JPH02191691A - Bonding method - Google Patents

Abstract

PURPOSE:To easily and firmly bond metals with each other or metal and cloth, wood, plastics, etc., by treating a surface of a metal with a specific primer solution and bonding the metal with a specific curable polyurethane adhesive. CONSTITUTION:A surface of a metal is treated with a primer solution produced by dissolving a compound of formula (R1 is H or CH3; R1 is SH-containing group; R2 is H or R1; X is group containing acidic phosphoric acid group; n is 2-20) in a volatile solvent. The treated metal is bonded with a curable polyurethane adhesive composed of a polyisocyanate (e.g. toluene diisocyanate) and an active hydrogen compound (e.g. polyol).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for bonding polyurethane adhesives to metal.

Conventionally, polyurethane adhesives have poor adhesion to metals, and it has been difficult to stably adhere to metals without surface treatment. With conventional technology, in order to firmly bond metals to each other or metals to plastics, etc., the surface of the metal is coated with an acid or alkali, or a primer (two-part, room-temperature curing type epoxy adhesive) dissolved in the respective solvent. It has been necessary to use either a liquid primer (referred to as a liquid primer) or a primer in which a resol resin or phenol resin is dissolved in a solvent (referred to as a liquid primer).

If these methods are used, the adhesion of polyurethane adhesives to metals can be greatly improved, but on the other hand, they have the following drawbacks: For example, acid or alkali treatment requires many processing steps; It requires strict management and takes a long time to process. In addition, the two-component primer takes a long time to dry, and requires a long period of time, approximately day and night, at room temperature. or,. -Liquid primer requires high temperature heating of about 150°C to dry the primer/primer. As a result 5. In putting polyurethane adhesives into practical use, this (-1+) disadvantage becomes an obstacle, and 2. the applications are also limited.

As a result of research to improve these drawbacks, the present inventor discovered that the use of a certain type of phosphorus compound in a polyurethane adhesive significantly improves the adhesion to metal, and arrived at the present invention. The adhesion method of the present invention includes:
(A) at least one polyisocyanate, (B
) A novel curable polyurethane adhesive (hereinafter referred to as F "polyurethane adhesive of the present invention") characterized by comprising at least one active hydrogen compound and (C) a compound represented by the following general formula fl) is used. .

General formula (1): R1-C-CL-C now total 2 (However, in the formula, R is a ! (or CH8 group, L is a group containing at least one S)I group in the molecule, R7 is;
] or R5, X is a group containing an acidic phosphoric acid group,
n is an integer from 2 to 20. ) The embodiments of the polyurethane adhesive of the present invention are shown in more detail: (1) r General formula (1)
The compound represented by the formula (hereinafter referred to as "P compound-1") is stored separately from the polyisocyanate F and the active hydrogen compound, that is, the three components are stored separately, and when used,
An adhesive of a type in which three components are brought into contact and mixed, (2) an adhesive consisting of two components: a solution in which a P compound is dissolved in an active hydrogen compound, and a solution containing a polyisocyanate, and (3) a P
3. A primer solution in which a compound is dissolved in a volatile solvent, a solution containing a polyisocyanate, and a solution containing an active hydrogen compound.
Although there are adhesives etc. consisting of the following components, the adhesive method of the present invention is (
It is characterized by the use of adhesive 3).

The present invention provides a bonding method for bonding metals using the polyurethane adhesive of the present invention.

That is, in the bonding method of the present invention, when bonding metals using a curable polyurethane adhesive comprising at least one type of polyisocyanate and at least one type of active hydrogen compound, the metal surface is preliminarily bonded to the above general formula (1). ) is characterized in that it is treated with a primer solution in which the compound shown in (a) is dissolved in a volatile solvent.

The components of the polyurethane adhesive of the present invention will be explained below.

Examples of the isocyanate include toluene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, hexamethylene diisocyanate, and derivatives thereof.

Examples of active hydrogen compounds include (a) polyols such as ethyl glycol, propylene glycol, glycerin, castor oil, and their derivatives such as polyether polyols and polyester polyols; (b)
) polyamines, such as ethylenediamine derivatives, aromatic polyamines such as methylene dianiline, etc.; and (Cl polythiols, such as 1,4-butanediol, dimercaptoacetate, l.limethylolprovantris(mercap)acetate), Examples include pentaerythritol tetrakis (mercaptoacetate).

Examples of P compounds include, for example, a compound obtained by aggregating a reaction product of phosphoric acid and 2-hydroxyethyl methacrylate (hereinafter referred to as PM) in the presence of a thiol, or a compound obtained by reacting PM with trimethylolpropane trismercaptoprobiotin. Examples include compounds obtained by polymerization in the presence of esters (hereinafter referred to as TP).

The degree of polymerization of the compound thus obtained is 20 or less.

Examples of thiols used in the reaction with PM include 1,4-butanediol dimercaptoacetate (hereinafter referred to as '
T:BA), trimethylol"7'i] vantris (mercaptoacetate-1), dipentaerythritol-\kiza (mercaptoacetate), 1.4=butanediol dimercaptoprobionate, l-limethylolpropane Examples include, but are not limited to, tris (mercap-1 propionate), pestaerythritol-lutetrakis (mercaptopropionate), dipentaerythritol hekiza (meth-captopropionate), and the like.

As examples of volatile solvents, acetyl/and ethyl acetate are preferred, but any solvent may be used as long as the P compound can be dissolved therein. For example, methanol, ethanol, water, etc., and mixtures thereof are used.

The preferred content of the P compound in the curable polyurethane adhesive of the present invention is 0.1 to 20% by weight, particularly 0.1 to 20% by weight.
Hexagonal adhesive, preferably 5 to 10 M hyperite, can optionally contain catalysts, plasticizers, fillers, resins, etc. to the polyurethane adhesive of the present invention.

According to the method of the invention, metals or metals and other adherends, such as cloth, wood, etc. Adhesion of plastics etc. can be carried out easily and strong adhesion force can be obtained. In particular, a primer solution in which a P compound is dissolved can be dried within a short time, for example, within 5 minutes, and its adhesion to metals is significantly improved.

J-Right 2-piece-Made by at-masu (A) Posmer M! ri QJ mole, 11A ri 21O
, 1 mol, BPO" 0.001 mol 4 200
ml separable flask, stir while blowing nitrogen gas, and remove 5 cu from the flask at 25°C for 1 hour.
Shine the light from where #! f (Toshiba fluorescent light)゛-230
0, Fioo)L reaction. A part of this reaction product was collected, and a high-speed liquid evaporator [2 Madograph (USA, Waters Co., Ltd., 2
44 type), and the fraction was analyzed by NMR and IR.As a result, a phosmer polymer with a degree of polymerization of 20 or less and a reaction product to B (hereinafter referred to as compound A) were obtained.

(B) Phosmer M0.1 mol, TA (460,1
Mol, BPOo, and ooi mole were taken, and the same operation as in (A) above was performed to obtain a reaction product of a phosmer polymer and TA having a degree of polymerization of 20 or less (hereinafter referred to as compound B).

Phosmer M 0.1 mol, pA+513.1 mol, BP
OO,001 mol was taken and the same operation as in (A) was performed to obtain a reaction product of a phosmer polymer and PA having a degree of polymerization of 20 or less (hereinafter referred to as compound C).

Phosmer MO, 1 mol, TP"' 0.1 mol, BPO
o, ooi moles were taken and the same operation as in (A) above was performed to obtain a reaction product of a phosmer polymer and TP (hereinafter referred to as compound) having a degree of polymerization of 20 or less.

Phosmer MO81 mol, BA 0.2 mol, BPOo,
Take ooi moles and perform the same operation as in (A) above,
A reaction product of a phosmer polymer with a degree of polymerization of lθ or less and BA (
(hereinafter referred to as compound E) was obtained.

[Note] (1) Compound having the following structure (product name of Unichemical Co., Ltd.) (C) (D) (H) (2) Compound having the following structure (3) Compound having the following structure CH2OC-CHzSI! (5) After bonding a compound with the following structure, after curing at room temperature for one week, the T peel strength was measured at a temperature of 25°C.
The results are shown in Table 1.

(6) Compound having the following structure Reference Example 1 A polyurethane adhesive was prepared by stirring at room temperature for 5 minutes in a beaker at the compounding ratios shown in Experimental Samples 1 to 6 in Table 1 below (hereinafter, (referred to as preparation liquid).

Take a portion of each prepared solution and place it on a piece of iron with a thickness of 0.3 mm (JI
SG 3145PCC-SB) Two sheets were coated and adhered.

Reference Example 2 A polyurethane adhesive was prepared using the formulations shown in Experiments 7 to 13 in Table 2 below (the content of the compound was varied). A portion of each prepared solution was taken and bonded in the same manner as in Reference Example 1, and the strength measurement results are shown in Table 2.

〔note〕

+1lpJ Product name: Sumidurto 21-1 (Sumitomo Bayer Urethane Co., Ltd.! 1) (2) Product name: ADEKA Polyether G-700 (M Denka Co., Ltd. 11) 131 P compound: The compound shown in *i example of P compound show.

(4!・In the peel strength column, the following symbols are used to describe each peeling situation along with the peeling II1 strength. The same applies below C) Force: interfacial failure, Gi: cohesive failure, Bougi: partial cohesive failure.

Reference Example 3 A portion of the prepared liquid shown in Experiment ml and 2 was taken and applied to various adhesives shown in Experiments 14 to 25 in Table 3 and adhered. After curing for one week at room temperature after adhesion, the Bell peel strength was measured at temperature 2.
The measurement was carried out at 5°C and the results are shown in Table 3.

Reference Example 4 The compound AiQ superimposed part obtained in the preparation example of P compound, 5, and polyol (-70090 parts by weight) were placed in a 200 d four-necked separable flask, and heated to room temperature while blowing nitrogen gas. After stirring and mixing for 10 minutes at room temperature, a mixed solution was prepared by standing at room temperature day and night. 50 parts by weight of this mixed solution and 50 parts by weight of polyisocyanate (Sumigel E-21-1) were added.
The weight parts were stirred in a beaker at room temperature for 5 minutes to prepare the polyurethane adhesive.

Then, a portion of this prepared solution was applied to two 0.3-thick iron pieces (JiS G 3145PCC-5B) and adhered.

Ta. After adhesion and curing for one week, the peel strength was measured at a temperature of 25°.
As a result of measurement at C, the strength was 8-7 kg/25 t.
tmO values were obtained. The state of failure of the adhesive surface was 8 failures.

Example I Compound A obtained in Preparation Example of P Compound was dissolved in ethyl acetate to prepare a 1% by weight solution, which was used as a primer.

Iron piece with a thickness of 0.3 s+ (JIS G 3145PCC
-SB) The above primer was brushed onto two sheets and dried.

Mix the following two-component polyurethane adhesives Parts A and 13 in a weight ratio of Part A/Part B - 1.6/1.0, and use the mixed solution to prepare the primer treated product of two iron pieces as shown below. It was applied and adhered to. After curing for one week at room temperature after adhesion, TjJ separation strength was measured.

For comparison, an iron piece of the same quality as above was adhered in the same manner using the above adhesive without primer treatment, and the T-peel strength was measured.

Envoy ↓, Car U-V upper Yunotan 1 rough Δ liquid: Boliiso... Anate (Sumifell 1 Sn-2
1-1) r3H,+polyol (ADEKA Polyether G-700
) T-N anal flow rate, Q, -value of the primer-treated product of the present invention, 9. ．． 3 kg/2
5ml (comparative example) value without primer treatment, 0.5 kg
/25wm patent applicant Denki Kagaku Kogyo Co., Ltd.

Claims (1)

[Claims] 1. When bonding metal using a curable polyurethane adhesive consisting of at least one polyisocyanate and at least one active hydrogen compound, the metal surface is
An adhesion method characterized by treating with a primer solution in which a compound represented by the following general formula (1) is dissolved in a volatile solvent. General formula (1): ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, in the formula, R is H or CH_3 group, R_1 is a group containing at least one SH group in the molecule, R_2
is H or R_1, X is a group containing an acidic phosphoric acid group, and n is an integer of 2 to 20. )