JP2011094072A - Aqueous polyamide resin dispersion, method for producing the same, and laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous polyamide resin dispersion which does not contains an emulsifier and a surfactant substantially, from which a polyamide resin coating film having excellent adhesiveness, flexibility, chemical resistance and heat-resistant adhesion properties can be obtained, which is excellent in dispersion stability even at room temperature and the polyamide resin of which has the small particle size enough to form a dense coating film. <P>SOLUTION: The aqueous polyamide resin dispersion is obtained by dispersing a dimer acid-based polyamide resin, which contains a dimer acid of ≥50 mol% of the whole dicarboxylic acid component as a dicarboxylic acid component and has 1-20 mg-KOH/g acid value, in an aqueous medium. The aqueous polyamide resin dispersion contains a basic compound having <185°C boiling point under normal pressure but does not contain an auxiliary dispersant, which has ≥185°C under normal pressure or is nonvolatile, substantially. The number-average particle diameter of the dimer acid-based polyamide resin in the aqueous medium is ≤0.5 μm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an aqueous dispersion capable of obtaining a polyamide resin coating film having good adhesion, flexibility, chemical resistance, and heat-resistant adhesion, and a method for producing the same.

  A polyamide resin having an amide bond in the main chain is a resin obtained mainly by a dehydration condensation reaction using a dicarboxylic acid component such as adipic acid or sebacic acid and a diamine component such as hexamethylenediamine or ethylenediamine. It is used in a wide range of fields such as applications and industrial applications.

The dimer acid is a dicarboxylic acid component having 36 carbon atoms, which is obtained by dimerizing an unsaturated fatty acid having 18 carbon atoms such as oleic acid and linoleic acid, and is a plant-derived fatty acid. A dimer acid-based polyamide resin can be obtained by a condensation reaction of a dicarboxylic acid component mainly composed of dimer acid and various diamine components.
Dimer acid-based polyamide resin is a resin with excellent adhesion, flexibility, chemical resistance, and heat-resistant adhesive, and it can be used as a hot-melt adhesive and additives for resin modification in a wide range of applications such as automotive parts and cables. It is used. Another characteristic is that the softening point, MFR, adhesive properties and flexibility of the resin can be widely controlled by the dicarboxylic acid component, diamine component, terminal acid component amount, terminal amine component amount, and the like. .

  If a solution or dispersion that does not impair the properties of the dimer acid-based polyamide resin can be obtained, for example, a dimer acid-based polyamide resin coating film can be easily formed on the surface of a resin film, sheet, paper, metal, etc. Adhesion, flexibility, chemical resistance, and heat-resistant adhesion can be imparted. However, dimer acid-based polyamide resins, particularly those having a low acid value, and resins having a high softening point have poor solubility in various solvents such as alcohols and toluene, and it is difficult to obtain a stable solution.

  Attempts have also been made to obtain aqueous polyamide resin dispersions containing dimer acid polyamide resins. For example, Patent Document 1 discusses a method of dispersing a polyamide resin having an acid value of 8 or more in an aqueous solvent containing usually 20% by mass or more of an alkylalkanolamine. However, the aqueous dispersion obtained by this method has gelled at room temperature, and an aqueous dispersion excellent in dispersion stability has not been obtained.

  Patent Documents 2 to 5 show a method for obtaining an aqueous dispersion of a polyamide resin containing a dimer acid-based polyamide resin, both of which have an emulsifier and a surfactant as an essential component, and thus have a coating film. In this case, emulsifiers and surfactants are contained in addition to the polyamide resin component, and there is a problem that these adversely affect the properties of the coating film, for example, good adhesion and chemical resistance inherently possessed by the polyamide resin. In addition, a dispersion having a low viscosity can be obtained under heating, but there is a problem that thickening starts by cooling and considerably thickens and gels at room temperature. Furthermore, in order to obtain an aqueous dispersion, use of a resin having a high acid value facilitates the formation of an aqueous solution, but there is a problem that the higher the acid value, the more the properties of the original polyamide resin are inhibited. In addition, even in an aqueous dispersion obtained without thickening at room temperature, the average particle diameter of the resin in the dispersion is 0.5 μm at the smallest, both of which are excellent in dispersion stability and a dense coating film It could not be said to be an aqueous dispersion having a small particle diameter sufficient to form the.

JP-A 64-20261 JP-A-2-4863 JP-A-2-4862 JP 2000-7787 JP 2001-270987 A

  The present invention solves the above-mentioned problems, and is a polyamide resin coating film substantially free of emulsifiers and surfactants and having good adhesion, flexibility, chemical resistance, and heat-resistant adhesiveness. It is a technical problem to provide an aqueous dispersion of a polyamide resin having a small particle diameter that is excellent in dispersion stability at room temperature and sufficient to form a dense coating film. To do.

  As a result of diligent studies to solve the above problems, the present inventors have used a dimer acid-based polyamide resin having a specific composition, so that a non-volatile aqueous additive such as a surfactant or a high boiling aqueous additive. It has been found that it can be dispersed in an aqueous medium with good stability and small particle size without adding. Furthermore, the present inventors have found that a coating film obtained by applying this aqueous dispersion exhibits good adhesion, flexibility, chemical resistance, and heat-resistant adhesion inherent in polyamide resins, and reached the present invention.

That is, the gist of the present invention is as follows.
(1) An aqueous dispersion in which dimer acid is contained as a dicarboxylic acid component in an amount of 50 mol% or more of the entire dicarboxylic acid component, and a dimer acid polyamide resin having an acid value of 1 to 20 mgKOH / g is dispersed in an aqueous medium, The dimer in the aqueous dispersion contains a basic compound having a boiling point under pressure of less than 185 ° C. and a boiling point under normal pressure of 185 ° C. or higher or substantially does not contain a non-volatile aqueous dispersion aid. An aqueous polyamide resin dispersion, wherein the acid-based polyamide resin has a number average particle size of 0.5 μm or less.
(2) The polyamide resin aqueous dispersion according to (1), which contains 0.01 to 15% by mass of a basic compound having a boiling point of less than 185 ° C. at normal pressure with respect to the solid content of the dimer acid-based polyamide resin. body.
(3) Adding a dimer acid-based polyamide resin and a basic compound having a boiling point of less than 185 ° C. at normal pressure to an aqueous medium containing a hydrophilic organic solvent, and heating and stirring at a temperature of 70 to 280 ° C. The manufacturing method of the polyamide resin aqueous dispersion as described in the item (1) or (2).
(4) The method for producing a polyamide resin aqueous dispersion according to (3), wherein the hydrophilic organic solvent is distilled off after heating and stirring.
(5) A laminate obtained by applying the aqueous polyamide resin dispersion according to (1) or (2) to a substrate.

The aqueous polyamide resin dispersion of the present invention does not substantially contain an emulsifier or a surfactant, and a dimer acid polyamide resin having a small particle diameter is dispersed, does not gel at room temperature, and has excellent dispersion stability. Is. Therefore, by applying the aqueous dispersion of polyamide resin of the present invention, it is possible to obtain a dense coating film of dimer acid-based polyamide resin, and the coating film obtained has adhesion, flexibility and chemical resistance. Excellent heat resistance.
According to the method for producing an aqueous dispersion of a polyamide resin of the present invention, a dimer acid-based polyamide resin having a small particle diameter, which does not substantially contain an emulsifier and a surfactant, and which has not been conventionally obtained, is dispersed. The aqueous polyamide resin dispersion of the present invention which does not gel at room temperature and has excellent dispersion stability can be obtained and can be produced efficiently.

Hereinafter, the present invention will be described in detail.
The aqueous polyamide resin dispersion of the present invention is an aqueous dispersion in which a dimer acid polyamide resin having an acid value of 1 to 20 mgKOH / g is dispersed in an aqueous medium.

  The aqueous medium in the present invention is a medium composed of a liquid containing water as a main component, and the aqueous medium may contain a hydrophilic organic solvent or a basic compound described later.

  The dimer acid-based polyamide resin dispersed in the aqueous dispersion of the present invention needs to have an acid value of 1 to 20 mgKOH / g, preferably 1 to 15 mgKOH / g, more preferably 3 to 12 mgKOH / g, most preferably. Is 2-7 mg KOH / g. Here, the acid value is defined by the number of milligrams of potassium hydroxide required to neutralize an acidic component contained in 1 g of resin, and is measured by the method described in JIS K 2501. . If the acid value of the dimer acid-based polyamide resin is less than 1 mgKOH / g, it is difficult to obtain a stable aqueous dispersion. On the other hand, if it exceeds 20 mgKOH / g, it is a good characteristic of the original dimer acid-based polyamide resin. Chemical resistance may decrease.

  The dimer acid-based polyamide resin in the present invention has an amide bond in the main chain, and is mainly obtained by a dehydration condensation reaction using a dicarboxylic acid component and a diamine component, and dimer acid is used as the dicarboxylic acid component. It contains 50 mol% or more of the entire dicarboxylic acid component. Here, the dimer acid is obtained by dimerizing an unsaturated fatty acid having 18 carbon atoms such as oleic acid or linoleic acid, and is a monomer if it is 25% by mass or less of the dimer acid component. Monomer acid (18 carbon atoms), trimer acid (carbon number 54) which is a trimer, other polymerized fatty acids having 20 to 54 carbon atoms, and further hydrogenated to lower the degree of unsaturation Good.

  The dimer acid-based polyamide resin has flexibility because it has a larger hydrocarbon group than resins such as nylon 6, nylon 6, 6, and nylon 12, which are widely used as polyamide resins. As the dimer acid, for example, a commercially available Hari dimer series (manufactured by Harima Chemicals Co., Ltd.), a pre-pole series (manufactured by Croda Japan Co., Ltd.), a tsuno dime series (manufactured by Tsukuno Food Industry Co., Ltd.), etc. can be used.

  In particular, the dimer acid-based polyamide resin in the present invention preferably contains dimer acid as a dicarboxylic acid component in an amount of 60 mol% or more, more preferably 70 mol% or more of the total dicarboxylic acid component. When the proportion of the dimer acid is less than 50 mol%, it becomes difficult to obtain the characteristics and effects of the dimer acid-based polyamide resin. On the other hand, when a component other than dimer acid is used as the dicarboxylic acid component, it is preferable to use adipic acid, azelaic acid, sebacic acid, pimelic acid, suberic acid, nonanedicarboxylic acid, fumaric acid, etc., and these are less than 50 mol%. By containing, it becomes easy to control the softening point and adhesiveness of the resin.

Further, as the diamine component, ethylenediamine, hexamethylenediamine, tetramethylenediamine, pentamethylenediamine, m-xylenediamine, phenylenediamine, diethylenetriamine, piperazine and the like can be used, among which ethylenediamine, hexamethylenediamine, diethylenetriamine, m- Xylenediamine and piperazine are preferred.
Furthermore, the polymerization degree, acid value, or amine value of the resin can be controlled by the charging ratio of the dicarboxylic acid component and the diamine component when polymerizing the resin.

  The aqueous polyamide resin dispersion of the present invention needs to contain a basic compound having a boiling point of less than 185 ° C. at normal pressure. By containing a basic compound having a boiling point of less than 185 ° C. at normal pressure, the carboxyl group of the dimer acid-based polyamide resin having an acid value of 1 to 20 mg KOH / g is neutralized, and between the carboxyl anions generated by neutralization Aggregation between the fine particles can be prevented by the electric repulsive force, and an aqueous dispersion excellent in dispersion stability can be obtained.

Examples of the basic compound having a boiling point of less than 185 ° C. under normal pressure include amines such as ammonia and organic amines. Specific examples of the organic amine compound include triethylamine, N, N-dimethylethanolamine, isopropylamine, iminobispropylamine, ethylamine, diethylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, Examples include methylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine and the like. As the basic compound having a boiling point of less than 185 ° C. at normal pressure, triethylamine and N, N-dimethylethanolamine are particularly preferable.
When the boiling point at normal pressure exceeds 185 ° C., it becomes difficult to volatilize basic compounds, especially organic amines, by drying when applying an aqueous dispersion to form a coating film. May adversely affect properties.

  In the aqueous polyamide resin dispersion of the present invention, the content of the basic compound is preferably 0.01 to 100% by mass, more preferably 1 to 40% by mass, based on the solid content of the dimer acid polyamide resin. -15 mass% is more preferable. If it is less than 0.01% by mass, the effect of adding the basic compound is poor, and it becomes difficult to obtain an aqueous dispersion having excellent dispersion stability. On the other hand, when it exceeds 100 mass%, the aqueous dispersion of the polyamide resin may be easily colored or gelled.

  And the polyamide resin aqueous dispersion of this invention does not contain the non-volatile aqueous | water-based auxiliary | assistant whose boiling point in a normal pressure is 185 degreeC or more. Here, the boiling point at normal pressure of 185 ° C. or higher or the non-volatile aqueous auxiliary agent means an emulsifier component or a compound having a protective colloid action. That is, it means that the polyamide resin aqueous dispersion of the present invention can be a stable aqueous dispersion without containing these emulsifier components or compounds having a protective colloid action.

  Examples of the emulsifier component 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. Nonionic emulsifiers include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyethylene glycol fatty acid ester, ethylene oxide propylene oxide block copolymer, polyoxyethylene fatty acid amide, ethylene oxide-propylene oxide. Examples thereof include compounds having a polyoxyethylene structure such as copolymers and sorbitan derivatives, and amphoteric emulsifiers include lauryl betai , Lauryl dimethylamine oxide, and the like.

  The compounds having protective colloids 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. Acid modified polyolefin waxes and their salts, acrylic acid-maleic anhydride copolymers and their salts, styrene- (meth) acrylic acid co-polymers having a number average molecular weight of usually 5000 or less, such as waxes and carboxyl group-containing polyethylene-propylene waxes Polymer, ethylene- (meth) acrylic acid copolymer, isobutylene-maleic anhydride alternating copolymer, (meth) acrylic acid- (meth) acrylic acid ester A carboxyl group-containing polymer having an unsaturated carboxylic acid content of 10% by mass or more, such as a polymer, and a salt thereof, polyitaconic acid and a salt thereof, a water-soluble acrylic copolymer having an amino group, gelatin, gum arabic, casein, etc. A compound generally used as a dispersion stabilizer for fine particles is exemplified.

  The aqueous dispersion of the present invention has a boiling point at normal pressure of 185 ° C. or higher or does not contain a non-volatile aqueous auxiliary agent, which has a boiling point at normal pressure of 185 ° C. or higher or non-volatile. This means that a stable aqueous polyamide resin dispersion can be obtained even without containing the water-based auxiliary. Therefore, when obtaining the coating agent which uses the polyamide resin aqueous dispersion of this invention as a part of structural component, according to the objective, it does not prevent adding the water-izing aid mentioned above.

  Thus, in the aqueous polyamide resin dispersion of the present invention, the dimer acid polyamide resin is stably dispersed in the aqueous medium, and the number average particle diameter of the dimer acid polyamide resin particles is 0.5 μm or less. Yes, preferably 0.4 μm or less, more preferably 0.2 μm or less, and most preferably 0.1 μm or less. When the number average particle diameter of the dimer acid-based polyamide resin particles exceeds 0.5 μm in the aqueous dispersion, the dispersion stability and dilution stability are lowered, and when it is formed into a coating film, it is difficult to form a dense film. Here, the number average particle diameter of the polyamide resin particles is measured by a dynamic light scattering method, and is measured using a Microtrac particle size distribution analyzer UPA150 (MODEL No. 9340) manufactured by Nikkiso Co., Ltd.

  Moreover, it is preferable that content (solid content concentration) of the dimer acid type polyamide resin in the aqueous dispersion of this invention is 3-40 mass%, and it is preferable that it is 10-30 mass% especially. When the content of the dimer acid-based polyamide resin in the aqueous dispersion is less than the above range, it may take time to form a coating film by the drying process, and it becomes difficult to obtain a thick coating film. On the other hand, when the content of the dimer acid-based polyamide resin in the aqueous dispersion is more than the above range, the storage stability of the dispersion tends to be lowered.

Next, the manufacturing method of the polyamide resin aqueous dispersion of this invention is demonstrated.
In the production method of the present invention, a predetermined amount of a dimer acid-based polyamide resin and a basic compound having a boiling point of less than 185 ° C. at normal pressure are added to an aqueous medium containing a hydrophilic organic solvent, and a temperature of 70 to 280 ° C. is added. It is heated and stirred at temperature. When stirring with heating, it is preferable to heat and stir at 100 to 1000 revolutions per minute until the resin is uniformly dispersed in the aqueous medium.

  The temperature at the time of heating and stirring is preferably 100 to 250 ° C. If the temperature during heating and stirring is less than 70 ° C., the dimer acid-based polyamide resin cannot be completely dispersed, and it becomes difficult to obtain an aqueous dispersion having a number average particle size of 0.5 μm or less. On the other hand, if the temperature at the time of heating and stirring exceeds 280 ° C., the molecular weight of the dimer acid-based polyamide resin may be lowered, and there is a problem that the internal pressure of the system is excessively increased.

  Moreover, in the manufacturing method of this invention, it is preferable to distill off a hydrophilic organic solvent from the polyamide resin aqueous dispersion obtained after heating and stirring. However, it is preferable to select a temperature and pressure at which the basic compound is not distilled off.

  In the production process of the aqueous polyamide resin dispersion of the present invention, the content of the hydrophilic organic solvent added to the aqueous medium is preferably 10 to 60% by mass of the aqueous medium, and more preferably 20 to 50% by mass. . If the content of the hydrophilic organic solvent is less than 10% by mass, the aqueous dispersion of the dimer acid-based polyamide resin may not sufficiently proceed. On the other hand, if it exceeds 60% by mass, the dispersion may be gelled.

  Moreover, it is preferable that the boiling point of a hydrophilic organic solvent is 30-180 degreeC, It is more preferable that it is 50-150 degreeC, It is especially preferable that it is 50-120 degreeC. When the boiling point of the hydrophilic organic solvent is less than 30 ° C., the proportion of volatilization when preparing the aqueous dispersion increases, and the effect of adding the hydrophilic organic solvent becomes poor, and the working environment tends to deteriorate. When the boiling point exceeds 180 ° C., it is difficult to remove the organic solvent from the aqueous dispersion, and when the coating film is formed, it tends to remain in the coating film and the solvent resistance may be lowered.

  Furthermore, as the hydrophilic organic solvent, those having a solubility in water at 20 ° C. of 50 g / L or more are preferable. Specific examples of such hydrophilic organic solvents include methanol, ethanol, n-propanol, isopropanol (hereinafter “IPA”). And alcohols such as tetrahydrofuran (hereinafter referred to as “THF”) dioxane, glycol derivatives such as ethylene glycol monomethyl ether, and the like. Among these hydrophilic organic solvents, IPA, n-propanol and THF are preferable from the viewpoint of promoting aqueous dispersion, and it is also preferable to use these in combination (IPA and THF, n-propanol and THF).

  In the method for producing an aqueous dispersion of polyamide resin according to the present invention, a hydrocarbon organic solvent such as toluene or cyclohexane is added in an amount of 10 mass of the aqueous medium for the purpose of promoting dispersion in the aqueous medium containing the hydrophilic organic solvent. % Or less may be added. When the addition amount of the hydrocarbon organic solvent exceeds 10% by mass, separation from water becomes severe in the production process, and a uniform aqueous dispersion may not be obtained.

  The aqueous dispersion obtained by heating and stirring by the method for producing an aqueous dispersion of the present invention is cooled to room temperature, but becomes a low-viscosity polyamide resin aqueous dispersion without agglomeration during the cooling process. Specifically, the aqueous dispersion of the present invention is a sufficiently low viscosity aqueous dispersion having a viscosity at 25 ° C. of 500 mPa · s or less, and is excellent in processability and stability. Among them, the aqueous dispersion of the present invention preferably has a viscosity of 300 mPa · s or less, more preferably 100 mPa · s or less.

  Further, in the aqueous dispersion of the present invention, various agents such as a leveling agent, an antifoaming agent, an anti-waxing agent, a pigment dispersant, an ultraviolet absorber, titanium oxide, zinc white, carbon black, etc. Pigments or dyes can be added.

  And the laminated body of this invention apply | coats the polyamide resin aqueous dispersion of this invention to a base material. As a method (coating method) for applying the aqueous polyamide resin dispersion of the present invention to a substrate, known methods such as gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, Examples thereof include spray coating, dip coating, and brushing. By these methods, the aqueous dispersion can be uniformly applied to the surface of the substrate.

  Examples of the substrate on which the aqueous dispersion is applied include those formed of a resin material, a glass material, or the like. Although the thickness of a base material is not specifically limited, 10-1000 micrometers is preferable, 10-500 micrometers is especially preferable, Furthermore, 10-200 micrometers is preferable.

  Resin materials that can be used for the substrate include poly (meth) acrylic resins, poly (meth) acrylonitrile resins, polystyrene resins, polysulfone resins, polyethersulfone resins, polyether resins, poly Methylpentene resin, triacetate cellulose resin, polyethylene terephthalate resin, polyurethane resin, regenerated cellulose resin, diacetyl cellulose resin, acetate butyrate cellulose resin, polyester resin, acrylonitrile-butadiene-styrene terpolymer Resin, polycarbonate resin, polyether ketone resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, nylon resin, polyethylene resin, polypropylene resin, polyamide Resin, polyimide resin, and norbornene resin. The resin material may be stretched. The resin material may contain known additives and stabilizers such as antistatic agents, plasticizers, lubricants, antioxidants and the like. The resin material may have a surface subjected to a corona treatment, a plasma treatment, an ozone treatment, a chemical treatment, a solvent treatment or the like as a pretreatment in order to improve adhesion when laminated with other materials. In addition, silica, alumina, etc. may be deposited, and other layers such as a barrier layer, an easy adhesion layer, an antistatic layer, an ultraviolet absorbing layer, an adhesive layer, a release layer, an antireflection layer, a hard coat layer, an antiglare layer, etc. Layers may be stacked.

  As described above, after applying the aqueous dispersion of polyamide resin of the present invention to the substrate, the aqueous medium can be removed by drying and heat treatment, and the dense dimer acid polyamide resin coating film is adhered to the substrate. Can be formed. At this time, it is preferable to remove the basic compound in the aqueous dispersion by carrying out a drying heat treatment under the condition that the basic compound in the aqueous dispersion is distilled off.

  The thickness of the dimer acid-based polyamide resin coating film formed on the substrate is not particularly limited, but is preferably in the range of 0.05 to 20 μm, more preferably 0.1 to 10 μm. If the thickness is less than 0.05 μm, the characteristics of the dimer acid-based polyamide resin coating film may not be sufficiently exhibited. If the thickness exceeds 20 μm, the characteristics (effect) of the polyamide resin coating film are saturated, which is disadvantageous in cost.

  Hereinafter, the present invention will be described specifically by way of examples. In addition, measurement and evaluation of various values in the examples were performed as follows.

(1) Characteristic values of polyamide resin [acid value, amine value]
It was measured by the method described in JIS K 2501.
[Softening point temperature]
Using 10 mg of resin as a sample, a microscope equipped with a microscope heating (cooling) device heat stage (Linking Co., Heating-Freezing ATAGE TH-600 type) is used for measurement at a heating rate of 20 ° C./min. The temperature at which the resin melted was defined as the softening point.
[Melt viscosity]
It was measured with a Brookfield melt viscometer DV-II + PRO type at a resin temperature of 200 ° C. and a shear rate of 1.25 / sec. After starting the melting, it was rotated for about 25 minutes, and the value of the melt viscosity at the time when the viscosity was stabilized at almost the elapsed time was read.
(2) Solid Content Concentration of Aqueous Dispersion An appropriate amount of the obtained aqueous dispersion was weighed and heated at 150 ° C. until the mass of the residue (solid content) reached a constant weight to obtain the solid content concentration.
(3) Dispersion stability of aqueous dispersion The obtained aqueous dispersion was allowed to stand at room temperature for 10 days, and the appearance of the aqueous dispersion was evaluated in the following three stages.
○: No change in appearance, Δ: Separation, partial gelation, ×: Complete gelation, occurrence of aggregates (4) pH of aqueous dispersion
The pH was measured using a pH meter (Horiba, Ltd., F-52).
(5) Viscosity of aqueous dispersion Using a B-type viscometer (DVL-BII type digital viscometer manufactured by Tokimec Co., Ltd.), the rotational viscosity (mPa · s) at a temperature of 25 ° C. was measured.
(6) Number average particle diameter of polyamide resin in aqueous dispersion Measured by the above method. Moreover, it measured similarly about the polyolefin resin aqueous dispersion.
(7) Adhesion Resin after drying the obtained polyamide resin aqueous dispersion and polyolefin resin aqueous dispersion (E-1 to E-9) on one side of this base material using a soft vinyl chloride sheet as the base material. The dimer acid-based polyamide resin coating film was formed on the surface of the soft vinyl chloride sheet by applying using a wire bar so that the thickness of the layer was 3 μm, and performing heat drying treatment at 120 ° C. for 1 minute. About the coating film of the obtained laminated body, according to the method of JISK5600, adhesiveness was evaluated in the following four steps by the crosscut method.
A: No peeling is observed on any lattice.
○: Slight peeling is observed along the edge of the lattice cut. Less than 5% of the total.
(Triangle | delta): About 5 to 15% of peeling of the whole is seen.
X: Peeling of 15% or more of the whole is observed.
(8) Adhesiveness (peel strength)
The thickness of the resin layer after drying the obtained polyamide resin aqueous dispersion and polyolefin resin aqueous dispersion (E-1 to E-9) on one side of this base material using a soft vinyl chloride sheet as the base material. A dimer acid-based polyamide resin coating film was formed on the surface of the soft vinyl chloride sheet by applying it using a wire bar so as to have a thickness of 3 μm, followed by heat drying at 120 ° C. for 1 minute. Then, another soft vinyl chloride sheet was laminated on the coating surface of the soft vinyl chloride sheet, and the film was pasted by press heat treatment at 90, 120, and 150 ° C. under a pressure of 0.2 MPa for 5 seconds. A sample obtained by cutting the obtained laminate to a width of 15 mm was used as a sample, and a 180 ° peel strength was measured at a speed of 200 mm / min using a tensile tester (precision universal material tester type 2020 manufactured by Intesco). The measurement was performed on five samples for each press heat treatment temperature, and the average value was taken as the peel strength.
(9) Heat-resistant adhesion Resin after drying the obtained polyamide resin aqueous dispersion and polyolefin resin aqueous dispersion (E-1 to E-9) on one side of this base material using a polyethylene terephthalate film as the base material The dimer acid-based polyamide resin coating film was formed on the surface of the base material by applying using a wire bar so that the thickness of the layer was 2.5 μm, and performing heat drying treatment at 120 ° C. for 90 seconds. An aluminum foil (non-glossy surface) was stacked on this surface and pressed (150 ° C./0.2 MPa / 5 seconds) to obtain a laminate. The peel strength of this laminate at room temperature, 60 ° C., 80 ° C., and 100 ° C. was measured in the same manner as in (8).
(10) Flexibility After the laminate obtained in the same manner as in the evaluation of (7) is treated 100 times with a gelboflex tester (treatment at 20 ° C., 40 reciprocations per minute with a stroke of about 15 cm). In the same manner as the adhesiveness of (7), the adhesiveness of the coating film of the obtained laminate was evaluated by the cross-cut method according to the method described in JIS K5600.

[Polyamide resin P-1]
In a 1-liter four-necked flask equipped with a stirrer and a distillation tube, 616.0 g of dimer acid (Tsunodaim 395, manufactured by Tsukino Food Industry Co., Ltd., 94% dimer acid content), 60.1 g of ethylenediamine, 11 of stearic acid .4 g was added, and the temperature was raised to 200 ° C. under a nitrogen atmosphere to carry out the reaction for 30 minutes. Furthermore, reaction time was adjusted so that it might become a desired acid value and an amine value, and polyamide resin P-1 was obtained. The obtained polyamide resin is a dimer acid-based polyamide resin containing 100 mol% of dimer acid in the total dicarboxylic acid component, and has an acid value of 15.0 mgKOH / g, an amine value of 0.3 mgKOH / g, a softening point of 110 ° C., and 200 ° C. The melt viscosity in was 1,100 mPa · s.

[Polyamide resin P-2]
504.0 g of dimer acid (Tsunodaim 395, manufactured by Tsukino Food Industry Co., Ltd., 94% dimer acid content), 18.8 g of azelaic acid, 18.0 g of ethylenediamine, 60.3 g of piperazine, and 5.7 g of stearic acid were used as reaction raw materials. Except for the above, a polyamide resin P-2 was obtained in the same manner as in the polyamide resin P-1. The obtained polyamide resin is a dimer acid-based polyamide resin containing 90% by mole of dimer acid in the whole dicarboxylic acid component, and has an acid value of 5.0 mgKOH / g, an amine value of 0.1 mgKOH / g, a softening point of 140 ° C., and 200 ° C. The melt viscosity in was 23,000 mPa · s.

[Polyamide resin P-3]
Dimer acid (Tsunodaim 395, manufactured by Tsukino Food Industry Co., Ltd., dimer acid content 94%) 476.0 g, azelaic acid 28.2 g, ethylenediamine 30.1 g, piperazine 43.1 g, and stearic acid 5.7 g were used as reaction raw materials. Except for the above, a polyamide resin P-3 was obtained in the same manner as in the polyamide resin P-1. The obtained polyamide resin is a dimer acid-based polyamide resin containing 85% by mole of dimer acid in the total dicarboxylic acid component, and has an acid value of 10.0 mgKOH / g, an amine value of 0.1 mgKOH / g, a softening point of 158 ° C., and 200 ° C. The melt viscosity in was 10,000 mPa · s.

[Polyamide resin P-4]
The same as polyamide resin P-1, except that 560.0 g of dimer acid (Tsunodaim 395, manufactured by Tsukino Food Industry Co., Ltd., 94% dimer acid content), 60.1 g of ethylenediamine and 11.4 g of stearic acid were used as reaction raw materials. Thus, a polyamide resin P-4 was obtained. The obtained polyamide resin is a dimer acid-based polyamide resin containing 100% by mole of dimer acid in the total dicarboxylic acid component, and has an acid value of 0.5 mgKOH / g, an amine value of 0.2 mgKOH / g, a softening point of 115 ° C., and 200 ° C. The melt viscosity in was 960 mPa · s.

Example 1
75.0 g of polyamide resin P-1, 37.5 g of IPA (manufactured by Wako Pure Chemical Industries), 37.5 g of THF (manufactured by Wako Pure Chemical Industries, Ltd.) ), 7.2 g of N, N-dimethylethanolamine (Wako Pure Chemical Industries, Ltd.) and 217.8 g of distilled water were charged. While stirring at a rotation speed of 300 rpm, the system was heated and stirred at 120 ° C. for 60 minutes. Thereafter, the mixture was cooled to around room temperature (about 30 ° C.) with stirring, 100 g of distilled water was added, and then filtered through a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) with very slight pressure. The obtained aqueous dispersion was put into a 1 L eggplant flask and reduced in pressure using an evaporator while being placed in a hot water bath heated to 80 ° C., and about 100 g of a mixed medium of IPA, THF and water was distilled off to obtain a milky white uniform polyamide resin. An aqueous dispersion (E-1) was obtained.

Example 2
75.0 g of polyamide resin P-2, 75.0 g of IPA (manufactured by Wako Pure Chemical Industries), 75.0 g of THF (manufactured by Wako Pure Chemical Industries, Ltd.) ), 6.0 g of N, N-dimethylethanolamine (manufactured by Wako Pure Chemical Industries, Ltd.), 7.5 g of toluene (manufactured by Wako Pure Chemical Industries, Ltd.) and 136.5 g of distilled water. While stirring at a rotation speed of 300 rpm, the system was heated and stirred at 130 ° C. for 60 minutes. Thereafter, the mixture was cooled to around room temperature (about 30 ° C.) with stirring, 230 g of distilled water was added, and then filtered with a 300 mesh stainless steel filter (wire diameter: 0.035 mm, plain weave) with very slight pressure. The obtained aqueous dispersion was put into a 1 L eggplant flask and reduced in pressure using an evaporator while being put in a hot water bath heated to 80 ° C., and about 230 g of a mixed medium of IPA, THF, toluene and water was distilled off to obtain a milky white uniform A polyamide resin aqueous dispersion (E-2) was obtained.

Example 3
75.0 g of polyamide resin P-3, 93.8 g of IPA (manufactured by Wako Pure Chemical Industries, Ltd.), 6.0 g of N, N-dimethylethanolamine in a sealable pressure-resistant 1 liter glass container equipped with a stirrer and a heater (Wako Pure Chemical Industries, Ltd.) and 200.3 g of distilled water were charged. While stirring at a rotation speed of 300 rpm, the system was heated and stirred at 120 ° C. for 60 minutes. Thereafter, the mixture was cooled to around room temperature (about 30 ° C.) with stirring, 130 g of distilled water was added, and then filtered with a 300 mesh stainless steel filter (wire diameter: 0.035 mm, plain weave) with very slight pressure. The obtained aqueous dispersion was put into a 1 L eggplant flask and reduced in pressure using an evaporator while being placed in a hot water bath heated to 80 ° C. to distill off about 130 g of a mixed medium of IPA and water to obtain a milky white uniform polyamide resin aqueous dispersion. The body (E-3) was obtained.

Example 4
A method similar to that described in Example 2, except that instead of 6.0 g of N, N-dimethylethanolamine, 6.8 g of triethylamine (manufactured by Wako Pure Chemical Industries, Ltd.) and 135.7 g of distilled water were added. Thus, a milky white uniform polyamide resin aqueous dispersion was obtained by heating and stirring. Then, it is cooled to around room temperature (about 30 ° C.) with stirring, 6.0 g of N, N-dimethylethanolamine (manufactured by Wako Pure Chemical Industries) and 230 g of distilled water are added, and then a 300 mesh stainless steel filter Filtration was carried out with very slight pressure (wire diameter 0.035 mm, plain weave). The obtained aqueous dispersion was put into a 1 L eggplant flask and reduced in pressure using an evaporator while being put in a hot water bath heated to 80 ° C., and about 230 g of a mixed medium of IPA, THF, toluene and water was distilled off to obtain a milky white uniform An aqueous polyamide resin dispersion (E-4) was obtained.

Example 5
A method similar to that described in Example 3, except that instead of 6.0 g of N, N-dimethylethanolamine, 6.8 g of triethylamine (manufactured by Wako Pure Chemical Industries, Ltd.) and 199.5 g of distilled water were added. Then, the mixture is cooled to near room temperature (about 30 ° C.) with stirring, filtered through a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) with very slight pressure, and milky white. A uniform aqueous polyamide resin dispersion (E-5) was obtained.

Example 6
Except for changing the addition amount of N, N-dimethylethanolamine to 22.5 g and the addition amount of distilled water to 202.5 g, a light brown uniform polyamide resin aqueous dispersion ( E-6) was obtained.

Example 7
A milky white uniform polyamide resin aqueous dispersion (E) was prepared in the same manner as described in Example 2 except that the addition amount of N, N-dimethylethanolamine was changed to 20.0 g and the addition amount of distilled water was changed to 122.5 g. -7) was obtained.

Example 8
A milky white uniform polyamide resin aqueous dispersion (E) was prepared in the same manner as described in Example 2 except that the addition amount of N, N-dimethylethanolamine was changed to 71.5 g and the addition amount of distilled water was changed to 71.0 g. -8) was obtained.

Comparative Example 1
60.0 g of polyamide resin P-1 and 240.0 g of IPA (manufactured by Wako Pure Chemical Industries, Ltd.) were charged into a sealable pressure-resistant 1 liter glass container equipped with a stirrer and a heater. While stirring at a rotation speed of 300 rpm, the system was heated and stirred at 80 ° C. for 60 minutes. At 80 ° C., a light yellow solution in which the resin was uniformly dissolved was obtained. Thereafter, the mixture was cooled to around room temperature (about 30 ° C.) with stirring, and further allowed to stand at room temperature (about 20 ° C.) for 1 day. As a result, the liquid partially gelled, and an aqueous dispersion could not be obtained.

Comparative Examples 2 and 3
An attempt was made to prepare an IPA solution of polyamide resin in the same manner as in Comparative Example 1 except that polyamide resins P-1 and P-2 were used. However, the resin did not dissolve in IPA, and a resin lump remained, which was aqueous. A dispersion was not obtained.

Comparative Example 4
The same operation as in Example 2 was performed except that the polyamide resin P-4 was used as the polyamide resin. However, a mass of the polyamide resin remained, and no aqueous dispersion was obtained.

Comparative Example 5
The same operation as in Example 2 was performed except that dimethylethanolamine was not added, but a mass of polyamide resin remained, and an aqueous dispersion was not obtained.

Comparative Example 6
Except that the temperature at the time of heating and stirring was 50 ° C., the same operation as in Example 2 was performed, but a lump of polyamide resin remained and an aqueous dispersion could not be obtained.

Comparative Example 7
Heating and stirring were performed in the same manner as described in Example 1 except that the amount of N, N-dimethylethanolamine added was changed to 80.5 g and the amount of distilled water added was changed to 144.5 g. Thereafter, when the system was cooled with stirring, the contents gelled at an internal temperature of 45 ° C., and an aqueous dispersion could not be obtained.

Comparative Example 8
In a sealable pressure-resistant 1 liter glass container equipped with a stirrer and a heater, 60.0 g polyolefin resin (Bondaine HX-8290, manufactured by Arkema, melting point 81 ° C.), 60.0 g IPA (manufactured by Wako Pure Chemical Industries, Ltd.), 3.0 g of triethylamine (manufactured by Wako Pure Chemical Industries, Ltd.) and 177.0 g of distilled water were charged. While stirring at a rotation speed of 300 rpm, the system was heated and stirred at 120 ° C. for 60 minutes. Then, it is cooled to around room temperature (about 30 ° C.) with stirring, filtered through a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) with very little pressure, and a milky white uniform polyolefin resin aqueous dispersion (E-9) was obtained.

  Table 1 shows the characteristic values and evaluation results of the aqueous dispersions obtained in Examples 1 to 8 and Comparative Example 8.

As shown in Table 1, in Examples 1 to 8, the boiling point at normal pressure is 185 ° C. or higher or the polyamide resin is finely and stably contained in an aqueous medium without substantially containing a non-volatile aqueous agent. An aqueous dispersion of a polyamide resin dispersed in can be obtained. The laminate obtained by applying the obtained aqueous dispersion was excellent in the adhesion and flexibility of the coating film, and excellent in heat-resistant adhesiveness.
On the other hand, in Comparative Examples 1-3, an attempt was made to dissolve the dimer acid-based polyamide resin in IPA, but in Comparative Example 1, the gelation occurred at room temperature, and in Comparative Examples 2, 3, the resin did not dissolve at all. None of the aqueous dispersions were obtained. In Comparative Example 4, since a dimer acid-based polyamide resin having an acid value of 0.5 mgKOH / g was used, a lump of polyamide resin remained and an aqueous dispersion could not be obtained. In Comparative Example 5, since no basic compound was added, a lump of polyamide resin remained, and an aqueous dispersion could not be obtained. In Comparative Example 6, since the temperature at the time of heating and stirring was too low, the polyamide resin was not sufficiently dispersed, a mass of the polyamide resin remained, and an aqueous dispersion was not obtained. In Comparative Example 7, since the content of the basic compound was too large, the liquid gelled during cooling, and no aqueous dispersion was obtained. Since Comparative Example 8 is an aqueous dispersion using a polyolefin resin as a resin, the laminate formed by applying the obtained aqueous dispersion was inferior in heat resistant adhesiveness.

Claims (5)

  An aqueous dispersion in which a dimer acid as a dicarboxylic acid component is contained in an amount of 50 mol% or more of the total dicarboxylic acid component, and a dimer acid-based polyamide resin having an acid value of 1 to 20 mgKOH / g is dispersed in an aqueous medium. The dimer acid-based polyamide in the aqueous dispersion contains a basic compound having a boiling point of less than 185 ° C., and has a boiling point at normal pressure of 185 ° C. or more or substantially does not contain a non-volatile aqueous dispersion aid. A polyamide resin aqueous dispersion, wherein the resin has a number average particle diameter of 0.5 μm or less.   2. The polyamide resin aqueous dispersion according to claim 1, comprising 0.01 to 100% by mass of a basic compound having a boiling point of less than 185 ° C. at normal pressure, based on the solid content of the dimer acid-based polyamide resin.   A dimer acid-based polyamide resin and a basic compound having a boiling point of less than 185 ° C. at normal pressure are added to an aqueous medium containing a hydrophilic organic solvent, and the mixture is heated and stirred at a temperature of 70 to 280 ° C. The manufacturing method of the polyamide resin aqueous dispersion of Claim 1 or 2.   The method for producing an aqueous dispersion of polyamide resin according to claim 3, wherein the hydrophilic organic solvent is distilled off after heating and stirring. A laminate comprising the polyamide resin aqueous dispersion according to claim 1 or 2 applied to a substrate.