JPWO2019059226A1 - Urethane-curable organic binder for casting mold, foundry sand composition obtained using the same, and casting mold - Google Patents

Abstract

It is an object of the present invention to provide a urethane-curable organic binder which can improve the mold strength and its moisture absorption and deterioration resistance, and can advantageously give a mold whose filling density can be effectively increased, and also after molding. It is also possible to provide a urethane-curable organic binder for a mold, which can effectively improve the mold strength by leaving it to stand. A urethane-curable organic binder used for molding urethane-based molds, which is a reaction product of a basic primary silane compound and hydrofluoric acid together with a polyol compound and a polyisocyanate compound, and a non-basic one. The second silane compound was further contained as a constituent component.

Description

The present invention is an organic binder used in sand mold casting, particularly an organic binder for a mold used for molding a urethane-based gas-curing mold or a self-hardening mold, and a molding sand obtained using the same. The present invention relates to a composition and a mold obtained by molding such a foundry sand composition.

Conventionally, as one of the typical organic molds used in sand mold casting, a polyol compound such as a phenol resin and a polyisocyanate compound such as diphenylmethane diisocyanate are used as a binder, and their polyaddition reaction (urethane formation) is performed. There is known a urethane-based template formed by utilizing the reaction), for example, a so-called phenol urethane-based template or the like. And as a urethane type mold such as a phenol urethane type mold, a mass production type gas curing mold produced by an amine cold box method using an amine gas as a catalyst that does not require heating at the time of molding, and a room temperature self-hardening mold. Non-mass production type self-hardening molds manufactured by the method are widely known.

Specifically, the gas-curing mold by the amine cold box method is usually a granular refractory molding sand for a mold, which is composed of a solution of a phenol resin using an organic solvent as a solvent and a solution of a polyisocyanate compound using a mixer. After kneading with an organic binder, a molding sand composition obtained by coating the surface of such molding sand with an organic binder is produced, and then the molding sand composition is blown into a predetermined molding die. It is manufactured by molding a mold with, and passing an amine catalyst gas through the mold to cure the mold. Further, the self-hardening mold by the normal-temperature self-hardening method, the granular refractory molding sand, when kneading with a mold organic binder comprising a solution of a phenol resin and a solution of a polyisocyanate compound using an organic solvent as a solvent, A curing catalyst is also mixed, and the obtained mixture is immediately formed into a desired shape, thereby producing the composition.

However, in the case of a urethane type template such as a phenol urethane type template obtained by utilizing the polyaddition reaction (urethane formation reaction) between such a phenol resin and a polyisocyanate compound, the air bonding property is There was a problem of so-called moisture absorption deterioration such as curing inhibition and strength deterioration due to moisture in the inside.

Therefore, in Japanese Patent Publication No. 1-501630 (Patent Document 1), it is apparent that a silane compound such as epoxysilane, aminosilane, or ureidosilane is added as a measure for preventing moisture absorption deterioration of a mold manufactured by the cold box method. However, even with such a silane compound, sufficient characteristics have not yet been secured, and further measures to prevent deterioration due to moisture absorption have been demanded.

Therefore, in JP2012-196700A (Patent Document 2), a urethane compound for a template is prepared by further combining a polyol compound and a polyisocyanate compound with a silane compound having an isocyanate group or an acrylic compound having an isocyanate group. It has been clarified that by constructing a curable organic binder, it is possible to prevent the deterioration of the mold due to moisture absorption and thereby maintain excellent mold strength, in which a special isocyanate group-containing compound is prepared. Had to do.

Further, in JP 2001-205386 A (Patent Document 3), a binder composition for producing a gaseous tertiary amine-curable template, which is a combination of a phenol resin and an isocyanate compound with boric acid, is disclosed. Furthermore, it has been clarified therein that a silane compound can be contained in order to improve the adhesiveness between the binder component and the aggregate. And, by using the binder composition containing such boric acid, the pot life is longer than that of the conventional mold-making composition, and therefore, the binder and the granular refractory aggregate. It is said that it is possible to maintain the strength as a mold even if it is kneaded and left for several hours, but the evaluation of the mold strength there is carried out under a dry condition where the humidity is not high. However, under high-humidity conditions, the strength of the mold is significantly reduced due to deterioration due to moisture absorption, and it becomes difficult to maintain sufficient strength.

Japanese Patent Publication No. 1-501630 JP, 2012-196700, A JP 2001-205386 A

Here, the present invention has been made in the background of such circumstances, the problem to be solved is to improve the mold strength and its moisture absorption resistance deterioration characteristics, the packing density is effective. The purpose of the present invention is to provide a urethane-curable organic binder that can advantageously give an enhanced mold, and also, a urethane-curable organic binder for a mold that can effectively improve the mold strength by leaving it after molding. There is also to provide a binder, further using such a urethane-curable organic binder, a molding sand composition capable of imparting excellent mold characteristics, and a molding using the molding sand composition , To provide a template having excellent properties.

In order to solve the above problems, the present invention can be suitably implemented in various aspects as listed below. In addition, each aspect described below can be adopted in any combination, and the aspects and technical features of the present invention are not limited to those described below, It should be understood that it can be recognized based on the grasped inventive idea.

(1) A urethane-curable organic binder used for molding a urethane-based template, which is a reaction product of a basic primary silane compound and hydrofluoric acid together with a polyol compound and a polyisocyanate compound, and A urethane-curable organic binder for a template, which further comprises a basic second silane compound as a constituent component.
(2) For the template according to the above aspect (1), characterized in that a reaction product of the first silane compound and hydrofluoric acid is formed in advance and is contained in the form of the reaction product. Urethane-curable organic binder.
(3) The urethane-curable organic binder for a mold according to the above aspect (1) or the aspect (2), wherein the polyol compound is a phenol resin.
(4) The urethane curable organic binder for a template according to the above aspect (3), wherein the phenol resin is an orthocresol-modified phenol resin.
(5) The reaction product is based on 100 parts by mass of the polyol compound.
It is used in a proportion of 0.01 to 10 parts by mass.
1) Through the urethane-curable organic binder for a mold according to any one of the aspects (4).
(6) The aspect (1) to aspect (5), wherein the second silane compound is used in a proportion of 0.01 to 10 parts by mass with respect to 100 parts by mass of the polyol compound. 2. The urethane hardening type organic binder for a mold according to any one of 1.
(7) The urethane curable organic material for a mold according to any one of the aspects (1) to (6), wherein the first silane compound is an alkoxysilane containing an amino group. Binder.
(8) The alkoxysilane containing an amino group is 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-
(Aminoethyl)-3-aminopropylmethyldimethoxysilane, N-
2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-
Triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-
(Vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane and 3-ureidopropyltrialkoxysilane are selected from the group consisting of urethane-curable organic materials for molds according to the above aspect (7). Binder.
(9) The second silane compound is epoxy silane, isocyanate silane,
The urethane-curable mold for a mold according to any one of the aspects (1) to (8), which is selected from the group consisting of chlorosilane, mercaptosilane, isocyanurate silane, acryl silane and methacryl silane. Organic binder.
(10) The reaction product of the basic first silane compound and hydrofluoric acid is
Any one of the above aspects (1) to (9), characterized in that the nonbasic second silane compound is contained in the polyisocyanate compound while being contained in the polyol compound. The urethane-curable organic binder for a mold according to 1.
(11) Any one of the above aspects (1) to (10), further comprising at least one of an acid halide, a phosphoryl halide compound and a phosphine halide as a constituent component. The urethane-curable organic binder for a mold according to [1].
(12) a step of preparing a polyol solution prepared by dissolving a polyol compound in an organic solvent; a step of preparing a polyisocyanate solution prepared by dissolving a polyisocyanate compound in an organic solvent; and the polyol solution and/or the poly A step of allowing a reaction product of a basic first silane compound and hydrofluoric acid to exist in an isocyanate solution; and a non-basic second silan compound in the polyol solution and/or the polyisocyanate solution. The method for preparing a urethane-curable organic binder for a mold, comprising:
(13) A foundry sand composition comprising the urethane-curable organic binder for a mold according to any one of the above aspects (1) to (11) and foundry sand.
(14) A mold comprising the molding sand composition according to the above aspect (13), which is molded and cured.

As described above, in the urethane-curable organic binder for a template according to the present invention, in addition to the polyol compound and the polyisocyanate compound, which are the essential components thereof, the basic primary silane compound and the fluorinated compound are further added. The reaction product with hydrogen acid and the non-basic second silane compound are included as constituent components, so that the strength of a mold molded using such an organic binder is improved. In addition to being able to effectively enhance the leaving strength of the mold after molding, it is also possible to advantageously improve the moisture absorption resistance deterioration property of the strength of such a mold. Of.

Moreover, in a foundry sand composition obtained by kneading such a mold organic binder according to the present invention into foundry sand, its fluidity can be effectively improved, and thus more In addition to providing a mold having excellent filling properties, the surface properties of the mold can be advantageously improved, and a mold having excellent strength characteristics as described above can be provided. In the mold molded using the sand composition, while having excellent mold strength, as a mold having improved moisture absorption and deterioration resistance of strength, a mold having further improved packing density and surface properties As a result, it can be advantageously used in the intended metal casting process.

In the present invention, the reaction product of the basic first silane compound and hydrofluoric acid as described above and the non-basic second silane compound are further used as an acid halide and a phosphoryl halide. It is preferable to use at least one of the compound and the phosphine halide in combination, which makes it possible to further improve the above-mentioned mold strength and its hygroscopic deterioration property, and to provide such characteristics. While maintaining the above, it is possible to exert the characteristic that the pot life of the foundry sand composition obtained by kneading with the foundry sand can be more effectively extended.

By the way, in such a urethane-curable organic binder for a mold according to the present invention, the polyol compound used as one of the main components is not particularly limited, and a urethane-based curable mold is conventionally used. Various well-known polyol compounds that are used in molding are appropriately selected and used. Specifically, phenol resin, polyether polyol, polypropylene polyol, polybutadiene polyol, polymer polyol, polypropylene glycol, polyethylene glycol, polytetramethylene ether glycol, polyoxybutylene glycol, a copolymer of ethylene oxide and propylene oxide, tetrahydrofuran and Examples thereof include a copolymer with ethylene oxide, a copolymer with tetrahydrofuran and propylene oxide, and a copolymer with tetrahydrofuran and 3-methyltetrahydrofuran.

Among them, as the polyol compound used in molding the urethane-based mold, various known phenol resins used in molding the phenol-urethane-based mold can be preferably used. Specifically, in the presence of a reaction catalyst, phenols and aldehydes are added in an amount of 0.5 to 3.0 moles of aldehydes relative to 1 mole of phenols. An organic solvent-soluble benzyl ether type phenolic resin, a resol type phenolic resin, a novolac type phenolic resin, and a modified phenolic resin thereof, and a mixture thereof obtained by the condensation reaction can be exemplified. One or more of them will be appropriately selected and used. Further, among these, in particular, orthocresol-modified phenolic resin modified with orthocresol, more preferably in the benzyl ether type orthocresol-modified phenolic resin and the mixture thereof, solubility in an organic solvent and a polyisocyanate compound In addition to being excellent in compatibility, the present invention can be preferably used in the present invention because it can effectively improve the strength (initial strength) of the obtained mold.

The catalyst used in the addition/condensation reaction of the above-mentioned phenols and aldehydes is not particularly limited, and a known acidic catalyst or basic catalyst may be used depending on the type of the desired phenol resin. In addition to the catalyst, various catalysts that have been conventionally used for producing phenolic resins are appropriately used. And as such a catalyst, tin, lead, zinc, cobalt, manganese, a metal salt having a metal element such as nickel can be exemplified, more specifically, lead naphthenate, zinc naphthenate, In addition to lead acetate, zinc chloride, zinc acetate, zinc borate, and lead oxide, a combination of an acid and a base capable of forming such a metal salt can be used. Further, when such a metal salt is adopted as a reaction catalyst, the amount used is not particularly limited, but is generally about 0.01 to 5 parts by mass with respect to 100 parts by mass of phenols. Will be used at a rate of.

Examples of phenols that give a phenol resin include phenol, orthocresol, metacresol, paracresol, 2,3-dimethylphenol, 2,4-dimethylphenol, 2,5-dimethylphenol, and 2,6-dimethyl. Polyphenols such as phenol, 3,4-dimethylphenol, 3,5-dimethylphenol, p-tert-butylphenol, o-tert-butylphenol, m-tert-butylphenol, nonylphenol, etc., resorcinol, bisphenol F, bisphenol A, etc. Examples of the aldehyde include phenol and formalin, paraformaldehyde, polyoxymethylene, glyoxal, furfural, and mixtures thereof.

Further, as described above, as the orthocresol-modified phenol resin which is one of the phenol resins advantageously used in the present invention, for example, in the presence of a reaction catalyst such as a metal salt, orthocresol and phenol, (1) a co-condensation type orthocresol-modified phenolic resin of orthocresol and phenol, (2) a mixed type orthocresol-modified phenolic resin of an orthocresol resin and a phenolic resin, and these (3) Modified orthocresol-modified phenolic resin obtained by modifying the resin of (1) and (2) with a modifier (modifier), and (1), (2) and (3) A mixture of two or more of the above) and the like can be exemplified. The orthocresol-modified phenolic resins of (1), (2) and (3) are well known, and in the present invention, such known resins are used as they are. .. The ratio of phenol/orthocresol is 1/9 to 9/1, preferably 3/7 to 7/3, and more preferably 4/6 to 6/4 on a mass basis. It will be.

And, such a polyol compound such as a phenolic resin used as one of the main components of the organic binder for a mold according to the present invention has a low viscosity, compatibility with a polyisocyanate solution described later, to molding sand. From the viewpoint of coating properties, template properties, etc., a solution that is generally dissolved in an organic solvent that is a combination of a polar organic solvent and a nonpolar organic solvent and has a concentration of about 30 to 80% by mass (hereinafter , "Polyol solution").

On the other hand, in the organic binder for a template according to the present invention, a polyisocyanate compound used as another one of its main components is obtained by polyaddition reaction with active hydrogen of a polyol compound such as a phenol resin as described above, It is a compound having two or more isocyanate groups in its molecule that can chemically bond foundry sands with each other by a urethane bond such as phenol urethane. Specific examples of such a polyisocyanate compound include aromatic, aliphatic, or alicyclic polyisocyanates, such as diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate (hereinafter referred to as "polymeric MDI"), and hexamethylene diisocyanate. In addition to 4,4'-dicyclohexylmethane diisocyanate, various known polyisocyanates such as prepolymers having two or more isocyanate groups obtained by reacting these compounds with a polyol can be exemplified. , Or may be used alone or in combination of two or more kinds.

Furthermore, even in such a polyisocyanate compound, for the same reason as the polyol compound such as the phenolic resin as described above, generally, a nonpolar organic solvent, or a mixed solvent of a nonpolar organic solvent and a polar solvent is used as a solvent, The solution is dissolved in this organic solvent to a concentration of about 40 to 90% by mass. Depending on the type of polyisocyanate compound used and the like, it is not always necessary to dissolve it in an organic solvent, and it is also possible to use the undiluted solution as it is. Hereinafter, the undiluted solution of the polyisocyanate compound and the solution obtained by dissolving the polyisocyanate compound in the organic solvent are referred to as a polyisocyanate solution.

Here, as the organic solvent for dissolving the above-mentioned polyol compound and polyisocyanate compound, the polyisocyanate compound is non-reactive, and the solute to be dissolved (polyol compound or polyisocyanate compound) Although it is not particularly limited as long as it is a good solvent, it is generally an amount such that i) a polar solvent for dissolving a polyol compound such as a phenol resin and ii) a polyol compound such as a phenol resin do not separate. Will be used in combination with a nonpolar solvent for dissolving the polyisocyanate compound.

More specifically, examples of the above-mentioned i) polar solvent include, for example, aliphatic carboxylic acid esters, and among them, particularly dicarboxylic acid methyl ester mixture (manufactured by DuPont, USA; trade name: DBE; dimethyl glutarate and adipine). Dicarboxylic acid alkyl ester (such as a mixture of dimethyl acid and dimethyl succinate), methyl ester of vegetable oil such as rapeseed oil methyl ester, and ketones such as isophorone, ethers such as isopropyl ether, and furfuryl alcohol. You can The non-polar solvent of the above ii) is, for example, petroleum hydrocarbons such as paraffins, naphthenes and alkylbenzenes, and specific examples are Ipsol 150 (manufactured by Idemitsu Kosan Co., Ltd.; petroleum solvent), Hisol 100 (manufactured by JXTG Energy Co., Ltd.; petroleum solvent), HAWS (manufactured by Shell Chemicals Japan Co., Ltd.; petroleum solvent) and the like can be exemplified.

And, in the present invention, in addition to the above-mentioned polyol compound and polyisocyanate compound, as a constituent component of the organic binder for the intended template, further, a basic first silane compound and hydrofluoric acid. The reaction product with and the non-basic second silane compound were allowed to be contained. The presence of the specific reaction product and the non-basic second silane compound advantageously realizes the improvement of the strength of the mold molded using the organic binder, particularly the improvement of the leaving strength of the mold after molding. At the same time, it is possible to effectively suppress or prevent the adverse effects of the external environment when the mold is stored and left, particularly the deterioration of the mold strength in a high humidity atmosphere. That is, it is possible to efficiently improve or prevent the strength reduction caused by the mold absorbing the moisture in the air during storage and standing, and to advantageously improve the moisture absorption resistance deterioration property of the mold. Of. Moreover, in this way, by using the reaction product of the basic first silane compound and hydrofluoric acid together with the non-basic second silane compound, the organic binder and the molding sand are kneaded. In addition to being able to advantageously improve the pot life of the foundry sand composition obtained as described above, the fluidity of such foundry sand composition can be effectively improved, and the filling property is more excellent. The mold can be formed, and the surface of the obtained mold can be made smoother, so that its surface quality can be advantageously improved.

The basic first silane compound that gives the specific reaction product is an organosilicon compound having a structure in which an organic group having a basic group such as an amino group is bonded to silicon (Si). And, for example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3- Aminopropyltrimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl- Examples thereof include alkoxysilanes having an amino group such as 3-aminopropyltrimethoxysilane, hexamethyldisilazane, and silane compounds having an ureido group such as 3-ureidopropyltrialkoxysilane. Moreover, among these basic primary silane compounds, it is preferable to use a basic alkoxysilane, and among them, an alkoxysilane having an amino group is more preferable, and N-2-(aminoethyl)-3- is more preferable. Aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-ureidopropyltrialkoxysilane will be advantageously used. The reason why the alkoxysilane having an amino group is the best is that, in addition to being easily available, the alkoxy group is hydrolyzed by the water in the polyol compound or hydrofluoric acid to be converted into a hydroxyl group. Thereby, the adhesion with the foundry sand (aggregate etc.) becomes stronger, and high mold strength can be exhibited.

Then, such a basic primary silane compound is reacted with hydrofluoric acid, and the obtained reaction product is to be used in the present invention. Based on the standard, a ratio of basic first silane compound/hydrofluoric acid=2/8 to 8/2, preferably 3/7 to 7/3, more preferably 4/6 to 6/4 is adopted. Will be done. The concentration of hydrofluoric acid used here is preferably 10 to 65%, more preferably 20 to 60%, and further preferably 40 to 55%.

By the way, in producing the specific reaction product used in the present invention as described above, for example, in a plastic container, a predetermined basic silane compound and hydrofluoric acid are mixed and reacted. The desired reaction product can be easily obtained by the addition. At this time, in order to suppress the reaction heat of the basic first silane compound and hydrofluoric acid, one of them is cooled and stirred, while the other is continuously or intermittently Therefore, it is desirable to prevent the rapid progress of the reaction by adding it. In addition, in those reactions, hydrofluoric acid is added to the basic first silane compound to allow the reaction to proceed, and conversely, hydrofluoric acid is added to the basic primary silane compound. It is also possible to add a monosilane compound. And, the temperature at the time of the reaction of the basic primary silane compound and hydrofluoric acid is preferably suppressed to 80° C. or lower, more preferably 70° C. or lower, further preferably 60° C. or lower, the reaction You can proceed.

Here, the basic first silane compound or hydrofluoric acid is continuously or intermittently added little by little, in the continuous addition method, a constant amount at a constant speed. The method of adding to the reaction system at a constant rate of addition is advantageously adopted, and in the intermittent addition method, it is possible to add at a constant interval and in a constant amount. desirable. In addition, in the intermittent addition method with such an interval, for example, every 1 second, every 10 seconds, or every 1 minute, the time is fixed and a fixed amount is added, or it is reacted. A method of gradually dropping into the system or the like can also be adopted. By adding little by little in such a method, it is possible to advantageously prevent an increase in reaction heat and effectively prevent deterioration of the physical properties of the obtained reaction product. Above all, if the dropping method is adopted, it is possible to more effectively suppress the temperature rise due to the reaction heat.

And, in the present invention, it is desirable that a reaction product obtained by the reaction of such a basic primary silane compound and hydrofluoric acid as described above is formed beforehand and then such a reaction product is obtained. In the above-mentioned form, when used together with a polyol compound or a polyisocyanate compound, the desired organic binder is advantageously constituted. As described above, by pre-forming the reaction product of the basic first silane compound and hydrofluoric acid, the step of directly adding hydrofluoric acid becomes unnecessary, and thus the organic binder The safety can be advantageously ensured when the agent is prepared and when the foundry sand composition is produced using the agent. In addition, since the step of directly adding hydrofluoric acid is not required, even when a manufacturing device made of stainless steel or glass is used at the time of manufacturing the organic binder or the foundry sand composition, the inside of the device is corroded. There is an advantage that it can be manufactured without Needless to say, the addition method of such a specific reaction product is not limited to the exemplified one, and such a reaction product is present as a constituent component in the organic binder. As long as it is a form to be obtained, the basic silane compound and hydrofluoric acid are added to the polyol compound and/or the polyisocyanate compound separately or together, in an appropriate addition form, It is possible to mix it with a polyol compound or a polyisocyanate compound to form a desired reaction product when used as an organic binder.

In the present invention, the amount of the reaction product of the basic primary silane compound and hydrofluoric acid used is 100 parts by mass of the polyol compound which is one of the constituents of the organic binder. On the other hand, a ratio of about 0.01 to 10.0 parts by mass, preferably about 0.1 to 2 parts by mass will be suitably adopted. When the amount of such a reaction product used is less than 0.01 parts by mass, it becomes difficult to sufficiently exert the effect of using such a reaction product, and when it is more than 10 parts by mass, Problems such as difficulty in contributing to sufficient improvement of strength of the obtained mold will occur.

On the other hand, the non-basic second silane compound used in combination with the reaction product as described above is an organosilicon compound in which a basic group such as an amino group is not bonded in its molecular structure, and is, for example, 3- Glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl Trimethoxysilane, 3-isocyanatopropyltriethoxysilane, chlorotrimethylsilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-acryloxypropyltrimethoxy Examples thereof include silane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and p-styryltrimethoxysilane. I can. Among them, preferably, 3-glycidoxypropyltrimethoxysilane and 3-isocyanatepropyltriethoxysilane are advantageously used. By using such a non-basic second silane compound in combination, the compatibility between the polyol compound side and the polyisocyanate compound side is improved, the fluidity as an organic binder is improved, and the molding sand (fire resistance The wettability with respect to the aggregate) is also improved, the fluidity of the foundry sand composition is improved, and a mold having more excellent filling properties can be advantageously molded in a form in which the surface properties are improved. ..

In the present invention, the amount of the non-basic second silane compound used is about 0.01 to 10.0 parts by mass, preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the polyol compound. A ratio of about a part is preferably adopted. If the amount used is less than 0.01 parts by mass, problems such as difficulty in fulfilling the expected function due to the use of such a second silane compound will occur, and more than 10 parts by mass. Then, there arises a problem that the cost for producing the organic binder becomes high.

Further, in the organic binder for a template according to the present invention, in addition to the above-mentioned polyol compound, polyisocyanate compound, specific reaction product, and non-basic second silane compound, an acid halide and a halogenated compound are further added. At least one of the phosphoryl compound and the phosphine halide will be advantageously contained as one of the constituents. Due to the presence of such an acid halide, a phosphoryl halide compound, or a phosphine halide, the strength of a mold molded using a molding sand composition obtained by kneading the organic binder according to the present invention and molding sand. And moisture absorption deterioration characteristics can be further improved, in particular, while maintaining excellent mold strength and moisture absorption deterioration characteristics, the pot life of the molding sand composition obtained by kneading with the molding sand, effectively, It is possible to improve. The acid halide, phosphoryl halide compound or phosphine halide is generally about 0.01 to 5 parts by mass, preferably about 0.1 to 2 parts by mass with respect to 100 parts by mass of the polyol compound. The ratio will be preferably adopted.

Here, the above-mentioned acid halide is a halide of an aliphatic carboxylic acid or an aromatic carboxylic acid, for example, isophthalic acid chloride, benzoyl chloride, caprylic acid chloride, lauric acid chloride, myristic acid chloride, palmitic acid chloride. , Isopalmitic acid chloride, stearic acid chloride, isostearic acid chloride, oleic acid chloride, sebacic acid dichloride, phenylacetyl chloride, 2-chlorobenzoyl chloride, 3-chlorobenzoyl chloride, 4-chlorobenzoyl chloride, 2-bromobenzoyl chloride, 3-bromobenzoyl chloride, 4-bromobenzoyl chloride, 2-iodobenzoyl chloride, 3-iodobenzoyl chloride, 4-iodobenzoyl chloride, butyric acid chloride, isobutyric acid chloride, valeric acid chloride, isovaleric acid chloride, caproic acid chloride, Enanthic acid chloride, pelargonic acid chloride, capric acid chloride, pentadecyl acid chloride, margaric acid chloride, linoleic acid chloride, linolenic acid chloride, phthalic acid chloride, terephthalic acid chloride, o-toluic acid chloride, m-toluic acid chloride, p- Examples thereof include toluic acid chloride, trimellitic anhydride chloride, trimethoxybenzoic acid chloride, benzoyl bromide and benzoyl iodide. Among them, isophthalic acid chloride and lauric acid chloride are preferably used. Further, halogenated phosphoryl compound has the _{formula: R n -P (= O)} X (3-n) [ where, R is an organic group, X is a halogen atom, n represents 0, 1 or 2 A compound having a halogen-substituted phosphoryl group (≡P═O), which includes, for example, phosphoryl chloride, phosphoryl bromide, phosphoryl iodide, phenylphosphonic acid dichloride, diphenylphosphinic acid chloride, etc. it is possible to use, further, halogenated phosphine has the _{formula: R n -P-X (3} -n) [ where, R is an organic group, X is a halogen atom, n represents 0, 1 or 2], and for example, dichlorophenylphosphine, chlorodiphenylphosphine and the like can be used, and among them, phenylphosphonic acid dichloride is preferably used.

As described above, the urethane-curable organic binder for a template according to the present invention includes, in addition to the polyol compound forming a urethane bond such as phenol urethane and the polyisocyanate compound, the basic primary silane compound and the fluorinated compound as described above. It comprises a reaction product with a hydrogen acid and a non-basic second silane compound as constituent components, more preferably at least one of an acid halide, a phosphoryl halide compound and a phosphine halide. However, such an organic binder may also include, if necessary, a pot life extender (hardening retarder: higher fatty acid ester, etc.) different from the above-mentioned compounding ingredients, It is also possible to appropriately select and blend various known additives conventionally used in organic binders for molds, such as a release agent, a strength deterioration inhibitor, and a drying inhibitor. Of course, it goes without saying that these various additives are used in a quantitative range that does not impair the effects that can be enjoyed by the present invention. Of these various additives, the pot life extender (hardening retarder) is used to suppress the urethanization reaction and extend the pot life of the foundry sand composition. The mold agent reduces the resistance when the molded mold is removed from the mold, and a part of the foundry sand composition blown and filled into the mold is attached to the mold when the mold is removed. It is used in order to prevent the occurrence of stains and to obtain a mold having a uniform molding surface and high accuracy.

Then, the urethane-curable organic binder for a mold according to the present invention having such a constitution is kneaded in a molding sand (refractory aggregate) in the same manner as in the conventional case to mold a urethane-based gas-curing mold. The foundry sand composition for forming is to be formed.

Specifically, for example, when molding a gas-curing mold by the cold box method, first, by kneading the casting sand (refractory aggregate) with the organic binder for a mold according to the present invention described above, A molding sand composition (kneading sand) obtained by coating the surface of the molding sand with an organic binder for a mold is produced. That is, with respect to foundry sand, as a organic binder, a polyol compound, a polyisocyanate compound, a reaction product of a basic first silane compound and hydrofluoric acid, and a non-basic second silane compound. Then, by further kneading and mixing the desired various additives, the surface of the molding sand is coated with the organic binder for molds to produce the molding sand composition.

At that time, the reaction product of the basic first silane compound and hydrofluoric acid, the non-basic second silane compound, and other various additives are uniformly added to the foundry sand composition. In order to be able to mix, either the solution of the polyol compound or the solution of the polyisocyanate compound prepared separately, or both are added and mixed, or dissolved or dissolved in a suitable organic solvent. It is dispersed and formed at the time of kneading with a solution of a polyol compound or a solution of a polyisocyanate compound in the molding sand or after completion of condensation during the production of a polyol compound such as a phenolic resin. It is also possible to directly add to the polyol compound and mix them. Among them, in the present invention, it is desirable that the specific reaction product is added to a solution of a separately prepared polyol compound, and the non-basic second silane compound is separately prepared. It is desirable that the polyisocyanate compound can be added to the solution.

By the way, in producing such a foundry sand composition, the solution of the polyol compound and the solution of the polyisocyanate compound that constitute the organic binder are gradually added to each other from the stage of mixing them (polyurization reaction). From the point where the process proceeds, it is prepared and prepared separately in advance, and is usually mixed at the time of kneading with the molding sand. The kneading/mixing operation is performed using a continuous or batch mixer similar to the conventional one, preferably at a temperature in the range of -10°C to 50°C.

Further, as the molding sand (fire-resistant aggregate) to be kneaded with the organic binder for a mold according to the present invention, natural sand may be used as long as it is a fire-resistant sand conventionally used for a mold. However, even artificial sand is not particularly limited and is not particularly limited. For example, silica sand, olivine sand, zircon sand, chromite sand, alumina sand, ferrochrome-based slag, ferro-nickel-based slag, converter slag, mullite-based artificial particles (for example, trade names available from ITOCHU CERATECH CO., LTD. Cera beads"), alumina-based artificial particles, various other artificial particles, and reclaimed sand and recovered sand thereof, and one kind or a combination of two or more kinds of them can be used. Among them, aggregates having a high silica content, such as silica sand, especially flattery sand, are more preferably adopted. By using such an aggregate having a high silica content, the affinity with the silane in the binder component is improved, the adhesiveness between the aggregate and the binder is increased, and when a mold is formed. It will lead to the improvement of strength.

Then, the molding sand composition obtained as described above is shaped in a molding die such as a die that gives a desired shape, and then a catalyst gas for curing is aerated. As a result, the hardening of the foundry sand composition is promoted, and the gas hardening mold is produced. Examples of the catalyst gas include conventionally known tertiary amine gases such as triethylamine, dimethylethylamine, and dimethylisopropylamine, as well as cyclic nitrogen compounds, pyridine, N-ethylmorpholine, and the like. At least one kind will be appropriately selected and used in the usual quantitative range.

Further, by the room-temperature self-hardening method, also when molding a desired self-hardening mold, similar to the case of the above-mentioned gas-hardening mold, first, a foundry sand composition obtained by coating the foundry sand surface with an organic binder. However, it is to be produced, at that time, in the molding sand composition used in the room temperature self-hardening method, at the time of kneading, together with the organic binder according to the present invention, a curing catalyst is further mixed. Become. Examples of the curing catalyst include bases, amines, metal ions and the like which are commonly used in the known Ashland method.

Furthermore, in the preparation of the foundry sand composition that gives the above-mentioned gas-hardening mold or self-hardening mold, as the mixing ratio of the polyol solution and the polyisocyanate solution, respectively, the compounding amount of the polyol compound and the polyisocyanate compound, which are active ingredients, A ratio of about 0.5 to 5.0 parts by mass, preferably about 1.0 to 3.0 parts by mass with respect to 100 parts by mass of the foundry sand will be suitably adopted. Further, the mixing ratio of the polyol compound and the polyisocyanate compound is not particularly limited, but in general, the polyol solution:polyisocyanate compound=4:6 to 6:4 on a mass basis so that the polyol solution And a polyisocyanate solution will be used in combination.

Thus, in the gas-curing mold or the self-hardening mold molded as described above, the packing density and the strength of the mold can be effectively improved, and further, the moisture absorption resistance deterioration property of the strength can be enhanced. The present invention can be advantageously used for casting casting products made of various metals such as aluminum alloys, magnesium alloys, and iron.

Hereinafter, some representative examples of the present invention will be shown to clarify the present invention more specifically, but the present invention is subject to any restrictions by the description of such examples. It goes without saying that things are not things. In addition to the embodiments described below, the invention is not limited to the specific description described above, and various changes and modifications are made based on the knowledge of those skilled in the art without departing from the spirit of the invention. It should be understood that improvements, etc. may be added.

Regarding the organic binders prepared in the following Examples and Comparative Examples, (1) measurement of the strength of a mold molded from a foundry sand composition obtained using the organic binder, (2) mold Measurement of strength after moisture deterioration, (3) evaluation of pot life of foundry sand composition, (4) measurement of packing density, and further (5) evaluation of casting surface were carried out as follows. It was

(1) Measurement of mold strength After the kneading molding sand composition was put into a sand magazine of a cold box molding machine, the molding sand composition was put into a mold for bending strength test piece production with a gauge pressure: Fill with 0.3 MPa. Then, a gas generator was used to ventilate triethylamine gas with a gas generator at a gauge pressure of 0.2 MPa for 1 second, and then air purge was performed at a gauge pressure of 0.2 MPa for 14 seconds, and then the die was removed. A bending test piece (mold) having a width of 3 cm, a length of 8.5 cm and a thickness of 1 cm is prepared. Then, the obtained test piece was left for 24 hours in i) immediately after the molding and ii) in a low humidity condition of temperature: 25° C. and relative humidity: 40%, and then a digital casting sand strength tester (Takachiho) The bending strength (kgf/cm ² ) is measured by Seiki Co., Ltd.).

(2) Measurement of mold strength after moisture absorption deterioration After making test pieces from each of the foundry sand compositions in the same manner as in the case of measuring the mold strength described above, the obtained test pieces (molds) were subjected to air temperature measurement. : 25° C., relative humidity: 90%, left in a closed container under a high humidity condition for 24 hours, and thereafter, using a digital foundry sand strength tester (manufactured by Takachiho Seiki Co., Ltd.), bending strength (kgf/ cm ² ) is measured.

(3) Evaluation of pot life of the foundry sand composition In the same manner as in the case of measuring the mold strength described above, when producing test pieces from the respective foundry sand compositions, the flattery sand and the organic caking as the foundry sand were used. For each foundry sand composition prepared by kneading with the agent, immediately after kneading, molding is performed (waiting time after kneading: 0 minutes), and the obtained test piece and molding is performed 120 minutes after kneading. Performed (waiting time after kneading: 120 minutes), the strength of each of the obtained test pieces was measured as the mold strength, and the values of the two mold strengths were compared to evaluate the pot life. To do.

(4) Measurement of Packing Density In the same manner as in the case of measuring the mold strength described above, after producing a test piece (width: 3 cm x length: 8.5 cm x thickness: 1 cm) from each foundry sand composition, The packing density (g/cm ³ ) was calculated from the obtained mass value of the test piece (mold) by the following formula. Two test pieces were prepared, and the average value of the numerical values of each mass was used as the packing density (g/cm ³ ).
Packing density = test piece (mold) mass / test piece volume

(5) Evaluation of mold surface properties After making test pieces from each of the foundry sand compositions in the same manner as in the case of measuring the mold strength described above, the surface properties of the obtained test pieces (molds) were evaluated ( The feeling of touch was evaluated. Specifically, five panelists evaluated the feel of the mold surface according to the following criteria, and evaluated the superiority and inferiority at the average level.
◎: Very smooth texture ○: Smooth texture △: Slightly rough texture ×: Very rough texture

-Preparation of phenol resin solution (1)-
In a three-neck reaction flask equipped with a reflux condenser, a thermometer and a stirrer, 100 parts by mass of phenol, 55.5 parts by mass of 92% by mass paraformaldehyde, and 0.2 parts of zinc naphthenate as a divalent metal salt were used. After mass parts were charged, the mixture was reacted at reflux temperature for 90 minutes and then heated and concentrated to obtain a benzyl ether type phenol resin having a water content of 1% or less. Next, 50.0 parts by mass of the obtained phenolic resin, 20.0 parts by mass of a polar organic solvent (DBE: manufactured by DuPont, USA) and a nonpolar organic solvent (Hisol 100: manufactured by JXTG Energy Co., Ltd.; petroleum-based) 30.0 parts by mass of (solvent) was dissolved to prepare a phenol resin solution (1) having a phenol resin content of 50.0% by mass.

-Preparation of phenol resin solution (2)-
In a three-neck reaction flask equipped with a reflux condenser, a thermometer and a stirrer, 50 parts by mass of phenol and 50 parts by mass of orthocresol (phenol/orthocresol=50/50) and 51 parts by mass of 92% by mass paraformaldehyde were added. .9 parts by mass, and 0.15 parts by mass of zinc naphthenate as a divalent metal salt were charged, reacted at reflux temperature for 90 minutes, and then concentrated by heating to modify orthocresol having a water content of 1% or less. A benzyl ether type phenol resin was obtained. Next, 50.0 parts by mass of the obtained phenol resin, 20.0 parts by mass of a polar organic solvent (DBE: manufactured by DuPont, USA) and a nonpolar solvent (Hisol 100: manufactured by JXTG Energy Co., Ltd.; petroleum-based solvent) ) Was dissolved using 30.0 parts by mass to prepare a phenol resin solution (2) having a phenol resin content of 50.0% by mass.

-Preparation of Polymeric MDI Solution-
75.0 parts by mass of polymeric MDI, which is a polyisocyanate compound, is dissolved using 25.0 parts by mass of a non-polar organic solvent (Ipsol 150: manufactured by Idemitsu Kosan Co., Ltd.; petroleum solvent) to contain a polyisocyanate compound. A polymeric MDI solution having an amount of 75.0% by mass was prepared.

-Production of reaction product of basic primary silane compound and hydrofluoric acid-
Using N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane (KBM602: manufactured by Shin-Etsu Chemical Co., Ltd.) as the basic first silane compound while stirring at a temperature of 60° C. or lower, A reaction product (amine hydrofluoric acid salt) is produced by adding 0.6 parts by mass of 46% hydrofluoric acid dropwise to 0.6 parts by mass of the first silane compound (KBM602) to cause a reaction. did.

(Examples 1 to 6)
First, the reaction product of the above-mentioned first silane compound (KBM602) and hydrofluoric acid was added to 100 parts by mass of the phenol resin solution (1) prepared above in the proportions shown in Table 1 below. The polyol solutions according to each of Examples 1 to 6 were prepared by adding, stirring and uniformly mixing. Further, to 100 parts by mass of the above-prepared polymeric MDI solution, various non-basic second silane compounds shown in Table 1 below were added at a ratio shown in Table 1 below, and the mixture was uniformly stirred. Each polyisocyanate solution according to each of Examples 1 to 6 was prepared by mixing.

Next, 1000 parts by mass of the flattery sand was put into a product Kawasaki tabletop mixer manufactured by Dalton Co., Ltd., and the polyol solution prepared as described above and the polyisocyanate solution prepared as described above were respectively mixed at 10 parts each. A casting sand composition was prepared by adding a mass part, stirring for 60 seconds, and kneading. Then, using each of the obtained various molding sand compositions, respective test pieces (molds) were prepared, and the mold strength (kgf/cm ² ) immediately after molding and after molding for 24 hours was measured according to the above measuring method. And the mold strength (kgf/cm ² ) after moisture absorption deterioration after 24 hours of molding were measured, and the obtained results are shown in Table 1 below. Further, the mold strength (kgf/cm ² ) immediately after molding and after 24 hours after molding was measured using the foundry sand composition after waiting for 120 minutes from kneading to evaluate the pot life. Furthermore, the measurement of the packing density and the evaluation of the mold surface properties were also performed. The results are shown in Table 1 below.

(Example 7)
A foundry sand composition was prepared in the same manner as in Example 1 except that the phenol resin solution (2) prepared above was used instead of the phenol resin solution (1). Then, a test piece (mold) is produced using the obtained foundry sand composition, and the mold strength (kgf/cm ² ) immediately after molding and 24 hours after molding, and the molding 24 according to the above measuring method. The mold strength (kgf/cm ² ) after moisture absorption deterioration after a lapse of time was measured, and the results are shown in Table 1 below. Further, the mold strength (kgf/cm ² ) immediately after molding and after 24 hours after molding was measured using the foundry sand composition after waiting for 120 minutes from kneading to evaluate the pot life. Furthermore, the measurement of the packing density and the evaluation of the mold surface properties were also performed. The results are also shown in Table 1 below.

(Example 8)
A foundry sand composition was prepared in the same manner as in Example 1 except that 0.3 part by mass of isophthalic acid chloride was further added during the preparation of the polyisocyanate solution. Then, a test piece (mold) is produced using the obtained foundry sand composition, and the mold strength (kgf/cm ² ) immediately after molding and 24 hours after molding, and the molding 24 according to the above measuring method. The mold strength (kgf/cm ² ) after moisture absorption deterioration after a lapse of time was measured, and the results are shown in Table 1 below. Further, the mold strength (kgf/cm ² ) immediately after molding and after 24 hours after molding was measured using the foundry sand composition after waiting for 120 minutes from kneading to evaluate the pot life. Furthermore, the measurement of the packing density and the evaluation of the mold surface properties were also performed. The results are also shown in Table 1 below.

(Examples 9 to 10)
A casting sand composition was prepared in the same manner as in Example 1 except that 0.3 part by mass of lauric acid chloride or phenylphosphonic acid dichloride was further added during the preparation of the polyisocyanate solution. And after making a test piece (mold) using the obtained foundry sand composition, according to the above-mentioned measuring method, the mold strength (kgf/cm ² ) immediately after molding and 24 hours after molding, and the molding 24 The mold strength (kgf/cm ² ) after moisture absorption deterioration after a lapse of time was measured, and the results are shown in Table 1 below. Further, the mold strength (kgf/cm ² ) immediately after molding and after 24 hours after molding was measured using the foundry sand composition after waiting for 120 minutes from kneading to evaluate the pot life. Furthermore, the measurement of the packing density and the evaluation of the mold surface properties were also performed. The results are also shown in Table 1 below.

(Comparative Examples 1-5)
While preparing the phenol resin solution (1) prepared above, various second silane compounds shown in Table 2 below are shown in Table 2 below with respect to 100 parts by mass of the polymeric MDI solution prepared above. The polyisocyanate solution according to each of Comparative Examples 1 to 5 was prepared by adding in a proportion and stirring to uniformly mix them. Then, while adding 1000 parts by mass of the flattery sand into Dalton Co., Ltd. product river-type tabletop mixer, 10 parts by mass of each of the phenol resin solution (polyol solution) and the polyisocyanate solution were added and stirred for 60 seconds. Then, a molding sand composition was prepared by kneading. Then, a test piece (mold) is produced using the obtained foundry sand composition, and the mold strength (kgf/cm ² ) immediately after molding and 24 hours after molding, and the molding 24 according to the above measuring method. The mold strength (kgf/cm ² ) after deterioration due to moisture absorption after a lapse of time was measured, and the results are shown in Table 2 below. Further, the mold strength (kgf/cm ² ) immediately after molding and after 24 hours after molding was measured using the foundry sand composition after waiting for 120 minutes from kneading to evaluate the pot life. Furthermore, the measurement of the packing density and the evaluation of the mold surface properties were also performed. The results are also shown in Table 2 below.

(Comparative example 6)
A foundry sand composition was prepared in the same manner as in Comparative Example 1 except that the phenol resin solution (2) prepared above was used instead of the phenol resin solution (1). Then, a test piece (mold) is produced using the obtained foundry sand composition, and the mold strength (kgf/cm ² ) immediately after molding and 24 hours after molding, and the molding 24 according to the above measuring method. The mold strength (kgf/cm ² ) after deterioration due to moisture absorption after a lapse of time was measured, and the results are shown in Table 2 below. Further, the mold strength (kgf/cm ² ) immediately after molding and after 24 hours after molding was measured using the foundry sand composition after waiting for 120 minutes from kneading to evaluate the pot life. Furthermore, the measurement of the packing density and the evaluation of the mold surface properties were also performed. The results are also shown in Table 2 below.

(Comparative Example 7)
A casting sand composition was prepared in the same manner as in Comparative Example 1 except that N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane (KBM602) was added when preparing the polyisocyanate solution. Then, a test piece (mold) is produced using the obtained foundry sand composition, and the mold strength (kgf/cm ² ) immediately after molding and 24 hours after molding, and the molding 24 according to the above measuring method. The mold strength (kgf/cm ² ) after deterioration due to moisture absorption after a lapse of time was measured, and the results are shown in Table 2 below. Further, the mold strength (kgf/cm ² ) immediately after molding and after 24 hours after molding was measured using the foundry sand composition after waiting for 120 minutes from kneading to evaluate the pot life. Furthermore, the measurement of the packing density and the evaluation of the mold surface properties were also performed. The results are also shown in Table 2 below.

(Comparative Example 8)
While preparing the phenol resin solution (1) prepared above, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane (KBM602) was added to 100 parts by mass of the polymeric MDI solution prepared above. ) Was added in the proportions shown in Table 2 below, and the mixture was stirred and mixed uniformly to prepare a polyisocyanate solution. Then, while adding 1000 parts by mass of the flattery sand into Dalton Co., Ltd. product river-type tabletop mixer, 10 parts by mass of each of the phenol resin solution (polyol solution) and the polyisocyanate solution were added and stirred for 60 seconds. Then, a molding sand composition was prepared by kneading. Then, a test piece (mold) is produced using the obtained foundry sand composition, and the mold strength (kgf/cm ² ) immediately after molding and 24 hours after molding, and the molding 24 according to the above measuring method. The mold strength (kgf/cm ² ) after deterioration due to moisture absorption after a lapse of time was measured, and the results are shown in Table 2 below. Further, the mold strength (kgf/cm ² ) immediately after molding and after 24 hours after molding was measured using the foundry sand composition after waiting for 120 minutes from kneading to evaluate the pot life. Furthermore, the measurement of the packing density and the evaluation of the mold surface properties were also performed. The results are also shown in Table 2 below.

(Comparative Example 9)
The reaction product of the above-mentioned first silane compound (KBM602) and hydrofluoric acid was added to 100 parts by mass of the phenol resin solution (1) prepared above in a ratio shown in Table 2 below. Then, the polyol solution was prepared by stirring and uniformly mixing, while a polyisocyanate solution containing no non-basic second silane compound was prepared. Then, while adding 1000 parts by mass of the flattery sand into Dalton Co., Ltd. product river-type tabletop mixer, 10 parts by mass of each of the polyol solution and the polyisocyanate solution were added, and the mixture was stirred for 60 seconds and kneaded. , A molding sand composition was prepared. Then, a test piece (mold) is produced using the obtained foundry sand composition, and the mold strength (kgf/cm ² ) immediately after molding and 24 hours after molding, and the molding 24 according to the above measuring method. The mold strength (kgf/cm ² ) after deterioration due to moisture absorption after a lapse of time was measured, and the results are shown in Table 2 below. Using the foundry sand composition after waiting 120 minutes after kneading, the mold strength (kgf/cm ² ) immediately after molding and after 24 hours after molding were measured to evaluate the pot life. Furthermore, the measurement of the packing density and the evaluation of the mold surface properties were also performed. The results are also shown in Table 2 below.

As is clear from the comparison of the results in Table 1 and Table 2, the reaction product of the basic primary silane compound and hydrofluoric acid and the non-basic substance according to the present invention, together with the predetermined phenolic resin and polyisocyanate, are obtained. The second silane compound of No. 1 is used as a constituent, and the organic binder obtained in Examples 1 to 7 is used to prepare a molding sand composition, and a mold obtained by molding the composition. The (test piece) has excellent properties not only in the mold strength under normal humidity environment but also in the mold strength after moisture absorption deterioration under high humidity, and the packing density of the mold. It is recognized that the mold surface is high and the surface texture of the mold is smooth. It is also clear from the results in Table 1 that such actions and effects can be further improved by the organic binders of Examples 8 to 10.

On the other hand, a template obtained using the organic binder (containing only the non-basic second silane compound) in Comparative Examples 1 to 8 to which such a reaction product (amine hydrofluoric acid salt) was not added ( In the test piece), the mold strength under normal humidity environment is not sufficient, the packing density is low, the surface properties of the mold are poor, and the mold strength after deterioration due to moisture absorption is It is recognized that the mold is remarkably deteriorated and is inferior in moisture absorption deterioration resistance property, and the mold obtained by using such an organic binder is not practical. In addition, in the organic binder according to Comparative Example 9 in which only the amine hydrofluoric acid salt (reaction product) is contained, the packing density of the mold is not particularly sufficient, and the surface property of the mold is It is recognized that it lacks smoothness.

Claims (14)

A urethane-curing organic binder used for molding a urethane-based template, which is a reaction product of a basic primary silane compound and hydrofluoric acid, and a non-basic, together with a polyol compound and a polyisocyanate compound. A urethane-curable organic binder for a template, which further comprises a second silane compound as a constituent component. The urethane curable organic binder for a mold according to claim 1, wherein a reaction product of the first silane compound and hydrofluoric acid is previously formed and is contained in the form of the reaction product. Agent. The urethane curable organic binder for a mold according to claim 1 or 2, wherein the polyol compound is a phenol resin. The urethane curable organic binder for a mold according to claim 3, wherein the phenol resin is an orthocresol-modified phenol resin. The mold of any one of claims 1 to 4, wherein the reaction product is used in a proportion of 0.01 to 10 parts by mass with respect to 100 parts by mass of the polyol compound. Urethane curable organic binder. The said 2nd silane compound is used in the ratio of 0.01-10 mass parts with respect to 100 mass parts of the said polyol compound, The any one of the Claims 1 thru|or 5 characterized by the above-mentioned. Urethane-curable organic binder for molds. The urethane curable organic binder for a mold according to any one of claims 1 to 6, wherein the first silane compound is an alkoxysilane containing an amino group. The alkoxysilane containing an amino group is 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl )-3-Aminopropyltrimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2 The urethane curable organic binder for a mold according to claim 7, which is selected from the group consisting of -aminoethyl-3-aminopropyltrimethoxysilane and 3-ureidopropyltrialkoxysilane. 9. The second silane compound is selected from the group consisting of epoxy silane, isocyanate silane, chlorosilane, mercapto silane, isocyanurate silane, acryl silane and methacryl silane, according to any one of claims 1 to 8. The urethane-curable organic binder for a mold according to [1]. The reaction product of the basic first silane compound and hydrofluoric acid is contained in the polyol compound, while the non-basic second silane compound is contained in the polyisocyanate compound. The urethane curable organic binder for a mold according to any one of claims 1 to 9, which is characterized. The urethane curable mold for a mold according to any one of claims 1 to 10, further comprising at least one of an acid halide, a phosphoryl halide compound and a phosphine halide as a constituent component. Organic binder. A step of preparing a polyol solution obtained by dissolving a polyol compound in an organic solvent,
A step of preparing a polyisocyanate solution obtained by dissolving a polyisocyanate compound in an organic solvent,
A step of allowing a reaction product of a basic primary silane compound and hydrofluoric acid to exist in the polyol solution and/or the polyisocyanate solution;
A step of allowing the polyol solution and/or the polyisocyanate solution to contain a non-basic second silane compound,
A method for preparing a urethane-curable organic binder for a template, which comprises: A molding sand composition comprising the urethane-curable organic binder for a mold according to any one of claims 1 to 11 and molding sand. A mold obtained by molding the molding sand composition according to claim 13 and curing it.