JPH0562623B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an emulsion composition that has improved various physical properties such as hot water adhesiveness, emulsion stability, water resistance, and solvent resistance. [Prior art] Acetoacetylated polyvinyl alcohol (hereinafter referred to as
Synthetic resin emulsions containing AA-PVA (abbreviated as AA-PVA) as a protective colloid have excellent low-temperature stability and freeze stability, and the film has good water resistance. It is expected to be put to practical use in various applications such as textile processing agents. Therefore, when used in fields that require a higher degree of water resistance, it is necessary to add a water-resistant agent to the emulsion, and various water-resistant mowing agents have been reported so far, and the present application People are also published in 1983
The patent application has been filed as JP-A-59971, JP-A-58-217571, and JP-A-59-1581. [Problems to be Solved by the Invention] However, according to further research by the present inventors, even with such an emulsion, there is still room for improvement in the following points depending on the environment and method in which it is used. It turns out that there is. That is, (1) Water-resistant adhesive properties, especially hot water-resistant adhesive properties at high temperatures, are poor, which poses a practical problem when used for decorative plywood, musical instruments, high-end furniture, cabinets, etc. (2) A decrease in adhesive strength may be observed when a plasticizer is used together. (3) There are problems with the long-term storage stability and freezing stability of the emulsion. etc. [Means for Solving the Problems] However, as a result of intensive research to eliminate the above-mentioned drawbacks, the present inventors have developed a vinyl acetate resin emulsion composition containing AA-PVA as a protective colloid. Vinyl acetate resin emulsion is
When a vinyl monomer having an acetoacetyl group (hereinafter abbreviated as AA group) is used as a copolymerization component, (1),
It has been discovered that both (2) and (3) can be improved, and that when a water-resistant agent is added to the composition, an emulsion composition having even more remarkable hot water-resistant adhesive properties can be obtained, and the present invention has been completed. I came to the point. The method for producing AA-PVA in the present invention is not particularly limited, and it may be produced by any method, but it is preferably obtained by reacting polyvinyl alcohol and diketene. Examples include a method in which polyvinyl alcohol is dispersed in an acetic acid solvent and diketene is added thereto, and a method in which polyvinyl alcohol is previously dissolved in a solvent such as dimethylformamide or dioxane and diketene is added thereto. Also, by directly contacting polyvinyl alcohol with diketene gas or liquid diketene,
A method of obtaining AA-modified PVA may also be adopted. The polyvinyl alcohol used to obtain the AA-PVA is not particularly limited, but from the viewpoint of protective colloidal properties, it preferably has an average degree of polymerization of 500 to 2,600 and an average degree of saponification of 85 to 99 mol%. The AA degree of AA PVA is 0.05~
A range of 20 mol% is suitable. If it is less than 0.05 mol%, the water resistance and stability of the emulsion composition will decrease, and if it exceeds 20 mol%, the dispersion system will be destroyed, making it impossible to obtain a homogeneous emulsion state, or the stability of the obtained emulsion will deteriorate. becomes inferior,
Not desirable as a practical product. In the present invention, the vinyl acetate resin emulsion containing such AA-PVA as a protective colloid refers to one containing at least 50 mol% of vinyl acetate component in the resin. The most distinctive feature is the use of a vinyl monomer having an AA group as a copolymerization component.
The presence of such monomers makes it possible to improve hot water-resistant adhesive properties, etc., which is the objective of the present application. The copolymerized amount of the vinyl monomer having an AA group in the resin is 0.05 to 50% by weight, more preferably 0.5 to 20% by weight based on the entire resin. 0.05
If it is less than 50% by weight, the effect of the present invention cannot be obtained, and if it is more than 50% by weight, the stability of the emulsion will be lost and should be avoided. Examples of such vinyl monomers are 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, hydroxypropyl acrylate or hydroxypropyl methacrylate, allyl alcohol or methallyl alcohol, 2-hydroxy-3-chloropropyl acrylate or 2-hydroxy-3
-chloropropyl methacrylate, β-hydroxyethyl-γ-acryloyloxyethylene phthalate or β-hydroxyethyl-γ-methacryloyloxyethylene phthalate, 1,4-butylene glycol monoacrylate or 1,4-
Examples include acetoacetylated monomers such as butylene glycol monomethacrylate, N-methylol acrylamide or N-methylol methacrylamide, and hydroxystyrene, and these may be used alone or in combination of two or more. Among these, it is practically most preferable to use an acetoacetylated product of 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, and an acetoacetylated product of allyl alcohol or methallyl alcohol. In addition to vinyl acetate and a vinyl monomer having an AA group, other known monomers copolymerizable therewith may be used in the vinyl acetate resin emulsion. Examples of such copolymer components are shown below. Vinyl ester monomers other than vinyl acetate Vinyl formate, vinyl propionate, vinyl butyrate, vinyl caprate, vinyl laurate, vinyl adipate, divinyl succinate, vinyl versatate, vinyl palmitate, vinyl stearate, etc. Ethylenically unsaturated carboxylic acids and their acyl esters, etc. Acrylic acid or methacrylic acid, crotonic acid,
(Anhydrous) maleic acid, fumaric acid, itaconic acid, and their alkali metal salts, ammonium salts, etc. Methyl acrylate or methyl methacrylate,
Ethyl acrylate or ethyl methacrylate, propyl acrylate or propyl methacrylate, butyl acrylate or butyl methacrylate, pentyl acrylate or pentyl methacrylate, heptyl acrylate or heptyl methacrylate, octyl acrylate or methacrylate, acrylic acid Decyl or decyl methacrylate, hexadecyl acrylate or hexadecyl methacrylate, octadecyl acrylate or octadecyl methacrylate, methyl crotonate, ethyl crotonate, methyl itaconate, ethyl itaconate, methyl sorbate, ethyl sorbate, monoalkyl maleate ester, dialkyl maleate, alkyl oleate, etc. Allyl esters of saturated carboxylic acids: allyl stearate, allyl laurate, allyl coconut oil fatty acid, allyl octylate, allyl acetate, etc. α-Olefin Ethylene, propylene, α-hexene, α-octene, α-decene, α-dodecene, α-hexadecene, α-octadecene, etc. Alkyl vinyl ether propyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, dodecyl vinyl ether, tetradecyl vinyl ether, hexadecyl vinyl ether, octadecyl vinyl ether, etc. Alkyl allyl ether Propyl allyl ether, butyl allyl ether, hexyl allyl ether, octyl allyl ether, decyl allyl ether, dodecyl allyl ether, tetradecyl allyl ether, hexadecyl allyl ether, octadecyl allyl ether, etc. Others, acrylamide or methacrylamide, acrylonitrile or methacrylonitrile,
N-methylol acrylamide or N-methylol methacrylamide, glycidyl acrylate or glycidyl methacrylate, glycidyl vinyl ether, allyl sulfonate or methallyl sulfonate, triallyl cyanurate, triallyl citrate, diallyl maleate, ethylenically unsaturated sulfone Acid salts, styrene, vinyl chloride, etc. However, to obtain the emulsion of the present invention,
A method of emulsion polymerization using AA-PVA as a protective colloid in the coexistence of a vinyl acetate monomer, a vinyl monomer having an AA group, and other copolymerizable monomers as necessary, polyvinyl alcohol, cellulose, Any method may be used, such as a method of post-adding AA-PVA to a vinyl acetate resin emulsion that has been subjected to emulsion polymerization in the presence of a surfactant or the like. Practically speaking, it is preferable to emulsion polymerize the monomers using AA-PVA as a protective colloid. During the polymerization, an emulsion polymerization catalyst commonly used for emulsion polymerization is used. Redox catalysts are particularly preferred, and specific examples include hydrogen peroxide, ammonium persulfate, or potassium persulfate and sodium metabisulfite, ferrous sulfate, dimethylaniline, formaldehyde zinc sulfoxylate, or formaldehyde sodium sulfoxylate. Examples include combinations. Also, nonionic surfactants and anionic surfactants
Can be used in combination with AA-PVA. Furthermore, other protective colloids and emulsifiers, such as cellulose derivatives (carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, etc.), polyacrylic acid derivatives, (anhydrous) maleic acid-vinyl ether copolymers, (anhydrous) maleic acid-vinyl acetate copolymers,
Saponified vinyl acetate-allylsulfonic acid (salt) copolymer or vinyl acetate metallisulfonic acid (salt)
Saponified copolymers can also be used in combination as appropriate. Other various additives, regulators, etc. used in ordinary emulsion polymerization may also be used as appropriate. Polymerization is carried out by dissolving the above-mentioned AA-PVA and catalyst in an aqueous medium, and carrying out the polymerization at a temperature of 30 to 90° C. while charging various monomers all at once or continuously. The resulting emulsion may be used as is or its concentration may be adjusted as appropriate. The solid content of the emulsion used in the present invention varies depending on its use and cannot be unconditionally defined, but a range of 30 to 60% by weight is usually appropriate. Furthermore, other known emulsions other than the vinyl acetate resin emulsion mentioned above may be used in combination as long as the effects of the present invention are not impaired. Such emulsions include vinyl acetate resin emulsions, acrylic ester emulsions, methacrylic ester emulsions, vinyl acetate acrylic ester copolymer emulsions, and vinyl acetate-methacrylic ester copolymer emulsions obtained by methods other than those of the present invention. ,
Vinyl chloride emulsion, ethylene resin emulsion, ethylene-vinyl acetate copolymer emulsion, styrene resin emulsion, styrene-acrylic ester copolymer emulsion or styrene-methacrylic ester copolymer emulsion, styrene-butadiene copolymer emulsion, Examples include chloroprene emulsion, acrylonitrile-butadiene copolymer emulsion, vinylpyridine resin emulsion, silicone resin emulsion, phenolic resin emulsion, butene resin emulsion, and the like. However, in the present invention, when a water resistant agent is further added to the above-mentioned vinyl acetate resin emulsion composition, it is possible to exhibit not only water resistance but also even more excellent hot water resistant adhesion. Particularly preferred examples of such waterproofing agents are illustrated below. ●Amine compounds urea, melamine or its methylol compound, hexamethylene diamine, etc. ●Aldehyde compounds glyoxal, glutaraldehyde, etc. ●Isocyanate compounds Tolylene diisocyanate, hydrogenated tolylene diisocyanate, trimethylolpropane tolylene diisocyanate adduct, triphenylmethane triisocyanate, methylenebis(4-phenyl)methane triisocyanate,
Isophorone diisocyanate and their ketoxime-blocked products or phenol-blocked products, etc. ●Epoxy compounds ethylene glycol diglycidyl ether,
Polyethylene glycol diglycidyl ether, glycerin di- or triglycidyl ether, 1,6-hexanediol glycidyl ether, trimethylolpropane di- or triglycidyl ether, diglycidyl aniline, diglycidyl amine, polyamide epichlorohydrin resin, etc. ●Radical generator Hydrogen peroxide, potassium persulfate, ammonium persulfate, succinic peroxide, t-butyl peroxide maleic acid, t-butyl hydroperoxide, benzoin alkyl such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, etc. Organic sulfur compounds such as ether, dibutyl sulfide, benzyl sulfide, and decyl phenyl sulfide, diazonium salts, tetrazonium salts, complex salts of these with zinc chloride, or condensates thereof, azobisisobutylnitrile, methylene blue, etc. Dyes or their combinations with p-toluenesulfonate ions, organic peroxides, pyrylium salts or thiapyrylium salts, ammonium dichromate, acetophenone, benzophenone, benzyl, phenanthrene, thioxanthone, dichloropropylphenyl ketone, anthraquinone, 2 -chloroanthraquinone, 2-bromoanthraquinone, anthraquinone-β-sodium sulfonate,
1,5-dinitroanthraquinone, 1,2-benzanthraquinone, phenanthrenequinone, 5
-Benzoylacenaphthene, 2-nitroacenaphthene, 1,4-naphthoquinone, 1,8-phthaloylnaphthalene, 2-nitrofluorene, p
-Nitroaniline, picramide, benzaldehyde, etc. ●Metal salts aluminum, iron, copper, zinc, tin, titanium,
Salts such as chlorides, bromides, nitrates, sulfates, and acetates of polyvalent metals such as nickel, antimony, magnesium, zirconium, vanadium, and chromium, specifically cupric chloride, aluminum chloride,
Ferric chloride, tin chloride, zinc chloride, nickel chloride, magnesium chloride, aluminum sulfate,
Copper acetate, chromium acetate, etc. In the composition of the present invention, the amount of the water resistant agent added to the emulsion containing AA-PVA as a protective colloid varies from a very small amount to a large amount depending on the purpose and type of use. 1 to 400 for the content of PVA
% by weight, more preferably from 5 to 150% by weight. When producing the composition, the water resistant agent may be added to the emulsion as it is, but it may also be dissolved or diluted in water or an organic solvent and blended. The emulsion composition thus obtained may be used as it is or, if necessary, further added with a plasticizer, a film-forming agent such as a high-boiling solvent, an extender pigment such as clay, calcium carbonate, kaolin, diatomaceous earth, a colored pigment such as titanium oxide, and a preservative. , insect repellent, rust preventive agent, antifoaming agent, flour/
It may be used by appropriately adding a filler such as wood flour.
Furthermore, although a small amount of formalin-based condensation resin can be blended into the composition of the present invention, a formalin catcher agent such as urea can also be blended at the same time. Furthermore, a water-soluble polymeric substance may be added for the purpose of thickening or the like. The amount added is usually in the range of 5 to 500% by weight based on the solid content of the emulsion. Examples of such water-soluble polymers include polyvinyl alcohol, starch, carboxymethyl cellulose, hydroxymethyl cellulose, methyl cellulose, casein, etc., and these may be mixed in any form of aqueous solution or powder. The emulsion composition obtained in the present invention can be used as an adhesive for paper, wood, plastics, fibers, etc.
It is used as a binder and coating agent, and its high viscosity makes it suitable for high-speed mechanization of wood adhesion and paper adhesion.It also has excellent hot water adhesion and water resistance, so it can be used for waterproof cardboard and plywood that require such water resistance. It is ideal for There are no particular restrictions on the means for adhering base materials using the emulsion composition, and it is sufficient to apply the emulsion composition to the next base material, then laminate another base material, adhere and dry it, but when manufacturing plywood etc. A typical example is as follows. The emulsion composition is applied to the veneer using a known coating machine such as a double roller glue spreader or a double roller glue spreader with a doctor roller. There are no particular restrictions on the type of veneer, but particularly remarkable adhesive strength can be obtained with lauan wood. There is no particular limit to the amount of application, but if it is less than 20g/m ² in terms of solid content of vinyl acetate resin, sufficient adhesion will not be obtained, while if it is more than 250g/m ² , it will not give enough adhesion considering the amount used. 20-250g/ since the force does not increase
m ² is preferably selected from the range of 50 to 150 g/m ² . The veneers coated with the emulsion composition are stacked one on top of the other and dried under pressure to be bonded, but any number of veneers, such as two or three, can be stacked on top of each other. There is no particular restriction on the temperature for heating and drying, and in short, it is sufficient to dry at a temperature equal to or higher than room temperature. However, in order to further reduce drying time and improve water resistance, the temperature is usually 20 to 150℃.
Preferably, it is necessary to select from the range of 20 to 120°C. Temperatures of 150°C or higher are not preferable because they tend to cause deterioration of the veneer. Drying pressure and processing time are 5-15Kg/cm ² , 10
About 24 hours is sufficient. [Example] Hereinafter, the emulsion composition of the present invention will be explained in more detail with reference to actual examples. In the examples, "parts" or "%" are based on weight unless otherwise specified. Example 1 Production of vinyl acetate resin emulsion using AA-PVA as a protective colloid Emulsion composition 2-Hydroxyethyl acrylate acetoacetylated product (hereinafter abbreviated as AA-HEA) content 5
% vinyl acetate/AA-HEA copolymer 100 parts Protective colloid consisting of polyvinyl alcohol with an average degree of polymerization of 1800 containing 7.8 mol % of AA groups and 1 mol % of residual acetic acid groups 8 parts Dibutyl phthalate 5 parts Water 138 parts This emulsion was obtained as follows. 130 parts of water and 8 parts of the protective colloid mentioned above were charged into a glass polymerization container, the internal temperature was raised to 80°C to dissolve the protective colloid, and then 95 parts of vinyl acetate and 5 parts of AA were added at 70°C. - 8 parts of a 1% aqueous solution of HEA and ammonium persulfate were simultaneously added dropwise over 5 hours to perform emulsion polymerization, and after aging for 1 hour, 5 parts of dibutyl phthalate was added and cooled to adjust the concentration to 45%. . The performance of the emulsion composition was evaluated either as it was or after adding a predetermined number of the water resistant agent shown in Table 1. Control Example 1 Experiment was carried out in the same manner as in Example 1, except that an emulsion composition was prepared using polyvinyl alcohol with an average degree of polymerization of 1700 and an average degree of saponification of 91 mol% as a protective colloid instead of the AA-PVA used in Example 1. We conducted a performance evaluation. Control example 2 Vinyl acetate/AA- used in Example 1
Example 1 except that the emulsion was prepared using vinyl acetate homopolymer instead of HEA copolymer.
Experiments were conducted in the same manner as above, and performance was evaluated. Example 2 An experiment was conducted in the same manner as in Example 1, except that the copolymerization ratio of vinyl acetate/AA-HEA copolymer was changed as shown in Table 1 to produce an emulsion composition. I conducted an evaluation. The above results are summarized in Table 1. Example 3 Vinyl acetate/AA- used in Example 1
Instead of HEA copolymer, acetoacetylated allyl alcohol (abbreviated as AA-AlyOH, content
An experiment was conducted in the same manner as in Example 1, except that a vinyl acetate/AA-AlyOH copolymer containing 10%) was used, and the performance was evaluated. However, as the protective colloid, AA-PVA having a degree of AA-containing of 12 mol % and an average degree of polymerization of 500 was used. The results are shown in Table 2. Example 4 Vinyl acetate/AA- used in Example 1
Acetoacetylated 2-hydroxyethyl methacrylate (AA-
An experiment was conducted in the same manner as in Example 1, except that a vinyl acetate/AA-HEMA copolymer (abbreviated as HEMA, content 5% by weight) was used, and performance was evaluated. The results are shown in Table 2. Example 5 Vinyl acetate/AA- used in Example 1
Vinyl acetate/AA− instead of HEA copolymer
HEA/acrylic acid/ethylene copolymer (copolymerization weight ratio 70/10.5/2/17.5) was used. However, this emulsion composition was manufactured as follows. 3 parts acrylic acid, 0.5 part ABS anion activator
3 parts of nonionic activator of HLB18, 0.3 part of partially saponified polyvinyl alcohol, AA degree of 3 mol%, average saponification degree of 99 mol%, average degree of polymerization of 1400 AA
3 parts of PVA and 100 parts of water were mixed and dissolved. A portion of the mixture was introduced into an autoclave, and 100 parts of vinyl acetate, 15 parts of AA-HEA, and 0.5 part of dibasic sodium phosphate (decahydrate) were charged therein. After replacing the internal space of the system with ethylene, the temperature and pressure were increased to 70° C. and 40 Kg/cm ² . Then a 1% aqueous solution of potassium persulfate
The reaction was started by adding 50 parts of the mixture, and the rest of the mixture was added dropwise over 5 hours to continue the reaction. After aging for 1 hour, the desired emulsion composition was obtained. Performance evaluation was performed in the same manner as in Example 1 using the emulsion composition. The results are shown in Table 2. Control example 3 Vinyl acetate/AA- used in Example 1
N-methylolacrylamide (abbreviated as N-MAM, content 5% by weight) instead of HEA copolymer
An experiment was conducted in the same manner as in Example 1, except that an emulsion was produced using a vinyl acetate/N-MAM copolymer using We performed a performance evaluation. The results are shown in Table 2. The physical properties and performance of the emulsion composition were evaluated by the following methods. 1) Emulsion viscosity: Rotor rotational speed using a BH type rotational viscometer.
Viscosity at 10 rpm and 30℃ 2) Freeze-thaw stability Approximately 100g of emulsion according to JIS K6826
was placed in a polyethylene bag bottle and brought to a temperature of -15℃.
The emulsion was kept for 20 hours, then left in a thermostat at 30°C for 1 hour, stirred with a glass rod, and its appearance was observed. Good emulsion status was marked as ○, moderately good as △, and poor as ×. Ta. 3) High-temperature storage stability Approximately 100 g of the emulsion was left in a constant temperature bath kept at 60°C for approximately 10 consecutive days, and then stirred with a glass rod to observe changes in the viscosity of the emulsion. Samples with no viscosity change were indicated as ○, samples with small viscosity change as △, and samples with large viscosity change as ×. 4) Adhesion test 1 The emulsion composition was 1.4 mm thick, 25 mm wide,
Apply it to both sides of a 75mm long lauan veneer (core board) at a solid content of 100g/ ^m2 ,
The core plate is interposed in the middle, thickness 0.8 mm, width 25
Two lauan veneers (front plate and back plate) each having a length of 75 mm were laminated on both sides of the core plate and compressed for 4 hours at a pressure of 10 kg/m ² to prepare 10 test pieces for each. The obtained test pieces were subjected to a hot and cold water immersion test (JAS type) and a boiling cyclic test (JAS type) specified in the ``Japanese Agricultural Standards for Ordinary Plywood''. 2 1 type each (for room temperature adhesion) in accordance with JIS K6852 (compression shear adhesive strength testing method for adhesives)
The birch wood was laminated under the following conditions, and repeated hot/cold water and boiling tests were conducted in the same manner as above. The abbreviations in the section for waterproofing agents in the table have the following meanings. ●MM: Methylolated melamine ●GX: Glyoxal ●TDI: Triresin isocyanate ●EGDGE: Ethylene glycol diglycidyl ether ●Al ₂ (SO ₄ ) ₃ : Aluminum sulfate ● (NH ₄ ) ₂ SO ₅ : Ammonium persulfate ●GDGE: Glycerin Diglycidyl ether ●ZrCl ₄ : Zirconium chloride

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Claims (1)

[Scope of Claims] 1. A vinyl acetate resin emulsion composition containing acetoacetylated polyvinyl alcohol as a protective colloid, wherein the vinyl acetate resin emulsion contains a vinyl monomer having an acetoacetyl group as a copolymerization component. An emulsion composition characterized by: 2 The vinyl monomer having an acetoacetyl group is 2-hydroxyethyl acrylate or 2-
The emulsion composition according to claim 1, which is at least one selected from acetoacetylated products of hydroxyethyl methacrylate, acetoacetylated products of allyl alcohol, or methallyl alcohol. 3. A vinyl acetate resin emulsion composition containing acetoacetylated polyvinyl alcohol as a protective colloid, the vinyl acetate resin emulsion containing a vinyl monomer having an acetoacetyl group as a copolymerization component, and containing an amine in the composition. 1. An emulsion composition characterized in that it contains a water-resistant agent selected from a water-resistant compound, an aldehyde-based compound, an isocyanate-based compound, an epoxy-based compound, a radical generator, and a metal salt. 4 The vinyl monomer having an acetoacetyl group is 2-hydroxyethyl acrylate or 2-
The emulsion composition according to claim 3, which is at least one selected from acetoacetylated products of hydroxyethyl methacrylate, acetoacetylated products of allyl alcohol, or methallyl alcohol.