JPH0446965B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is directed to a method in which a crystalline polymer containing a high proportion of unsaturated hydrocarbon groups in the side chain obtained by polymerization of a conjugated diene monomer and other polymers are the same. The present invention relates to a method for producing polymer particles that coexist within the particles. [Prior Art] 1,2-polybutadiene, which is a crystalline polymer having a high proportion of vinyl groups in its side chains, has features such as a high melting point, excellent mechanical properties, and solvent resistance. JP-A-56-79169), coating agents (JP-A-56-98160), asphalt compositions (JP-A-50-135114), thermal adhesives (JP-A-50-13674) , Japanese Patent Publication No. 56-89934
Publication No.), Photosensitive resin for flexo printing plates (Unexamined Japanese Patent Publication No. 1983), Photosensitive resin for flexographic printing plates
-12004, JP-A-52-64301), carpet backing agent (JP-A-52-72683), foam (JP-A-55-73071, JP-A-52)
-43873 Publication) and other fields. However, since it is generally necessary to use an organometallic compound as a catalyst in the synthesis of such crystalline polymers, it is difficult to polymerize them in an aqueous system, and therefore it is generally said that they must be produced by solution polymerization. However, this causes various problems such as the following. (1) The viscosity of the reaction solution increases as the polymerization reaction progresses, making it difficult to control the agitation and temperature of the solution, making it difficult to obtain a crystalline polymer with desired properties. be. (2) Since the obtained crystalline polymer is in a solution state, it is not easy to separate it, and the solvent must be recovered, so handling is complicated and work efficiency is poor. (3) When using the resulting crystalline polymer in a solution state, it is not only necessary to ensure safety against the odor, toxicity, or flammability of organic solvents, but also to ensure that the organic solvents are not used in the final stage. It must be removed and recovered, and there are limits to its usage. For these reasons, it is desired to develop a method for producing crystalline polymers in an aqueous system. [Problems to be Solved by the Invention] The present invention has been made against the above-mentioned background, and it solves the problem of deactivation of organometallic compound catalysts in aqueous systems, and can be used in various applications. A method for efficiently and easily producing polymer particles in an aqueous dispersion in which a crystalline polymer having a high proportion of unsaturated hydrocarbon groups in the side chain and other polymers coexist in the same particle, which is useful for The purpose is to provide a manufacturing method that can. [Means for solving the problems] Particularly characteristic points of the manufacturing method of the present invention are as follows.
The catalyst to be used is a specific one that is composed of a first catalyst component solution and a second catalyst component, which will be described in detail later, and exhibits a catalytic effect only when both catalyst components are combined, and each of these catalyst components is added stepwise to the reaction system dispersion in the following steps () and () to carry out polymerization. Step (): Mixing an aqueous dispersion formed by dispersing polymer seed particles containing a conjugated diene monomer in water and an aqueous dispersion formed by dispersing the first catalyst component solution in water, The first catalyst component solution is brought into contact with and absorbed by the polymer seed particles. Step (): A second catalyst component is added to the system obtained in step () to perform polymerization. The present invention will be explained in detail below. The aqueous dispersion of polymer seed particles used in the step () contains a conjugated diene monomer in the polymer seed particles, and such an aqueous dispersion is prepared, for example, by the following method. be able to. The first method for preparing an aqueous dispersion is to add an amount equivalent to 200 parts by weight or less per 100 parts by weight of the polymer seed particles to an aqueous dispersion (emulsion or suspension) containing polymer seed particles as a dispersed phase. An example of this method is to add a conjugated diene monomer and mix and stir the mixture. Here, if the amount of conjugated diene monomer used is excessive with respect to the polymer seed particles, the amount of conjugated diene monomer remaining in the dispersion medium without being absorbed by the polymer seed particles will increase. As a result, unexpected new polymer particles are generated, which is undesirable. The aqueous dispersion in which polymer seed particles are dispersed used in the above step () is not particularly limited, and examples include an emulsion made of dispersed particles with a particle size of 0.05 to 6 μm obtained by emulsion polymerization, or A suspension made of dispersed particles with a particle size of 1 to 100 μm and the like obtained by suspension polymerization can be used. Polymers constituting such dispersed particles include polystyrene, polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, acrylic ester copolymer, methacrylic ester copolymer, polyisoprene, butadiene-isoprene copolymer. Polychloroprene, etc. can be mentioned. The aqueous dispersion may be a known dispersion such as a cis-1,4 polyisoprene dispersion, which is formed by redispersing a polymer obtained by solution polymerization or the like in water using an emulsifier. It is also possible to use natural rubber latex or a concentrate thereof. The second method for preparing an aqueous dispersion is to prepare an emulsion containing a conjugated diene monomer and perform emulsion polymerization, and when the polymerization conversion rate reaches 99% or less, preferably 90% or less, a polymerization terminator is added. An example of this method is to add a substance to stop the polymerization. Any polymerization terminator can be used as long as it does not cause loss of activity of step () or the first or second catalyst component used in step (), and N,N-diethylhydroxylamine , amine compounds such as tetraethylenepentamine; phenolic compounds such as p-tert-butylcatechol, di-tert-amylhydroquinone, α-nitroso-β-naphthol;
Examples include hydrazine compounds such as phenylhydrazine; sodium nitrite; and the like. As the conjugated diene monomer contained in the polymer seed particles in the above aqueous dispersion, those having 4 to 5 carbon atoms such as butadiene and isoprene can be used, and 1,3-butadiene is particularly preferred. Moreover, these conjugated diene monomers can also be used after being dissolved in an organic solvent, if necessary. Examples of such organic solvents include aromatic hydrocarbon compounds such as benzene, toluene, and xylene; aliphatic hydrocarbon compounds such as pentane, hexane, heptane, and octane; and halogenated hydrocarbon compounds such as methylene chloride, ethylene dichloride, trichloroethane, and chlorobenzene. Hydrogen compounds; Ester solvents such as ethyl acetate, propyl acetate, butyl acetate, ethyl octylate, ε-caprolactone, γ-valerolactone; methanol, ethanol, isopropyl alcohol, n-butanol, sec-butanol,
Alcohol solvents such as octanol and ethylene glycol; Ketone solvents such as acetone, methyl ethyl ketone, acetophenone, and acetylacetone; Nitrile solvents such as acetonitrile, adiponitrile, and benzonitrile; ε-caprolactam, propiolactam, butyrolactam, valerolactam, N- Amide solvents such as methylpyrrolidone, N-ethylpyrrolidone, N-methylformamide, N-ethylformamide, and N,N-dimethylformamide can be mentioned. Furthermore, these organic solvents can also be used as a solution for the second catalyst component described below. The first catalyst component solution used in step () of the present invention comprises (A) a cobalt compound and (B) an organometallic compound formed by an alkali metal, a metal of Groups 1 to 3 of the periodic table; Similarly, at least one metal or compound selected from the group of metal hydrides formed by metals from Groups to Groups of the Periodic Table is added in a molar amount of 1 to 1000 times the cobalt compound (A). (C) in the presence of a conjugated diene compound. Examples of the cobalt compound (A) for forming the first catalyst component solution include organic acid salts such as cobalt octylate, cobalt naphthenate, cobalt benzoate, cobalt oxalate, cobalt malonate, and cobalt acetate; Cobalt complexes such as cobalt acetylacetonate, cobalt trisacetylacetonate, cobalt acetoacetate ethyl ester, triphenylphosphine complex of cobalt bromide, tri-m-trisphosphine complex of cobalt bromide, tri-m-cobalt bromide Triarylphosphine complexes of cobalt halides such as xylylphosphine complexes, pyridine complexes of cobalt chloride, pyridine derivative complexes of cobalt halides such as β-picoline complexes of cobalt chloride, ethyl alcohol complexes of cobalt chloride, (1 ,3-butadiene)[1-(2-methyl-3-butenyl)-π
-allyl]cobalt, tris-π-allylcobalt, bicyclo-[3,3,0]-octidienyl-
1,5-cyclooctadiene cobalt, bis-
Examples include monovalent or zero-valent cobalt complexes such as (π-allyl)-halogenocobalt (where the halogen is any one of I, Br, and Cl) and octacarbonyl dicobalt. These cobalt compounds can be used alone or in combination of two or more. Among group (B) for forming the first catalyst component solution, sodium and lithium are preferably used as alkali metals, and organometallic compounds of metals from Groups to Groups of the periodic table or metal hydrogen are preferably used. As the compound, a compound that reduces a cobalt compound is preferably used. Metals from Groups to Groups of the Periodic Table include a, b, a, b, a, b
Metals of the groups a, a,
Group a is preferred, and preferred metals include lithium, sodium, potassium, magnesium, zinc, and aluminum, and particularly preferred metals include lithium, magnesium, and aluminum. Preferred organometallic compounds or metal hydrides include alkyl derivatives having 1 to 6 carbon atoms or hydrogenated derivatives of the above metals, such as ethyllithium, n-butyllithium, sec-butyllithium, t-butyllithium, etc. Organolithium compounds, organozinc compounds such as diethylzinc and dimethylzinc, butylmagnesium chloride,
Organomagnesium compounds such as ethylmagnesium bromide, dibutylmagnesium, dihexylmagnesium, trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tridodecylaluminum, diethylaluminum chloride, diisobutylaluminum chloride, ethylaluminum sesquichloride, ethyl Examples include organoaluminum compounds such as aluminum dichloride and tetraethylaluminoxane, and metal hydride compounds such as lithium aluminum hydride, sodium boron hydride, and lithium boron hydride. These metal compounds can be used alone or in combination of two or more. The conjugated diene compound (C) for forming the first catalyst component solution may be the same or different from the conjugated diene monomer used in step (), for example, a carbon compound such as butadiene or isoprene. It mainly refers to conjugated diene compounds of numbers 4 to 5, but is not limited thereto, and also includes oligomers or complexes of these conjugated diene compounds. The method of preparing the first catalyst component solution is extremely important. The method for preparing this catalyst component solution is as follows: First, in the presence of (C) a conjugated diene compound, a specific amount of (A) a cobalt compound and (B) an alkali metal,
and an organometallic compound or a metal hydride of the above group. In this preparation, the amount of the conjugated diene compound (C) to be used is preferably 1 to 1000 mol, more preferably 6 to 300 mol, per 1 mol of the cobalt compound (A), and (B) an alkali metal, periodic The amount of the organometallic compound or metal hydride in Table 1 and Group 1 to be used is preferably 0.3 to 100 mol, more preferably 0.9 to 50 mol, per 1 mol of cobalt compound (A). The temperature during preparation is preferably -78°C to 100°C, more preferably -30°C to 50°C. By stirring the solvent and catalyst component as necessary during preparation, the reaction between (A) the cobalt compound and (B) the alkali metal, organometallic compound, or metal hydride can be carried out uniformly. Here, the solvent used for the preparation is a solvent with low solubility in water such as n-hexane, n-heptane, n-pentane, refined kerosene, or toluene, xylene,
Although a solvent having relatively high solubility in water such as cyclohexane can be used, the former solvent or a mixed solvent of this solution and the latter solvent can be preferably used. The second catalyst component used in step () consists of at least one compound selected from carbon disulfide, phenylisothiocyanate, and a xanthogel compound. There are no particular restrictions on the use of these second catalyst components, but
It is desirable to remove dissolved oxygen by bubbling with nitrogen gas or the like before use. The above xanthogen compound has the general formula

〔Effect of the invention〕

According to the production method of the present invention, polymer seed particles containing a conjugated diene monomer in advance,
By absorbing the first catalyst component solution and then absorbing the second catalyst component to carry out the polymerization reaction, a crystalline conjugated diene polymer which is extremely useful industrially can be produced, as is clear from the examples described later. and other polymers coexisting within the same particle can be easily produced in high yield. By pre-containing a conjugated diene monomer in the polymer seed particles and then adding a catalyst to carry out polymerization, it is possible to carry out polymerization without significantly changing the emulsion polymerization process used in ordinary synthetic rubber production, and with the addition of some additional equipment. Since it can be implemented by providing it, it has the advantage of being easy to industrialize. Further, by preparing the first catalyst component solution as an aqueous dispersion in advance and mixing and stirring this with an aqueous dispersion of polymer seed particles containing a conjugated diene monomer, the first catalyst component solution and the polymer This is advantageous in that the first catalyst component solution can be efficiently absorbed into the polymer seed particles as a result of the increased opportunity for contact with the seed particles. In addition, by appropriately selecting the type of polymer constituting the polymer seed particles, the composition ratio of the polymer and the conjugated diene monomer contained in the polymer seed particles, etc., the results can be obtained. The melting point or fine structure of the polymer can be controlled, and the polymer can be easily modified. Such polymers are crystalline polymers that have a high proportion of vinyl groups in their side chains, have a high degree of crystallinity, have a high melting point, and are excellent in impact resistance, solvent resistance, etc. It can be used in a wide variety of applications, especially in the form of aqueous dispersions, such as paper coating compositions, carpet backing agents, asphalt compositions, foam rubbers, paints. , adhesives, and organic fillers for rubber or resin, and is effective for improving and modifying the strength and heat resistance of these various materials. [Embodiments of the Invention] Examples of the present invention will be described below, but the present invention is not limited thereto. In addition, “department”
and "%" represent parts by weight and % by weight. Example 1 15.5 parts of solid content of natural rubber latex (manufactured in Felda, Malaysia) with an average particle diameter of 0.4 μm and 48 parts of distilled water were placed in a pressure-resistant reaction vessel, and the system was sufficiently bubbled with nitrogen gas. Next, the system was heated to 5°C.
After the mixture was cooled to 3.1 parts, 3.1 parts of 1,3-butadiene was added and stirred for 30 minutes to allow the latex particles (seed particles) to absorb 1,3-butadiene. This will be referred to as "seed dispersion A." 0.33 part of a solution of 0.2 mol/l of cobalt octylic acid in n-hexane was placed in a pressure-resistant container that had been previously purged with nitrogen, and then 0.56 part of cyclohexane was added thereto and stirred well. After the system was cooled to 5°C, 0.11 part of 1,3-butadiene was added and stirred for 30 minutes. To this was added 0.5 mol/l of triisobutylaluminum.
0.39 parts of hexane solution was added and stirred for 30 minutes while cooling to obtain a first catalyst component solution. To this first catalyst component solution, 0.2 parts of sodium dodecylbenzenesulfonate (solid content) and 10 parts of distilled water bubbled with nitrogen were added, and the mixture was preliminarily dispersed using a homomixer under a nitrogen gas atmosphere. Emulsifying and dispersing with Manton Gaulin's "15M type"), the particle size of the dispersed particles is 0.1 ~
A 0.3 μm aqueous dispersion was prepared. This is called "first catalyst dispersion A." This first catalyst dispersion A was added to the seed dispersion A prepared previously and stirred for 30 minutes while maintaining the temperature at 5°C. Next, add 0.6 mol/l of carbon disulfide to this liquid.
n-hexane solution (hereinafter referred to as "second catalyst solution A")
That's what it means. 0.11 part was added, and polymerization was carried out with gentle stirring for 3 hours while controlling the temperature at 5°C. In the above polymerization, the polymerization yield was 95%, and no coagulum was observed. When we examined the obtained polymer, we found that its melting point was 200°C by differential scanning calorimetry, and the infrared absorption spectrum showed a melting point of 200°C.
The content of vinyl groups was found to be 98% by analytical method. Example 2 70 parts of 1,3-butadiene, 30 parts of styrene, 5.0 parts of potassium stearate, 0.1 part of potassium phosphate,
Reaction in which 0.06 parts of sodium ethylenediaminetetraacetate, 0.005 parts of ferrous sulfate, 0.03 parts of sodium formaldehyde sulfoxylate, 0.03 parts of diisopropylbenzene hydroperoxide, 0.2 parts of tertiary dodecyl mercaptan, and 190 parts of distilled water were replaced with nitrogen gas. The mixture was charged into a vessel, and polymerization was started at 5°C while stirring. Approximately 15 hours after starting the reaction, the polymerization rate reached 72%, so 0.15 parts of N,N-diethylhydroxylamine was added to the polymerization system.
The reaction was stopped. This will be referred to as "seed dispersion B." Hereinafter, the above seed dispersion B was used instead of the seed dispersion A in Example 1, and Example 1
first catalyst dispersion A corresponding to 5 times the amount of
Polymerization was carried out in the same manner as in Example 1, except that the second catalyst solution A was used, and when the polymerization conversion rate reached 70%, potassium dimethyldithiocarbamate
Polymerization was stopped by adding 0.1 part. As a result, a latex with no coagulum and good dispersion stability was obtained. When the obtained polymer was examined, the melting point was 200° C. as measured by differential scanning calorimetry, and the vinyl group content was 95% as determined by Morero analysis of infrared absorption spectrum. Example 3 Polymerization was carried out in the same manner as in Example 2 using the multistage polymerization reactor system shown in FIG. As a result, as in Example 2, a latex with good dispersion stability without the generation of coagulum could be obtained continuously and efficiently. Example 4 124 parts of commercially available acrylic latex "AE203" (manufactured by Japan Synthetic Rubber Co., Ltd.) as a solid content and 400 parts of distilled water were placed in a pressure-resistant reaction vessel, and the system was sufficiently bubbled with nitrogen gas. Next, after cooling the system to 5℃, 3.1 parts of 1,3-butadiene was added to
Stir for a minute to allow the seed particles to absorb the 1,3-butadiene. This will be referred to as "seed dispersion C." After putting 0.39 parts of a cyclohexane solution containing 0.2 mol/l of cobalt octylic acid into a pressure-resistant container that had been purged with nitrogen in advance, the system was cooled to 5°C, and then 1,3
- After adding 0.11 parts of butadiene, the mixture was stirred for 30 minutes. In this, sodium boron hydride
1.2 parts of a 0.2 mol/l iso-propanol solution was added and stirred for 30 minutes while cooling to obtain a first catalyst component solution. To this first catalyst component solution, 0.2 parts of sodium dodecylbenzenesulfonate (solid content) and 10 parts of distilled water bubbled with nitrogen were added, and the mixture was preliminarily dispersed using a homomixer under a nitrogen gas atmosphere. An aqueous dispersion was prepared by emulsifying and dispersing the mixture using a Manton-Gaulin (Model 15M). This will be referred to as "first catalyst dispersion B." This first catalyst dispersion B was added to the seed dispersion C prepared previously and stirred for 30 minutes while maintaining the temperature at 5°C. Next, 0.11 part of the second catalyst solution A (an n-hexane solution containing 0.6 mol/l of carbon disulfide) was added, and the polymerization was carried out with gentle stirring for 3 hours while maintaining the temperature at 5°C. I did it. As a result, a latex with a polymerization yield of 97% and good dispersion stability with little coagulum was obtained. When the obtained polymer was examined, its melting point was 197°C by differential scanning calorimetry, and the vinyl group content was 96% by Morero analysis. Example 5 0.45 parts of a tetrahydrofuran solution with a cobalt chloride concentration of 0.2 mol/l prepared at a weight ratio of cobalt chloride and pyridine of 1:5.7 was placed in a pressure-resistant container that had been purged with nitrogen in advance, and after cooling the system at 5°C, 1.
0.1 part of 3-butadiene was added and stirred for 30 minutes.
To this was added 0.31 parts of a 1.5% by weight (0.4 mol/l) solution of metallic sodium suspended and dispersed in n-hexane, and the mixture was stirred for 30 minutes while cooling to obtain a first catalyst component solution. To this catalyst component solution, 0.2 parts of sodium dodecylbenzenesulfonate (solid content) and 10 parts of distilled water bubbled with nitrogen gas were added, and after preliminary dispersion using a homomixer under a nitrogen gas atmosphere,
An aqueous dispersion was prepared by emulsifying and dispersing with a homogenizer. This will be referred to as "first catalyst dispersion C." Seed dispersion A was prepared in the same manner as in Example 1, the above-mentioned first catalyst dispersion C was added thereto, and the mixture was heated at 5°C.
The mixture was stirred for 30 minutes while maintaining the temperature. Next, the second catalyst solution A (carbon disulfide 0.6 mol/l
0.11 part of n-hexane solution) was added, and polymerization was carried out with gentle stirring for 3 hours while controlling the polymerization temperature at 5°C. The polymerization yield in the above polymerization reaction was 70%, and no coagulum was observed. Further, the melting point of the polymer determined in the same manner as described above was 188°C, and the content of vinyl groups was 93%. Example 6 After putting 0.39 parts of a cyclohexane solution containing 0.2 mol/l of cobalt naphthenate into a pressure-resistant container that had been purged with nitrogen in advance, the system was cooled to 5°C, and then 1,3-
0.11 part of butadiene was added, followed by stirring for 30 minutes. Sodium aluminum hydride
1.2 parts of a 0.2 mol/l tetrahydrofuran solution was added and stirred for 30 minutes while cooling to obtain a first catalyst component solution. Using the above as the first catalyst component solution,
Also, as a second catalyst component, dimethylxanthogen disulfide 0.6 mol/l n-hexane solution 0.11
Polymerization was carried out in the same manner as in Example 4, except that The polymerization yield in the above polymerization reaction was 20%, and a latex with good dispersion stability and little coagulum was obtained. Further, the melting point of the polymer determined in the same manner as described above was 160°C, and the content of vinyl groups was 88%. Example 7 Instead of 1.2 parts of iso-propanol solution containing 0.2 mol/l of sodium boron hydride in Example 4, metallic sodium minaphthalene (weight ratio
15:85) 0.7mol/l tetrahydrofuran solution
Polymerization was carried out in the same manner as in Example 4 except that 0.78 part was used. As a result, a latex with a polymerization yield of 98% and good dispersion stability with little coagulum was obtained. In addition, when examining the obtained polymer, the melting point measured by differential scanning calorimetry was 150°C;
The content of vinyl groups is 94% according to Morero analysis method.
It was hot.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram schematically showing a multistage polymerization reaction tank system that can be used to carry out the production method of the present invention. 1-6...Raw material supply source, 8(1)-8(1
2)... Polymerization reaction tank, 12... Source of first catalyst component solution, 10... Source of second catalyst component solution.

Claims (1)

[Claims] 1. In step (), an aqueous dispersion (a) of polymer seed particles containing a conjugated diene monomer, (A) a cobalt compound, (B) an alkali metal, group group of the periodic table. ~ At least one selected from the group of organometallic compounds containing metals of Group 3 and metal hydrides containing metals of Groups 1 to 10 of the periodic table, (C) 1 to 1000 times as much as the cobalt compound (A) above. and an aqueous dispersion (b) of a first catalyst component solution containing a conjugated diene compound corresponding to the mole thereof, and in step (b), a dispersion of a first catalyst component solution selected from the group of carbon disulfide, phenylisothiocyanate and A method for producing polymer particles, characterized in that polymerization is carried out by adding a second catalyst component consisting of at least one type of compound. 2 The average particle size of the dispersed particles made of the first catalyst component solution in the aqueous dispersion (b) is equal to or less than the average particle size of the polymer seed particles containing the conjugated diene monomer in the aqueous dispersion (a). A method for producing polymer particles according to claim 1. 3. A state in which the aqueous dispersion (a) of polymer seed particles containing a conjugated diene monomer emulsion polymerizes the monomer composition containing the conjugated diene monomer, and the conjugated diene monomer remains. 2. The method for producing polymer particles according to claim 1, wherein the polymer particles are obtained by stopping polymerization. 4. The method for producing polymer particles according to claim 1, wherein the preparation of the aqueous dispersion (a), step (), and step () are carried out continuously using a multistage polymerization reaction tank system.