JPH0912999A - Water-based adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-based adhesive composition, excellent in heat and water resistances and useful for a vinyl chloride resin sheet, etc., by blending a specific copolymer emulsion with a water-based anionic polyurethane resin and an aliphatic polyisocyanate compound in a specific proportion. SOLUTION: This water-based adhesive composition comprises a blend of (A) a copolymer emulsion prepared by copolymerizing ethylene monomer with a vinyl ester monomer and a monomer having acetoacetyl group (e.g. a vinyl acetoacetate) with (B) a water-based anionic polyurethane resin and (C) an aliphatic polyisocyanate compound having >=2 isocyanate groups in one molecule such as hexamethylene diisocyanate. The solid weight ratio of the components (A) to (B) is (90/10) to (30/70) and the solid weight ratio of the sum total of the components (A) and (B) to the component (C) is (100/1) to (100/30).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based adhesive composition that exhibits a high degree of heat resistance and water resistance even if it is not subjected to heat treatment or the like at the time of bonding, and particularly to a vinyl chloride resin sheet (hereinafter referred to as a vinyl chloride sheet). The present invention relates to a water-based adhesive composition suitable for use in bonding plywood to plywood and various boards.

[0002]

2. Description of the Related Art As a water-based adhesive composition which can be cured at room temperature and has good adhesiveness, heat resistance and water resistance, for example,
It is proposed in Japanese Examined Patent Publication No. 63-335518, Japanese Examined Patent Publication No. 3-54149, and Japanese Unexamined Patent Publication No. 6-158509.

[0003]

[Problems to be Solved by the Invention] Japanese Patent Publication No. 63-335
18 is a mixture of a carboxyl group-containing aromatic isocyanate-based polyester type water-soluble or water-dispersible urethane resin and an aqueous latex, and 4 or 4 as a curing agent.
-Bis (ethyleneiminocarbonylamino) diphenylmethane and at least one aziridine ring compound selected from the group consisting of ω-aziridinylpropionic acid-2,2-dihydroxymethyl-butanol-triester The thing is disclosed. This water-based adhesive composition can be cured at room temperature, and as a bonding performance of a vinyl chloride sheet stuck to plywood or various boards using this, although it has a high level of water resistance, it does not have heat resistance. It wasn't enough.

Japanese Patent Publication No. 3-54149 discloses an adhesive composition containing an ethylene-vinyl acetate copolymer and an anionic polyurethane emulsion. Since this adhesive composition is a one-component type, there is no need to add a curing agent immediately before use, but the adhesive performance of a PVC sheet stuck to plywood or various boards using this is a building interior material. However, it cannot be said to be particularly sufficient for applications requiring a high degree of heat resistance and water resistance, such as window frames and stair members.

Japanese Unexamined Patent Publication (Kokai) No. 6-15809 discloses an adhesive composition containing a 2-acetoacetoxyethyl methacrylate-ethylene-vinyl acetate copolymer emulsion and an anionic polyurethane water-based resin. Since this adhesive composition is also a one-pack type, there is no need to add a curing agent immediately before use, but the adhesive performance of a PVC sheet stuck to plywood or various boards using this is 60 ° C. Although it has a high degree of performance in terms of heat resistance in water and water resistance under the condition of being immersed in water at 23 ° C for 1 day, it has heat resistance under higher temperature conditions and water resistance after being immersed in water for a long time. It wasn't enough.

An object of the present invention is to provide a water-based adhesive composition which exhibits a high degree of heat resistance and water resistance even if it is not subjected to a treatment such as heating during adhesion.

[0007]

The aqueous adhesive composition of the present invention comprises a copolymer emulsion (A) obtained by copolymerizing an ethylene monomer, a vinyl ester monomer and an acetoacetyl group-containing monomer [hereinafter Expressed as a copolymer emulsion (A). ] And anionic polyurethane water-based resin (B) and aliphatic polyisocyanate compound (C) having two or more isocyanate groups in one molecule
And a solid content weight ratio of the copolymer emulsion (A) and the anionic polyurethane water-based resin (B) is 90:10 to 30:70, and the copolymer emulsion (A) and the anionic The solid content weight ratio of the total amount (A + B) of the polyurethane aqueous resin (B) and the aliphatic polyisocyanate compound (C) is 100: 1 to 100: 20.
Which solves the above problems.

The details will be described below. The copolymer emulsion used in the present invention contains ethylene monomer, vinyl ester monomer, and acetoacetyl group-containing monomer as constituents, and the ratio thereof is ethylene monomer: vinyl ester monomer: acetoacetyl group-containing monomer =
[5-70]: 100: [0.1-10] (weight ratio).

Specific examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, vinyl pivalate, vinyl isononanoate, vinyl versatate, etc., and one of them may be used, or two or more of them may be used. You may use together. Among these, vinyl acetate or a combination of vinyl acetate and another vinyl ester is preferable.

As the acetoacetyl group-containing monomer,
Specifically, acetoacetic acid vinyl ester, acetoacetic acid allyl ester, diacetoacetic acid allyl ester, acetoacetoxyethyl methacrylate, acetoacetoxyethyl acrylate, acetoacetoxypropyl methacrylate, acetoacetoxypropyl acrylate, (2-acetylacetoxy-propyl) -allyl- Examples thereof include ether.

In the copolymer emulsion (A) used in the present invention, the ratio of ethylene monomer, vinyl ester monomer, and acetoacetyl group-containing monomer is ethylene monomer: vinyl ester monomer: acetoacetyl group-containing monomer = [5 to 70]. ]: 100: [0.1-10]
(Weight ratio), preferably ethylene monomer: vinyl ester monomer: acetoacetyl group-containing monomer =
[5 to 55]: 100: [0.5 to 5] (weight ratio). When the amount of ethylene monomer is less than this range, the adhesion to the vinyl chloride sheet at low temperature is reduced, and when it is more than this range, heat resistance is reduced, which is not preferable. On the other hand, when the amount of the acetoacetyl group-containing monomer is less than this range, the heat resistance is lowered, and when it is more than this range, the polymerization stability of the copolymer emulsion (A) is deteriorated, which is not preferable.

The copolymer emulsion (A) used in the present invention contains the above-mentioned constituents (ethylene monomer,
Vinyl ester monomer, acetoacetyl group-containing monomer), and other constituent components such as vinyl halides, (meth) acrylic acid esters, maleic acid esters, crotonic acid esters, itaconic acid esters It is also possible to use a copolymer containing one or two or more of such copolymerizable monomers in an amount of 20% by weight or less in the copolymer as long as the effect of the present invention is not impaired. Further, one or two selected from carboxyl group-containing monomers and anhydrides, N-methylol derivative monomers, hydroxyl group-containing monomers, amino group-containing monomers, amide group-containing monomers, sulfone group-containing monomers, polyvinyl compounds and the like. The above monomers
It is also possible to use a copolymer contained in the copolymer in an amount of 10% by weight or less.

The anionic polyurethane aqueous resin used in the present invention is obtained by introducing a sulfonate or carboxylate into the main chain or side chain of a urethane resin and emulsifying and dispersing it in water.

The solid content weight ratio of the copolymer emulsion (A) and the anionic polyurethane water-based resin (B) used in the present invention is 90:10 to 30:70, preferably 80:20 to 50:50. However, if the ratio is outside this range, the desired heat resistance and water resistance will decrease, which is not preferable.

On the other hand, examples of the aliphatic polyisocyanate compounds used in the present invention include hexamethylene diisocyanate compounds. In addition, a material in which a hydrophilic group is introduced to give self-emulsifying property is preferable because it has excellent dispersibility in an aqueous resin. Further, among those having self-emulsifying property, in order to suppress the reactivity between the aliphatic polyisocyanate compound and water, the one in which a hydrophobic group is introduced in addition to the hydrophilic group is self-emulsifying aliphatic polyisocyanate. It is more preferable in that the deterioration of the adhesive performance with the passage of time after the addition of the compound is delayed.

Further, in the present invention, the solid content weight ratio of the total amount (A + B) of the copolymer emulsion (A) and the anionic polyurethane aqueous resin (B) to the aliphatic polyisocyanate compound (C) is 100: 1. ~ 100: 3
0, preferably 100: 2 to 100: 20, and when the aliphatic polyisocyanate compound (C) is less than this range, the water resistance is lowered, and when it is more than this range, the heat resistance is low. It is not preferable because it decreases.

The adhesive composition of the present invention contains, in addition to the copolymer emulsion (A), the anionic polyurethane water-based resin (B) and the aliphatic polyisocyanate compound (C), if necessary, an additional composition. Additives that are commonly used for water-based adhesives, such as viscous agents, organic solvents, plasticizers, film-forming aids, organic threads or inorganic fillers, titanium, colorants, wetting agents, penetrants, etc. You can

[0018]

The adhesive composition of the present invention thus obtained is very excellent in heat resistance and water resistance, so that it is required to have a high degree of heat resistance and water resistance such as window frames and stair members. It is suitable as an adhesive for adhering vinyl chloride sheets to building interior materials. Further, the application is not limited to the adhesion of a PVC sheet and plywood or a board, but is also made of polystyrene, surface-treated polyolefins, plastic materials such as polyester, cellulose materials such as paper, fibers and wood, concrete, slate boards, and calcareous boards. It can also be used for adhesion of the same kind of adherend such as an inorganic material, an adherend such as a metal such as aluminum, or between different materials.

[0019]

Example 1 SUMIKAFLEX # 480 as a copolymer emulsion [nonvolatile content 55%; Sumitomo Chemical Co., Ltd.]
64 parts by weight, Hydran HW-333 [nonvolatile content 40%; manufactured by Dainippon Ink and Chemicals, Inc.] as an anionic polyurethane aqueous resin, 36 parts by weight, 2 parts by weight of a water-soluble polyurethane thickener and toluene 5 parts by weight and further 3 parts by weight of Coronate HX (manufactured by Nippon Polyurethane Co., Ltd.) as an aliphatic polyisocyanate compound were mixed to give a viscosity of 36000 mPa · s and a nonvolatile content of 49%.
Was obtained.

[0020]

Example 2 D, which is a self-emulsifying aliphatic polyisocyanate compound as the aliphatic polyisocyanate compound
C-3900 (manufactured by Nippon Polyurethane Co., Ltd.) was used in the same composition as in Example 1 except that 3 parts by weight was used, and the viscosity was 35,000 m.
An adhesive composition having Pa · s and a nonvolatile content of 49% was obtained.

[0021]

Example 3 Self-emulsifying aliphatic polyisocyanate compound D as an aliphatic polyisocyanate compound
C-3901 (manufactured by Nippon Polyurethane Co., Ltd.) was used in the same composition as in Example 1 except that 3 parts by weight was used, and the viscosity was 33,000 m.
An adhesive composition having Pa · s and a nonvolatile content of 49% was obtained.

[0022]

Example 4 As an aliphatic polyisocyanate compound, a self-emulsifying aliphatic polyisocyanate compound D
C-3901 (manufactured by Nippon Polyurethane Co., Ltd.) was used in the same composition as in Example 1 except that 9 parts by weight was used, and the viscosity was 34,000 m.
An adhesive composition having a Pa · s and a nonvolatile content of 51% was obtained.

[0023]

[Example 5] D, which is a self-emulsifying aliphatic polyisocyanate compound as the aliphatic polyisocyanate compound
C-3712 (manufactured by Nippon Polyurethane Co., Ltd.) was used in the same composition as in Example 1 except that 3 parts by weight was used, and the viscosity was 33,000 m.
An adhesive composition having Pa · s and a nonvolatile content of 49% was obtained.

[0024]

Example 6 A self-emulsifying aliphatic polyisocyanate compound as the aliphatic polyisocyanate compound D
C-3725 (manufactured by Nippon Polyurethane Co., Ltd.) was used in the same composition as in Example 1 except that 3 parts by weight was used, and the viscosity was 34,000 m.
An adhesive composition having Pa · s and a nonvolatile content of 49% was obtained.

[0025]

Example 7 39 parts by weight of SUMIKAFLEX # 480 as a copolymer emulsion, 61 parts by weight of Hydran HW-333 as an anionic polyurethane aqueous resin, 2.5 parts by weight of a water-soluble polyurethane thickener and toluene. 5 parts by weight were mixed, and further 3 parts by weight of DC-3901 [manufactured by Nippon Polyurethane Industry Co., Ltd.] as a self-emulsifying aliphatic polyisocyanate compound were mixed to give a viscosity of 28,000.
An adhesive composition having mPa · s and a nonvolatile content of 45% was obtained.

[0026]

[Embodiment 8] 10 parts of ion-exchanged water, Kuraray Poval KL
-506 [Kuraray Co., Ltd., carboxy-modified PVA] 1
Parts, 0.5 parts of nonionic surfactant, 2 liters of 4 parts
The flask was charged into a single-necked flask and heated to 80 ° C. to completely dissolve the contents. Next, Sumikaflex # 450 [solid content 55, which is an ethylene-vinyl acetate copolymer emulsion,
%; Sumitomo Chemical Co., Ltd.] 70 parts were charged, and at 80 ° C., 10 parts of vinyl acetate monomer, VeoVa10 monomer [manufactured by Shell Chemical Co., Ltd.] 1.5 parts, and 1.5 parts of allyl acetoacetate monomer were added. A solution prepared by dissolving 0.1 part of potassium sulfate in 2 parts of ion-exchanged water was added dropwise over 80 minutes. Then, the mixture was aged at 80 ° C. for 1 hour to complete the polymerization and then cooled to room temperature. 60 parts of Hydran HW-333, 3 parts of a water-soluble polyurethane thickener, and 8 parts of toluene were added and mixed, and further self-mixed. As an emulsifying type aliphatic polyisocyanate compound, DC-3901 [Nippon Polyurethane Co., Ltd.]
Manufactured by mixing 3 parts by weight to obtain a viscosity of 26000 mPa · s,
An adhesive composition having a nonvolatile content of 50% was obtained.

[0027]

[Comparative Example 1] An adhesive having the same composition as in Example 3 except that Sumikaflex # 450 which is an ethylene-vinyl acetate copolymer emulsion was used as the copolymer emulsion, and the viscosity was 28,000 mPa · s and the nonvolatile content was 48%. A composition was obtained.

[0028]

Comparative Example 2 D, which is a self-emulsifying aliphatic polyisocyanate compound as the aliphatic polyisocyanate compound
C-3901 (manufactured by Nippon Polyurethane Co., Ltd.) was used in the same composition as in Example 1 except that 0.3 part by weight was used, and the viscosity was 3200.
An adhesive composition having 0 mPa · s and a nonvolatile content of 48% was obtained.

[0029]

Comparative Example 3 DC which is a self-emulsifying type fatty polyisocyanate compound as the aliphatic polyisocyanate compound
-3901 [manufactured by Nippon Polyurethane Industry Co., Ltd.] The same formulation as in Example 1 except that 20 parts by weight was used, and the viscosity was 36,000 m.
An adhesive composition having a Pa · s and a nonvolatile content of 55% was obtained.

[0030]

Comparative Example 4 Crude MDI which is an aromatic isocyanate-based compound instead of the aliphatic polyisocyanate-based compound
The same formulation as in Example 1 except that (4,4-diphenylmethane diisocyanate) was used, and the viscosity was 32,000 mP.
An adhesive composition having an a · s and a nonvolatile content of 49% was obtained.

[0031]

Comparative Example 5 The same composition as in Example 1 except that Coronate 3053 (manufactured by Nippon Polyurethane Industry Co., Ltd.), which is a self-emulsifying MDI-based isocyanate prepolymer, was used instead of the aliphatic polyisocyanate compound. An adhesive composition having a viscosity of 33,000 mPa · s and a nonvolatile content of 48% was obtained.

[0032]

[Comparative Example 6] 95 parts by weight of SUMIKAFLEX # 480 as a copolymer emulsion and 5 parts by weight of HYDRAN HW-333 as an anionic polyurethane aqueous resin,
2 parts by weight of a water-soluble polyurethane thickener and 5 parts by weight of toluene were mixed, and further 3 parts by weight of DC-3901 [manufactured by Nippon Polyurethane Co., Ltd.] as a self-emulsifying aliphatic polyisocyanate compound was mixed to obtain a viscosity. 36000 mPa
An adhesive composition containing s and a nonvolatile content of 53% was obtained.

[0033]

Comparative Example 7 30 parts by weight of SUMIKAFLEX # 400 as a copolymer emulsion, 70 parts by weight of HYDRAN HW-311 as an anionic polyurethane aqueous resin, 1 part by weight of a water-soluble polyurethane thickener and 5 parts by weight of toluene. And 5 parts by weight of 4,4-bis (ethyleneiminocarbonylamino) diphenylmethane as a curing agent are mixed to obtain a viscosity of 25,000 mPa · s and a nonvolatile content of 51
% Adhesive composition was obtained.

[0034]

[Comparative Example 8] SUMIKAFLEX # 480 as a copolymer emulsion [nonvolatile content 55%; Sumitomo Chemical Co., Ltd.]
64 parts by weight, Hydran HW-333 [nonvolatile content 40%; manufactured by Dainippon Ink and Chemicals, Inc.] as an anionic polyurethane aqueous resin, 36 parts by weight, 1 part by weight of a water-soluble polyurethane thickener and toluene 5 parts by weight were mixed to obtain an adhesive composition having a viscosity of 32000 mPa · s and a nonvolatile content of 47%.

[0035]

[Evaluation of Examples 1 to 8 and Comparative Examples 1 to 8] Example 1 above
~ 8 and the adhesive compositions obtained in Comparative Examples 1 to 8 were used to bond a vinyl chloride sheet and plywood under the following conditions, and the bonding performance was evaluated by the test method described below. Table 1 shows the results. Adhesion conditions (1) PVC sheet: Semi-hard doubling sheet (thickness 0.2 mm) (2) Plywood: JAS type I plywood (thickness 2.5)
mm) (3) Coating amount: 110 g / m ² (4) Clamping: Room temperature 23 ± 2 ° C. 0.2 MPa
× 1 hour Low temperature 5 ± 2 ° C 0.2 MPa × 1 hour (5) Curing: Room temperature 23 ± 2 ° C for 5 days Low temperature 5 ± 2 ° C for 5 days Test condition (1) Normal adhesive strength: 23 ± 2 ° C , 180 ° peel strength in 50 ± 10% RH. The width of the test piece is 2
5 mm, pulling speed is 200 mm / min. (2) Water resistant adhesive strength: 23 ± 3 ° C in water for 1 day and 10 days
After soaking for a day, in the wet condition, 23 ± 2 ℃, 50 ±
180 ° bee ring strength is measured in 10% RH. The width of the test piece is 25 mm and the pulling speed is 200 mm / min. (3) Heat resistance: The PVC sheet was peeled from one end of the test piece cut into a size of 25 mm × 150 mm by about 1/3, and the test piece was heated at 60 ° C and 80 ° C. In a thermostat, a static load of 500 g is applied to the end of the peeled PVC sheet in the direction of 90 ° C., and the peeled length is measured for 24 hours. (4) Low temperature adhesion: A vinyl chloride sheet is adhered in 5 ± 2 ° C., pressure is applied, and after curing for 5 days, the vinyl chloride sheet is forcibly peeled in 5 ± 2 ° C. and the adhesion state is observed.

Claims (1)

[Claims] 1. A copolymer emulsion (A) obtained by copolymerizing an ethylene monomer, a vinyl ester monomer and an acetoacetyl group-containing monomer, an anionic polyurethane aqueous resin (B) and an isocyanate group.
It is composed of a mixture with an aliphatic polyisocyanate compound (C) having two or more in the molecule, and the solid content weight ratio of the copolymer emulsion (A) and the anionic polyurethane water-based resin (B) is 90:10 to 30. : 70, and the solid content weight ratio of the total amount (A + B) of the copolymer emulsion (A) and the anionic polyurethane aqueous resin (B) to the aliphatic polyisocyanate compound (C) is 100: 1 to 1
It is 00:30, The water-based adhesive composition characterized by the above-mentioned.