturing method of the aqueous dispersion of a polyester resin is demonstrated. As its manufacturing method,
1) A method in which an aqueous dispersion is obtained by dissolving a polyester resin in an organic solvent and adding water to the polyester resin solution.
2) Similar to the above-described method for producing an aqueous dispersion of polyolefin resin, a method in which a polyester resin, a basic compound, an organic solvent, and water are charged all at once in a container and heated while stirring the system.

  For example, when the acid value of the polyester resin is 10 mgKOH / g or less, the method 1) is preferable, and when the acid value exceeds 10 mgKOH / g, the method 2) is preferable.

  About points other than said manufacturing method, the aqueous dispersion of a polyester resin can be prepared with the method similar to the preparation method of the aqueous dispersion of polyolefin resin mentioned above. Commercially available aqueous polyester resin dispersions can also be used. For example, “Elitel” series manufactured by Unitika, “Bironal” series manufactured by Toyobo, etc. can be mentioned.

  In the aqueous adhesive production method (a) described above, the aqueous dispersion of polyolefin resin and the aqueous dispersion of polyester resin obtained by the above-described method may be mixed. In mixing, a known liquid / liquid mixing apparatus may be used as appropriate. Since the dispersion and mixing properties of the aqueous polyolefin resin dispersion and the aqueous polyester resin dispersion are good, a simple mixing operation can be performed for a very short time. Moreover, it can also adjust by the method of distilling an aqueous medium or diluting with water so that it may become a desired solid content density | concentration after mixing.

  As the method (a) for producing an aqueous adhesive, for example, the above-described method of heating and stirring a polyolefin resin, a polyester resin, a basic compound, and an aqueous medium in a container can be employed. Specifically, the polyolefin resin and the polyester resin are sufficiently dispersed by, for example, heating to 45 to 200 ° C. after the raw materials are charged into the apparatus and continuing stirring for 5 to 120 minutes until coarse particles disappear. . Thereafter, the aqueous adhesive can be obtained by cooling to 40 ° C. or lower under stirring. The solid content concentration can be adjusted by a method such as evaporation of the aqueous medium or dilution with water, as in the case of the production method (a).

  In the aqueous adhesive of the present invention, a non-volatile aqueous auxiliary agent such as an emulsifier may be used. However, from the viewpoint of water resistance and heat sealability, the amount used is preferably 5% by mass or less of the final aqueous adhesive, and most preferably not used. In addition, if the said manufacturing method is used, a fine and stable aqueous dispersion can be obtained without adding a non-volatile aqueous | water-based auxiliary agent, and the aqueous adhesive of this invention is prepared using this. can do. Examples of the non-volatile aqueous auxiliary agent include emulsifiers described later, compounds having a protective colloid action, modified waxes, high acid value acid-modified compounds, water-soluble polymers, and the like.

  Examples of the emulsifier include a cationic emulsifier, an anionic emulsifier, a nonionic emulsifier, and an amphoteric emulsifier. In addition to those generally used for emulsion polymerization, surfactants are also included. For example, anionic emulsifiers include higher alcohol sulfates, higher alkyl sulfonates, higher carboxylates, alkyl benzene sulfonates, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkyl phenyl ether sulfate salts, vinyl sulfosuccinates. And the like. Nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyethylene glycol fatty acid esters, ethylene oxide propylene oxide block copolymers, polyoxyethylene fatty acid amides, ethylene oxide-propylene oxide copolymers, and the like. Examples thereof include compounds having an oxyethylene structure and sorbitan derivatives such as polyoxyethylene sorbitan fatty acid esters. Examples of amphoteric emulsifiers include lauryl betaine and lauryl dimethylamine oxide. 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 number 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 Carboxyl group-containing polymer having an unsaturated carboxylic acid content of 10% by mass or more, such as an alternating copolymer, (meth) acrylic acid- (meth) acrylic acid ester copolymer, and its salt, polyitaconic acid and its salt, 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.

  If necessary, an aqueous dispersion of another polymer can be added to the aqueous adhesive of the present invention. The kind of the aqueous dispersion of another polymer is not particularly limited. For example, polyvinyl acetate, ethylene-vinyl acetate copolymer, styrene-maleic acid resin, styrene-butadiene resin, butadiene resin, acrylonitrile-butadiene resin, (meth) acrylamide resin, polyurethane resin, polyester resin, modified nylon resin, phenol Examples thereof include aqueous dispersions such as resins, silicone resins, fatty acid amide resins, rosin resins, and terpene resins. You may use these in mixture of 2 or more types.

  The aqueous adhesive of the present invention can form a good adhesive layer on a polyethylene terephthalate resin substrate by removing the liquid medium after being applied to the polyethylene terephthalate resin substrate. At this time, since the surface of the formed adhesive layer is excellent in blocking resistance, handling is easy. Moreover, since the formed contact bonding layer is excellent in heat-sealability, a laminated body can be obtained by heat-pressing another base material on the contact bonding layer. Examples of the base material to be laminated include polyethylene terephthalate resin, polypropylene resin, other resins, paper, synthetic paper, wood, woven fabric, knitted fabric, nonwoven fabric, and metal. In particular, it is suitable for lamination of a polyethylene terephthalate resin and a polyolefin resin.

  The shape of a polypropylene resin base material or a polyethylene terephthalate resin base material can be a film or a sheet, and is not particularly limited. The film may be an unstretched film or a stretched film, and its production method is not limited. Moreover, although the thickness of a base film is not specifically limited, Usually, what is necessary is just to be the range of 1-500 micrometers. Furthermore, after applying the aqueous adhesive of the present invention to an unstretched film, so-called in-line coating may be performed in which the coated film is stretched.

  The method of applying the aqueous adhesive of the present invention to a substrate is not particularly limited, but gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dipping Coating, brushing, etc. can be used. What is necessary is just to determine the application quantity of a water-based adhesive suitably with a base material. In the case where the substrate is a thermoplastic resin film, the thickness of the coating film is preferably at least 0.1 μm, more preferably 0.1 to 10 μm, in order to sufficiently enhance the heat sealability. 2-8 micrometers is further more preferable and 0.3-7 micrometers is especially preferable.

  The drying temperature after application of the aqueous adhesive of the present invention is not particularly limited, and may be appropriately determined depending on the heat-resistant temperature of the substrate. In detail, it may be 50-150 degreeC normally, 60-100 degreeC is more preferable, and 70-90 degreeC is further more preferable. When the drying temperature is less than 50 ° C., the aqueous medium cannot be volatilized sufficiently, or it takes time to volatilize, and it becomes difficult to develop good adhesive performance. On the other hand, when the drying temperature exceeds 150 ° C., the adhesion performance tends to be lowered.

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

1. Resin characteristics (1) Resin composition
^{It was determined by 1} H-NMR analysis (analyzer manufactured by Varian, 300 MHz). The polyolefin resin was measured at 120 ° C. using orthodichlorobenzene (d ₄ ) as a solvent. The polyester resin was measured at room temperature using chloroform (d) or trifluoroacetic acid (d) as a solvent. For polyester resins containing constituent monomers for which no peaks that can be assigned or quantified are observed on the ¹ H-NMR spectrum, methanol decomposition was performed at 230 ° C. for 3 hours in a sealed tube, and then subjected to gas chromatogram analysis for quantitative analysis. went.

(2) Glass transition temperature (Tg) of polyester resin
Using a resin 10 mg as a sample, a DSC (Differential Scanning Calorimetry) device (DSC7 manufactured by PerkinElmer Co., Ltd.) was used for measurement at a temperature rising rate of 10 ° C./min, and the melting point was obtained from the obtained temperature rising curve. . Moreover, the intermediate value of the temperature of two bending points originating in the glass transition in the obtained temperature rising curve was calculated | required, and this was made into Tg.

(3) Acid value of polyester resin 0.5 g of polyester resin was dissolved in 50 ml of water / dioxane = 10/1 (volume ratio), titrated with KOH using cresol red as an indicator, and the amount of KOH consumed for neutralization. The acid value (mgKOH / g) in the polyester resin was determined from the mg number.

(4) Weight average molecular weight It was 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). .

2. Characteristics of aqueous dispersion (1) Solid 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. Asked.

(2) Average particle diameter of aqueous dispersion The number average particle diameter (mn) and the weight average particle diameter (mw) using a Microtrac particle size distribution analyzer UPA150 (MODEL No. 9340, dynamic light scattering method) manufactured by Nikkiso Co., Ltd. Asked. The refractive index of the resin used for particle diameter calculation was 1.50.

(3) 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], aqueous dispersion or aqueous 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.

3. Characteristics of the coating In the following evaluation, as a base material, a biaxially stretched polyethylene terephthalate (PET) film (manufactured by Unitika, Emblet PET12, thickness 12 μm), a stretched polypropylene (OPP) film (manufactured by Tosero, thickness 20 μm), An unstretched polypropylene (CPP) film (manufactured by Tosero Co., Ltd., thickness 50 μm) was used.

(1) Water resistance The water-based adhesive was applied to the non-corona-treated surface of the PET film using a Mayer bar so that the film thickness after drying was 2 μm. Then, it was dried at 100 ° C. for 2 minutes. The obtained laminated film was evaluated after being left at room temperature for 1 day. Specifically, the coating film was rubbed several times with a cloth wetted with water, and the state of the coating film at that time was visually evaluated according to the following criteria.

○: No change Δ: The coating film is cloudy ×: The coating film is completely peeled off

(2) Blocking resistance of resin coating A water-based adhesive was applied to a non-corona-treated surface of a biaxially stretched PET film using a Mayer bar so that the film thickness after drying was 2 μm, and then 2 at 100 ° C. Allow to dry for a minute. The obtained laminated film was allowed to stand at room temperature for 1 day, and then a non-corona-treated surface of another biaxially stretched PET film was superimposed on the adhesive surface, and a load of 0.02 MPa was applied at 25 ° C. and 65% RH. For 24 hours. Thereafter, the blocking resistance was evaluated in the following three stages.

○: Peel off by lifting the film lightly △: Peel off by pulling the film ×: Peel off even when the film is pulled

(3) Adhesion (tape peeling test)
A water-based adhesive was applied to each non-corona treated surface of the biaxially stretched PET film and the OPP film using a Meyer bar so that the film thickness after drying was 5 μm, and then dried at 100 ° C. for 2 minutes. It was. The obtained laminated film was evaluated after standing at room temperature for 1 day. Specifically, cellophane tape (TF-12 manufactured by Nichiban Co., Ltd.) was attached to the adhesive surface, and the degree of peeling when the tape was peeled at a stretch was visually evaluated according to the following criteria.

○: No peeling at all △: Partial peeling ×: All peeling

(4) Adhesiveness (OPPvsPET adhesiveness)
The aqueous adhesive was applied to the non-corona-treated surface of the PET film so that the film thickness after drying was 2 μm, and dried at 100 ° C. for 2 minutes. The coated layer of the obtained laminated film and the non-corona surface of the OPP film were bonded together and pressed at 120 ° C. for 2 seconds with a heat press machine (sealing pressure 0.3 MPa). This sample was cut out at a width of 15 mm, and one day later, the peel strength of the coating was measured at a tensile speed of 200 mm / min and a tensile angle of 180 degrees using a tensile tester (manufactured by Intesco, Intesco precision universal material tester type 2020). . A film having a peel strength of 2.0 N / 15 mm width or more was considered acceptable.

(CPP vs PET adhesion)
The aqueous adhesive was applied to the non-corona-treated surface of the PET film so that the film thickness after drying was 2 μm, and dried at 100 ° C. for 2 minutes. The coating layer of the obtained laminated film and the non-corona surface of the CPP film were bonded together and pressed at 120 ° C. for 2 seconds with a heat press machine (sealing pressure 0.3 MPa). This sample was cut out at a width of 15 mm, and one day later, the peel strength of the coating was measured at a tensile speed of 200 mm / min and a tensile angle of 180 degrees using a tensile tester (manufactured by Intesco, Intesco precision universal material tester type 2020). . A film having a peel strength of 2.0 N / 15 mm width or more was considered acceptable.

[Production of resin]
The production method of the polyolefin resin and polyester resin used in the following examples and comparative examples will be described.

(Manufacture of polyolefin resin “PO-1”)
280 g of a propylene-butene-ethylene terpolymer (manufactured by Huls Japan, Bestplast 708, propylene / butene / ethylene = 64.8 / 23.9 / 11.3 mass%) In a four-necked flask equipped with a dropping funnel, the mixture was heated and melted under a nitrogen atmosphere. Thereafter, while stirring the system temperature at 165 ° C., 32.0 g of maleic anhydride as an unsaturated carboxylic acid and 20 g of a heptane solution of 6.0 g of dicumyl peroxide as a radical generator were each 1 It was added over time, and then allowed to react for 1 hour. After completion of the reaction, the obtained reaction product was put into a large amount of acetone to precipitate a resin. This resin was further washed several times with acetone to remove unreacted maleic anhydride and then dried under reduced pressure in a vacuum dryer to obtain polyolefin resin “PO-1”. The properties of the obtained resin are shown in Table 1.

(Manufacture of polyolefin resin “PO-2”)
In a four-necked flask equipped with a stirrer, a condenser tube, and a dropping funnel, 100 g of propylene-butene-ethylene terpolymer (manufactured by Huls Japan Co., Ltd., Best Plast 708) and 500 g of toluene, under a nitrogen atmosphere And melted by heating. Thereafter, a solution of 1.0 g of dicumyl peroxide as a radical generator in 20 g of heptane was added over 1 hour while maintaining the system temperature at 110 ° C. and stirring. Next, 7.0 g of maleic anhydride as an unsaturated carboxylic acid, 10.0 g of lauryl acrylate, and 10 g of a heptane solution of 0.5 g of dicumyl peroxide were added dropwise over 1 hour, followed by reaction for 30 minutes. I let you. After completion of the reaction, the reaction mixture was cooled to room temperature, and the resulting reaction product was put into a large amount of acetone to precipitate a resin. This resin was further washed several times with acetone to remove unreacted substances and then dried under reduced pressure in a vacuum dryer to obtain a polyolefin resin “PO-2”.

(Manufacture of polyolefin resin “PO-3”)
280 g of a propylene-ethylene copolymer (propylene / ethylene = 81.8 / 18.2% by mass, weight average molecular weight 85,000) was heated and melted in a four-necked flask under a nitrogen atmosphere. Thereafter, with the system kept at 180 ° C., 35.0 g of maleic anhydride as an unsaturated carboxylic acid and 6.0 g of di-t-butyl peroxide as a radical generator were added over 2 hours with stirring. Then, the reaction was allowed to proceed for 1 hour. After completion of the reaction, the obtained reaction product was put into a large amount of acetone to precipitate a resin. This resin was further washed several times with acetone to remove unreacted maleic anhydride and then dried under reduced pressure in a vacuum dryer to obtain a polyolefin resin “PO-3”.

  Table 1 shows the compositions and the like of the obtained polyolefin resins “PO-1” to “PO-3”.

  In a comparative example described later, Bondine HX-8290 manufactured by Arkema Co., which is a commercially available polyolefin resin, was also used. The composition of this resin is shown in Table 2. As shown in Table 2, this polyolefin resin did not contain a propylene component or a butene component, and was outside the scope of the present invention.

(Preparation of aqueous polyolefin resin dispersion “E-1”)
Using a stirrer equipped with a heat-resistant 1 L glass container with a heater, 60.0 g of polyolefin resin “PO-1”, 45.0 g of ethylene glycol-n-butyl ether (manufactured by Wako Pure Chemical Industries, Ltd.) 6.9 g of N, N-dimethylethanolamine (manufactured by Wako Pure Chemical Industries, Ltd.) as a basic compound and 188.1 g of distilled water were charged in a glass container and stirred at a rotation speed of 300 rpm. . As a result, no resin precipitation was observed at the bottom of the container, and it was confirmed that the container was floating. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 140 ° C. and further stirred for 60 minutes. Next, after cooling to room temperature (about 25 ° C.) with stirring at a rotational speed of 300 rpm by air cooling, pressure filtration (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave). ) To obtain a milky-yellow uniform polyolefin resin aqueous dispersion “E-1”. The physical properties are shown in Table 3.

(Preparation of aqueous polyolefin resin dispersion “E-2”)
Using a stirrer equipped with a heat-resistant 1 L glass container with a heater, 60.0 g of polyolefin resin “PO-2”, 45.0 g of ethylene glycol-n-butyl ether (manufactured by Wako Pure Chemical Industries, Ltd.) 6.9 g of N, N-dimethylethanolamine (manufactured by Wako Pure Chemical Industries, Ltd.) as a basic compound and 188.1 g of distilled water were charged in a glass container and stirred at a rotation speed of 300 rpm. . As a result, no resin precipitation was observed at the bottom of the container, and it was confirmed that the container was floating. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 140 ° C. and further stirred for 60 minutes. Next, after cooling to room temperature (about 25 ° C.) with stirring at a rotational speed of 300 rpm by air cooling, pressure filtration (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave). ) To obtain a milky-yellow uniform aqueous polyolefin resin dispersion “E-2”. The physical properties are shown in Table 3.

(Preparation of aqueous polyolefin resin dispersion “E-3”)
Using a stirrer equipped with a 1 L glass container that can be sealed with a heater, 60.0 g of polyolefin resin [Bondaine HX-8290], 60.0 g of isopropanol (IPA), 4.5 g (in the resin) Triethylamine (TEA) as a basic compound (1.8 times equivalent to the carboxyl group of maleic anhydride) and 175.5 g of distilled water were charged in a glass container and stirred at a stirring blade rotation speed of 300 rpm. did. As a result, no sedimentation of resin particles was observed at the bottom of the container, confirming that it was in a floating state. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 140 to 145 ° C. and further stirred for 20 minutes. Next, after putting it in a water bath and cooling to room temperature (about 25 ° C.) while stirring at a rotational speed of 300 rpm, pressure filtration (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave). Thus, a milky white uniform aqueous polyolefin resin dispersion “E-3” containing a polyolefin resin [Bondaine HX-8290] outside the scope of the present invention was obtained. The physical properties are shown in Table 3.

(Preparation of aqueous polyolefin resin dispersion “E-4”)
Using a stirrer equipped with a 1 L glass container that can be sealed with a heater, 60.0 g of polyolefin resin “PO-3”, 45.0 g of ethylene glycol-n-butyl ether (manufactured by Wako Pure Chemical Industries, Ltd.) 188.1 g of distilled water was charged into a glass container, and the stirring blade was stirred at a rotational speed of 300 rpm. As a result, no resin precipitation was observed at the bottom of the container, and it was confirmed that the container was floating. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 140 ° C. and further stirred for 60 minutes. Next, after cooling to room temperature (about 25 ° C.) with stirring at a rotational speed of 300 rpm by air cooling, pressure filtration (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave). ) To obtain a milky-yellow uniform polyolefin resin aqueous dispersion “E-4”. The physical properties are shown in Table 3.

(Manufacture of polyester resin “PES-1”)
A mixture of 2492 g of terephthalic acid, 415 g of isophthalic acid, 1516 g of sebacic acid, 1210 g of ethylene glycol, and 1484 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 these conditions, the polycondensation reaction was continued for another 4 hours. Thereafter, the system was brought to atmospheric pressure with nitrogen gas, the temperature of the system was lowered, and when it reached 265 ° C., 29 g of trimellitic anhydride was added, and the mixture was stirred at 265 ° C. for 2 hours to carry out a depolymerization reaction. Thereafter, the system was put under pressure with nitrogen gas, and the resin was dispensed into a sheet form and allowed to cool at room temperature to obtain a sheet-like polyester resin “PES-1”. The physical properties are shown in Table 4.

(Manufacture of polyester resin “PES-2”)
A mixture of 2492 g of terephthalic acid, 415 and g of isophthalic acid, 1516 g of sebacic acid, 1210 g of ethylene glycol, and 1484 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 these conditions, the polycondensation reaction was continued for another 4 hours. Thereafter, the system was brought to normal pressure with nitrogen gas, the temperature of the system was lowered, and when the temperature reached 265 ° C., 58 g of trimellitic anhydride was added, and the mixture was stirred at 265 ° C. for 2 hours to perform a depolymerization reaction. Thereafter, the system was kept pressurized with nitrogen gas, and the resin was dispensed in a sheet form and allowed to cool at room temperature to obtain a sheet-like polyester resin “PES-2”. The physical properties are shown in Table 4.

(Manufacture of polyester resin “PES-3”)
A mixture of 1578 g of terephthalic acid, 83 g of isophthalic acid, 374 g of ethylene glycol, and 730 g of neopentyl glycol was heated at 260 ° C. for 2.5 hours in an autoclave to carry out an esterification reaction. Next, after adding 0.262 g of germanium dioxide as a catalyst, the temperature of the system was raised to 280 ° C. in 30 minutes, and the pressure of the system was gradually reduced to 13 Pa after 1 hour. Under this condition, the polycondensation reaction was further continued. After 1.5 hours, the system was brought to atmospheric pressure with nitrogen gas, the temperature of the system was lowered, and when the temperature reached 260 ° C., 50 g of isophthalic acid and 57 g of trimellitic anhydride were added. The mixture was added and further stirred at 255 ° C. for 30 minutes, and then discharged into a sheet. And after fully cooling to room temperature, this was grind | pulverized with the crusher and the polyester resin "PES-3" with a particle size of 1-6 mm was obtained using the sieve. The physical properties are shown in Table 4. This polyester resin “PES-3” had an acid value of 45.1 mg KOH / g and was outside the scope of the present invention.

(Production of aqueous polyester resin dispersion “T-1”)
(1-1):
A 3 L polyethylene container is charged with 400 g of polyester resin “PES-1” and 600 g of methyl ethyl ketone (MEK), and a stirrer (manufactured by Tokyo Rika Co., Ltd., MAZELA1000) is heated while heating the container with hot water of about 60 ° C. By using and stirring, the polyester resin was completely dissolved in MEK to obtain a polyester resin solution having a solid concentration of 40% by mass.

  Next, 500 g of the above-mentioned polyester resin solution was charged into a jacketed glass container (internal volume 2 L), the temperature inside the system was kept at 13 ° C. through the jacket, and stirred with a stirrer (Tokyo Rika Co., Ltd., MAZELA1000) ). Next, 23.3 g of triethylamine (TEA) was added as a basic compound with stirring, and then 476.7 g of distilled water at 13 ° C. was added at a rate of 100 g / min. During addition of the whole amount of distilled water, the system temperature was always 15 ° C. or lower. After completion of the addition of distilled water, the mixture was stirred for 30 minutes to obtain an aqueous polyester resin dispersion having a solid content concentration of 20% by mass and an organic solvent content of 3% by mass or more.

(1-2):
The organic solvent was removed by putting 800 g of the polyester resin aqueous dispersion obtained in (1-1) and 52.3 g of distilled water into a 2 L flask and performing distillation at normal pressure. Distillation was completed when the amount of distillation reached about 360 g, then cooled to room temperature, and filtered through a 250 mesh (opening 0.071 mm) stainless steel filter. Subsequently, after measuring the solid content concentration of this aqueous dispersion, distilled water was added so that the solid content concentration was 30% by mass. In this way, an aqueous polyester resin dispersion was obtained. The solid content concentration was 30.3% by mass, and the organic solvent content was 0.01% by mass or less.

(1-3):
While stirring 500 g of the aqueous polyester resin dispersion obtained in (1-2), 2.6 g of triethylamine (TEA) was added to obtain an aqueous polyester resin dispersion “T-1”.

  This aqueous dispersion had a solid content concentration of 30.1% by mass, an organic solvent content of 0.01% by mass or less, and a pH of 10.8. The physical properties are shown in Table 5.

(Production of aqueous polyester resin dispersion “T-2”)
(2-1):
While adding 400 g of polyester resin “PES-2” to a 3 L polyethylene container, 600 g of MEK is charged and the container is heated with hot water of about 60 ° C., using a stirrer (manufactured by Tokyo Rika Co., Ltd., MAZELA1000). The polyester resin was completely dissolved in MEK by stirring to obtain a polyester resin solution having a solid content concentration of 40% by mass.

  Next, 500 g of the above-mentioned polyester resin solution was charged into a jacketed glass container (internal volume 2 L), the temperature inside the system was kept at 13 ° C. through the jacket, and stirred with a stirrer (Tokyo Rika Co., Ltd., MAZELA1000) ). Next, 2.5 g of 28% by mass of ammonia water was added as a basic compound while stirring, and then 497.5 g of distilled water at 13 ° C. was added at a rate of 100 g / min. During addition of the whole amount of distilled water, the system temperature was always 15 ° C. or lower. After completion of the addition of distilled water, the mixture was stirred for 30 minutes to obtain an aqueous polyester resin dispersion having a solid content concentration of 20% by mass and an organic solvent content of 3% by mass or more.

(2-2):
The organic solvent was removed by putting 800 g of the polyester resin aqueous dispersion obtained in (2-1) and 52.3 g of distilled water into a 2 L flask and performing distillation at normal pressure. Distillation was completed when the amount of distillation reached about 360 g, then cooled to room temperature, and filtered through a 250 mesh (opening 0.071 mm) stainless steel filter. Subsequently, after measuring the solid content concentration of this aqueous dispersion, distilled water was added so that the solid content concentration was 30% by mass. In this way, an aqueous polyester resin dispersion was obtained. Its solid content concentration was 30.2% by mass, and the organic solvent content was 0.01% by mass or less.

(2-3):
While stirring 500 g of the polyester resin aqueous dispersion obtained in (2-2), 2.6 g of triethylamine was added to obtain an aqueous polyester resin dispersion “T-2”.

  This aqueous dispersion had a solid content concentration of 30.0% by mass, an organic solvent content of 0.01% by mass or less, and a pH of 10.5. The physical properties are shown in Table 5.

(Production of aqueous polyester resin dispersion “T-3”)
Using a tabletop homodisper (made by TK Robotics Co., Ltd., TK Robotics Co., Ltd.) that has a 2L glass container with a jacket and that is hermetically sealed when installed, 300 g of polyester resin “PES-3” and 80 g of ethylene glycol-n-butyl ether and N, N-dimethylethanolamine (DMEA) corresponding to 1.2 times the total amount of carboxyl groups contained in the polyester resin were added and stirred at 6,000 rpm. . As a result, no sedimentation of resin particles was observed at the bottom of the container, and it was confirmed that the container was completely suspended. Therefore, while keeping this state, the jacket was heated through hot water after 10 minutes. When the temperature in the container reached 68 ° C., the stirring was set at 7,000 rpm, the temperature in the container was kept at 70 to 72 ° C., and the mixture was further stirred for 20 minutes to obtain a milky white uniform aqueous dispersion. Next, cold water is allowed to flow through the jacket and cooled to room temperature while stirring at 3,500 rpm, and filtered using a stainless steel filter (635 mesh, plain weave). A polyester resin “PES-3” outside the scope of the present invention is obtained. An aqueous polyester resin dispersion “T-3” was obtained. This aqueous dispersion had a solid content concentration of 30.0% by mass and a pH of 10.4. The physical properties are shown in Table 3.

Example 1
Stir the aqueous polyolefin resin dispersion “E-1” and the aqueous polyester resin dispersion “T-1” with a mechanical stirrer at room temperature so that the polyester resin is 10 parts by mass with respect to 100 parts by mass of the polyolefin resin. (100 rpm)-It mixed and the water-based adhesive "J-1" was prepared. The evaluation results are shown in Table 6.

Examples 2-19
Compared to Example 1, the types of the polyolefin resin aqueous dispersion and the polyester resin aqueous dispersion and the mixing ratio of the resin components were changed as shown in Tables 6 and 7. Otherwise by performing the same operations as in Example 1, aqueous adhesives “J-2” to “J-19” were obtained.

  Table 6 and Table 7 show the evaluation results for the aqueous adhesives “J-2” to “J-19” of Examples 2 to 19.

Comparative Examples 1, 7, 10
Without adding the polyester resin aqueous dispersion, the aqueous polyolefin resin dispersions “E-1”, “E-2”, and “E-3” were used individually, respectively. 7 ”and“ H-13 ”. The evaluation results are shown in Table 8 and Table 9.

Comparative Examples 2-6, 8-9, 11-14
Compared to Example 1, the types of the polyolefin resin aqueous dispersion and the polyester resin aqueous dispersion and the mixing ratio of the resin components were changed as shown in Tables 8 and 9. Otherwise, the same operation as in Example 1 was performed, and the water-based adhesives “H-2” to “H-6”, “H-8”, “H-9”, “H-11” to “H— 14 "was obtained. The evaluation results are shown in Table 8 and Table 9.

  In Examples 1 to 19, the coating obtained from the aqueous dispersion is excellent in adhesion to the untreated OPP resin substrate and untreated PET resin substrate, water resistance, and blocking resistance, and untreated OPP resin substrate. The adhesion between the untreated OPP resin substrate and the untreated PET resin substrate was excellent.

  On the other hand, since Comparative Examples 1, 7, and 10 did not contain a polyester resin, adhesion between the untreated OPP resin substrate and the untreated PET resin substrate, and the untreated OPP resin substrate and untreated There was a problem in adhesion and blocking resistance with the OPP resin substrate and the untreated PET resin substrate. In Comparative Examples 2, 4, and 8, the content of the polyester resin was too small compared to the range of the present invention, so that the adhesion with the PET resin substrate, the blocking resistance, and the adhesiveness were inferior. In Comparative Examples 3, 5, and 9, since the content of the polyester resin was too much compared to the range of the present invention, the adhesion to the untreated OPP resin substrate, the untreated OPP resin substrate, and the untreated PET resin substrate Was inferior. In Comparative Example 6, the acid value of the polyester resin was outside the range of the present invention, and thus the adhesiveness was inferior. Comparative Example 10 did not contain a polyester resin and contained only a polyolefin resin, but because the polyolefin resin contained ethyl acrylate, the untreated OPP resin substrate and the untreated PET resin substrate Adhesion with was good. However, the adhesion to the untreated OPP resin substrate, the untreated OPP resin substrate, and the untreated PET resin substrate was poor. Since Comparative Examples 11, 12, 13, and 14 contained a polyolefin resin having a composition outside the scope of the present invention, the content value was within the scope of the present invention, but the untreated OPP resin base material, Adhesiveness with an untreated OPP resin substrate and an untreated PET resin substrate and blocking resistance were inferior.

Claims (4)

  100 parts by mass of a polyolefin resin containing 0.5 to 20% by mass of an unsaturated carboxylic acid unit, 10 to 60 parts by mass of a polyester resin having an acid value of 2 to 20 mg KOH / g, and an aqueous medium, An aqueous adhesive comprising 50 to 98 parts by mass of a propylene component and 2 to 50 parts by mass of an ethylene component when the total of the two components of the propylene component and the ethylene component is 100 parts by mass.   100 parts by mass of a polyolefin resin containing 0.5 to 20% by mass of an unsaturated carboxylic acid unit, 10 to 60 parts by mass of a polyester resin having an acid value of 2 to 20 mg KOH / g, and an aqueous medium, When the total of the three components of the propylene component, butene component, and ethylene component is 100 parts by mass, the propylene component is 8 to 90 parts by mass, the butene component is 8 to 90 parts by mass, and the ethylene component is 2 to 50 parts by mass. A water-based adhesive characterized by containing.   The water-based adhesive according to claim 1 or 2, wherein the polyester resin has a glass transition temperature of 10 ° C or lower.   A polypropylene resin base material, an adhesive layer formed by removing an aqueous medium from the aqueous adhesive according to any one of claims 1 to 3, and a polyethylene terephthalate resin base material are laminated in this order. A laminate characterized by being.