JP2000256639A - Polyurethane adhesive composition and coated material made by using the composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition which is free from leaving of the adhesive when the coated material is peeled off by blending a polyfunctional isocyanate compound with a polyurethane reaction product obtained through the reaction of a polyester polyol, a polyether polyol and an organic polyisocyanate by using a specified number of catalysts in the presence of a tackifier having a functional group reactive with an NCO group. SOLUTION: Two catalysts are used. It is desirable that at least one of them comprises an organometallic compound and at least one of them comprises an organotin compound. Two catalysts used preferably comprise tin 2- ethylhexanoate and dibutyltin laurate, the weight ratio of the former to the latter preferably being less than 1:1. It is desirable that the tackifier (e.g. a rosin ester) is present in an amount of 5-40 wt.% in the polyurethane and that the temperature at which the polyurethane is obtained is 100 deg.C or lower. The composition has high cohesive power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane pressure-sensitive adhesive composition and a tape, label, seal, decorative sheet, non-slip sheet, double-sided pressure-sensitive adhesive tape, etc. using the pressure-sensitive adhesive composition. Related to coatings.

[0002]

2. Description of the Related Art Conventional acrylic tapes, labels, seals, decorative sheets, non-slip sheets,
Coated products such as double-sided adhesive tape have excellent adhesive strength,
When it was peeled off from the adherend after being adhered to the adherend because the re-adhesive property was not sufficient, there was a problem that adhesive remained on the adherend and the adhesive strength increased, and re-pasting was not possible. Also, when a sheet coated with an adhesive on PET is attached to window glass, glass for automobiles, or the like, it is not easy to reattach the sheet in order to remove the bubbles without bubbles.

On the other hand, tapes using urethane-based adhesives,
Coatings such as labels, seals, cosmetic sheets, non-slip sheets, and double-sided adhesive tapes can satisfy various physical properties required for coatings, but increase the viscosity of resin solutions, control reactions, and reduce raw material costs. There was a problem. In particular, it was difficult to control the compatibility and crosslinkability of the resin solution as the reaction progressed. Further, urethane-based pressure-sensitive adhesives generally have a problem of low adhesive strength. As a solution to this problem, it is conceivable to add a tackifier. However, in general, the tackifier has poor compatibility with the urethane resin, and the coating liquid itself is turbid and the coating film is liable to be turbid.

[0004]

DISCLOSURE OF THE INVENTION The present invention has the drawbacks of leaving adhesive when peeling off a coated article using an acrylic pressure-sensitive adhesive, increasing the adhesive strength, and making it difficult to obtain stable tackiness. An object of the present invention is to provide a polyurethane pressure-sensitive adhesive composition in which the various disadvantages described above have been improved and a coated article having good re-sticking properties using the pressure-sensitive adhesive composition.

[0005]

Conventionally, two or more kinds of polyols such as polyester polyol and polyether polyol having different compatibility and reactivity and an organic polyisocyanate compound have been reacted in the presence of a single catalyst. . In this system, there was a problem that the reaction solution often became turbid or gelled. In particular, it is remarkable when the reaction temperature is 100 ° C. or lower. Therefore, as a result of various studies of reaction conditions, it was found that a polyurethane resin can be obtained by using two types of catalysts without causing the reaction solution to become turbid or gelled. In addition, it has been found that by performing the reaction in the presence of a tackifier, a pressure-sensitive adhesive having good compatibility with the urethane resin and strong adhesive strength can be obtained.

That is, the first invention uses two kinds of catalysts in the presence of a tackifier having a functional group capable of reacting a polyester polyol, a polyether polyol, and an organic polyisocyanate with an isocyanate group. It is a polyurethane pressure-sensitive adhesive composition obtained by blending a polyfunctional isocyanate compound (B) with a reacted polyurethane reactant (A). A second invention is the polyurethane pressure-sensitive adhesive composition according to the first invention, wherein at least one of the two catalysts is an organometallic compound. A third invention is the polyurethane pressure-sensitive adhesive composition according to the first invention, wherein at least one of the two catalysts is an organotin compound.

[0007] A fourth invention is the polyurethane pressure-sensitive adhesive composition according to the first invention, wherein the two kinds of catalysts are tin 2-ethylhexanoate and dibutyltin dilaurate. A fifth invention is the polyurethane pressure-sensitive adhesive composition according to the fourth invention, wherein the weight ratio of tin 2-ethylhexanoate and dibutyltin dilaurate is less than 1 of tin 2-ethylhexanoate / dibutyltin dilaurate. It is. The sixth invention is characterized in that the tackifier is contained in the polyurethane reactant (A),
The polyurethane pressure-sensitive adhesive composition according to the first invention, which is 5 to 40% by weight. A seventh invention is the polyurethane pressure-sensitive adhesive composition according to any one of the first to sixth inventions, wherein the temperature at which the polyurethane reactant (A) is obtained is 100 ° C. or lower.

The eighth invention is characterized in that a part or all of the polyester polyol has a molecular weight of 2,000 to 4,000 and has at least three or more hydroxyl groups in one molecule. A polyurethane pressure-sensitive adhesive composition according to any one of the seven inventions. In the ninth invention, a part or all of the polyether polyol has a molecular weight of 2,000.
The polyurethane pressure-sensitive adhesive composition according to any one of the first to seventh inventions, which is 0 to 4,000 and has at least three or more hydroxyl groups in one molecule.

A tenth invention is a coated product of the polyurethane pressure-sensitive adhesive composition according to any one of the first to ninth inventions. An eleventh invention is the coated article according to the tenth invention, wherein the base material is a plastic film or a plastic sheet. A twelfth invention is the coated article according to the tenth invention, wherein the base material is polyurethane. A thirteenth invention is the coated article according to the tenth invention, wherein the base material is paper.

A fourteenth invention is the coated article according to the tenth invention, wherein the base material is a polyurethane foam.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As the polyester polyol used in the present invention, a known polyester polyol is used. Examples of the acid component include terephthalic acid, adipic acid, azelaic acid, sebacic acid, phthalic anhydride, isophthalic acid, and trimellitic acid, and the glycol components include ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, and 1,6-hexane glycol. , 3-methyl-1,5-pentanediol, 3,
3′-dimethylol heptane, polyoxyethylene glycol, polyoxypropylene glycol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol, glycerin as a polyol component,
Trimethylolpropane, pentaerythritol and the like. Other examples include polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone, poly (β-methyl-γ-valerolactone) and polyvalerolactone. The molecular weight of the polyester polyol can be used from a low molecular weight to a high molecular weight. Preferably, the molecular weight is 1,000 to 5,000, and a bifunctional or more functional polyester polyol, and more preferably, a part or all of the polyester has a molecular weight of 2,000. ~ 4,000-3
More than sensuality. The amount of the polyester polyol used is 1 to 5 in the polyol constituting the polyurethane reactant (A).
0 mol% is preferred.

Known polyether polyols are used as the polyether polyol used in the present invention. For example, propylene glycol, ethylene glycol, glycerin, using a low molecular weight polyol such as trimethylolpropane as an initiator, ethylene oxide, propylene oxide, butylene oxide, polyether polyol obtained by polymerizing an oxirane compound such as tetrahydrofuran, specifically Specifically, those having two or more functional groups, such as polypropylene glycol, polyethylene glycol, and polytetramethylene glycol, are used. The molecular weight of the polyether polyol can be used from a low molecular weight to a high molecular weight, but preferably the molecular weight is 1,
A polyether polyol having a molecular weight of 2,000 to 5,000, more preferably bifunctional or more, and more preferably a part or all of the polyether polyol is trifunctional or more having a molecular weight of 2,000 to 4,000. The amount of the polyether polyol to be used is preferably from 1 to 80 mol% in the polyol constituting the polyurethane reactant (A).

When the molecular weight is 2,000 or less, the trifunctional or more functional polyol used in the present invention has high reactivity and is easily gelled. If the molecular weight is 4,000 or more, the reactivity of the polyol becomes poor, and the cohesive force of the urethane pressure-sensitive adhesive decreases.

In the present invention, if necessary, some glycols such as ethylene glycol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol, glycerin, trimethylolpropane, and pentaerythritol; ethylenediamine; Polyvalent amines such as aminoethylethanolamine, isophoronediamine and xylylenediamine can also be used in combination.

Examples of the organic polyisocyanate compound used in the present invention include known aromatic polyisocyanates, aliphatic polyisocyanates, araliphatic polyisocyanates, and alicyclic polyisocyanates.

As aromatic polyisocyanates, 1,3
-Phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate,
2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,
Examples thereof include 3,5-triisocyanatebenzene, dianisidine diisocyanate, 4,4'-diphenylether diisocyanate, and 4,4 ', 4 "-triphenylmethane triisocyanate.

Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, Examples include 2,4,4-trimethylhexamethylene diisocyanate.

As the araliphatic polyisocyanates, ω, ω′-diisocyanate-1,3-dimethylbenzene, ω, ω′-diisocyanate-1,4-dimethylbenzene, ω, ω′-diisocyanate-1,4-diethylbenzene , 1,4-tetramethylxylylene diisocyanate, 1,3-tetramethyl xylylene diisocyanate, and the like.

As the alicyclic polyisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2 , 4-cyclohexanediisocyanate, methyl-
2,6-cyclohexane diisocyanate, 4,4'-
Methylene bis (cyclohexyl isocyanate), 1,
4-bis (isocyanatomethyl) cyclohexane,
1,4-bis (isocyanatomethyl) cyclohexane and the like can be mentioned.

In addition, a trimethylolpropane adduct of the above polyisocyanate, a burette that has been reacted with water, a trimer having an isocyanurate ring, and the like can also be used in combination.

As the polyisocyanate used in the present invention, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate) and the like are preferable.

As the tackifier having a functional group capable of reacting with the isocyanate group used in the present invention, known tackifiers can be used. For example, there are a natural rosin having a carboxyl group, a modified rosin and its derivative, a phenolic resin having a hydroxyl group and the like. These tackifiers are compounded through chemical bonding with the urethane resin, so that compatibility between the two is improved. In addition, other tackifiers such as polyterpene resins, aliphatic hydrocarbon resins, cyclopentadiene resins, etc., as described in “Adhesion. Adhesion Encyclopedia” (edited by Shozaburo Yamaguchi, Asakura Shoten), etc., may be appropriately modified. Then, it can be used.

As the catalyst used in the present invention, a known catalyst can be used. For example, tertiary amine compounds, organometallic compounds and the like can be mentioned.

Examples of the tertiary amine compound include triethylamine, triethylenediamine, 1,8-diazabicyclo (5,4,0) -undecene-7 (DBU) and the like.

The organometallic compounds include tin compounds and non-tin compounds.

As the tin compound, dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide,
Dibutyltin dimaleate, dibutyltin dilaurate (D
BTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, tributyltin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, 2-ethylhexanoic acid Tin etc. are mentioned.

Examples of the non-tin compounds include titanium compounds such as dibutyl titanium dichloride, tetrabutyl titanate and butoxy titanium trichloride, and lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate and lead naphthenate. Iron, such as iron, 2-ethylhexanoate and iron acetylacetonate; cobalt, such as cobalt benzoate and cobalt 2-ethylhexanoate; zinc, such as zinc naphthenate and zinc 2-ethylhexanoate; zirconium naphthenate And the like.

When these catalysts are used, in a system in which two kinds of polyols, that is, a polyester polyol and a polyether polyol, are present, due to a difference in reactivity and compatibility, a system using a single catalyst gels or a reaction solution is formed. The problem of cloudiness is likely to occur. By using two types of catalysts, the coordination property and reaction rate of the catalyst can be controlled, and these problems can be solved. As the combination, a tertiary amine / organic metal type, tin type / non-tin type, tin type / tin type or the like is used, preferably tin type / tin type, more preferably dibutyltin dilaurate and 2-ethylhexane. It is a combination of tin acid. The compounding ratio is tin 2-ethylhexanoate / dibutyltin dilaurate <1 by weight. More preferably, it is 0.2 to 0.6. Mixing ratio is 1
Above, it becomes easy to gel due to the balance of the catalytic activity. These catalysts are used in an amount of 0.01 to 1.0% by weight based on the total amount of the polyol and the organic polyisocyanate.

As the polyfunctional isocyanate compound (B) used in the present invention, the above-mentioned organic polyisocyanate compounds and their trimethylolpropane adducts,
A buret body reacted with water, a trimer having an isocyanurate ring, or the like is used.

Various methods are available for obtaining the polyurethane reactant (A). For example, 1) charging the whole amount, 2) charging the polyester polyol, polyether polyol, tackifier, and catalyst into a flask to prepare an organic polyisocyanate. 3) In the first stage, a polyester polyol, a polyether polyol and a catalyst are charged into a flask, and the organic polyisocyanate is dropped. In the second stage, a tackifier or, if necessary, an organic polyisocyanate is also added. Drip. Further, the tackifier can be divided and added. In particular, the method 3) is preferable for controlling the reaction.

The mixing ratio of the polyurethane reactant (A) and the polyfunctional isocyanate (B) used in the present invention is (A)
(B) 1 to 20 parts is used per 100 parts (parts by weight). If it is 1 part or less, the cohesive strength decreases, and if it is 20 parts or more, the adhesive strength decreases. Preferably it is 2 to 10 parts.

The reaction temperature for obtaining the polyurethane reactant (A) containing the tackifier of the present invention is preferably 100 ° C. or lower. More preferably, the temperature is from 85C to 95C. If the reaction temperature is 100 ° C. or higher, it is difficult to control the reaction rate and the crosslinked structure, and it is difficult to obtain a polyurethane reactant (A) having a predetermined molecular weight.

As the solvent used in the present invention, known solvents can be used. Examples include methyl ethyl ketone, ethyl acetate, toluene, xylene, acetone and the like. Toluene is particularly preferred in view of the solubility of the tackifier and the polyurethane reactant (A), the boiling point of the solvent, and the like.

The polyurethane adhesive according to the present invention may contain additives such as fillers such as talc, calcium carbonate, and titanium oxide, coloring agents, ultraviolet absorbers, antioxidants, defoamers, and light stabilizers. May be blended.

The polyurethane pressure-sensitive adhesive according to the present invention is used by being applied to a base material such as a plastic film, a plastic sheet, polyurethane, paper, or polyurethane foam. The coated product is suitably used as a tape, a label, a seal, a cosmetic sheet, a non-slip sheet, a double-sided adhesive tape, and the like.

The plastic film or the plastic sheet in the present invention includes a polyvinyl chloride film, a polyethylene terephthalate (PET) film,
Examples include a nylon film, a treated polyolefin film, and an untreated polyolefin film. In particular, a PET film or sheet is preferable from the viewpoint of adhesion and ease of application. The thickness of the base material is preferably 15 to 100 μm. The coating thickness of the adhesive on the base material is 5 to 5.
100 μm is preferred.

Examples of the polyurethane substrate in the present invention include polyurethane molded products such as polyurethane sheets, polyurethane films, and polyurethane foams. The thickness of these substrates is 20 including the case of foam.
50,000 μm, and the coating thickness on the substrate is 5-1
00 μm is preferred.

As the paper substrate in the present invention, plain paper,
Examples include coated paper and art paper. The thickness of these substrates is preferably from 15 to 5,000 μm. Further, the coating thickness of the pressure-sensitive adhesive on the substrate is preferably 5 to 100 μm.

Hereinafter, a synthesis example will be described.

Synthesis Example 1 Polyester polyol P-1 was placed in a four-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet, thermometer, and dropping funnel.
010 (bifunctional polyester polyol, OH value 11
2, 108 g of Kuraray Co., Ltd., polyether polyol G-2000 (trifunctional polyether polyol, O
H value 112, manufactured by Asahi Denka Co., Ltd.) 67 g, hexamethylene diisocyanate (Sumitomo Bayer Co., Ltd.) 26
g, 147 g of toluene, 0.03 g of iron 2-ethylhexanoate and 0.04 g of lead naphthenate as catalysts, and 9
The temperature is gradually raised to 0 ° C., and the reaction is performed for 60 minutes. Next, 20 g of rosin ester (Superester A-115, manufactured by Arakawa Chemical Industries, Ltd., acid value 20 or less) was added, and the mixture was further reacted for 3 hours. The residual isocyanate group is confirmed by an infrared spectrophotometer (IR). If the remaining isocyanate group disappears, the reaction is terminated and cooled. This reaction solution is transparent, has a solid content of 60%, and has a viscosity of 3,500 cp.
s, MN (number average molecular weight) was 13,000, and MW (weight average molecular weight) was 45,000.

Synthesis Example 2 Polyester polyol F-2 was placed in a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet, a thermometer, and a dropping funnel.
010 (trifunctional polyester polyol, OH value 85,
31 g, Kuraray Co., Ltd., polyether polyol P
P-2000 (bifunctional polyether polyol, OH value 56, manufactured by Sanyo Chemical Industries, Ltd.) 152 g, isophorone diisocyanate (manufactured by Huls Japan KK) 1
7.5 g, toluene 147 g, iron 2-ethylhexanoate 0.03 g as a catalyst, tin 2-ethylhexanoate 0.0
2 g is charged, the temperature is gradually raised to 90 ° C., and the reaction is carried out for 60 minutes. Next, rosin ester (Superester A-11)
5, Arakawa Chemical Industry Co., Ltd., acid value 20 or less) was added, and the mixture was further reacted for 4 hours. The residual isocyanate group is confirmed by IR, and if it has disappeared, the reaction is terminated and cooled. This reaction solution is transparent, has a solid content of 60%, and has a viscosity of 3,000 cp.
s, MN 15,000 and MW 50,000.

Synthesis Example 3 Polyester polyol P-1 was placed in a four-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet, thermometer, and dropping funnel.
010 (bifunctional polyester polyol, OH value 11
2, Kuraray Co., Ltd.) 81 g, polyether polyol G-3000B (trifunctional polyether polyol, O
H value: 56, Asahi Denka Co., Ltd.) 101 g, hexamethylene diisocyanate (Sumitomo Bayer Co., Ltd.)
5 g, 148 g of ethyl acetate, 0.03 g of iron 2-ethylhexanoate as a catalyst, 0.02 g of tetrabutyl titanate
g, and gradually heated to 75 ° C., and reacted for 60 minutes. Next, rosin ester (Superester A-11)
5, Arakawa Chemical Industry Co., Ltd., acid value 20 or less) was added, and the mixture was further reacted for 4 hours. The residual isocyanate group is confirmed by IR, and if it has disappeared, the reaction is terminated and cooled. This reaction solution is transparent, has a solid content of 60%, and has a viscosity of 3,000 cp.
s, MN 16,500 and MW 50,000.

Synthesis Example 4 Polyester polyol P-1 was placed in a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, and a dropping funnel.
010 (bifunctional polyester polyol, OH value 11
2, Kuraray Co., Ltd.) 81 g, polyether polyol G-3000B (trifunctional polyether polyol, O
H value: 56, Asahi Denka Co., Ltd.) 101 g, hexamethylene diisocyanate (Sumitomo Bayer Co., Ltd.)
5 g, toluene 148 g, dibutyltin dilaurate 0.05 g as a catalyst, tin 2-ethylhexanoate 0.02 g
And the temperature is gradually raised to 90 ° C., and the reaction is carried out for 20 minutes. Next, rosin ester (Superester A-11)
5, Arakawa Chemical Industry Co., Ltd., acid value 20 or less) was added, and the mixture was further reacted for 3 hours. The residual isocyanate group is confirmed by IR, and if it has disappeared, the reaction is terminated and cooled. This reaction solution is transparent, has a solid content of 60%, and has a viscosity of 2,800 cp.
s, MN 14,500 and MW 40,000.

Synthesis Example 5 Polyester polyol P-1 was placed in a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, and a dropping funnel.
010 (bifunctional polyester polyol, OH value 11
2, 67 g of Kuraray Co., Ltd., polyether polyol PP-2000 (bifunctional polyether polyol, O
H value 56, manufactured by Sanyo Chemical Industries, Ltd.) 107 g, hexamethylene diisocyanate (manufactured by Sumitomo Bayer, Ltd.)
27 g, toluene 147 g, dibutyltin dilaurate 0.03 g as a catalyst, tin 2-ethylhexanoate 0.02
g, the temperature is gradually raised to 90 ° C., and the reaction is carried out for 20 minutes. Next, rosin ester (super-ester A-11)
5, Arakawa Chemical Industry Co., Ltd., acid value 20 or less) was added, and the mixture was further reacted for 3 hours. The residual isocyanate group is confirmed by IR, and if it has disappeared, the reaction is terminated and cooled. The reaction solution was transparent, solid content 60%, viscosity 3300 cps,
MN 16,000 and MW 42,000.

Synthesis Example 6 Polyester polyol P-1 was placed in a four-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping funnel.
010 (bifunctional polyester polyol, OH value 11
2, Kuraray Co., Ltd.) 56 g, polyether polyol PP-2000 (bifunctional polyether polyol, O
H value 56, 91 g of Sanyo Kasei Kogyo Co., Ltd., 20 g of rosin ester (Super Ester A-125, manufactured by Arakawa Chemical Industry Co., Ltd., acid value 20 or less), 22 g of isophorone diisocyanate (Huls Japan K.K.), Takenate 31 g of D-140N (isophorone diisocyanate trimethylolpropane adduct, manufactured by Takeda Pharmaceutical Co., Ltd.), 147 g of toluene, 0.03 g of dibutyltin dilaurate as a catalyst, and 0.1 g of tin 2-ethylhexanoate.
After charging 02 g, the temperature was gradually raised to 90 ° C., and the reaction was carried out for 4 hours. The residual isocyanate group is confirmed by IR, and if it has disappeared, the reaction is terminated and cooled. This reaction solution was transparent and had a solid content of 60%, viscosity of 2200 cps, MN of 13,500, and MW.
43,000.

Synthesis Example 7 Polyester polyol P-2 was placed in a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, and a dropping funnel.
010 (bifunctional polyester polyol, OH value 56,
90 g, Kuraray Co., Ltd., polyether polyol G
-2000 (trifunctional polyether polyol, OH value 8
5, 24 g of Asahi Denka Co., Ltd., 17.5 g of hexamethylene diisocyanate (manufactured by Sumitomo Bayer Co., Ltd.), 101 g of ethyl acetate, and 0.05 g of dibutyltin dilaurate as a catalyst were gradually heated to the boiling point temperature and reacted for 20 minutes. I do. Next, 20 g of rosin ester (Superester A-115, manufactured by Arakawa Chemical Industries, Ltd., acid value 20 or less) was added, and the mixture was further reacted for 3 hours. The residual isocyanate group is confirmed by IR, and if it has disappeared, the reaction is terminated and cooled. This reaction solution was slightly turbid, and had a solid content of 60%, a viscosity of 3200 cps, MN of 14,500, and a MW of 50,000.
It was 0.

Synthesis Example 8 Polyester polyol P-2 was placed in a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet, a thermometer, and a dropping funnel.
010 (bifunctional polyester polyol, OH value 56,
90 g, Kuraray Co., Ltd., polyether polyol G
-2000 (trifunctional polyether polyol, OH value 8
5, 24 g of hexamethylene diisocyanate (manufactured by Sumitomo Bayer Ltd.), 87 g of ethyl acetate, dibutyltin dilaurate 0.0 as a catalyst
5 g is charged, the temperature is gradually raised to 80 ° C., and the reaction is carried out for 4 hours. The residual isocyanate group is confirmed by IR, and if it has disappeared, the reaction is terminated and cooled. This reaction solution was slightly turbid, having a solid content of 60%, a viscosity of 3,500 cps, and a MN of 15,50.
0, MW 52,000. Synthesis Example 9 75 g of butyl acrylate, 20 g of 2-ethylhexyl acrylate, 5 g of 2-hydroxyethyl acrylate, 135 g of ethyl acetate, 15 g of toluene, 15 g of toluene and 0 g of benzoyl peroxide were placed in a four-necked flask equipped with a stirrer, nitrogen inlet tube, thermometer, and dropping funnel. 0.2 g of the solution was placed in a reactor equipped with a reflux condenser, and reacted at about 80 ° C. for 8 hours under a nitrogen gas stream. This solution was colorless and transparent, had a solid content of 40%, and had a viscosity of 5,200 cps.

[0048]

EXAMPLES Examples and comparative examples will be described below.

Table 1 shows the composition of the polyurethane pressure-sensitive adhesive.

Table 2 shows the results of the adhesion and holding force tests.

Table 3 shows the results of the ball tack test and the removability test.

The test items are as follows. Coating method: 25μ dry coating film of the above adhesive solution on release paper
m and dried at 100 ° C. for 2 minutes to prepare a coated product. After aging at room temperature for one week, physical properties were measured. Adhesive strength: Adhesive sheet is made of 2mm thick stainless steel plate (SU
S304) at 23 ° C.-65% RH, roll-pressed according to JIS, and after 20 minutes, peel strength (180 ° peel, pulling speed 300 m) with a shopper type peel tester.
m / min).

Holding force: A pressure-sensitive adhesive sheet was adhered to a stainless steel plate (SUS304) having a thickness of 2 mm with an area of 25 mm × 25 mm, roll-pressed in accordance with JIS, left at 40 ° C. for 20 minutes, and then subjected to a load of 1 kg and dropped. The number of seconds required to perform the measurement or the deviation after 60 minutes was measured. Ball tack: J. 2 by Dow type rolling ball method
It was measured under the conditions of 3 ° C. and 65% RH. Peelability: Stainless steel plate (SUS304),
After adhering to a glass plate, it was left under conditions of 40 ° C.-65% RH, cooled to 23 ° C.-65% RH, peeled off, and visually evaluated for adhesive residue. After peeling, ◎ indicates no adhesive transfer to the adherend, ○ indicates extremely slight transfer, △ indicates partial transfer, and X indicates complete transfer.

[0054]

[Table 1]

The polyfunctional isocyanate compound (B) was mixed with 100 g of the solid content of the polyurethane reactant (A).
Of solids was added. Polyfunctional isocyanate compound (B) Takenate D-160N (hexamethylene diisocyanate-trimethylolpropane adduct), manufactured by Takeda Pharmaceutical Co., Ltd.

[0056]

[Table 2]

[0057]

[Table 3]

Substrate: PET (polyethylene terephthalate) film thickness; 25 μ PU (polyurethane) film thickness; 50 μ paper film thickness; 30 μ * N. C. : Non-creep * S. D. : Slip down

From the above results, the polyurethane pressure-sensitive adhesive of the present invention has no gelation and no turbidity of the resin solution when two kinds of catalysts are used in combination, and is synthesized in the presence of a tackifier. And an adhesive having excellent compatibility is obtained. It is understood that the coated product using the urethane pressure-sensitive adhesive composition has excellent adhesive strength, holding power, and removability.

[0060]

The polyurethane pressure-sensitive adhesive composition of the present invention is
Gelation by using two types of catalysts in the synthesis,
The resin solution does not become turbid and a resin having a high cohesive force can be obtained. In addition, less adhesive residue than acrylic adhesives,
A coating having excellent removability can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08G 18/64 C08G 18/64 F term (Reference) 4J004 AA14 AA17 AB01 CA02 CA04 CA06 CB02 CB04 CC02 EA05 FA01 FA10 4J034 BA03 DC06 DF11 DF12 DF16 DF21 DG02 DG03 DG04 HA01 HA07 HA08 HA13 HC03 HC08 HC12 HC22 JA43 JA44 KA01 KC17 KD04 QB19 QC03 RA07 RA08 SA01 SB04 SB05 SC03 4J040 EF101 EF102 EF111 EF131 EF132 EF141 EF142 EF141 EF142 EF141 EF142 EF141 EF142 EF141 EF142 EF141 EF142 EF142 EF141 EF142 LA01 LA06 MA09 MA10 MB01 MB03 QA01 QA05

Claims (14)

[Claims] 1. A polyurethane reactant obtained by reacting a polyester polyol, a polyether polyol, and an organic polyisocyanate with two types of catalysts in the presence of a tackifier having a functional group capable of reacting with an isocyanate group. A polyurethane pressure-sensitive adhesive composition comprising (A) and a polyfunctional isocyanate compound (B). 2. At least one of the two catalysts is
The polyurethane pressure-sensitive adhesive composition according to claim 1, which is an organometallic compound. 3. The method according to claim 1, wherein at least one of the two catalysts is
The polyurethane pressure-sensitive adhesive composition according to claim 1, which is an organic tin compound. 4. The polyurethane pressure-sensitive adhesive composition according to claim 1, wherein the two kinds of catalysts are tin 2-ethylhexanoate and dibutyltin dilaurate. 5. The weight ratio of tin 2-ethylhexanoate to dibutyltin dilaurate is such that tin 2-ethylhexanoate / dibutyltin dilaurate <1.
The polyurethane pressure-sensitive adhesive composition according to the above. 6. The polyurethane reactant (A) wherein the tackifier is a polyurethane reactant (A).
The polyurethane pressure-sensitive adhesive composition according to claim 1, wherein the content is 5 to 40% by weight. 7. The temperature at which the polyurethane reactant (A) is obtained,
7. The temperature is not higher than 100 ° C.
The polyurethane pressure-sensitive adhesive composition according to any one of the above. 8. The polyester polyol according to claim 1, wherein a part or all of the polyester polyol has a molecular weight of 2,000 to 4,000 and has at least three or more hydroxyl groups in one molecule. Polyurethane pressure-sensitive adhesive composition. 9. The polyether polyol according to claim 1, wherein a part or all of the polyether polyol has a molecular weight of 2,000 to 4,000 and has at least three or more hydroxyl groups in one molecule. The polyurethane pressure-sensitive adhesive composition according to the above. 10. A coated product of the polyurethane pressure-sensitive adhesive composition according to claim 1. 11. The coated article according to claim 10, wherein the substrate is a plastic film or a plastic sheet. 12. The coated article according to claim 10, wherein the substrate is polyurethane. 13. The coated article according to claim 10, wherein the substrate is paper. 14. The coated article according to claim 10, wherein the substrate is a polyurethane foam.