Ethylene propylene diene monomer material as well as preparation method and matched process thereof

Abstract

The invention provides an ethylene propylene diene monomer material as well as a preparation method and a matching process thereof, and relates to the technical field of rubber materials. The ethylene propylene diene monomer material is prepared from the following raw materials in parts by mass: 70 to 80 parts of ethylene propylene diene monomer, 20 to 30 parts of chloroprene rubber, 30 to 50 parts of carbon black, 20 to 30 parts of white carbon black, 5 to 20 parts of naphthenic oil, 5 to 13 parts of metal oxide, 0.5 to 1.5 parts of stearic acid, 2 to 3 parts of compatibilizer and 2 to 5 parts of vulcanization crosslinking agent. The EPDM material prepared by the invention and the process flow matched with the EPDM material have the characteristic of improving the bonding strength of the rubber material and the framework material, and can be applied to EPDM and framework composite rubber products.

Description

Technical Field

[0001] The invention relates to the technical field of rubber materials, and in particular to an EPDM rubber material and a preparation method and a matching process thereof. Background Art

[0002] In the rubber industry, bonding refers to the bonding between rubber and the surface of homogeneous or heterogeneous materials, which is produced by the physical action of van der Waals force or the chemical action of bonding force. The good bonding of rubber materials and skeleton materials can produce composite parts with different configurations and characteristics. This composite system is widely used in industry. However, due to the huge differences in chemical structure and mechanical properties between rubber and skeleton materials, it is very difficult to obtain high-strength bonding, which greatly limits the upper limit of rubber material performance and also reduces the service life of products to a certain extent.

[0003] As a saturated non-polar rubber, EPDM has poor self-adhesiveness, and its adhesion is generally 2-3N / mm. In addition, a large amount of carbon black and paraffin oil are often added as fillers during the production of EPDM rubber materials, which will further reduce the adhesion between EPDM rubber and skeleton materials. At present, pretreatment solvents are commonly used in industry to pretreat EPDM materials to enhance adhesion, but this pretreatment machine is often only effective for rubber materials with a certain specific formula, and the cost is relatively high, which has great limitations in the production process of multiple product layouts of enterprises. Summary of the invention

[0004] Based on the technical problems existing in the background technology, the present invention proposes an EPDM rubber material and a preparation method and a supporting process thereof.

[0005] The invention provides an EPDM rubber material, which comprises the following raw materials in parts by mass: 70-80 parts of EPDM rubber, 20-30 parts of chloroprene rubber, 30-50 parts of carbon black, 20-30 parts of white carbon black, 5-20 parts of cyclohexane oil, 5-13 parts of metal oxide, 0.5-1.5 parts of stearic acid, 2-3 parts of a compatibilizer, and 2-5 parts of a vulcanization crosslinking agent.

[0006] Preferably, the third monomer of the EPDM rubber is vinylidene norbornene, and the content of the third monomer is 5.5%-9.0%.

[0007] Preferably, the Mooney viscosity ML (1+4) of the EPDM rubber at 125°C is 25-55.

[0008] Preferably, the cycloparaffinic oil is selected from one or more of 4010, Tudalen 3370, and Tudalen 33767.

[0009] Preferably, the chloroprene rubber is sulfur-modified and has a low cross-linking property.

[0010] Preferably, the white carbon black is precipitated white carbon black, and the surface silanol content is 3-8%.

[0011] Preferably, the metal oxide is selected from one or more of zinc oxide and magnesium oxide.

[0012] More preferably, the mass ratio of zinc oxide to magnesium oxide is (3-7):(2-6).

[0013] Preferably, the compatibilizer is EPDM-g-MAH.

[0014] Preferably, the vulcanization crosslinking agent is selected from one or more of DCP, TAIC, bis-25, and TMPTMA.

[0015] More preferably, the vulcanization cross-linking agent is composed of DCP and TAIC in a mass ratio of (1.5-3.5): (0.5-1.5).

[0016] More preferably, the vulcanization crosslinking agent is composed of bis-25 and TMPTMA in a mass ratio of (1.5-3.5): (0.5-1.5).

[0017] The present invention also provides a method for preparing an EPDM rubber material, comprising the following steps:

[0018] The EPDM rubber, chloroprene rubber and a compatibilizer are mixed and plasticized, and then allowed to stand after plasticization. Then, metal oxides, stearic acid, carbon black, white carbon black, cyclohexane oil and a vulcanization crosslinking agent are added in sequence, and after mixing evenly, sheets are produced to obtain the EPDM rubber material.

[0019] Preferably, the plasticating equipment is a Farrell internal mixer.

[0020] Preferably, the plasticizing temperature is 90-120° C., and the plasticizing time is 10-25 min.

[0021] Preferably, the standing is standing at room temperature for 45-55 hours.

[0022] The present invention also provides a matching process for EPDM rubber material, comprising the following steps:

[0023] S1, surface treating the skeleton material to obtain a surface treated skeleton material;

[0024] S2, coating the surface treated skeleton material with rubber slurry to obtain a coated skeleton material;

[0025] S3, vulcanizing the coated skeleton material and the EPDM rubber material to obtain a composite component after matching construction.

[0026] Preferably, the skeleton material is selected from one of brass, carbon structural steel DC01, and 45# steel.

[0027] Preferably, in said S1, the surface treatment includes roughening treatment and degreasing treatment.

[0028] More preferably, the roughening treatment comprises subjecting the framework material to plasma treatment for 2-3 minutes.

[0029] More preferably, the power of the plasma processor is 800-1200W.

[0030] The purpose of the roughening treatment in the present invention is to increase the surface roughness of the skeleton, which is beneficial to the adhesion between the skeleton and the glue.

[0031] More preferably, the degreasing treatment comprises soaking the skeleton material after the plasma treatment in a solvent and drying it.

[0032] More preferably, the solvent is trichloroethylene.

[0033] More preferably, the soaking time is 10-20 minutes.

[0034] More preferably, the drying is drying at room temperature.

[0035] The degreasing treatment of the present invention is used to remove grease on the surface of the skeleton, which is beneficial to the adhesion between the skeleton and the glue.

[0036] Preferably, in S2, the rubber mortar includes chloroprene rubber mortar and EPDM rubber mortar.

[0037] More preferably, the preparation of the chloroprene rubber mortar comprises: adding dichloromethane to the chloroprene rubber, stirring and dissolving, to obtain the mortar.

[0038] More preferably, the mass ratio of the chloroprene rubber to the dichloromethane is (20-30):(70-80).

[0039] More preferably, the preparation of the EPDM rubber mortar comprises: adding dichloromethane to the EPDM rubber, stirring and dissolving, to obtain the mortar.

[0040] More preferably, the mass ratio of the EPDM rubber to the dichloromethane is (20-30):(70-80).

[0041] Preferably, the rubber slurry coating treatment includes applying chloroprene rubber slurry to the surface treatment skeleton material, drying at room temperature, and then coating EPDM rubber slurry and drying.

[0042] More preferably, the drying temperature is 40-50°C.

[0043] More preferably, the EPDM rubber mortar is coated on the chloroprene rubber mortar.

[0044] Preferably, in S3, the coated bonding surface of the skeleton material is bonded to the EPDM rubber material.

[0045] Preferably, in S3, the vulcanization treatment is selected from co-vulcanization and separate vulcanization.

[0046] More preferably, the co-vulcanization comprises co-vulcanizing the coated skeleton material and the EPDM rubber material, specifically: hot pressing the coated skeleton material and the EPDM rubber material at 165-185° C. and 100-200 kPa for 5-10 minutes.

[0047] More preferably, the separate vulcanization includes first vulcanizing the EPDM rubber material, and then laminating and heating it with the coated skeleton material, specifically: first treating the EPDM rubber material at 165-185°C for 5-10 minutes to obtain a vulcanized rubber, and then laminating the vulcanized rubber with the coated skeleton material at 140-160°C for 7-9 hours.

[0048] The beneficial effects of the present invention are:

[0049] On the one hand, the present invention adopts EPDM rubber material and chloroprene rubber (CR) material to blend, and utilizes the 1,4-trans structure in the CR rubber molecular chain and the strong polarity of chlorine atoms to effectively improve the cohesion and adhesion of the blended rubber; the surface of white carbon black is rich in siloxane structure, spaced hydroxyl structure and adjacent hydroxyl structure, and has high reaction activity, and is very easy to absorb water molecules in the system, and forms hydrogen bonds on the surface. Due to the effect of this hydrogen bond, water is bound and evenly distributed in the entire rubber material, thereby effectively reducing the enrichment of water in the system on the bonding interface, and preventing water from destroying the bonding structure. The above two effects increase the bonding strength with the skeleton material at the rubber matrix level. On the other hand, by treating the bonding surface of the skeleton material, the surface energy of the bonding surface is increased, and by coating two adhesives, the interface structure of the contact surface between the skeleton and the rubber material is changed, and the bonding strength between the rubber material and the skeleton material is further increased. Therefore, the EPDM rubber material prepared by the present invention and the process flow matched therewith have the characteristics of improving the bonding strength between the rubber material and the skeleton material, and can be applied to EPDM and skeleton composite rubber products.

[0050] The present invention starts from two aspects: EPDM rubber formula and the bonding process of rubber and brass skeleton material. After testing, the bonding force between EPDM rubber and brass skeleton is increased from 11N / mm to 22N / mm, which effectively improves the bonding force between EPDM rubber and metal skeleton. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a process flow chart of the present invention;

[0052] Figure 2 Schematic diagram of surface groups of silica;

[0053] Figure 3 Schematic diagram of hydrogen bonding between surface groups of silica and water;

[0054] Figure 4 Schematic diagram of the bonding surface structure of the rubber material and the skeleton material; 1- skeleton material, 2- bonding surface, 3- EPDM rubber material. DETAILED DESCRIPTION

[0055] The technical solution of the present invention is described in detail through specific embodiments.

[0056] Unless otherwise specified, the materials, reagents, etc. used in the following examples and comparative examples can be obtained from commercial sources.

[0057] White carbon black SG2: Manufacturer: Jinhua Zinc Oxide Factory, Hanshan County, Anhui Province;

[0058] Naphthenic oil 4010: Manufacturer: Shanghai Lianyi Special Oil Products Co., Ltd.

[0059] Example 1

[0060] An EPDM rubber material comprises the following raw materials in parts by mass: 80 parts of EPDM rubber, 20 parts of chloroprene rubber, 30 parts of carbon black N770, 30 parts of white carbon black SG2, 20 parts of naphthenic oil 4010, 5 parts of indirect zinc oxide, 4 parts of magnesium oxide, 1 part of stearic acid, 2 parts of compatibilizer EPDM-g-MAH, 1.5 parts of TAIC, and 2 parts of vulcanizing agent DCP; wherein the third monomer of the EPDM rubber is vinylidene norbornene, and the content of the third monomer is 7.0%, and the Mooney viscosity ML (1+4) of the EPDM rubber at 125°C is 35.

[0061] A method for preparing an EPDM rubber material comprises the following steps:

[0062] Put EPDM rubber, chloroprene rubber and a compatibilizer into a Farrell internal mixer for mixing and plasticizing. After plasticizing, let it stand at room temperature for 48 hours. Then, add metal oxides, stearic acid, carbon black, white carbon black, cyclohexane oil and a vulcanization crosslinking agent in sequence, mix well and form sheets to obtain EPDM rubber material. The plasticizing temperature is 110°C and the plasticizing time is 15 minutes.

[0063] A matching process for EPDM rubber material comprises the following steps:

[0064] S1. Plasma-treat the skeleton material at 1000W for 3 minutes, soak the plasma-treated skeleton material in trichloroethylene solvent for 15 minutes, take it out and place it in a clean area to fully dry, and obtain a surface-treated skeleton material;

[0065] S2, coating the surface of the surface treated skeleton material with chloroprene rubber paste and EPDM rubber paste to obtain a coated skeleton material; specifically: dip the chloroprene rubber paste with a brush, evenly apply it on the surface of the surface treated skeleton material, and place it at room temperature until the paste is completely dry; dip the EPDM rubber paste with a brush, and evenly apply it again on the same position as above, and place the skeleton material in a 40°C oven to dry for 0.5h before use; wherein the preparation of the chloroprene rubber paste includes: cutting the chloroprene rubber into a length×width×height of about 3× 3×3mm small pieces are weighed and recorded, and then placed in a beaker; dichloromethane solvent is added to the beaker according to a weight ratio of chloroprene rubber: dichloromethane = 25:75, and the mixture is stirred until completely dissolved and then sealed for later use; the preparation of EPDM rubber mortar includes: cutting EPDM rubber into small pieces of about 3×3×3mm in length×width×height, weighing and recording the weight, and then placing in a beaker; dichloromethane solvent is added to the beaker according to a weight ratio of EPDM rubber: dichloromethane = 25:75, and the mixture is stirred until completely dissolved and then sealed for later use;

[0066] S3. Firstly, subject the EPDM rubber material to a vulcanization process at 170°C for 6 min to obtain a vulcanized rubber. Then, the vulcanized rubber and the coated skeleton material are laminated together and heated in an oven at 150°C for 8 hours to obtain a composite component after matching construction.

[0067] Example 2

[0068] The difference between Example 2 and Example 1 is that in the raw materials of the EPDM rubber material, there are 70 parts of EPDM rubber and 30 parts of chloroprene rubber, and the other raw materials and their proportions are the same as those in Example 1; in the supporting process of the EPDM rubber material, the S3 vulcanization treatment is to hot-press the coated skeleton material and the EPDM rubber material in a flat vulcanizer at 170°C and 150kPa for 6 minutes, and the other steps are the same as those in Example 1.

[0069] The preparation method of the EPDM rubber material is the same as that in Example 1.

[0070] Comparative Example 1

[0071] The difference between Comparative Example 1 and Example 1 is that in the EPDM rubber raw material, 100 parts of EPDM rubber and 0 parts of chloroprene rubber are used, and the other raw materials and their proportions are the same as those in Example 1.

[0072] The preparation method and supporting process of the EPDM rubber material are the same as those in Example 1.

[0073] Comparative Example 2

[0074] The only difference between Comparative Example 2 and Example 1 is that in the EPDM rubber material raw material, the weight portion of carbon black N770 is 60 parts, and the weight portion of white carbon black is 0 parts.

[0075] The preparation method and supporting process of the EPDM rubber material are the same as those in Example 1.

[0076] Comparative Example 3

[0077] The difference between Comparative Example 3 and Example 1 is that in the matching process of the EPDM rubber material, the skeleton material is not subjected to surface treatment or rubber mortar coating treatment, and the rest is the same as Example 1.

[0078] For Examples 1-2 and Comparative Examples 1-3, the basic physical properties of the EPDM rubber material were tested according to GB / T 531.1 and GB / T 528. The test results are shown in Table 1.

[0079] Table 1 Basic physical properties of examples and comparative examples

[0080]

[0081] By comparing Example 1-2 with Comparative Example 1-3, there is no significant difference in the basic physical properties of the rubber, which shows that the blending of EPDM and CR and the addition of white carbon black do not affect the practicality of EPDM.

[0082] Comparative Example 1-2 and Comparative Example 1-3, with brass as the skeleton, the bonding strength test was carried out according to GB / T 2792 standard. The test results are shown in Table 2.

[0083] Table 2 Adhesion strength values ​​of examples and comparative examples

[0084]

[0085] From the data in Table 2, it can be seen that the blending of CR materials, the addition of white carbon black to the system, and the surface treatment of the skeleton material all have a great influence on the adhesion between the EPDM rubber and the skeleton material. Overall, Examples 1 and 2 have a good bonding effect. This shows that the use of the high-adhesion EPDM rubber material and the surface treatment process proposed in the present invention can effectively increase the bonding strength between the rubber and the skeleton material.

[0086] In summary, the EPDM rubber material prepared by the present invention and the process flow matched therewith have the characteristics of improving the bonding strength between the rubber material and the skeleton material, and can be applied to EPDM and skeleton composite rubber products.

[0087] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An EPDM rubber material, characterized in that: The invention comprises the following raw materials in parts by weight: 70-80 parts of EPDM rubber, 20-30 parts of chloroprene rubber, 30-50 parts of carbon black, 20-30 parts of white carbon black, 5-20 parts of cyclohexane oil, 5-13 parts of metal oxide, 0.5-1.5 parts of stearic acid, 2-3 parts of a compatibilizer and 2-5 parts of a vulcanization crosslinking agent.

2. The EPDM rubber material according to claim 1, characterized in that: The white carbon black is precipitated white carbon black, and the surface silanol content is 3-8%.

3. The EPDM rubber material according to claim 1, characterized in that: The metal oxide is selected from one or more of zinc oxide and magnesium oxide; the mass ratio of zinc oxide to magnesium oxide is (3-7): (2-6).

4. The EPDM rubber material according to claim 1, characterized in that: The compatibilizer is EPDM-g-MAH; the vulcanization crosslinking agent is selected from one or more of DCP, TAIC, bis-25, and TMPTMA.

5. A method for preparing the EPDM rubber material according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: mixing and plasticizing EPDM rubber, chloroprene rubber and a compatibilizer, and allowing the mixture to stand after plasticizing; then sequentially adding metal oxide, stearic acid, carbon black, white carbon black, cyclohexane oil and a vulcanization crosslinking agent, mixing the mixture evenly and then producing sheets to obtain the EPDM rubber material.

6. The preparation method according to claim 5, characterized in that: The plasticizing temperature is 90-120° C., and the plasticizing time is 10-25 minutes.

7. A matching process for the EPDM rubber material according to any one of claims 1 to 4, comprising the following steps: S1, surface treating the skeleton material to obtain a surface treated skeleton material; S2, coating the surface treated skeleton material with rubber slurry to obtain a coated skeleton material; S3, vulcanizing the coated skeleton material and the EPDM rubber material to obtain a composite component after matching construction.

8. The matching process according to claim 7, characterized in that: In the S1, the surface treatment includes roughening treatment and degreasing treatment; the roughening treatment includes subjecting the skeleton material to plasma treatment for 2-3 minutes, and the power of the plasma treatment machine is 800-1200W; the degreasing treatment includes soaking the skeleton material after plasma treatment in a solvent and drying it, and the solvent is trichloroethylene.

9. The matching process according to claim 7, characterized in that: In the above-mentioned S2, the rubber mortar includes chloroprene rubber mortar and EPDM rubber mortar; The preparation of the chloroprene rubber mortar comprises: adding dichloromethane to the chloroprene rubber, stirring and dissolving, and obtaining the mortar; the preparation of the EPDM rubber mortar comprises: adding dichloromethane to the EPDM rubber, stirring and dissolving, and obtaining the mortar.

10. The matching process according to claim 7, characterized in that: In the above-mentioned S3, the vulcanization treatment is selected from one of co-vulcanization and single vulcanization.

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