阅读说明：本技术 用于生产汽车空调管的nbr胶芯及其制备方法 (NBR rubber core for producing automobile air conditioner pipe and preparation method thereof ) 是由 王海洋 黄英 汤宝光 聂军 刘松涛 林龙龙 于 2019-10-29 设计创作，主要内容包括：本发明公开了用于生产汽车空调管的NBR胶芯及其制作方法,该方法包括以下步骤：(1)备料：称取制备NBR胶芯的原料备用,所述原料包括NBR橡胶、N660炭黑、滑石粉、防老剂、硫化剂和硫化促进剂；(2)一次密炼：将除硫化剂和硫化促进剂外的原料全部加入到密炼机中进行一次密炼,所述一次密炼的密炼时间为4-8min,排胶温度为150℃-165℃,得一次密炼产物；(3)二次密炼：将一次密炼产物、硫化剂和硫化促进剂加入到密炼机中进行二次密炼得NBR混炼胶；(4)挤出：将NBR混炼胶通过挤出机挤出并包覆在钢丝芯上,缠盘制成半成品胶芯；(5)硫化：对半成品胶芯进行硫化得NBR胶芯。该NBR胶芯生产成本低,耐热性好,可延迟胶芯使用寿命,且容易脱芯。(The invention discloses an NBR rubber core for producing an automobile air conditioning pipe and a manufacturing method thereof, wherein the method comprises the following steps: (1) preparing materials: weighing raw materials for preparing the NBR rubber core for later use, wherein the raw materials comprise NBR rubber, N660 carbon black, talcum powder, an anti-aging agent, a vulcanizing agent and a vulcanization accelerator; (2) primary banburying: adding all the raw materials except the vulcanizing agent and the vulcanization accelerator into an internal mixer for primary internal mixing, wherein the internal mixing time of the primary internal mixing is 4-8min, and the rubber discharge temperature is 150-165 ℃, so as to obtain a primary internal mixing product; (3) secondary banburying: adding the primary banburying product, a vulcanizing agent and a vulcanization accelerator into a banbury mixer for secondary banburying to obtain NBR rubber compound; (4) extruding: extruding the NBR rubber compound through an extruder, coating the NBR rubber compound on a steel wire core, and coiling to prepare a semi-finished rubber core; (5) and (3) vulcanization: and vulcanizing the semi-finished rubber core to obtain the NBR rubber core. The NBR rubber core has low production cost and good heat resistance, can delay the service life of the rubber core, and is easy to depoling.)

1. A manufacturing method of an NBR rubber core for producing an automobile air conditioning pipe is characterized by comprising the following steps:

(1) preparing materials: weighing raw materials for preparing the NBR rubber core for later use, wherein the raw materials comprise NBR rubber, N660 carbon black, talcum powder, an anti-aging agent, a vulcanizing agent and a vulcanization accelerator;

(2) primary banburying: adding all the raw materials except the vulcanizing agent and the vulcanization accelerator prepared in the step (1) into an internal mixer for primary internal mixing, wherein the internal mixing time of the primary internal mixing is 4-8min, and the rubber discharge temperature is 150-165 ℃, so as to obtain a primary internal mixing product;

(3) secondary banburying: adding the primary banburying product obtained in the step (2), a vulcanizing agent and a vulcanization accelerator into a banbury mixer for secondary banburying, wherein the banburying time of the secondary banburying is 4-8min, and the rubber discharge temperature is 90-110 ℃, so as to obtain NBR rubber compound;

(4) extruding: extruding the NBR rubber compound obtained in the step (3) through an extruder, coating the NBR rubber compound on a steel wire core, and coiling to prepare a semi-finished rubber core;

(5) and (3) vulcanization: and (4) vulcanizing the semi-finished rubber core obtained in the step (4) to obtain the NBR rubber core for producing the automobile air conditioner pipe after vulcanization.

2. The method for manufacturing the NBR rubber core for an automobile air-conditioning pipe according to claim 1, wherein the raw material components and the parts by weight thereof for preparing the NBR rubber core in the step (1) include: 100 parts of NBR rubber, 60-100 parts of N660 carbon black, 30-60 parts of talcum powder, 1-5 parts of anti-aging agent, 0.5-3 parts of vulcanizing agent and 1-5 parts of vulcanization accelerator.

3. The method of manufacturing the NBR rubber core for an automobile air-conditioning pipe according to claim 1, wherein the anti-aging agent is anti-aging agent RD, the vulcanizing agent is insoluble sulfur, and the vulcanization accelerator is accelerator DM.

4. The method of manufacturing the NBR gel core for an automobile air-conditioning pipe according to claim 1, wherein the raw material for preparing the NBR gel core in the step (1) does not contain a plasticizer.

5. The method for manufacturing the NBR rubber core for an automobile air-conditioning pipe according to claim 1, wherein the internal mixer for the primary internal mixing of the step (2) has a rotation speed of 20 to 30rpm, and the internal mixer for the secondary internal mixing of the step (3) has a rotation speed of 20 to 30 rpm.

6. The method of manufacturing the NBR gel core for an automobile air-conditioning pipe according to claim 1, wherein the head temperature of the extruder used in the step (4) is 80 to 100 ℃, the screw temperature is 75 to 95 ℃, and the feed inlet temperature is 65 to 75 ℃.

7. The method for manufacturing the NBR gel core for an automobile air-conditioning pipe according to claim 1, wherein the vulcanization temperature in the step (5) is 150 ℃ to 165 ℃, and the vulcanization time is 60min to 80 min.

8. An NBR rubber core for producing an automotive air conditioning tube, characterized in that it is produced by the production method of any one of claims 1 to 8.

9. The NBR rubber core for producing tubes for automobile air conditioners according to claim 9, wherein the tensile strength of the rubber of the NBR rubber core is not less than 12MPa, the elongation is not less than 200%, and the hardness is 85-95 shore a; the ellipticity of the NBR rubber core is less than or equal to 0.10.

Technical Field

The invention belongs to the technical field of automobile part manufacturing, and particularly relates to an NBR rubber core for producing an automobile air conditioner pipe and a preparation method thereof.

Background

The automobile air-conditioning pipe is an important part in an automobile pipeline, mainly used for transmitting a refrigerant in an automobile air-conditioning system, and mainly has a four-layer structure and a five-layer structure; the innermost layer of the four-layer structure is a nylon shielding layer, the innermost layer of the five-layer structure is rubber, and the inner layer rubber of the five-layer structure is Ethylene Propylene Diene Monomer (EPDM) generally because the automobile air conditioner hose needs higher heat resistance. The inner diameter of the automobile air-conditioning hose is large, a core forming mode is required to be adopted for extrusion during production, and the inner diameter size of the air-conditioning pipe needs to be controlled through the rubber core during the extrusion process.

At present, the rubber core used for producing the automobile air-conditioning pipe is mostly made of nylon and TPX (poly 4-methyl 1-pentene), the rubber cores of the two materials have good heat resistance, stable size, easy core release and can be reused, but the rubber cores have the defects of high price and high cost, and the manufacturing cost of the rubber core required by the air-conditioning hose with larger inner diameter (such as the inner diameter of 16mm, 19mm and 26mm) is higher; if the conventional rubber core is adopted, although the production cost of the rubber core is reduced, the rubber core is made of the same material as the rubber material of the automobile air-conditioning pipe, the rubber core is easy to adhere to the rubber in the air-conditioning hose and difficult to strip, the whole batch of air-conditioning pipes are easy to scrap, and the finished product rate of the air-conditioning pipes is influenced.

Disclosure of Invention

The invention provides the NBR rubber core for producing the automobile air conditioner pipe and the preparation method thereof aiming at the technical problems.

In order to achieve the purpose, the invention adopts the technical scheme that:

a manufacturing method of an NBR rubber core for producing an automobile air conditioning pipe comprises the following steps:

(1) preparing materials: weighing raw materials for preparing the NBR rubber core for later use, wherein the raw materials comprise NBR rubber (nitrile-butadiene rubber), N660 carbon black, talcum powder, an anti-aging agent, a vulcanizing agent and a vulcanization accelerator;

(2) primary banburying: adding all the raw materials except the vulcanizing agent and the vulcanization accelerator prepared in the step (1) into an internal mixer for primary internal mixing, wherein the internal mixing time of the primary internal mixing is 4-8min, and the rubber discharge temperature is 150-165 ℃, so as to obtain a primary internal mixing product;

(3) secondary banburying: adding the primary banburying product obtained in the step (2), a vulcanizing agent and a vulcanization accelerator into a banbury mixer for secondary banburying, wherein the banburying time of the secondary banburying is 4-8min, and the rubber discharge temperature is 90-110 ℃, so as to obtain NBR rubber compound;

(4) extruding: extruding the NBR rubber compound obtained in the step (3) through an extruder, coating the NBR rubber compound on a steel wire core, and coiling to prepare a semi-finished rubber core;

(5) and (3) vulcanization: and (4) vulcanizing the semi-finished rubber core obtained in the step (4) to obtain the NBR rubber core for producing the automobile air conditioner pipe after vulcanization.

Preferably, the raw material components and the parts by weight thereof for preparing the NBR rubber core in the step (1) comprise: 100 parts of NBR rubber, 60-100 parts of N660 carbon black, 30-60 parts of talcum powder, 1-5 parts of anti-aging agent, 0.5-3 parts of vulcanizing agent and 1-5 parts of vulcanization accelerator.

Preferably, the anti-aging agent is an anti-aging agent RD, the vulcanizing agent is insoluble sulfur, and the vulcanization accelerator is an accelerator DM.

Preferably, the raw materials for preparing the NBR rubber core in the step (1) do not contain a plasticizer.

Preferably, the rotation speed of the internal mixer for the primary banburying of the step (2) is 20-30rpm, and the rotation speed of the internal mixer for the secondary banburying of the step (3) is 20-30 rpm.

Preferably, the temperature of the head of the extruder used in the step (4) is 80-100 ℃, the temperature of the screw is 75-95 ℃, and the temperature of the feeding port is 65-75 ℃.

Preferably, the vulcanization temperature in the step (5) is 150-165 ℃, and the vulcanization time is 60-80 min.

The invention also discloses the NBR rubber core for producing the automobile air conditioning pipe, which is prepared by the preparation method.

Preferably, the tensile strength of the rubber of the NBR rubber core is more than or equal to 12MPa, the elongation is more than or equal to 200 percent, and the hardness is 85-95 Shore A; the ellipticity of the NBR rubber core is less than or equal to 0.10.

Compared with the prior art, the invention has the advantages and positive effects that: the NBR rubber core takes cheap NBR rubber as a main raw material for manufacturing the rubber core, so that the production cost of the rubber core is reduced, the heat resistance of the NBR rubber is improved and the service life of the rubber core is prolonged by improving the temperature of primary banburying and optimizing the raw materials in the preparation method, and the prepared NBR rubber core has the advantages of good heat resistance, good dimensional stability, recycling and easy core removal when being applied to the production of the automobile air-conditioning tube.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A manufacturing method of an NBR rubber core for producing an automobile air conditioning pipe comprises the following steps:

(1) preparing materials: weighing raw materials for preparing the NBR rubber core for later use, wherein the raw materials comprise NBR rubber (nitrile-butadiene rubber), N660 carbon black, talcum powder, an anti-aging agent, a vulcanizing agent and a vulcanization accelerator;

(2) primary banburying: adding all the raw materials except the vulcanizing agent and the vulcanization accelerator prepared in the step (1) into an internal mixer for primary internal mixing, wherein the internal mixing time of the primary internal mixing is 4-8min, and the rubber discharge temperature is 150-165 ℃, so as to obtain a primary internal mixing product;

(3) secondary banburying: adding the primary banburying product obtained in the step (2), a vulcanizing agent and a vulcanization accelerator into a banbury mixer for secondary banburying, wherein the banburying time of the secondary banburying is 4-8min, and the rubber discharge temperature is 90-110 ℃, so as to obtain NBR rubber compound;

(4) extruding: extruding the NBR rubber compound obtained in the step (3) through an extruder, coating the NBR rubber compound on a steel wire core, and coiling to prepare a semi-finished rubber core;

(5) and (3) vulcanization: and (4) vulcanizing the semi-finished rubber core obtained in the step (4) to obtain the NBR rubber core for producing the automobile air conditioner pipe after vulcanization.

Tests show that the tensile strength of the rubber of the NBR rubber core for producing the automobile air-conditioning tube prepared by the method is more than or equal to 12MPa, the elongation is more than or equal to 200 percent, and the hardness is 85-95 Shore A; the ellipticity of the NBR rubber core is less than or equal to 0.10.

The NBR rubber (nitrile rubber) is prepared from butadiene and acrylonitrile by an emulsion polymerization method, has better oil resistance and wear resistance, is cheaper than nylon and TPX, and can be used for manufacturing rubber cores to reduce the production cost, but the heat resistance of the conventional NBR rubber cannot meet the heat resistance requirement of the high-temperature use environment for producing the rubber cores for rubber tubes, and the rubber cores made of the conventional NBR rubber can be damaged and deformed after being applied to the production of automobile air-conditioning tubes for several times and cannot be recycled. The heat resistance of the NBR rubber and the service life of the rubber core are improved by improving the temperature of once banburying and optimizing the raw materials, so that the NBR rubber can adapt to the high-temperature use environment of the rubber core.

Specifically, the raw material components for preparing the NBR rubber core in the step (1) and the parts by weight thereof comprise: 100 parts of NBR rubber, 60-100 parts of N660 carbon black, 30-60 parts of talcum powder, 1-5 parts of anti-aging agent, 0.5-3 parts of vulcanizing agent and 1-5 parts of vulcanization accelerator.

Specifically, the anti-aging agent is an anti-aging agent RD, the vulcanizing agent is insoluble sulfur, and the vulcanization accelerator is an accelerator DM.

Specifically, the raw materials for preparing the NBR rubber core in the step (1) do not contain a plasticizer. The NBR rubber core formula does not contain a plasticizer, so that the heat resistance of the NBR rubber can be further improved, and the dimensional stability of the NBR rubber can be further improved.

Specifically, the rotation speed of the internal mixer for the primary internal mixing in the step (2) is 20-30rpm, and the rotation speed of the internal mixer for the secondary internal mixing in the step (3) is 20-30 rpm.

Specifically, the temperature of the head of the extruder used in the step (4) is 80-100 ℃, the temperature of the screw is 75-95 ℃, and the temperature of the feeding port is 65-75 ℃.

Specifically, the vulcanization temperature in the step (5) is 150-165 ℃, and the vulcanization time is 60-80 min.