JPS6092037A - Binder composition for molding sand - Google Patents

Abstract

PURPOSE:To provide a compsn. consisting of an org. polyisocyanate compd., the residue produced in the stage of producing bisphenol A or the deriv. thereof, and phenolic resin obtd. by bringing phenol and aldehyde into reaction in the presence of a catalyst or org. salt. CONSTITUTION:The binder compsn. contg. an org. polyisocyanate compd. (A), the residue in the stage of producing bisphenol A or the separating component in the residue or the deriv. thereof (B), and a phenolic resin (C) obtd. by compounding phenol and aldehyde and bringing the same into reaction in the presence of an acidic or alkaline catalyst or org. acid salt as main constituting components is used for light alloy molding sand. The molding sand which has excellent mold strength, has the heat resistance required in the stage of pouring and has a good collapsing property of the mold after pouring is thus obtd.

Description

[Detailed Description of the Invention] Mold making methods that harden at room temperature include organic methods using water glass, cement, etc., acid curing methods typified by French resin, organic methods such as oil urethane resins, and phenol urethane resins. Things, etc. can be kicked. All of them have advantages and disadvantages, and are currently used depending on the purpose.

The present invention relates to a binder composition for foundry sand that is self-curing at room temperature or hardened by K when brought into contact with a gaseous amine. In particular, it relates to a method of manufacturing a mold suitable for light alloy castings, which has excellent strength during pouring and disintegration during mold disassembly.

As a binder composition for conventional light alloys,
No. 1-33506 and Japanese Patent Publication No. 55-7338 are known, but these binder compositions had drawbacks such as poor initial curing and short pot life.

There is also a method of reacting bisphenols with formaldehyde (see, for example, Japanese Patent Laid-Open No. 56-47239). These foundry sand binder compositions had the drawbacks of low heat resistance, too good disintegration, and sand spilling out during pouring. For this reason, during the casting process, the sand used as the core gets stuck in the pouring ring, deteriorating the working environment and requiring extra man-hours to remove it.

As a result of intensive research into the foundry Sunagawa binder for light alloys, which does not have the above-mentioned drawbacks, the present inventors have found that mold strength, initial hardenability,
We have succeeded in developing a binder composition for light alloy foundry sand that has an excellent balance between heat resistance and disintegration after pouring and has a long pot life, leading to the completion of the present invention.

That is, the present invention provides a foundry Sunagawa binder composition for light alloys containing the following component.

(A) Organic polyisocyanate compound, (13 bisphenol/l/: separated components in the residue and/or residue during A production or derivatives thereof, (Q) mixed with phenols and aldehydes, acidic or alkaline catalyst or organic A phenolic resin obtained by reaction in the presence of an acid salt.

For example, the binder composition of the present invention may contain 0.6 to 1 part of the binder for foundry sand of the present invention per 100 parts by weight of foundry sand.
The above-mentioned mixed sand can be mixed with a tertiary amine etc. as an accelerator in liquid form and cured at room temperature, or brought into contact in a gaseous state and rapidly cured at room temperature. It can also be applied to methods.

The organic polyinsyanate used in the present invention includes 2.
4-Toluene diisocyanate, 2,6-toluene diisocyanate and mixtures thereof, especially crude mixtures thereof, are commercially available.

Other representative polyisocyanates include methylene bis(4
-phenol) isocyanate, n-hexyl diisocyanate, 1,5 naphthalene diisocyanate 4-), 1.3
-Cyclopenbenzeni diisocyanate, 1.3-
Included are cyclopentylene diisocyanate, p-phenylene diisocyanate, 2,4.6-toluene diisocyanate, and 4,4?4#-triphenylmethyltriisocyanate.

Also contemplated by this invention are many commercially available impure or crude polyisocyanates. Particularly preferred for use in the present invention are aromatic polyisocyanates, especially diphenylmethane diisocyanate, triphenylmethane triincyanate and mixtures thereof. , aromatic hydrocarbons having 6 to 10 carbon atoms such as cyisoglobilbenzene and ethylbenzene, or by-product heavy oils during their production, and by-product heavy oils during the production of cumene. It may be dissolved in group hydrocarbons.

Residue and/or during production of zero component bisphenol A of the present invention
The separated component or its derivative in the residue is a by-product produced in the process of subjecting phenol and a7tone to a "t" reaction in the presence of an acidic catalyst and purifying bisphenol A from this reaction product. By-products containing bisphenols, chroman compounds, trisphenol, etc. (e.g. Honshu Kagaku ■, SR acid) or by-products containing dihydroxydiphenylprono derivatives, chroman compounds, other polyphenol compounds, etc. (e.g. Mitsui Toatsu ■) , “
Mirex BPA-ZKJ).

The zero-component phenolic resin shall mean any condensation polymerization product produced by the reaction of phenols and aldehydes. The phenols used in the production of such phenolic resins include Km-cresol, p-cresol, and 3.5-cresol other than the most preferred phenol.
Examples include xylenol, 3,4-xylenol, pt-butylphenol, nonylphenol, and the like. Aldehydes that react with phenols include formaldehyde, acetaldehyde, acetaldehyde, propionaldehyde,
Furfural, benzaldehyde and mixtures thereof.

By reacting with an organic polyisocyanate compound, polycrethane is produced, and the optimum conditions for the blending ratio of the (input) component and (Q component) used to make a mold vary depending on the shape, size, and method of use of the mold. General K (
[Blending 5 to 900 parts by weight, more preferably 10 to 300 parts by weight, of component 0 to 100 parts by weight of each component provides excellent mold strength, has the heat resistance required during pouring, and is suitable for pouring. After molten water, a well-balanced foundry sand with good mold disintegration properties is obtained.

(If the Q component is less than 5 parts, the initial strength will be insufficient and the mold will be easily damaged when handled immediately after molding. Also, the heat resistance will be insufficient and there is a risk of damage to the sand mold during pouring.) If the amount is 900 parts by weight, the disintegration after pouring will be poor and additional finishing steps will be required.

((F) component and (Q component) are used with or without addition of a suitable solvent or diluent. Examples of the solvent or diluent used include cellosolve, cellosolve acetate, ethylene glycol diacetate, 3-methoxy acetic acid. Polar solvents such as butyl, isopolone, diethylene chloride monoethyl ether acetate, cyclohethanone furfural, furfuryl alcohol, etc.Also, aromatic hydrocarbon solvents such as toluene, xylene, ethylbenzene are used in combination with the above solvents. You can also do that.

In the present invention, a silane coupling agent such as γ-aminopropylethoxysilane, N-β-(aminoethyl)-r-aminopropyltrimethoxysilane, or r-mercaptobrobylmerimethoxysilane is used as needed to make the mold moisture resistant. For the purpose of improving properties, it is also possible to add 0.005 to 1.0 parts by weight per 100 parts by weight of the total amount of components 0 and (Q).

To improve the properties of the foundry sand binder of the invention, substances such as release agents may be added.

An example of use of the binder for foundry sand of the present invention will be described.

If necessary, a reactive solvent, a crosslinking agent, an inert diluent, and an organic silane may be added to the solution consisting of the 0 component and the 0 component.
Add to the mixer in an amount of 0.3 to 5 parts by weight to 0 parts by weight. The preferred amount added is 0.6 to 2.5 parts by weight. (0 after adding the solution consisting of component and (Q component)
．． Mix for 5 to 3 minutes. Next, an organic polyisocyanate compound as component (A) is added to the mixer in an amount of 0.3 to 5 parts by weight based on the foundry sand. The preferred amount is 0.
．． 6 to 2.5 parts by weight. After an additional 0.15 to 3 minutes of mixing, the mixture is filled into a suitable mold and cured at room temperature in the presence of a tertiary amine.

The tertiary amine may be in gaseous or liquid form. When vaporizing into gaseous form, the tertiary amine is preferably supplied in a stream of inert gas such as nitrogen, carbon dioxide, or dry air. .

Suitable tertiary amines include triethylamine, trimethylamine, dimethylethylamine, tributylamine, N,N-dimethylaniline, N-methylmorpholine,
N-ethylmorpholine, tetramethylguanidine, and the like.

In order to use a tertiary amine in liquid form, a self-curing mold must be formed. In this case, a known catalyst, such as an organic acid metal salt such as dibutyltin dilaurate, or a tertiary amine such as N-methylmorpholine, is added at the time of mixing with the solution or foundry sand consisting of component (B) and component (Q). At this time, the amount of catalyst added is preferably 20 parts by weight or less per 0 parts by weight of the solution consisting of component (2) and component (Q).

The present invention will be explained in more detail with reference to Examples below.

Production example 1゜phenol 2,830#, paraformaldehyde 2.1
10y, Toluay y180II, 15g of zinc naphthenate (8% product), 3 lofras: l K, 1oo~120
The mixture was refluxed at ℃ for 3 hours. Then, the valve was fully opened to create a sufficient vacuum to remove toluene and condensed water.

Ethylene glycol acetate and an aromatic solution were added to this and mixed to give a resin content of 45 to 50% to obtain a phenol resin solution. The product was analyzed by IR and NMR and confirmed to be a benzylic ether type phenol resin.

Examples 1 to 3 The phenol resin solution obtained in Production Example 1 as the component (B) and the Cellosolver→=tate solution (concentration 50% by weight) of Millex BPA-ZK, the residue from the production of bisphenol A, as the component (B), They were mixed in the proportions shown in Table 1, and 10 parts of the mixed solution was added to 1000 parts of No. 5 silica sand and mixed uniformly. Next, a xylene solution (a) of commercially available diphenylmethane diisocyanate (component (A))
75% by weight) was added and mixed. After the obtained mixed sand was placed in a 50 x 50 anti-pressure test mold and hardened, nitrogen gas containing triethylamine was passed through the mold for 10 seconds to harden it, and the anti-pressure was measured immediately and after 24 hours. Separately, as a method for measuring collapsibility, a 28 x 350 iron pipe was filled with the above foundry sand and molded. This iron pipe mold 4
The sample was treated at 00° C. for 90 minutes in a reducing atmosphere. After cooling, the center of the iron pipe was hammered to see how many times it would take to remove the sand. These results are shown in Table 1.

In order to compare with Examples 1 to 3, Comparative Examples 1 to 2 were carried out using the blending ratios listed in Table 1.

Procedural amendment (voluntary) April 13, 1980 Commissioner of the Japan Patent Office1, Indication of the case, 1982 Patent Application No. 1976512, Name of the invention Cast Sunagawa Baingu Composition 3, Person making the amendment Relationship with the case Patent Applicant 1r Address: 1-2-2-4 Uchisaiwai-cho, Chiyoda-ku, Tokyo, Claims column and Detailed Description of the Invention column of the specification to be amended.

(1) The scope of the claims shall be amended as shown in the attached sheet.

(2) 6th line from the bottom of page 1 Correct "organic" to "inorganic".

(3) Lines 6 to 5 from the bottom of the first page "French resin" is replaced by "furan resin" (two corrections).

(4) In the second line from the bottom of the first page, "separate but" is replaced with "separately" (two corrections).

(5) Page 2, line 14 Two corrections are made for "low <" and "low".

(6) Page 3, line 5, “(A) to (C)” is corrected to [(A) to (C)Jl2.

(Page 4, line 7, "1.5 naphthalene" is corrected to "1,5-naphthalene".

(8) Delete "rl, 3-en clopenpentylene diisocyanate" from line 8 to line 9 of page 4.

(9) Page 6, line 6 Delete "acetaldehyde".

ao Page 6, 5th line from the bottom "When pouring" is corrected by "cJc when pouring."

αB Page 7, line 2 ``When you get up'' is ``when you exceed'' (= correct.

α2 Page 7, line 3 Correct "becomes worse" to "become worse".

0■ @Page 77 No. 5 Correct "diluent" to "diluent".

(+4) On page 7, line 11, "clohexanone" is corrected to "clohexanone," 6 (151 on page 7, line 3 from the bottom, "merimetoxinran" is changed to "trimethoxysilane" (=
to correct.

Oe page 8 line 9 Correct "foundry sand" to "foundry sand".

(1 card, page 10, line 11 ``Residue'' is changed to ``residue'' (two corrections).

Oe 4th line from the bottom of the Comparative Example 1 column in Table 1 on page 12 “
``Initial intensity strong'' is corrected to ``Initial intensity disease'' (=.

"Claims after amendment" [An organic polyisocyanate compound (A), a residue from the production of bisphenol A and/or a separated component in the residual soaking or its derivative (B), and an acidic compound containing phenols and aldehydes] Or a binder composition for foundry sand, characterized in that the main component is a phenolic resin (C) obtained by reaction in the presence of an alkaline catalyst or an organic acid salt.

"that's all

Claims (1)

[Scope of Claims] Organic polyisocyanate compound (A), separated components in the residue and/or residue during the production of bisphenol A, or derivatives thereof (uniform, or by blending phenols and aldehydes with acidic or alkaline catalysts or organic A baingoo composition for foundry sand characterized by containing a phenolic resin (Q) as a main component obtained by reaction in the presence of an acid salt.