A middle rubber material of an air conditioner rubber tube, a preparation method and an air conditioner rubber tube

Abstract

The application relates to the field of rubber pipes, in particular to a middle rubber layer rubber material of an air conditioner rubber pipe, a preparation method and the air conditioner rubber pipe, wherein the middle rubber layer rubber material comprises the following components in parts by weight: chlorinated butyl rubber 100 parts, natural rubber 20-40 parts, reinforcing agent 30-50 parts, tackifying resin 8-20 parts, plasticizer 2-6 parts, vulcanizing agent 5-10 parts, vulcanization accelerator 3-5 parts. The rubber material is excellent in heat aging resistance and low compression permanent deformation, can be applied to the middle rubber layer of a new energy automobile air conditioner hose, has good adhesion between the barrier layer and the middle rubber layer, and the obtained air conditioner rubber pipe has low permeability to water and refrigerant.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rubber tube, in particular to a middle rubber layer rubber material of air conditioner rubber tube, a preparation method and the air conditioner rubber tube. BACKGROUND

[0002] In recent years, new energy vehicles and electric vehicles have developed rapidly at home and abroad, and new energy vehicle technology is changing rapidly. The new energy vehicle air conditioning system is different from the traditional vehicle air conditioning system. The belt type motor is changed to an electric motor. There are more electronic components in the new energy vehicle air conditioning system, and the humidity requirement for the working environment is higher. High water content in the air conditioning system can cause system blockage, part corrosion and other serious problems.

[0003] The air conditioner rubber tube as a key component of the air conditioning system plays a role in flexible connection in the air conditioning system and needs to meet various performance requirements. As a key performance indicator, the water permeability of the air conditioner rubber tube is required to be less than 1.5 g / (m 2 ·168h) in the standard issued by international automobile manufacturers, while the water permeability of the new energy vehicle air conditioner rubber tube is required to be less than 0.2 g / (m 2 ·168h). It can be seen that the water permeability requirement of the new energy vehicle air conditioner rubber tube is more stringent than the original requirement. At the same time, the rubber tube transports gaseous or liquid refrigerant in the air conditioning system, and the low permeability of the refrigerant is also very important.

[0004] The low permeability of the air conditioner rubber tube is closely related to the middle rubber layer material and the adhesion between the middle rubber layer and the barrier layer. Therefore, it is of great value to develop a new type of middle rubber layer formula to meet the low permeability requirements of the rubber tube for water and refrigerant. SUMMARY

[0005] The purpose of the present application is to provide a middle rubber layer rubber material of air conditioner rubber tube, a preparation method and the air conditioner rubber tube. The heat aging resistance and low compression permanent deformation of the rubber material are excellent, and it can be applied to the middle rubber layer of new energy vehicle air conditioner hose. The adhesion between the middle rubber layer and the barrier layer is good, so that the obtained air conditioner rubber tube has low permeability for water and refrigerant.

[0006] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] In one aspect, the present application provides a middle rubber layer rubber material of air conditioner rubber tube, which comprises the following components in parts by weight: chlorinated butyl rubber 100 parts, natural rubber 20-40 parts, reinforcing agent 30-50 parts, tackifying resin 8-20 parts, plasticizer 2-6 parts, vulcanizing agent 5-10 parts, and vulcanization accelerator 3-5 parts.

[0008] The chlorinated butyl rubber and the natural rubber are not specially limited in the present application, and can be commercially available, including but not limited to the chlorinated butyl rubber of the present application, which is purchased from Arlanxeo High Performance Elastomers (Changzhou) Co., Ltd., with a trade name of 1240; and the natural rubber from Thailand, with a type of STR20.

[0009] In some embodiments, the reinforcing agent comprises one or more of carbon black, white carbon black, and organic montmorillonite.

[0010] Preferably, the reinforcing agent comprises carbon black, white carbon black, and organic montmorillonite, with a weight ratio of (3-6):1:(1.2-1.5).

[0011] In some embodiments, the carbon black has a trade name of N550, which can be commercially available.

[0012] In some embodiments, the white carbon black has a specific surface area of 180-220 m 2 / g and an average particle size of 5-10 μm.

[0013] Preferably, the white carbon black has a specific surface area of 200 m 2 / g and an average particle size of 5-10 μm.

[0014] The white carbon black of the present application is purchased from Feida Chemical Factory in Rugao, with a type of 365.

[0015] In some embodiments, the organic montmorillonite is selected from the company of Nanocor in the United States, with a trade name of 1.44P.

[0016] The chlorinated butyl rubber contains a saturated polyisobutylene structure in the molecule, which endows it with high barrier properties to air and water vapor, but the chlorinated butyl rubber has poor heat aging resistance and compression permanent deformation. By adding the natural rubber and the specific reinforcing agent, in particular, the reinforcing agent is carbon black, white carbon black, and organic montmorillonite, with a weight ratio of (3-6):1:(1.2-1.5), the present application not only can make the middle rubber layer have excellent heat aging resistance and low compression permanent deformation, but also can further improve the permeation resistance. The applicant believes that the possible reason is that on the one hand, the addition of the natural rubber can promote the dispersion of the carbon black and the white carbon black in the system, and the reinforcing effect is obviously improved; on the other hand, the addition of the organic montmorillonite can play a role of physical crosslinking point in the rubber, and can produce strong binding force with the chlorinated butyl rubber, which is beneficial to increase the crosslinking density of the rubber material, form a stable network structure, increase the structural tightness, increase the difficulty of gas / liquid entering or exiting the rubber network, and at the same time, the lamellar structure of the organic montmorillonite can prolong the penetration path of the gas or liquid molecules entering or exiting the rubber material, and the two effects endow the rubber material with low permeability.

[0017] In some embodiments, the tackifying resin is a terpene-modified phenol-formaldehyde resin.

[0018] In some embodiments, the terpene-modified phenol-formaldehyde resin is obtained by the following steps:

[0019] (1) phenol is added into a container, heated and stirred, when the temperature rises to 95-105°C, concentrated sulfuric acid is added dropwise, then aqueous formaldehyde solution is added dropwise, and the reaction is kept for 0.9-1.1 h to obtain a phenol-formaldehyde resin;

[0020] (2) pine oil is added dropwise under boiling state of the phenol-formaldehyde resin obtained in step (1), when the temperature rises to 148-152°C, the reaction is kept for 2-4 h, then formaldehyde and toluene are added dropwise, the reaction is kept for 2.5-3.5 h at 98-102°C, water is evaporated, and then the toluene solution is washed with water, toluene and low-boiling components are evaporated, the temperature is raised to 268-275°C, and the remaining substance is kept for 0.4-0.6 h to obtain the terpene-modified phenol-formaldehyde resin.

[0021] In some embodiments, the molar ratio of formaldehyde to phenol in step (1) is 1:(0.9-1.1).

[0022] Preferably, the molar ratio of formaldehyde to phenol in step (1) is 1:1.

[0023] In some embodiments, the mass fraction of concentrated sulfuric acid is 75%.

[0024] In some embodiments, the amount of concentrated sulfuric acid added is 0.3-0.4 wt% of the phenol in step (1), preferably 0.32 wt%.

[0025] In some embodiments, the mass fraction of the aqueous methanol solution is 37%.

[0026] In some embodiments, the molar ratio of pine oil, phenol and formaldehyde in step (2) is 1:(0.9-1.1):0.15.

[0027] Preferably, the molar ratio of pine oil, phenol and formaldehyde in step (2) is 1:1:0.15.

[0028] In some embodiments, the ratio of the amount of toluene added to the phenol is 1 ml:(2.5-3) g.

[0029] Preferably, the ratio of the amount of toluene added to the phenol is 1 ml:2.75 g.

[0030] Currently, adhesive resins are often added to the formulations used to prepare the intermediate adhesive layer to increase the adhesion between the intermediate adhesive layer and the barrier layer and the reinforcing layer. The resulting intermediate adhesive layer has high initial tack, but the adhesion retention time is short. In his research, the applicant discovered that by preparing a rosin-modified phenolic resin, the intermediate adhesive layer can have excellent adhesion and mechanical properties, and the adhesion is long-lasting. It can form a strong bond with the barrier layer and the reinforcing layer respectively, preventing water permeation and refrigerant leakage from the air conditioning hose, and improving the anti-permeability performance. The possible reason is that the molecular structure of this terpene-modified phenolic resin contains more active groups such as carboxyl, hydroxyl, and hydroxymethyl groups, which can help increase the adhesion performance between the intermediate adhesive layer and the barrier layer and the reinforcing layer.

[0031] In some embodiments, the plasticizer is an aromatic oil, preferably Shell Environmentally Friendly Aromatic Oil (RAE).

[0032] In some embodiments, the vulcanizing agent comprises sulfur and dicumyl peroxide in a weight ratio of (0.3-1):1.

[0033] Preferably, the vulcanizing agent comprises sulfur and dicumyl peroxide in a weight ratio of 0.6:1.

[0034] The present invention uses a vulcanization system formed by the combination of sulfur and dicumyl peroxide, which can improve the heat resistance of the rubber material, reduce low compression set, improve the adhesion between the middle rubber layer and the barrier layer, and improve the overall impermeability.

[0035] In some embodiments, the vulcanization accelerator comprises stearic acid and zinc oxide in a weight ratio of (0.2-0.5):1.

[0036] A second aspect of the present invention provides a method for preparing the middle rubber layer material of an air conditioning hose, comprising the following steps:

[0037] S1. Add 40-50wt% chlorinated butyl rubber, 30-40wt% reinforcing agent, and 50wt% plasticizer to a mixer for the first mixing to obtain compound A.

[0038] S2. Add the remaining chlorinated butyl rubber, reinforcing agent, and plasticizer to the compound A obtained in step S1, and then add natural rubber and tackifying resin for a second mixing to obtain compound B.

[0039] S3. The compound B obtained in step S2, the vulcanizing agent and the vulcanization accelerator are mixed for the third time on a two-mill to obtain the final compound.

[0040] S4. After the final rubber compound obtained in step S3 is placed for 7-10 hours, it is vulcanized on a flat vulcanizing machine. After completion, the intermediate rubber layer material is obtained.

[0041] In some embodiments, the conditions for vulcanization in the S3 step are 148-155℃ for 0.8-1.2h.

[0042] Preferably, the conditions for vulcanization in the S3 step are 150℃ for 1h.

[0043] The third aspect of the present application provides a new energy automobile air conditioning rubber tube, the rubber tube comprises a barrier layer, a middle rubber layer, a reinforcing layer and an outer rubber layer in sequence, wherein the middle rubber layer is prepared from the middle rubber layer rubber material of the present application.

[0044] Compared with the prior art, the present application has the following advantages:

[0045] (1) The present application can not only make the middle rubber layer have excellent heat aging resistance and low compression permanent deformation, but also further improve the permeation resistance by adding natural rubber and specific carbon black, white carbon black and organic montmorillonite as reinforcing agents.

[0046] (2) The terpene-modified phenolic resin of the present application can make the middle rubber layer have excellent adhesion and mechanical properties, and the adhesion is durable, which can produce firm bonding strength with the barrier layer and the reinforcing layer respectively, prevent the water permeation and refrigerant exudation of the air conditioning rubber tube, and improve the permeation resistance. DETAILED DESCRIPTION

[0047] The technical solutions of the present application will be described below in conjunction with the embodiments, obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0048] Example 1

[0049] A middle rubber layer rubber material of an air conditioning rubber tube, comprising the following components by weight: chlorinated butyl rubber 100 parts, natural rubber 30 parts, reinforcing agent 40 parts, tackifying resin 14 parts, plasticizer 4 parts, vulcanizing agent 7 parts, vulcanization accelerator 4 parts.

[0050] The chlorinated butyl rubber is purchased from Arlanxeo High Performance Elastomers (Changzhou) Co., Ltd., with the brand 1240; the natural rubber is from Thailand, with the type STR20.

[0051] The reinforcing agent includes carbon black, white carbon black and organic montmorillonite, with a weight ratio of 4.5:1:1.4.

[0052] The brand of carbon black is N550; the white carbon black is purchased from Rugao Feida Chemical Factory, with the type 365, and the specific surface area is 200m 2 / g, and the average particle size is 8 μm; the organic montmorillonite is selected from the US Nanocor Company, and the trade name is 1.44P.

[0053] The tackifying resin is a terpene-modified phenolic resin, and the terpene-modified phenolic resin is obtained by the following steps:

[0054] (1) Phenol is added into a container, heated and stirred, and concentrated sulfuric acid is dropped in when the temperature rises to 100℃, and an aqueous formaldehyde solution is dropped in, and the reaction is kept for 1h to obtain a phenolic resin;

[0055] (2) Turpentine is dropped in under the boiling state of the phenolic resin obtained in step (1), and the temperature is kept at 150℃ for 3h, and then formaldehyde and toluene are dropped in, and the reaction is kept at 101℃ for 3h, and water is evaporated, and then the toluene solution is cooled, washed with water, and toluene and low-boiling components are evaporated, and the temperature is raised to 268-275℃ for 0.4-0.6h, and the remaining substance is distilled to obtain the terpene-modified phenolic resin.

[0056] The molar ratio of formaldehyde to phenol in step (1) is 1:1.

[0057] The mass fraction of the concentrated sulfuric acid is 75%, and the amount of the concentrated sulfuric acid added is 0.32wt% of the phenol.

[0058] The mass fraction of the aqueous methanol solution is 37%.

[0059] The molar ratio of turpentine, phenol and formaldehyde in step (2) is 1:1:0.15; and the ratio of the amount of toluene dropped in to the phenol in step (2) is 1ml:2.75g.

[0060] The plasticizer is Shell environmentally friendly aromatic oil RAE; the vulcanizing agent includes sulfur and dicumyl peroxide, and the weight ratio is 0.6:1; the vulcanization accelerator includes stearic acid and zinc oxide, and the weight ratio is 0.35:1.

[0061] The preparation method of the rubber material of the middle rubber layer of the air conditioner rubber tube in the embodiment includes the following steps:

[0062] S1, 45wt% of chlorinated butyl rubber, 35wt% of reinforcing agent, and 50wt% of plasticizer are added into a mixer to perform first mixing at a temperature of 90℃ for 20min to obtain a mixed rubber A;

[0063] S2, the remaining chlorinated butyl rubber, reinforcing agent, and plasticizer are added into the mixed rubber A obtained in step S1, and then natural rubber and tackifying resin are added, and second mixing is performed at a temperature of 100℃ for 20min to obtain a mixed rubber B;

[0064] S3, the mixing B obtained in step S2, vulcanizing agent and vulcanizing accelerator on the open mill at a temperature of 115℃, 30min for the third mixing, the final mixing rubber is obtained;

[0065] S4, the final mixing rubber obtained in S3 is placed for 9h, and then vulcanized at 150℃ for 1h on a flat vulcanizing machine. The middle rubber material is obtained.

[0066] The middle rubber material prepared by the embodiment is used to prepare an air conditioning rubber tube for new energy vehicles. The rubber tube comprises, from the inside out, a barrier layer, a middle rubber layer, a reinforcing layer, and an outer rubber layer.

[0067] The material of the barrier layer is PPA, specifically Arkema PPA GF30. The material of the reinforcing layer is polyester. The outer rubber layer is ethylene propylene diene rubber, specifically Japan Mitsui EPDM3045.

[0068] The air conditioning rubber tube has a tube diameter of 40mm, a barrier layer thickness of 0.3mm, a middle rubber layer thickness of 1mm, and an outer rubber layer thickness of 2mm.

[0069] Example 2

[0070] A middle rubber layer rubber material for an air conditioning rubber tube, comprising the following components by weight: chlorinated butyl rubber 100 parts, natural rubber 20 parts, reinforcing agent 30 parts, tackifying resin 8 parts, plasticizer 2 parts, vulcanizing agent 5 parts, and vulcanizing accelerator 3 parts.

[0071] The chlorinated butyl rubber is purchased from Arlanxeo High Performance Elastomers (Changzhou) Co., Ltd., with a brand of 1240. The natural rubber is from Thailand, with a model of STR20.

[0072] The reinforcing agent includes carbon black, white carbon black, and organic montmorillonite, with a weight ratio of 3:1:1.2.

[0073] The brand of carbon black is N550. The white carbon black is purchased from Rugao Feida Chemical Factory, with a model of 365, a specific surface area of 200m 2 / g, and an average particle size of 8μm. The organic montmorillonite is selected from the United States Nanocor Company, with a brand of 1.44P.

[0074] The tackifying resin is a terpene-modified phenolic resin, which is obtained by the following steps:

[0075] (1) Phenol is added to a container and heated and stirred. When the temperature rises to 100℃, concentrated sulfuric acid is added dropwise, and formaldehyde aqueous solution is added dropwise. The reaction is kept for 1h to obtain a phenolic resin;

[0076] (2) The phenolic resin obtained in step (1) is boiled and turpentine is added dropwise, and the temperature is raised to 150℃ and reacted for 3h, then formaldehyde and toluene are added dropwise, and reacted for 3h at 101℃, and water is removed by evaporation, and then dissolved in toluene, and washed with water, and toluene and low boiling point components are evaporated, and the temperature is raised to 268-275℃ and reacted for 0.4-0.6h, and the remaining substance is distilled to obtain the terpene-modified phenolic resin.

[0077] The molar ratio of formaldehyde to phenol in step (1) is 1:1.

[0078] The mass fraction of concentrated sulfuric acid is 75%, and the amount of concentrated sulfuric acid added is 0.32wt% of phenol.

[0079] The mass fraction of the aqueous methanol solution is 37%.

[0080] The molar ratio of turpentine, phenol and formaldehyde in step (2) is 1:1:0.15; the amount of toluene added in step (2) is 1ml to 2.75g of phenol.

[0081] The plasticizer is Shell environmentally friendly aromatic oil RAE; the vulcanizing agent includes sulfur and dicumyl peroxide, and the weight ratio is 0.6:1; the vulcanization accelerator includes stearic acid and zinc oxide, and the weight ratio is 0.35:1.

[0082] The preparation method of the rubber material of the middle rubber layer of the air conditioning rubber tube of the embodiment comprises the following steps:

[0083] S1, 40wt% of chlorinated butyl rubber, 30wt% of reinforcing agent, and 50wt% of plasticizer are added to a mixer to perform first mixing at a temperature of 90℃ for 20min to obtain a mixed rubber A;

[0084] S2, the remaining chlorinated butyl rubber, reinforcing agent, and plasticizer are added to the mixed rubber A obtained in step S1, and then natural rubber and tackifying resin are added, and second mixing is performed at a temperature of 100℃ for 20min to obtain a mixed rubber B;

[0085] S3, the mixed rubber B obtained in step S2, a vulcanizing agent, and a vulcanization accelerator are mixed on an open mill at a temperature of 115℃ for 30min to obtain a final mixed rubber;

[0086] S4, the final mixed rubber obtained in step S3 is placed for 9h, and then vulcanized on a flat vulcanizing machine at 150℃ for 1h, and the process is completed to obtain the rubber material of the middle rubber layer.

[0087] An air conditioning rubber tube for new energy vehicles is prepared using the middle rubber layer material prepared in the embodiment, and the rubber tube comprises, from the inside out, a barrier layer, a middle rubber layer, a reinforcing layer, and an outer rubber layer.

[0088] The material of the barrier layer is PPA, specifically, Arkema PPA GF30; the material of the reinforcing layer is polyester; and the material of the outer rubber layer is ethylene propylene diene rubber, specifically, Japan Mitsui EPDM3045.

[0089] The air conditioner rubber tube has a tube diameter of 40 mm, a barrier layer thickness of 0.3 mm, a middle rubber layer thickness of 1 mm, and an outer rubber layer thickness of 2 mm.

[0090] Example 3

[0091] A middle rubber layer rubber material of an air conditioner rubber tube, by weight, comprises the following components: chlorinated butyl rubber 100 parts, natural rubber 40 parts, reinforcing agent 50 parts, tackifying resin 20 parts, plasticizer 6 parts, vulcanizing agent 10 parts, and vulcanizing accelerator 5 parts.

[0092] The chlorinated butyl rubber is purchased from Arlanxeo High Performance Elastomers (Changzhou) Co., Ltd., with a brand of 1240; and the natural rubber is from Thailand, with a model of STR20.

[0093] The reinforcing agent comprises carbon black, white carbon black, and organic montmorillonite, with a weight ratio of 6:1:1.5.

[0094] The carbon black has a brand of N550; the white carbon black is purchased from Rugao Feida Chemical Factory, with a model of 365, a specific surface area of 200 m 2 / g, and an average particle size of 8 μm; and the organic montmorillonite is selected from the United States Nanocor Company, with a brand of 1.44P.

[0095] The tackifying resin is a terpene-modified phenolic resin, which is obtained by the following steps:

[0096] (1) phenol is added into a container, heated and stirred, when the temperature rises to 100℃, concentrated sulfuric acid is dropped, and then formaldehyde aqueous solution is dropped, and the reaction is kept for 1h to obtain a phenolic resin;

[0097] (2) the phenolic resin obtained in step (1) is boiled, and then pine oil is dropped, when the temperature rises to 150℃, the reaction is kept for 3h, then formaldehyde and toluene are dropped, and the reaction is kept for 3h at 101℃, water is evaporated, and then the product is dissolved in toluene, washed with water, and then toluene and low-boiling components are evaporated, the temperature is raised to 268-275℃, and the reaction is kept for 0.4-0.6h, and then the remaining substance is distilled to obtain the terpene-modified phenolic resin.

[0098] The molar ratio of formaldehyde to phenol in step (1) is 1:1.

[0099] The mass fraction of the concentrated sulfuric acid is 75%, and the amount of the concentrated sulfuric acid added is 0.32wt% of the phenol.

[0100] The mass fraction of the methanol aqueous solution is 37%.

[0101] The molar ratio of turpentine, phenol and formaldehyde in step (2) is 1:1:0.15; the ratio of the amount of toluene dropped in step (2) to the phenol is 1ml:2.75g.

[0102] The plasticizer is Shell environmentally friendly aromatic oil RAE; the vulcanizing agent includes sulfur and dicumyl peroxide, with a weight ratio of 0.6:1; the vulcanization accelerator includes stearic acid and zinc oxide, with a weight ratio of 0.35:1.

[0103] The method for preparing the middle rubber material of the air conditioner rubber tube in this embodiment comprises the following steps:

[0104] S1, 50wt% of chlorinated butyl rubber, 40wt% of reinforcing agent, and 50wt% of plasticizer are added to a mixer for first mixing at a temperature of 90℃ for 20min to obtain a mixed rubber A;

[0105] S2, the remaining chlorinated butyl rubber, reinforcing agent, and plasticizer are added to the mixed rubber A obtained in step S1, and then natural rubber and tackifying resin are added for second mixing at a temperature of 100℃ for 20min to obtain a mixed rubber B;

[0106] S3, the mixed rubber B obtained in step S2, a vulcanizing agent, and a vulcanization accelerator are mixed on an open mill at a temperature of 115℃ for 30min to obtain a final mixed rubber;

[0107] S4, the final mixed rubber obtained in step S3 is placed for 9h and then vulcanized on a flat vulcanizing machine at 150℃ for 1h, and the middle rubber material is obtained after completion.

[0108] An air conditioner rubber tube for new energy vehicles is prepared by using the middle rubber material prepared in this embodiment, and the rubber tube comprises, from inside to outside, a barrier layer, a middle rubber layer, a reinforcing layer, and an outer rubber layer.

[0109] The material of the barrier layer is PPA, specifically Arkema PPA GF30; the material of the reinforcing layer is polyester; and the outer rubber layer is ethylene propylene diene rubber, specifically Japan Mitsui EPDM3045.

[0110] The air conditioner rubber tube has a tube diameter of 40mm, a barrier layer thickness of 0.3mm, a middle rubber layer thickness of 1mm, and an outer rubber layer thickness of 2mm.

[0111] Example 4

[0112] This embodiment provides a middle rubber material of an air conditioner rubber tube, and the specific implementation manner is the same as that in embodiment 1, except that no natural rubber is added.

[0113] The middle rubber layer material prepared by the embodiment is used to prepare an air conditioner rubber tube for new energy vehicles, and the rubber tube comprises, from inside to outside, a barrier layer, a middle rubber layer, a reinforcing layer and an outer rubber layer.

[0114] The material of the barrier layer is PPA, specifically Arkema PPA GF30; the material of the reinforcing layer is polyester; and the outer rubber layer is a ternary ethylene-propylene rubber, specifically Japan Mitsui EPDM3045.

[0115] The air conditioner rubber tube has a tube diameter of 40 mm, the thickness of the barrier layer is 0.3 mm, the thickness of the middle rubber layer is 1 mm, and the thickness of the outer rubber layer is 2 mm.

[0116] Example 5

[0117] The embodiment provides a middle rubber layer rubber material of an air conditioner rubber tube, and the specific implementation manner is the same as that in Embodiment 1, except that the reinforcing agent does not comprise organic montmorillonite.

[0118] The middle rubber layer material prepared by the embodiment is used to prepare an air conditioner rubber tube for new energy vehicles, and the rubber tube comprises, from inside to outside, a barrier layer, a middle rubber layer, a reinforcing layer and an outer rubber layer.

[0119] The material of the barrier layer is PPA, specifically Arkema PPA GF30; the material of the reinforcing layer is polyester; and the outer rubber layer is a ternary ethylene-propylene rubber, specifically Japan Mitsui EPDM3045.

[0120] The air conditioner rubber tube has a tube diameter of 40 mm, the thickness of the barrier layer is 0.3 mm, the thickness of the middle rubber layer is 1 mm, and the thickness of the outer rubber layer is 2 mm.

[0121] Performance test

[0122] 1. Aging resistance

[0123] The middle rubber layer rubber material prepared in Embodiments 1-5 is subjected to initial tensile property and elongation at break tests according to GB / T528-2009, and the test conditions are as follows: 500±50 mm / min, type I.

[0124] The tests of the change rates of tensile strength and elongation at break after hot air aging are performed according to GB / T 3512-2001, and the test conditions are as follows: 150℃×168h, 500±50 mm / min, type I.

[0125] The test results are shown in Table 1.

[0126] 2. Compression set

[0127] The rubber material of the middle rubber layer prepared in Examples 1-5 was subjected to compression set test according to GB / T7759.1-2015 standard, the test condition was 150℃x168h, method A, compression 25%, and the test results are shown in Table 1.

[0128] 3. Permeability

[0129] The air conditioning rubber tube of Examples 1-5 was subjected to water and refrigerant R314a permeability test, the test condition was: 0.6mg water or refrigerant was filled in per cubic millimeter volume of the hose, and the test results are shown in Table 2.

[0130] 4. Adhesion strength

[0131] The air conditioning rubber tube of Examples 1-5 was subjected to adhesion strength test between the middle rubber layer and the barrier layer, the test index ≥2.0kN / m was qualified, and the test results are shown in Table 2.

[0132] Table 1

[0133]

[0134] Table 2

[0135]

[0136] From the data of Table 1 and Table 2, it can be seen that the rubber material prepared in Examples 1-3 has excellent aging resistance and low compression set, and the air conditioning hose with the rubber material as the middle rubber layer has low water permeability and refrigerant permeability, good adhesion between the middle rubber layer and the barrier layer, and excellent overall structure tightness, which can meet the requirements of new energy automobile air conditioning hose; Example 4 affects the reinforcing effect of the reinforcing agent due to not adding natural rubber, resulting in poor aging resistance and compression set of the rubber material, and slightly increased water permeability and refrigerant permeability of the hose, but has little effect on the adhesion strength between the middle rubber layer and the barrier layer; Example 5 changes the type of the reinforcing agent, resulting in significantly poor aging resistance and compression set of the rubber material, and significantly increased water permeability and refrigerant permeability of the hose, but has little effect on the adhesion strength between the middle rubber layer and the barrier layer.

[0137] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the examples, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A rubber material for the middle layer of an air conditioning hose, characterized in that, By weight, it includes the following components: 100 parts chlorinated butyl rubber, 20-40 parts natural rubber, 30-50 parts reinforcing agent, 8-20 parts tackifying resin, 2-6 parts plasticizer, 5-10 parts vulcanizing agent, and 3-5 parts vulcanization accelerator. The reinforcing agent includes carbon black, silica, and organomontmorillonite in a weight ratio of (3-6):1:(1.2-1.5); The tackifying resin is a terpene-modified phenolic resin; The vulcanizing agent comprises sulfur and dicumyl peroxide in a weight ratio of (0.3-1):1; The vulcanization accelerator comprises stearic acid and zinc oxide in a weight ratio of (0.2-0.5):

1.

2. The middle rubber layer material of an air conditioning hose according to claim 1, characterized in that, The terpene-modified phenolic resin is obtained through the following steps: (1) Add phenol to a container, heat and stir. When the temperature rises to 95-105℃, add concentrated sulfuric acid dropwise, then add an aqueous solution of formaldehyde dropwise. Keep the reaction at the temperature for 0.9-1.1h to obtain phenolic resin. (2) Turpentine oil is added dropwise to the phenolic resin obtained in step (1) under boiling conditions. The temperature is raised to 148-152℃ and kept at this temperature for 2-4 hours. Then formaldehyde and toluene are added dropwise and reacted at 98-102℃ for 2.5-3.5 hours. The water is evaporated, the mixture is cooled, dissolved in toluene, washed with water, and the toluene and low-boiling-point components are evaporated. The temperature is raised to 268-275℃ and kept at this temperature for 0.4-0.6 hours. The remaining substance after distillation is the terpene-modified phenolic resin.

3. The middle rubber layer material of an air conditioning hose according to claim 2, characterized in that, In step (1), the molar ratio of formaldehyde to phenol is 1:(0.9-1.1).

4. A method for preparing the middle rubber layer material of an air conditioning hose according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Add 40-50wt% chlorinated butyl rubber, 30-40wt% reinforcing agent, and 50wt% plasticizer to a mixer for one mixing to obtain compound A. S2. Add the remaining chlorinated butyl rubber, reinforcing agent, and plasticizer to the compound A obtained in step S1, and then add natural rubber and tackifying resin for secondary mixing to obtain compound B. S3. The compound B obtained in step S2, the vulcanizing agent and the vulcanization accelerator are mixed three times on a two-mill to obtain the final compound. S4. After the final rubber compound obtained in step S3 is placed for 7-10 hours, it is vulcanized on a flat vulcanizing machine. After completion, the intermediate rubber layer material is obtained.

5. The method for preparing the middle rubber layer of the air conditioning hose according to claim 4, characterized in that, The vulcanization conditions in step S3 are 148-155℃ and the time is 0.8-1.2h.

6. An air conditioning hose for new energy vehicles, characterized in that, The hose comprises, in sequence, a barrier layer, a middle rubber layer, a reinforcing layer, and an outer rubber layer, wherein the middle rubber layer is prepared from the rubber material described in any one of claims 1-5.

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