JP3514121B2 - Manufacturing method of rubber laminated metal sheet - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for manufacturing a rubber laminated metal plate . More specifically, it relates to a method for producing a rubber laminated metal sheet having excellent antifreeze resistance.

[0002]

2. Description of the Related Art In the invention of the applicant described in JP-A-6-335990, NBR is provided on one or both sides of a metal plate, and 20% by weight or more of a white filler, carbon black, and oxidation Primer layer and NB formed from a phenol resin-based primer containing zinc and organic peroxide
R, a rubber laminated metal plate in which a vulcanized rubber layer formed from a rubber compound containing 20% by weight or more of a white filler, carbon black, zinc oxide, and an organic peroxide is sequentially laminated is an antifreeze-resistant liquid. It is said that it has excellent properties and can be effectively used as a gasket or the like.

However, when it is used as a gasket, a rubber solution is applied to a metal plate, vulcanized under pressure, and then punched into a gasket shape. The metal burr after punching has vulcanized rubber, an adhesive agent, etc. However, there is a problem that it is difficult to reuse the metal burr. In addition, in the method of applying a rubber solution after punching and vulcanizing under pressure, unevenness is generated in the gasket, resulting in a pressure distribution, and due to rubber flow during vulcanization, the metal surface is exposed and unvulcanized portions are generated, resulting in a uniform pressure. There is a problem that it cannot be vulcanized.

In vulcanization using sulfur, it is possible to punch a gasket shape, apply a rubber solution thereto, and vulcanize with heated air as it is. In the method using organic peroxide, heated air is used. Do not vulcanize as it is,
Since it is necessary to replace the air with nitrogen gas or the like, it is inevitable that the material manufacturing process becomes complicated.

[0005]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a method for producing a rubber laminated metal plate which is capable of vulcanization by heated air on a metal plate punched into a gasket shape and which is excellent in antifreeze resistance. To provide.

[0006]

The object of the present invention is as follows.
On one or both sides of a metal plate that has been surface-treated with a complex type chromate treatment and punched into a prescribed shape, (1) a phenol resin adhesive (2) silicic acid, calcium silicate and
At least one of calcium carbonate and sulfur or io
C Nitrile rubber compound containing a donor compound
A solution of at least one of silicic acid, calcium silicate and calcium carbonate and a nitrile rubber compound containing sulfur or a sulfur donating compound is applied through the added adhesive layer and then vulcanized using heated air. Is manufactured by

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As the metal plate, a stainless steel plate whose surface is roughened by shot blasting, scotch bride, hairline, dull finishing, SPCC steel plate, aluminum plate, etc. , A phosphoric acid compound and a chromic acid complex type chromate treatment agent (about 20 to 100 mg / m ² ) and subjected to chemical conversion treatment to form an anticorrosive film. In the case of stainless steel sheets, conventionally, the adhesion has been improved by simply roughening the surface of the sheet by methods such as shot blasting and scotch bride.However, it is largely peeled off due to long-term air heating aging and immersion in high temperature antifreeze solution. When the film is further formed, such peeling is not observed. In the case of SPCC plate, zinc phosphate coating and iron phosphate coating are also formed. A metal plate having a thickness of about 0.2 to 0.8 mm is used for the gasket material.

On a metal plate having one or both surfaces subjected to composite chromate treatment, a phenol resin adhesive, generally an adhesive containing at least one of a novolac phenol resin and a resole phenol resin as a main component. Is applied as an alcohol, a ketone or a mixed solvent thereof, preferably a methyl ethyl ketone solution, and the one-sided thickness is about 1-1O.
An adhesive layer of .mu.m, preferably about 2-5 .mu.m is formed.

The novolac type phenolic resin is obtained by reacting phenols and formaldehyde in a molar ratio of about 0.1 to 1.0 in the presence of an acidic catalyst such as hydrochloric acid or oxalic acid. For example, phenol, m-cresol, a mixture of m-cresol and p-cresol, bisphenol A and the like are used.
In the present invention, the melting point is about 60 to 170 ° C., preferably about 1
Alcohol, which is solid at room temperature of 00-150 ℃,
Those soluble in organic solvents such as ketones are used.

The resol type phenolic resin contains phenols and formaldehyde in a molar ratio of about 1 to 3,
It can be obtained by reacting in the presence of a basic catalyst such as an alkali metal or magnesium hydroxide. At that time, as the phenols, for example, phenol, a mixture of m-cresol and p-cresol, p-tertiary butylphenol, p-phenylphenol, o-position to the phenolic hydroxyl group such as bisphenol A, p-position Or 2 in o, p-position
Any one can be used as long as it has one or three substitutable nuclear hydrogen atoms.

In the adhesive, as a curing agent for these phenolic resins, about 0.5 to 5 relative to their total amount is used.
Hexamethylenetetramine is added and used in a weight% ratio. If the amount added is less than this, the heat resistance of the adhesive layer will decrease, while if it is added in a ratio greater than this, there is a tendency for the amount of gas generated to increase during heat curing of the rubber.

A bisphenol A type epoxy resin may be further added to the adhesive for use. Bisphenol A type epoxy resin has an epoxy equivalent of about 1
The total amount of phenolic resin is 80 to 2700, which is liquid or soft at room temperature (25 ° C) and has a softening point of about 150 ° C or less.
It is used in a proportion of about 30 to 200 parts by weight, preferably about 50 to 150 parts by weight, per 00 parts by weight. Bisphenol A used
As the proportion of the type epoxy resin increases, the heat resistance improves, but the antifreeze resistance tends to decrease.

When a bisphenol A type epoxy resin is used, the reaction between the bisphenol A type epoxy resin and the phenol resin proceeds even if the bisphenol A type epoxy resin is heated to about 100 ° C. or more in the absence of a catalyst. Methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzylimidazole, 1-benzil-2-methylimidazole, 2,4-diamino- 6- [2-methylimidazoline
Imidazole compounds such as-(1)]-ethyl s-triazine are used as curing catalysts in a proportion of about 4% by weight or less with respect to the bisphenol A type epoxy resin. Stability will be reduced.

In the adhesive, the nitrile rubber compound is further contained in an amount of about 40 parts by weight or less, preferably about 10 to 3 per 100 parts by weight of the total amount of the phenol resin or the epoxy resin.
It is used by adding at a ratio of 0 part by weight. The addition of the nitrile rubber compound further improves the adhesiveness between the rubber layer and the adhesive layer, but if it is used in a ratio higher than this, peeling occurs by immersion in the high temperature antifreeze. As nitrile rubber, about 28-42 mol% acrylonitrile and about 72
Copolymer rubber with ~ 58 mol% butadiene is used, which can be crosslinked with sulfur or a sulfur donating compound, and thiurams, sulfenamides, etc. must be used together as a vulcanization accelerator during crosslinking. Is preferred.

Incorporation of an inorganic filler into the nitrile rubber compound is effective in preventing the adhesive layer from peeling off when immersed in a high temperature antifreeze solution. As the inorganic filler, it is effective to add at least one of silicic acid, calcium silicate and calcium carbonate in addition to carbon black. As silicic acid, dry method white carbon produced by thermal decomposition method of halogenated silicic acid or organic silicon compound or method of heating and reducing silica sand and oxidizing air vaporized SiO, thermal decomposition of sodium silicate Wet method white carbon etc. manufactured by the method such as specific surface area (by nitrogen adsorption method)
There about 20 to 200 m ² / g, preferably is used of about 30 to 100 m ² / g. Calcium silicate has a specific surface area of about 20
~ 150m ² / g, pH weak alkaline is used. Also, as calcium carbonate, the specific surface area is about 5 to 100 m ² /
g, an average particle size of about 10 μm or less, and a weakly alkaline pH are used. Any of these may be a commercially available product that is generally marketed for the rubber industry. In addition, these can be used after treating the particle surface with a fatty acid salt, a rosin salt or an epoxy resin.

At least one of silicic acid, calcium silicate and calcium carbonate is used in a proportion of about 20 to 150 parts by weight, preferably about 40 to 100 parts by weight, per 100 parts by weight of nitrile rubber. If the blending ratio is less than this, it becomes difficult to prevent the occurrence of blisters in the vapor portion and peeling in the liquid contact portion during the semi-soaking of the antifreeze liquid. On the other hand, if it is used at a ratio higher than this, the antifreeze resistance is satisfied, but the heat aging resistance is significantly reduced.

Sulfur or a sulfur donating compound is used as the vulcanizing agent, and by using such a sulfur-based vulcanizing agent, vulcanization with heated air becomes possible. As the sulfur-donating compound, trithiocyanuric acid, polymeric polysulfide, etc. are used. These sulfur (donor compounds)
Is used in an amount of about 0.5 to 5 parts by weight, preferably about 1 to 3 parts by weight, per 100 parts by weight of nitrile rubber.

The adhesive comprising the above components is prepared as a solution dissolved in an organic solvent such as a ketone-based or alcohol-based solvent at a concentration of about 2 to 10% by weight, and is prepared on one side or both sides of the metal plate. It is applied to a dry thickness of about 1 to 10 μm and air-dried under room temperature conditions, and preferably about 1 to 10 μm.
Heat treatment is performed at 100 to 200 ° C. for about 5 to 30 minutes to form an adhesive layer there.

On the adhesive layer thus formed, about 5 to 1000 unvulcanized nitrile rubber compound is added.
A method of applying the nitrile rubber compound as an organic solvent solution is applied so as to form a one-sided vulcanized product layer having a thickness of about μm, preferably about 10 to 120 μm.

Thereafter , for the purpose of preventing tackiness of the surface of the vulcanized rubber, graphite, carbon black, paraffin wax, etc. are the main components, and a binder such as cellulose, acrylic resin, polybutadiene resin, etc. is added thereto, and the mixture is placed in a solvent such as toluene. The dispersion liquid is applied to the
By forming a non-adhesive layer having a thickness of 2 to 10 μm, seizure prevention and adhesion prevention are achieved.

One of the features of the present invention is, for example, as in the embodiment.
It is possible to perform vulcanization with heated air on a metal plate punched into a gasket shape including a circular recess ( embossed shape ) . In this case, after applying an organic solvent solution of an unvulcanized nitrile rubber compound containing an inorganic filler and sulfur (donor compound) on the adhesive layer, a non-adhesive layer with an antiblocking agent is formed, and After about 150-250 ℃
Vulcanization with heated air is carried out for about 3 to 30 minutes.

[0022]

The rubber laminated metal sheet according to the present invention has excellent antifreeze resistance and does not cause blister or peeling even when immersed in a high temperature antifreeze solution.

Further, since vulcanization with heated air is possible, it is possible to manufacture the material in the order of punching a metal plate into, for example, a gasket shape, applying a rubber solution, and vulcanizing. When materials are manufactured in this order, rubber burrs and adhesive layers are not attached to the metal burrs that occur when punching into a predetermined shape such as a gasket shape, and the conventional pressure vulcanization method is used. It facilitates the reuse of metal burrs compared to the type ones.

[0024]

EXAMPLES The present invention will now be described with reference to examples.

Reference Example 1 Surface dull-finished SUS301 steel plate (thickness 0.2 mm) was degreased on its surface with an alkali, and then a composite type chromate treatment agent containing silica, a phosphoric acid compound and chromic acid was applied at an application amount of 50 mg / m ^2. Then, an adhesive having the following composition was formed on both surfaces of the formed anticorrosion coating so as to have a thickness of about 2 μm on one surface.

A rubber solution (solids concentration 25% by weight) prepared from 25 parts by weight of the above-mentioned nitrile rubber compound, 7.5 parts by weight of methyl ethyl ketone and 67.5 parts by weight of toluene was applied onto this adhesive layer, and the mixture was applied at 60 ° C. for 15 minutes. After drying to form an unvulcanized rubber layer having a thickness of 20 μm on one surface, a toluene dispersion of polyethylene wax added with a polybutadiene resin binder was applied thereto for the purpose of preventing adhesion of the vulcanized rubber surface, and 220 ° C. , and the vulcanization treatment <br/> management by heating for 10 minutes air to form a tackiness preventive layer having a thickness of 5 [mu] m.

The rubber laminated metal plate thus obtained was tested for the following items.

Semi-immersion test of antifreeze: Anti-freeze solution of rubber laminated metal plate (non-amine long life coolant; genuine Toyota LL
C) half dip in 50% by volume water dilution, in a pressure vessel, 1
Visually determine the presence or absence of blisters at the gas-liquid interface (vapor portion) and peeling at the liquid phase immersion portion (wetted portion) after 100 hours, 300 hours or 500 hours at 50 ° C.

Reference Example 2 In the nitrile rubber compound of Reference Example 1, the amount of calcium carbonate was changed to 80 parts by weight without using silica and calcium silicate.

Reference Example 3 In the nitrile rubber compound of Reference Example 1, the amount of silica was changed to 40 parts by weight without using calcium carbonate.

Reference Example 4 In Reference Example 1, an adhesive having the following composition was used.

In the half-soaking test of the antifreeze solution in each of the above-mentioned reference examples, blister formation and peeling were not observed at any test time.

Comparative Example 1 In the nitrile rubber compound of Reference Example 1, the amount of calcium carbonate was changed to 10 parts by weight without using silica and calcium silicate.

Comparative Example 2 In the nitrile rubber compound of Reference Example 1, the amount of silica was changed to 10 parts by weight without using calcium carbonate and calcium silicate.

Comparative Example 3 In the nitrile rubber compound of Reference Example 1, the amount of calcium carbonate and the amount of silica were changed to 5 parts by weight, respectively, without using calcium silicate.

Comparative Example 4 In Reference Example 1, Chemlok 205 manufactured by Lord Far East Co. was used as an adhesive.

Comparative Example 5 In Reference Example 1, a surface dull-finished SUS301 steel sheet which was not surface-treated with the composite type chromate treatment agent was used.

The results of the antifreeze half-soaking test in each of the above comparative examples are shown in the following table.

The punched metal plate of Example Reference Example 1 the gasket shape, after providing a circular recess, the following Reference Examples 1 and similar adhesive coating, formed of unvulcanized rubber, the formation of the adhesion-preventing layer and heat treatment I went. In the obtained rubber-laminated metal plate, no metal part was exposed on both sides of the recess, and a uniform rubber vulcanizate layer was formed.

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Claims (3)

(57) [Claims] 1. A surface treatment with a complex type chromate treatment agent.
And one side or both sides of the metal plate punched out into a predetermined shape
To, (1) a phenolic resin-based adhesive (2) silicate, silicic acid
At least one of calcium and calcium carbonate and
Nitrigo containing sulfur or sulfur donating compounds
Through the adhesive layer containing mu compound,
At least acid, calcium silicate and calcium carbonate
Contains one and sulfur or a sulfur donating compound
After applying the nitrile rubber compound solution,
Of rubber laminated metal plate characterized by being vulcanized using air
Manufacturing method. 2. A bisphenol A type epoxy resin
The rubber laminate according to claim 1, wherein an added adhesive is used.
Metal plate manufacturing method. 3. A metal plate punched into a predetermined shape is a gasket.
The rubber laminated metal according to claim 1, which is a metal plate having a shape for a cot.
Board manufacturing method.