CN101724172B - Industrial production method for ethylene propylene diene rubber molded sealed cell sponge rubber - Google Patents

Abstract

The invention relates to an industrial production method of EPDM rubber molded closed-cell sponge rubber, which relates to an industrial production method of high expansion ratio foaming materials. Including plasticizing, mixing, refining, foaming vulcanization molding of raw rubber, characterized in that: carbon black, naphthenic oil, foaming aid, vulcanization accelerator and anti-aging agent are added during mixing; Foaming agent Ac and vulcanizing agent are refined; the vulcanization conditions of foam vulcanization molding are: pressure 15-20MPa, temperature 160-180°C, vulcanization time 3000-3500s. The invention is researched and developed based on market demand, so that the research purpose is shifted from laboratory research to industrial research, and the production conditions can be controlled, and the production process is relatively stable. The present invention selects domestic rubber material, selects foaming agent Ac to replace foaming agent H, and can prepare EPDM molded sponge rubber products that meet industrial production requirements by adjusting the ratio of various auxiliary agents in the formula and controlling the process conditions.

Description

A kind of industrial production method of EPDM rubber molded closed-cell sponge rubber

technical field

The invention relates to an industrial preparation method of a foaming material with a high expansion ratio. More specifically, the present invention relates to an industrial production method of EPDM molded closed-cell sponge rubber.

Background technique

As we all know, foam rubber is a composite material filled with gas. Compared with rubber, it has many valuable properties, such as light weight, high specific strength, strong ability to absorb impact loads, and good heat and sound insulation effects. Therefore, it is widely used in industries such as automobile, electronics, chemical industry and machinery.

Sponge rubber is a porous high-elastic material, commonly known as porous rubber, foam rubber, microporous rubber or mesh rubber, and is a general term for various rubbers with a porous structure. According to different pore structures, it can be divided into closed pores (the pores are not connected to each other), open pores (the pores are not completely separated by the pore wall, and have a certain degree of connectivity) and mixed pores ( Both open cell and closed cell structure) three. Sponge rubber and its special structure can produce various special effects, such as: reducing density and reducing weight; elasticity and softness, improving cushioning effect; increasing heat insulation; improving sound insulation and sound absorption effects. Sponge rubber products are widely used in sealing, shock absorption, heat insulation, sound insulation, printing and dyeing, and even ion exchange. Its shapes include plate shape, strip shape, roller, liner, gasket, etc., with various specifications and shapes. Moreover, different service conditions require different cell structures and aperture sizes.

Sponge rubber is different from ordinary solid rubber products. Two main processes occur simultaneously during the vulcanization heating process: the foaming agent decomposes to release gas and the rubber is cross-linked under the action of the vulcanizing agent. Since the gas released by the blowing agent is initially dissolved in the rubber, when the gas dissolves to saturation, a gas phase product is formed, and the rubber is boiled and foamed under the pressure of the formed gas, and at the same time the rubber is vulcanized and cross-linked. Fix the hole structure. For this reason, it is required that the vulcanization rate can be adjusted so that the tensile expansion force on the hole wall generated by the precipitated gas is slightly greater than the corresponding resistance of the hole wall itself. If the formation speed of the gas phase is too fast, the formed bubbles will burst because the rubber has no time to vulcanize, causing the gas to diffuse and escape from each hole, and the foaming pressure will decrease; on the contrary, if the formation speed of the gas phase is too slow or vulcanization If the speed is too fast, the compound will be cured before the porous structure is formed.

At present, the domestic research on EPDM sponge rubber is only based on experimental research, and most of the selected rubber materials are imported, because the heat generation of foaming agent H is greater than that of foaming agent Ac, and foaming agent H is mostly selected in the experimental process. However, this experimental condition can only be adapted to small-scale foaming materials in the laboratory, and cannot meet the requirements for industrial production. At the same time, the foaming agent H generates a large amount of heat and rubber is a poor conductor of heat, so it is prone to scorching. The present invention is researched and developed based on market demand, so that the research purpose is shifted from laboratory research to industrial research, and the production conditions can be controlled, and the production process is relatively stable. The present invention selects domestic rubber material, selects foaming agent Ac to replace foaming agent H, and can prepare EPDM molded sponge rubber products that meet industrial production requirements by adjusting the ratio of various auxiliary agents in the formula and controlling the process conditions.

Contents of the invention

The purpose of this invention is to provide a kind of industrial production method of EPDM molded closed-cell sponge glue. This process is divided into the following steps: plasticizing, mixing, refining, foaming and vulcanization of raw rubber.

The technical scheme adopted in the present invention comprises the following contents:

1. Material selection and proportioning (calculated in parts by weight)

Raw rubber: EPDM: 100

Foaming agent: Ac 0.1～0.16

Foaming aids: zinc oxide ZnO and stearic acid HSt, of which zinc oxide is 0.02-0.05; stearic acid is 0.008-0.01

Vulcanizing agent: S 0.1～0.16

Vulcanization accelerators: promote D, promote M, promote BZ and promote TRA

Among them, promoting D is 0.001-0.003; promoting M is 0.001-0.003; promoting BZ is 0.001-0.005; promoting TRA is 0.002-0.006.

Antiaging agent: RD and 4020, all parts by weight are 0.001

Softener: naphthenic oil 40～60

Filler: carbon black (SRF N550) 50

Mooney viscosity ML _{(1+4) 100° C.} of the aforementioned raw rubber EPDM = 46.

2. Preparation process:

1) Mastication

Control the temperature of the open mill below 50°C, and masticate EPDM raw rubber on the open mill for 2-3 minutes until the rubber material is transparent;

2) Mixing (CMB)

Put the masticated rubber into the internal mixer, add carbon black, naphthenic oil, foaming aid, vulcanization accelerator and anti-aging agent when mixing to 80-100°C, continue to pressurize and mix until the temperature is 100°C Glue removal at ~120°C;

3) Refining (FMB)

Preheat the internal mixer to 60-70°C, put the mixed rubber into the internal mixer, pressurize and internally knead for 60-90 seconds, then add foaming agent Ac and vulcanizing agent, half-close the pressure cover and air beat 1 Completely press down the upper pressure cover in 2 minutes, lift the pressure cover after 2 minutes of mixing, let the rubber turn over 4 times in the mixing room, and then discharge the glue;

4) Foam vulcanization molding

Adjust the temperature of the vulcanizer to 160-180°C, and the pressure to 15-20MPa. The refined rubber material is first refined once when the scale of the two rollers is 0.5, and then the roller distance is adjusted to 0, and the triangle bag is 4-5. Second, adjust the roller distance to 2.5 scales to produce the sheet, cut the sheet rubber according to the size of the mold, and send it to the press for vulcanization and foaming. The foaming time is 3000-3500s.

The invention is researched and developed based on market demand, so that the research purpose is shifted from laboratory research to industrial research, and the production conditions can be controlled, and the production process is relatively stable. The present invention selects domestic rubber material, selects foaming agent Ac to replace foaming agent H, and can prepare EPDM molded sponge rubber products that meet industrial production requirements by adjusting the ratio of various auxiliary agents in the formula and controlling the process conditions.

Detailed ways

Example 1:

Weigh materials according to the following formula: EPDM: 500g, carbon black: 250g, naphthenic oil: 250g, pro-BZ: 0.6g, pro-D: 0.5g, pro-TRA: 0.6g, pro-M: 0.5g, stearic acid: 8g, Zinc Oxide: 15g, Ac: 30g, S: 0.8g

Molding: Control the temperature of the two rollers of the open mill to be kept below 50°C. The raw rubber is smelted twice when the roller distance scale is 1, and then the roller distance is adjusted to 0 scale, and the triangular bag is made 4 to 6 times. Until the glue is translucent.

Mixing: Put the qualified EPDM rubber into the internal mixer and pressurize it. When the temperature rises to 80°C, raise the pressure cover, add carbon black, naphthenic oil and foaming aids, vulcanization accelerators, anti-aging After the pressure cover is semi-closed and empty for about 1 minute, the upper pressure cover is completely pressed, and the glue is removed when the temperature rises to 120°C, and it is sent to the two-roller for kneading. The kneaded rubber material is kneaded once when the scale of the two rolls is 0.5; then the roll distance is adjusted to 0, and the triangle bag is made 4 to 5 times; use.

Refining: Preheat the internal mixer to 65°C, put the qualified CMB rubber into the internal mixer and pressurize it for 70 seconds, raise the pressure cover and add foaming agent Ac and vulcanizing agent, and the pressure cover is half-closed After beating for about 1 minute, press down the upper pressure cover completely, lift the pressure cover after 2 minutes of mixing, let the rubber turn over 4 times in the mixing room, and then discharge the glue, and send it to the two rollers for mixing.

Foam vulcanization molding: adjust the temperature of the vulcanizer to 160°C, adjust the pressure to 15MPa, start the kneading of the kneaded rubber material with the scale of the two rolls at 0.5, and then adjust the roll distance to 0 to make triangle bags 4~ 5 times, the roller distance is adjusted to 2.5 scale, and the sheet is produced. The sheet rubber is cut according to the size of the mold and sent to the press for vulcanization and foaming. The foaming time is 3000s.

The performance of the product obtained according to the above formula is as follows:

Example 2:

Weigh materials according to the following formula: EPDM: 500g, carbon black: 250g, naphthenic oil: 100g, pro-BZ: 0.6g, pro-D: 0.5g, pro-TRA: 0.6g, pro-M: 0.5g, stearic acid: 4g, Zinc Oxide: 8g, Ac: 16g, S: 13g

Plastic refining: control the temperature of the two rollers of the open mill, refine the raw rubber for 2 times when the roller distance scale is 1, then adjust the roller distance to 0 scale, make triangular bags 4 to 6 times, until the rubber material is Translucent.

Mixing: put the qualified EPDM rubber into the internal mixer and pressurize it. When the temperature rises to 85°C, raise the pressure cover, add carbon black, naphthenic oil, foaming aids, vulcanization accelerators, anti-aging After the pressure cover is half-closed for about 1 minute, press the upper pressure cover completely, and when the temperature rises to 118°C, the glue will be removed and sent to the two rollers for kneading. The kneaded rubber material is kneaded once when the scale of the two rolls is 0.5; then the roll distance is adjusted to 0, and the triangle bag is made 4 to 5 times; use.

Refining: Preheat the internal mixer to 65°C, put qualified CMB rubber into the internal mixer and pressurize it for 70 seconds, raise the pressure cover and add foaming agent Ac and vulcanizing agent. After the pressure cover is half-closed and empty for about 1 minute, press the upper pressure cover completely, lift the pressure cover after 2 minutes of mixing, let the rubber turn over 4 times in the mixing room, and then discharge the glue, and send it to the two rollers for mixing.

Foam vulcanization molding: Adjust the temperature of the vulcanizer to 165°C and the pressure to 15MPa. The mixed rubber material is kneaded once when the scale of the two rollers is 0.5; then the roller distance is adjusted to 0, and the triangle bag is made 4 ~ 5 times; adjust the roller distance to 2.5 scale to produce the sheet, cut the sheet rubber according to the size of the mold, and send it to the press for vulcanization and foaming. The foaming time is 3300s. The properties of the products obtained according to the above formula are as follows:

Example 3:

Weigh the materials according to the following formula: EPDM: 500g, carbon black: 250g, naphthenic oil: 100, promote BZ: 0.6g, promote D: 0.5g, promote TRA: 0.6g, promote M: 0.5g, stearic acid: 8g, Zinc Oxide: 8g, Ac: 16g, S: 5g

Plastic refining: control the temperature of the two rollers of the open mill, refine the raw rubber for 2 times when the roller distance scale is 1, then adjust the roller distance to 0 scale, make triangular bags 4 to 6 times, until the rubber material is Translucent.

Mixing: Put the qualified EPDM rubber into the internal mixer and pressurize it. When the temperature rises to 90°C, raise the pressure cover, add carbon black, naphthenic oil and foaming aids, vulcanization accelerators, anti-aging agent. After the pressure cover is half-closed and empty for about 1 minute, the upper pressure cover is completely pressed, and when the temperature rises to 110°C, the glue is removed and sent to the two-roller for kneading. The kneaded rubber material is kneaded once when the scale of the two rolls is 0.5; then the roll distance is adjusted to 0, and the triangle bag is made 4 to 5 times; use.

Refining: Preheat the internal mixer to 65°C, put the qualified CMB glue into the internal mixer and pressurize it for 70 seconds, lift the pressure cover and add the second package of additives. After the pressure cover is half-closed and empty for about 1 minute, press the upper pressure cover completely, lift the pressure cover after 2 minutes of mixing, let the rubber turn over 4 times in the mixing room, and then discharge the glue, and send it to the two rollers for mixing.

Foam vulcanization molding: adjust the temperature of the vulcanizer to 165°C, adjust the pressure to 20MPa, and start the kneading of the mixed rubber with the scale of the two rollers at 0.5; then adjust the roller distance to 0, and make a triangle bag 4 ~5 times; adjust the roller distance to 2.5 scales to produce the sheet, cut the sheet rubber according to the size of the mold, and send it to the press for vulcanization and foaming. The foaming time is 3400s.

The performance of the product obtained according to the above formula is as follows:

Claims (6)

1. the industrial process of a terpolymer EP rubber (EPDM) mold pressing sealed cell sponge rubber; Comprise the plasticating of rubber, mixing, refining, foaming sulfidization molding, it is characterized in that: add carbon black, NO, frothing aid, vulcanization accelerator and anti-aging agent when mixing and carry out mixing; Adding foaming agent ac and vulcanizing agent carry out refining during refining; The cure conditions of foaming sulfidization molding is: pressure 15～20MPa, 160～180 ℃ of temperature, curing time 3000～3500s;

The material of above-mentioned adding calculates with parts by weight, is respectively:

Rubber: EPDM:100;

Whipping agent: Ac 0.1～0.16;

Frothing aid: zinc oxide and Triple Pressed Stearic Acid, wherein zinc oxide is 0.02～0.05; Triple Pressed Stearic Acid is 0.008～0.01;

Vulcanizing agent: S 0.1～0.16;

Vulcanization accelerator: short D, short M, short BZ and short TRA,

Wherein short D is 0.001～0.003; Short M is 0.001～0.003; Short BZ is 0.001～0.005; Short TRA is 0.002～0.006;

Anti-aging agent; RD and 4020, parts by weight all are 0.001;

Tenderizer: NO 40～60;

Weighting agent: carbon black SRFN550 50.

2. the industrial process of a kind of terpolymer EP rubber as claimed in claim 1 (EPDM) mold pressing sealed cell sponge rubber is characterized in that:

The concrete technology of plasticating of rubber is: the mill temperature is controlled at below 50 ℃, and the EPDM rubber 2-3min that in mill, plasticates is transparence until sizing material.

3. the industrial process of a kind of terpolymer EP rubber as claimed in claim 1 (EPDM) mold pressing sealed cell sponge rubber is characterized in that:

Mixing concrete technology is: the sizing material that will plasticate is put into Banbury mixer, and mixing carbon black, NO, frothing aid, vulcanization accelerator and the anti-aging agent of adding during to 80～100 ℃ continues the mixing binder removal during to 100～120 ℃ of temperature of pressurization.

4. the industrial process of a kind of terpolymer EP rubber as claimed in claim 1 (EPDM) mold pressing sealed cell sponge rubber is characterized in that:

The concrete technology of purified is: Banbury mixer is preheated to 60～70 ℃; The sizing material that mixes packed into, and the pressurization banburying adds foaming agent ac and vulcanizing agent after 60～90 seconds in the Banbury mixer; Empty the making a call to of pressure cover semi-closure depressed the upward pressure lid fully after 1 minute, banburying is lifted pressure cover by sizing material binder removal after banburying chamber stands up 4 times after 2 minutes.

5. the industrial process of a kind of terpolymer EP rubber as claimed in claim 1 (EPDM) mold pressing sealed cell sponge rubber is characterized in that:

The concrete technology of foaming sulfidization molding is: the vulcanizer temperature is transferred to 165 ℃; Pressure transfers to 15MPa, and the sizing material that refining is good is to open refining earlier once under 0.5 situation at two roller scales, and the roll spacing adjustment will be 0 then; Play the triangle bag 4～5 times; Roll spacing is adjusted to 2.5 scale slices, and according to delivering to the press sulfur foam behind the mould size cut-parts shape glue, foamed time is 3300s.

6. the industrial process of a kind of terpolymer EP rubber as claimed in claim 1 (EPDM) mold pressing sealed cell sponge rubber is characterized in that: the mooney viscosity ML of rubber EPDM _{(1+4) 100 ℃}=46.