A phenol formaldehyde resin binder for a slip sheet and a method for preparing the same

Abstract

The present application provides a kind of phenolic resin binder for skateboard brick, including the following mass parts of raw materials: 350-450 parts of phenol, 150-250 parts of p-cresol, 800-1000 parts of aqueous formaldehyde solution, 250-350 parts of triphenol derivative, 20-30 parts of sodium hydroxide, 100-140 parts of epoxide, 10-20 parts of acid, 50-70 parts of urea, 50-80 parts of methyl glycolate, 10-30 parts of methanol.The phenolic resin binder of the present application adds triphenol derivative and epoxide, especially the compounded triphenol derivative, 2,2'-[oxybis (2,1-ethyleneoxy methylene)] bisoxirane can improve the bonding performance of resin, improve the compressive strength and flexural strength of phenolic resin cured product;Add the mixture of glacial acetic acid and boric acid, which can improve the oxidation resistance and heat resistance of resin;Increase the use frequency of skateboard brick.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of phenolic resin resin adhesives for refractory materials, in particular to a phenolic resin binder for slide plate bricks and a preparation method thereof. BACKGROUND

[0002] Slide plate bricks are functional refractory materials for continuous casting, and are widely used in the slide nozzle systems of ladles and tundish for electric furnaces, converter furnaces, and secondary refining. The slide nozzle is a mechanism for controlling the flow of steel by the relative misalignment of two perforated refractory bricks connected and assembled together by a sliding mechanism installed at the bottom of the ladle. The upper nozzle and the upper slide plate are fixed in the mechanism, and the lower slide plate and the lower nozzle are installed in the drag plate and can move left and right. When the inner holes of the upper and lower slide plates coincide, the nozzle opening is maximum, and when they do not coincide, the nozzle is closed. The slide nozzle moves left and right with the help of a hydraulic cylinder, and the lower slide plate is pressed against the upper slide plate with a spring, so that no gap is generated between the slide plates during movement, preventing the occurrence of leakage phenomenon of the slide plates.

[0003] At present, steel plants are in a state of slight profit or loss, and hope to reduce the manufacturing cost per ton of steel. For refractory material manufacturers, the manufacturing cost per ton of steel in the existing manufacturing environment is composed of two parts: 1. The ladle can contain more steel, and the more steel the ladle contains, the lower the cost per ton of steel; 2. The maintenance cost of the ladle, the less the ladle is used, the higher the maintenance cost per ton of steel, and the maintenance takes a long time, resulting in low production efficiency of the steel plant.

[0004] For refractory material manufacturers, the only way to reduce the manufacturing cost per ton of steel is to increase the number of uses of the ladle and reduce the maintenance cost of the ladle. The structure and use of the entire ladle brick are analyzed, among which the service life of the ladle with magnesia-carbon bricks is 20-22 times, the service life of the ladle with converter magnesia-carbon bricks is 15-18 times, and the service life of the slide plate brick is only 2-4 times.

[0005] During the use of the slide plate brick, it is analyzed that the slide plate is located at the nozzle of the ladle, and the steel flows from the slide plate to the steel channel, which causes a large amount of long-time scouring of the slide plate. The slide plate needs to withstand the chemical corrosion and physical scouring of high-temperature steel for a long period of time, and is subjected to intense and transient thermal shock and mechanical wear, which has extremely harsh use conditions, resulting in that the service life cannot be improved.

[0006] The inventor communicates with refractory manufacturers and steel mills, and finds that the service life of the slide plate is mainly composed of brick peeling, cracking, hole melting loss and other factors. Among the statistical probability of slide plate brick problems, peeling accounts for 70%, cracking accounts for 20%, and hole melting loss accounts for 10%. Peeling is the peeling of the brick surface caused by low density and low strength of the brick body. Cracking is caused by the fact that the internal stress of the brick is larger than the bonding performance of the resin, which causes the resin to fail to bond the brick product, resulting in brick cracking. Hole melting loss is the slag resistance of the brick product, which requires the brick to have high heat resistance. Therefore, the slide plate must have high strength, wear resistance, slag erosion resistance and good thermal shock stability to improve the service life of the slide plate brick.

[0007] CN117303924A discloses a high-life slide plate brick and a preparation method thereof, which comprises the following components by mass fraction: corundum 70-90 parts, epoxy compound modified metal powder 10-30 parts, carbon-containing additive 1-5 parts, boron-containing additive 2-5 parts, and phenolic resin 5-8 parts. CN111410519A discloses an Al2O3-C slide plate brick, the raw material composition of the slide plate brick is 68-90% corundum, 3-15% active alumina powder, 5-15% aluminum titanate, 0.5-1% boron carbide, 0-1% flaky graphite, and 0-1% carbon black, plus 3-5% of the total amount of the above raw materials thermosetting phenolic resin as a binder. CN105801145A discloses an organic silicon modified phenolic resin combined with non-burning impregnation-free environmentally friendly slide plate brick, which uses 4-6% of organic silicon modified phenolic resin as a binder.

[0008] Because of the strong smell of asphalt, this is an important reason why the use of asphalt in many refractories has been canceled. Currently, manufacturers have begun to use phenolic resin as a binder to replace asphalt for producing slide plates. The high-temperature strength of the slide plate bonded with phenolic resin is higher than that of asphalt. The service life of the slide plate bonded with asphalt is 2-3 times on average, while the service life of the slide plate bonded with phenolic resin is 3-4 times. Currently, the service life of the slide plate using phenolic resin as a binder on the market has increased, but it still cannot meet the use demand. It is necessary to modify the phenolic resin to improve the service life of the slide plate brick.

[0009] The prior art uses phenolic resin as the slide plate brick binder, but there are still some problems: the slide plate brick produced by the prior art phenolic resin has a low use frequency in the steel plant, resulting in that the steel plant spends a lot of time and money to replace the slide plate, increases the operation cost of the steel plant, the steel plant needs to reduce the operation cost to reduce the price of the ton of molten iron ladle manufactured by the refractory manufacturer, so that the refractory manufacturer has lower profits when using more bricks in the ladle, and the resin manufacturer increases the price of the resin with high use frequency. The phenolic resin produced by the patent is used on the slide plate, improves the strength, wear resistance and heat resistance of the slide plate brick, thereby increasing the use frequency of the slide plate brick, reducing the production quantity of the slide plate brick of the refractory manufacturer, reducing the operation cost of the steel plant, and improving the profits of the steel plant and the refractory manufacturer. SUMMARY

[0010] In order to solve the problem that the phenolic resin for slide plate bricks in the prior art cannot meet the actual demand, especially the use frequency of the conventional phenolic resin slide plate in the steel plant is not high, the application provides a phenolic resin binder for slide plate bricks and a preparation method thereof. The phenolic resin produced by the application is used on the slide plate, improves the strength, wear resistance and heat resistance of the slide plate brick, thereby increasing the use frequency of the slide plate brick, reducing the production quantity of the slide plate brick of the refractory manufacturer, reducing the operation cost of the steel plant, and improving the profits of the steel plant and the refractory manufacturer.

[0011] The first object of the application is to provide a phenolic resin binder for slide plate bricks, which comprises the following raw materials by mass: 350-450 parts of phenol, 150-250 parts of p-cresol, 800-1000 parts of formaldehyde aqueous solution, 250-350 parts of triphenol derivative, 20-30 parts of sodium hydroxide, 100-140 parts of epoxide, 10-20 parts of acid, 50-70 parts of urea, 50-80 parts of methyl glycolate, and 10-30 parts of methanol.

[0012] The inventor communicates with the refractory manufacturer and the steel plant, finds that the use frequency of the slide plate is mainly composed of peeling, cracking and hole melting loss of the brick, among which the peeling accounts for 70%, the cracking accounts for 20%, and the hole melting loss accounts for 10% in the statistical probability of the problems of the slide plate brick. The peeling is the peeling of the surface of the brick caused by low density and low strength of the brick body, the cracking is caused by the fact that the internal stress of the brick is larger than the bonding property of the resin, so that the resin cannot bond the brick product, resulting in cracking of the brick, and the hole melting loss is the slag resistance of the brick product, which requires that the brick has high heat resistance.

[0013] The phenolic resin is shrunk in volume when it is cured, and the internal stress is the shrinkage stress, the main reason is that the intermolecular distance between monomers is shortened to the covalent distance, which causes the product to shrink in volume and increase the internal stress of the product. The volume shrinkage rate of the product is not fundamentally solved by the physical modification method of adding high molecular toughening agent and inorganic powdery filler to modify the phenolic resin. The volume density of the product is not increased under high temperature conditions, the strength of the product is not high, and the use frequency of the product is small. Only by chemically modifying the phenolic resin, adjusting the curing process of the resin and other methods to reduce the volume shrinkage rate, increase the volume density of the product and improve the use strength of the product, can the use frequency of the slide plate brick be ultimately improved. The resin is chemically modified by adding a triphenol derivative and an acid during the resin reaction stage, so as to ultimately improve the use frequency of the product.

[0014] The triphenol derivative includes one or more of m-phloroglucinol, o-phloroglucinol, magnolia triphenol, and 3,4,5-trihydroxybenzoic acid. Preferably, the triphenol derivative is a mixture of at least one of m-phloroglucinol, o-phloroglucinol, and magnolia triphenol and 3,4,5-trihydroxybenzoic acid in a mass ratio of 3-5:1. The reaction speed of m-phloroglucinol and o-phloroglucinol is faster than that of phenol, and the reaction with the phenolic resin forms a larger system chain group, increases the resin bonding capacity, and reacts with the epoxy group of the epoxide in the subsequent reaction to lengthen the chain segment of the phenolic resin, improve the bonding performance of the resin, and form a large network type of cured resin in the curing process, so that the inorganic particles are wrapped more tightly by the resin, and the bulk density of the brick is improved. 3,4,5-trihydroxybenzoic acid has three phenolic hydroxyl groups and a carboxyl group available for reaction, and can significantly improve the comprehensive performance of the phenolic resin binder when compounded with m-phloroglucinol and / or o-phloroglucinol.

[0015] The epoxide is one or more of 2,2'-[oxybis(2,1-ethylenyloxy methylene)] bisoxirane, epoxypropanol, and epoxypropylene aldehyde glycol.

[0016] The addition of the epoxide to the phenolic resin binder of the present application can lengthen the chain segment of the phenolic resin through ring-opening etherification reaction between the epoxy epoxide and the phenolic hydroxyl group of the phenolic resin, cross-link into a complex body type structure, improve the pressure resistance and bending strength of the product after the phenolic resin is cured, reduce the volume shrinkage of the resin and the product during curing, reduce the internal stress of the brick, increase the bonding performance of the brick, reduce the cracking of the product, and improve the use frequency of the slide plate.

[0017] The formaldehyde aqueous solution is a 30-40wt% formaldehyde aqueous solution.

[0018] The acid is a mixture of glacial acetic acid and boric acid in a mass ratio of 15-25:10-16.

[0019] The boric acid is mixed with the phenolic resin, and can be alkylated with the phenolic hydroxyl group in the resin at high temperature to form B-O bond, and the B-O bond has higher bond energy than C-C and C-O bonds, so that the heat resistance of the resin after curing can be improved. Through experiments, the inventor found that the heat resistance of the resin cannot be improved when the boric acid is added to a certain amount. The inventor unexpectedly found that the use of boric acid can make up for the deficiency of glacial acetic acid. If a strong acid such as hydrochloric acid is directly used, the curing process is too fast, and the small molecules generated during curing cannot be discharged in time, causing the brick to crack. The use of acetic acid alone cannot improve the heat resistance of the resin after curing, and the use of boric acid alone cannot reduce the pH value of the resin from 14 to 7.0-8.5, which cannot meet the use requirements of the resin. Under the condition of ensuring the performance of the product, further selection of glacial acetic acid and boric acid according to the mass ratio of 20-25:10-14 is carried out.

[0020] According to the above-mentioned triphenol derivative, a small amount of epoxide is used, and the above-mentioned compounded acid is used, and finally the prepared phenolic resin has high heat resistance, high bonding performance, high bulk density, high strength, and excellent comprehensive performance.

[0021] The phenolic resin binder for the skateboard brick provided by the application has a viscosity of 9000-12000 mPa·s / 25℃.

[0022] The application further provides a preparation method of the modified phenolic resin binder for the skateboard brick, which comprises the following preparation steps:

[0023] phenol, p-cresol, formaldehyde and sodium hydroxide are added, and the temperature is raised to 55-60 DEG C and kept for 1-2 hours, then the triphenol derivative is added, and the temperature is raised to 88-92 DEG C and kept for 1-2 hours, then the epoxide is added, and the temperature is raised to 95-100 DEG C and kept for 1-2 hours, then the acid is added for neutralization, and then the negative pressure dehydration is started and the temperature is raised to 70-75 DEG C until the moisture content is qualified, then the methyl glycolate is added, and finally the methanol is used to adjust the viscosity to the preset value, so that the modified phenolic resin for the skateboard brick is obtained.

[0024] The boiling point of the selected methyl glycolate is above 150 DEG C, and through experiments on the product, it is found that the methyl glycolate can replace the conventional glycerol or ethylene glycol to keep the product moist, and the product is not prone to dry during the production process.

[0025] The amount of the added methanol is such that the preset viscosity of the modified phenolic resin binder is 9000-12000 mPa·s / 25℃. Since the boiling point of the methanol is low, the methanol is added into the kettle through a methanol high tank, and the temperature is selected to be 50-60 DEG C during the viscosity adjustment. If the temperature is too high, the alcohol volatilization is too large, resulting in large methanol reflux and high safety risk. If the temperature is too low, the viscosity is too large when the methanol is added due to the temperature drop, the stirring load is very large, and the stirring stop affects the resin production.

[0026] The application also provides a sliding plate brick characterized in that the modified phenolic resin is used as the binder for the sliding plate brick.

[0027] Preferably, the sliding plate brick comprises the following mass parts of raw materials: 3-5 parts of the phenolic resin binder for the sliding plate brick, 20-30 parts of 1-2 mm tabular corundum, 10-18 parts of 0.5-1 mm tabular corundum, 10-20 parts of 0.1-0.5 mm white corundum, 8-14 parts of 1-2.5 mm zircon corundum, 7-15 parts of 0.1-0.2 mm zircon corundum, 9-16 parts of 325 mesh corundum, 6-10 parts of 600-800 mesh corundum powder, 12-20 parts of carbon black, 20-30 parts of flaky graphite, 2-6 parts of 625 mesh silicon powder, and 2-6 parts of 600-800 mesh aluminum powder.

[0028] The modified phenolic resin for the sliding plate brick of the application has at least the following technical effects:

[0029] First, the phenolic resin binder of the application is added with triphenol derivatives and epoxides, in particular, compounded triphenol derivatives, 2,2'-[oxybis(2,1-ethyleneoxy methylene)] bisoxirane, which can improve the bonding performance of the resin, increase the bulk density of the sliding plate brick, and improve the compressive and bending strength of the product after curing of the phenolic resin.

[0030] Second, the addition of a mixture of glacial acetic acid and boric acid can improve the oxidation resistance and heat resistance of the resin; the high bulk density, high compressive and bending strength of the sliding plate brick can improve the number of uses of the sliding plate brick, reduce the production quantity of the sliding plate brick by the refractory material manufacturer, reduce the operation cost of the steel plant, and improve the profits of the steel plant and the refractory material manufacturer. DETAILED DESCRIPTION

[0031] The content of the application is further explained and described below with specific examples. The reagents used in the examples of the application are all commercially available conventional reagents.

[0032] Example 1

[0033] In a reaction kettle equipped with a stirrer, a thermometer, a vacuum gauge and a temperature rising and falling device, 400 g of phenol, 200 g of p-cresol and 900 g of 37.5% formaldehyde aqueous solution were added, and then 25 g of flaky sodium hydroxide was added after the stirrer was started. The temperature was raised to 55-60°C and kept for 1-2 h. Then 300 g of triphenol derivative (the mass ratio of phloroglucinol: 3,4,5-trihydroxybenzoic acid = 3:1) was added, and the temperature was raised to 88-92°C and kept for 1-2 h. Then 120 g of 2,2'-[oxybis(2,1-ethylenyloxy methylene)] bisoxirane was added, and the temperature was raised to 95-100°C and kept for 1-2 h. Then 14 g of acid (the mass ratio of glacial acetic acid: boric acid = 20:14) was added for neutralization. After the temperature was lowered to 60°C, 60 g of urea was added, and then the water was removed under negative pressure until the water content reached 70-75°C. Then 60 g of methyl glycolate was added, and finally the viscosity was adjusted to the preset value with methanol to obtain the modified phenolic resin for slide plates, which had a viscosity of 10000 mPa·s / 25°C, a solid content of 87.98% and a water content of 0.08%.

[0034] Example 2

[0035] The other conditions and operations were the same as in Example 1, except that 300 g of triphenol derivative was orthophenol: 3,4,5-trihydroxybenzoic acid with a mass ratio of 5:1.

[0036] Example 3

[0037] The other conditions and operations were the same as in Example 1, except that 300 g of triphenol derivative was all phloroglucinol.

[0038] Example 4

[0039] The other conditions and operations were the same as in Example 1, except that the amount of triphenol derivative was 350 g.

[0040] Example 5

[0041] The other conditions and operations were the same as in Example 1, except that the amount of triphenol derivative was 250 g.

[0042] Example 6

[0043] The other conditions and operations were the same as in Example 1, except that 120 g of epoxide was epoxypropylene glycol.

[0044] Example 7

[0045] The other conditions and operations were the same as in Example 1, except that 16 g of acid was a mixture of glacial acetic acid: boric acid with a mass ratio of 25:10.

[0046] Example 8

[0047] Other conditions and operations are the same as in Example 1, except that 14 g of acid is all glacial acetic acid.

[0048] Comparative Example 1

[0049] Other conditions and operations are the same as in Example 1, except that the amount of phenol is 650 g, and no triphenol derivative is added.

[0050] Comparative Example 2

[0051] Other conditions and operations are the same as in Example 1, except that no epoxide is added.

[0052] Comparative Example 3

[0053] The binder used in a certain brand of skateboard brick on the market.

[0054] Application Example

[0055] The raw materials of the skateboard brick are mixed with the above examples and comparative examples to obtain the raw material ratio. The raw material ratio of the skateboard brick is shown in Table 1 in mass parts.

[0056] Table 1

[0057] Raw materials Mass parts (parts) 1-2 mm tabular alumina 24 0.5-1 mm tabular alumina 12 0.1-0.5 mm white alumina 14 1-2.5 mm zirconia alumina 10 0.1-0.2 mm zirconia alumina 10 325 mesh alumina 12 625 mesh alumina micropowder 8 Carbon black 15 Flaky graphite 25 625 mesh silicon powder 3 625 mesh aluminum powder 3 Resin binder 3.8

[0058] The binder obtained from the examples and comparative examples is added to the coarse and medium particles of corundum in the automatic feeding system of the high-speed stirring and mixing wet mill, and then the binder is added, mixed for 2 minutes, and then the fine powder and graphite are added, and the mixing time is 50 minutes. After mixing, the material needs to be placed for 24 hours at a constant temperature before pressing. Pressing and molding are performed on a 1800T hydraulic machine, and the bulk density of the molded product is 3.23-3.26 g / cm 3 After molding, the bricks are stacked and need to be stacked in single stacks, which is beneficial for drying and impregnation. After molding, the bricks are baked in a tunnel kiln at a baking temperature of 1400°C for 8-10 hours. The baked skateboard bricks need to be treated with oil and then baked again in an oven at 180°C for 3-4 hours. After taking them out, the surface is polished, and after passing the test, they are packaged and boxed. The skateboard before assembly is tested for performance.

[0059] The results are shown in Table 2 below.

[0060] Mechanical strength : The mechanical strength is detected according to the test methods for high-temperature compressive strength of refractory materials GB / T 34218-2017 and the test method for high-temperature bending strength of refractory materials GB / T 3002-2017.

[0061] Oxidation resistance : The oxidation resistance is represented by the temperature corresponding to the oxidation exothermic peak in the differential scanning calorimetry curve.

[0062] Number of uses : Each time when the molten steel in the converter flow, the slide plate cooling can be manually inspected, found that the slide plate surface peeling, cracking, hole melting loss, the need to replace the slide plate, the slide plate from the use to replace the converter molten steel times is the use of the number of slide plate bricks.

[0063] Table 2

[0064]

[0065] Through the data in table 2, the phenolic resin binder prepared by the application can obviously improve the comprehensive performance of the slide plate brick, and obvious effects are achieved in high-temperature folding strength, bulk density, oxidation resistance and use frequency.

Claims

1. A phenolic resin binder for skateboard bricks, characterized in that, The raw materials include the following components by mass: 350-450 parts of phenol, 150-250 parts of p-cresol, 800-1000 parts of an aqueous formaldehyde solution, 250-350 parts of a triphenol derivative, 20-30 parts of sodium hydroxide, 100-140 parts of an epoxide, 10-20 parts of an acid, 50-70 parts of urea, 50-80 parts of methyl glycolate, and 10-30 parts of methanol; the triphenol derivative is a mixture of at least one of m-phloroglucinol, o-phloroglucinol, magnolia triphenol, and 3,4,5-trihydroxybenzoic acid in a mass ratio of 3-5:1; the acid is a mixture of glacial acetic acid and boric acid in a mass ratio of 15-25:10-16; The preparation method of the modified phenolic resin binder for the skateboard brick comprises the following preparation steps: phenol, p-cresol, formaldehyde, and sodium hydroxide are added, and the temperature is raised to 55-60 DEG C for reaction for 1-2 h; the triphenol derivative is added, and the temperature is raised to 88-92 DEG C for reaction for 1-2 h; the epoxide is added, and the temperature is raised to 95-100 DEG C for reaction for 1-2 h; the acid is added for neutralization; after cooling to 60 DEG C, the urea is added; negative pressure dewatering is started until the temperature reaches 70-75 DEG C; the methyl glycolate is added; finally, the methanol is added to adjust the viscosity to the preset value, and the modified phenolic resin for the skateboard brick is obtained.

2. The phenol-aldehyde resin binder for a slip sheet according to claim 1, characterized by The viscosity of the phenolic resin binder for the skateboard brick is 9000-12000 mPa s / 25 DEG C.

3. The phenol-aldehyde resin binder for a sliding board brick according to claim 1, characterized by, The aqueous formaldehyde solution is an aqueous formaldehyde solution with a concentration of 30-40 wt%.

4. The method of making a modified phenol formaldehyde resin binder for a waferboard according to any one of claims 1 to 3, characterized in that, The preparation method comprises the following steps: phenol, p-cresol, formaldehyde, and sodium hydroxide are added, and the temperature is raised to 55-60 DEG C for reaction for 1-2 h; the triphenol derivative is added, and the temperature is raised to 88-92 DEG C for reaction for 1-2 h; the epoxide is added, and the temperature is raised to 95-100 DEG C for reaction for 1-2 h; the acid is added for neutralization; after cooling to 60 DEG C, the urea is added; negative pressure dewatering is started until the temperature reaches 70-75 DEG C; the methyl glycolate is added; finally, the methanol is added to adjust the viscosity to the preset value, and the modified phenolic resin for the skateboard brick is obtained.

5. A slipform brick characterized by, The modified phenolic resin for the skateboard brick according to any one of claims 1-3 is used as the binder.

6. The slipform according to claim 5, wherein, The raw materials include the following components by mass: 3-5 parts of the phenolic resin binder for the skateboard brick, 20-30 parts of 1-2 mm tabular corundum, 10-18 parts of 0.5-1 mm tabular corundum, 10-20 parts of 0.1-0.5 mm white corundum, 8-14 parts of 1-2.5 mm zircon corundum, 7-15 parts of 0.1-0.2 mm zircon corundum, 9-16 parts of 325 mesh corundum, 6-10 parts of 600-800 mesh corundum powder, 12-20 parts of carbon black, 20-30 parts of flaky graphite, 2-6 parts of 625 mesh silicon powder, and 2-6 parts of 600-800 mesh aluminum powder.

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