JP2002201384A - Primer for 2-cyanoacrylate-based adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a primer for 2-cyanoacrylate-based adhesives capable of firmly bonding a wide range of hard-to-bond materials represented by nonpolar resins, highly crystallized resins and the like, and enabling a bonding to the carried out easily and quickly. SOLUTION: This primer for 2-cyanoacrylate-based adhesives is characterized by comprising as the active ingredient a compound having at least three tertiary amino groups mutually linked through alkylene chains.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The primer for 2-cyanoacrylate adhesives of the present invention comprises a so-called non-adhesive material such as a non-polar or highly crystalline resin or rubber, which has been considered to be difficult to adhere to. Used for effective bonding using cyanoacrylate-based adhesives, widely used in various fields including the automotive industry and the electrical equipment industry, where non-polar or highly crystalline resins are widely used as raw materials. Is what is done.

[0002]

2. Description of the Related Art Non-adhesive materials such as non-polar or highly crystalline resins, for example, polyolefins such as polyethylene, polypropylene, polybutene and polyfluoroethylene, polyethylene terephthalate, polyacetal, and nylon. Soft polyvinyl chloride film, silicone rubber, etc., which contain a large amount of plasticizer, are materials that are difficult to bond, paint, print, etc. The surface could not be well painted or printed. In order to improve the adhesiveness of these difficult-to-bond materials, for example, in the case of a polyolefin resin,
A corona discharge treatment (Japanese Unexamined Patent Publication No. 5-317116), a plasma jet treatment (Japanese Unexamined Patent Publication No. 62-169827) or a dichromate treatment (Japanese Unexamined Patent Publication No. 2-117968) is applied to the surface of the resin to form a carbonyl group or the like. A method of forming a polar group, and a method of treating a resin using a primer obtained by dissolving chlorinated polyethylene, chlorinated polypropylene, or a fatty acid-modified alkyd alkyd resin in an organic solvent (JP-A-61-166842). No.) has been proposed.

On the other hand, when bonding these non-polar or highly crystalline resins with a 2-cyanoacrylate adhesive which is an instant adhesive, there have been many proposals to use a primer containing a specific compound as an active ingredient. ing. For example, organometallic compounds such as aluminum alcoholate and aluminum chelate salt (JP-A-59-215376) or phosphine compounds (JP-A-63-162781)
), Phosphite compounds (JP-A-63-10796)
No.), pyridine compounds (JP-A-62-195071)
No.), an amidine compound (JP-A-6-100839),
Amine compounds (JP-A-63-51489), polyamine compounds (JP-A-9-53052), lutidine (JP-A-62-18485), 4-vinylpyridine (JP-A-62-18486), Grade amine (JP-A-6-57)
No. 218), bicyclo compounds (Tokuhyo Hei 1-503630)
No.), imidazole derivative (Tokuhyohei 5-506470)
No.) has been proposed as an active ingredient.

[0004]

Each of the above-mentioned primers achieves the intended purpose and exhibits an excellent function, and these functions are based on various compounds at the interface between the polyolefin and the adhesive. Is believed to be based on the strong coupling action of However, none of these primers are still compatible with all adhesive substrates, some substrates are not applicable,
It has points to be improved such as a slow set time and a restriction on the time from application of the primer to bonding (hereinafter referred to as “open time”). In view of this situation, the present inventors have conducted intensive studies to find a primer having a wider application range, a faster set time, and a longer open time than conventional ones. As a result, a specific tertiary amine compound was selected from various compounds. By using, it has been found that an excellent primer that has solved the above problems can be obtained,
The present invention has been completed.

An object of the present invention is to provide a 2-cyanoacrylate-based resin which can strongly adhere a wide range of difficult-to-bond materials represented by a non-polar or highly crystallized resin, and which can be easily and quickly bonded. It does not provide a primer for the adhesive.

[0006]

Means for Solving the Problems According to the present invention, claim 1 is included.
The invention according to claim 2, wherein the active ingredient is a compound having three or more tertiary amino groups linked by an alkylene chain, and a primer for a 2-cyanoacrylate-based adhesive, The present invention provides a tertiary amine compound represented by the general formula (1) (wherein R ₁ , R ₂ , R ₃ , R ₄ and R ₇ each represent an alkyl group having 1 to 2 carbon atoms).
R _5, R ₆ each represents a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms. ) As an active ingredient.

[0007]

Embedded image

[0008] Of the present invention, the invention according to claim 3 is:
When the compound represented by the general formula (1) has R ₅ and R ₆ having 2 carbon atoms
A primer for a 2-cyanoacrylate-based adhesive, which is a compound of a linear alkylene group of Nos. 1 to 6.

In the present invention, the invention according to claim 4 is:
Compounds represented by the general formula (1) are represented by R ₁ , R ₂ , R ₃ , R ₄
And R ₇ is a methyl group, R _5, R ₆ is a primer for the 2-cyanoacrylate-based adhesive which is a compound of propylene.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a primer for a 2-cyanoacrylate adhesive (hereinafter, simply referred to as "primer") of the present invention will be described in detail below.

[0011] The primer of the present invention uses a 2-cyanoacrylate-based adhesive (hereinafter, simply referred to as "cyano-based adhesive") mainly for a non-adhesive material such as a non-polar or highly crystallized resin. It is used for bonding, and can improve the adhesive strength between the poorly-bonded material and the cyano-based adhesive.

The compound having three or more tertiary amino groups linked by an alkylene chain (hereinafter referred to as "tertiary amine compound"), which is an active ingredient of the primer of the present invention, includes N, N, N ', N ″, N ″ -pentamethyldiethylenetriamine, N, N, N ′, N ″, N ″ -pentamethyldipropylenetriamine, N, N, N ′, N ″, N ″
-Pentamethyldibutylenetriamine, N, N, N ',
N ″, N ″ -pentamethyldipentylenetriamine,
N, N, N ′, N ″, N ″ -pentamethyldihexylenetriamine, N, N, N ′, N ″, N ″ -pentamethyldiheptylenetriamine, N, N, N ′, N '', N ''-
Pentamethyldioctylenetriamine, N, N, N ',
N ″, N ″ -pentamethyldinonylenetriamine, N,
N, N ′, N ″, N ″ -pentamethyldidecylenetriamine, N, N, N ′, N ″, N ″ -pentaethyldiethylenetriamine, N, N, N ′, N ″, N '' -Pentaethyldipropylenetriamine, N, N, N ', N'',
N ″ -pentaethyldibutylenetriamine, N, N,
N ′, N ″, N ″ -pentaethyldipentylenetriamine, N, N, N ′, N ″, N ″ -pentaethyldihexylenetriamine, N, N, N ′, N ″, N ″ -pentaethyldiheptylenetriamine, N, N, N ′, N ″,
N ″ -pentaethyldioctylenetriamine, N, N,
N ', N ", N" -pentaethyldinonylenetriamine, N, N, N', N ", N" -pentaethyldidecylenetriamine, N, N, N ', N ", N ''',N'''-hexamethyltriethylenetetraamine, N, N, N ',
N ″, N ′ ″, N ″ ″-hexamethyltripropylenetetraamine, N, N, N ′, N ″, N ″ ″, N ′ ″-hexamethyltributylenetetraamine, N , N, N ',
N ″, N ′ ″, N ″ ″-hexamethyltripentylenetetraamine, N, N, N ′, N ″, N ′ ″, N ′ ″-hexamethyltrihexylenetetraamine, N, N, N ',
N ″, N ′ ″, N ″ ″-hexamethyltriheptylenetetraamine, N, N, N ′, N ″, N ′ ″, N ′ ″-hexamethyltrioctylenetetramine Amines, N, N, N ',
N ″, N ′ ″, N ″ ″-hexamethyltrinonylenetetraamine, N, N, N ′, N ″, N ′ ″, N ′ ″-hexamethyltridecylenetetraamine, N , N, N ', N'',
N ′ ″, N ′ ″-hexaethyltriethylenetetraamine, N, N, N ′, N ″, N ′ ″, N ′ ″-hexaethyltripropylenetetraamine, N, N, N ', N'',
N ′ ″, N ′ ″-hexaethyltributylenetetraamine, N, N, N ′, N ″, N ′ ″, N ′ ″-hexaethyltripentylenetetraamine, N, N, N ', N'',
N ′ ″, N ′ ″-hexaethyltrihexylenetetraamine, N, N, N ′, N ″, N ′ ″, N ′ ″-hexaethyltriheptylenetetraamine, N, N , N ', N'',
N ′ ″, N ′ ″-hexaethyltrioctylenetetraamine, N, N, N ′, N ″, N ″ ″, N ′ ″-hexaethyltrinonenylenetetraamine and N, N, N ', N'',
N ′ ″, N ′ ″-hexaethyltridecylenetetraamine and the like.

Among the tertiary amine compounds, the longer the alkylene chain, the better the adhesive strength and the open time. However, if the alkylene chain is too long, the production becomes difficult and expensive, so that the alkylene chain is a linear alkylene chain having 2 to 6 carbon atoms. Are preferred. More preferably, it has 3 to 6 carbon atoms, particularly preferably 3 carbon atoms.
If the alkyl group bonded to the tertiary amino group is too large, steric hindrance will reduce the effect of the amino group,
Choose methyl or ethyl groups. More preferably, it is a methyl group.

The primer of the present invention is applied to a hard-to-bond material such as a non-polar or highly crystallized resin by using a cyano-based adhesive. At the time of its use, it is desirable to control the coating thickness in order to sufficiently exert the effects of the present invention.

The organic solvent used for forming the solution is a general organic solvent capable of completely dissolving and dispersing the tertiary amine compound, has a suitable volatility, and It is desirable that it be easily available industrially.

In order to make the primer act more efficiently, the organic solvent is preferably capable of sufficiently wetting the surface of a resin such as polyolefin. It is more desirable to select and use a material having a critical surface tension (rc) smaller than the critical surface tension (rc).

Specific examples of the organic solvent that can be used include:
For example, regarding critical surface tension, polyacetal has rc = 40, nylon 66 has rc = 46, and PET has r = 46.
Since c = 46 and rc = 31 for polyethylene, the organic solvent for them is 1,1,2-trichloro-1,2,2 having a surface tension lower than the critical surface tension.
-Trifluoroethane (19), ethanol (22),
It is preferable to use acetone (23), n-hexane (18), ethyl acetate (24) or toluene (28). Note that the values in parentheses indicate the surface tension.

The concentration of the tertiary amine compound in the primer solution when used as a solution is such that when the compound is used as a primer, the compound is formed into a thin film, preferably a monomolecular film, on the resin surface. Since the effect is most exhibited, the content is preferably 0.01 to 30% by mass, more preferably 0.05 to 5% by mass, and particularly preferably 0.2 to 2% by mass.

If the concentration is less than 0.01% by mass, it is difficult to form a tertiary amine compound layer in a thin film or monomolecular film, and if it exceeds 30% by mass, the layer becomes thick. It is not preferable because the effect of the primer is reduced due to excessively increasing.

The primer of the present invention is preferably used in combination with various organic polymers as a thickener, since coating properties and the like are improved. Since the organic polymer is used in combination when the other components of the primer of the present invention are used by being dispersed or dissolved in an organic solvent, the organic polymer is also preferably a polymer soluble in the organic solvent. .

Specific examples of the organic polymer that can be used in combination include olefin copolymers such as ethylene / vinyl acetate copolymer, ethylene / acrylate copolymer, 2-olefin / maleic acid copolymer; Chlorinated olefin polymers such as chlorinated polyethylene, chlorinated polypropylene, chlorinated ethylene / propylene copolymer, chlorinated ethylene / vinyl acetate copolymer; polyvinyl chloride, polyvinyl acetate, poly (meth) acrylate , Polyvinyl ethers, vinyl polymers such as vinyl chloride / vinylidene chloride copolymers; and synthetic rubbers such as polychloroprene, NBR, SBR, and chlorinated rubber.

Among the above various organic polymers, more preferred are chlorinated polyolefin polymers which are chlorides of polymers such as propylene and ethylene; chlorinated rubbers; propylene, ethylene and methyl methacrylate. Homopolymers or copolymers, particularly preferred are chlorinated polypropylene and methyl methacrylate / chloroprene copolymer.

The amount of the organic polymer used in combination with the organic polymer depends on the type of the organic polymer.
It is preferably about 1% by mass. If the concentration is less than 0.1% by mass, the effect of improving coatability is small, and if it exceeds 10% by mass, the effect as a primer is reduced. In addition, the addition of the organic polymer has a viscosity of 2 to 5000 mPa · s (temperature 25
(° C.), it is preferable to determine the type and amount thereof.

[Cyano Adhesive] The primer of the present invention is used as a primer for a cyano adhesive. 2-Cyanoacrylate, which is a main component of the adhesive, is represented by the following general formula. Compound.

[0025]

Embedded image

In the formula, R is an alkyl, alkenyl, cyclohexyl, aryl or alkoxyalkyl group, and specifically, methyl, ethyl, n-propyl, n-
Butyl, isobutyl, n-pentyl, furyl, cyclohexyl, benzyl, methoxypropyl and the like. The cyano-based adhesive to which the primer of the present invention is most suitably applied is one containing ethyl-2-cyanoacrylate as a main component.

The cyano-based adhesive is prepared by blending the following stabilizers, polymerization accelerators, thickeners, and other additives as desired components. Again, the primer of the present invention can be applied.

[Stabilizer] As a polymerization inhibitor, for example, hydroquinone or sulfur dioxide may be added to improve the storage stability.

[Polymerization Accelerator / Initiator] In order to increase the bonding speed, anionic polymerization accelerators such as polyalkylene oxides or derivatives thereof, crown ethers or derivatives thereof, silacrown ethers or derivatives thereof, calixarene derivatives, etc. As a radical initiator, an organic peroxide such as hydroperoxide, peroxyester, ketone peroxide, peroxyketal, dialkyl peroxide, diacyl peroxide, or peroxydicarbonate may be added.

[Thickener] The 2-cyanoacrylate monomer is originally a colorless and transparent low-viscosity liquid, and as a thickener, for example, various acrylic monomers or methacrylic monomers may be used. A homopolymer or a copolymer, an acrylic rubber, a cellulose derivative, a silicic acid, or the like may be dissolved or dispersed to form a viscous liquid or a thixotropic adhesive.

[Other additives] Other dyes, pigments, plasticizers, diluents and the like may be added.

Examples of the non-adhesive material such as non-polar or highly crystallized resin to which the primer of the present invention is applied include olefin polymers such as polyethylene, polypropylene, polybutene and polymethylpentene, or olefin polymers such as these. And talc, alumina, mica or glass fiber; polyethylene terephthalate, polyacetal, polyurethane, silicone rubber or flexible PVC.

The primer of the present invention comprises a specific tertiary amine compound as an active ingredient, an organic solvent and an organic polymer added as required, and these components are mixed and uniformly dispersed. It is prepared by dissolving.

The application of the primer of the present invention to the resin surface does not require any special operation, and can be carried out by immersing the adherend in the primer, or by brushing, spraying or the like. The coating material to which the primer solution has been applied is air-dried at room temperature to remove the organic solvent and form a primer layer on the surface.

The adherend having the primer layer can be firmly bonded to each other or to another material by the above-mentioned cyano-based adhesive.

[0036]

The primer of the present invention is used for bonding a non-adhesive material such as a non-polar or highly crystallized resin using a cyano-based adhesive. It is estimated that the force is improved by the following mechanism.

That is, the specific tertiary amine compound which is an active ingredient of the primer of the present invention has a coupling function having both a polar atom and a non-polar group in its molecular structure. When applied to a material in the form of a thin film, the alkyl group of the compound diffuses and has affinity for the material, the polar atoms are oriented upward on the surface of the material, and the surface is activated.

When a cyano-based adhesive having a polar group is applied to the activated material surface as described above, a strong bond is formed by a secondary bond based on an intermolecular attractive force or a hydrogen bond. This strong bonding is considered to be most effective when the primer layer is formed into a monomolecular film or a thin film close thereto, and has been experimentally confirmed.

[0039]

The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1, Comparative Examples 1 to 5 Preparation of primers Four kinds of solution-like primers were prepared by the following operations. Example 1 N, N, N ′, N ″, N ″ -pentamethyldipropylenetriamine (Comparative Example 1) 4,4′-butylidene-bis (3-methyl-6-t-butylphenyl- (Comparative Example 2) Triphenylphosphine (Comparative Example 3) Aluminum monosec-butoxydiisopropylate (Comparative Example 4) N, N, N ′, N′-tetramethylhexanediamine (Comparative Example 5) ) No processing

1 g of each of the above compounds was mixed with 99 g of n-heptane.
(Industrial grade: manufactured by Maruzen Petrochemical Co., Ltd.) to give a primer. 2. Performance test of primer (based on JIS K6861) [Test piece] (1) Polyethylene plate, 25 × 100 × 2 mm (2) Polypropylene plate, 25 × 100 × 2 mm (3) Nylon 66 plate, 25 × 100 × 2 mm (4) Silicone rubber plate, 25 × 100 × 2 mm [Adhesive] Aron Alpha # 20 as a cyano-based adhesive
1 (manufactured by Toagosei Co., Ltd., main component: ethyl-2-cyanoacrylate) was used. Both the test pieces were brush-coated with the above primer, and (a) air-dried for about 3 minutes, (b) allowed to stand for 12 hours, an adhesive was applied to one side of the test piece, and both sides were combined to obtain a pressing load of 0.1 mm. 01N / mm ² was added and the mixture was cured for 24 hours. Next, the tensile shear adhesive strength was measured using a Strograph W-type testing machine at a tensile speed of 20 mm / min.
Was measured. As Comparative Example 5, the tensile shear adhesive strength was measured in the same manner as in Example 1 except that no primer was used. The results are shown in Tables 1 and 2.

[0042]

[Table 1]

[0043]

[Table 2]

As is clear from the test results in Table 1, the primer of the present invention can be used for bonding a wide range of difficult-to-bond materials.
It can be seen that as the material is destroyed, a higher adhesive strength is obtained, the set time is excellent, and the adhesiveness is remarkably improved. Further, as is clear from the test results in Table 2, the primer of the present invention has a high adhesive strength as the material is destroyed even in the adhesive after being left for a long time after the application of the primer, and has an excellent set time. It can be seen that the adhesiveness is remarkably excellent.

[0045]

The primer of the present invention makes it possible to easily and speedily carry out adhesion, coating or printing of a non-adhesive material represented by a non-polar or highly crystalline resin with a cyano-based adhesive. It has many advantages such as utilization of excellent physical properties, weight reduction, rust resistance and cost reduction in place of metal materials, and has a very large contribution to various fields such as automobile industry and electric equipment industry. It is.

Claims (4)

[Claims] 1. A primer for a 2-cyanoacrylate adhesive, comprising as an active ingredient a compound having three or more tertiary amino groups linked by an alkylene chain. 2. The following general formula (1) wherein R ₁ , R ₂ , R
₃ , R ₄ and R ₇ each represent an alkyl group having 1 to 2 carbon atoms. R _5, R ₆ each represents a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms. 2. The primer for a 2-cyanoacrylate adhesive according to claim 1, wherein the compound represented by the formula (1) is used as an active ingredient. Embedded image 3. A compound represented by the general formula (1) is, R _5,
The primer for a 2-cyanoacrylate adhesive according to claim 2, wherein R6 is a compound of a linear alkylene group having 2 to ₆ carbon atoms. 4. A compound represented by the general formula (1) is, R _1,
The primer for a 2-cyanoacrylate adhesive according to claim ₃ , wherein R ₂ , R ₃ , R ₄ and R ₇ are compounds having a methyl group, and R ₅ and R ₆ are compounds having a propylene group.