JP2000219748A - Preparation of styrene thermoplastic elastomer latex - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a styrene thermoplastic elastomer latex which generates few coagulates and exerts a high mechanical stability, even when a mechanical shear force is applied by agitators or pumps. SOLUTION: A preparation process of a styrene thermoplastic elastomer latex contains a step wherein an organic phase containing 100 pts.wt. styrene thermoplastic elastomer and 0.1 to 230 pts.wt. adhesion imparting resin is prepared, and a step wherein the organic phase is emulsified. Here, the adhesion imparting resin used is, e.g. at least one chosen from the group consisting of rosin resins, terpene resins, chroman resins, phenol resins and petroleum hydrocarbon resins.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a latex, and more particularly, to a method for producing a styrene-based thermoplastic elastomer latex.

[0002]

2. Description of the Related Art Styrene-based thermoplastic elastomer latex has high cohesive strength and high elasticity even at low temperatures, so it can be used for plastics, thermosetting resins, asphalt for road pavement, and asphalt emulsion. Is widely used as a modifier, a tackifier / adhesive, a sealing material, or a plastic molding, a coating agent for various films and various sheets.

[0003] Such a styrene-based thermoplastic elastomer latex is usually a mixture of an organic phase in which a styrene-based thermoplastic elastomer is dissolved in an organic solvent such as toluene and an aqueous phase in which an anionic or nonionic emulsifier is dissolved. It is manufactured by emulsifying this using a homomixer or an ultrasonic dispersing machine and then removing the organic solvent (for example,
JP-B-55-8020, JP-A-4-161460
Reference).

However, the styrene-based thermoplastic elastomer latex thus produced tends to form aggregates when mechanical shearing force is applied by a stirrer, a pump, or the like, and is inferior in mechanical stability.

An object of the present invention is to provide a styrene-based thermoplastic elastomer latex which is less likely to form agglomerates even when mechanical shearing force is applied by a stirrer or a pump and has excellent mechanical stability. It is in.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, when a styrene-based thermoplastic elastomer and a tackifying resin are dissolved in an organic phase before emulsification, a mechanical It has been found that a styrene-based thermoplastic elastomer latex having excellent thermal stability can be obtained, and the present invention has been completed.

That is, the method for producing a styrene-based thermoplastic elastomer latex according to the present invention comprises the steps of:
And a step of preparing an organic phase containing 部 230 parts by weight, and a step of emulsifying the organic phase.

The tackifying resin used here is, for example, rosin resin, terpene resin, cumarone resin,
It is at least one selected from the group consisting of phenolic resins and petroleum hydrocarbon resins. Styrene-based thermoplastic elastomers include, for example, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butadiene-styrene block copolymer, styrene-ethylene-butylene-styrene It is at least one selected from the group consisting of a block copolymer and a styrene-ethylene-propylene-styrene block copolymer.

[0009] The weight average particle diameter of the styrene-based thermoplastic elastomer latex obtained by the production method of the present invention is usually 0.1 to 10 µm.

The styrene-based thermoplastic elastomer latex of the present invention comprises a step of preparing an organic phase containing 100 parts by weight of a styrene-based thermoplastic elastomer and 0.1 to 230 parts by weight of a tackifier resin; And a step including an emulsifying step.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method for producing a styrene-based thermoplastic elastomer latex according to the present invention generally comprises an organic phase in which a styrene-based thermoplastic elastomer and a tackifying resin are dissolved in an organic solvent and an aqueous phase in which a dispersant is dissolved. , A step of mixing and emulsifying the obtained organic phase and the aqueous phase, and a step of removing an organic solvent from the obtained emulsion.

The styrenic thermoplastic elastomer used in the present invention is not particularly limited as long as it contains a repeating unit of styrene, and various known styrenic thermoplastic elastomers are available. Specific examples of such styrene-based thermoplastic elastomer include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butadiene-styrene block copolymer, styrene-ethylene- Examples thereof include a butylene-styrene block copolymer and a styrene-ethylene-propylene-styrene block copolymer. Among them, styrene-butadiene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer and styrene-isoprene-
Styrene block copolymers are particularly preferably used.

The proportion of the repeating unit derived from styrene in the above-mentioned styrene-based thermoplastic elastomer is not particularly limited, but is usually set to 10 to 50% by weight in terms of styrene monomer at the time of polymerization. Is preferably set to 15 to 40% by weight. Further, two or more of the above-mentioned styrene-based thermoplastic elastomers may be used as a mixture.

The tackifier resin used in the present invention is not particularly limited, and may be various known ones.
For example, rosin resin, terpene resin, cumarone resin, phenol resin, petroleum hydrocarbon resin, and the like.

Here, specific examples of the rosin resin include:
Rosin, polymerized rosin, disproportionated rosin, hydrogenated rosin, maleated rosin and fumarated rosin, glycerin ester of these rosins, pentaerythritol ester,
Examples thereof include ester derivatives such as methyl ester and triethylene glycol ester, and rosin-modified phenol resin.

Specific examples of the terpene resin include polyterpene resin, terpene phenol resin, terpene hydrogenated resin, styrene-modified terpene resin, α-pinene resin and β-pinene resin. Specific examples of the coumarone-based resin include a coumarone resin, a coumarone-indene resin, and a mixture of a coumarone resin with a naphthenic oil, a phenol resin, rosin, and the like.

Examples of the phenol resin include pt
Examples include tert-butylphenol / acetylene resin, phenol / formaldehyde resin, and xylene / formaldehyde resin. Specific examples of petroleum hydrocarbon resins include aromatic hydrocarbon resins, aliphatic hydrocarbon resins, aliphatic cyclic hydrocarbon resins, and aliphatic hydrocarbon resins.
Alicyclic petroleum resin, aliphatic / aromatic petroleum resin, polymer of unsaturated hydrocarbon, hydrogenated hydrocarbon resin, polybutene, atactic polypropylene, liquid polybutadiene, cis-1,4-polyisoprene rubber, modified Liquid polyisoprene rubber and the like can be mentioned.

In the present invention, among the above-mentioned various tackifying resins, rosin glycerin ester, rosin pentaerythritol ester, rosin-modified phenol resin and terpene phenol resin are preferably used. The above-mentioned various tackifier resins may be used alone or in combination of two or more.

The mixing ratio of the tackifier resin to the styrene-based thermoplastic elastomer is usually preferably set to 0.1 to 230 parts by weight, preferably to 1 to 45 parts by weight, per 100 parts by weight of the styrene-based thermoplastic elastomer. It is more preferable to set. When the mixing ratio of the tackifier resin is less than 0.1 part by weight, it may be difficult to obtain a latex having excellent mechanical stability. Conversely, if the amount exceeds 230 parts by weight, a styrene-based thermoplastic elastomer latex having excellent mechanical stability can be obtained, but the latex may impair essential functions required for the styrene-based thermoplastic elastomer latex. There is.

The method for preparing the organic phase in which the above-mentioned styrene-based thermoplastic elastomer and tackifying resin are dissolved in an organic solvent is not particularly limited. And a method of separately dissolving a styrene-based thermoplastic elastomer and a tackifier resin in an organic solvent and mixing, or a method of previously kneading a styrene-based thermoplastic elastomer and a tackifier resin with a kneader or a roll. And a method of dissolving the resulting mixture in an organic solvent.

The organic solvent used for preparing the organic phase is not particularly limited as long as it can dissolve both the styrenic thermoplastic elastomer and the tackifying resin. For example, hexane or heptane And alicyclic hydrocarbon-based organic solvents such as cyclohexane, and aromatic hydrocarbon-based organic solvents such as benzene, toluene and xylene.
These organic solvents may be used alone or in combination of two or more.

The concentration of the styrenic thermoplastic elastomer and the tackifier resin in the organic phase is not particularly limited, but is usually such that the total concentration of the two in the organic solvent is 5 to 40% by weight. It is preferable to set.

On the other hand, the dispersants used for preparing the aqueous phase are various emulsifiers of anionic type, cationic type and nonionic type. Here, as the anionic emulsifier, for example, sodium polyoxyethylene lauryl ether sulfate, sodium alkylbenzene sulfonate,
Sodium alkyl sulfate, sodium naphthalene sulfonate formalin condensate, fatty acid salts such as sodium dialkyl sulfosuccinate and aliphatic potassium, sodium polyacrylate, sodium polymethacrylate and sodium salt of styrene maleic anhydride copolymer can be exemplified. . Among these, sodium dialkyl sulfosuccinate is particularly preferably used.

Examples of the cationic emulsifier include quaternary oleylethyldimethylammonium chloride, quaternary didecyldimethylammonium chloride, quaternary tallow alkyltrimethylammonium bromide, and quaternary cocoalkyldimethylbenzylammonium chloride. Quaternary ammonium salts such as quaternary alkyltrimethylammonium chloride and quaternary dodecylethyldimethylammonium sulfate ethyl ester, octadecylamine acetate, tetradecylamine acetate, octylamine acetate, cocoalkylamine acetate, tallow Alkylamine salts such as alkylamine acetate, cocoalkylamine hydrochloride, dodecylamine hydrochloride, tallow alkyldiamine acetate and cocoalkyldiamine hydrochloride, tallow alkyl Ethylene oxide adducts of diamines, cationized polyvinyl alcohol, cationized hydroxyethyl cellulose and poly dimethyl diallyl ammonium chloride and the like. Among these, quaternary dodecylethyldimethylammonium sulfate ethyl ester, tetradecylamine acetate,
Tallow alkyldiamine acetate is particularly preferably used.

Further, nonionic emulsifiers include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene sorbitan alkylate, oxyethylene oxypropylene block copolymer, polyglycerin ester,
Polyvinyl alcohol, hydroxyethyl cellulose,
Methyl cellulose and hydroxypropyl cellulose can be exemplified. Among these, polyoxyethylene alkylphenyl ether is particularly preferably used.

The above-mentioned dispersants may be used alone or in combination of two or more.

When preparing the aqueous phase containing the above dispersant, the dispersant is usually added to water and dissolved. At this time, the amount of the dispersant to be added is not particularly limited, but it is usually preferable to set the concentration in water to be 0.1 to 50% by weight.

In the step of mixing and emulsifying the organic phase containing the styrene-based thermoplastic elastomer and the aqueous phase containing the dispersant, the mixing ratio of the organic phase and the aqueous phase is usually the same as that of the styrene-based heat contained in the organic phase. The ratio of the dispersant is preferably set to 1 to 15% by weight, more preferably 2 to 10% by weight, based on the total amount of the plastic elastomer and the tackifier resin. When the proportion of the dispersant is less than 1% by weight, it may be difficult to obtain a stable emulsion. On the other hand, if it exceeds 15% by weight, emulsification becomes easy but uneconomical, and various physical properties of the obtained styrene-based thermoplastic elastomer latex may be impaired.

The method for mixing and emulsifying the organic phase and the aqueous phase is not particularly limited, and for example, stirring and mixing may be performed using an emulsifier having an appropriate shearing force, such as a homogenizer or a colloid mill. Or a method of dispersing and mixing using an ultrasonic disperser or the like, but it is usually preferable to employ a method of stirring and mixing. The temperature at the time of emulsification is not particularly limited, but is usually preferably set in the range of 5 to 70 ° C.

The intended styrene-based thermoplastic elastomer latex can be obtained by removing the organic solvent from the emulsion obtained by the above-mentioned emulsification step. The removal of the organic solvent can be generally carried out according to a usual distillation method in which the emulsion is heated under reduced pressure. The styrene-based thermoplastic elastomer latex thus obtained can be concentrated to a desired concentration by an operation such as heat concentration, centrifugation or wet separation if necessary.

The styrene-based thermoplastic elastomer latex obtained according to the production method of the present invention as described above is
Those having a weight average particle diameter of 0.1 to 10 μm are preferred.
When the weight average particle diameter is less than 0.1 μm, the mechanical stability of the styrene-based thermoplastic elastomer latex is increased, but the viscosity is increased, so that handling becomes difficult. Conversely, if it exceeds 10 μm, not only the mechanical stability of the styrene-based thermoplastic elastomer latex may be reduced, but also the static stability may be reduced. In addition, this weight average particle diameter can be achieved by appropriately adjusting the stirring and mixing operation or the dispersion and mixing operation in the emulsification step.

The styrene-based thermoplastic elastomer latex obtained by the production method of the present invention is, for example, a modifier for a plastic, a thermosetting resin, asphalt or asphalt emulsion for road pavement, a tackifier / adhesive, a sealing material or a plastic molding. It can be widely used as a coating agent for bodies, various films and various sheets.

The styrene-based thermoplastic elastomer latex obtained by the present invention is produced after dissolving a predetermined amount of the styrene-based thermoplastic elastomer and the above-mentioned tackifying resin in an organic phase. When used for various applications, even when mechanical shearing force is applied by a stirrer, pump, or the like, aggregates are hardly generated, and mechanical stability is good.

[0034]

EXAMPLE 1 In a separable flask having an internal volume of 500 ml, 27 g of a styrene-butadiene-styrene block copolymer (trade name "Clayton D1101" manufactured by Shell Chemicals: styrene content = 31% by weight), rosin-modified Phenolic resin (trade name “TAMANOL 135” of Arakawa Chemical Co., Ltd.) 3
g and 170 g of toluene were added and dissolved under stirring at room temperature.

To the obtained toluene solution, quaternary dodecylethyldimethylammonium sulfate ethyl ester 1.5
g was dissolved in 100 g of water, and the mixture was stirred and mixed for 2 minutes using a homomixer (trade name “TK homomixer M type” of Tokushu Kika Kogyo Co., Ltd.) to obtain an emulsion. The rotation speed and temperature during stirring and mixing were set at 12,000 rpm and 30 ° C., respectively. The obtained emulsion is subjected to 40 to 7 under reduced pressure of 100 to 500 torr.
The mixture was heated to 0 ° C., and toluene was distilled off. As a result, a styrene-butadiene-styrene block copolymer latex was obtained.

Example 2 A styrene-ethylene-butylene-styrene block copolymer (trade name "Clayton G1650" of Shell Chemicals) was placed in a separable flask having an internal volume of 500 ml:
24 g of styrene content = 29% by weight), 6 g of rosin pentaerythritol ester (trade name “Pencel A” of Arakawa Chemical Co., Ltd.) and 170 g of xylene were added and dissolved while heating to 50 ° C. with stirring.

To the obtained xylene solution, a solution prepared by dissolving 1.7 g of polyoxyethylene nonylphenyl ether in 100 g of water was added, and the mixture was homogenized (trade name “TK homomixer M, manufactured by Tokushu Kika Kogyo Co., Ltd.). The mixture was stirred and mixed for 2 minutes using a mold “)” to obtain an emulsion. The rotation speed and the temperature during the stirring and mixing were 12,000 rpm, respectively.
m and 30 ° C. The obtained emulsion is 100-
The mixture was heated to 40 to 80 ° C. under a reduced pressure of 500 torr to distill off xylene. As a result, a styrene-ethylene-butylene-styrene block copolymer latex was obtained.

Example 3 In a separable flask having an inner volume of 500 ml, 27 g of a styrene-butadiene-styrene block copolymer (trade name "Clayton D1101" manufactured by Shell Chemicals: styrene content = 31% by weight), and rosin-modified phenol Resin (trade name “TAMANOL 135” of Arakawa Chemical Co., Ltd.) 3
g and 170 g of toluene were added and dissolved under stirring at room temperature.

To the obtained toluene solution, a solution prepared by dissolving 1.5 g of tallow alkyldiamine acetate in 80 g of water was added, and the mixture was homogenized (trade name “TK homomixer M type, manufactured by Tokushu Kika Kogyo Co., Ltd.). )) To obtain an emulsion by stirring and mixing for 2 minutes. The rotation speed and temperature during stirring and mixing were set at 12,000 rpm and 30 ° C., respectively. The obtained emulsion was heated to 40 to 70 ° C. under reduced pressure of 100 to 500 torr, and toluene was distilled off.
As a result, a styrene-butadiene-styrene block copolymer latex was obtained.

Example 4 In a separable flask having an inner volume of 500 ml, 27 g of a styrene-butadiene-styrene block copolymer (trade name "Clayton D1101" of Shell Chemicals: styrene content = 31% by weight), terpene phenol resin (Yasuhara Chemical Co., Ltd. product name "YS polystar 150") 3g and toluene 160g were added, and it melt | dissolved at room temperature under stirring.

A solution prepared by dissolving 2.0 g of sodium dialkylsulfosuccinate in 120 g of water was added to the obtained toluene solution, and the mixture was added to a homomixer (trade name “TK homomixer M type” manufactured by Tokushu Kika Kogyo Co., Ltd.). ) Was stirred and mixed for 2 minutes to obtain an emulsion. The rotation speed and temperature during stirring and mixing were set at 12,000 rpm and 30 ° C., respectively. 100-500 of the obtained emulsion
The mixture was heated to 40 to 70 ° C. under a reduced pressure of torr, and toluene was distilled off. As a result, a styrene-butadiene-styrene block copolymer latex was obtained.

Example 5 In a separable flask having an internal volume of 500 ml, 24 g of styrene-isoprene-styrene block copolymer (trade name "Clayton D1107" of Shell Chemicals: styrene content = 15% by weight), rosin glycerin ester (Arakawa Chemical Co., Ltd. product name "Super Ester A
6 g of -100 ″) and 170 g of toluene were added and dissolved while heating to 50 ° C. with stirring.

To the obtained toluene solution, a solution prepared by dissolving 1.8 g of tetradecylamine acetate in 100 g of water was added, and this was mixed with a homomixer (trade name “TK homomixer M type, manufactured by Tokushu Kika Kogyo Co., Ltd.). )) To obtain an emulsion by stirring and mixing for 2 minutes. The rotation speed and temperature during stirring and mixing were set at 12,000 rpm and 30 ° C., respectively. The obtained emulsion was heated to 40 to 70 ° C. under reduced pressure of 100 to 500 torr, and toluene was distilled off.
As a result, a styrene-isoprene-styrene block copolymer latex was obtained.

Comparative Example 1 A latex of a styrene-butadiene-styrene block copolymer was obtained in the same manner as in Example 1 except that the rosin-modified phenol resin was not used.

Evaluation The latex obtained in each of Examples and Comparative Example 1 was examined for weight average particle diameter and mechanical stability according to the following methods. Table 1 shows the results. (Weight average particle diameter) A latex particle size distribution analyzer (trade name “SALD-
2000 J ").

(Mechanical Stability) Evaluation was made using a Claxson latex mechanical stability tester. Here, the latex was adjusted to a solid content of 55% by weight, and then 80 g was weighed in a predetermined container.
14.0 using a 0.8 mm, 1.57 mm thick disk
The mixture was stirred at 00 rpm. At this time, the time required until a visually-determinable aggregate was formed in the latex was measured, and the mechanical stability of the latex was evaluated according to the time. The time required for the formation of aggregates is 15
If it is not less than minutes, it can be determined that the mechanical stability of the latex is excellent.

[0047]

[Table 1]

[0048]

According to the production method of the present invention, since the styrene-based thermoplastic elastomer and the tackifier resin are dissolved in the organic phase before emulsification, a styrene-based thermoplastic elastomer latex having excellent mechanical stability is obtained. be able to.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masato Utsumi 1st Irifunecho, Shikarima-ku, Himeji-shi, Hyogo Sumitomo Seika Co., Ltd. Sumitomo Seika Co., Ltd. 2nd Research Laboratory F-term (Reference) 4F070 AA06 AA08 AA12 AA15 AA44 AA64 AA68 AB01 AB08 AB11 AC12 AE11 AE14 AE28 CA01 CB03 CB13 4J002 AC03X AC06X AF02X BA00X BB13X BB17X BG00X BP00X GL00X

Claims (5)

[Claims] 1. A styrene thermoplastic resin comprising: a step of preparing an organic phase containing 100 parts by weight of a styrene-based thermoplastic elastomer and 0.1 to 230 parts by weight of a tackifier resin; and a step of emulsifying the organic phase. A method for producing an elastomer latex. 2. The method according to claim 1, wherein the tackifying resin is at least one selected from the group consisting of a rosin resin, a terpene resin, a coumarone resin, a phenol resin and a petroleum hydrocarbon resin. A method for producing a styrene-based thermoplastic elastomer latex. 3. The styrenic thermoplastic elastomer according to claim 1,
Styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butadiene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer and styrene-ethylene-propylene- The method for producing a styrene-based thermoplastic elastomer latex according to claim 1, wherein the latex is at least one member selected from the group consisting of a styrene block copolymer. 4. The method for producing a styrene-based thermoplastic elastomer latex according to claim 1, wherein the weight-average particle diameter of the styrene-based thermoplastic elastomer latex is 0.1 to 10 μm. 5. A process comprising preparing an organic phase containing 100 parts by weight of a styrenic thermoplastic elastomer and 0.1 to 230 parts by weight of a tackifying resin, and emulsifying the organic phase. Styrene-based thermoplastic elastomer latex.