CN110340278B

CN110340278B - Thermosetting phosphate binder auxiliary material, binder and preparation and use methods

Info

Publication number: CN110340278B
Application number: CN201910689952.1A
Authority: CN
Inventors: 张友寿; 周磊; 叶锦瑞; 夏露; 王性军; 刘志红
Original assignee: Wuhan Jinrui Technology Co ltd; Hubei University of Technology
Current assignee: Wuhan Jinrui Technology Co ltd; Hubei University of Technology
Priority date: 2019-07-29
Filing date: 2019-07-29
Publication date: 2021-01-15
Anticipated expiration: 2039-07-29
Also published as: CN110340278A

Abstract

本发明提供了热固化磷酸盐粘结剂辅料、粘结剂以及制备与使用方法，本发明提供的热固化磷酸盐粘结剂辅料，其特征在于，包括：组分Ⅰ：氨基硅烷偶联剂；和组分Ⅱ：有机酸水溶液与表面活性剂的混合溶液，其中，有机酸选自：草酸、柠檬酸、酒石酸，表面活性剂选自：十二烷基二甲基苄基氯化铵、琥珀酸二辛酯磺酸钠。经测试，在采用本发明所提供的热固化磷酸盐粘结剂辅料的情况下，砂样固化时间明显缩短，所制备砂样抗吸湿性明显提高，存放稳定性提高。使用该辅料后，型砂的流动性指标由1.184％提升至1.701％，型砂流动性改善明显，在进行复杂砂芯生产时，可明显减少砂芯缺陷，降低生产废品率，节约生产成本，具有非常显著的效果。The invention provides heat-curing phosphate binder auxiliary materials, binders, and preparation and use methods. The heat-curing phosphate binder auxiliary materials provided by the invention are characterized in that: Component I: aminosilane coupling agent ; and component II: a mixed solution of an organic acid aqueous solution and a surfactant, wherein the organic acid is selected from: oxalic acid, citric acid, tartaric acid, and the surfactant is selected from: dodecyldimethylbenzylammonium chloride, Sodium dioctyl succinate sulfonate. Tests show that when the thermal curing phosphate binder auxiliary material provided by the present invention is used, the curing time of the sand sample is significantly shortened, the moisture absorption resistance of the prepared sand sample is obviously improved, and the storage stability is improved. After using this auxiliary material, the fluidity index of the molding sand is increased from 1.184% to 1.701%, and the fluidity of the molding sand is obviously improved. In the production of complex sand cores, the defects of the sand core can be significantly reduced, the production rejection rate can be reduced, and the production cost can be saved. significant effect.

Description

Thermosetting phosphate binder auxiliary material, binder and preparation and use methods

Technical Field

The invention belongs to the field of casting, and particularly relates to a thermosetting phosphate binder auxiliary material, a binder, and preparation and use methods thereof.

Technical Field

In the casting production, the problem of environmental pollution caused by organic resin is difficult to solve all the time, and the phosphate binder serving as a novel casting inorganic binder has the characteristics of excellent environmental protection property and collapsibility, no odor, no toxicity and no pollution, can obviously reduce the pollution to the environment, and improves the working environment of workers at the same line. But has the characteristics of slower curing speed, poor moisture absorption resistance and the like compared with the traditional organic resin binder. According to the relevant characteristics of the phosphate binder, the research and development of relevant auxiliary materials are matched with the binder for use, so that the performance of the phosphate binder is improved to a certain extent, such as the solidification speed is accelerated, and the moisture absorption resistance is obviously improved. How to comprehensively modify the phosphate binder, improve the storage stability of the binder sand, select proper auxiliary materials, improve the solidification efficiency of the sand mold, and achieve the same use requirements as the traditional organic resin binder, so that the binder meets the actual production requirements, which is a problem existing at present.

Disclosure of Invention

The invention aims to solve the problems and provides a thermosetting phosphate binder auxiliary material, a binder and a preparation and use method.

In order to achieve the purpose, the invention adopts the following scheme:

< auxiliary materials >

The invention provides a thermosetting phosphate binder auxiliary material, which is characterized by comprising the following components in percentage by weight: the component I: an aminosilane coupling agent; and component II: a mixed solution of an aqueous organic acid solution and a surfactant, wherein the organic acid is selected from: oxalic acid, citric acid, tartaric acid, and surfactant selected from: dodecyl dimethyl benzyl ammonium chloride and dioctyl sodium sulfosuccinate.

Preferably, the heat-curable phosphate binder adjuvant provided by the invention can also have the following characteristics: the mass ratio of the component I: the component II is 26-45: 34 to 56.

Preferably, the heat-curable phosphate binder adjuvant provided by the invention can also have the following characteristics: wherein the aminosilane coupling agent is selected from: gamma-aminopropyltriethoxysilane KH550, gamma-aminopropylmethyldiethoxysilane KH902, N-beta (aminoethyl) -gamma-aminopropylmethyldimethoxysilane KH602, an aqueous oxalic acid solution at a concentration of 12.5 wt.%, an aqueous citric acid solution at a concentration of 33.3 wt.%, and an aqueous tartaric acid solution at a concentration of 20 wt.%.

Preferably, the heat-curable phosphate binder adjuvant provided by the invention can also have the following characteristics: the mass ratio of the organic acid aqueous solution to the surfactant is 100: 1.

< method of use >

Further, the invention also provides a using method of the thermosetting phosphate binder auxiliary material, which is characterized by comprising the following steps: (1) uniformly mixing quartz sand with the component II in the thermosetting phosphate binder auxiliary material, then uniformly mixing the quartz sand with the component I, and finally uniformly mixing the quartz sand with the phosphate binder to obtain the molding sand meeting the requirement; (2) manufacturing the molding sand into a sand sample by using a core shooter, and directly heating and curing by using a mold; alternatively, the molding sand is poured into a mold and cured by heating with a microwave.

Preferably, the method for using the heat-curable phosphate binder adjuvant provided by the invention can also have the following characteristics: when a core shooter was used, the shooting time was 2 seconds and the mould temperature was 150 ℃.

Preferably, the method for using the heat-curable phosphate binder adjuvant provided by the invention can also have the following characteristics: according to the proportion of the component I to the sand, the amount of the phosphate binder is 2.5 wt%, the amount of the component I is 0.26-0.45 wt%, and the amount of the component II is 0.34-0.56 wt%.

< Binder >

In addition, the present invention provides a thermosetting phosphate binder, characterized in that: disodium ethylene diamine tetraacetate and polyvinylpyrrolidone are used for modification. The use of the thermosetting phosphate binder in combination with the adjuvants described above is most effective.

Preferably, the method for using the heat-curable phosphate binder adjuvant provided by the invention can also have the following characteristics: the content of disodium ethylenediamine tetraacetic acid is 1.86 wt.%, and the content of polyvinylpyrrolidone is 0.15 wt.%.

< preparation method >

Further, the invention also provides a preparation method of the thermosetting phosphate binder, which is characterized by comprising the following steps: (1) adding a polyvinylpyrrolidone aqueous solution into the raw material solution, stirring and heating to 110-120 ℃; (2) adding disodium ethylene diamine tetraacetate powder, continuously heating and stirring until the solution is transparent and clear, and discharging.

Action and Effect of the invention

Tests show that under the condition of adopting the thermosetting phosphate binder auxiliary material provided by the invention, the sand sample curing time is obviously shortened, the moisture absorption resistance of the prepared sand sample is obviously improved, and the storage stability is improved. Tests show that under the adding amounts of 2.5 wt% of phosphate adhesive, 0.26-0.45 wt% of component I and 0.34-0.56 wt% of component II, when a core shooter is used for sample preparation, the instant tensile strength of a sand sample reaches 1.47-1.58 MPa, the instant bending strength reaches 5.48-5.66 MPa, the tensile strength of the sand sample still reaches 1.6-1.8 MPa after 72-hour storage, and the bending strength still reaches 5.43-5.6 MPa; and the sand sample curing time is shortened from 6 minutes to 2 minutes after the auxiliary materials are used. The sand core in all molding modes can be stored in an environment with the humidity below 70% RH, and the strength can be kept unchanged. After the auxiliary material is used, the fluidity index of the molding sand is improved from 1.184% to 1.701%, the fluidity of the molding sand is obviously improved, and when the complex sand core is produced, the defects of the sand core can be obviously reduced, the production rejection rate is reduced, the production cost is saved, and the auxiliary material has very obvious effects.

Detailed Description

Specific embodiments of the heat-curable phosphate binder adjuvants, binders, and methods of making and using the same according to the present invention are described in detail below.

< example one >

The first thermosetting phosphate binder adjuvant provided by this embodiment includes:

the component I: gamma-aminopropyltriethoxysilane KH 550;

and (2) component II: 100 parts of an aqueous oxalic acid solution (12.5% strength by weight), 1 part of dodecyldimethylbenzylammonium chloride (liquid, with an active content ≥ 45%).

Sample preparation using an experimental core shooter:

2000g of standard 50-100 mesh quartz sand is weighed, 6g of component I and 8g of component II are weighed, added into 2000g of standard quartz sand and stirred uniformly, and then 50g of phosphate binder is weighed, added into 2000g of standard quartz sand and stirred uniformly. And pouring the stirred molding sand into a sand shooting barrel, directly heating and solidifying a sand sample by adopting a mold through a core shooting machine, shooting the sand for 2 seconds, and recording the sample preparation time at the mold temperature of 150 ℃.

Table 1 example one sand model performance test

In the first embodiment, the curing time is 120 s.

As shown in table 1 above, after the thermosetting phosphate binder adjuvant provided in this embodiment is used, when a core shooter is used to prepare a sample, the tensile strength of the sand sample still reaches 1.6MPa and the bending strength still reaches 5.6MPa after the sand sample is stored for 72 hours in a humidity environment of 47% to 56% RH, and the curing time is only 120 seconds, that is, the curing time is very short under the condition that the strength performance of the sand sample is basically maintained.

In addition, in this embodiment, the phosphate binder is prepared by the following components: industrial phosphoric acid: 52.38 parts; aluminum hydroxide powder: 10.54 parts; silicic acid: 0.62 part; boric acid: 1.86 parts of; magnesium oxide: 1.24 parts; water: 31 parts of (B); copper oxide: 0.31 part; iron sulfate: 0.04 parts; EDTA-2 Na: 1.86 parts of; 0.15 part of PVP.

The preparation method of the phosphate binder comprises the following steps: (1) weighing the components in proportion; dissolving PVP powder in 100ml of water, and fully stirring to obtain a PVP aqueous solution; (2) adding industrial phosphoric acid into a reaction kettle, and heating to 110-120 ℃ while stirring; (3) adding aluminum hydroxide powder into a reaction kettle, slowly stirring, keeping the temperature stable, and continuously stirring until the reaction solution is transparent; (4) adding 50ml of water, stirring and heating to 110-120 ℃; (5) adding boric acid and silicic acid powder, and continuously heating and stirring until the reaction solution is transparent; (6) adding 50ml of water, stirring and heating to 110-120 ℃; (7) adding light magnesium oxide powder into a reaction kettle, and continuously heating and stirring until the reaction solution is transparent; (8) adding copper oxide powder and ferric sulfate powder into a reaction kettle, and continuously heating and stirring until the reaction solution is transparent; (9) adding 100ml of polyvinylpyrrolidone (PVP) water solution, stirring and heating to 110-120 ℃; (10) adding disodium ethylene diamine tetraacetate (EDTA-2Na) powder, continuously heating and stirring until the reaction solution is transparent and clear, and discharging.

The phosphate binders prepared according to the ratio and the preparation method are adopted in the following examples and comparative examples.

< example two >

The second embodiment provides a thermosetting phosphate binder adjuvant including:

the component I: gamma-aminopropyltriethoxysilane KH 550; and

and (2) component II: 100 parts of oxalic acid in water (12.5 wt.% concentration), 1 part of dioctyl sodium sulfosuccinate (liquid, and active content ≥ 50%).

Sample preparation using an experimental core shooter:

Table 2 sand model performance test in example two

In the second embodiment, the curing time is 120 s.

As shown in table 2 above, after the thermosetting phosphate binder adjuvant provided in this embodiment two is used, when a core shooter is used to prepare a sample, the tensile strength of the sand sample still reaches 1.8MPa and the bending strength still reaches 5.43MPa after the sand sample is stored for 72 hours in a humidity environment of 47% -56% RH, and the curing time is only 120 seconds, that is, the curing time is very short under the condition that the strength performance of the sand sample is basically maintained.

< example three >

The third embodiment provides a thermosetting phosphate binder adjuvant including:

the component I: gamma-aminopropyltriethoxysilane KH 550; and

Preparing a sample by using a cam type hammering sampling machine:

weighing 1000g of standard 50-100 mesh quartz sand, weighing 3g of component I and 4g of component II, adding the components into 1000g of standard quartz sand, uniformly stirring, weighing 25g of phosphate binder, adding into 1000g of standard quartz sand, and fully and uniformly stirring. 185g of the stirred molding sand is weighed and poured into a cylindrical standard sample cylinder, a cam type hammering sampling machine is used for carrying out experiments, and experimental data are recorded.

Determination of fluidity of molding sand:

the experimental method comprises the following steps: a side hole mass method is selected for carrying out the fluidity test, and the experimental method comprises the following steps: the side of a cylindrical standard sample cylinder is provided with a small hole with the diameter of 12mm, 185g of molding sand is weighed into the sample cylinder, a cam type hammering sample making machine is used for hammering for 10 times, the sand flowing out of the measuring hole is collected and weighed, the mass fraction of the sand accounting for 185g of total molding sand is used as the fluidity index of the molding sand, and the surface molding sand has better fluidity when the index value is larger.

Table 3 flowability of sand prepared in example three

< comparative example A >

In the first comparative example, no thermosetting phosphate binder auxiliary material is adopted, and the other sample preparation methods are the same as the three phases of the example:

weighing 1000g of standard 50-100 mesh quartz sand, weighing 25g of phosphate binder, adding into 1000g of standard quartz sand, and stirring completely. 185g of the stirred molding sand is weighed and poured into a cylindrical standard sample cylinder, a cam type hammering sampling machine is used for carrying out experiments, and experimental data are recorded.

The fluidity of the molding sand was measured in exactly the same manner as in example three above:

TABLE 4 fluidity of molding sand prepared in comparative example I (without using auxiliary materials)

< comparative example II >

In the second comparative example, no surfactant was added to the adjuvants, and the rest of the sample preparation methods were completely the same as those in the first example:

sample preparation using an experimental core shooter:

weighing 2000g of standard 50-100 mesh quartz sand, weighing 6gKH550 and 8g of oxalic acid aqueous solution, adding the weighed materials into 2000g of standard quartz sand, stirring uniformly, weighing 50g of phosphate binder, adding the weighed materials into 2000g of standard quartz sand, and stirring uniformly. And pouring the stirred molding sand into a sand shooting barrel, directly heating and solidifying a sand sample by adopting a mold through a core shooting machine, shooting the sand for 2 seconds, and recording the sample preparation time at the mold temperature of 150 ℃.

And (3) performance testing: the sand sample was tested for immediate strength upon hardening and post-storage strength (47% -61% RH constant humidity warehouse). The test results are shown in table 5 below:

TABLE 5 Sand Performance test of comparative example II

In the second comparative example, the curing time was 240 seconds.

Comparing the first and second examples with the second comparative example, it can be seen that the curing time of the adjuvant materials of the first and second examples is reduced by half, and the adjuvant materials still have excellent properties of high tensile strength and high flexural strength, and the strength is not reduced by the addition of the surfactant.

< comparative example III >

In the third comparative example, no auxiliary materials are adopted, and the rest sample preparation methods are completely the same as those of the second comparative example:

sample preparation using an experimental core shooter:

2000g of standard 50-100 mesh quartz sand is weighed, 50g of phosphate binder is weighed and added into 2000g of standard quartz sand, and the mixture is fully and uniformly stirred. And pouring the stirred molding sand into a sand shooting barrel, directly heating and solidifying a sand sample by adopting a mold through a core shooting machine, shooting the sand for 2 seconds, and recording the sample preparation time at the mold temperature of 150 ℃.

And (3) performance testing: the sand sample was tested for immediate strength upon hardening and post-storage strength (47% -61% RH constant humidity warehouse). The test results are shown in table 6 below:

TABLE 6 Sand Performance test in COMPARATIVE EXAMPLE III (without use of auxiliary Material)

In the third comparative example, the curing time was 360 seconds.

As shown in table 6, in the case of using no auxiliary material, the decrease in moisture absorption resistance of the sand sample was significant when the sample was produced by the core shooter, and in the humidity environment of 47% to 62% RH, the tensile strength was decreased from 1.52MPa to 0.65MPa immediately after the sand sample was stored for 24 hours without the auxiliary material, and the flexural strength was decreased from 4.59MPa immediately to 2.79 MPa.

Compared with the prior art, as shown in table 5 in the second comparative example, when the auxiliary materials are used, the tensile strength of the sand sample still reaches 1.67MPa after 72 hours of storage, and the bending strength still reaches 5.05 MPa; and the sand sample curing time is shortened by 120 seconds after the auxiliary materials are used.

< comparative example four >

In the fourth comparative example, the sample was prepared by microwave curing with 1KW power:

weighing 2000g of standard 50-100 mesh quartz sand, weighing 6gKH550 and 8g of oxalic acid aqueous solution, adding the weighed materials into 2000g of standard quartz sand, stirring uniformly, weighing 50g of phosphate binder, adding the weighed materials into 2000g of standard quartz sand, and stirring uniformly. And pouring the stirred sand into an 8-shaped mold, heating by using microwaves, and recording the sample preparation time.

And (3) performance testing: testing the hardening instant strength and the storage strength (45-56% RH humidity environment) of the sand sample. The test results are shown in table 7 below:

TABLE 7 Sand Performance test in COMPARATIVE EXAMPLE IV (use of oxalic acid as adjuvant)

In the fourth comparative example, the microwave curing time was 300 seconds.

< fifth comparative example >

In the fifth comparative example, no auxiliary materials are adopted, and the rest sample preparation methods are completely the same as those in the fourth comparative example:

using 1KW power to cure and prepare samples:

2000g of standard 50-100 mesh quartz sand is weighed, 50g of phosphate binder is weighed and added into 2000g of standard quartz sand, and the mixture is fully and uniformly stirred. And pouring the stirred sand into an 8-shaped mold, heating by using microwaves, and recording the sample preparation time.

And (3) performance testing: testing the hardening instant strength and the storage strength (45-56% RH humidity environment) of the sand sample. The test results are shown in table 8 below:

TABLE 8 Sand Performance test in COMPARATIVE EXAMPLE FIVE (without auxiliary Material)

In the fifth comparative example, the microwave curing time was 390 seconds.

As shown in Table 8, when the sand sample was solidified by 1KW microwave without using the auxiliary materials, the strength of the sand sample was reduced from 1.34MPa immediately after the sand sample was stored for 6 hours to 0.76 MPa.

Compared with the prior art, as shown in table 7 in the fourth comparative example, the moisture absorption resistance of the sand sample is obviously improved under the condition of using the auxiliary materials, and the strength of the sand sample still reaches 1.49MPa after the sand sample is stored for 48 hours under the humidity environment of 45-56% RH; and the sand sample curing time is shortened by 90 seconds after the auxiliary materials are used.

< sixth comparative example >

In the sixth comparative example, the microwave curing power is 3KW, and the other sample preparation methods are the same as the fourth comparative example:

And (3) performance testing: testing the hardening instant strength and the storage strength of the sand sample (40 to 52 percent RH humidity environment). The test results are shown in table 9 below:

TABLE 9 Sand Performance test in COMPARATIVE EXAMPLE VI (use of oxalic acid as adjuvant)

In the sixth comparative example, the microwave curing time was 120 seconds.

< seventh comparative example >

In the seventh comparative example, no auxiliary materials are adopted, and the rest sample preparation methods are completely the same as those in the sixth comparative example:

and (3) microwave curing sample preparation by using 3KW power:

And (3) performance testing: testing the hardening instant strength and the storage strength of the sand sample (40 to 52 percent RH humidity environment). The test results are shown in table 10 below:

TABLE 10 Sand Performance test in COMPARATIVE EXAMPLE seventy (without auxiliary Material)

In the seventh comparative example, the microwave curing time was 230 seconds.

As shown in Table 10, when the sand sample was cured by a 3KW microwave without using the auxiliary materials, the strength of the sand sample was reduced from 1.03MPa immediately after the sand sample was stored for 6 hours to 0.54 MPa.

Compared with the prior art, as shown in table 9 in the sixth comparative example, the moisture absorption resistance of the sand sample is obviously improved under the condition of using the auxiliary materials, and the strength of the sand sample still reaches 1.74MPa after 72 hours of storage; and the sand sample curing time is shortened by 110 seconds after the auxiliary materials are used. Compared with the fourth comparative example, the reaction temperature is increased due to the increase of the microwave power, and the use of the auxiliary materials can improve the heat resistance of the molding sand, namely, the molding sand can still maintain high performance at high temperature.

< eighth comparative example >

In the eighth comparative example, γ -aminopropylmethyldiethoxysilane (KH902) was used as the aminosilane coupling agent, and the other sample preparation methods were the same as in the sixth comparative example:

and (3) microwave curing sample preparation by using 3KW power:

2000g of standard 50-100 mesh quartz sand is weighed, 6g of KH902 and 8g of oxalic acid aqueous solution are weighed, added into 2000g of standard quartz sand and stirred uniformly, and then 50g of phosphate binder is weighed, added into 2000g of standard quartz sand and stirred uniformly. And pouring the stirred sand into an 8-shaped mold, heating by using microwaves, and recording the sample preparation time.

And (3) performance testing: testing the hardening instant strength and the storage strength (52 to 60 percent RH humidity environment) of the sand sample. The test results are shown in table 11 below:

TABLE 11 Sand Performance test in COMPARATIVE EXAMPLE eighty (KH602)

In the eighth comparative example, the microwave curing time was 120 seconds.

As shown in Table 11, when 3KW microwave is used for curing, the intensity of the sand sample still reaches 1.48MPa after 24-hour storage after KH902 auxiliary material is used in a humidity environment of 52-60% RH.

< ninth comparative example >

In this comparative example nine, N- β (aminoethyl) - γ -aminopropylmethyldimethoxysilane (KH602) was used as the aminosilane coupling agent, and the rest of the sample preparation method was exactly the same as in comparative example eight:

and (3) microwave curing sample preparation by using 3KW power:

2000g of standard 50-100 mesh quartz sand is weighed, 6g of KH602 and 8g of oxalic acid aqueous solution are weighed, added into 2000g of standard quartz sand and stirred uniformly, and then 50g of phosphate binder is weighed, added into 2000g of standard quartz sand and stirred uniformly. And pouring the stirred sand into an 8-shaped mold, heating by using microwaves, and recording the sample preparation time.

And (3) performance testing: testing the hardening instant strength and the storage strength (52 to 60 percent RH humidity environment) of the sand sample. The test results are shown in table 12 below:

TABLE 12 Sand Performance test in COMPARATIVE EXAMPLE eighty (KH602)

In this comparative example nine, the microwave curing time was 120 seconds.

As shown in Table 12, when 3KW microwave is used for curing, the intensity of the sand sample still reaches 1.57MPa after 24-hour storage after KH602 auxiliary material is used in a humidity environment of 52-60% RH.

According to the ninth, eighth and sixth comparative examples, it can be seen that three kinds of amino coupling agents can be used as auxiliary materials.

< comparative example ten >

In the tenth comparative example, γ -aminopropyltriethoxysilane (KH550) was used as the aminosilane coupling agent, and citric acid aqueous solution was used as an auxiliary material, and the other sample preparation methods were the same as those in the eighth comparative example:

and (3) microwave curing sample preparation by using 3KW power:

2000g of standard 50-100 mesh quartz sand is weighed, 6gKH550 and 8g of citric acid aqueous solution are weighed, added into 2000g of standard quartz sand and stirred uniformly, and then 50g of phosphate binder is weighed, added into 2000g of standard quartz sand and stirred uniformly. And pouring the stirred sand into an 8-shaped mold, heating by using microwaves, and recording the sample preparation time.

And (3) performance testing: the hardening instant strength and the storage strength (50 to 56 percent RH humidity environment) of the sand sample are tested. The test results are shown in table 13 below:

TABLE 13 Sand Performance test of comparative example ten (KH550+ citric acid)

In this comparative example ten, the microwave curing time was 120 s.

As shown in Table 13, when 3KW microwave is used for curing, the sand sample strength still reaches 1.43MPa after 24-hour storage in a humidity environment of 50-56% RH by using citric acid auxiliary materials.

< comparative example eleven >

In the eleventh comparative example, tartaric acid aqueous solution is used as an auxiliary material, and the rest sample preparation methods are completely the same as those of the tenth comparative example:

and (3) microwave curing sample preparation by using 3KW power:

2000g of standard 50-100 mesh quartz sand is weighed, 6gKH550 and 8g of tartaric acid aqueous solution are weighed, added into 2000g of standard quartz sand and stirred uniformly, and then 50g of phosphate binder is weighed, added into 2000g of standard quartz sand and stirred uniformly. And pouring the stirred sand into an 8-shaped mold, heating by using microwaves, and recording the sample preparation time.

And (3) performance testing: testing the hardening instant strength and the storage strength (52 to 60 percent RH humidity environment) of the sand sample. The test results are shown in table 14 below:

TABLE 14 Sand Performance test of comparative example eleven (KH550+ tartaric acid)

In the eleventh comparative example, the microwave curing time was 120 seconds.

As shown in Table 14, when 3KW microwave is used for curing, the strength of the sand sample still reaches 1.48MPa after 24-hour storage after tartaric acid auxiliary materials are used in a humidity environment of 50-56% RH.

According to the eleventh, tenth and sixth comparative examples, three kinds of aqueous organic acid solutions can be used as auxiliary materials.

< twelfth comparative example >

In this comparative example, the range of the amount of the auxiliary materials added was determined based on the following 7 protocols.

Using 1KW power to cure and prepare samples:

scheme 1: 2000g of standard 50-100 mesh quartz sand is weighed (0.06 wt% of aminosilane coupling agent and 0.07 wt% of organic acid aqueous solution), 1.2gKH550 and 1.4g of oxalic acid aqueous solution are weighed, added into 2000g of standard quartz sand and stirred uniformly, 50g of phosphate binder is weighed, added into 2000g of standard quartz sand and stirred uniformly. And pouring the stirred sand into an 8-shaped mold, heating by using microwaves, and recording the sample preparation time.

Scheme 2: 2000g of standard 50-100 mesh quartz sand is weighed (0.12 wt% of aminosilane coupling agent and 0.14 wt% of organic acid aqueous solution), 2.4gKH550 and 2.8g of oxalic acid aqueous solution are weighed, added into 2000g of standard quartz sand and stirred uniformly, 50g of phosphate binder is weighed, added into 2000g of standard quartz sand and stirred uniformly. And pouring the stirred sand into an 8-shaped mold, heating by using microwaves, and recording the sample preparation time.

Scheme 3: 2000g of standard 50-100 mesh quartz sand is weighed (0.23 wt% of aminosilane coupling agent and 0.28 wt% of organic acid aqueous solution), 4.6gKH550 and 5.6g of oxalic acid aqueous solution are weighed, added into 2000g of standard quartz sand and stirred uniformly, 50g of phosphate binder is weighed, added into 2000g of standard quartz sand and stirred uniformly. And pouring the stirred sand into an 8-shaped mold, heating by using microwaves, and recording the sample preparation time.

Scheme 4: 2000g of standard 50-100 mesh quartz sand is weighed (0.26 wt% of aminosilane coupling agent and 0.34 wt% of organic acid aqueous solution), 5.2gKH550 and 6.8g of oxalic acid aqueous solution are weighed, added into 2000g of standard quartz sand and stirred uniformly, 50g of phosphate binder is weighed, added into 2000g of standard quartz sand and stirred uniformly. And pouring the stirred sand into an 8-shaped mold, heating by using microwaves, and recording the sample preparation time.

Scheme 5: 2000g of standard 50-100 mesh quartz sand is weighed (0.3 wt% of aminosilane coupling agent and 0.4 wt% of organic acid aqueous solution), 6gKH550 and 8g of oxalic acid aqueous solution are weighed, the standard quartz sand is added into 2000g of oxalic acid aqueous solution and stirred uniformly, and then 50g of phosphate binder is weighed and added into 2000g of standard quartz sand and stirred uniformly. And pouring the stirred sand into an 8-shaped mold, heating by using microwaves, and recording the sample preparation time.

Scheme 6: 2000g of standard 50-100 mesh quartz sand is weighed (0.45 wt% of aminosilane coupling agent and 0.56 wt% of organic acid aqueous solution), 9gKH550 and 11g of oxalic acid aqueous solution are weighed, the aqueous solution is added into 2000g of standard quartz sand and stirred uniformly, 50g of phosphate binder is weighed and added into 2000g of standard quartz sand and stirred uniformly. And pouring the stirred sand into an 8-shaped mold, heating by using microwaves, and recording the sample preparation time.

Scheme 7: 2000g of standard 50-100 mesh quartz sand is weighed (0.5 wt% of aminosilane coupling agent and 0.6 wt% of organic acid aqueous solution), 10gKH550 and 12g of oxalic acid aqueous solution are weighed, the standard quartz sand is added with 2000g of oxalic acid aqueous solution and stirred uniformly, and then 50g of phosphate binder is weighed and added with 2000g of standard quartz sand and stirred uniformly. Pouring the stirred sand into an 8-shaped mold, heating by using microwave, and recording the sample preparation time

And (3) performance testing: the hardening instant strength and the storage strength (48-54% RH humidity environment) of the sand sample are tested and compared.

The test results are shown in the following table:

TABLE 15 Performance testing of Molding sands prepared with different additive proportions

TABLE 16 microwave curing time for Sand molds prepared with different adjuvant addition ratios

As can be seen from tables 15 and 16: in the scheme 1-3, the addition content of auxiliary materials is low, the curing time is long, and the sand sample is poor in moisture absorption resistance; scheme 7, the auxiliary material adds the content on the high side, and molding sand live time obviously descends, leads to the sand sample bulk strength on the low side. Obtaining the optimal range of the addition amount of the auxiliary materials: 0.26 to 0.45 wt% of an aminosilane coupling agent, and 0.34 to 0.56 wt% of an aqueous solution of an organic acid.

The above embodiments are merely illustrative of the technical solutions of the present invention. The heat-curable phosphate binder adjuvant, the binder and the methods for preparing and using the binder according to the present invention are not limited to the contents described in the above embodiments, but are subject to the scope defined by the claims. Any modification or supplement or equivalent replacement made by a person skilled in the art on the basis of this embodiment is within the scope of the invention as claimed in the claims.

Claims

1. A heat-curable phosphate binder adjuvant characterized by comprising:

the component I: an aminosilane coupling agent; and

and (2) component II: a mixed solution of an organic acid aqueous solution and a surfactant,

wherein the organic acid is selected from: oxalic acid, citric acid and tartaric acid,

the surfactant is selected from: dodecyl dimethyl benzyl ammonium chloride, dioctyl sodium sulfosuccinate,

the use method of the thermosetting phosphate binder auxiliary material comprises the following steps: (1) uniformly mixing quartz sand with the component II in the thermosetting phosphate binder auxiliary material, then uniformly mixing the quartz sand with the component I, and finally uniformly mixing the quartz sand with the phosphate binder to obtain the molding sand meeting the requirement; (2) manufacturing the molding sand into a sand sample by using a core shooter, and directly heating and curing by using a mold; alternatively, the molding sand is poured into a mold and cured by heating with a microwave.

2. The thermally curable phosphate binder formulation according to claim 1, wherein:

wherein, the mass ratio of the component I: the component II is 26-45: 34 to 56.

3. The thermally curable phosphate binder formulation according to claim 1, wherein:

wherein the aminosilane coupling agent is selected from: gamma-aminopropyltriethoxysilane KH550, gamma-aminopropylmethyldiethoxysilane KH902, N-beta (aminoethyl) -gamma-aminopropylmethyldimethoxysilane KH602,

the concentration of the oxalic acid aqueous solution was 12.5 wt.%, the concentration of the citric acid aqueous solution was 33.3 wt.%, and the concentration of the tartaric acid aqueous solution was 20 wt.%.

4. The thermally curable phosphate binder formulation according to claim 1, wherein:

wherein the mass ratio of the organic acid aqueous solution to the surfactant is 100: 1.

5. the method of using a heat-curable phosphate binder adjuvant according to any one of claims 1 to 4, characterized in that it comprises the following steps:

(1) uniformly mixing quartz sand with the component II in the thermosetting phosphate binder auxiliary material, then uniformly mixing the quartz sand with the component I, and finally uniformly mixing the quartz sand with the phosphate binder to obtain the molding sand meeting the requirement;

(2) manufacturing the molding sand into a sand sample by using a core shooter, and directly heating and curing by using a mold; alternatively, the molding sand is poured into a mold and cured by heating with a microwave.

6. The method of using a heat-curable phosphate binder formulation according to claim 5, wherein:

wherein, when a core shooter is used, the sand shooting time is 2 seconds, and the mold temperature is 150 ℃.

7. The method of using a heat-curable phosphate binder formulation according to claim 5, wherein:

wherein, according to the proportion of the component I to the sand, the dosage of the phosphate binder is 2.5 wt%, the dosage of the component I is 0.26-0.45 wt%, and the dosage of the component II is 0.34-0.56 wt%.