JP2003342376A - Method for producing aqueous emulsified thermoplastic elastomer dispersion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an aqueous emulsified styrene thermoplastic elastomer dispersion effective as a coating agent which, when applied to the surface of an article such as a plastic molding, a film, or a sheet, imparts thereto moist touch and quality. <P>SOLUTION: The aqueous emulsified thermoplastic elastomer dispersion is produced by emulsifying a mixture containing a styrene thermoplastic elastomer (A) component and a process oil (B) component in a ratio of 1/5 to 1/50 by weight with an emulsifier in the presence of a hydrocarbon solvent and removing the hydrocarbon solvent from the emulsion by distillation. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a thermoplastic elastomer aqueous emulsion dispersion for forming a film having a moist feel and a high-grade feel.

[0002]

BACKGROUND OF THE INVENTION Conventionally, styrene thermoplastic elastomer emulsions have been widely used as coating agents for plastics, asphalt modifiers, coated papers, tire coats, fiber processing, waterproofing agents, etc. A manufacturing method is disclosed (for example, JP-A-4-161460, JP-A-2000-219748, JP-B-52-).
22651, JP 2001-294766 A). The styrene-based thermoplastic elastomer emulsion produced in this way gives the product "high elasticity even at low temperatures".
The purpose is to give.

Recently, the surface of the product has a soft feel to the touch (hereinafter referred to as "moist feel"),
There is a strong demand for a styrene-based thermoplastic elastomer aqueous emulsion dispersion capable of forming a film having a high-quality appearance on the product surface. However, the present situation is that the demands of the market have not been sufficiently satisfied.

Further, in these publications, there is no description regarding the production of an aqueous emulsion dispersion of a thermoplastic elastomer capable of forming a film having a moist feeling, and there is no description suggesting this.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing a thermoplastic elastomer aqueous emulsion dispersion capable of forming a film which gives a moist feeling to the surface of a product and further gives a high-grade feeling. To aim.

[0006]

As a result of intensive studies to solve the above problems, the present inventors have found that the weight ratio of the styrene-based thermoplastic elastomer component to the process oil component is 1/5 to.
A thermoplastic elastomer aqueous emulsion dispersion obtained by emulsifying a 1/50 mixture in the presence of a hydrocarbon solvent and then distilling off the hydrocarbon solvent has a moist feeling.
It was found that a high quality film was formed.

The present invention has been completed based on such findings, and provides the following inventions.

Item 1 The weight ratio of the styrene thermoplastic elastomer (A) component to the process oil (B) component is 1 /
A method for producing a thermoplastic elastomer aqueous emulsion dispersion, which comprises emulsifying a mixture of 5 to 1/50 with an emulsifier in the presence of a hydrocarbon solvent, and then distilling off the hydrocarbon solvent.

Item 2 The method for producing an aqueous thermoplastic elastomer dispersion according to Item 1, wherein the emulsification method is a phase inversion emulsification method.

Item 3 (A) component is styrene-isoprene-styrene copolymer hydride, styrene-butadiene-
Styrene copolymer hydride, styrene-isoprene-butadiene-styrene copolymer hydride, styrene-ethylene-isoprene-styrene copolymer hydride and styrene-ethylene-butadiene-styrene copolymer hydride selected from the group consisting of Item 3. The method for producing the aqueous thermoplastic elastomer dispersion, according to Item 1 or 2, which is at least one styrene-based thermoplastic elastomer.

Item 4 The method for producing an aqueous emulsion of a thermoplastic elastomer according to Item 3, wherein the solution of a 5% by weight toluene solution of the component (A) has a solution viscosity of 20 to 500 mPa · s (30 ° C).

Item 5 (B) component is at least one process oil selected from the group consisting of paraffinic hydrocarbons and naphthenic hydrocarbons, and the thermoplastic elastomer aqueous emulsion according to any one of Items 1 to 4 above. A method for producing a dispersion.

Item 6. Component (A) is the thermoplastic thermoplastic elastomer according to item 3 or 4, and component (B) is a paraffin hydrocarbon. Process for producing elastomer aqueous emulsion dispersion.

Item 7 The emulsifier is at least one selected from the group consisting of alkylbenzene sulfonates, higher alcohol sulfuric acid ester salts, higher alcohol / ethylene oxide adduct sulfuric acid ester salts, and alkylphenol / ethylene oxide adduct sulfuric acid ester salts. 7. A method for producing the thermoplastic elastomer aqueous emulsion dispersion according to any one of Items 1 to 6 above.

Item 8. The method for producing an aqueous thermoplastic elastomer dispersion according to any one of Items 1 to 6, wherein the emulsifier is an alkylbenzenesulfonic acid triethanolamine salt.

Item 9 After emulsification, a foam suppressor and / or
Alternatively, the method for producing the thermoplastic elastomer aqueous emulsion dispersion according to any one of Items 1 to 8, which comprises adding an antifoaming agent.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION < Styrenic thermoplastic elastomer
- > The styrene-based thermoplastic elastomer (A) according to the present invention is not particularly limited as long as it contains a repeating unit of styrene and / or α-methylstyrene,
Known ones can be used. Specifically, styrene-isoprene-styrene block copolymer, styrene-butadiene-styrene copolymer, styrene-butadiene-ethylene-styrene copolymer, styrene-ethylene-butylene-styrene copolymer, styrene-ethylene- Examples thereof include a propylene-styrene copolymer, a styrene-ethylene-isoprene-styrene copolymer, a styrene-butadiene-isoprene-styrene copolymer, and hydrides of these polymers. These may be used alone or in combination of two or more.

The term "polymer hydride" as used herein means a polymer obtained by hydrogenating the double bond site of the above copolymer.

The component (A) is a copolymer composed of an inelastic polymer block having a second-order transition temperature of 25 ° C. or higher and an elastic polymer block having a second-order transfer temperature of 10 ° C. or lower.

The non-elastic polymer block having a second-order transition temperature of 25 ° C. or higher may be a homopolymer block of a monomer selected from monovinyl aromatic hydrocarbons such as styrene and α-methylstyrene, or two or more of them. And a copolymer block consisting of

As the block having a second-order transition temperature of 10 ° C. or lower, a homopolymer block of a monomer selected from aliphatic conjugated diene compounds such as butadiene and isoprene, and two types of the above-mentioned monomers. Examples thereof include the above-mentioned copolymer blocks and polymer blocks obtained by hydrogenating these polymer blocks. Specific examples of the block include butadiene polymer, isoprene polymer, butadiene and isoprene copolymer, hydrogenated butadiene polymer, hydrogenated isoprene polymer, hydrogenated ethylene-butadiene copolymer, hydrogenated Butadiene-isoprene copolymer, hydrogenated ethylene-isoprene copolymer, and the like.

Of these, the styrene content is 12
To about 66% by weight, preferably about 20 to 40% by weight, and is a styrene-isoprene-styrene copolymer hydride, styrene-butadiene-styrene copolymer hydride, styrene-isoprene-butadiene-styrene. Copolymer hydride, styrene-ethylene-butadiene-styrene copolymer hydride, styrene-butadiene-isoprene-styrene copolymer hydride, styrene-
At least one styrene thermoplastic elastomer of ethylene-isoprene-styrene copolymer hydride is preferred.

Further, among these, a hydrogenated copolymer having a solution viscosity of a 5% by weight toluene solution of about 20 to 500 mPa · s, preferably about 40 to 400 mPa · s is particularly preferable.

As such a copolymer, specifically, Septon 100 sold by Kuraray Co., Ltd.
1, septon 2002, septon 2004, septon 2
007, Septon 2005, Septon 2006, Septon 2063, Septon 2104, Septon 4033, Septon 4044, Septon 4055, Septon 407.
7, Septon 8007, Septon 8004, Septon 8
006, Septon 8104, etc. are illustrated. Of these, Septon 2005, Septon 4055, Septon 4077, and Septon 8006 are more preferable because the moist feeling of the film is good.

< Process Oil > Examples of the process oil (B) in the present invention include naphthene hydrocarbons and paraffin hydrocarbons. In particular, it is preferable to use an aromatic component content of 5% by weight or less because the weather resistance of the film surface formed on the product surface is excellent.

The weight ratio of the component (A) to the component (B) in the present invention is usually about 1/5 to 1/50, preferably about 1/5 to 1/20. If the amount of component (B) is less than this range, a moist feeling will not occur, and if it is more than this range, the strength of the film to be formed will be reduced and the coating performance will tend to be reduced. Within this range, there is no problem in use.

< Hydrocarbon-based solvent > The hydrocarbon-based solvent used in the present invention is not particularly limited, and specifically, toluene, xylene, ethylbenzene, trimethylbenzene, methylethylbenzene, cyclohexane, methylcyclohexane, Dimethylcyclohexane,
Ethylcyclohexane, trimethylcyclohexane, methylethylcyclohexane, decalin, aromatic solvent of carbon number C8 fraction, solvent obtained by nuclear hydrogenation of aromatic solvent of carbon number C8 fraction (for example, manufactured by Shin Nippon Rika Co., Ltd., trade name "Ricasolve 800"), an aromatic solvent having a carbon number C9 fraction, a solvent obtained by nuclear hydrogenation of an aromatic solvent having a carbon number C9 fraction (for example,
New Japan Rika Co., Ltd., trade name "Ricasolve 900"),
Examples include a solvent obtained by nuclear hydrogenating an aromatic solvent having a C10 carbon number fraction, and a hydrocarbon solvent having a carbon number of 10 or less such as a mixture thereof. Of these, toluene and xylene, which are inexpensive and have excellent solubility, are preferable.

From the viewpoint of protection of natural environment, safety of working environment and safety to human body, non-aromatic solvents such as methylcyclohexane, ethylcyclohexane, Ricasolve 800 and Ricasolve 900 are preferable.

The above solvents may be used alone or in combination of two or more.

The amount of these solvents to be used is generally 0.1 to 0.1 based on the weight of the mixture of the components (A) and (B).
The range is about 20 times by weight, preferably about 0.5 to 10 times by weight.

< Emulsifier > As the emulsifier used in the present invention, at least one selected from anionic surfactants and nonionic surfactants can be used.

As the anionic surfactant, for example,
The following carboxylic acid type anionic surfactants, sulfate ester type anionic surfactants, sulfonic acid type anionic surfactants and phosphate ester type anionic surfactants can be mentioned.

Specific examples of the carboxylic acid type anionic surfactant (1) include abietic acid salts, naphthenic acid salts, and
Examples thereof include alkenyl succinate.

(2) Specific examples of the sulfate ester type anionic surfactant include a saturated or unsaturated higher alcohol (having 8 to 18 carbon atoms) sulfate ester salt, a saturated or unsaturated higher alcohol (having 8 carbon atoms). To 18) ethylene oxide adducts of sulfuric acid ester salts, alkyls (having 8 to 1 carbon atoms)
2) Examples include sulfuric acid ester salts of ethylene oxide adducts of phenol.

(3) Specific examples of the sulfonic acid type anionic surfactant include alkyl (C 2-20, branched or straight chain) benzene sulfonate, alkyl (C 2-20, branched or straight chain). (Chain) naphthalene sulfonate, petroleum sulfonate, lignin sulfonate, etc. are exemplified.

(4) Specific examples of the phosphoric acid ester type anionic surfactant include alkyl (having 8 to 18 carbon atoms).
Phosphoric acid monoester salt, alkyl (C 8-18) phosphoric acid diester salt, phosphoric acid monoester salt of alkyl (C 8-12) phenol ethylene oxide adduct, alkyl (C 8-12) phenol ethylene oxide Examples include phosphoric acid diester salts of adducts.

Specific examples of salts of the anionic surfactants (1) to (4) include sodium salt, potassium salt,
Examples are ammonium salts and alkanolamine salts.

Examples of the nonionic surfactants include ethylene oxide adducts of saturated or unsaturated alcohols (C8 to C18), propylene oxide / ethylene oxide adducts of saturated or unsaturated alcohols (C8 to C18), Examples thereof include ethylene oxide of alkyl (carbon nest 8 to 12) phenol, propylene oxide / ethylene oxide adduct of alkyl (carbon number 8 to 12) phenol, and the like.

The above-mentioned anionic surfactant and nonionic surfactant can be used alone or in combination of two or more kinds.

Among the above-mentioned anionic surfactants and nonionic surfactants, alkyl (having 2 to 20 carbon atoms, carbon atoms having 2 to 20 carbon atoms) is preferable because the solubility in the organic phase or the aqueous phase and the particle size of the emulsion dispersion can be controlled. (Branched or linear) benzenesulfonic acid triethanolamine salt is preferable, and of these, dodecylbenzenesulfonic acid triethanolamine salt is most preferable because it is inexpensive and easily available.

The emulsifier of the present invention is usually used in an amount of 0.5 to 30 based on the weight of the mixture of the components (A) and (B).
A weight range of from 1 to 15% by weight is preferred.
If it is less than 0.5% by weight, it is difficult to obtain a stable emulsion dispersion. On the contrary, if it exceeds 30% by weight, emulsification occurs but it is uneconomical, and the film originally obtained from the obtained emulsion dispersion is There is a tendency that the characteristics of (1) are impaired.

< Preparation Method of Emulsified Dispersion Liquid > The emulsification method of the present invention is not particularly limited, but the following method can be exemplified.

(1) A method in which a mixed solution consisting of the components (A), (B) and a hydrocarbon solvent is charged into water in which an emulsifier is dissolved and mixed and emulsified under high shearing force.

(2) An emulsifier is mixed with a mixed solution consisting of the components (A), (B) and a hydrocarbon solvent, water is then added, and the mixture is stirred and phase-inverted. Below, how to emulsify,

(3) A mixed solution consisting of the components (A) and (B) and a hydrocarbon solvent, an emulsifier, and water are added all at once, and the mixture is stirred and phase-inverted. Below,
A method of emulsification or the like can be adopted.

Among these, the method (2) and (3) of phase inversion emulsification (hereinafter referred to as "phase inversion emulsification method") gives an emulsion dispersion in which the particle size of the thermoplastic elastomer is below a certain level. Is preferred.

For the mixed emulsification and the phase inversion emulsification, a known emulsification device commonly used in the art such as a homomixer, a homogenizer, a flimix, a nanomizer, a cavitron, a line mixer, a universal stirrer and a bottom ribbon impeller is used. can do.

In the case of continuous production, it is preferable to use a line mixer for efficient production. On the other hand,
In the case of batch production, a simple production method using a production apparatus equipped with a condenser and a bottom ribbon impeller agitator is preferable.

The temperature at the time of emulsification is not particularly limited and is usually about 10 ° C to 200 ° C, preferably 20 ° C.
The temperature is in the range of about 150 ° C, more preferably about 25 to 100 ° C.

The emulsified dispersion containing the hydrocarbon solvent thus obtained is azeotropically distilled with water under the conditions of 80 to 100 ° C. and atmospheric pressure to 300 kPa to remove the hydrocarbon solvent. can do.

Depending on the type of emulsifier used, when the organic solvent is distilled off, defoaming may take a long time due to foaming, and if the foaming is more vigorous, it may be difficult to distill off the solvent. It is recommended to add an antifoaming agent.

The above-mentioned defoaming agent / defoaming agent is not particularly limited, and examples thereof include amide type, silica / silicone type, silicone type and wax type defoaming agents / defoaming agents. . Specific examples of the foam suppressor / antifoaming agent include SN deformer 477 and SN deformer 47.
5-L, SN deformer 5013, SN deformer 5016 (all manufactured by San Nopco Ltd.) and the like are exemplified.
The amount added is 0.0 based on the weight of the emulsion dispersion.
It is about 1 to 0.5% by weight, preferably about 0.02 to 0.3% by weight.

Further, water can be distilled off or added as required to obtain the thermoplastic elastomer aqueous emulsion dispersion of the present invention adjusted to a desired solid content concentration. The solid content concentration is usually about 10 to 90%, preferably about 20 to 60%.

The styrene thermoplastic elastomer emulsion (median size) thus obtained is usually 0.0
It is in the range of 5 to 50 μm, preferably 0.1 to 30 μm. If it is less than 0.05 μm, the viscosity is high and handling becomes difficult, and if it exceeds 50 μm, mechanical stability (stability against shearing force during stirring and pumping) and stationary stability tend to be deteriorated.

< Use > The styrene-based thermoplastic elastomer aqueous emulsion dispersion obtained by the production method of the present invention is applied to a product when used as a coating agent for the surface of a product such as a plastic molded product, various films and various sheets. It is effective as a coating agent that gives a moist feeling to the touch and gives a high-grade feeling to the product.

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples. The invention is not limited to these examples. The viscosity of the aqueous emulsion dispersion, the particle size (median size) of the emulsion, the solid content concentration (%), the toluene content, and the feel test were according to the following methods.

Viscosity Toki Sangyo Co., Ltd. BL type viscometer was used for measurement. Emulsion particle size (median size) Laser scattering / diffraction particle size distribution analyzer L, manufactured by Horiba, Ltd.
It was measured using A-910. Solid content concentration (%) The aqueous emulsion dispersion was placed in a petri dish and dried at 105 ° C. for 2 hours, the weight of the solid content was determined, and the solid content concentration (%) was determined from the following formula. Solid content concentration (%) = [weight (g) after evaporative drying / sample amount (g)] × 100 toluene content It was measured using gas chromatography. Feel test feel Test Examples 1 and 2, and Comparative Example 1, an aqueous emulsion dispersion was coated and subjected to tactile test by monitors ten film obtained by drying. The judgment was made according to the following judgment criteria. ◎: Moist feeling is recognized ○: Slightly moist feeling △: Rubber feeling ×: Rugged feeling

Example 1 In an emulsifying pot equipped with a homomixer (trade name "TK Homomixer Mark II" manufactured by Tokushu Kika Kogyo Co., Ltd.), water 1
119 g and 71 g of dodecylbenzenesulfonic acid triethanolamine salt (manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., trade name "Haimar No. 2") were added and the temperature was raised to 90 ° C. Next, a solution of 75 g of "Septon 4055" and 600 g of paraffin-based process oil (manufactured by Idemitsu Kosan Co., Ltd., trade name "Diana Process Oil PW-90") in 750 g of toluene was added, and the peripheral speed of the homomixer was 8 m. 90 ° C / s
The mixture was stirred and mixed for 5 minutes to carry out preliminary emulsification. Then, this pre-emulsified liquid was homogenized at 90 ° C. and 50 MPa (Ga
made by ulin, product name "LAB40-10RBFI type")
After the treatment, the mixture was cooled to obtain 2561 g of a toluene-containing emulsion dispersion. The obtained toluene-containing emulsion dispersion and an antifoaming agent (manufactured by San Nopco Ltd., trade name “SN Deformer 50”).
13 ") 1.0 g was placed in a 5 L four-necked flask equipped with a condenser, a decanter, and a dropping funnel, and the temperature was raised with stirring with a propeller under normal pressure, while supplementing the same amount of water as the azeotropic water. The toluene was distilled off. The content of toluene in the emulsified dispersion was 500 pp by gas chromatography.
When it reached m, heating was stopped and the mixture was cooled to room temperature.

The solid content concentration of the obtained aqueous emulsion dispersion is 4
0 wt% and the median diameter of the emulsion were 0.5 μm.

As a result of the tactile sensation test, all the monitors answered that they had a moist feeling.

Example 2 A septum 40 was placed in a stirrer (universal mixing stirrer manufactured by Dalton Co., Ltd.) equipped with a condenser, a decanter and a dropping funnel.
55 "75 g, paraffin-based process oil (manufactured by Idemitsu Kosan Co., Ltd., trade name" Diana Process Oil PW-9 "
0 ") 600 g and toluene 750 g were added, and the mixture was heated to 90 ° C. with stirring and dissolved. After cooling to room temperature, 71 g of dodecylbenzenesulfonic acid triethanolamine salt (manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., trade name "Haimar No. 2"), water 60
g was added and stirred, and the phase was inverted. After the phase inversion, stirring was continued for another hour. Water 1059 g, defoamer (manufactured by San Nopco Ltd.,
(Trade name "SN deformer 5013") (1.0 g) was added, and the mixture was heated under atmospheric pressure with stirring, and toluene was distilled off while supplementing water with the same weight as the azeotropic water. The content of toluene in the emulsion was 500 by gas chromatography.
When it reached ppm, heating was stopped and the mixture was cooled to room temperature. The solid concentration of the obtained aqueous emulsion dispersion is 40 wt.
%, And the median diameter of the emulsion was 0.6 μm. Furthermore, all of the monitors responded that the results of the tactile test were moist.

Comparative Example 1 Example 1 except that the weight ratio of 75 g of "Septon 4055" to 600 g of paraffin-based process oil (manufactured by Idemitsu Kosan Co., Ltd., trade name "Diana Process Oil PW-90") was 1/1. The same operation as above was performed to obtain an aqueous emulsion dispersion. As a result of a touch test of the obtained film, 8 people answered that it was rubbery and uncomfortable, and 2 people felt that it was slightly moist.

Comparative Example 2 Example 1 except that the weight ratio of 75 g of "Septon 4055" to 600 g of paraffin-based process oil (trade name "Diana Process Oil PW-90" manufactured by Idemitsu Kosan Co., Ltd.) was 1/80. The same operation as above was performed to obtain an aqueous emulsion dispersion. Regarding the result of the feel test of the obtained film, it was broken by the touch of the hand, and no answer was obtained.

[0064]

The styrene-based thermoplastic elastomer aqueous emulsion dispersion obtained by the production method of the present invention, when used as a coating agent for the surface of products such as plastic moldings, various films, various sheets, etc. It is effective as a coating agent that gives a moist feeling and a high-class feeling.

Claims (9)

[Claims] 1. A styrene-based thermoplastic elastomer (A)
The weight ratio of the component to the process oil (B) component is 1/5 to 1
A method for producing a thermoplastic elastomer aqueous emulsion dispersion, which comprises emulsifying a mixture of / 50 with an emulsifier in the presence of a hydrocarbon solvent, and then distilling off the hydrocarbon solvent. 2. The method for producing a thermoplastic elastomer aqueous emulsion dispersion according to claim 1, wherein the emulsification method is a phase inversion emulsification method. 3. The component (A) is styrene-isoprene-
Styrene copolymer hydride, styrene-butadiene-styrene copolymer hydride, styrene-isoprene-butadiene-styrene copolymer hydride, styrene-ethylene-isoprene-styrene copolymer hydride and styrene-ethylene-butadiene-styrene The method for producing an aqueous emulsion of a thermoplastic elastomer according to claim 1 or 2, which is at least one styrene-based thermoplastic elastomer selected from the group consisting of copolymer hydrides. 4. The method for producing an aqueous emulsion of a thermoplastic elastomer according to claim 3, wherein the 5% by weight toluene solution of the component (A) has a solution viscosity of 20 to 500 mPa · s (30 ° C.). 5. The thermoplastic elastomer aqueous emulsion according to claim 1, wherein the component (B) is at least one process oil selected from the group consisting of paraffin hydrocarbons and naphthene hydrocarbons. A method for producing a dispersion. 6. The thermoplastic elastomer aqueous solution according to claim 1, wherein the component (A) is the thermoplastic elastomer according to claim 3 or 4, and the component (B) is a paraffin hydrocarbon. Method for producing emulsified dispersion. 7. The emulsifier is an alkylbenzene sulfonate, a higher alcohol sulfate ester salt, or a higher alcohol.
The method for producing an aqueous emulsion dispersion of a thermoplastic elastomer according to any one of claims 1 to 6, which is at least one selected from the group consisting of a sulfuric acid ester salt of an ethylene oxide adduct and a sulfuric acid ester salt of an alkylphenol / ethylene oxide adduct. . 8. The method for producing an aqueous emulsion dispersion of a thermoplastic elastomer according to claim 1, wherein the emulsifier is an alkylbenzenesulfonic acid triethanolamine salt. 9. The method for producing an aqueous dispersion of a thermoplastic elastomer according to claim 1, which further comprises adding a foam suppressor and / or a defoaming agent after the emulsification.