阅读说明：本技术 自粘性模具清洗用橡胶混合物、制备方法及其使用方法 (Rubber mixture for cleaning self-adhesive mold, preparation method and use method thereof ) 是由 刘韬 钱寒东 于 2020-04-23 设计创作，主要内容包括：自粘性模具清洗用橡胶混合物、制备方法及其使用方法,涉及复合材料的生产和模具的清洁技术领域。将NR和1,2-聚丁二烯在密炼机中塑炼,物料温度达到180℃后,再将白炭黑、钛白粉、氧化锌、三乙醇胺、增塑剂和石油树脂投入再混炼,再将混炼后得到的混合物料停放冷却至室温后,置于开炼机上进行降温分散混炼,同时添加硫化剂和促进剂,混炼均匀拉薄通后成片,然后将片材冷却后取得橡胶混合物。将该橡胶混合物置于模腔中硫化或注塑,完成对模具的清洁。该材料与橡胶的相容性好,采用该材料不但可以增加交联材料的强度,还可以在高温下有一定的粘性,有利于材料在高温高压模腔中对杂质的吸附。(A self-adhesive rubber mixture for cleaning a mold, a preparation method and a use method thereof relate to the technical field of production of composite materials and cleaning of molds. Plasticating NR and 1, 2-polybutadiene in an internal mixer, adding white carbon black, titanium dioxide, zinc oxide, triethanolamine, a plasticizer and petroleum resin after the material temperature reaches 180 ℃, mixing again, standing and cooling the mixed material obtained after mixing to room temperature, placing on an open mill for cooling, dispersing and mixing, simultaneously adding a vulcanizing agent and an accelerator, mixing uniformly, thinning and slicing, and cooling the sheet to obtain the rubber mixture. The rubber mixture is placed in a mold cavity for vulcanization or injection molding, and the mold is cleaned. The material has good compatibility with rubber, can increase the strength of a cross-linking material, has certain viscosity at high temperature, and is favorable for adsorbing impurities in a high-temperature and high-pressure die cavity.)

1. A self-adhesive rubber mixture for cleaning moulds is characterized by mainly comprising NR, 1, 2-polybutadiene, white carbon black, titanium dioxide, zinc oxide, triethanolamine, 1, 2-ethylene glycol, naphthenic oil, petroleum resin, sulfur and an accelerator.

2. The rubber mixture according to claim 1, wherein the weight mixing ratio of the NR, the 1, 2-polybutadiene, the white carbon black, the titanium dioxide, the zinc oxide, the triethanolamine, the 1, 2-ethylene glycol, the naphthenic oil, the petroleum resin, the sulfur and the accelerator is 70-80: 30-20: 20-30: 3-5: 10-20: 2-4: 10-20: 5-10: 0.6-1.0.

3. A process for the preparation of a rubber mixture as claimed in claim 1 or 2, characterized in that it comprises the following steps:

1) plasticating NR and 1, 2-polybutadiene in an internal mixer for at least 10 minutes, feeding white carbon black, titanium dioxide, zinc oxide, triethanolamine, a plasticizer and petroleum resin into the internal mixer after the material temperature reaches 180 ℃, and then mixing for 12-20 minutes under the condition that the temperature is less than or equal to 120 ℃;

2) standing and cooling the mixed material obtained after mixing to room temperature, placing the mixed material on an open mill for cooling, dispersing and mixing, adding a vulcanizing agent and an accelerator, uniformly mixing, thinning and slicing, and cooling the slices to below 70 ℃ to obtain the rubber mixture.

4. The method for producing a rubber compound according to claim 3, wherein said NR is 3L natural rubber, and the Mooney viscosity is 60 to 90.

5. The method for producing a rubber compound according to claim 3, wherein the Mooney viscosity of the 1, 2-polybutadiene is 60 to 90, the crystallinity is 50 to 70%, and the melting temperature is 170 to 200 ℃.

6. The process for producing a rubber compound according to claim 5, wherein the 1, 2-polybutadiene is syndiotactic 1, 2-polybutadiene synthesized by using an iron-based catalyst.

7. The method for preparing a rubber mixture according to claim 3, wherein the petroleum resin is ethylene tar and carbon nine which are used as raw materials and are obtained by catalytic polymerization, and the product is yellow, brown and blocky solid in appearance and has a softening point of 75-135 ℃.

8. Method for using a rubber mixture according to claim 1, characterized in that: and adding the rubber mixture into a mold cavity, vulcanizing for 3-10 min on vulcanization equipment under the conditions that the pressure is 5-12 MPa and the temperature is 150-170 ℃ to enable dirt in the mold cavity and the rubber mixture to be crosslinked into solid, opening the mold and taking out the solid mixture with the dirt, and finishing cleaning the metal mold cavity.

9. Method for using a rubber mixture according to claim 1, characterized in that: and (3) performing extrusion molding on the rubber mixture in an injection molding machine under the conditions that the pressure is 5-12 MPa and the temperature is 150-170 ℃, and cleaning a mold cavity and a mold of the injection molding machine.

Technical Field

The invention relates to the technical field of composite material production and also relates to the technical field of mold cleaning.

Background

In the production process of rubber and plastic products, a large number of metal molds are used, and because the high-molecular products are easily decomposed at high temperature and high pressure to generate low-molecular pollutants, small parts of the pollutants can be adhered to the metal molds, and on the other hand, moisture in the air can also react with the metal molds to generate rust and the like, the molds can be seriously polluted in the use or parking process in a long-term process, so that qualified products cannot be produced, and the product quality is influenced. The traditional mode of washing the mould is with the mould cooling, and the manual work is pulled out from the machine, puts to spacious place, washs with acid solution, has washd, installs on equipment after the sunning.

The traditional method has two serious problems, on one hand, the acidic solvent is used, waste liquid is generated, and the environmental hazard is great; on the other hand, the mold needs to be cooled, disassembled and assembled, and long working hours are needed, so that the influence on production is serious, and the efficiency is low.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention provides a self-adhesive rubber composition for mold cleaning that can be conveniently used for cleaning molds.

The invention mainly comprises NR (natural rubber), 1, 2-polybutadiene, white carbon black, titanium dioxide, zinc oxide, triethanolamine, 1, 2-ethylene glycol, naphthenic oil, petroleum resin, sulfur and an accelerant.

The invention uses NR (natural rubber) and 1, 2-polybutadiene as main materials, and combines petroleum resin capable of increasing viscosity and amine compound capable of reacting with metal ions such as rust, and then combines with a vulcanization crosslinking system. The material can be directly used on a mould using device, various impurity pollutants on the surface of the mould are reacted and adhered under high pressure and high temperature, and the material and the adhered impurities are solidified into a whole together after a certain time at high temperature and high pressure by utilizing the thermosetting characteristic of rubber, so that the material can be easily removed after mould opening.

The 1, 2-polybutadiene can increase the adhesive property of sizing materials and improve the adhesive effect on metal surfaces, the naphthenic oil also has the effects of reducing the hardness, increasing the fluidity of the sizing materials and improving the adsorption effect, and the 1, 2-ethylene glycol can adjust the acidity and alkalinity of the whole mixture to increase the crosslinking density of the materials, thereby being beneficial to the effect of opening the molds and demoulding.

Furthermore, the weight mixing ratio of the NR (natural rubber), the 1, 2-polybutadiene, the white carbon black, the titanium dioxide, the zinc oxide, the triethanolamine, the 1, 2-ethylene glycol, the naphthenic oil, the petroleum resin, the sulfur and the accelerator is 70-80: 30-20: 20-30: 3-5: 10-20: 2-4: 10-20: 5-10: 0.6-1.0.

The invention takes the natural rubber as the main base material, on one hand, the price is lower, on the other hand, the natural rubber can be crosslinked, and the vulcanization speed is higher; the 1, 2-polybutadiene is matched with natural rubber, so that the compatibility is good, the self-adhesion is good, and the material has good adsorption effect; the triethanolamine has a good cleaning effect and can react with impurities such as the rust in the die cavity and the like to remove stubborn surface dirt. The petroleum resin and the naphthenic oil can improve the viscosity of the material and are beneficial to the processing performance of the material. The other materials are basically matched with rubber materials, so that the materials can be quickly vulcanized and crosslinked at high temperature, the sulfide strength is also endowed, and the mixture can be easily taken out of a mold cavity.

A second object of the present invention is to propose a process for the preparation of the above cleaning rubber mixture.

The invention comprises the following steps:

1) plasticating NR and 1, 2-polybutadiene in an internal mixer for at least 10 minutes, feeding white carbon black, titanium dioxide, zinc oxide, triethanolamine, a plasticizer and petroleum resin into the internal mixer after the material temperature reaches 180 ℃, and then mixing for 12-20 minutes under the condition that the temperature is less than or equal to 120 ℃;

2) standing and cooling the mixed material obtained after mixing to room temperature, placing the mixed material on an open mill for cooling, dispersing and mixing, adding a vulcanizing agent and an accelerator, uniformly mixing, thinning and slicing, and cooling the slices to below 70 ℃ to obtain the rubber mixture.

In the step 1), the purpose of plasticating the NR and the 1, 2-polybutadiene is to utilize the thermal oxidation degradation to break the macromolecular chain of the 1, 2-polybutadiene and generate the micromolecular polybutene, so that the 1, 2-polybutadiene and the NR can be better mixed, and stronger viscosity is generated, so that the rubber has better effect on adhering impurities on the surface of a mold in the using process of a product. The mixing time after the white carbon black, the titanium white, the zinc oxide, the triethanolamine, the plasticizer and the petroleum resin are added is that partial low molecular weight liquid volatilizes at high temperature so that the obtained mixture loses partial viscosity; when the materials are uniformly mixed and have uniform color and no particles, the material can be discharged.

The vulcanizing agent and the accelerator are added in an open mill after the temperature of the material is reduced, and the vulcanizing agent and the accelerator are mainly used for preventing the material from being crosslinked in advance at high temperature, so that partial adhesiveness is lost, and the mold washing efficiency is reduced.

In the above step 2), the cooling time is usually at least 8 hours, and the temperature is not higher than 70 ℃ so as to avoid the premature crosslinking reaction inside the mixture when the vulcanization system is added.

In a word, through the above process, the purposes of uniform material mixing, uniform performance, high strength, difficult self-vulcanization and long retention period are realized.

In addition, the NR is 3L natural rubber, the Mooney viscosity is 60-90, and the natural rubber is easy to process and is beneficial to uniform dispersion of materials.

The Mooney viscosity of the 1, 2-polybutadiene is 60-90, the crystallinity is 50-70%, the melting temperature is 170-200 ℃, the compatibility with natural rubber is facilitated, and the 1, 2-polybutadiene has certain viscosity and strength.

The 1, 2-polybutadiene is syndiotactic 1, 2-polybutadiene synthesized by an iron catalyst. The syndiotactic 1, 2-polybutadiene synthesized by the method has high crystallinity, high melting temperature, high viscosity at high temperature and low viscosity at low temperature, and is beneficial to processing.

The petroleum resin is obtained by catalytic polymerization reaction of ethylene tar and carbon nine serving as raw materials, and the product is yellow, brown and blocky solid in appearance and has a softening point of 75-135 ℃. The material has good compatibility with rubber, can increase the strength of a cross-linking material, has certain viscosity at high temperature, and is favorable for adsorbing impurities in a high-temperature and high-pressure die cavity.

A third object of the invention is to propose two methods of use of the above rubber mixtures.

The first method is as follows: and adding the rubber mixture into a mold cavity, vulcanizing for 3-10 min on vulcanization equipment under the conditions that the pressure is 5-12 MPa and the temperature is 150-170 ℃ to crosslink dirt in the mold cavity and the rubber mixture into a solid mixture, opening the mold and taking out the solid mixture with the dirt, and finishing cleaning the metal mold cavity.

If the used equipment is a flat vulcanizing machine and a common mold, the rubber mixture is properly weighed according to the shape and size of the mold cavity of the mold, and by the method, dirt in the mold cavity is reacted or bonded in the rubber mixture and permeates into vulcanized colloid, and the solid mixture with the dirt is crosslinked at high temperature and high pressure, so that the impurity dirt is easily taken away, and the bright surface of the mold cavity of the mold is recovered; if the effect is insufficient, the rubber mixture can be repeatedly used in the above-mentioned manner.

The second method is as follows: and (3) performing extrusion molding on the rubber mixture in an injection molding machine under the conditions that the pressure is 5-12 MPa and the temperature is 150-170 ℃, and cleaning a mold cavity and a mold of the injection molding machine.

If the used equipment is rubber and plastic injection molding equipment and a mold, on one hand, the rubber mixture can be extruded in the injection molding machine for a long time or circularly by adopting the method, so that impurities and rust in the internal channel of the equipment are taken out by the rubber mixture, and the mold is bright; if the effect is insufficient, the material can be used for multiple operations by adopting the method.

Detailed Description

Firstly, preparing a cleaning rubber mixture:

1. preparing materials:

NR is 3L natural rubber, and the Mooney viscosity is 60-90.

The 1, 2-polybutadiene is syndiotactic 1, 2-polybutadiene synthesized by using an iron-based catalyst, and the Mooney viscosity of the 1, 2-polybutadiene is 60-90, the crystallinity is 50-70%, and the melting temperature is 170-200 ℃ as disclosed in the method of Z L2017105401007.

The petroleum resin is ethylene tar and carbon nine which are used as raw materials and are obtained by catalytic polymerization, the product is yellow, brown and blocky solid in appearance, and the softening point is 75-135 ℃.

2. Weighing table:

weighing the following ten formulas respectively:

3. the process comprises the following steps:

(1) plasticating NR and 1, 2-polybutadiene in an internal mixer for at least 10 minutes, setting the rotating speed of the internal mixer to be 100 r/min, rapidly increasing the temperature along with the continuous friction between a rubber material and a cavity, opening an upper top bolt of the internal mixer after the material temperature reaches 180 ℃ and is stabilized for 1 minute, then adding white carbon black, titanium dioxide, zinc oxide, triethanolamine, a plasticizer and petroleum resin into the internal mixer, closing the upper top bolt, continuously mixing for 12-20 minutes under the condition that the temperature is less than or equal to 120 ℃, and opening a lower top bolt for discharging.

(2) Standing and cooling the mixed material obtained after mixing to room temperature, placing the mixed material on an open mill for cooling, dispersing and mixing, adding a vulcanizing agent and an accelerant, uniformly mixing, thinning and slicing, and cooling the slices to below 70 ℃ to obtain the mixed material.

4. The application comprises the following steps:

(1) and respectively putting the rubber mixtures respectively formed by the formula 1, the formula 2, the formula 3 and the formula 4 into a mold cavity, vulcanizing for 3-10 min on vulcanization equipment under the conditions of the pressure of 5-12 mPa and the temperature of 150-170 ℃, taking out the rubber mixtures from the mold, taking out the solid mixtures with dirt, and finishing cleaning a flat vulcanizing machine or a common mold. If the effect is insufficient, the rubber mixture can be repeatedly used in the above-mentioned manner.

(2) And respectively adding the rubber mixtures formed by the formula 5, the formula 6, the formula 7 and the formula 8 into an injection molding machine, and performing extrusion molding under the conditions of 5-12 MPa of pressure and 150-170 ℃ to complete cleaning of a mold cavity and a mold of the injection molding machine. If the effect is insufficient, the material can be used for multiple operations by adopting the method.

(3) And respectively adding the rubber mixtures respectively formed by the formula 1, the formula 2, the formula 9 and the formula 10 into a metal mold cavity, and vulcanizing for 3-10 min under the conditions that the pressure is 5-12 MPa and the temperature is 150-170 ℃, so that the dirt in the mold cavity and the rubber mixture are crosslinked into a solid mixture with the dirt, and the cleaning of the metal mold cavity is completed.