Moisture-resistant water glass sand for casting and preparation method thereof

Abstract

The invention discloses a kind of moisture-resistant water glass sand for casting and its preparation method, relate to the technical field of water glass sand. The water glass modifier provided by the present invention includes silane-modified polyisobutylene resin, toluene, isopropanolamine and aluminum dihydrogen phosphate. Silane-modified polyisobutylene resin has good hydrophobicity, isopropanolamine and aluminum dihydrogen phosphate can accelerate resin curing, improve resin surface density, and by combining the water glass modifier with water glass, the moisture resistance of water glass sand can be greatly improved. The composite silane coupling agent provided by the present invention includes vinyl tris (2-methoxyethoxy) silane and trimethoxy (4-vinylphenyl) silane. The vinyl group in the silane coupling agent can react with the resin, and the methoxy group can undergo coupling reaction with the water glass. Therefore, the silane coupling agent can form a "molecular bridge" between the silane-modified polyisobutylene resin and the water glass binder, thereby enhancing the bonding strength of the water glass. The reasonable combination of the water glass modifier, the composite silane coupling agent and the water glass in the present invention can significantly improve the moisture resistance of the water glass sand.

Description

Technical Field

[0001] The present invention relates to the technical field of water glass sand, in particular to a water glass modifier, a composite silane coupling agent and modified water glass sand and a preparation method thereof. Background Art

[0002] As a commonly used binder in sand casting, water glass has the advantages of being non-toxic, odorless, low-cost, and environmentally friendly. In recent years, the water glass sand process has become increasingly mature and is widely used in the foundry industry.

[0003] Although water glass sand has many advantages, it still has some shortcomings. For example, water glass sand has strong hygroscopicity and is difficult to maintain strength at room temperature, making it difficult to meet the needs of industrial production. Therefore, it is particularly important to solve the problem of water glass sand's moisture resistance.

[0004] Modified water glass sand is currently the main way to solve the moisture resistance problem of water glass sand. Resin modification is one of the important ways to improve the moisture resistance of water glass. By utilizing the lipophilic and hydrophobic properties of the resin and combining it with the water glass binder, the moisture resistance of the water glass sand can be greatly improved. Resins are divided into thermoplastic resins and thermosetting resins. Thermoplastic resins have good adhesion, but are not resistant to high temperatures. They are easily decomposed during pouring, which reduces the quality of castings. Thermosetting resins are resistant to high temperatures, but have poor adhesion. At present, thermoplastic resin modified water glass sand is widely used, but due to the problem of thermoplasticity not being resistant to high temperatures, the quality of its modified water glass sand needs to be improved, and the connection effect between the resin and the water glass binder is poor, resulting in poor moisture resistance of the resin modified water glass sand, which needs to be improved.

[0005] In view of this, the present invention is proposed to solve the above technical problems. Summary of the Invention

[0006] The first object of the present invention is to provide a water glass modifier that can effectively improve the moisture resistance of water glass sand. The hydrophobicity of polyisobutylene resin modified by silane, as well as isopropylamine and aluminum dihydrogen phosphate, can accelerate the curing of the resin, increase the surface density of the resin, and thus improve the moisture resistance of the water glass sand.

[0007] The second object of the present invention is to provide a composite silane coupling agent to solve the problem of poor bonding between resin and water glass, thereby improving the moisture resistance of modified water glass sand.

[0008] The third object of the present invention is to provide a moisture-resistant water glass sand for casting and a preparation method thereof, so as to solve the problem of poor moisture resistance of ordinary water glass sand and further improve the application of water glass sand in the casting industry.

[0009] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted:

[0010] The moisture-resistant water glass sand for casting provided by the present invention comprises modified water glass and ceramic sand. Calculated by weight percentage, the modified water glass comprises 2% to 4% and the ceramic sand comprises 96% to 98%, and the total content of the above components is 100%. The modified water glass comprises a water glass modifier, water glass, and a composite silane coupling agent. Calculated by weight percentage, the water glass modifier comprises 1.95% to 4.9%, the water glass comprises 95% to 98%, and the composite silane coupling agent comprises 0.05% to 0.1%, and the total content of the above components is 100%.

[0011] The water glass modifier provided by the invention comprises 5% to 10% of silane-modified polyisobutylene resin, 50% to 70% of toluene, 10% to 20% of isopropanolamine and 10% to 20% of aluminum dihydrogen phosphate, wherein the total content of the above components is 100%.

[0012] The composite silane coupling agent provided by the present invention comprises vinyltris(2-methoxyethoxy)silane and trimethoxy(4-vinylphenyl)silane, wherein the mass fraction ratio of the components is 40% to 60% of vinyltris(2-methoxyethoxy)silane and 40% to 60% of trimethoxy(4-vinylphenyl)silane, and the total content of the above components is 100%.

[0013] The method for preparing moisture-resistant water glass sand for casting provided by the present invention is characterized in that it mainly comprises the following steps:

[0014] Step 1. dissolving the silane-modified polyisobutylene resin in toluene according to the formula ratio, heating to 80-100° C., and dissolving for 1-3 hours to obtain a silane-modified polyisobutylene resin solution;

[0015] Step 2. Add the raw materials of the composite silane coupling agent according to the formula amount to the silane-modified polyisobutylene resin solution, and stir for 20 to 30 minutes to obtain a mixture A;

[0016] Step 3. Mix mixture A and water glass according to the formula ratio, heat in a water bath at 50-70°C, and stir for 20-30 minutes to obtain mixture B;

[0017] Step 4. Add isopropylamine and aluminum dihydrogen phosphate to mixture B according to the formula ratio and stir evenly, then mix with ceramic sand according to the formula ratio, heat to 120-140° C., and stir for 2-3 minutes to obtain modified water glass sand.

[0018] The beneficial effects of the present invention are:

[0019] (1) The present invention provides a water glass modifier, which utilizes silane to modify the hydrophobicity of polyisobutylene resin, and isopropanolamine and aluminum dihydrogen phosphate to accelerate resin curing, increase the surface density of the resin, and thus improve the moisture resistance of water glass sand.

[0020] (2) The present invention also provides a composite silane coupling agent comprising vinyl tris(2-methoxyethoxy)silane and trimethoxy(4-vinylphenyl)silane. The vinyl group in the composite silane coupling agent can react with the resin, and the methoxy group can undergo a coupling reaction with water glass. Thus, the silane coupling agent can form a "molecular bridge" between the silane-modified polyisobutylene resin and the water glass binder, thereby enhancing the bonding strength of the water glass binder.

[0021] (3) The moisture-resistant water glass sand for casting provided by the present invention has extremely strong moisture resistance and can be used in a humid environment, which effectively solves the problem of poor moisture resistance of unmodified water glass sand. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to specific embodiments.

[0023] The moisture-resistant water glass sand for casting provided by the present invention comprises modified water glass and ceramic sand. Calculated by weight percentage, the modified water glass comprises 2% to 4% and the ceramic sand comprises 96% to 98%, and the total content of the above components is 100%. The modified water glass comprises a water glass modifier, water glass, and a composite silane coupling agent. Calculated by weight percentage, the water glass modifier comprises 1.95% to 4.9%, the water glass comprises 95% to 98%, and the composite silane coupling agent comprises 0.05% to 0.1%, and the total content of the above components is 100%.

[0024] The water glass modifier provided by the invention comprises 5% to 10% of silane-modified polyisobutylene resin, 50% to 70% of toluene, 10% to 20% of isopropanolamine and 10% to 20% of aluminum dihydrogen phosphate, wherein the total content of the above components is 100%.

[0025] The mass fraction ratio of each component of the silane coupling agent is 40% to 60% of vinyl tris (2-methoxyethoxy) silane and 40% to 60% of trimethoxy (4-vinylphenyl) silane, and the total content of the above components is 100%.

[0026] The preparation method of moisture-resistant water glass sand for casting is specifically implemented according to the following steps:

[0027] Step 1. dissolving the silane-modified polyisobutylene resin in toluene according to the formula ratio, heating to 80-100° C., and dissolving for 1-3 hours to obtain a silane-modified polyisobutylene resin solution;

[0028] Step 2. Add the raw materials of the water glass sand silane coupling agent to the silane-modified polyisobutylene resin solution according to the formula amount, and stir for 20 to 30 minutes to obtain a mixture A;

[0029] Step 3. Mix mixture A and water glass according to the formula ratio, heat in a water bath at 50-70°C, and stir for 20-30 minutes to obtain mixture B;

[0030] Step 4. Add isopropylamine and aluminum dihydrogen phosphate to mixture B according to the formula ratio and stir evenly, then mix with ceramic sand according to the formula ratio, heat to 120-140° C., and stir for 2-3 minutes to obtain modified water glass sand.

[0031] The moisture-resistant water glass sand for casting provided by the present invention can significantly improve the moisture resistance of the water glass sand by mixing the water glass modifier, the composite silane coupling agent, the water glass and the ceramic sand according to technical proportions.

[0032] By rationally selecting and matching water glass modifiers and composite silane coupling agents, the amount of water glass added can be reduced and the moisture resistance of the modified water glass sand can be improved to an ideal level.

[0033] Example 1

[0034] The weight percentages of the modified water glass sand are: 2% modified water glass, 98% ceramic sand, the total of which is 100%. The weight percentages of the modified water glass raw materials are: 1.95% water glass modifier, 98% water glass, and 0.05% composite silane coupling agent, the total of which is 100%.

[0035] The water glass modifier is composed of the following raw materials in terms of weight percentage: 5% of silane-modified polyisobutylene resin, 60% of toluene, 15% of isopropanolamine, and 20% of aluminum dihydrogen phosphate, and the total content of the above components is 100%.

[0036] The mass fraction ratio of each component of the silane coupling agent is 40% of vinyltris(2-methoxyethoxy)silane and 60% of trimethoxy(4-vinylphenyl)silane, and the total content of the above components is 100%.

[0037] Step 1. dissolving the silane-modified polyisobutylene resin in toluene according to the formula ratio, heating to 80° C., and dissolving for 1 hour to obtain a silane-modified polyisobutylene resin solution;

[0038] Step 2. Add the raw materials of the composite silane coupling agent according to the formula amount to the silane-modified polyisobutylene resin solution, and stir for 20 minutes to obtain a mixture A;

[0039] Step 3. Mix mixture A and water glass according to the formula ratio, heat in a water bath at 50°C, and stir for 20 minutes to obtain mixture B;

[0040] Step 4. Add isopropylamine and aluminum dihydrogen phosphate to mixture B according to the formula ratio and stir evenly, then mix with ceramic sand according to the formula ratio, heat to 120° C., and stir for 2 minutes to obtain modified water glass sand.

[0041] Example 2

[0042] The weight percentage of the modified water glass sand is: 3% modified water glass, 97% ceramic sand, the total content of these components is 100%. The weight percentage of the modified water glass raw materials is: 2.9% water glass modifier, 97% water glass, and 0.1% composite silane coupling agent, the total content of these components is 100%.

[0043] The water glass modifier is composed of the following raw materials in terms of weight percentage: 10% of silane-modified polyisobutylene resin, 65% of toluene, 15% of isopropanolamine, and 10% of aluminum dihydrogen phosphate, and the total content of the above components is 100%.

[0044] The mass fraction ratio of each component of the silane coupling agent is 50% of vinyltris(2-methoxyethoxy)silane and 50% of trimethoxy(4-vinylphenyl)silane, and the total content of the above components is 100%.

[0045] Step 1. Dissolve the silane-modified polyisobutylene resin in toluene according to the formula ratio, heat to 90° C., and dissolve for 1.5 hours to obtain a silane-modified polyisobutylene resin solution;

[0046] Step 2. Add the raw materials of the composite silane coupling agent according to the formula amount to the silane-modified polyisobutylene resin solution, and stir for 30 minutes to obtain a mixture A;

[0047] Step 3. Mix mixture A and water glass according to the formula ratio, heat in a water bath at 60°C, and stir for 30 minutes to obtain mixture B;

[0048] Step 4. Add isopropylamine and aluminum dihydrogen phosphate to mixture B according to the formula ratio and stir evenly, then mix with ceramic sand according to the formula ratio, heat to 130° C., and stir for 3 minutes to obtain modified water glass sand.

[0049] Example 3

[0050] The weight percentages of the modified water glass sand are: 4% modified water glass, 96% ceramic sand, and the total content of these components is 100%. The weight percentages of the modified water glass raw materials are: 4.9% water glass modifier, 95% water glass, and 0.1% composite silane coupling agent, and the total content of these components is 100%.

[0051] The water glass modifier is composed of the following raw materials in weight percentage: 8% of silane-modified polyisobutylene resin, 70% of toluene, 10% of isopropanolamine, and 12% of aluminum dihydrogen phosphate, and the total content of the above components is 100%.

[0052] The mass fraction ratio of each component of the silane coupling agent is 60% of vinyltris(2-methoxyethoxy)silane and 40% of trimethoxy(4-vinylphenyl)silane, and the total content of the above components is 100%.

[0053] Step 1. dissolving the silane-modified polyisobutylene resin in toluene according to the formula ratio, heating to 100° C., and dissolving for 3 hours to obtain a silane-modified polyisobutylene resin solution;

[0054] Step 2. Add the raw materials of the composite silane coupling agent according to the formula amount to the silane-modified polyisobutylene resin solution, and stir for 25 minutes to obtain a mixture A;

[0055] Step 3. Mix mixture A and water glass according to the formula ratio, heat in a water bath at 60°C, and stir for 25 minutes to obtain mixture B;

[0056] Step 4. Add isopropylamine and aluminum dihydrogen phosphate to mixture B according to the formula ratio and stir evenly, then mix with ceramic sand according to the formula ratio, heat to 120° C., and stir for 4 minutes to obtain modified water glass sand.

Claims

1. A moisture-resistant water glass sand for casting, characterized in that The water glass sand comprises modified water glass and ceramic sand, which are calculated by weight as follows: 2% to 4% of modified water glass and 96% to 98% of ceramic sand, and the total content of the above components is 100%. The modified water glass comprises a water glass modifier, water glass and a composite silane coupling agent, which are calculated by weight as follows: 1.95% to 4.9% of the water glass modifier, 95% to 98% of the water glass, and 0.05% to 0.1% of the silane coupling agent, and the total content of the above components is 100%. The water glass modifier comprises silane-modified polyisobutylene resin, toluene, isopropanolamine and aluminum dihydrogen phosphate, wherein the mass fraction ratio of the components is 5% to 10% of silane-modified polyisobutylene resin, 50% to 70% of toluene, 10% to 20% of isopropanolamine, and 10% to 20% of aluminum dihydrogen phosphate, and the total content of the above components is 100%; The composite silane coupling agent comprises vinyltris(2-methoxyethoxy)silane and trimethoxy(4-vinylphenyl)silane, wherein the mass fraction ratio of the components is 40% to 60% of vinyltris(2-methoxyethoxy)silane and 40% to 60% of trimethoxy(4-vinylphenyl)silane, and the total content of the above components is 100%.

2. A method for preparing moisture-resistant water glass sand for casting according to claim 1, characterized in that: The main steps include: Step 1. dissolving the silane-modified polyisobutylene resin in toluene according to the formula ratio, heating to 80-100° C., and dissolving for 1-3 hours to obtain a silane-modified polyisobutylene resin solution; Step 2. Add the raw materials of the composite silane coupling agent according to the formula amount to the silane-modified polyisobutylene resin solution, and stir for 20 to 30 minutes to obtain a mixture A; Step 3. Mix mixture A and water glass according to the formula ratio, heat in a water bath at 50-70°C, and stir for 20-30 minutes to obtain mixture B; Step 4. Add isopropylamine and aluminum dihydrogen phosphate to mixture B according to the formula ratio and stir evenly, then mix with ceramic sand according to the formula ratio, heat to 120-140° C., and stir for 2-3 minutes to obtain modified water glass sand.