JPS60215085A - Vulcanization type rubber adhesive - Google Patents

Abstract

PURPOSE:To provide the titled adhesive which has excellent storage stability though it is a one-pack type and which can form a bonding layer having excellent elasticity and rigidity, by adding zinc flower, (meth)acrylic acid and an org. peroxide in this order to a synthetic diene rubber and uniformly dispersing them therein. CONSTITUTION:10-80pts.wt. zinc flower, 5-40pts.wt. (meth)acrylic acid and an org. peroxide (dissolved or dispersed in an appropriate quantity of an org. solvent) in this order are kneaded with 100pts.wt. synthetic diene rubber such as polybutadiene or a styrene/butadiene copolymer to disperse them therein.

Description

[Detailed description of the invention] The present invention relates to a vulcanized rubber adhesive.

That is, in the present invention, after kneading 10 to 80 parts by weight of zinc white to 100 parts by weight of diene thread synthetic rubber, 5 to 40 parts by weight of acrylic acid and/or methacrylic acid and an organic peroxide are sequentially added. Regarding vulcanized rubber adhesives that are added and blended uniformly, there are also solution-based vulcanized rubber adhesives that are dissolved and dispersed in aromatic or mixed aromatic and aliphatic solvents; This invention relates to a film-like vulcanized rubber adhesive formed into a film.

The above-mentioned vulcanized rubber adhesive is an adhesive for bonding any metal as an adherend, for example, metal such as iron, aluminum, stainless steel, etc., to various vulcanized rubbers, various unvulcanized rubbers, etc.

Further, in the solution-form vulcanized rubber adhesive described in claim 8, it is applied to one side of the adherend so that the dry film thickness is 10 μm or more, and the organic peroxide is not easily decomposed under temperature conditions. After preliminary drying, the other adherend is placed on top of the other adherend, and the adhesive is heated under pressure to achieve a good adhesion state. Furthermore, in the film-like vulcanized rubber adhesive according to claim 4, the film thickness Q between the adherends is
A film adhesive having a thickness of 1 am or more is sandwiched between the two, and the adhesive is heated under pressure to achieve a good adhesion state. These vulcanization conditions are such that during pressure vulcanization, pressure is applied to prevent air from entering the adherend and adhesive, and the adherend rubber fabric is heated at a temperature higher than the 1-minute half-life temperature of organic peroxide. Vulcanize under pressure and heat for the appropriate time.

Incidentally, when unvulcanized rubber or unvulcanized rubber and various metals are vulcanized and bonded together using the vulcanized rubber adhesive of the present invention, simultaneous vulcanization is also possible.

Conventional rubber-metal vulcanization adhesives are used for rubber rolls, rubber coatings, valves, hoses, belts, anti-vibration rubber, oil seals, etc.; A method using a co-glue containing last lamer has been practiced for a long time. This method uses a highly hard composition containing a large amount of metal oxide as a primer formulation on the metal side, and an elastic composition with a high rubber content as a stock formulation on the rubber side. Although it has the characteristics of being able to provide strength and impact resistance, it requires many types of adhesives.
This creates a hassle in the process.

In addition, general-purpose two-component adhesives are well known, in which a metal primer is applied to the metal surface of the adherend and dried, then a top coat adhesive is applied and dried, and unvulcanized fabrics etc. are simultaneously vulcanized and bonded. ing. This adhesive is excellent at simultaneous vulcanization adhesion between most unvulcanized rubber fabrics and metals, but since the primer and adhesive must be applied and dried twice, the process is time consuming and economically wasteful. However, it has disadvantages such as generating toxic gas due to dehalogenation reaction.

In addition, one-component type adhesives containing irisyanate compounds and the like in a phenolic resin solution have excellent heat resistance and oil resistance, and are excellent at adhering general-purpose synthetic rubbers and natural rubbers. Due to the pot life of the adhesive, a decrease in adhesive strength at high temperatures, and problems with flexibility, it has disadvantages such as peeling at cut edges and bent parts during product processing. ing.

Adhesives for vulcanized rubber include polar rubbers such as chloroprene rubber, acrylonitrile, and butadiene rubber, and polyacrylic acid resins, but they have poor heat resistance and are even more difficult to bond with olefin synthetic rubbers and olefin threads. There are also problems such as extremely difficult adhesion with other materials.

The vulcanized rubber adhesive of the present invention eliminates such conventional drawbacks, and after kneading 10 to 80 parts by weight of zinc white with 100 parts by weight of diene synthetic rubber, acrylic acid and/or It is characterized in that 5 to 40 parts by weight of methacrylic acid and an organic peroxide are sequentially added and blended uniformly.

It is also a vulcanized rubber adhesive that is dissolved and dispersed in an aromatic or a mixed aromatic and aliphatic solvent, or is formed into a film.

Since this adhesive is an adhesive, it is possible to not only simultaneously vulcanize and bond unvulcanized rubber sheets and metals, but also bond vulcanized rubbers together and metals together by press bonding.

It is also possible to bond with olefin-based synthetic rubber, which has been difficult to bond with in the past.

A solution type adhesive dissolved and dispersed in an aromatic type or a mixed type solvent of an aromatic type and an aliphatic type is a -liquid coating type adhesive, and the adhesive layer after drying is non-tacky, Because of this, it can be stacked, making it easy to work and shortening the work process.Since diene synthetic rubber is the main component, it is easy to obtain an adhesive layer with high rubber elasticity and high rigidity, and it can be used in high temperature atmospheres. Although it is a liquid coating type adhesive, it has excellent storage stability due to the use of aromatic or a mixed aromatic and aliphatic solvent as the organic solvent. It is excellent in

Adhesives formed into a film, by their nature, contain solvents, which greatly contributes to environmental protection, health and safety, disaster prevention, etc., improving working conditions for workers, and improving adhesion by omitting the drying process. This leads to cost reduction by shortening the process, etc., and since the main component is diene-based synthetic rubber, an adhesive layer with high rubber elasticity and high rigidity can be obtained, and also has excellent adhesion in a high-temperature atmosphere.

The diene-based synthetic rubber used in the present invention includes polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, etc., or a combination of the diene-based synthetic rubber and other polymers such as olefin-based synthetic rubber. By using them together, it is possible to improve the adhesion with many wide rubbers. Here, olefin-based synthetic rubbers include ethylene-propylene copolymers, isobutylene-based isobutylene-diene copolymers, chlorosulfonated polyethylene, etc., and depending on the blend ratio of diene-based synthetic rubber and olefin-based synthetic rubber, Adhesiveness to rubber,
The Young's modulus changes, and the blending ratio can be arbitrarily determined depending on the required physical properties.

In the present invention, 10 to 80 parts by weight of zinc white is used with respect to 100 parts by weight of the synthetic rubber.
If the weight part is divided, vulcanization cannot be performed in a short time, and even if vulcanization is performed for a long time, adhesive strength cannot be secured because the adhesive layer has no rubber elasticity and is soft. On the other hand, if it exceeds 80 parts by weight, there is a high possibility that the rubber adhesive will gel, making application difficult and at the same time reducing the rubber elasticity of the adhesive layer after vulcanization, resulting in poor processing properties of the vulcanized product. This is not preferable because it lowers the temperature.

In addition, 5 to 40 parts by weight of acrylic acid and/or methacrylic acid are added to 100 parts by weight of the synthetic rubber, but if the organic acid is less than 5 parts by weight, the adhesive layer becomes soft regardless of the vulcanization conditions. On the other hand, if the amount added exceeds 40 parts by weight, the storage stability of the adhesive deteriorates, and it often gels after several days of indoor storage, and the vulcanized adhesive layer also loses its rubber elasticity. This results in problems such as hardness and brittleness, extremely reduced bending performance, and poor workability.

Examples of the organic peroxide used in the present invention include benzoyl peroxide, 1,1-bis(tert-butylperoxy)8.21.5-trimethylcyclohexane, tert-butyl silver oxide, 2-5-ditertiary-butyl Peroxyhexane 2,5-dimethyl 2
It is commonly used as a crosslinking agent for synthetic rubber such as 5-dibenzoyl peroxyhexane and dixyl oxide, but it is desirable that it decomposes less at normal humidity. In addition, vulcanization trapping agents, vulcanization retarders, fillers,
A decolorizing agent, a tackifier, an anti-aging agent, an anti-scorch agent, a preservative, an anti-mold agent, a flame retardant, etc. may be added.

Examples of the organic solvent used in the vulcanized rubber adhesive described in claim 8 include aromatic solvents such as toluene, xylene, and ethylbenzene, pentane, hexane, heptane,
Aliphatic solvents such as octane, methylcyclohexane, and cyclohexane.

In addition, by using scaly fillers such as mica, vermiculite, and talc, and high specific gravity fillers such as metal powder, barium sulfate, ferrite, and metal oxides, vibration damping and sound insulation functions are added. You can also give.

Of course, it is also possible to use fillers such as calcium carbonate, white carbon, carbon, comb, magnesium carbonate, etc., which are generally used in the rubber and paint industries.

The vulcanized rubber adhesive described in claim 8 is:
Using the above materials, a compound is prepared by kneading synthetic rubber with zinc white, acrylic acid and/or methacrylic acid in this order,
It can be obtained by dissolving and dispersing in an appropriate amount of an organic solvent depending on the coating method and adding an appropriate amount of an organic peroxide.

This vulcanized rubber adhesive is applied using the P-Rufut method.
There are methods such as barcode method, spray method, and coating, but it is possible to use cloth by freely adjusting the viscosity with an organic solvent. Further, by subjecting the adhered surface to a surface treatment suitable for the type of metal and the type of synthetic rubber selected, it is possible to provide even stronger adhesion to the adhered surface.

In addition, the vulcanized rubber adhesive described in claim 4 is prepared by mixing an appropriate amount of the above-mentioned materials into a synthetic rubber mixture in the order of zinc white, 7-IJ acid, and/or methacrylic acid. This vulcanized rubber adhesive is obtained by blending organic peroxide and forming it into a film.
Strong adhesive strength can be obtained by directly sandwiching the adhesive between adherends and vulcanizing it under pressure and heat. Further, it is possible to provide even stronger adhesion to the adhered surface by subjecting the adhered surface to a surface treatment suitable for the type of metal and the type of synthetic rubber selected.

The present invention will be explained in detail with reference to Examples and Comparative Examples.
The invention is not limited to the following examples.

(1) Test conditions and test methods; Table 1 shows the formulations of Examples and Comparative Examples of the solution-like and film-like vulcanized rubber adhesives of the present invention. In addition, the unit is expressed in parts by weight.

Table 2 shows the test results and vulcanization conditions of Examples and Comparative Examples of the solution and film-like vulcanized rubber adhesives of the present invention.

b) Solution viscosity Based on JIS-68138 general test method for adhesives.

The conditions are B-H type viscometer, No. 7 rotor, 2 rotations, and 25°C.

(1) Storage-stable solution adhesives are allowed to stand in an atmosphere of 50°C for 6 months, and then their condition and adhesive performance are confirmed.

After leaving the film adhesive in a 50°C atmosphere for 6 months, its condition and adhesive performance are confirmed.

c) Adhesive strength (180° peel adhesive strength) JIS-6
Based on the peel adhesion test method for 854 adhesive. However, the pulling speed was 50 mm/ml.

2) Flexibility: Observe the state when bent using a 2-diameter mandrel.

Table 8 shows the results of adhesion tests between various rubber sheets and various metal plates. The test conditions are as follows.

B) Vulcanization conditions for adhesives Conditions for simultaneous vulcanization of various unvulcanized rubber sheets, adhesives, and various metal plates 180℃ x 50 ~ / cJ x 5 minutes (press temperature x press pressure x press time) Vulcanization Vulcanization conditions for adhesives between rubber sheets and various metal plates: 180°C x 20 x 9/CTI x 5 minutes (pressing temperature x pressing pressure x pressing time) W) Types of adhesive - Example 1 and Examples listed in Table-1 7 c) Test method: According to JIS-6854 adhesive peel adhesion test method.

However, the tensile speed was 59 as/min.

Table 4 shows the test results for adhesion between metals. The test conditions are: a) Vulcanization conditions: l 80'CX 50 to 9/CJX
5 minutes (Press temperature x Press pressure x Press time) Type of adhesive Examples 1 and 7 listed in Table 1 C) Test method: T-type peel resistance adhesion test JIS-685
According to 4.

Table 5 shows the adhesive strength test results at each ambient temperature. The test conditions are as follows.

The type of adhesive was the same as Example 1 and Example 7. A) Vulcanization conditions: 180°C x 20 kg/cox,
5 minutes (Press temperature After applying the adhesive to the iron plate and the vulcanized rubber sheet and drying them, the adhesive sides are brought together and pressed together using a rubber roll.

1) Adherent: Vulcanized styrene-butadiene copolymer rubber and polished iron plate 3) Test method 20"C, 50'C, 80"C, 100'C, 180°
After leaving each test piece in each atmosphere of C for 20 minutes,
The 180° peel adhesion strength is measured at that ambient temperature.

(2) Method for preparing specimens: In the case of a solution adhesive, it is applied to various metal plates as adherends so that the dry film thickness is approximately 70 μm, and dried for 20 minutes in an atmosphere of 50°C. Samples were prepared by bonding adherends (unha-cured rubber sheet, vulcanized rubber sheet, various metal plates) under the vulcanization conditions specified separately.

In the case of a film adhesive, the film adhesive was sandwiched between the various adherends and samples were prepared under the same vulcanization conditions.

*1 is made by Japan Synthetic Rubber Special BRφO1 (product name) *2 is made by Katayama Chemical Industry ■ *8 is made by Katayama Chemical Industry ■ *4 is made by NOF ■ Perhexa aM (product name) *5 is made by NOF ■ Percmill D (trade name) *6 is manufactured by Nippon Oil & Fats ■ Niver B (trade name) As is clear from the Examples and Comparative Examples, the present invention uses 10 to 80 parts by weight of zinc white and acrylic acid and or A vulcanized adhesive consisting of 5 to 40 parts by weight of methacrylic acid and an organic peroxide has good simultaneous vulcanization adhesion between an unvulcanized rubber sheet and various metals, and also has good adhesion between metals and between metals and vulcanized rubber. Adhesion is also good.

In the present invention, if 10 to 80 parts by weight of zinc white is used or if the zinc white is less than 10 parts by weight, vulcanization cannot be performed in a short time, even if vulcanization is performed for a long time. However, the adhesive layer has no rubber elasticity and is soft, making it impossible to secure adhesive strength.

On the other hand, if the amount exceeds 80 parts by weight, there is a high possibility that the rubber adhesive will gel, making application difficult, and at the same time, the rubber elasticity of the adhesive layer after vulcanization will decrease, and the processing properties of the vulcanized product will deteriorate. So I don't like it. In addition, 5 parts by weight of acrylic acid and/or methacrylic acid are added to 100 parts by weight of the synthetic rubber.
~40 parts by weight is added, but if the organic acid is less than 5 parts by weight, the adhesive layer becomes soft regardless of the vulcanization conditions, and the adhesive strength decreases prematurely.On the other hand, if the addition exceeds 40 parts by weight, The storage stability of the adhesive deteriorates and it often gels after a few days of storage indoors, and the vulcanized adhesive layer also loses its rubber elasticity and becomes hard and brittle, causing problems in processing performance as the bending performance is extremely reduced. occurs.

Table 3 shows the results of simultaneous vulcanization adhesion between various metal plates and various unvulcanized rubber sheets, as well as vulcanization adhesion test results between vulcanized rubber sheets.As is clear from this table, butadiene thread synthetic rubber and various Co-vulcanization adhesion with metals is particularly excellent.

Table 4 shows the state of adhesion between various metal plates, and all of them are good.

Table 5 shows the adhesive strength test results in a high temperature atmosphere, and the adhesive of the present invention has a high adhesive strength retention rate at high temperatures.

As is clear from the above, the vulcanizable rubber adhesive of the present invention can be used not only for simultaneous vulcanization adhesion of general-purpose unvulcanized rubber sheets and metals by press bonding, but also for simultaneous vulcanization adhesion with diene thread synthetic rubber. It has particularly excellent adhesion, and when used in combination with olefin-based synthetic rubber, it can improve simultaneous vulcanization adhesion when using olefin-based synthetic rubber as an adherend, which was previously difficult to bond. It has excellent adhesion between various metals and between vulcanized rubber and various metals, and the adhesive layer has high rubber elasticity and high rigidity, and has excellent adhesion in high-temperature atmospheres.

Furthermore, although the solution-form vulcanized rubber adhesive is a one-component coating adhesive, it has excellent storage stability, and since the adhesive layer after application and drying is non-tacky, it can be stacked. The film-form vulcanized rubber adhesive has excellent workability, and in addition to being excellent in storage stability, it is an adhesive that has many features such as not emitting harmful substances such as solvents in the working environment. It has extremely high industrial value as it is being used in rubber parts, electric wire coatings, anti-vibration rubber, etc. due to the recent rise in vehicle temperatures.

Procedural amendment May 31, 1980 Vulcanized rubber adhesive 3. Relationship with the case of the person making the amendment Patent applicant Hayakawa Rubber Co., Ltd. 5゜6. Subject of the amendment ``Detailed description of the invention'' in the specification Column 1
, "Rion Bren rubber" on page 5, line 6 of the specification is replaced with "Rion h".
Corrected to ``a Blen rubber''.

2. Corrected "tert-butyl cumyl peroxide" in lines 1-2 of page 9 to "tert-butyl cumyl peroxide," and corrected "dicumyl peroxide" in lines 4-5 of the same page to "dicumyl peroxide." Corrected to ``Milperoxide.''

8. Correct "kushi" in line 8 of page 1O of the same page to "klee".

4. “Kaisei rubber” in line 8 of page 21 of the same page is “synthetic rubber”
Correct.

Claims (1)

[Claims] L diene thread synthetic rubber 100 parts by weight, zinc white i
A vulcanized rubber adhesive characterized in that after kneading 0 to 80 parts by weight, 5 to 40 parts by weight of acrylic acid and/or methacrylic acid and an organic peroxide are sequentially added and blended uniformly. ＆ し
A vulcanized rubber adhesive characterized in that after kneading ~80 parts by weight, 5 to 40 parts by weight of acrylic acid and/or methacrylic acid and an organic peroxide are sequentially added and blended uniformly. & Claim 1 or 2, wherein the vulcanized rubber adhesive is dissolved and dispersed in an aromatic solvent or a mixed aromatic and aliphatic solvent. The vulcanized rubber adhesive described in any of the above. 4. The vulcanized rubber adhesive according to claim 1 or 2, characterized in that the vulcanized rubber adhesive is formed into a film.