JP3493529B2 - Method for producing water-dispersible polyurethane - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a water-dispersible polyurethane and an adhesive composition containing the water-dispersible polyurethane obtained by the method.

[0002]

BACKGROUND OF THE INVENTION Aqueous polyurethane emulsions are useful in various applications such as paints, fiber treatments, and adhesives. As such an aqueous polyurethane emulsion, it is known that a urethane resin having a carboxyl group as a hydrophilic group in a resin is dispersed in water, but such a carboxyl group-containing urethane resin is easily hydrolyzed. The storage stability is poor, and the stability due to pH change and the heat resistance of the film are insufficient. Also, taurine, N-
A method for producing a sulfonic acid group-containing urethane emulsion by introducing a sulfonic acid (salt) group into a urethane resin using (2-aminoethyl) -2-aminoethanesulfonic acid or the like is also known (for example, JP-A-42-24
192, etc.), and when introducing sulfonic acid (salt) using taurine, only a small amount of sulfonic acid (salt) group can be introduced into polyurethane, and therefore the molecular weight of urethane resin is required to form an aqueous emulsion. There are restrictions.
Further, when N- (2-aminoethyl) -2-aminoethanesulfonic acid (salt) is used, the amount of sulfonic acid (salt) groups introduced can be increased to some extent, but the heat resistance of the obtained film is high. There is a defect that the properties and water resistance are poor.

[0003]

The main object of the present invention is to:
Provided is a polyurethane emulsion which is excellent in storage stability, mechanical stability, etc. and is stable against pH change, and in which the formed film has excellent water resistance, heat resistance, etc. Is.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems. As a result, a diol component and an organic diisocyanate are reacted to obtain a prepolymer having a terminal isocyanate group, and then the prepolymer is chain-extended using an addition reaction product of a (meth) acrylamide alkanesulfonate and a diamine. The polyurethane emulsion obtained by dispersing polyurethane in water is excellent in storage stability, mechanical stability, and stability against pH changes, and the film obtained from it has excellent heat resistance, water resistance, etc. I found that. Furthermore, it was found that the adhesive composition containing the polyurethane emulsion obtained by such a method has high adhesive strength, and in particular, the properties such as heat resistance and water resistance are remarkably excellent, The present invention has been completed here.

That is, in the present invention, a diol component is reacted with an organic diisocyanate to obtain a prepolymer having a terminal isocyanate group, and then the prepolymer is subjected to an addition reaction of a (meth) acrylamide alkane sulfonate and a diamine. The present invention relates to a method for producing a water-dispersible polyurethane, which comprises reacting a product, and an adhesive composition containing the water-dispersible polyurethane obtained by the production method.

The diol component used in the method of the present invention means a compound having two hydroxyl groups, which may be appropriately selected and used from those used in the production of ordinary urethane resins. Specific examples thereof include ethylene glycol, propylene glycol, 1,3-propanediol, 1,
3-butanediol, 1,4-butanediol, 1,5
-Comparison of pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, trimethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, etc. In addition to low molecular weight diols, succinic acid, adipic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, phthalic acid, 2,5-
Examples thereof include polyester diol obtained by esterification reaction with a dicarboxylic acid component such as naphthalenedicarboxylic acid and 2,6-naphthalenedicarboxylic acid.

The organic diisocyanate used in the present invention refers to a compound having two isocyanate groups, which can be appropriately selected from those used in the production of ordinary urethane resins, and specific examples thereof include:
2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate,
p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 1.5-naphthalene diisocyanate,
1,5-tetrahydronaphthalene diisocyanate, tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane Examples thereof include diisocyanate.

In order to obtain an addition reaction product of a (meth) acrylamidoalkanesulfonic acid salt and a diamine used as a chain extender in the method of the present invention, first, an aqueous solution containing (meth) acrylamidoalkanesulfonic acid is added to (meth) acetic acid. Add a salt forming agent in an amount equivalent to that of acrylamide alkanesulfonic acid, and add about 0 to 30 ° C, preferably 0 to 25 ° C.
Neutralize the reaction to a certain degree. At this time, if the temperature exceeds about 30 ° C., a polymerization reaction of the (meth) acrylamidealkanesulfonic acid may occur, which is not preferable.

Next, diamine was added to the obtained aqueous solution of (meth) acrylamide alkane sulfonate to obtain 0
At about 100 ° C for about 0.5 to 10 hours, preferably
The reaction is performed at about 50 to 80 ° C. for about 2 to 8 hours. The amount of diamine used is preferably about 0.5 to 1 in terms of molar ratio with respect to the amount of (meth) acrylamide alkane sulfonate. Depending on the amount of the diamine used, an addition reaction product in which one or two amino groups of the diamine are added to the (meth) acrylamidoalkanesulfonate, or a mixture thereof or the like can be obtained. The concentration of the aqueous solution during the reaction is
Although it is not particularly limited, if it is usually about 20 to 60% by weight, the reaction is likely to proceed uniformly.

As the acrylamidoalkanesulfonic acid used in the production of the addition reaction product, 2-acrylamidopropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methacrylamido-2-methylpropanesulfonic acid, 2 -Acrylamidobutanesulfonic acid, 3-acrylamidobutane-2-sulfonic acid and the like can be mentioned. Particularly preferred is 2-acrylamido-2-methylpropanesulfonic acid. Examples of diamine compounds include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, and isophoronediamine. Examples of the salt forming agent include organic bases such as methylamine, diethylamine, triethylamine, trimethylamine, dimethylamine, ethylamine, tributylamine, pyridine, aniline and toluidine, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, sodium carbonate. , Alkali metal carbonates such as potassium carbonate, ammonia, and the like.

Examples of the addition reaction product of the above-mentioned (meth) acrylamide alkane sulfonate and diamine include those represented by the general formula [I]

[0012]

[Chemical 4]

A compound represented by the general formula [II]

[0014]

[Chemical 5]

Examples thereof include compounds represented by: In the above general formula [I] and general formula [II], R ₁
And R ₁ ′ is each a hydrogen atom or a methyl group,
R ₂ , R ₂ ′, R ₃ , R ₃ ′, R ₄ , R ₄ ′, R ₅ and R ₅ ′ are each a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and R ₆ is a carbon number. 2-12 alkylene groups or groups

[0016]

[Chemical 6]

And M is an alkali metal atom, a group derived from an organic base, or an ammonium group.

In the above general formula, specific examples of the alkyl group having 1 to 12 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl. And straight chain or branched chain alkyl groups such as undecyl, dodecyl, 6-methylheptyl, 7-methyloctyl, 8-methylnonyl, 9-methyldecyl, 10-methylundecyl. Examples of the alkylene group having 2 to 12 carbon atoms include ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, 2-methyltrimethylene, heptamethylene, octamethylene,
Examples thereof include nonamethylene, decamethylene, undecamethylene, dodecamethylene and the like. Examples of the alkali metal atom include sodium and potassium. Examples of the group derived from an organic base include the groups derived from the organic bases described above.

Specific examples of the addition reaction product of (meth) acrylamide alkane sulfonate and diamine include:
The following can be illustrated.

[0020]

[Chemical 7]

Among the addition reaction products represented by the above general formula, in particular, according to the polyurethane emulsion obtained by using the addition reaction product of the general formula [II] as the chain extender, the film formed is heat resistant. It is particularly excellent in properties and water resistance. The addition reaction product of the general formula [II] is obtained by using diamine and (meth) acrylamide alkane sulfonate at a ratio of diamine / (meth) acrylamide alkane sulfonate (molar ratio) = 0.5 and the above-mentioned conditions. Can be easily obtained according to.

In the method for producing a water-dispersible polyurethane according to the present invention, first, a diol component and an organic diisocyanate are reacted to obtain a prepolymer having a terminal isocyanate group. In the reaction for producing the prepolymer, the amount of the organic diisocyanate used is based on the diol component.
The equivalent ratio is about 1.1 to 2.5, preferably 1.2 to
It may be about 2.0. This reaction can be carried out without a solvent, but in order to carry out the reaction uniformly, dioxane, acetone, methyl ethyl ketone, acetonitrile,
You may use the organic solvent which is inactive with respect to isocyanate groups, such as ethyl acetate and tetrahydrofuran, and has big affinity with water. The reaction is usually carried out at 30 to 120 ° C.
It may be carried out for about 1 to 20 hours, preferably about 50 to 100 ° C. for about 0.5 to 10 hours. The number average molecular weight of the prepolymer thus obtained is 500 to 50,000.
It will be about 0.

After the prepolymer having a terminal isocyanate group is thus obtained, the prepolymer solution is diluted with an organic solvent which is inactive to the isocyanate group and has a high affinity for water as described above. Solid content of 10-6
It is suitable that the amount is about 0% by weight, preferably about 20 to 50% by weight. If the viscosity of the prepolymer solution is too high, an emulsion with good stability may not be obtained, which is not preferable.

Then, the addition reaction product of (meth) acrylamide alkane sulfonate and diamine is added,
The water-dispersible polyurethane can be obtained by carrying out the reaction at about 30 to 80 ° C. for about 1 to 120 minutes. The addition reaction product can be added as a solid content, but by adding it as an aqueous solution having a concentration of about 20 to 50% by weight, the dispersibility in the prepolymer solution becomes good and a more uniform product is obtained. The reaction can be carried out. The amount of the addition reaction product used is preferably about 0.05 to 1.2 equivalents based on the terminal isocyanate groups of the prepolymer. The resulting polyurethane resin has a number average molecular weight of about 1,000 to 200,000. Next, water is added to this to make an aqueous dispersion, and the organic solvent is removed by a heating operation, a pressure reducing operation, or the like to obtain a polyurethane emulsion. The solid content of the obtained emulsion is about 10 to 70% by weight, preferably 30 to 5%.
It is suitable to adjust it to be about 0% by weight.

The polyurethane emulsion obtained by the method of the present invention can be effectively used for various applications such as paints, fiber treatments, and adhesives, like conventional polyurethane emulsions.

In particular, the adhesive composition containing the polyurethane emulsion has excellent adhesive strength and is remarkably excellent in properties such as heat resistance and water resistance, and plywood for building materials, It can be particularly usefully used in the fields of adhesion between an inorganic plate or the like and a vinyl chloride sheet, an olefin sheet or the like, adhesion between a fiber and a nylon film, a polyester film, a vinyl chloride film or the like. It is not clear why the adhesive composition containing the polyurethane emulsion obtained by the method of the present invention enables excellent adhesion such as heat resistance and water resistance. However, in the polyurethane emulsion, the sulfonic acid group is an amide group. By bonding to the polymer main chain via a group, the cohesive force of the polymer increases due to the hydrogen bonding action of the amide group, which improves heat resistance and water-resistant adhesion to the adherend. It is speculated that the effect will occur.

As the adhesive composition containing the polyurethane emulsion, the polyurethane emulsion may be used alone, or the polyurethane emulsion and vinyl acetate copolymer emulsion, acrylic copolymer emulsion, vinyl chloride copolymer emulsion, etc. It is possible to use a mixture of the other emulsions. In particular, by using the polyurethane emulsion mixed with another emulsion, the adhesiveness to a porous substrate such as a plywood or an inorganic plate can be improved.

A vinyl acetate copolymer emulsion which can be used by mixing with the polyurethane emulsion,
As an emulsion such as an acrylic copolymer-based emulsion or a vinyl chloride copolymer-based emulsion, a solid concentration of about 30 to 70% by weight is usually preferable, and 40 to
It is preferably about 65% by weight. By using an emulsion having a solid content concentration within this range, it is possible to easily produce an adhesive composition having an appropriate solid content concentration. The resin component of these emulsions is
A suitable number average molecular weight is about 50,000 to 1,000,000, preferably about 200,000 to 800,000.

When the above polyurethane emulsion is mixed with other emulsion such as vinyl acetate copolymer emulsion, acrylic copolymer emulsion, vinyl chloride copolymer emulsion, the polyurethane emulsion and other emulsion are mixed. The mixing ratio of
Polyurethane emulsion / other emulsion (solid content weight ratio) = about 2/98 to 90/10, preferably 5 /
It may be about 95 to 80/20. If the blending ratio of the polyurethane emulsion is too low, the adhesiveness to a plastic film, a plastic sheet or the like and the heat resistance tend to decrease, which is not preferable.

In the present invention, it is particularly preferable to use a vinyl acetate copolymer emulsion as the emulsion to be mixed with the polyurethane emulsion. As the vinyl acetate copolymer-based emulsion, a vinyl acetate-acrylic copolymer resin emulsion, an ethylene-vinyl acetate copolymer resin emulsion, or the like can be used. Particularly, from the viewpoint of adhesiveness and heat resistance, ethylene-vinyl acetate Copolymer resin emulsions are preferred. The ethylene-vinyl acetate copolymer resin emulsion having an ethylene content of about 5 to 40% by weight may be used.
Particularly, it is preferable to use one having an ethylene content of about 10 to 30% by weight. If the ethylene content is too low, the adhesion to plastic films, plastic sheets, etc. will be inferior, while if the ethylene content is too high, the resin will tend to become too soft and heat resistance will decrease, which is not preferred. .

In the present invention, the adhesive composition is preferably a mixture of the above-mentioned polyurethane emulsion and ethylene-vinyl acetate copolymer resin emulsion, and in particular, the addition reaction product of the above general formula [II] is formed. It is preferable to use a mixture of a polyurethane emulsion obtained as a chain extender and an ethylene-vinyl acetate copolymer resin emulsion. By using such a mixture, it is possible to obtain an adhesive composition having excellent adhesiveness to various materials and particularly excellent properties such as heat resistance and water resistance.

In the adhesive composition according to the present invention, if necessary, a solvent such as toluene, xylene, ethylene glycol diethyl ether, ethylene glycol diethyl ether acetate, cyclohexane, isophorone, ethyl acetate, butyl acetate, dibutyl phthalate or phthalate is used. By incorporating a plasticizer such as dioctyl acid or the like, the adhesive performance at low temperatures can be improved. Regarding the solvent and the plasticizer, either one or both of them can be added, and the addition amount thereof is 100 parts by weight of the resin component in the adhesive composition in order to improve the adhesive performance at low temperature. hand,
The total amount of the solvent and the plasticizer is preferably about 2 to 40 parts by weight, more preferably about 5 to 30 parts by weight. Further, if necessary, a filler such as calcium carbonate, clay, corn starch, wheat flour, etc., a thickener such as methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, glycol ether compounds and the like may be added.

In the adhesive composition of the present invention, the concentration of total solids contained in the adhesive composition is preferably in the range of about 30 to 80% by weight, and more preferably in the range of about 40 to 70% by weight. Is more preferable. Therefore, an emulsion having an appropriate solid content concentration may be selected and used so that the solid content concentration falls within this range, and water may be added as necessary or the addition amount of optional additives such as a filler. It may be prepared so as to have an appropriate solid content concentration by appropriately adjusting the above. If the solid content concentration in the adhesive composition is too low, the drying rate when used as an adhesive decreases, while if too high, the production becomes difficult, and the viscosity becomes too high and the workability is increased. Is reduced, which is not preferable.

[0034]

The water-dispersible polyurethane obtained by the method of the present invention is dispersed in water, and the polyurethane emulsion has excellent storage stability, mechanical stability, etc., and is stable against pH change. Has excellent heat resistance and water resistance. Like the conventional polyurethane emulsion, the polyurethane emulsion can be effectively used for various applications such as coating, fiber treatment, and adhesion.

In particular, the adhesive composition containing the polyurethane emulsion has high adhesiveness and has very excellent properties such as heat resistance and water resistance.

[0036]

EXAMPLES The present invention will be described in detail below with reference to examples. In the examples, "part" means "part by weight".

Example 1 In a four-necked flask equipped with a thermometer, a stirrer and a reflux condenser, butanediol-adipic acid polyester (O
After adding 120 parts of H value 56) and dissolving at 60 ° C., 16 parts of tolylene diisocyanate (80/20 (weight ratio) mixture of 2,4- and 2,6-diisocyanate) was added,
After heating to 80 ° C. and reacting at this temperature for 2 hours, after completion of the reaction, the mixture is diluted with 300 parts of acetone to give a number average molecular weight of about 5,
000 prepolymer solutions were obtained.

Then, 207 parts of 2-acrylamido-2-methylpropanesulfonic acid was neutralized with 40 parts of NaOH in an aqueous solution (concentration of 40% by weight), and then 60 parts of ethylenediamine was added and reacted at 80 ° C. for 3 hours. As a result, a pale yellow aqueous solution containing the above-mentioned two-component addition reaction product was obtained (solid content adjusted to 30%). The viscosity of this aqueous solution was 10 cps / 25 ° C. IR analysis of the product showed that the main absorption was 3300 cm.
^-1 , 2,950 cm ^-1 , 1660 cm ^-1 , 1550c
^{m -1, 1460cm -1, 1220cm -1} , 1050cm
^-1 , 630 cm ^-1 . In addition, the disappearance of the double bond at 1620 cm ⁻¹ was confirmed, and the addition reaction product thus obtained was obtained by adding 1 mol of 2-acrylamido-2-methylpropanesulfonic acid sodium salt to 1 mol of ethylenediamine. It was confirmed that there is.

15 parts of a 30% aqueous solution of the addition reaction product was added to the prepolymer solution, and the mixture was stirred at 50 ° C. for 10 minutes. Then, 210 parts of water was added to prepare an aqueous dispersion. The milky white dispersion liquid thus obtained was gradually heated to about 100 ° C. to remove acetone and obtain a milky white polyurethane emulsion.

This product has a nonvolatile content of 40% and a viscosity of 15c.
It had a ps / 25 ° C. and a particle size of 150 nm, was excellent in storage stability, and was stable against pH change. The film obtained from this had excellent heat resistance and water resistance.

Example 2 A 4-necked flask equipped with a thermometer, a stirrer and a reflux condenser was placed in a butanediol-adipic acid polyester (O
After adding 120 parts of H value 56) and heating at 60 degreeC, 16 parts of tolylene diisocyanate (80/20 (weight ratio) mixture of 2,4- and 2,6-diisocyanate) was added, and
After heating to 0 ° C. and reacting at this temperature for 2 hours, after completion of the reaction, it is diluted with 300 parts of acetone to give a number average molecular weight of about 5,
000 prepolymer solutions were obtained.

Then, 415 parts of 2-acrylamido-2-methylpropanesulfonic acid was neutralized with 80 parts of NaOH in an aqueous solution (concentration of 40% by weight), and then 60 parts of ethylenediamine was added and reacted at 80 ° C. for 3 hours. As a result, a pale yellow aqueous solution containing the above-mentioned two-component addition reaction product was obtained (solid content adjusted to 30%). The viscosity of this aqueous solution was 10 cps / 25 ° C. IR analysis of the product showed that the main absorption was 3300 cm.
^-1 , 2,950 cm ^-1 , 1660 cm ^-1 , 1550c
^{m -1, 1460cm -1, 1220cm -1} , 1050cm
^-1 , 630 cm ^-1 . In addition, the disappearance of the double bond at 1620 cm ⁻¹ was confirmed, and thus the obtained addition reaction product was obtained by adding 2 mol of 2-acrylamido-2-methylpropanesulfonic acid sodium salt to 1 mol of ethylenediamine. It was confirmed that there is.

An aqueous dispersion was prepared by adding 13 parts of a 30% aqueous solution of the addition reaction product to the prepolymer solution and stirring the mixture at 50 ° C. for 10 minutes, and then adding 210 parts of water. The milky white dispersion liquid thus obtained was gradually heated to about 100 ° C. to remove acetone and obtain a milky white polyurethane emulsion.

This product has a nonvolatile content of 40% and a viscosity of 30c.
It had a ps / 25 ° C. and a particle size of 130 nm, was excellent in storage stability, and was stable against pH change. The film obtained from this had excellent heat resistance and water resistance.

Example 3 In a four-necked flask equipped with a thermometer, a stirrer and a reflux condenser, butanediol-adipate polyester (O
After adding 80 parts of H value 56) and 2 parts of 1,4-butanediol and heating at 60 ° C., tolylene diisocyanate (2,
16 parts (80/20 (weight ratio) mixture of 4- and 2,6-diisocyanate) are added, heated to 80 ° C., reacted at this temperature for 2 hours, and after the reaction is completed, diluted with 250 parts of acetone, A prepolymer solution having a number average molecular weight of about 3,000 was obtained.

Then, 415 parts of 2-acrylamido-2-methylpropanesulfonic acid was neutralized with 80 parts of NaOH in an aqueous solution (concentration of 40% by weight), and then 60 parts of ethylenediamine was added and reacted at 80 ° C. for 3 hours. As a result, a pale yellow aqueous solution containing the above-mentioned two-component addition reaction product was obtained (solid content adjusted to 30%). The viscosity of this aqueous solution was 15 cps / 25 ° C. Product I
R analysis showed that the main absorption was 3300c.
^{m -1, 2950cm -1, 1660cm -1} , 1550cm
^{-1, 1460cm -1, 1220cm -1,} 1050c
It was m- ¹ and 630 cm- ¹ . In addition, the disappearance of the double bond at 1620 cm ^-1 was confirmed, whereby the addition reaction product obtained was obtained by adding 2-acrylamido-2-methylpropanesulfonic acid sodium salt 2 to 1 mol of ethylenediamine.
It was confirmed that the mole was added.

13 parts of a 30% aqueous solution of the addition reaction product was added to the prepolymer solution and stirred at 50 ° C. for 10 minutes, then 180 parts of water was added to prepare an aqueous dispersion. The milky white translucent dispersion thus obtained is
The mixture was gradually heated to about 0 ° C. to remove acetone to obtain a milky white polyurethane emulsion.

This product has a nonvolatile content of 40% and a viscosity of 20c.
It had a ps / 25 ° C. and a particle size of 150 nm, was excellent in storage stability, and was stable against pH change. The film obtained from this had excellent heat resistance and water resistance.

Comparative Example 1 In a 4-necked flask equipped with a thermometer, a stirrer and a reflux condenser, 80 parts of 1,6-hexanediol-neopentyl glycol-adipic acid type polyester (OH value 57) and 2,2 '-Dimethylolpropionic acid (5.5 parts) was added, and then methyl ethyl ketone (60 parts) was added.
After heating to 0 ° C, 21 parts of tolylene diisocyanate (80/20 (weight ratio) mixture of 2,4- and 2,6-diisocyanate) was added, heated to 80 ° C, reacted at this temperature for 5 hours, and reacted. After the completion, 4.1 parts of triethylamine was added dropwise for neutralization, and then 140 parts of water was added. The milky white dispersion liquid thus obtained was gradually heated to about 100 ° C. to remove methyl ethyl ketone to obtain a milky white polyurethane emulsion.

This product has a nonvolatile content of 45% and a viscosity of 200.
cps / 25 ° C., particle size 200 nm. When the pH of this polyurethane emulsion was set to 6 or less, generation of aggregates was observed. When this emulsion was stored at 50 ° C. for 5 days, an increase in acid value due to hydrolysis was confirmed, and the elasticity of the film formed was reduced.

Using the polyurethane emulsions obtained in Examples 1 to 3 and Comparative Example 1 above, an adhesive composition was prepared and an adhesion test was conducted. The compounding amount of the adhesive composition and the test results are shown in Table 1 below. In Table 1, the vinyl acetate-ethylene copolymer means Sumikaflex S-400 (20% by weight of ethylene in the resin, Sumitomo Chemical Co., Ltd.).
Resin content 55% by weight).

The test method is as follows.

(Adhesion conditions) An adhesive composition was applied on a JASI type plywood to a coating film thickness of 0.1 mm (roll coating method),
Then, the semi-rigid vinyl chloride sheets were superposed to obtain a laminate. Next, the obtained laminated body is treated with 0.5 kgf / cm ²
After being pressed for 24 hours, it was decompressed, cured at 20 ° C. for 3 days, and then cured at 50 ° C. for 1 day to prepare a test body.

(Adhesion test method) (1) Normal peel strength: 180 degree peel test at 25 ° C. and 60% RH (pulling speed: 120 mm / min, width of test piece 25 mm) (2) Water resistant peel strength: at room temperature After soaking in water for 24 hours,
180 degree peel test in normal wet condition (pulling speed: 120
mm / min, width of test piece 25 mm) (3) Heat-resistant creep resistance: 0.5 kgf static load is applied to the end of a semi-rigid vinyl chloride sheet (sheet width 25 mm) at a 90 degree angle of 60 ° C x 24. Measure the peel length after time.

[0055]

[Table 1]

From the above results, it is understood that the adhesive composition using the polyurethane emulsion obtained by the present invention is excellent in water resistance, heat resistance and the like.

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI C09D 175/04 C09D 175/04

Claims (5)

(57) [Claims] 1. A diol component is reacted with an organic diisocyanate to obtain a prepolymer having a terminal isocyanate group, and the prepolymer is reacted with an addition reaction product of a (meth) acrylamide alkane sulfonate and a diamine. A method for producing a water-dispersible polyurethane, comprising: 2. The addition reaction product is represented by the general formula [I]: Alternatively, a compound represented by the general formula [II] (In the formula, R ₁ and R ₁ ′ are each a hydrogen atom or a methyl group, and R ₂ , R ₂ ′, R ₃ , R ₃ ′, R ₄ , R ₄ ′,
R ₅ and R ₅ ′ are each a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and R ₆ is an alkylene group having 2 to 12 carbon atoms or a group And M is an alkali metal atom, a group derived from an organic base, or an ammonium group. The method for producing a water-dispersible polyurethane according to claim 1, which is a compound represented by the formula (1). 3. The method for producing a water-dispersible polyurethane according to claim 2, wherein the addition reaction product is a compound represented by the general formula [II]. 4. An adhesive composition comprising a water-dispersible polyurethane obtained by the method according to claim 1. 5. An adhesive composition comprising a water-dispersible polyurethane obtained by the method according to claim 3 and an ethylene-vinyl acetate copolymer resin emulsion.