A method for preparing resorcinol formaldehyde resin for enhancing skeleton-rubber adhesion

Abstract

The present invention discloses a method for preparing a resorcinol formaldehyde resin for enhancing the adhesion of skeleton-rubber, comprising the following steps: S1, preparation of a resorcinol mixed solution; S2, preparation of a modified biomass powder; S3, preparation of biomass pyrolysis oil: the modified biomass powder obtained in step S2 is placed in a pyrolysis furnace and pyrolyzed at 650-750°C for 10-15min, and the steam generated by the pyrolysis is condensed to obtain biomass pyrolysis oil; S4, primary mixing; S5, secondary mixing; S6, deep reaction. The present invention optimizes and adjusts the main components inside the resorcinol formaldehyde resin so that, under the premise of maintaining good adhesion, a part of resorcinol and formaldehyde is replaced by low-toxic or non-toxic biomass pyrolysis oil, guaiacol and red mud, which saves costs while reducing pollution, effectively reduces the overflow of formaldehyde, and realizes the low-toxicity production of resorcinol formaldehyde resin.

Description

Technical Field

[0001] The invention relates to the technical field of resorcinol formaldehyde resin preparation, in particular to a method for preparing a resorcinol formaldehyde resin that enhances skeleton-rubber adhesion. Background Art

[0002] Due to its fast curing speed, resorcinol formaldehyde resin is widely used in adhesives, plywood and surface coatings, especially in the field of automobile tires, where it is a common adhesive between rubber and steel wire or polyester cord. There are some disadvantages in using pure resorcinol as an adhesive. Resorcinol is easy to sublimate at high temperatures, resulting in large amounts of smoke and environmental pollution during the production and use of rubber. In addition, resorcinol is easy to precipitate onto the surface of the rubber, affecting the process viscosity of the semi-finished product.

[0003] In rubber products such as tires and conveyor belts, some metal wires are often added quantitatively to improve their strength or wear resistance. In this case, the adhesion between the skeleton and the rubber is also greatly strengthened. If the adhesion between the skeleton and the rubber is too low, the rubber product will be unqualified. Therefore, resorcinol or styrene resorcinol formaldehyde resin is added to the rubber to improve the skeleton-rubber adhesion. However, the environmental friendliness of resorcinol formaldehyde resin has always been a problem criticized by people, and the pollution to the environment is also very high. Summary of the invention

[0004] In view of the above problems, the present invention provides a method for preparing a resorcinol formaldehyde resin for enhancing skeleton-rubber adhesion.

[0005] The technical solution of the present invention is:

[0006] A method for preparing a resorcinol formaldehyde resin for enhancing skeleton-rubber adhesion comprises the following steps:

[0007] S1. Preparation of resorcinol mixed solution: 16-18 parts of resorcinol powder are placed in a container by weight, 14-16 parts of water and 1-2 parts of NaOH powder are added, and the mixture is heated to 60-65° C. and stirred for 10-15 minutes to obtain a resorcinol mixed solution;

[0008] S2. Preparation of modified biomass powder: 10 to 12 parts by weight of corn stalks or cotton stalks are ground and crushed through an 80-100 mesh sieve to obtain biomass powder, and the biomass powder is placed in a container containing 50 to 60 parts of a phenol solution, wherein the mass concentration of the phenol solution is 2%, and the mixture is heated to 50 to 55° C. and stirred for 1.5 to 2 hours. Solid particles are obtained after filtration, and the solid particles are washed with deionized water until the washing liquid is neutral, and the solid particles are dried to obtain modified biomass powder;

[0009] S3, preparation of biomass pyrolysis oil: placing the modified biomass powder obtained in step S2 in a pyrolysis furnace and pyrolyzing it at 650-750° C. for 10-15 min, and condensing the steam generated by the pyrolysis to obtain biomass pyrolysis oil;

[0010] S4, primary mixing: adding 4 to 5 parts by weight of a formaldehyde solution having a mass concentration of 20 to 25% to the resorcinol mixed solution obtained in step S1, and adding the biomass pyrolysis oil obtained in step S3, heating to 35 to 40° C., stirring and mixing for 10 to 15 minutes, and then cooling to 20 to 25° C. to obtain a primary mixed solution;

[0011] S5, secondary mixing: adding 4 to 5 parts by weight of a formaldehyde solution having a mass concentration of 30 to 35% to the primary mixed solution obtained in step S4, and adding 3 to 4 parts by weight of guaiacol, heating to 35 to 40° C. and stirring and mixing for 10 to 15 minutes, then cooling to 20 to 25° C. to obtain a secondary mixed solution;

[0012] S6, deep reaction: add 4 to 5 parts by weight of a formaldehyde solution with a mass concentration of 40 to 45% to the secondary mixed liquid obtained in step S5, and add 1 to 2 parts by weight of red mud, heat to 55 to 60° C. and stir for 2 to 3 hours, then cool to 20 to 25° C. to obtain resorcinol formaldehyde resin.

[0013] Furthermore, the stirring and mixing methods in steps S1 and S2 are both magnetic stirring, the stirring and mixing rotation speed in step S1 is 80-100 rpm, the stirring and mixing rotation speed in step S2 is 150-200 rpm, the heating rate in step S1 is 10-15°C / min, and the heating rate in step S2 is 5-10°C / min.

[0014] Description: By optimizing and adjusting the stirring speed and the heating rate, the resorcinol mixture is mixed more evenly and the particle size of the modified biomass powder is made more uniform.

[0015] Furthermore, in the step S3, the modified biomass powder is first placed in a quartz tube, and then the quartz tube is placed in a pyrolysis furnace, nitrogen is introduced to exhaust oxygen, the microwave power is set to 1.5 kW, the ratio of the material feeding amount to the microwave input power is 0.3 kg / kW each time, and the quartz tube is taken out after every three pyrolysis is completed, and the residual biomass pyrolysis oil attached to the inner wall of the quartz tube is washed with an ethanol solution for three times, and then the ethanol is removed by a rotary evaporator to obtain purified residual biomass pyrolysis oil, which is cooled to room temperature, and the purified residual biomass pyrolysis oil is mixed with the biomass pyrolysis oil obtained by condensing steam as the biomass pyrolysis oil for one mixing in step S4.

[0016] Description: By optimizing and adjusting the preparation method of biomass pyrolysis oil, the extraction rate is higher, the extracted biomass pyrolysis oil is purer, the impurity content is low, and it meets the use requirements of resorcinol formaldehyde resin.

[0017] Furthermore, the red mud in step S5 is produced by Bayer process alumina, and the red mud has a particle size of 0.1-0.25 mm, a specific gravity of 2.7 g, and a moisture content of 10-12%.

[0018] Description: By adding a portion of red mud to the resorcinol formaldehyde resin, the adhesion of the resorcinol formaldehyde resin can be further improved, and at the same time, the red mud as a pollutant is consumed, thereby achieving the purpose of waste utilization.

[0019] Furthermore, the heating rates in steps S4 and S5 are both 5-10° C. / min, and the heating rate in step S6 is 12-15° C. / min.

[0020] Note: The best reaction conditions are achieved by optimizing the heating rates during the primary and secondary mixing and deep reaction processes.

[0021] Furthermore, the stirring and mixing in steps S4 to S6 are all performed by mechanical stirring through a stirring component, the stirring component is arranged inside a stirring cylinder, the stirring cylinder is located above a fixed platform, and a heating box is provided on one side of the fixed platform;

[0022] The stirring assembly comprises a stirring motor located at the top of the stirring drum, a stirring shaft is provided at the output end at the bottom of the stirring motor, the stirring shaft passes through the stirring drum, two accommodating cavities are symmetrically provided at the top of the stirring drum, the outer edges of the accommodating cavities are in contact with the inner wall of the stirring drum, a gap is left between the two accommodating cavities for the stirring shaft to pass through, a plurality of guide holes are provided at the bottom of the accommodating cavities, a baffle plate having the same shape and size as the bottom of the accommodating cavities is fixedly connected by a fixing rod on both sides of the top of the stirring shaft, the baffle plate is located at the bottom of the accommodating cavities and in contact with the bottom of the accommodating cavities, and when the stirring shaft is in the initial position, the two baffle plates are completely in contact with the bottoms of the two accommodating cavities, and a plurality of stirring rod groups are evenly spaced on the stirring shaft below the baffle plate;

[0023] A first feed pipe is provided at each position on the top of the mixing cylinder corresponding to the two accommodating cavities, a second feed pipe is provided at a position below the accommodating cavity on one side of the mixing cylinder, and a feed discharge port is provided at the bottom of one side of the mixing cylinder.

[0024] Description: The introduction of the stirring component can coordinate the addition of materials in the primary and secondary mixing and deep reaction processes to the greatest extent, making the addition of formaldehyde solutions of different concentrations more convenient and quick, improving the preparation efficiency and continuity.

[0025] Furthermore, the stirring speed of the stirring component in steps S4 and S5 is 120-160 rpm, and the stirring speed of the stirring component in step S6 is 200-220 rpm.

[0026] Note: By optimizing the stirring speed, the stirring and feeding process of the stirring component can be made more refined.

[0027] Furthermore, the diameter of the guide hole is 0.5-2 mm.

[0028] Description: The water and formaldehyde solution pre-stored in the two containing chambers are released synchronously by cooperating with the guide hole and the baffle, so as to achieve the purpose of automatically adding the formaldehyde solution of the specified concentration.

[0029] Furthermore, the number of the stirring rod groups is 3 to 5, and each stirring rod group includes 3 to 4 stirring rods.

[0030] Description: The mixed liquid in the mixing cylinder is stirred by the stirring rod group.

[0031] The beneficial effects of the present invention are:

[0032] (1) The method for preparing a resorcinol formaldehyde resin for enhancing skeleton-rubber adhesion of the present invention optimizes and adjusts the main components inside the resorcinol formaldehyde resin so that a portion of the resorcinol and formaldehyde are replaced with low-toxic or non-toxic biomass pyrolysis oil, guaiacol and red mud while maintaining good adhesion, thereby saving costs and reducing pollution, effectively reducing formaldehyde overflow, and realizing low-toxic production of resorcinol formaldehyde resin.

[0033] (2) The method for preparing a resorcinol formaldehyde resin for enhancing skeleton-rubber adhesion of the present invention optimizes and adjusts the preparation method of biomass pyrolysis oil to make its extraction rate higher. The extracted biomass pyrolysis oil is purer and has a lower impurity content, which meets the use requirements of the resorcinol formaldehyde resin.

[0034] (3) The method for preparing a hydroquinone formaldehyde resin with enhanced skeleton-rubber adhesion of the present invention introduces a stirring component that can coordinate the addition of materials during the primary and secondary mixing and deep reaction processes to the greatest extent, making the addition of formaldehyde solutions of different concentrations more convenient and quick, thereby improving the preparation efficiency and continuity; the guide hole and the baffle are coordinated to simultaneously release the water and formaldehyde solution pre-stored in the two containing chambers, effectively reducing the overflow of formaldehyde, thereby achieving the purpose of automatically adding a formaldehyde solution of a specified concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the structure of a stirring assembly and a stirring barrel in a method for preparing a resorcinol formaldehyde resin that enhances skeleton-rubber adhesion of the present invention;

[0036] Figure 2 This is a schematic diagram of the internal structure of a stirring component in a method for preparing a resorcinol formaldehyde resin that enhances skeleton-rubber adhesion of the present invention;

[0037] Figure 3 The present invention is a schematic structural diagram of the bottom of a stirring component when a stirring motor is turned on in a method for preparing a resorcinol formaldehyde resin that enhances skeleton-rubber adhesion.

[0038] Among them, 1-stirring cylinder, 11-accommodating chamber, 12-guiding hole, 13-first feeding pipe, 14-second feeding pipe, 15-discharging port, 2-fixed platform, 3-heating box, 4-stirring motor, 5-stirring shaft, 51-fixed rod, 6-baffle, 7-stirring rod group. DETAILED DESCRIPTION

[0039] Example 1

[0040] A method for preparing a resorcinol formaldehyde resin for enhancing skeleton-rubber adhesion comprises the following steps:

[0041] S1. Preparation of resorcinol mixed solution: 17 parts of resorcinol powder were placed in a container by weight, 15 parts of water and 1.5 parts of NaOH powder were added, the mixture was heated to 63°C and magnetically stirred for 12 min, the stirring speed was 90 rpm, and the heating rate was 12°C / min to obtain a resorcinol mixed solution;

[0042] S2. Preparation of modified biomass powder: 11 parts of corn stalks were taken by weight and ground and crushed through a 90-mesh sieve to obtain biomass powder. The biomass powder was placed in a container containing 55 parts of phenol solution, the mass concentration of the phenol solution was 2%, and the mixture was heated to 52° C. and magnetically stirred for 1.8 h. The stirring speed was 165 rpm and the heating rate was 7° C. / min. Solid particles were obtained after filtration. The solid particles were washed with deionized water until the washing solution was neutral. The solid particles were dried to obtain modified biomass powder.

[0043] S3, preparation of biomass pyrolysis oil: the modified biomass powder obtained in step S2 is placed in a pyrolysis furnace and pyrolyzed at 700°C for 12 minutes. The steam generated by the pyrolysis is condensed to obtain biomass pyrolysis oil. First, the modified biomass powder is placed in a quartz tube, and then the quartz tube is placed in the pyrolysis furnace, nitrogen is introduced to discharge oxygen, the microwave power is set to 1.5kW, and the ratio of the material feeding amount to the microwave input power is 0.3kg / kW each time. After the pyrolysis is completed every three times, the quartz tube is taken out, and the residual biomass pyrolysis oil attached to the inner wall of the quartz tube is washed with an ethanol solution for three times, and the ethanol is removed by a rotary evaporator to obtain purified residual biomass pyrolysis oil, which is cooled to room temperature, and the purified residual biomass pyrolysis oil is mixed with the biomass pyrolysis oil obtained by condensing the steam as the biomass pyrolysis oil for the first mixing in step S4;

[0044] S4, primary mixing: add 4.5 parts by weight of a 23% formaldehyde solution to the resorcinol mixed solution obtained in step S1, and simultaneously add the biomass pyrolysis oil obtained in step S3, heat to 37°C, stir and mix for 12 minutes, heat at a rate of 8°C / min, and then cool to 23°C to obtain a primary mixed solution;

[0045] S5, secondary mixing: add 4.5 parts by weight of a 33% formaldehyde solution to the primary mixed solution obtained in step S4, and add 3.5 parts by weight of guaiacol, heat to 38° C., stir and mix for 12 min, heat at a rate of 8° C. / min, and then cool to 23° C. to obtain a secondary mixed solution;

[0046] S6, deep reaction: add 4.5 parts by weight of formaldehyde solution with a mass concentration of 41% to the secondary mixed liquid obtained in step S5, and at the same time add 1.5 parts by weight of red mud, the red mud is produced by Bayer process alumina, the red mud particle size is 0.2 mm, the specific gravity is 2.7 g, the water content is 11%, heat to 56°C and stir and mix for 2.5h, the heating rate is 13°C / min, and then cool to 23°C to obtain resorcinol formaldehyde resin; the stirring method for stirring and mixing in steps S4 to S6 is mechanical stirring by a conventional commercially available stirring device.

[0047] Example 2

[0048] The difference between this embodiment and embodiment 1 is that the preparation parameters in step S1 are different.

[0049] S1. Preparation of resorcinol mixed solution: 16 parts of resorcinol powder were placed in a container by weight, and 14 parts of water and 1 part of NaOH powder were added. After mixing, the mixture was heated to 60° C. and magnetically stirred for 10 min. The stirring speed was 80 rpm and the heating rate was 10° C. / min to obtain a resorcinol mixed solution.

[0050] Example 3

[0051] The difference between this embodiment and embodiment 1 is that the preparation parameters in step S1 are different.

[0052] S1. Preparation of resorcinol mixed solution: 18 parts of resorcinol powder were placed in a container by weight, 16 parts of water and 2 parts of NaOH powder were added, the mixture was heated to 65°C and magnetically stirred for 15 minutes at a stirring speed of 100 rpm and a heating rate of 15°C / min to obtain a resorcinol mixed solution.

[0053] Example 4

[0054] The difference between this embodiment and embodiment 1 is that the preparation parameters in step S2 are different.

[0055] S2. Preparation of modified biomass powder: 10 to 12 parts of corn stalks are taken by weight, ground and crushed through an 80-100 mesh sieve to obtain biomass powder, and the biomass powder is placed in a container containing 50 to 60 parts of phenol solution, the mass concentration of the phenol solution is 2%, and the mixture is heated to 50 to 55°C and magnetically stirred for 1.5 to 2h. The stirring speed is 150 to 200 rpm, and the heating rate is 5 to 10°C / min. Solid particles are obtained after filtration, and the solid particles are washed with deionized water until the washing liquid is neutral. The solid particles are dried to obtain modified biomass powder.

[0056] Example 5

[0057] The difference between this embodiment and embodiment 1 is that the preparation parameters in step S2 are different.

[0058] S2. Preparation of modified biomass powder: 12 parts of corn stalks were taken by weight, ground and crushed through a 100-mesh sieve to obtain biomass powder, and the biomass powder was placed in a container containing 60 parts of phenol solution, the mass concentration of the phenol solution was 2%, and the mixture was heated to 55°C and magnetically stirred for 2 hours. The stirring speed was 200 rpm, and the heating rate was 10°C / min. Solid particles were obtained after filtration, and the solid particles were washed with deionized water until the washing liquid was neutral. The solid particles were dried to obtain modified biomass powder.

[0059] Example 6

[0060] The difference between this embodiment and embodiment 1 is that the preparation parameters in step S3 are different.

[0061] S3. Preparation of biomass pyrolysis oil: The modified biomass powder obtained in step S2 is placed in a pyrolysis furnace and pyrolyzed at 650° C. for 10 min. The steam generated by the pyrolysis is condensed to obtain biomass pyrolysis oil.

[0062] Example 7

[0063] The difference between this embodiment and embodiment 1 is that the preparation parameters in step S3 are different.

[0064] S3. Preparation of biomass pyrolysis oil: The modified biomass powder obtained in step S2 is placed in a pyrolysis furnace and pyrolyzed at 750° C. for 15 min. The steam generated by the pyrolysis is condensed to obtain biomass pyrolysis oil.

[0065] Example 8

[0066] The difference between this embodiment and embodiment 1 is that the preparation parameters in steps S4 to S6 are different.

[0067] S4, primary mixing: add 4 parts by weight of a 20% formaldehyde solution to the resorcinol mixed solution obtained in step S1, and add the biomass pyrolysis oil obtained in step S3, heat to 35°C, stir and mix for 10 minutes, and heat at a rate of 5°C / min, then cool to 20°C to obtain a primary mixed solution;

[0068] S5, secondary mixing: add 4 parts by weight of a 30% formaldehyde solution to the primary mixed solution obtained in step S4, and add 3 parts by weight of guaiacol, heat to 35° C., stir and mix for 10 min, heat at a rate of 5° C. / min, and then cool to 20° C. to obtain a secondary mixed solution;

[0069] S6, deep reaction: add 4 parts by weight of a 40% formaldehyde solution to the secondary mixed liquid obtained in step S5, and add 1 part by weight of red mud, wherein the red mud is produced by the Bayer process alumina, has a particle size of 0.1 mm, a specific gravity of 2.7 g, and a moisture content of 10%. Heat to 55° C. and stir for 2 h at a heating rate of 12° C. / min, then cool to 20° C. to obtain resorcinol formaldehyde resin.

[0070] Example 9

[0071] The difference between this embodiment and embodiment 1 is that the preparation parameters in steps S4 to S6 are different.

[0072] S4, primary mixing: add 5 parts by weight of a 25% formaldehyde solution to the resorcinol mixed solution obtained in step S1, and simultaneously add the biomass pyrolysis oil obtained in step S3, heat to 40°C, stir and mix for 15 minutes, heat at a rate of 10°C / min, and then cool to 25°C to obtain a primary mixed solution;

[0073] S5, secondary mixing: add 5 parts by weight of a 35% formaldehyde solution to the primary mixed solution obtained in step S4, and simultaneously add 4 parts by weight of guaiacol, heat to 40°C, stir and mix for 15 minutes at a heating rate of 10°C / min, and then cool to 25°C to obtain a secondary mixed solution;

[0074] S6, deep reaction: add 5 parts by weight of a formaldehyde solution with a mass concentration of 45% to the secondary mixed liquid obtained in step S5, and add 2 parts by weight of red mud, wherein the red mud is produced by Bayer process alumina, the red mud particle size is 0.25 mm, the specific gravity is 2.7 g, and the moisture content is 12%. Heat to 60°C and stir for 3 hours at a heating rate of 15°C / min, then cool to 25°C to obtain resorcinol formaldehyde resin.

[0075] Example 10

[0076] This embodiment provides a stirring assembly on the basis of the embodiment 1. The stirring and mixing in steps S4 to S6 are all performed by mechanical stirring through the stirring assembly. The stirring assembly is arranged inside the stirring cylinder 1. The stirring cylinder 1 is located above the fixed platform 2. A heating box 3 is provided on one side of the fixed platform 2.

[0077] The stirring assembly includes a stirring motor 4 located at the top of the stirring drum 1, the stirring motor 4 is a commercially available gear reduction motor, a stirring shaft 5 is provided at the output end at the bottom of the stirring motor 4, the stirring shaft 5 passes through the stirring drum 1, two accommodating chambers 11 are symmetrically provided at the top of the stirring drum 1, the outer edge of the accommodating chamber 11 is in contact with the inner wall of the stirring drum 1, a gap for the stirring shaft 5 to pass through is reserved between the two accommodating chambers 11, a plurality of guide holes 12 are provided at the bottom of the accommodating chamber 11, a baffle 6 of the same shape and size as the bottom of the accommodating chamber 11 is fixedly connected by a fixing rod 51 on both sides of the top of the stirring shaft 5, the baffle 6 is located at the bottom of the accommodating chamber 11 and is in contact with the bottom of the accommodating chamber 11, and when the stirring shaft 5 is in the initial position, the two baffles 6 are completely in contact with the bottoms of the two accommodating chambers 11, and a plurality of stirring rod groups 7 are evenly spaced on the stirring shaft 5 below the baffle 6;

[0078] A first feed pipe 13 is provided at each position of the two accommodating chambers 11 at the top of the mixing cylinder 1, a second feed pipe 14 is provided at a position below the accommodating chamber 11 on one side of the mixing cylinder 1, and a feed outlet 15 is provided at the bottom of one side of the mixing cylinder 1;

[0079] Correspondingly, the stirring speed of the stirring assembly in steps S4 and S5 is 150 rpm, the stirring speed of the stirring assembly in step S6 is 210 rpm, the aperture of the guide hole 12 is 1 mm, the number of stirring rod groups 7 is 4, and each stirring rod group 7 includes 3 stirring rods.

[0080] Embodiment 11

[0081] The difference between this embodiment and embodiment 10 is that:

[0082] The stirring speed of the stirring assembly in steps S4 and S5 is 120 rpm, the stirring speed of the stirring assembly in step S6 is 200 rpm, the aperture of the flow guide hole 12 is 0.5 mm, the number of stirring rod groups 7 is 3, and each stirring rod group 7 includes 3 stirring rods.

[0083] Example 12

[0084] The difference between this embodiment and embodiment 10 is that:

[0085] The stirring speed of the stirring assembly in steps S4 and S5 is 160 rpm, the stirring speed of the stirring assembly in step S6 is 220 rpm, the aperture of the flow guide hole 12 is 2 mm, the number of stirring rod groups 7 is 5, and each stirring rod group 7 includes 4 stirring rods.

[0086] Working principle:

[0087] The working principle of the stirring assembly of the present invention is briefly described below in conjunction with steps S4 to S6 of the present invention.

[0088] Taking Example 1 as an example, before performing step S4, the required amounts of water and formaldehyde solution are first accurately calculated. The formaldehyde solution is the formaldehyde solution with a mass concentration of 41% in step S6. When performing step S4, biomass pyrolysis oil is added through the second feed pipe 14, and the stirring shaft 5 is driven to rotate by turning on the stirring motor 4, so that the two baffles 6 rotate. After the baffles 6 rotate over the bottom of the two accommodating chambers 11, the water and formaldehyde solution inside the baffles flow out to the inside of the stirring cylinder 1 through the guide holes 12, and are stirred and mixed with the biomass pyrolysis oil through the stirring rod group 7. At this time, the guide holes 12 corresponding to the two accommodating chambers 11 are at a preset flow rate. The formaldehyde solution with a mass concentration of 41% flowing out in 12 minutes has a concentration of just 23% after mixing with water, which meets the preparation requirements of step S4;

[0089] When performing step S5, there is no need to stop the stirring motor 4, and guaiacol is added to the second feeding pipe 14. The flow guide holes 12 corresponding to the two receiving chambers 11 flow at a preset flow rate. After the formaldehyde solution with a mass concentration of 41% flows out in 12 minutes and is mixed with the remaining water in the receiving chamber 11 filled with water, the concentration just reaches 33%, which meets the preparation requirements of step S5;

[0090] When performing step S6, the rotation speed of the stirring motor 4 is increased, and red mud is added to the second feeding pipe 14. At this time, no water in the accommodating chamber 11 containing water can flow out through the guide hole 12. Only the guide hole 12 of the other accommodating chamber 11 discharges the remaining formaldehyde solution with a mass concentration of 41%. The required amount is exactly 4.5 parts by weight, thereby achieving the preparation requirement of step S6, and the interior of the stirring cylinder 1 is heated to the specified temperature by the heating box 3.

[0091] Experimental Example 1

[0092] The resorcinol formaldehyde resin prepared by the methods in Example 1 and Examples 8 and 9 was used in the bonding of tire carcass cords, and its adhesive properties were tested and compared with the conventional resorcinol formaldehyde resin in Comparative Example 1. The results are shown in Table 1.

[0093] Table 1 Adhesive properties of the resorcinol formaldehyde resins prepared in Examples 1, 8, 9 and Comparative Example 1

[0094] Case Shear strength MPa Tensile strength MPa Tensile elongation% Example 1 9.6 21.5 392 Example 8 9.4 21.0 391 Example 9 9.3 21.2 394 Comparative Example 1 10.6 19.2 380

[0095] It can be seen from the data in Table 1 that the shear strength of the resorcinol formaldehyde resin prepared by the method of the present invention is slightly lower than that of the conventional resorcinol formaldehyde resin. This is because the addition of biomass pyrolysis oil, guaiacol and red mud has a certain effect on the shear strength of the material, but the overall effect is not significant and still meets the national standard; at the same time, the tensile strength of the resorcinol formaldehyde resin prepared by the method of the present invention is improved compared with the conventional resorcinol formaldehyde resin. This is because the biomass pyrolysis oil and red mud are added in the present invention, thereby improving the adhesion between the skeleton and the rubber; at the same time, the tensile elongation of the resorcinol formaldehyde resin prepared by the method of the present invention is improved compared with the conventional resorcinol formaldehyde resin. This is because the guaiacol and red mud are added in the present invention, thereby improving the tensile elongation of the tire carcass cord. Comprehensively considering the use of the preparation parameters in Example 1 is optimal, and the preparation parameters in Examples 8 and 9 are acceptable.

[0096] Experimental Example 2

[0097] The viscosity and formaldehyde release of the resorcinol formaldehyde resin prepared by the method in Example 10 were tested and compared with Comparative Examples 2 to 4, wherein Comparative Example 2 differs from Example 1 in that: the biomass pyrolysis oil in step S4 is replaced with an equal amount of formaldehyde solution with a mass concentration of 45%;

[0098] The difference between Comparative Example 2 and Example 1 is that the biomass pyrolysis oil in step S4 is replaced by an equal amount of formaldehyde solution with a mass concentration of 45%, and the guaiacol in step S5 is replaced by an equal amount of formaldehyde solution with a mass concentration of 45%;

[0099] Comparative Example 4 is to replace the biomass pyrolysis oil in step S4 with an equal amount of formaldehyde solution with a mass concentration of 45%, replace the guaiacol in step S5 with an equal amount of formaldehyde solution with a mass concentration of 45%, and replace the red mud in step S6 with an equal amount of formaldehyde solution with a mass concentration of 45%; the results are shown in Table 2.

[0100] Table 2 Properties of the resorcinol formaldehyde resin prepared in Example 10 and Comparative Examples 2 to 4

[0101] Case Viscosity mPa / s Formaldehyde emission mg / L Example 10 465 0.27 Comparative Example 2 472 0.32 Comparative Example 3 461 0.51 Comparative Example 4 432 1.06

[0102] It can be seen from the data in Table 2 that the content of resorcinol and formaldehyde is an important factor in determining the performance of the adhesive, and also determines the toxicity of resorcinol formaldehyde resin. After replacing the biomass pyrolysis oil with an equal amount of formaldehyde solution with a mass concentration of 45%, the viscosity increased slightly, and the formaldehyde release also increased; and after further replacing guaiacol and red mud with an equal amount of formaldehyde solution with a mass concentration of 45%, the viscosity not only did not increase but also decreased significantly, and the formaldehyde release also increased a lot. This is because when the amount of formaldehyde is small, the resorcinol reaction is incomplete, and the microscopic network structure of the formed resin is not firm; when the amount of formaldehyde is excessive, the by-product hydroxybenzoic acid will reduce the viscosity of the resin and reduce the tensile properties of the adhesive.

[0103] Therefore, after replacing part of the formaldehyde with biomass pyrolysis oil, guaiacol and red mud, although the viscosity is slightly reduced, the formaldehyde release is significantly reduced, and the effect is better when used together with the device of the present invention.

Claims

1. A method for preparing a resorcinol formaldehyde resin for enhancing skeleton-rubber adhesion, characterized in that: The following steps are involved: S1. Preparation of resorcinol mixed solution: 16-18 parts of resorcinol powder are placed in a container by weight, 14-16 parts of water and 1-2 parts of NaOH powder are added, and the mixture is heated to 60-65° C. and stirred for 10-15 minutes to obtain a resorcinol mixed solution; S2. Preparation of modified biomass powder: 10-12 parts of corn stalks or cotton stalks are taken by weight, ground and crushed through an 80-100 mesh sieve to obtain biomass powder, and the biomass powder is placed in a container containing 50-60 parts of phenol solution, the mass concentration of the phenol solution is 2%, and the mixture is heated to 50-55° C. and stirred for 1.5-2 hours, and solid particles are obtained after filtration, and the solid particles are washed with deionized water until the washing liquid is neutral, and the solid particles are dried to obtain modified biomass powder; The stirring and mixing methods in steps S1 and S2 are both magnetic stirring, the stirring and mixing speed in step S1 is 80-100 rpm, the stirring and mixing speed in step S2 is 150-200 rpm, the heating rate in step S1 is 10-15°C / min, and the heating rate in step S2 is 5-10°C / min; S3, preparation of biomass pyrolysis oil: placing the modified biomass powder obtained in step S2 in a pyrolysis furnace at 650-750° C. for 10-15 min, and condensing the steam generated by the pyrolysis to obtain biomass pyrolysis oil; In the step S3, the modified biomass powder is first placed in a quartz tube, and then the quartz tube is placed in a pyrolysis furnace, nitrogen is introduced to exhaust oxygen, the microwave power is set to 1.5 kW, and the ratio of the material feeding amount to the microwave input power is 0.3 kg / kW each time. After the pyrolysis is completed every three times, the quartz tube is taken out, and the residual biomass pyrolysis oil attached to the inner wall of the quartz tube is washed with an ethanol solution for three times, and the ethanol is removed by a rotary evaporator to obtain a purified residual biomass pyrolysis oil, which is cooled to room temperature, and the purified residual biomass pyrolysis oil is mixed with the biomass pyrolysis oil obtained by condensing steam as the biomass pyrolysis oil for the first mixing in step S4; S4, primary mixing: add 4-5 parts by weight of a formaldehyde solution having a mass concentration of 20-25% to the resorcinol mixed solution obtained in step S1, and simultaneously add the biomass pyrolysis oil obtained in step S3, heat to 35-40° C., stir and mix for 10-15 minutes, and then cool to 20-25° C. to obtain a primary mixed solution; S5, secondary mixing: add 4-5 parts by weight of a formaldehyde solution having a mass concentration of 30-35% to the primary mixed solution obtained in step S4, and simultaneously add 3-4 parts by weight of guaiacol, heat to 35-40° C., stir and mix for 10-15 min, and then cool to 20-25° C. to obtain a secondary mixed solution; S6, deep reaction: add 4-5 parts by weight of a formaldehyde solution with a mass concentration of 40-45% to the secondary mixed solution obtained in step S5, and add 1-2 parts by weight of red mud, heat to 55-60° C., stir and mix for 2-3 hours, and then cool to 20-25° C. to obtain resorcinol formaldehyde resin; The heating rates in steps S4 and S5 are both 5-10°C / min, and the heating rate in step S6 is 12-15°C / min; The stirring speed of the stirring assembly in steps S4 and S5 is 120-160 rpm, and the stirring speed of the stirring assembly in step S6 is 200-220 rpm; The stirring and mixing in steps S4 to S6 is performed by mechanical stirring through a stirring component, wherein the stirring component is arranged inside a stirring cylinder (1), the stirring cylinder (1) is located above a fixed platform (2), and a heating box (3) is provided on one side of the fixed platform (2); The stirring assembly comprises a stirring motor (4) located at the top of the stirring drum (1); a stirring shaft (5) is provided at the output end at the bottom of the stirring motor (4); the stirring shaft (5) penetrates the stirring drum (1); two accommodating chambers (11) are symmetrically provided at the top of the stirring drum (1); the outer edges of the accommodating chambers (11) are in contact with the inner wall of the stirring drum (1); a gap for the stirring shaft (5) to pass through is left between the two accommodating chambers (11); a plurality of guide holes (12) are provided at the bottom of the accommodating chamber (11); a baffle (6) having the same shape and size as the bottom of the accommodating chamber (11) is provided on both sides of the top of the stirring shaft (5) and is fixedly connected by a fixing rod (51); the baffle (6) is located at the bottom of the accommodating chamber (11) and is in contact with the bottom of the accommodating chamber (11); and when the stirring shaft (5) is located at the initial position, the two baffles (6) are completely in contact with the bottoms of the two accommodating chambers (11); and a plurality of stirring rod groups (7) are provided at equal intervals on the stirring shaft (5) located below the baffle (6); A first feed pipe (13) is provided at each position on the top of the mixing drum (1) corresponding to the two accommodating chambers (11), a second feed pipe (14) is provided at a position below the accommodating chambers (11) on one side of the mixing drum (1), and a discharge port (15) is provided at the bottom of one side of the mixing drum (1).

2. The method for preparing a resorcinol formaldehyde resin for enhancing skeleton-rubber adhesion according to claim 1, characterized in that: The red mud in step S5 is produced by the Bayer process of alumina production, and has a particle size of 0.1-0.25 mm, a specific gravity of 2.7 g, and a moisture content of 10-12%.

3. The method for preparing a resorcinol formaldehyde resin for enhancing skeleton-rubber adhesion according to claim 1, characterized in that: The diameter of the guide hole (12) is 0.5-2 mm.

4. The method for preparing a resorcinol formaldehyde resin for enhancing skeleton-rubber adhesion according to claim 1, characterized in that: The number of stirring rod groups (7) is 3 to 5, and each stirring rod group (7) includes 3 to 4 stirring rods.

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