JPH0657218A - Primer for instantaneous 2-cyanoacrylate-based adhesive - Google Patents

Abstract

PURPOSE:To provide a primer for an instantaneous 2-cyanoacrylate-based adhesive which can make even a hard-to-bond adherend such as polyethylene or polypropylene exhibit an excellent adhesion, has a very long serviceable life ranging from the time of application of the primer on an adherend to the time of application thereon of an adhesive, has so little smell as to present to problems, and has such a quality that neither foaming nor whitening is caused on the site of bonding during a bonding operation. CONSTITUTION:This primer comprises, as the active ingredient, a tert. amine represented by the formula; R3N (wherein Rs are each a hydrocarbon group) and having at least one 8-24C hydrocarbon group among the hydrocarbon groups thereof. An esp. pref. example of such a tert. amine is trilaurylamine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a primer which can markedly improve the adhesive strength even when it is used for adhesion with a 2-cyanoacrylate type instant adhesive, even for an adherend which is difficult to adhere. It is a thing.

[0002]

2. Description of the Related Art 2-Cyanoacrylate instant adhesives are widely used as industrial and household adhesives because they have fast curing properties. However, they are difficult to adhere to adhesive materials such as polyethylene and polypropylene. Cannot obtain sufficient adhesive strength. Therefore, prior to bonding, the surface of the adherend is treated with a primer.

In Japanese Patent Publication No. 43-5004,
Polyethylene, polypropylene, polyformaldehyde, polyfluorinated ethylene, etc. The surface of these synthetic resin bodies is pre-inorganic in order to give the adhesive force to the synthetic resin bodies that show almost no adhesiveness with 2-cyanoacrylate instant adhesives. A method of treating with a basic substance or an organic basic substance has been proposed, and as examples of the organic basic substance, formamide, dimethylformamide, dimethylacetamide, ethylamine, triethylamine,
Examples include monoethanolamine, diethanolamine, piperidine and pyrroline.

Japanese Patent Publication No. 47-8718 discloses that base materials such as bakelite, polyvinyl chloride, polyethylene, acrylonitrile-styrene copolymer, and natural rubber are prepared in advance with dimethylaniline and tris [1- (2methyl) aziridinyl. A method of treating with phosphine oxide is disclosed, and in Japanese Patent Publication No. Sho 49-12094, a base material such as polyester, nylon, polyacetal, and aluminum is preliminarily diethylamine, o-phenylenediamine, dimethyl-p-toluidine, diethyl-. p-toluidine,
A method of treating with N.N diethylaniline, trichloroacetamide and succinimide is disclosed.

JP-A-59-66471 discloses three components, an amine compound having a boiling point of 50 to 250 ° C., a deodorant and a solvent, for the purpose of accelerating the curing of an instant adhesive when adhering wood, paper and leather. A curing accelerator composition for a cyanoacrylate-based instant adhesive composed of a uniform solution has been proposed,
Examples of amine compounds include triethylamine, diethylamine, butylamine, isopropylamine, dibutylamine, tributylamine, N, N-dimethylaniline, N, N-diethylaniline, N, N-dimethyl-p.
-Toluidine, N, N-dimethyl-m-toluidine,
N, N-dimethyl-o-toluidine, dimethylbenzylamine, pyridine, picoline, vinylpyridine, ethanolamine, propanolamine and ethylenediamine are mentioned.

Japanese Patent Application Laid-Open No. 62-18 filed by the present applicant
No. 485, from the group consisting of 2,4-lutidine, 3,4-lutidine, 6-amino-2-picoline, 4-dimethylaminopyridine, 2-aminopyridine, 3-aminopyridine and 1-vinylimidazole. A 2-cyanoacrylate-based instant adhesive primer consisting of a selected compound or a solvent solution thereof is shown.

Similarly, Japanese Patent Application Laid-Open No. Sho 62-62, filed by the present applicant.
No. 18486 discloses a primer for 2-cyanoacrylate-based instant adhesive, which comprises 4-vinylpyridine as an essential component and a compound containing β-picoline or / and 3,4-lutidine as an optional component or a solvent solution thereof. It is shown.

In addition, Japanese Patent Publication No. 54-19416, Japanese Patent Publication No. 62-29471, and Japanese Patent Publication No. 61-12.
6190, JP-A-63-51489, JP-A-63-128090, JP-A-64-66222.
The publication also discloses a primer composed of a nitrogen-containing compound similar to the above.

[0009]

However, many of the above-mentioned organic basic substances and amine compounds do not improve the adhesive strength, and even if the adhesive strength is improved with respect to a certain specific plastic substrate. Even if the effect was exhibited, even in the same grade base material, there was a large variation in adhesive strength, and even if the grade was different, the adhesive strength could be greatly reduced. Even in the case of a certain type of plastics base material, the adhesive strength may vary widely in some cases, or the adhesive strength may decrease due to differences in grades. Is extremely difficult to perform, and it is strongly desired that a constant and sufficient adhesive force is always obtained.

[0010] Also, the pot life after application to the adherend is severely limited (For example, if the adhesive operation is not performed within a narrow time range of about 10 minutes after application of the primer, the desired adhesive strength can be obtained. There are some restrictions such as not being able to do so) and the method of applying the primer depends on the skill of the worker. Therefore, the required adhesive strength may not be obtained without skill.

In addition, many of the above-mentioned primers have a peculiar amine odor or pyridine odor, cause foaming due to heat generation due to rapid curing during the bonding operation, or whiten the bonding site during the bonding operation. It often causes a phenomenon, which is also a hindrance to practical use.

Under such a background, the present invention can exhibit excellent adhesive force even to a difficult-to-adhere adherend such as polyethylene or polypropylene, and a primer is applied to the adherend. For 2-cyanoacrylate instant adhesives, which has the characteristics that the pot life before applying the adhesive is extremely long, the odor is small enough not to cause a problem, and that foaming and whitening phenomena do not occur at the bonding site during the bonding operation. The purpose is to provide a primer.

[0013]

The primer for 2-cyanoacrylate instant adhesives of the present invention is a hydrocarbon group of an amine represented by the formula R ₃ N (provided that all three R are hydrocarbon groups). At least one hydrocarbon group has a tertiary amine, which is a long-chain hydrocarbon group having 8 to 24 carbon atoms, as an active ingredient.

The present invention will be described in detail below.

The active ingredient of the primer of the present invention has the formula R
A tertiary amine in which at least one of the hydrocarbon groups of the amine represented by ₃ N (wherein all three R are hydrocarbon groups) is a long-chain hydrocarbon group having 8 to 24 carbon atoms. is there. A typical hydrocarbon group is an alkyl group, but it may be a halogen-substituted alkyl group, an OH group-substituted alkyl group, an alkenyl group, or the like.

Specific examples of the long-chain hydrocarbon group having 8 to 24 carbon atoms include octyl group, nonyl group, decyl group, undecyl group,
A dodecyl group (lauryl group), a tetradecyl group, a hexadecyl group, an octadecyl group, an eicosyl group, a tetracosyl group, and the like, and a straight chain one is more effective than one having a side chain.

The most preferred of the above-mentioned tertiary amines are primer performance, low odor or no odor, pot life,
Considering cost and the like comprehensively, it is trilaurylamine (that is, tri-n-dodecylamine).

The above-mentioned tertiary amine is used in the form of a solvent solution prepared by dissolving it in a solvent by applying it to an adherend by means of coating, spraying, dipping or the like. The primer-coated surface is often dried before applying the instant adhesive, but the adhesive may be applied in an undried wet state.

The above-mentioned solvent comprises ketones, alcohols, hydrocarbons, esters, ethers, fluorine-containing solvents, chlorine-containing solvents, nitrogen-containing solvents, water and the like, or two or more kinds of solvents. Mixed solvents are used.

The concentration of the tertiary amine in the solution is not particularly limited, but it is preferably used as a solution having a concentration of about 0.001 to 10% by weight, particularly 0.01 to 2% by weight. Since the primer of the present invention is preferably closer to a monomolecular film than thick coating, it is preferably used as a dilute solution as described above rather than as a concentrated solution.

The primer of the present invention can be used in combination with another primer for instant adhesives.

As the adherend to be treated with the primer, any material may be used, such as polyethylene,
Polyolefins such as polypropylene and ethylene-propylene terpolymer, or polyacetal (polyoxymethylene), polyethylene terephthalate, polybutylene terephthalate, polyamide, polyvinyl chloride,
The present invention can be applied to adhesion between materials that cannot be adhered with a conventional 2-cyanoacrylate adhesive or have poor adhesive strength, or adhesion between these materials and a polar substrate.

After applying the above primer to the adherend,
The bonding operation is carried out with a 2-cyanoacrylate instant adhesive with or without drying.

Examples of 2-cyanoacrylate instant adhesives include alkyl 2-cyanoacrylate, cycloalkyl 2-cyanoacrylate, and alkoxyalkyl.
2-cyanoacrylate such as 2-cyanoacrylate, alkenyl 2-cyanoacrylate, and alkynyl 2-cyanoacrylate as a main agent, and if necessary, a polymerization inhibitor, stabilizer, thickener, heat resistance imparting agent, plasticizer, coloring Agents, thixotropy improvers, pH adjusters, ethylene carbonate, organic solvents, fillers, synthetic resins other than those for the purpose of thickening are used.

[0025]

The primer of the present invention is applied to the surface of the adherend to be adhered prior to the application of the instantaneous adhesive, and then the 2-cyanoacrylate instantaneous adhesive is used for adhesion. At that time, the primer plays a role of exerting sufficient adhesive strength even if the adherend has a difficulty in adhesion.

In the primer of the present invention, the amine odor is small (especially, the amine odor is practically not felt in the solvent solution of trilaurylamine), and the pot life after application to the adherend is low. It is surprisingly long, for example, one week or more from immediately after undried, no special know-how is required for the coating operation, and neither foaming nor whitening phenomenon occurs during the bonding operation.

[0027]

The present invention will be described in more detail with reference to the following examples. Hereinafter, "%" means% by weight.

Example 1 First, as a preliminary experiment, a 1% isopropanol solution was prepared for each nitrogen-containing compound shown in Table 1 below, and A odor, B solubility and C primer effect were examined. As the adherend, a polyethylene molded body and a polypropylene molded body are used,
As the adhesive, an instant adhesive containing ethyl 2-cyanoacrylate as a main component and manufactured by Alpha Giken Co., Ltd. and having a viscosity of 2.5 cps / 25 ° C. was used. The judgment was made according to the following criteria. The results are shown in Table 1 below. A ○: Almost no odor, △: Slight odor, × odor B ○: Good, △: Slightly cloudy, ×: Cloudy C ○: Effective, △: Slightly insufficient effect, ×: Insufficient effect,
#: Effective but premature foaming and whitening

Regarding the primer effect among the above, a polyethylene molded product having a length of 100 mm, a width of 25 mm and a thickness of 2 mm is used as an adherend and a stock containing ethyl 2-cyanoacrylate as a main component as an adhesive is used. Almost 2 on each end of each of the two test pieces using an instant adhesive with a viscosity of 2.5 cps / 25 ° C manufactured by Alpha Giken Co., Ltd.
Apply the above primer with a brush to the area of 5 mm x 12.5 mm, then after 5 to 10 minutes, apply the above instant adhesive in dots on the primer application surface of one test piece, and apply the primer of the other test piece. Lightly crimp the coated surfaces together and leave in that state for 10 seconds to create a sample for adhesion testing.
Qualitative adhesive strength was observed by holding both ends of this sample by hand and bending strongly in the direction of 90 °. In this evaluation of the primer effect, the open time from application of the primer to application of the adhesive is 5-10 as described above.
It's fixed at minutes, and I haven't seen the effects of open time.

The results are shown in Table 1 below. The value of tensile shear strength is an average value for three test pieces.

[0031]

[Table 1] Nitrogen-containing compound A Odor B Solubility C Primer effect Trilaurylamine ○ ○ ○ N, N-dimethyl n-octylamine ○ ○ ○ ~ △ Tri n-hexylamine × ○ ○ ~ △ Tri n-pentylamine × ○ ○ ~ △ tri-n-butylamine × ○ △ triisobutylamine × ○ × triallylamine × ○ ^* ○ ~ △ tribenzylamine × × × laurylamine △ ○ × β-picoline × ○ △ γ-picoline × ○ △ 2,6-lutidine × ○ × 2,4-lutidine × ○ × 2-Vinyl pyridine × ○ ^** × 4-Dimethylaminopyridine ○ ○ # 6-Amino-β-picoline ○ ○ # N, N-dimethylacrylamide Δ ○ × 1-vinyl imidazole × ○ ○ amino-modified silicone oil ○ ○ × methacrylate 2-dimethylaminoethyl × ○ ○ methacrylate 2- diethyl Minoechiru × ○ △ (Note) ^* is pale yellow, ^** is the solution colored in yellow-brown.

Example 2 A polypropylene molding (100 mm in length, which is a typical difficult-to-adhere material for 2-cyanoacrylate instant adhesives)
A width of 25 mm and a thickness of 2 mm) was prepared as a test piece. As an adhesive, an instant adhesive containing ethyl 2-cyanoacrylate as a main component and manufactured by Alpha Giken Co., Ltd. and having a viscosity of 2.5 cps / 25 ° C. was prepared. Further, a 0.5% isopropanol solution of trilaurylamine was prepared as a primer.

Approximately 2 on one end side of each of the two test pieces
The above primer was applied to a 5 mm × 12.5 mm area with a brush. Then, immediately (after about 30 seconds), 5 minutes, 30 minutes,
After 14 hours, 24 hours (1 day), 3 days, and 7 days (1 week), the above-mentioned instant adhesive was applied in dots on the primer-coated surface of one of the test pieces, and the other test piece Lightly crimp the primer-coated surfaces together and then 10
The sample was left for 2 seconds for the adhesion test. A large number of such samples were prepared, and after standing for 24 hours, the tensile shear strength was measured using a tensile tester. The primer-coated surface of the test piece after 30 seconds in the above is still undried. No degreasing was performed on any of the test pieces.

The results are shown in Table 2 below. The value of tensile shear strength is an average value for three test pieces. In all cases, neither foaming nor whitening occurred in the adhesive part.

[0035]

[Table 2] Open time Tensile shear strength (kg / cm ² ) 30 seconds later 29.6 (partial base material destruction) 5 minutes later 25.8 (partial base material destruction) 30 minutes 39.5 (base material destruction) 14 hours later 52.5 (base material destruction) ) 1 day later 43.8 (base material destruction) 3 days later 45.0 (base material destruction) 7 days later 40.0 (base material destruction)

Example 3 Using the same test piece as in Example 1 (however, one having an open time of 1 hour after applying the primer was used), the rising strength was measured. The rising strength is the time from dropping the adhesive to aligning both surfaces and measuring. The results are shown in Table 3.

[0037]

[Table 3] Rise time Tensile shear strength (kg / cm ² ) 1 minute later 11.0 3 minutes later 11.8 5 minutes later 12.8 10 minutes later 13.0 15 minutes later 13.2 30 minutes later 23.0 1 hour later 32.0 (partial base metal fracture) 1 day later 42.0 ( Destruction of base material)

Example 4 The adhesive strength was evaluated in the same manner as in Example 1 except that the adherend was variously changed and a 0.5% acetone solution of trilaurylamine was used as a primer. No degreasing was performed on any of the test pieces, and the open time after application of the primer was set to 1 hour.

The results are shown in Table 4 below. The value of tensile shear strength is an average value for three test pieces. EPT is an ethylene-propylene terpolymer.

[0040]

[Table 4] Type of adherend Tensile shear strength (kg / cm ² ) Polyoxymethylene 54.5 (Fracture of base material) Nylon 6 36.1 (Fracture of base material) EPT 4.5 (Fracture of base material) Polyethylene 40.0 (Fracture of base material)Silicone 6.3 (base material destruction)

Example 5 Adhesion of polypropylene was evaluated using 0.5% isopropanol solutions of various tertiary amines. The measurement was also performed when the primer was not used as a control.

The results are shown in Table 5 below. The value of tensile shear strength is an average value for three test pieces.

[0043]

[Table 5] Type of primer Tensile shear strength (kg / cm ² ) Trilaurylamine 42.5 (base material fracture) Tri-n-octylamine 40.0 (base material fracture) N, N-dimethyldodecylamine 40.0 (base material fracture) N, N-dimethyl Hexadecylamine 38.5 (destruction of base material) Tri-n-butylamine ^* 26.0 (partial destruction of base material) Triethylamine ^* 24.6 Triallylamine ^* 25.6 (without primer) 2.9 (Note) ^* mark has a strong amine odor and whitens when adhered The phenomenon is also seen. Almost no amine odor is felt with other amines, and no whitening phenomenon is observed.

Example 6 0.1%, 0.2%, 0.5%, 0.7% of trilaurylamine
Then, a 1% isopropanol solution was prepared, and the primer effect on polyethylene, polypropylene, and corona discharge treated polypropylene was examined in the same manner as in Example 1. As a result, polyethylene was found to have a strong effect although the base material was not destroyed. Adhesive strength was obtained, and for polypropylene and corona discharge treated polypropylene, adhesive strength leading to base material destruction was obtained. In both cases, neither foaming nor whitening was observed at the adhesion site.

Example 7 Trilaurylamine was used as cyclopentane, "Zeonsolve HP" (95% cyclopentane, manufactured by Nippon Zeon Co., Ltd.), "Axarel" (mixture of aliphatic hydrocarbon and aliphatic ester, Mitsui DuPont). Fluorochemical Co., Ltd.), acetone, methylcyclohexane, and “ASAHIKLIN AK-225” (alternative CFC, manufactured by Asahi Glass Co., Ltd.) to prepare 0.5% concentration solutions. Using these solutions, the primer effect on polyethylene, polypropylene, and corona-discharge-treated polypropylene was examined in the same manner as in Example 1. As a result, a strong adhesive force was obtained for polyethylene, although the base material was not destroyed. Was obtained, and the adhesive force to the base material fracture was obtained for polypropylene and corona discharge treated polypropylene. In both cases, neither foaming nor whitening was observed at the adhesion site.

[0046]

EFFECT OF THE INVENTION The primer of the present invention has the following effects and is extremely practical. (1) Adhesives such as polyethylene and polypropylene that are difficult to adhere to can be firmly adhered by the instant adhesive. Also,
With respect to a specific adherend, a constant adhesive force corresponding to the adherend is always obtained, and variations in the adhesive force are small. (2) The pot life after application to the adherend is remarkably long, and the instant adhesive may be applied for a week or more immediately after application of the primer, and there is no limitation on the method of applying the primer.
With such a wide allowable width, workability is extremely good,
Does not require special skill. It is also possible, for example, to apply the primer to the object all at once on the previous day and then perform the bonding operation with the instant adhesive on the next day. (3) The odor is so small that it does not matter. (4) Does not cause excessive rapid curing during the bonding operation, and does not cause foaming or whitening of the bonded part.

The discovery of a primer having such characteristics is incredibly surprising from the common sense of conventional primers for instant adhesives.

Claims (3)

[Claims] 1. A long-chain hydrocarbon group having 8 to 24 carbon atoms, wherein at least one of the hydrocarbon groups of the amine represented by the formula R ₃ N (wherein all three R are hydrocarbon groups) is a hydrocarbon group having 8 to 24 carbon atoms. A 2-cyanoacrylate-based instant adhesive primer containing the tertiary amine as an active ingredient. 2. The primer according to claim 1, wherein the tertiary amine is trilaurylamine. 3. The tertiary amine of claim 1 is dissolved in a solvent.
The primer according to claim 1, which comprises a solvent solution having a concentration of 0.001 to 10% by weight.