CN115971405A - Modified phenolic resin precoated sand and preparation method thereof - Google Patents
Modified phenolic resin precoated sand and preparation method thereof Download PDFInfo
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- CN115971405A CN115971405A CN202211551154.0A CN202211551154A CN115971405A CN 115971405 A CN115971405 A CN 115971405A CN 202211551154 A CN202211551154 A CN 202211551154A CN 115971405 A CN115971405 A CN 115971405A
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- phenolic resin
- modified phenolic
- sand
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- 239000004576 sand Substances 0.000 title claims abstract description 68
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical class [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 title claims abstract description 43
- 238000002360 preparation method Methods 0.000 title claims abstract description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 120
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 26
- FUGYGGDSWSUORM-UHFFFAOYSA-N 4-hydroxystyrene Chemical compound OC1=CC=C(C=C)C=C1 FUGYGGDSWSUORM-UHFFFAOYSA-N 0.000 claims abstract description 12
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 claims abstract description 12
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 claims abstract description 9
- CJZGTCYPCWQAJB-UHFFFAOYSA-L calcium stearate Chemical compound [Ca+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O CJZGTCYPCWQAJB-UHFFFAOYSA-L 0.000 claims abstract description 9
- 235000013539 calcium stearate Nutrition 0.000 claims abstract description 9
- 239000008116 calcium stearate Substances 0.000 claims abstract description 9
- VKYKSIONXSXAKP-UHFFFAOYSA-N hexamethylenetetramine Chemical compound C1N(C2)CN3CN1CN2C3 VKYKSIONXSXAKP-UHFFFAOYSA-N 0.000 claims abstract description 9
- 238000002156 mixing Methods 0.000 claims description 22
- 238000003756 stirring Methods 0.000 claims description 18
- 238000010438 heat treatment Methods 0.000 claims description 12
- 229920001577 copolymer Polymers 0.000 claims description 11
- 238000000034 method Methods 0.000 claims description 9
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 8
- MZRVEZGGRBJDDB-UHFFFAOYSA-N N-Butyllithium Chemical compound [Li]CCCC MZRVEZGGRBJDDB-UHFFFAOYSA-N 0.000 claims description 6
- 238000001816 cooling Methods 0.000 claims description 6
- 238000012216 screening Methods 0.000 claims description 6
- 238000006243 chemical reaction Methods 0.000 claims description 5
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 claims description 4
- 238000010992 reflux Methods 0.000 claims description 4
- 239000002904 solvent Substances 0.000 claims description 3
- 238000010539 anionic addition polymerization reaction Methods 0.000 claims description 2
- 239000003999 initiator Substances 0.000 claims description 2
- 239000000178 monomer Substances 0.000 claims description 2
- 238000006116 polymerization reaction Methods 0.000 claims description 2
- 230000015572 biosynthetic process Effects 0.000 claims 1
- 238000003786 synthesis reaction Methods 0.000 claims 1
- 238000005266 casting Methods 0.000 abstract description 11
- 239000010437 gem Substances 0.000 abstract description 2
- 229910001751 gemstone Inorganic materials 0.000 abstract description 2
- 238000005058 metal casting Methods 0.000 abstract description 2
- 239000005011 phenolic resin Substances 0.000 description 9
- 229920001568 phenolic resin Polymers 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- IJOOHPMOJXWVHK-UHFFFAOYSA-N chlorotrimethylsilane Chemical compound C[Si](C)(C)Cl IJOOHPMOJXWVHK-UHFFFAOYSA-N 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000004132 cross linking Methods 0.000 description 2
- 238000002329 infrared spectrum Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000007528 sand casting Methods 0.000 description 2
- 229910001018 Cast iron Inorganic materials 0.000 description 1
- 229910001208 Crucible steel Inorganic materials 0.000 description 1
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- ANUZKYYBDVLEEI-UHFFFAOYSA-N butane;hexane;lithium Chemical compound [Li]CCCC.CCCCCC ANUZKYYBDVLEEI-UHFFFAOYSA-N 0.000 description 1
- 239000010431 corundum Substances 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003110 molding sand Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 239000005051 trimethylchlorosilane Substances 0.000 description 1
- 210000003462 vein Anatomy 0.000 description 1
- 229910052845 zircon Inorganic materials 0.000 description 1
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 0.000 description 1
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Abstract
The invention relates to modified phenolic resin precoated sand and a preparation method thereof, belonging to the technical field of metal casting. The modified precoated sand comprises the following components in percentage by weight: 2 plus or minus 1 percent of modified phenolic resin, 0.2 plus or minus 0.1 percent of urotropine, 0.18 plus or minus 0.1 percent of calcium stearate, and the balance of silica sand: the modified phenolic resin is synthesized by 4-hydroxystyrene, butadiene and formaldehyde. The modified phenolic resin precoated sand obtained by the invention shows low expansion coefficient and high heat resistance under the condition of not introducing special sand such as jewel sand and the like, and meets higher casting requirement.
Description
Technical Field
The invention relates to sand for casting, in particular to modified phenolic resin coated sand and a preparation method thereof, belonging to the technical field of metal casting.
Background
The precoated sand casting process is an important basic process in the modern machinery manufacturing industry, the main body of the process is a precoated sand material for press forming a precoated sand mold (core), and the precoated sand refers to the molding sand or sand core of which the surface of sand grains is coated with a layer of solid resin film before molding or core making, and has the advantages of high dimensional precision, low gas evolution, smooth surface, high strength, convenient storage and the like of produced castings, and achieves unusual performances in the fields of cast iron, cast steel and other alloy castings. Because the conventional precoated sand silica sand has high expansion coefficient and short heat-resisting time, the defects of casting surface vein and local position deformation, even cracking and the like in the sand casting process are easy to occur when the conventional precoated sand silica sand is used for producing castings, and the size precision of the finally produced castings can not meet the higher casting requirement of the castings. In order to solve the problem, special sands such as baozhu sand, corundum sand, zircon sand and the like are introduced into the industry, the low expansion coefficient of the special sands can meet the higher requirement of dimensional accuracy, but the cost of the sand mold is greatly improved, and the economic benefit is reduced. Therefore, the method has important significance for reducing the expansion coefficient of the silica sand and improving the heat resistance under the condition of not introducing special sand such as the precious pearl sand and the like.
Disclosure of Invention
The technical problem is as follows: the invention aims to provide modified phenolic resin precoated sand with low expansion coefficient and strong heat resistance and a preparation method thereof, so as to meet higher casting requirement.
The technical scheme is as follows: in order to achieve the purpose, the preparation method of the modified phenolic resin precoated sand adopts the following technical scheme:
firstly, heating silica sand, adding modified phenolic resin, stirring and mixing uniformly;
secondly, adding urotropine, stirring and mixing uniformly;
thirdly, adding calcium stearate, stirring and mixing uniformly;
and fourthly, cooling, crushing and screening to obtain the modified phenolic resin precoated sand.
The silica sand is heated to 140-160 ℃.
The weight percentages of the components are as follows: 2 plus or minus 1 percent of modified phenolic resin, 0.2 plus or minus 0.1 percent of urotropine and 0.18 plus or minus 0.1 percent of calcium stearate.
The preparation method of the modified phenolic resin comprises the following steps:
firstly, taking butyl lithium as an initiator, 4-hydroxystyrene and butadiene as polymerization monomers, and THF as a solvent to carry out anionic polymerization reaction to obtain a copolymer C;
and step two, mixing the copolymer C and formaldehyde, adjusting the pH value of the system by using hydrochloric acid, heating, refluxing, reacting, dehydrating and vacuumizing to obtain the modified phenolic resin.
The molar ratio of the 4-hydroxystyrene to the butadiene is 1.
The molecular weight of the copolymer C is 5000-20000 g/mol;
the mass ratio of the copolymer C to formaldehyde is 5.
Has the advantages that: according to the invention, the phenolic resin is modified by introducing the carbon chain polymer chain segment, so that the crosslinking degree of the phenolic resin on the surface of the silica sand is improved, the phenolic resin is better attached to and covers the surface of the silica sand, and when the silica sand expands under heating, the tight coating of the resin can prevent the silica sand from volume expansion to a certain extent, and the expansion coefficient of the silica sand is reduced; in addition, when the silica sand works at high temperature, the polymer chain segment is gradually carbonized, and the compact carbon chain structure can prolong the heat-resistant time of the silica sand and enhance the heat-resistant performance; therefore, the modified phenolic resin coated sand disclosed by the invention shows low expansion coefficient and high heat resistance under the condition that special sand such as jewel sand is not introduced, and meets higher casting requirements.
Drawings
FIG. 1 is an infrared spectrum of the modified phenolic resin of example 1.
Detailed Description
Example 1
Firstly, adding 12g of 4-hydroxystyrene into a reaction bottle, vacuumizing and filling nitrogen for 3 times, adding 1mL of n-butyl lithium n-hexane solution (2.5M) and 41mL of butadiene THF solution (13 wt%), reacting for 24 hours at 0 +/-5 ℃, adding trimethylchlorosilane (n-butyl lithium 1 eq) for quenching reaction, and filtering, removing solvent and drying a product to obtain a copolymer C.
The weight-average molecular weight of copolymer C was found to be 8580g/mol using a gel permeation chromatograph (mobile phase THF, column temperature 40 ℃ C., PS as internal standard).
And secondly, mixing 15g of copolymer C and 3g of formaldehyde, adjusting the pH value of the system to 1.5-2 by using hydrochloric acid, heating and refluxing for 5 hours, dehydrating, and vacuumizing to obtain the modified phenolic resin. The infrared spectrum of the modified phenolic resin is shown in figure 1.
Comparative example 1
Mixing 15g of phenol and 3g of formaldehyde, adjusting the pH value of the system to 1.5-2 by using hydrochloric acid, heating and refluxing for 5 hours, dehydrating, and vacuumizing to obtain the phenolic resin.
Example 2
Firstly, heating silica sand to 140 ℃, adding 1 wt% of modified phenolic resin, and stirring and mixing uniformly;
secondly, adding urotropine with the weight percentage of 0.1 percent, stirring and mixing evenly;
thirdly, adding calcium stearate with the weight percentage of 0.08 percent, and stirring and mixing uniformly;
and step four, cooling, crushing and screening to obtain the modified phenolic resin precoated sand.
Example 3
Firstly, heating silica sand to 150 ℃, adding 2 wt% of modified phenolic resin, and stirring and mixing uniformly;
secondly, adding urotropine with the weight percentage of 0.2 percent, stirring and mixing evenly;
thirdly, adding calcium stearate with the weight percentage of 0.18 percent, and stirring and mixing uniformly;
and step four, cooling, crushing and screening to obtain the modified phenolic resin precoated sand.
Example 4
Firstly, heating silica sand to 160 ℃, adding 3wt% of modified phenolic resin, and stirring and mixing uniformly;
secondly, adding urotropine with the weight percentage of 0.3 percent, stirring and mixing evenly;
thirdly, adding calcium stearate with the weight percentage of 0.28 percent, and stirring and mixing uniformly;
and step four, cooling, crushing and screening to obtain the modified phenolic resin precoated sand.
Comparative example 2
Firstly, heating silica sand to 140 ℃, adding 1 wt% of the phenolic resin prepared in the comparative example 1, and uniformly stirring and mixing;
secondly, adding urotropine with the weight percentage of 0.1 percent, and stirring and mixing uniformly;
thirdly, adding calcium stearate with the weight percentage of 0.08 percent, and stirring and mixing evenly;
and fourthly, cooling, crushing and screening to obtain the phenolic resin coated sand.
Example 5
The performances of the precoated sand synthesized in examples 2 to 4 and comparative example 2 were measured by an SQW type material high-temperature strength tester, and the test results are shown in table 1:
TABLE 1
| Sample (I) | Coefficient of swelling/%) | Heat resistance time/s |
| Example 2 | 0.91 | 128 |
| Example 3 | 0.90 | 129 |
| Example 4 | 0.89 | 132 |
| Comparative example 2 | 1.5 | 72 |
The modified phenolic resin coated sand has a lower expansion coefficient and a higher heat-resistant time, and the carbon chain polymer chain segment is introduced between the phenolic resins, so that the crosslinking degree of the phenolic resins on the surface of the silica sand is improved, the phenolic resins are better attached and covered on the surface of the silica sand, and when the silica sand expands due to heating, the tight coating of the resins can prevent the silica sand from volume expansion to a certain extent, and the expansion coefficient of the silica sand is reduced; in addition, when the silica sand works at high temperature, the polymer chain segment is gradually carbonized, and the compact carbon chain structure can prolong the heat-resistant time of the silica sand and enhance the heat-resistant performance.
Example 6
The performance tests of the precoated sand synthesized in the examples 2 to 4 and the comparative example 2 were carried out according to the national industry standard JB/T8583-2008, and the experimental results are shown in Table 2:
TABLE 2
| Sample (I) | Tensile strength at room temperature/MPa | Normal temperature bending strength/MPa | Reduction on ignition/% |
| Example 2 | 7.01 | 13.87 | 5.66 |
| Example 3 | 7.11 | 13.94 | 5.71 |
| Example 4 | 7.28 | 14.05 | 5.78 |
| Comparative example 2 | 5.87 | 11.02 | 5.58 |
As can be seen from the above table, the strength of the modified phenolic resin coated sand of the present invention was improved.
The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose of the embodiments is to enable people to understand the content of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the main technical scheme of the invention are covered in the protection scope of the invention.
Claims (6)
1. The preparation method of the modified phenolic resin precoated sand is characterized by comprising the following steps:
firstly, heating silica sand, adding modified phenolic resin, stirring and mixing uniformly;
secondly, adding urotropine, stirring and mixing uniformly;
thirdly, adding calcium stearate, stirring and mixing uniformly;
fourthly, cooling, crushing and screening to obtain modified phenolic resin precoated sand;
the synthesis steps of the modified phenolic resin are as follows:
firstly, taking butyl lithium as an initiator, 4-hydroxystyrene and butadiene as polymerization monomers, and THF as a solvent to carry out anionic polymerization reaction to obtain a copolymer C;
and secondly, mixing the copolymer C and formaldehyde, adjusting the pH value of the system by using hydrochloric acid, heating for reflux reaction, dehydrating, and vacuumizing to obtain the modified phenolic resin.
2. The method for preparing modified phenolic resin coated sand according to claim 1, wherein the molar ratio of the 4-hydroxystyrene to the butadiene is 1.
3. The method for preparing the modified phenolic resin coated sand according to claim 1, wherein the molecular weight of the copolymer C is 5000-20000 g/mol.
4. The method for preparing the modified phenolic resin coated sand as claimed in claim 1, wherein the mass ratio of the copolymer C to formaldehyde is 5.
5. The method for preparing the modified phenolic resin coated sand according to claim 1, wherein the silica sand is heated to 140-160 ℃.
6. The preparation method of the modified phenolic resin coated sand as claimed in claim 1, wherein the weight percentages of the components are as follows: 2 plus or minus 1 percent of modified phenolic resin, 0.2 plus or minus 0.1 percent of urotropine and 0.18 plus or minus 0.1 percent of calcium stearate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211551154.0A CN115971405A (en) | 2022-12-05 | 2022-12-05 | Modified phenolic resin precoated sand and preparation method thereof |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211551154.0A CN115971405A (en) | 2022-12-05 | 2022-12-05 | Modified phenolic resin precoated sand and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
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| CN115971405A true CN115971405A (en) | 2023-04-18 |
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| CN202211551154.0A Withdrawn CN115971405A (en) | 2022-12-05 | 2022-12-05 | Modified phenolic resin precoated sand and preparation method thereof |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102688979A (en) * | 2012-06-26 | 2012-09-26 | 长沙南托造型材料有限公司 | Coated sand with long shelf life, and production method of coated sand |
| CN104084518A (en) * | 2014-06-13 | 2014-10-08 | 吴江市液铸液压件铸造有限公司 | Heatproof precoated sand and preparation method thereof |
| CN105251938A (en) * | 2015-10-30 | 2016-01-20 | 彰武联信金莹铸造材料有限公司 | Production technology for precoated sand |
| CN114574132A (en) * | 2022-05-09 | 2022-06-03 | 常熟东南塑料有限公司 | High-temperature-resistant phenolic resin adhesive and preparation method thereof |
-
2022
- 2022-12-05 CN CN202211551154.0A patent/CN115971405A/en not_active Withdrawn
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102688979A (en) * | 2012-06-26 | 2012-09-26 | 长沙南托造型材料有限公司 | Coated sand with long shelf life, and production method of coated sand |
| CN104084518A (en) * | 2014-06-13 | 2014-10-08 | 吴江市液铸液压件铸造有限公司 | Heatproof precoated sand and preparation method thereof |
| CN105251938A (en) * | 2015-10-30 | 2016-01-20 | 彰武联信金莹铸造材料有限公司 | Production technology for precoated sand |
| CN114574132A (en) * | 2022-05-09 | 2022-06-03 | 常熟东南塑料有限公司 | High-temperature-resistant phenolic resin adhesive and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 岳泉 等: "高强度酚醛树脂覆膜砂的研究", 热固性树脂, vol. 35, no. 02, pages 26 - 29 * |
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Application publication date: 20230418 |