JPH0641577B2 - Primer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (b) Purpose of the Invention "Industrial field of application" The primer of the present invention is made of an α-cyanoacrylate based material such as a highly crystallized resin or a non-polar resin, which has been conventionally difficult to adhere. It is mainly used for good adhesion with adhesives, and it is widely used as a raw material for highly crystallized resins such as polyacetal typified by engineering plastics or nonpolar resins such as polyolefin. It is used in the fields of equipment industry and machine industry.

"Prior art" Highly crystallized resin, such as engineering plastics polyacetal, nylon or polyethylene terephthalate, or non-polar resin polyethylene,
Polypropylene or polybutene is a material which is difficult to adhere, paint and plate, and it is the current situation that these resins cannot be adhered well or painted or plated by a usual method.

Several proposals have already been made in order to improve the adhesiveness of these resins. For example, in the case of a highly crystallized resin, acid treatment with sulfuric acid, phosphoric acid, p-toluenesulfonic acid or the like or carbonation of the resin is performed. A method of blending an inorganic filler such as calcium or a method of sputtering has been proposed. (JP-A-56-152845 and 57-9602)
In the case of polyolefin, flame treatment, corona discharge, plasma jet treatment, treatment with a chlorinated polyolefin-based primer, and a method of adding an inorganic filler or solid rubber to the resin are also mentioned.

As a result of intensive research efforts by the inventors for the purpose of developing a technique superior to these methods, an organometallic compound,
We found a primer containing a fluorine-based compound or a phosphite-based compound as an active ingredient, and proposed it together. (JP-A-62-115078, 62-164768, 63-
10796) “Problems to be solved by the invention” The primer proposed by the present inventors has an extremely excellent function for achieving the intended purpose, and its mechanism is that the resin and the adhesive are combined. Since it seems to be based on the coupling action of the organometallic compound or phosphite compound at the interface, it is necessary to search for a novel compound having such action and having the same or higher functionality as the above compounds. The present inventors continued their earnest research efforts.

(B) Structure of the Invention "Means for Solving Problems" The present inventors have found that a specific organic phosphine compound among the various compounds has the above-mentioned function, and a primer containing these compounds as an active ingredient. The inventors have completed the present invention by discovering that a highly crystallized resin or a non-polar resin can be firmly bonded by using.

That is, the present invention relates to an α-cyanoacrylate-based adhesive primer, which comprises an organic phosphine compound having a benzene ring as an active ingredient.

Organic Phosphine Compound The organic phosphine compound used in the present invention has a benzene ring, and is specifically the following compounds.

Phosphine (PH ₃ ) such as phenylphosphine, diphenylphosphine, triphenylphosphine, methyldiphenylphosphine, dimethylphenylphosphine, tritolylphosphine, diphenylstyrylphosphine, diphenylmetastyrylphosphine, etc. contains all or part of hydrogen atoms as an aryl group or an aryl group. And a compound substituted with an alkyl group. Bisdiarylphosphinoalkanes such as bisdiphenylphosphinomethane, bisdiphenylphosphinoethane, bisdiphenylphosphinopropane, bisdiphenylphosphinobutane, bisdiphenylphosphinopentane, and bisdiphenylphosphinohexane.

A preferred compound for achieving the object of the present invention is a tertiary phosphine and alkane in which all of the hydrogen atoms of the phosphine are substituted with phenyl group, tolyl group, cytylyl group or metastyryl group, and the alkane has 1 to 4 carbon atoms. A bisdiarylphosphinoalkane whose group is a phenyl group or a tolyl group.

Organic solvent A primer containing an organic phosphine compound of the present invention as an active ingredient is used as a pretreatment agent for highly crystallizing or adhering a nonpolar resin using an α-cyanoacrylate adhesive, In order to form the above organic phosphine compound on the surface of the resin in a uniform and thin film form, it is preferably used as an organic solvent solution.

As the organic solvent, a general organic solvent which can completely dissolve or disperse the organic phosphine compound of the present invention, which has appropriate volatility, and which is industrially easily available is desirable.

Further, as the property of the organic solvent, one capable of sufficiently wetting the surface of the resin is preferable, and for this purpose, it is more preferable to select and use one having a surface tension of the organic solvent smaller than the critical surface tension rc of the resin. For example, regarding rc, polyacetal is 40, nylon 66 is 46, PET is 46, and polyethylene is 31, while the organic solvent is 1,1,2-trichloro-1 having a surface tension lower than that of rc. , 2,2-Trifluoroethane (19), ethanol (22), acetone (23), m-hexane (1
8), ethyl acetate (24), toluene (28) and the like are preferably used (both in parentheses are surface tension).

The concentration of the organic phosphine compound in the primer composition liquid is 0.01 to 10 wt% because the effect is most exerted when the organic phosphine compound is formed into a thin film form when used as a primer, preferably a monomolecular film form. It is preferably, and more preferably 0.05 to 5 wt%. If the concentration is less than 0.01 wt%, it becomes difficult to form the organic phosphine compound in the form of a thin film, and 10 wt%
%, It becomes a brittle thick layer and the function as a primer is deteriorated, which is not preferable.

Organic Polymer Various commonly known organic polymers can be used in combination with the primer of the present invention, whereby the coatability and the like can be improved. As the organic polymer, the primer of the present invention is preferably used by being dispersed or dissolved in an organic solvent at the time of use, so that it is preferable to use a polymer soluble in those organic solvents in combination. This is a preferred method for using the primer.

Specific examples of organic polymers that can be used in combination include ethylene / vinyl acetate copolymers, ethylene / acrylic acid ester copolymers, olefin copolymers such as α-olefin / maleic acid copolymers, and chlorinated polyethylene. Chlorinated polypropylene, chlorinated ethylene / propylene copolymers, chlorinated ethylene / vinyl acetate copolymers and other chlorinated off-in polymers: polyvinyl chloride, polyvinyl acetate, poly (meth) acrylic acid ester, polyvinyl ether Vinyl-based polymers such as vinyl chloride / vinylidene chloride copolymer: polychloroprene NBR, SBR, synthetic rubber such as chlorinated rubber, and the like.

Among the various organic polymers described above, more preferred is a chloride of a polymer or copolymer of propylene or ethylene, etc. Chlorinated olefin polymer: Chlorinated rubber: Copolymer of propylene or ethylene, etc. Olefin-based copolymer which is a polymer: methylmethacrylate / chloroprene copolymer, particularly preferred are chlorinated polypropylene and methylmethacrylate / chloroprene copolymer.

The amount of addition when the organic polymer is used in combination depends on the type of the organic polymer, but is preferably 0.1 to 20% by weight in the primer solution. If this concentration is less than 0.1% by weight, it has little effect on improving the coating property, and if it exceeds 20% by weight, it interferes with the function of the organic phosphine compound acting as a primer, and the effect as a primer is Reduce. The type and amount of the organic polymer added are preferably determined so that the viscosity of the primer solution is in the range of 2 to 5,000 cp / 25 ° C.

α-Cyanoacrylate Adhesive The primer of the present invention is used as a primer for an α-cyanoacrylate adhesive, and α-cyanoacrylate is represented by the following general formula.

R in the above formula includes alkyl, alkenyl, cyclohexyl, aryl, and alkoxyalkyl groups, and specifically, methyl, ethyl, n-propyl, n
-Butyl, isobutyl, n-pentyl, allyl, cyclohexyl, benzyl, methoxypropyl groups and the like can be mentioned.

These α-cyanoacrylates are commercially available α-cyanoacrylates.
It is a main component of a cyanoacrylate-based instant adhesive, and the primer of the present invention has a sufficient function as a primer for these commercially available adhesives.

Crystalline or nonpolar resin As the highly crystallized or nonpolar resin in which the primer of the present invention is used, polyacetal, polyamide, polyethylene terephthalate, polybutylene terephthalate, polyether ether ketone, polyethylene, polypropylene, polybutene, polymethylpentene, Examples include silicone rubber and polyphenylene ether.

Method of use The primer of the present invention comprises an organic phosphine compound as an active ingredient, and optionally an organic solvent and an organic polymer, and by mixing these components and uniformly dissolving or dispersing them. It can be mixed.

The method of applying the present primer to the resin surface does not require a special operation, and may be applied by brushing, spraying or dipping in a primer.

A primer layer is formed on the surface of the resin coated with the primer by air-drying at room temperature. The resin having the primer layer can firmly adhere to the resin or other materials by the above-mentioned α-cyanoacrylate adhesive.

In order to bring out the effect of the present primer more effectively, it is necessary to consider the type of the target resin and determine the type and concentration of the organic phosphine compound to be supported.

As for the coating amount, it is preferable that the coating amount of the organic phosphine compound is 0.001 to 1 g / m ² , and more preferably 0.01 because the thickness of the primer layer has a large influence on the effect as described above. It is to be applied so as to be 0.1 g / m ² .

"Action" It is presumed that the primer of the present invention exhibits effects by the following mechanism.

That is, the organic phosphine compound which is the active ingredient of the primer of the present invention has a coupling function having both polar atoms and non-polar groups in its molecular structure, and when the primer is applied to a resin in a thin film form, the organic phosphine compound The non-polar group of the compound diffuses and binds to the resin, the polar atom of the organic phosphine compound is oriented upward on the surface of the resin, and the resin surface is activated. When α-cyanoacrylate having a polar group is applied to the surface of the resin thus activated, a strong bond is formed by a secondary bond or hydrogen bond based on the intermolecular attractive force.

Therefore, this strong bonding seems to exert its effect most when the primer layer is formed in a monomolecular film shape or a thin film shape close thereto, and was confirmed experimentally.

"Examples" The present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1 and Comparative Example 1 0.2 g of triphenylphosphine and tri-p-tolylphosphine (manufactured by Hokuko Kagaku Kogyo Co., Ltd.) were each added to methyl chloroform (industrial grade, Toagosei Kagaku Co., Ltd.).
The product was dissolved in 99.8 g to prepare a primer.

The performance test of the primer was performed according to JIS K6861.

Test piece (Shape 25 × 100 × 2 mm) Polyacetal, Delrin 500 DuPont 〃 Duracon M90-02 Polyplastics Polyacetal, Iupital F20-02 Mitsubishi Gas Chemical Industry Co., Ltd. Adhesive Aron Alpha # 201 (α-cyanoacrylate type) Adhesive, manufactured by Toagosei Kagaku Kogyo Co., Ltd. After applying the above-mentioned primer on both sides of the test piece and air-drying for about 5 minutes, apply the adhesive on one side of the test piece and lay the both sides on top of each other and apply a pressing load of about 0.1. kgf / cm ² was added and the mixture was cured at room temperature for 24 hours. The tensile shear adhesive strength was measured at a tensile speed of 20 mm / min using a strograph w type tester.

In addition, as Comparative Example 1, a test was performed in the same manner as in Example 1 except that the primer treatment was not performed.

The results are shown in Table 1.

Example 2 and Comparative Example 2 0.5 g each of bisdiphenylphosphinoethane and bisdiphenylphosphinobutane (manufactured by Kitako Chemical Co., Ltd.)
Toluene (reagent first grade, Tokyo Chemical Industry Co., Ltd.)
The product was dissolved in 99.5 g to prepare a primer.

The following test pieces were used in the primer performance test.

Test piece (shape 25 × 100 × 2 or 0.1 mm) Polyacetal Tenac 7050 Asahi Kasei Corp. PBT Duranex 3300 Polyplastics Corp. PET # 100 Mitsubishi Plastics Co., Ltd. Other test methods are described in Example 1 It was done according to.

Further, as Comparative Example 2, the test was performed in the same manner as in Example 2 except that the primer treatment was not performed.

The results are shown in Table 2. Example 3, Comparative Example 3 Diphenylstyrylphosphine (Kitako Chemical Industry Co., Ltd.)
0.3 g) was dissolved in acetone, m-hexane and 99.7 g of ethyl acetate to prepare a primer.

The following test pieces were used in the primer performance test.

Test piece (shape 25 × 100 × 2 mm) Nylon 66 CM3001N Toray Industries, Inc. Polyethylene Hi-Zex 5000H Mitsui Petrochemical Industry Co., Ltd. polypropylene Mitsui Noblen # 100 Mitsui Toatsu Kagaku Co., Ltd. It was done according to. Further, as Comparative Example 3, a test was performed in the same manner as in Example 3 except that the primer treatment was not performed.

The results are shown in Table 3.

(C) Effect of the Invention By using the primer of the present invention, it becomes possible to easily and speedily adhere a highly crystallized resin or a non-polar resin with an α-cyanoacrylate adhesive, and thus engineering plastic or polyolefin etc. There are many merits such as weight reduction, rustlessness, and cost reduction in place of metal materials, and the contribution to each field such as automobile industry and electric equipment industry is very large.

Claims (1)

[Claims] 1. A primer for an α-cyanoacrylate adhesive, which comprises an organic phosphine compound having a benzene ring as an active ingredient.