JP3128235B2 - Curing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for curing a phenolic resin at a low temperature and in a short time, particularly, a phenolic resin used as a binder for fibers, wood flour, ceramics, molding sand and the like at a low temperature. It relates to a method of curing in a short time.

[Conventional Problems] Conventionally, as this type of binder, a resol-type phenol resin powder or a mixed powder of a novolak-type phenol resin and an aldehyde donor such as hexamethylenetetramine has been used. However, such a phenolic resin has a high curing temperature of about 200 ° C, and when used as a binder for felt, the fiber is denatured and embrittled by heat, and when used as a low melting point fiber such as polypropylene fiber, it is used as a binder at all. Can not. Even when used as a binder for ceramics or foundry sand, curing at such a high temperature requires a large-scale heating device or wastes heat energy.

For this reason, a high-ortho-type fast-curing phenol resin may be used, but when cured at a low temperature for a short time, the apparent curing speed is fast, but the strength of the cured resin is lower than that of a normal phenol resin. There is a disadvantage that it becomes significantly weaker.

[Means for solving the problem]

The present invention provides a curing method for curing a phenolic resin with a curing catalyst which is a salt of an organic acid or an inorganic acid (excluding an oxidizing agent) and nitrogen-containing chlorine, and a novolak-type phenol. An object of the present invention is to provide a curing method in which a mixture of a resin and an aldehyde donor as a curing agent thereof is cured with a curing catalyst which is a salt of an organic acid or an inorganic acid (excluding an oxidizing agent) and a nitrogen-containing base.

Hereinafter, the present invention will be described in detail, but the following examples do not limit the present invention.

[Phenol resin] Needless to say, the phenol resin is obtained by reacting one or a mixture of two or more phenols such as phenol, cresol and xylenol with formaldehyde. Cresol, p-cresol, ethylphenol, iso-propylphenol, xylenol, 3,5-
Alkylphenols such as xylenol, butylphenol and nonylphenol, o-fluorophenol, m-
Fluorophenol, p-fluorophenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, o-bromophenol, m-bromophenol, p-bromophenol, o-iodophenol, m
-Iodophenol, p-iodophenol, o-aminophenol, m-aminophenol, p-aminophenol, o-nitrophenol, m-nitrophenol, p-nitrophenol, 2,4-dinitrophenol, 2,4, It is obtained by reacting a monohydric phenol substituent such as 6-trinitrophenol, or a mixture of one or more monohydric phenols such as naphthols with an aldehyde donor such as formaldehyde. Any of resol type phenol resins using an alkali catalyst such as sodium hydroxide and caustic soda, and novolak type phenol resins using an acid catalyst such as sulfuric acid and hydrochloric acid can be used as the phenol resin of the present invention.

In the present invention, if desired in the phenolic resin,
Resorcin, alkyl resorcin, catechol, alkyl catechol, hydroquinone, alkyl hydroquinone, pyrogallol, phloroglysin, urea, melamine,
Thiourea, benzoguanamine, toluene, xylene, coumarone, cyclohexanone, cashew oil, tannins, dammer, shellac, rosin or rosin derivative,
Petroleum resin, methanol, ethanol, islopanol,
It may be modified with one or more of butanol, ethylene glycol, glycerin, furfuryl alcohol, linseed oil, tung oil, castor oil and the like.

[Curing Catalyst] In the present invention, a salt of an organic acid or an inorganic acid (excluding an oxidizing agent) and a nitrogen-containing base is used as a curing catalyst. The organic acids include formic acid, acetic acid, propionic acid,
Butyric acid, valeric acid, oxalic acid, succinic acid, maleic acid, tartaric acid,
Fatty acids such as caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, picric acid,
Phenylacetic acid, benzoic acid, o-toluic acid, m-toluic acid, p-toluic acid, o-chlorobenzoic acid, m-chlorobenzoic acid, p-chlorobenzoic acid, o-bromobenzoic acid, m-bromobenzoic acid Acid, p-bromobenzoic acid, o-nitrobenzoic acid, m-nitrobenzoic acid, p-nitrobenzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, p-hydroxybenzoic acid, anthranilic acid, o-aminobenzoic acid Acid, m-aminobenzoic acid, p-aminobenzoic acid, o-methoxybenzoic acid, m-methoxybenzoic acid, p
Aromatic carboxylic acids such as -methoxybenzoic acid, and cyclobutanecarboxylic acid, cyclobutane-1,2-dicarboxylic acid, cyclobutane-1,3-dicarboxylic acid, cyclopropanecarboxylic acid, cyclopropane-1,1-dicarboxylic acid,
Cyclopropane-1,2-dicarboxylic acid, cyclopropane-1,1,2-tricarboxylic acid, cyclopropane-1,2,3-tricarboxylic acid, 1,3-cyclohexadiene-1-carboxylic acid, 1,3- Cyclohexadiene-1,2-dicarboxylic acid,
1,3-cyclohexadiene-1,3-dicarboxylic acid, 1,3-
Cyclohexadiene-1,4-dicarboxylic acid, 1,3-cyclohexadiene-1,6-dicarboxylic acid, 1,3-cyclohexadiene-2,3-dicarboxylic acid, 1,3-cyclohexadiene-2,5-dicarboxylic acid Acid, 1,3-cyclohexadiene-3,5
-Dicarboxylic acid, 1,3-cyclohexadiene-5,6-dicarboxylic acid, 1,4-cyclohexadiene-1,2-dicarboxylic acid, 1,4-cyclohexadiene-1,4-dicarboxylic acid,
4-cyclohexadiene-1,6-dicarboxylic acid, 1,4-cyclohexadiene-3,6-dicarboxylic acid, cyclohexanol-2-carboxylic acid, cyclohexanonecarboxylic acid, cyclohexanecarboxylic acid, cyclohexane-1,2
-Dicarboxylic acid, cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, cyclohexanehexacarboxylic acid, cyclohexylacetic acid, cyclohexenecarboxylic acid, cyclohexene-1,2-dicarboxylic acid, cyclohexene-1,3-dicarboxylic acid Acid, cyclohexene-1,4-dicarboxylic acid, cyclohexene-1,5-dicarboxylic acid, cyclohexene-1,6-dicarboxylic acid, cyclohexene-3,4-dicarboxylic acid, cyclohexene-3,5
-Dicarboxylic acid, cyclohexene-3,6-dicarboxylic acid, cyclohexene-4,5-dicarboxylic acid, cyclopentanecarboxylic acid, cyclopentane-1,1-dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, cyclopentane- Alicyclic carboxylic acids such as 1,3-dicarboxylic acid and cyclopentene-3-carboxylic acid are exemplified, and examples of the inorganic acid include sulfuric acid, hydrochloric acid, and phosphoric acid. Examples of the nitrogen-containing base include ammonia and ammonia derivatives such as hydroxylamine, phenylhydrazine, semicarbazide, and hydrazine, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine, di-n-propylamine, and tri-n -Propylamine, iso-propylamine, di-iso-propylamine, n-butylamine, iso
-Butylamine, sec-butylamine, ter-butylamine, benzylamine, α-phenylethylamine, β-
Aliphatic amines such as phenylethylamine, ethylenediamine, tetramethylenediamine, tetraethylenediamine, hexamethylenediamine, tetramethylammonium hydroxide, aniline, methylaniline, ethylaniline, dimethylaniline, diethylaniline, diphenylamine, triphenylamine, o-toluidine , M-toluidine, p-toluidine, o-anisidine, m-anisidine, p-anisidine, o-chloroaniline, m-chloroaniline, p-chloroaniline, o-bromoaniline, m-bromoaniline, p-bromoaniline , O-nitroaniline, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 1,2,3-triaminobenzene, 1,2,4-triaminobenzene, 1,2,5-triaminobenzene , 1-na Butylamine, 2-naphthylamine and aromatic amines such as derivatives thereof, cyclobutylamine, cyclohexylamine, cyclopropylamine, cycloheptylamine, alicyclic amines such as cyclopentylamine, piperidine, pyridine, quinoline,
Bases of heterocyclic compounds such as imidazole are exemplified.

[Aldehyde Donor] When a novolak type phenol resin is used, an aldehyde donor is added as a curing agent. As the aldehyde donor, formalin, formaldehyde,
Paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, polyoxymethylene, chloral, hexamethylenetetramine, furfural, glyoxal, n-butyraldehyde, caproaldehyde, benzaldehyde, acrolein, tetraoxymethylene, phenylacetaldehyde, o-tolualdehyde, m Examples include -tolualdehyde, p-tolualdehyde, salicylaldehyde, and the like, or a mixture of two or more thereof.

[Blending] The curing method of the present invention cures the phenolic resin using a salt of a nitrogen-containing base with an inorganic acid other than an organic acid or an oxidizing agent as a curing catalyst. The curing catalyst is used in an amount of about 0.05 to 30 parts by weight based on 100 parts by weight of the phenol resin.

The method of blending the curing catalyst with the phenol resin includes (1) a method in which the phenol resin and the curing catalyst are mixed together in a powder state, and (2) a solution state before the phenol resin is produced and made into a solid powder. , A method of adding a curing catalyst to obtain a solid powder, and (3) a method of mixing and dissolving the curing catalyst in the solution of the phenol resin. In the above methods (1) and (2), a powdery composition is obtained, and in the method (3), a solution-like composition is obtained.

When the phenolic resin is a novolak type, the aldehyde donor is used as a curing agent.
In this case, usually 1 to 100 parts by weight of the above phenol resin
About 30 parts by weight are blended. Further, even in the case of a resol type phenol resin, the above aldehyde donor may be appropriately added if necessary.

[Third substance] In the present invention, a third substance can be further added to the above-mentioned compound if necessary. As the third substance, for example,
Natural rubber and its derivatives, synthetic rubber such as SBR, NBR, CR, EPT, vinyl acetate resin, ethylene-vinyl acetate copolymer resin, acrylic resin, methacrylic resin, vinyl chloride resin,
Vinylidene chloride resin, polystyrene, polyethylene, polypropylene, chlorinated polyethylene, chlorinated polypropylene, polyester resin, urethane resin, polyamide resin, epoxy resin, butyral resin, polyacrylic acid,
Cellulose derivatives such as polyacrylamide, polyvinyl alcohol, methylcellulose, carboxymethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, sodium alginate, starch, starch derivatives, gelatin, glue, blood powder and other proteins, calcium carbonate, talc, carbon black, silica , Wood flour, walnut flour, coconut husk flour, flour and other fillers, pigments, dyes, preservatives, insect repellents, anti-aging agents, ultraviolet absorbers, antioxidants,
Antimony trioxide, aluminum hydroxide, flame retardants such as bromo compounds, waxes, release agents such as silicone resins, water repellents, etc., even if one or a mixture of two or more of these is added and denatured Good.

[Action] In the present invention, when the phenol resin or the phenol resin is of a novolak type, a mixture of an aldehyde donor and a salt of an inorganic acid excluding an organic acid or an oxidizing agent and a nitrogen-containing base are mixed. It hardly cures at room temperature, but when heated, the above salt acts as a catalyst, rapidly curing the phenolic resin, curing is completed in a short time at low temperature,
Further, the produced resin does not cause a decrease in strength as in the case of a commercially available high ortho-type phenol resin.

〔Example〕

Examples 1-4, Comparative Examples 1-2 Novolak-type phenolic resin powder (hereinafter referred to as resin NB-A) and high-ortho novolac phenolic resin (hereinafter referred to as resin NB-B) were prepared by adding a salt of an acid and a nitrogen-containing base to a resin. Using oxalic acid-p-phenylenediamine as a curing catalyst, and hexamethylenetetramine as an aldehyde donor, a curing composition having a mixing ratio shown in Table 1 was used to test the gelation time, moldability, and stress with a curastometer. went.

 The results are shown in Table 1.

Examples 5 to 6 and Comparative Examples 3 to 4 The same novolak type phenol resin powder (resin NB-A) as used in Examples 1 and 3 was cured with a salt curing catalyst of an acid and a nitrogen-containing base, and an acid and a nitrogen-free catalyst. Using the salt with the contained base, the same gelation time and moldability test as in the above Examples were performed.

Table 2 shows the formulation and the result of the curing test.

From the above results, it can be seen that in Examples in which a curing catalyst which is a salt of an acid and a nitrogen-containing base was added, curing was performed at a lower temperature and in a shorter time than in Comparative Examples.

〔The invention's effect〕

Therefore, in the present invention, the curing temperature of the phenolic resin is lowered, so that the phenolic resin can be used as a binder for fibers having low heat resistance, and the heat energy during curing is greatly reduced. In the present invention, the strength of the phenol resin after curing is equal to or higher than that of a normal phenol resin.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-B-43-17803 (JP, B1) US Patent 3,470,544 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08J 3 / 00-3/28 C08L 61/06

Claims (2)

(57) [Claims] 1. A curing method comprising curing a phenol resin with a curing catalyst which is a salt of an organic acid or an inorganic acid (excluding an oxidizing agent) and nitrogen-containing chlorine. 2. A mixture of a novolak type phenol resin and an aldehyde donor as a curing agent thereof is cured by a curing catalyst which is a salt of an organic acid or an inorganic acid (excluding an oxidizing agent) and a nitrogen-containing base. And curing method