JP2000072879A - Aqueous dispersion and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aqueous dispersion capable of forming a coating film having excellent water resistance and hydrophilicity, excellent in dispersion stability, useful as a coating agent or the like, by including a specific copolymer, a prescribed counter cation or the like, but substantially not an aggregate or the like. SOLUTION: This dispersion comprises (A) an ethylene/unsaturated carboxylic acid copolymer having 5-30 wt.% unsaturated carboxylic acid (e.g. methacrylic acid or the like) content, (B) a counter cation (preferably an ion of an alkali metal such as potassium or the like) capable of neutralizing the carboxyl group of the component A and (C) a sulfate such as potassium sulfate or the like, preferably in the ratios of the component B of >=30 equivalent based on the carboxyl group of the component A and the component C of 0.1-15 pts.wt. based on 100 pts.wt. of the component A. The dispersion substantially contains neither an aggregate nor a sediment. The dispersion has preferably <=300 nm average particle diameter of dispersed particles and preferably >=100 day pot life.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an aqueous dispersion capable of forming a coating film having excellent hydrophilicity. In particular, the present invention relates to an aqueous dispersion having sufficient water resistance, capable of forming a coating film having excellent hydrophilicity, and having excellent dispersion stability.

[0002]

2. Description of the Related Art An aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer represented by an ethylene / acrylic acid copolymer or an ethylene / methacrylic acid copolymer has been known for a long time, and is commercially available. Various things are available. Among them, those obtained by dispersing the copolymer in water using an alkali metal compound or ammonia are generally used.

[0003] Of these, a coating film formed from an ammonia dispersion is known to exhibit excellent water resistance, but has poor wettability (hydrophilicity) on the surface of the coating film. May occur. In the case of using an aqueous dispersion dispersed with an alkali metal compound and having a small degree of neutralization, a coating film excellent in water resistance can be obtained although it is not as good as that obtained from an ammonia dispersion. However, also in this case, it cannot be said that the hydrophilicity is sufficient. On the other hand, a coating film obtained from an alkali dispersion having a high degree of neutralization using an ethylene / unsaturated carboxylic acid copolymer having a large unsaturated carboxylic acid content is excellent in hydrophilicity but poor in water resistance and forms a coating film. When the immersed product is immersed in water, the coating film is peeled off from the substrate in a short time.

It is possible to improve the hydrophilicity by subjecting the coating film having excellent water resistance to surface treatment such as corona treatment, ozone treatment, electron beam treatment and radiation treatment, but the operation is complicated. In many cases, the degree of improvement was not sufficient.

As described above, it is very difficult to obtain a coating film obtained from an aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer having both good water resistance and good hydrophilicity by a simple method. there were.

[0006]

Therefore, the present inventor has proposed:
Attempts were made to impart hydrophilicity to the coating film by blending inorganic compounds, but many did not show a sufficient improvement effect. Some of the inorganic compounds, when added to the aqueous dispersion of the ethylene / unsaturated carboxylic acid copolymer, rapidly aggregated and could not be stably dispersed. For example, when aqueous solutions of various sulfates were added to such an aqueous dispersion and stirred, rapid aggregation and sedimentation of the aqueous dispersion was observed. However, after further study, when various sulfates were added during the preparation of the aqueous dispersion of the ethylene / unsaturated carboxylic acid copolymer, such coagulation and sedimentation was not observed at all, and a stable dispersion was obtained. It has been found that the obtained coating film has a significantly improved hydrophilicity, and that the coating film formed from such a dispersion liquid has a remarkably improved hydrophilicity. In this case, even when a water-insoluble sulfate such as calcium sulfate or barium sulfate is used, in the resulting aqueous dispersion, there is no large-sized particle used as a raw material, and further 100 days or more. Since no phenomenon such as precipitation, aggregation, or gelation was observed over a long period of time, it is presumed that the particles were dispersed in an extremely small form due to the interaction with the copolymer. On the other hand, if the method of adding the above-mentioned sulfate after preparing the aqueous dispersion of the ethylene / unsaturated carboxylic acid copolymer is adopted, even if a uniform product is temporarily obtained, the sulfate is immediately separated. Resulting in precipitation.

Accordingly, an object of the present invention is to provide an aqueous dispersion capable of forming a coating film having an excellent combination of wettability with water and water resistance and having excellent dispersion stability, and a method for producing the same. To provide. Another object of the present invention is to provide a laminate in which such an aqueous dispersion is applied to a substrate to form a coating film having an excellent combination of wettability and water resistance.

[0008]

The present invention provides an ethylene / unsaturated carboxylic acid copolymer (A) having an unsaturated carboxylic acid content of 5 to 30% by weight, and neutralizes the carboxyl groups of the copolymer (A). Possible counter cations (B) and sulfates (C)
And an aqueous dispersion substantially free of aggregates or sediments. The present invention also provides an ethylene / unsaturated carboxylic acid copolymer (A) having an unsaturated carboxylic acid content of 5 to 30% by weight, and a counter cation (B) capable of neutralizing a carboxyl group of the copolymer (A). An alkali metal compound serving as a supply source, a compound (B ′) selected from ammonia and alkanolamine, and a sulfate (C) are mixed in water at a temperature equal to or higher than the melting point of the copolymer (A). And a method for producing an aqueous dispersion substantially free of aggregates or sediments.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The aqueous dispersion of the present invention comprises an ethylene / unsaturated carboxylic acid copolymer (A) having an unsaturated carboxylic acid content of 5 to 30% by weight, and a carboxyl group of the copolymer (A). It is a remarkable feature that, despite containing the neutralizable counter cation (B) and sulfate (C) as essential components, it does not substantially contain aggregates or precipitates. As already pointed out, when producing an aqueous dispersion comprising the above three components, the unsaturated carboxylic acid content is 5-30.
A sulfate (C) is added to an aqueous dispersion containing an ethylene / unsaturated carboxylic acid copolymer (A) and a counter cation (B) capable of neutralizing a carboxyl group of the copolymer (A) by weight.
Is the most common and representative means,
In this case, as shown in Comparative Examples 10 and 11, which will be described later, aggregation or sedimentation occurs, making it impossible to even form a stable aqueous dispersion. That is, sulfates are roughly classified into an alkali metal salt that is easily soluble in water and an alkaline earth metal salt that is hardly soluble in water. At the same time, aggregation of the dispersed resin particles occurs, and even with the latter alkaline earth metal salt, precipitation of the added alkaline earth metal salt particles immediately occurs, and aggregation of the dispersed resin particles also gradually occurs. The formation of such agglomerates or sediments can be easily confirmed by visually observing the aqueous dispersion. However, in the aqueous dispersion of the present invention, unexpectedly, the sulfate was dissolved in the aqueous dispersion. The aqueous dispersion and the poorly water-soluble one are contained in a stable form without forming an aggregation or sediment of the aqueous dispersion.

The aqueous dispersion of the present invention, despite containing a sulfate, is remarkably excellent in dispersion stability, the average particle size of the dispersed particles is generally 300 nm or less, and the aqueous dispersion when stored at room temperature. It has a remarkably excellent preservability, such as a pot life of 100 days or more.

Further, this aqueous dispersion has an excellent effect of being able to form a film having excellent wettability while having water resistance, without impairing the water resistance of the film. Hydrophilicity can be imparted. That is,
With reference to the examples described below, when the aqueous dispersion of the present invention is used for forming a film, the contact angle with water is reduced as compared to the case where the same aqueous dispersion is used except that it does not contain a sulfate,
It is also understood that it has the effect of increasing the wetting tension with water.

The aqueous dispersion of the present invention is an ethylene / unsaturated carboxylic acid copolymer (A) having an unsaturated carboxylic acid content of 5 to 30% by weight, and is capable of neutralizing carboxyl groups of the copolymer (A). An alkali metal compound serving as a source of the counter cation (B), a compound (B ′) selected from ammonia and an alkanolamine, and a sulfate (C) are dissolved in water,
It is produced by mixing at a temperature equal to or higher than the melting point of the copolymer (A). Under the above mixing conditions, a stable aqueous dispersion can be obtained even when a water-insoluble salt such as calcium sulfate or barium sulfate is used. It is presumed to have an effect.

The ethylene-unsaturated carboxylic acid copolymer serving as the base polymer of the aqueous dispersion of the present invention has an unsaturated carboxylic acid content of 5 to 30% by weight, preferably 10 to 30% by weight.
〜30% by weight of the copolymer. If the content of unsaturated carboxylic acid in the copolymer is too small, it is difficult to obtain a dispersion having good water dispersibility, while if the content of unsaturated carboxylic acid is larger than the above range, stable aqueous dispersion is obtained. Not only is it not possible to obtain a liquid, but also the water resistance and mechanical strength of the formed coating film decrease, which is not preferable.

Such an ethylene / unsaturated carboxylic acid copolymer is not only a binary copolymer of ethylene and an unsaturated carboxylic acid, but also a multi-component copolymer obtained by optionally copolymerizing other monomers. The optional monomer may be, for example, 0 to 3
It may be copolymerized in an amount of 0% by weight, preferably 0-20% by weight.

Here, examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, itaconic anhydride, monomethyl maleate, monoethyl maleate and the like. be able to. Particularly preferred is acrylic acid or methacrylic acid.

Other monomers that may optionally be copolymerized include vinyl esters such as vinyl acetate and vinyl propionate, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, and the like. N-butyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate,
Examples include unsaturated carboxylic acid esters such as ethyl methacrylate, isobutyl methacrylate, dimethyl maleate, and diethyl maleate, carbon monoxide, sulfur dioxide, and the like.

The ethylene / unsaturated carboxylic acid copolymer also has a melt flow rate (MFR) at 190 ° C. under a load of 2160 g of 10 to 10,000 g / 10 min.
It is desirable to use one having a range of 20 to 5000 g / 10 minutes. That is, when using a very low melt flow rate, it is difficult to obtain a good aqueous dispersion, and when using a very large value, the strength of the coating film obtained from the aqueous dispersion Is not preferred because of the shortage.

These ethylene copolymers can be obtained by copolymerizing the constituting monomers by a high-pressure radical polymerization method.

In the aqueous dispersion of the present invention, the ethylene / unsaturated carboxylic acid copolymer (A) is a counter cation (B) capable of neutralizing its carboxyl group.
Is finely dispersed in water. Counter cations (B) include alkali metal ions such as lithium, sodium and potassium, ammonia, monoalkanolamines such as ethanolamine and isopropanolamine, dialkanolamines such as diethanolamine, and trialkanolamines such as triethanolamine. Is an ion. These counter cations are formed by using an alkali metal hydroxide such as lithium hydroxide, sodium hydroxide, or potassium hydroxide, concentrated ammonia water, various alkanolamines, etc. when preparing the aqueous dispersion. Can be done.

The counter cation is preferably present in an amount which neutralizes at least 30% mol based on the carboxyl group of the copolymer (A), although it depends on the kind of the counter cation. In particular, only an alkali metal ion is used as the counter cation. In the case where 3 is used, 3 based on the carboxyl group of the copolymer (A)
In order to obtain an aqueous dispersion having good dispersibility, it is desirable that the aqueous dispersion be present in an amount of 0 mol% or more, preferably 40 mol% or more, and among these, an aqueous dispersion which forms a coating film having relatively excellent water resistance. In order to obtain, it is desirable to limit the amount to 70 mol% or less, particularly to 60 mol% or less.

When the counter cation is an ion of ammonia or alkanolamine, 70 to 120 moles based on the carboxyl group of the copolymer (A) is required to obtain an aqueous dispersant having good dispersibility. %, Especially 75 ~
It is desirable to have an amount corresponding to 100 mole% neutralization.

When an alkali metal ion and an ion of ammonia or an alkanolamine are used in combination as the counter cation, the amount of the counter cation should be determined according to the ratio of the two, for example, based on the carboxyl group of the copolymer (A). 10 to 70 mol% of alkali metal ions and 10 to 120 mol of ammonia or alkanolamine ions.
An amount corresponding to mole% neutralization may be present.

The counter cation may further include ions of alkaline earth metals such as magnesium, calcium and barium, and ions of polyvalent metals such as zinc, copper, cobalt and aluminum. In this case, based on the carboxyl group of the copolymer (A), for example, alkali metal ions, ammonium ions, or a mixture of these ions is 40 mol% or more, preferably 45 to 90 mol%, and the polyvalent metal ion is 1 mol. %, Preferably 5 to 90 mol%, more preferably 10 to 80 mol%.

The aqueous dispersion of the present invention contains a sulfate (C) in addition to the ethylene / unsaturated carboxylic acid copolymer (A) and the counter cation (B).
Examples of the sulfate (C) include alkali metal sulfates such as lithium sulfate, sodium sulfate, potassium sulfate, cesium sulfate, rubidium sulfate, lithium hydrogen sulfate, sodium hydrogen sulfate, and potassium hydrogen sulfate, magnesium sulfate, calcium sulfate, and barium sulfate. Such as alkaline earth metal sulfates, manganese sulfate, iron sulfate, cobalt sulfate, nickel sulfate, zinc sulfate, aluminum sulfate, ruthenium sulfate,
Rhodium sulfate, palladium sulfate, silver sulfate, cadmium sulfate, lead sulfate, ammonium sulfate, or a compound thereof. Of these, the use of alkali metal sulfates or alkaline earth metal sulfates is preferred, and the use of alkali metal sulfates is particularly preferred.

The proportion of the sulfate (C) used is about 0.1 to 15 parts by weight per 100 parts by weight of the copolymer (A),
In particular, it is preferably about 0.2 to 10 parts by weight. That is, if the amount is too small, the effect of improving the hydrophilicity is small, while the effect of improving the hydrophilicity is not significantly changed even if the amount is excessively used, and the stability of the aqueous dispersion is impaired with an increase in viscosity. become.

The aqueous dispersion of the present invention has an average particle size of dispersed particles of 300 nm or less, preferably 5 to 100 nm, and a solid concentration of 5 to 50% by weight, preferably 10 to 40% by weight. Range. That is, by having such properties, an aqueous dispersion having an appropriate solution viscosity, being stable, and having excellent uniformity of a coating film is obtained.

[0027] Such aqueous dispersions also have a pot life of 100 days or more. Here is pot life
When the aqueous dispersion is allowed to stand, the presence or absence of precipitation, aggregation, or gelation is visually checked, and refers to a period in which the appearance does not change. The aqueous dispersion of the present invention has a pot life of 100 days or more regardless of whether a water-soluble or water-insoluble sulfate is used.

The aqueous dispersion of the present invention has a viscosity of 5 to 1000 mPa · s, preferably 10 to 500 mP.
a · s, and the pH is in the range of 9.5 to 12, preferably 10 to 11.5.

The following method can be used to produce the above-mentioned aqueous dispersion having a stable and small particle size. That is, a raw material ethylene / (meth) acrylic acid copolymer, a source of a counter cation selected from an alkali metal compound, ammonia and alkanolamine, and a sulfate,
Use a predetermined amount of each, 100 ℃ or more, preferably 130 ~ 1
It is obtained by reacting in water at a temperature of 60 ° C. while applying a shearing force.

As the alkali metal compound, hydroxide,
Carbonates, bicarbonates, carboxylate and the like can be exemplified. By employing such a method, the sulfate is finely dispersed and a stable aqueous dispersion can be obtained.

Such an aqueous dispersion can also be obtained by a method in which a low-concentration aqueous solution of a sulfate is added to an aqueous dispersion comprising a copolymer (A) and a counter cation (B) and mixed. However, considering the solid concentration, uniformity, long-term stability of the dispersion, and the like, it is desirable to employ the above method. In particular, when a water-insoluble sulfate is used, it is very difficult to produce a stable aqueous dispersion by such a method.

Various additives can be optionally added to the aqueous dispersion of the present invention. Examples of such additives include antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, plasticizers, pigments, dyes, lubricants, antiblocking agents, adhesives, crosslinkers, reinforcing agents, thickeners Agents, foaming agents, antibacterial agents, fungicides, writability improvers, inorganic fillers and the like.

The aqueous dispersion of the present invention comprises a coating agent,
A film can be formed by applying it to various substrates as an adhesive, an ink material, or the like.

The aqueous dispersion of the present invention may be modified with another polymer dispersion, or mixed with the other polymer dispersion at an arbitrary ratio for the purpose of modifying the other polymer dispersion. Can be. Generally, it is 10 / in terms of solid content (weight ratio).
It is preferable to mix at a ratio of 90 to 90/10, particularly 20/80 to 80/20.

Examples of such other polymer aqueous dispersions include those having a pH of 7 or more, or aqueous ammonia or the like.
It is necessary to select a material having H of 7 or more, which does not gel when mixed with the aqueous dispersion of the present invention. The solid content concentration is 2 to 60%, preferably about 5 to 50%, and the average particle size is 1 to 60%.
It is desirable to select one having a thickness of 10,000 nm, preferably 5 to 500 nm.

Examples of such other polymer aqueous dispersions include polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, water-soluble acrylic resin, acrylamide resin, methacrylamide resin, and the like. Acrylonitrile resin, methacrylonitrile resin, styrene / acrylic acid copolymer, water-soluble polyurethane resin, water-soluble styrene / maleic acid copolymer, styrene / butadiene copolymer, high impact polystyrene resin, butadiene resin, polyester resin, acrylonitrile・ Butadiene copolymer, polyethylene, polyethylene oxide, propylene / ethylene copolymer, maleic anhydride grafted polyolefin, chlorinated polyethylene, chlorinated polypropylene, EPDM, phenolic resin, silicone resin, epoxy It can be exemplified an aqueous dispersion of butter, and the like. Of course, two or more of these may be used.

The aqueous dispersion of the present invention or a mixed aqueous dispersion of this and another polymer aqueous dispersion can be applied to any substrate. As such a substrate, high,
Medium, low density polyethylene, ethylene / α-olefin copolymer, ethylene / vinyl acetate copolymer, ethylene /
(Meth) acrylic acid ester copolymer, ethylene / (meth) acrylic acid copolymer or ionomer thereof, ethylene / (meth) acrylic acid / (meth) acrylic acid ester copolymer or ionomer thereof, polypropylene, poly-1 Styrene polymers such as olefin polymers or copolymers such as butene, poly-4-methyl-1-pentene, polystyrene, high impact polystyrene, ABS type resins, styrene / butadiene block copolymers or hydrogenated products thereof Thermoplastic polymers such as polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 66, polycarbonates, polyvinyl chloride, and mixtures thereof in any proportion; rubbers such as natural rubber and synthetic rubber Material, phenolic resin Thermosetting resin, iron, such as polyurethane, copper, aluminum, metal such as stainless steel,
Examples thereof include natural materials such as wood, paper, rayon, and leather. For thermoplastic polymers, films,
The present invention can be applied to various molded products such as a sheet, a hollow molded product, an injection molded product, a woven fabric, a nonwoven fabric, and a synthetic leather.

For applying the aqueous dispersion to the substrate, a known method, for example, roll coating, brush coating, spray coating or the like can be adopted. The base material may be coated with an undercoating agent for the purpose of improving adhesiveness or the like, or may be subjected to a surface treatment such as a corona treatment. The thickness of the coating film is arbitrary, but is usually 1 to 20 μm, preferably 1 to 10 μm. The coating film may be subjected to a crosslinking treatment by electron beam irradiation for the purpose of improving water resistance, durability and the like.

[0039]

According to the present invention, an aqueous dispersion containing a sulfate and having excellent storage stability can be provided. Since the coating film obtained from such an aqueous dispersion has improved hydrophilicity as compared with the coating film obtained from the one without the addition of sulfate, it is necessary to form a coating film having both excellent water resistance and hydrophilicity. Is possible. Therefore, it can be used in the fields of various coating agents, adhesives, ink materials and the like.

[0040]

The present invention will be described below in detail with reference to examples. The types, physical properties, and measuring methods of the aqueous dispersions constituting the aqueous dispersions used in the examples and comparative examples are as follows.

Ethylene / unsaturated carboxylic acid copolymer (A) In the following copolymer, E represents an ethylene unit, MAA represents a methacrylic acid unit, and AA represents an acrylic acid unit. Copolymer 1: E / 20% MAA (MFR: 60) Copolymer 2: E / 20% MAA (MFR: 500) Copolymer 3: E / 15% MAA (MFR: 60) Copolymer 4: E / 20% AA (MFR: 300) Copolymer 5: E / 15% AA (MFR: 60)

Counter cation (B) Cation 1: KOH (purity 86%) Cation 2: NaOH manufactured by Wako Pure Chemical Co., Ltd. Cation 3: NH ₃ aqueous solution (29% concentration) manufactured by Kanto Chemical Co., Ltd.

Sulfate (C) Sulfate 1: K ₂ SO ₄ manufactured by Wako Pure Chemical Industries, Ltd. Sulfate 2: Na ₂ SO ₄ manufactured by Wako Pure Chemical Industries, Ltd. Sulfate 3: NaHSO ₄ manufactured by Wako Pure Chemical Industries, Ltd. Sulfate 4: BaSO ₄ Sulfate manufactured by Wako Pure Chemical Co., Ltd. 5: CaSO ₄ Sulfate manufactured by Wako Pure Chemical Co., Ltd. Sulfate 6: (NH ₄ ) ₂ SO ₄ manufactured by Wako Pure Chemical Co., Ltd.

Metal salt Metal salt 1: ZnO metal salt 2: Ca (OH) ₂

Other emulsion type Manufacturer name pH average particle size Solid content (μm) Concentration (wt%) Emulsion Chlorinated PP Toyo Kasei Co., Ltd. 9 0.5 21 1 Emulsion Emulsion VAE Sumitomo Chemical Co., Ltd. 5.5 0.8 65 2 Emulsion

Evaluation method of dispersion pH JIS K6833 compliant Particle size Laser light scattering type particle size distribution analyzer NICOMP 3
70 HPL

Substrate Biaxially oriented polyethylene terephthalate (OPET) Thickness: 50 μm

Evaluation method of coating film Wetting tension (mN / m) JIS K6768 compliant Contact angle JIS K2396 compliant Apparatus: contact angle meter CA-S micro type 2 (manufactured by Kyowa Interface Chemistry) Test temperature: 23 ° C. Test solution: Mizumoto Using a device, the contact angle of a water droplet on the coating film surface was measured. Water resistance The coated film applied to the base material is immersed in tap water for 1 hour, and the presence or absence of peeling / rupture of the coated film is visually evaluated. ：: No change in appearance. ×: Peeling / breaking of the coating film occurs.

[Examples 1 to 15] The copolymer (A), the cation (B) and the sulfate (C) were charged into a 300 ml autoclave at the compounding ratio shown in Table 1, and stirred at 150 ° C for 1 hour to disperse. Got John. The prepared dispersion was applied to stretched PET, and the wettability and contact angle of the coating film surface were evaluated. Table 2 shows the results. Although the wettability varies slightly depending on the type of base resin,
It exhibited high wetting tension of over 40 mN / m and low contact angle. The water resistance was also satisfactory.

[Examples 16 and 17] The dispersion and the emulsion described in Example 1 were blended in the mixing ratio shown in Table 1.
The prepared blend liquid was applied to stretched PET, and the wettability and contact angle of the coating film surface were evaluated. The results are shown in Table 2. The water resistance of the coating film as well as the high wetting tension of 40 mN / m or more and the low contact angle were all exhibited.

Comparative Examples 1 to 6 The copolymer (A) and the cation (B) were charged into a 300 ml autoclave at the compounding ratio shown in Table 1, and stirred at 150 ° C. for 1 hour to obtain a dispersion. The prepared dispersion is stretched PET
And the wettability and contact angle of the coating film surface were evaluated. Table 2 shows the results. Although there is a slight difference in wettability depending on the type of base resin, all are 30 mN /
Only low m wet tension and high contact angles were shown.
There was no problem with water resistance.

Comparative Examples 7 and 8 In Example 1, metal salts 1 and 2 were used in the amounts shown in Table 1 in place of the sulfonate salt 1. The prepared dispersion was applied to Nobunaka PET, and the wettability and contact angle of the coating film surface were evaluated. The results are summarized in Table 2, all of which showed only a low wetting tension and contact angle on the order of 30 mN / m.

Comparative Example 9 In Comparative Example 1, cation 1 was used in an amount corresponding to a degree of neutralization of 90%. The prepared dispersion was applied to stretched PET, and the wettability and contact angle of the coating film surface were evaluated. The results are summarized in Table 2. As a result, although high wetting tension of 40 mN / m or more and low contact angle were exhibited, water resistance was insufficient.

Comparative Examples 10 and 11 In Example 1, the sulfate (C) was added later. Table 2 shows the results.
In Comparative Example 10, suspicion occurred immediately, and in Comparative Example 11, the added calcium sulfate precipitated immediately, and aggregation occurred several days later.

[0055]

Table 1 Composition resin concentration copolymer (A) Cation (B) Sulfate (C) (%) [Degree of neutralization,%] * a [Addition amount,%] * b Example 1 Copolymer 1 Cation 1 [50] Sulfate 1 [5] 20 Example 2 Copolymer 1 Cation 1 [50] Sulfate 2 [5] 20 Example 3 Copolymer 1 Cation 1 [50] Sulfate 3 [5] 20 Example 4 Copolymer 1 Cation 1 [50] Sulfate 4 [5] 15 Example 5 Copolymer 1 Cation 1 [50] Sulfate 5 [5] 15 Example 6 Copolymer 1 Cation 1 [50] Sulfate 6 [5] 15 Example 7 Copolymer 1 Cation 2 [50] Sulfate 1 [5] 15 Example 8 Copolymer 1 Cation 1 [15] Sulfate 1 [5] 15 / Cation 3 [90 Example 9 Copolymer 2 Cation 1 [50] Sulfate 1 [5] 15 Example 10 Copolymer 3 Cation 1 [ 0] Sulfate 1 [5] 10 Example 11 Copolymer 4 Cation 1 [50] Sulfate 1 [5] 20 Example 12 Copolymer 4 Cation 3 [90] Sulfate 1 [5] 20 Example 13 Copolymer 5 Cation 1 [50] Sulfate 1 [5] 10 Example 14 Copolymer 1 Cation 1 [50] Sulfate 1 [1] 20 Example 15 Copolymer 1 Cation 1 [50] Sulfate 1 [7.5] 15 Example 16 Example 1 / Emulsion 1 (based on 1/1 resin) Example 17 Example 1 / Emulsion 2 (based on 1/1 resin) Comparative Example 1 Copolymer 1 Cation 1 [50] 25 Comparison Example 2 Copolymer 1 Cation 2 [50] 25 Comparative Example 3 Copolymer 3 Cation 1 [50] 25 Comparative Example 4 Copolymer 4 Cation 1 [50] 25 Comparative Example 5 Copolymer 4 Cation 3 [90] 25 Comparative Example 6 Copolymer 5 Cation 1 [50] 25 Ratio Comparative Example 7 Copolymer 1 Cation 1 [50] Metal Salt 125 Comparative Example 8 Copolymer 1 Cation 1 [50] Metal Salt 2 25 Comparative Example 9 Copolymer 1 Cation 1 [90] 25 Comparative Example 10 * c Copolymer 1 Cation 1 [50] Sulfate 1 [5] 20 Comparative Example 11 * c Copolymer 1 Cation 1 [50] Sulfate 5 [5] 20 * a: Neutralization of copolymer to all carboxylic acids Every time. * B: The amount added to the weight of the copolymer. * C: An aqueous solution of sulfate was added later.

[0056]

[Table 2] Aggregation pot pH Average particle size Contact angle Wetting tension Water resistant sediment Life (nm) (゜) (mN / m) Example 1 N / A 100 days or more 10.6 2877 45 ○ Example 2 N / A 100 days or more 10.1 42 79 44 ○ Example 3 None 100 days or more 9.8 44 80 46 ○ Example 4 None 100 days or more 10 16 80 50 ○ Example 5 None 100 days or more 9.8 30 80 42 ○ Example 6 None 100 days or more 9.5 40 79 46 ○ Example 7 None 100 days or more 10.1 19 70 46 ○ Example 8 None 100 days or more 10.1 22 78 46 ○ Example 9 None 100 days or more 9.9 17 73 48 ○ Example 10 None 100 days or more 10.6 28 80 40 ○ Example 11 None 100 days or more 9.2 26 60 54 ○ Example 12 None 100 days or more 9.8 128 79 46 ○ Example 13 None 100 days or more 10.5 14 68 46 ○ Example 14 None 100 days or more 10 17 80 50 ○ Example 15 None 100 days or more 9.7 14 80 48 ○ Example 16 None 100 days or more--8043 ○ Example 17 None 100 days or more--80 42 ○ Comparative Example 1 None 100 days or more 10.8 18 85 37 ○ Compare Example 2 None 100 days or more 10.5 19 90 36 ○ Comparative Example 3 None 100 days or more 10.1 14 90 37 ○ Comparative Example 4 None 100 days or more 9.8 18 87 36 ○ Comparative Example 5 None 100 days or more 9.9 75 86 35 ○ Comparative Example 6 None 100 days or more 9.7 16 85 35 ○ Comparative Example 7 None 100 days or more 10 20 85 36 ○ Comparative Example 8 None 100 days or more 10.2 21 82 39 ○ Comparative Example 9 None 100 days or more 11.1 16 70 50 × Comparative Example 10 Ali 0 Day -----Comparative Example 11 Ants 7 days or less 9.7 102---

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 123/08 F term (Reference) 4F070 AA13 AA29 AC14 AC20 AC46 CA14 CA18 CB12 4F100 AA02B AA07B AK42 AK70B AT00A BA02 CC01 DE01B EH46B JB05 JB07 JM01B YY00B 4J002 BB081 BB091 DE056 DF006 DG047 EN106 GH00 GJ00 HA06 4J038 CB061 GA06 GA13 MA02 MA08 MA10 MA14 PA07 PB03

Claims (11)

[Claims] An unsaturated carboxylic acid content of 5 to 30% by weight.
Containing an ethylene / unsaturated carboxylic acid copolymer (A), a counter cation (B) capable of neutralizing a carboxyl group of the copolymer (A) and a sulfate (C), and substantially preventing aggregation or sediment. An aqueous dispersion characterized by not containing. 2. The aqueous dispersion according to claim 1, wherein the average particle size of the dispersion is 300 nm or less. 3. The aqueous dispersion according to claim 1, wherein the pot life is 100 days or more. 4. Sulfate (C) is added to copolymer (A) 100
The aqueous dispersion according to claim 1, which is contained in an amount of 0.1 to 15 parts by weight per part by weight. 5. The aqueous dispersion according to claim 1, wherein the amount of the counter cation (B) is at least 30 equivalent% based on the carboxyl group of the copolymer (A). 6. The aqueous dispersion according to claim 5, wherein the counter cation (B) is an alkali metal ion and is present in an amount of 30 to 70 equivalent% based on the carboxyl group of the copolymer (A). . 7. The method according to claim 5, wherein the counter cation (B) is an ion of ammonia or an alkanolamine, and is present in an amount of 70 to 120 equivalent% based on the carboxyl group of the copolymer (A). Aqueous dispersion of 8. The method according to claim 1, wherein the counter cation (B) is an alkali metal ion in an amount of 10 to 70 equivalent% and an ammonia or alkanolamine in an amount of 10 to 120 equivalent% based on the carboxyl group of the copolymer (A). The aqueous dispersion according to claim 5, comprising an ion. 9. An unsaturated carboxylic acid content of 5 to 30% by weight.
Ethylene / unsaturated carboxylic acid copolymer (A), an alkali metal compound serving as a source of a counter cation (B) capable of neutralizing a carboxyl group of the copolymer (A), a compound selected from ammonia and alkanolamine (B ′) and a sulfate (C) are prepared by copolymerizing the copolymer (A) in water.
Mixing at a temperature equal to or higher than the melting point of the aqueous dispersion. 10. A mixed aqueous dispersion comprising a mixture of the aqueous dispersion according to claim 1 and an aqueous dispersion of another polymer. 11. A laminate comprising applying the aqueous dispersion according to any one of claims 1 to 8 or the mixed aqueous dispersion according to claim 10 to a substrate to form a coating film. body.