Rubber tape for railway track friction mainboard and preparation method thereof

Abstract

The invention belongs to the field of composite materials, and relates to a rubberized cloth for railway track friction mainboard, comprising a substrate and a glue liquid cured on the substrate; the substrate is an alkali-free glass cloth treated with a coupling agent; the glue liquid comprises the following components: 0.25-0.3 parts of epoxy resin, 0.2-0.35 parts of curing agent, 0.0005-0.0008 parts of accelerator, 0.15-0.20 parts of filler, 0.0004-0.0006 parts of silane coupling agent, 0.001-0.003 parts of inorganic dye, and 0.18-0.25 parts of solvent. The curing agent is selected from phenolic resin, and the reaction curing temperature of epoxy resin and phenolic resin is low, and the energy consumption is low, so that the curing molding is ensured, and the stiffness and hardness of the rubberized cloth and the storage adhesion problem of the rubberized cloth are improved; the inorganic filler increases the viscosity of the resin, improves the amount of glue squeezed during the pressing process, and increases the stiffness and hardness of the rubberized cloth; the accelerator is added to promote the reaction of epoxy resin and phenolic resin, and improve the reaction speed.

Description

Technical Field

[0001] The invention belongs to the field of composite materials, and in particular relates to a rubberized tape for a railway track friction mainboard and a preparation method thereof. Background Art

[0002] The main friction plate of the railway track bogie is a friction plate formed by composite pressing of rubber tape, phenolic resin and wear-resistant material. The rubber tape, phenolic resin and wear-resistant material must have good bonding strength and tensile strength. The product manufacturing process requires easy operation and energy saving.

[0003] The main friction plate of the prior art uses a bismaleimide resin or a benzoxazine resin. The substrate of the bismaleimide resin is glass cloth, and the glass cloth is 0.18mm7628 electronic cloth. The curing temperature of bismaleimide resin and benzoxazine resin is 200℃, and the interlayer bonding strength of 0.18mm thick glass cloth is low. The resin can only be completely cured by heating. If the curing temperature is high, the mold needs to be heated to 200℃ to cure the resin, and the high temperature causes high energy consumption; and the 0.18mm thick glass cloth has poor permeability of the adhesive liquid, which affects the interlayer bonding strength of the plate pressed by the bismaleimide resin. Summary of the invention

[0004] The purpose of the present invention is to provide a rubberized plaster for railway track friction mainboard and a preparation method thereof, so as to solve the problems of high energy consumption and low bonding strength in the preparation process of the existing rubberized plaster.

[0005] The present invention is achieved through the following technical solutions:

[0006] A rubber tape for a railway track friction main board, comprising a substrate and a glue liquid solidified on the substrate;

[0007] The substrate is alkali-free glass cloth treated with coupling agent;

[0008] The glue solution includes the following components by weight:

[0009] 0.25-0.3 parts of epoxy resin, 0.2-0.35 parts of curing agent, 0.0005-0.0008 parts of accelerator, 0.15-0.20 parts of filler, 0.0004-0.0006 parts of coupling agent, 0.001-0.003 parts of inorganic dye, 0.18-0.25 parts of solvent;

[0010] Phenolic resin is selected as the curing agent.

[0011] Furthermore, the epoxy resin adopts glycidyl ether bisphenol A type epoxy.

[0012] Furthermore, the glycidyl ether bisphenol A type epoxy is a mixture of E44 type epoxy resin, E20 type epoxy resin and E12 type epoxy resin.

[0013] Furthermore, the curing agent is one or a mixture of thermoplastic phenolic resin and thermosetting phenolic resin.

[0014] Furthermore, the accelerator is selected from one or a mixture of imidazole accelerator and dicyandiamide.

[0015] Furthermore, the filler contains magnesium hydroxide; and the inorganic dye is a brown-red inorganic dye.

[0016] Furthermore, the solvent is toluene, methanol or dimethylformamide.

[0017] Further, the content of the glue accounts for 40%-45% of the weight of the upper adhesive tape;

[0018] The volatile matter content in the adhesive tape is ≤2%, the soluble resin content is ≥85%-95%, and the fluidity is 13%-15%.

[0019] Furthermore, the coupling agent adopts silane coupling agent KH560.

[0020] The present invention also discloses a method for preparing the rubberized tape for the railway track friction mainboard, which comprises the following steps:

[0021] S1. treating the alkali-free glass cloth with a coupling agent to obtain a substrate;

[0022] S2, heating the epoxy resin and the solvent at 60-70° C., stirring and mixing, and then cooling to room temperature to obtain liquid A;

[0023] S3, stirring and mixing the curing agent and the solvent to obtain liquid B;

[0024] S4, stirring and mixing liquid A and liquid B to obtain a mixed resin;

[0025] S5. Before gluing, add accelerator, filler, coupling agent and inorganic dye to the mixed resin, mix with solvent to prepare glue solution, and control the molding time of glue solution by adjusting the amount of accelerator. The glue solution is required to be tested by knife method at 160℃, and the molding time is 1'30"~3'30";

[0026] S6, applying glue liquid on the substrate, and then curing at 80-160° C. to obtain a glued cloth.

[0027] Compared with the prior art, the present invention has the following beneficial technical effects:

[0028] The invention discloses a rubber sheet for railway track friction main board, comprising a substrate and a glue liquid cured on the substrate; the substrate is an alkali-free glass cloth treated with a coupling agent, which increases the adhesion between the inorganic interface and the organic interface, and after the rubber sheet is pressed into a friction main board, the tensile strength and impact strength are significantly improved; the glue liquid comprises an epoxy resin, a curing agent, an accelerator, a coupling agent, an inorganic filler, an inorganic dye and a solvent. The invention selects epoxy resin, and the material price is low; the curing agent selects phenolic resin, and the reaction curing temperature of epoxy resin and phenolic resin is low, and the energy consumption is low; the addition of a high softening point phenolic resin curing agent ensures the curing molding, improves the stiffness and hardness of the rubber sheet and the storage adhesion problem of the rubber sheet; the addition of inorganic fillers can increase the viscosity of the resin, improve the amount of glue squeezed during the pressing process, and at the same time increase the stiffness and hardness of the rubber sheet, and at the same time can reduce the cost; the addition of a silane coupling agent can improve the uniform dispersibility of the inorganic filler, and improve the wettability of the resin with the inorganic filler and the glass cloth; the addition of an accelerator can promote the reaction of the epoxy resin and the phenolic resin, and increase the reaction speed.

[0029] When users adopt the invented adhesive tape to press the friction main board, the pressing temperature is reduced from 200°C to 160°C, reducing the power consumption by about 20%; when the invented adhesive tape is adopted to produce the main friction plate, the adhesive tape is easy to cut, the adhesive liquid has good fluidity and less adhesive is extruded during the pressing production process, there is no void inside the main board, the bonding strength is excellent, the qualified rate is increased from the previous 8‰ to within 5‰, and the material cost of the invented adhesive tape is reduced by 40% compared with the existing adhesive tape.

[0030] Furthermore, by selecting an adhesive that is a combination of resins with different softening points and epoxy values, the semi-cured state has higher strength after baking, which can improve the stiffness and hardness of the adhesive tape. By selecting suitable resins and curing agents, the adhesive can be completely cured at a lower temperature; E44 epoxy has good viscosity and is cheap. After adding E20 epoxy and E12 epoxy, the stiffness and hardness are improved.

[0031] Furthermore, the curing agent is selected from high softening point thermoplastic phenolic resin, or a mixture of thermoplastic phenolic resin and thermosetting phenolic resin, which can improve the stiffness of the adhesive tape and solve the problem of sticking between films at room temperature.

[0032] Furthermore, the content of the adhesive liquid accounts for 40%-45% of the weight of the upper adhesive cloth. Tests have shown that the friction main board pressed within this range has high bonding strength.

[0033] Furthermore, suitable fillers are added to control the soluble resin content to 85%-95%, so that the amount of rubber extruded during the pressing process is small.

[0034] Furthermore, the coupling agent uses silane coupling agent KH560 to improve the bonding force between the resin and the glass cloth substrate and the inorganic filler. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present invention clearer, the following is further described in detail with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments.

[0036] The detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the invention claimed for protection, but merely represents a selected embodiment of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0037] It is required that there is good bonding strength between the adhesive tape and the phenolic resin and the wear-resistant material. The resin material in the adhesive solution of the adhesive tape of the present invention is epoxy resin. The phenolic resin itself can react and solidify with the epoxy resin. Selecting the adhesive tape of epoxy resin can improve the bonding strength between the adhesive tape and the wear-resistant phenolic resin.

[0038] Select a suitable substrate to meet the composite material strength, cutting requirements and adhesion. By selecting a suitable glass cloth reinforcement material, the resin impregnation and reinforcement are excellent. After screening, the present invention selects an alkali-free glass cloth with a thickness of 0.14mm and treated with a coupling agent. Compared with the 0.18mm thick glass cloth used before, the 0.14mm thick glass cloth has better impregnation with the same resin, and the bonding strength between the glass cloth and the resin after the coupling agent treatment is higher.

[0039] The coupling agent molecule has a unique chemical structure. One end of it can react chemically with the hydroxyl and other active groups on the surface of the alkali-free glass cloth (inorganic material) to form a strong chemical bond; the other end can interact with the corresponding active functional groups in the glue (organic material), thereby building a "chemical bridge" between the inorganic glass cloth and the organic glue, significantly enhancing the bonding force between the two. After the adhesive cloth is pressed into the friction main board, due to this good interface bonding, the entire structure is more compact and stable, and it is not easy for the components to separate or peel off, which greatly improves the integrity of the friction main board, thereby significantly improving its tensile strength and impact strength.

[0040] Develop an adhesive. The semi-cured state of the developed adhesive needs to have good hardness and is suitable for the production of adhesive tape. The adhesive tape produced by the adhesive can be pressed into the main board of the friction board to meet the bonding strength between the main board layers while not flowing during the pressing process. The semi-cured state of the resin is required to have good hardness for easy cutting and processing of the adhesive tape. The adhesive is cured by heating, and the curing temperature and curing time are heated at 160°C for 45 minutes. By controlling the thermal softening point of the adhesive and adding inorganic fillers, the semi-cured adhesive tape has good hardness and stiffness for easy processing, and less adhesive is extruded during the pressing process. The addition of inorganic fillers can increase the viscosity of the resin, improve the amount of glue extruded during the pressing process, and at the same time increase the stiffness and hardness of the adhesive tape. The adhesive with resins of different softening points and epoxy values ​​is selected. After baking, the semi-cured state has higher strength, which can improve the stiffness and hardness of the adhesive tape. At the same time, the choice of curing agent also affects the stiffness and hardness of the adhesive tape. By selecting suitable resins and curing agents, the adhesive can be completely cured at a lower temperature.

[0041] The features and performances of the present invention are further described in detail below in conjunction with the embodiments.

[0042] Example 1

[0043] The method for preparing the rubber tape for the railway track friction mainboard comprises the following steps:

[0044] S1. Using coupling agent KH560 to treat alkali-free glass cloth to obtain a substrate;

[0045] S2. Heat and stir 0.21 parts of E44 epoxy, 0.09 parts of E20 epoxy and 0.2 parts of toluene at 60°C until evenly mixed and then cool to room temperature.

[0046] S3. Stir and mix 0.115 parts of highly softened 470 thermoplastic phenolic resin, 0.11 parts of 472 thermosetting phenolic resin and 0.05 parts of methanol at room temperature until uniform.

[0047] S4, stirring and mixing S2 and S3 at room temperature to obtain a mixed resin.

[0048] S5. Before gluing, add 0.0005 parts of dicyandiamide, 0.15 parts of magnesium hydroxide, 0.0005 parts of KH560 silane coupling agent, and 0.001 parts of brown red 247 inorganic dye to the mixed resin, and mix them into a glue solution. The molding time at 160° C. is 2'21";

[0049] S6. Use a vertical glue coating machine to apply glue liquid on the substrate, and then bake and cure at 110-155°C to obtain a glued cloth.

[0050] Among them, the temperature settings of the vertical gluing machine are 80±5 for Zone I, 120±5 for Zone II, 155±5 for Zone III, 115±5 for Zone IV, cold wind ≤50, 110±5 for Zone V, 140±5 for Zone VI, 115±5 for Zone VII, and 80±5 for Zone VIII.

[0051] This temperature can make the adhesive reach a semi-cured state and achieve appropriate degree of curing and fluidity.

[0052] After testing, the adhesive content of the adhesive cloth prepared in this embodiment is: 44%;

[0053] Volatile matter: 0.5%;

[0054] Soluble resin content: 88%;

[0055] Fluidity: 14%.

[0056] The performance of the friction main board pressed with rubber tape is as follows: tensile strength 140Mpa, unnotched impact (23℃) 130KJ / ㎡, unnotched impact (-50℃) 60KJ / ㎡.

[0057] Example 2

[0058] S1. treating the alkali-free glass cloth with a coupling agent to obtain a substrate;

[0059] S2. Heat and stir 0.15 parts of E44 epoxy, 0.09 parts of E20, 0.06 parts of E12 epoxy and toluene at 60°C until evenly mixed and then cool to room temperature.

[0060] S3. Stir and mix 0.35 parts of highly softened 470 thermoplastic phenolic resin and 0.05 parts of methanol at room temperature.

[0061] S4, stirring and mixing S2 and S3 at room temperature to obtain a mixed resin.

[0062] S5. Before gluing, add 0.0005 parts of dicyandiamide, 0.2 parts of magnesium hydroxide, 0.0006 parts of KH560 silane coupling agent, and 0.001 parts of brown red 247 inorganic dye to the mixed resin, and mix them into a glue solution. The molding time at 160° C. is 2'01";

[0063] S6. Use a vertical glue coating machine to apply glue liquid on the substrate, and then bake and cure at 80-150° C. for 40 minutes to obtain a glued cloth.

[0064] Among them, the temperature settings of the vertical gluing machine are 80±5 for Zone I, 120±5 for Zone II, 150±5 for Zone III, 115±5 for Zone IV, cold wind ≤50, 110±5 for Zone V, 140±5 for Zone VI, 115±5 for Zone VII, and 80±5 for Zone VIII.

[0065] This temperature can make the adhesive reach a semi-cured state and achieve appropriate degree of curing and fluidity.

[0066] The adhesive content of the adhesive cloth prepared in this embodiment is 43%;

[0067] Volatile matter: 0.3%;

[0068] Soluble resin content: 90%;

[0069] Fluidity: 15%.

[0070] The performance of the friction main board pressed with rubber tape is as follows: tensile strength 141Mpa, unnotched impact (23℃) 132KJ / ㎡, unnotched impact (-50℃) 70KJ / ㎡.

[0071] Example 3

[0072] The method for preparing the rubber tape for the railway track friction mainboard comprises the following steps:

[0073] S1. treating the alkali-free glass cloth with a coupling agent to obtain a substrate;

[0074] S2. Heat and stir 0.27 parts of E44 epoxy, 0.03 parts of E20 epoxy and toluene at 60°C until evenly mixed and then cool to room temperature.

[0075] S3. Stir and mix 0.002 parts of highly softened 470 thermoplastic phenolic resin, 0.23 parts of 472 thermosetting phenolic resin and methanol at room temperature until uniform.

[0076] S4, stirring and mixing S2 and S3 at room temperature to obtain a mixed resin.

[0077] S5. Before gluing, add 0.0004 dicyandiamide, 0.0004 dimethylimidazole, 0.15 parts of magnesium hydroxide, 0.0005 KH560 silane coupling agent, and 0.001 parts of brown red 247 inorganic dye to the mixed resin, which accounts for the weight of the mixed resin, to form a glue solution. The molding time is 1'51" at 160°C;

[0078] S6. Use a vertical glue coating machine to apply glue liquid on the substrate, and then bake and cure at 80-160° C. to obtain a glued cloth.

[0079] Among them, the temperature settings of the vertical gluing machine are 80±5 for Zone I, 120±5 for Zone II, 160±5 for Zone III, 115±5 for Zone IV, cold wind ≤50, 110±5 for Zone V, 140±5 for Zone VI, 115±5 for Zone VII, and 80±5 for Zone VIII.

[0080] This temperature can make the adhesive reach a semi-cured state and achieve appropriate degree of curing and fluidity.

[0081] The adhesive content of the adhesive cloth prepared in this embodiment is 43%;

[0082] Volatile matter: 0.5%;

[0083] Soluble resin content: 85%;

[0084] Fluidity: 13%.

[0085] The performance of the friction main board pressed with rubber tape is as follows: tensile strength 138Mpa, unnotched impact (23℃) 131KJ / ㎡, unnotched impact (-50℃) 68KJ / ㎡.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A rubber tape for railway track friction mainboard, characterized in that: It includes a substrate and a glue solution cured on the substrate; The substrate is alkali-free glass cloth treated with coupling agent; The glue solution includes the following components by weight: 0.25-0.3 parts of epoxy resin, 0.2-0.35 parts of curing agent, 0.0005-0.0008 parts of accelerator, 0.15-0.20 parts of filler, 0.0004-0.0006 parts of coupling agent, 0.001-0.003 parts of inorganic dye, 0.18-0.25 parts of solvent; Phenolic resin is selected as the curing agent.

2. The rubberized tape for railway track friction mainboard according to claim 1, characterized in that: The epoxy resin adopts glycidyl ether bisphenol A type epoxy.

3. The rubberized tape for railway track friction mainboard according to claim 1, characterized in that: The glycidyl ether bisphenol A type epoxy is a mixture of E44 type epoxy resin, E20 type epoxy resin and E12 type epoxy resin.

4. The rubberized tape for railway track friction mainboard according to claim 1, characterized in that: The curing agent is one or a mixture of thermoplastic phenolic resin and thermosetting phenolic resin.

5. The rubberized tape for railway track friction mainboard according to claim 1, characterized in that: The accelerator is selected from one or a mixture of imidazole accelerator and dicyandiamide.

6. The rubberized tape for railway track friction mainboard according to claim 1, characterized in that: The filler comprises magnesium hydroxide; and the inorganic dye is a brown-red inorganic dye.

7. The rubberized tape for railway track friction mainboard according to claim 1, characterized in that: The solvent is toluene, methanol or dimethylformamide.

8. The rubberized tape for railway track friction mainboard according to claim 1, characterized in that: The glue content accounts for 40%-45% of the weight of the upper adhesive tape; The volatile matter content in the adhesive tape is ≤2%, the soluble resin content is ≥85%-95%, and the fluidity is 13%-15%.

9. The rubberized tape for railway track friction mainboard according to claim 1, characterized in that: The coupling agent used is silane coupling agent KH560.

10. The method for preparing the rubberized tape for railway track friction mainboard according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. treating the alkali-free glass cloth with a coupling agent to obtain a substrate; S2, heating the epoxy resin and the solvent at 60-70° C., stirring and mixing, and then cooling to room temperature to obtain liquid A; S3, stirring and mixing the curing agent and the solvent to obtain liquid B; S4, stirring and mixing liquid A and liquid B to obtain a mixed resin; S5. Before gluing, add accelerator, filler, coupling agent and inorganic dye to the mixed resin, mix with solvent to prepare glue solution, and control the molding time of glue solution by adjusting the amount of accelerator. The glue solution is required to be tested by knife method at 160℃, and the molding time is 1'30"~3'30"; S6, applying glue liquid on the substrate, and then curing at 80-160° C. to obtain a glued cloth.