JPH0853506A - Method for curing air contact surface of anaerobic curable composition - Google Patents

Abstract

(57) [Summary] [Objective] A method for curing an air-contacting surface of an anaerobic curable composition at room temperature in a short time. [Structure] (a) Paraffin wax, (b) Soluble vanadium compound, (c) Acid phosphorus compound such as phosphorous acid, hypophosphorous acid, and acid phosphate, or one or two selected from ascorbic acid. A method for curing an air-contacting surface of an anaerobic curable composition, which comprises applying a curing accelerator solution obtained by dissolving one or more species in an organic solvent to the surface of the anaerobic curable composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for curing an air-contacting surface of an anaerobic curable composition at room temperature in a short time.

[0002]

An anaerobic curable composition containing an unsaturated polymerizable monomer and an organic peroxide has a property that it is difficult to cure a portion in contact with oxygen or air, and a typical one is Has an anaerobic adhesive. The anaerobic adhesive is packed in a container made of polyethylene having good oxygen permeability in an amount of ½ or less, and in this state, it can be stably kept in a liquid state without being cured at room temperature for a long period of time. When this is filled in the gap of the fitting portion such as a screw or a pipe, it is cured at room temperature in a short time by blocking oxygen or air, and exhibits a locking effect and a sealing effect. in this way,
An anaerobic adhesive is an adhesive that is one-component and has an excellent workability such as room temperature curability, and is widely used in the industrial fields of electronics, electricity, vehicles, machines and the like. However, due to its characteristics,
The part that sticks out of the joint and is in contact with the air will not harden forever, so dust or dirt may adhere, the skin of the worker may get inflamed, or other parts may become unneeded. There were drawbacks such as sticking and causing malfunction. As a method for solving these problems, a method of irradiating the protruding portion of the anaerobic curable composition with ultraviolet rays to cure the composition has been reported (JP-A-53-94349).
There is a problem that not only the composition of the anaerobic curable composition itself is specified but also a dedicated ultraviolet irradiation device is required and the cost becomes high. Further, as a simpler solution method, a method of applying an organic solvent solution in which a substance having an air barrier property is dissolved to the protruding portion (JP-A-53-16049)
However, as a result of additional tests by the present inventors, a system in which the anaerobic curable composition almost cures like the two-component acrylic adhesive, where the portion overflowing from the joint leaves only the air contact surface. However, in the case of a one-part anaerobic adhesive in which the overflowed portion hardly cures from the surface to the inside, neither the surface nor the inside was cured and no effect was observed. Further, the present inventors have proposed a method of applying an organic solvent solution in which a specific substance is dissolved to the protruding portion (Japanese Patent Laid-Open No. 3-244683). This method is very simple, and the surface of the anaerobic curable composition can be treated in 60 to 90 minutes at room temperature.
It has excellent workability that it completely cures the inside.

[0003]

However, among various recent needs, from the viewpoint of improving productivity, the surface of an anaerobic curable composition, the one having a short internal curing time, especially the surface stickiness. There is a demand for the feeling to disappear in a short time, and the above proposal is somewhat insufficient to satisfy this demand. An object of the present invention is to provide a method for eliminating the sticky feeling on the air contact surface of an anaerobic curable composition at room temperature in a short time.

[0004]

The inventors of the present invention applied the composition to an anaerobic curable composition protruding from a joint, particularly an anaerobic adhesive and applied it to an air contact surface at room temperature in a shorter time than in the prior art. A curing accelerator that can eliminate the sticky feeling was examined. As a result, by adding the paraffin wax to the curing accelerator in which the soluble vanadium compound and the ascorbic acid or / and the specific acidic phosphorus compound are combined, the stickiness of the air contact surface of the anaerobic curable composition can be made extremely high at room temperature. The present inventors have found that they have an excellent effect that they can be eliminated in a short time, and have reached the present invention.

According to the present invention, 1 is selected from (a) paraffin wax, (b) soluble vanadium compound, (c) acidic phosphorous compound such as phosphorous acid, hypophosphorous acid and acidic phosphoric acid ester, or ascorbic acid. There is provided a method for curing an air-contacting surface of an anaerobic curable composition, which comprises applying a curing accelerator solution obtained by dissolving one or more kinds in an organic solvent to the surface of the anaerobic curable composition. More preferably, one or two kinds selected from (a) paraffin wax, (b) soluble vanadium compound, and (c) acidic phosphoric acid ester represented by the following general formula (1) or (2): A method for curing an air-contacting surface of an anaerobic curable composition is provided, which comprises applying a solution of a curing accelerator obtained by dissolving the above in an organic solvent to the surface of the anaerobic curable composition. (However, R ₁ is an alkyl group having 1 to 4 carbon atoms, R ₂ is hydrogen or a methyl group, R ₃ is an alkylene group having 1 to ₃ carbon atoms, and n is an integer of 1 or 2.)

The anaerobic curable composition capable of curing the air contact surface by the method of the present invention may be any adhesive composition having an anaerobic property such that the portion in contact with oxygen or air is not cured, For example, JP-A-48-25050
JP-A-60-32868, one-component type anaerobic adhesive disclosed in JP-A-49-132119 and JP-A-53
The two-pack type acrylic adhesives and other unsaturated polyester resins disclosed in Japanese Patent Publication No. 16049 are listed.

As the paraffin wax used in the present invention, those having a melting point of 30 to 100 ° C., preferably 40 to 80 ° C. are suitable for handling. The amount used is 0.01-5 parts by weight, especially 0.05-0.
5 parts by weight is suitable. This acts as an air barrier coating agent, and if it is too small, the air barrier effect is poor, and conversely, if it is too high, the evaporation of the solvent may be hindered and the curing promotion effect may be poor.

The vanadium compound is not particularly limited as long as it is soluble in an organic solvent, and examples thereof include vanadyl acetylacetonate, vanadium acetylacetonate, vanadium benzoylacetonate, vanadyl oxalate and vanadyl stearate. The amount used is 0.01 to 5 parts by weight based on 100 parts by weight of the organic solvent,
Particularly, 0.05 to 0.5 parts by weight is suitable. This acts as a curing accelerator, and if it is too small, the curing promoting effect is poor, and if it is too large, the physical properties of the cured product may deteriorate. The amount of ascorbic acid or the acidic phosphorus compound is 0.01 to 10 parts by weight, and usually 1 to 5 parts by weight, based on 100 parts by weight of the organic solvent. This acts as a curing accelerator, and if it is too small, the curing promoting effect is poor, and if it is too large, the physical properties of the cured product may deteriorate. The acidic phosphorus compound is selected from phosphorous acid, hypophosphorous acid, acidic phosphoric acid ester, and the like, and even more preferably, as an acidic phosphorus compound, a compound represented by the following general formula (1) or (2) An acidic phosphoric acid ester having a -P-OH group is preferably used. (However, R ₁ is an alkyl group having 1 to 4 carbon atoms, R ₂ is hydrogen or a methyl group, R ₃ is an alkylene group having 1 to ₃ carbon atoms, and n is an integer of 1 or 2.)

Further, the following compounds may be further added to the curing accelerator solution of the present invention. That is, thioureas such as ethylenethiourea, acetylthiourea and benzoylthiourea which are reducing agents, hydroxyacetone,
Α-Hydroxyketones such as dihydroxyacetone and benzoin, polycondensates of butyraldehyde and aniline, and polyvinyl butyral, which is a polymer soluble in an organic solvent, polymethyl methacrylate, polyvinyl acetate,
Examples include ethyl cellulose, polycarbonate, and phenoxy resin.

The organic solvent uniformly dissolves the above-mentioned additives,
There is no particular limitation as long as it is volatile at room temperature. As an organic solvent for dissolving paraffin wax having an air barrier property, n-pentane, n-hexane,
Hydrocarbons such as n-heptane and cyclohexane, halogenated hydrocarbons such as methylene chloride, chloroform and carbon tetrachloride, and methyl methacrylate and ethyl methacrylate are preferable. Methyl alcohol, ethyl alcohol, isopropyl alcohol, ethyl acetate, acetone, methyl methacrylate, ethyl methacrylate and the like are preferable as the organic solvent in which the vanadium compound, ascorbic acid or acidic phosphorus compound having a curing acceleration effect is dissolved. These are generally used as a mixture.

[0011]

The present invention will be described in more detail with reference to Examples and Comparative Examples. All parts are parts by weight. The anaerobic curable composition used in this example is an anaerobic adhesive having the following composition described in JP-A-48-25050. <Anaerobic adhesive> -Tetramethylene glycol methacrylate 92 parts-Polymethyl methacrylate (Mitsubishi Rayon Co., Ltd., Diner BR-75) 8 parts-O-Benzoxyl imide 0.4 parts-N, N-dimethyl -p-toluene 0.8 parts-cumene hydoperoxide-oxide 3 parts-p-benzoquinone 0.04 parts-fine powder anhydrous silicic acid 5 parts

Examples 1 to 12 Ethyl alcohol 70
Parts, n-hexane 30 parts, vanadyl acetylacetonate 0.2 parts, paraffin wax (melting point 48-50 ° C)
The curing test of the anaerobic curable composition was conducted using the curing accelerator solution obtained by adding and dissolving the additives shown in Table 1 to the solution consisting of 0.2 parts. A drop of an anaerobic adhesive was dropped on a polished iron plate in a room at 23 ° C. and 50% RH, and a drop of a curing accelerator solution was immediately dropped on it. After the dropping, the dry time to the touch where the sticky feeling is not felt even if the surface is touched with a finger and the complete curing time to cure to the inside were measured. The thickness of the adhesive is 2 mm. The results are shown in Table 1.

[Comparative Examples 1 to 5] Ethyl alcohol 70
Part, and a curing accelerator solution obtained by adding and dissolving the additives shown in Table 2 to a solution consisting of 30 parts of n-hexane, and using the same anaerobic adhesives as in Examples 1 to 12, a curability test. I went. Table 2 shows the results. As is clear from Table 2, if any one of (a), (b) and (c) shown in the claims of the present invention is missing, the air-contacting surface of the anaerobic curable composition has a sticky feeling at room temperature. It cannot be lost in a short time.

[Examples 13 to 16] 0.1% by weight and 1% by weight of cobalt naphthenate and methyl ethyl ketone peroxide were added to and mixed with an unsaturated polyester resin (Rigolac 2004M-2, manufactured by Showa High Polymer Co., Ltd.). As a result of leaving still for 24 hours at 50 ° C and 50% RH, the inside was cured leaving the surface adhesive layer. Next, 70 parts of ethyl alcohol, 30 parts of n-hexane, 0.2 part of vanadyl acetylacetonate were added to the surface of the cured product having surface tackiness.
A hardening accelerator solution obtained by adding and dissolving the additives shown in Table 3 to a solution consisting of 0.2 part of paraffin wax (melting point 48 to 50 ° C.) is applied, and the dryness to the touch of the air contact surface disappears. Observed the time. The results are shown in Table 3. Further, the main component of the two-component acrylic adhesive (hard Sony bond manufactured by Sony Chemical Co., Ltd.) and the primer were mixed at a ratio of 10: 1. As a result, heat was generated within one minute, and the parts other than the surface were cured. However, the surface was tacky even after 24 hours. Next, the same curing accelerator solution as described above was applied to the surface of the cured product having surface tackiness, and the dry time to touch when the tackiness of the air contact surface disappeared was observed. The results are shown in Table 3.
Shown in As is apparent from Table 3, the stickiness of the air contact surface of the anaerobic curable composition such as the two-component acrylic adhesive and the unsaturated polyester resin can be eliminated in a short time at room temperature by the method of the present invention.

[Examples 17 to 20 and Comparative Example 6] M1
0 4 drops of anaerobic adhesive were applied on the threads of the mild steel nut, and the same type of bolt was screwed in. 70 parts of ethyl alcohol, 30 parts of n-hexane,
The curing accelerator solution obtained by adding and dissolving the additives shown in Table 4 to a solution consisting of 0.2 part of vanadyl acetylacetonate and 0.2 part of paraffin wax (melting point 48 to 50 ° C.) was applied, Curability was measured in the same manner as 1-12. 23
In the environment of ° C, after 24 hours, the returning torque was measured according to JAI-6-1979 and the curability of the overflowed portion was observed. The results are shown in Table 4. As is clear from Table 4, the method of the present invention can eliminate the sticky feeling of the air contact surface in a short time at room temperature without adversely affecting the adhesive strength.

[0016]

[Table 1]

[0017]

[Table 2]

[0018]

[Table 3]

[0019]

[Table 4]

[0020]

EFFECTS OF THE INVENTION According to the method of the present invention, a sticky feeling on the air contact surface can be obtained at room temperature for a short time by a simple method of simply applying a curing accelerator solution to the air contact surface of the anaerobic curable composition. Therefore, the work efficiency can be improved in each industrial field using the anaerobic curable composition, and the production line can be shortened and rationalized.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location C09J 11/08 JBC (72) Inventor Hisaichi Mori 1515 Nakatsu-cho, Marugame-shi, Kagawa Okura Industrial Co., Ltd. In-house (72) Inventor Matsuda ▲ Hide ▼ Akira 1515 Nakatsu-cho, Marugame-shi, Kagawa Okura Industrial Co., Ltd.

Claims (2)

[Claims] 1. A paraffin wax (a), a soluble vanadium compound (b), (c) phosphorous acid, hypophosphorous acid,
An acidic phosphorus compound such as an acidic phosphoric acid ester, or a curing accelerator solution obtained by dissolving one or more selected from ascorbic acid in an organic solvent is applied to the surface of the anaerobic curable composition. And a method for curing an air-contacting surface of the anaerobic curable composition. 2. One or two kinds selected from (a) paraffin wax, (b) soluble vanadium compound, and (c) acidic phosphoric acid ester represented by the following general formula (1) or (2). A method for curing an air-contacting surface of an anaerobic curable composition, which comprises applying a solution of a curing accelerator obtained by dissolving the above in an organic solvent to the surface of the anaerobic curable composition. (However, R ₁ is an alkyl group having 1 to 4 carbon atoms, R ₂ is hydrogen or a methyl group, R ₃ is an alkylene group having 1 to ₃ carbon atoms, and n is an integer of 1 or 2.)