JPH0251576A - Bonding method - Google Patents

Abstract

PURPOSE:To prolong the pot life of an adhesive solution and realize a firm bonding within a short curing time by coating the bonding surface of one material with a polyisocyanate compound, coating the bonding surface of another material with a mixture of a polymercapto compound and a tert. amine compound and bonding them together. CONSTITUTION:The bonding surface of one material is coated with an NCO- terminated polyisocyanate compound [e.g., 'OLESTER NP-1100' (a prepolymer of an NCO content of 23%, a product of Mitshui Toatsu Kagaku)] while the bonding surface of another material is coated with a mixture comprising S- terminated polymercapto compound [e.g., trimethylolpropane tris(2-mercapto acetate)] and a tert. amine compound (e.g., triethylamine), and the both are bonded together. This adhesive solution has a long pot life and rapid curability and can firmly bond the materials. This solution thus markedly differs from that free of the tert. amine.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is a bonding method that is used particularly in the field of assembly industries such as the automobile and electrical industries.

More specifically, a polyfunctional isocyanate compound having an isocyanate group at the end is applied to one adhesive surface of the materials to be adhered, and a polyfunctional mercapto compound having a mercapto group at the end and a tertiary amine compound are applied to the other adhesive surface. It relates to an adhesion method of applying and adhering a mixture consisting of:

[Prior Art] Conventionally, in the field of assembly industry, adhesives mainly composed of acrylic monomers, which are two-component non-mixable adhesives, have been widely used.

However, since this type of adhesive uses acrylic monomer as a raw material, it has problems in terms of odor and irritation during work.

[Problem to be solved by the invention]

Because two-component urethane adhesives have high reactivity, this type of fast-curing adhesive has the problem of short bond life of the adhesive liquid before it is applied to the adhesive surface and poor workability. It has points.

Further, when the pot life after heating the two liquids was set to such a level that workability was not a problem, there was a problem in that the curing properties after adhesion were poor.

In view of this situation, the present inventors have conducted various studies and have finally completed the present invention.

An object of the present invention is to provide a method for bonding an adhesive that maintains a long pot life as an adhesive liquid and has fast curing properties.

[Means to solve the problem]

That is, in the present invention, a polyfunctional isocyanate compound (A) having isocyanate l at the terminal is applied to one adhesive surface of the materials to be bonded, and a polyfunctional mercapto compound having a mercapto group at the terminal and This is accomplished by applying and adhering a mixture (B) consisting of a class amine compound.

The polyfunctional isocyanate compound (A) having an isocyanate at the end used in the present invention is a conventionally known isocyanate such as aliphatic polyisocyanate, alicyclic polyisocyanate, aromatic polyisocyanate, or one or two of these. Prepolymers modified from a mixture of more than one species, such as hexamethylene diisocyanate, isophorone diisocyanate, 4.4"-dicyclohexylmethane diisocyanate, diisocyanatecyclohexane, bis(isocyanatemethyl)cyclohexane, diisocyanatemethylcyclohexane, bicyclohebutane triisocyanate, and the like. Isocyanate groups are bonded directly to aliphatic or alicyclic polyisocyanates such as lysine isocyanate-β-incyanate ethyl ester, aromatic groups such as tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, tolidine isocyanate, and triphenylmethane triisocyanate. polyisocyanate, xylylene diisocyanate, mesitylene triisocyanate and bis(α-
Polyisocyanates bonded to an aromatic group such as α-dimethylisocyanate methyl) benzene in the form of an isocyanatomethylene group, and the above polyisocyanates and polyester polyols, polyether polyols,
Low molecular weight polyols such as ethylene glycol, 1.4 bucundiol, trimethylolpropane and NCO10i
Examples include reactants reacted at an equivalent ratio of 1>1, and isocyanurated products of the above polyisocyanates.

Examples of the polyfunctional mercapto compound having a mercapto group at the end used in the present invention include bis(2-mercaptoethyl) ether, 1,2-ethanedithiol,
1.4-Butanedithiol, bis(2-mercaptoethyl) sulfide, ethylene glycol bis(2-mercaptoacetate), ethylene glycol bis(3-mercaptopropionate), 2.2-dimethylpropanediol bis(2-mercapto Acetate L2,2-dimethylpropane diol bis(3-mercaptopropionate), trimethylolpropane tris(2-mercaptoacetate), trimethylolpropane tris(3-mercaptoacetate)
mercaptopropionate), trimethylolethane tris (2-mercaptoacetate), trimethylolethane tris (3-mercaptopropionate), pentaerythritol tetrakis (2-mercaptoacetate)
, pentaerythritol tetrakis (3-mercaptopropionate), dipene erythritol hexacis (
2-mercaptoacetate), dipene erythritol hexas (3-mercaptopropionate L 1,2
-dimercaptobenzene, 4-methyl-1,2-dimercaptobenzene, 3.6-dichloro-1,2-dimercaptobenzene, 3.4,5.6-tetrachloro-1,2
-dimercaptobenzene, xylylene dithiol, 1.
Examples include 3.5-) lis(3-mercaptopropyl)isocyanurate. Further examples include reaction products obtained by reacting the above-mentioned mercapto compound with a compound having an epoxy group or a compound having an isocyanate group under conditions in which an excess of mercapto functional groups is present.

Among these, trimethylolpropane tris (2-mercaptoacetate), trimethylolpropane tris (3-mercaptoacetate),
-mercaptopropionate), trimethylolethane tris (2-mercaptoacetate), trimethylolethane tris (3-mercaptopropionate), pentaerythritol tetrakis (2-mercaptoacetate), pentaerythritol tetrakis (3-mercaptopropionate) ), derivatives thereof, or mixtures thereof are preferred.

Furthermore, the tertiary amine compounds used in the present invention include:
Aliphatic tertiary amines, aliphatic alkanolamines, heterocyclic compounds containing nitrogen, or mixtures thereof, such as triethylamine, dimethylethylamine, trimethylamine, tributylamine, dimethylhensylamine, dimethylcyclohexylamine, dimethylethanol. Examples include amines, diethylethanolamine, triethanolamine, pyridine, 4-phenylpropylpyridine, 2,4,6-nylicune, quinoline, isoquinoline, N-ethylmorpholine, triethylenediamine and derivatives thereof and mixtures thereof.

In the present invention, in the mixture (B) consisting of a mercapto compound and a tertiary amine compound, the mixing ratio of the tertiary amine compound to the mercapto compound is 95:5 to 99.
It is preferably in the range of 9:0.1, particularly preferably in the range of 98.0:2.0 to 99.8:0.2. (The blending ratio is a weight ratio.) When the mixing ratio of the tertiary amine compound is more than 5 weight ratio, there is a problem that the curing property during adhesion is too fast.

Moreover, when the weight ratio is less than 0.1, there is a problem that curing properties during adhesion are poor.

The present invention is particularly utilized in the field of assembly industries such as the automobile and electrical industries, and is suitable for adhesives for materials such as metals, plastics, rubber, and glass.

In the bonding method of the present invention, in order to maintain an appropriate viscosity of the adhesive liquid during bonding of compound (A) and compound (B), fillers, Additive,
A solvent etc. can be added and mixed.

The bonding method in the present invention is to apply 1 layer to the surface of the material to be bonded.
This is achieved by coating and pressing the image material surface to a coating thickness of about 0 to 100 II.

The pressing pressure varies depending on the material and adhesive area, but it is 10g /
cd=1 kg/cA Clamping time is 30 seconds to 5
About a minute is enough.

〔Example〕

EXAMPLES Hereinafter, in order to explain the present invention more specifically, Examples and Comparative Examples will be given and explained, but the present invention is not limited to these Examples.

Moreover, parts in the examples indicate parts by weight.

Example 1 Olestar N as a polyfunctional polyisocyanate compound
P-1100 (manufactured by Mitsui Toatsu Chemical Co., Ltd., trade name.

The following compound was prepared as a polyfunctional mercapto compound (NCO group content % = 23% prepolymer).

A 470 flask equipped with a PA stirrer was charged with 168 g of hexamethylene diisocyanate and 976 g of pentaerythritol tetrakis (3-mercaptopropionate), and the temperature was raised to 120° C. under a nitrogen atmosphere, followed by reaction for 5 hours.

1.0 part by weight of dimethylethanolamine was mixed and blended with 100 parts by weight of the obtained polyfunctional mercapto compound to obtain a mixture (B). Using these adhesives, use two aluminum test pieces and attach Orestar NP-1 to one adhesive surface.
100 was applied, and mixture (B) was applied to one adhesive surface, and then both sides were pressed together with a force of 50 g/d. After about 5 minutes of pressing time, the pressure was released.

After observing the state after depressurization, and after leaving it at room temperature for one day, the shear force was measured at a speed of 50 m/min in an atmosphere of 25°C in an adhesive strength test.

The measurement results are shown in Table-1.

Example 2 Olestar P as a polyfunctional polyisocyanate compound
-75 (manufactured by Mitsui Toatsu Chemical Co., Ltd., product name, NCO group content% =
12.5% Fes non-volatile content 75% ethyl acetate solvent),
As a functional mercapto compound, 0.5 parts by weight of triethylamine was added to 100 parts by weight of the polyfunctional mercapto compound of Example 1.
Parts by weight were blended to obtain a mixture. An adhesion test was conducted in the same manner as in Example 1 using these adhesives.

The evaluation results are shown in Table-1.

Example 3 As a polyfunctional polyisocyanate compound, 13 xylylene diisocyanate, as a polyfunctional mercapto compound,
A mixture was obtained by mixing and blending 3 parts of dimethylethanolamine with 100 parts by weight of pentaerythritol tetrakis (3-mercaptopropione). An adhesion test was conducted in the same manner as in Example 1 using these adhesives.

The evaluation results are shown in Table-1.

Comparative Example 1 An adhesive was obtained using the same polyisocyanate compound Olester NP-1100 as in Example 1 and a polyfunctional mercapto compound without mixing and blending dimethylethanolamine.

An adhesion test was conducted in the same manner as in Example 1 using this adhesive.

The evaluation results are shown in Table-1.

Comparative Example 2 An adhesive similar to that of Example 3 was obtained without adding dimethylethanolamine.

An adhesion test was conducted in the same manner as in Example 1 using this adhesive.

The evaluation results are shown in Table-1.

Reference Example 1 Adhesive Strength Test Method Shear force was measured at a speed of 50 mm/min in a temperature-controlled room at 25° C. using an Autograph manufactured by Shimadzu Corporation.

〔Effect of the invention〕

It is clear from Table 1 that the method (Example) of the present invention shows extremely high adhesive strength.

On the other hand, in the comparative example, which was carried out in exactly the same manner as in the example except that no tertiary amine was blended, both sides became peeled off immediately after depressurization, and the method was significantly inferior to the method of the present invention. is clear.

Table-1 Note: ◎: Indicates complete adhesion even after decompression.

XX: Indicates a state in which both sides peel off immediately after the pressure is released.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] 1. A polyfunctional isocyanate compound (A) having an isocyanate group at the end is applied to one adhesive surface of the materials to be adhered, and a polyfunctional mercapto compound (A) having a mercapto group at the end is applied to one adhesive surface. An adhesion method characterized by applying and adhering a mixture (B) consisting of a compound and a tertiary amine compound. 2. The polyfunctional isocyanate compound (A) having an isocyanate group at the terminal is a prepolymer modified from an aliphatic polyisocyanate, an alicyclic polyisocyanate, an aromatic polyisocyanate, or a mixture of one or more of these. The bonding method according to claim 1. 3. Polyfunctional mercapto compounds having a mercapto group at the end include trimethylolpropane tris (2-mercaptoacetate), trimethylolpropane tris (3-mercaptopropionate), trimethylolethane tris (2-mercaptoacetate), and trimethylolpropane tris (2-mercaptoacetate). Methylolethane tris (3-mercaptopropionate), pentaerythritol tetrakis (2-mercaptoacetate)
, pentaerythritol tetrakis (3-mercaptopropionate), a derivative thereof, or a mixture thereof. 4. The bonding method according to claim 1, wherein the tertiary amine compound is an aliphatic tertiary amine, an aliphatic alkanolamine, a nitrogen element-containing heterocyclic compound, or a mixture thereof. 5. The mixture (B) consisting of a polyfunctional mercapto compound having a mercapto group at the end and a tertiary amine compound has a mixing ratio of the tertiary amine compound to the mercapto compound,
The bonding method according to claim 1, wherein the bonding ratio is in the range of 95:5 to 99.9:0.1.