JPS6343401B2 - - Google Patents

Description

[Detailed description of the invention]

A. Industrial Application Field The present invention relates to a method for producing a cationic emulsion, and more particularly, it relates to a method for producing a cationic emulsion containing a quaternary nitrogen atom and having the general formula (Here, R and R′ represent an alkyl group having 1 to 20 carbon atoms, and R″ represents a carbon atom of 1 to 20.
R represents an alkyl group having 20 atoms or an aromatic or alicyclic group having 6 to 15 carbon atoms;
has 2 to 6 carbon atoms and 1 ethylene bond
represents an aliphatic hydrocarbon group, and X represents a chlorine or bromine atom. ) and methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methacrylic acid Acrylic acid ester monomers such as hydroxyethyl, styrene, acrylonitrile, butadiene,
The present invention relates to a method for producing a cationic emulsion, which comprises polymerizing a vinyl monomer in the presence of a cationic copolymer comprising at least one of isoprene, vinyl chloride, and vinyl acetate. B. Prior Art Conventionally, cationic emulsions obtained by polymerizing vinyl monomers in the presence of cationic emulsifiers have hardly been produced on an industrial scale, although they have various possible uses. The current situation is that this is not the case. There are various reasons for this, but one is that it lacks stability throughout the entire polymerization process and tends to generate a large amount of coagulum. Although it is not impossible to solve this problem, the cationic emulsifiers selected for this purpose are highly toxic, which not only causes problems in the treatment of emulsion waste liquid, but in some cases may interfere with the applications to which the emulsion is applied. Even pollution may be expected due to the release of the cationic emulsifier. Also, cationic emulsions obtained by polymerizing vinyl monomers in the presence of a cationic emulsifier or emulsions obtained by polymerizing vinyl monomers in the presence of a nonionic emulsifier or using a hydrophilic polymer as a protective colloid. Cationic emulsions obtained by adding cationic emulsifiers often have serious deficiencies when used to take advantage of their cationic properties. That is, upon adsorption to an anionic substance, the cationic emulsifier is preferentially removed from the surface of the emulsion particles, causing destabilization of the emulsion particles. As a result, homogeneous adsorption of the emulsion particles to the anionic substance does not occur, making it impossible to achieve the objective. On the other hand, in emulsions in which cationic groups are chemically bonded or strongly adsorbed to the particle surface, the above phenomenon is not observed and adsorption to anionic substances occurs homogeneously, but it is said that the desired performance cannot be obtained. There are often cases. This is often due to a problem with the particle size of the emulsion, and if the emulsion is simply cationic, adsorption will occur but sufficient performance will not be obtained in many cases. C Problems to be Solved by the Invention In view of the above-mentioned drawbacks of the prior art, the present invention provides a stable cationic emulsion with a small particle size, which is extremely superior in adsorption ability to negatively charged substances. The present invention provides a method for manufacturing. D. Means for Solving the Problems In view of the above-mentioned shortcomings of the prior art, the present inventors have developed a cationic emulsion that is stable and has small particle diameters, which has significantly superior ability to adsorb negatively charged substances. As a result of intensive study on the method of manufacturing (Here, R and R′ represent an alkyl group having 1 to 20 carbon atoms, and R″ represents a carbon atom of 1 to 20.
R represents an alkyl group having 20 atoms or an aromatic or alicyclic group having 6 to 15 carbon atoms;
represents an aliphatic hydrocarbon group having 2 to 6 carbon atoms and one ethylene bond, and X represents a chlorine or bromine atom. ) and methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methacrylic acid Acrylic acid ester monomers such as hydroxyethyl, styrene, acrylonitrile, butadiene,
By polymerizing a vinyl monomer in the presence of a cationic copolymer consisting of at least one hydrophobic polymerizable monomer selected from isoprene, vinyl chloride, or vinyl acetate, the above-mentioned effect can be achieved. The present inventors have discovered that the above objectives can be achieved, and have completed the present invention. The cationic copolymer used in the present invention contains a quaternary nitrogen atom and has the general formula (Here, R and R′ represent an alkyl group having 1 to 20 carbon atoms, and R″ represents a carbon atom of 1 to 20.
R represents an alkyl group having 20 atoms or an aromatic or alicyclic group having 6 to 15 carbon atoms;
represents an aliphatic hydrocarbon group having 2 to 6 carbon atoms and one ethylene bond, and X represents a chlorine or bromine atom. ) and methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methacrylic acid Acrylic acid ester monomers such as hydroxyethyl, styrene, acrylonitrile, butadiene,
It means a copolymer with at least one hydrophobic polymerizable monomer selected from isoprene, vinyl chloride, and vinyl acetate. Specific examples of the polymerizable quaternary ammonium salt represented by the above general formula include 2-hydroxy-3-methacryloxypropyltrimethylammonium chloride, 2-hydroxy-3-acryloxypropyltrimethylammonium chloride, and 2-hydroxy-3-methacryloxypropyltrimethylammonium chloride.
-Hydroxy-3-methacryloxypropyltriethylammonium bromide, 2-hydroxy-3-methacryloxypropyltributylammonium chloride, 2-hydroxy-3-methacryloxypropylmethylethylbutylammonium chloride, 2-hydroxy-3-methacryloxypropyl dimethyl Examples include phenylammonium chloride, 2-hydroxy-3-methacryloxypropyldimethylcyclohexylammonium chloride, and the like. These can be used alone or in combination of two or more, and 2-hydroxy-3-methacryloxypropyltrimethylammonium chloride is particularly preferred. The cationic copolymer used in the present invention includes the polymerizable quaternary ammonium salt, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and methacrylate. At least one hydrophobic polymer selected from acrylic acid ester monomers such as propyl acid, butyl methacrylate, and hydroxyethyl methacrylate, styrene, acrylonitrile, butadiene, isoprene, vinyl chloride, or vinyl acetate. It can be obtained by radical copolymerization with a monomer using a polymerization initiator. Any compound that generates cationic or nonionic free radicals can be used as the polymerization initiator, such as 2,2'-azobis(2-amidinopropane) hydrochloride, hydrogen peroxide, or the like. and a reducing agent, cumene hydroperoxide, t-butyl hydroperoxide, or a combination of these and a reducing agent. Other known anionic polymerization initiators can also be used as long as they do not impair the intended effects of the present invention. Any commonly used polymerization solvent can be used, but water is preferably used since the emulsion polymerization of the present invention can be directly carried out after producing the cationic copolymer. A more preferable example of the cationic copolymer used is one or more of 2-hydroxy-3-methacryloxypropyltrimethylammonium chloride and an acrylic acid ester monomer, styrene or vinyl acetate. Copolymers with monomers and the like are particularly preferably used to obtain the desired stable cationic emulsion with a small particle size. Polymerizable quaternary ammonium salt and methyl acrylate, ethyl acrylate, propyl acrylate,
Acrylic acid ester monomers such as butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, styrene, acrylonitrile, butadiene, isoprene, vinyl chloride, or The content of the polymerizable quaternary ammonium salt in the copolymer with at least one hydrophobic polymerizable monomer selected from vinyl acetate is 10% to 90% by weight of the copolymer. %, particularly preferably 20% to 85% by weight, particularly preferably 35% to 85% by weight. Furthermore, for the purpose of imparting cationic properties to the target emulsion particles, it is preferably present in an amount of 0.01% by weight or more based on the total polymer in the emulsion. Vinyl monomers used in the emulsion polymerization of the present invention include vinyl acetate, vinyl propionate, substituted vinyl versatate, vinyl chloride, and vinylidene chloride, and these can be used alone or in combination of two or more. Among them, vinyl acetate is most preferably used. In addition, styrene, substituted styrene, esters of acrylic acid or methacrylic acid with alcohols having 1 to 12 carbon atoms, acrylonitrile, butadiene, isoprene, etc. can be used, but these are used in combination with the above-mentioned vinyl acetate, etc. It is desirable that the emulsion be kept in a stable condition, in which case the stability of the emulsion is improved. In addition, for the purpose of modifying the emulsion mentioned above, ethylene, isobutene, acrylamide, N-methylol acrylamide,
There is no problem even if N,N-dimethylmethacrylamide, methacrylonitrile, divinylbenzene, ethylene glycol dimethyl acrylate, etc. are copolymerized. Furthermore, a small amount of cationic monomers such as dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and 2-hydroxy-3-methacryloxypropyltrimethylammonium chloride can also be added during the polymerization. The emulsion polymerization method in the present invention includes:
Polymerizable quaternary ammonium salts and methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, etc. first synthesize a copolymer with at least one hydrophobic polymerizable monomer selected from acrylic acid ester monomers, styrene, acrylonitrile, butadiene, isoprene, vinyl chloride or vinyl acetate, A method consisting of clearly separated steps of emulsion polymerization of a vinyl monomer in the presence of a vinyl monomer is preferred, but the following methods are also included. That is, for example, when a polymerizable quaternary ammonium salt and vinyl acetate to be subjected to emulsion polymerization are copolymerized in an aqueous medium, an emulsion is apparently obtained. As the polymerization progresses, the content of polymerizable quaternary ammonium salt in the newly formed copolymer decreases, and in some cases, the final polymer becomes substantially hydrophilic. Some are made of polyvinyl acetate. In this case, the initially formed polymerizable quaternary
The highly hydrophilic copolymer containing ammonium acts as a kind of protective colloid, and emulsion polymerization proceeds. At this time, the presence of a hydrophilic polymeric substance such as polyvinyl alcohol improves stability during polymerization. Polymerization agents used here include polymerizable quaternary ammonium salts, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, At least one hydrophobic polymerizable monomer selected from acrylic acid ester monomers such as butyl methacrylate and hydroxyethyl methacrylate, styrene, acrylonitrile, butadiene, isoprene, vinyl chloride, and vinyl acetate. The same material used for copolymerization with the polymer is used. The cationic copolymer used in the present invention is preferably 0.01 to 20 parts by weight per 100 parts by weight of the vinyl monomer to be emulsion polymerized.
It is used in a range of 0.05 to 10 parts by weight. In addition, in order to maintain stability during polymerization, other protective colloids, such as water-soluble polymeric substances such as polyvinyl alcohol and its derivatives, cellulose derivatives such as hydroxyl ethyl cellulose, and methyl cellulose, may be added to the polymerization system as necessary. Can be done.
Further, known nonionic emulsifiers and cationic emulsifiers can be added as long as they do not impair the spirit of the present invention. The emulsion obtained by the present invention has a remarkable ability to adsorb negatively charged substances, is stable, and has small particle diameters, and the film made from it has excellent water resistance. It also has one characteristic. In addition, compared to emulsions produced using ordinary emulsifiers or emulsion production methods using hydrophilic polymer substances such as polyvinyl alcohol as protective colloids, the method of the present invention has the advantage that emulsifiers or hydrophilic polymer substances such as polyvinyl alcohol are used as protective colloids. Another feature is that even if used, only a small amount is required. E Actions and Effects of the Invention The cationic emulsion obtained by the present invention is
It has remarkable adsorption ability to negatively charged substances, good stability, and small particle size, making it useful for adhesives, cement joints, etc. A substance such as dibutyl phthalate may be added to the emulsion as an external plasticizer for the polymer in the emulsion during or after the polymerization, depending on the final purpose. EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples at all. In addition, in the examples, “department”
means "parts by weight" unless otherwise specified. Example 1 After purging a separable flask equipped with a stirrer and a nitrogen inlet tube with nitrogen, 2.0 parts of 2-hydroxy-3-methacryloxypropyltrimethylammonium chloride monomer (hereinafter abbreviated as monomer []) and methacrylic were added. 70 parts of ion-exchanged water that had been substituted with nitrogen in advance was added to 0.5 parts of acid methyl monomer and dissolved at room temperature. After raising the temperature to 70°C, an initiator aqueous solution of 0.5 parts of 2,2'-azobis(2-amidinopropane) hydrochloride and 5 parts of ion-exchanged water was added, and polymerization was carried out for 1 hour to form [] and methyl methacrylate. An aqueous copolymer solution was obtained. Subsequently, the temperature was adjusted to 60°C, 5 parts of vinyl acetate monomer was added, and after polymerization for 30 minutes, 90 parts of vinyl acetate monomer was continuously added over 100 minutes.
Polymerized. 10 minutes after starting the addition of the vinyl acetate monomer, add 30% of a 10% Newpol PE-68 (nonionic emulsifier, manufactured by Sanyo Chemical Industries, Ltd.) aqueous solution.
Added in bulk. After the continuous addition of the vinyl acetate monomer was completed, the temperature was raised to 70°C, and the reaction was aged for 1 hour to complete the polymerization. The resulting emulsion was stable, with a solid content concentration of 48.0% and a particle size of 0.1-0.3μ. Example 2 A separable flask equipped with a stirrer and a nitrogen inlet tube was purged with nitrogen, and then 70 parts of ion-exchanged water, which had been purged with nitrogen in advance, was added to 2.0 parts of monomer [] and 0.5 parts of vinyl acetate monomer, and the mixture was dissolved at room temperature.
After raising the temperature to 70℃, add 0.5 part of 2,2'-azobis(2-amidinopropane) hydrochloride and 5 parts of ion-exchanged water.
Add part of an aqueous initiator solution and polymerize for 1 hour [ ]
A copolymer of and vinyl acetate was obtained. Then 60℃
Adjust the temperature and add 5 parts of vinyl acetate monomer to 30
After polymerizing for minutes, 90 parts of vinyl acetate monomer was added to
It was continuously added and polymerized over 100 minutes. 30 minutes after the start of addition of vinyl acetate monomer, 20 parts of a 10% (by weight) aqueous solution of polyvinyl alcohol (partially saponified product, degree of polymerization 500) was continuously added, and 70 minutes after the continuous addition of vinyl acetate monomer was completed. The temperature was raised to .degree. C., and the reaction was aged for 1 hour to complete the polymerization. The obtained emulsion was stable, had a solid content concentration of 47.9%, and a small particle size of 0.1 to 0.3μ. Example 3 After purging a separable flask equipped with a stirrer and a nitrogen inlet tube with nitrogen, 70 parts of ion-exchanged water, which had been purged with nitrogen in advance, were added to 2.0 parts of monomer [] and 1.0 part of methyl acrylate monomer, and the mixture was dissolved at room temperature. After raising the temperature to 70°C, an aqueous initiator solution of 0.5 parts of 2,2'-azobis(2-amidinopropane) hydrochloride and 5 parts of ion-exchanged water was added and polymerized for 1 hour to form a mixture of [] and methyl acrylate. A copolymer was obtained.
Subsequently, the temperature was adjusted to 60°C, 5 parts of vinyl acetate monomer was added and polymerized for 30 minutes, and then 90 parts of vinyl acetate monomer was continuously added and polymerized over 100 minutes. 30 minutes after starting addition of vinyl acetate monomer
After separation, 20 parts of 10% (by weight) polyvinyl alcohol (partially saponified product, degree of polymerization 500) aqueous solution was added continuously, and after the continuous addition of vinyl acetate monomer was completed, the temperature was raised to 70℃ and reaction aged for 1 hour. was carried out to complete the polymerization. The obtained emulsion was stable, had a solid content concentration of 48.1%, and a small particle size of 0.1 to 0.3μ. Comparative Example 1 After replacing the reactor with nitrogen in the same reactor as in Example 1,
70 parts of ion-exchanged water that had been purged with nitrogen was added to 2.0 parts of the monomer [] and dissolved at room temperature. 70℃
After raising the temperature to
An aqueous homopolymer solution of 0.18 [] was obtained. Subsequently, the temperature was adjusted to 60°C, 5 parts of vinyl acetate monomer was added, and after polymerization for 30 minutes, 90 parts of vinyl acetate monomer was continuously added over 100 minutes.
Polymerized. After starting addition of vinyl acetate monomer in the middle
After 30 minutes, continuous addition of 20 parts of a 10% (by weight) aqueous solution of polyvinyl alcohol (partially saponified product, degree of polymerization 500) was started, and the addition was completed at the same time as the vinyl acetate monomer. After the continuous addition was completed, the temperature was raised to 70°C, and reaction aging was performed for 1 hour to complete the polymerization. Although the obtained emulsion (solid content concentration 50.2%) shows good stability, the particle size is 0.2-0.4μ.
It was relatively large. Comparative Example 2 After replacing the reactor with nitrogen in the same reactor as in Example 1, 70 parts of ion-exchanged water that had been previously replaced with nitrogen was added to 0.5 parts of monomer [] and 0.75 parts of acrylamide as a hydrophilic polymerizable monomer, and the mixture was heated at room temperature. It was dissolved in After raising the temperature to 70℃, 2,2′-azobis(2
An initiator aqueous solution of 0.25 parts of (amidinopropane) hydrochloride and 5 parts of ion-exchanged water was added and polymerized for 1 hour to obtain a copolymer of [] and acrylamide as a hydrophilic polymerizable monomer. . Next, adjust the temperature to 60℃, add 3 parts of vinyl acetate monomer,
After polymerizing for minutes, 92 parts of vinyl acetate monomer was added to
It was continuously added and polymerized over 100 minutes.
10 minutes after the start of the addition of the vinyl acetate monomer, 20 parts of a 10% (by weight) aqueous solution of polyvinyl alcohol (partially saponified product, degree of polymerization 500) was added all at once.
70 minutes after the continuous addition of vinyl acetate monomer is completed.
The temperature was raised to .degree. C., and the mixture was aged for 1 hour to complete the polymerization. Although the obtained emulsion (solid content concentration: 49.8%) was stable, the particle size was quite large, ranging from 0.5 to 1.0μ. Comparative Example 3 After purging a separable flask equipped with a stirrer and a nitrogen inlet tube with nitrogen, 70 parts of ion-exchanged water, which had been purged with nitrogen in advance, was added to 2.0 parts of monomer [] and 0.1 part of methyl methacrylate monomer, and the mixture was dissolved at room temperature. After raising the temperature to 70°C, an initiator aqueous solution of 0.5 parts of 2,2'-azobis(2-amidinopropane) hydrochloride and 5 parts of ion-exchanged water was added and polymerized for 1 hour to form a mixture of [] and methyl methacrylate. A copolymer was obtained.
Subsequently, the temperature was adjusted to 60°C, 5 parts of vinyl acetate monomer was added and polymerized for 30 minutes, and then 90 parts of vinyl acetate monomer was continuously added and polymerized over 100 minutes. 10 minutes after starting addition of vinyl acetate monomer
minutes, then 10% (by weight) of Newpol PE−
68 (nonionic emulsifier, manufactured by Sanyo Chemical Industries, Ltd.) aqueous solution was added at once. After the continuous addition of vinyl acetate monomer was completed, the temperature was raised to 70°C and reaction aging was carried out for 1 hour to complete the polymerization. The obtained emulsion was stable, had a solid content concentration of 47.9%, a particle size of 0.2 to 0.4μ, and no effect of copolymerization of methyl methacrylate was observed. Comparative Example 4 After purging a separable flask equipped with a stirrer and a nitrogen inlet tube with nitrogen, 70 parts of ion-exchanged water, which had been purged with nitrogen in advance, was added to 0.15 parts of monomer [] and 2.0 parts of methyl methacrylate monomer, and the mixture was dissolved at room temperature. After raising the temperature to 70°C, an initiator aqueous solution of 0.5 parts of 2,2'-azobis(2-amidinopropane) hydrochloride and 5 parts of ion-exchanged water was added and polymerized for 1 hour to form a mixture of [] and methyl methacrylate. A copolymer was obtained.
Subsequently, the temperature was adjusted to 60°C, 5 parts of vinyl acetate monomer was added and polymerized for 30 minutes, and then 90 parts of vinyl acetate monomer was continuously added and polymerized over 100 minutes. 30 minutes after starting addition of vinyl acetate monomer
minutes, then 10% (by weight) of Newpol PE−
68 (nonionic emulsifier, manufactured by Sanyo Chemical Industries, Ltd.) aqueous solution was added at once. However, when the continuous addition of the vinyl acetate monomer was completed, coagulation occurred and a stable emulsion could not be obtained. Next, in order to examine the effects of the cationic emulsions obtained in the above Examples and Comparative Examples, the following two
Two tests were conducted. (1) Adhesion test Each of the emulsions of Example 1, Comparative Example 1, and Comparative Example 2 was diluted to a solid content of 40% and placed on an asbestos slate board. Apply the film so that the dry film is 200 μm, and place a cotton cloth on top as a reinforcing material.
A film was formed by air drying for several days. This film was cut with a cutter knife to a width of 1 cm, and the temperature and humidity were controlled for 3 days at a temperature of 20°C and a relative humidity of 65% RH, and the peeling strength was measured using an autograph at a 90° angle. The results are shown in Table 1.

[Table] As is clear from Table 1, the cationic emulsion with small particle size obtained by the present invention has extremely excellent adhesion to asbestos slate boards, while the 2-hydroxy-3- Even when using a homopolymer of methacryloxypropyltrimethylammonium chloride (Comparative Example 1) or a copolymer of 2-hydroxy-3-methacryloxypropyltrimethylammonium chloride, the other side of the copolymer When the component is a hydrophilic polymerizable monomer such as acrylamide (Comparative Example 2), the particle size of the resulting cationic emulsion is quite large at 0.5 to 1.0μ, making it unsuitable for asbestos slate. It can be seen that it has only a strong adhesive force. (2) Water resistance test The emulsion obtained by the present invention, especially the polyvinyl acetate emulsion that uses polyvinyl alcohol as part of the stabilizer, has excellent water resistance as a film, unlike ordinary polyvinyl acetate emulsion. This is shown for the emulsions obtained in Examples 1, 2 and 3 in comparison with commercially available polyvinyl acetate emulsions. Test method is JIS
Based on water drop test of K6828-1977. (Table 2)

【table】

Claims (1)

[Claims] 1 Contains a quaternary nitrogen atom and has the general formula (Here, R and R′ represent an alkyl group having 1 to 20 carbon atoms, and R″ represents a carbon atom of 1 to 20.
R represents an alkyl group having 20 atoms or an aromatic or alicyclic group having 6 to 15 carbon atoms;
represents an aliphatic hydrocarbon group having 2 to 6 carbon atoms and one ethylene bond, and X represents a chlorine or bromine atom. ) and methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methacrylic acid Acrylic acid ester monomers such as hydroxyethyl, styrene, acrylonitrile, butadiene,
A method for producing a cationic emulsion, which comprises polymerizing a vinyl monomer in the presence of a cationic copolymer comprising at least one of isoprene, vinyl chloride, and vinyl acetate. 2 Contains a quaternary nitrogen atom and has a general formula 2. The production method according to claim 1, wherein the polymerizable quaternary ammonium salt having the following formula is 2-hydroxy-3-methacryloxypropyltrimethylammonium chloride. 3. The manufacturing method according to claim 1, wherein the vinyl monomer is vinyl acetate. 4. The production method according to claim 1, wherein the cationic polymer is a copolymer of 2-hydroxy-3-methacryloxypropyltrimethylammonium chloride and vinyl acetate, and the vinyl monomer is vinyl acetate. 5. The production method according to claim 1, wherein the content of the polymerizable quaternary ammonium salt in the cationic copolymer is 10% by weight to 90% by weight.