Binder for preventing veining in castings, preparation method and use method thereof

Abstract

The invention belongs to the technical field of casting auxiliary materials and relates to a casting binder capable of preventing veining of castings. The binder comprises a modified phenyl ether type phenolic resin solution system and a polyisocyanate solution system. The modified phenyl ether type phenolic resin solution system comprises, by mass percentage, 35%-55% of phenyl ether type phenolic resin, 3%-10% of amide compound, 5%-15% of ethyl silicate, 12%-24% of dibasic ester, 18%-38% of high boiling point aromatic hydrocarbon solvent, 0.1%-2% of reinforcing agent, and 0.1%-1% of anti-wetting agent; and the polyisocyanate solution system comprises, by mass percentage, 70%-85% of polyisocyanate, 9%-20% of high boiling point aromatic hydrocarbon solvent, and 5%-12% of ethyl silicate. The binder can significantly improve the residual strength, improve the high-temperature performance of molding sand, and prevent the occurrence of veining in castings due to cracks in the molding sand after casting.

Description

Technical Field

[0001] The invention belongs to the technical field of casting auxiliary materials, and more particularly relates to a casting binder capable of preventing veining of castings. Background Art

[0002] Triethylamine cold-box core making offers advantages such as high resin sand strength, smooth casting surface finish, high dimensional accuracy, high core-making efficiency, and relatively low production costs. Currently, it has become the most commonly used core-making process in the foundry industry, and is particularly competitive in mass-produced automotive and internal combustion engine castings. The current share of cold-box resin used in China is increasing annually, indicating strong growth potential in future market demand. However, existing binders suffer from poor high-temperature performance, which can lead to cracks in sand cores after casting and veining defects in castings. Veining defects require subsequent treatments such as grinding, which severely impacts casting production efficiency. Typically, to prevent veining defects in castings, anti-veining additives are added to the sand during sand mixing. However, the addition of anti-veining additives not only increases production costs but also reduces sand strength, necessitating an increase in the amount of resin added, further increasing production costs. Summary of the Invention

[0003] Based on this, the purpose of the present invention is to overcome the veining defects that occur in the casting production process in the prior art, and to provide a binder for preventing veining in castings. By directly improving the phenolic resin structure and the combination of resin components, the high-temperature residual strength of the molding sand is increased, and the veining of the casting caused by cracks in the molding sand after casting is prevented. The problem of veining defects in castings is effectively solved with a simple method and low cost.

[0004] One of the objects of the present invention is to provide a binder for preventing veining in castings.

[0005] A second object of the present invention is to provide a method for preparing a binder for preventing veining in castings.

[0006] A third object of the present invention is to provide a method for using a binder for preventing veining in castings.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A binder for preventing veining in castings, characterized by comprising a modified phenyl ether phenolic resin solution system and a polyisocyanate solution system; wherein the modified phenyl ether phenolic resin solution system comprises, by mass percentage, 35%-55% of phenyl ether phenolic resin, 3%-10% of amide compound, 5%-15% of ethyl silicate, 12%-24% of dibasic ester, 18%-38% of high-boiling point aromatic hydrocarbon solvent, 0.1%-2% of reinforcing agent, and 0.1%-1% of anti-moisture agent; and the polyisocyanate solution system comprises, by mass percentage, 70%-85% of polyisocyanate, 9%-20% of high-boiling point aromatic hydrocarbon solvent, and 5%-12% of ethyl silicate.

[0009] Furthermore, the phenyl ether phenolic resin is synthesized by using phenol and paraformaldehyde in a molar ratio of 1:(0.65-0.85) under the catalysis of a divalent metal salt; the molecular weight of the phenyl ether phenolic resin is 800-2000.

[0010] Furthermore, the amide compounds may be low molecular weight amides and long chain fatty acid amides, including one or a combination of N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylpropionamide, N-ethyl-p-toluenesulfonamide, 2-amino-5-methylbenzamide, 2-phenylacetamide, N-methylsuccinimide, stearic acid amide, erucic acid amide, and fatty amides. Preferably, one or a combination of N,N-dimethylformamide, N,N-dimethylacetamide, N-ethyl-p-toluenesulfonamide, 2-phenylacetamide, and stearic acid amide.

[0011] Furthermore, the high boiling point aromatic hydrocarbon solvent is a liquid petroleum aromatic hydrocarbon fraction with a distillation range of 178 to 270° C., preferably one or a combination of S-150, S-180, and S-200.

[0012] Furthermore, the dibasic ester is the main solvent of the phenyl ether type phenolic resin, preferably one or a combination of dimethyl succinate, dimethyl glutarate, and dimethyl adipate.

[0013] Furthermore, the reinforcing agent is one or a combination of titanate coupling agents, aluminate coupling agents, silane coupling agents, and borate coupling agents. Preferably, the silane coupling agent is one or more of aminosilane, epoxysilane, mercaptosilane, hydroxysilane, and ureasilane. Most preferably, the reinforcing agent is an aminosilane coupling agent, such as one or more of KH-550, KH-560, KH-570, and KH-602.

[0014] Furthermore, the anti-wetting agent is 40% hydrofluoric acid.

[0015] Furthermore, the polyisocyanate in the present invention is an aromatic polyisocyanate. Preferably, it is one or more of toluene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, xylylene diisocyanate and its methyl derivatives, and polymethylene polyphenyl polyisocyanate. Most preferably, it is one or more of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and polymethylene polyphenyl polyisocyanate (PAPI).

[0016] A method for preparing a binder for preventing veining in castings, wherein the preparation of a modified phenyl ether phenolic resin solution system comprises the following steps:

[0017] (1) Add phenyl ether type phenolic resin into a reactor and start stirring;

[0018] (2) Add the amide compound to the reactor, open the steam valve, raise the temperature to 85-100°C, and keep it warm for 0.5-3 hours;

[0019] (3) Add ethyl silicate and keep warm at 75-95°C for 0.5-1h;

[0020] (4) Cooling to below 60°C, adding dibasic ester and high-boiling-point aromatic solvent, and stirring for 1 hour;

[0021] (5) Cool to below 40°C, add enhancer, and stir for 1 hour;

[0022] (6) adding an anti-wetting agent and stirring for 1 hour to obtain a modified phenyl ether type phenolic resin solution system;

[0023] The preparation of the polyisocyanate solution system comprises the following steps:

[0024] (1) Put polyisocyanate into a reactor and start stirring;

[0025] (2) Add a high-boiling-point aromatic hydrocarbon solvent and ethyl silicate, and stir for 1 hour to obtain a polyisocyanate solution system.

[0026] A method for using a binder for preventing veining in castings comprises taking foundry sand, a modified phenyl ether type phenolic resin solution system, and a polyisocyanate solution system, wherein the amount of the modified phenyl ether type phenolic resin solution system is 0.6%-0.9% by weight of the foundry sand, and the amount of the polyisocyanate solution system is 0.6%-0.9% by weight of the foundry sand; and mixing the modified phenyl ether type phenolic resin solution system and the polyisocyanate solution system with the foundry sand.

[0027] The present invention provides a binder for preventing veining in castings or a binder for preventing veining in castings prepared by the preparation method of the present invention, and its use in sand molds (cores) for casting various types of cast steel, cast iron and nonferrous alloy castings.

[0028] The binder system of the present invention is used for casting resin sand mixture. The resin sand is solidified under the catalysis of gaseous amine to form a sand mold (core) for manufacturing metal castings. It is suitable for casting various cast steel, cast iron and non-ferrous alloy castings.

[0029] The present invention further modifies the phenyl ether phenolic resin by adding an amide compound to the phenyl ether phenolic resin, thereby increasing the high-temperature residual strength of the tensile specimen by 10%-20%, significantly improving the high-temperature performance of the molding sand. Ethyl silicate is added to both the modified phenyl ether phenolic resin solution system and the polyisocyanate solution system, and the high-temperature residual strength of the tensile specimen can be increased by 5%-10%, which has a significant effect on improving the high-temperature performance of the molding sand. Liquid petroleum aromatic hydrocarbon fractions with a distillation range of 178-270°C are added to both the modified phenyl ether phenolic resin solution system and the polyisocyanate solution system, and the addition ratio is significantly higher than that of ordinary cold box resins, and the high-temperature residual strength of the tensile specimen can be increased by 5%-10%. 10%, which has a significant effect on improving the high-temperature performance of molding sand; the polyisocyanate used in the polyisocyanate solution system is aromatic polyisocyanate. Compared with aliphatic and alicyclic polyisocyanates, the high-temperature residual strength of the tensile specimen using aromatic polyisocyanate can be increased by 3%-5%. The aromatic structure is not easy to decompose after high-temperature casting, which has a certain effect on improving the high-temperature performance of molding sand; through the combination of the above phenyl ether type phenolic resin + amide compounds, ethyl silicate, liquid petroleum aromatic fractions and aromatic polyisocyanate, the effects are superimposed, the high-temperature residual strength of the tensile specimen can be increased by at least 20%, which can significantly improve the high-temperature performance of molding sand and prevent the appearance of veins in castings caused by cracks in the molding sand after casting. DETAILED DESCRIPTION

[0030] To facilitate understanding of the present invention, the present invention will be described more fully below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of the present invention.

[0031] Implementation Case 1:

[0032] A binder for preventing veining in castings comprises a modified phenyl ether phenolic resin solution system and a polyisocyanate solution system, wherein the modified phenyl ether phenolic resin solution system comprises, by mass, 35% of a phenyl ether phenolic resin with an average molecular weight of 2000, 5% of N,N-dimethylformamide, 8% of ethyl silicate, 13% of dimethyl succinate, 38% of S-150, 0.5% of KH-550, and 0.5% of hydrofluoric acid; and the polyisocyanate solution system comprises, by mass, 70% of toluene diisocyanate, 19% of S-150, and 11% of ethyl silicate.

[0033] The modified phenyl ether phenolic resin solution system is prepared according to the following method:

[0034] (1) Add 35% of phenyl ether type phenolic resin into a reaction kettle and start stirring;

[0035] (2) Add 5% N,N-dimethylformamide into the reactor, open the steam valve, raise the temperature to 85°C, and keep it warm for 3 hours;

[0036] (3) Add 8% ethyl silicate and keep warm at 85°C for 1 hour;

[0037] (4) Cooling to below 60°C, adding 13% dimethyl succinate and 38% high-boiling-point aromatic solvent S-150, and stirring for 1 hour;

[0038] (4) Cool to below 40°C, add 0.5% enhancer KH-550, and stir for 1 hour;

[0039] (5) Add 0.5% hydrofluoric acid and stir for 1 hour to obtain a modified phenyl ether phenolic resin solution system.

[0040] The polyisocyanate solution system is prepared according to the following method:

[0041] (1) Add 70% toluene diisocyanate into a reactor and start stirring;

[0042] (2) Add 19% high boiling point aromatic hydrocarbon solvent S-150 and 11% ethyl silicate and stir for 1 hour to obtain a polyisocyanate solution system.

[0043] The binder obtained in this embodiment is used to prepare a cold core box binder sand mold (core). A modified phenyl ether phenolic resin solution system with a weight of 0.75% of the weight of the casting sand and a polyisocyanate solution system with a weight of 0.60% of the weight of the casting sand are mixed with the casting sand. The mixture is then shot into a metal core box by a core shooter and triethylamine is blown into the mixture for hardening to obtain a sand mold (core) that can be used for casting various types of cast steel, cast iron, and non-ferrous alloy castings.

[0044] Implementation Case 2:

[0045] A binder for preventing veining in castings comprises a modified phenyl ether phenolic resin solution system and a polyisocyanate solution system, wherein the modified phenyl ether phenolic resin solution system comprises, by mass, 40% of a phenyl ether phenolic resin with an average molecular weight of 1600, 7% of N,N-dimethylacetyl, 5% of ethyl silicate, 15% of dimethyl glutarate, 30.7% of S-180, 2% of KH-560, and 0.3% of hydrofluoric acid; and the polyisocyanate solution system comprises, by mass, 73% of diphenylmethane diisocyanate, 20% of S-180, and 7% of ethyl silicate.

[0046] The modified phenyl ether phenolic resin solution system is prepared according to the following method:

[0047] (1) Add 40% of phenyl ether type phenolic resin into a reaction kettle and start stirring;

[0048] (2) Add 7% N,N-dimethylacetamide into the reactor, open the steam valve, raise the temperature to 90°C, and keep it warm for 2 hours;

[0049] (3) Add 5% ethyl silicate and keep warm at 90°C for 0.5h;

[0050] (4) Cool to below 60°C, add 15% dimethyl glutarate and 30.7% high boiling point aromatic solvent S-180, and stir for 1 hour;

[0051] (5) Cool to below 40°C, add 2% enhancer KH-560, and stir for 1 hour;

[0052] (6) Add 0.3% hydrofluoric acid and stir for 1 hour to obtain a modified phenyl ether phenolic resin solution system.

[0053] The polyisocyanate solution system is prepared according to the following method:

[0054] (1) Add 73% diphenylmethane diisocyanate into a reaction kettle and start stirring;

[0055] (2) Add 20% high boiling point aromatic hydrocarbon solvent S-180 and 7% ethyl silicate and stir for 1 hour to obtain a polyisocyanate solution system.

[0056] The binder obtained in this embodiment is used to prepare a cold core box binder sand mold (core). A modified phenyl ether phenolic resin solution system with a weight of 0.6% of the weight of the casting sand and a polyisocyanate solution system with a weight of 0.85% of the weight of the casting sand are mixed with the casting sand. The mixture is then injected into a metal core box by a core shooter and triethylamine is blown into the mixture for hardening to obtain a sand mold (core) that can be used for casting various types of cast steel, cast iron, and non-ferrous alloy castings.

[0057] Implementation Case 3:

[0058] A binder for preventing veining in castings comprises a modified phenyl ether phenolic resin solution system and a polyisocyanate solution system, wherein the modified phenyl ether phenolic resin solution system comprises, by mass, 45% of a phenyl ether phenolic resin with an average molecular weight of 1200, 4.5% of N-ethyl p-toluenesulfonamide, 15% of ethyl silicate, 14% of dimethyl adipate, 20.4% of S-200, 1% of KH-570, and 0.1% of hydrofluoric acid; and the polyisocyanate solution system comprises, by mass, 76% of polymethylene polyphenyl polyisocyanate, 12% of S-200, and 12% of ethyl silicate.

[0059] The modified phenyl ether phenolic resin solution system is prepared according to the following method:

[0060] (1) Add 45% of phenyl ether type phenolic resin into a reaction kettle and start stirring;

[0061] (2) Add 4.5% N-ethyl-p-toluenesulfonamide into the reactor, open the steam valve, raise the temperature to 95°C, and keep it warm for 1 hour;

[0062] (3) Add 15% ethyl silicate and keep warm at 95°C for 0.5h;

[0063] (4) Cooling to below 60°C, adding 14% dimethyl adipate and 20.4% high-boiling-point aromatic solvent S-200, and stirring for 1 hour;

[0064] (4) Cool to below 40°C, add 1% enhancer KH-570, and stir for 1 hour;

[0065] (5) Add 0.1% hydrofluoric acid and stir for 1 hour to obtain a modified phenyl ether phenolic resin solution system.

[0066] The polyisocyanate solution system is prepared according to the following method:

[0067] (1) Add 76% of polymethylene polyphenyl polyisocyanate into a reaction kettle and start stirring;

[0068] (2) Add 12% of a high-boiling-point aromatic hydrocarbon solvent S-200 and 12% of ethyl silicate, and stir for 1 hour to obtain a polyisocyanate solution system.

[0069] The binder obtained in this embodiment is used to prepare a cold core box binder sand mold (core). A modified phenyl ether phenolic resin solution system with a weight of 0.8% of the weight of the casting sand and a polyisocyanate solution system with a weight of 0.7% of the weight of the casting sand are mixed with the casting sand, injected into a metal core box by a core shooter, and blown into triethylamine for hardening to obtain a sand mold (core) that can be used for casting various types of cast steel, cast iron and non-ferrous alloy castings.

[0070] Implementation Case 4:

[0071] A binder for preventing veining in castings comprises a modified phenyl ether phenolic resin solution system and a polyisocyanate solution system, wherein the modified phenyl ether phenolic resin solution system comprises, by mass, 50% of a phenyl ether phenolic resin with an average molecular weight of 1000, 8.9% of 2-phenylacetamide, 10% of ethyl silicate, 6% of dimethyl succinate, 6% of dimethyl glutarate, 18% of S-150, 0.1% of KH-602, and 1% of hydrofluoric acid; and the polyisocyanate solution system comprises, by mass, 80% of toluene diisocyanate, 15% of S-150, and 5% of ethyl silicate.

[0072] The modified phenyl ether phenolic resin solution system is prepared according to the following method:

[0073] (1) Add 50% of phenyl ether type phenolic resin into the reactor and start stirring;

[0074] (2) Add 8.9% 2-phenylacetamide into the reactor, open the steam valve, raise the temperature to 100°C, and keep warm for 1 hour;

[0075] (3) Add 10% ethyl silicate and keep warm at 100°C for 0.5h;

[0076] (4) Cooling to below 60°C, adding 6% dimethyl succinate, 6% dimethyl glutarate, and 18% high-boiling-point aromatic solvent S-150, and stirring for 1 hour;

[0077] (5) Cool to below 40°C, add 0.1% enhancer KH-602, and stir for 1 hour;

[0078] (6) Add 1% hydrofluoric acid and stir for 1 hour to obtain a modified phenyl ether phenolic resin solution system.

[0079] The polyisocyanate solution system is prepared according to the following method:

[0080] (1) Add 80% of toluene diisocyanate into a reactor and start stirring;

[0081] (2) Add 15% of a high-boiling-point aromatic hydrocarbon solvent S-150 and 5% of ethyl silicate, and stir for 1 hour to obtain a polyisocyanate solution system.

[0082] The binder obtained in this embodiment is used to prepare a cold core box binder sand mold (core). A modified phenyl ether phenolic resin solution system with a weight of 0.9% of the weight of the casting sand and a polyisocyanate solution system with a weight of 0.7% of the weight of the casting sand are mixed with the casting sand, injected into a metal core box by a core shooter, and blown into triethylamine for hardening to obtain a sand mold (core) that can be used for casting various types of cast steel, cast iron and non-ferrous alloy castings.

[0083] Implementation Case 5:

[0084] A binder for preventing veining in castings comprises a modified phenyl ether phenolic resin solution system and a polyisocyanate solution system, wherein the modified phenyl ether phenolic resin solution system comprises, by mass, 55% of phenyl ether phenolic resin with an average molecular weight of 800, 3% of stearic acid amide, 5% of ethyl silicate, 5% of dimethyl glutarate, 5% of dimethyl adipate, 26.1% of S-180, 0.2% of KH-550, and 0.7% of hydrofluoric acid; and the polyisocyanate solution system comprises, by mass, 85% of diphenylmethane diisocyanate, 9% of S-180, and 6% of ethyl silicate.

[0085] The modified phenyl ether phenolic resin solution system is prepared according to the following method:

[0086] (1) Add 55% of phenyl ether type phenolic resin into a reaction kettle and start stirring;

[0087] (2) Add 3% stearamide to the reactor, open the steam valve, raise the temperature to 100°C, and keep warm for 0.5h;

[0088] (3) Add 5% ethyl silicate and keep warm at 100°C for 0.5h;

[0089] (4) Cooling to below 60°C, adding 5% dimethyl glutarate, 5% dimethyl adipate, and 26.1% high-boiling-point aromatic solvent S-180, and stirring for 1 hour;

[0090] (5) Cool to below 40°C, add 0.2% enhancer KH-550, and stir for 1 hour;

[0091] (6) Add 0.7% hydrofluoric acid and stir for 1 hour to obtain a modified phenyl ether phenolic resin solution system.

[0092] The polyisocyanate solution system is prepared according to the following method:

[0093] (1) Add 85% of diphenylmethane diisocyanate into a reaction kettle and start stirring;

[0094] (2) Add 9% of high-boiling-point aromatic hydrocarbon solvent S-180 and 6% of ethyl silicate, and stir for 1 hour to obtain a polyisocyanate solution system.

[0095] The binder obtained in this embodiment is used to prepare a cold core box binder sand mold (core). A modified phenyl ether phenolic resin solution system with a weight of 0.85% of the weight of the casting sand and a polyisocyanate solution system with a weight of 0.7% of the weight of the casting sand are mixed with the casting sand, injected into a metal core box by a core shooter, and blown into triethylamine for hardening to obtain a sand mold (core) that can be used for casting various types of cast steel, cast iron and non-ferrous alloy castings.

[0096] The effect of the above embodiment is evaluated and the effect of the implementation case is summarized as follows:

[0097]

[0098] The binder provided by the present invention further modifies the phenyl ether phenolic resin by adding an amide compound, thereby increasing the high-temperature residual strength of the tensile test specimen by 10%-20%, significantly improving the high-temperature performance of the molding sand. Ethyl silicate is added to both the modified phenyl ether phenolic resin solution system and the polyisocyanate solution system of the present invention, and after the addition, the high-temperature residual strength of the tensile test specimen can be increased by 5%-10%, which has a significant effect on improving the high-temperature performance of the molding sand. In an embodiment, the high-temperature residual strength of the tensile test is 17%-25% higher than that of the experimental group, and the high-temperature residual strength of the tensile test specimen can be increased by at least 20%. The high-temperature residual strength of the molding sand is significantly improved, thereby preventing the occurrence of veining in the casting due to cracks in the molding sand after casting. The test results of the embodiment also show that the castings using the binder of the present invention do not produce veining, effectively solving the problem of veining defects in castings, and the method is simple and low in cost.

[0099] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A binder for preventing veining in castings, characterized in that: The invention comprises a modified phenyl ether phenolic resin solution system and a polyisocyanate solution system; wherein the modified phenyl ether phenolic resin solution system comprises, by mass percentage, 35%-55% of phenyl ether phenolic resin, 3%-10% of amide compound, 5%-15% of ethyl silicate, 12%-24% of dibasic ester, 18%-38% of high-boiling-point aromatic hydrocarbon solvent, 0.1%-2% of reinforcing agent, and 0.1%-1% of anti-moisture agent; and the polyisocyanate solution system comprises, by mass percentage, 70%-85% of polyisocyanate, 9%-20% of high-boiling-point aromatic hydrocarbon solvent, and 5%-12% of ethyl silicate.

2. The binder for preventing casting veining according to claim 1, characterized in that: The phenyl ether phenolic resin is synthesized by using phenol and paraformaldehyde in a molar ratio of 1:(0.65-0.85) under the catalysis of a divalent metal salt; the molecular weight of the phenyl ether phenolic resin is 800-2000.

3. The binder for preventing casting veining according to claim 1, characterized in that: The amide compound is one or a combination of N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylpropionamide, N-ethyl p-toluenesulfonamide, 2-amino-5-methylbenzamide, 2-phenylacetamide, N-methylsuccinimide, stearic acid amide, erucic acid amide, and fatty amide.

4. The binder for preventing casting veining according to claim 1, characterized in that The dibasic ester is one or a combination of dimethyl succinate, dimethyl glutarate, and dimethyl adipate.

5. The binder for preventing casting veining according to claim 1, characterized in that: The high boiling point aromatic hydrocarbon solvent is a liquid petroleum aromatic hydrocarbon fraction with a distillation range of 178 to 270°C.

6. The binder for preventing casting veining according to claim 1, characterized in that: The anti-wetting agent is 40% hydrofluoric acid.

7. The binder for preventing casting veining according to claim 1, characterized in that: Used in sand cores for casting cast steel, cast iron and non-ferrous alloy castings.

8. A method for preparing a binder for preventing casting veining according to any one of claims 1 to 7, characterized in that: The preparation of the modified phenylene ether phenolic resin solution system comprises the following steps: (1) Add phenyl ether type phenolic resin into a reactor and start stirring; (2) Add the amide compound to the reactor, open the steam valve, raise the temperature to 85-100°C, and keep it warm for 0.5-3 hours; (3) Add ethyl silicate and keep warm at 75-95°C for 0.5-1h; (4) Cooling to below 60°C, adding dibasic ester and high-boiling-point aromatic solvent, and stirring for 1 hour; (5) Cool to below 40°C, add enhancer, and stir for 1 hour; (6) adding an anti-wetting agent and stirring for 1 hour to obtain a modified phenyl ether phenolic resin solution system; The preparation of the polyisocyanate solution system comprises the following steps: (1) Put polyisocyanate into a reactor and start stirring; (2) adding a high-boiling-point aromatic hydrocarbon solvent and ethyl silicate, and stirring for 1 hour to obtain the polyisocyanate solution system.

9. A method for using the binder for preventing casting veining according to any one of claims 1 to 7, characterized in that: Separately prepare foundry sand, a modified phenyl ether phenolic resin solution system, and a polyisocyanate solution system, wherein the amount of the modified phenyl ether phenolic resin solution system is 0.6%-0.9% by weight of the foundry sand, and the amount of the polyisocyanate solution system is 0.6%-0.9% by weight of the foundry sand; A modified phenylene ether phenolic resin solution system and a polyisocyanate solution system are mixed with the foundry sand.

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