JP2769103B2 - Pasting method of gas impermeable material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for bonding a gas-impermeable material and a reactive hot melt adhesive used for the method.

[0002]

2. Description of the Related Art Conventionally, a plate-shaped composite material used for a top plate such as a desk or a table has been manufactured by bonding a melamine decorative plate and a metal plate with an adhesive. In general, a solvent-type rubber-based adhesive is used.
However, when a solvent type rubber adhesive is used, the following ~
There are the following problems.

[0003] A solvent-type rubber-based adhesive must be applied to both substrates to be bonded. After applying the solvent-type rubber-based adhesive to the base material, it is necessary to provide a separate drying step before bonding. An organic solvent is used for the solvent-type rubber-based adhesive, and the organic solvent evaporates during the drying and is released into the atmosphere, which has a bad influence on the human body and the global environment.

In the case of applying a solvent-type rubber-based adhesive using a spray, it takes time and effort to remove the solvent-type rubber-based adhesive oversprayed on a portion that does not need to be applied. descend. When a solvent-type thermoplastic rubber-based adhesive is used, heat resistance is not sufficient. In order to solve such problems, use of a reactive hot melt adhesive instead of a solvent type rubber adhesive has been studied. Advantages of reactive hot-melt adhesive include excellent heat resistance after curing, easy melting by heating and high coating properties, high initial strength of adhesive, and bonding with single-sided coating And the like.

When such a reactive hot-melt adhesive is used, it is possible to apply the reactive hot-melt adhesive to only one of the substrates to be bonded in a molten state and bond the adhesive. it can. Since a crosslinked structure is formed by the progress of a curing reaction after application, heat resistance is improved. Further, since the reactive hot melt adhesive does not contain an organic solvent, there is no adverse effect on the environment due to the solvent, and the workability is good.

[0006]

When the adhesive is a urethane-based hot-melt adhesive, the above-mentioned curing reaction is carried out by the isocyanate contained in the urethane prepolymer in the air or the moisture contained in the substrate and the adhesive. By the reaction with the group, the molecular weight is increased with the generation of carbon dioxide, and the reaction further proceeds to crosslink and cure.

When a usual urethane-based reactive hot melt adhesive is applied to a substrate and bonded together, generation of carbon dioxide is inevitable due to the above-mentioned reaction. At that time, if both the base materials are gas-impermeable, the generated carbon dioxide does not escape to the outside, and the carbon dioxide concentrates and accumulates in a part of the adhesive layer between the bonding surfaces. Therefore, there is a problem that blisters are generated in the bonded product, and the appearance and quality are deteriorated.

The present invention solves the above-mentioned problems, and a method for bonding a gas-impermeable material which does not cause blisters even when a material having no gas permeability is bonded, and a reactive hot melt adhesive used for the method. It is an object to provide an agent.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to solve the above-mentioned problems, and as a result, the cause of blisters is the generation of carbon dioxide. We focused on hot melt adhesives and proceeded with research, and completed the present invention. Gas according to the present invention
The method of bonding non-permeable material is carbonic
Gas-impermeable first material and metal plate impermeable to carbon dioxide
With reactive second material with reactive hot melt adhesive
In the method, the reactive hot melt adhesive is used.
Urethane prepolymer having an alkoxysilyl group
Using a reactive hot melt adhesive containing
Urethane having an isocyanate group
Prepolymer and arylamino group-containing silane represented by the following formula
Isocyanate obtained by reacting with a coupling agent
It is characterized by having a group content of 0%.

[0010]

## STR2 ## ^{ArNH R 1 SiR 2 n (OR} 3) 3-n ( Formula 1)

(Wherein, in the formula, Ar represents an alkane having 6 to 10 carbon atoms)
A reel group, R ¹ is a divalent organic group having 1 to 10 carbon atoms , R ²
And R ³ is an alkyl group having 1 to 5 carbon atoms, and n is 0 to 3
It is an integer. ) Reactive hot-melt adhesive used in the bonding method for a gas-impermeable material of the present invention, Ri reactive hot-melt adhesive der having an alkoxysilyl group, in particular among them, urethane having an alkoxysilyl group it is a reactive hot melt adhesive comprising a polymer. Examples of the urethane prepolymer having an alkoxysilyl group include the following.

A urethane prepolymer having an alkoxysilyl group obtained by reacting a urethane prepolymer having an isocyanate group with an silane coupling agent having an arylamino group, a urethane prepolymer having an isocyanate group and a silane coupling agent having an alkylamino group Urethane prepolymer having an alkoxysilyl group obtained by the reaction of a urethane prepolymer having an isocyanate group and a urethane prepolymer having an alkoxysilyl group obtained by reacting a urethane prepolymer having an isocyanate group with a mercapto group-containing silane coupling agent Urethane prepolymer having alkoxysilyl group obtained by reaction with epoxy group-containing silane coupling agent Urethane prepolymer having hydroxyl group and isocyanate group-containing sila Urethane prepolymer (hereinafter, the urethane prepolymer or a hydroxy having "isocyanate group containing urethane prepolymer or a hydroxy containing isocyanate groups used in the urethane prepolymer above having an alkoxysilyl group obtained by the reaction of the coupling agent Is sometimes referred to as "urethane prepolymer having isocyanate group / hydroxyl group") is preferably obtained by reacting an organic isocyanate compound with a polyol.

Here, when the equivalent ratio (NCO / OH) represented by the ratio of the number of hydroxyl groups in the polyol to the number of isocyanate groups in the organic isocyanate compound is larger than 1, a urethane prepolymer having isocyanate groups is obtained. Conversely, when the equivalent ratio (NCO / OH) is smaller than 1, a urethane prepolymer having a hydroxyl group is obtained. In a urethane prepolymer having an isocyanate group, the equivalent ratio (N
If the value of (CO / OH) is greater than 1, there is no particular limitation, but the equivalent ratio (NCO / OH) is preferred because it is easy to apply when finished as a reactive hot melt adhesive.
Is preferably from 1.2 to 2.2. In a urethane prepolymer having a hydroxyl group, its equivalent ratio (NCO / OH)
Is not particularly limited as long as the value is smaller than 1, for the same reason as above, the equivalent ratio (NCO / OH) is 0.86 to 0.86.
It is preferably 0.40.

[0014] as the upper Symbol organic isocyanate compound,
There is no particular limitation as long as it has two or more isocyanate groups in the molecule. For example, tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (polymeric MDI) , 1,4'-phenylene diisocyanate (PPDI), tetramethyl xylene diisocyanate (TMXDI), 4,4'-
Dicyclohexylmethane diisocyanate (H ₁₂ MD
I), cyclohexane diisocyanate (CHDI),
1,6-hexamethylene diisocyanate (HMD
I), isophorone diisocyanate (IPDI) and the like.

The polyol is not particularly limited as long as it has two or more hydroxyl groups in the molecule. As the polyol, a crystalline polyester polyol, a non-crystalline polyester polyol, a polyether polyol, an olefin polyol and the like are preferable. Examples of the crystalline polyester polyol include dicarboxylic acids such as succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanediic acid and ethylene glycol, 1,4-butanediol, 1,5-
Pentanediol, 1,6-hexanediol, 1,9
-It is obtained by reacting with a glycol such as nonanediol. Among them, those having a long carbon chain in the skeleton (specifically, polyester polyols obtained by reacting 1,6-hexanediol and sebacic acid, and 1,9-nonanediol and adipic acid, for example) Is more preferable because the reaction type hot melt adhesive can be rapidly crystallized and a good initial cohesive force can be obtained.

The non-crystalline polyester polyol includes, for example, dicarboxylic acids such as phthalic acid, terephthalic acid and isophthalic acid;
-It is obtained by reacting with glycols such as butanediol, neopentyl glycol, diethylene glycol, 3-methyl-1,5-pentanediol, and bis (hydroxyethyl) benzene. In this case, as the dicarboxylic acid component, polymerized rosin, which is a resin dimer obtained by dimerizing a resin acid monomer having an abietic acid monomer as a main component, may be used. Of these, the use of a rosin component in the skeleton is particularly preferable because the reactive hot melt adhesive has a low viscosity and a high initial cohesive force.

Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like. Examples of the olefin-based polyol include polybutadiene, polyisoprene, hydrogenated polybutadiene, and hydrogenated polyisoprene-based polyol. The urethane prepolymer having an isocyanate group / hydroxyl group is obtained, for example, by reacting the above organic isocyanate compound with a polyol. The crystalline polyester polyol, the non-crystalline polyester polyol, reacting only one of the polyether polyol or the olefin polyol, the resulting crystalline urethane prepolymer or non-crystalline urethane prepolymer,
These can be used alone or in combination of the above for the reactions of-. Further, the above-mentioned crystalline polyester polyol, non-crystalline polyester polyol, polyether polyol, and olefin polyol may be mixed and reacted in advance. The urethane prepolymer obtained thereby can also be used for the reaction of The urethane prepolymer preferably contains at least one selected from a crystalline urethane prepolymer and a non-crystalline urethane prepolymer.

The urethane prepolymer having isocyanate groups / hydroxyl groups may be further combined with a thermoplastic polymer. As the thermoplastic polymer, ethylene-vinyl acetate copolymer (EVA), styrene-butadiene-
Styrene copolymer (SBS), styrene-isoprene-
Styrene copolymer (SIS), styrene-ethylene-butylene-styrene copolymer (SEBS), styrene-ethylene-propylene-styrene copolymer (SEPS),
α-olefin-based copolymer, atactic polypropylene (APP), polyethylene, saturated polyester resin, polyurethane resin and the like. The molecular weight of these thermoplastic polymers is desirably 10,000 to 400,000.

The mixing ratio of the crystalline urethane prepolymer and the non-crystalline urethane prepolymer in the urethane prepolymer having an isocyanate group / hydroxyl group is not limited, and any mixing ratio can be used. For example, in the case of consisting of a crystalline urethane prepolymer, a non-crystalline urethane prepolymer and a thermoplastic polymer, the crystalline urethane prepolymer 5-6
Those comprising 0 parts by weight, 30 to 85 parts by weight of an amorphous urethane prepolymer and 10 to 30 parts by weight of a thermoplastic polymer can be preferably used.

In the present invention, the compound has an alkoxysilyl group.
The urethane prepolymer shown above is used.
Although the use, as the arylamino group-containing silane coupling agent used as one of its raw material, an arylamino group containing silane coupling agent represented by the formula 1 below SL is used.

[0021]

Embedded image ArNH R ¹ SiR ² n (OR ³ ) _3-n (Formula 1)

(Wherein, Ar is an aryl group having 6 to 10 carbon atoms, R ¹ is a divalent organic group having 1 to 10 carbon atoms, R ²
And R ³ is an alkyl group having 1 to 5 carbon atoms, and n is an integer of 0 to 3. ) Examples of the amino group-containing silane coupling agent represented by Formula 1 include γ- (N-phenylamino) propyltrimethoxysilane, γ- (N-phenylamino) propyltriethoxysilane, and γ- (N-phenyl). Amino) propylmethyldimethoxysilane, γ-
(N-phenylamino) propylmethyldiethoxysilane, γ- (N-phenylamino) propylethyldimethoxysilane, γ- (N-phenylamino) propylethyldiethoxysilane, γ- (N-phenylamino) ethyltrimethoxy Silane, γ- (N-phenylamino) ethyltriethoxysilane, γ- (N-phenylamino)
Ethylmethyldimethoxysilane, γ- (N-phenylamino) ethylmethyldiethoxysilane, γ- (N-phenylamino) ethylethyldimethoxysilane, γ- (N
-Phenylamino) ethylethyldiethoxysilane and the like.

The reactive hot-melt adhesive used in the method for bonding a gas-impermeable material of the present invention includes the ease of reaction between a urethane prepolymer having an isocyanate group / hydroxyl group and a silane coupling agent, and the ease of a silane coupling agent. From the viewpoint of ease of handling of the ring agent, a reactive hot melt adhesive containing a urethane prepolymer having the alkoxysilyl group is used, and
In the production process, as one of its raw materials, although the use of an arylamino group-containing silane coupling agent having a structure shown by the formula 1 above, represented by Formula 1 above
Arylamino group-containing silane coupling agent
When used as a raw material, the following (1) to (5) advantages there Ru as listed.

(1) Due to the steric hindrance and electron-withdrawing effect of the aryl group bonded to the amino group, the amino group and the isocyanate group can react under mild conditions without causing gelation. (2) Excellent heat resistance because the aryl group is bonded to the amino group. (3) The storage stability of the silane coupling agent is also good.

(4) When reacting with a urethane prepolymer having an isocyanate group, there is no problem about odor when applying as an adhesive. (5) Good compatibility with aromatic-containing polyols, urethane prepolymers, and thermoplastic elastomers. The reactive hot melt adhesive used in the bonding method of the present invention is not particularly limited with respect to the type and content of components other than the urethane prepolymer having the alkoxysilyl group as a main component, although there is no particular limitation. Copolymers, thermoplastic elastomers, inorganic or organic fillers, coloring pigments, plasticizers, tackifiers, waxes, curing catalysts, antioxidants,
An antioxidant, an ultraviolet absorber, a flame retardant, a fungicide, a silane compound, and the like can be appropriately added.

If the reactive hot-melt adhesive used in the present invention contains isocyanate groups, it causes blisters at the time of laminating a gas-impermeable material. rather good, in the present invention are not contain any isocyanate groups. The amount of the reactive hot melt adhesive used in the present invention may be appropriately set in consideration of securing the adhesive strength. In general, it is desired to reduce the amount of application as much as possible from the viewpoint of economy. However, due to the unevenness of the material and the accuracy of the applicator, a problem occurs at the time of application with a small amount of application. To avoid the problems mentioned above,
Further, from the balance between securing strength and economy, it is preferable that the application amount of the reactive hot melt adhesive is 50 to 300 g / m ² .

In the method for bonding a gas-impermeable material according to the present invention, the reactive hot-melt adhesive may be applied to either the first material or the second material which is gas-impermeable. Also, there is no need to provide a separate drying step after application,
Immediately after the application, the other material can be bonded and pressed, so that workability is good.

[0028]

SUMMARY OF] The use of those containing a urethane prepolymer having an alkoxysilyl group as an anti応型hot melt adhesive, since then polymerized via siloxane bonds, in which further reaction to crosslink cure proceeds, the crosslinking no production of carbon dioxide in the curing reaction.

[0029] A urethane prepolymer having an alkoxysilyl group obtained by reacting a urethane prepolymer and the amino group-containing silane coupling agent having an i isocyanate groups, in particular, as the amino group-containing silane coupling agent, wherein when using those represented by the 1
Is because the amino group and the isocyanate group can react under mild conditions without causing gelation due to the steric hindrance and electron-withdrawing effect of the aryl group bonded to the amino group, and the aryl group is bonded to the amino group Therefore, it becomes excellent in heat resistance.

[0030]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples. However, the present invention is not limited to the following Examples. ( Example) Crystalline polyester diol (molecular weight: 350) obtained by reacting 1,6-hexanediol with sebacic acid
0, hydroxyl value: 30.5) 15 parts by weight, Nipporan 4032 (manufactured by Nippon Polyurethane Co., molecular weight: 2500, hydroxyl value: 60.8) as an amorphous polyester polyol 6
0 parts by weight and 25 parts by weight of Hardeck A-3200 (a thermoplastic polyester polymer manufactured by Asahi Kasei Kogyo Co., Ltd.) as a thermoplastic elastomer are put into a flask equipped with a stirrer, a thermometer, a nitrogen inlet and a vacuum port, and then melt-mixed. And dried under reduced pressure at 105 ° C. for 3 hours.

Next, nitrogen was gradually introduced into the flask to return the pressure in the flask to normal pressure, and at about 80 ° C., 18.3 parts by weight of diphenylmethane diisocyanate (MDI) was added.
The reaction was carried out at a temperature of 3 ° C. for 3 hours to obtain a reactive hot melt adhesive containing a urethane prepolymer having an isocyanate group. The reactive hot melt adhesive had an isocyanate group content of 2.6% and a viscosity of 30,0 at 120 ° C.
00 cps.

1,000 g of a reactive hot-melt adhesive containing a urethane prepolymer having an isocyanate group synthesized above and 158 g of γ- (N-phenylamino) propyltrimethoxysilane as a silane coupling agent containing an arylamino group were used. Mix under nitrogen atmosphere 100
C. for 1 hour to form a reactive hot melt adhesive X containing a urethane prepolymer having an alkoxysilyl group.
-201 was obtained. No isocyanate group was detected in X-201. The viscosity was also measured.

The X-201 obtained above was heated to 120 ° C. and melted at 120 ° C. on the entire back surface of the melamine decorative board having a size of 0.8 mm × 300 mm × 700 mm by roll coating.
It is applied at a rate of 50 g / m ² , and a galvanized steel sheet (bonding steel sheet) having a size of 1.2 mm × 300 mm × 700 mm is positioned on this adhesive-coated surface and overlapped.
/ Cm ² with pressure. The time from application to pressure bonding was 60 seconds, and workability was good. 20-2
The reactive hot-melt adhesive was moisture-cured by being left for one week in an atmosphere of 3 ° C. and 50 to 60% RH. The obtained melamine decorative board / galvanized steel sheet top plate was examined with fingers and visually for the presence of blisters, but no blisters were found. The adhesive strength was also good. Table 1 shows the results .

(Comparative Example 1) In the examples, a reactive hot melt adhesive containing a urethane prepolymer having an alkoxysilyl group was prepared using "ARX-1217" manufactured by Nitta Gelatin Co., Ltd. (isocyanate group content: 2.55 (% By weight), and in the same manner as in Example 1, the presence or absence of swelling and the adhesive strength of the top plate obtained by bonding the melamine decorative plate and the galvanized steel plate were examined.

Comparative Example 2 In the same manner as in the example , a reactive hot melt adhesive 1,0 containing a urethane prepolymer having an isocyanate group was prepared.
00g and 60.7 g of γ- (N-phenylamino) propyltrimethoxysilane, and mixed at 100 ° C. under a nitrogen atmosphere.
For 1 hour, a reactive hot melt adhesive X- containing a urethane prepolymer having an alkoxysilyl group.
207 were obtained.

The isocyanate groups in the reactive hot melt adhesive were 0.94%. Further, the same evaluation as in Example 1 was performed, and the results are shown in Table 1.

[0037]

[Table 1]

[0038] In Comparative Examples 1-2 and our above example, the determination of the presence or absence of blisters of the top plate obtained by bonding, none blistering ○, that there is wavy △, and as × Yes blister. The adhesive strength was determined by comparing the surface tensile strength of a top plate obtained by bonding at room temperature to a universal tensile tester Autograph AG- manufactured by Shimadzu Corporation.
It was measured at 2000E (crosshead speed: 50 mm / min). Further, the value measured at 80 ° C. was defined as the heat-resistant adhesive strength. The viscosity of the adhesive was measured using a Brookfield type T
120 ° C. using a hermsel system viscometer
Was measured.

As shown in Table 1, no blistering occurred in the examples and the adhesive strength was good, while in the comparative example, blistering occurred or the strength was low.

[0040]

The method of bonding a gas-impermeable material with a reactive hot melt adhesive of the present invention uses a reactive hot melt adhesive having an alkoxysilyl group, so that a siloxane bond is formed by a reaction with moisture. Generate. Since it is polymerized through this siloxane bond, and further proceeds to cross-link and cure, no carbon dioxide is generated in this cross-linking and curing reaction, and blistering due to gas generation does not occur. The appearance and quality can be prevented from deteriorating.

Urethane having the above-mentioned alkoxysilyl group
Emissions prepolymer is that obtained by reacting a urethane prepolymer and the amino group-containing silane coupling agent having an isocyanate group, stability, excellent in handling ease, the swelling caused by generation of gas in the crosslinking curing process occurs are allowed without <br/> Rukoto, it is possible to prevent deterioration of appearance and quality of the bonded products. In particular, since the amino group-containing silane coupling agent is represented by the formula 1, to prevent gelation, it can react the amino group and an isocyanate group under mild conditions. Further, since the aryl group is directly bonded to the amino group, the heat resistance is excellent.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09J 175/04 C09J 175/04 // B29L 9:00 (72) Inventor Kazuaki Nakamura 2--22 Futama, Yao-shi, Osaka Nitta (56) References JP-A-2-163186 (JP, A) JP-A-4-5023 (JP, A) JP-A-6-500585 (JP, A) JP-A-4- 145187 (JP, A) JP-A-7-179839 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08J 5/12 C09J 175/00 B32B 27/40

Claims (1)

(57) [Claims] 1. A method according to claim 1, wherein the first material, which is impermeable to carbon dioxide, which is a decorative board made of resin , and the second material, which is impermeable to carbon dioxide, which is a metal plate, is bonded with a reactive hot melt adhesive. Alkoxy hot melt adhesive
Reaction type e containing urethane prepolymer having silyl group
Using a urethane prepolymer
Is a urethane prepolymer having an isocyanate group and
Arylamino group-containing silane coupling agent represented by the following formula
And isocyanate group content of 0%
A method of laminating a gas impermeable material, characterized in that it is a material. Embedded image ArNH R ¹ SiR ² n (OR ³ ) _3-n (Formula 1) (where Ar is an aryl group having 6 to 10 carbon atoms, R
¹ is a divalent organic group having 1 to 10 carbon atoms, R ² and R ³ are alkyl groups having 1 to 5 carbon atoms, and n is an integer of 0 to 3. )