JPS5952881B2 - Method for producing hydrous polymer - Google Patents

Description

Detailed Description of the Invention The present invention involves forming a vinyl monomer into a water-in-oil inverse emulsion in the presence of a liquid rubber having a neutralized carboxyl group at the end, and converting the inverse emulsion into a water-in-oil inverse emulsion in the presence of a polymerization catalyst. The present invention relates to a method for producing a water-containing polymer, which is characterized in that the polymerization is carried out below.

Conventionally, the method of uniformly dispersing water as minute droplets in a liquid resin using a W/0 emulsion mold and then curing the resin as it is to disperse water droplets in the cured resin is well known for unsaturated polyester resins. , the method involves inversely emulsifying water into a vinyl monomer-containing unsaturated polyester in the presence of a surfactant or a basic substance that forms a salt to form a W/O type inverse emulsion; An unsaturated polyester cured product is obtained by polymerizing the emulsion in the presence of a radical polymerization catalyst or a redox polymerization catalyst. This product is known as a cured hydrous unsaturated polyester that not only has the advantage of being inexpensive as an extender but also has excellent heat resistance and flame resistance. Among these methods, the method of preparing an inverse emulsion using a basic substance (Japanese Patent Publication No. 44-31831, Japanese Patent Publication No. 45-10824)
The method disclosed in Japanese Patent Publication No. 2003-111012 is a very convenient method in which the terminal carboxyl group of the polyester itself is converted into a salt and used as an emulsifier. That is, it is advantageous to add an appropriate amount of base to the uncured unsaturated polyester for making the resin, without having to prepare a new inverse emulsifier, because a portion of the base will directly convert into salt and act as an inverse emulsifier. However, polyesters prepared by converting the terminal carboxyl groups into salts usually contain about 10 to 50% of vinyl monomer, but if the vinyl monomer content is further increased, it becomes difficult to prepare an inverse emulsion. Therefore, polyesters whose terminal carboxyl groups have been neutralized are unsuitable as inverse emulsifiers for vinyl monomers. On the other hand, for the preparation of inverse emulsions in which water is dispersed in various liquid vinyl monomers, 5-graft copolymers in which styrene, vinyl acetate, and other vinyl monomers are grafted onto polyethylene oxide or polypropylene oxide are used as inverse emulsifiers. It is known to be used.

(Special Publication No. 38-23491).

However, the problem with all of the above-mentioned known examples is that the inverse emulsion has a high viscosity, making it inconvenient to handle such as casting, and making it difficult to add organic or inorganic fillers and reinforcing materials. The present invention has solved this drawback, and since the viscosity of the inverse emulsion is significantly lower than that of the above-mentioned known examples, workability such as casting is good, and organic and inorganic fillers and reinforcing materials can be used. It can be easily cast even if the desired amount is added. On the other hand, liquid rubber has recently been attracting industrial attention.

Since it is a liquid, all kinds of rubber products can be made using liquid process technology, using simpler equipment than general-purpose rubber. It is used not only for elastomer molded products obtained from general-purpose rubber, but also for caulking materials, sealants, foams such as sponges, adhesives, and binders for mouthpiece fuels. However, little is known about the application of liquid rubber to the field of surfactants. As a result of intensive studies aimed at developing new uses for liquid rubber as an inverse emulsifier, the present inventors discovered that vinyl monomers can be produced by introducing neutralized carboxyl groups into the terminals of liquid rubber. It was discovered that it acts as an excellent inverse emulsifier for

That is, in the present invention, a polymerizable monomer is formed into an inverse emulsion in the presence of a liquid rubber having a neutralized carboxyl group at the end, and the inverse emulsion is polymerized in the presence of a polymerization catalyst. Two:=:. The liquid rubber having a neutralized terminal carboxyl group used in the present invention in the method for producing a water-containing polymer is derived from a liquid rubber having a terminal carboxyl group. The liquid rubber having terminal carboxyl groups is not particularly limited as long as it has an average of two terminal carboxyl groups in the molecule. Further, in addition to the terminal carboxyl group, there is no problem in having a side chain carboxyl group as well. The carboxyl group in the carboxyl group-terminated liquid rubber may be directly connected to the liquid rubber main chain in the molecule, or may be connected through an ester bond. A liquid rubber whose terminal carboxyl groups are linked by an ester bond can be obtained by an addition reaction (monoesterification reaction) between a hydroxyl group-terminated liquid rubber and a dibasic acid anhydride. The liquid rubber in which the carboxyl group is directly connected to the main chain is preferably a carboxyl-terminated liquid rubber containing butadiene as a main component. Particularly preferred liquid rubber for the purpose of the present invention is, for example, polybutadiene having a terminal carboxyl group. , butadiene-atarylonitrile copolymer, butadiene-styrene copolymer, and the like. Furthermore, the hydroxyl group-terminated liquid rubber used to prepare the liquid rubber in which the carboxyl groups are connected by ester bonds is preferably a hydroxyl group-terminated liquid rubber containing butadiene as a main component.
Particularly preferred liquid rubbers for the purpose of the present invention include, for example, polybutadiene having a terminal hydroxyl group, butadiene-acrylonitrile copolymer, butadiene-styrene copolymer, and the like. The dibasic acid anhydride to be added to the terminal hydroxyl group is not particularly limited, and examples thereof include phthalic anhydride, maleic anhydride, succinic anhydride, hexahydrophthalic anhydride, etc., but in particular, the dibasic acid anhydride to which the addition reaction proceeds easily Succinic anhydride is preferred. The neutralized carboxyl group is introduced into the liquid rubber by neutralizing the terminal carboxyl group in the liquid rubber with a basic substance that generates cations, and the cations include metal ions. preferable.

The metal ion is not particularly limited, but typically includes monovalent or divalent metals. Monovalent metals such as Na and K
Examples of the divalent metals include alkaline metals such as alkaline metals, and examples of divalent metals include metals from the alkaline earth group and sub-alkaline earth group. Particularly preferred from an industrial standpoint are Na, Mg, Ca, and the like. The carboxyl group neutralization reaction is preferably carried out to such an extent that at least one neutralized terminal carboxyl group is introduced into the molecules of the liquid rubber on average. There is no problem in the present invention even if the liquid rubber has unreacted carboxyl groups.
Of course, the terminal carboxyl groups may be completely neutralized, but liquid rubber in which both terminal carboxyl groups are completely neutralized is difficult to completely dissolve in vinyl monomers, and is rather partially neutralized. Liquid rubber is preferred in some cases.
On the other hand, when no neutralization is performed, that is, a liquid rubber containing only unreacted terminal carboxyl groups has no effect as an inverse emulsifier. In the present invention, vinyl monomers are first made into an inverse emulsion in the presence of the liquid rubber having neutralized carboxyl groups at the ends prepared as described above.

The vinyl monomer used here is not particularly limited, but examples include styrene, α-methylstyrene, acrylic ester, methacrylic ester, acrylonitrile, divinylbenzene, diacrylic acid or dimethacrylic ester of alkylene glycol, etc. can be mentioned. These may be used alone or in combination of two or more. In order to improve the heat resistance and physical properties of the resulting vinyl polymer, it is generally preferable to use a divinyl compound such as ethylene glycol dimethacrylate.
An inverse emulsion is prepared by vigorously stirring a mixture of a vinyl monomer and a liquid rubber having a neutralized carboxylic group at the end as described above while adding water, to obtain a stable inverse emulsion. In this case, the amount of the liquid rubber used is generally about 0.51 to 15%, preferably about 2 to 10%, based on the vinyl monomer. The inverse emulsion thus obtained is a conventional inverse emulsifier. Inverse emulsions of vinyl monomers obtained using graft copolymer 2, which is obtained by grafting styrene, vinyl acetate, or other vinyl monomers onto polyethylene oxide or polypropylene oxide, or unsaturated emulsions obtained by conventional known methods. They have discovered the remarkable characteristic that they exhibit a significantly lower viscosity than inverse emulsions of polyester resins. This is very advantageous in the case of casting, and furthermore, even if a considerable amount of inorganic or organic fillers, reinforcing agents, etc. are added to the inverse emulsion, the inverse emulsion can be easily cast. Next, in the present invention, the inverse emulsion prepared as described above is further polymerized in the presence of a polymerization catalyst, and the polymerization catalyst used here may be a radical forming agent or a redox catalyst. .

The polymerization temperature should generally be 100°C or less, but in consideration of water evaporation, a range of room temperature to 60°C is preferable. The polymer thus obtained is a hydrous polymer with excellent physical properties, containing almost all the water contained during emulsification. Water-containing resins generally have a tendency to gradually lose the water held in the resin through evaporation, but when making use of this tendency to create porous molded products by evaporating water from a water-containing resin, It is preferable that the volatilization rate of water be faster.

It has been found that among the liquid rubbers having neutralized carboxyl groups at the terminals as described above used in the present invention, some give water-containing resins in which water volatilization rate is significantly faster than that of conventional hydrous resins. It is.

Therefore, this tendency is very advantageous when a porous molded article is made by volatilizing water from a hydrous resin. The present invention has a significant feature in this respect as well. Furthermore, it is known that conventional cured hydrated polyester products exhibit considerable dimensional changes as water evaporates, but the hydrated polymer obtained by the method of the present invention exhibits almost no dimensional change due to evaporation of water. It has the characteristic that it is not shown.

Next, the present invention will be explained in more detail with reference to Examples, Production Examples, Reference Examples, and Application Examples.

Production example 1 of inverse emulsifier Carboxyl group-terminated liquid butadiene-acrylonitrile copolymer (HycarCTBNl3OOx8, GOOd
Manufactured by Rich, main characteristic values, carboxyl group% 2.37
, molecular weight 3500, functionality 1.85, acrylonitrile content 18%, specific gravity 0.948 at 25°C) was dissolved in 120 parts of benzene, and while stirring thoroughly at room temperature, a 1% by weight NaOH-methanol solution was prepared. was gradually added dropwise to neutralize 50% of the terminal carboxyl groups to form Na salt.

After the reaction was completed, benzene, methanol, and produced water were distilled off under reduced pressure to obtain inverse emulsifier 1. Production example 2 of inverse emulsifier Carboxyl group-terminated liquid polybutadiene (HycarCTB2OOOxl62, GOOdric
Manufactured by h company, main characteristic values, carboxyl group% 1.9, molecular weight 4800, functionality 2.01, specific gravity 0.9 at 25°C
07) Charge 50 parts of CaOO. After adding 27 parts, the mixture was reacted for about 2 hours at 140° C. under a nitrogen gas stream while stirring well, to obtain an inverse emulsifier 2.

Production example 3 of inverse emulsifier Hydroxyl group-terminated liquid polybutadiene (POlybdR-45
HT. Idemitsu Petrochemical Co., Ltd.) 300 parts, succinic anhydride 32
．． 3 parts (anhydride group/OH group: 1.3 (equivalent ratio)) A small amount of dimethylbenzylamine as a catalyst and 200 parts of chloroform as a solvent were charged into a reaction vessel, and the mixture was reacted at 80 to 90° C. with thorough stirring for 6 hours.

After the reaction, the contents were thoroughly washed with a large amount of water to remove the unreacted succinic anhydride. Next, a 1% by weight NaOH-methanol solution was added dropwise to the chloroform solution of the adduct having a carboxyl group at the terminal, thereby neutralizing 50% of the carboxyl groups to form an Na salt. . After the neutralization reaction, the solvent and produced water were concentrated under reduced pressure to obtain an inverse emulsifier 3. Production example 4 of inverse emulsifier Hydroxyl group-terminated liquid polybutadiene (POlybdR-45
HT) and 31.7 parts of maleic anhydride (acid anhydride group/OH group: 1.3 (equivalent ratio)) in the same manner as in Inverse Emulsifier Production Example 3 to obtain Inverse Emulsifier 4.

Production example 5 of inverse emulsifier Hydroxyl group-terminated liquid polybutadiene, (POlybdR-4
5HT) and 24.9 parts of succinic anhydride (acid anhydride group/0H group = 1.0 (equivalent ratio)) were charged into a reaction vessel.
The mixture was reacted at 20° C. for 4 hours to obtain an adduct having a carboxyl group at the end.

Next, 2.5 parts of MgO, which is equivalent to neutralizing 50% of the carboxyl groups, was added, and a neutralization reaction was carried out at 140° C. for 6 hours to obtain inverse emulsifier 5. Example 1 6 parts of the inverse emulsifier 1 obtained as above was added to a vinyl monomer consisting of 80 parts of styrene and 20 parts of acrylonitrile, and 106 parts of water was added to this while stirring well, resulting in a low viscosity. A stable W/O type inverse emulsion was obtained.

This is added to methyl ethyl ketone peroxide (MEKPO).
) 0.5% by weight and naphthene! Added 0.5% by weight of 10% styrene solution of cobalt acid! ,．． When hexagonal polymerization was carried out using T6OV5, a milky white water-containing polymer was obtained which contained a lot of water contained during emulsification. Example 25 9 parts of the inverse emulsifier 1 obtained above was dissolved in a vinyl monomer consisting of 90 parts of styrene, 30 parts of acrylonitrile, and 30 parts of ethylene glycol dimethacrylate, and 159 parts of water was added dropwise to this with strong stirring. A stable inverse emulsion with low viscosity was obtained.

When this inverse emulsion was polymerized in the same manner as in Example 1, a milky white water-containing polymer was obtained. Example 3 6 parts of the inverse emulsifier 2 obtained in 4 above was dissolved in a vinyl monomer consisting of 90 parts of styrene and 10 parts of ethylene glycol dimethacrylate, and 106 parts of water was added to this with strong stirring to reduce the viscosity. A low and stable inverse emulsion was obtained.

When 0.5% by weight of benzoyl peroxide was added to this inverse emulsion and polymerized at 60° C. for 8 hours, a milky white water-containing polymer containing almost all the water contained during emulsification was obtained. Example 4 To a vinyl monomer consisting of 60 parts of styrene, 20 parts of acrylonitrile, and 20 parts of ethylene glycol dimethacrylate, 4 parts of the inverse emulsifier 3 obtained above was added and dissolved well, and 104 parts of water was stirred vigorously. A stable inverse emulsion with a low viscosity was obtained when the mixture was added at the same time.

This reverse emulsion is MEKPOO. When polymerized for 4 hours at 60°C in the presence of 0.5% by weight of a 10% styrene solution of cobalt naphthenate and 0.5% by weight of a 10% styrene solution, a milky white hydrated polymer containing almost all the water contained during emulsification was obtained. .

Example 5 To a vinyl monomer consisting of 80 parts of methyl methacrylate and 20 parts of ethylene glycol dimethacrylate were added 6 parts of the inverse emulsifier 3 obtained above, and to this was added 106 parts of water.
A stable inverse emulsion with low viscosity was obtained by adding 1 part with strong stirring.

This is MEKPOO. Polymerization was carried out at 60° C. for 4 hours in the presence of 5% by weight and 0.5% by weight of a 10% styrene solution of cobalt naphthenate to obtain a milky white hydrous polymer. Example 6 A stable inverse emulsion with low viscosity was prepared in the same manner as in Example 4, except that the weight ratio of the vinyl monomer solution and water was 1:2, and this was polymerized to form a milky white water-containing polymer. I got it.

Example 7 A stable inverse emulsion with low viscosity was prepared in the same manner as in Example 5, except that the weight ratio of the vinyl monomer solution and water was 1:2, and this was polymerized to form a milky white water-containing polymer. I got it.

Example 8 A stable inverse emulsion with low viscosity was prepared in the same manner as in Example 4, except that the weight ratio of the vinyl monomer solution and water was 1:3, and this was polymerized to form a milky white water-containing polymer. I got it.

Example 9 8 parts of the inverse emulsifier 4 obtained above was added and dissolved in 100 parts of methyl methacrylate, and 108 parts of water was added thereto with thorough stirring to obtain a stable inverse emulsion with low viscosity.

To this was added 1% by weight of benzoyl peroxide and heated to 80°C at 60°C.
After polymerization for a period of time, a milky white water-containing polymer was obtained. Example 10 A stable inverse emulsion with low viscosity was prepared in the same manner as in Example 4, except that inverse emulsifier 5 obtained above was used as the inverse emulsifier, and this was polymerized to obtain a milky white water-containing polymer. .

Example 11 Vinyl monomer 1 consisting of styrene, acrylonitrile and ethylene glycol dimethacrylate (3:1:1)
To 00 parts, 6 parts of the inverse emulsion agent 3 obtained above was added and dissolved well, and 106 parts of water was added thereto to obtain a stable inverse emulsion with low viscosity.

To 100 parts of this inverse emulsion, 10 parts of glass fibers (chopped strands with a length of 1.5 mm) were added and sufficiently stirred to uniformly disperse the fibers. This was polymerized in the same manner as in Example 4 to obtain a milky white water-containing polymer. Example 12 4 parts of the inverse emulsifier 3 obtained above was added to 100 parts of vinyl monomer consisting of styrene, acrylonitrile, and ethylene glycol dimethacrylate (3:1:1).
A vinyl monomer solution was obtained.

To 100 parts of this solution, 320 parts of a slurry of water and calcium monocarbonate (weight ratio 3:5) was added with thorough stirring to form an inverse emulsion. The resulting emulsion had a low viscosity and was easy to cast despite containing a large amount of filler. When this was polymerized in the same manner as in Example 4, a milky white hard hydrated polymer was obtained. Example 13 Vinyl monomer solution 1 prepared in the same manner as Example 12
00 parts of water and 200 parts of a slurry of monocalcium carbonate (weight ratio 1:1) was added to make an inverse emulsion, and chopped strands with a length of 1.5 mm were added to this in a ratio of 5 parts to 100 parts of the emulsion. When these are added in the same proportions, uniformly dispersed, and polymerized in the same manner as in Example 4, a milky white hard hydrated polymer is obtained.

Example 14 10 parts of the inverse emulsifier 4 obtained above was added and dissolved in 100 parts of a vinyl monomer consisting of styrene, acrylonitrile, and divinylbenzene (40:5:2), and 110 parts of water was stirred vigorously. A stable inverse emulsion with low viscosity was prepared by adding the mixture while stirring.

This inverse emulsion was polymerized in the same manner as in Example 9 to obtain a milky white water-containing polymer. All of the hydrous polymers obtained in the above examples are milky white, hard, and excellent solids.

Table 1 shows the physical properties of typical water-containing polymers. The inverse emulsion before polymerization is characterized in that it exhibits a significantly lower viscosity than the inverse emulsion of vinyl monomer or unsaturated polyester resin obtained by conventional known methods. This is also clear from Comparative Examples 3, 4, and 5 shown below. This trend is very advantageous for casting. Comparative Example 1 Carboxyl group-terminated liquid butadiene-acrylonitrile copolymer, (HycarCTBNl3OO×8) 6
1 part was dissolved in a vinyl monomer consisting of 80 parts of styrene and 20 parts of acrylonitrile, and 106 parts of water was added thereto with thorough stirring.

When stirring was stopped after the addition, water separated immediately and no inverse emulsion was formed. Comparative Example 2 Hydroxyl group-terminated liquid polybutadiene, (POlybdR-
45HT) with succinic anhydride and having a carboxyl group at the end was dissolved in a vinyl monomer consisting of 60 parts of styrene, 20 parts of acrylonitrile, and 20 parts of ethylene glycol dimethacrylate, and 1 part of water was dissolved in this.
Add 0.6 parts with vigorous stirring.

Immediately after the addition, stirring was stopped, water began to separate and no inverse emulsion could be formed. Comparative Example 3 15 parts of triethanolamine was added to 300 parts of an unsaturated polyester resin (Kostar Cl5lO, manufactured by Mitsui Toatsu Chemical Co., Ltd.).
．． 300 parts of water in which 2 parts were dissolved was gradually added dropwise while stirring well.

The resulting emulsion was an inverse emulsion and had a very high viscosity, 54,500 CPS at room temperature. Next, add 1 to this
% by weight of benzoyl peroxide was added and polymerized at 60° C. for 4 hours to obtain a white hard hydrous cured product. Comparative Example 4 When 300 parts of water was gradually added dropwise to 300 parts of an unsaturated polyester resin (Rigorak W 1OO5BQ already contains an inverse emulsifier) manufactured by Showa Kobunshi Co., Ltd. with thorough stirring, an inverse emulsion was obtained. Ta.

The viscosity of this at room temperature was 176 CPS. Next, 0.5% by weight of MEKPO and 0.5% by weight of a 10% styrene solution of cobalt naphthenate was added and cured at room temperature for 1 hour to obtain a light brown hard hydrated cured product. Comparative Example 5 Polyethylene oxide (molecular weight 400) and acetic acid. An inverse emulsion was obtained by dissolving 5 parts of an inverse emulsifier obtained by graft polymerization of the same amount of vinyl in a vinyl monomer consisting of 95 parts of styrene and 5 parts of divinylbenzene and adding 105 parts of water with strong stirring. .

This inverse emulsion was extremely viscous and creamy at room temperature. Next, add MEKPO (7) 0.
5% by weight and 10% styrene solution of cobalt naphthenate 0
．． When 5% by weight was added and polymerized at 60°C for 5 hours, a milky white hard hydrated polymer was obtained.

Reference Example Weight loss rate due to water volatilization in a constant temperature and humidity room at 23°C and 50% RH and in a dryer at 60°C for the hydrous polymers obtained in Examples 4 to 7 and Comparative Examples 4 and 5. It was measured.

The time when water volatilization reaches 50% is expressed as half-life,
The results are shown in Table 2. As is clear from this, the water-containing polymer of the present invention is characterized in that the water volatilization rate is extremely fast. This tendency is advantageous when porous moldings are made by volatilization of water. Application Examples The hydrous polymers obtained in Examples 2, 4 to 7, 10, 11, and 13 were dried at 60° C. until they had a constant weight, and water was evaporated to obtain porous polymers.

Their physical properties are shown in Table 3. Filler (calcium carbonate)
It is noteworthy that the porous polymers containing no carbon fibers have a low specific gravity, and the glass fiber-reinforced porous polymers (Examples 11 and 13) have significantly improved impact strength.
On the other hand, although the hydrous cured products obtained in Comparative Examples 3 and 4 were also dried at 60° C., the deformation of the samples became significant as the water evaporated, making it impossible to measure the physical properties.

Claims (1)

[Scope of Claims] 1. Making a vinyl monomer into a water-in-oil inverse emulsion in the presence of a liquid rubber having a neutralized carboxyl group at the terminal, and polymerizing the inverse emulsion in the presence of a polymerization catalyst. A method for producing a hydrous polymer, characterized by: 2. The method for producing a hydrous polymer according to claim 1, wherein the liquid rubber having a neutralized carboxyl group at the terminal is a liquid rubber derived from a carboxyl group-terminated liquid rubber containing butadiene as a main component. 3. The liquid rubber having a neutralized carboxyl group at the terminal is a liquid rubber derived from an adduct of a hydroxyl-terminated liquid rubber containing butadiene as a main component and a dibasic acid anhydride. A method for producing a hydrous polymer.