JPH0912806A - Epdm composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an EPDM composition prepared by using a small amount of an expensive organopolysiloxane or the like and giving a cured product having high adhesion to a silicone rubber. SOLUTION: This EPDM composition comprises 100 pts.wt. EPDM polymer, 60-150 pts.wt. silane-treated filler, 5-10 pts.wt. reactive silicone oil and 5-30 pts.wt. tackifier.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EPDM composition which gives a molded article having good adhesion to silicone rubber.

[0002]

2. Description of the Related Art EPDM (ethylene-propylene-diene copolymer) resin has excellent weather resistance, heat resistance and chemical resistance,
It is applied to the coating of electric wires and automobile parts. Among them, in the case of being applied to electric wire coating, the end portion of the electric wire is generally connected to a terminal or the like. Such terminals are protected by rubber caps as necessary to prevent leakage of high voltage currents. In order to completely prevent the leak, the electric wire coating portion and the rubber cap are bonded with an adhesive. A rubber cap is often made of a silicone rubber if heat resistance is required, but a molded article made of a conventional EPDM polymer (hereinafter referred to as "EPDM molded article") has excellent adhesiveness to a silicone rubber adhesive. Unfortunately, these adhesion points were very easy to peel off, and therefore their electrical insulation was unreliable.

Here, by adding an organopolysiloxane or a polyoxyalkylene / alkylpolysiloxane copolymer to an EPDM polymer at a compounding amount of 7 to 97% by weight in an EPDM composition excluding a vulcanizing agent,
It has been known that the adhesive property of the EPDM molded product is improved (JP-A-59-15143). However, since these organopolysiloxanes and the like are expensive, the EPDM composition mixed in such a mixing ratio is also expensive.

Similarly, a composition (JP-A-60-248746) for treating the surface of an EPDM molded article in order to improve the adhesiveness of the EPDM molded article is known, but a harmful organic solvent is known. Since toluene is used, special care is required in handling, and the adhesiveness with silicone rubber is unsatisfactory because almost no effect is obtained.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an EPDM composition which has a small amount of expensive organopolysiloxane and the like and which gives a molded article having high adhesiveness to silicone rubber. To do.

[0006]

In order to solve the above-mentioned problems, an EPDM composition according to the present invention comprises 60 parts by weight or more and 150 parts by weight or less of a silane-treated filler, 100 parts by weight of a EPDM polymer, and a reactive silicone. 5 parts by weight to 10 parts by weight of oil and 5 parts by weight or more of tackifier 3
It has a composition in which it is contained in an amount of 0 parts by weight or less.

Here, the amount of the silane-treated filler added is E
If the amount is less than 60 parts by weight based on 100 parts by weight of the PDM polymer, the adhesiveness required in the molded product cannot be obtained.
When it is more than 0 parts by weight, the kneading property is extremely lowered and the adhesiveness required for the molded product cannot be obtained. If the amount of reactive silicone oil added is less than 5 parts by weight with respect to 100 parts by weight of EPDM polymer, the adhesiveness required in the molded article will not be obtained, and if it is more than 10 parts by weight, the phase with the polymer will be lost. Solubility is significantly reduced and kneading becomes impossible.

When the addition amount of the tackifier is less than 5 parts by weight with respect to 100 parts by weight of EPDM polymer, the brittleness of the composition becomes extremely high and the necessary adhesiveness in the molded product cannot be obtained. On the other hand, if it exceeds 30 parts by weight, the composition becomes too sticky to be kneaded.

In the above EPDM composition, when the compounding amount (part by weight) of the silane-treated filler to 100 parts by weight of EPDM polymer is Mf, the compounding amount Ms (part by weight) of reactive silicone oil and the compounding of tackifier. Amount Ma
When each (part by weight) is in the range represented by the formula: 0.05Mf ≤ Ms ≤ 0.083Mf 0.083Mf ≤ Ma ≤ 0.2Mf, good handleability, optimum processability, sufficient adhesiveness and flexibility are obtained. It is preferable because an EPDM composition having properties is obtained.

Here, as the EPDM polymer component,
The ones that are normally available are sufficient. As described above, even when the ordinary EPDM polymer is used, the molded article according to the present invention has excellent adhesiveness to silicone rubber. Therefore,
It is not necessary to use a special EPDM polymer component with particularly improved adhesion. However, a specialized EPDM polymer can be used in order to improve the performance other than the adhesiveness.

The silane-treated filler is obtained by reacting a filler usually used for obtaining an EPDM molded product with a so-called silane coupling agent, and is silane-treated talc, silane-treated mica or silane-treated clay. Etc. can be used. Here, a silane-treated clay is preferable because a molded product having excellent adhesiveness to silicone rubber can be obtained. As such, those manufactured by Burgess Pigment Co., etc. are generally commercially available. If a filler that has not been treated with silane is used, good adhesion with silicone rubber cannot be obtained.

Reactive silicone oil acts as a lubricant before the reaction to reduce the viscosity of the system, facilitates kneading, and imparts shapeability, but after the reaction, it is combined with the EPDM polymer to form a system. Since it contributes to the improvement of strength and sufficient bondability is required, it is necessary to use a silicone oil reactive at both ends. The reactive silicone oil also has the effect of increasing the affinity with the silicone resin adhesive used for adhering the molded product to the silicone resin. A vinyl group is preferred as the both end groups of the silicone oil reactive at both ends, and the molded product has improved adhesiveness with the adhesive for silicone rubber, which is preferable.

Polybutene as a tackifier is
It improves adhesiveness with silicone rubber and plasticity at the stage when a vulcanizing agent is added.
Since this compound has excellent compatibility with the EPDM polymer, the molded product becomes strong. In addition, here, EPT and EP
When a so-called plasticizer such as a process oil that is commonly used for imparting plasticity to DM and the like is used, sufficient adhesiveness cannot be obtained.

The EPDM composition according to the present invention is a mixture of the above-mentioned components generally used in a kneader or roll mill,
It is obtained by mixing with a kneading means. After mixing, the EPDM composition is added with a usual vulcanizing agent and vulcanization accelerator used for EPDM at the time of use and mixed again by the above-mentioned means to obtain a vulcanizing agent-added composition. Used for molding. In addition, in the EPDM composition, when the period until its use is short and the effect of the vulcanizing agent is considered to be small, a vulcanizing agent-added composition obtained by adding a vulcanizing agent and a vulcanization accelerator together with each composition It may be used as a consumer.

A molded product can be obtained from the EPDM composition according to the present invention as follows. That is, as described above, an appropriate amount of a vulcanizing agent and a vulcanization accelerator are added and kneaded, and then, utilizing the plasticity of the EPDM composition,
After being placed in a mold or shaped into an arbitrary shape by a press treatment or the like, it is vulcanized by heating or the like while being pressurized as necessary, and molded.

Here, the heating conditions need not be particularly careful, and the heating can be carried out under the conditions suitable for the EPDM polymer, vulcanizing agent or vulcanization accelerator used, which is very simple. In addition, the EPDM composition of the present invention is not corrosive and does not generate toxic vapors or the like at the time of molding, and thus has excellent handleability, and jigs and equipment used during kneading and molding are also used in ordinary EPDM. The thing can be used as it is.

The EPDM molded article produced by using the EPDM composition according to the present invention easily and firmly adheres to the silicone rubber by using an ordinary silicone rubber adhesive.

[0018]

In the present invention, silane-treated clay is treated with EPDM.
By adding it to the polymer, a silane group is introduced into the composition to improve the adhesiveness with the adhesive for silicone rubber.
Further, the reactive silicone oil reacts with the EPDM polymer and is incorporated into the base polymer, which greatly contributes to the improvement of the adhesiveness with the silicone rubber. Polybutene as a tackifier also has the effect of a plasticizer, while preventing the viscosity of the intermediate product from extremely increasing by the addition of the silane-treated clay, imparts tackiness to the surface of the molded product, and the silane treatment The effect of improving the adhesion of clay and reactive silicone oil is further enhanced.

[0019]

【Example】

Examples 1 to 7 and Comparative Example 1 EPD of base polymer
MPT is EPT-3045 manufactured by Mitsui Petrochemical Co., Ltd., and filler (filler 1) is silane-treated anhydrous aluminum silicate Burgess K manufactured by Burgess Pigment Co., Ltd.
E, SLM made by Wacker as reactive silicone oil
-HTV and polybis 5 SH made by NOF CORPORATION, which is polybutene as a tackifier, were mixed at a mixing ratio as shown in Table 1 using a roll mill to obtain 7 kinds of EPDM compositions according to the present invention (Example 1 ~ 7).

[0020]

[Table 1]

To each of these compositions, NK Ester TMPT manufactured by Shin Nakamura Kagaku Co., Ltd. as a vulcanization accelerator and Park Mill D-40 manufactured by NOF CORPORATION as a vulcanization agent were added at the same mixing ratio as shown in Table 1 and kneaded again by a roll mill. A vulcanizing agent-added composition was obtained. After shaping these vulcanizing agent-added compositions, press vulcanization at 180 ° C. for 5 minutes was performed to obtain sheet-shaped 7 types of EPDM molded products each having a thickness of 1.5 mm. On the other hand, after molding SH-855 manufactured by Toray Dow Corning Co., Ltd. which is a silicone raw rubber composition, 170 ° C./1
A sheet-shaped silicone rubber molded product having a thickness of 1.5 mm was obtained by performing press vulcanization for 0 minutes and oven vulcanization at 200 ° C. for 4 hours.

Next, a method for preparing a sample and an evaluation method for evaluating the adhesion between the EPDM molded product and the silicone rubber molded product will be described below. First, these EPDM molded products and silicone rubber molded products are cut into 150 mm × 25
mm sheet was obtained.

Next, 100 of each of these
Toray Dow Corning Silicone C which is an adhesive for silicone rubber with the area of mm x 25 mm as the adhesive surface
Y54-16 was applied, and the adhesive surfaces of the EPDM molded product sheet and the silicone rubber molded product sheet were overlapped. After that, apply a load of 4 g / cm ² to the adhesive surface for 96
It was cured while giving time, and a sample for T-type peel test as shown in FIG. 1 was obtained. The evaluation of the adhesiveness was carried out by measuring the adhesive strength of these adhesive surfaces at a tensile speed of 100 mm / min using a strograph manufactured by Toyo Seiki Seisakusho.

Here, for comparison, EPD molded by adding a vulcanizing agent and a vulcanization accelerator to EPDM polymer.
A sample was similarly prepared for the M-only molded product (Comparative Example 1), and its adhesiveness was evaluated. Table 1 shows the adhesiveness evaluation results at this time. From Table 1, EPD according to the present invention
It is clear that the adhesiveness of the molded article produced using the M composition with the silicone rubber is very excellent.

[Comparative Examples 2 to 11] Next, as Comparative Examples 2 to 11, the adhesiveness of the EPDM composition having no constitution peculiar to the invention to silicone rubber will be shown. In addition to the components used in the above-mentioned examples, as a filler, talc (hydrous magnesium silicate) HYTRON (hereinafter referred to as "filler 2") commonly used as a filler in EPDM molded products, and Ordinary clay that has not been subjected to silane treatment, an ice cap K (hereinafter referred to as "filler 3") manufactured by Hages Pigment Co.,
Toray as a normal silicone oil that has no reactivity
Dow Corning Silicone SH-200 (100
cs) (hereinafter referred to as “silicone oil”),
As a plasticizer for imparting plasticity to the system, Diana Process PW-380 manufactured by Idemitsu Kosan (hereinafter referred to as "plasticizer")
Was used to obtain EPDM compositions having 10 types of compositions of Comparative Examples 2 to 11 each having the compounding ratio shown in Table 2. Since the composition according to Comparative Example 8 could not be kneaded because the amount of the reactive silicone oil having low compatibility with the base polymer was large, the following study was not conducted.

[0026]

[Table 2]

Using these EPDM compositions except for Comparative Example 8, a vulcanizing agent-added composition was prepared in the same manner as in the Example.
Sheet-shaped EPDM molded products were obtained. Here, in Comparative Example 6, a normal silicone oil was used instead of the reactive silicone oil, but bleeding of the silicone oil was observed in the molded product.

Using these sheet-shaped EPDM molded products,
Also in the same manner as in the examples, T-type peel test samples were prepared and the adhesiveness to silicone rubber was evaluated. Table 2 shows the evaluation results. From Table 2, it is clear that Comparative Examples 2 to 10 having no constitution peculiar to the present invention have extremely low adhesiveness to the silicone rubber, and therefore the effects of the present invention cannot be obtained.

[0029]

As is clear from Tables 1 and 2, the EPDM composition of the present invention having a unique constitution contains a small amount of expensive organopolysiloxane and the like and has excellent adhesiveness to silicone rubber. An excellent EPDM molded product can be obtained.

[Brief description of the drawings]

FIG. 1 T for evaluating adhesiveness with silicone rubber
It is the figure which showed the shape of the sample for a mold peeling test.

[Explanation of symbols]

 1 EPDM molded sheet 2 Silicone rubber molded sheet 3 Adhesive surface

Claims (4)

[Claims] 1. To 100 parts by weight of EPDM polymer,
Silane-treated filler is 60 parts by weight or more and 150 parts by weight or less, reactive silicone oil is 5 parts by weight or more and 10 parts by weight or less, and polybutene is 5 parts by weight or more as a tackifier.
EPD characterized by being contained in an amount of less than or equal to parts by weight
M composition. 2. The EPDM composition, wherein EPDM
When the blending amount (parts by weight) of the silane-treated filler with respect to 100 parts by weight of the polymer is Mf, the blending amount Ms (parts by weight) of the reactive silicone oil and the blending amount M of the tackifier.
The EPDM composition according to claim 1, wherein each a (part by weight) is in a range represented by the formula: 0.05Mf ≤ Ms ≤ 0.083Mf 0.083Mf ≤ Ma ≤ 0.2Mf. 3. The EPDM composition according to claim 1 or 2, wherein the silane-treated filler is a silane-treated clay. 4. The EPDM composition according to claim 1, further comprising a vulcanizing agent and a vulcanization accelerator.