JP3348920B2 - Emulsion composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emulsion composition, and more particularly, to an aqueous emulsion composition having excellent water resistance, heat resistance and compressive strength, and being suitably used as an adhesive for woodwork and paper tubes. About.

[0002]

2. Description of the Related Art Conventionally, a water-soluble polymer compound such as polyvinyl alcohol, a copolymer of isobutylene and maleic anhydride or a derivative thereof has been used as a dispersion stabilizer (protective colloid) as an adhesive for paper tubes and woodwork. Containing aqueous emulsions are widely used. Such an aqueous emulsion, particularly an aqueous emulsion containing polyvinyl alcohol as a protective colloid, has a high initial adhesive force and an appropriate viscosity, and thus is excellent in high-speed laminating property and workability. Is suitable as an adhesive for paper tubes and woodwork. However, since the aqueous emulsion uses a water-soluble polymer compound as a protective colloid, it has a disadvantage that it is inferior in water-resistant adhesive strength and insufficient in heat resistance and compressive strength.

[0003]

SUMMARY OF THE INVENTION Under such circumstances, the present invention is characterized by the characteristics of polyvinyl alcohol-protected colloid-based aqueous emulsion (high initial adhesive strength, moderate viscosity).
It is an object of the present invention to provide an aqueous emulsion composition having excellent water resistance, heat resistance and compressive strength without impairing the aqueous emulsion composition.

[0004]

The present inventors have made intensive studies to develop an aqueous emulsion composition having the above-mentioned preferable properties. As a result, carboxyl-modified polyvinyl alcohol and isobutylene were used as dispersants, that is, protective colloids. An aqueous emulsion (A) obtained by emulsion polymerization of an ethylenically unsaturated monomer using a copolymer with maleic anhydride or a derivative thereof, and a polyamide and epoxy resin
It has been found that an emulsion composition comprising the reaction product (B) with a compound having a silicic group can be suitable for the purpose. The present invention has been completed based on such findings. That is, the present invention provides emulsion polymerization of an ethylenically unsaturated monomer in the presence of a carboxyl group-modified polyvinyl alcohol (a) as a dispersant and a copolymer of isobutylene and maleic anhydride or a derivative (b) thereof. Aqueous Emulsion (A) and Polyamide and Epoxy Group Containing
It is intended to provide an emulsion composition comprising a reactant (B) with a compound .

The emulsion composition of the present invention comprises a specific aqueous emulsion (A), a polyamide and an epoxy group-containing emulsion .
And a reaction product (B) with the compound . Here, the aqueous emulsion (A) is prepared by mixing a carboxyl group-modified polyvinyl alcohol (a) and a copolymer of isobutylene and maleic anhydride or a derivative (b) thereof as a dispersant with an ethylenically unsaturated monomer. It is used at the time of emulsion polymerization. The carboxyl group-modified polyvinyl alcohol used as the component (a) of the dispersant is not particularly limited as long as it is a modified polyvinyl alcohol having a carboxyl group in the molecule, but is usually a vinyl ester monomer represented by vinyl acetate. the dimer, acrylic acid, methacrylic acid, (anhydrous) phthalic acid, (anhydrous) maleic acid, then copolymerized with ethylenically unsaturated carboxylic acids, such as Lee data <br/> Con acid, which was saponified (random copolymer Polymer) or a product obtained by radically polymerizing the above ethylenically unsaturated carboxylic acid in the presence of a polyvinyl alcohol-based polymer having a thiol group at the end (block copolymer) is preferably used. In addition, as the above-mentioned vinyl ester monomer, besides vinyl acetate, vinyl formate, vinyl propionate, vinyl versatate, vinyl pivalate and the like can also be used.

[0006] The degree of polymerization of the carboxyl group-modified polyvinyl alcohol in the present invention is not particularly limited,
A range of 50 to 3000 is preferred, and a range of 100 to 2000 is more preferred. The saponification degree of the carboxyl group-modified polyvinyl alcohol is not particularly limited, but is preferably in the range of 70 to 100 mol%,
A mole% range is more preferred. Further, the amount of carboxyl group modification is not particularly limited, but is 0.1 to 50 mol%.
Is preferable, the range of 0.5 to 10 mol% is more preferable, and the range of 0.5 to 5 mol% is particularly preferable. If the carboxyl group modification amount is less than 0.1 mol%, a sufficient crosslink density cannot be obtained and the water resistance does not improve. On the other hand, when the carboxyl group modification amount exceeds 50 mol%, it is difficult to obtain a stable emulsion, and even if a stable emulsion is obtained, it is difficult to sufficiently exhibit water resistance and the like.

Further, the carboxyl group-modified polyvinyl alcohol in the present invention can be copolymerized with a copolymerizable ethylenically unsaturated monomer as long as the effects of the present invention are not impaired. Such ethylenically unsaturated monomers include, for example, ethylene, isobutylene, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, trimethyl- (3-acrylamide-3-
Dimethylpropyl) -ammonium chloride, ethyl vinyl ether, butyl vinyl ether, N-vinyl pyrrolidone, vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene chloride, vinylidene fluoride, tetrafluoroethylene, sodium vinyl sulfonate, sodium allyl sulfonate, etc. Is mentioned. Further, in the presence of a thiol compound such as thiolacetic acid or mercaptopropionic acid, a terminal modified product obtained by copolymerizing a vinyl ester monomer such as vinyl acetate with an ethylenically unsaturated carboxylic acid and saponifying it. Can also be used.

On the other hand, as a copolymer of isobutylene and maleic anhydride and a derivative thereof used as the component (b) of the dispersant, for example, besides a binary copolymer of isobutylene and maleic anhydride, isobutylene and maleic anhydride may be used. / Long chain α-olefin / maleic anhydride copolymer, isobutylene / long chain alkyl acrylate / maleic anhydride copolymer, isobutylene / N-phenylmaleimide / maleic anhydride copolymer, isobutylene / n-butyl (meth) Modified copolymers such as acrylate / maleic anhydride copolymers, and derivatives such as partially imidized isobutylene / maleic anhydride copolymers, all of which can be converted to an aqueous solution with an alkali such as sodium hydroxide or ammonia. Used. These copolymers of isobutylene and maleic anhydride or derivatives thereof may be used alone,
Two or more kinds may be used as a mixture.

Next, the polymer of the ethylenically unsaturated monomer, which is a dispersoid in the aqueous emulsion of the component (A),
Although there are various types, preferred examples of the ethylenically unsaturated monomer as a raw material of the polymer include olefins such as ethylene, propylene and isobutylene, vinyl chloride, and the like.
Halogenated olefins such as vinyl fluoride, vinylidene chloride, and vinylidene fluoride; vinyl esters such as vinyl formate, vinyl acetate, vinyl propionate, and vinyl versatate; acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, and acrylic acid Acrylates such as butyl, 2-ethylhexyl acrylate, dodecyl acrylate, 2-hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, 2-methyl methacrylate Methacrylic esters such as hydroxyethyl, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate and their quaternaries, and furthermore, acrylamide, methacrylamide, N-methyl Acrylamide, N, N-dimethylacrylamide, acrylamide-based monomers such as acrylamido-2-methylpropanesulfonic acid and its sodium salt, styrene, alpha-methyl styrene, p
-Styrene-based monomers such as styrenesulfonic acid and its sodium and potassium salts, other N-vinylpyrrolidone, and diene-based monomers such as butadiene, isoprene, and chloroprene. These may be used alone or in combination. These are used as a mixture.

Among the above ethylenically unsaturated monomers, vinyl esters, (meth) acrylic esters, styrene and diene monomers are preferred, especially vinyl esters, combined use of ethylene and vinyl esters, and (meth)
Acrylic esters are preferred. The method for preparing the aqueous emulsion as the component (A) is not particularly limited, and various methods can be used. For example, using the aqueous solution of a copolymer of carboxyl group-modified polyvinyl alcohol and isobutylene and maleic anhydride as described above or a derivative thereof as a dispersant, in the presence of a polymerization initiator, the ethylenically unsaturated monomer is temporarily or A normal emulsion polymerization method such as continuous addition, heating and stirring can be used. In addition, an ethylenically unsaturated monomer previously mixed and emulsified with an aqueous solution containing a carboxyl group-modified polyvinyl alcohol and a copolymer of isobutylene and maleic anhydride or a derivative thereof is continuously added to the polymerization reaction system. Emulsion polymerization can also be employed. further,
An aqueous solution of a carboxyl group-modified polyvinyl alcohol, or a copolymer of isobutylene and maleic anhydride or a derivative thereof may be partially added during or after polymerization.

The amount of the carboxyl group-modified polyvinyl alcohol, the copolymer of isobutylene and maleic anhydride or the derivative thereof is not particularly limited, but the amount of the carboxyl group is based on 100 parts by weight of the ethylenically unsaturated monomer. Modified polyvinyl alcohol is preferably 1 to 30 parts by weight, particularly preferably 2 to 20 parts by weight, a copolymer of isobutylene and maleic anhydride or a derivative thereof is preferably 1 to 30 parts by weight, and particularly preferably 2 to 20 parts by weight. . As the aqueous emulsion used in the present invention, the aqueous emulsion obtained by the above method may be used as it is, but if necessary, various conventionally known emulsions may be added as long as the effects of the present invention are not impaired. Can be. In the composition of the present invention, as the dispersant in the aqueous emulsion used as the component (A), a carboxyl group-modified polyvinyl alcohol and a copolymer of isobutylene and maleic anhydride or a derivative thereof are used.
If necessary, a conventionally known anionic, nonionic or cationic surfactant, a polyvinyl alcohol-based polymer, or hydroxyethyl cellulose can be used in combination.

In the composition of the present invention, the reaction between the polyamide used as the component (B) and the epoxy group-containing compound is performed.
The Applied Physics, The type is not particularly limited in its, more preferably a reaction product of a port Riami <br/> de and a glycidyl group-containing compounds, polyamide epichlorohydrin is particularly preferred is the reaction product of polyamides and epichlorohydrin.

The polyamide epichlorohydrin is a quaternized water-soluble resin obtained by reacting epichlorohydrin with a polyamide resin obtained by a condensation reaction between an alkylpolyamine compound and an alkyldicarboxylic acid,
For example, a polyamide obtained by allowing epichlorohydrin to act on a polyamide obtained from adipic acid and diethylenetriamine is exemplified. Polyamide and d is the component (B)
The degree of polymerization of the reaction product with the oxy group-containing compound is not particularly limited, but a Brookfield type viscosity (B type viscosity) at a temperature of 25 ° C. of a 10% by weight aqueous solution is preferably 5 to 10,000 mPas · s. (Millipascal second), more preferably 10 to 5,000 mPas · s,
More preferably, it is in the range of 10 to 1,000 mPas · s. The polyamide and the epoxy group-containing compound
The functional group content of the reaction product with is not particularly limited, but is preferably in the range of 0.01 to 1 mol / 100 g.
The range is more preferably from 0.03 to 0.5 mol / 100 g.

There are various methods for preparing the emulsion composition of the present invention. Generally, the reaction product of the above-mentioned component (B), the polyamide and the epoxy group-containing compound, is used as it is, or as an aqueous solution, or It is prepared by dissolving in a water-soluble solvent and then adding and mixing with the aqueous emulsion as the component (A). In this case, the amount of the component (B) to be added was 10% of the solid content of the emulsion.
The range is preferably from 0.1 to 30 parts by weight, more preferably from 0.2 to 15 parts by weight, based on 0 parts by weight. When the addition amount of the component (B) is less than 0.1 part by weight or more than 30 parts by weight, the water-resistant adhesive strength and heat resistance may decrease, which is not preferable.

The emulsion composition of the present invention basically comprises the aqueous emulsion as the component (A) and the reaction product of the polyamide and the epoxy group-containing compound as the component (B). And various organic solvents such as toluene, perclene, dichlorobenzene, trichlorobenzene, starch, modified starch, oxidized starch, sodium alginate, carboxymethylcellulose, methylcellulose, hydroxymethylcellulose, maleic anhydride / styrene copolymer, maleic anhydride / methyl Water-soluble polymer compounds such as vinyl ether copolymers and urea /
Thermosetting resins generally used as adhesives, such as formalin resin, urea / melamine / formalin resin, and phenol / formalin resin, can also be used as appropriate. Further, in the emulsion composition of the present invention,
Fillers such as clay, kaolin, talc, calcium carbonate, and wood flour, fillers such as flour, reaction accelerators such as boric acid and aluminum sulfate, pigments such as titanium oxide, and other defoamers, dispersants, and antifreeze Various additives such as a preservative, a preservative, and a rust inhibitor can also be appropriately added.

[0016]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the following Examples and Comparative Examples, “parts” and “%” mean on a weight basis unless otherwise specified. The wood / wood (hemi wood) adhesion test, the plywood / vinyl chloride (PVC) sheet adhesion test (heat resistance) and the compression resistance test were carried out in the following manner. (1) Wood / wood (hedgewood) adhesion test A specimen was prepared under the following conditions, and the adhesion was measured. <Adhesion conditions> Adherend material: Tsuga / Higa (masa), water content 8% Coating amount: 150 g / m ² (both sides coated) Deposition time: 1 minute Pressing condition: 20 ° C., 24 hours, pressure 10 kg / cm ² <Measurement conditions> Compressive shear adhesive strength according to JIS K-6852 was measured. Normal strength: Measured as it was after curing for 7 days at 20 ° C. Water resistance strength: After curing for 7 days at 20 ° C. After immersion in water for 3 hours, measured in a wet state Resistance to warm water: After curing for 7 days at 20 ° C., the test piece was immersed in warm water at 60 ° C. for 3 hours, then cooled in 20 ° C. water and wetted Measure as it is

(2) Plywood / PVC Sheet Adhesion Test (Heat Resistance) A specimen was prepared under the following conditions, and the adhesion was measured. <Adhesion conditions> Adherend material: Plywood (first class) / Soft PVC sheet (Mitsubishi Kasei Co., Ltd., Altron, 500 μm) Coating amount: 150 g / m ² (applied to plywood) Deposition time: 0.5 min. : Lightly pressed with a rubber hand roller <Measurement conditions> Cut a test piece to a width of 25 mm, attach a 550 g weight to the end of PVC, hang it in a hot air dryer at 77 ° C, and measure the time until the weight falls. did. (3) Compressive strength test A base paper for paper tube with a weight of 580 g / m ² was cut into a width of 6 cm,
The emulsion composition is applied thereto at 60 g / m ² , and after 2 seconds, the emulsion composition is wound around a 6.5 cm outer diameter PVC pipe and bonded. Further, in the same manner, a total of ten base papers were stacked and wound to form a ten-layer paper tube. This was left for 24 hours, then dried at 105 ° C. for 5 minutes, and then dried at 20 ° C. and a relative humidity (RH) of 65.
% For 3 days. The paper tube thus obtained was cut to a length of 10 cm, and the compression strength was measured at a compression speed of 2 mm / min.

Example 1 A 1-liter glass polymerization vessel equipped with a reflux condenser, a dropping funnel, a thermometer and a nitrogen inlet was charged with 400 g of water, carboxyl group-modified polyvinyl alcohol (degree of polymerization 1750,
A saponification degree of 87.5 mol%, a random copolymerization modification of 1 mol% of itaconic acid) and 12 g of a partially imidized product of a copolymer of isobutylene and maleic anhydride (Isoban 304, manufactured by Kuraray Co., Ltd.) were further added. Sodium oxide 1.6
g was added and completely dissolved at 95 ° C. Next, the aqueous solution was cooled, and after purging with nitrogen, 400 g of vinyl acetate was charged with stirring at 140 rpm, the temperature was raised to 60 ° C., and polymerization was carried out with a redox initiator system of hydrogen peroxide / Rongalite. The polymerization was completed in 2 hours, and a stable polyvinyl acetate emulsion having a polymerization rate of 99.9%, a solid content of 50.6%, and a viscosity of 2,400 mPas · s was obtained. Dibutyl phthalate 10
Was mixed with 1 part of polyamide epichlorohydrin (WS-525, manufactured by PMC Japan) to prepare an emulsion composition. The emulsion composition was subjected to a wood / wood adhesion test, a plywood / PVC sheet adhesion test, and a compression resistance test. The results are shown in Table 1.

Comparative Example 1 In Example 1, 24 parts of isovan 304 were used as a dispersant.
An emulsion was obtained in the same manner as in Example 1 except that g was used alone. This emulsion has a solids content of 49.8%,
The viscosity was 1700 mPas · s. An emulsion composition was prepared and evaluated using this emulsion in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 An emulsion composition was prepared and evaluated in the same manner as in Example 1 except that polyamide epichlorohydrin was not added. Table 1 shows the results.

Comparative Example 3 In the same manner as in Example 1, except that 12 g of unmodified polyvinyl alcohol (polymerization degree: 1750, saponification degree: 88.0 mol%) was used instead of carboxyl group-modified polyvinyl alcohol. An emulsion was obtained. This emulsion had a solid content of 50.3% and a viscosity of 3000 mPa.
s · s. Using this emulsion, an emulsion composition was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 2 Carboxyl group-modified polyvinyl alcohol (polymerization degree 17
50 g, saponification degree 87.5 mol%, random copolymerization modification of 1 mol% of itaconic acid) and 3.6 g of a partially imidized product of a copolymer of isobutylene and maleic anhydride (Isoban 30
4, manufactured by Kuraray Co., Ltd.) and 290 g of deionized water
And 5 g of 10% aqueous ammonia,
The mixture was heated and stirred at ℃. This was charged into a pressure-resistant autoclave equipped with a nitrogen inlet and a thermometer, 300 g of vinyl acetate was further charged, and then ethylene was charged at 45 kg / cm ^2.
The pressure was increased to G. After the temperature was raised to 60 ° C., polymerization was started using a hydrogen peroxide-Rongalit redox initiator.
Two hours later, the polymerization was terminated when the residual vinyl acetate concentration reached 0.7%. Solids concentration 51.8%, viscosity 1600
An mPas · s stable poly (vinyl acetate-ethylene) copolymer emulsion was obtained. One part of polyamide epichlorohydrin (WS-525, manufactured by PMC Japan) was added to 100 parts of the solid content of this emulsion to prepare an emulsion composition. This emulsion composition was subjected to a wood / wood adhesion test, a plywood / PVC sheet adhesion test, and a compression resistance test. The results are shown in Table 1.

Example 3 In a 1-liter glass polymerization vessel equipped with a reflux condenser, a dropping funnel, a thermometer and a nitrogen inlet, 300 g of water and a carboxyl group-modified polyvinyl alcohol having a thiol group at a terminal (polymerization degree 500, saponification degree) Degree 88.2 mol%,
Itaconic acid 1 mol% random copolymerization modified, [SH] concentration: 5 × 10 ⁻⁵ mol / g-polyvinyl alcohol) 20
g was completely dissolved at 95 ° C. Next, after cooling the aqueous polyvinyl alcohol solution, the pH was adjusted to 4.0 with dilute sulfuric acid, and the atmosphere was replaced with nitrogen. While stirring at 140 rpm, 80 g of methyl methacrylate and 80 g of n-butyl acrylate were charged and heated to 70 ° C. After the rise, 5 g of a 5% aqueous solution of ammonium persulfate was added to initiate polymerization. Thereafter, to 120 g of methyl methacrylate, 120 g of n-butyl acrylate, and 100 g of water, 10 g of a copolymer of isobutylene and maleic anhydride (Isovan # 04, manufactured by Kuraray Co., Ltd.) and 5.2 g of 25% aqueous ammonia were added. The mixture was heated and dissolved, and added sequentially over 2 hours. The polymerization was completed in 4 hours, and a stable poly (methyl methacrylate / n-butyl acrylate) copolymer emulsion having a polymerization rate of 99.9%, a solid content of 51.8% and a viscosity of 1400 mPas · s was obtained. . Using this emulsion, an emulsion composition was prepared and evaluated in the same manner as in Example 2. The results are shown in Table 1.

Example 4 Carboxyl group-modified polyvinyl alcohol having a thiol group at a terminal (degree of polymerization: 300, degree of saponification: 96.0 mol%,
1 mol% of itaconic acid random copolymerization modified, [SH] concentration: 7 × 10 ⁻⁵ mol / g-polyvinyl alcohol) 12
g and a partially imidized product of a copolymer of isobutylene and maleic anhydride (Isoban 304, manufactured by Kuraray Co., Ltd.) 8
g was added to 290 g of ion-exchanged water, and 5 g of 10% ammonia water was further added and dissolved by heating at 95 ° C. This was charged into a pressure-resistant autoclave equipped with a nitrogen inlet and a thermometer. After adjusting the pH to 4.0 with dilute sulfuric acid, 165 g of styrene and then 135 g of butadiene were measured using a pressure gauge.
After the temperature was raised to 70 ° C., 10 g of a 2% aqueous potassium persulfate solution was injected to initiate polymerization. The internal pressure is 4.8kg /
cm ² G and decreases with the progress of polymerization, and after 15 hours
It was 0.4 kg / cm ² G, and the conversion was determined to be 99.
2%. The resulting emulsion was adjusted to pH 6.0 with aqueous ammonia, and had a solid content of 49.0% and a viscosity of 2500.
An mPas · s stable poly (styrene-butadiene) copolymer emulsion was obtained. Using this emulsion, an emulsion composition was prepared and evaluated in the same manner as in Example 2. The results are shown in Table 1.

[0025]

[Table 1]

Note 1) IA-PVA: itaconic acid (1 mol%) random copolymerized modified polyvinyl alcohol, degree of polymerization 1750, degree of saponification 87.5 mol% 2) Unmodified PVA: degree of polymerization 1750, degree of saponification 88.0 Mol% 3) SH-IA-PVA: a terminal thiol group, itaconic acid (1 mol%) random copolymerized polyvinyl alcohol, polymerization degree 500, saponification degree 88.2 mol%, [S
H] 5 × 10 ⁻⁵ mol / g-PVA 4) SH-IA-PVA: having a terminal thiol group, itaconic acid (1 mol%) random copolymerized polyvinyl alcohol, degree of polymerization 300, degree of saponification 96.0 Mol%, [S
H] 7 × 10 ⁻⁵ mol / g-PVA Meaning of monomer symbol VAC: Vinyl acetate MMA: Methyl methacrylate n-BA: n-butyl acrylate St: Styrene Bu: Butadiene Et: Ethylene

[0027]

[Table 2]

[0028]

The emulsion composition of the present invention maintains the characteristics (high initial adhesive strength, moderate viscosity) of a polyvinyl alcohol protective colloid-based aqueous emulsion,
In particular, it has excellent water-resistant adhesive strength, heat resistance, and compressive strength, and is suitably used as an adhesive for woodworking and paper tubes.

Continuation of the front page (56) References JP-A-5-78541 (JP, A) JP-A-57-94002 (JP, A) JP-A-55-131001 (JP, A) JP-A-4-328185 (JP) JP-A-3-45656 (JP, A) JP-A-2-58583 (JP, A) JP-A-6-172728 (JP, A) JP-A-6-128495 (JP, A) (58) Surveyed field (Int.Cl. ⁷ , DB name) C09J 151/00 C08L 23/00 C08L 51/06 C09J 177/00

Claims (1)

(57) [Claims] An emulsion polymerization of an ethylenically unsaturated monomer in the presence of a carboxyl group-modified polyvinyl alcohol (a) as a dispersant and a copolymer of isobutylene and maleic anhydride or a derivative (b) thereof. Aqueous emulsion (A) and polyamide and epoxy group containing
An emulsion composition comprising a reaction product (B) with a compound .