JP3234157B2 - Polyurethane adhesive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a solventless polyurethane adhesive composition. More particularly, the present invention relates to a two-component solventless polyurethane adhesive composition which is suitably used particularly for laminating a polyester film and a polyvinyl chloride film or sheet.

[0002]

2. Description of the Related Art Polyurethane adhesives used for bonding plastic films or sheets include:
A two-component solvent-type adhesive comprising a urethane prepolymer having a free isocyanate group and a polyol (for example, JP-A-63-196678), a polyurethane polyisocyanate using a polyol or a polyurethane polyol and an aromatic polyisocyanate; Two-component non-solvent adhesive (for example, JP-A-3-182584)
No. 1).

[0003]

However, the above-mentioned ones have problems in working safety due to the organic solvent contained in the adhesive composition, and the above-mentioned ones have problems in terms of weather resistance and hot water resistance. there were.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that by using a combination of a main component and a curing agent having a specific composition, adhesion, flexibility, transparency, The present inventors have found that a two-component solventless polyurethane adhesive having excellent weather resistance, warm water resistance and work safety can be obtained, and have reached the present invention.

That is, the present invention provides a number average molecular weight of 800 to
A main agent (A) comprising a urethane prepolymer having a terminal isocyanate group obtained from a polyol (a1) of 3,000 and an aliphatic and / or alicyclic polyisocyanate (a2), and a number average molecular weight of 1,000 to 3, 000 of a polydiene polyol (b1) having a terminal hydroxyl group-containing derivative (b2);
(B2) at least one solvent-free polyurethane selected from the group consisting of a modified polydiene polyol with a polyisocyanate containing an isocyanurate ring and a modified polydiene polyol with a polyisocyanate containing a burette bond. Adhesive composition; polyol having a number average molecular weight of 800 to 3,000 (a
1) a main agent (A) comprising a terminal isocyanate group-containing urethane prepolymer obtained from an aliphatic and / or alicyclic polyisocyanate (a2), and a polydiene polyol having a number average molecular weight of 1,000 to 3,000 ( b
1) and / or a curing agent (B) comprising a terminal hydroxyl group-containing derivative thereof (b2); (b2) is a hydrogenated product of a polydiene polyol, and a modified product of a polydiene polyol with a polyisocyanate having an isocyanurate ring And at least one selected from the group consisting of modified polydiene polyols with burette-bonded polyisocyanates; and polyol (a1) comprising a mixture of two or more of polyether polyols, polyester polyols and polydiene polyols. A solvent-free polyurethane adhesive composition wherein at least 50% by weight of (a1) is polyoxytetramethylene glycol; and a polyester film and a polyvinyl chloride-based film or sheet, comprising: Agent group And a plastic film or sheet, or a plastic film or sheet and FRP or metal foil, using the adhesive composition according to any one of claims 1 to 6. It is a bonded body that is bonded.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The polyol (a1) used for the urethane prepolymer having terminal isocyanate groups constituting the main agent (A) in the present invention includes polyether polyols, polyester polyols, polydiene polyols and two or more of these. And mixtures thereof.
Examples of the polyether polyol include polyoxytetramethylene glycol obtainable by ring-opening polymerization of tetrahydrofuran, and low-molecular-weight polyols (bi- or tri-functional low-molecular-weight polyols having a molecular weight per hydroxyl group of usually 30 to 200, preferably 30 to 100, For example, ethylene glycol, propylene glycol, 1,4-butanediol,
Alkylene oxide (ethylene oxide, propylene oxide, tetrahydrofuran, etc.) adducts of 1,6-hexanediol, glycerin, trimethylolpropane, and mixtures of two or more thereof. Examples of the polyester polyol include dicarboxylic acids [aliphatic dicarboxylic acids (adipic acid, sebacic acid, maleic acid, dimer acid, etc.), aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, etc.) or ester-forming derivatives thereof (lower alkyl esters). , Halide, etc.)]
Condensed polyester polyols obtained by polycondensation with low molecular weight polyols exemplified as the starting materials for the polyether polyols, polylactone polyols obtained by ring-opening polymerization of lactones (such as polycaprolactone diol), and polycarbonate polyols (poly Hexamethylene carbonate diol and the like). As polydiene polyol, polybutadiene polyol, hydrogenated polybutadiene polyol,
Polyisoprene polyol, hydrogenated polyisoprene polyol and the like can be mentioned. Among these, preferred are polyether polyols and polydiene polyols, and particularly preferred are polyoxytetramethylene glycol among the polyether polyols and polybutadiene polyol among the polydiene polyols. When two or more polyols are used in combination, it is preferable that at least 50% by weight of the polyol is polyoxytetramethylene glycol in terms of warm water resistance.

The number average molecular weight of the polyol (a1) is usually from 800 to 3,000, preferably from 1,000 to 2,500.
0. When the number average molecular weight is less than 800, there is a problem that the flexibility of the obtained adhesive composition is reduced, and 3,000
If it exceeds, the adhesiveness to the substrate will be reduced.

The aliphatic and / or alicyclic polyisocyanate (a2) used for the urethane prepolymer having a terminal isocyanate group includes hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMDI), lysine diisocyanate (LDI) and the like. Aliphatic diisocyanates such as dicyclohexylmethane diisocyanate (HMDI), isophorone diisocyanate (IPDI), 1,4-cyclohexane diisocyanate (CHDI), hydrogenated xylene diisocyanate (HXDI), and hydrogenated tolylene diisocyanate (HTDI) Formula diisocyanates; and mixtures of two or more of these. Preferred among these are IPDI, HMDI and HDI, and particularly preferred are IPDI and HDI.

The equivalent ratio of the hydroxyl group of (a1) to the isocyanate group of (a2) is usually 1: (1.5 to 1.5
2.5), preferably 1: (1.8-2.2).
When the equivalent ratio is less than 1.5, the urethane prepolymer has a high viscosity, and when it exceeds 2.5, on the contrary, the urethane prepolymer has a too low viscosity. In either case, the coating workability is not preferable. The reaction temperature of the urethane prepolymerization is usually 50 to 100 ° C. In the reaction of the urethane prepolymer, if necessary, a known urethane polymerization catalyst (such as dibutyltin dilaurate) can be added to accelerate the reaction. The free isocyanate group (NCO) content of the urethane prepolymer is usually 1 to 8% by weight, preferably 2 to 6% by weight.

In the present invention, the viscosity of the main agent (A) (25)
℃) is usually 50 to 800 Pa · s, preferably 80 to 6
00 Pa · s. If the viscosity of (A) is less than 50 Pa · s, the thickness of the adhesive layer becomes partially non-uniform when the film is wound up after laminating various plastic films, and if it exceeds 800 Pa · s, the coating surface becomes uneven. Workability decreases.

The curing agent (B) in the present invention comprises a polydiene polyol (b1) and / or a derivative (b2) containing a terminal hydroxyl group of the (b1). The (b
Examples of 1) include polybutadiene polyol, polyisoprene polyol, and a mixture thereof. Of these, polybutadiene polyol is preferable, and polybutadiene polyol having a 1,2-bond in the molecule is particularly preferable.

The number average molecular weight of (b1) is usually 1.0 or less.
00 to 3,000, preferably 1,100 to 2,500
It is. When the number average molecular weight is less than 1,000, there is a problem that the flexibility of the obtained adhesive layer is reduced.

The terminal hydroxyl group-containing derivative (b2) of (b1) includes a partially or completely hydrogenated product of (b1), a modified product of (b1) with a polyisocyanate containing an isocyanurate ring, and a buret bond of (b1) And a modified product of the polyisocyanate.
Partially or completely hydrogenated polybutadiene polyol and partially or completely hydrogenated polyisoprene polyol are examples of the partially or completely hydrogenated product of (b1). The modified product of (b1) with the isocyanurate ring-containing polyisocyanate can be obtained by reacting (b1) with the isocyanurate ring-containing polyisocyanate. The isocyanurate ring-containing polyisocyanate can be obtained, for example, by adding a catalyst [eg, alkoxide (eg, sodium methylate), amine (eg, triethylamine), carboxylate (eg, calcium naphthenate), an organometallic compound (eg, dibutyltin dilaurate) to the above-mentioned (a2). etc)
Etc.] alone or in combination of two or more, and the reaction is usually carried out at a reaction temperature of 50 to 150 ° C. The reaction equivalent ratio of the hydroxyl group of (b1) to the isocyanate group of the isocyanurate ring-containing polyisocyanate in the modified product is usually 1: (0.1 to 0.7), preferably 1: (0.2 to 0). .6). The reaction temperature is usually 5
The reaction is carried out at 0 to 100 ° C., and a known urethane polymerization catalyst (such as dibutyltin dilaurate) can be added as required to accelerate the reaction. O of the modified product
H equivalent is usually 500-3,000, preferably 700-
2,500. Further, the modified product of the polyisocyanate containing a burette bond (b1) is the above-mentioned (b1)
With a burette-bonded polyisocyanate. The burette-containing polyisocyanate can be obtained, for example, by a method of removing excess (a2) after the burette conversion reaction using 3 mol or more of water per 1 mol of (a2) described above. The reaction can be usually performed by using a strong base (such as tertiary amine such as triethyldiamine) and an organic metal compound (such as dibutyltin dilaurate) as a catalyst at a reaction temperature of usually 50 to 150 ° C. The reaction equivalent ratio of the hydroxyl group of (b1) to the isocyanate group of the polyisocyanate containing a burette bond in the modified product is usually 1: (0.1
-0.7), preferably 1: (0.2-0.6). The reaction temperature is usually 50 to 100 ° C. In the reaction, if necessary, a known urethane polymerization catalyst (such as dibutyltin dilaurate) can be added to accelerate the reaction. The OH equivalent of the modified product is usually 500 to 3,000.
0, preferably 700 to 2,500.

Preferred as (B) are modified products of polydiene polyols with polyisocyanates containing isocyanurate rings and modified polydiene polyols with polyisocyanates containing burette bonds.
Particularly preferred are modified products of polydiene polyols with polyisocyanates containing isocyanurate rings.

The viscosity (25 ° C.) of the curing agent (B) is usually 50
To 800 Pa · s, preferably 80 to 600 Pa · s. When the viscosity of (B) is less than 50 Pa · s, the thickness of the adhesive layer becomes partially non-uniform at the time of film winding after laminating various plastic films, and 800 Pa
If it exceeds s, the workability in the process such as unevenness of the coating surface will decrease.

In the present invention, the equivalent ratio of the isocyanate group of (A) to the hydroxyl group of (B) is usually 1:
(0.4-1), preferably 1: (0.5-0.9). If the equivalent of (B) is less than 0.4 or more than 1, the adhesiveness (peel strength) will be reduced.

In the present invention, a catalyst (C) can be used if necessary for the purpose of accelerating the curing reaction between the main agent (A) and the curing agent (B). Examples of the (C) include potassium or sodium salts of alkyl phosphonic acids;
Sodium, potassium, nickel, cobalt, cadmium, barium, calcium of fatty acids having 8 to 20 carbon atoms,
Metal salts such as zinc; organics such as dibutyltin dilaurate, dioctyltin maleate, dibutyldibutoxytin, bis (2-ethylhexyl) tin oxide, 1,1,3,3-tetrabutyl-1,3-diacetoxydistannoxane A tin compound; and a mixture of two or more thereof. Particularly preferred among these are dibutyltin dilaurate and dioctyltin maleate.

The amount of the catalyst (C) used is usually 0.001 to 0.05 with respect to the total weight of the main agent (A) and the curing agent (B).
% By weight, preferably 0.005 to 0.03% by weight.

The adhesive composition of the present invention may contain additives such as known antioxidants and ultraviolet absorbers, if necessary. The amount of the additive is usually 0.1 to 3% by weight, preferably 0.5 to 2% by weight based on the weight of the adhesive composition.
% By weight.

The polyurethane adhesive composition of the present invention is used for bonding various plastic films or sheets to each other or for bonding these to other members. In particular, a polyester film used for decorative interior and a polyvinyl chloride-based material are used. It is suitably used for laminating with a film or sheet. The adhesive composition is also useful for bonding various plastic films or sheets to FRP (such as a fiber-reinforced unsaturated polyester resin molded product) and metal foil (such as aluminum foil and copper foil). It can also be suitably used as a building material or the like which requires the above, and as an adhesive for electromagnetic wave shielding in the field of electric and electronic devices.

A nip roll device, a gravure coating device, a reverse coating device, or the like is used for coating the adhesive composition on the plastic film or sheet. The coating amount is usually 5 to 50 g / m ²
It is. The laminated film or sheet is usually cured at room temperature to 50 ° C. for about 50 hours.

[0022]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto. In the following, "parts" indicates parts by weight and "%" indicates% by weight.

Example 1 A 1-liter volume 4 equipped with a stirrer, thermometer and nitrogen inlet tube
In a mouth mouth corben, 659 parts of polyoxytetramethylene glycol “PTMG-2000” (manufactured by Sanyo Chemical Industries, number average molecular weight 2,000), 141 parts of isophorone diisocyanate and 0.06 part of dibutyltin dilaurate were charged, and 95 parts of nitrogen was supplied. The reaction was carried out at a temperature of 5 ° C. for 5 hours to obtain an urethane prepolymer containing an isocyanate group having a terminal isocyanate group having an NCO content of 3.3% and a viscosity of 150 Pa · s (25 ° C.). In a similar reaction vessel, polybutadiene polyol "G-100"
900 (manufactured by Nippon Soda, hydroxyl value: 71) and an isocyanurate ring-containing polyisocyanate "Duranate TPA-100" (manufactured by Asahi Kasei Corporation, NCO content: 23.
4%) 31 parts and dibutyltin dilaurate 0.06 parts were charged and reacted at 95 ° C. for 5 hours under a nitrogen stream.
2.5 parts of “Irganox 1076” (manufactured by Ciba-Geigy, antioxidant) and 5 parts of “Tinuvin P” (manufactured by Ciba-Geigy, ultraviolet absorber) were mixed and dissolved at 80 ° C. for 1 hour, and the hydroxyl value was 60 and the viscosity was 180 Pa · s (2
(5 ° C.). 100 parts of the main agent, curing agent 53
Part and 0.01 part of dibutyltin dilaurate were uniformly mixed to prepare an adhesive of the present invention. Apply this adhesive to thickness 1
A 90 μm flexible polyvinyl chloride sheet was coated on the surface so as to have a coating amount of 10 g / m ^2, and a 30 μm-thick surface-untreated polyethylene terephthalate film was adhered to the surface with a nip roll and cured at 45 ° C. for 50 hours. Table 1 shows the performance evaluation results.

Example 2 387 parts of polyoxytetramethylene glycol “PTMG-2000” (manufactured by Sanyo Chemical Industries, number average molecular weight 2,000) and polybutadiene polyol “G-1000” (reacted in the same reactor as in Example 1) Nippon Soda, hydroxyl value 71) 258 parts and isophorone diisocyanate 15
5 parts and 0.06 part of dibutyltin dilaurate were charged and reacted at 95 ° C. for 5 hours under a nitrogen stream to obtain a main component of a terminal isocyanate group-containing urethane prepolymer having an NCO content of 3.6% and a viscosity of 250 Pa · s (25 ° C.). Obtained. In a similar reaction vessel, polybutadiene polyol "G-100"
0 (manufactured by Nippon Soda, hydroxyl value: 71) and 900 parts of burette-containing polyisocyanate "Duranate 2"
4A-100 "(manufactured by Asahi Kasei Corporation, NCO content: 23.2)
%) 31 parts and dibutyltin dilaurate 0.06 part were reacted under a nitrogen stream at 95 ° C. for 5 hours, and then 2.5 parts of “Irganox 1076” (manufactured by Ciba Geigy, antioxidant) and “tinuvin P” (Ciba Geigy,
5 parts of an ultraviolet absorber were mixed and dissolved at 80 ° C. for 1 hour, and the hydroxyl value was 60 and the viscosity was 150 Pa · s (25
C). The adhesive of the present invention was prepared by uniformly mixing 100 parts of the main agent, 58 parts of the curing agent and 0.01 part of dibutyltin dilaurate. Apply this adhesive to a thickness of 19
10 μm on the surface of a soft polyvinyl chloride sheet of 0 μm
g / m ² and a thickness of 3
A 0 μm surface-untreated polyethylene terephthalate film was bonded with a nip roll and cured at 45 ° C. for 50 hours. Table 1 shows the performance evaluation results.

Example 3 In the same reactor as in Example 1, polypropylene glycol "Sanix PP-2000" (manufactured by Sanyo Chemical Industries, Ltd.)
259 parts of number average molecular weight (2,000), 200 parts of polyoxytetramethylene glycol “PTMG-2000” (manufactured by Sanyo Chemical Industries, number average molecular weight of 2,000), 200 parts, polyoxytetramethylene glycol “PTMG-1000”
(Manufactured by Sanyo Chemical Industries, number average molecular weight 1,000) 200
Parts, isophorone diisocyanate (190 parts) and dibutyltin dilaurate (0.06 part) were charged under a nitrogen stream.
C. for 5 hours, NCO content 5.3%, viscosity 190
A main agent of a urethane prepolymer having a terminal isocyanate group of Pa · s (25 ° C.) was obtained. In a similar reaction vessel, 900 parts of a hydrogenated polybutadiene polyol "GI-1000" (manufactured by Nippon Soda, hydroxyl value 69) and an isocyanurate ring-containing polyisocyanate "Duranate TPA-10"
No. 0 "(manufactured by Asahi Kasei Corporation, NCO content: 23.4%) and 30 parts of dibutyltin dilaurate were charged and reacted at 95 ° C. for 5 hours under a nitrogen stream, and then“ Irganox 1076 ”(manufactured by Ciba Geigy, 2.5 parts of antioxidant) and 5 parts of “Tinuvin P” (manufactured by Ciba Geigy, ultraviolet absorber) were charged and mixed and dissolved at 80 ° C. for 1 hour to obtain a curing agent having a hydroxyl value of 57 and a viscosity of 200 Pa · s (25 ° C.). Obtained. The adhesive of the present invention was prepared by uniformly mixing 100 parts of the main agent, 75 parts of the curing agent and 0.01 part of dibutyltin dilaurate. This adhesive was coated on the surface of a 190 μm-thick flexible polyvinyl chloride sheet so that the coating amount became 10 g / m ^2, and a 30 μm-thick surface-untreated polyethylene terephthalate film was stuck on the surface with a nip roll. Cured for hours. Table 1 shows the performance evaluation results.

Comparative Example 1 In a reaction apparatus similar to that in Example 1, 659 parts of polyoxytetramethylene glycol "PTMG-2000" (manufactured by Sanyo Chemical Industries, number average molecular weight: 2,000), 141 parts of isophorone diisocyanate and dibutyltin dilaurate were used. 0.06 parts were charged and reacted at 95 ° C. for 5 hours under a nitrogen stream, NCO content 3.3%, viscosity 35 Pa · s (25 ° C.)
Of a urethane prepolymer having a terminal isocyanate group was obtained. 100 parts of the main agent and “San Ester 24625Y” as a curing agent (manufactured by Sanyo Chemical Industries, polyethylene butylene adipate diol, number average molecular weight 2,500)
70 parts and 0.01 part of dibutyltin dilaurate were charged and uniformly mixed to prepare a comparative adhesive. Using this adhesive, a bonded sheet was prepared in the same manner as in Example 1. Table 1 shows the performance evaluation results.

Comparative Example 2 685 parts of polyoxytetramethylene glycol "PTMG-2000" (manufactured by Sanyo Chemical Industries, number average molecular weight: 2,000) and 115 parts of tolylene diisocyanate were charged into the same reactor as in Example 1. 80 ° C under nitrogen stream
For 5 hours, NCO content 3.2%, viscosity 20Pa
A main agent of a urethane prepolymer having an isocyanate group at a terminal of s (25 ° C.) was obtained. 100 parts of this base material, Example 1
46 parts of the same curing agent and 0.01 part of dibutyltin dilaurate were uniformly mixed to prepare a comparative adhesive.
Using this adhesive, a bonded sheet was prepared in the same manner as in Example 1. Table 1 shows the performance evaluation results.

The performance evaluation items and evaluation methods in Table 1 are as follows. Transparency: The appearance of the laminated sheet must be transparent.
(Visual evaluation) Flexibility: No cracking, cracking, peeling, etc. occurs when the laminated sheet is bent or stressed. (Visual evaluation) Adhesion: Peel strength (180 ° peel peel strength, tensile speed 100 mm / min, unit: Kg) with an adhesive strength measuring device
f / 25 mm). Warm water resistance: Peel strength after immersion in warm water of 60 ° C. for 24 hours (180 ° peel peel strength, pulling speed 100 mm
/ Min, unit: Kgf / 25 mm). Weather resistance: 1,000 hours of xenon weather meter irradiation [irradiation conditions: 60 ° C (black panel temperature) x 60%
RH, irradiation 102 minutes / rainfall + irradiation 18 minutes] without yellowing (things that slightly yellowed were referred to as “yellowing”).

[0029]

[Table 1]

[0030]

The solvent-free polyurethane adhesive composition of the present invention has the following features as compared with conventional ones. (1) Since no organic solvent is contained, work safety can be ensured. (2) Good adhesiveness, flexibility, transparency, weather resistance, warm water resistance and the like. (3) Sufficient adhesion can be obtained without pretreatment (primer treatment, plasma or corona discharge treatment, etc.) of the adherend. Due to the above effects, the polyurethane adhesive composition of the present invention is a laminate adhesive of a polyester film and a polyvinyl chloride film or sheet, particularly a polyester film and a polyvinyl chloride film or sheet used for decorative interior. It can be suitably used for laminating the composite sheet. Also FRP
(Fiber-reinforced unsaturated polyester resin molded product, etc.), metal foil (aluminum foil, copper foil, etc.) and polyester film or polyvinyl chloride film or sheet is also useful, especially building materials that require design And an adhesive for electromagnetic wave shielding in the field of electric and electronic devices.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08G 18/10 C08G 18/10 18/69 18/69 18/72 18/72 C09J 175/08 C09J 175/08 // C08J 5 / 12 CEV C08J 5/12 CEV CFD CFD (56) References JP-A-58-122977 (JP, A) JP-A-60-173011 (JP, A) JP-A-51-81833 (JP, A) JP-A-57-185314 (JP, A) JP-A-58-213072 (JP, A) JP-A-2-274788 (JP, A) JP-A-4-202283 (JP, A) JP-A-63-95282 (JP, A) JP-A-59-230076 (JP, A) JP-A-57-42781 (JP, A) JP-A-63-196678 (JP, A) JP-A-3-182584 (JP, A) 54-8307 (JP, A) JP-A-3-12473 (JP, A) JP-A-1-138218 (JP, A) JP 56-82864 (JP, A) JP-A-53-40392 (JP, A) JP-A-61-287977 (JP, A) JP-A 64-60678 (JP, A) JP-A-1-207373 (JP, A) A) JP-A-2-127491 (JP, A) JP-A-2-182774 (JP, A) JP-A-3-81316 (JP, A) JP-A-3-205473 (JP, A) JP-A-50 JP-A-51143 (JP, A) JP-A-49-81453 (JP, A) JP-A-57-38850 (JP, A) JP-A-50-8851 (JP, A) JP-A-54-95640 (JP, A) JP-A-6-128347 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09J 175/00-175/16 C08G 18/00-18/87

Claims (8)

(57) [Claims] A main agent (A) comprising a terminal isocyanate group-containing urethane prepolymer obtained from a polyol (a1) having a number average molecular weight of 800 to 3,000 and an aliphatic and / or alicyclic polyisocyanate (a2). , A terminal hydroxyl group-containing derivative (b2) of a polydiene polyol (b1) having a number average molecular weight of 1,000 to 3,000
At least one member selected from the group consisting of a modified product of a polydiene polyol with an isocyanurate ring-containing polyisocyanate and a modified product of a polydiene polyol with a burette-bond-containing polyisocyanate Solventless polyurethane adhesive composition characterized by the following. 2. The method according to claim 1, wherein the polyol (a1) is a polyether polyol or a polyol mixture comprising a polyether polyol and a polydiene polyol, and at least 50% by weight of (a1) is polyoxytetramethylene glycol. Adhesive composition. 3. A main component (A) comprising a terminal isocyanate group-containing urethane prepolymer obtained from a polyol (a1) having a number average molecular weight of 800 to 3,000 and an aliphatic and / or alicyclic polyisocyanate (a2). A curing agent (B) comprising a polydiene polyol (b1) having a number average molecular weight of 1,000 to 3,000 and / or a terminal hydroxyl group-containing derivative (b2) thereof;
(B2) is at least one selected from the group consisting of hydrogenated polydiene polyols, modified polydiene polyols with isocyanurate ring-containing polyisocyanates, and modified polydiene polyols with burette-bonded polyisocyanates; The polyol (a1) comprises a mixture of two or more of polyether polyol, polyester polyol and polydiene polyol, and at least 50% by weight of (a1)
Is a solvent-free polyurethane adhesive composition wherein is polyoxytetramethylene glycol. 4. The reaction equivalent ratio of the hydroxyl group of the polydiene polyol to the isocyanate group of the isocyanurate ring-containing polyisocyanate in the modified product of the polydiene polyol with the isocyanurate ring-containing polyisocyanate is 1: (0.1 to 0.1.%). 7), wherein the reaction equivalent ratio of the hydroxyl group of the polydiene polyol to the isocyanate group of the burette-bonded polyisocyanate in the modified product of the polydiene polyol with the burette-bonded polyisocyanate is 1: (0.1 to 0.1. 7)
The adhesive composition according to any one of claims 1 to 3, wherein 5. The adhesive composition according to claim 1, wherein the equivalent ratio of the isocyanate group of (A) to the hydroxyl group of (B) is 1: (0.4 to 1). 6. The adhesive composition according to claim 1, further comprising a catalyst (C). 7. A laminate bonded body obtained by laminating a polyester film and a polyvinyl chloride film or sheet using the adhesive composition according to claim 1. 8. A plastic film or sheet, or a plastic film or sheet and FR
An adhesive body formed by bonding P or a metal foil using the adhesive composition according to any one of claims 1 to 6.