WO1997031732A1 - Binder-coated sand for moulds - Google Patents
Binder-coated sand for moulds Download PDFInfo
- Publication number
- WO1997031732A1 WO1997031732A1 PCT/EP1997/001004 EP9701004W WO9731732A1 WO 1997031732 A1 WO1997031732 A1 WO 1997031732A1 EP 9701004 W EP9701004 W EP 9701004W WO 9731732 A1 WO9731732 A1 WO 9731732A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- acid
- curing
- coated sand
- sand
- moulds
- Prior art date
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
- B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
- B22C1/20—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents
- B22C1/22—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of resins or rosins
- B22C1/2233—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of resins or rosins obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- B22C1/224—Furan polymers
Definitions
- the present invention relates to a binder-coated sand (hereinafter, coated sand) for moulds, suitable for producing a furan-based resin self-curable mould which is cured with acid.
- coated sand for moulds, suitable for producing a furan-based resin self-curable mould which is cured with acid.
- Known mould forming techniques other than the shell mould method in which dry sand is used as the moulded material of the mould include the hot box method in which wet sand is used and the self-cure mould forming method.
- the mould is produced by blowing or compacting coated sand comprising moulding sand, furan-based resin and curing acid in a metal or wooden mould at ambient temperature.
- the conventional curing acids generally used are paratoluenesulfonic acid, benzenesulfonic acid and xylenesulfonic acid.
- An object of this invention is to provide a self-curing type binder-coated sand for mouldings having a rapid curing rate at low temperature such as below 25 °C and hence improve productivity.
- the present invention provides self-curing type binder-coated sand for moulding comprising moulding sand, furan resin and curing acid, characterized in that the said curing acid is methanesulfonic acid or a mixture of methanesulfonic acid and organic sulfonic acid or inorganic acid.
- Methanesulfonic acid of the present invention is preferably used in a form of solution dissolved in a solvent such as water, methanol, ethanol or isopropanol
- a solvent such as water, methanol, ethanol or isopropanol
- Aqueous solutions of methanesulfonic acid have preferably a concentration of 10 to 90 % by weight, preferably 50 to 80 % by weight.
- the organic sulfonic acids which can be combined with methane ⁇ sulfonic acid include paratoluenesulfonic acid, benzenesulfonic acid and xylenesulfonic acid.
- the inorganic acid may be sulfuric acid.
- These acids can be used at a proportion of 0.1 to 10 parts by weight, preferably 0.2 to 8 parts by weight with respect to 1 part by weight of methanesulfonic acid (MSA).
- MSA methanesulfonic acid
- the aqueous solution of methanesulfonic acid or the aqueous solution of methanesulfonic acid / organic sulfonic acid or inorganic acid can be used at a proportion of 20 to 80 parts, preferably 40 to 60 parts by weight with respect to 100 parts by weight of furan based resin.
- the furan-based resin used in the present invention is liquid furan resin prepared by condensation of furans and formaldehyde in alkaline medium (pH
- Furans indicate ftirfural, furfuryl alcohol and the like.
- Coated sand according to the present invention can be prepared by mixing moulding sand and a curing acid such as methanesulfonic acid for several rninutes in a mixer such as a sand mill, adding furan resin and further mixing.
- Methanesulfonic acid releases protons FT* " more readily than paratoluenesulfonic acid, benzenesulfonic acid and xylenesulfonic acid even at lower temperatures and possesses good compatibility with resin.
- the coated sand prepared by using methanesulfonic acid or a mixture of methanesulfonic acid and organic sulfonic acid or inorganic acid can cure rapidly, in particular at lower temperatures, so that the mould-fo ⁇ ning cycle can be shortened.
- the resulting coated sand was compacted in a wooden mould (diameter of 50 mm, length of 50 mm) and was cured in a humidity chamber whose temperature was fixed at 25 °C and whose humidity was fixed at 60 % to l o obtain a cured test piece. Test results shown in the Table.
- Example 2 The procedure of Example 1 was repeated, except that 15.4 g of 70 % aqueous solution of methanesulfomc acid (pure part 10.8 g, 60 % by weight to 15 resin) were used and the humidity chamber temperature was 5°C. A coated sand and a test piece were obtained. Test results are shown in the Table.
- Example 2 The procedure of Example 1 was repeated, except that 7.7 g of 70 % 20 aqueous solution of methanesulfonic acid (pure part 5.4 g, 30 % by weight to resin) and 9 g of 60 % sulfuric acid solution (pure part 5.4 g, 30 % by weight to resin) were used and the temperature of the humidity chamber was changed to 5 °C. A coated sand and a test piece were obtained. Test results are shown in the Table. 5
- Example 2 The procedure of Example 1 was repeated, except that 70 % aqueous solution of methanesulfonic acid was changed to equimolar 60 % xylene sulfonic acid (40 % by weight to resin). A coated sand and a test piece were o obtained. Test results are shown in the Table.
- Example 2 The procedure of Example 1 was repeated, except that 70 % aqueous solution of methanesulfonic acid was changed to 18 g of 60 % xylene sulfonic 5 acid (pure part 10.8 g, 60 % by weight to resin) and the temperature of the humidity chamber was changed to 5 °C. A coated sand and a test piece were obtained. Test results are shown in the Table. Comparative Example 3
- Example 1 The procedure of Example 1 was repeated, except that 70 % aqueous solution of methanesulfonic acid was changed to 18 g of 60 % sulfuric acid
- Example 2 The procedure of Example 1 was repeated, except that 70 % aqueous solution of methanesulfonic acid was changed to 9 g of 60 % xylenesulfonic acid (pure part 5.4 g, 30 % by weight to resin) and 9 g of 60 % sulfuric acid (pure part 5.4 g, 30 % by weight to resin) and the temperature of the humidity chamber was changed to 5 °C. A coated sand and a test piece were obtained. Test results are shown in the Table.
- the binder-coated sands for moulds according to the present invention show faster curing rates than the conventional curing agents paratoluenesulfonic acid, benzenesulfonic acid, xylenesulfonic acid and mixtures thereof, in particular at lower temperatures and that the resulting self-curable binder coated sand for moulds shows higher strength, and hence is very practical.
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Mold Materials And Core Materials (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
To provide binder-coated sand for moulds wherein the curing is excellent and the acid curing of the furan-based resin proceeds at a rapid curing rate not only at high temperatures but also at temperatures below ambient temperature, the curing acid is methanesulfonic acid or a mixture of methanesulfonic acid and organic sulfonic acid or inorganic acid.
Description
BINDER-COATED SAND FOR MOULDS
Field of the Invention
The present invention relates to a binder-coated sand (hereinafter, coated sand) for moulds, suitable for producing a furan-based resin self-curable mould which is cured with acid.
Background of the Invention
Known mould forming techniques other than the shell mould method in which dry sand is used as the moulded material of the mould, include the hot box method in which wet sand is used and the self-cure mould forming method.
In the acid-cured type furan-based resin, self-curable mould forming technique which is one of self-cure mould forming methods, the mould is produced by blowing or compacting coated sand comprising moulding sand, furan-based resin and curing acid in a metal or wooden mould at ambient temperature.
The conventional curing acids generally used are paratoluenesulfonic acid, benzenesulfonic acid and xylenesulfonic acid. When moulds are made under high temperature condition in summer time with coated sand containing one of the above-mentioned acids, the mould-making proceeds with a fast curing rate, so that there is no problem with productivity.
However, it takes rather long time to produce a sand mould under such low temperatures as below 25 °C, in particular in winter, and more particularly below 10 °C, so there is a problem in that the mould forming cycle becomes longer.
An object of this invention is to provide a self-curing type binder-coated sand for mouldings having a rapid curing rate at low temperature such as below 25 °C and hence improve productivity.
Summary of the Invention
The present invention provides self-curing type binder-coated sand for moulding comprising moulding sand, furan resin and curing acid, characterized in that the said curing acid is methanesulfonic acid or a mixture of methanesulfonic acid and organic sulfonic acid or inorganic acid.
Detailed description of the Invention
Methanesulfonic acid of the present invention is preferably used in a form of solution dissolved in a solvent such as water, methanol, ethanol or isopropanol Aqueous solutions of methanesulfonic acid have preferably a concentration of 10 to 90 % by weight, preferably 50 to 80 % by weight.
The organic sulfonic acids which can be combined with methane¬ sulfonic acid include paratoluenesulfonic acid, benzenesulfonic acid and xylenesulfonic acid. The inorganic acid may be sulfuric acid.
These acids can be used at a proportion of 0.1 to 10 parts by weight, preferably 0.2 to 8 parts by weight with respect to 1 part by weight of methanesulfonic acid (MSA).
The aqueous solution of methanesulfonic acid or the aqueous solution of methanesulfonic acid / organic sulfonic acid or inorganic acid can be used at a proportion of 20 to 80 parts, preferably 40 to 60 parts by weight with respect to 100 parts by weight of furan based resin.
The furan-based resin used in the present invention is liquid furan resin prepared by condensation of furans and formaldehyde in alkaline medium (pH
8-14), followed by condensation, or denatured furan resin prepared by co- polycondensation of formaldehyde with furans combined with an optional proportion of urea. Furans indicate ftirfural, furfuryl alcohol and the like.
Coated sand according to the present invention can be prepared by mixing moulding sand and a curing acid such as methanesulfonic acid for several rninutes in a mixer such as a sand mill, adding furan resin and further mixing. Methanesulfonic acid releases protons FT*" more readily than paratoluenesulfonic acid, benzenesulfonic acid and xylenesulfonic acid even at lower temperatures and possesses good compatibility with resin. Therefore, the coated sand prepared by using methanesulfonic acid or a mixture of methanesulfonic acid and organic sulfonic acid or inorganic acid can cure rapidly, in particular at lower temperatures, so that the mould-foπning cycle can be shortened.
Examples Now, the present invention will be explained in more detail with reference to Examples but the present invention is not limited to the following Examples.
Example
2 kg of moulding sand (FR1MENTOL silica sand) and 5 1 g of 70 % aqueous solution of methanesulfonic acid (pure part 3 6 g, 20 % bv weight to resin) were mixed in a Simpson type sand mill for 2 minutes Then, 18 g of
5 urea-denatured furan resin (Hitach Chemical, VF-954K) were added and kneaded for 2 minutes to obtain coated sand.
The resulting coated sand was compacted in a wooden mould (diameter of 50 mm, length of 50 mm) and was cured in a humidity chamber whose temperature was fixed at 25 °C and whose humidity was fixed at 60 % to l o obtain a cured test piece. Test results shown in the Table.
Example 2
The procedure of Example 1 was repeated, except that 15.4 g of 70 % aqueous solution of methanesulfomc acid (pure part 10.8 g, 60 % by weight to 15 resin) were used and the humidity chamber temperature was 5°C. A coated sand and a test piece were obtained. Test results are shown in the Table.
Example 3
The procedure of Example 1 was repeated, except that 7.7 g of 70 % 20 aqueous solution of methanesulfonic acid (pure part 5.4 g, 30 % by weight to resin) and 9 g of 60 % sulfuric acid solution (pure part 5.4 g, 30 % by weight to resin) were used and the temperature of the humidity chamber was changed to 5 °C. A coated sand and a test piece were obtained. Test results are shown in the Table. 5
Comparative Example 1
The procedure of Example 1 was repeated, except that 70 % aqueous solution of methanesulfonic acid was changed to equimolar 60 % xylene sulfonic acid (40 % by weight to resin). A coated sand and a test piece were o obtained. Test results are shown in the Table.
Comparative Example 2
The procedure of Example 1 was repeated, except that 70 % aqueous solution of methanesulfonic acid was changed to 18 g of 60 % xylene sulfonic 5 acid (pure part 10.8 g, 60 % by weight to resin) and the temperature of the humidity chamber was changed to 5 °C. A coated sand and a test piece were obtained. Test results are shown in the Table.
Comparative Example 3
The procedure of Example 1 was repeated, except that 70 % aqueous solution of methanesulfonic acid was changed to 18 g of 60 % sulfuric acid
(pure part 10.8g, 60 % by weight to resin) and the temperature of the humidity chamber was changed to 5 °C. A coated sand and a test piece were obtained.
Test results are shown in the Table.
Comparative Example 4
The procedure of Example 1 was repeated, except that 70 % aqueous solution of methanesulfonic acid was changed to 9 g of 60 % xylenesulfonic acid (pure part 5.4 g, 30 % by weight to resin) and 9 g of 60 % sulfuric acid (pure part 5.4 g, 30 % by weight to resin) and the temperature of the humidity chamber was changed to 5 °C. A coated sand and a test piece were obtained. Test results are shown in the Table.
The compression strengths of the pieces obtained in Examples 1, 2 and 3 and Comparative Examples 1, 2, 3 and 4 were measured at 1, 3, 6, 18 and 24 hours after the samples were produced.
TABLE
Compression strength (KgfVcm^)
Time passed 1 3 6 18 24
Example 1 18.5 26.7 32.0 35.5 41.0
Comparative Ex. 1 11.8 20.4 26.5 36.1 41.5
Example 2 9.7 22.0 25.9 30.8 35.7
Example 3 13.3 23.4 28.4 29.4 34.6
Comparative Ex. 2 0 0 1.9 16.2 18.7
Comparative Ex. 3 1.4 8.0 9.7 17.6 28.5
Comparative Ex. 4 0 12.9 20.1 23.9 32.3
From the results shown in the following Table, it is apparent that the binder-coated sands for moulds according to the present invention show faster curing rates than the conventional curing agents paratoluenesulfonic acid, benzenesulfonic acid, xylenesulfonic acid and mixtures thereof, in particular at lower temperatures and that the resulting self-curable binder coated sand for moulds shows higher strength, and hence is very practical.
Claims
1. Self-curing type binder-coated sand for moulds comprising 5 moulding sand, furan-based resin and curing acid, characterized in that said curing acid is methanesulfonic acid.
2. The binder-coated sand for moulds set forth in claim 1, characterized in that the curing acid is a mixture of methanesulfonic acid and l o organic sulfonic acid or inorganic acid.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8/42356 | 1996-02-29 | ||
| JP4235696A JPH09234540A (en) | 1996-02-29 | 1996-02-29 | Binder coated sand grain for mold |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1997031732A1 true WO1997031732A1 (en) | 1997-09-04 |
Family
ID=12633764
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP1997/001004 WO1997031732A1 (en) | 1996-02-29 | 1997-02-28 | Binder-coated sand for moulds |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH09234540A (en) |
| WO (1) | WO1997031732A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102008024727A1 (en) | 2008-05-23 | 2009-11-26 | Ashland-Südchemie-Kernfest GmbH | Methanesulfonic acid containing catalysts for the acid cure process |
| CN104785709A (en) * | 2015-04-30 | 2015-07-22 | 成都桐林铸造实业有限公司 | Precoated sand for casting and preparation method thereof |
| EP3093081A4 (en) * | 2015-03-09 | 2017-04-26 | Technology Research Association For Future Additive Manufacturing | Organic binder, granular material, device for producing three-dimensional-laminate moudling mould, and method for producing three-dimensional-laminate moulding mould |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5250300B2 (en) * | 2008-04-30 | 2013-07-31 | 花王株式会社 | Mold manufacturing method |
| JP5250301B2 (en) * | 2008-04-30 | 2013-07-31 | 花王株式会社 | Mold manufacturing method |
| CN104841854A (en) * | 2015-05-07 | 2015-08-19 | 马鞍山市恒毅机械制造有限公司 | Low-thermal-expansion molding sand and preparation method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4317763A (en) * | 1980-03-24 | 1982-03-02 | The Quaker Oats Company | Catalysts and binder systems for manufacturing sand shapes |
| JPS5772750A (en) * | 1980-10-27 | 1982-05-07 | Aisin Chem Co Ltd | Binder composition for mold |
| US4543373A (en) * | 1984-11-08 | 1985-09-24 | Qo Chemicals, Inc. | Fast curing furan foundry binder system containing a metal salt accelerator |
| US4761441A (en) * | 1985-07-01 | 1988-08-02 | Cl Industries, Inc. | Acid-curable compositions comprising mixtures of furan and epoxy resins and use in preparing formed, shaped, filled bodies |
-
1996
- 1996-02-29 JP JP4235696A patent/JPH09234540A/en active Pending
-
1997
- 1997-02-28 WO PCT/EP1997/001004 patent/WO1997031732A1/en active Application Filing
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4317763A (en) * | 1980-03-24 | 1982-03-02 | The Quaker Oats Company | Catalysts and binder systems for manufacturing sand shapes |
| JPS5772750A (en) * | 1980-10-27 | 1982-05-07 | Aisin Chem Co Ltd | Binder composition for mold |
| US4543373A (en) * | 1984-11-08 | 1985-09-24 | Qo Chemicals, Inc. | Fast curing furan foundry binder system containing a metal salt accelerator |
| US4761441A (en) * | 1985-07-01 | 1988-08-02 | Cl Industries, Inc. | Acid-curable compositions comprising mixtures of furan and epoxy resins and use in preparing formed, shaped, filled bodies |
Non-Patent Citations (1)
| Title |
|---|
| DATABASE WPI Section Ch Week 8250, Derwent World Patents Index; Class A21, AN 82-07572J, XP002032339 * |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102008024727A1 (en) | 2008-05-23 | 2009-11-26 | Ashland-Südchemie-Kernfest GmbH | Methanesulfonic acid containing catalysts for the acid cure process |
| WO2009141158A1 (en) | 2008-05-23 | 2009-11-26 | Ashland-Südchemie-Kernfest GmbH | Catalysts comprising methane sulfonic acid for the acid hardening method |
| KR20110010795A (en) * | 2008-05-23 | 2011-02-07 | 아슈란트-쥐트케미-케른페스트 게엠베하 | Catalysts comprising methane sulfonic acid for the acid hardening method |
| US20110073269A1 (en) * | 2008-05-23 | 2011-03-31 | Ashland-Sudchemie-Kernfest Gmbh | Catalysts comprising methane sulfonic acid for the acid hardening method |
| CN102076440A (en) * | 2008-05-23 | 2011-05-25 | 阿什兰-苏德舍米-克恩费斯特有限公司 | Catalysts comprising methane sulfonic acid for the acid hardening method |
| US8919421B2 (en) * | 2008-05-23 | 2014-12-30 | Ask Chemicals Gmbh | Catalysts comprising methane sulfonic acid for the acid hardening method |
| EA021549B1 (en) * | 2008-05-23 | 2015-07-30 | Аск Кемикалс Гмбх | Method for producing molds |
| KR101643703B1 (en) | 2008-05-23 | 2016-07-29 | 아에스카 케미컬스 게엠베하 | Catalysts comprising methane sulfonic acid for the acid hardening method |
| EP3093081A4 (en) * | 2015-03-09 | 2017-04-26 | Technology Research Association For Future Additive Manufacturing | Organic binder, granular material, device for producing three-dimensional-laminate moudling mould, and method for producing three-dimensional-laminate moulding mould |
| US10174183B2 (en) | 2015-03-09 | 2019-01-08 | Technology Research Association For Future Additive Manufacturing | Organic binder, granular material, three-dimensional lamination-shaped mold manufacturing apparatus, and three-dimensional lamination-shaped mold manufacturing method |
| CN104785709A (en) * | 2015-04-30 | 2015-07-22 | 成都桐林铸造实业有限公司 | Precoated sand for casting and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH09234540A (en) | 1997-09-09 |
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