JPS62212143A - Manufacture of composite material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing composite materials. For more details,
The present invention relates to a method for producing a composite material in which different rubber compounds are brought into contact with each other and co-crosslinked by heating at the contact surface.

[Conventional technology]

Of course, none of the various rubber materials currently in use are superior in all properties, and therefore the uses are divided according to the properties of the rubber. On the other hand, attempts have been made to blend various rubbers in an attempt to somehow improve their poor properties, but rather than obtaining high performance blends, the blends tend to exhibit poor properties.

Rather than modifying by such a blending method, composite materials are also produced by bringing different rubber compounds into contact with each other and co-crosslinking them by heating at the contact surfaces. What is important in this case is which rubbers to combine and which co-crosslinking agent to select and use.

[Problem that the invention seeks to solve]

From this viewpoint, the present inventors investigated the types of rubbers to be combined and the co-crosslinking agent.

It has already been found that amine-based co-crosslinking agents are superior in co-crosslinking between fluororubber and acrylic rubber, but in this case, even if the co-crosslinking itself proceeds smoothly, it is difficult to form a composite material. The problem is that it does not lead to improved performance.

Therefore, we investigated peroxide-based, sulfur-based, guanidine-based, thiazole-based, dithiocarbamate-based, thiuram-based, and onium salt-based crosslinking agents as co-crosslinking agents for various rubbers; Peroxide-based materials are the best in terms of co-crosslinking properties, and by applying this peroxide-based co-crosslinking agent to specific combinations of rubber as shown below, composite materials with improved performance can be obtained. I discovered that.

[Means for Solving the Problems] and [Operation] Therefore, the present invention relates to a method for manufacturing a composite material, and for manufacturing a composite material, a rubber compound containing an organic peroxide as a compounding component is prepared as follows. This is carried out by bringing the respective rubber compounds into contact with each other in combination, and heating and crosslinking the contact surfaces.

(1) Hydrogenated NBR-propylene/tetrafluoroethylene copolymer rubber (2) Hydrogenated NBR-halogenated fluororubber (3)
Propylene/tetrafluoroethylene copolymer rubber - halogen-added fluororubber (4) Propylene/tetrafluoroethylene copolymer rubber - fluorosilicone rubber The rubbers used here will be explained individually.

Hydrogenated NBR: Hydrogenated butadiene double bond in acrylonitrile-butadiene copolymer, hydrogenation rate approximately 80%
As described above, it exhibits chemical stability and is particularly excellent in cold resistance, chemical resistance, and oil resistance, and also has strong rubber strength. Regarding heat resistance, the higher the hydrogenation rate, the better the heat resistance.
% exhibits the best heat resistance, but it still falls short of the heat resistance of acrylic rubber (withstands 150° C.), so further improvement in heat resistance is desired.

Propylene/tetrafluoroethylene copolymer rubber Generally, propylene and tetrafluoroethylene are copolymerized at a copolymerization molar ratio of 1=1, and compared to fluororubber, propylene is copolymerized. Although it has excellent cost advantages and water resistance, it has poor heat resistance and cold resistance.

Halogen-added fluororubber: An example is one obtained by copolymerizing tetrafluoroethylene and hexafluoropropene so as to have an iodine group at both ends or a bromine group in the middle.

This rubber has superior chemical resistance compared to fluororubber, but has a drawback in terms of cold resistance.

Fluorosilicone rubber: For example, the first order can be mentioned.

113 This rubber has excellent heat resistance, cold resistance, and chemical resistance, but is inferior in tear strength and adhesiveness.

All of these rubbers are used in the form of a rubber compound containing an organic peroxide as a compounding component. Examples of organic peroxides include 1. dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2.
5-2,5-di(tert-butylperoxy)hexyne-3
,1,3-bis(tert-butylperoxyisopropyl)
Benzene etc. is about 0.1 to 100 parts by weight of the rubber component.
It is used in a proportion of 15 parts by weight.

In addition to organic peroxides, various compounding agents are blended into rubber compounds depending on the type of rubber, but polyfunctional monomers such as triallylisocyanurate or trimethylolpropane trimethacrylate, Ethylene glycol dimethacrylate.

It is preferable to use a methacrylate such as dimethylaminoethyl methacrylate in an amount of about 1 to 20 parts by weight per 100 parts by weight of the rubber component, since the crosslinking density will be improved.

Contact between these rubber compounds is made in such a way that the surfaces of each compound are in contact with each other, and generally the contact area is increased and the layers are multilayered. This may also be done only with correspondingly small contact areas.

To give a specific example, when molding an oil seal with hydrogenated NBR, each rubber compound is made in such a way that only the lip area is made of propylene/tetrafluoroethylene copolymer rubber or halogenated fluororubber. A method of improving the heat resistance of hydrogenated NBR and the cold resistance of the oil-resistant fluororubber part by co-crosslinking the hydrogenated NBR by contacting the hose in such a manner that the hose is made of hydrogenated NBR. A method of forming a layer of tetrafluoroethylene copolymer rubber or halogen-added fluororubber, a method of partially forming the diaphragm with rubbers with different strengths and hardness, and joining them at the thick parts are shown.
In addition, packings, gaskets, O-rings, etc. can be made into composite materials by this method.

The combination of the rubber compounds described in (1) to (4) above is
Although it merely shows the combination of two types of rubber compounds,
It is natural to consider compounding using three or more types of rubber compounds; for example, from (1) and (3), hydrogenated Nn
Composite composition by combining Rn bupyrene/tetrafluoroethylene copolymer rubber and fluorosilicone rubber also produces (3)
and (4) to produce halogenated fluororubber - propylene.
Composite composition using a combination of tetrafluoroethylene copolymer rubber and fluorosilicone rubber is similarly carried out.

〔Effect of the invention〕

When hydrogenated N[]R, propylene/tetrafluoroethylene copolymer rubber, halogen-added fluororubber, and fluorosilicone rubber are co-crosslinked with each other using an organic peroxide as a co-crosslinking agent, favorable properties of each rubber are obtained. It has been discovered that a composite material with improved performance can be obtained by effectively utilizing the two and compensating for the shortcomings of each to obtain high performance properties. However, there are limits to the combinations, and in the case of fluorosilicone rubber, hydrogenated NB
Since R and the halogen-added fluororubber do not have co-crosslinking properties, they are ultimately specified as rubber compound combinations described in (1) to (4) above.

〔Example〕

Next, the present invention will be explained with reference to examples.

Example 1 (Hydrogenated NBR blend) Hydrogenated NBR (B Zeon product Zetpol 2000)
100 parts by weight carbon black (N-3
30) 20 natural graphite
20 Diatomaceous earth 70 Stearic acid 12-mercaptobenzimidazole 2 Ditert-butylperoxyisopropylbenzene (40%)
8 triallyl isocyanurate (70%)
zinc dioxide
5 (propylene/tetrafluoroethylene copolymer rubber compound) copolymer rubber (Asahi Glass Products Aflas 200
) 100 parts by weight Meta, calcium silicate 30 Carbon black (N-990) 5 Calcium hydroxide Magnesium trioxide 3
Ditert-butylperoxyisopropylbenzene (40%
) 3 triallyl isocyanurate (70%)
After kneading each of the six or more formulations using a 12-inch open roll, crosslinking was performed as follows.

Crosslinked product A: The hydrogenated NBR formulation was pre-crosslinked at 180°C for 8 minutes and then secondarily crosslinked at 150°C for 5 hours.

Crosslinked product B: Propylene/tetrafluoroethylene copolymer rubber compound, 1
After crosslinking was carried out at 80°C for 10 minutes, secondary crosslinking was carried out at 175°C for 5 hours.

Co-crosslinked product ■: In a mold with length 120fffffil, width 240mm, and depth 2mm, each has a length of 40 strokes, a width of 200 rm, and a height of 4II.
The above two rubber compounds having dimensions of N11 were placed at a distance of 10 m in the longitudinal direction and press-crosslinked. Press crosslinking was carried out under conditions of primary crosslinking at 180°C for 8 minutes and secondary crosslinking at 150°C for 5 hours.

The physical properties of the above crosslinked products were measured, and the results are shown in Table 1 below. Note that the tensile strength and elongation were measured in the direction perpendicular to the bonding surface.

Table 1 Hardness (points) 75 77 - Tensile strength MPa) 18.5 12.4 14.5
Elongation (%) 500 230 360 Example 2 (Propylene/tetrafluoroethylene copolymer rubber compound) Copolymer rubber (Afras 200)
100 parts by weight carbon black (N-990)
302.5-dimethyl-2,5
-di(tert-butylperoxy)hexane 2triallylisocyanurate (70%) 4(
Halogenated fluororubber compound) Halogenated fluororubber (Daikin product G-901)
80 parts by weight halogenated fluororubber (Daikin product G-902) 20 carbon black (N-9
90) 202.5-dimethyl-2,5-di(tert-butylperoxy)hexyne 1.5 triallyl isocyanurate (70%)
All of the four or more formulations were kneaded using a 12-inch open roll, and then crosslinked in the following manner.

Crosslinked product C: Propylene/tetrafluoroethylene copolymer rubber compound, 1
After crosslinking was carried out at 80°C for 8 minutes, secondary crosslinking was carried out at 180°C for 4 hours.

Crosslinked product C: A halogenated fluororubber compound was heated at 180°C for 8 minutes.
After the second crosslinking, secondary crosslinking was performed at 180° C. for 4 hours.

Co-crosslinked product■: Press crosslinking was carried out in the same manner as for co-crosslinked product (3).

However, the secondary crosslinking conditions were 180° C. for 4 hours.

The physical properties of the above crosslinked product were measured, and the results are shown in Table 2 below.

Table 2 Hardness (points) 75 70 - Tensile strength MPa) 16.5 18.2 17.0
Elongation (%) 320 300 260 Example 3 Carbon black (N-330)
40 stearic acid
12-Mercaptobenzimidazole
22.5-dimethyl-2,5-di(tert-butylperoxy)hexane 2-trimethylolpropane trimethacrylate Zinc pentoxide
5 Crosslinked product E: After kneading the above blend with a 12-inch open roll,
After crosslinking was performed at 180°C for 8 minutes, secondary crosslinking was performed at 180°C for 4 hours.

Crosslinked product D: Same as above co-crosslinked product ① Using each rubber compound used for crosslinked products E and D, press crosslinking was carried out in the same manner as co-crosslinked product I.

However, the secondary crosslinking conditions were 180° C. for 4 hours.

The physical properties of the above crosslinked products were measured, and the results are shown in Table 3 below.

Table 3 1-j1 company m-Co-crosslinked material 11 ■ Constant temperature - EDm Hardness (points) 73 70 - Tensile strength MPa) 24.8 18.2 20.0
Elongation (%) 270 300 250 Example 4 (Fluorosilicone rubber compound) Fluorosilicone rubber (Shin-Etsu Chemical FH261L)
100 parts by weight carbon black (N-990)
52,5-dimethyl-2
,5-di(tert-butylperoxy)hexane (40%)
Crosslinked product F: After kneading the above blend with a 12-inch open roll,
After crosslinking was performed at 170°C for 8 minutes, secondary crosslinking was performed at 180°C for 4 hours.

Co-crosslinked product (2) Each of the rubber compounds used in crosslinked products A, B, and F had dimensions of 80 m long, 200 m1 wide, and 1.5 mm thick, and were stacked in this order and press-crosslinked.

Press crosslinking was carried out at 170°C for 8 minutes - second crosslinking and 150°C.
It was carried out under conditions of secondary crosslinking for 2 hours at °C.

Co-crosslinked product (2): Each of the rubber compounds used in crosslinked product B and F was press-crosslinked in this order in the same manner as in co-crosslinked product (2).

The physical properties of the above crosslinked products were measured, and the results are shown in Table 4 below.

Table 4 Hardness (points) 65 - -Tensile strength MPa) 10.6 11.2 12.8 Elongation (%) 310 210 230 Co-crosslinked products I to ■ have smooth surface conditions including joints. It can be seen that the bonding by co-crosslinking is carried out smoothly. In contrast, fluorosilicone rubber and hydrogenated NBR
Or, it did not bond at all with the halogen-added fluororubber.

Claims (1)

[Claims] 1. Rubber compounds each containing an organic peroxide as a compounding component are brought into contact with each other in the following combinations, and the contact surface is heated and co-crosslinked. Method of manufacturing composite materials. (1) Hydrogenated NBR-propylene/tetrafluoroethylene copolymer rubber (2) Hydrogenated NBR-halogenated fluororubber (3)
Propylene/tetrafluoroethylene copolymer rubber - halogenated fluororubber (4) Propylene/tetrafluoroethylene copolymer rubber - fluorosilicone rubber 2, about 0.1 to 15 parts by weight of organic peroxide per 100 parts by weight of the rubber component 2. A method for producing a composite material according to claim 1, wherein a rubber compound containing a compound is used. 3. The method for producing a composite material according to claim 1, wherein a rubber compound is used in which a polyfunctional monomer is blended in an amount of about 1 to 20 parts by weight per 100 parts by weight of the rubber component. 4. The method for producing a composite material according to claim 3, wherein the polyfunctional monomer is triallylisocyanurate. 5. The method for producing a composite material according to claim 3, wherein the polyfunctional monomer is methacrylate.