JP4609608B2 - Emulsion polymerization method and composition - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for producing an emulsion having excellent stability by emulsion polymerization, and when used in paints, adhesives, paper processing agents, textile processing agents, leather processing agents, planting aids, etc., The present invention relates to a method for producing a vinyl emulsion having excellent adhesion and adhesion to a material, and a composition obtained thereby.
[0002]
[Prior art]
Conventionally, when a polymer emulsion is produced by emulsion polymerization of unsaturated compounds such as vinyl acetate and acrylic acid esters, emulsifiers such as nonionic surfactants, anionic surfactants and cationic surfactants, polyvinyl alcohol Water-soluble polymers such as arabic gum and hydroxyethyl cellulose have been used as stabilizers. While these play a major role in stabilizing the emulsion, on the other hand, the film processed from the emulsion becomes water-absorbing, and therefore the durability of the paint and adhesive using the emulsion is lowered. For this reason, attempts have been made to lower the hydrophilicity by adding a substituent to the emulsifier or water-soluble polymer, but this reduces the protective action of the emulsion particles and makes the emulsion unstable. In addition, emulsions produced using emulsifiers tend to coagulate with additives such as salts, and emulsions produced using water-soluble polymers cause a so-called gum-up phenomenon in which polymers are precipitated by mechanical stirring, There is a disadvantage that the freeze-thaw stability is insufficient. For this reason, various emulsifiers and water-soluble polymers have been studied, but a method that fully satisfies the stability, workability, and quality of processed products has not yet been obtained.
[0003]
[Problems to be solved by the invention]
The present invention has been made in view of such a situation, solves the problems that could not be achieved by conventional emulsion polymerization, and can perform polymerization smoothly without any inhibition or delay action during emulsion polymerization. In addition to the stability of the resulting emulsion (standability, low temperature and high temperature stability, mechanical stability, additive stability, etc.) When used as an agent or the like, it is an object of the present invention to provide a method for producing an emulsion excellent in application and a composition comprising the same, in which adhesion to a substrate, adhesion, water resistance, durability and the like are balanced.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have found that a homopolymer of N-vinylcarboxylic acid amide or a water-soluble copolymer with a polymerizable compound copolymerizable with N-vinylcarboxylic acid amide. As a protective colloid, the inventors have found that the above-mentioned problems can be achieved by emulsion polymerization of an unsaturated compound having an ethylenically unsaturated group, and the present invention has been completed.
[0005]
That is, the present invention relates to the following matters.
[1] N-vinylcarboxylic acid amide homopolymer or water-soluble copolymer of polymerizable compound copolymerizable with N-vinylcarboxylic acid amide as a protective colloid to produce an unsaturated compound having an ethylenically unsaturated group A method of emulsion polymerization.
[2] An unsaturated compound having an ethylenically unsaturated group for emulsion polymerization is vinyl ester, acrylic ester, methacrylic ester, vinyl ether, acrylonitrile, styrene, ethylene, allyl ester, acrylamide, methacrylamide, unsaturated carboxylic acid and The emulsion polymerization method according to the above [1], which is at least one compound selected from the group consisting of salts thereof.
[3] The copolymerizable polymerizable compound is selected from the group consisting of vinyl ester, acrylic ester, methacrylic ester, vinyl ether, acrylonitrile, styrene, ethylene, allyl ester, acrylamide, methacrylamide, unsaturated carboxylic acid and salts thereof. The emulsion polymerization method according to the above [1] or [2], which is one or more selected compounds.
[4] The above-mentioned [1], wherein one or more surfactants selected from nonionic surfactants, anionic surfactants and cationic surfactants are further used in emulsion polymerization. Or the emulsion polymerization method according to any one of [3].
[5] The emulsion polymerization method according to any one of the above [1] to [4], in which another water-soluble polymer compound is further used as a protective colloid in emulsion polymerization.
[0006]
[6] The emulsion polymerization method according to any one of [1] to [5], wherein the N-vinylcarboxylic amide is N-vinylacetamide.
  [7] An unsaturated compound having an ethylenically unsaturated group is used as a protective colloid using an N-vinylcarboxylic acid amide homopolymer or a water-soluble copolymer copolymerizable with N-vinylcarboxylic amide as a protective colloid. An emulsion composition comprising a polymer obtained by polymerization by the method according to any one of [1] to [6].
  [8] An adhesive composition comprising the emulsion composition according to [7] above.
  [9] The adhesive composition according to [8], which is used for bonding at least one selected from the group consisting of woodwork, paper, fiber, leather, plastic, and metal.
  [10] A composition for impregnating a fiber comprising the emulsion composition according to [7] above.
  [11] A paper impregnating composition comprising the emulsion composition according to [7] above.
  [12] A coating composition comprising the emulsion composition according to [7].
  [13] N-vinylcarboxylic acid amide or a water-soluble compound copolymerizable with N-vinylcarboxylic acid amide is polymerized to copolymerize with N-vinylcarboxylic acid amide homopolymer or N-vinylcarboxylic acid amide A step of generating a protective colloid comprising a water-soluble copolymer with a polymerizable compound, and a step of emulsion polymerization by adding water and an unsaturated compound having an ethylenically unsaturated group to the protective colloid. A method for producing a vinyl emulsion.
  [14] The step of producing the protective colloid includes a step of dissolving or dispersing N-vinylcarboxylic acid amide or a water-soluble compound copolymerizable with N-vinylcarboxylic acid amide in water or an organic solvent; Or a step of performing polymerization by adding a polymerization initiator while heating the dispersion, and the method for producing a vinyl emulsion according to [13] above.
  [15] The step of emulsion polymerization includes adding an unsaturated compound having an ethylenically unsaturated group while heating with stirring after adding water and a polymerization initiator to the protective colloid. [13] The method for producing a vinyl emulsion according to [13].
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the N-vinylcarboxylic amide used in the present invention include N-vinylformamide, N-vinylacetamide, N-vinylpropylamide, N-vinylbutyramide, N-methyl-N-vinylformamide, N-ethyl-N- Vinylformamide, N-methyl-N-vinylacetamide and the like can be mentioned, and N-vinylacetamide is particularly preferable from the standpoint of performance as a protective colloid.
[0008]
The N-vinylcarboxylic acid amide homopolymer is produced by aqueous solution polymerization or polymerization in an organic solvent, reverse layer suspension polymerization, etc., and the polymer or reverse layer suspension polymer in an organic solvent is dried to be a solid, Dissolve in water before use.
[0009]
A water-soluble copolymer of N-vinylcarboxylic amide and a polymerizable compound capable of copolymerization may be an aqueous solution polymerization or polymerization in an organic solvent, or a reverse layer suspension, similar to a homopolymer of N-vinylcarboxylic amide. It can be made by polymerization or the like. Examples of the copolymerizable compound include vinyl esters such as vinyl acetate, vinyl propionate, and C8-10 branched fatty acid vinyl esters; methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, acrylic acid acrylic esters such as i-butyl, 2-ethylhexyl acrylate, glycidyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, dimethylaminoethyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, methacrylate n -Methacrylates such as butyl, i-butyl methacrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, etc. Tel; methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, isobutyl vinyl ether, benzyl vinyl ether, vinyl ether such as octyl vinyl ether; allyl esters such as allyl acetate; acrylonitrile; styrene; ethylene; acrylamide, methacrylamide, acrylic acid, methacrylic acid, And unsaturated carboxylic acids such as crotonic acid, itaconic acid, maleic acid and fumaric acid; or salts thereof.
[0010]
In the water-soluble copolymer of N-vinylcarboxylic acid amide and a copolymerizable polymerizable compound, the monomer mass ratio is preferably in the range of 99.9: 0.1 to 50:50. The range of 9: 0.1 to 60:40 is more preferable. A water-soluble copolymer in which N-vinylcarboxylic acid amide is less than 50 in terms of monomer mass ratio is not preferable because the emulsion obtained by emulsion polymerization has poor stability.
[0011]
The molecular weight (Mw) of N-vinylcarboxylic acid amide homopolymer or water-soluble copolymer used as protective colloid is 10,000 to 2,000,000, preferably 10,000 to 1,000,000. Preferably it is 10,000-500,000. If the molecular weight is 2,000,000 or more, coagulation of the emulsion occurs during emulsion polymerization, and if the molecular weight is 10,000 or less, the stabilizing action is insufficient, which is not preferable.
[0012]
In the present invention, emulsion polymerization is carried out by adding a polymerization initiator to an aqueous solution of a homopolymer of N-vinylcarboxylic amide or a water-soluble copolymer of a polymerizable compound copolymerizable with N-vinylcarboxylic amide, A method of polymerizing by adding an unsaturated compound having an ethylenically unsaturated group is used.
[0013]
Examples of the polymerization initiator include ammonium persulfate, sodium persulfate, hydrogen peroxide-tartaric acid, and azobis compounds that are generally used in emulsion polymerization. The polymerization is usually carried out at a reaction temperature in the range of 60 to 90 ° C, but it is also possible to carry out the polymerization at 60 ° C or lower by using a peroxide and a ferrous salt, ascorbic acid or the like in combination.
[0014]
As the unsaturated compound having an ethylenically unsaturated group used for emulsion polymerization, a monomer used for general emulsion polymerization can be used, and it is preferable to select and use it according to the application. Vinyl acetate, vinyl propionate, C8-10 branched fatty acid vinyl ester, vinyl stearate and other vinyl esters; methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, i-butyl acrylate, acrylic 2-ethylhexyl acid, glycidyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, dimethylaminoethyl acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, polyethyl glycol diacrylate, propylene glycol diacryl Acrylic acid esters, dipropylene glycol diacrylic acid esters, polypropylene glycol diacrylic acid esters, etc .; methyl methacrylate, methacrylic acid ester , Propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, glycidyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, ethylene glycol Dimethacrylic acid ester, diethylene glycol dimethacrylic acid ester, polyethylene glycol dimethacrylic acid ester, propylene glycol dimethacrylic acid ester, dipropylene glycol dimethacrylic acid ester, polypropylene glycol dimethacrylic acid ester, etc .; methyl vinyl ether, ethyl vinyl ether , Propyl vinyl ether, butyl vinyl ether, isobutyl vinyl ether, ben Vinyl ethers such as ruvinyl ether and octyl vinyl ether; Acrylonitrile; Styrene; Ethylene; Allyl esters such as allyl acetate; Acrylamide; Methacrylamide; It may be selected from acids; or salts thereof.
[0015]
Corresponding monomers can also be added for purposes such as increasing the stability of the emulsion, crosslinking the polymer or imparting functionality. For example, monomers such as trimethylolpropane triacrylate, pentaerythritol tetraacrylate, methacryloxyethyltrimethoxysilane, and isobornyl acrylate can be copolymerized to provide new physical properties.
[0016]
In the emulsion polymerization, as a surfactant used in combination with a homopolymer of N-vinylcarboxylic amide or a water-soluble copolymer with a polymerizable compound copolymerizable with N-vinylcarboxylic amide, lauryl sulfate, poly Oxyethylene alkyl ether sulfate, alkyl benzene sulfonate, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl phenyl ether sulfate, N-acyl amino acid salt, alkyl phosphate, alkane sulfonate, oleate, stearin Anionic surfactants such as acid salts, alkyl naphthalene sulfonates, dialkyl sulfosuccinates, alkyl diphenyl ether disulfonates, naphthalene sulfonic acid formalin condensate salts; benzalkonium chloride, benzethonium chloride, stearyl trimethy chloride Cationic surfactants such as ammonium, distearyldimethylammonium chloride, lauryltrimethylammonium chloride; alkyldiaminoethylglycine hydrochloride, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, lauryldimethylaminoacetic acid betaine, etc. Amphoteric surfactants: polyol fatty acid esters, glyceryl monostearate, glyceryl monooleate, ethylene glycol monostearate, propylene glycol monostearate, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene fatty acid Esters, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene sorbitol fatty acids Ester, N- acylamino acid ester, sucrose fatty acid esters, nonionic surfactants such as fatty acid alkylol amides.
[0017]
In emulsion polymerization, examples of other water-soluble polymer compounds used in combination with a homopolymer of N-vinylcarboxylic amide or a water-soluble copolymer of N-vinylcarboxylic amide include, for example, gum arabic, gellan gum, tragacanth gum, Locust bean gum, guar gum, echo gum, karaya gum, agar, starch, carrageenan, alginic acid, alginate (eg, sodium alginate), propylene glycol alginate, dextran, dextrin, amylose, gelatin, collagen, pullulan, pectin, amylopectin, starch, Natural polymers such as sodium amylopectin semiglycolate, albumin, casein; polyglutamic acid, polyaspartic acid, methylcellulose, ethylcellulose, propylcellulose, ethyl Methyl cellulose, hydroxyalkyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl starch, carboxymethyl starch, alkali metal carboxymethyl cellulose, alkali metal cellulose sulfate, cellulose graft polymer, crosslinked gelatin, cellulose acetate phthalate, starch-acrylic acid graft polymerization, anhydrous Semi-synthetic polymers such as phthalic acid-modified gelatin and succinic acid-modified gelatin; polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl methyl ether, methyl vinyl ester, polyacrylate (for example, sodium polyacrylate), carboxyvinyl polymer, vinyl Pyrrolidone-ethyl acrylate copolymer, vinyl pyrrolidone-styrene copolymer, vinyl pyrrolidone-vinyl acetate copolymer , Vinyl acetate-crotonic acid copolymer, vinyl acetate- (meth) acrylic acid copolymer, vinyl acetate-crotonic acid copolymer, polyvinyl sulfonic acid, polyitaconic acid, polyhydroxyethyl acrylate, polyacrylamide, styrene-maleic acid Synthetic polymers such as acid anhydride copolymers and acrylamide-acrylic acid copolymers are exemplified, but the invention is not particularly limited thereto.
[0018]
In the present invention, the protective colloid generation step is preferably performed as follows. Copolymerizable with N-vinylcarboxylic acid amide or N-vinylcarboxylic acid amidepolymerizationsexCompoundThe product is placed in a reactor with water or an organic solvent and dissolved or dispersed with vigorous stirring. Polymerization is carried out by adding a polymerization initiator while heating the reactor. The obtained water-soluble (co) polymer remains as an aqueous solution, or is concentrated and dried to proceed to the next emulsion polymerization process.
[0019]
In emulsion polymerization, the protective colloid obtained in the above step is put into a reactor together with water, a polymerization initiator is added, and then an unsaturated compound having an ethylenically unsaturated group is added while heating with stirring. The unsaturated compound having an ethylenically unsaturated group may be dropped as it is, or may be dropped as an aqueous solution or an aqueous dispersion. When emulsion polymerization starts, the temperature rises, so cool it with a jacket and keep it at an appropriate temperature, and at the end of the reaction when the reflux has stopped, raise the temperature or add additional initiator to complete the reaction .
[0020]
The resulting emulsion is a smooth milky liquid with the following characteristics:
1. Excellent storage stability, heat test at 50 ° C., freeze-thaw stability.
2. Even if the emulsion is vigorously stirred, coagulates and precipitates are hardly formed.
3. It is stable even when additives such as salts are added.
4). Emulsion bubbles are difficult to form.
5. Excellent adhesion and adhesion to the substrate.
6). The film has excellent light resistance and heat resistance.
[0021]
The emulsion obtained in the present invention has excellent properties as described in 1 to 6 above, and therefore can be used for a wide variety of applications.
For example, pigments, fillers, etc. are blended, and emulsion raw materials such as wall materials, ceiling materials, metal plates, plastics, etc .; wood, paper products, textile products, leather products, plastic products, adhesives for metal products; Adhesive material used for tapes and sheets; impregnation processing such as non-woven fabric production, increased paper strength; other use as a planting aid, leather luster, waterproofing agent, etc.
[0022]
【Example】
Hereinafter, although an example and a comparative example explain the present invention still in detail, the present invention is not limited to these examples at all.
[0023]
(Synthesis example 1 of protective colloid)
10 parts by mass of N-vinylacetamide (hereinafter referred to as “parts”) is dissolved in 90 parts of ion-exchanged water, and the temperature is raised to 50 ° C. while stirring in a nitrogen stream. Thereafter, the warm water in the jacket is drained, and 0.05 part of 2,2'-azobis (2-amidinopropane) .dihydrochloride is added as an initiator to initiate the polymerization. Since the polymerization is completed in 6 hours, it is cooled to room temperature. The aqueous solution can be used as it is as a protective colloid for the next emulsion polymerization, or it can be dried and ground to obtain a polymer powder. The polymer dissolves well in water. The molecular weight by GPC was 750,000.
[0024]
(Protective colloid synthesis example 2)
20 parts of N-vinylacetamide, 4 parts of methyl acrylate and 2 parts of acrylamide are dissolved in 100 parts of ion-exchanged water and kept at 70 ° C. with stirring in a nitrogen stream, and 2,2′-azobis (2- Amidinopropane) · dihydrochloride 0.16 part is added and polymerized. Since the polymerization is completed in 5 hours, it is cooled to room temperature. The molecular weight by GPC was 340,000. The aqueous solution can be used as it is as a protective colloid for the next emulsion polymerization, or it can be dried and ground to obtain a polymer powder.
[0025]
(Protective colloid synthesis example 3)
20 parts of N-vinylformamide and 3 parts of sodium methacrylate are dissolved in 100 parts of ion-exchanged water and kept at 70 ° C. with stirring in a nitrogen stream, and 2,2′-azobis (2-amidinopropane). Add 0.12 parts of dihydrochloride and polymerize. Since the polymerization is completed in 5 hours, it is cooled to room temperature. The molecular weight by GPC was 410,000. The aqueous solution can be used as it is as a protective colloid for the next emulsion polymerization, or it can be dried and ground to obtain a polymer powder.
[0026]
(Protective colloid synthesis example 4)
20 parts of N-vinylacetamide is dissolved in 13 parts of ion-exchanged water, 0.4 part of 2,2′-azobis (2-amidinopropane) dihydrochloride as an initiator, and 0.2 part of thioglycerin as a chain transfer agent Then, 17 parts of ion-exchanged water is stirred in a nitrogen stream and kept at 100 ° C., and polymerized dropwise over 1 hour. Since the polymerization is completed in 6 hours, it is cooled to room temperature. The molecular weight by GPC was 22,000. The aqueous solution can be used as it is as a protective colloid for the next emulsion polymerization, or can be dried and ground to obtain a polymer powder.
[0027]
(Emulsion polymerization example 1)
40 parts of the poly N-vinylacetamide aqueous solution (solid content 10.4%) obtained in Synthesis Example 1 of the protective colloid was mixed with 80 parts of ion-exchanged water and charged into a reactor. 3 parts of 30% hydrogen peroxide solution, tartaric acid Dissolve 2 parts. While stirring, 20 parts of vinyl acetate monomer is added and the temperature is raised and maintained at 70 ° C. When reflux begins, 100 parts of vinyl acetate monomer is added dropwise over 3 hours. When the reflux disappears, the temperature is raised to 90 ° C. and maintained at this temperature for 1 hour to complete the polymerization. The contents are naturally cooled to room temperature. The properties of the resulting emulsion are as follows.
Solid content: 51.6%
Viscosity (20 ° C., BM viscometer 30 rpm): 11,000 mPa · s
Minimum film-forming temperature: 18 ° C
Left at 50 ° C for 1 hour: No abnormality was observed
Freeze-thaw stability (JIS K6826, 1 cycle): No abnormalities observed
[0028]
Using this emulsion, the results of an adhesion test between the birch material and the birch material in accordance with JIS 6851 were as follows.
Normal bond strength: 145 Kgf / cm²
Water-resistant adhesive strength: 110 kgf / cm²
Similarly, polyvinyl acetate emulsions with polyvinyl alcohol as protective colloids tested
Normal adhesive strength: 120 kgf / cm²
Water-resistant adhesive strength: 88 kgf / cm²
Thus, the superiority of the present invention was recognized.
[0029]
(Emulsion polymerization example 2)
20 parts of an aqueous solution of N-vinylacetamide copolymer (solid content 20.6%) obtained in Synthesis Example 2 of protective colloid was mixed with 50 parts of ion-exchanged water and charged into a reactor, and 0.6 part of ammonium persulfate was added. Add and dissolve. Separately, 3 parts of a nonionic surfactant (polyethylene oxide nonylphenyl ether) and 0.8 part of an anionic surfactant (sodium dodecylbenzenesulfonate) are dissolved in 50 parts of water, and the following monomer mixture 110 is dissolved in this aqueous solution. Emulsify the part. The mass ratio of butyl acrylate, methyl methacrylate, methacrylic acid, 2-hydroxyethyl methacrylate, and glycidyl methacrylate was 10: 40: 2: 5: 3. An aqueous N-vinylacetamide copolymer solution and an aqueous solution of ammonium persulfate are heated with stirring, and the monomer mixed emulsion is added dropwise over 3 hours. Meanwhile, the internal temperature is kept at 70-80 ° C. Further, 0.2 part of ammonium persulfate is added at the end of the polymerization, the temperature is raised to 90 ° C., and maintained for 1 hour to complete the polymerization, and then naturally cooled to room temperature. Triethanolamine is then added to bring the pH to 7.5.
[0030]
The properties of the obtained emulsion were as follows.
Solid content: 54.1%
Viscosity (20 ° C., BM viscometer 30 rpm): 620 mPa · s
Average particle size: 0.8μm
Minimum filming temperature: 5 ° C
Left at 50 ° C for 1 hour: No abnormality was observed
Freeze-thaw stability (JIS K6826, 3 cycles): No abnormalities observed
[0031]
A white paint was prepared from this emulsion with the following formulation.
Emulsion: 50 parts
Titanium white: 15 parts
Calcium carbonate: 30 parts
Butyl carbitol acetate: 3 parts
Silicone defoamer: 0.1 part
Phosphoric acid pigment dispersant: 2 parts
[0032]
This paint was applied to a slate plate, dried at room temperature for 3 days, and then evaluated according to JIS K5400.
Adhesion: 100/100
Water resistance (25 ° C, 5 days): No abnormalities
Gloss (60 °): 92%
Weather meter (Sunshine) 1000 hours later: 87%
[0033]
For comparison, emulsion polymerization was performed with exactly the same monomer composition as described above, using only polyethylene oxide noniphenol ether and sodium dodecylbenzenesulfonate as emulsifiers. The properties of the resulting emulsion are as follows.
Solid content: 53.0%
Viscosity (20 ° C., BM viscometer 30 rpm): 340 mPa · s
Average particle size: 0.7 μm
Minimum filming temperature: 1 ° C
Left at 50 ° C for 1 hour: No abnormality was observed
Freeze-thaw stability (JIS K6826, 3 cycles): No abnormalities observed
[0034]
This emulsion was made into a paint with the same formulation as before, applied to a slate plate, and evaluated according to the same JIS K5400 as before.
Adhesion: 100/100
Water resistance (25 ° C, 5 days): Slightly blistered
Gloss (60 °): 90%
Weather meter (Sunshine) 1000 hours later: 76% (choking was observed.)
Thus, the emulsion of the present invention is superior in performance when used as a coating material than an emulsion prepared using only a conventional emulsifier.
[0035]
(Emulsion polymerization example 3)
20 parts of an aqueous solution of N-vinylformamide copolymer (solid content 19.1%) obtained in Synthesis Example 3 of protective colloid was mixed with 50 parts of ion-exchanged water and charged into a reactor, and 0.7 part of ammonium persulfate was added. Add and dissolve. Separately, 5 parts of a nonionic surfactant (polyethylene oxide nonylphenol ether) and 0.6 part of an anionic surfactant (sodium dioctyl sulfosuccinate) are dissolved in 50 parts of water, and 2-ethylhexyl acrylate is dissolved in this aqueous solution. , Methyl methacrylate, acrylic acid, 2-hydroxyethyl methacrylate, glycidyl methacrylate, and trimethylolpropane triacrylate were emulsified in a mass ratio of 30: 17: 2: 4: 4: 3. An aqueous solution of N-vinylformamide copolymer and an aqueous solution of ammonium persulfate are heated with stirring, and the monomer mixed emulsion is added dropwise over 4 hours. Meanwhile, the internal temperature is kept at 70-80 ° C. At the end of the polymerization, 0.2 part of ammonium persulfate and 0.3 part of ascorbic acid are added, the temperature is raised to 90 ° C., and the polymerization is completed by maintaining for 1 hour, followed by natural cooling to room temperature. A sodium hydroxide solution is then added to bring the pH to 7.5. The properties of the obtained emulsion were as follows.
[0036]
Solid content: 47.6%
Viscosity (20 ° C., BM viscometer 30 rpm): 580 mPa · s
Average particle size: 0.7 μm
Minimum filming temperature: 0 ° C
Left at 50 ° C for 1 hour: No abnormality was observed
Freeze-thaw stability (JIS K6826, 3 cycles): No abnormalities observed
[0037]
This emulsion was blended as follows to obtain a nonwoven fabric binder.
Emulsion: 57.5 parts
Water: 40 parts
Cross-linking aid (amine hydrochloride): 2 parts
Fluorescent dye: 0.5 part
[0038]
The binder compounding solution was kept at 40 ° C., the polyester fiber web was dipped into 70% pickup, dried at 90 ° C. for 15 minutes, and then cured by heating at 150 ° C. for 20 minutes. After cooling, the expansion force and the shrinkage rate of immersion in water (25 ° C., 30 minutes) were measured according to JIS L1085.
Expansion force: Vertical 5.6Kgf / cm, Horizontal 3.4Kgf / cm
Shrinkage: Vertical 0.9%, Horizontal 1.0%
[0039]
The measurement results of the nonwoven fabric produced in the same manner using an emulsion obtained by emulsion polymerization using only an emulsifier without using an aqueous N-vinylformamide copolymer solution as a protective colloid are as follows.
Expansion force: Vertical 4.0Kgf / cm, Horizontal 2.8Kgf / cm
Shrinkage: Vertical 1.8%, Horizontal 1.5%
Thus, it was found that the nonwoven fabric made from the emulsion obtained in the present invention has a larger expansion force and a smaller shrinkage rate than the nonwoven fabric made from the emulsion not using the N-vinylformamide copolymer. It was.
[0040]
(Emulsion polymerization example 4)
50 parts of an aqueous solution (solid content 40.5%) of the N-vinylacetamide copolymer obtained in Synthesis Example 4 of protective colloid, 50 parts of a 15% aqueous solution of polyvinyl alcohol 15% having a saponification degree of 88 mol% and a molecular weight of 30,800, Charge 100 parts of ion-exchanged water to the reactor, add 8 parts of potassium persulfate, dissolve, and raise the temperature while stirring. Next, 200 parts of vinyl acetate monomer is dropped over 3 hours, and the internal temperature is kept at 80 to 85 ° C. during that time. When the reflux is completed, 0.6 part of potassium persulfate is additionally added, the internal temperature is raised to 90 ° C., and the polymerization is terminated by keeping for 1 hour. Cool to room temperature naturally with stirring.
[0041]
The properties of the resulting emulsion are as follows.
Solid content: 58.4%
Viscosity (20 ° C., BM viscometer 30 rpm): 5200 mPa · s
pH: 6.1
Average particle size: 0.7 μm
Minimum filming temperature: 15 ° C
Left at 50 ° C for 1 hour: No abnormality was observed
Freeze-thaw stability (JIS K6826, 1 cycle): No abnormalities observed
[0042]
Using this emulsion, an adhesion test between the birch material and the birch material was performed based on JIS K6851. That is, the emulsion is 0.1 g / cm²After being applied to the adhesive surface at a ratio of
Normal bond strength: 134 kgf / cm²
Water-resistant adhesive strength: 128Kgf / cm²
Met.
[0043]
On the other hand, the protective colloid synthesis example 4 was omitted, and instead 100 parts of a 15% aqueous solution of polyvinyl alcohol 15% having a saponification degree of 88 mol% and a molecular weight of 30,800 and 100 parts of ion-exchanged water were placed in a reactor, Emulsion polymerization of vinyl monomer was performed. An adhesion test between the birch material and birch material was performed using the obtained emulsion. The result is normal bond strength: 120 kgf / cm²Water-resistant adhesive strength: 89 kgf / cm²In particular, it was found that the emulsion of the present invention has excellent water-resistant adhesive strength.
[0044]
【The invention's effect】
The present invention relates to an unsaturated compound having an ethylenically unsaturated group, using, as a protective colloid, an N-vinylcarboxylic acid amide polymer or a water-soluble copolymer of a polymerizable compound copolymerizable with N-vinylcarboxylic acid amide. The present invention relates to a method for emulsion polymerization and an emulsion composition obtained by the emulsion polymerization. Compared to surfactants and water-soluble polymers conventionally used as stabilizers in emulsion polymerization, the emulsion of the present invention has excellent stability, water resistance after processing, etc. Since it can be widely applied for adhesives, pressure-sensitive adhesives, impregnating agents, textile processing agents, paper processing agents, leather processing agents, planting aids, etc., the use of emulsions will be expanded and the quality of processed products will be improved. Can do.

Claims (3)

N- vinyl acetamide homopolymer thereof, or N- vinylacetamide copolymerizable with generating a protective colloid comprising a water-soluble copolymers with polymerizable compounds, water and an ethylenically unsaturated group to the protective colloid And a step of carrying out emulsion polymerization by adding an unsaturated compound having a solvent. Heating generation step of the protective colloid, N- vinyl acetamide, or N- and vinylacetamide co-polymerizable compound, and a step of dissolving or dispersing in water or an organic solvent, the solution or dispersion The method for producing a vinyl emulsion according to claim 1 , further comprising: adding a polymerization initiator while performing polymerization. The emulsion polymerization to step, water to the protective colloids, to claim 1, characterized in that it comprises the step of adding an unsaturated compound having an ethylenically unsaturated group while heating with stirring after addition of a polymerization initiator A method for producing the vinyl emulsion as described.