JPS6119643B2 - - Google Patents

Description

[Detailed description of the invention]

The emulsion polymerization of the present invention is easy to operate, and the obtained emulsion has a small particle size, good viscosity stability and mechanical stability, and a coating film with excellent water resistance and heat resistance by heating or adding a crosslinking agent. The present invention relates to a method for producing a vinyl polymer emulsion that can be made into a vinyl polymer emulsion. Previously, the present inventors discovered that a water-soluble product of a multicomponent copolymer containing as essential components a unit based on maleic imide and/or N-substituted maleic imide and a unit based on α-olefin in the main chain is a vinyl After discovering that the monomer had excellent properties as an emulsion stabilizer, he applied for a patent, but as a result of further research, he found that (A) a unit based on α-olefin, (B) a maleic acid imide in the main chain. Alternatively, a water-soluble multi-component copolymer containing as constituent components a unit based on N-substituted maleic acid imide, and (C) a unit based on an unsaturated carboxylic acid, its ester, or its amide, is added to the multi-component copolymer in the presence of radicals. As a result of emulsion polymerization of a vinyl monomer using a vinyl monomer as an emulsion stabilizer after heat cleavage so that the degree of polymerization is 1/2 to 1/30 of the original, an emulsion with small particle size and low viscosity can be obtained with a simple polymerization operation. It was discovered that the emulsion has excellent performance in terms of storage stability, pigment miscibility, mechanical stability, freezing stability, etc., with little change in viscosity over time, and has led to the completion of the present invention. Ivy. That is, in the main chain, (A) a unit based on an α-olefin, (B) a unit based on a maleic acid imide or an N-substituted maleic acid imide group, and (C) a unit based on an unsaturated carboxylic acid, its ester, or its amide. When a water-soluble multi-component copolymer containing the unit as a constituent component is directly emulsion polymerized as a protective colloid, the viscosity of the resulting emulsion tends to increase;
The emulsion itself may have poor mechanical stability, storage stability, and freezing stability. On the other hand, the main chain contains (A) a unit based on an α-olefin, (B) a unit based on a maleic acid imide or an N-substituted maleic acid imide group, and (C) an unsaturated carboxylic acid, its ester, or its amide. A water-soluble multi-component copolymer containing a unit based on as a constituent component is thermally cleaved in the presence of a radical so that the degree of polymerization of the multi-component polymer becomes 1/2 to 1/30 of the original value, and then this is protected. As a result of emulsion polymerization of unsaturated monomers such as vinyl monomers as colloids, it is possible to obtain emulsions with excellent mechanical stability, storage stability, and freeze stability through simple emulsion polymerization operations. Depending on the amount of copolymer added, it is possible to obtain an emulsion with any viscosity from low to high. Especially when the viscosity is low, the heat of polymerization can be easily removed and a highly concentrated emulsion can be obtained. Efficiency can be increased. Furthermore, removing the emulsion,
Also, workability such as compatibility with other pigments is improved. Furthermore, by adding a crosslinking agent or coexisting a crosslinking monomer to the polymerization system of the present invention, the above-mentioned multi-component polymer constituting the protective colloid can be crosslinked, resulting in a coating film with excellent water resistance and heat resistance. be able to. (A)α in the main chain used in the method of the present invention
- units based on olefins, (B) units based on maleic imides or N-substituted maleic imides,
and (C) a water-soluble multi-component copolymer containing units based on an unsaturated carboxylic acid, its ester, or its amide, represented by the following general formula. However, in the formula, R ₁ and R ₂ are the same group or different groups selected from the group consisting of a hydrogen atom, an alkyl group, and an alkenyl group, and R ₃ is an alkyl group that may contain a hydrogen atom, a halogen atom, or a hydroxyl group. P, Q, R and S are groups selected from the group consisting of a carboxyl group, an alkenyl group and an aromatic hydrocarbon residue, and at least one of P, Q, R and S is a group selected from the group consisting of a carboxyl group, an ester thereof and an amide thereof, Others that are different from this are hydrogen atoms or alkyl groups. In the above general formula, the α-olefins that can constitute (A) include ethylene, propylene, 1-butene, isobutene, 1-pentene, 1-hexane, 1-heptene, 2-methyl-1-hexene, 1-octene, It refers to 1-nonene, styrene, α-methylstyrene, 1,3-butadiene, isoprene, etc. The N-substituted maleic acid imide that can constitute (B) includes N-substituted maleic acid which is N-substituted with a saturated or unsaturated hydrocarbon group having 1 to 18 carbon atoms or a derivative thereof. It includes N-substituted maleic imide, N-halogen maleic imide, N-hydroxyalkyl maleic imide, etc., which are N-substituted with a compound having an imide, benzene, or naphthalene skeleton. Furthermore, unsaturated carboxylic acids, esters thereof, or amides thereof that may constitute (C) include acrylic acid,
Methacrylic acid, maleic acid, maleic anhydride,
Monomethyl maleate, monoethyl maleate, monobutyl maleate, monohexyl maleate, monooctyl maleate, monostearyl maleate, fumaric acid, monomethyl fumarate, monoethyl fumarate, mono Butyl fumarate, monohexyl fumarate, monooctyl fumarate, monostearyl fumarate, acrylamide, monomethylacrylamide, monoethylacrylamide, dimethylacrylamide, diethylacrylamide, hydroxyethylacrylamide, maleic acid amide, fumaric acid amide, Included are water-soluble monomer derivatives such as hydroxyethyl acrylate. Regarding the composition of x, y, and z, y is x+y+z
= 100, it is a value of 55 or less, and z is often included as a value such that the multi-component copolymer becomes a water-soluble polymer, and its value is not particularly limited. The degree of polymerization of the multi-component copolymer used in the present invention greatly influences the degree of emulsification and the viscosity of the resulting emulsion, but is not particularly limited in the present invention. There are two main methods for producing these multi-component copolymers. One is a method of copolymerizing maleic imide or N-substituted maleic imide, α-olefin, a more unsaturated carboxylic acid, an ester thereof, or an amide thereof. That is, α−
Olefin, N-substituted maleimide or N
-Substituted maleic acid imide and unsaturated carboxylic acid, its ester or its amide with benzene, toluene, xylene, tetrahydrofuran,
Dioxane, methyl ethyl ketone, cyclohexanone, acetone, ethanol, n-butanol,
It is obtained by polymerization in a solvent such as t-butanol, ethylene glycol, chloroform, or ethyl acetate using a radical initiator such as benzoyl peroxide or azobisisobutylnitrile at a temperature of 0 to 100°C. Another method is to prepare a copolymer of maleic anhydride and α-olefin, react it with ammonia or amine to produce an amide or ammonium salt of the copolymer, and then heat the copolymer at 100°C to 300°C, preferably at 150°C. This is a method in which the amide or ammonium salt is partially closed by heat treatment at a temperature of .degree. C. to 250.degree. C. to form an imide group. In addition, this ring-closing reaction is as follows when ammonia is used. (However, in the formula, V is H or NH _4. ) In particular, when the α-olefin used in the multi-component copolymer has 4 or more carbon atoms, a basic substance is added to make the copolymer water-soluble. They often coexist. The basic substances include alkali hydroxide, alkali carbonate, alkali acetate, ammonium hydroxide, ammonium carbonate, ammonium acetate,
These are basic inorganic substances and basic organic substances such as hydrazine, hydroxylamine, and pyridine. Among these, alkali hydroxide and ammonium hydroxide are particularly preferred. The amount of these additions is approximately
In a 50 mole% copolymer, 0.2 equivalent or more is required per equivalent of carboxyl group. 0.2
If the amount is less than the equivalent amount, complete water solubilization is often not possible.
Also, increasing the amount added makes water solubilization easier, but the PH
Usually, because the emulsion polymerization property becomes high and the
The amount is preferably 0.3 to 0.8 equivalent. The main chain contains (A) a unit based on an α-olefin, (B) a unit based on a maleic acid imide or an N-substituted maleic acid imide group, and (C) a unit based on an unsaturated carboxylic acid, its ester, or its amide. When a water-soluble multi-component copolymer containing at least as an essential component is thermally decomposed by radicals, a peroxide is exclusively used. Inorganic persulfates, alkali metal persulfates such as sodium persulfate, potassium persulfate, alkali metal percarbonates such as sodium percarbonate or potassium percarbonate, alkali metal perborates such as sodium perborate or potassium perborate. , alkali metal superphosphates such as sodium perphosphate or potassium perphosphate, hydrogen peroxide, t-butyl hydroperoxide, and cumene hydroperoxide. In addition, reducing agents such as l-ascobic acid, tartaric acid, Rongarit, thioglycolic acid, and N-phenylhydrokylamine may be used in combination. The amount of these cleavage agents added is 0.1 to 20% by weight, preferably 0.5 to 10% by weight, based on the above copolymer, and these are added at once when the above copolymer is made water-soluble. It may be cleaved at the same time as melting at a temperature of 20 to 99°C, or it may be reheated to 20 to 99°C with the addition of a cleavage agent after dissolution. The cleavage reaction of the above-mentioned multi-component copolymer with peroxide is carried out at 20 to 99 DEG C., and the reaction time is not limited as it varies greatly depending on the type of multi-component copolymer and the type and concentration of peroxide.
By this cleavage, the degree of polymerization, that is, the average molecular weight can be reduced to about 1/2 to 1/30. The amount used in the emulsion polymerization of the radical thermal decomposition product of the above multi-component copolymer used in the present invention greatly affects the viscosity of the emulsion and its physical properties, and is preferably 2% by weight or more, preferably 3% by weight or more based on the monomer. .
If the amount is less than 2% by weight, it becomes difficult to obtain a stable emulsion. In the present invention, commonly used emulsion stabilizers can be used in combination. Furthermore, water-soluble polymers such as cellulose derivatives and polyvinyl alcohol can also be used as protective colloids. The amount of these added is 50% by weight based on the multi-component copolymer mentioned above.
The following are preferred. Addition of 50% by weight or more is not preferable because it gives an unstable emulsion, deteriorates the physical properties of the emulsion, and deteriorates performance such as water resistance of the coating film. In addition, unsaturated monomers that can be used in the emulsion polymerization method of the present invention include vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl versatate, methyl acrylate, acrylic Acrylic acid esters such as ethyl acid, butyl acrylate, 2-ethylhexyl acrylate, etc., methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, etc., vinyl chloride, vinylidene chloride, etc. vinyl halides or vinylidene compounds, α-olefins such as ethylene, propylene, isobutylene, octyne, etc., acrylic acid,
Unsaturated substances such as methacrylic acid, crotonic acid, vinylsulfonic acid, vinyltoluenesulfonic acid, etc.
Basic acids and their salts, unsaturated dibasic acids and their salts and half esters such as itaconic acid, maleic acid, falic acid, etc., nitrogen-containing vinyl compounds such as N-vinylpyrrolidone, acrylonitrile, acrylamide, etc. , hydroxyl group-containing vinyl compounds such as β-hydroxyethyl acrylate, N-methylol acrylamide, etc., allyl compounds such as triacryl cyanurate, trimethylolpropane diallyl ether, diallyl phthalate, etc., and epoxy group-containing non-vinyl compounds such as glycidyl methacrylate, etc. Saturated compounds, divinyl compounds such as divinylbenzene, cyclopentadiene, butadiene, etc., styrene, methylstyrene,
Examples include one or a mixture of two or more styrene derivatives such as dimethylstyrene, ethylstyrene, vinylstyrene, isopropylstyrene, phenylstyrene, chlorostyrene, and the like. The polymerization method for obtaining the emulsion composition of the present invention employs the most common polymerization method of adding a polymerization initiator to the aqueous solution of the multi-component copolymer and initially adding monomers all at once, or dropping polymerization. Therefore, the reaction operation is very simple. As a polymerization initiator, peroxides such as persulfates and hydrogen peroxide, organic peroxides such as tertiary butyl hydroperoxide and cumene hydroperoxide, and combinations of these peroxides and reducing agents are used. Known initiators such as redox catalysts can be used. The concentration of the emulsion of the present invention can be changed as appropriate within the range of 15 to 70% depending on the application. Additionally, additives can be added during or before or after emulsion polymerization, if necessary. These additives include plasticizers, solvents, fillers, and pigments, and in some cases, latex produced by other methods may also be added. By adding a crosslinking agent to the emulsion composition thus obtained, the water resistance and heat resistance of the emulsion film can be significantly improved. As the crosslinking agent used in this case, isocyanate compounds, epoxy compounds, urea resins, melamine resins, or polyvalent metal compounds are effective. Thus, the emulsion composition of the present invention can be economically used in a wide range of applications such as non-woven fabrics, coating agents such as paints, adhesives, binders for inorganic materials, hard finishing agents for paper processing, fibers, paper, etc., soil stabilizers, and dust preventive agents. This is something that can be supplied in a timely manner. EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Example 1 44 g of isobutylene and 70 g of maleic anhydride were polymerized in toluene with 0.6 g of a polymerization catalyst (benzoyl peroxide),
Copolymerization was carried out at 68 to 70° C. using a chain transfer agent to obtain 110 g of a copolymer powder having a molar ratio of isobutylene to maleic anhydride of 1:1. The intrinsic viscosity of the copolymer measured in dimethylformamide (DMF) at 30°C was 0.45 dl/g. Put 100g of the above copolymer () into a 3-necked flask, and while stirring, pour it into one of the flask openings.
A nitrogen gas mixture containing 40% ammonia gas is introduced at a rate of 30 to 50 ml per minute to form a copolymer () in which units based on maleic anhydride are replaced with units based on maleic acid amide or ammonium salt. Obtained. When the copolymer () was examined for units based on maleic acid amide or ammonium salt in the copolymer by elemental analysis and nuclear magnetic resonance method, 72% of the units based on maleic anhydride were found.
was found to be a unit based on maleic acid amide or ammonium salt. The thus obtained copolymer (2) was placed in a flask equipped with a condenser and heated to 185°C, and the produced water was distilled off.
Heating was stopped when the distilled water amounted to 6.5% of the original weight. The thus obtained copolymer () was hydrolyzed in an aqueous solution under hydrochloric acid acidity to convert the amide and ammonium salt into carboxylic acid, and the composition was then investigated by potentiometric titration, nuclear magnetic resonance, and elemental analysis. As a result, it was found that the copolymer () had a composition as shown in Table 1.
Further, when the intrinsic viscosity at 30°C in dimethylformamide was measured, it was 0.4 dl/g, and the average molecular weight calculated from this was 50,000.

[Table] 400g of the multi-component copolymer thus obtained
68 g of 28% ammonia water, 1300 g of water, and 114 g of 35% hydrogen peroxide were added and dissolved by heating at 90 to 95° C. for 5 hours. As a result, the average molecular weight of the multi-component copolymer was approximately 20,000. In other words, the degree of polymerization was 2/5 that of the original multicomponent copolymer. After charging 500 g of the aqueous solution obtained in this manner and 100 g of vinyl acetate into two separable flasks, 400 g of vinyl acetate was added while maintaining the internal temperature at 60°C.
g, 0.8% hydrogen peroxide 120ml, 72% Rongarit 60
Emulsion polymerization is carried out by continuously adding ml of each sample over a period of about 1.5 hours. Table 3 shows the physical properties of the emulsion thus obtained. Example 2 Polymerization was carried out in the same manner as in Example 1 except that 20% of the vinyl acetate in Example 1 was replaced with vinyl versatate. The physical properties of the emulsion are shown in Table 3. Example 3 The vinyl acetate of Example 1 was reduced by 20%, charged into an autoclave, and the autoclave was pressurized to ethylene pressure of 40 Kg/cm ² , and polymerization was carried out in the same manner as in Example 1. The physical properties of this emulsion are shown in Table 3. Example 4 Polymerization was carried out in the same manner as in Example 1 except that vinyl acetate in Example 1 was replaced with butyl acrylate. Table 3 shows the physical properties of the emulsion obtained. Example 5 In an autoclave of 10, 5.0 kg of hetoluene, 600 g of maleic anhydride, 4.5 g of polymerization initiator (α・α′-azobisisobutyronitrile) and chain transfer agent were charged, sufficiently dissolved, and nitrogen gas was blown into the system. After removing the oxygen inside, the ethylene gas is heated to an internal pressure of 20Kg/
cm ² and polymerized at 68°C for 10 hours. The resulting polymer had an ethylene/maleic anhydride molar ratio of 1:1 and an intrinsic viscosity at 30°C in DMF.
It was a copolymer of 0.42 dl/g. Ammonia gas was introduced into 100 g of this copolymer powder and then heated to 180 to 185°C to obtain a multi-component copolymer having the following components. (However, in the formula, R' represents CH ₂ - CH ₂ , and V represents H or NH _4. ) This multi-component copolymer has an intrinsic viscosity of 0.40 dl/g measured at 30°C in DMF. Ta. The average molecular weight calculated from this is 64,000. 28 to 400g of this multi-component copolymer with an average molecular weight of 64,000
% ammonia water 68g, water 1300g, 35% hydrogen peroxide
114 g was added and dissolved by heating at 90 to 95°C for 5 hours.
As a result, the molecular weight of the multi-component copolymer was 24,000. That is, the multicomponent copolymer has an original 3/
The average molecular weight was 8. After charging 500g of this aqueous solution and 100g of vinyl acetate into two separable flasks, while maintaining the internal temperature at 60℃, add 400g of vinyl acetate and 120g of 0.8% hydrogen peroxide.
ml and 60 ml of 72% Rongalit were polymerized while continuously adding each for about 1.5 hours. Table 3 shows the physical properties of the emulsion thus obtained. Example 6 28% ammonia water was added to 400 g of a multi-component copolymer having an average molecular weight of 84,000 and a composition shown in Table 2.
%, add 1300 g of water, 114 g of 35% hydrogen peroxide, 90
The mixture was heated and dissolved at ~95°C for 5 hours. As a result, the molecular weight of the multi-component copolymer was 27,000. In addition, the above multi-component copolymer is isobutylene 355
g, obtained by copolymerizing 95 g of methyl vinyl ether and 700 g of maleic anhydride in toluene in the presence of benzoyl peroxide and a chain transfer agent, treating the resulting powder with ammonia gas, and then heat-treating it. It is.

[Table] Using 500g of the aqueous solution obtained in this way,
Other than that, polymerization was carried out under the same conditions as in Example 1. Table 3 shows the physical properties of the emulsion obtained. Comparative Example 1 114g of 35% hydrogen peroxide in the method of Example 1
Polymerization was carried out in the same manner as in Example 1 except that 114 g of water was used instead of 114 g of water. Table 3 shows the physical properties of the emulsion obtained. Comparative Example 2 500 g of the aqueous solution of the multi-component copolymer of Example 1 was replaced with a partially saponified polyvinyl alcohol (degree of saponification = 88%, degree of polymerization = 500) aqueous solution (concentration = 20%) 500 g.
Polymerization was carried out in the same manner as in Example 1, except for replacing with g. Table 3 shows the physical properties of the emulsion obtained.

[Table] As is clear from the results shown in Table 3, all emulsion compositions obtained based on the emulsion polymerization method of the present invention are excellent in stability.

Claims (1)

[Claims] 1 In the main chain (A) a unit based on α-olefin, (B)
A water-soluble multicomponent copolymer containing as constituent components a unit based on maleic imide or an N-substituted maleic imide, and a unit based on (C) an unsaturated carboxylic acid, an ester thereof, or an amide thereof is prepared in the presence of a radical. The degree of polymerization of the copolymer is 1/2 of the original
1. A method for producing an emulsion composition, which comprises heating to cleave the cleavage to 1/30 and then emulsion polymerizing an unsaturated monomer using the cleavage as a protective colloid.