KR20050052833A - An aqueous hot-melt polyurethane adhesive and the method for preparing the same - Google Patents

Abstract

The present invention relates to an aqueous meltable polyurethane adhesive having excellent initial adhesive strength, adhesive strength and heat resistance, and a method of manufacturing the same. More specifically, (a) an organic polyisocyanate having an average molecular weight of 100 or more; (b) a crystalline polyester polyol having a number average molecular weight of at least 2000; (c) polyols having a bifunctional or higher number average molecular weight of 100 to 1200 or more; (d) polyamines having a number average molecular weight of 600 or less with sulfonates; And (e) an aqueous molten polyurethane adhesive prepared from an aqueous polyurethane resin liquid obtained as a primary 2-3 functional polyamine having a molecular weight of 200 or less.

Description

An aqueous hot-melt polyurethane adhesive and the method for preparing the same

The present invention relates to an aqueous meltable polyurethane adhesive having excellent initial adhesive strength, adhesive strength and heat resistance, and a method of manufacturing the same. More specifically, (a) an organic polyisocyanate having an average molecular weight of 100 or more; (b) a crystalline polyester polyol having a number average molecular weight of at least 2000; (c) polyols having a bifunctional or higher number average molecular weight of 100 to 1200 or more; (d) polyamines having a number average molecular weight of 600 or less with sulfonates; And (e) an aqueous molten polyurethane adhesive prepared from an aqueous polyurethane resin liquid obtained as a primary 2-3 functional polyamine having a molecular weight of 200 or less.

Until now, solvent-type polyurethane resins have been widely used as adhesives because of their excellent adhesion, heat resistance, oil resistance, cold resistance, flexibility, etc. However, since organic solvents used in manufacturing adversely affect environmental pollution and worker's health, Development of water-dispersed polyurethane adhesives in place of polyurethane resins is being rapidly made.

As a specific example of the water-dispersed polyurethane adhesive, Japanese Laid-Open Patent Publication No. 59-30186 discloses a polyurethane resin obtained from a polyol and a polyisocyanate compound with an amorphous polyester having sulfonic acid metal salt groups. Although it has been described that adhesion, water resistance and the like have been improved when bonding the PET film using the polyurethane resin, the main component of the polyurethane resin is an aromatic polyester polyol, which is reactivated at 100 ° C. or higher and exhibits adhesive strength. There is a possibility of damage to the adherend by heat.

In addition, Japanese Patent No. 2001-00325378 describes a water-dispersed urethane having excellent storage stability, initial adhesion, and heat and moisture resistance by preparing an aqueous adhesive synthesized from aliphatic isocyanate using polycaprolactone polyol and dimethylolbutanoic acid. However, since the aqueous adhesive uses a polycaprolactone polyol having a molecular weight of 3000 or more, it takes a long time when synthesized with an aliphatic isocyanate at low temperature, and the amount of acetone must be high to lower the viscosity of the prepolymer. In addition, the use of dimethylolbutanoic acid at a solid content of 3% or less in the embodiment has a problem that results in a decrease in the aqueous stability and storage stability when preparing the aqueous dispersion.

Accordingly, the present inventors have studied to provide a good aqueous melt-type polyurethane adhesive such as initial adhesion, adhesion, heat resistance, etc. to solve the above problems, (a) an organic polyisocyanate having an average molecular weight of 100 or more; (b) a crystalline polyester polyol having a number average molecular weight of at least 2000; (c) polyols having a bifunctional or higher number average molecular weight of 100 to 1200 or more; (d) polyamines having a number average molecular weight of 600 or less with sulfonates; And (e) when the polyurethane adhesive is prepared using an aqueous polyurethane resin solution obtained from a primary 2-3 functional polyamine having a molecular weight of 200 or less, the aqueous polyurethane adhesive exhibits excellent initial adhesion, adhesion and heat resistance. Discovered and completed the present invention.

It is therefore an object of the present invention to provide an aqueous meltable polyurethane adhesive which exhibits excellent initial adhesion, adhesion and heat resistance.

In addition, another object of the present invention is to provide a method for producing the aqueous meltable polyurethane adhesive.

In order to achieve the above object, the aqueous hot-melt polyurethane adhesive of the present invention

(a) an organic polyisocyanate having an average molecular weight of 100 or more;

(b) a crystalline polyester polyol having a number average molecular weight of at least 2000;

(c) polyols having a bifunctional or higher number average molecular weight of 100 to 1200 or more;

(d) polyamines having a number average molecular weight of 600 or less with sulfonates; And

(e) A crosslinking agent may be added to an aqueous polyurethane resin liquid obtained as a primary 2-3 trifunctional polyamine having a molecular weight of 200 or less.

Here, the NCO / OH ratio is 1.3 or less at the equivalent ratio in the reaction of (a) to (c), diluted with a low boiling organic solvent free of active hydrogen, chain extended to (d) and (e), and then added with water to disperse. After distillation under reduced pressure, an organic solvent is prepared to prepare an aqueous polyurethane resin containing no organic solvent.

Hereinafter, the present invention will be described in more detail.

The aqueous polyurethane adhesive of the present invention firstly comprises: (a) an organic polyisocyanate having an average molecular weight of 100 or more; (b) a crystalline polyester polyol having a number average molecular weight of at least 2000; And (c) a polyol having a bifunctional or higher functional number average molecular weight of 100 to 1200 or more; an NCO / OH ratio of 1.5 or less in an equivalent ratio, diluted with a low boiling organic solvent free of active hydrogen, and (d) a number average molecular weight having a sulfonate. The polyamine having a polyamine of 600 or less and (e) a primary 2-3 functional polyamine having a molecular weight of 200 or less is chain-extended and dispersed by adding water, followed by distillation under reduced pressure to prepare an aqueous polyurethane resin. Next, a crosslinking agent is added to the aqueous polyurethane resin to prepare an aqueous polyurethane adhesive.

 Hereinafter, the aqueous meltable polyurethane adhesive of the present invention will be described in more detail for each component.

(a) organic polyisocyanates with an average molecular weight of 100 or more

There is no restriction | limiting in particular in the organic polyisocyanate used for manufacture of the water-based polyurethane resin of this invention, It is a function to use normally used aliphatic polyisocyanate, alicyclic polyisocyanate, aromatic polyisocyanate, and these alone or in mixture.

Specific examples of the polyisocyanate compound include 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodeca methylene diisocyanate, cyclohexane-1,3- or 1,4-diisocyanate , 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane (isophorone diisocyanate; IPDI), bis- (4-isocyanatocyclohexyl) methane (hereinafter hydrogenated MDI) 2- or 4-isocyanatocyclohexyl-2'-isocyanatocyclohexyl methane, 1,3- or 1,4-bis (isocyanatomethyl) -cyclohexane, bis- (4-iso Cyanato-3-methylcyclohexyl) methane, 1,3- or 1,4-α, α, α ', α'-tetramethylxylene diisocyanate, 2,4- or 2,6-toluene diisocyanate, 2 , 2'-, 2,4'- or 4,4'-diisocyanatodiphenylmethane (MDI), 1,5-naphthalenediisocyanate, p- or m-phenylenediisocyanate, xylenedi It is cyano carbonate and diphenyl-4,4'-yisosiahneyiteuyi. Among these, 2, 4- toluene diisocyanate and 2, 6-toluene diisocyanate are used as an isomer of 65:35 or 80:20 ratio, respectively.

Among the above compounds, it is preferable to use an aromatic diisocyanate compound from the viewpoint of mechanical properties and heat resistance, and more preferably to use an aromatic and alicyclic isocyanate compound from the viewpoint of cohesion and adhesion. On the other hand, it is preferable to use a bifunctional or lower polyisocyanate from the viewpoint of obtaining a linear polyurethane resin having more suitable cohesive force and adhesiveness.

The polyisocyanate content in the final aqueous urethane resin solids is preferably in the range of 10 to 25% by weight. Within this range, the polyol properties in the polyurethane molecules are in a suitable range so that the initial adhesive strength can be preferably exerted at low temperatures. have.

(b) crystalline polyester polyols having a number average molecular weight of at least 2000

The polyester polyol used in the preparation of the aqueous polyurethane resin of the present invention is a polyol having a number average molecular weight of 2000 or more, a polycaprolactone polyol condensation-polymerized with epsilon-caprolactone using a diol having 4 to 8 carbon atoms as an initiator. It is preferable to contain the polyol polycondensed into the dicarboxylic acid which consists of a linear structure of 6-10, and the diol which consists of a linear structure of 4-8 carbon atoms. In the aqueous urethane resin of the present invention, the content of the polyester polyol having a number average molecular weight of 2000 or more is preferably contained in a ratio of 70 to 81% by weight based on the solid content of the aqueous polyurethane resin.

(c) polyols having a bifunctional or higher number average molecular weight of 100 to 1200 or more;

As polyols having a number average molecular weight of 100 to 1200 bifunctional or higher used in the preparation of the aqueous polyurethane resin of the present invention, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexane Polyol which is a nonionic reactive diol in which one hydroxyl group of trimethylolpropane is ether-bonded to dimethanol, hydrogenated bisphenol A, trimethylolpropane, glycerol, pentaerythritol, and alkoxyalkylene oxide (trade name: Tegomer D-3123, D-3403 Tego).

It is preferable to use a trifunctional or more than trifunctional polyol from a heat resistant viewpoint among said compounds, and it is more preferable to mix and use a trifunctional trimethylol propane polyol and a nonionic reactive diol from a heat resistant, water resistance, and a thermal activity viewpoint. In the aqueous polyurethane resin of the present invention, it is preferable that the content of the polyol having a number average molecular weight of 100 to 1200 bifunctional or higher is contained at a ratio of 1 to 10% by weight based on the solid content of the aqueous polyurethane resin.

(d) polyamines having a number average molecular weight of 600 or less with sulfonates

Examples of polyamines having a number average molecular weight of 600 or less having a sulfonic acid metal salt used in the preparation of the aqueous polyurethane resin of the present invention include α, ω-polypropylene glycol diamine-sulfonei containing metals such as Na, K, Li, and Ca. Teds and derivatives thereof. In the present invention, the content of sulfonic acid ion groups in the polyamine is preferably contained in a ratio of 0.1 to 5% by weight, more preferably 0.1 to 4% by weight based on the solid content of the aqueous polyurethane resin.

(e) polyamines having a molecular weight of 200 or less

The polyamine having a molecular weight of 200 or less used in the present invention serves as a chain extender for the low molecular weight polyurethane resin obtained above. Specific examples of the polyamine include 1,2-diaminoethane, 1,2- or 1,3-diaminopropane, 1,2-, 1,3- or 1,4-diaminobutane, 1,5-di Aminopentane, 1,6-diaminohexane, piperazine, N-N'-bis- (2-aminoethyl) piperazine, 1-amino-3-aminomethyl-3,5,5-trimethyl-cyclohexane ( Isophoronediamine), bis- (4-aminocyclohexyl) methane, bis- (4-amino-3butylcyclohexyl) methane, 1,2-, 1,3- or 1,4-diaminocyclohexane, 1 Diamines such as, 3-diaminopropane, polyamines such as diethylenetriamine and triethylenetetramine, and hydrazine derivatives such as hydrazine and adipic acid hydrazide.

Among the above compounds, hydrazine and 1,2-diaminoethane are preferable, and are used in an amount of 1 to 5% by weight, preferably 0.5 to 2% by weight, based on the solid content of the aqueous polyurethane resin. When the above range is exceeded, the low solid content and the thermal activity temperature become high due to the increase in molecular weight.

When the polyamine having a molecular weight of 200 or less is used as a chain extender, the cohesive force of the polyurethane resin can be improved by increasing the molecular weight, and the thermal activity of the aqueous polyurethane resin can be improved. At this time, in order to improve the cohesion force of the polyurethane resin, it is preferable to adjust the molecular weight to 100 or less.

The sulfonic acid ion group contains 0.1 to 5% by weight based on the total weight of the polyurethane resin solid content obtained by the reaction of the isocyanate terminated prepolymer and the polyamine chain extender having a sulfonate salt in the aqueous polyurethane resin of the present invention. Moreover, it is preferable that solid content is contained in the said aqueous polyurethane resin in the ratio of 40% or more.

On the other hand, examples of the organic solvent used in the preparation of the aqueous polyurethane resin of the present invention are benzene, toluene, ethyl acetate, acetone, methyl ethyl ketone, diethyl ether, tetrahydrofuran, methyl acetate, acetonitrile, chloroform, methylene chloride , Carbon tetrachloride, 1,2-dichloroethane, 1,1,2-trichloroethane, tetrachloroethylene, N-methylpyrrolidone, and the like, and these may be used alone or in combination. It is preferable to use acetone or methyl ethyl ketone as a solvent with high solubility with a polyurethane resin among the above.

On the other hand, an emulsifier may also be used in the preparation of the aqueous polyurethane resin of the present invention. Examples of the emulsifier include polyoxyethylene polyoxypropylene glycol ether type, polyoxyethylene nonylphenyl ether type, polyoxyethylene octylphenyl ether type, polyoxyethylene lauryl ether type, polyoxyethylene laurate type, polyoxyethylene alkyl Nonionic emulsifiers such as ether type, sorbitan derivative type, polyoxyethylene polycyclic phenyl ether type, anionic emulsifiers such as alkylbenzene sulfonate type, dialkyl succinate sulfonate type, and cationic emulsifier. It is preferable to use a nonionic emulsifier and an anionic emulsifier among the said emulsifiers, and can add 0-5 weight% in solid content ratio with respect to an aqueous polyurethane resin. When using the said emulsifier, it is preferable to add in water and emulsify and disperse beforehand at the time of an emulsion dispersion process. However, you may add after completion | finish of an emulsion dispersion process, and these emulsifiers can be used individually or in mixture.

In addition, a catalyst for forming a urethane may be used as needed in the preparation of the aqueous polyurethane resin of the present invention. Representative examples of the catalyst for forming the urethane include various nitrogen-containing compounds such as triethylamine, triethylenediamine and N-methylmorpholine, various metal salts such as potassium acetate, zinc stearate and tin octylate, and dibutyl tin dilaurate. Various organometallic compounds, such as these, are mentioned.

The manufacturing method of the aqueous melt-type polyurethane adhesive composition of this invention is demonstrated by each step.

(1) urethane reacting a polyol mixture and a polyisocyanate to prepare a polyurethane prepolymer at the end of the isocyanate group:

The isocyanate group terminated polyurethane prepolymers used in the adhesive composition of the present invention are urethane reaction products of polyol mixtures and polyisocyanates. In forming the polyurethane prepolymer, the ratio of the NCO group of the diisocyanate component to the OH group of the polyol component is 1.9: 1, preferably 1.2 to 1.6: 1, and the prepolymer reacts appropriately so that the NCO is 1 to 5% by weight. Included with the level.

The polyurethane prepolymer may be prepared without a solvent or in the presence of a solvent by appropriate reaction at a temperature of room temperature to 85 ° C., generally 40 to 70 ° C., and a catalyst such as tertiary amine or tin salt may be used and the reaction time is 1 It takes about 3 hours. The prepolymer is excellent in compatibility with water such as methyl ethyl ketone or acetone, and lowers the viscosity of the polyurethane prepolymer to 100 to 300 cps at 30 ° C. using a solvent free of active hydrogen.

(2) chain extending the isocyanate group terminated polyurethane prepolymer with a polyamine:

Polyurethane prepolymers can be chain-extended by using α, ω-polypropyleneglycoldiamine-sulfonated sodium salts, polyamines having a number average molecular weight of 600 or less, alone or in combination with hydrazine, ethylene diamine, triethylene tetramine, tetraethylene, pentamine and the like. have.

The polyurethane prepolymer dissolved in acetone or methylethyl ketone is reacted with the polyamine at a temperature of 30-50 ° C. to produce a polyurethane-urea solution.

(3) dispersing the polyurethane-urea in water and vacuum distilling the solvent:

The water was slowly added dropwise to the polyurethane-urea polymer for 10 minutes, and then stirred at high speed at 2000 rpm for 10 minutes. The solvent present in the dispersed polyurethane-urea polymer aqueous solution is distilled off in a vacuum of 30 to 40 ° C. and 700 mm Hg.

Through the steps (1) to (3) to prepare an aqueous melted polyurethane adhesive.

The aqueous polyurethane adhesive according to the present invention is produced by mixing the above aqueous polyurethane resin alone or other resin.

In the preparation of an aqueous polyurethane adhesive, a bifunctional or higher polyisocyanate compound may be used as a crosslinking agent, and examples of the bifunctional or higher polyisocyanate compound include 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 4 Polyisocyanate compound which consists of trimers, such as 4'- diisocyanato diphenyl methane (MDI), xylene diisocyanate, isophorone diisocyanate, these polyisocyanate compounds, ethylene glycol, 1, 3- butylene glycol, 1 The compound which has terminal isocyanate comprised by low molecular weight active hydrogen compounds, such as a 4-4-butylene glycol, polyoxyethylene glycol, and a long chain higher alcohol, and which can be water-soluble is mentioned.

The use of such crosslinking agents results in excellent heat resistance and durability when using an aqueous polyurethane resin as an adhesive.

On the other hand, other resins that may be included in the production of the aqueous polyurethane adhesive of the present invention may be used by mixing an emulsion polymer such as ethylene vinyl acetate emulsion, polyvinylacetate emulsion, the polyurethane resin content of 10 to the total solids 50 weight%, Preferably it is used so that it may be 10-30 weight%.

The aqueous polyurethane adhesive according to the present invention may further contain adhesive resins and additives commonly used in adhesives in a range that does not impair the thermally active adhesion of the adhesives. Examples of these adhesive resins and additives include adhesive resins such as rosin resins, rosin ester resins, terpene resins, terpene phenol resins, petroleum resins, coumarone resins, fillers, dyes, thickeners, antioxidants, ultraviolet absorbers and flame retardants. .

The aqueous polyurethane adhesive according to the present invention exhibits excellent initial adhesive strength, adhesive strength and heat resistance, and can be suitably used for bonding substrates such as shoes, films, metals, foams, rubber, fibers, and various plastics.

Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited only to these examples. In the following, 'parts' and '%' are all based on weight unless otherwise specified.

Example 1

290.7 parts of polycaprolactone diol (A) of the number average molecular weight 2000 which ring-opened epsilon-caprolactone using 1, 4- butanediol as an initiator was dehydrated under 110 degreeC vacuum, and it cooled to 50 degreeC. Subsequently, 47.4 parts of toluene diisocyanate (a ratio of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate is 80:20) was added and reacted at 50 to 60 ° C for 2 hours, followed by 1.6 parts of trimethylolpropane. 43.6 parts of Tegomer D-3403 was added, and reaction was performed at 60 degreeC for 1 hour. Next, 700 parts of acetone was slowly added to dissolve the prepolymer. The temperature was adjusted to 40 ° C., and 13 parts of α, ω-polypropylene glycoldiamine-sulfonated sodium salt and 3.6 parts of ethylenediamine were added diluted by 80 parts of water. Subsequently, 519.8 parts of water was added slowly, and it emulsified-dispersed. The emulsion thus obtained was desolvated at 40 to 50 ° C. with a vacuum pump to obtain an aqueous urethane resin having a nonvolatile content of 40% (SO ₃ ⁻ content was 0.47% based on solid content).

Example 2

292.0 parts of the polyester polyol (B) of the number average molecular weight 2000 condensation-polymerized by 1, 4- butanediol and adipic acid were dehydrated under 110 degreeC vacuum, and it cooled to 50 degreeC. Subsequently, 47.6 parts of toluene diisocyanate (the ratio of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate is 80:20) was added, and after reacting at 50-60 degreeC for 2 hours, 1.6 parts of trimethylol propanes were carried out. 43.8 parts of Tegomer D-3403 were added and reacted at 60 ° C. for 1 hour. Then, 700 parts of acetone was slowly added to dissolve the prepolymer. The temperature was adjusted to 40 ° C. and 13 parts of α, ω-polypropylene glycoldiamine-sulfonated sodium salt and 2.4 parts of 80% aqueous hydrazine aqueous solution were diluted with 80 parts of water. Subsequently, 519.3 parts of water was added slowly, and it emulsified-dispersed. The emulsion thus obtained was desolvated with a vacuum pump at 40 to 50 ° C. to obtain an aqueous urethane resin having a nonvolatile content of 40% (based on solids content of SO ₃ ⁻ content of 0.47%).

Example 3

292.0 parts of polyester polyol (C) of the number average molecular weight 2000 condensation-polymerized by 1, 6- hexanediol and adipic acid were dehydrated under 110 degreeC vacuum, and it cooled to 50 degreeC. Subsequently, 47.6 parts of toluene diisocyanate (a ratio of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate is 80:20) was added and reacted at 50 to 60 ° C for 2 hours, followed by 1.6 parts of trimethylolpropane and Tegomer. 43.8 parts of D-3403 were added and reaction was performed for 1 hour at 60 degreeC. Then, 700 parts of acetone was slowly added to dissolve the prepolymer. The temperature was adjusted to 40 ° C. and 13 parts of α, ω-polypropylene glycoldiamine-sulfonated sodium salt and 2.4 parts of 80% aqueous hydrazine aqueous solution were diluted with 80 parts of water. Subsequently, 519.3 parts of water was added slowly, and it emulsified-dispersed. The emulsion thus obtained was desolvated at 40 to 50 ° C. with a vacuum pump to obtain an aqueous urethane resin having a nonvolatile content of 40% (SO ₃ ⁻ content was 0.47% based on solid content).

Example 4

290.3 parts of polyester polyol (D) of the number average molecular weight 2000 condensation-polymerized by 1, 4- butanediol and azeraic acid were dehydrated under 110 degreeC vacuum, and it cooled to 50 degreeC. Subsequently, 47.4 parts of toluene diisocyanate (the ratio of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate is 80:20) was added, and the reaction was carried out at 50 to 60 ° C. for 2 hours, followed by 1,6-hexanediol 2.1 Part and 43.6 part of Tegomer D-3403 were added, and reaction was performed further at 60 degreeC for 1 hour. Then, 700 parts of acetone was slowly added to dissolve the prepolymer. The temperature was adjusted to 40 ° C., and 13 parts of α, ω-polypropylene glycoldiamine-sulfonated sodium salt and 3.6 parts of ethylenediamine were added diluted by 80 parts of water. Subsequently, 519.8 parts of water was added slowly, and it emulsified-dispersed. The emulsion thus obtained was desolvated with a vacuum pump at 40 to 50 ° C. to obtain an aqueous urethane resin having a nonvolatile content of 40% (based on solids content of SO ₃ ⁻ content of 0.47%).

Comparative Example 1

360 parts of the polyester polyol (B) used in Example 2 were dehydrated under 110 ° C. vacuum and cooled to 70 ° C., followed by addition of 2 parts of 1,4-butanediol and stirred uniformly. Next, 30 parts of hexamethylene diisocyanate and 15 parts of isophorone diisocyanate were added, and it was made to react at 85 degreeC for 3 hours. Then, 800 parts of acetone was slowly cooled to 50 ° C and uniformly dissolved, and then 22.9 parts of a 50% N- (2-aminoethyl) -2-aminoethane sulfonate aqueous solution was added, and 500 parts of water was added to emulsify and disperse. The emulsion thus obtained was desolvated at 40 to 50 ° C. with a vacuum pump to obtain an aqueous urethane resin having a nonvolatile content of 40% (SO ₃ ⁻ content is 1.14% based on solid content).

Comparative Example 2

360 parts of the polyester polyol (C) used in Example 3 was dehydrated under 110 ° C. vacuum and cooled to 70 ° C., followed by addition of 2 parts of 1,4-butanediol and stirred uniformly. Next, 30 parts of hexamethylene diisocyanate and 15 parts of isophorone diisocyanate were added, and it was made to react at 85 degreeC for 3 hours. Then, 800 parts of acetone was slowly cooled to 50 ° C and uniformly dissolved, and then 22.9 parts of a 50% N- (2-aminoethyl) -2-aminoethane sulfonate aqueous solution was added, and 500 parts of water was added to emulsify and disperse. The emulsion thus obtained was desolvated at 40 to 50 ° C. with a vacuum pump to obtain an aqueous urethane resin having a nonvolatile content of 40% (SO ₃ ⁻ content is 1.14% based on solid content).

Comparative Example 3

308 parts of the polyester polyol (C) used in Example 3 was dehydrated under vacuum at 110 ° C. and cooled to 70 ° C., and then 47.5 parts of hexamethylene diisocyanate and 23.2 parts of isophorone diisocyanate were added and reacted at 85 ° C. for 2 hours. I was. Next, 300 parts of acetone, 16.5 parts of dimethylolbutanoic acid and 1.5 parts of 1,4-butanediol were added and reacted at 50 ° C for 4 hours. Thereafter, 11.2 parts of triethylamine was added to form a prepolymer, and 548 parts of water were added to emulsify and disperse. Subsequently, the mixture was diluted with 3.8 parts of 80% aqueous hydrazine solution and 40 parts of water at 35 ° C. or lower, and then dropwise added for about 30 minutes to perform a chain extension reaction. The emulsion thus obtained was desolvated at 40 to 50 ° C. with a vacuum pump to obtain an aqueous urethane resin having a nonvolatile content of 40%.

Examples 1 to 4 and Comparative Examples 1 to 3 are summarized in Table 1 below.

Example Comparative example One 2 3 4 One 2 3 Polyol (A) (B) (C) (D) 290.7 292 292 290.3 360 360 308 Polyol 1,4-butanediol 1,6-hexanedioltrimethylolpropaneTegomer D-3403 1.643.6 1.643.8 1.643.8 2.1 43.6 2 2 1.5 Isocyanate toluene diisocyanate hexamethylene diisocyanate isophorone diisocyanate 47.4 47.6 47.6 47.4 3015 3015 47.523.2 Diluent Solvent Acetone 700 700 700 700 800 800 300 Ionomerdimethylolbutanoic acid 50% N- (2-aminoethyl) -2-aminoethane sulfonate aqueous solution α, ω-polypropylene glycoldiamine-sulfonated sodium salt 13 13 13 13 22.9 22.9 16.5 Neutralizer Triethylamine 11.3 Polyamine 80% Hydrazine solution Ethylenediamine 3.6 2.4 2.4 3.6 - - 3.8 water 600 599.4 599.4 600 616 616 588 Polyol Content (%) 72.7 73 73 72.7 86 86 77 SO ₃ ^- Content (%) 0.47 0.47 0.47 0.47 1.14 1.14 - 40 ℃ shelf life (30 days) Good Good Good Good Good Good Good

[Production Examples 1 to 4 Comparative Production Examples 1 to 3]

5 parts by weight of a water-soluble polyisocyanate (trade name: Desmodur DA, Bayer) was added to 100 parts by weight of the aqueous urethane resin solution prepared in Examples 1 to 4 and Comparative Examples 1 to 3 to prepare an aqueous polyurethane adhesive.

[Test Example]

The mechanical properties of the aqueous urethane adhesives of Preparation Examples 1 to 4 Comparative Production Examples 1 to 3 were evaluated by the following methods, and the results are shown in Table 2.

Initial Adhesion Test

0.2 mm (thickness) x 25 mm (width) x 100 mm (length) of PVC was washed with acetone and dried by hot air at 60 ° C. Apply 90g / ㎡ to the PVC specimen, dry it for 30 seconds in an 80 ℃ hot air dryer, take it out, and press the two specimens with pressure of 4㎏ / ㎠ for 15 seconds and attach them to a tensile strength tester to remove the T-shape. The test was conducted. The peeling rate was measured at 100 mm / min, and was measured within 1 minute after pressing (however, the number of samples was 3 and the average value was taken).

Adhesion test

0.2 mm (thickness) x 25 mm (width) x 100 mm (length) of PVC was washed with acetone and dried by hot air at 60 ° C. Apply 90 g / m 2 amount to the PVC specimen and dry at room temperature for 1 hour. Two dried specimens were thermally activated at 60 ° C. in a hot air dryer for 90 seconds, and the surfaces with adhesive were pressed for 15 seconds at a pressure of 4㎏ / ㎠ and mounted on a tensile strength tester. The peel rate was 100 mm / min in the peel strength measurement (however, the number of samples was 3 and an average value was taken).

Heat resistance test

Specimens were prepared in the same manner as the method of measuring the adhesion properties and left to stand at room temperature for 24 hours. The specimen was allowed to stand for 30 minutes with a load of 500 g on a specimen in an 80 ° C. × 50% (relative humidity) dryer, and then the peeled length of the adhesive surface was measured as a ruler. Was taken).

Production Example Comparative Production Example One 2 3 4 One 2 3 Initial Adhesion (kg _f / cm ² ) 2.6 2.5 2.6 3 2 1.5 One Adhesive force (kg _f / cm ² ) Destruction 6 Destruction Destruction 4 3 4 Heat and humidity resistance (mm) 0.3 0.2 0.2 0.1 3 5 6

As described above, the aqueous meltable polyurethane adhesive of the present invention has excellent initial adhesive strength, excellent adhesive strength and heat resistance, and is provided to furniture, interior materials, fibers, and the like.

Claims (8)

(a) an organic polyisocyanate having an average molecular weight of 100 or more; (b) a crystalline polyester polyol having a number average molecular weight of at least 2000; (c) polyols having a bifunctional or higher number average molecular weight of 100 to 1200 or more; (d) polyamines having a number average molecular weight of 600 or less with sulfonates; And (e) primary 2- to 3-functional polyamines having a molecular weight of 200 or less; Aqueous polyurethane resin liquid containing. The method of claim 1, wherein (a) the organic polyisocyanate is 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodeca methylene diisocyanate, cyclohexane-1,3- or 1,4-diisocyanate, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane (isophorone diisocyanate; IPDI), bis- (4-isocyanatocyclohexyl) methane (Hereinafter referred to as hydrogenated MDI), 2- or 4-isocyanatocyclohexyl-2'-isocyanatocyclohexyl methane, 1,3- or 1,4-bis (isocyanatomethyl) -cyclohexane, Bis- (4-isocyanato-3-methylcyclohexyl) methane, 1,3- or 1,4-α, α, α ', α'-tetramethylxylene diisocyanate, 2,4- or 2,6 Toluene diisocyanate, 2,2'-, 2,4'- or 4,4'-diisocyanatodiphenylmethane (MDI), 1,5-naphthalene diisocyanate, p- or m-phenylene diisocyanate, xylene Dee Cyanate and di aqueous polyurethane resin solution, characterized in that selected from the group consisting of biphenyl-4,4'-diisocyanate. The aqueous polyurethane resin solution according to claim 2, wherein the 2,4-toluene diisocyanate and 2,6-toluene diisocyanate are used as isomers in the ratio of 65:35 to 80:20, respectively. According to claim 1, (b) the polyester polyol is a polyol having a number average molecular weight of 2000 or more, a polycaprolactone polyol condensation-polymerized with epsilon-caprolactone, or a carbon number 6 using a diol having 4 to 8 carbon atoms as an initiator An aqueous polyurethane resin solution, characterized in that the polyol is polycondensed with dicarboxylic acid having a linear structure of 10 members and diol having a linear structure having 4 to 8 carbon atoms. The polyol of claim 1, wherein the polyol having a number average molecular weight of 100 to 1200 is neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol. An aqueous polyurethane resin liquid wherein A, a trimethylolpropane, glycerol, pentaerythritol, or alkoxyalkylene oxide is a polyol which is a nonionic reactive diol in which one hydroxyl group of trimethylolpropane is ether-bonded. The polyamine having a number average molecular weight of 600 or less having a sulfonate of (d) is α, ω-polypropylene glycoldiamine-sulfonated or a derivative thereof containing a metal of Na, K, Li, or Ca. An aqueous polyurethane resin solution characterized in that. 7. The aqueous polyurethane resin solution according to claim 6, wherein the content of sulfonic acid ion groups in the polyamine is 0.1 to 5% by weight based on the solid content of the aqueous polyurethane resin. An aqueous molten polyurethane adhesive, which is prepared by adding a crosslinking agent to the aqueous polyurethane resin liquid obtained in claim 1.