JPH10110153A - Moisture-setting type hot melt adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a moisture-setting type hot melt adhesive excellent in heatresistant adhesion, resistance to oil and solvents, and adhesion to steel plate and polar adherends, such as polyvinyl chloride. SOLUTION: This adhesive composition is obtained by reacting a block polyol having both polyester and polyamide blocks with a polyisocyanate compound or a compound having hydrolyzable silyl group at the molecular terminal. It has at least both polyester and polyamide blocks in the molecular skeleton, and consists mainly of a urethane prepolymer having isocyanate or hydrolyzable silyl group at the molecular terminal, or prepolymer containing hydrolyzable silyl group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a moisture-curable hot melt adhesive composition containing a urethane prepolymer having an isocyanate group at a molecular terminal or a prepolymer having a hydrolyzable silyl group at a molecular terminal, and more particularly to the invention. Is a moisture-curable hot-melt adhesive that has excellent durability after moisture-curing, oil resistance and heat-resistant adhesiveness, and excellent adhesion to various polar adherends such as steel plates and polyvinyl chloride. Agent composition.

[0002]

2. Description of the Related Art Hitherto, a moisture-curable adhesive using a urethane prepolymer obtained by reacting a polyol compound such as a polyester polyol, a polyether polyol or a hydrocarbon-based polyol with an isocyanate compound has been known (for example, see, for example, Japanese Patent Application Laid-Open No. H11-157556). JP-A-63-18948
6, JP-A-2-16180, JP-A 2-2
9483, JP-A-2-32189, JP-A-3-32
No. 285982).

[0003] In the moisture-curable adhesive, the physical properties of the adhesive are controlled by selecting a polyol compound to be used or by variously combining the polyol compounds.
However, in a conventional moisture-curable adhesive, when a polyol compound, for example, a polyether-based polyol is used, not only the initial cohesive strength is not sufficient, but also the heat-resistant adhesive strength (the heat resistance of the cured adhesive product) is low. In addition, when a polyester-based polyol is used, there is a problem that the adhesive cured product lacks oil resistance.

On the other hand, conventionally, various moisture-curable adhesives using a prepolymer having a hydrolyzable silyl group at a molecular terminal have been proposed. For example, a method for producing a polyether having an alkoxysilyl group at a molecular terminal (Japanese Patent Application Laid-Open No.
No. 137129) and a moisture-curable hot-melt adhesive made of a urethane prepolymer having an active silyl group at a molecular terminal comprising a skeleton derived from a polyester polyol and a skeleton derived from a hydrocarbon-based resin (JP-A-4-145187). Have been.

However, since the moisture-curable adhesive obtained by the above method is liquid at room temperature, after the adhesive is applied to the adherend, the clip is held in place so that the bonded object does not shift until it is cured by moisture. It is necessary to fix using a jig such as the above, and the bonding operation is complicated.

Further, in the moisture-curable hot-melt adhesive using the urethane prepolymer, the terminal is silylated based on two kinds of poorly compatible polyols. Due to poor solubility and thixotropy, it was not possible to apply uniformly with a thickness of 100 μm or less, and the adhesion stability was not sufficient.

In addition, in any of the above-mentioned moisture-curable adhesives, as in the case of the urethane prepolymer-based moisture-curable hot-melt adhesive described above, the physical properties of the adhesive are determined by the selection and combination of the polyol compound used. Was controlled. However, when the polyether polyol is used, not only the initial cohesion is not sufficient, but also the heat-resistant adhesive strength is low, and when the polyester polyol is used, the adhesiveness to metal decreases. However, there are problems such as insufficient oil resistance of the cured adhesive.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the conventional moisture-curable hot-melt adhesive, and to provide an adhesive cured product having excellent oil resistance, chemical resistance and heat-resistant adhesive strength. Another object of the present invention is to provide a moisture-curable hot-melt adhesive composition having excellent adhesion to polar adherends such as steel plates and polyvinyl chloride.

[0009]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, in a moisture-curable hot melt adhesive using a urethane prepolymer, a polyol used for synthesizing the urethane prepolymer was used. As a result of paying attention to the structure, the inventors have found that the above object can be achieved by using a block polyol having both a polyamide block and a polyester block, and have accomplished the present invention.

That is, the first aspect of the present invention provides a moisture-curable adhesive comprising a urethane prepolymer having at least a polyester block and a polyamide block in a molecular skeleton and having an isocyanate group at a molecular terminal. Agent composition.

[0011] The present inventors have also found that a moisture-curable hot-melt adhesive containing a prepolymer having a hydrolyzable silyl group at the molecular end also has a main chain structure at the time of synthesizing the moisture-curable prepolymer. As a result of attention, it has been found that the above problem can be solved by using a moisture-curable prepolymer obtained from a block polyol having both a polyamide block and a polyester block and an organic silane compound, and the present invention has been accomplished.

According to a second aspect of the present invention, there is provided a moisture-curable type comprising a prepolymer having at least a polyester block and a polyamide block in a molecular skeleton and having a hydrolyzable silyl at a molecular terminal. It is a hot melt adhesive composition.

In any of the first and second aspects of the present invention, the polyamide block is preferably made of aliphatic nylon. Also,
In any of the first and second aspects of the present invention, preferably, as described in the fourth aspect, the polyester block is made of an aliphatic polyester.

More preferably, in any of claims 1 and 2, the polyamide block is made of aliphatic nylon and the polyester block is made of aliphatic polyester. You.

Hereinafter, the present invention will be described in detail. Block polio used in the invention according to claims 1 and 2.
The invention described in Lumpur claim 1 is characterized and the block polyols containing polyester component and a polyamide component, comprises a urethane prepolymer obtained by reacting an isocyanate compound. The invention described in claim 2 is characterized in that it comprises a moisture-curable prepolymer obtained by reacting a block polyol containing a polyester component and a polyamide component with an organic silane compound.

The block polyol used for obtaining the adhesive according to the first and second aspects of the present invention is prepared by, for example, dissolving a polyamide component in a polyester component and then esterifying the polyester component. And then polycondensation under reduced pressure. Further, the resin obtained as described above is heated at a temperature of 30 ° C. below the melting point.
Solid-state polymerization may be performed at a temperature from a low temperature to a melting point under a pressure of 5 Torr or less. However, the method for producing the block polyol is not particularly limited.

Dicarboxylic acids and diols can be used as components for constituting the polyester used to obtain the above-mentioned block polyol. Examples of dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decamethylene dicarboxylic acid, dodecamethylene dicarboxylic acid, and the like. ,
The dicarboxylic acid is not limited to these, and various dicarboxylic acids can be appropriately used without impairing the object of the present invention.

The diol to be reacted with the dicarboxylic acid to constitute the block polyol is, for example, ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, neopentyl glycol, or the like. Examples thereof include 1,5-pentanediol and 1,6-hexanediol, but are not limited thereto, and other glycol components such as, for example,
1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,3 Glycols such as diol, cyclohexane-1,4-diol and cyclohexane-1,4-dimethanol, and polyalkylene oxides such as polyethylene oxide, polypropylene oxide, polytetramethylene oxide, and polyhexamethylene oxide. it can.

The polyester block formed by the reaction between the dicarboxylic acid and the diol has a low melting temperature of the obtained hot melt adhesive, and has a high cohesive strength when solidified and a good solid shape. Group polyesters are preferred.

In the present invention, the polyamide component in the block polyol is, for example, 4-nylon, 6-nylon, 6,6-nylon, 11-nylon, 12-nylon, 6,10-nylon, 6,12-nylon.
-Aliphatic nylons such as nylon, isophthalic acid, terephthalic acid, metaxylylenediamine, 2,2-bis (paraaminocyclohexyl) propane, 4,4'-diaminodicyclohexylmethane, 2,2,4-trimethylhexamethylenediamine And polyamides obtained by polycondensation of aromatic, alicyclic or side-chain-substituted aliphatic monomers such as 2,4,4-trimethylhexamethylenediamine. Of these, aliphatic nylons are preferred from the viewpoints of the low melting temperature of the obtained hot melt adhesive, the cohesive strength when solidified, and the maintenance of the solid shape.

The preferable ratio of the above-mentioned polyester component and polyamide component is 90:10 to 4 by weight.
0:60. If the amount of the polyamide component is less than 10% by weight, the adhesiveness may not be sufficient, and if it exceeds 60% by weight, the viscosity may be high and the use as a hot melt adhesive may be limited.

The urethane tamper according to the first aspect of the present invention.
Repolymer The urethane prepolymer used in the first aspect of the present invention is obtained by reacting the block polyol with an organic polyisocyanate compound.
In this case, the ratio of reacting the block polyol with the organic polyisocyanate compound is preferably such that [NCO] / [OH] = 1.3 to 2.5 in equivalent ratio, and at a temperature of 60 to 120 ° C. , For 2 to 12 hours. The equivalent ratio [NCO] / [OH]
If it is less than 1.3, the molecular weight of the prepolymer becomes too large, gelling may occur during the reaction with the isocyanate compound, or hot melt suitability (such as not melting by heating) may not be obtained. The terminal of the molecule becomes a hydroxyl group, resulting in a composition outside the scope of the present invention. If it exceeds 2.5, the remaining amount of the isocyanate monomer in the adhesive increases, so that a problem such as peeling due to carbon dioxide gas generated during moisture curing may occur.

Further, the polyisocyanate includes
Examples thereof include tolylene diisocyanate, diphenylmethane diisocyanate, liquid modified products of diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, cyclohexanephenylenediisocyanate, and naphthalene-1,5-diisocyanate. Among these polyisocyanates, it is preferable to use diphenylmethane diisocyanate and its liquid modified product from the viewpoints of vapor pressure, toxicity and ease of handling.

The prepolymer according to the second aspect of the present invention.
Hydrolyzable silyl group-containing prepolymer in the present invention according to chromatography claim 2, obtained by reacting the above block polyol, an organic silane compound, i.e.,
It can be obtained by reacting a functional group at the molecular end of the block polyol with a commercially available silane coupling agent as an organic silane compound, but the method itself is not particularly limited. As the hydrolyzable silyl group at the molecular end,

[0025]

Embedded image

[0026] However, in the above formula, X
Represents an alkoxy group and a = 0, 1, or 2, and Ra represents an alkyl group or hydrogen. For example, the terminal functional group of the block polyol can be silylated by various combinations shown in Table 1 below.

[0027]

[Table 1]

Examples of the silane coupling agent include γ-aminopropylmethyldiethoxysilane and γ-aminopropylmethyldiethoxysilane.
Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-aminoethylaminopropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, mercaptoethyl Examples thereof include triethoxysilane and γ-mercaptopropyltrimethoxysilane.

The moisture-curable hot-melt adhesive according to the invention described in the other additives according to claim 1 is characterized by comprising the urethane prepolymer or a hydrolyzable silyl group-containing prepolymer, the If desired, other urethane prepolymers, thermoplastic elastomers, tackifier resins, plasticizers, catalysts, fillers, dyes, pigments, etc. may be added as long as the objects of the invention are not impaired.

[0030] In using the moisture-curable hot-melt adhesive according to the invention described in the adhesive claim 1 and 2, a roll coater, a spray coater, may be used various coating devices such as a handgun. Further, upon bonding, the moisture-curable hot melt adhesive may be heated, melted, and applied to the adherend in various patterns, and the adhesive may be bonded before the adhesive is cured,
Alternatively, it may be heated again to activate and adhere after curing.

The adherend is not particularly limited, either.
Metal products such as iron, copper, aluminum, tin, stainless steel, painted steel plates, zinc steel plates; synthetic resin products such as polyethylene, polypropylene, acrylic resin, ABS resin, vinyl chloride resin, polycarbonate, nylon, polystyrene, polyurethane; Examples include wood, plywood, particle board, cardboard, paper, leather, cloth material, and the like.

The application temperature of the moisture-curable hot-melt adhesive according to the first and second aspects of the present invention is not particularly limited, and usually the temperature range in which this kind of hot-melt adhesive is applied is used. It is not particularly limited because it depends on the application, the type of the adherend and the bonding conditions. However, from the viewpoint of the viscosity and stability of the adhesive, preferably 70 to 150 ° C, more preferably 80 to 150 ° C.
It is preferable to apply the composition by heating and melting at a temperature of 130 ° C.

The method of activating the moisture-curable reactive hot-melt adhesive according to the first and second aspects of the present invention by heating includes simultaneously heating and activating the adhesive layer by a hot press or a hot roll press. A method for attaching an adherend can be generally used. However, the adherend to which the adhesive is applied is heated in a heating tank to thermally activate the adhesive layer, and then the adherend is taken out of the heating tank until the adhesive layer loses its activity (solidifies). Up to), a method of bonding the adherends under pressure may be used.

The heating activation temperature varies depending on the difference in the heating method, the type and thickness of the adherend, the amount and thickness of the applied adhesive, and the ambient temperature at which the bonding operation is performed. Although not particularly limited, in order to sufficiently activate, preferably 40 ° C to 200 ° C.
It is desirable to heat at ℃, more preferably 70 to 100 ℃ for several tens of seconds to a few minutes.

[0035]

The present invention will be clarified below by describing non-limiting examples of the present invention. In the following, parts mean parts by weight unless otherwise specified.

Example 1 146 parts of adipic acid, 108 parts of butylene glycol, and 125 of neopentyl glycol
Part (butylene glycol and neopentyl glycol in a molar ratio of 50:50) and 6-nylon (manufactured by Toyobo Co., Ltd.)
Trade name: T-850) To 40 parts, 0.25 part of tetrabutoxytitanium as a catalyst was added, and the mixture was heated at 200 ° C under a nitrogen atmosphere.
And the esterification reaction was carried out for 1 hour.
C., and a polycondensation reaction was performed for 1 hour under reduced pressure (1 mmHg or less) to obtain a transparent polyester polyamide block polyol. The hydroxyl value of this polyester polyamide block polyol was 32.

300 parts of the above block polyol and 700 parts of a polyester polyol (trade name: Dynacol 7360, manufactured by Huls, hydroxyl value = 30) are mixed in 150 parts.
Melt kneading under heating at ℃, reduced pressure to 1 mmHg or less,
Dehydrated. Then, after adjusting the temperature of the system to 100 ° C,
Under a nitrogen atmosphere, diphenylmethane diisocyanate (M
DI) [Mitsubishi Chemical Corporation, trade name: Isonate125
M], 134 parts. The equivalent ratio [NCO] / [OH] between the isocyanate group of the MDI and the hydroxyl group of the polyol (total of two kinds of polyols) is 2.0. After reacting for 3 hours, a crystalline solid urethane prepolymer was obtained at room temperature. This urethane prepolymer is used as the moisture-curable hot melt adhesive of Example 1.

Example 2 A polyester polyamide block polyol was obtained in the same manner as in Example 1 except that the amount of 6-nylon was changed to 80 parts. The hydroxyl value of this block polyol was 25.

Using 500 parts of the above block polyol, 500 parts of a polyester polyol (trade name: Nipporan N-165, manufactured by Nippon Polyurethane Co., hydroxyl value = 55), and 180 parts of MDI used in Example 1 Except for the above, a crystalline solid urethane prepolymer was obtained at room temperature in the same manner as in Example 1. This urethane prepolymer is used as the moisture-curable hot melt adhesive of Example 2.

Comparative Example 1 Polyester polyol (H
uls, trade name: Dynacol 7360, hydroxyl value = 30) 1000 parts were heated and melted at 120 ° C., and 1 mm
The pressure was reduced to Hg or less, and dehydration was performed. Then, add 10
After the temperature was adjusted to 0 ° C., MDI (manufactured by Mitsubishi Chemical Corporation, trade name: Isonate 125M) 134.4 under a nitrogen atmosphere.
The mixture was added ([NCO] / [OH] = 2.0) and reacted for 3 hours to obtain a crystalline solid urethane prepolymer at room temperature. This urethane prepolymer is used as the moisture-curable hot melt adhesive of Comparative Example 1.

Comparative Example 2 Polyester polyol (manufactured by Nippon Polyurethane Co., trade name: Nipporan N-165)
(Hydroxyl value = 55) 1000 parts and MD used in Example 1
A urethane prepolymer having a viscous tone at room temperature was obtained in the same manner as in Comparative Example 1 except that 246.4 parts of I was used.
This urethane prepolymer is used as a moisture-curable hot melt adhesive of Comparative Example 2.

Example 3 300 parts of the polyester polyamide block polyol obtained in Example 1 was mixed with a polyester polyol (Dynacol 736, manufactured by Huls).
(0, hydroxyl value = 30) 700 parts was melt-kneaded at 150 ° C. under heating, depressurized to 1 mmHg or less, and dehydrated. Thereafter, the temperature of the system was adjusted to 100 ° C., and then MDI (manufactured by Mitsubishi Chemical Corporation, trade name: Isonate 12) was performed under a nitrogen atmosphere.
5M) 134 parts ([NCO] / [OH] = 2.
0) The reaction was carried out for 3 hours, and further 102 parts of γ-aminopropyltriethoxysilane was added and reacted for 1 hour to obtain a prepolymer having a silyl group at a terminal. This prepolymer was used as the moisture-curable hot melt adhesive of Example 3.

(Example 4) 500 parts of the polyester polyamide block polyol obtained in Example 2, 500 parts of a polyester polyol (Nipporan N-165, manufactured by Nippon Polyurethane Co., Ltd., hydroxyl value = 55), and Example 3 A prepolymer having a terminal silyl group was obtained in the same manner as in Example 3, except that 180 parts of the MDI used in the above was used and that the amount of γ-aminopropyltriethoxysilane was 141 parts. This prepolymer was used as the moisture-curable hot melt adhesive of Example 4.

Comparative Example 3 Polyester polyol (H
uls Co., Ltd., trade name: Dynacol 7360, under hydroxyl group = 30), heated and melted at 120 ° C., 1 m
The pressure was reduced to mHg or less, and dehydration was performed. Then, change the system to 1
After the temperature was adjusted to 00 ° C., 134.4 parts of MDI used in Example 3 was added under a nitrogen atmosphere ([NCO] / [O
H] = 2.0) 3 hours, further added 101 parts of γ-aminopropyltriethoxysilane, and reacted for 1 hour to obtain a crystalline solid prepolymer at room temperature. This prepolymer is used as the moisture-curable hot melt adhesive of Comparative Example 3.

Comparative Example 4 Polyester polyol (manufactured by Nippon Polyurethane Co., trade name: Nipporan N-165)
Hydroxy value 55) 1000 parts, MDI used in Example 1 was used 246.4 parts, and γ-aminopropyltriethoxysilane 185 parts was used in the same manner as in Comparative Example 3 except that a viscous mixture was obtained at room temperature. A urethane prepolymer was obtained. This urethane prepolymer was used as a moisture-curable hot melt adhesive of Comparative Example 4.

Evaluation of Examples and Comparative Examples The performance of each of the moisture-curable hot melt adhesive compositions of Examples 1 to 4 and Comparative Examples 1 to 4 obtained as described above was evaluated in the following manner.

(1) Preparation of Adhesive Sample The adhesive composition was applied to a 3 mm-thick soft vinyl chloride plate at 120 ° C. using a hand gun so that the application amount was 50 g / m ² . A pentite steel sheet was overlaid on the above-mentioned soft vinyl chloride sheet so that the overlapping area was 25 × 25 mm ² , hot-pressed at 80 ° C. for 20 seconds, immediately cooled and solidified by a normal-temperature press, and bonded. The press pressure is 0.5 kg / c in both the hot press and the room temperature press.
It was m ^2.

(2) Evaluation of Normal Adhesive Strength After the adhesive sample obtained as described above was cured for 72 hours in an atmosphere of 20 ° C. and a relative humidity of 65%, a pulling speed of 200 mm / min was determined by an autograph. At 180 ° C. at a temperature of 20 ° C.

(3) Evaluation of adhesive strength during heating The above adhesive sample was cured for 72 hours in an atmosphere of 20 ° C. and a relative humidity of 65%, left for 1 hour in an atmosphere of 80 ° C., and then left in an atmosphere of 80 ° C. The 180 ° peel strength was measured in the same manner as in the evaluation of the normal adhesive strength in (2).

(4) Evaluation of physical properties of the cured adhesive After each adhesive composition was heated and melted at 120 ° C., it was coated and shaped into a release sheet having a surface having a release treatment so as to have a thickness of 1 mm. Curing was performed for 7 days under an atmosphere of 20 ° C. and 65% relative humidity to obtain a cured film of each adhesive composition. The obtained cured film was drawn out into a No. 2 dumbbell shape, and the breaking strength was measured.

The evaluation results are shown in Table 2 below.

[0052]

[Table 2]

In Table 2, MI indicates breakage at the interface between the steel sheet and the adhesive, and PI indicates that breakage occurred at the interface between the polyvinyl chloride plate and the adhesive. In addition, solid indicates that the adhesive was cohesively broken, and * indicates that the polyvinyl chloride plate was broken.

As is clear from Table 2, the moisture-curable hot-melt adhesive of Comparative Example 1 obtained by reacting a polyester polyol with a polyisocyanate compound has a low normal adhesive strength of 8.2 kg / cm, Adhesive strength is as low as 5.3 kg / cm ² and the breaking strength is 270.
kg / cm ² (20 ° C.), 160 kg / cm ² (80
° C), whereas Example 1 corresponding to Comparative Example 1
Then, normal adhesive strength, hot adhesive strength, 20 ° C and 8
It can be seen that sufficient adhesive strength was obtained at any of the breaking strengths at 0 ° C. This is because, in Comparative Example 1, a polyester polyol was reacted with a polyisocyanate compound, whereas in Example 1, a polyol having both a polyamide block and a polyester block was used. It is considered to show excellent adhesiveness.

Similarly, as is clear from the results of Example 2 corresponding to Comparative Example 2, the adhesive strength in normal state, the adhesive strength at heating, and the breaking strength at 20 ° C. and 80 ° C. were all the same as those of Comparative Example 2. Excellent results were obtained with the moisture-curable hot-melt adhesive of Example 2 as compared with the case. However, the adhesiveness was also improved because a polyol having both a polyester block and a polyamide block was used. It seems to have been.

As is clear from the comparison between the results of Comparative Example 3 and Example 3, the moisture-curable hot melt adhesive of Example 3 is different from the moisture-curable hot melt adhesive of Comparative Example 3 in the normal state. Adhesive strength, hot adhesive strength, 20 ° C and 8
Good results were shown for any of the breaking strengths at 0 ° C. This is presumably because, in Comparative Example 3, a polyester polyol was used, whereas in Example 3, a polyol having not only a polyester block but also a polyamide block was used.

Similarly, the moisture-curable hot-melt adhesive of Example 4 is different from the moisture-curable hot-melt adhesive of Comparative Example 4 in that it has a normal adhesive strength, a hot adhesive strength, and breakage at 20 ° C. and 80 ° C. Although good results were obtained with respect to the point strength, also in Comparative Example 4, only the polyester polyol was used, but in Example 4, an organosilane compound was reacted with the polyol having a polyester block and a polyamide block to form a pre-polymer. This is probably because the polymer was obtained.

[0058]

According to the first aspect of the present invention, a moisture-curable hot melt adhesive composition using a urethane prepolymer having at least a polyester block and a polyamide block in a molecular skeleton and having an isocyanate group at a molecular terminal. The heat resistance of the cured adhesive after moisture curing is increased by the action of the polyester block and the polyamide block, and the adhesion to polar adherends such as steel plates and polyvinyl chloride is improved. Enhanced.

Similarly, in the second aspect of the present invention, a moisture-curable hot melt adhesive comprising a prepolymer having at least a polyester block and a polyamide block in a molecular skeleton and having a hydrolyzable silyl group at a molecular terminal. Since the composition is constituted, since the polyester block and the polyamide block are present, the heat-resistant adhesiveness of the moisture-cured product after moisture-curing is enhanced, and adhesion to a polar adherend such as a steel plate or polyvinyl chloride. Sex is enhanced.

Therefore, the moisture-curable hot-melt adhesive composition according to the first and second aspects of the present invention can be suitably used for various applications in the automotive field, the industrial field, and the like. It can also be used in fields where solvent resistance such as gasoline resistance is required.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08G 77/455 C08G 77/455 77/54 77/54

Claims (4)

[Claims] 1. A moisture-curable hot-melt adhesive composition comprising a urethane prepolymer having at least a polyester block and a polyamide block in a molecular skeleton and having an isocyanate group at a molecular terminal. 2. A moisture-curable hot-melt adhesive composition comprising a prepolymer having at least a polyester block and a polyamide block in a molecular skeleton and having a hydrolyzable silyl group at a molecular terminal. 3. The moisture-curable hot melt adhesive composition according to claim 1, wherein the polyamide block is an aliphatic nylon. 4. The moisture-curable hot melt adhesive composition according to claim 1, wherein the polyester block is an aliphatic polyester.