Oil-resistant wrapped rubber hose and method of making same

Abstract

This invention discloses an oil-resistant spiral hose and its preparation method, belonging to the field of rubber hoses. It includes a chloroprene rubber layer and a silicone layer located outside the chloroprene rubber layer. The chloroprene rubber layer comprises the following components by weight: 90-110 parts of ternary copolymer chloroprene rubber, 30-80 parts of reinforcing agent, 20-50 parts of diatomaceous earth, 4-10 parts of magnesium oxide, 5-10 parts of light calcium carbonate, 3-8 parts of plasticizer, 2.0-3.0 parts of antioxidant, 1.0-2.0 parts of additive, 1.0-2.0 parts of flow agent, 2.0-6.0 parts of tackifier, 2.0-4.0 parts of activator, 1.0-2.0 parts of vulcanizing agent, and 0.2-1 parts of co-crosslinking agent. This invention has excellent oil resistance, weather aging resistance, ozone resistance, and good airtightness. It is very suitable for the inner layer of oil-resistant hoses and has a low cost. It solves the problem of the lack of a hose with good oil resistance and low cost in existing turbochargers.

Description

Technical Field

[0001] This invention relates to the field of rubber hoses, and more particularly to an oil-resistant spiral rubber hose and its preparation method. Background Technology

[0002] In turbocharger hoses, traditional silicone hoses are prone to aging and damage due to their poor oil resistance. While fluororubber and fluorosilicone rubber have the advantage of resistance to oil and gas penetration, their high cost limits their application. Therefore, there is a need for a hose that is relatively low-cost and has good oil resistance.

[0003] For example, the "Preparation Process of a Large-Diameter Silicone Tube" disclosed in Chinese patent literature, with publication number CN102642291B, includes the following preparation steps: (a) Feeding and mixing: 95%~98.2% by weight of silicone rubber, 1%~4.8% of vulcanizing agent, and 0.2%~0.8% of color masterbatch are fed into a feeding device and mixed to obtain a mixture; (b) Extrusion and gas filling: The mixed mixture is extruded through the extrusion die of an extrusion molding machine to produce a large-diameter silicone tube pre-finished product, while gas is continuously filled into the cavity of the large-diameter silicone tube pre-finished product; (c) Vulcanization molding: The large-diameter silicone tube pre-finished product is vulcanized through a vulcanizing machine to obtain a large-diameter silicone tube finished product. However, the drawback of this patent is that the resulting silicone tube has poor oil resistance and is not suitable for use as a turbocharger hose. Summary of the Invention

[0004] This invention aims to overcome the problem of the lack of a rubber hose with good oil resistance and low cost in existing turbochargers. It provides an oil-resistant spiral rubber hose and its preparation method. The hose has good oil resistance, solves the bonding problem and calendering process problem, and has a huge cost advantage compared with the original internal fluoropolymer and external silicone spiral rubber hose. It is suitable for internal temperatures of -40~150℃ and working environments requiring oil and oil gas resistance, and the external working temperature can reach 180℃.

[0005] Another objective of this invention is to select a ternary copolymer of chloroprene rubber, wherein the third monomer of the chloroprene rubber is vulcanized using an oxygen vulcanization system, and co-vulcanization with silicone can be achieved; at the same time, this invention adds a tackifier to enhance the adhesion performance of the two; at the same time, this formula also effectively solves the problem of chloroprene rubber sticking to the calendering roller; and solves the adhesion problem between the inner oil-resistant rubber and the outer silicone, so that the adhesion meets the requirements.

[0006] Another objective of this invention is to: wind calendered chloroprene rubber sheets and silicone sheets onto a vulcanizing mold, and introduce hot air or steam into the vulcanizing mold for vulcanization; the inner core of the vulcanizing mold is provided with an inner channel, through which hot air or steam can be introduced into the inner channel of the rubber tube, thereby ensuring that the vulcanization temperature of the inner chloroprene rubber layer is guaranteed; the outer surface of the inner core of the mold is provided with several vulcanization notches, and during the vulcanization process, the gas in the vulcanization notches can increase the contact area between the chloroprene rubber layer and the hot air or steam; so that the inner and outer layers of the rubber tube are in contact with hot air or steam simultaneously, ensuring the vulcanization effect.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This invention discloses an oil-resistant spiral wound hose, comprising a chlorinated polyurethane rubber layer and a silicone layer located outside the chlorinated polyurethane rubber layer. The chlorinated polyurethane rubber layer comprises the following components in parts by weight: 90-110 parts of ternary copolymer chlorinated polyurethane rubber, 30-80 parts of reinforcing agent, 20-50 parts of diatomaceous earth, 4-10 parts of magnesium oxide, 5-10 parts of light calcium carbonate, 3-8 parts of plasticizer, 2.0-3.0 parts of antioxidant, 1.0-2.0 parts of additive, 1.0-2.0 parts of flow agent, 2.0-6.0 parts of tackifier, 2.0-4.0 parts of activator, 1.0-2.0 parts of vulcanizing agent, and 0.2-1 parts of co-crosslinking agent.

[0009] Preferably, the silicone layer comprises the following components in parts by weight: 90-110 parts vinyl silicone rubber, 10-20 parts fumed silica, 2-4 parts heat resistant agent, 2-4 parts tackifier, 1-3 parts colorant, and 1-2 parts vulcanizing agent.

[0010] Chlorinated polyvinyl chloride (CPVC) rubber possesses excellent oil resistance, weather aging resistance, ozone resistance, and good airtightness, making it highly suitable for the inner layer of oil-resistant hoses at a relatively low cost. However, despite its superior oil resistance and cost advantages, CPVC rubber is typically difficult to bond with silicone rubber, leading to hose delamination and affecting practical use. CPVC rubber is usually a soap-based or TCY-based vulcanization system, incompatible with the peroxide-based system of silicone rubber. Furthermore, CPVC rubber is a polar rubber, while silicone rubber is non-polar, resulting in poor affinity and exacerbating adhesion difficulties. This invention utilizes a ternary copolymer of CPVC rubber, with the third monomer vulcanized using a peroxide vulcanization system, enabling co-vulcanization with silicone rubber. Additionally, this invention incorporates a tackifier to enhance adhesion. Moreover, this formulation effectively solves the problem of CPVC rubber sticking to calendering rollers.

[0011] Preferably, the vulcanizing agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0012] Preferably, the crosslinking agent is triallyl isocyanurate.

[0013] Preferably, the reinforcing agent is one or both of carbon black N330 and N774.

[0014] A method for preparing an oil-resistant spiral hose includes the following steps:

[0015] ① Chlorinated polyurethane rubber layer mixing: Weigh each material according to the mass ratio, add all materials except vulcanizing agent into the internal mixer and mix evenly. After cooling, add the previously mixed rubber compound into the internal mixer and add vulcanizing agent to make mixed chlorinated polyurethane rubber for later use.

[0016] ②Silicone layer mixing: Weigh each material according to the mass ratio, add all materials except vulcanizing agent into the open mill and mix them into raw silicone rubber. Then add vulcanizing agent and mix evenly to make mixed silicone rubber. Roll it up and store it.

[0017] ③ Calendering: After the compounded chloroprene rubber is hot-melted, it is put into the calendering machine, the roller gap and roller temperature are adjusted, and the rubber compound is pressed into chloroprene rubber sheets of the required thickness. Then the compounded silicone rubber is calendered into silicone rubber sheets in the same way.

[0018] ④ Wrap the calendered chlorinated ether film and silicone film onto the vulcanizing mold;

[0019] ⑤ Pass hot air or steam into the vulcanizing mold to carry out vulcanization.

[0020] Preferably, the median thickness of the chloroprene film is between 0.8 and 1.5 mm, and the median thickness of the silicone film is between 0.5 mm and 1.0 mm.

[0021] Preferably, the vulcanizing mold includes a mold core, a mounting base, and a mold shell. The mold core has an inner channel for introducing hot air or steam into the inner side of the rubber tube. Gas can be introduced into the inner channel of the rubber tube through the inner channel, thereby ensuring that the vulcanization temperature of the inner chloroprene rubber layer is maintained.

[0022] Preferably, the outer surface of the mold core is provided with several vulcanization recesses. During the vulcanization process, the gas in the vulcanization recesses can increase the contact area between the chlorinated ether resin layer and hot air or steam, thereby ensuring the vulcanization effect.

[0023] Preferably, a connecting channel is provided between the vulcanization notch and the inner channel.

[0024] Therefore, the present invention has the following beneficial effects: (1) good oil resistance; (2) low cost; (3) solves the problem of adhesion between the inner oil-resistant adhesive and the outer silicone, so that the adhesion meets the requirements; (4) allows the inner and outer layers of the tubing to be in contact with hot air or steam at the same time, ensuring the curing effect. Attached Figure Description

[0025] Figure 1 This is a cross-sectional structural schematic diagram of the vulcanizing mold of the present invention.

[0026] In the diagram: 1. Mold core; 2. Mounting base; 3. Mold shell; 4. Inner channel; 5. Vulcanization notch; 6. Connecting channel; 7. Air inlet; 8. Air outlet. Detailed Implementation

[0027] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0028] Example 1, as Figure 1 As shown, an oil-resistant spiral wound hose includes a chlorinated polyurethane rubber layer and a silicone layer located outside the chlorinated polyurethane rubber layer. The chlorinated polyurethane rubber layer includes the following components: ternary copolymer chlorinated polyurethane rubber, reinforcing agent, diatomaceous earth, magnesium oxide, light calcium carbonate, plasticizer, antioxidant, flow agent, additive, tackifier, activator, vulcanizing agent, and crosslinking agent.

[0029] The silicone layer comprises the following components: vinyl silicone rubber, fumed silica, heat resistant agent, tackifier, colorant, and vulcanizing agent.

[0030] The magnesium oxide in the chlorinated ether adhesive layer is active magnesium oxide with an activity value of 150~170.

[0031] The antioxidant in the chloroether adhesive layer is 445 (4,4'-bis(α,α-dimethylbenzyl)diphenylamine).

[0032] The flow agent in the chlorinated ether adhesive layer is WA48.

[0033] The additive in the chlorinated ether adhesive layer is polyethylene glycol with a molecular weight of 6000.

[0034] The tackifier in the chlorinated ether adhesive layer is RS35.

[0035] The reinforcing agent in the chlorinated ether adhesive layer is one or two of carbon black N330 and N774.

[0036] The plasticizer in the chlorinated ether adhesive layer is an ester plasticizer, such as RS107.

[0037] The vulcanizing agent in the chlorinated ether adhesive layer is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0038] The crosslinking agent in the chlorinated ether adhesive layer is TAIC triallyl isocyanurate.

[0039] The vinyl silicone rubber in the silicone layer is methyl vinyl silicone rubber compound 40~50A.

[0040] The heat-resistant agent in the silicone layer is HT00, which is nano-cerium oxide.

[0041] The colorant in the silicone layer is either iron oxide red or iron oxide black.

[0042] The vulcanizing agent in the silicone layer is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0043] The adhesive in the silicone layer is RS35.

[0044] The weight ratio of each component in the chloroprene rubber layer is as follows: 100 parts ternary copolymer chloroprene rubber, 4 parts active magnesium oxide, 2 parts 445 (4,4'-bis(α.α-dimethylbenzyl)diphenylamine), 1.5 parts WA48, 2 parts polyethylene glycol, 4 parts RS35, 20 parts carbon black N330, 30 parts carbon black N774, 5 parts light calcium carbonate, 50 parts diatomaceous earth, 3 parts plasticizer R107, 1.8 parts 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 0.5 parts triallyl isocyanurate.

[0045] The weight ratio of each component in the silicone layer is as follows: 100 parts methyl vinyl silicone rubber compound, 10 parts fumed silica, 3 parts RS35, 3 parts HT00, 1 part 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 2 parts iron oxide red.

[0046] A method for preparing an oil-resistant spiral hose includes the following steps:

[0047] ① Chlorinated polyurethane rubber layer mixing: Weigh each material according to the mass ratio, add all materials except vulcanizing agent into the internal mixer and mix evenly. After cooling, add the previously mixed rubber compound into the internal mixer and add vulcanizing agent to make mixed chlorinated polyurethane rubber for later use.

[0048] ②Silicone layer mixing: Weigh each material according to the mass ratio, add all materials except vulcanizing agent into the open mill and mix them into raw silicone rubber. Then add vulcanizing agent and mix evenly to make mixed silicone rubber. Roll it up and store it.

[0049] ③ Calendering: After the compounded chloroprene rubber is hot-melted, it is put into the calendering machine, the roller gap and roller temperature are adjusted, and the rubber compound is pressed into chloroprene rubber sheets of the required thickness. Then the compounded silicone rubber is calendered into silicone rubber sheets in the same way.

[0050] ④ Wrap the calendered chlorinated ether film and silicone film onto the vulcanizing mold;

[0051] ⑤ Pass hot air or steam into the vulcanizing mold to carry out vulcanization.

[0052] The median thickness of the chloroprene film is between 0.8 and 1.5 mm, and the median thickness of the silicone film is between 0.5 mm and 1.0 mm. The vulcanizing mold includes a mold core 1, a mounting base 2, and a mold shell 3. The mold core has an inner channel 4 for introducing hot air or steam into the inner side of the rubber tube. The outer surface of the mold core has several vulcanizing recesses 5. A connecting channel 6 is provided between the vulcanizing recesses and the inner channel. An outer vulcanizing cavity is formed between the mold shell and the rubber tube. The mold shell also has an air inlet 7 and an air outlet 8.

[0053] Example 2 differs from Example 1 in that the weight ratio of the chlorinated polyurethane adhesive layer and the silicone layer is different:

[0054] The weight ratio of each component in the chloroprene rubber layer is as follows: 100 parts ternary copolymer chloroprene rubber, 4 parts active magnesium oxide, 2 parts 445 (4,4'-bis(α.α-dimethylbenzyl)diphenylamine), 2 parts WA48, 2 parts polyethylene glycol, 3 parts RS35, 40 parts carbon black N330, 0 parts carbon black N774, 5 parts light calcium carbonate, 30 parts diatomaceous earth, 3 parts plasticizer R107, 1.8 parts 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 0.2 parts triallyl isocyanurate.

[0055] The weight ratio of each component in the silicone layer is as follows: 100 parts methyl vinyl silicone rubber compound, 15 parts fumed silica, 3.5 parts RS35, 1.2 parts HT00, 1.1 parts 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 0.8 parts iron oxide black.

[0056] Example 3 differs from Example 1 in that the weight ratio of the chlorinated polyurethane adhesive layer component is different:

[0057] The weight ratio of each component in the chloroprene rubber layer is as follows: 90 parts ternary copolymer chloroprene rubber, 4 parts active magnesium oxide, 2 parts 445 (4,4'-bis(α.α-dimethylbenzyl)diphenylamine), 0.8 parts WA48, 2 parts polyethylene glycol, 2 parts RS35, 30 parts carbon black N330, 20 parts carbon black N774, 5 parts light calcium carbonate, 20 parts diatomaceous earth, 3 parts plasticizer R107, 1.7 parts 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 0.3 parts triallyl isocyanurate.

[0058] The weight ratio of each component in the silicone layer is as follows: 100 parts methyl vinyl silicone rubber compound, 10 parts fumed silica, 3 parts RS35, 3 parts HT00, 1 part 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 2 parts iron oxide red.

[0059] In Comparative Example 1, both the inner and outer layers of the spiral wound tubing are made of ordinary silicone rubber.

[0060] Comparative Example 2: In this comparative example, the inner layer of the spiral wound tubing is peroxide-cured fluororubber, which contains a tackifier, and the outer layer is silicone rubber.

[0061] Comparative Example 3: In this comparative example, the inner layer of the spiral wound tubing is fluorosilicone rubber, which contains an tackifier, and the outer layer is silicone rubber.

[0062] Comparative Example 4: In this comparative example, the inner layer formulation is a binary chloroether rubber with a conventional soap vulcanization system, and the outer layer is silicone rubber.

[0063] Table 1:

[0064]

[0065] Table 1 shows the performance parameters of the rubber compounds prepared in Examples 1-3 and Comparative Examples 1-4. The hot air aging performance was tested at 150°C for 70 hours; the oil resistance performance was tested in ASTM 3# oil at 100°C for 70 hours; the fuel oil resistance performance was tested in fuel C at 23°C for 48 hours; the low-temperature performance was measured at the glass transition temperature; the cost of the inner layer rubber was calculated based on the formulation; and the calendering performance was statistically analyzed based on actual calendering conditions.

[0066] As shown in Table 1, the spiral wound hoses prepared in Examples 1-3 possess excellent oil resistance and moderate low-temperature performance, while significantly reducing relative costs. The ordinary silicone rubber prepared in Comparative Example 1 lacks sufficient oil resistance and cannot meet the application requirements for oil and gas resistance in hoses. Comparative Example 2 uses a fluororubber inner layer, exhibiting excellent oil and high-temperature resistance, but its cost is high and its low-temperature performance is poor. Comparative Example 3 uses fluorosilicone rubber, with only average oil resistance and high cost. Comparative Example 4 uses an ordinary chloroprene rubber formulation, which exhibits poor adhesion to the silicone layer and cannot meet the application requirements.

Claims

1. An oil resistant wrapped hose characterized by, The product comprises a chloroprene rubber layer and a silicone layer located outside the chloroprene rubber layer. The chloroprene rubber layer comprises the following components by weight: 90-110 parts of ternary copolymer chloroprene rubber, 30-80 parts of reinforcing agent, 20-50 parts of diatomaceous earth, 4-10 parts of magnesium oxide, 5-10 parts of light calcium carbonate, 3-8 parts of plasticizer, 2.0-3.0 parts of antioxidant, 1.0-2.0 parts of additives, 1.0-2.0 parts of flow agent, 2.0-6.0 parts of tackifier, 2.0-4.0 parts of activator, and 1.0-2.0 parts of vulcanizing agent. 0.2-1 parts of crosslinking agent; the ternary copolymer chloroprene rubber is selected, the third monomer of the chloroprene rubber is vulcanized with a peroxide vulcanization system, and co-vulcanization with silicone can be achieved; the silicone layer includes the following components by weight: 90-110 parts of vinyl silicone rubber, 10-20 parts of fumed silica, 2-4 parts of heat resistant agent, 2-4 parts of tackifier, 1-3 parts of colorant, and 1-2 parts of vulcanizing agent; the vulcanizing agent in the chloroprene rubber layer and the vulcanizing agent in the silicone layer are 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

2. The oil resistant wrapped hose of claim 1 wherein, The vinyl silicone rubber is methyl vinyl silicone rubber compound 40-50A; the heat resistant agent is nano cerium oxide; and the colorant is either iron oxide red or iron oxide black.

3. The oil resistant wound hose according to claim 1 or 2, wherein The tackifier is RS35.

4. The oil resistant wrapped hose of claim 1 wherein, The crosslinking agent is triallyl isocyanurate; the magnesium oxide is active magnesium oxide with an activity value of 150-170; the additive is polyethylene glycol with a molecular weight of 6000; and the flow agent is WA48.

5. The oil resistant wrapped rubber hose of claim 1 wherein, The reinforcing agent is one or both of carbon black N330 and N774; the plasticizer is an ester plasticizer; and the antioxidant is 4,4'-bis(α,α-dimethylbenzyl)diphenylamine.

6. The method of claim 1, wherein the oil resistant wrapped rubber hose is characterized by, Includes the following steps: ① Chlorinated polyurethane rubber layer mixing: Weigh each material according to the mass ratio, add all materials except vulcanizing agent into the internal mixer and mix evenly. After cooling, add the previously mixed rubber compound into the internal mixer and add vulcanizing agent to make mixed chlorinated polyurethane rubber for later use. ②Silicone layer mixing: Weigh each material according to the mass ratio, add all materials except vulcanizing agent into the open mill and mix them into raw silicone rubber. Then add vulcanizing agent and mix evenly to make mixed silicone rubber. Roll it up and store it. ③ Calendering: After the compounded chloroprene rubber is hot-melted, it is put into the calendering machine, the roller gap and roller temperature are adjusted, and the rubber compound is pressed into chloroprene rubber sheets of the required thickness. Then the compounded silicone rubber is calendered into silicone rubber sheets in the same way. ④ Wrap the calendered chlorinated ether film and silicone film onto the vulcanizing mold; ⑤ Pass hot air or steam into the vulcanizing mold to carry out vulcanization.

7. The method of claim 6, wherein the oil resistant wrapped hose is prepared by the steps of: The median thickness of the chloroprene film is between 0.8 and 1.5 mm, and the median thickness of the silicone film is between 0.5 mm and 1.0 mm.

8. The method of claim 6, wherein the oil resistant wrapped hose is prepared by the steps of: The vulcanizing mold includes a mold core, a mounting base, and a mold shell. The mold core has an inner channel for introducing hot air or steam into the inside of the rubber tube. An outer vulcanizing cavity is formed between the mold shell and the rubber tube. The mold shell is also provided with an air inlet and an air outlet.

9. The method of claim 8, wherein the oil resistant wrapped hose is prepared by the steps of: The outer side of the mold core is provided with several vulcanization recesses; during the vulcanization process, the gas in the vulcanization recesses can increase the contact area between the chlorinated ether rubber layer and hot air or steam.

10. The method of claim 9, wherein the oil resistant wrapped hose is prepared by the steps of: A connecting channel is provided between the vulcanization notch and the inner channel.

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