Self-hardening organic synthetic resin mixture used for additive manufacturing, and application therefor

A self-curing organic synthetic resin composition for additive manufacturing, comprising 30-75% by weight of a linear thermoplastic phenolic resin and 25-70% by weight of a phenol modified furan resin, wherein the self-curing organic synthetic resin composition has a viscosity of 10-14 mPa·s at 25° C. and has a tensile strength of more than 1.2 MPa at 1000° C., and all of the percents by weight are based on the total weight of the linear thermoplastic phenolic resin and the phenol modified furan resin;

• the linear thermoplastic phenolic resin is prepared by following operations:
• (1a) adding a first phenolic compound, a first organic acid as a catalyst, and a polymerization inhibitor to an enamel reactor and stirring, and adding a first aldehyde compound to the enamel reactor;
• (2a) heating a mixture of step (1a), heating the mixture to 85-90° C. in 25-30 min and maintaining the temperature at 85-90° C. for 30-40 min;
• (3a) heating the mixture further to 100-105° C. in 10-20 min and maintaining the temperature at 100-105° C. for 120-150 min;
• (4a) vacuum dehydrating the mixture;
• (5a) cooling the mixture to 70-75° C., and adding an organic solvent, a toughening agent and a modifier to the enamel reactor, and stirring the mixture for 60-90 min;
• and
• (6a) cooling the mixture of step (5a) to 30-35° C., and adding a first coupling agent to the enamel reactor and stirring the mixture for 40-60 min, and wherein
• in the preparation of the linear thermoplastic phenolic resin:
• the first phenolic compound is selected from the group consisting of phenol, p-aminophenol, p-cresol, m-cresol, m-aminophenol, p-nitrophenol, p-chloro-m-xylenol, p-tert-octyl phenol and a combination thereof;
• the first aldehyde compound is selected from the group consisting of formaldehyde and a liquid aldehyde containing two or more carbon atoms;
• and the liquid aldehyde is selected from the group consisting of acetaldehyde, butyraldehyde, valeraldehyde, terephthalaldehyde, trioxane, metaldehyde, dimethoxymethane, o-chlorobenzaldehyde and a combination thereof;
• the first organic acid is selected from the group consisting of formic acid, acetic acid, p-toluene sulfonic acid, acrylic acid, benzoic acid, propionic acid and a combination thereof;
• the polymerization inhibitor is molecular, and is selected from the group consisting of hydroquinone, p-benzoquinone, 4-tert-butylcatechol, phenothiazine and a combination thereof;
• the organic solvent is a polar organic solvent, and is selected from the group consisting of methanol, ethylene glycol, ethanol, acetone, isopropanol, methyl butanone and a combination thereof;
• the first coupling agent is silane which is selected from the group consisting of 3-Glycidoxypropyltrimethoxysilane, 3-Aminopropyltriethoxysilane, 3-(2-Aminoethylamino) propyl-dimethoxymethylsilane, and a combination thereof;
• the toughening agent is selected from the group consisting of polyvinyl butyral, polyether sulfone, polyphenylene ether ketone, polyvinyl alcohol and a combination thereof;
• the modifier is an aromatic solvent oil;
• and wherein
• the phenol modified furan resin is prepared by following operations:
• (1b) adding a second phenolic compound, a second aldehyde compound and a second organic acid to an enamel reactor and stirring;
• (2b) heating a mixture of step (1b) to 70-75° C., adding half of furfuryl alcohol to the enamel reactor, and maintaining the temperature at 70-75° C. for 55-60 min;
• (3b) heating the mixture of step (2b) to 80-85° C. in 10-20 minutes, and adding a quarter of furfuryl alcohol to the enamel reactor, and maintaining the temperature at 80-85° C. for 60-90 min;
• (4b) heating the mixture of step (3b) to 95-100° C. in 10-20 minutes, and adding a pH regulator to the enamel reactor to adjust pH of the mixture of step (3b) to 5.7-6.0, and adding a quarter of furfuryl alcohol to the enamel reactor, and maintaining the temperature at 95-100° C. for 120-150 min;
• (5b) adding an organic waste liquid, a heat stabilizer and an additive to the enamel reactor at 95-100° C., and stirring the mixture for 50-60 min;
• (6b) cooling the mixture of step (5b) to 60-65° C., and adding a diluent to the enamel reactor, and stirring the mixture for 30-60 min;
• (7b) cooling the mixture of step (6b) to 40-45° C., and adding an aldehyde trapping agent to the enamel reactor, and stirring for 30-60 min;
• and
• (8b) cooling the mixture of step (7b) to 30-35° C., and adding a second coupling agent to the enamel reactor, and stirring the mixture for 30-60 min, and wherein
• in the preparation of the phenol modified furan resin:
• the second phenolic compound is phenol, bisphenol A, or a monoalkyl- or dialkyl-substituted phenol;
• the furfuryl alcohol comprises 0.7% or less by weight of residual aldehyde, 0.3% or less by weight of water and 98% or more by weight of furfuryl alcohol;
• and the furfuryl alcohol has a cloud point of 10° C. or less and an acidity of 0.01 mol/L or less, and all of the percents by weight are based on the total weight of the residual aldehyde, the water and the furfuryl alcohol;
• the second aldehyde compound is selected from the group consisting of an aqueous formaldehyde solution having 36.5 wt. % formaldehyde, furfural, acetaldehyde, paraformaldehyde powders, benzaldehyde, phenylacetaldehyde, citral and a combination thereof;
• the second organic acid is selected from the group consisting of formic acid, acetic acid, citric acid, benzoic acid, phthalic acid, oxalic acid, malonic acid, phenylacetic acid, succinic acid and a combination thereof;
• the diluent is selected from the group consisting of methanol, ethanol, isopropanol, furfuryl alcohol, ethylene glycol, toluene, petroleum ether and a combination thereof;
• the pH regulator is an aqueous alkali metal hydroxide solution having 48 wt. % alkali metal hydroxide, and the alkali metal hydroxide is one or two of sodium hydroxide and potassium hydroxide;
• the aldehyde trapping agent is an ammonia solution having 25-28 wt. % ammonia;
• the second coupling agent is an aqueous silane which is selected from the group consisting of 3-Glycidoxypropyltrimethoxysilane, 3-Aminopropyltriethoxysilane, 3-(2-Aminoethylamino) propyl-dimethoxymethylsilane, and a combination thereof;
• the organic waste liquid is produced by cleaning a printhead of a 3D inkjet printer during 3D inkjet printing in casting, and the organic waste liquid comprises 54% by weight of ethylene glycol, 36% by weight of ethanol, 2% by weight of furan resin and 8% by weight of furfuryl alcohol, and all of the percents by weight are based on the total weight of the ethylene glycol, the ethanol, the furan resin and furfuryl alcohol;
• the heat stabilizer is selected from the group consisting of phosphite, epoxy soybean oil, epoxy ester, pentaerythritol, xylitol, mannitol and a combination thereof;
• and
• the additive is one or two of syrup and fructose, and wherein
• the self-curing organic synthetic resin composition is prepared by following operations:
• (3a) adding the linear thermoplastic phenolic resin and the phenol modified furan resin to an enamel reactor and stirring a mixture;
• (3b) heating the mixture to 35-40° C., and maintaining 35-40° C. for 60-90 min;
• and
• (3c) unloading, testing, and packaging the mixture to obtain the self-curing organic synthetic resin composition for additive manufacturing.