JPH11349914A - Polyurethane for aqueous emulsion adhesive and adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyurethane for an aqueous emulsion adhesive having excellent adhesivity to various adherends having remarkably different surface polarity such as various plastics, metals, wood, etc., and provide an aqueous emulsion adhesive produced by using the polyurethane. SOLUTION: The objective aqueous emulsion-type polyurethane adhesive is produced by preparing a urethane prepolymer from (A) a carboxyl-containing polyester diol produced by the ring-opening addition polymerization of ε- caprolactam to 2,2-dimethylol butanoic acid and having a hydroxyl value of 45-320 KOHmg/g and an acid value of 22.5-160 KOHmg/g, (B) other polyol and (C) a diisocyanate compound, neutralizing the prepolymer with a base and reacting the product with (D) a chain extender. The acid value of the polyurethane resin is 10-50 KOHmg/g.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous emulsion type adhesive, and more particularly, to a polyurethane for an aqueous emulsion type adhesive which is excellent in adhesion and flexibility to various substrates such as plastics and the polyurethane. The present invention relates to an aqueous emulsion type adhesive using the same.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of resource saving, no pollution, safety and health, etc., a conventional organic solvent-based adhesive has been shifted to a water-based adhesive. In particular, aqueous emulsion-type polyurethane resins have been actively studied in terms of their excellent flexibility and elasticity, and are used for bonding plastics base materials and the like, and for treating artificial leather and fibers. . However, in comparison with organic solvent-based polyurethane resin adhesives, the adhesive properties have not yet reached satisfactory performance.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the disadvantages of conventional aqueous emulsion type polyurethane resins. That is, a polyurethane for an aqueous emulsion type adhesive, which not only satisfies the required performances such as flexibility but also improved adhesiveness to various base materials, which has been regarded as a disadvantage of the aqueous emulsion type polyurethane resin, and was used. It is an object to provide an aqueous emulsion type adhesive.

[0004]

Means for Solving the Problems The present inventors diligently studied to achieve the above object, and developed ε-caprolactone into a specific polyester polyol, ie, dimethylolbutanoic acid, as a polyurethane for an aqueous emulsion type adhesive. The acid value obtained by cycloaddition polymerization is 22.5-1.
It has been found that the above-mentioned problems can be solved by using a carboxyl group-containing polyester diol of 60 KOH mg / g, and the present invention has been completed.

That is, the first aspect of the present invention is (A) 2,2
An acid value of 22.5 to 160 KOH obtained by ring-opening addition polymerization of ε-caprolactone to dimethylolbutanoic acid
An aqueous emulsion-type adhesive polyurethane obtained by reacting a carboxyl group-containing polyester diol having a concentration of mg / g, (B) another polyol, (C) a diisocyanate compound, and (D) a chain extender. Having an acid value of from 10 to 50 KOHmg / g. A second aspect of the present invention is that the (B) other polyol is a polyol having a molecular weight of 400 to 5,000 or a mixture of the polyol having a molecular weight of 400 to 5,000 and a short-chain diol. The present invention relates to a polyurethane for an aqueous emulsion type adhesive. A third aspect of the present invention is that the carboxyl group contained in the molecular chain of the polyurethane for an aqueous emulsion type adhesive according to the first or second aspect of the present invention is neutralized to make the polyurethane water-soluble or water-dispersed. An aqueous emulsion type adhesive characterized by the following.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, each raw material used in the present invention, a carboxyl group-containing polyurethane resin using them, and an aqueous emulsion type adhesive obtained by neutralizing the carboxyl group-containing polyurethane resin will be specifically described. .

Carboxyl group-containing polyester diol (A) Carboxyl group-containing polyester diol (A)
It is obtained by ring-opening addition polymerization of ε-caprolactone to 2,2-dimethylolbutanoic acid, and has a hydroxyl value of 45 to 320K.
OHmg / g, preferably 74 to 320 KOHmg / g
g, acid value is 22.5 to 160 KOH mg / g, preferably 37 to 160 KOH mg / g. The carboxyl group-containing polyester diol has an anionic property to the obtained polyurethane by having a carboxyl group in the molecular chain, and neutralizes the carboxyl group contained in the molecular chain according to a method described later, thereby converting the polyurethane. It can be solubilized or dispersed in water.

[0008] When 2,2-dimethylolpropionic acid is used as the initiator, the aqueous emulsion type adhesive cannot provide sufficient adhesion depending on the material to be bonded.
Further, a carboxyl group-containing polyester diol (A)
Even if the acid value of the aqueous emulsion type adhesive is larger or smaller than the above range, the aqueous emulsion type adhesive cannot obtain sufficient adhesion depending on the material to be bonded.

If the hydroxyl value is more than 320 KOH mg / g, the compatibility with other raw materials during the urethanization reaction tends to be poor, the reaction tends to be uneven, and the obtained aqueous emulsion type adhesive composition Is inferior in adhesiveness. When the hydroxyl value is less than 45 KOHmg / g, the content of carboxyl groups in the polyester diol is small, and therefore, it is not preferable as a raw material of the aqueous polyurethane resin from the viewpoint of imparting hydrophilicity to the polyurethane resin.

The component (A) comprises 2,2-dimethylolbutanoic acid as an initiator and ε-caprolactone in an amount of 50 to 240.
It can be easily obtained by heating at ℃ for several hours to effect ring-opening polymerization. In consideration of the color tone of the obtained polymer polyol, the ring-opening polymerization reaction is preferably performed under a stream of an inert gas such as a nitrogen gas.

In ring-opening polymerization, it is preferable to use a catalyst for accelerating the reaction. As the catalyst, organic titanium compounds such as tetrabutyl titanate and tetrapropyl titanate, organic tin compounds such as dibutyltin laurate, tin octylate, dibutyltin oxide, stannous chloride, stannous bromide, stannous iodide and the like Stannous halide. The amount of the catalyst used is 0.01 to 1,0 with respect to the total amount of the initiator and the lactone.
It is preferable to select in the range of 00 ppm.

Other Polyol (B) The component (B) is a polyol having a molecular weight of about 400 to 5,000. Examples of such polyols include polyether polyols, bifunctional polyester diols having terminal hydroxyl groups obtained by a condensation reaction of diol and dicarboxylic acid, lactone-based polyester polyols, polycarbonate polyols, silicone polyols, polybutadiene polyols, polyolefin-based polyols, and the like. Is mentioned. Examples of the polyether polyol include polytetramethylene ether glycol, polypropylene glycol, polyethylene glycol and the like. Examples of the bifunctional polyester diol having a terminal hydroxyl group obtained by a condensation reaction between a diol and a dicarboxylic acid include polyethylene adipate, polyethylene butylene adipate,
Polybutylene adipate, polypropylene adipate,
Polyhexamethylene adipate, polyneopenthylene adipate, poly-3-methyl-1,5-pentylene adipate, 2,4,4-trimethyl-1,6-hexanediol and / or 2,2,4-trimethyl- Condensate of 1,6-hexanediol and adipic acid, terephthalic acid alone or 1,6 in combination with isophthalic acid and adipic acid
Examples thereof include condensation products with -hexanediol, 3-methyl-1,5-pentanediol, and the like. Examples of the lactone-based polyester polyol include those obtained by ring-opening addition polymerization of lactones such as ε-caprolactone, γ-butyrolactone, and δ-valerolactone using a short-chain polyol as an initiator. These lactone-based polyester polyols can be obtained in the same manner as the component (A), but have no carboxyl group in the molecule unlike the component (A). The other polyol (B) is 2
A combination of more than one species may be used.

Short-chain polyol (B ') Short-chain polyol (B') can be added to other polyols (B), if necessary. As the short-chain polyol (B '), diols, triols, polyols, and mixtures thereof can be used. As diols, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol,
1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,5-heptanediol,
1,6-hexanediol, 2,2,4- and / or 2,4,4-trimethylhexane-1,6-diol,
2,2,4-trimethylpentane-1,3-diol,
1,10-decanediol, 1,12-dodecanediol, 1,4-cyclohexanedimethanol, dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolpentanoic acid, dimethylolheptanoic acid, dimethyloloctanoic acid, dimethylolnonane Acids and the like. Triols include glycerin, trimethylolethane, and trimethylolpropane, and tetrols include pentaerythritol. These short-chain polyols (B ') may be used in combination of two or more.

These polyols may be used in combination of two or more kinds. However, at least one of the polyols used for the polyurethane resin as the base polymer contains (A) 2,2-dimethylolbutanoic acid and ε-caprolactone. The hydroxyl value obtained by ring-opening addition polymerization is 45 to 45.
320KOHmg / g, acid value 22.5-160KOH
A carboxyl group-containing polyester diol of mg / g must be used.

Diisocyanate compound (C) Another component of the polyurethane resin of the present invention (C)
Diisocyanate compounds are aromatic, aliphatic and alicyclic diisocyanates. Examples of the diisocyanates include 1,5-naphthylene diisocyanate,
4'-diphenylmethane diisocyanate, 4,4'-
Diphenyldimethylmethane diisocyanate, 4,4 '
-Dibenzyl diisocyanate, dialkyl diphenyl methane diisocyanate, tetraalkyl diphenyl methane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, 1,6-hexamethylene diisocyanate, 2,
2,4-trimethylhexamethylene-1,6-diisocyanate, 2,4,4-trimethylhexamethylene-
1,6-diisocyanate, lysine diisocyanate,
Cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate,
1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexanediisocyanate and the like are mentioned as typical examples. These diisocyanates may be used alone or in combination of two or more.

The amount of the diisocyanate compound (C), which is a component of the polyurethane resin of the present invention, is (A)
(B) an NCO / OH ratio of 2.0 to 1.0 with respect to the total of the component (B ') polyols used as required;
Preferably, it is 1.5 to 1.05. If the diisocyanate compound is less than the above range, it becomes difficult to produce a self-emulsifying polyurethane emulsion, and if it is more than the above range, the properties of the obtained adhesive are poor.

Chain extender (D) Examples of the chain extender (D) include ethylenediamine, propylenediamine, hexamethylenediamine,
Diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-
And diamines. Furthermore, water-soluble alicyclic polyamines such as piperazine can be used in the same manner.
These polyamines may be used alone or in combination of two or more.

Production of Polyurethane Resin The method for producing polyurethane for an aqueous emulsion type adhesive is not particularly limited, and can be obtained by a known method.
For example, (A) a hydroxyl value obtained by subjecting 2,2-dimethylolbutanoic acid to ring-opening addition polymerization of ε-caprolactone, having a hydroxyl value of 45 to 320 KOH mg / g and an acid value of 22.5 to 16
A carboxyl group can be introduced into a polyurethane resin by using a carboxyl group-containing polyester diol of 0 KOH mg / g as an essential component to impart hydrophilicity. Further, if necessary, dimethylol propionic acid, dimethylol butanoic acid, dimethylol pentanoic acid, dimethylol heptanoic acid, dimethylol octanoic acid, dimethylol nonanoic acid, etc. may be used as a part of the polyol component to further form a carboxyl group in the polyurethane resin. Groups can also be introduced. However, the carboxyl group concentration of the base polymer of the polyurethane resin is adjusted to an acid value of 10 to 50 KOHmg.
/ G, preferably in the range of 20-40 KOHmg / g. If the acid value based on the carboxyl group in the polyurethane resin solid content is less than 10 KOH mg / g, self-emulsification of the resin is difficult, and the acid value is 50 KOHm.
If the amount exceeds g / g, the water resistance of the obtained urethane resin adhesive composition decreases.

More specifically, an example of a method for producing a self-emulsifying aqueous polyurethane adhesive will be described. The hydroxyl value obtained by ring-opening addition polymerization of 2,2-dimethylolbutanoic acid with ε-caprolactone is 45 to 320 KOH mg. / G, a carboxyl group-containing polyester diol having an acid value of 22.5 to 160 KOH mg / g, and a urethane prepolymer having an isocyanate group at a terminal obtained by reacting another polyol with a diisocyanate compound. In this case, the reaction is preferably performed with the equivalent ratio of the diisocyanate compound and the polyol component usually being NCO / OH = 1.01 to 2/1.

The urethane prepolymer obtained by this method can be obtained without solvent, but in order to facilitate the operation of adding water and emulsifying and dispersing it in an oil-in-water type, a small amount of acetone, methyl ethyl ketone, tetrahydrofuran is used. It is more desirable to dilute the mixture with an organic solvent such as dimethylformamide, N-methylpyrrolidone, or the like, or to react in advance in a solution of a small amount of an organic solvent to lower the viscosity of the urethane prepolymer.

The organic solvent used in the reaction for obtaining the urethane prepolymer is usually removed after the resin is converted to an aqueous solution. In order to facilitate the removal, an organic solvent having a boiling point of 100 ° C. or less is preferable. , Methyl ethyl ketone, tetrahydrofuran and the like. Among the solvents used, acetone and methyl ethyl ketone are preferred, and acetone is most preferred.

As a method for making the urethane prepolymer aqueous, a basic compound is used to neutralize the carboxyl group of the urethane prepolymer, disperse or dissolve in water, and extend the chain with a chain extender to produce an aqueous polyurethane resin. There is a way. Examples of the basic compound used for neutralizing the carboxyl group include ammonia, triethylamine, trimethylamine, tripropylamine, triethanolamine, monoethanolamine, N-methylmorpholine, morpholine, 2,2-dimethylmonoethanolamine, N, N-
Examples include amines such as dimethylmonoethanolamine, sodium hydroxide, potassium hydroxide and the like.

The weight average molecular weight of the polyurethane resin for an aqueous emulsion type adhesive obtained as described above is usually preferably in the range of 20,000 to 90,000. If the molecular weight is less than 20,000, the adhesive obtained will have poor cohesive strength and heat resistance, while
If it exceeds 00, the viscosity of the polyurethane resin solution becomes high and the handling efficiency decreases, and the stability of the emulsion deteriorates, which is not preferable. The solid content concentration of the polyurethane resin emulsion is not particularly limited, and is appropriately determined in consideration of workability at the time of bonding, and is usually 5 to 50% by weight, and the viscosity is several tens to several thousand cP (25 C) is practically suitable.

Other Aqueous Resins In addition, other conventionally known aqueous resins may be used in combination with the water-soluble aqueous polyurethane resin, if necessary. Examples of the water-based resin that can be used in combination here include water-based polyurethane resins other than those described above, water-based polyamide resins, water-based acrylate-based copolymer salts, and water-based styrene-maleic acid-based copolymer salts.

Other Additives When an aqueous emulsion type adhesive is prepared using the aqueous emulsion type polyurethane resin obtained above, the preparation method is not particularly limited. Normally, the aqueous emulsion-type polyurethane resin obtained above is mixed with the above-mentioned water-based resin, an anti-blocking agent, an additive such as a plasticizer, etc., as necessary, so that the aqueous emulsion-type adhesive composition is extremely easily formed. Can be prepared.

In the present invention, as the bonding method, any known method may be used. However, the aqueous emulsion type adhesive according to the present invention may be applied to the whole surface of various substrates such as plastics, or may be wavy or linear. Alternatively, it can be carried out by partially adhering, for example, in the form of dots, and attaching an object to be adhered.

[0027]

EXAMPLES The polyurethane for an aqueous emulsion type adhesive of the present invention and the adhesive obtained therefrom will be described in detail with reference to Production Examples, Examples and Comparative Examples, but the present invention is limited to only these Examples. Not something. In addition, in each example, all parts and percentages are by weight unless otherwise specified.

In the following Production Examples and Examples, the hydroxyl value, acid value, weight average molecular weight and viscosity of the resin solids were measured by the methods described below. (1) Hydroxyl value: Measured according to JIS K-1557. (2) Acid value: Measured according to JIS K-1557. (3) Weight average molecular weight: According to a method in which a calibration curve was first prepared by GPC using polystyrene having a clear molecular weight, then the resin of the sample was measured, and the measured value was converted by a universal calibration method. Equipment: Shimadzu HPLC LC-6A (Detector RI
D-6A) System Column: SHOdex KF-800P, KF-804, KF-802.5, K
F-801 Measurement conditions: solvent THF, flow rate 1.0 ml / min, temperature 50
° C (5) Viscosity: Using an E-type rotational viscometer (Tokyo Keiki Co., Ltd.)
It was measured at 25 ° C.

[Production of carboxyl group-containing polyester diol] [Production Example 1] 1,628 g of 2,2-dimethylolbutanoic acid and ε- were placed in a four-necked flask equipped with a nitrogen inlet tube, a thermometer, a condenser and a stirrer. Caprolactone 3,872
g, and 0.0275 g of SnCl ₂ as a catalyst were charged and reacted at a reaction temperature of 120 ° C. for 3 hours with stirring. The obtained carboxyl group-containing polyester diol is in a liquid state, and has a hydroxyl value of 225.5 KOH mg / g and an acid value of 11
4.6 KOH mg / g. The obtained carboxyl group-containing polyester diol is referred to as Compound 1.

[Preparation Example 2] In the same flask as in Preparation Example 1, 148 g of 2,2-dimethylolbutanoic acid, 852 g of ε-caprolactone, and 0.005 of SnCl ₂ as a catalyst were used.
g was charged and reacted at a reaction temperature of 120 ° C. for 4 hours with stirring. The obtained carboxyl group-containing polyester diol is waxy and has a hydroxyl value of 115.0 KOHmg /
g, and the acid value was 58.9 KOH mg / g. The obtained carboxyl group-containing polyester diol is referred to as Compound 2.

[Production Example 3] In a flask similar to that of Production Example 1, 74 g of 2,2-dimethylolbutanoic acid, 926 g of ε-caprolactone, and 0.005 g of SnCl ₂ as a catalyst.
And reacted at a reaction temperature of 120 ° C. for 7 hours with stirring. The obtained carboxyl group-containing polyester diol was wax-like, and had a hydroxyl value of 56.9 KOH mg / g and an acid value of 28.8 KOH mg / g. The obtained carboxyl group-containing polyester diol is referred to as Compound 3.

Production Example 4 For comparison, 2,2-dimethylolpropionic acid was used. 1,474 g of 2,2-dimethylolpropionic acid was placed in the same flask as in Production Example 1,
3,872 g of ε-caprolactone, and Sn as a catalyst
0.0275 g of Cl ₂ was charged, and the reaction temperature was adjusted to 12 under stirring.
The reaction was performed at 0 ° C. for 3 hours. The properties of the obtained carboxyl group-containing polyester diol are as follows:
4.3 KOH mg / g, acid value 113.8 KOH mg / g
Met. The obtained carboxyl group-containing polyester diol is referred to as Compound 4.

[Synthesis of Aqueous Emulsion Adhesive] Example 1 289.2 g of isophorone diisocyanate and 90 g of acetone were charged into a four-necked flask equipped with a nitrogen inlet tube, a thermometer, a condenser and a stirrer.
While stirring under a nitrogen stream, 143.5 g of compound 1 which was heated to 60 ° C. and melted, and 345.3 g of polycaprolactone diol having a hydroxyl value of 115.2 KOH mg / g manufactured by Daicel Chemical Industries, Ltd. 4-butanediol 3
2.0 g was added and reacted while stirring at a temperature of 60 ° C. for 4 hours to obtain a uniform solution of an NCO-terminated urethane prepolymer. This NCO-terminated urethane prepolymer 30
While stirring with a homomixer, 0.0 g was added to 509.3 g of deionized water to which 9.7 g of triethylamine had been previously added to make the urethane prepolymer aqueous, and 5.3 g of hexamethylene diamine was further added to 20 g of deionized water. A chain extension was performed by adding a dissolved aqueous solution. Then, under reduced pressure,
Acetone was distilled off at 60 ° C. for 3 hours to obtain a milky white aqueous emulsion type adhesive 1 having a solid content of 35% and an acid value (hereinafter referred to as solid content) of 20.5 KOH mg / g.

Example 2 287.0 g of isophorone diisocyanate and 90 g of acetone were placed in a four-necked flask equipped with a nitrogen inlet tube, a thermometer, a condenser and a stirrer, and then stirred at 60 ° C. under a nitrogen stream. Then, 100.9 g of the compound 1 heated and melted, 386.3 g of polycaprolactone diol having a hydroxyl value of 115.2 KOH mg / g, manufactured by Daicel Chemical Industries, Ltd., and 35.7 g of 1,4-butanediol were added thereto. The reaction was carried out while stirring at a temperature of 60 ° C. for 4 hours to obtain a uniform solution of an NCO-terminated urethane prepolymer. 300.0 g of this NCO group-terminated urethane prepolymer was added to 503.7 g of demineralized water to which triethylamine had been previously added while stirring with a homomixer, and 5.2 g of hexamethylenediamine was further added to 20 g of demineralized water. Was added. Then, acetone was distilled off at 60 ° C. for 3 hours under reduced pressure to obtain a milky white aqueous emulsion type adhesive 2 having a solid content of 35% and an acid value of 13.8 KOH mg / g.

Example 3 215.5 g of isophorone diisocyanate and 90 g of acetone were placed in a four-necked flask equipped with a nitrogen inlet tube, a thermometer, a condenser and a stirrer, and then stirred at 60 ° C. under a nitrogen stream. 253.8 g of compound 2 heated and melted, 321.0 g of polycaprolactone diol having a hydroxyl value of 115.2 KOH mg / g, manufactured by Daicel Chemical Industries, Ltd., and 19.8 g of 1,4-butanediol were added thereto. The reaction was carried out with stirring at 60 ° C. for 4 hours to obtain a uniform solution of an NCO-terminated urethane prepolymer. While stirring the NCO group-terminated urethane prepolymer 300.0 g with a homomixer,
Demineralized water 50 to which 8.8 g of triethylamine has been previously added.
2.9 g, and then hexamethylenediamine 2.8.
g was dissolved in 20 g of demineralized water. Then, acetone was distilled off at 60 ° C. for 3 hours under reduced pressure to obtain a milky white aqueous emulsion type adhesive 3 having a solid content of 35% and an acid value of 18.2 KOH mg / g.

Example 4 127.5 g of isophorone diisocyanate and 90 g of acetone were charged into a four-necked flask equipped with a nitrogen inlet tube, a thermometer, a condenser and a stirrer, and then stirred at 60 ° C. under a nitrogen stream. 626.7 g of compound 3 heated and melted, 52.7 g of polycaprolactone diol having a hydroxyl value of 115.2 KOH mg / g, manufactured by Daicel Chemical Industries, Ltd., and 3.3 g of 1,4-butanediol were added thereto. The reaction was carried out with stirring at 60 ° C. for 4 hours to obtain a uniform solution of an NCO-terminated urethane prepolymer. 300.0 g of the NCO-terminated urethane prepolymer was stirred with a homomixer, and 50 ml of deionized water to which 10.7 g of triethylamine had been added in advance.
6.7 g, and then 2.9 g of hexamethylenediamine.
g was dissolved in 20 g of demineralized water. Then, acetone was distilled off under reduced pressure at 60 ° C. for 3 hours to obtain a solid content of 3%.
A milky-white aqueous emulsion-type adhesive 4 having a 5% acid value and an acid value of 22.6 KOH mg / g was obtained.

Comparative Example 1 288.9 g of isophorone diisocyanate and 90 g of acetone were placed in a four-necked flask equipped with a nitrogen inlet tube, a thermometer, a condenser and a stirrer, and then stirred at 60 ° C. under a nitrogen stream. 144.2 g of compound 4 heated and melted, 345.0 g of polycaprolactone diol having a hydroxyl value of 115.2 KOH mg / g, manufactured by Daicel Chemical Industries, Ltd., and 31.9 g of 1,4-butanediol were added. The reaction was carried out with stirring at 60 ° C. for 4 hours to obtain a uniform solution of an NCO-terminated urethane prepolymer. While stirring the NCO group-terminated urethane prepolymer 300.0 g with a homomixer,
Demineralized water 50 to which 9.7 g of triethylamine has been previously added.
9.3 g, and then further added hexamethylenediamine 5.3.
g was dissolved in 20 g of demineralized water. Then, acetone was distilled off under reduced pressure at 60 ° C. for 3 hours to obtain a solid content of 3%.
A 5%, milky-white aqueous emulsion-type adhesive having an acid value of 20.6 KOH mg / g was obtained. This aqueous emulsion adhesive is referred to as Comparative Adhesive 1.

[Comparative Example 2] In a four-necked flask equipped with a nitrogen inlet tube, a thermometer, a condenser and a stirrer were charged 325.4 g of isophorone diisocyanate and 40 g of acetone. 408.3 g of polycaprolactone diol having a hydroxyl value of 115.2 KOH mg / g manufactured by Kogyo Co., Ltd.
37.8 g of butanediol and 38.5 g of dimethylolpropionic acid were added and reacted while stirring at a temperature of 60 ° C. for 4 hours to obtain a uniform solution of an NCO-terminated urethane prepolymer. 300.0 g of the NCO group-terminated urethane prepolymer was stirred with a homomixer, and 510.4 ml of deionized water to which 9.7 g of triethylamine had been previously added.
g, and an aqueous solution in which 5.9 g of hexamethylenediamine was dissolved in 20 g of demineralized water was further added. Then, acetone was distilled off at 60 ° C. under reduced pressure for 3 hours, and the solid content was 35%.
A milky white aqueous emulsion type adhesive having an acid value of 20.4 KOH mg / g was obtained. This aqueous emulsion type adhesive is referred to as Comparative Adhesive 2.

Comparative Example 3 A four-necked flask equipped with a nitrogen inlet tube, a thermometer, a condenser, and a stirrer was charged with 323.6 g of isophorone diisocyanate and 40 g of acetone. 406.0 g of polycaprolactone diol having a hydroxyl value of 115.2 KOH mg / g manufactured by Kogyo Co., Ltd.
37.6 g of butanediol and dimethylolbutanoic acid 3
7.6 g was added and reacted while stirring at a temperature of 60 ° C. for 4 hours to obtain a uniform solution of an NCO-terminated urethane prepolymer. This NCO-terminated urethane prepolymer 30
While stirring with a homomixer, 0.0 g was added to 510.3 g of deionized water to which 9.7 g of triethylamine had been added in advance, and further, an aqueous solution in which 5.8 g of hexamethylenediamine was dissolved in 20 g of deionized water was added. Then, acetone was distilled off under reduced pressure at 60 ° C. for 3 hours to obtain a milky white aqueous emulsion type adhesive having a solid content of 35% and an acid value of 20.2 KOH mg / g. This aqueous emulsion type adhesive is referred to as Comparative Adhesive 3.

The adhesives of Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated by the methods described below.
Shown in [Adhesion test] The aqueous emulsion-type adhesives obtained in Examples and Comparative Examples were treated with corona-treated biaxially stretched polyethylene terephthalate film (manufactured by Toyobo Ester Co., Ltd .; product number: E5100, thickness: 50 µm), and corona-treated. 2
Axial stretched polypropylene film (Toyobo Pyren Co., Ltd.)
Product number: P2161, thickness: 50 μm), acrylic plate (manufactured by Nitto Jushi Kogyo Co., Ltd .; product number: CRAREX)
S), aluminum plate (manufactured by Nippon Test Panel Kogyo Co., Ltd .; product number: A5052P (specification: Ryusan alumite)) and veneer plywood (general commercially available product). 5 and dried at room temperature for one day and night, and then a cellophane tape peeling test was performed. 3-5 μm coating thickness after drying
The coating conditions were set so as to fall within the range of 5 (100) from the area ratio of the remaining portion of the coating film after the cellophane tape peeling test.
% (Residual 90% or more), 3 (residual 70% or more), 2 (residual 50% or more), and 1 (residual less than 50%).

[0041]

[Table 1]

As is evident from Table 1, the aqueous emulsion type adhesive of the present invention has excellent adhesiveness to various substrates having significantly different surface polarities.

[0043]

The aqueous emulsion type adhesive of the present invention comprises:
It is excellent in adhesiveness to various substrates having significantly different polarities on the surface of various plastics, metals, woods and the like, and is extremely useful in industry.

Claims (3)

[Claims] (A) a carboxyl group-containing polyester diol having an acid value of 22.5 to 160 KOH mg / g, which is obtained by ring-opening addition polymerization of ε-caprolactone to 2,2-dimethylolbutanoic acid; B) A polyurethane for an aqueous emulsion type adhesive obtained by reacting another polyol, (C) a diisocyanate compound, and (D) a chain extender, wherein the polyurethane has an acid value of 10 to 10.
A polyurethane for an aqueous emulsion-type adhesive, which is 50 KOHmg / g. (B) The other polyol has a molecular weight of 4
A polyol having a molecular weight of 400 to 5,000 or a molecular weight of 400 to
The polyurethane for an aqueous emulsion type adhesive according to claim 1, which is a mixture of 5,000 polyols and short-chain diols. 3. A water-soluble or water-dispersed neutralizing carboxyl group contained in the molecular chain of the polyurethane for an aqueous emulsion type adhesive according to claim 1 or 2. , Aqueous emulsion type adhesive.