Application background and overview of triglycidyl isocyanurate
Triglycidyl isocyanurate (TGIC) is a new type of epoxy resin. It has excellent heat resistance, weather resistance, adhesiveness and high-temperature electrical properties, and is stable against acids, alkalis and other chemicals. High resistance and particularly excellent cross-linking and curing properties. It is one of the most important curing agents for base materials containing carboxyl functional groups, and is especially suitable as a curing agent for carboxylic acid polyester in powder coatings.
At present, the main production process of TGIC is to add ECH (epoxy chloropropane) and CA (isocyanuric acid) into the reactor in a certain ratio, and perform a synthesis reaction under the action of an esterification catalyst to obtain a synthetic The product 1,3,5-triisocyanurate is reacted with NaOH to obtain the cyclized TGIC crude liquid, and then the TGIC crude liquid is filtered to remove residue, and then the filtered cyclized mother liquor is passed through After washing, distillation, crystallization, separation, drying and other steps, the final TGIC product is obtained.
Test analysis shows that TGIC is a curing agent with excellent comprehensive physical and chemical properties. Weather-resistant carboxyl polyester powder coatings can resist sunlight and rain after being cured by TGIC, thereby effectively avoiding powdering or aging of the coating film. Therefore, TGIC It occupies a very important position in the powder coating industry at home and abroad. TGIC is highly toxic to both breathing and eating. It is an eye irritant and mildly irritating to the skin and nose.
Pure TGIC and TGIC powder coatings are allergic to the skin of some people, and may cause rashes in severe cases. At present, China is a major country in the production of TGIC. However, due to its carcinogenicity and the gradual standardization of environmental protection regulations, the use of TGIC in powder coatings has also been restricted in Europe and Australia. It can be expected that China will do the same. Since there is still little research and application in flame retardant, printed circuit boards and optical functions, the high-end market is still occupied by companies such as Nissan and Vantico.
Applications of triglycidyl isocyanurate
Application of triglycidyl isocyanurate 1. Curing agent for powder coatings
Polyester-TGIC powder coating is a commercialized polyester powder coating. In this powder coating, low molecular weight glycidyl or epoxy functional group curing agents are added to react with the hydroxyl groups in the polyester. In this way, polyester accounts for a high proportion of powder coatings, so polyester-TGIC powder coatings have excellent weather resistance and corrosion resistance. However, the solvent and chemical resistance of polyester-TGIC powder coatings is less than ideal. The reaction between polyester resin and sericite powder TGIC is shown in the figure:
The stable structure of TGIC and the three functional groups of TGIC can make the coating film form a stable three-dimensional structure, thus having good flexibility and weather resistance. Polyester-TGIC powder coating has good adhesion, corrosion resistance and outdoor durability. The curing temperature is lower than that of polyurethane-polyester powder coating, and the curing cycle is also shorter than that of polyurethane-polyester powder coating. Plus, polyester-TGIC powder coating is thick and tough with good edge coverage. Therefore, it can be used in applications where sharp edges or corners exist, such as car wheels, air conditioners, lawn furniture and cabinet air conditioners.
Application of triglycidyl isocyanurate 2. UV curing coatings
Using tris(epoxypropyl)isocyanurate as the resin matrix and adding esterification with acrylic acid, trifunctional epoxypropyl isocyanurate acrylate (TGICA) was obtained. The effects of catalyst type, raw material ratio, polymerization inhibitor type, esterification temperature and reaction time on product properties were studied.
The results show that the optimal conditions for the synthesis of TGICA are: n(TGIC): n(AA): 1:2179, the catalyst is IV, IV-dimethylaniline, and the polymerization inhibitor is 2,6-di-tert-butyl p-cresol, reaction temperature (105±2)℃, reaction time 3 h. The conversion rate of acrylic acid can reach 99.17%. Application research shows that TGICA is a UV-curable coating film-forming resin with excellent performance, low price and simple synthesis method.
With different monomers and photosensitizers, UV coatings for different purposes are obtained. After UV curing, a coating film with excellent performance is obtained. It can be used for gravure printing paper glazing UV coating, metal varnishing UV coating, etc. The coating film has the advantages of fast curing response, good antifouling performance, and hard coating film.
Application of triglycidyl isocyanurate 3. Flame retardant epoxy resin
Using phenol, xylene formaldehyde resin (XF) and TGIC as raw materials, a new type of nitrogen-containing flame retardant epoxy resin was synthesized through a two-step reaction. GPC was used to monitor the reaction process and conversion rate, and IR and H NMR were used to characterize the structure of the resin. Through the study of this two-step reaction, the optimal synthesis process of phenol-modified xylene formaldehyde resin (PXF) was determined. PXF resin and TGIC were subjected to a ring-opening reaction under alkaline conditions, and a TGIC conversion rate of more than 85% was obtained. Nitrogen-containing epoxy resin. Introducing TGIC into the PXF molecular chain is expected to produce a new nitrogen-containing flame-retardant epoxy resin with good resistance, electrical and mechanical properties, and is green and environmentally friendly.
Because TGIC has a high nitrogen content (14%), it has certain self-extinguishing properties and arc resistance. TGIC is mainly used as molding materials such as electrical laminates, insulating coatings for electronic and electrical devices, and semiconductor packaging materials. Flame retardants for flame-retardant plastics and composite materials are also one of the main varieties of flame-retardant copper-clad laminates. Combining TGIC with acrylic resin can make a water-soluble pressure�Adhesive, this adhesive can be used on non-woven fabrics, plastic tapes and paper tapes, and its bonding strength, water resistance and heat resistance can be greatly improved.
Solder resist ink is one of the most commonly used chemicals for printed circuit boards (PCBs). Except for solder joints, other parts of the PCB need to be covered with a layer of solder resist ink as a permanent protective coating. There are options Protective shielding of wire patterns from damage, preventing short circuits caused by solder overlapping, increasing insulation, and preventing circuit corrosion and breakage; at the same time, the solder mask ink has excellent electrical properties, heat resistance, chemical resistance, moisture resistance, and salt spray resistance. performance and physical and mechanical properties to ensure the safety and electrical performance stability of PCB in production, transportation, storage, and use, and to play an aesthetic role in PCB.
Application of triglycidyl isocyanurate 4. Application of optical properties
Motorola uses TGIC and alkaline zinc-based borosilicate glass as compositions for semiconductor devices. The main molding material is TGIC, whose refractive index is 1.52. Alkaline zinc-based borosilicate glass with a similar refractive index is selected as the filler, and acid anhydride is used as the curing agent. This device allows 50% of -900 nm optical signals to directly pass through the packaging material, and the packaging material has a refractive index of 1.50 to 1.58, and can convert optical signals into digital signals. This kind of device can be used as optical isolator, optical connector and optical display, etc., and can work in the environment of -40~130℃.
Application and preparation of triglycidyl isocyanurate
Method 1: A preparation method of triglycidyl isocyanurate, the steps are as follows:
a) Collect the cyclized triglycidyl isocyanurate crude liquid, let it stand for layering, and remove the cyclized mother liquor. The crude triglycidyl isocyanurate liquid is directly prepared using existing technology. , that is, using ECH, CA, esterification catalyst and NaOH solution as raw materials to carry out synthesis and cyclization reaction in sequence, and then filtering out the solid salt waste residue, as shown in the figure;
b) Distill the cyclization mother liquor under reduced pressure at 55-100°C for 2.4-3.5 hours, remove the distillate, and obtain the distilled product. The vacuum distillation is carried out in at least two stages. The first The distillation temperature of the first stage is lower than the distillation temperature of the second stage;
c) Add ethanol with a purity of more than 99.0% to the distilled product, then place it in a cold bath device, cool to 6-10°C under stirring conditions, vacuum filtrate, and dry to obtain isocyanuric acid trihydride. Glyceride, the mass addition amount of ethanol is 55%-65% of the cyclization mother liquor.
Method 2: A new preparation method of triglycidyl isocyanurate. The technical solution is: using sodium cyanate as raw material, preparing triglycidyl isocyanurate through substitution and condensation reaction. Ester,
The specific steps include the following steps: mix sodium cyanate, epichlorohydrin, benzyl bromide organic catalyst, 30% hydrogen peroxide, and polar solvent into the reactor at one time in proportion, stir at room temperature for 10 minutes, and then heat and control the temperature At 70-90°C, reflux for 3-5 hours and then undergo post-treatment to obtain triglycidyl isocyanurate; including 65 parts by weight of sodium cyanate, 90-120 parts by weight of epichlorohydrin, and benzyl bromide organic catalyst 3-6 parts by weight, 2-5 parts by weight of 30% hydrogen peroxide, and 90-120 parts by weight of polar solvent.
Reaction principle: A displacement reaction occurs between benzyl bromide organic matter and epichlorohydrin to generate epibromide; epibromide reacts with sodium cyanate to remove a sodium bromide, because sodium bromide is slightly soluble in polarity The solvent slowly precipitates, and the chemical balance of the entire reaction moves toward the product of the removal reaction until the chemical equilibrium is reached. The reaction formula is as follows:
Since the isocyanate product of the removal reaction is unstable in an environment above 60°C, it is easy to undergo a tridehydration condensation reaction to form stable triglycidyl isocyanurate. Since the epoxy group is easily reduced and ring-opened, a small amount Hydrogen peroxide can make the epoxy group exist more stably in a polar solvent environment. The reaction formula is as follows:
