WO2018181814A1

WO2018181814A1 - Urethane curable organic binding agent for mold, casting sand composition obtained using same, and mold

Info

Publication number: WO2018181814A1
Application number: PCT/JP2018/013456
Authority: WO
Inventors: 芳也千田
Original assignee: 旭有機材株式会社
Priority date: 2017-03-30
Filing date: 2018-03-29
Publication date: 2018-10-04
Also published as: CN110461498A; CN110461498B; MX2019011418A

Abstract

The purpose of the present invention is to provide a urethane curable organic binding agent with which a mold having improved resistance to deterioration in strength due to moisture can be advantageously obtained, and also to provide a urethane curable organic binding agent for mold with which the mold strength due to being left after shaping can be effectively improved. The urethane curable organic binding agent is used for shaping a urethane-based mold and is configured to include, as constituent components, a polyol compound, a polyisocyanate compound, and additionally a reaction product of a basic silane compound and an acid or a halide thereof.

Description

Urethane curable organic binder for mold, foundry sand composition and mold obtained using the same

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

Conventionally, as one of the typical organic molds used in sand 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 (urethanization). There are known urethane molds made by utilizing the reaction), for example, phenolic urethane molds. And as such urethane-type molds such as phenol-urethane-type molds, there is no need for heating during molding, mass-produced gas-cured molds produced by the amine cold box method using amine gas as a catalyst, 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 foundry sand, a mixer, and an organic viscosity for a mold comprising a phenol resin solution using an organic solvent as a solvent and a polyisocyanate compound solution. After producing a foundry sand composition obtained by coating the surface of such foundry sand with an organic binder by kneading with a binder, the foundry sand composition is blown into a predetermined mold to form a mold. And is cured by passing an amine-based catalyst gas through it. In addition, a self-hardening mold by the room temperature self-hardening method is used when a granular refractory casting sand is kneaded with an organic binder for a mold comprising a phenol resin solution and a polyisocyanate compound solution using an organic solvent as a solvent. And the resulting mixture is immediately formed into a desired shape.

Therefore, in a urethane-based mold such as a phenol-urethane-based mold obtained by utilizing such a polyaddition reaction (urethanization reaction) between a phenol resin and a polyisocyanate compound, the chemical bonding characteristics cause air There are inherent problems of so-called moisture absorption deterioration such as hardening inhibition and strength deterioration due to moisture in the inside.

Therefore, in JP-A-1-501630 (Patent Document 1), it is clear that silane compounds such as epoxy silane, amino silane, and ureido silane are added as a countermeasure for preventing moisture absorption deterioration of the mold produced by the cold box method. However, even with such a silane compound, sufficient characteristics have not yet been secured, and further establishment of measures for preventing moisture absorption deterioration has been desired.

Therefore, in Japanese Patent Application Laid-Open No. 2012-196700 (Patent Document 2), a urethane for a mold is obtained 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 configuring a curable organic binder, it is possible to prevent moisture absorption deterioration of the mold and maintain excellent mold strength, but there is prepared a special isocyanate group-containing compound. There was a need to do.

Japanese Patent Laid-Open No. 2001-205386 (Patent Document 3) discloses a binder composition for producing a gaseous tertiary amine curable mold comprising a phenol resin and an isocyanate compound combined with boric acid. Further, it has been clarified that a silane compound can be contained in order to improve the adhesion 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 manufacturing composition, and therefore, the binder and the granular refractory aggregate It is said that the strength as a mold can be maintained even if it is kneaded and left for several hours, but the evaluation of the mold strength there is performed under dry conditions where the humidity is not high. However, under high humidity conditions, the mold strength was significantly lowered due to moisture absorption deterioration, and it was difficult to maintain sufficient strength.

JP-T-1-501630 JP 2012-196700 A JP 2001-205386 A

Here, the present invention has been made in the background of such circumstances, and the problem to be solved is a urethane-curable organic material that can advantageously provide a mold having improved moisture absorption resistance characteristics. It is also intended to provide a binder, and also to provide a urethane-curable organic binder for molds that can effectively improve the mold strength by leaving after molding, and such An object of the present invention is to provide a foundry sand composition capable of imparting excellent mold characteristics using a urethane curable organic binder, and a mold having excellent characteristics formed using the foundry sand composition.

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

(1) A urethane-curing organic binder used for molding urethane-based molds, comprising a reaction product of a basic silane compound and an acid or a halide thereof together with a polyol compound and a polyisocyanate compound. A urethane curable organic binder for molds, further comprising:
(2) It is composed of two liquids, liquid A containing the polyol compound and liquid B containing the polyisocyanate compound, and the liquid A reacts with the basic silane compound and an acid or a halide thereof. The urethane-cured organic caking for mold according to the above aspect (1), wherein the product contains the product as a constituent component, and the water content of the liquid A is 0.1 to 15% by mass. Agent.
(3) The above embodiment wherein the acid or halide thereof is hydrofluoric acid (
The urethane-curing organic binder for molds according to 1) or aspect (2).
(4) Any one of the above aspects (1) to (3), wherein a reaction product of the basic silane compound and an acid or a halide thereof is formed in advance and used in the form of the reaction product. The urethane-curing organic binder for molds described in 1.
(5) The urethane curable organic binder for molds according to any one of the aspects (1) to (4), wherein the polyol compound is a phenol resin.
(6) The urethane curable organic binder for mold according to the aspect (5), wherein the phenol resin is an ortho-cresol-modified phenol resin.
(7) For 100 parts by mass of the polyol compound, the reaction product is
Used in a proportion of 0.1 to 2.0 parts by mass,
1) The urethane-cured organic binder for molds according to any one of the embodiments (6).
(8) The urethane curable organic viscosity for a mold according to any one of the above aspects (1) to (7), wherein the basic silane compound is an alkoxysilane containing an amino group. Binder.
(9) The above-mentioned 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 selected from the group consisting of urethane for molds according to the aspect (8), curable organic Binder.
(10) The acid or halide thereof is hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, boric acid, benzenesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, formic acid, acetic acid. , Benzoic acid, phenylphosphonic acid dichloride, 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 and It is selected from the group consisting of sebacic acid dichloride, The urethane curable organic binder for casting molds according to any one of the above aspects (1) to (9).
(11) The urethane-curable organic binder for molds according to any one of the above aspects (1) to (10), further comprising a higher fatty acid ester as a constituent component.
(12) A foundry sand composition comprising the urethane curable organic binder for molds according to any one of the aforementioned aspects (1) to (11) and foundry sand.
(13) A mold obtained by molding and curing the foundry sand composition according to the aspect (12).

As described above, in the urethane curable organic binder for mold according to the present invention, in addition to the polyol compound and polyisocyanate compound which are essential constituent components, a basic silane compound and an acid or a halide thereof are further added. In this way, it is possible to advantageously improve the strength of a mold molded using such an organic binder, and in particular, a mold after molding. In addition to being able to effectively increase the standing strength of the mold, it is also possible to advantageously improve the hygroscopic deterioration characteristic of the strength of such a mold.

Therefore, in the foundry sand composition obtained by kneading the organic binder for molds according to the present invention into foundry sand, it is possible to provide a mold having the above-mentioned excellent characteristics, and such a cast product. In the mold molded using the sand composition, it has excellent mold strength and can be advantageously used in the casting process of the target metal as a mold having improved strength and moisture absorption resistance. It becomes.

In the present invention, it is preferably recommended to use a higher fatty acid ester together with the reaction product of the basic silane compound and the acid or the halide thereof as described above. Strength and its hygroscopic deterioration characteristics can be further improved, and more effective extension of the pot life of the foundry sand composition obtained by kneading with foundry sand is maintained while maintaining such characteristics. The characteristic of obtaining can be demonstrated.

By the way, in such a urethane curable organic binder for molds according to the present invention, the polyol compound used as one of the main components is not particularly limited. Various known polyol compounds used for 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 of ethylene oxide, a copolymer of tetrahydrofuran and propylene oxide, and a copolymer of tetrahydrofuran and 3-methyltetrahydrofuran.

Among them, as the polyol compound used when molding a urethane mold, various known phenol resins used when molding a phenol urethane mold can be suitably used. Specifically, in the presence of a reaction catalyst, phenols and aldehydes are added so that the aldehydes are generally in a ratio of 0.5 to 3.0 moles per mole of the phenols. Examples of the benzyl ether type phenol resin, resol type phenol resin, novolak type phenol resin, and their modified phenol resins, which are soluble in organic solvents, obtained by condensation reaction, and mixtures thereof can be exemplified. One or two or more of them are appropriately selected and used. Of these, in particular, ortho-cresol-modified phenol resins modified with ortho-cresol, more preferably benzyl ether-type ortho-cresol-modified phenol resins and mixtures thereof include solubility in organic solvents and polyisocyanate compounds. In addition to being excellent in compatibility, the strength (initial strength) of the obtained mold can be effectively improved, and therefore it is preferably used in the present invention.

The catalyst used in the addition / condensation reaction between the phenols and aldehydes is not particularly limited, and may be a known acidic catalyst or basic acid depending on the type of phenol resin desired. In addition to the catalyst, various catalysts conventionally used for producing phenolic resins are appropriately used. Examples of such catalysts include metal salts having metal elements such as tin, lead, zinc, cobalt, manganese, and nickel. More specifically, lead naphthenate, zinc naphthenate, In addition to lead acetate, zinc chloride, zinc acetate, zinc borate, lead oxide, a combination of an acid and a base capable of forming such a metal salt can be exemplified. Further, when such a metal salt is employed 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 phenol resins include alkylphenols such as phenol, cresol, xylenol, p-tert-butylphenol, and nonylphenol, polyhydric phenols such as resorcinol, bisphenol F, and bisphenol A, and mixtures thereof. On the other hand, examples of aldehydes include formaldehyde, formalin, paraformaldehyde, polyoxymethylene, glyoxal, furfural, and mixtures thereof.

Furthermore, as described above, orthocresol-modified phenol resin that is one of the phenol resins advantageously employed in the present invention includes, for example, orthocresol and phenol in the presence of a reaction catalyst such as a metal salt. (1) Ortho-cresol-modified phenol resin of co-condensation of ortho-cresol and phenol, (2) Mixed ortho-cresol-modified phenol resin of ortho-cresol resin and phenol resin (3) Modified orthocresol-modified phenolic resins obtained by modifying the resins of (1) and (2) with a modifying agent (modifier), and (1), (2) and (3) ) And a mixture of two or more of them can be exemplified. The ortho-cresol-modified phenol resins (1), (2) and (3) are well known, and such known ones are used as they are in the present invention. . The ratio of phenol / orthocresol is 1/9 to 9/1, preferably 3/7 to 7/3, more preferably 4/6 to 6/4, based on mass. It will be.

A polyol compound such as a phenol resin used as one of the main components of the organic binder for a mold according to the present invention as described above has a low viscosity, compatibility with a polyisocyanate compound solution described later, and casting sand. In general, from the viewpoint of coating properties, mold physical properties, etc., a solution (in which the concentration is about 30 to 80% by mass, which is dissolved in an organic solvent formed by combining a polar organic solvent and a nonpolar organic solvent) Hereinafter, it is used in the state of “polyol compound solution”.

On the other hand, in the organic binder for molds according to the present invention, the polyisocyanate compound used as the other main component is subjected to a polyaddition reaction with active hydrogen of a polyol compound such as a phenol resin as described above. It is a compound having in the molecule two or more isocyanate groups capable of chemically bonding foundry sands with urethane bonds such as phenol urethane. Specific examples of such polyisocyanate compounds include aromatic, aliphatic or alicyclic polyisocyanates such as diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate (hereinafter referred to as “polymeric MDI”), hexamethylene diisocyanate, In addition to 4,4′-dicyclohexylmethane diisocyanate, various conventionally known polyisocyanates such as prepolymers having two or more isocyanate groups obtained by reacting these compounds with polyols can be mentioned. You may use, or may use it in combination of 2 or more types.

Further, even in such a polyisocyanate compound, for the same reason as the polyol compound such as the phenol 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. It is used as a solution dissolved in this organic solvent so that the concentration is about 40 to 90% by mass. Depending on the type of polyisocyanate compound to be used, it is not always necessary to dissolve it in an organic solvent, and it can be used as it is. Hereinafter, a polyisocyanate compound stock solution and a solution obtained by dissolving a polyisocyanate compound in an organic solvent are referred to as a polyisocyanate compound solution.

Here, as the organic solvent for dissolving the above-described polyol compound and polyisocyanate compound, the organic solvent is non-reactive with the polyisocyanate compound and is a solute (polyol compound or polyisocyanate compound) to be dissolved. Although it is not particularly limited as long as it is a good solvent, in general, i) an amount that does not cause separation of i) a polar solvent for dissolving a polyol compound such as a phenol resin, and ii) a polyol compound such as a phenol resin. In combination with a non-polar solvent for dissolving the polyisocyanate compound.

More specifically, examples of the polar solvent of i) described above include, for example, aliphatic carboxylic acid esters, in particular, dicarboxylic acid methyl ester mixture (manufactured by DuPont, USA; trade name: DBE; dimethyl glutarate and adipine) In addition to dicarboxylic acid alkyl esters such as dimethyl acid and dimethyl succinate), vegetable oils such as rapeseed oil methyl ester, ketones such as isophorone, ethers such as isopropyl ether, and furfuryl alcohol. I can do it. In addition, as the non-polar solvent of the above ii), for example, petroleum hydrocarbons such as paraffins, naphthenes, and alkylbenzenes, specific examples include Ipsol 150 (manufactured by Idemitsu Kosan Co., Ltd .; petroleum solvent), Hysol 100 (manufactured by JX Energy Co., Ltd .; petroleum solvent), HAWS (manufactured by Shell Chemicals Japan Co., Ltd .; petroleum solvent) and the like can be exemplified.

And in this invention, in addition to the above-mentioned polyol compound and polyisocyanate compound, in addition to the above-described polyol compound and polyisocyanate compound, as a constituent component of the target organic binder for the template, a basic silane compound and an acid or a halide thereof The reaction product was used. The presence of such a specific reaction product can advantageously improve the strength of a mold formed using an organic binder, particularly improve the standing strength of the mold after molding, and store such a mold. -It is possible to effectively suppress or prevent the adverse effect of the external environment when left untreated, especially the decrease in 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 moisture in the air during storage and standing, and to improve the moisture absorption resistance deterioration characteristics of the mold. In addition, by using such a reaction product of a basic silane compound and an acid or a halide thereof, the working time of a foundry sand composition obtained by kneading an organic binder and foundry sand can be reduced. Improvements can also be advantageously achieved.

The basic silane compound that gives such a 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). For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltri Methoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-amino Alkoxysilanes having amino groups such as propyltrimethoxysilane, and further 3-ureidopropylto Alkoxysilane compounds having a ureido group such as a silane and the like. Of the basic silane compounds, basic alkoxysilanes are preferably used, and among them, alkoxysilanes having an amino group are more preferable, and N-2- (aminoethyl) -3-aminopropylmethyldimethoxy is more preferable. Silane, 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 the alkoxy group is hydrolyzed by the water in the polyol compound, acid or halide thereof in addition to being easily available, and changes to a hydroxyl group. This is because adhesion to foundry sand (such as aggregate) becomes stronger and high mold strength can be exhibited.

Examples of the acid or halide thereof that can be reacted with such a basic silane compound include inorganic acids, organic acids, and halides thereof such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid. Inorganic acids such as hydrofluoric acid and boric acid, organic sulfonic acids such as benzenesulfonic acid, paratoluenesulfonic acid and trifluoromethanesulfonic acid; organic carboxylic acids such as formic acid, acetic acid and benzoic acid; organic phosphonic acids and the like Among them, hydrochloric acid, hydrobromic acid, phosphoric acid, hydrofluoric acid, benzenesulfonic acid, paratoluenesulfonic acid, trifluoromethanesulfonic acid and the like are advantageously used, and particularly hydrofluoric acid. Recommended to use. Examples of the halide include halides of organic acids such as the above organic sulfonic acids, organic carboxylic acids, and organic phosphonic acids. For example, phenylphosphonic acid dichloride, 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, etc., among them, phenylphosphonic acid dichloride, lauric acid chloride, etc. Preferably used.

Furthermore, as a combination of the above basic silane compound and an acid or a halide thereof, any combination can be adopted as long as it can form a reaction product thereof. -2- (Aminoethyl) -3-aminopropylmethyldimethoxysilane and hydrochloric acid, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane and hydrofluoric acid, N-2- (aminoethyl) -3 -Combinations of aminopropylmethyldimethoxysilane and phenylphosphonic acid dichloride can be mentioned. The ratio of basic silane compound / acid or halide thereof used to obtain the desired reaction product is 2/8 to 8/2, preferably 3/7 to 7/3 on a mass basis. More preferably, a ratio of 4/6 to 6/4 is adopted.

The use amount of the reaction product of the basic silane compound and the acid or its halide is 0.1 to 100 parts by mass of 100 parts by mass of the polyol compound which is one of the components of the organic binder. A ratio of about 2.0 parts by mass, preferably about 0.2 to 1.0 parts by mass is suitably employed. When the amount of such reaction product used is less than 0.1 parts by mass, the effect of the use of such a reaction product is not sufficiently exhibited, and more than 2.0 parts by mass. As a result, problems such as difficulty in contributing to sufficient improvement in the strength of the obtained mold arise.

By the way, when producing a specific reaction product used in the present invention as described above, for example, a predetermined basic silane compound and a predetermined acid or a halide thereof are mixed and reacted in a plastic container. By causing the reaction, the target reaction product can be easily obtained. At this time, in order to suppress the heat of reaction between the basic silane compound and the acid or its halide, one of them is cooled or stirred while the other is continuously or intermittently. It is desirable to prevent the rapid progress of the reaction by adding them. In addition, in those reactions, in addition to the case where the reaction proceeds by adding an acid or a halide thereof to the basic silane compound, on the contrary, the basic silane compound is added to the acid or the halide thereof. It is also possible to add them. The temperature during the reaction between the basic silane compound and the acid or its halide is preferably 80 ° C. or less, more preferably 70 ° C. or less, and even more preferably 60 ° C. or less. It is done.

Here, adding a basic silane compound or an acid or a halide thereof little by little continuously or intermittently means that a constant amount is added at a constant speed in the continuous addition method. In addition, a method of adding to the reaction system at a constant rate of addition is advantageously employed, and in the intermittent addition method, it is possible to add at regular intervals and at regular intervals. desirable. In addition, in the intermittent addition method with such an interval, for example, every 1 second, every 10 seconds, every 1 minute, etc., a predetermined amount of time is added or a reaction is made. It is also possible to adopt a method of gradually dropping into the system. By adding little by little by such a method, it is possible to advantageously prevent an increase in the heat of reaction and to effectively prevent deterioration of physical properties of the reaction product obtained. Especially, if the method by dripping is employ | adopted, it is possible to suppress the temperature rise by reaction heat more effectively.

In the present invention, preferably, after a reaction product obtained by the reaction of such a basic silane compound and an acid or a halide thereof is formed in advance, the form of such a reaction product is used. In this case, it is used together with a polyol compound or a polyisocyanate compound to advantageously constitute a target organic binder. In this way, a reaction product of a basic silane compound and an acid or a halide thereof is formed in advance, so that a step of adding an acidic substance such as an acid is not required, and therefore a strong acid is used. In some cases, the safety in producing the foundry sand composition can be advantageously ensured. Needless to say, the method of adding such a specific reaction product is not limited to those exemplified, and such a reaction product exists as a component in the organic binder. As long as it is a form to be obtained, these basic silane compounds, acids or halides thereof can be blended with polyol compounds or polyisocyanate compounds in an appropriate form.

Moreover, in the organic binder for molds according to the present invention, in addition to the above-described polyol compound, polyisocyanate compound and specific reaction product, a higher fatty acid ester is advantageously contained as one of the constituent components. It will be. Due to the presence of this higher fatty acid ester, the strength and moisture absorption deterioration characteristics of a mold molded using such an organic binder can be further improved, and in particular, excellent mold strength and moisture absorption deterioration characteristics are maintained. As it is, it is possible to effectively improve the pot life of the foundry sand composition obtained by kneading with the foundry sand. Here, the higher fatty acid of the higher fatty acid ester, as is well known, refers to a fatty acid having a large number of carbon atoms in the molecule and generally having 12 or more carbon atoms, Usually, fatty acids having 12 to 30 carbon atoms, preferably 14 to 25, more preferably 16 to 20 carbon atoms are suitably used. The higher fatty acid ester is generally in a proportion of generally 0.1 to 40 parts by weight, preferably 0.5 to 30 parts by weight, more preferably 1 to 20 parts by weight with respect to 100 parts by weight of the polyol compound. In addition, it is desirable to be used in addition to the polyisocyanate compound solution described above. This is because if the amount of the higher fatty acid ester used is reduced, it is difficult to sufficiently exert the effect of the use of the higher fatty acid ester, and excessive use of the higher fatty acid ester adversely affects the characteristics of the molding sand composition and the mold. Because it comes to bring.

Examples of such higher fatty acid esters include saturated fatty acid esters such as lauric acid esters, palmitic acid esters, stearic acid esters, isostearic acid esters, hydroxystearic acid esters, and myristic acid esters, oleic acid esters, and linoleic acid. Examples thereof include unsaturated fatty acid esters such as esters, linolenic acid esters, and ricinoleic acid esters. Among these, it is particularly desirable to use an unsaturated fatty acid ester, more preferably a ricinoleic acid ester, more preferably a polycondensate of ricinoleic acid and ethylene glycol or glycerin, and a self-condensate of ricinoleic acid. More preferably it is.

Thus, the urethane curable organic binder for molds according to the present invention comprises a basic silane compound and an acid or a halide thereof as described above in addition to a polyol compound and a polyisocyanate compound that form a urethane bond such as phenol urethane. The reaction product is included as a constituent component, and more preferably a higher fatty acid ester is included. Such an organic binder may also contain the above-described compounding as necessary. Various known additives conventionally used in organic binders for molds, such as pot life extenders (curing retarders) different from the ingredients, mold release agents, strength deterioration inhibitors, and drying inhibitors Can be appropriately selected and blended. Of course, it goes without saying that these various additives are used within a quantitative range that does not impair the effects that can be enjoyed by the present invention. Among these various additives, the pot life extender (curing retarder) is used to suppress the urethanization reaction and extend the pot life of the casting sand composition. The mold agent reduces resistance when the molded mold is removed from the mold, and part of the foundry sand composition blown and filled in the mold adheres to the mold when the mold is removed. This is used to prevent the occurrence of spotting and to obtain a mold with a uniform molding surface and high accuracy.

The urethane curable organic binder for molds according to the present invention thus obtained is kneaded into foundry sand (refractory aggregate) in the same manner as in the prior art to form a urethane-based gas curable mold. Therefore, the foundry sand composition is to be formed.

Specifically, for example, when molding a gas-hardening mold by a cold box method, first, the above-described organic binder for mold according to the present invention is kneaded with foundry sand (fireproof aggregate). A casting sand composition (kneaded sand) is produced by coating the casting sand surface with an organic binder for molds. That is, for the foundry sand, as an organic binder, a polyol compound, a polyisocyanate compound, a reaction product of a basic silane compound and an acid or a halide thereof, and further various desired additives are sufficiently provided. By kneading and mixing, the molding sand composition is produced by coating the molding sand surface with the organic binder for casting. At this time, the reaction product of the basic silane compound and the acid or its halide and other various additives are separately prepared so that the compound can be uniformly mixed with the foundry sand composition. It is added to or mixed with one or both of the solution and the polyisocyanate compound solution, or dissolved or dispersed in an appropriate organic solvent, and this is mixed with a polyol compound solution or It can be mixed with the polyisocyanate compound solution into the foundry sand, or it can be added directly to the formed polyol compound and mixed, such as after completion of the condensation during the production of the polyol compound such as phenol resin. Is possible.

In particular, in the present invention, a specific reaction product obtained by reacting a basic silane compound with an acid or a halide thereof is added to a separately prepared solution of a polyol compound. Is desirable. Specifically, the organic binder for a mold according to the present invention is composed of two liquids, a liquid A containing a polyol compound (polyol compound solution) and a liquid B containing a polyisocyanate compound (polyisocyanate compound solution). The solution A is made to contain the specific reaction product. By incorporating such a specific reaction product in the liquid A, it is advantageous to improve the strength of the mold molded using the organic binder of the present invention, particularly to improve the standing strength of the mold after molding. In addition to being able to achieve this, it is possible to effectively suppress or prevent adverse effects of the external environment when such a mold is stored and left, particularly a decrease in 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 moisture in the air during storage and standing, and to improve the moisture absorption resistance deterioration characteristics of the mold. Further, by using such a specific reaction product, it is possible to advantageously improve the pot life of the foundry sand composition obtained by kneading the organic binder and the foundry sand. In addition, when such a specific reaction product is contained (added) in the B liquid mainly composed of a polyisocyanate compound, the reaction product reacts with the polyisocyanate compound, and the various effects described above are obtained. There is a risk that you will not be able to enjoy it.

In addition, in this invention, it cannot be overemphasized that the addition system with respect to A liquid of this specific reaction product is not what is limited to the thing of an illustration, and such reaction product is liquid A ( In a solution containing a polyol compound as a main component, a basic silane compound, an acid, or a halide thereof may be added to the liquid A in an appropriate form as long as it can be present as a constituent component. Is possible. In addition, when the specific reaction product formed in advance is added to the liquid A, the water content is 0.2 to 99.5% by mass, preferably 0.5 to 50% by mass, more preferably 1 to 25% by mass. % Of the reaction product is appropriately prepared and added to the liquid A (solution containing a polyol compound as a main component).

In the present invention, when the specific reaction product as described above is contained in the liquid A mainly composed of a polyol compound, the water content in the liquid A is 0.1 to 15% by mass. It is important to adjust. By setting the water content in the liquid A constituting the organic binder to a predetermined ratio, the effects of the present invention described above (improvement of the standing strength of the mold, improvement of the moisture absorption resistance of the mold, and the molding sand composition) (Improvement of pot life) can be enjoyed more advantageously. In the present invention, the water content in the liquid A is 0.1 to 15% by mass, preferably 0.15 to 10% by mass, and more preferably 0.2 to 6% by mass.

By the way, when manufacturing the foundry sand composition as described above, the polyol compound solution and the polyisocyanate compound solution constituting the organic binder are gradually polyaddition reaction (urethanization reaction) from the stage of mixing them. Therefore, it is prepared separately and prepared in advance, and usually mixed at the time of kneading with foundry sand. The kneading / mixing operation is preferably performed at a temperature in the range of −10 ° C. to 50 ° C. using a continuous or batch mixer similar to the conventional one.

The foundry sand (fire-resistant aggregate) kneaded with the organic binder for molds according to the present invention is natural sand as long as it is a fire-resistant one conventionally used for molds. Even artificial sand is not particularly limited. For example, silica sand, olivine sand, zircon sand, chromite sand, alumina sand, ferrochrome slag, ferronickel slag, converter slag, mullite artificial particles (for example, trade names “available from ITOCHU CERATECH CORPORATION” Cerabeads ”), alumina-based artificial particles, other various artificial particles, and regenerated sand and recovered sand thereof, and one or a combination of two or more of these can be used. Of these, natural silica sand (including reclaimed sand) having a high silica content is more suitably employed.

The casting sand composition obtained as described above is shaped in a mold such as a mold having a molding cavity that gives a desired shape, and then a catalyst gas for curing is formed. By aeration, the curing of the foundry sand composition is promoted and a gas curing mold is produced. Examples of the catalyst gas include conventionally known tertiary amine gases such as triethylamine, dimethylethylamine, dimethylisopropylamine, and cyclic nitrogen compounds such as pyridine and N-ethylmorpholine. At least one of these is appropriately selected and used in a normal quantitative range.

In addition, when molding a target self-hardening mold by a room temperature self-hardening method, as in the case of the above-described gas-curing mold, first, a casting sand composition in which the surface of the casting sand is coated with an organic binder. However, at that time, the molding sand composition used in the room temperature self-hardening method is further mixed with a curing catalyst together with the organic binder according to the present invention at the time of kneading. Become. Examples of the curing catalyst include bases, amines, metal ions and the like that are usually used in the known Ashland method.

Furthermore, in the preparation of the foundry sand composition that gives the gas-curing mold and the self-hardening mold, the blending amounts of the polyol compound solution and the polyisocyanate compound solution are the blending amounts of the polyol compound and the polyisocyanate compound, which are active ingredients, respectively. However, 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 is suitably employed. . Further, the mixing ratio of the polyol compound and the polyisocyanate compound is not particularly limited, but in general, the polyol compound: polyisocyanate compound = 4: 6 to 6: 4 on a mass basis. A solution or a polyisocyanate compound solution is used in combination.

Thus, in the case of a gas-curing mold and a self-hardening mold formed as described above, the strength can be effectively improved, and further, the moisture absorption deterioration resistance characteristic of the strength can be enhanced. Therefore, it can be advantageously used for casting casting products made of various metals such as magnesium alloy and iron.

In the following, some typical embodiments of the present invention will be shown to clarify the present invention more specifically. However, the present invention is not restricted by the description of such embodiments. It goes without saying that it is not a thing. In addition to the following examples, the present invention includes various changes and modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention, in addition to the specific description described above. It should be understood that improvements and the like can be added.

Further, the measurement of the strength of the mold formed from the molding sand composition obtained using the organic binder prepared in the following Examples and Comparative Examples, the measurement of the strength after the moisture absorption deterioration of the mold, and further Evaluation of the pot life of such a casting sand composition and measurement of the water content in the liquid A constituting the organic binder were carried out as follows.

(1) Measurement of mold strength After the kneaded foundry sand composition was put into a sand magazine of a cold box molding machine, the foundry sand composition was put into a bending strength test piece preparation mold with a gauge pressure: Fill with 0.3 MPa. Next, after a triethylamine gas was aerated with a gas generator at a gauge pressure of 0.2 MPa for 1 second in the mold, air purge was performed at a gauge pressure of 0.2 MPa for 14 seconds, and then the mold was removed, A bending test piece (mold) of width: 30 mm × length: 85 mm × thickness: 10 mm is prepared. The obtained test piece was left standing for 24 hours under the conditions of i) immediately after the molding and ii) normal temperature and humidity of air temperature: 25 ° C. and relative humidity: 50%. The bending strength (kgf / cm ² ) of each is measured by Takachiho Seiki Co., Ltd.).

(2) Measurement of mold strength after moisture absorption deterioration In the same manner as the measurement of mold strength described above, after preparing a test piece from each casting sand composition, the obtained test piece (mold) is : 10 ° C, relative humidity: 90% in a sealed container for 120 minutes or 24 hours, and then bending strength (kgf / cm ² ) using a digital foundry sand strength tester (manufactured by Takachiho Seiki Co., Ltd.) ).

(3) Evaluation of pot life of foundry sand composition When producing test pieces from the respective foundry sand compositions in the same manner as in the measurement of mold strength, Enshu reclaimed sand or flattery sand as foundry sand And a molding sand composition prepared by kneading with an organic binder (phenol resin solution + reaction product + polyisocyanate compound solution), immediately after the kneading, molding is performed (wait time after kneading: 0 minutes) ), Molding was performed after 120 minutes after kneading (standby time after kneading: 120 minutes), and the strength of each of the obtained test pieces was measured as mold strength. The pot life is evaluated by comparing two mold strength values.

(4) Measurement of water content in liquid A In accordance with Karl Fischer titration specified in JIS-K-0113: 2005, using a moisture measuring device (trade name: AQV-7) manufactured by Hiranuma Sangyo Co., Ltd. The water content in the liquid A constituting the organic binder was measured.

-Preparation of phenol resin solution (1)-
In a three-necked reaction flask equipped with a reflux, a thermometer and a stirrer, 100 parts by mass of phenol, 55.5 parts by mass of paraformaldehyde of 92% by mass, and 0.2 mass of zinc naphthenate as a divalent metal salt Then, the mixture was reacted at the reflux temperature for 90 minutes and then concentrated by heating to obtain a benzyl ether type phenol resin having a water content of 1% or less. Next, 100 parts by mass of the obtained phenol resin was used with 36 parts by mass of a polar organic solvent (DBE: manufactured by DuPont, USA) and 61 parts by mass of a nonpolar organic solvent (Hysol 100: manufactured by JX Energy Co., Ltd.). Then, a phenol resin solution having a phenol resin content of about 51% by mass was prepared.

-Preparation of phenol resin solution (2)-
In a three-necked reaction flask equipped with a reflux, a thermometer and a stirrer, 50 parts by mass of phenol and 50 parts by mass of orthocresol (phenol / orthocresol = 50/50) and 51% by mass of paraformaldehyde of 92% by mass .9 parts by mass and 0.15 parts by mass of zinc naphthenate as a divalent metal salt were reacted at the reflux temperature for 90 minutes, and then concentrated by heating to give orthocresol-modified benzyl having a water content of 1% or less. An ether type phenolic resin was obtained. Next, 100 parts by mass of the obtained ortho-cresol-modified phenol resin was replaced with 36 parts by mass of a polar organic solvent (DBE: manufactured by DuPont, USA) and 61 parts by mass of a nonpolar organic solvent (Hysol 100: manufactured by JX Energy Co., Ltd.). A phenol resin solution having a phenol resin content of about 51% by mass was prepared by dissolving using a part.

-Preparation of phenol resin solution (3)-
In a three-necked reaction flask equipped with a reflux, a thermometer and a stirrer, 100 parts by mass of phenol, 55.5 parts by mass of paraformaldehyde of 92% by mass, and 0.2 mass of zinc naphthenate as a divalent metal salt Then, the mixture was reacted at the reflux temperature for 90 minutes and then concentrated by heating to obtain a benzyl ether type phenol resin having a water content of 1% or less. Next, 52.0 parts by mass of the obtained phenolic resin was mixed with 10.0 parts by mass of a polar organic solvent (DBE: manufactured by DuPont, USA) and 38 of a nonpolar organic solvent (Ipsol 150: manufactured by Idemitsu Kosan Co., Ltd.). 0.0 part by mass was dissolved to prepare a phenol resin solution having a phenol resin content of 52.0% by mass.

-Preparation of phenol resin solution (4)-
In a three-necked reaction flask equipped with a reflux, a thermometer and a stirrer, 50 parts by mass of phenol and 50 parts by mass of orthocresol (phenol / orthocresol = 50/50) and 51% by mass of paraformaldehyde of 92% by mass .9 parts by mass and 0.15 parts by mass of zinc naphthenate as a divalent metal salt were reacted at the reflux temperature for 90 minutes, and then concentrated by heating to give orthocresol-modified benzyl having a water content of 1% or less. An ether type phenolic resin was obtained. Next, 52.0 parts by mass of the obtained ortho-cresol-modified phenol resin was mixed with 10.0 parts by mass of a polar organic solvent (DBE: manufactured by DuPont, USA) and a nonpolar organic solvent (Ipsol 150: manufactured by Idemitsu Kosan Co., Ltd.). ) 38.0 parts by mass to prepare a phenol resin solution having a phenol resin content of 52.0% by mass.

-Preparation of polyisocyanate compound solution (1)-
While dissolving 146 mass parts of polymeric MDI which is a polyisocyanate compound using 38.24 mass parts of a nonpolar organic solvent (Ipsol 150: made by Idemitsu Kosan Co., Ltd.), 0.93 of polymeric MDI amount was added there. A polyisocyanate compound solution containing about 79% by mass of a polyisocyanate compound was prepared by adding mass% of isophthalic acid chloride.

-Preparation of polyisocyanate compound solution (2)-
78.0 parts by mass of polymeric MDI, which is a polyisocyanate compound, was dissolved using 22.0 parts by mass of a nonpolar organic solvent (Ipsol 150), and 0. 2 of a reaction retarder (isophthalic acid chloride) was added thereto. 3 mass parts was added and the polyisocyanate compound solution whose polyisocyanate compound is 78.0 mass% was prepared.

-Formation of reaction products between basic silane compounds and acids / halides-
As the basic silane compound, 3-aminopropyltriethoxysilane (KBE903) or N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane (KBM602) is used, and the acid or its halide is shown in the following table. Using the predetermined compounds shown in Tables 1 and 2 respectively, in the ratios shown in Tables 1 and 2 below, the basic acid silane compound was stirred in the basic silane compound at a temperature of 60 ° C. or lower. Alternatively, the reaction products A to T shown in Tables 1 and 2 below were prepared by reacting the halides dropwise thereto.

(Examples 1 to 20)
First, the reaction product prepared by previously reacting 197 parts by mass of the phenol resin solution prepared in the preparation (1) of the phenol resin solution with a predetermined basic silane compound and an acid or a halide thereof. Products A to T were added in the proportions shown in Tables 3 and 4 below, and stirred to mix uniformly. Next, the Enshu reclaimed sand is put into Dalton Co., Ltd. product type river table mixer, and the mixture of the above phenol resin solution and reaction products A to T with respect to 1000 parts by mass thereof, and the above poly Casting sand composition was prepared by adding 10 parts by mass of the polyisocyanate compound solution prepared in Preparation (1) of isocyanate compound solution, stirring for 60 seconds, and kneading. And each test piece (mold) was produced using the obtained various foundry sand compositions, and according to the above measurement method, the mold strength (kgf / cm ² ) immediately after molding and 24 hours after molding. ) And mold strength (kgf / cm ² ) after moisture absorption deterioration for 120 minutes after molding were measured, and the obtained results are shown in Tables 3 and 4 below.

(Example 21)
In Example 18, foundry sand was obtained in the same manner as in Example 18 except that the solution of the ortho-cresol-modified phenol resin prepared in the preparation (2) of the phenol resin solution was used as the polyol compound. A composition was prepared, and a test piece (mold) formed from the obtained foundry sand composition was subjected to the above-described measurement method, and the mold strength (kgf / cm ² ) immediately after molding and 24 hours after molding. The mold strength (kgf / cm ² ) after moisture absorption deterioration for 120 minutes after molding was measured, and the obtained results are shown in Table 4 below.

(Comparative Examples 1 and 2)
Foundry sand composition in the same manner as in these examples except that only 0.6 parts by mass of the basic silane compound (KBM602 or KBE903) was used instead of the reaction product in Examples 1-20. In accordance with the measurement method described above, the mold strength (kgf / cm ² ) and the mold strength immediately after molding and after 24 hours of molding were prepared for the test piece (mold) molded from the obtained foundry sand composition. Thereafter, the mold strength (kgf / cm ² ) after moisture absorption deterioration for 120 minutes was measured, and the obtained results are shown in Table 5 below.

(Comparative Examples 3 to 8)
A casting sand composition was prepared in the same manner as in these examples except that 0.4 parts by mass of an acid or a halide thereof was used alone instead of the reaction product in Examples 1 to 20, and About the test piece (mold) obtained from the foundry sand composition, according to the measurement method described above, the mold strength (kgf / cm ² ) immediately after molding and 24 hours after molding and the mold after moisture absorption deterioration for 120 minutes after molding. The strength (kgf / cm ² ) was measured, and the results are shown in Table 5 below.

(Comparative Example 9)
In Examples 1 to 20, a casting sand composition was prepared in the same manner as in Examples except that reaction products A to T of a basic silane compound and an acid or a halide thereof were not added. For a test piece (mold) molded from a foundry sand composition, according to the measurement method described above, mold strength (kgf / cm ² ) immediately after molding and 24 hours after molding, and mold strength after moisture absorption deterioration for 120 minutes after molding. (Kgf / cm ² ) was measured, and the results are shown in Table 5 below.

As apparent from the comparison of the results in Tables 3 to 5, according to the present invention, a reaction product of a basic silane compound and an acid or a halide thereof is further added as a constituent component together with a predetermined phenol resin and polyisocyanate. In the mold (test piece) obtained by preparing a molding sand composition using the organic binder obtained in Examples 1 to 21 to be contained, and then molding the composition, a conventional molding sand composition is used. It is recognized that the mold has excellent properties not only in the mold strength under the humidity environment but also in the mold strength after the moisture absorption deterioration under the high humidity. Among these examples, in Example 21, since ortho-cresol-modified phenol resin is used as the phenol resin, the mold strength is further improved, and the moisture absorption resistance is further improved. It has become.

On the other hand, the organic binder in Comparative Example 9 to which such a reaction product is not added, the organic binders in Comparative Examples 1 to 8 which are added in the basic silane compound alone or in the acid or its halide alone. The mold (test piece) obtained using a binder does not have sufficient mold strength in a normal humidity environment. Furthermore, the mold strength after moisture absorption deterioration is significantly reduced, and moisture absorption resistance is deteriorated. It is recognized that the mold is inferior in properties, and the mold obtained using such an organic binder is not practical.

(Example 22)
After preparing the foundry sand composition in the same manner as in Example 18, the waiting time after kneading of the obtained foundry sand composition: 0 minutes and 120 minutes for the test piece (mold) molded from the test piece (mold) according to the measurement method and evaluation method, mold strength immediately and molding 24 hours after molding (kgf / cm ^2), as well as mold strength after moisture absorption degradation of 24 hours after molding the (kgf / cm ^2), were measured, respectively, The obtained results are shown in Table 6 below.

(Examples 23 to 30)
In Example 22, as the higher fatty acid ester, except that a polycondensate of ricinoleic acid and glycerin or a self-condensate of ricinoleic acid was further added to the organic binder in the ratio shown in Table 6 below, After preparing the foundry sand composition in the same manner as in Example 22, and waiting time after kneading of the obtained foundry sand composition: test pieces (molds) molded from those having 0 minutes and 120 minutes for, according to the measurement method and evaluation method described above, after molding, and mold strength after molding 24 hours (kgf / cm ²⁾ and mold strength after moisture absorption degradation of 24 hours after molding the (kgf / cm ^2), respectively measured The results obtained are shown in Table 6 below.

(Comparative Example 10)
Molding was performed in the same manner as in Comparative Example 9, using the standby time after kneading of the foundry sand composition containing no reaction product or higher fatty acid ester obtained in Comparative Example 9: 0 minutes and 120 minutes. For the test piece (mold), according to the measurement method and the evaluation method described above, the mold strength (kgf / cm ² ) immediately after molding and 24 hours after molding, and the mold strength (kgf / cm2) after deterioration of moisture absorption for 24 hours after molding, respectively. cm ² ) were measured, and the obtained results are shown in Table 6 below.

As is clear from the comparison of the results shown in Table 6, in Examples 23 to 30 using the organic binder further containing a higher fatty acid ester according to the present invention, the waiting time after kneading was 120 minutes. Even in this case, it is recognized that the mold has an excellent mold strength, which confirms that the pot life can be advantageously improved.

(Examples 31 to 35)
Reaction obtained by reacting a basic silane compound (KBM602) and hydrofluoric acid as described above with respect to 100 parts by mass of the phenol resin solution prepared in the preparation (3) of the above phenol resin solution Product A was added in the proportions shown in Table 7 below, and stirred and mixed uniformly to prepare solution A according to each of Examples 31 to 35. Subsequently, while putting flattery sand into Dalton Co., Ltd. product river type tabletop mixer, with respect to 1000 parts by mass, preparation of the liquid A prepared as described above and the polyisocyanate compound solution (2) 10 parts by mass of each of the polyisocyanate compound solution as the liquid B prepared in the above was added, stirred for 60 seconds, and kneaded to prepare a foundry sand composition. And each test piece (mold) was produced using the obtained various foundry sand compositions, and the mold strength (kgf / cm ² ) immediately after molding and 24 hours after molding according to the above measurement method. The mold strength (kgf / cm ² ) after moisture absorption deterioration for 24 hours after molding was measured, and the obtained results are shown in Table 7 below.

(Examples 36 to 41, Comparative Example 12)
When preparing the liquid A, the reaction product R of the basic silane compound (KBM602) and hydrofluoric acid was used together with the water content in the proportions shown in Tables 7 and 8 (the amount of water added in Tables 7 and 8 below). A casting sand composition was prepared in accordance with the same conditions and procedures as in Example 32 except that was added. And each test piece (mold) was produced using the obtained various foundry sand compositions, and the mold strength (kgf / cm ² ) immediately after molding and 24 hours after molding according to the above measurement method. The mold strength (kgf / cm ² ) after moisture absorption deterioration for 24 hours after molding was measured, and the obtained results are shown in Table 7 and Table 8 below.

(Example 42)
In place of the phenol resin solution prepared in the preparation (3) of the phenol resin solution described above, except that the ortho-cresol-modified phenol resin solution prepared in the preparation (4) of the phenol resin solution was used, A foundry sand composition was prepared in the same manner as in Example 32. Then, using the obtained foundry sand composition, a test piece (mold) was prepared, and according to the above measurement method, the mold strength (kgf / cm ² ) immediately after molding and 24 hours after molding, and after molding The mold strength (kgf / cm ² ) after moisture absorption deterioration for 24 hours was measured, and the results are shown in Table 8 below.

(Comparative Example 11)
In addition to the addition of flattery sand into Dalton Co., Ltd. product river type tabletop mixer, it is shown in Table 8 for the phenol resin solution prepared in the preparation (3) of the above phenol resin solution with respect to 1000 parts by mass. 10 parts by weight of each of the polyisocyanate compound solution as the B liquid prepared in the preparation (2) of the above polyisocyanate compound solution, and stirred for 60 seconds, A foundry sand composition was prepared. Then, using the obtained foundry sand composition, a test piece (mold) was prepared, and according to the above measurement method, the mold strength (kgf / cm ² ) immediately after molding and 24 hours after molding, and after molding The mold strength (kgf / cm ² ) after moisture absorption deterioration for 24 hours was measured, and the results are shown in Table 8 below.

As apparent from the comparison of the results in Tables 7 and 8, the solution is a solution containing a phenol resin and a reaction product R of a basic silane compound and hydrofluoric acid, and has a predetermined moisture content. A molding sand composition was prepared using an organic binder (Examples 31 to 42) composed of a solution (solution A) and a solution of a polyisocyanate compound (solution B), Furthermore, the mold (test piece) obtained by molding has excellent characteristics not only in mold strength under normal humidity environment but also in mold strength after moisture absorption deterioration under high humidity. It is recognized that Among these examples, in Example 42, since ortho-cresol-modified phenol resin is used as the phenol resin, the mold strength is further improved, and the moisture absorption resistance is further improved. It has become.

Next, the following experiment was conducted in order to confirm the effect when the higher fatty acid ester was contained in the liquid B.

(Examples 43 to 50)
The ratio of the nonpolar organic solvent (Ipsol 150) used in the preparation of the polyisocyanate compound solution is set to the ratio shown in Table 9 below. Foundry sand composition according to the same conditions and procedures as in Example 40 except that a polycondensate of ricinoleic acid and glycerin as a fatty acid ester or a self-condensate of ricinoleic acid was added in the ratio shown in Table 9 below. Were prepared respectively. And each test piece (mold) was produced using the obtained various foundry sand compositions, and the mold strength (kgf / cm ² ) immediately after molding and 24 hours after molding according to the above measurement method. The mold strength (kgf / cm ² ) after moisture absorption deterioration for 24 hours after molding was measured, and the results are shown in Table 9 below. Further, using the foundry sand composition after waiting for 120 minutes from the kneading, the mold strength immediately after molding and after molding for 24 hours (kgf / cm ² ), and the mold strength after deterioration of moisture absorption for 24 hours after molding (kgf / Cm ² ) were measured, and the pot life was evaluated. The obtained results are shown in Table 9 below.

(Comparative Example 13)
Dalton Co., Ltd. product river type table mixer, while adding the flattery sand, with respect to 1000 parts by mass of the phenol resin solution prepared in the preparation of the phenol resin solution (3), and the polyisocyanate compound 10 parts by mass of each of the polyisocyanate compound solutions prepared in Preparation (2) of the solution was added and stirred for 60 seconds to prepare a foundry sand composition. Then, using the obtained foundry sand composition, a test piece (mold) was prepared, and according to the above measurement method, the mold strength (kgf / cm ² ) immediately after molding and 24 hours after molding, and after molding The mold strength (kgf / cm ² ) after moisture absorption deterioration for 24 hours was measured, and the results are shown in Table 9 below. Further, using the foundry sand composition after waiting for 120 minutes from the kneading, the mold strength immediately after molding and after molding for 24 hours (kgf / cm ² ), and the mold strength after deterioration of moisture absorption for 24 hours after molding (kgf / Cm ² ) was measured, and the pot life was evaluated. The obtained results are shown in Table 9 below.

For comparison, the pot life of each casting sand composition according to Example 32 and Example 40 was similarly evaluated. The obtained results are shown in Table 9 below.

As is apparent from the comparison of the results shown in Table 9, in Examples 43 to 50 in which the predetermined higher fatty acid ester is contained in the liquid B constituting the organic binder according to the present invention, the standby after kneading is performed. Even when the time is 120 minutes, it is recognized that the mold has excellent mold strength, which confirms that the pot life can be advantageously improved.

Claims

A urethane curable organic binder used for molding a urethane-based mold, which further includes a reaction product of a basic silane compound and an acid or a halide thereof together with a polyol compound and a polyisocyanate compound. A urethane curable organic binder for molds characterized by
The liquid A is composed of two liquids, the liquid A containing the polyol compound and the liquid B containing the polyisocyanate compound, and the liquid A constitutes a reaction product of the basic silane compound and an acid or a halide thereof. 2. The urethane curable organic binder for molds according to claim 1, which is contained as a component, and the water content of the liquid A is 0.1 to 15% by mass.
3. The urethane curable organic binder for molds according to claim 1 or 2, wherein the acid or its halide is hydrofluoric acid.
The urethane curing for a mold according to any one of claims 1 to 3, wherein a reaction product of the basic silane compound and an acid or a halide thereof is formed in advance and used in the form of the reaction product. Type organic binder.
The said urethane compound is a phenol resin, The urethane hardening type organic binder for casting_mold | templates in any one of Claim 1 thru | or 4.
The urethane curable organic binder for mold according to claim 5, wherein the phenol resin is an ortho-cresol-modified phenol resin.
The reaction product according to any one of claims 1 to 6, wherein the reaction product is used in a proportion of 0.1 to 2.0 parts by mass with respect to 100 parts by mass of the polyol compound. Urethane curing organic binder for molds.
The urethane curable organic binder for mold according to any one of claims 1 to 7, wherein the basic silane compound is an alkoxysilane containing an amino group.
The amino group-containing alkoxysilane 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 9. The urethane curable organic binder for molds according to claim 8, which is selected from the group consisting of -aminoethyl-3-aminopropyltrimethoxysilane and 3-ureidopropyltrialkoxysilane.
The acid or its halide is hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, boric acid, benzenesulfonic acid, paratoluenesulfonic acid, trifluoromethanesulfonic acid, formic acid, acetic acid, benzoic acid , Phenylphosphonic acid dichloride, 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 and sebacic acid dichloride 10. The urethane curable organic binder for molds according to any one of claims 1 to 9, wherein the urethane curable organic binder for molds is selected from the group consisting of:
The urethane curable organic binder for mold according to any one of claims 1 to 10, further comprising a higher fatty acid ester as a constituent component.
A foundry sand composition comprising the urethane curable organic binder for molds according to any one of claims 1 to 11 and a foundry sand.
A mold formed by molding and curing the foundry sand composition according to claim 12.