CN112778501B - Solid mercaptan curing agent, powder coating and preparation method thereof - Google Patents
Solid mercaptan curing agent, powder coating and preparation method thereof Download PDFInfo
- Publication number
- CN112778501B CN112778501B CN202011543547.8A CN202011543547A CN112778501B CN 112778501 B CN112778501 B CN 112778501B CN 202011543547 A CN202011543547 A CN 202011543547A CN 112778501 B CN112778501 B CN 112778501B
- Authority
- CN
- China
- Prior art keywords
- powder coating
- mercaptan
- solid
- epoxy
- component
- 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
- 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
- C08G59/66—Mercaptans
-
- 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
- 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
- C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
- C08K3/20—Oxides; Hydroxides
- C08K3/22—Oxides; Hydroxides of metals
- C08K2003/2237—Oxides; Hydroxides of metals of titanium
- C08K2003/2241—Titanium dioxide
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
- C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Wood Science & Technology (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Paints Or Removers (AREA)
Abstract
The invention discloses a solid mercaptan curing agent, a powder coating and a preparation method thereof, wherein the solid mercaptan curing agent comprises mercaptan and a solid substance containing an epoxy group, wherein the ratio of active hydrogen equivalent of the mercaptan to epoxy equivalent of the solid substance containing the epoxy group is (2-4): 1; the solid mercaptan curing agent is prepared by heating mercaptan to the temperature of 120-200 ℃, adding solid matters containing epoxy groups under the condition of stirring mercaptan liquid, then continuing stirring and cooling. Correspondingly, the invention also provides a powder coating prepared by adopting the solid mercaptan curing agent and a preparation method of the powder coating. By adopting the invention, ultralow temperature curing at the temperature of less than 100 ℃ can be realized, a coating film with excellent performance can be obtained after curing, and the production efficiency can be greatly improved.
Description
Technical Field
The invention relates to the technical field of powder coatings, and particularly relates to a solid mercaptan curing agent, a powder coating and a preparation method thereof.
Background
The powder coating is a novel solvent-free one-hundred percent solid coating, does not contain VOC, and is an environment-friendly coating. The powder paint is prepared by mixing resin, pigment and filler, curing agent and other assistants in certain proportion, and then carrying out hot extrusion molding, crushing, sieving and other processes. They are stable in storage at normal temperature, and can be used for forming flat and bright permanent coating film by electrostatic spraying, friction spraying or fluidized bed dip-coating, heating, baking, melting and solidifying so as to attain the goal of decoration or corrosion prevention. Powder coatings have developed very rapidly over the last 40 years, and are currently sold in the Chinese market at around 100 million tons per year, and at a rate of around 10% by weight per year. The corrosion-resistant coating is mainly applied to corrosion resistance of building aluminum profiles, household appliances, furniture and oil and water delivery pipelines. Especially in the last years, with the increasing requirements of the country on environmental protection, the use of solvent-based coatings is greatly limited, and powder coatings are increasingly popular.
The traditional powder coating is prepared in the following way: the polyester, epoxy, pigment, filler and other additives are mixed uniformly and put into an extruder to be extruded to form a uniform substance. The polyester and epoxy are extruded together and are present simultaneously in the same powder coating particles.
The prior art CN109762440A discloses a low-temperature curing powder coating and a preparation method thereof, and the preparation method comprises the following steps: respectively premixing the component A (including epoxy resin and curing agent, the curing agent can be polyester resin) and the component B (including polyester resin and curing accelerator), melting and extruding, tabletting, cooling and crushing, then stirring and heating the A, B component at 50-80 ℃, bonding and granulating, and finally crushing and screening to obtain the low-temperature curing powder coating.
In the prior art, the curing temperature of the selected polyester resin or epoxy resin must be higher than the melt processing temperature, and because the melt processing temperature is constant, the prior art cannot produce and obtain ultralow-temperature powder coating, and the curing temperature of the low-temperature powder coating adopting the mode of producing the powder coating is at least 130 ℃. This is because, even if an extruder having the best cooling effect is used, the temperature of the discharge port of the extruder is generally 100 ℃ or higher, and thus, the epoxy resin and the polyester resin begin to undergo a crosslinking reaction during the extrusion process. The comparative document shows that although the a component (including epoxy resin) and the B component (including polyester resin) are extruded separately, the a component includes a curing agent, which is polyester resin or amino curing agent, so that the epoxy resin and the polyester resin start to undergo a crosslinking reaction during the extrusion of the a component. On the other hand, the component B contains a curing accelerator (corresponding to the catalyst of the application) in addition to the polyester resin, and the polyester resin and the curing accelerator are extruded together, so that the powder coating with ultralow temperature of 90-110 ℃ cannot be produced.
Disclosure of Invention
The invention aims to provide a solid mercaptan curing agent and a powder coating using the same, which can realize ultralow temperature curing at the temperature of less than 100 ℃ and can obtain a coating with excellent performance after curing.
The invention aims to provide a solid mercaptan curing agent and a powder coating adopting the same, and the powder coating can greatly improve the production efficiency.
The invention aims to solve the technical problem of providing a preparation method of a powder coating, which has the advantages of simple method, strong practicability and lower cost and can prepare the ultralow-temperature powder coating with the curing temperature lower than 100 ℃.
In order to achieve the technical effects, the invention provides a solid thiol curing agent, which comprises thiol and a solid substance containing an epoxy group, wherein the ratio of the active hydrogen equivalent of the thiol to the epoxy equivalent of the solid substance containing the epoxy group is (2-4): 1;
the solid mercaptan curing agent is prepared by heating mercaptan to 200 ℃ at 120 ℃, adding solid matters containing epoxy groups while stirring mercaptan liquid, then continuing stirring, and cooling.
As a modification of the above scheme, the thiol is one or more of a polythiol and a polythiol;
the solid matter containing the epoxy group is one or more of epoxy resin with the epoxy equivalent of 650-5500 and triglycidyl isocyanurate.
As a modification of the above scheme, the thiol is one or more of alkane polythiol, polyester polythiol, polyether polythiol and modified thiol.
As a modification of the above scheme, the thiol is one or more of pentaerythritol tetrakis (3-mercaptopropionate), sorbitol polymercaptoacetate, pentaerythritol tetramercaptoacetate, inositol hexakis (mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), 3-mercaptopropionate- [2,4, 6-trioxo-1, 3, 5-triazine-1, 3,5(2H,4H,6H) -ylidene ] tris-2, 1-ethanediol ester.
Correspondingly, the invention also provides a powder coating, which comprises 1-99wt% of the component A of the powder coating and 1-99wt% of the component B of the powder coating;
the component A of the powder coating is a powder coating obtained by extruding and crushing solid matter containing epoxy groups and an auxiliary A together or directly crushing the solid matter containing epoxy groups;
the component B of the powder coating is a powder coating obtained by extruding and crushing a solid mercaptan curing agent and an auxiliary agent B together, wherein the solid mercaptan curing agent is a product obtained by reacting mercaptan and a solid substance containing an epoxy group, and the ratio of the active hydrogen equivalent of the mercaptan to the epoxy equivalent of the solid substance containing the epoxy group is (2-4): 1.
as a modification of the above scheme, the powder coating component A is a powder coating with the particle size of 5-50 μm, which is obtained by extruding and crushing 30-100wt% of solid matter containing epoxy groups and 0-70wt% of assistant A together;
wherein the solid matter containing epoxy group selected by the powder coating component A is one or more of epoxy resin with the epoxy equivalent of 200-1500 and triglycidyl isocyanurate;
the assistant A comprises 0-5wt% of a flatting agent, 0-2 wt% of a degassing agent, 0-40 wt% of a pigment and 0-20 wt% of a filler.
As an improvement of the scheme, the powder coating component B is a powder coating with the particle size of 5-50 μm, which is obtained by extruding and crushing 30-80wt% of solid mercaptan curing agent and 20-70wt% of assistant B together;
wherein the solid mercaptan curing agent is prepared by heating mercaptan to 200 ℃ at 120 ℃, adding a solid substance containing an epoxy group while stirring a mercaptan liquid, continuing stirring, and cooling.
As a modification of the above scheme, the thiol is one or more of polythiol and polythiol;
the solid matter containing epoxy group selected by the powder coating component B is one or more of epoxy resin with the epoxy equivalent of 650-5500, epoxy acrylic resin and triglycidyl isocyanurate.
As a modification of the above scheme, the thiol is one or more of alkane polythiol, polyester polythiol, polyether polythiol and modified thiol.
As a modification of the above scheme, the thiol is one or more of pentaerythritol tetrakis (3-mercaptopropionate), sorbitol polymercaptoacetate, pentaerythritol tetramercaptoacetate, inositol hexakis (mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), 3-mercaptopropionate- [2,4, 6-trioxo-1, 3, 5-triazine-1, 3,5(2H,4H,6H) -ylidene ] tris-2, 1-ethanediol ester.
As an improvement of the scheme, the assistant B comprises 0-3 wt% of a leveling agent, 0-2 wt% of a degassing agent, 0-40 wt% of a pigment, 0-20 wt% of a filler and 0-5wt% of an assistant.
Correspondingly, the invention also discloses a preparation method of the powder coating, which comprises the following steps:
heating mercaptan to the temperature of 120-200 ℃, and adding solid matter containing epoxy groups while stirring mercaptan liquid, wherein the ratio of active hydrogen equivalent of the mercaptan to epoxy equivalent of the solid matter containing epoxy groups is (2-4): 1, continuously stirring, and cooling to obtain a solid mercaptan curing agent;
extruding and crushing the solid matter containing the epoxy group and the auxiliary A together, or directly crushing the solid matter containing the epoxy group into powder to obtain a component A of the powder coating;
extruding and crushing the solid mercaptan curing agent and the auxiliary agent B together to obtain a powder coating component B;
and mixing the powder coating A component and the powder coating B component to obtain a finished product.
The implementation of the invention has the following beneficial effects:
the invention provides a solid mercaptan curing agent, which comprises the following components in an equivalent ratio of (2-4): 1 and an epoxy group-containing solid substance, and is obtained by heating mercaptan to 120-200 ℃ and adding the epoxy group-containing solid substance with stirring of the mercaptan liquid, followed by continuing stirring and cooling. The solid mercaptan curing agent can be used for preparing ultralow temperature powder coating cured at ultralow temperature lower than 100 ℃, and a coating film with excellent performance can be obtained after the ultralow temperature powder coating is cured.
The invention provides a powder coating which comprises a powder coating A component and a powder coating B component, wherein the powder coating A component is a powder coating obtained by extruding and crushing solid substances containing epoxy groups and an auxiliary agent A together or directly crushing powder of the solid substances containing the epoxy groups, and the powder coating B component is a powder coating obtained by extruding and crushing solid thiol curing agents and the auxiliary agent B together. The powder coating can realize ultralow temperature curing at the temperature of lower than 100 ℃, and a coating film with excellent performance can be obtained after curing. In addition, in the process of curing the powder coating, the powder coating can be melted and leveled only, so that the rest crosslinking reaction can be carried out at the later stage, the production efficiency is greatly improved, the damage to various performances of the substrate due to long-time heating of the substrate due to curing can be avoided, and the powder coating is suitable for thermosensitive substrates.
The invention provides a method for preparing the powder coating, which comprises the steps of firstly preparing a component A of the powder coating, then preparing a component B of the powder coating from a solid mercaptan curing agent and an auxiliary agent B, and finally mixing the component A of the powder coating and the component B of the powder coating to obtain a finished product. The preparation method has the advantages of simple process and strong controllability, and is suitable for large-scale production.
Therefore, the solid mercaptan curing agent and the powder coating prepared by the solid mercaptan curing agent can realize ultralow-temperature curing at the temperature lower than 100 ℃, can be applied to heat-sensitive substrates such as medium-density fiberboard (MDF) and plastics, have strong decorative effect and cannot cause adverse effect on the performance of the heat-sensitive substrates.
Drawings
FIG. 1 is a flow chart of a process for preparing a powder coating according to the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below.
The invention provides a solid mercaptan curing agent, which comprises mercaptan and solid matter containing epoxy groups, wherein the ratio of active hydrogen equivalent of the mercaptan to epoxy equivalent of the solid matter containing epoxy groups is (2-4): 1.
the epoxy equivalent is the mass of an epoxy resin containing 1mol of epoxy groups. The active hydrogen equivalent means the mass of the mercaptan containing 1mol of active hydrogen.
In organic chemistry, a class of non-aromatic compounds containing a mercapto functional group (-SH) is referred to as thiols. Structurally, it can be seen that oxygen in a common alcohol is replaced by sulfur and then formed. Except that methyl mercaptan is a gas at room temperature, other mercaptans are liquids or solids. Thiol groups are the main manifestation of thiol chemistry. Wherein S-H bond relates to the bonding of the hybrid orbital composed of 3S/3p with larger sulfur and 1S orbital with smaller hydrogen, so that the S-H bond is weaker and the mercaptan has acidity. The active hydrogen in the-SH can perform affinity reaction with an epoxy group, so that the reactive hydrogen can be used as a curing agent of epoxy, and the reaction can be performed at room temperature.
The mercaptan is one or more of polyhydric mercaptan and polythiol. Preferably, the thiol is one or more of alkane polythiols, polyester polythiols, polyether polythiols, modified thiols, including, but not limited to, one or more of pentaerythritol tetrakis (3-mercaptopropionate), sorbitol polythioacetates, pentaerythritol tetramercaptoacetate, inositol hexakis (mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), 3-mercaptopropionic acid- [2,4, 6-trioxo-1, 3, 5-triazine-1, 3,5(2H,4H,6H) -ylidene ] tris-2, 1-ethanediol esters. More preferably, the mercaptan is pentaerythritol tetrakis (3-mercaptopropionate) or sorbitol polymercaptoacetate. The thiol has a characteristic of reacting with an epoxy group at room temperature, and thus, can play a role of reducing the reaction temperature in the present invention.
The solid matter containing the epoxy group is one or more of epoxy resin with the epoxy equivalent of 650-5500 and triglycidyl isocyanurate. The solid substance containing epoxy group has a high softening point, such as NEPS-907 manufactured by south Asia corporation, and the softening point is 120-130 ℃. After the solid substance containing epoxy groups has reacted with the liquid thiol, the softening point of the product may reach 60 ℃. If a resin with a too low softening point is used, the softening point of the product is too low and storage stability problems can occur.
The ratio of the active hydrogen equivalent of the mercaptan to the epoxy equivalent of the solid substance containing an epoxy group is (2-4): 1, in order to remove a part of active hydrogen in the mercaptan, the liquid mercaptan is converted into solid mercaptan containing active hydrogen, which can be further reacted with epoxy group.
Preferably, the ratio of the active hydrogen equivalents of the thiol to the epoxy equivalents of the solid material containing epoxy groups is (2-3): 1. more preferably, the ratio of the active hydrogen equivalent of the thiol to the epoxy equivalent of the solid substance containing an epoxy group is 2: 1.
further, the solid mercaptan curing agent is prepared by heating mercaptan to 120-200 ℃, adding solid matter containing epoxy groups while stirring mercaptan liquid, and the added solid matter containing epoxy groups needs to be crushed into powder with the particle size of 10-100 μm in advance, so that the solid matter containing epoxy groups can be rapidly melted and reacted with mercaptan without local coking. Then stirring continuously and cooling to obtain the product.
The solid mercaptan curing agent needs to heat mercaptan to 200 ℃ at 120 ℃ and can enable the added epoxy powder resin to be rapidly melted and reacted with mercaptan when the temperature of the mercaptan exceeds 120 ℃.
The invention reacts polythiol or polythiol with epoxy resin with higher softening point, and makes part of thiol react first, and leaves part of thiol as the reactive group of curing agent and epoxy resin of powder coating. The solid mercaptan curing agent can be used for preparing ultralow temperature powder coating, ultralow temperature curing of the ultralow temperature powder coating at a temperature lower than 100 ℃ can be realized, and a coating film with excellent performance can be obtained after curing.
Correspondingly, the invention also provides a powder coating, which comprises 1-99wt% of the powder coating A component and 1-99wt% of the powder coating B component, and is obtained by directly mixing the powder coating A component and the powder coating B component.
The particle size of the A component of the powder coating is preferably 5 to 50 μm, preferably 10 to 30 μm. The particle size of the B component of the powder coating is preferably 5 to 50 μm, preferably 10 to 30 μm.
Specifically, the component A of the powder coating is obtained by extruding and crushing an epoxy group-containing solid substance and the auxiliary A together, or directly crushing epoxy group-containing solid substance. Preferably, the powder coating component A is a powder coating with a particle size of 5-50 μm obtained by extruding and crushing 30-100wt% of solid matter containing epoxy groups and 0-70wt% of the assistant A together. Or the powder coating component A is prepared by directly powder-crushing solid substances containing epoxy groups.
Wherein the solid matter containing epoxy group selected for the powder coating component A is one or more of epoxy resin with the epoxy equivalent of 200-1500 and triglycidyl isocyanurate. The solid substance containing epoxy group selected for the powder coating component A has the characteristic of low softening point, and is easy to soften and level during melting to form a surface with good leveling property. Meanwhile, the paint has low softening point, low viscosity and fast molecular motion, and is easy to react with the group of the powder paint component B. In addition, the invention is mainly used for heat-sensitive substrates such as MDF, and therefore, the damage to the substrate caused by lower reaction temperature is small.
The epoxy resin of the component A of the powder coating is different from the epoxy resin of the component B of the powder coating in the selection principle, because the component A needs to be directly prepared into the powder coating, and the component A reacts with the component B at a later stage to form a final coating film, so that the lower the viscosity and the softening point of the powder coating are, the better the final coating film is. While the epoxy of component B needs to be reacted first with liquid mercaptan, the reaction with liquid mercaptan requires that the resulting product be solid, and the higher the softening point and viscosity of the epoxy the better, so that a solid product is produced. If the viscosity and softening point are too low, no solid product can be formed.
It should be noted that, the solid substances containing epoxy groups selected for the component a and the component B of the powder coating are different in epoxy equivalent and softening point, and those skilled in the art can select epoxy resins or related substances of different manufacturers and different types according to the epoxy equivalent and the softening point.
The assistant A comprises 0-5wt% of a leveling agent, 0-2 wt% of a degassing agent, 0-40 wt% of a pigment and 0-20 wt% of a filler, but is not limited thereto.
The component B of the powder coating is a powder coating obtained by extruding and crushing a solid mercaptan curing agent and an auxiliary agent B together, and preferably, the component B of the powder coating is a powder coating with the particle size of 5-50 mu m obtained by extruding and crushing 30-80wt% of the solid mercaptan curing agent and 20-70wt% of the auxiliary agent B together.
In organic chemistry, a class of non-aromatic compounds containing a mercapto functional group (-SH) is referred to as thiols. Structurally, it can be seen that oxygen in a common alcohol is replaced by sulfur and then formed. Except that methyl mercaptan is a gas at room temperature, other mercaptans are liquids or solids. Thiol groups are the main manifestation of thiol chemistry. Wherein S-H bond relates to the bonding of the hybrid orbital composed of 3S/3p with larger sulfur and 1S orbital with smaller hydrogen, so that the S-H bond is weaker and the mercaptan has acidity. The active hydrogen in the-SH can perform affinity reaction with an epoxy group, so that the reactive hydrogen can be used as a curing agent of epoxy, and the reaction can be performed at room temperature.
The mercaptan is one or more of polyhydric mercaptan and polythiol. Preferably, the thiol is one or more of alkane polythiols, polyester polythiols, polyether polythiols, modified thiols, including, but not limited to, one or more of pentaerythritol tetrakis (3-mercaptopropionate), sorbitol polythioacetates, pentaerythritol tetramercaptoacetate, inositol hexakis (mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), 3-mercaptopropionic acid- [2,4, 6-trioxo-1, 3, 5-triazine-1, 3,5(2H,4H,6H) -ylidene ] tris-2, 1-ethanediol esters. More preferably, the mercaptan is pentaerythritol tetrakis (3-mercaptopropionate) or sorbitol polymercaptoacetate. The thiol has a characteristic of reacting with an epoxy group at room temperature, and thus, can play a role of reducing the reaction temperature in the present invention.
The solid matter containing the epoxy group is one or more of epoxy resin with the epoxy equivalent of 650-5500 and triglycidyl isocyanurate. The solid substance containing epoxy group has a high softening point, such as NEPS-907 manufactured by south Asia corporation, and the softening point is 120-130 ℃. After the solid substance containing epoxy groups has reacted with the liquid thiol, the softening point of the product may reach 60 ℃. If a resin with a too low softening point is used, the softening point of the product is too low and storage stability problems can occur.
The ratio of the active hydrogen equivalent of the mercaptan to the epoxy equivalent of the solid substance containing an epoxy group is (2-4): this is to convert a liquid thiol into a solid thiol containing active hydrogens, which can be reacted further with epoxide groups.
Preferably, the ratio of the active hydrogen equivalent of the thiol to the epoxy equivalent of the solid substance containing an epoxy group is (2-3): 1. more preferably, the ratio of the equivalent of active hydrogen of the thiol to the equivalent of epoxy of the solid substance containing an epoxy group is 2: 1.
further, the solid mercaptan curing agent is prepared by heating mercaptan to 120-200 ℃, adding solid matter containing epoxy groups while stirring mercaptan liquid, and the added solid matter containing epoxy groups needs to be crushed into powder with the particle size of 10-100 μm in advance, so that the solid matter containing epoxy groups can be rapidly melted and reacted with mercaptan without local coking. Then stirring continuously and cooling to obtain the product.
The solid mercaptan curing agent needs to heat mercaptan to 200 ℃ at 120 ℃ and can enable the added epoxy powder resin to be rapidly melted and reacted with mercaptan when the temperature of the mercaptan exceeds 120 ℃.
The invention reacts polythiol or polythiol with epoxy resin with higher softening point, and makes part of thiol react first, and leaves part of thiol as the reactive group of curing agent and epoxy resin of powder coating. The solid mercaptan curing agent can be used for preparing ultralow temperature powder coating, ultralow temperature curing of the ultralow temperature powder coating at a temperature lower than 100 ℃ can be realized, and a coating film with excellent performance can be obtained after curing.
The assistant B comprises 0-3 wt% of a leveling agent, 0-2 wt% of a degassing agent, 0-40 wt% of a pigment, 0-20 wt% of a filler and 0-5wt% of an assistant, but is not limited thereto.
In the assistant A and the assistant B, the leveling agent can promote the powder coating to form a flat, smooth and uniform coating film in the curing and film-forming process, improve the leveling property and uniformity of the powder coating, reduce the possibility of generating pits, spots and stains, increase the coverage property and enable the film to be formed uniformly and naturally.
The degassing agent can eliminate bubbles formed in the curing film-forming process of the powder coating, and ensure that the powder coating forms a flat, smooth and uniform coating film in the curing film-forming process.
The filler is an inorganic compound with certain rigidity, strength and covering power, can improve the rigidity and strength of the powder coating, and can save the formula cost. Preferably, the filler is one or more of barium sulfate, calcium carbonate, talcum powder, kaolin, silicon micropowder and mica powder.
The barium sulfate has stable chemical properties, fine particle size dispersion and small influence on gloss, and the prepared powder coating has ideal gloss leveling; the calcium carbonate has large specific surface area and large oil absorption, and is generally used in texture powder; the talcum powder has a flaky structure, has certain thixotropy, has larger influence on the melt flowability of a powder coating, is low in price, has large oil absorption, is commonly used in texture powder, and improves the scratch resistance of the coating; mica powder is a complex silicate composition which can improve the hardness and scratch resistance of the coating. Fillers such as silica powder and mica powder can provide good hardness and scratch resistance.
The pigment can endow the coating with colorful color, improve the mechanical and chemical properties of the coating and reduce the cost of the coating. The pigment can be one or more of coloring pigment, metallic pigment, functional pigment and extender pigment. Among them, extender pigments have a wide range of variation in other properties such as relative density, volume value, particle shape, particle size distribution, oil absorption, chemical activity, etc., and they are different in the size and shape of the constituent particles, so that they exhibit very small hiding power in high-gloss and semi-gloss coatings, and have the effects of reducing formulation cost and controlling gloss, etc.
Correspondingly, as shown in fig. 1, the invention also discloses a preparation method of the powder coating, which comprises the following steps:
s101, heating mercaptan to the temperature of 120-200 ℃, and adding a solid substance containing an epoxy group while stirring a mercaptan liquid, wherein the ratio of active hydrogen equivalent of the mercaptan to epoxy equivalent of the solid substance containing the epoxy group is (2-4): 1, continuously stirring, and cooling to obtain a solid mercaptan curing agent;
s102, extruding and crushing the solid matter containing the epoxy group and the auxiliary A together, or directly crushing the solid matter containing the epoxy group into powder to obtain a component A of the powder coating;
s103, extruding and crushing the solid mercaptan curing agent and the auxiliary agent B together to obtain a powder coating component B;
and S104, mixing the powder coating A component and the powder coating B component to obtain a finished product.
In the preparation process of the existing powder coating, solid epoxy resin and curing agent are extruded by an extruder, the extrusion temperature is generally 120-140 ℃, epoxy and mercaptan can react at room temperature, if the epoxy resin and the curing agent are extruded by the extruder, a crosslinking reaction can occur in the extrusion process, and the ultralow temperature powder coating cannot be prepared.
The component A of the powder coating and the component B of the powder coating are prepared separately, and specifically, the solid matter containing epoxy groups and the auxiliary A are extruded and crushed together, or the solid matter containing epoxy groups is directly subjected to powder crushing to prepare the component A of the powder coating. The epoxy resin with a low softening point and the auxiliary agent are extruded in advance to form the powder coating.
And then preparing a component B of the powder coating from a solid mercaptan curing agent and an auxiliary agent B, wherein polythiol or polythiol reacts with the solid substance with the epoxy group and a high softening point, and a part of mercaptan is reacted to leave a part of mercaptan as a reaction group of the curing agent and the solid substance with the epoxy group of the powder coating. The reaction of the thiol with the high softening point epoxy is here the key point. Particularly, the softening point of the solid substance containing epoxy groups needs to be as high as possible, and the prepared solid thiol can not be liquid or a substance with a very low softening point, so that the powder coating can not be prepared, or the prepared powder coating has the problems of low glass transition temperature, poor storage stability and the like.
And finally, only mixing the powder coating A component and the powder coating B component to obtain a finished product. The preparation method has the advantages of simple process and strong controllability, and is suitable for large-scale production.
Because the reaction of epoxy and mercaptan can be reacted at room temperature, but in the powder coating, a uniform coating film can be formed only after melting, so that the ultralow temperature curing of less than 100 ℃ can be realized only by selecting the epoxy resin with the softening point of less than 80 ℃ and preparing the ultralow temperature curing powder coating by the method.
In addition, because the reaction of epoxy and mercaptan can be carried out at room temperature, the residual crosslinking reaction can be carried out at a later stage only by melting and leveling the powder coating in the process of curing the coating, and thus, the production efficiency can be greatly improved.
Furthermore, the powder coating can avoid the damage to various properties of the substrate caused by long-time heating of the substrate due to the need of curing in production. Therefore, the powder coating can be applied to Medium Density Fiberboard (MDF), plastics and other heat-sensitive substrates. Thereby realizing curing at ultralow temperature, which is lower than 100 ℃.
It should be noted that, in the preparation method of the powder coating, the technical details of the thiol, the epoxy resin, the powder coating a component, the powder coating B component, and the like are the same as those described above, and are not described herein again.
The invention is further illustrated by the following specific examples
Example 1
Preparation of powder coating A component:
weighing the epoxy resin with the epoxy equivalent of 550-600, the flatting agent, the benzoin and the titanium dioxide according to the following proportion:
the mixed material was placed in an extruder with a set temperature of 120 ℃. The extruded material is put into a coffee mill to be smashed and sieved, and the grain size is controlled to be about 15 mu m.
(II) preparing a component B of the powder coating:
1. preparation of solid thiol curing agent:
24.4g of pentaerythritol tetrakis (3-mercaptopropionate) and 150g of an epoxy resin having an epoxy equivalent of 1500-2000 (YD 017 Kahn chemical) were prepared. That is, the ratio of the active hydrogen equivalent of pentaerythritol tetrakis (3-mercaptopropionate) to the epoxy equivalent of the epoxy resin was 2: 1.
crushing the epoxy resin into powder; the average particle size is 30-50 μm.
Putting pentaerythritol tetrakis (3-mercaptopropionate) into a three-neck flask, heating to 180 ℃, gradually adding epoxy resin powder into the flask under the condition of stirring, discharging the product in the flask after 10 minutes, cooling and smashing to obtain the solid thiol curing agent.
2. The solid mercaptan curing agent, the flatting agent, the benzoin and the titanium dioxide are weighed according to the following proportion:
the mixed material was placed in an extruder with a set temperature of 120 ℃. The extruded material is put into a coffee mill to be smashed and sieved, and the grain size is controlled to be about 15 mu m.
3. 30g of powder coating A component and 70g of powder coating B component were mixed to obtain a finished product.
Example 2
Preparation of powder coating A component:
weighing the epoxy resin with the epoxy equivalent of 550-600, the flatting agent, the benzoin and the titanium dioxide according to the following proportion:
the mixed material was placed in an extruder with a set temperature of 120 ℃. The extruded material is put into a coffee mill to be smashed and sieved, and the grain size is controlled to be about 20 mu m.
(II) preparation of a component B of the powder coating:
1. preparation of solid thiol curing agent:
50g of EH-316 thiol of Asahi electro chemical industry, 137g of SH equivalent 131, 137g of epoxy resin having a viscosity (25 ℃) of 500 mPaS and 300g of epoxy resin having an epoxy equivalent of 3000 (KD-9010 manufactured by China) were prepared. That is, the ratio of the active hydrogen equivalents of EH-316 thiol to the epoxy equivalents of the epoxy resin is 4: 1.
Crushing the epoxy resin into powder;
placing EH-316 mercaptan into a three-neck flask, heating to 200 ℃, gradually adding epoxy resin powder into the flask under the condition of stirring, discharging the product in the flask after 10 minutes, cooling and smashing to obtain the solid mercaptan curing agent.
2. Solid mercaptan curing agent, flatting agent, benzoin and titanium dioxide are weighed according to the following proportion:
the mixed material was placed in an extruder with a set temperature of 120 ℃. The extruded material is put into a coffee mill to be smashed and sieved, and the grain size is controlled to be about 15 mu m.
3. 100g of powder coating A component and 20g of powder coating B component were mixed to obtain a finished product.
Example 3
Preparation of powder coating A component:
triglycidyl isocyanurate TGIC is crushed to the particle size of 3-15 mu m.
(II) preparation of a component B of the powder coating:
1. preparation of solid thiol curing agent:
27g of EH-316 thiol of Asahi electro chemical industry, 137g of SH equivalent 131, 137g of epoxy resin having a viscosity (25 ℃) of 500 mPaS and 300g of epoxy resin having an epoxy equivalent of 3000 (KD-9010 manufactured by China) were prepared. That is, the ratio of the active hydrogen equivalents of EH-316 thiol to the epoxy equivalents of the epoxy resin is 2: 1.
Crushing the epoxy resin into powder;
placing EH-316 mercaptan into a three-neck flask, heating to 200 ℃, gradually adding epoxy resin powder into the flask under the condition of stirring, discharging the product in the flask after 10 minutes, cooling and smashing to obtain the solid mercaptan curing agent.
2. The solid mercaptan curing agent, the flatting agent, the benzoin and the titanium dioxide are weighed according to the following proportion:
the mixed material was placed in an extruder with a set temperature of 120 ℃. The extruded material is put into a coffee mill to be smashed and sieved, and the grain size is controlled to be about 15 mu m.
3. 22g of powder coating A component and 100g of powder coating B component were mixed to give the finished product.
The powder coatings obtained in examples 1 to 3 were subjected to technical tests and the results were as follows:
(1) the powder coatings of examples 1 to 3 were placed in a gelator set at 100 ℃, 90 ℃ and 80 ℃ and the scorch times were measured:
| item | Example 1 | Example 2 | Example 3 |
| Coking time (100 ℃ C.) | 220 seconds | 131 seconds | 173 seconds |
| Coking time (90 ℃ C.) | 308 seconds | 236 seconds | 272 seconds |
| Coking time (80 ℃ C.) | 437 seconds | 365 seconds | 391 second |
From the above, the curing reaction of the present invention can be carried out at 100 ℃ and the reaction speed is very high. Furthermore, the present invention can be carried out at temperatures lower than 100 ℃ such as 90 ℃ and 80 ℃ and the reaction rate is relatively high.
(2) The powder coatings of examples 1-3 were applied to an aluminum panel by electrostatic spray coating, placed in an oven, baked at 100 ℃ for 10 minutes, removed from the aluminum panel, and cooled to form a powder coating on the surface of the aluminum panel. The powder coating formed by the method is technically detected, and the results are as follows:
as can be seen from the above, the powder coating formed on the metal plate by the powder coating of the present invention was wiped with acetone 50 times, and no bottom exposure occurred, thus confirming complete curing by reaction. Moreover, the gloss of the powder coating is 67-78% tested by a gloss meter, which proves that the powder coating can obtain a plane effect on a metal plate. In addition, the coating has good adhesion, high pencil hardness and good service performance.
(3) The powder coatings of examples 1-3 were sprayed onto medium density fiberboard using an electrostatic gun and placed in an infrared curing oven set at 100 ℃ for 3 minutes, after which the board was removed and a powder coating was formed on the surface of the medium density fiberboard. The powder coating formed by the method is technically detected, and the results are as follows:
| item | Examples1 | Example 2 | Example 3 |
| Wiping with acetone 50 times | Without bottom exposure | Without bottom exposure | Without bottom exposure |
| Adhesion force | Level 0 | Level 0 | Level 0 |
| Hardness of pencil | HB | HB | HB |
| Gloss of | 71％ | 75％ | 81％ |
As can be seen from the above, the powder coating formed by the powder coating of the invention on a heat-sensitive substrate such as a medium-density fiberboard and the like is wiped for 50 times by using acetone, and the phenomenon of bottom exposure is avoided, thus proving that the reaction curing is complete. Furthermore, the gloss measured by a gloss meter was 78 to 81, which confirmed that the flat effect was obtained on the medium density fiberboard. In addition, the coating has good adhesion, high pencil hardness and good service performance.
Note that the gloss is the gloss of the coating surface measured at an incident angle of 60 °.
The detection basis of the adhesive force is GB9286, 0-5 shows that the adhesive force is from good to bad, and the specific grading standard is described as follows: 0-the cut edge was completely smooth with no peeling.
Pencil hardness was according to ASTM 3363.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.
Claims (7)
1. A solid thiol curing agent, comprising a thiol and an epoxy group-containing solid substance, wherein the ratio of active hydrogen equivalents of the thiol to epoxy equivalents of the epoxy group-containing solid substance is (2-4): 1;
the solid mercaptan curing agent is prepared by heating mercaptan to the temperature of 120-200 ℃, adding a solid substance containing an epoxy group under the condition of stirring mercaptan liquid, continuing stirring, and cooling;
wherein the solid matter containing the epoxy group is one or more of epoxy resin with the epoxy equivalent of 650-5500 and triglycidyl isocyanurate;
the mercaptan is one or more of pentaerythritol tetra (3-mercaptopropionate), sorbitol polymercaptoacetate, pentaerythritol tetramercaptoacetate, inositol hexa (mercaptopropionate) and 3-mercaptopropionic acid- [2,4, 6-trioxo-1, 3, 5-triazine-1, 3,5(2H,4H,6H) -ylidene ] tri-2, 1-ethanediol ester.
2. A powder coating comprising 1 to 99wt% of a powder coating a component and 1 to 99wt% of a powder coating B component;
the component A of the powder coating is a powder coating obtained by extruding and crushing solid matter containing epoxy groups and an auxiliary A together or directly crushing solid matter containing epoxy groups; the solid matter containing the epoxy group selected by the component A of the powder coating is one or more of epoxy resin with the epoxy equivalent of 200-1500 and triglycidyl isocyanurate;
the component B of the powder coating is a powder coating obtained by extruding and crushing a solid mercaptan curing agent and an auxiliary agent B together, wherein the solid mercaptan curing agent is a product obtained by reacting mercaptan and a solid substance containing an epoxy group, and the ratio of the active hydrogen equivalent of the mercaptan to the epoxy equivalent of the solid substance containing the epoxy group is (2-4): 1;
the solid mercaptan curing agent is prepared by heating mercaptan to the temperature of 120-200 ℃, adding a solid substance containing an epoxy group under the condition of stirring mercaptan liquid, continuing stirring, and cooling; the solid matter containing epoxy group selected by the component B of the powder coating is one or more of epoxy resin with the epoxy equivalent of 650-5500 and triglycidyl isocyanurate;
the mercaptan is one or more of pentaerythritol tetra (3-mercaptopropionate), sorbitol polymercaptoacetate, pentaerythritol tetramercaptoacetate, inositol hexa (mercaptopropionate) and 3-mercaptopropionic acid- [2,4, 6-trioxo-1, 3, 5-triazine-1, 3,5(2H,4H,6H) -ylidene ] tri-2, 1-ethanediol ester.
3. The powder coating according to claim 2, wherein the powder coating component A is a powder coating having a particle size of 5 to 50 μm obtained by extrusion-pulverizing 30 to 100% by weight of an epoxy group-containing solid substance together with 0 to 70% by weight of the assistant A.
4. A powder coating according to claim 3, wherein the assistant a comprises 0 to 5wt% of a leveling agent, 0 to 2 wt% of a degassing agent, 0 to 40 wt% of a pigment, and 0 to 20 wt% of a filler.
5. The powder coating according to claim 2, wherein the powder coating component B is a powder coating having a particle size of 5 to 50 μm obtained by extrusion-pulverizing 30 to 80wt% of a solid thiol curing agent together with 20 to 70wt% of an auxiliary B.
6. The powder coating according to claim 5, wherein the assistant B comprises 0 to 3 wt% of a leveling agent, 0 to 2 wt% of a degassing agent, 0 to 40 wt% of a pigment, 0 to 20 wt% of a filler, and 0 to 5wt% of an assistant.
7. A method of preparing a powder coating, comprising:
heating mercaptan to the temperature of 120-200 ℃, and adding solid matter containing epoxy groups while stirring mercaptan liquid, wherein the ratio of active hydrogen equivalent of the mercaptan to epoxy equivalent of the solid matter containing epoxy groups is (2-4): 1, continuously stirring, and cooling to obtain a solid mercaptan curing agent;
extruding and crushing the solid matter containing the epoxy group and the auxiliary A together, or directly crushing the solid matter containing the epoxy group into powder to obtain a component A of the powder coating;
extruding and crushing the solid mercaptan curing agent and the auxiliary agent B together to obtain a powder coating component B;
mixing the powder coating A component and the powder coating B component to obtain a finished product;
wherein the solid matter containing epoxy group selected by the component A of the powder coating is one or more of epoxy resin with the epoxy equivalent of 200-1500 and triglycidyl isocyanurate;
the solid matter containing epoxy group selected by the component B of the powder coating is one or more of epoxy resin with the epoxy equivalent of 650-5500 and triglycidyl isocyanurate;
the mercaptan is one or more of pentaerythritol tetra (3-mercaptopropionate), sorbitol polymercaptoacetate, pentaerythritol tetramercaptoacetate, inositol hexa (mercaptopropionate) and 3-mercaptopropionic acid- [2,4, 6-trioxo-1, 3, 5-triazine-1, 3,5(2H,4H,6H) -ylidene ] tri-2, 1-ethanediol ester.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011543547.8A CN112778501B (en) | 2020-12-24 | 2020-12-24 | Solid mercaptan curing agent, powder coating and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011543547.8A CN112778501B (en) | 2020-12-24 | 2020-12-24 | Solid mercaptan curing agent, powder coating and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112778501A CN112778501A (en) | 2021-05-11 |
| CN112778501B true CN112778501B (en) | 2022-05-20 |
Family
ID=75751977
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011543547.8A Active CN112778501B (en) | 2020-12-24 | 2020-12-24 | Solid mercaptan curing agent, powder coating and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112778501B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113150728A (en) * | 2021-06-08 | 2021-07-23 | 湖南创瑾技术研究院有限公司 | Heat-conducting pouring sealant and preparation method thereof |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6540942B2 (en) * | 2000-11-09 | 2003-04-01 | Cognis Corporation | Nonaqueous compositions and additives therefor |
| CN1934158B (en) * | 2004-01-22 | 2010-06-09 | 味之素株式会社 | One-component epoxy resin composition |
| WO2015002301A1 (en) * | 2013-07-05 | 2015-01-08 | 味の素株式会社 | Thiol-group-containing compound and single-liquid epoxy resin composition |
| CN106947357A (en) * | 2017-03-21 | 2017-07-14 | 运研材料科技（上海）有限公司 | A kind of quick-setting ceramic particle abrasion-resistant coating material of energy |
| CN106947364A (en) * | 2017-04-26 | 2017-07-14 | 安徽联硕实业有限公司 | A kind of epoxide powder coating and preparation method thereof |
| CN107814915B (en) * | 2017-11-17 | 2020-10-23 | 江苏苏博特新材料股份有限公司 | Modifying agent of coating, modified epoxy resin coating, and preparation method and application thereof |
| CN108753101B (en) * | 2018-05-07 | 2021-02-26 | 江门市新会区新日旭电子材料有限公司 | Epoxy powder coating and application thereof |
-
2020
- 2020-12-24 CN CN202011543547.8A patent/CN112778501B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN112778501A (en) | 2021-05-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2405522C (en) | Powder coating composition, method for the curing thereof, and articles derived therefrom | |
| JP5010806B2 (en) | Powder coating composition and method for coating aluminum wheel | |
| US7691451B2 (en) | Composite powder coating material, process for production thereof and method for the color matching of powder coating material | |
| EP1852453B1 (en) | Acid functional phosphorus-containing polyester powder compositions and powder coatings made therefrom | |
| EP2342289B1 (en) | Two component heat-curable powder coating composition comprising hydroquinone | |
| KR101818348B1 (en) | high-gloss high-leveling powder coating composition | |
| CN112300667B (en) | Powder coating and preparation method thereof | |
| EA031640B1 (en) | 2k thermosetting powder coating compositions | |
| CN112778501B (en) | Solid mercaptan curing agent, powder coating and preparation method thereof | |
| US20040157961A1 (en) | Curable coating powders and powder coatings formed therefrom | |
| CN114806353B (en) | Powder coating composition | |
| CN109517494B (en) | High-hardness epoxy-polyester powder coating composition, preparation method and application thereof | |
| CA3068268A1 (en) | Epoxidized oil and resin compositions | |
| KR20190053403A (en) | Powder coating composition | |
| KR100236392B1 (en) | Powder paint compositions | |
| CN107177289B (en) | One-component coating composition and substrates coated therewith | |
| CN114736604B (en) | High-solid-content DTM polyurethane coating and preparation method thereof | |
| JP4925567B2 (en) | Two-component thermosetting resin composition, coating film forming method, and article to be coated | |
| CN110256949A (en) | A kind of high adhesion force extinction powder coating and preparation method thereof | |
| US3687879A (en) | Coating composition of an epoxy resin,an aromatic sulfonamide,a silicone resin and a cross-linking catalyst | |
| EP3191558A1 (en) | Powder coating | |
| JP2008184523A (en) | Primer and coating method using the same | |
| JP3994493B2 (en) | Coating composition, coating finishing method, and coated article | |
| KR102672986B1 (en) | Metallic powder coating composition for strengthening alkali resistance | |
| JP4646545B2 (en) | Two-component thermosetting resin composition, coating film forming method, and article to be coated |
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 |