CN114539647B - Oil-resistant high-temperature-resistant low-friction-coefficient tooth cloth adhesive and preparation method and application thereof - Google Patents

Abstract

The invention proposes an oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue and its preparation method and application. The invention includes the following components: 100 parts of hydrogenated nitrile rubber, 55-100 parts of polytetrafluoroethylene, 3-6 parts of cross-linking agent, 1-3 parts of auxiliary cross-linking agent. The polytetrafluoroethylene is composed of zinc methacrylate and modified polytetrafluoroethylene grafted with polybutadiene and coated with maleic anhydride; the invention also provides a preparation method of the above-mentioned tooth cloth glue, and this tooth cloth glue is used to make timing belts. Polytetrafluoroethylene is added to the tooth cloth glue of the present invention. The friction coefficient of polytetrafluoroethylene is extremely low, which greatly reduces the friction coefficient of the tooth cloth glue and improves the friction performance of the tooth cloth glue. Polytetrafluoroethylene also has very low friction coefficient. Good high temperature resistance, almost insoluble in all solvents, further improving the high temperature resistance and oil resistance of tooth cloth glue; this modified polytetrafluoroethylene has good compatibility with hydrogenated nitrile rubber, is easy to disperse, and can bond Good performance, thereby improving the overall performance of the synchronous belt.

Description

An oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue and its preparation method and application

Technical field

The present invention relates to the technical field of adhesives, in particular to an oil-resistant, high-temperature resistant, low-friction coefficient tooth cloth adhesive and its preparation method and application.

Background technique

The timing belt, also known as the toothed cloth belt, includes a top rubber layer, a bottom rubber layer and a tensile cord embedded between the two. The bottom rubber layer has a pattern formed by alternating wave peaks and wave troughs along the length of the timing belt. The tooth surface is also covered with a tooth reinforcement layer. The tooth reinforcement layer is a tooth cloth covered with tooth cloth glue on the tooth surface.

The existing toothpaste rubber is hydrogenated nitrile rubber. Hydrogenated nitrile rubber has good oil resistance (good resistance to fuel oil, lubricating oil, aromatic solvents), and due to its highly saturated structure, it has good Heat resistance; however, this hydrogenated butadiene rubber has a high friction coefficient and is not friction-resistant, thus reducing the wear resistance of the synchronous belt obtained therefrom.

Contents of the invention

The purpose of the present invention is to provide an oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue and its preparation method and application, aiming to solve the problem of the high friction coefficient of the tooth cloth glue in the prior art, thereby reducing the wear resistance of the synchronous belt obtained therefrom. The problem.

In order to solve the above technical problems, the technical solution of the present invention is implemented as follows:

In one aspect, an oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth adhesive of the present invention includes the following components by weight: 100 parts of hydrogenated nitrile rubber, 55-100 parts of polytetrafluoroethylene, and 3-6 parts of cross-linking agent. , 1-3 parts of assistant cross-linking agent; the polytetrafluoroethylene is a modified polytetrafluoroethylene coated with zinc methacrylate and polybutadiene grafted with maleic anhydride, and the modified polytetrafluoroethylene The preparation method is: take polytetrafluoroethylene, use plasma treatment, add methacrylic acid, the amount of methacrylic acid added is 3-15% of the mass of polytetrafluoroethylene, at a pressure of 30-45MPa and 40-80℃ At a temperature of The amount of maleic anhydride added is 4-6% of the mass of polytetrafluoroethylene, and the mixture is stirred to obtain modified polytetrafluoroethylene.

The tooth cloth rubber of the present invention is formed of hydrogenated nitrile butadiene rubber (HNBR), polytetrafluoroethylene (PTFE), a cross-linking agent, an auxiliary cross-linking agent, etc. This tooth cloth rubber adds polyethylene to hydrogenated nitrile butadiene rubber. The friction coefficients of tetrafluoroethylene and polytetrafluoroethylene are extremely low. Therefore, the friction coefficient of the tooth cloth rubber is greatly reduced, the friction performance of the tooth cloth rubber is improved, and the resulting synchronous belt is more wear-resistant; at the same time, PTFE Ethylene also has good high temperature resistance and is almost insoluble in all solvents, which further improves the high temperature resistance and oil resistance of the tooth cloth glue, thus improving the overall performance of the synchronous belt.

The polytetrafluoroethylene of the present invention is first treated with plasma to complete the surface modification of the polytetrafluoroethylene and improve the reactivity of the polytetrafluoroethylene; under the action of supercritical pressure treatment, the methacrylic acid is allowed to penetrate and Coated on the surface of polytetrafluoroethylene; after adding zinc oxide, methacrylic acid reacts with zinc oxide in situ, and the surface of polytetrafluoroethylene is coated with zinc methacrylate generated in situ, and then polybutadiene is added Grafting maleic anhydride, under stirring, polybutadiene grafted maleic anhydride is embedded between zinc methacrylate and fully interacts with zinc methacrylate. The surface of this modified polytetrafluoroethylene is coated with zinc methacrylate and polybutadiene grafted with maleic anhydride. Moreover, zinc methacrylate also penetrates into the surface of polytetrafluoroethylene, and zinc methacrylate and polybutadiene graft Butadiene-grafted maleic anhydride has a strong interaction with polytetrafluoroethylene, so that the surface of polytetrafluoroethylene has many active groups. This modified polytetrafluoroethylene has good compatibility with hydrogenated nitrile rubber and is very easy to use. It is easy to disperse into the hydrogenated nitrile rubber matrix and achieves uniform dispersion in the hydrogenated nitrile rubber matrix; moreover, this modified polytetrafluoroethylene has low surface activation energy, strong reactivity, and strong adhesion to fabrics, thus It improves the bonding performance of the tooth cloth glue and further improves the structural solidity of the synchronous belt.

As a preferred embodiment, the frequency of the plasma is 10-14MHz, and the processing time is 160-200s. The present invention uses plasma to modify the surface of polytetrafluoroethylene, and this plasma can be argon plasma.

As a preferred embodiment, during the supercritical treatment, the fluid used is either carbon dioxide or nitrogen. The supercritical fluid of the present invention has good use effect, no pollution to the environment, and is green and environmentally friendly.

As a preferred embodiment, the stirring is performed at a stirring speed of 2000-3000 r/min for 3-6 minutes. When zinc oxide of the present invention is added to polytetrafluoroethylene with methacrylic acid permeated on the surface, zinc oxide and methacrylic acid react immediately to generate zinc methacrylate in situ; then, polybutadiene is grafted with maleic anhydride. , under stirring, the polybutadiene-grafted maleic anhydride is well dispersed into the zinc methacrylate generated in situ on the surface of polytetrafluoroethylene, with good dispersion and strong interaction with zinc methacrylate. , in toothpaste glue, zinc methacrylate and polybutadiene grafted maleic anhydride are always an organic whole with polytetrafluoroethylene and migrate together with polytetrafluoroethylene, thereby comprehensively improving the performance of polytetrafluoroethylene. performance.

As a preferred embodiment, the stirring is completed in a high-speed mixer. The stirring speed of this high-speed mixer is fast, which accelerates the dispersion of polybutadiene-grafted maleic anhydride in polytetrafluoroethylene with zinc methacrylate generated in situ on the surface, and also enhances the dispersion of polybutadiene-grafted maleic anhydride. Interaction between lytic anhydride and zinc methacrylate.

As a preferred embodiment, the cross-linking agent is a peroxide cross-linking agent, and the peroxide cross-linking agent is any one of DCP, BIBP, bis-25, and BPO. The cross-linking agent of the present invention is a peroxide cross-linking agent. The peroxide cross-linking agent can react with zinc methacrylate coated on the surface of PTFE to form a cross-linking bond, so that PTFE and rubber can be better combined; cross-linking Agents DCP (dicumyl peroxide), BIBP (bis-(2-tert-butylperoxyisopropyl)benzene), bis-25 (also known as 101, DBPH-99, 2,5-dimethyl-2, 5-Bis(tert-butylperoxy)ethane) and BPO (dibenzoyl peroxide) have excellent performance and good use effects.

As a preferred embodiment, the co-crosslinking agent is any one of TAIC, TAC, and TMP. The co-crosslinking agent mainly promotes the cross-linking reaction of peroxide to make the cross-linking reaction faster; the co-crosslinking agent TAIC (triallyl isocyanurate), TAC (triallyl cyanurate) , TMP (trimethylolpropane) can cooperate well with peroxide cross-linking agent, and the cross-linking effect is good.

As a preferred embodiment, the acrylonitrile content of the hydrogenated nitrile rubber is 30-43%. The acrylonitrile content affects the high temperature resistance and oil resistance of hydrogenated nitrile. High acrylonitrile content means good high temperature and oil resistance. If the acrylonitrile content is too low, the oil resistance and high temperature resistance will deteriorate.

In another aspect, the preparation method of the oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth rubber of the present invention includes the following steps: take hydrogenated nitrile rubber, mix it at 70-100°C for 1-2 minutes, and add polytetrafluoroethylene Ethylene, continue to be mixed for 6-10 minutes; then add cross-linking agent and co-cross-linking agent, continue to mix for 1-3 minutes; then, vulcanize at 160-180°C for 20-30 minutes to obtain toothpaste glue.

The preparation method of the tooth cloth glue of the present invention is to first mix the hydrogenated nitrile rubber in an internal mixer, then add polytetrafluoroethylene and then add a cross-linking agent and an auxiliary cross-linking agent to continue the internal mixing; Finally, the four raw materials are vulcanized together; this step-by-step mixing can make the polytetrafluoroethylene more evenly dispersed in the hydrogenated nitrile rubber. The cross-linking reaction will occur after the cross-linking agent and co-cross-linking agent are added, improving the reaction rubber. fluidity; the preparation method of this tooth cloth glue is simple to operate, easy to control, and easy to implement.

In yet another aspect, the present invention provides an application of an oil-resistant, high-temperature-resistant and low-friction coefficient toothed cloth glue, which is used to make synchronous belts.

The tooth cloth glue of the present invention is used to make synchronous belts. The tooth cloth glue is attached to the tooth cloth through calendering. The tooth cloth is bonded to the bottom rubber layer of the synchronous belt through the tooth cloth glue. Therefore, the tooth cloth glue can also be called Laminating glue. The use of the tooth cloth glue of the present invention can significantly improve the wear resistance of the synchronous belt, and further improve the high temperature resistance and oil resistance of the synchronous belt.

Compared with the existing technology, the beneficial effects of the present invention are: the tooth cloth glue of the present invention is formed of hydrogenated nitrile butadiene rubber (HNBR), polytetrafluoroethylene (PTFE), cross-linking agent and co-cross-linking agent, etc. This kind of tooth cloth rubber adds polytetrafluoroethylene to hydrogenated nitrile rubber. The friction coefficient of polytetrafluoroethylene is extremely low. Therefore, the friction coefficient of the tooth cloth rubber is greatly reduced and the friction performance of the tooth cloth rubber is improved. The resulting timing belt is more wear-resistant; at the same time, polytetrafluoroethylene also has good high-temperature resistance and is almost insoluble in all solvents, further improving the high-temperature resistance and oil resistance of tooth cloth glue; this kind of polytetrafluoroethylene is made of methyl Modified polytetrafluoroethylene coated with zinc acrylate and polybutadiene grafted with maleic anhydride has good compatibility with hydrogenated nitrile rubber and is easily dispersed into the hydrogenated nitrile rubber matrix. In addition, this modified polytetrafluoroethylene has low surface activation energy, strong reaction ability, and strong bonding ability with fabrics, thereby improving the bonding performance of tooth cloth glue and thus improving the overall performance of the synchronous belt. . The preparation method of tooth cloth glue of the present invention is simple to operate, easy to control, and easy to implement. The tooth cloth glue of the present invention is bonded to the tooth cloth through calendering, and the tooth cloth is bonded to the bottom rubber layer of the synchronous belt through the tooth cloth glue, thereby producing a synchronous belt. The obtained synchronous belt has significantly improved wear resistance and further Improved high temperature resistance and oil resistance.

Description of drawings

Figure 1 is the infrared spectrum of pure polytetrafluoroethylene;

Figure 2 is the infrared spectrum of pure zinc methacrylate;

Figure 3 is an infrared spectrum of zinc methacrylate modified polytetrafluoroethylene obtained in Example 1 of the present invention;

Figure 4 is a scanning electron microscope image of pure polytetrafluoroethylene;

Figure 5 is a scanning electron microscope image of pure zinc methacrylate;

Figure 6 is a scanning electron microscope image of modified polytetrafluoroethylene obtained in Example 1 of the present invention;

Figure 7 is an infrared spectrum of zinc methacrylate modified polytetrafluoroethylene obtained in Example 2 of the present invention;

Figure 8 is a scanning electron microscope image of modified polytetrafluoroethylene obtained in Example 2 of the present invention;

Figure 9 is an infrared spectrum of zinc methacrylate modified polytetrafluoroethylene obtained in Example 3 of the present invention;

Figure 10 is a scanning electron microscope image of modified polytetrafluoroethylene obtained in Example 3 of the present invention;

Figure 11 is an infrared spectrum of zinc methacrylate modified polytetrafluoroethylene obtained in Example 4 of the present invention;

Figure 12 is a scanning electron microscope image of modified polytetrafluoroethylene obtained in Example 4 of the present invention.

Detailed ways

The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

The invention is an oil-resistant, high-temperature resistant and low-friction coefficient tooth cloth glue, which includes the following components by weight: 100 parts of hydrogenated nitrile rubber, 55-100 parts of polytetrafluoroethylene, 3-6 parts of cross-linking agent, and cross-linking assisting agent. 1-3 parts of agent; the polytetrafluoroethylene is a modified polytetrafluoroethylene coated by zinc methacrylate and polybutadiene grafted with maleic anhydride, and the preparation method of the modified polytetrafluoroethylene is : Take polytetrafluoroethylene, use plasma treatment, add methacrylic acid, the amount of methacrylic acid added is 3-15% of the mass of polytetrafluoroethylene, at a pressure of 30-45MPa and a temperature of 40-80℃, Supercritical treatment for 3-5 minutes, add zinc oxide, the amount of zinc oxide added is 2-6% of the mass of polytetrafluoroethylene, then add polybutadiene grafted with maleic anhydride, polybutadiene grafted with maleic anhydride The added amount is 4-6% of the mass of polytetrafluoroethylene, and the reaction is stirred for 3-6 minutes at a stirring speed of 2000-3000 r/min.

Specifically, the frequency of the plasma is 10-14MHz, and the processing time is 160-200s.

Preferably, during the supercritical treatment, the fluid used is either carbon dioxide or nitrogen.

Preferably, the stirring is performed at a stirring speed of 2000-3000 r/min for 3-6 minutes.

Preferably, the stirring is accomplished in a high-speed mixer.

Preferably, the cross-linking agent is a peroxide cross-linking agent, and the peroxide cross-linking agent is any one of DCP, BIBP, bis-25, and BPO.

Preferably, the co-crosslinking agent is any one of TAIC, TAC, and TMP.

Preferably, the acrylonitrile content of the hydrogenated nitrile rubber is 30-43%.

The preparation method of the oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue of the present invention includes the following steps: take hydrogenated nitrile rubber, mix it at 70-100°C for 1-2 minutes, add polytetrafluoroethylene, and continue to mix it. 6-10 minutes; then add cross-linking agent and co-cross-linking agent, continue to mix for 1-3 minutes; then vulcanize at 160-180°C for 20-30 minutes to obtain toothpaste glue.

The present invention is an application of an oil-resistant, high-temperature-resistant and low-friction coefficient toothed cloth glue, which is used to make synchronous belts.

Example 1

The preparation method of the oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue of the present invention includes the following steps:

1) Take 100 parts of polytetrafluoroethylene, use plasma treatment, add 3 parts of methacrylic acid, supercritically treat it for 3 minutes at a pressure of 30MPa and a temperature of 80°C, add 2 parts of zinc oxide, and then add polybutadiene Graft 4 parts of maleic anhydride, stir and react for 6 minutes at a stirring speed of 2000r/min, to obtain modified polytetrafluoroethylene;

2) Take 100 parts of hydrogenated nitrile rubber and mix it for 1.5 minutes at 80°C; add 55 parts of the above modified polytetrafluoroethylene and continue mixing for 7 minutes; then add 4 parts of cross-linking agent DCP and auxiliary cross-linking agent TAIC 1 part, continue internal mixing for 2 minutes; then, vulcanize at 170°C for 25 minutes to obtain toothpaste glue.

In order to clearly prove that zinc methacrylate grows in situ on the surface of polytetrafluoroethylene in step 1) of this example, according to the method of step 1), without adding polybutadiene grafted maleic anhydride, preparation Zinc methacrylate modified polytetrafluoroethylene.

Zinc methacrylate modified polytetrafluoroethylene, pure zinc methacrylate and pure polytetrafluoroethylene were measured on a VERTEX70 infrared spectrometer produced by Bruker, Germany.

As can be seen from Figure 3, the absorption peaks at 2960cm ^-1 and 2900cm ^-1 are the asymmetric stretching vibration absorption peak and symmetric stretching vibration absorption peak of methyl-CH ₃ respectively; the absorption peak at 1420cm ^-1 is the methyl - Bending vibration absorption peak in the CH ₃ plane. Usually the absorption peaks of C=C bonds and C=O bonds overlap in the high-frequency region, but because C=O has a large dipole moment, the C=O absorption peak is stronger than the C=C absorption peak. This feature can be used to distinguish The absorption peaks of both. Therefore, 1660 cm ^-1 and 1610 cm ^-1 are the absorption peaks of carbonyl C=O and olefin C=C double bonds respectively. The characteristic peaks at 1530cm ^-1 and 1437cm ^-1 are the characteristic peaks of unsaturated carboxylic acid metal salts. The absorption peaks located at 947 cm ^-1 and 827 cm ^-1 are generated by the out-of-plane bending vibration of the carbon-hydrogen single bond on the olefin double bond. As can be seen from Figure 2, pure zinc methacrylate (ZDMA) contains the above characteristic peaks. As can be seen from Figure 1, the surface of pure polytetrafluoroethylene (PTFE) does not contain the above characteristic peaks. Therefore, zinc methacrylate in modified polytetrafluoroethylene is grafted onto polytetrafluoroethylene through in-situ polymerization.

The modified polytetrafluoroethylene, pure zinc methacrylate and pure polytetrafluoroethylene obtained in step 1) of this example were respectively placed on a JSM-7500F scanning electron microscope produced by JEOL for observation.

As can be seen from Figures 4, 5 and 6, pure polytetrafluoroethylene (PTFE) is a spherical particle with a diameter of about 200nm, with a smooth surface and the particles are adhered together. Pure zinc methacrylate (ZDMA) is filamentous particles with larger particle size. Polytetrafluoroethylene modified in situ with maleic anhydride grafted with zinc methacrylate and polybutadiene is used. Zinc methacrylate still exists in the form of filaments and is evenly dispersed with polytetrafluoroethylene. Methacrylic acid Zinc adheres to PTFE, indicating that zinc methacrylate coats and penetrates into the surface of PTFE.

Comparative example 1

A preparation method of toothpaste glue, including the following steps:

1) Take 50 parts of polytetrafluoroethylene, add 3.5 parts of zinc methacrylate and 1.5 parts of polybutadiene grafted maleic anhydride, stir and mix evenly to obtain modified polytetrafluoroethylene;

2) Take 100 parts of hydrogenated nitrile rubber and mix it for 1.5 minutes at 80°C; add 55 parts of the above modified polytetrafluoroethylene and continue mixing for 7 minutes; then add 4 parts of cross-linking agent DCP and auxiliary cross-linking agent TAIC 1 part, continue internal mixing for 2 minutes; then, vulcanize at 170°C for 25 minutes to obtain toothpaste glue.

Example 2

The preparation method of the oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue of the present invention includes the following steps:

1) Take 100 parts of polytetrafluoroethylene, use plasma treatment, add 7 parts of methacrylic acid, supercritically treat it for 5 minutes at a pressure of 45MPa and a temperature of 40°C, add 3 parts of zinc oxide, and then add polybutadiene Graft 5 parts of maleic anhydride, stir and react for 3 minutes at a stirring speed of 3000r/min, to obtain modified polytetrafluoroethylene;

2) Take 100 parts of hydrogenated nitrile rubber and mix it for 2 minutes at 70°C; add 60 parts of the above modified polytetrafluoroethylene and continue to mix it for 10 minutes; then add 6 parts of cross-linking agent Double 25 and auxiliary cross-linking agent TMP 3 parts, continue to mix for 3 minutes; then, vulcanize for 30 minutes at 160°C to obtain toothpaste glue.

In order to clearly prove that zinc methacrylate grows in situ on the surface of polytetrafluoroethylene in step 1) of this example, according to the method of step 1), without adding polybutadiene grafted maleic anhydride, preparation Zinc methacrylate modified polytetrafluoroethylene. The zinc methacrylate modified polytetrafluoroethylene was also placed on the infrared spectrometer of Example 1 for measurement.

It can be seen from Figure 7 that the infrared spectrum of the modified polytetrafluoroethylene obtained in this example is basically consistent with the infrared spectrum of the modified polytetrafluoroethylene obtained in Example 3. The modified polytetrafluoroethylene in this example Zinc methacrylate in vinyl fluoride is also grafted onto polytetrafluoroethylene through in-situ polymerization, and the modified polytetrafluoroethylene obtained in this example has stronger characteristics.

The modified polytetrafluoroethylene obtained in step 1) of this example was also placed on the scanning electron microscope of Example 1 for observation. It can be seen from Figure 8 that in the modified polytetrafluoroethylene obtained in this example, zinc methacrylate still exists in the form of filaments and is evenly dispersed with polytetrafluoroethylene; however, in this example, zinc methacrylate The filamentary structure of zinc methacrylate is thinner than that of zinc methacrylate in Example 3, which shows that zinc methacrylate and polytetrafluoroethylene are more closely adhered to each other in this embodiment.

Comparative example 2

A preparation method of toothpaste glue, including the following steps:

1) Take 50 parts of polytetrafluoroethylene, add 8 parts of zinc methacrylate and 2 parts of polybutadiene grafted maleic anhydride, stir and mix evenly to obtain modified polytetrafluoroethylene;

2) Take 100 parts of hydrogenated nitrile rubber and mix it for 2 minutes at 70°C; add 60 parts of the above modified polytetrafluoroethylene and continue to mix it for 10 minutes; then add 6 parts of cross-linking agent Double 25 and auxiliary cross-linking agent TMP 3 parts, continue to mix for 3 minutes; then, vulcanize for 30 minutes at 160°C to obtain toothpaste glue.

Example 3

The preparation method of the oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue of the present invention includes the following steps:

1) Take 100 parts of polytetrafluoroethylene, use plasma treatment, add 10.5 parts of methacrylic acid, supercritically treat it for 4 minutes at a pressure of 35MPa and a temperature of 60°C, add 4.5 parts of zinc oxide, and then add polybutadiene Graft 5 parts of maleic anhydride, stir and react for 3 minutes at a stirring speed of 2500r/min, to obtain modified polytetrafluoroethylene;

2) Take 100 parts of hydrogenated nitrile rubber and mix it for 1 minute at 100°C; add 65 parts of the above modified polytetrafluoroethylene and continue to mix for 6 minutes; then add 5 parts of cross-linking agent BPO and 2 parts of cross-linking agent TMA portion, continue to mix for 1 minute; then vulcanize at 180°C for 20 minutes to obtain toothpaste glue.

In order to clearly prove that zinc methacrylate grows in situ on the surface of polytetrafluoroethylene in step 1) of this example, according to the method of step 1), without adding polybutadiene grafted maleic anhydride, preparation Zinc methacrylate modified polytetrafluoroethylene. The zinc methacrylate modified polytetrafluoroethylene was also placed on the infrared spectrometer of Example 1 for measurement.

It can be seen from Figure 9 that the infrared spectrum of the modified polytetrafluoroethylene obtained in this example is basically consistent with the infrared spectrum of the modified polytetrafluoroethylene obtained in Example 3 and Example 5. The zinc methacrylate in the final polytetrafluoroethylene is also grafted to the polytetrafluoroethylene through in-situ polymerization, and the intensity of the above characteristic peaks of the modified polytetrafluoroethylene obtained in this example is stronger.

The modified polytetrafluoroethylene obtained in step 1) of this example was also placed on the scanning electron microscope of Example 1 for observation.

It can be seen from Figure 10 that in the modified polytetrafluoroethylene obtained in this example, zinc methacrylate exists in the form of particles and is evenly dispersed with polytetrafluoroethylene. This shows that in this example, the methyl Zinc acrylate achieves tighter adhesion with PTFE.

Comparative example 3

A preparation method of toothpaste glue, including the following steps:

1) Take 55 parts of polytetrafluoroethylene, add 7 parts of zinc methacrylate and 3 parts of polybutadiene grafted maleic anhydride, stir and mix evenly to obtain modified polytetrafluoroethylene;

2) Take 100 parts of hydrogenated nitrile rubber and mix it for 1 minute at 100°C; add 65 parts of the above modified polytetrafluoroethylene and continue to mix for 6 minutes; then add 5 parts of cross-linking agent BPO and 2 parts of cross-linking agent TMA portion, continue to mix for 1 minute; then vulcanize at 180°C for 20 minutes to obtain toothpaste glue.

Example 4

The preparation method of the oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue of the present invention includes the following steps:

1) Take 100 parts of polytetrafluoroethylene, use plasma treatment, add 14 parts of methacrylic acid, supercritically treat it for 4 minutes at a pressure of 40MPa and a temperature of 70°C, add 6 parts of zinc oxide, and then add polybutadiene Graft 6 parts of maleic anhydride, stir and react for 3 minutes at a stirring speed of 2500r/min, to obtain modified polytetrafluoroethylene;

2) Take 100 parts of hydrogenated nitrile rubber and mix at 90°C for 1.5 minutes; add 70 parts of the above modified polytetrafluoroethylene and continue to mix for 7 minutes; then add 3 parts of cross-linking agent DCP and auxiliary cross-linking agent TAIC 1 part, continue internal mixing for 2 minutes; then, vulcanize at 170°C for 25 minutes to obtain toothpaste glue.

In order to clearly prove that zinc methacrylate grows in situ on the surface of polytetrafluoroethylene in step 1) of this example, according to the method of step 1), without adding polybutadiene grafted maleic anhydride, preparation Zinc methacrylate modified polytetrafluoroethylene. The zinc methacrylate modified polytetrafluoroethylene was also placed on the infrared spectrometer of Example 1 for measurement.

It can be seen from Figure 11 that the infrared spectrum of the modified polytetrafluoroethylene obtained in this example is basically consistent with the infrared spectrum of the modified polytetrafluoroethylene obtained in example three, five and seven. The zinc methacrylate in the modified polytetrafluoroethylene in the example is also grafted to the polytetrafluoroethylene through in-situ polymerization. Moreover, the intensity of the above characteristic peaks of the modified polytetrafluoroethylene obtained in this example is Stronger.

The modified polytetrafluoroethylene obtained in step 1) of this example was also placed on the scanning electron microscope of Example 1 for observation.

It can be seen from Figure 12 that in the modified polytetrafluoroethylene obtained in this example, zinc methacrylate also exists in the form of particles. Moreover, the particle shape of zinc methacrylate in this example is better and is similar to that of polytetrafluoroethylene. The vinyl fluoride is evenly dispersed together, which shows that zinc methacrylate and polytetrafluoroethylene achieve tighter adhesion in this embodiment.

Comparative example 4

A preparation method of toothpaste glue, including the following steps:

1) Take 56 parts of polytetrafluoroethylene, add 10.5 parts of zinc methacrylate and 3.5 parts of polybutadiene grafted maleic anhydride, stir and mix evenly to obtain modified polytetrafluoroethylene;

2) Take 100 parts of hydrogenated nitrile rubber and mix for 2 minutes at 80°C; add 70 parts of the above modified polytetrafluoroethylene and continue to mix for 9 minutes; then add 5 parts of cross-linking agent DCP and auxiliary cross-linking agent TAIC 2 portion, continue to mix for 2 minutes; then, vulcanize for 30 minutes at 170°C to obtain toothpaste glue.

Comparative example

A preparation method of toothpaste glue, including the following steps:

Take 100 parts of hydrogenated nitrile rubber and mix for 2 minutes at 80°C; add 60 parts of polytetrafluoroethylene and continue to mix for 8 minutes; then add 4 parts of cross-linking agent DCP and 1 part of auxiliary cross-linking agent TIAC and continue to mix 2 minutes; then, vulcanize at 170°C for 25 minutes to obtain toothpaste glue.

Experiment 1

The tooth cloth adhesives obtained from Examples 1 to 4, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4 and Comparative Example were respectively subjected to adhesive performance test experiments. The test method was to soak in accordance with GB/T32109-2015. The adhesive yarn and cord fabric bonding and peeling performance test method was carried out, and the experimental results are listed in Table 1.

Table 1 Peel strength measurement results of different tooth cloth glues

sample name Peel strength (N·mm ^-1 ) Example 1 2.70 Comparative example 1 2.60 Example 2 3.05 Comparative example 2 2.90 Example 3 3.28 Comparative example 3 2.90 Example 4 3.51 Comparative example 4 3.07 Comparative example 1.80

As can be seen from Table 1, the peel strength between the tooth rubber and tooth cloth obtained by the present invention is between 2.70-3.51N/mm, which is significantly greater than the peel strength between the comparative example and the tooth cloth; moreover, the peel strength between the tooth cloth obtained by the present invention The peel strength between the tooth rubber and the tooth cloth is also greater than the peel strength between the comparative example of simply mixing zinc methacrylate and polybutadiene grafted maleic anhydride in polytetrafluoroethylene and the tooth cloth under the same conditions. Therefore, the tooth rubber of the present invention has good bonding performance with the tooth cloth, so the tooth rubber of the present invention improves the structural stability of the synchronous belt.

Experiment 2

The tooth cloth glue obtained from Examples 1 to 4, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4 and Comparative Example were respectively subjected to mechanical property testing experiments. Among them, tensile properties, 100% elongation strength and 300% elongation strength were tested on an electronic tensile machine in accordance with the national standard GB/T 528-2009, the tearing performance was tested on an electronic tensile machine in accordance with GB/T 529-2008, and the Shore A hardness was tested in accordance with GB/T 531 -2008, the wear volume was measured in accordance with GBT 25262-2010 vulcanized rubber or thermoplastic rubber wear test, and the test results are listed in Table 2.

Table 2 Measuring results of mechanical properties of different tooth cloth glues

It can be seen from Table 2 that the tensile strength of the cloth tooth rubber obtained by the present invention is between 4.8-23.6MPa, which is significantly greater than the tensile strength of the comparative example; moreover, the tensile strength of the cloth tooth rubber obtained by the present invention is also greater than that of the same Tensile strength of a comparative example of a simple mixture of zinc methacrylate and polybutadiene grafted maleic anhydride in polytetrafluoroethylene under the same conditions. The tensile elongation at break of the tooth rubber obtained by the present invention is between 333-481%, which is significantly greater than the tensile elongation at break of the comparative example; moreover, the tensile elongation at break of the tooth rubber obtained by the present invention is also greater than that under the same conditions. Below is the tensile elongation at break of a comparative example of a simple mixture of zinc methacrylate and polybutadiene grafted maleic anhydride in polytetrafluoroethylene. The 100% elongation strength of the tooth rubber obtained by the present invention is between 1.7-2.9 MPa, which is significantly greater than the 100% elongation strength of the control sample; moreover, the 100% elongation strength of the tooth rubber obtained by the present invention is also greater than that under the same conditions. 100% elongation of the comparative example of a simple mixture of zinc methacrylate and polybutadiene grafted maleic anhydride in polytetrafluoroethylene. The 300% elongation strength of the tooth rubber obtained by the present invention is between 4.3-12.9MPa, which is significantly greater than the 300% elongation strength of the comparative example; moreover, the 300% elongation strength of the tooth rubber obtained by the present invention is also greater than that under the same conditions. 300% elongation for the comparative example of simply mixing zinc methacrylate and polybutadiene grafted maleic anhydride in polytetrafluoroethylene. The tear strength of the cloth tooth rubber obtained by the present invention is 20.0-37.9N/mm, which is significantly greater than the tear strength of the comparative example; moreover, the tear strength of the cloth tooth rubber obtained by the present invention is also greater than that of polytetrafluoroethylene under the same conditions. Tear strength of a comparative example of a simple mixture of zinc methacrylate and polybutadiene grafted with maleic anhydride. Therefore, the polytetrafluoroethylene modified by in-situ coating with zinc methacrylate and polybutadiene grafted with maleic anhydride of the present invention has good compatibility with hydrogenated nitrile butadiene rubber.

As can be seen from Table 2, the Shore A (Shore A) hardness of the cloth tooth rubber obtained by the present invention is between 60 and 71, which is significantly greater than the Shore A (Shore A) hardness of the comparative example; moreover, the cloth tooth rubber obtained by the present invention has a Shore A hardness of between 60 and 71. The Shore A hardness is also greater than the Shore A hardness of the comparative example of simply mixing zinc methacrylate and polybutadiene grafted maleic anhydride in polytetrafluoroethylene under the same conditions.

It can also be seen from Table 2 that the wear volume of the tooth rubber obtained by the present invention is between ^25-52mm3 , which is significantly smaller than the wear volume of the comparative example; moreover, the wear volume of the tooth rubber obtained by the present invention is also smaller than that under the same conditions. Abrasion volume of a comparative example of simple mixing of zinc methacrylate and polybutadiene grafted maleic anhydride in polytetrafluoroethylene. This shows that the tooth rubber of the present invention significantly improves the wear resistance.

Experiment 3

The tooth cloth rubber obtained from Examples 1 to 4, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4 and Comparative Example were respectively subjected to a vulcanization characteristic test experiment. The vulcanization characteristic test experiment was conducted in accordance with GB/T9869-2014 The test was carried out according to the prescribed method, in which the test temperature was 170°C. The experimental results are listed in Table 3.

Table 3 Measurement results of vulcanization characteristics of different tooth cloth rubbers

It can be seen from Table 3 that the minimum torque M _L of the tooth rubber obtained by the present invention is between 1.64-2.01 dN·m, which is significantly greater than the minimum torque M L of the comparative example; moreover, the minimum torque M _L of the tooth rubber obtained by the present invention _L is greater than the minimum torque M _L of the comparative example of simply mixing zinc methacrylate and polybutadiene grafted maleic anhydride in polytetrafluoroethylene under the same conditions. The maximum torque M _H of the tooth rubber obtained by the present invention is between 21.53-30.45dN·m, which is significantly greater than the maximum torque M _H of the comparative example; moreover, the maximum torque M _H of the tooth rubber obtained by the present invention is greater than that of the tooth rubber obtained under the same conditions. Maximum torque M _H for a comparative example of a simple mixture of zinc methacrylate and polybutadiene grafted with maleic anhydride in polytetrafluoroethylene. The difference between the maximum torque M _H and the minimum torque M _L of the tooth rubber obtained by the present invention, that is, the degree of cross-linking, is between 19.89-29.02dN·m, and its changing pattern is consistent with the maximum torque M _H ; this shows that zinc methacrylate The in situ introduction of zinc methacrylate and polybutadiene grafted maleic anhydride increases the interaction between hydrogenated nitrile rubber and polytetrafluoroethylene. Moreover, this zinc methacrylate and polybutadiene grafted maleic anhydride original The interaction between modified polytetrafluoroethylene and hydrogenated butadiene rubber is greater than directly adding zinc methacrylate and polybutadiene grafted maleic anhydride to polytetrafluoroethylene. Polytetrafluoroethylene and hydrogenated butadiene rubber interaction between.

It can be seen from Table 3 that the scorch time T _s1 of the cloth tooth rubber obtained by the present invention is between 27-36 s, which is significantly smaller than the scorch time T s1 of the comparative example; moreover, the scorch time T _s1 of the cloth tooth rubber obtained by the present invention is _s1 are all less than the scorch time T _s1 of the comparative example of simply mixing zinc methacrylate and polybutadiene grafted maleic anhydride in polytetrafluoroethylene under the same conditions. The scorch time T ₁₀ of the tooth rubber obtained by the present invention is between 35-46 s, which is significantly less than the scorch time T ₁₀ of the comparative example; moreover, the scorch time T ₁₀ of the tooth rubber obtained by the present invention is also shorter than that under the same conditions. Scorch time T ₁₀ for the comparative example of a simple mixture of zinc methacrylate and polybutadiene grafted maleic anhydride in polytetrafluoroethylene. The normal vulcanization time T ₉₀ of the cloth tooth rubber obtained by the present invention is between 575-613 s, which is significantly less than the normal vulcanization time T _{90 of the comparative example; moreover, the normal vulcanization time T 90 of} the cloth tooth rubber obtained by the present invention is also shorter than the same conditions. Normal cure time T ₉₀ for the comparative example of simple mixing of zinc methacrylate and polybutadiene grafted maleic anhydride in polytetrafluoroethylene. Therefore, the in-situ modified polytetrafluoroethylene with zinc methacrylate and polybutadiene grafted with maleic anhydride in the tooth cloth glue of the present invention has the effect of promoting the vulcanization of hydrogenated butadiene rubber.

It can be seen from Table 3 that the Mooney viscosity ML (1+4) of the cloth tooth glue obtained by the present invention is between 86.7-94.6, which is significantly greater than the Mooney viscosity ML (1+4) of the comparative example. Moreover, the Mooney viscosity ML (1+4) obtained by the present invention The Mooney viscosity ML (1+4) of the cloth gum is greater than the Mooney viscosity ML (1) of the comparative example of simply mixing zinc methacrylate and polybutadiene grafted maleic anhydride in polytetrafluoroethylene under the same conditions. +4).

Therefore, compared with the prior art, the beneficial effects of the present invention are: the tooth cloth glue of the present invention is formed of hydrogenated nitrile butadiene rubber (HNBR), polytetrafluoroethylene (PTFE), cross-linking agents, co-cross-linking agents, etc. This kind of tooth cloth rubber adds polytetrafluoroethylene to hydrogenated nitrile rubber. The friction coefficient of polytetrafluoroethylene is extremely low. Therefore, the friction coefficient of the tooth cloth rubber is greatly reduced and the friction performance of the tooth cloth rubber is improved. , the resulting synchronous belt is more wear-resistant; at the same time, PTFE also has good high-temperature resistance and is almost insoluble in all solvents, further improving the high-temperature resistance and oil resistance of the tooth cloth glue; this kind of Modified polytetrafluoroethylene coated with zinc methacrylate and polybutadiene grafted with maleic anhydride has good compatibility with hydrogenated nitrile rubber and is easily dispersed into the hydrogenated nitrile rubber matrix. Uniform dispersion is achieved; moreover, this modified polytetrafluoroethylene has low surface activation energy, strong reaction ability, and strong bonding ability with fabrics, thereby improving the bonding performance of tooth cloth glue and thus improving the performance of the synchronous belt. Overall performance. The preparation method of tooth cloth glue of the present invention is simple to operate, easy to control, and easy to implement. The tooth cloth glue of the present invention is attached to the tooth cloth through calendering, and the tooth cloth is bonded to the bottom rubber layer of the synchronous belt through the tooth cloth glue, thereby producing a synchronous belt. The obtained synchronous belt has significantly improved wear resistance and further Improved high temperature resistance and oil resistance.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims (10)

1. An oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue, characterized in that it includes the following components by weight: 100 parts of hydrogenated nitrile rubber, 55-100 parts of modified polytetrafluoroethylene, 3-6 parts of cross-linking agent, 1-3 parts of auxiliary cross-linking agent; The modified polytetrafluoroethylene is a modified polytetrafluoroethylene coated by zinc methacrylate and polybutadiene grafted with maleic anhydride. The preparation method of the modified polytetrafluoroethylene is: taking polytetrafluoroethylene Vinyl fluoride, using plasma treatment, adding methacrylic acid, the amount of methacrylic acid added is 3-15% of the mass of polytetrafluoroethylene, supercritical treatment at a pressure of 30-45MPa and a temperature of 40-80℃ 3 -5min, add zinc oxide, the amount of zinc oxide added is 2-6% of the mass of polytetrafluoroethylene, then add polybutadiene grafted maleic anhydride, the amount of polybutadiene grafted maleic anhydride is polytetrafluoroethylene 4-6% of the mass of tetrafluoroethylene, stir to obtain modified polytetrafluoroethylene. 2. The oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue according to claim 1, characterized in that: The frequency of the plasma is 10-14MHz, and the processing time is 160-200s. 3. The oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue according to claim 1, characterized in that: During the supercritical treatment, the fluid used is either carbon dioxide or nitrogen. 4. The oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue according to claim 1, characterized in that: The stirring is performed at a stirring speed of 2000-3000 r/min for 3-6 minutes. 5. The oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue according to claim 4, characterized in that: The mixing is done in a high-speed mixer. 6. The oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue according to any one of claims 1-5, characterized by: The cross-linking agent is a peroxide cross-linking agent, and the peroxide cross-linking agent is any one of DCP, BIBP, bis-25, and BPO. 7. The oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue according to any one of claims 1-5, characterized by: The co-crosslinking agent is any one of TAIC, TAC and TMP. 8. The oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue according to any one of claims 1-5, characterized by: The acrylonitrile content of the hydrogenated nitrile rubber is 30-43%. 9. A method for preparing oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue according to any one of claims 1-8, characterized in that it includes the following steps: Take hydrogenated nitrile rubber, mix it for 1-2 minutes at 70-100℃, add modified polytetrafluoroethylene, and continue mixing for 6-10 minutes; then add cross-linking agent and co-cross-linking agent, and continue mixing for 1- 3 minutes; then, vulcanize at 160-180°C for 20-30 minutes to obtain toothpaste glue. 10. An application of oil-resistant, high-temperature-resistant and low-friction coefficient tooth cloth glue according to any one of claims 1-8, characterized by: The oil-resistant, high-temperature resistant and low-friction coefficient tooth cloth glue is used to make timing belts.