CN107674540B - Low-temperature curing powder coating and preparation method and application thereof - Google Patents
Low-temperature curing powder coating and preparation method and application thereof Download PDFInfo
- Publication number
- CN107674540B CN107674540B CN201710846930.2A CN201710846930A CN107674540B CN 107674540 B CN107674540 B CN 107674540B CN 201710846930 A CN201710846930 A CN 201710846930A CN 107674540 B CN107674540 B CN 107674540B
- Authority
- CN
- China
- Prior art keywords
- low
- temperature
- parts
- powder coating
- temperature curing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D163/00—Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
- C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
- C08G59/50—Amines
- C08G59/5046—Amines heterocyclic
- C08G59/5053—Amines heterocyclic containing only nitrogen as a heteroatom
- C08G59/5073—Amines heterocyclic containing only nitrogen as a heteroatom having two nitrogen atoms in the ring
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
- C08G59/68—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the catalysts used
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/03—Powdery paints
- C09D5/033—Powdery paints characterised by the additives
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/30—Sulfur-, selenium- or tellurium-containing compounds
- C08K2003/3045—Sulfates
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Wood Science & Technology (AREA)
- Paints Or Removers (AREA)
- Epoxy Resins (AREA)
Abstract
The invention discloses a low-temperature curing powder coating which is prepared from the following raw materials in parts by weight: 60-70 parts of epoxy resin; 2-3 parts of a low-temperature curing agent; 0-1.5 parts of a leveling agent; 0-1.5 parts of wetting agent; 20-35 parts of precipitated barium sulfate; 0.5-1.5 parts of a curing accelerator; 0-2 parts of other auxiliary agents; the low-temperature curing agent is a modified imidazole compound; the curing accelerator is prepared from the following raw materials in parts by weight: 65-70 parts of glycidyl ether; 30-35 parts of fumed silica. The invention also discloses a preparation method and application of the low-temperature curing powder coating. According to the invention, through the synergistic effect of the low-temperature curing agent and the curing accelerator and the optimization of the formula, the powder coating of the formula can be completely cured by heat preservation for 5-20min at the temperature of 100-120 ℃, and the powder coating of the formula has low curing temperature, good room-temperature storage performance and low-temperature curing property and room-temperature storage property.
Description
Technical Field
The invention relates to the field of coatings and coating, in particular to a low-temperature curing powder coating and a preparation method and application thereof.
Background
The powder coating has the characteristics of nearly zero VOC emission, good film quality, capability of recycling the overspray coating and the like, is considered as a 4E type coating product, and becomes a rapidly-developed hot field under the large background of national advocation of energy conservation and environmental protection. However, the recommended construction conditions of ordinary thermosetting powder coatings are (180 ℃.) × (10-20min), so that the powder coatings do not have absolute advantages in energy conservation and environmental protection compared with the traditional solvent-based coatings. In addition, high temperature curing restricts the popularization and application of the powder coating in the new fields of thermosensitive substrates such as MDF boards, plastics, electronic components and the like. Therefore, the development of a novel low-temperature curing type powder system has important scientific research value and social significance.
At present, the development of low-temperature curing powder coatings mainly has three aspects: (1) based on special resin, the Ultraviolet (UV) induced curing reaction is realized by using a photoinitiator, and no additional heat source is needed; (2) by adding a proper curing accelerator, the activation energy barrier of the curing reaction is reduced, and the reaction activity of the existing system is improved; (3) and optimizing the storage performance on the basis of ensuring the low-temperature curing performance.
The UV curing powder coating can realize real low-energy environmental protection theoretically, but the leveling property and the adhesive force of a coating film of the UV curing powder coating under the condition of relatively low temperature (less than or equal to 140 ℃) need to be further improved, and in addition, the UV curing powder coating has various problems of development of high-efficiency photoinitiator, design of photocuring main body resin, system compatibility and the like. At present, the photocuring powder coating has no outstanding advantages in curing temperature and time. The latest research shows that the photocureable powder coating needs to be baked at 140 ℃ for 5-10 min at 120 ℃ and then at 1500MJ/cm2Can be cured only by irradiation of ultraviolet light energy (preparation of low-temperature high-leveling photocureable powder coating, powder coating and painting, 2017, 2: 54-57).
On the basis of the existing thermosetting powder coating, the system reactivity is improved by adding a proper curing accelerator and optimizing the formula, and the method is a development hotspot of the existing low-temperature curing powder coating.
Chinese patent publication No. CN103483993A discloses a low-temperature curable powder coating, which is composed of the following raw materials in parts by weight: 50-60 parts of m-benzene unsaturated polyester resin, 20-25 parts of E-12 epoxy resin, 0.1-0.5 part of white carbon black, 3.5-4.5 parts of lanthanum oxide, 10-13 parts of activated carbon powder, 1-2 parts of azobisisobutyronitrile, 2-3 parts of sodium silicate, 2-3 parts of ferrous sulfate, 1-2 parts of phenolic resin, 0.1-1 part of dimethyl silicone oil and 10-20 parts of composite filler; the composite filler is prepared from the following raw materials in parts by weight: 30-40 parts of gibbsite, 20-30 parts of attapulgite, 6-10 parts of silicon carbide, 3-5 parts of magnesium hydroxide, 1-2 parts of carboxymethyl cellulose and 2-3 parts of jojoba oil. During the spraying process, the object is preheated at 50-70 ℃ for 5-8 minutes, then is subjected to electrostatic spraying, and is cured after being kept at 120 ℃ for 20 minutes.
Chinese patent document with publication number CN104962170A discloses a 120 ℃ low-temperature curing powder coating, which comprises the following components in percentage by mass: 45-50 parts of epoxy resin, 5-15 parts of polyester resin, 3-6 parts of epoxy curing agent, 0.5-1.5 parts of flatting agent, 0.5-0.8 part of wetting agent, 0.3-0.6 part of benzoin, 25-30 parts of barium sulfate, 0.2-0.5 part of wax powder, 0.2-0.5 part of charging agent, 2-3 parts of low-temperature flatting agent and 0.5-1.0 part of carbon black. The powder formulation can be completely cured by heat preservation at 120 ℃ for 30 min.
The Chinese patent publication No. CN105907233A discloses a low-temperature curing powder coating, which is a powder coating with the mildest curing condition reported at present, wherein the curing temperature of the system can be reduced to 110 ℃ by compounding polyester and an anionic catalytic curing agent.
It is worth noting that although the low-temperature curing powder is obviously improved in curing temperature, the room-temperature storage performance of the low-temperature curing powder is generally poor, the pot life is generally less than 7 days, and no low-temperature curing powder coating can achieve both low-temperature curing performance and room-temperature storage performance at present.
Disclosure of Invention
The invention provides a low-temperature curing powder coating which is low in curing temperature and good in room-temperature storage performance.
The low-temperature curing powder coating is prepared from the following raw materials in parts by weight:
the low-temperature curing agent is a modified imidazole compound;
the curing accelerator is prepared from the following raw materials in parts by weight:
65-70 parts of glycidyl ether;
30-35 parts of fumed silica.
According to the technical scheme, the powder coating of the formula can be completely cured by heat preservation for 5-20min at the temperature of 120 ℃ under the condition of 100-materials through the synergistic effect of the low-temperature curing agent and the curing accelerator and the optimization of the formula, the construction condition is the mildest condition in the reported thermosetting powder coatings, and the powder coating of the formula has low curing temperature and good room-temperature storage performance, and can give consideration to both low-temperature curing property and room-temperature storage property.
The other auxiliary agents comprise benzoin, solid paraffin and carbon black.
Preferably, the low-temperature curing powder coating is prepared from the following raw materials in parts by weight:
the low-temperature curing agent is a modified imidazole compound;
the curing accelerator is prepared from the following raw materials in parts by weight:
65-70 parts of glycidyl ether;
30-35 parts of fumed silica.
Preferably, the epoxy value of the epoxy resin is not more than 0.2.
Preferably, the low-temperature curing agent is coated with polyethylene wax;
the preparation method of the low-temperature curing agent coated with polyethylene wax comprises the following steps:
(1) the imidazole compound and liquid epoxy resin or isocyanate are stirred and react for 0.5 to 1.5 hours in a solvent, the reaction temperature is between 60 and 120 ℃, and the modified imidazole low-temperature curing agent is obtained through post-treatment;
(2) and melting, stirring and mixing the modified imidazole low-temperature curing agent and the polyethylene wax at the temperature of 80-110 ℃, and cooling and crushing to obtain the polyethylene wax-coated low-temperature curing agent.
Preferably, in the step (1), the molar ratio of the secondary amino group of the imidazole compound to the epoxy group of the liquid epoxy resin is 1: 1-1.3; the liquid epoxy resin is bisphenol A or bisphenol F with an epoxy value of more than 0.5.
Preferably, in the step (1), the molar ratio of the secondary amino group of the imidazole compound to the isocyanate group of the isocyanate is 1: 0.8-1; the isocyanate is hexamethylene diisocyanate, diphenylmethane diisocyanate or toluene diisocyanate.
In the step (1), the solvent is xylene, chloroform or dimethylformamide.
In the step (1), the post-treatment comprises the following steps: filtering after the reaction is stopped, dynamically vacuum desolventizing the filtered solid at 60-140 ℃ for 0.5-1.5 hours, heating to 80-180 ℃ and drying.
Preferably, in the step (2), the mass ratio of the modified imidazole low-temperature curing agent to the polyethylene wax is 3-5: 1.
Preferably, the preparation method of the curing accelerator comprises the following steps: stirring glycidyl ether and fumed silica at 35-40 deg.C for 10-15 min.
Further, the glycidyl ether is one or more of benzyl glycidyl ether, allyl glycidyl ether, ethylene glycol diglycidyl ether and n-butyl glycidyl ether.
The invention also provides a preparation method of the low-temperature curing powder coating, which comprises the following steps: weighing the raw materials according to the formula ratio, uniformly mixing, melting, extruding, crushing and screening to obtain the low-temperature curing powder coating;
in the melt extrusion process, the temperature of the zone I of the extruder is set to be 85-90 ℃, and the temperature of the zone II of the extruder is set to be 75-80 ℃; the rotation speed of the extruder is 70-90 rpm.
The invention also provides application of the low-temperature curing powder coating in repairing powder coating or solvent-based coating.
Preferably, the curing conditions of the low-temperature curing powder coating in repairing the coating are as follows: keeping the temperature at 120 ℃ for 5-20min at 100-.
The low-temperature curing powder coating disclosed by the invention is high in compatibility, can be applied to repairing defects of powder coatings and solvent-based coatings, and the defects can not be leveled, and the gloss and the adhesive force are not deteriorated.
Compared with the prior art, the invention has the beneficial effects that:
through component modification and formula content optimization, Kissinger and Crane curves show that the coating can be completely cured by heat preservation for 5-20min at the temperature of 100-120 ℃, and is the mildest construction condition in reported thermosetting powder coatings.
The low-temperature curing agent takes imidazole as a matrix, can control the molecular weight and the grafting group of the curing agent by epoxy addition or isocyanate blocking, further effectively regulates and controls the reaction activity of the curing agent at different temperatures, further blocks the room-temperature reaction of the curing agent and resin by combining polyethylene wax wrapping, improves the room-temperature storage property of the powder coating containing the imidazole curing agent to a certain extent while optimizing the curing effect, and results show that the prepared powder can be stably stored for at least 20 days at the temperature of less than 35 ℃.
The curing accelerator consists of glycidyl ether, contains an epoxy group, has excellent compatibility with matrix resin, plays a role in diluting, can effectively reduce the softening point and viscosity of the matrix resin, improves the heated fluidity of the matrix resin, and improves the leveling property of the powder coating under the low-temperature condition; with the rise of the temperature, the curing accelerator participates in the reaction, regulates and controls the dynamic performance of curing, and influences the curing and leveling processes of the coating in cooperation with the curing agent and other components, so that the gelling time, the curing temperature and the curing rate of the system are effectively balanced.
The powder coating prepared by the invention has the advantages of good leveling property, good mechanical property, high film gloss, easiness in storage and the like, has certain compatibility, can be applied to repairing defects of the powder coating and solvent type coating, and cannot cause the situations of leveling property, gloss and poor adhesive force at the defects.
Drawings
FIG. 1 is a graph of the performance characteristics of a low temperature-curable powder coating prepared in example 6, wherein:
(a) DSC curve, (b) Kissinger curve, and (c) Crane curve;
FIG. 2 is a DSC curve of the low temperature curing type powder coatings prepared in example 6 and comparative example 1.
Detailed Description
EXAMPLE 1 preparation of Low temperature curing agent
Weighing bisphenol F and 2-methylimidazole with epoxy equivalent of 170 according to the molar ratio of epoxy group to secondary amino group of 1.1: 1, dissolving 40g of 2-methylimidazole in 120g of xylene solution, stirring and dissolving at 120 ℃, slowly dripping 92g of bisphenol F resin, and gradually producing a reddish brown precipitate; after the reaction is completed, filtering out a xylene solvent, and vacuumizing the reddish-brown product at 140 ℃ to remove residual xylene; then, the reddish brown product is placed in a forced air drying oven at 180 ℃ for drying for 1 hour, and is cooled to room temperature to obtain a dark reddish brown solid; mixing the dark reddish brown solid with polyethylene wax (melting point of 110 ℃) according to the mass ratio of 3: 1, stirring uniformly at 120 ℃, cooling to room temperature and crushing to obtain the wax-coated low-temperature curing agent.
EXAMPLE 2 preparation of Low temperature curing agent
Toluene diisocyanate and 2-methylimidazole were weighed in a molar ratio of isocyanato group to secondary amino group of 0.95: 1, 30g of 2-methylimidazole was dissolved in 100g of chloroform solution, dissolved with stirring at 70 ℃ and 61g of toluene diisocyanate was slowly added dropwise to the above solution. And after the reaction is finished, vacuumizing at 70 ℃, and removing chloroform to finally obtain the dimethyl imidazole modified by toluene diisocyanate. Further, the modified imidazole and the polyethylene wax (melting point is 110 ℃) are mixed according to the mass ratio of 3: 1, stirred evenly at 120 ℃, cooled to room temperature and crushed to obtain the wax-coated low-temperature curing agent.
EXAMPLE 3 preparation of Low temperature curing agent
Weighing bisphenol F and 2-methylimidazole with epoxy equivalent of 170 according to the molar ratio of epoxy group to secondary amino group of 1.2: 1, dissolving 40g of 2-methylimidazole in 120g of xylene solution, stirring and dissolving at 110 ℃, slowly dripping 100g of bisphenol F resin, and gradually producing a reddish brown precipitate; after the reaction is completed, filtering out a xylene solvent, and vacuumizing the reddish brown product at 120 ℃ to remove residual xylene; and then, drying the reddish brown product in a 150 ℃ forced air drying oven for 1 hour, and cooling to room temperature to obtain the epoxy modified dimethyl imidazole curing agent.
EXAMPLE 4 preparation of Low temperature curing agent
Hexamethylene diisocyanate and 2-methylimidazole were weighed in a molar ratio of isocyanato group to secondary amino group of 0.9: 1, 30g of 2-methylimidazole was dissolved in 100g of dimethylformamide solution, dissolved with stirring at 80 ℃ and 55g of hexamethylene diisocyanate was slowly added dropwise to the above solution. After the reaction is finished, vacuumizing at 120 ℃ to remove dimethylformamide, and finally obtaining the hexamethylene diisocyanate modified dimethyl imidazole curing agent.
EXAMPLE 5 preparation of curing Accelerator
Benzyl glycidyl ether, allyl glycidyl ether, n-butyl glycidyl ether and fumed silica are weighed according to the weight ratio of 23: 31, placed in a reaction kettle and stirred for 15min at the temperature of 35 ℃ and at the speed of 200rpm to obtain the curing accelerator with 69 wt% of effective active substances.
EXAMPLE 6 preparation of Low-temperature curing powder coating
Weighing raw materials according to the formula → machine mixing in a mixing pot (10min) → melt extrusion (area II 75 ℃, area I85 ℃, extruder rotation speed 80rpm) → tablet pressing → ACM crushing → cyclone separation → powder coating product detection and packaging → finished product.
The formula is as follows:
the composition is characterized by comprising the following raw materials in parts by weight:
the DSC curve, Kissinger curve and Crane curve of the low-temperature curing powder coating of the formula are respectively shown as (a), (b) and (c) in figure 1. As can be seen from FIG. 1, the activation energy of curing reaction of the low-temperature curing powder coating of the formulation was 70.918 kJ/mol; after the heat preservation is carried out for 20min at the temperature of 100 ℃, the curing rate of the film layer can reach 96.9 percent, and the calculation formula of the solid content rate is as follows:
example 7 preparation of Low-temperature-curable powder coating
Weighing raw materials according to the formula → machine mixing in a mixing pot (10min) → melt extrusion (70 ℃ in the area I and 80 ℃ in the area II and the rotating speed of an extruder 80rpm) → tablet pressing → ACM crushing → cyclone separation → powder coating product detection and packaging → finished product.
The formula is as follows:
the composition is characterized by comprising the following raw materials in parts by weight:
EXAMPLE 8 preparation of Low-temperature curing powder coating
Weighing raw materials according to the formula → machine mixing in a mixing pot (10min) → melt extrusion (area II 75 ℃, area I85 ℃, extruder rotation speed 80rpm) → tablet pressing → ACM crushing → cyclone separation → powder coating product detection and packaging → finished product.
The formula is as follows:
the composition is characterized by comprising the following raw materials in parts by weight:
EXAMPLE 9 preparation of Low-temperature curing powder coating
Weighing raw materials according to the formula → machine mixing in a mixing pot (10min) → melt extrusion (80 ℃ in a region II, 90 ℃ in a region I and 80rpm in an extruder) → tablet pressing → ACM crushing → cyclone separation → powder coating product detection and packaging → finished product.
The formula is as follows:
the composition is characterized by comprising the following raw materials in parts by weight:
comparative example 1
The powder coating was prepared as in example 6, with the following formulation:
the composition is characterized by comprising the following raw materials in parts by weight:
FIG. 2 is a DSC curve of the low temperature curing powder coating of the formulation of example 6 and comparative example 1, and it can be seen that the use of the self-made curing agent and the curing accelerator can reduce the peak temperature of the curing reaction of the system from 125 ℃ to 110 ℃, so that the powder coating of the present invention has milder curing conditions.
Comparative example 2
The powder coating was prepared as in example 6, with the following formulation:
the composition is characterized by comprising the following raw materials in parts by weight:
comparative example 3
The powder coating was prepared as in example 6, with the following formulation:
the composition is characterized by comprising the following raw materials in parts by weight:
test example
The powder coatings of examples 6-9 and comparative examples 1-3 were spray cured under the curing conditions shown in Table 1.
After curing, respectively carrying out impact resistance test, bending test, salt spray test, adhesive force test, pencil hardness test and glossiness test on the coating, wherein the test standards are as follows:
1. impact resistance: GB/T1732-1993;
2. flexibility: GB/T6742-2007;
3. salt spray test: GB/T1771-1991, 500 h;
4. adhesion force: GB/T9286-1998, 1mm cross-hatch method;
5. pencil hardness: GB/T6739-1996;
6. 60 ° average gloss: GB/T9754-2007.
The results of testing the powder coating films of examples 6-9 and comparative examples 1-3 are shown in Table 1.
TABLE 1
The low temperature-curable powder coatings of the formulations of example 6 and comparative examples 1 to 3 were spray cured after storage at room temperature (. ltoreq.35 ℃) for 15 days, and the flatness of the film layer was observed to find that: the low-temperature curing powder coating of the embodiment 6 can still maintain the film effect at the initial stage of powder preparation after being stored for 15 days, and the surface is smooth and flat; comparative example 1 the powder coating added with the common curing agent has obvious deterioration, and the film layer is changed from smooth to uneven, because the common curing agent is easy to react with the matrix resin at room temperature; comparative example 2 the powder coating without the self-made curing accelerator maintained good film appearance after 15 days, but the film had poor gloss due to poor low temperature leveling property; comparative example 3 because the content of the active curing agent, the leveling agent, the wetting agent, the curing accelerator and other components is not optimized, the flatness of the film layer of the powder coating of comparative example 3 is also obviously affected after the powder coating is stored for 15 days.
The above-mentioned embodiments are intended to illustrate the technical solutions and advantages of the present invention, and it should be understood that the above-mentioned embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention, and any modifications, additions, equivalents, etc. made within the scope of the principles of the present invention should be included in the scope of the present invention.
Claims (9)
1. The low-temperature curing powder coating is characterized by being prepared from the following raw materials in parts by weight:
60-70 parts of epoxy resin;
2-3 parts of a low-temperature curing agent;
0-1.5 parts of a leveling agent;
0-1.5 parts of wetting agent;
20-35 parts of precipitated barium sulfate;
0.5-1.5 parts of a curing accelerator;
0-2 parts of other auxiliary agents;
the low-temperature curing agent is a modified imidazole compound; the low-temperature curing agent is coated with polyethylene wax; the preparation method of the low-temperature curing agent coated with polyethylene wax comprises the following steps:
(1) the imidazole compound and liquid epoxy resin or isocyanate are stirred and react for 0.5 to 1.5 hours in a solvent, the reaction temperature is between 60 and 120 ℃, and the modified imidazole low-temperature curing agent is obtained through post-treatment;
(2) melting, stirring and mixing the modified imidazole low-temperature curing agent and polyethylene wax at the temperature of 80-110 ℃, and cooling and crushing to obtain a polyethylene wax-coated low-temperature curing agent;
the curing accelerator is prepared from the following raw materials in parts by weight:
65-70 parts of glycidyl ether;
30-35 parts of fumed silica.
2. The low-temperature curing powder coating according to claim 1, wherein in the step (1), the molar ratio of the secondary amino group of the imidazole compound to the epoxy group of the liquid epoxy resin is 1: 1-1.3; the liquid epoxy resin is bisphenol A or bisphenol F with an epoxy value of more than 0.5.
3. The low-temperature curable powder coating according to claim 1, wherein in step (1), the molar ratio of the secondary amino group of the imidazole compound to the isocyanate group of the isocyanate is 1: 0.8-1; the isocyanate is hexamethylene diisocyanate, diphenylmethane diisocyanate or toluene diisocyanate.
4. The low-temperature curing powder coating as claimed in claim 1, wherein in the step (2), the mass ratio of the modified imidazole low-temperature curing agent to the polyethylene wax is 3-5: 1.
5. The low-temperature curable powder coating according to claim 1, wherein the curing accelerator is prepared by a method comprising: stirring glycidyl ether and fumed silica at 35-40 deg.C for 10-15 min.
6. The low-temperature curing powder coating as claimed in claim 5, wherein the glycidyl ether is one or more of benzyl glycidyl ether, allyl glycidyl ether, ethylene glycol diglycidyl ether and n-butyl glycidyl ether.
7. A method for preparing the low-temperature curing powder coating according to any one of claims 1 to 6, comprising: weighing the raw materials according to the formula ratio, uniformly mixing, melting, extruding, crushing and screening to obtain the low-temperature curing powder coating;
in the melt extrusion process, the temperature of the zone I of the extruder is set to be 85-90 ℃, and the temperature of the zone II of the extruder is set to be 75-80 ℃; the rotation speed of the extruder is 70-90 rpm.
8. Use of the low temperature curable powder coating according to any one of claims 1 to 6 for repairing powder coating or solvent borne coating.
9. Use according to claim 8, wherein the curing conditions of the low temperature curing powder coating are: keeping the temperature at 120 ℃ for 5-20min at 100-.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710846930.2A CN107674540B (en) | 2017-09-18 | 2017-09-18 | Low-temperature curing powder coating and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710846930.2A CN107674540B (en) | 2017-09-18 | 2017-09-18 | Low-temperature curing powder coating and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107674540A CN107674540A (en) | 2018-02-09 |
| CN107674540B true CN107674540B (en) | 2020-03-31 |
Family
ID=61135874
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710846930.2A Active CN107674540B (en) | 2017-09-18 | 2017-09-18 | Low-temperature curing powder coating and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107674540B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109439142B (en) * | 2018-10-30 | 2020-12-11 | 江苏锐康新材料科技有限公司 | Acrylate modified nano powder coating interpenetrating network aqueous dispersion, preparation method and curing method thereof |
| CN109825121B (en) * | 2019-03-04 | 2023-10-03 | 南京天诗新材料科技有限公司 | Functional composite wax powder for low-temperature curing powder coating and preparation method and application thereof |
| EP3950149A4 (en) * | 2019-03-29 | 2022-12-07 | Kansai Paint Co., Ltd | Cationic electrodeposition coating material composition |
| CN112920684B (en) * | 2021-02-26 | 2022-05-17 | 北京碧海云智新材料技术有限公司 | Low-temperature curing powder coating and preparation method and application thereof |
| CN114015327B (en) * | 2022-01-06 | 2022-04-26 | 天津凯华绝缘材料股份有限公司 | Halogen-free phosphorus-free low-temperature curing epoxy powder composition with storage stability and preparation method thereof |
| CN116426192A (en) * | 2023-03-02 | 2023-07-14 | 庞贝捷粉末涂料(上海)有限公司 | Low temperature curing powder coating compositions |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4335228A (en) * | 1978-02-27 | 1982-06-15 | Air Products And Chemicals, Inc. | Isocyanate blocked imidazoles and imidazolines for epoxy powder coating |
| CN102504671A (en) * | 2011-10-27 | 2012-06-20 | 西安大禾化工材料有限公司 | Anticorrosion energy-saving type curing agent for rapidly curing epoxy powder coating at low temperature and preparation method thereof |
| CN103666203A (en) * | 2013-11-08 | 2014-03-26 | 洛阳双瑞防腐工程技术有限公司 | Low-temperature fast-curing epoxide powder paint and preparation method thereof |
-
2017
- 2017-09-18 CN CN201710846930.2A patent/CN107674540B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4335228A (en) * | 1978-02-27 | 1982-06-15 | Air Products And Chemicals, Inc. | Isocyanate blocked imidazoles and imidazolines for epoxy powder coating |
| CN102504671A (en) * | 2011-10-27 | 2012-06-20 | 西安大禾化工材料有限公司 | Anticorrosion energy-saving type curing agent for rapidly curing epoxy powder coating at low temperature and preparation method thereof |
| CN103666203A (en) * | 2013-11-08 | 2014-03-26 | 洛阳双瑞防腐工程技术有限公司 | Low-temperature fast-curing epoxide powder paint and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 用于粉末涂料的咪唑及其衍生物研究进展;祁光明;《上海涂料》;20110228;第49卷(第2期);参见第27页第一栏第二段，第29页第二栏倒数第三段，第30页第一栏第4段，第30页第二栏第2段 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107674540A (en) | 2018-02-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107674540B (en) | Low-temperature curing powder coating and preparation method and application thereof | |
| CN102702753B (en) | Curable resin composition, cured product thereof, and various articles derived from those | |
| CN1708522A (en) | Resin composition, transfer material and process for producing shaped item | |
| WO1996011988A1 (en) | Powder coating resin composition | |
| KR20190075217A (en) | Epoxy resin formulation with fast cure property and high thermal resistance and prepreg comprising the same | |
| TWI709606B (en) | Resin composition for high-strength fiber-reinforced plastic, cured material thereof, the cured material-containing high-strength fiber-reinforced plastic, and method for manufacturing the high-strength fiber-reinforced plastic | |
| WO2016039486A1 (en) | Thermosetting resin composition | |
| CN110128376B (en) | Compound, preparation method and application of compound as latent epoxy curing agent | |
| CN109762440B (en) | Low-temperature curing powder coating and preparation method thereof | |
| CN114574091B (en) | UV-moisture dual-curing three-proofing paint for optical module and preparation method and application thereof | |
| CN110885458B (en) | Polymer wax powder with self-repairing function and preparation method thereof | |
| CN109134825B (en) | Modified epoxy resin and preparation and application thereof | |
| CN111410907B (en) | Self-repairing type temperature-resistant wear-resistant polyaspartic acid ester coating and preparation method thereof | |
| CN110982464B (en) | Toughening epoxy adhesive capable of being reprocessed and recycled and curing method | |
| CN109486459B (en) | Non-yellowing, moisture-heat-resistant and low-temperature-curable adhesive and preparation method thereof | |
| CN114752333B (en) | Normal-temperature-cured high-strength high-toughness high-temperature-resistant epoxy structural adhesive and preparation method thereof | |
| EP0407554B1 (en) | Metallic oxide-oxirane polymers and prepolymers | |
| JP3819254B2 (en) | Curing agent for thermosetting coating and coating composition | |
| CN110746854B (en) | Room temperature fast curing coating with high infrared radiation coating as cured product and preparation method thereof | |
| CN108352365A (en) | Protective film formation piece | |
| CN110437655B (en) | TiO2 modified polyacrylate/organosilicon hybrid coating and preparation method thereof | |
| CN108503798B (en) | High-heat-residue-weight modified epoxy resin and preparation method and application thereof | |
| CN108260356A (en) | Curable resin film and the 1st protective film formation piece | |
| CN108140586A (en) | The forming method of thermosetting resin film, the 1st protective film formation piece and the 1st protective film | |
| CN107142007B (en) | A kind of impact-resistant coating and its preparation process for stamping die |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |