JP5323321B2 - Aqueous dispersion and method for producing the same - Google Patents

Description

  The present invention relates to an aqueous dispersion mainly composed of polypropylene having a low crystallinity and a method for producing the same.

Conventionally, when a polyolefin resin molded body is coated or bonded, a solvent containing a chlorinated polyolefin in a solvent has been often used. However, in consideration of recent environmental problems, a water-based dispersion that can be used as a component of a paint or adhesive containing no solvent or chlorine, or a primer is required.
Therefore, Patent Document 1 proposes an aqueous dispersion having an acid-modified polyolefin, a modified starch, and an emulsifier, and having a pH of 6 or more.
JP 2004-285227 A

However, the aqueous dispersion described in Patent Document 1 did not exhibit as much adhesion as a solvent-type paint or adhesive. In particular, when the substrate was a polypropylene molded body, the adhesion was low. In addition, the aqueous dispersion described in Patent Document 1 has insufficient water resistance of the resulting film.
The present invention has been made in view of the above circumstances, and although it does not contain an organic solvent and a chlorine atom-containing polymer, it has sufficient adhesion, particularly high adhesion to a polypropylene molded article, and the water resistance of the resulting coating is high. An object is to provide an aqueous dispersion having excellent properties and a method for producing the same.

The present invention includes the following aspects.
[1] Polyolefin (A), 5 to 20 parts by mass of acid-modified polyolefin (B) with respect to 100 parts by mass of polyolefin (A), and 1 to 10 parts by mass of anion with respect to 100 parts by mass of polyolefin (A) An aqueous dispersion containing a type surfactant (C) and 0.5 to 20 parts by mass of water (D),
Polyolefin (A) are propylene units of consists of 8 0 to 99 wt% and 20 wt% alpha-olefin units other than propylene units, alpha-olefin unit containing 1-butene units, and the crystallization The degree is 0.1 to 16%,
An aqueous dispersion, wherein the acid-modified polyolefin (B) has a weight average molecular weight of 1,800 to 35,000 and an acid value of 3 to 80 mg / g.
[2] The aqueous dispersion according to [1], wherein the acid-modified polyolefin (B) is acid-modified propylene.
[3] The aqueous dispersion according to [1] or [2], wherein the anionic surfactant (C) is an alkali metal salt of a higher fatty acid having 10 to 20 carbon atoms .
[4] Polyolefin (A), 5 to 20 parts by mass of acid-modified polyolefin (B) with respect to 100 parts by mass of polyolefin (A), and 1 to 10 parts by mass of anion with respect to 100 parts by mass of polyolefin (A) A step of melt-kneading the mold surfactant (C) to obtain a kneaded product,
A method for producing an aqueous dispersion, comprising adding 0.5 to 20 parts by mass of water (D) to 100 parts by mass of polyolefin (A), and further melt-kneading the kneaded product,
As the polyolefin (A), propylene Unit consists of 8 0 to 99 wt% and 20 wt% alpha-olefin units other than propylene units, alpha-olefin unit containing 1-butene units, and the crystallization Using a degree of 0.1 to 16%,
A method for producing an aqueous dispersion, wherein the acid-modified polyolefin (B) has a weight average molecular weight of 1,800 to 35,000 and an acid value of 3 to 80 mg / g.

Although the aqueous dispersion of the present invention does not contain an organic solvent and a chlorine atom-containing polymer, the aqueous dispersion has sufficient adhesion, particularly adhesion to a polypropylene molded article, and is excellent in water resistance of the resulting film.
According to the method for producing an aqueous dispersion of the present invention, although it does not contain an organic solvent and a chlorine atom-containing polymer, sufficient adhesion, particularly adhesion to a polypropylene molded article is high, and the resulting coating has water resistance. An excellent aqueous dispersion can be produced.

"Aqueous dispersion"
The aqueous dispersion of the present invention contains a polyolefin (A), an acid-modified polyolefin (B), an anionic surfactant (C), and water (D).

(Polyolefin (A))
The polyolefin (A) contains propylene units in an amount of 80 to 99% by mass, preferably 87 to 99% by mass. When the propylene unit content in the polyolefin (A) is less than 80% by mass, the resulting aqueous dispersion has low adhesion when applied to a polypropylene molded product, and the water resistance of the resulting coating is low. descend. When the propylene unit content exceeds 99% by mass, the adhesion, particularly the adhesion of polypropylene to a molded article is lowered, and the water resistance of the resulting coating is lowered.

The crystallinity of the polyolefin (A) is 0.1 to 16%, preferably 0.1 to 8.0%. If the crystallinity of the polyolefin (A) exceeds 16%, the adhesion and water resistance of the resulting aqueous dispersion will be low, and even if it is less than 0.1%, the adhesion and water resistance of the resulting aqueous dispersion will be low. Low.
As a method for producing the polyolefin (A) with controlled crystallinity, it is preferable to use a metallocene catalyst. Examples of the metallocene catalyst include transition metal complexes of Groups 4 to 6 of the periodic table having at least one cyclopentadienyl skeleton. For example, a metallocene catalyst described in JP-A-9-151205 can be used.

The composition of the polyolefin (A) can be adjusted by appropriately changing the supply composition of propylene and the other α-olefin during polymerization of the polyolefin (A).
The weight average molecular weight of the polyolefin (A) can be adjusted by supplying hydrogen gas during the polymerization and appropriately changing the supply amount.

(Acid-modified polyolefin (B))
Examples of the acid-modified polyolefin (B) include a modified product in which a carboxylic acid or a carboxylic acid anhydride is bonded to a homopolymer or copolymer of an α-olefin. Examples of the carboxylic acid include (meth) acrylic acid, and examples of the carboxylic acid anhydride include maleic anhydride.
Examples of the acid-modified polyolefin (B) include acid-modified polyethylene having an acid value of 3 to 80 mg / g, acid-modified ethylene-propylene copolymer, acid-modified polypropylene, and ethylene- (meth) acrylic acid copolymer. It is done. Among these, acid-modified polypropylene is preferable because adhesion to a polypropylene molded body becomes higher.
Acid-modified polyolefin (B) may be used individually by 1 type, and may use 2 or more types together.

  The weight average molecular weight of the acid-modified polyolefin (B) is 1,800 to 35,000, preferably 1,800 to 20,000. If the weight average molecular weight of the acid-modified polyolefin (B) is less than 1,800, the polyolefin (A) cannot be dispersed, so an aqueous dispersion cannot be obtained. If it exceeds 35,000, adhesion and water resistance Sex is reduced.

  The acid value of the acid-modified polyolefin (B) is 3 to 80 mg / g, preferably 10 to 70 mg / g. The acid value here is the number of mg of potassium hydroxide required to neutralize 1 g of the modified polyolefin. If the acid value of the acid-modified polyolefin (B) is less than 3 mg / g, the polyolefin (A) cannot be dispersed, so that an aqueous dispersion cannot be obtained. If the acid value exceeds 80 mg / g, adhesion and water resistance are not obtained. Becomes lower.

  The amount of the acid-modified polyolefin (B) is 5 to 20 parts by mass, preferably 5 to 10 parts by mass with respect to 100 parts by mass of the polyolefin (A). If the amount of the acid-modified polyolefin (B) is less than 5 parts by mass, the polyolefin (A) cannot be dispersed, so an aqueous dispersion cannot be obtained. If the amount exceeds 20 parts by mass, the resulting aqueous dispersion is The particle size becomes large, and the adhesion and water resistance decrease.

(Anionic surfactant (C))
Examples of the anionic surfactant (C) include primary higher fatty acid salts, secondary higher fatty acid salts, primary higher alcohol sulfates, secondary higher alcohol sulfates, and primary higher alkyls. Sulfonates, secondary higher alkyl sulfonates, higher alkyl disulfonates, sulfonated higher fatty acid salts, higher fatty acid sulfate esters, higher fatty acid ester sulfonates, higher alcohol ether sulfates, higher alcohol ethers Examples thereof include sulfonates, alkylol sulfates of higher fatty acid amides, alkylbenzene sulfonates, alkylphenol sulfonates, alkylnaphthalene sulfonates, and alkylbenzoylimidazole sulfonates.
Higher fatty acids constituting the above anionic surfactants include capric acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, arachidic acid and other saturated fatty acids, Linderic acid, Tuzic acid, Examples include unsaturated fatty acids such as petroceric acid, oleic acid, linoleic acid, linolenic acid, and arachidonic acid, and mixtures thereof.
Examples of elements for forming salts with higher fatty acids include alkali metals such as sodium and potassium.
An anionic surfactant may be used individually by 1 type, and may be used in combination of 2 or more type. Among these anionic surfactants, potassium tallow fatty acid and potassium oleate are more preferable from the viewpoint of water resistance.

  The amount of the anionic surfactant (C) is 1 to 10 parts by mass, preferably 2 to 5 parts by mass with respect to 100 parts by mass of the polyolefin (A). When the amount of the anionic surfactant (C) is less than 1 part by mass, the dispersion stability of the aqueous dispersion is lowered, and when it exceeds 10 parts by mass, adhesion and water resistance are lowered.

(Water (D))
Water (D) in the aqueous dispersion is water necessary for phase inversion, and is 0.5 to 20 parts by mass with respect to 100 parts by mass of the polyolefin (A).
In addition, solid content concentration of the aqueous dispersion whose quantity of water (D) is the said range is 84 mass% or more, and is substantially solid. Therefore, in order to apply the existing coating method to this aqueous dispersion, or to make it easy to mix other chemicals, 50 parts by mass or more is added to the aqueous dispersion for the purpose of adjusting the viscosity to an appropriate range. It is preferable to add dilution water and dilute to obtain an aqueous dispersion having a solid content concentration of 10 to 60% by mass.

(Auxiliary materials)
The aqueous dispersion may contain various auxiliary materials as necessary. Secondary materials include, for example, dispersants such as cationic surfactants and nonionic surfactants, emulsifiers, stabilizers, wetting agents, thickeners, foaming agents, antifoaming agents, gelling agents, and anti-aging agents. Agents, softeners, plasticizers, fillers, colorants, flavoring agents, anti-tacking agents, mold release agents, film-forming aids, leveling agents and the like.

The aqueous dispersion described above contains the acid-modified polyolefin (B), which is presumed to have an effect of uniformly dispersing the surfactant in the stage before phase inversion. As a result of the uniform dispersion of the surfactant, the polyolefin (A) is dispersed in water with an average particle diameter of less than 1 μm even if the content of the anionic surfactant (C) is as small as 1 to 10 parts by mass. Can be made. As a result, the adhesion of the aqueous dispersion to the substrate can be improved, and the water resistance of the resulting coating can be improved.
In addition, since the aqueous dispersion uses water as a dispersion medium, there are few environmental problems and excellent handleability.

(how to use)
The aqueous dispersion is used by being applied to various substrates. Examples of the substrate include paper, fiber fabric, plastic molded product, wood, metal, and the like. Among these, high adhesiveness of the aqueous dispersion is remarkably exhibited for plastic molded products, particularly polypropylene molded products. The polypropylene molded product includes various additives such as other polyolefins (for example, ethylene / propylene copolymer rubber), inorganic fillers (for example, talc, glass fiber, calcium carbonate, etc.), stabilizers, and coloring agents. Even if it is, the effect exhibited is equivalent.
As a coating method of the aqueous dispersion, for example, a method using various coating machines, a method using a spray, a brush coating, or the like can be employed.

"Method for producing aqueous dispersion"
The method for producing an aqueous dispersion of the present invention comprises a step of melting and kneading a mixture containing a polyolefin (A), an acid-modified polyolefin (B) and an anionic surfactant (C) to obtain a kneaded product (hereinafter referred to as “first”). And after adding water (D) to the kneaded product, it is further melt-kneaded (hereinafter referred to as the second step).

(First step)
The blending amount of the acid-modified polyolefin (B) in the first step is 5 to 20 parts by mass with respect to 100 parts by mass of the polyolefin (A), similarly to the content of the acid-modified polyolefin (B) in the aqueous dispersion. , Preferably it is 5-10 mass parts.
The compounding quantity of an anionic surfactant (C) is 1-10 mass parts with respect to 100 mass parts of polyolefin (A) similarly to content of the anionic surfactant (C) in an aqueous dispersion, Preferably it is 2-5 mass parts.

When the polyolefin (A), the acid-modified polyolefin (B), and the anionic surfactant (C) are melt-kneaded, for example, a kneader, a Banbury mixer, or a multi-screw extruder can be applied.
The melt-kneading conditions are appropriately selected depending on the physical properties of the polyolefin (A), but the melt-kneading temperature is preferably 160 ° C to 250 ° C. If the melt kneading temperature is 160 ° C. or higher, the melt viscosity is sufficiently low so that it can be easily kneaded. Energy consumption can be reduced.

(Second step)
In the second step subsequent to the first step, water (D) is injected into the kneaded product obtained in the first step, and water is added to the resin solids containing the polyolefin (A) and the acid-modified polyolefin (B). Containing. In the addition of water (D), only water may be added, or it may be added in the form of an aqueous solution in which other additive components are dissolved. As other additive components, alkaline components such as potassium hydroxide, sodium hydroxide and organic amines are preferable because the acid-modified polyolefin (B) -derived acid can be neutralized to produce an aqueous dispersion more easily.
The amount of water (D) added is preferably 0.5 to 20 parts by mass and more preferably 2 to 10 parts by mass with respect to 100 parts by mass of the polyolefin (A). If the amount of water (D) added is less than 0.5 parts by mass, an aqueous dispersion cannot be obtained, and if it exceeds 20 parts by mass, the average particle size of the resin solid content of the aqueous dispersion becomes large and adheres. And water resistance are lowered.

In the melt-kneading in the second step, the phase is changed from a state in which the resin solid content contains water to a state in which the resin solid content is dispersed in water.
Also in the melt-kneading in the second step, a kneader, a Banbury mixer, and a multi-screw extruder can be applied as in the first step.
The melt kneading temperature in the second step is preferably 160 to 250 ° C. as in the first step. If the melt kneading temperature is 160 ° C. or higher, phase inversion can be easily performed, and if it is 250 ° C. or lower, the resin is not heated more than necessary. Can be reduced.

  After completion of the second step, it is preferable to further add water to the obtained aqueous dispersion to obtain a diluted aqueous dispersion. If water is added, the viscosity of the aqueous dispersion decreases and the fluidity increases. Further, the amount of water to be added is appropriately selected depending on the purpose and method of use of the aqueous dispersion, but is preferably such that the solid content concentration of the aqueous dispersion is in the range of 10 to 60% by mass.

In other production methods other than the present invention, it is difficult to obtain an aqueous dispersion having a small average particle diameter of about 0.1 to 1 μm when the amount of the surfactant is as small as 1 to 10 parts by mass. However, according to the method for producing an aqueous dispersion, an aqueous dispersion having a small average particle diameter of about 0.1 to 1 μm can be obtained even with a small amount of surfactant of 1 to 10 parts by mass. This is presumed to be because the acid-modified polyolefin (B) used in this production method exhibits the effect of microdispersing the surfactant at the stage where the polyolefin (A) before phase inversion is a continuous phase. The Accordingly, the acid-modified polyolefin (B) is an essential component in the production method. On the other hand, other dispersion methods show only a slight viscosity reduction effect and are not essential.
Moreover, the coating film formed from the aqueous dispersion obtained by the said manufacturing method becomes what was excellent in adhesiveness and water resistance.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to a following example. In the following examples, “%” means “mass%” and “part” means “part by mass”.
Moreover, the characteristics of the polyolefin and acid-modified polyolefin in the following examples were measured as follows.
-Quantification of polyolefin unit: It was determined by measuring the molar ratio with a high resolution Fourier transform nuclear magnetic resonance apparatus JNM-AL400 manufactured by JEOL Ltd.
-Weight average molecular weight of polyolefin and acid-modified polyolefin: Measured by Alliance GPC V2000, manufactured by Waters.
Polyolefin crystallinity: Determined by a wide-angle X-ray diffractometer RAD-RX manufactured by Rigaku Corporation.
Average particle size: Measured with a Microtrac UPA manufactured by Mounttech.

In the following examples and comparative examples, the following (A-1) to (A-9) were used as the component (A).
Polyolefin (A-1):
A 100 L stainless steel polymerization tank equipped with a stirrer was dried under reduced pressure, hydrogen was supplied for molecular weight adjustment, and polymerized continuously by the following method to obtain polyolefin (A-1).
From the bottom of the polymerization tank, hexane as a polymerization solvent is supplied at a rate of 100 L / hour, propylene is supplied at a rate of 20.7 kg / hour, 1-butene is supplied at a rate of 4.2 kg / hour, and hydrogen gas is 120 g. Each was continuously fed at a feed rate of / hour.
Further, 0.005 g / hour of dimethylsilyl (tetramethylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride as a component of the polymerization catalyst is supplied from the lower part of the polymerization tank. At a rate, triphenylmethyltetrakis (pentafluorophenyl) borate was continuously fed at a feed rate of 0.30 g / hr and triisobutylaluminum was fed at a feed rate of 2.32 g / hr.
At the same time, the reaction mixture was continuously extracted from the upper part of the polymerization tank so that the volume of the reaction mixture in the polymerization tank was maintained at 100 L.
The polymerization reaction was performed at 45 ° C. by circulating cooling water through a jacket provided outside the polymerization tank.
A small amount of ethanol was added to the reaction mixture continuously extracted from the upper part of the polymerization tank to stop the polymerization reaction, and the remaining hydrogen and monomers were devolatilized, followed by washing with water. Next, the solvent was removed with steam in a large amount of water, and dried under reduced pressure at 80 ° C. for one day to obtain a propylene-1-butene copolymer (polyolefin (A-1)). The production rate of the propylene-1-butene copolymer was 7.0 kg / hour.
The propylene unit content in the propylene-1-butene copolymer, which is the polyolefin (A-1), is 88%, the 1-butene unit content is 12%, the crystallinity is 6%, and the weight average molecular weight is 110%. 000.

  Polyolefin (A-2): Sumitomo Chemical manufactured by Sumitomo Chemical, which contains a crystal component only in the surface part of the pellet (15%), contains 99% propylene units, has a crystallinity of 7%, and a weight average molecular weight of 200,000 Tough selenium T3712 "was used.

  Polyolefin (A-3): As one of the polymerization catalyst components, dimethylsilyl (cyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride is used and 24.0 kg of propylene is used. Production method of polyolefin (A-1) except that 1-butene was continuously supplied at a supply rate of 1.0 kg / hour and hydrogen gas was continuously supplied at a supply rate of 100 g / hour. In the same manner, a polyolefin (A-3) having a propylene unit content of 98%, a 1-butene unit content of 2%, a crystallinity of 0.2%, and a weight average molecular weight of 102,000 is obtained. Obtained.

  Polyolefin (A-4): An amorphous α-olefin copolymer containing 85% of propylene units, having a weight average molecular weight of 56,000 and a crystallinity of 7%, manufactured by Huntsman Polymers “REXTAC RT2535” was used.

  Polyolefin (A-5): “REXTAC RT2280” manufactured by Huntsman Polymers Co., which contains 96% of propylene units, has a crystallinity of 15% and a weight average molecular weight of 69,000 was used.

  Polyolefin (A-6): As one of the polymerization catalyst components, dimethylsilyl (methylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride was used, and propylene was treated with 26. In the same manner as polyolefin (A-1) except that hydrogen gas was continuously supplied at a supply rate of 0 kg / hour and hydrogen gas was supplied at a supply rate of 80 g / hour, and 1-butene was not supplied. A certain polyolefin (A-6) was obtained. The obtained polyolefin (A-6) had a crystallinity of 7% and a weight average molecular weight of 94,000.

Polyolefin (A-7): As one of the polymerization catalyst components, dimethylsilyl (n-butylcyclopentadienyl) (3-tert-butyl-5-methyl-2-phenoxy) titanium dichloride and propylene in 20. Production method of polyolefin (A-1) except that 1-butene was supplied at a supply rate of 0 kg / hour, a supply rate of 5.0 kg / hour, and hydrogen gas was supplied continuously at a supply rate of 150 g / hour. In the same manner as above, a polyolefin (A-7) which is a propylene-1-butene copolymer was obtained.
The content of propylene units in the propylene-1-butene copolymer of polyolefin (A-7) is 85%, the content of 1-butene units is 15%, the crystallinity is 0%, and the weight average molecular weight is 96, 000.

  Polyolefin (A-8): “REXTAC RT2180” manufactured by Huntsman Polymers Co., which contains 98% propylene units, has a crystallinity of 19% and a weight average molecular weight of 71,000 was used.

  Polyolefin (A-9): “REXTAC RT2780” manufactured by Huntsman Polymers Co., which contains 62% propylene units, has a crystallinity of 7.5% and a weight average molecular weight of 68,000 was used.

As the component (B), the following (B-1) to (B-8) were used.
Acid-modified polyolefin (B-1): “TP Licocene PPMA 6252” manufactured by Clariant, which is an acid-modified polypropylene wax having an acid value of 40 mg / g and a weight average molecular weight of 3,000.
Acid-modified polyolefin (B-2): “Yumex 100TS” manufactured by Sanyo Chemical Industries, which is an acid-modified polypropylene having an acid value of 3.5 mg / g and a weight average molecular weight of 10,000.
Acid-modified polyolefin (B-3): “High Wax 2203A” manufactured by Mitsui Chemicals, which is an acid-modified polyethylene wax having an acid value of 30 mg / g and a weight average molecular weight of 2,000.
Acid-modified polyolefin (B-4): “Yumex 1010” manufactured by Sanyo Chemical Industries, which is an acid-modified polypropylene having an acid value of 52 mg / g and a weight average molecular weight of 30,000.
Acid-modified polyolefin (B-5): “Yumex 1001” manufactured by Sanyo Chemical Industries, which is an acid-modified polypropylene having an acid value of 26 mg / g and a weight average molecular weight of 40,000.
Acid-modified polyolefin (B-6): “High Wax 1105A” manufactured by Mitsui Chemicals, which is acid-modified polyethylene having an acid value of 60 mg / g and a weight average molecular weight of 1,100.
Polypropylene wax (B-7): “High Wax NP055” manufactured by Mitsui Chemicals, which is a polypropylene wax that is not acid-modified and has a weight average molecular weight of 7,000.
Acid-modified polyolefin (B-8): “Diacarna 30” manufactured by Mitsubishi Chemical, which is an α-olefin / maleic anhydride copolymer having an acid value of 110 mg / g and a weight average molecular weight of 10,000.

Example 1
To the polyolefin (A-1), 100 parts of polyolefin, 10 parts of acid-modified polyolefin (B-1), and 3 parts of potassium oleate to 100 parts of polyolefin, twin screw extruder (screw diameter; 30 mm, L / D; 40, barrel temperature; 200 ° C.) from the inlet, and melt-kneaded.
Further, a 14% potassium hydroxide aqueous solution was press-fitted at 1.8 MPa so that the amount of water relative to 100 parts of polyolefin was 4 parts from a supply port provided in the vent part of the twin-screw extruder.
Then, the solid aqueous dispersion extruded from the tip of the twin-screw extruder is dispersed in 165 parts by mass of warm water to obtain an aqueous dispersion having a solid content concentration of 40% and an average particle size of 0.21 μm. It was.

The adhesion of the obtained aqueous dispersion and the water resistance of the coating obtained from the aqueous dispersion were evaluated as follows. The results are shown in Table 1. This evaluation method was applied to other examples and comparative examples.
[Preparation of test piece]
A plate of 100 × 100 mm and a thickness of 2 mm was obtained by injection molding for “J106G” manufactured by Prime Polymer Co., which is a homo PP, and “J715M” of a block PP, respectively.
After degreasing the surface of this flat plate, No. The aqueous dispersion was applied to a thickness of 10 μm using 13 coating bars. And it dried at 70 degreeC for 20 minute (s), and left still at room temperature for 24 hours, the film was formed, and the flat plate in which the film was formed was used as a test piece.
[Adhesion test]
The cuts reaching the PP flat plate were formed on the film by a cutter so that 100 squares were formed at 1 mm intervals. Cellophane tape (registered trademark, manufactured by Nichiban Co., Ltd.) was adhered to the cells, and then peeled off, and the number of cells remaining was recorded. The greater the number of remaining cells, the better the adhesion.
[Water resistance test]
The test piece placed in a metal cage was completely immersed in warm water at 40 ° C. and left for 10 days. Then, it took out from warm water, and if the abnormality was not recognized in the external appearance, the same test as the said adhesion test was performed continuously. The greater the number of remaining cells, the better the water resistance.

(Example 2)
An aqueous dispersion having an average particle size of 0.26 μm was obtained in the same manner as in Example 1 except that 6 parts of acid-modified polypropylene wax (B-1) was added to 100 parts of polyolefin. Then, adhesion and water resistance were evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Example 3)
An aqueous dispersion having an average particle size of 0.30 μm was obtained in the same manner as in Example 2 except that the polyolefin (A-2) was used instead of the polyolefin (A-1). The results are shown in Table 1.

Example 4
An aqueous dispersion having an average particle diameter of 0.28 μm was obtained in the same manner as in Example 2 except that the polyolefin (A-3) was used instead of the polyolefin (A-1). The results are shown in Table 1.

( Reference Example 5)
An aqueous dispersion having an average particle size of 0.32 μm was obtained in the same manner as in Example 2 except that the polyolefin (A-4) was used instead of the polyolefin (A-1). The results are shown in Table 1.

( Reference Example 6)
An aqueous dispersion having an average particle size of 0.40 μm was obtained in the same manner as in Example 2 except that the polyolefin (A-5) was used instead of the polyolefin (A-1). The results are shown in Table 1.

(Example 7)
An average particle size of 0.45 μm was used in the same manner as in Example 1 except that acid-modified polyolefin (B-2) was used instead of acid-modified polyolefin (B-1) and the amount of potassium oleate was 8 parts. An aqueous dispersion was obtained. The results are shown in Table 1.

(Example 8)
An aqueous dispersion having an average particle size of 0.48 μm was obtained in the same manner as in Example 7 except that the acid-modified polyolefin (B-3) was used instead of the acid-modified polyolefin (B-2). The results are shown in Table 1.

Example 9
An aqueous dispersion having an average particle size of 0.47 μm was obtained in the same manner as in Example 7 except that the acid-modified polyolefin (B-4) was used instead of the acid-modified polyolefin (B-2). The results are shown in Table 1.

(Example 10)
Example 1 except that the amount of the acid-modified polyolefin (B-1) was 16 parts, and dodecylbenzenesulfonic acid (indicated in the table as DBS) was used instead of potassium oleate as an anionic surfactant. In the same manner, an aqueous dispersion having an average particle diameter of 0.38 μm was obtained. The results are shown in Table 1.

(Example 11)
The average amount of acid-modified polyolefin (B-1) was 16 parts, and an aqueous potassium hydroxide solution was added in the same manner as in Example 1 except that the amount of water relative to 100 parts of polyolefin was 0.9 parts. An aqueous dispersion having a particle size of 0.60 μm was obtained. The results are shown in Table 1.

(Example 12)
An aqueous dispersion having an average particle diameter of 0.90 μm was obtained in the same manner as in Example 11 except that an aqueous potassium hydroxide solution was added so that the amount of water relative to 100 parts of polyolefin was 15 parts. The results are shown in Table 1.

(Comparative Example 1)
In an autoclave having an internal volume of 2 liters equipped with a stirrer, 500 parts of toluene was charged with respect to 100 parts of polyolefin (A-1), dissolved by stirring at 125 ° C. for 1 hour, and then cooled to 90 ° C.
Separately, an aqueous solution containing 3 parts of potassium oleate and 600 parts of water is heated to 90 ° C. in an autoclave having an internal volume of 2 liters equipped with a stirrer, and the toluene solution of the polyolefin is stirred therein. Added under continuation. After stirring for 2 hours to disperse, the mixture was dispersed with a high speed homogenizer manufactured by SMT (HG-92) at 10,000 rpm for 10 minutes.
Next, while continuing the stirring by the stirring blade, while condensing water is refluxed, the steam is distilled for 2 hours to distill off the toluene, but as the toluene is distilled off, agglomerates are generated and the entire amount of toluene is distilled off. The aggregate reached 99 parts before and an aqueous dispersion could not be obtained.

(Comparative Example 2)
An attempt was made to obtain an aqueous dispersion in the same manner as in Comparative Example 1 except that the amount of potassium oleate was changed to 10 parts. However, 90 parts of aggregates were formed, and an aqueous dispersion could not be obtained.

(Comparative Example 3)
Except that the amount of potassium oleate was changed to 20 parts, the same procedure as in Comparative Example 1 was carried out. As a result, 12 parts of agglomerates were produced as a by-product. Obtained. Then, adhesion and water resistance were evaluated in the same manner as in Example 1. The results are shown in Table 2.

(Comparative Example 4)
In the preparation method of the aqueous dispersion of Comparative Example 3, in addition to the polyolefin (A-1), 10 parts of the acid-modified polyolefin (B-1) were dissolved in toluene, and 0.5 part of the aqueous potassium oleate solution was dissolved. Except for the addition of potassium hydroxide, the same procedure as in Comparative Example 3 was performed. As a result, 2 parts of aggregates were by-produced, but an aqueous dispersion having a solid content concentration of 17% and an average particle size of 8.5 μm was obtained. The results are shown in Table 2.

(Comparative Example 5)
Instead of the total amount of polyolefin (A-1), 100 parts of acid-modified polyolefin (B-1) was dissolved in toluene, except that 10 parts of potassium oleate and 5 parts of potassium hydroxide were dissolved in 600 parts of water. When the same procedure as in Comparative Example 3 was performed, 2 parts of aggregates were by-produced, and an aqueous dispersion having a concentration of 16% and an average particle size of 0.4 μm was obtained. The results are shown in Table 2.

(Comparative Example 6)
An aqueous dispersion having an average particle size of 0.27 μm was obtained in the same manner as in Example 1 except that the polyolefin (A-6) was used instead of the polyolefin (A-1). The results are shown in Table 2.

(Comparative Example 7)
An aqueous dispersion having an average particle size of 0.29 μm was obtained in the same manner as in Example 1 except that the polyolefin (A-7) was used instead of the polyolefin (A-1). The results are shown in Table 2.

(Comparative Example 8)
An aqueous dispersion having an average particle size of 0.24 μm was obtained in the same manner as in Example 1 except that the polyolefin (A-8) was used instead of the polyolefin (A-1). The results are shown in Table 2.

(Comparative Example 9)
An aqueous dispersion having an average particle size of 0.30 μm was obtained in the same manner as in Example 1 except that the polyolefin (A-9) was used instead of the polyolefin (A-1). The results are shown in Table 2.

(Comparative Example 10)
An aqueous dispersion was obtained in the same manner as in Example 1 except that the amount of the acid-modified polyolefin (B-1) was changed to 4 parts. However, the aqueous dispersion was not diluted with warm water but only aggregates were formed. No body was obtained.

(Comparative Example 11)
An aqueous dispersion having an average particle size of 2.3 μm was obtained in the same manner as in Example 1 except that the amount of the acid-modified polyolefin (B-1) was changed to 25 parts. Then, adhesion and water resistance were evaluated in the same manner as in Example 1. The results are shown in Table 3.

(Comparative Example 12)
An aqueous dispersion having an average particle size of 0.50 μm was obtained in the same manner as in Example 1 except that the acid-modified polyolefin (B-5) was used instead of the acid-modified polyolefin (B-1). The results are shown in Table 3.

(Comparative Example 13)
An aqueous dispersion was obtained in the same manner as in Example 1 except that the acid-modified polyolefin (B-6) was used in place of the acid-modified polyolefin (B-1). As a result, an aqueous dispersion was not obtained.

(Comparative Example 14)
An aqueous dispersion was obtained in the same manner as in Example 1 except that the acid-modified polyolefin (B-7) was used in place of the acid-modified polyolefin (B-1). As a result, an aqueous dispersion was not obtained.

(Comparative Example 15)
An aqueous dispersion having an average particle diameter of 0.61 μm was obtained in the same manner as in Example 1 except that the acid-modified polyolefin (B-8) was used instead of the acid-modified polyolefin (B-1). The results are shown in Table 3.

(Comparative Example 16)
An aqueous dispersion was obtained in the same manner as in Example 1 except that the amount of potassium oleate was changed to 0.5 part. However, the aqueous dispersion was not diluted with warm water and only aggregates were formed. I couldn't.

(Comparative Example 17)
An aqueous dispersion having an average particle size of 0.42 μm was obtained in the same manner as in Example 1 except that the amount of potassium oleate was changed to 12 parts. The results are shown in Table 3.

(Comparative Example 18)
An aqueous dispersion was obtained in the same manner as in Example 1 except that an aqueous potassium hydroxide solution was added so that the amount of water relative to 100 parts of polyolefin was 0.4 parts. No matter how much was formed, no aqueous dispersion was obtained.

(Comparative Example 19)
An aqueous dispersion having an average particle diameter of 2.1 μm was obtained in the same manner as in Example 1 except that an aqueous potassium hydroxide solution was added so that the amount of water relative to 100 parts of polyolefin was 25 parts. The results are shown in Table 3.

A step of melting and kneading a specific polyolefin (A), an acid-modified polyolefin (B) and an anionic surfactant (C) to obtain a kneaded product, injecting water (D) into the kneaded product, and further melting In the production methods of Examples 1 to 4, 7 to 12 and Reference Examples 5 and 6 having a kneading step, the adhesion to polypropylene and the water resistance of the coating obtained from the aqueous dispersion were excellent.
In contrast, in the production methods of Comparative Examples 1 and 2 in which the polyolefin (A) was dispersed by high-speed stirring under the condition that the amount of potassium oleate was 10 parts by mass or less in the presence of a solvent, an aqueous dispersion was not obtained. .
In Comparative Example 3 in which the amount of potassium oleate was increased to 20 parts by mass, an aqueous dispersion was obtained. However, the average particle size was large, the yield was low, and the adhesion and water resistance were also low.
Also in Comparative Example 4 in which acid-modified polyolefin (B) was added to the production method of Comparative Example 3, the adhesion and water resistance were low.
In the production method of Comparative Example 5 containing acid-modified polyolefin (B) but not containing polyolefin (A), an average particle size of 0.4 μm was obtained, but adhesion and water resistance were not expressed. .
In the production method of Comparative Example 6 in which the polyolefin (A) was homopolypropylene, adhesion and water resistance were low.
In the production method of Comparative Example 7 using the polyolefin (A) having a crystallinity of less than 0.1%, adhesion and water resistance were low.
In the production method of Comparative Example 8 using the polyolefin (A) having a crystallinity exceeding 16%, adhesion and water resistance were low.
In the production method of Comparative Example 9 using the polyolefin (A) having a propylene unit of less than 80%, adhesion and water resistance were low.
In the production method of Comparative Example 10 in which the addition amount of the acid-modified polyolefin (B) was less than 5 parts, an aqueous dispersion could not be obtained.
In the production method of Comparative Example 11 in which the addition amount of the acid-modified polyolefin (B) was more than 20 parts, adhesion and water resistance were low.
In the production method of Comparative Example 12 using the acid-modified polyolefin (B) having a weight average molecular weight exceeding 35,000, adhesion and water resistance were low.
In the production method of Comparative Example 13 using the acid-modified polyolefin (B) having a weight average molecular weight of less than 1,800, an aqueous dispersion could not be obtained.
In the production method of Comparative Example 14 using the acid-modified polyolefin (B) having an acid value of less than 3 mg / g, an aqueous dispersion was not obtained.
In the production method of Comparative Example 15 using the acid-modified polyolefin (B) having an acid value exceeding 80 mg / g, adhesion and water resistance were low.
In the production method of Comparative Example 16 in which the amount of potassium oleate added was less than 1 part, an aqueous dispersion could not be obtained.
In the production method of Comparative Example 17 in which the amount of potassium oleate added exceeded 10 parts, an aqueous dispersion could not be obtained.
In the production method of Comparative Example 18 in which the amount of water added was less than 0.5 part, an aqueous dispersion could not be obtained.
In the production method of Comparative Example 19 in which the amount of water added exceeded 20 parts, an aqueous dispersion could not be obtained.

Claims (4)

Polyolefin (A), 5 to 20 parts by mass of acid-modified polyolefin (B) with respect to 100 parts by mass of polyolefin (A), and 1 to 10 parts by mass of anionic surfactant for 100 parts by mass of polyolefin (A) agent (C), and an aqueous dispersion containing the water (D) 0.5 to 20 parts by weight, the polyolefin (a) is other than propylene units of 8 0 to 99 wt% of propylene units α The olefin unit is 1 to 20% by mass, the α-olefin unit contains 1-butene unit , and the crystallinity is 0.1 to 16%,
An aqueous dispersion, wherein the acid-modified polyolefin (B) has a weight average molecular weight of 1,800 to 35,000 and an acid value of 3 to 80 mg / g.   The aqueous dispersion according to claim 1, wherein the acid-modified polyolefin (B) is acid-modified propylene. The aqueous dispersion according to claim 1 or 2, wherein the anionic surfactant (C) is an alkali metal salt of a higher fatty acid having 10 to 20 carbon atoms . Polyolefin (A), 5 to 20 parts by mass of acid-modified polyolefin (B) with respect to 100 parts by mass of polyolefin (A), and 1 to 10 parts by mass of anionic surfactant for 100 parts by mass of polyolefin (A) A step of melt-kneading the agent (C) to obtain a kneaded product,
A method for producing an aqueous dispersion, comprising adding 0.5 to 20 parts by mass of water (D) to 100 parts by mass of polyolefin (A), and further melt-kneading the kneaded product,
As the polyolefin (A), propylene Unit consists of 8 0 to 99 wt% and 20 wt% alpha-olefin units other than propylene units, alpha-olefin unit containing 1-butene units, and the crystallization Using a degree of 0.1 to 16%,
A method for producing an aqueous dispersion, wherein the acid-modified polyolefin (B) has a weight average molecular weight of 1,800 to 35,000 and an acid value of 3 to 80 mg / g.