A cold core box resin for casting core shooting riser and its preparation method and application

Abstract

The invention belongs to the field of casting technology, and specifically relates to a cold box resin for casting core shooting risers and a preparation method and application thereof. The present application selects polyol acetate and 230# solvent oil to replace commonly used mixed dibasic esters and other types of high-boiling aromatic hydrocarbons, and screens out the coupling agent γ-glycidyl ether oxypropyl trimethoxy silane (coupling agent KH560) that is most suitable for core shooting riser aggregates as a component of cold box resin I. In the present application, the inventors make adaptation adjustments according to the solubility and mutual solubility of the first and second components and ingredients of the cold box, and take into account the wettability of the core shooting heating and heat insulation riser aggregates in the mixing process to prevent agglomeration and uneven dispersion. Finally, a cold box resin suitable for core shooting risers is formulated. The core shooting risers prepared using the cold box resin of the present application have greatly improved strengths such as resistance and compressive strength.

Description

Technical Field

[0001] The invention belongs to the technical field of casting, and in particular relates to a cold box resin for casting core shooting riser and a preparation method and application thereof. Background Art

[0002] The core shooting process in the foundry industry is a process in which the cold box resin is mixed with the riser premix, and then triethylamine gas is blown in for catalytic curing and molding. Most cold box resins use the same resin as the resin sand process in the foundry field. However, the basic use process of the resin sand process in the casting process is to mix the cold box resin with the resin sand. The resin sand process generally uses resin sand. In the actual production process, the molding sand is generally composed of old resin sand, original resin sand, bentonite and additives (FS powder). Among them, the old resin sand accounts for more than 95%, and the main component of the old resin sand is still SiO2. Therefore, the main component of the raw materials of the resin sand process in the foundry field is SiO2.

[0003] The casting core shooting riser (cold core box process) is a heat preservation and heating riser. Its main components are floating beads, aluminum powder, and other auxiliary materials. The main function of floating beads is heat preservation. Floating beads are a kind of fly ash hollow balls that can float on the water. They are grayish white, thin-walled and hollow, very light in weight, and have a bulk density of 720kg / m 3 (Heavy), 418.8kg / m 3 (Lightweight), particle size is about 0.1 mm, the surface is closed and smooth, thermal conductivity is low, refractoriness is ≥1610℃, the chemical composition of the floating beads is mainly silicon dioxide and aluminum oxide, and its conventional proportion is SiO2 (56-62%), Al2O3 (33-38%), Fe2O3 (2-4%), SO3 (0.1-0.2%), CaO (0.2-0.4%), MgO (0.8-1.2%), K2O (0.5-1.1%), Na2O (0.3-0.9%); aluminum powder and its combustion aid are the main heat-generating components. According to the requirements of heating and heat preservation, the general amount of aluminum powder added accounts for 20-40% of the mass of the entire riser, while the mass of the floating beads accounts for 40-60%. In other words, the main modeling materials of the aggregate of the heating and heat-insulating riser for casting using the core shooting process are floating beads and aluminum powder, and the main components are mainly SiO 2， Al, Al2O3, therefore, the aggregate composition of the riser for casting core shooting process and the resin sand process for casting has undergone significant changes in the proportion of Al and Al2O3.

[0004] In the prior art, the core shooting process riser for casting is mixed with the cold box resin used in the resin sand process for casting. At present, the cold box resin includes two components, component I is a phenolic resin solution, and component II is a polyisocyanate solution. More specifically, component I also includes a solvent, a coupling agent, and an anti-moisture agent (added as needed), etc., while the main medium of the resin sand process for casting is silica sand, and the main component of silica sand is Sio2, which does not react with cold box resin components one and two. However, the core shooting process riser, especially the core shooting process heating and insulation riser, contains aluminum powder, aluminum chips, potassium nitrate, magnesium oxide, manganese dioxide, etc. in the premix, which are all oxides, and will have a chemical reaction effect on the organic matter in the cold box resin component. The exothermic reaction may cause solvent volatilization, increased viscosity, agglomeration and uneven dispersion, and the coupling effect of the coupling agent may also be poorly affected by the aggregate, thereby making the prepared core shooting riser lack in tensile strength and compressive strength.

[0005] Therefore, it is necessary to develop a component of cold box resin suitable for the riser of the core shooting process for casting. Summary of the invention

[0006] In order to solve at least one of the above problems, the first aspect of the present invention provides a cold box resin component I suitable for a casting riser, comprising phenol, paraformaldehyde, zinc acetate, o-octyl adipate, polyol acetate, alkane oil, hydrofluoric acid, and a coupling agent.

[0007] According to a specific embodiment of the present invention, the coupling agent is γ-glycidyloxypropyltrimethoxysilane.

[0008] In the existing cold box resin component I, the coupling agent is generally selected from silane coupling agent 1160 (γ-ureapropyl triethoxysilane) or silane coupling agent 602 (N-β-(aminoethyl)-γ-aminopropyl methyl dimethoxy silane) or silane coupling agent 603 (N-(β-aminoethyl)-γ-aminopropyl trimethoxy silane) which are suitable for the molding material with silica as the main component. Compared with the aggregate of the more suitable resin sand process for casting, the riser of the core shooting process for casting has a metal phase added. The coupling agent is no longer a simple connection between the organic phase and the inorganic phase, which makes the coupling effect poor, and thus makes the prepared core shooting riser lack in tensile strength and compressive strength. After a lot of tests, the inventors of this application found that when the coupling agent is γ-glycidyloxypropyltrimethoxysilane, it can not only greatly improve the coupling effect between the resin and the riser aggregate, so that the riser has better tensile and compressive strength, but also further improve the stability of the cold box resin.

[0009] According to a specific embodiment of the present invention, the boiling point of the alkane oil is 200-230°C.

[0010] According to a specific embodiment of the present invention, the alkane oil includes 200# alkane oil and / or 230# alkane oil.

[0011] The existing core shooting process riser contains a variety of oxides in the premix, which may have a chemical reaction with the organic matter in the existing cold box resin component, and the exothermic reaction may cause solvent volatilization, increased viscosity, agglomeration and uneven dispersion. The solvent used in this application is a high-boiling point solvent. The commonly used low-boiling point alkanes have a low boiling point and are easy to volatilize, while the high-boiling point alkanes have a high boiling point and are difficult to volatilize. After a large number of experiments, the present application finally concluded that when the boiling point of the solvent is 200-230°C, the prepared cold box resin component I has better stability.

[0012] According to a specific embodiment of the present invention, the mass ratio of phenol, paraformaldehyde, zinc acetate, o-octyl adipate, polyol acetate, alkane oil, hydrofluoric acid, and coupling agent is (40-48): (15-22): (0.07-0.13): (7-15): (7-15): (15-30): (0.1-0.3): (0.4-1).

[0013] The prior art mostly uses mixed dibasic esters to dissolve a component of phenolic resin, such as MDBE. The inventors of this application have found that replacing the mixed dibasic ester with polyol acetate, such as polyether polyol acetate, can better dissolve a component of phenolic resin, so that the prepared cold core box resin has good fluidity and thermal stability, and the riser premix can be mixed more evenly during the core shooting molding process, which is more conducive to molding. At the same time, due to its thermal stability, it is more stable during the stirring and dispersion process, and is not easy to volatilize and cause agglomeration. The inventor speculates that polyol acetate has more hydroxyl groups and ester bonds, and these functional groups give them specific chemical and physical properties, such as good solubility, fluidity, lubricity, thermal stability, etc., making it more suitable for configuring the cold core box resin component of the core shooting process riser for casting.

[0014] According to a specific embodiment of the present invention, the components of the aggregate of the casting riser include SiO2, Al, and Al2O3. When the main components of the riser aggregate include metals or metal oxides, the cold box resin prepared by the present application is more suitable than traditional cold box resins.

[0015] According to a specific embodiment of the present invention, the casting riser is a core shooting process riser.

[0016] The second aspect of the present invention provides a method for preparing the cold box resin component I described in the first aspect, comprising:

[0017] S1. Addition treatment: phenol, zinc acetate and paraformaldehyde are mixed, and kept warm at 55-65°C for 20-45min in a steam controlled kettle to obtain a mixed solution 1;

[0018] S2, heating treatment: the steam control kettle is heated to 105-110° C. at a uniform speed for the first time, and kept warm until the refractive index is 1.54-1.56;

[0019] S3, distillation treatment: the steam control kettle is heated to 120-130°C at a uniform speed for the second time, and kept warm until the refractive index is 1.59-1.61;

[0020] S4, dehydration treatment: start vacuum negative pressure dehydration, when the temperature in the kettle starts to drop from 120-130℃ to 105-110℃, dehydrate at a constant temperature of 105-110℃ for 80-90min;

[0021] S5, first mixing treatment: after the dehydration treatment is completed, the temperature is lowered in the kettle to below 90°C, and alkane oil is added and stirred for the first time to obtain a mixed solvent 1;

[0022] S6, a second mixing treatment, cooling to below 65°C, adding o-octyl adipate, polyol acetate, hydrofluoric acid, and a coupling agent to the mixed solvent 1, stirring for a second time, and mixing the mixed solvent 2, wherein the mixed solvent 2 is the cold box resin component I.

[0023] According to a specific embodiment of the present invention, the coupling agent is γ-glycidyloxypropyltrimethoxysilane.

[0024] According to a specific embodiment of the present invention, the boiling point of the alkane oil is 200-230°C.

[0025] According to a specific embodiment of the present invention, the alkane oil includes 200# alkane oil and / or 230# alkane oil.

[0026] According to a specific embodiment of the present invention, the mass ratio of phenol, paraformaldehyde, zinc acetate, o-octyl adipate, polyol acetate, alkane oil, hydrofluoric acid, and coupling agent is (40-48): (15-22): (0.07-0.13): (7-15): (7-15): (15-30): (0.1-0.3): (0.4-1).

[0027] A third aspect of the present invention provides a cold box resin, wherein the cold box resin comprises the cold box resin component I described in the first aspect.

[0028] The fourth aspect of the present invention provides use of the cold box resin component I described in the first aspect or the cold box resin described in the third aspect in preparing a riser for casting.

[0029] According to a specific embodiment of the present invention, main components of the aggregate of the casting riser include SiO2, Al, and Al2O3.

[0030] According to a specific embodiment of the present invention, the casting riser is a core shooting process riser, including a core shooting process heat preservation and heating riser.

[0031] The inventors selected polyol acetate and 230# solvent oil to replace commonly used mixed dibasic esters and other types of high-boiling point aromatic hydrocarbons, and screened out the coupling agent γ-glycidyloxypropyltrimethoxysilane (coupling agent KH560) that is most suitable for core-shooting riser aggregates as a component of cold box resin I. In the present application, the inventors made adaptive adjustments based on the solubility and miscibility of the first and second components and ingredients of the cold box, and took into account the wettability of the core-shooting heating and insulation riser aggregates during the mixing process to prevent agglomeration and uneven dispersion. Finally, a cold box resin suitable for core-shooting risers was prepared. The core-shooting risers prepared using the cold box resin of the present application have greatly improved strengths such as resistance and compressive strength. DETAILED DESCRIPTION

[0032] The following is a detailed description of embodiments of the present invention. The embodiments are intended to explain the present invention but are not to be construed as limiting the present invention.

[0033] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Further, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0034] In this document, the terms “contain”, “include” or “comprise” are open expressions, that is, they include the contents specified in the present invention but do not exclude other contents.

[0035] As used herein, the terms "optionally", "optional" or "optionally" generally mean that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0036] In the present invention, "polyol ester" refers to esters formed by diols, polyols, triols, tetraols and saturated fatty acids or benzoic acid. According to their plasticizing properties, they can be roughly divided into four categories: 1. Plasticizers with excellent low-temperature properties, mainly diol fatty acid esters; 2. Plasticizers with excellent heat resistance, aging resistance and extraction resistance, mainly dipentaerythritol esters; 3. Plasticizers with good pollution resistance, mainly diol (polyol) benzoate; 4. Non-toxic plasticizers, mainly glycerol triacetate.

[0037] In the present invention, the term "heat-generating riser" refers to a supplementary part added to the top or side of a casting to avoid defects in the casting. Its shrinkage compensation effect is much higher than that of a floating bead insulation riser. The heat-generating riser casting is dense and defect-free, fully meeting the basic technical requirements of explosive hardening. At the same time, the excellent density, i.e., the internal quality, provides a strong guarantee for improving the wear resistance of the casting and extending the service life of the frog.

[0038] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the relevant descriptions in the specification are used to explain the operating principles of the embodiments. By referring to these contents, ordinary technicians in this field should be able to understand other possible implementation methods and advantages of the present invention.

[0039] The purchase sources and product numbers of the main reagents used in the examples of this application are shown in Table 1

[0040] Table 1

[0041]

[0042] In the present invention, the riser premix includes the aggregate of the core shooting process riser commonly used in the art. The riser premix used in the embodiments of the present invention is the core shooting process heat riser premix, and its main components include heat-generating materials, heat-generating insulation materials, oxygen supply materials, refractory backbone materials and adhesives, etc. In the present invention, the agglomeration is caused by the reaction and solvent volatilization during use, the viscosity increases, the reaction cross-links, etc.; the turbidity is caused by the insufficient solubility of the solvent, which causes some components to precipitate out or are in an incompletely dissolved state.

[0043] In the present invention, the models of the finished core shooting risers during inspection are all 70mm in inner diameter, 110mm in height, and weigh 255g.

[0044] The coupling agent KH560 selected in this application has a chemical name of γ-glycidyloxypropyltrimethoxysilane, a molecular formula of CH2CH(O)CH2O(CH2)3Si(OCH3)3, and a structural formula as shown in Formula 1:

[0045] Formula 1.

[0046] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] Example 1

[0048] 1. Add materials: add 40 parts of phenol, 0.07 parts of zinc acetate, and 15 parts of 92% polyformaldehyde, and control the temperature in the kettle to 60°C by steam for 35 minutes;

[0049] 2. Heating: Heating to 109°C (rate: 1°C / min, 109°C (109+1°C), keeping warm until the refractive index is 1.545-1.547;

[0050] 3. Distillation: After the insulation is completed, heat up to 125℃ at a uniform rate (rate 2.5℃ / 10min), and keep at 125℃ (125℃+0.5℃) until the refractive index is 1.593-1.602;

[0051] 4. Dehydration: After the 125℃ insulation is completed, stop the steam and start vacuum negative pressure dehydration. The temperature in the kettle starts to drop from 125℃ to 109℃. Control the dehydration temperature: 109℃, dehydration for 80-90min;

[0052] 5. Mixing: After dehydration, turn on the cooling water, cool down to below 90°C, add 15 parts of 230# solvent oil, and stir at 65-90°C for 30 minutes; when the temperature drops to below 65°C, add 7 parts of o-octyl adipate, 7 parts of polyether polyol acetate, 0.1 parts of hydrofluoric acid, and 0.35 parts of coupling agent KH560 ((3-epoxypropoxy)propyltrimethoxysilane), and mix well to obtain cold box resin 1;

[0053] 6. The prepared cold box resin 1 and the cold box resin 2 with 24% isocyanate content are mixed in a mass ratio of 1:1 to obtain a cold box resin mixed liquid. The cold box resin and the riser premix are evenly mixed in a mass ratio of 7.5:92.5, and then cast according to the cold box resin process industry standard JB∕T 11738-2013 triethylamine cold box resin industry standard for casting to obtain a core shooting riser.

[0054] Comparative Example 1

[0055] Compared with Example 1, in step 5, the coupling agent used is silane coupling agent 1160 (γ-ureapropyltriethoxysilane).

[0056] Comparative Example 2

[0057] Compared with Example 1, in step 5, the coupling agent used is silane coupling agent 602 (N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane).

[0058] Comparative Example 3

[0059] Compared with Example 1, in step 5, the coupling agent used is silane coupling agent 603 (N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane).

[0060] Comparative Example 4

[0061] Compared with Example 1, the polyol acetate in step 5 is replaced by a common mixed dibasic ester MDBE.

[0062] Comparative Example 5

[0063] Compared with Example 1, in step 5, no polyol acetate is added.

[0064] Comparative Example 6

[0065] Compared with Example 1, step 5 does not add 230# solvent oil.

[0066] Comparative Example 7

[0067] The 230# solvent oil in step 5 was replaced with a low-boiling-point alkane. 100#, 120#, and 150# were used for equal replacement, but the mixed cold core boxes of one component all became turbid.

[0068] The inventors conducted an 8-block tensile test on the finished core-shooting risers prepared in Example 1 and Comparative Examples 1-13 at 20° C. and 55% humidity to detect the strength of the prepared risers. The results are shown in Tables 2 and 3, in MPa.

[0069] Table 2

[0070]

[0071] Table 3

[0072]

[0073] The inventors selected polyol acetate and 230# solvent oil to replace commonly used mixed dibasic esters and other types of high-boiling point aromatics, and screened out the coupling agent γ-glycidyloxypropyltrimethoxysilane (coupling agent KH560) that is most suitable for core-shooting riser aggregates as a component of cold box resin I. In the present application, the inventors made adaptive adjustments based on the solubility and miscibility of the components and ingredients of cold box I, and took into account the wettability of the core-shooting heating and insulation riser aggregates during the mixing process to prevent agglomeration and uneven dispersion. Finally, a cold box resin suitable for core-shooting risers was prepared. The core-shooting risers prepared using the cold box resin of the present application have greatly improved strengths such as resistance and compressive strength.

[0074] In order to further improve the compatibility of cold box resin and core shooting riser, the inventors further explored the suitable concentration of some of the selected solvents, as follows:

[0075] Comparative Example 8

[0076] Compared with Example 1, in step 5, the mass proportion of the coupling agent used in the cold box resin 1 is 2‰.

[0077] Comparative Example 9

[0078] Compared with Example 1, in step 5, the mass proportion of the coupling agent used in the cold box resin 1 is 3‰.

[0079] Comparative Example 10

[0080] Compared with Example 1, in step 5, the mass proportion of the coupling agent used in the cold box resin 1 is 4‰.

[0081] Comparative Example 11

[0082] Compared with Example 1, in step 5, the mass proportion of the coupling agent used in the cold box resin 1 is 5‰.

[0083] The inventors continued to conduct compression tests on the finished core-shooting risers prepared in Example 1 and Comparative Examples 8-13 at 20°C and 55% humidity. The results are shown in Tables 4 and 5, with the unit (KN)

[0084] Table 4

[0085]

[0086] Table 5

[0087]

[0088] The inventors verified the strength of KH560 with different addition amounts, and the results showed that the best addition amount of KH560 was around 4‰. Continuing to increase the addition amount would not continue to increase the strength and would increase the cost of raw materials.

[0089] In summary, the present application has developed a cold core box resin component for a heat-generating riser sleeve of a core-shooting process for casting, selected a new silane coupling agent KH560 to adapt to the coupling fact that the main components of the riser sleeve are floating beads, aluminum powder, and aluminum oxide, selected 92% of polyformaldehyde, polyol acetate, 230# solvent oil and other new components, fixed the hydrofluoric acid concentration to 48%, and adjusted the production process, such as the temperature during the reaction, the refractive index, etc.

[0090] A cold box resin component suitable for risers is produced. After tensile and compressive tests, the strength of the risers prepared using the cold box resin provided by the present application is significantly improved compared with the risers prepared by the prior art.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A cold box resin component I adapted for a casting riser, characterized in that: Including phenol, paraformaldehyde, zinc acetate, o-octyl adipate, polyol acetate, alkane oil, hydrofluoric acid, coupling agent; The coupling agent is γ-glycidyloxypropyltrimethoxysilane; The boiling point of the alkane oil is 200-230°C; The aggregate components of the casting riser include SiO2, Al, and Al2O3, and the casting riser is a core shooting process riser.

2. The cold box resin component I according to claim 1, characterized in that: The alkane oil includes 200# alkane oil and / or 230# alkane oil.

3. The cold box resin component I according to claim 1, characterized in that: The mass ratio of phenol, paraformaldehyde, zinc acetate, o-octyl adipate, polyol acetate, alkane oil, hydrofluoric acid and coupling agent is (40-48): (15-22): (0.07-0.13): (7-15): (7-15): (15-30): (0.1-0.3): (0.4-1).

4. A method for preparing the cold box resin component I according to any one of claims 1 to 3, characterized in that: include: S1. Addition treatment: phenol, zinc acetate and paraformaldehyde are mixed, and kept warm at 55-65°C for 20-45min in a steam controlled kettle to obtain a mixed solution 1; S2, heating treatment: the steam control kettle is heated to 105-110° C. at a uniform speed for the first time, and kept warm until the refractive index is 1.54-1.56; S3, distillation treatment: the steam control kettle is heated to 120-130°C at a uniform speed for the second time, and kept warm until the refractive index is 1.59-1.61; S4, dehydration treatment: start vacuum negative pressure dehydration, when the temperature in the kettle starts to drop from 120-130℃ to 105-110℃, dehydrate at a constant temperature of 105-110℃ for 80-90min; S5, first mixing treatment: after the dehydration treatment is completed, the temperature is lowered in the kettle to below 90° C., alkane oil is added, and the first stirring is performed to obtain a mixed solvent 1; S6, a second mixing treatment, cooling to below 65°C, adding o-octyl adipate, polyol acetate, hydrofluoric acid, and a coupling agent to the mixed solvent 1, and stirring for a second time to obtain a mixed solvent 2, wherein the mixed solvent 2 is the cold box resin component I.

5. The method according to claim 4, characterized in that The coupling agent is γ-glycidyloxypropyltrimethoxysilane; The boiling point of the alkane oil is 200-230°C, The alkane oil includes 200# alkane oil and / or 230# alkane oil; The mass ratio of phenol, paraformaldehyde, zinc acetate, o-octyl adipate, polyol acetate, alkane oil, hydrofluoric acid and coupling agent is (40-48): (15-22): (0.07-0.13): (7-15): (7-15): (15-30): (0.1-0.3): (0.4-1).

6. A cold box resin suitable for a casting riser, characterized in that: It comprises the cold box resin component I according to any one of claims 1 to 3, the aggregate components of the casting riser include SiO2, Al, and Al2O3, and the casting riser is a core shooting process riser.

7. Use of the cold box resin component I according to any one of claims 1 to 3 or the cold box resin according to claim 6 in preparing a casting riser, wherein the aggregate components of the casting riser include SiO2, Al, and Al2O3, and the casting riser is a core shooting process riser.

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