CN108659208A - A kind of preparation method and applications of difunctional polyester resin - Google Patents

Abstract

The invention discloses a bifunctional polyester resin. The polyester resin has two functional groups of carboxyl end and hydroxyl end, its acid value is 10-56 mgKOH/g, its hydroxyl value is 33-53 mgKOH/g, and its viscosity at 200°C is 2400～6000mPa.s, number average molecular weight is 2000～5000, glass transition temperature is 50～65℃, it is mainly formed by melt polymerization of the following mole percentage components: diol 30～60mol%, diol 35-50 mol% of a basic acid, 0.05-3.5 mol% of a branching agent, 2-20 mol% of an acidolysis agent, and 0.01-0.20 mol% of an esterification catalyst. The polyester resin has outstanding comprehensive performance in leveling performance, mechanical performance, weather resistance, boiling resistance, heat resistance, solvent resistance and thermal transfer performance. The preparation method and application of the above-mentioned bifunctional polyester resin are also disclosed.

Description

A kind of preparation method and application of bifunctional polyester resin

technical field

The invention belongs to the technical field of polyester resins, and in particular relates to a preparation method and application of a bifunctional polyester resin.

Background technique

The carboxyl-terminated polyester resin is cured with TGIC, T-105 and epoxy, and the hydroxyl-terminated polyester resin is cured with blocked isocyanate. The polyester resins of the two systems have their own advantages. After the carboxyl-terminated polyester resin and the curing agent are cured to form a film, the overall performance is relatively balanced, the price is low, and the application is wide; while the hydroxyl-terminated polyester resin has excellent properties after being cured with isocyanate. It has outstanding properties such as leveling, solvent resistance and weather resistance, but due to price and other factors, the polyester resins currently used in the market are mainly carboxyl-terminated polyester resins. However, with the improvement of people's living standards, the requirements for the comprehensive performance of coatings are also getting higher and higher, and there are more or less partial performance defects in carboxyl-terminated polyester resins or hydroxyl-terminated polyesters. For this reason, how to break through the technical bottleneck and develop polyester resins with excellent comprehensive properties is particularly important.

Pure polyester powder coatings are divided into polyester/TGIC (triglycidyl isocyanuric acid value) type and polyester/HAA (β-hydroxyalkylamide) type according to different curing systems, among which polyester/TGIC type Pure polyester powder coating is the earliest powder coating used in the field of weather resistance. Its curing agent is TGIC, which is a triglycidyl isocyanurate compound. It has the following three characteristics: (1) It has three functions: Reactive active groups can obtain higher crosslinking density during curing. Due to the rigid ring structure, the hardness of the cured coating film is higher; (2) The molecular skeleton after curing has unsaturated double bonds, so it is weather-resistant (3) The nitrogen content in the molecule is as high as 14%, and it has certain self-extinguishing and flame retardancy. When curing, the carboxyl group in the saturated carboxyl polyester and the epoxy group in TGIC are cross-linked to form a film. Its advantages are obvious, such as excellent mechanical properties, good chemical resistance, and yellowing phenomenon is not easy to occur when baking at high temperature. The weather resistance is also very good, so it was widely used in the 20th century. However, studies in recent years have found that TGIC monomer has strong toxicity to animal cells, can cause genetic damage to animals, affect male fertility and cause cell variation and is hereditary, so its use has been limited in recent years. On the other hand, TGIC A higher curing temperature is required, so more energy is consumed during coating and curing. As people gradually pay attention to issues such as environmental protection and energy saving, the use of TGIC systems is more and more restricted. Taking Europe as an example, Europe once used TGIC as the main weather-resistant curing agent, which once occupied about 70% of the European weather-resistant powder coating market. However, since the European Community (now the European Union) officially listed it as a highly toxic substance in the mid-1990s and stipulated that any product using it must be printed with hazard signs, its market share in weather-resistant powder coatings has been less than 25%. , it is also basically extinct in Australia.

β-Hydroxyalkylamide is a new type of carboxyl resin curing agent with almost no toxicity. Its application in Europe and America is on the rise. It has the following characteristics: (1) fast curing speed and energy saving; (2) curing agent dosage (3) Only water molecules are released during curing, which will not pollute the environment. The coating film cured with β-hydroxyalkylamide has excellent outdoor weather resistance, and the physical and mechanical properties and chemical resistance of the coating are relatively outstanding. It should be said that this system is a new type of curing system with great development prospects. Great potential for development.

At present, the powder coating market is developing rapidly. Not only building materials, furniture materials and other fields have been widely used, but also many daily necessities and household products have been coated with powder coatings around us. Of course, the safety of these coatings needs to be paid attention to. Among them, the thermos cup is used as a daily drinking tool for people. The effect and quality of its surface treatment and coating are not only related to the appearance and performance of the product, but also related to the health of users. Different from coatings in other fields, the food industry poses unprecedented challenges to powder coatings in terms of safety. Countries have formulated relevant health and safety regulations, product standards and implementation rules, and developed food-grade coatings that are safe for human health. my country has standards such as "Food Sanitation Law of the People's Republic of China", GB 4805 "Hygienic Standards for Epoxy Phenolic Coatings on the Inner Walls of Food Cans", GB7105 "Hygienic Standards for Perchlorethylene Inner Wall Coatings of Food Containers" and other standards, and developed food-grade solvent-based coatings and water-based coatings . The U.S. Food and Drug Administration (FDA) formulates regulations on food and packaging. The United States and the European Union implement FDA regulations, requiring the migration of surface coatings of household appliances, food processing machinery, and daily necessities in contact with food to meet the technical indicators specified in US FDA 21 CFR 175.300, and use food-grade coatings. As a drinking water product in daily life, the thermos cup has higher requirements for its safety. Therefore, there is a large gap in the application of powder coatings in the thermos cup market. If this gap can be filled, it will definitely bring economic benefits and technological revolution.

Due to the particularity of the object of use, the use of powder coatings for thermos cups has very stringent requirements and faces many problems. For example, the content of bisphenol A in the existing finished powder cannot meet the relevant standards. Bisphenol A, also known as BPA, is used industrially to synthesize materials such as polycarbonate (PC) and epoxy resin. Since the 1960s, it has been used to make plastic (milk) bottles, suction cups for children, and coating the inside of food and beverage (milk powder) cans. BPA is everywhere, from mineral water bottles, medical equipment to the inside of food packaging. Every year, 27 million tons of plastic containing BPA are produced worldwide. But BPA can also lead to endocrine disorders, threatening the health of fetuses and children. Obesity from cancer and metabolic disorders is also thought to be involved. The European Union believes that baby bottles containing bisphenol A can induce precocious puberty, and since March 2, 2011, the production of baby bottles containing the chemical substance bisphenol A (BPA) has been banned. Therefore reducing the content of bisphenol A in the product is the key to improving product safety. In addition, due to the material and use characteristics of the thermos cup, the powder coating on its surface is likely to cause problems such as poor adhesion, poor temperature resistance, poor water boiling resistance and wear resistance.

In order to solve the problems of poor weather resistance and poor adhesion of coatings, Chinese patent application 201610226583.9 discloses a water-based transparent weather-resistant coating for thermos cups, the components of which include: 20-50 parts of amino resin, hydroxyacrylic acid 10-30 parts of resin, 2-5 parts of epoxy soybean oil, 5-10 parts of fluorocarbon emulsion, 5-10 parts of styrene-acrylic emulsion, 2-10 parts of nano-pigment, 1.5-3 parts of nano-titanium dioxide, tourmaline powder 1 -2 parts, 1-3 parts of basalt fiber, 15-30 parts of deionized water, 0.5-1 part of coupling agent, 0.5-1.5 parts of other additives, the coating has good weather resistance, good coating performance, strong adhesion, Good color and gloss retention, but the paint uses a variety of emulsions, which contain a certain amount of organic solvents, and the volatilization of organic solvents will cause a certain degree of pollution.

Chinese patent application 201210486310.X discloses the preparation method of water-based environmentally friendly color-changing paint for thermos cups. The weight ratios of the raw material components disclosed are: water acrylic resin 35-45, ethylene glycol monobutyl ether 4-6, n-butanol 4 -6, color changing powder 4-6, glycerin 1-2, diffusing agent MF1-2, silane coupling agent Z60400.2-0.3, dimethyl silicone oil 0.20-0.30, deionized water 40-45, the coating is based on water The thinner is non-toxic and tasteless, and the paint film has strong adhesion. However, the paint contains organic solvents such as glycerin, which are volatile and will still have a certain degree of impact on the environment.

Since the existing coatings for thermos cups have a certain degree of impact on the environment, and the coatings have poor boiling and acid and alkali resistance properties, the industry is in urgent need of preparing an environmentally friendly coating that has good boiling, acid and alkali resistance, antibacterial and unsuitable. Special powder coating for BPA thermos cups.

Contents of the invention

The object of the present invention is to provide a kind of bifunctional polyester resin, which has outstanding performance in leveling performance, mechanical performance, weather resistance, boiling resistance, heat resistance, solvent resistance and thermal transfer performance. Comprehensive performance

The object of the present invention is also to provide the preparation method of above-mentioned bifunctional polyester resin.

The first object of the present invention is achieved through the following technical scheme: a kind of bifunctional polyester resin, described polyester resin has two kinds of functional groups of terminal carboxyl group and terminal hydroxyl group, its acid value is 10～56mgKOH/g, hydroxyl The value is 33-53mgKOH/g, the viscosity at 200°C is 2400-6000mPa·s, the number-average molecular weight is 2000-5000, and the glass transition temperature is 50-65°C. It is mainly composed of the following mole percentage components through melt polymerization Preparation: 30-60 mol% of dibasic alcohol, 35-50 mol% of dibasic acid, 0.05-3.5 mol% of branching agent, 2-20 mol% of acidolysis agent, and 0.01-0.20 mol% of esterification catalyst.

In each component of the bifunctional polyester resin: the molar ratio of the total molar weight of the dihydric alcohol and the branching agent to the dibasic acid is preferably 1.0˜1.25:1.

The total molar ratio of the dibasic acid and the acidolysis agent to the total molar ratio of the dihydric alcohol and the branching agent is preferably 0.5˜1.2:1.

In the present invention, by controlling the molar ratio of acid to alcohol and adopting a suitable synthesis process, a polyester resin having two functional groups of carboxyl and hydroxyl groups is obtained. Carboxyl polyester resin and hydroxyl-terminated polyester resin have the advantages of two polyester resin systems, so the overall performance of the coating film is outstanding, and it has a huge market application prospect.

The dihydric alcohol is preferably one or a mixture of two or more of neopentyl glycol, 1,3-butanediol, 2-methyl-2,4-pentanediol, ethylene glycol and propylene glycol.

The dibasic acid is preferably one or a mixture of two or more of terephthalic acid, isophthalic acid and adipic acid.

The branching agent is preferably one or a mixture of pentaerythritol and trimethylolpropane.

The acidolysis agent is preferably one or a mixture of two or more of isophthalic acid, adipic acid and 1,4-cyclohexanedicarboxylic acid.

The esterification catalyst is preferably an organotin catalyst.

The organotin catalyst is preferably one or both of monobutyltin oxide and dihydroxytin chloride.

Above-mentioned second object of the present invention is achieved by following technical scheme: the preparation method of above-mentioned bifunctional polyester resin, comprises the following steps:

(1) According to the above dosage relationship, take diol and branching agent, heat up until the material melts, add dibasic acid and esterification catalyst, and continue to heat up the reaction with nitrogen, until 170 ° C ~ 180 ° C esterification water begins to form and distill After 8-10 hours, the temperature is gradually raised to 230°C-255°C, and kept at this temperature for 2-4 hours until the material system is clear and transparent;

(2) Then lower the temperature to 200°C-210°C, and vacuumize for 3-5 hours. At this time, the acid value of the material reaches below 15mgKOH/g, and the hydroxyl value is 55-95mgKOH/g;

(3) Continue to heat up to 228°C-236°C, add acidolysis agent, react for 3-5 hours until the material system is clear and transparent, the acid value reaches 30-55mgKOH/g, and the hydroxyl value is 40-55mgKOH/g;

(4) Then lower the temperature to 220°C-226°C, vacuumize and polycondense for 1-1.5h, the acid value reaches 10-56mgKOH/g, the hydroxyl value reaches 33-53mgKOH/g, and the bifunctional polyester resin is obtained.

The bifunctional polyester resin prepared by the method of the present invention has an acid value of 10-56mgKOH/g, a hydroxyl value of 33-53mgKOH/g, a viscosity of 2400-6000mPa·s at 200°C, a number-average molecular weight of 2000-5000, and a glass transition The temperature is 50-65°C.

The present invention provides a powder coating for spraying on the surface of a thermos cup, and its components include: 50-80% of carboxyl-terminated polyester resin, 2.6-4.2% of curing agent HAA, 1-6% of NW-5, Filler A 0.01-43%, filler B 0.01-43%, texture agent 0.06-1.0%, pigment 1-25%, additive 0.3-8%;

Described filler A is wet process sericite powder;

The filler B is one or both of titanium dioxide and silicon micropowder.

The carboxyl-terminated polyester resin can be selected from carboxyl-terminated polyester resins with an acid value of 10-56 mgKOH/g, a softening value of 100-120°C and a glass transition temperature of 50-65°C;

Preferably, the carboxyl-terminated polyester resin can be selected from carboxyl-terminated polyester resins with an acid value of 20-50 mgKOH/g, a softening value of 105-120°C and a glass transition temperature of 55-65°C;

Further preferably, the carboxyl-terminated polyester resin can be selected from carboxyl-terminated polyester resins with an acid value of 30-40 mg KOH/g, a softening value of 110-115°C and a glass transition temperature of 55-60°C.

In some embodiments, the carboxyl-terminated polyester resin is the carboxyl-terminated polyester resin product GH-2208 purchased from Zhejiang Guanghua Science and Technology Co., Ltd.

The curing agent HAA is a kind of β-hydroxyalkylamide curing agent. Compared with the TGIC curing agent widely used at home and abroad at present, it has the characteristics of non-toxicity, no irritation to the skin, and fast curing speed. It is prepared by using this product The powder coating has outstanding outdoor performance and is a real green and environmentally friendly high-quality product.

In some embodiments, the β-hydroxyalkylamide curing agent adopts XL552 from EMS Company or T-105M from Ningbo Nanhai Chemical Co., Ltd.

The NW-5 is a blocked polyisocyanate, and in some embodiments, the NW-5 is purchased from Bayer, Germany.

In some embodiments, the wet-process sericite powder is purchased from Chuzhou Gerui Mining Co., Ltd. with a product number of GA-1.

The filler B is preferably silicon micropowder.

The texture agent is one or both of a leveling agent, a sand grain agent and a wrinkle agent;

The leveling agent in the powder coating is 0.7-1.0% by weight;

The sand texture agent in the powder coating is 0.3-0.8% by weight;

The wrinkle agent in the powder coating is 0.06-0.1% by weight.

The leveling agent is an acrylic resin, specifically GLP588 purchased from Ningbo Nanhai Chemical Co., Ltd. or Modaflow Powder III/2000 produced by Solutia;

The sand texture agent is the sand texture agent 815 or sand texture agent 810 purchased from Hubei Laisi Chemical New Material Co., Ltd.;

The wrinkle agent is Eastman cellulose acetate butyl CAB551-0.2;

Described pigment is inorganic pigment, organic pigment or pearlescent pigment;

The inorganic pigment is selected from one or more of titanium dioxide, carbon black, iron red, iron yellow, etc.;

The organic pigment is selected from one or more of phthalocyanine blue, pigment red and pigment yellow 4G, etc.;

The pearlescent pigment is selected from one or more of Merck's 103, 153 and the like.

The auxiliary agent is one or more of brightening agent, matting agent, antioxidant, antibacterial agent, ultraviolet absorber, degassing agent and anti-scratch agent.

For example, in some embodiments, the brightening agent is brightening agent 701B purchased from Ningbo Nanhai Chemical Co., Ltd., or WK701 from Ningbo Weikai Chemical Co., Ltd.

For another example, in some embodiments, the matting agent is pure polyester matting resin RB608 or Huntsman pure polyester matting agent DP3329-1 or A9 of Wuzhou Zehe Chemical Co., Ltd.

For another example, in some embodiments, the antioxidant is 168 available from Ciba (BASF) or 626 available from Double Bond Chemical Co., Ltd.

For another example, in some embodiments, the antibacterial agent is a product with a product number of HY-KYZ01 purchased from Shenzhen Hengyang Nano Material Co., Ltd.

For another example, in some embodiments, the ultraviolet absorber is 2-hydroxyl-4-n-octyloxybenzophenone, 2-(2'-hydroxyl-3',5'-di-tert-phenyl) -5-chlorinated benzotriazole, such as Double Bond Chemical Co., Ltd. BP-12 or 234, etc.

For another example, in some embodiments, the degassing agent is one or both of benzoin or modified benzoin.

For another example, in some embodiments, the anti-scratch agent is polytetrafluoroethylene wax powder.

In some preferred embodiments, the mass ratio of the carboxyl-terminated polyester resin to the curing agent HAA is 12-44:1.

In some preferred embodiments, the mass ratio of NW-5 to curing agent HAA is 0.25-3.0:1.

The preparation method of the powder coating used for spraying on the surface of the thermos cup provided by the invention is as follows:

(1) Take the carboxyl-terminated polyester resin, curing agent HAA, NW5, filler A, filler B, texturing agent, pigment and auxiliary agent by weight and ratio according to the present invention, place high-speed mixer and mix 3- 5 minutes, obtain mixture;

(2) Place the mixture obtained in step (1) in a melt extruder and extrude at a temperature of 80 to 120°C to obtain an extrudate; the melt extruder is a twin-screw or single-screw extruder ;

(3) Place the extruded material obtained in step (2) into a vertical pulverizer to pulverize, and pass through a 180-mesh sieve to make a powder product with a particle size (equivalent particle size D50) of 32-40 microns for later use.

The powder coating prepared by the preparation method of the present invention is coated on the stainless steel surface with a high-voltage electrostatic method, the high-voltage static electricity is 60-90KV high-voltage static electricity, the average film thickness is 50-120 microns, and the curing temperature is 180-200 ℃, the curing time is 10-20 minutes, and can be cured by oven or infrared.

Preferably, the average coating film thickness is 60-110 microns, the curing temperature is 180-190° C., and the curing time is 12-15 minutes.

Compared with the prior art, the beneficial effects are:

(1) The curing agent used in the present invention is β-hydroxyalkylamide, and the resin used is carboxyl-terminated polyester resin, and its reaction mechanism is the carboxyl polycondensation of hydroxyl and carboxyl-terminated polyester in β-hydroxyalkylamide , to generate water molecules, if the curing rate is too fast and the difference in reactivity is large, the coating film has been partially cured, which may cause the water molecules generated by the concentrated reaction to become water vapor when heated and removed, which will easily produce pinholes on the coating film. And the present invention has added the blocked polyisocyanate of the disclosed content of the present invention in the formula, by controlling the mass ratio of the three, it is unexpectedly found that the addition of blocked polyisocyanate can play a role in regulating the reaction rate of the resin and the curing agent, thereby enabling Effectively reduce the generation of coating pinholes.

(2) The softening value of the carboxyl-terminated polyester resin disclosed and used in the present invention is 100-120°C. Using the carboxyl-terminated polyester resin with the softening value disclosed in the present invention can improve the adhesion of the powder coating, and the coating will not fall off after long-term use , non-foaming and durable.

(3) in the present invention, various auxiliary agents have been added in the implementation process, the addition of auxiliary agents can adjust the various properties of the coating, and a certain amount of wax powder has been added in the present invention, its effect is to improve the scratch resistance of powder coatings Scratch performance and feel, can reduce the paint pile phenomenon, the wax powder used in the present invention is polytetrafluoroethylene wax powder and other additives mixed use, can significantly improve the scratch resistance and salt spray corrosion resistance of powder coatings .

(4) Two kinds of fillers, filler A and filler B, are used in the present invention, and various auxiliary agents and texturing agents are used in combination to make the prepared coating have beautiful decoration and multiple functions.

(5) Various additives are added in the paint prepared by the present invention to make the paint have certain acid and alkali resistance and antibacterial properties. Because the thermos cup can breed some bacteria in the process of using, the paint prepared by the present invention has a certain degree of antibacterial properties. Antibacterial performance, which can ensure the safety of use.

(6) The coating prepared by the present invention is a powder coating, so it hardly contains harmful ingredients, has low VOC content, and will not cause any harm to the environment.

Detailed ways

The microsilica powder used in the following examples is a product purchased from Guangzhou Rongyue Chemical Raw Materials Co., Ltd., the benzoin used is a product purchased from Ningbo Weikai Chemical Co., Ltd., and the polytetrafluoroethylene wax powder used is purchased from Products of Jiashan Shenjia Technology Co., Ltd.

Embodiment 1-5 is plane powder coating

Embodiment 1 A kind of plane powder coating that is used for thermos cup surface spraying

Formula: GH-2208 50%, XL552 2.8%, NW-5 2%, Silica Powder 40.5%, GLP588 0.7%, Carbon Black 1%, 701B 0.6%, HY-KYZ01 1.5%, Benzoin 0.4%, PTFE Wax powder 0.5%.

Preparation method: the specific steps are:

(1) Take carboxyl-terminated polyester resin, XL552, NW-5, microsilica powder B, GLP588, carbon black, 701B, HY-KYZ01, benzoin and polytetrafluoroethylene wax according to the parts by weight and ratio described in the present invention powder, placed in a high-speed mixer and mixed for 5 minutes to obtain a mixture;

(2) extruding the mixture obtained in step (1) in a twin-screw melting extruder at a temperature of 100° C. to obtain an extrudate;

(3) The extruded material obtained in step (2) is placed in a vertical mill to pulverize, and then passed through a 180-mesh sieve to make a powder product with a particle size (equivalent particle size D50) of 32 microns for later use.

The powder coating prepared above is coated on the surface of stainless steel by high-voltage electrostatic method. The high-voltage electrostatic is 60KV high-voltage electrostatic, the average film thickness is 50 microns, the curing temperature is 180 ° C, and the curing time is 15 minutes. Baking can be used. Oven or infrared curing.

Embodiment 2 A kind of plane powder coating that is used for thermos cup surface spraying

Formula: GH-2208 60%, XL552 3.2%, NW-5 4%, GA-1 17.7%, GLP588 0.8%, titanium dioxide 7%, iron yellow 1.5%, iron red 2.0%, carbon black 0.2%, 701B 1.0 %, HY-KYZ01 1.6%, benzoin 0.3%, polytetrafluoroethylene wax powder 0.7%.

Preparation method: the specific steps are:

(1) Weigh GH-2208, XL552, NW-5, GA-1, GLP588, titanium dioxide, iron yellow, iron red, carbon black, 701B, HY-KYZ01, Benzoin and polytetrafluoroethylene wax powder were placed in a high-speed mixer and mixed for 5 minutes to obtain a mixture;

(2) extruding the mixture obtained in step (1) in a twin-screw melting extruder at a temperature of 105°C to obtain an extrudate;

(3) Put the extruded material obtained in step (2) into a vertical mill for pulverization, and pass through a 180-mesh sieve to make a powder product with a particle size (equivalent particle size D50) of 40 microns for future use.

The powder coating prepared above is coated on the surface of stainless steel by high-voltage electrostatic method. The high-voltage electrostatic is 70KV high-voltage electrostatic, the average film thickness is 80 microns, the curing temperature is 190 ° C, and the curing time is 12 minutes. Baking can be used. Oven or infrared curing.

Embodiment 3 A kind of plane powder coating that is used for thermos cup surface spraying

Formula: GH-2208 70%, T-105M 3.9%, NW-5 4.9%, Silica Powder 8.4%, Modaflow PowderIII/2000 1.0%, Titanium Dioxide 3%, Iron Yellow 0.6%, Carbon Black 0.4%, WK701 1.0% , DP3329-1 4%, HY-KYZ01 1.5%, benzoin 0.5%, 168 0.3%, PTFE wax powder 0.5%.

Preparation method: the specific steps are:

(1) Weigh GH-2208, T-105M, NW-5, silicon micropowder, Modaflow Powder III/2000, titanium dioxide, iron yellow, carbon black, WK701, DP3329 according to the weight parts and ratios described in the present invention -1. HY-KYZ01, benzoin, 168 and polytetrafluoroethylene wax powder were placed in a high-speed mixer and mixed for 5 minutes to obtain a mixture;

(2) extruding the mixture obtained in step (1) in a twin-screw melting extruder at a temperature of 110°C to obtain an extrudate;

(3) The extruded material obtained in step (2) is placed in a vertical mill for pulverization, and then passed through a 180-mesh sieve to make a powder product with a particle size (equivalent particle size D50) of 35 microns for subsequent use.

The powder coating prepared above is coated on the surface of stainless steel by high-voltage electrostatic method. The high-voltage electrostatic is 80KV high-voltage electrostatic, the average film thickness is 100 microns, the curing temperature is 200 ° C, and the curing time is 15 minutes. Baking can be used. Oven or infrared curing.

Embodiment 4 A kind of plane powder coating that is used for thermos cup surface spraying

Formula: GH-2208 55%, T-105M 2.9%, NW-5 5%, GA-1 15.2%, Silica Powder 9.2%, Modaflow Powder III/2000 0.9%, Titanium Dioxide 0.7%, Iron Red 3.0%, Carbon Black 0.1%, WK701 1.0%, DP3329-1 3.3%, HY-KYZ01 1.8%, Benzoin 0.5%, BP-12 0.6%, 168 0.3%, PTFE wax powder 0.5%.

Preparation method: the specific steps are:

(1) Weigh GH-2208, T-105M, NW-5, GA-1, silicon micropowder, Modaflow Powder III/2000, titanium dioxide, iron red, carbon black, WK701, DP3329-1, HY-KYZ01, benzoin, BP-12, 168 and polytetrafluoroethylene wax powder were placed in a high-speed mixer and mixed for 5 minutes to obtain a mixture;

(2) extruding the mixture obtained in step (1) in a twin-screw melting extruder at a temperature of 115°C to obtain an extrudate;

(3) The extruded material obtained in step (2) is placed in a vertical mill to pulverize, and then passed through a 180-mesh sieve to make a powder product with a particle size (equivalent particle size D50) of 37 microns for later use.

The powder coating prepared above is coated on the surface of stainless steel by high-voltage electrostatic method. The high-voltage electrostatic is 90KV high-voltage electrostatic, the average film thickness is 120 microns, the curing temperature is 200 ° C, and the curing time is 14 minutes. Baking can be used. Oven or infrared curing.

Embodiment 5 A kind of plane powder coating that is used for thermos cup surface spraying

Formula: GH-2208 50%, XL552 2.5%, NW-5 4%, GA-1 9.3%, silicon micropowder 4.5%, GLP5881.0%, titanium dioxide 18%, iron red 2.5%, carbon black 0.2%, 701B 0.5%, A9 3.7%, HY-KYZ01 1.5%, benzoin 0.8%, 234 0.3%, 626 0.5%, PTFE wax powder 0.7%.

Preparation method: the specific steps are:

(1) Weigh GH-2208, XL552, NW-5, GA-1, silicon micropowder, GLP588, titanium dioxide, iron red, carbon black, 701B, A9, HY- KYZ01, benzoin, 234, 626 and polytetrafluoroethylene wax powder were placed in a high-speed mixer and mixed for 5 minutes to obtain a mixture;

(2) extruding the mixture obtained in step (1) in a twin-screw melting extruder at a temperature of 120°C to obtain an extrudate;

(3) The extruded material obtained in step (2) is placed in a vertical mill for pulverization, and then passed through a 180-mesh sieve to make a powder product with a particle size (equivalent particle size D50) of 35 microns for subsequent use.

The powder coating prepared above is coated on the surface of stainless steel by high-voltage electrostatic method. The high-voltage electrostatic is 80KV high-voltage electrostatic, the average film thickness is 100 microns, the curing temperature is 200 ° C, and the curing time is 10 minutes. Baking can be used. Oven or infrared curing.

Embodiment 6-10 is sand pattern powder coating

Embodiment 6 A kind of sand pattern powder coating that is used for thermos cup surface spraying

Formula: GH-2208 65%, XL552 3.4%, NW-5 2%, silica powder 23.2%, GLP588 0.2%, sanding agent 815 0.3%, phthalocyanine blue 0.9%, carbon black 1%, HY-KYZ01 1.9% , Benzoin 0.5%, 234 0.3%, 6260.5%, PTFE wax powder 0.8%.

Preparation method: except that the formula is different, other operations and steps are the same as in Example 1.

Spraying method: same as embodiment 1.

Embodiment 7 A kind of sand pattern powder coating that is used for thermos cup surface spraying

Formula: GH-2208 55%, XL552 2.9%, NW-5 6%, GA-1 14.7%, silica powder 14.3%, GLP588 0.2%, sanding agent 810 0.5%, phthalocyanine blue 2.0%, carbon black 0.2% , Everlasting Purple 0.3%, HY-KYZ011.8%, Benzoin 0.6%, 234 0.4%, 626 0.6%, PTFE Wax Powder 0.5%.

Preparation method: except that the formula is different, other operations and steps are the same as in Example 2.

Spraying method: same as embodiment 2.

Embodiment 8 A kind of sand pattern powder coating that is used for thermos cup surface spraying

Formula: GH-2208 60%, T-105M 3.2%, NW-54%, GA-1 26.3%, Sand Texture Agent 815 0.8%, Phthalocyanine Blue 1.2%, Carbon Black 0.1%, Permanent Violet 0.2%, HY -KYZ01 2.0%, benzoin 0.8%, BP-12 0.5%, 1680.5%, PTFE wax powder 0.4%.

Preparation method: except that the formula is different, other operations and steps are the same as in Example 3.

Spraying method: same as embodiment 3.

Embodiment 9 A kind of sand pattern powder coating that is used for thermos cup surface spraying

Formula: GH-2208 70%, T-105M 3.7%, NW-5 1%, GA-1 10.5%, silica powder 8.9%, sanding agent 810 0.6%, phthalocyanine blue 0.6%, permanent violet 0.1%, HY-KYZ01 2.3%, benzoin 0.5%, BP-12 0.6%, 168 0.8%, PTFE wax powder 0.4%.

Preparation method: except that the formula is different, other operations and steps are the same as in Example 4.

Spraying method: same as embodiment 4.

Embodiment 10 A kind of sand pattern powder coating that is used for thermos cup surface spraying

Formula: GH-2208 65%, T-105M 3.4%, NW-5 4%, GA-1 16.1%, Silica Powder 5.0%, Modaflow Powder III/2000 0.1%, Sanding Agent 810 0.7%, Phthalocyanine Blue 0.8 %, Everlasting Violet 0.3%, HY-KYZ01 2.4%, Benzoin 0.8%, BP-12 0.5%, 168 0.4%, PTFE Wax Powder 0.5%.

Preparation method: except that the formula is different, other operations and steps are the same as in Example 5.

Spraying method: same as embodiment 5.

Examples 11-14 are wrinkled powder coatings

Embodiment 11 A kind of wrinkle powder coating for spraying on the surface of thermos cup

Formula: GH-2208 50%, XL552 2.6%, NW-5 2%, GA-1 19.7%, Silica Powder 19.2%, CAB551-0.2 0.1%, Carbon Black 1%, Pigment Yellow 4G 1.3%, HY-KYZ01 2.0 %, benzoin 0.5%, 234 0.3%, 626 0.5%, PTFE wax powder 0.8%.

Preparation method: except that the formula is different, other operations and steps are the same as in Example 1.

Spraying method: same as embodiment 1.

Embodiment 12 A kind of wrinkle powder coating for spraying on the surface of thermos cup

Formula: GH-2208 80%, XL552 4.2%, NW-5 6%, silicon micropowder 0.54%, CAB551-0.20.06%, titanium dioxide 2.0%, pigment red 1.5%, carbon black 0.2%, pigment yellow 4G 1.1% , HY-KYZ01 2.5%, benzoin 0.4%, 234 0.4%, 626 0.6%, PTFE wax powder 0.5%.

Preparation method: except that the formula is different, other operations and steps are the same as in Example 2.

Spraying method: same as embodiment 2.

Embodiment 13 A kind of wrinkle powder coating for spraying on the surface of thermos cup

Formula: GH-2208 60%, T-105M 3.2%, NW-5 4%, GA-1 21.82%, CAB551-0.20.08%, titanium dioxide 2%, pigment red 2.3%, carbon black 0.1%, pigment yellow 4G 2.3%, HY-KYZ01 2.0%, Benzoin 0.8%, BP-12 0.5%, 168 0.5%, PTFE wax powder 0.4%.

Preparation method: except that the formula is different, other operations and steps are the same as in Example 4.

Spraying method: same as embodiment 4.

Embodiment 14 A kind of wrinkle powder coating for spraying on the surface of thermos cup

Formula: GH-2208 65%, T-105M 3.4%, NW-5 4%, GA-1 11%, silica powder 5%, CAB551-0.2 0.1%, titanium dioxide 6.7%, pigment red 0.6%, pigment yellow 4G 0.1%, HY-KYZ01 1.9%, benzoin 0.8%, BP-12 0.5%, 168 0.4%, PTFE wax powder 0.5%.

Preparation method: except that the formula is different, other operations and steps are the same as in Example 5.

Spraying method: same as embodiment 5.

Comparative example 1 a kind of powder coating

Formula: The difference from Example 2 is that the mass ratio of carboxyl-terminated polyester resin to curing agent HAA is 8:1, and other ingredients are the same as in Example 2.

Preparation method: same as Example 2.

Spraying method: same as embodiment 6.

Comparative example 2 a kind of powder coating

Recipe: The difference from Example 2 is that the mass ratio of carboxyl-terminated polyester resin to curing agent HAA is 50:1, and other ingredients are the same as in Example 2.

Preparation method: same as Example 2.

Spraying method: same as embodiment 2.

Comparative example 3 a kind of powder coating

Formula: The difference from Example 4 is that the mass ratio of blocked polyisocyanate (NW-5) to curing agent HAA (T-105M) is 0.2:1. , other ingredients are identical with embodiment 4.

Preparation method: same as Example 4.

Spraying method: same as embodiment 4.

Comparative example 4 a kind of powder coating

Formula: The difference from Example 4 is that the mass ratio of blocked polyisocyanate (NW-5) to curing agent HAA (T-105M) is 5:1, and other ingredients are the same as in Example 4.

Preparation method: same as Example 4.

Spraying method: same as embodiment 4.

Comparative example 5 a kind of powder coating

Formula: The difference from Example 1 is that the softening value of the carboxyl-terminated polyester resin used is 130° C., and other ingredients are the same as in Example 1.

Preparation method: same as Example 1.

Spraying method: same as embodiment 1.

Comparative example 6 a kind of powder coating

Formula: The difference from Example 1 is that the softening value of the carboxyl-terminated polyester resin used is 90° C., and other ingredients are the same as in Example 1.

Preparation method: same as Example 1.

Spraying method: same as embodiment 1.

Performance Testing:

1. Coating film adhesion test is carried out according to the national standard GB/T 9286-1998. On the surface of the glass test plate, use a pencil to evenly draw intersecting squares with a distance of 2mm, and then use a knife to scratch along the traces of the pencil , there are traces scratched by the knife, and then adhere the tape to the test board with force. After 5 minutes, hold one end of the adhesive tape, and quickly tear the adhesive tape off the glass test board at an angle of 60° with the glass test board.

2. Water resistance test

Test according to the national standard GB/T 1733-93 paint film water resistance test method.

3. Performance test of chemical resistance

The test is carried out according to the national standard GB1763-(79)88 paint film chemical resistance test method.

The test results are as follows,

Table 1 Performance Test of Plane Powder Coatings

Note: The full name of ND in all tables is No Detectable

Table 2 Performance test of sand grain powder coating

Table 3 Performance tests of wrinkled powder coatings

From the test results in the above table 1-3, it can be clearly seen that the special coatings for different types of thermos cups prepared by formulas and preparation methods thereof provided in the present invention have excellent properties, such as boiling resistance, bisphenol A content (BPA) index, The anti-chemical agent performance is better than the coatings currently prepared, and the coatings prepared by the present invention have good antibacterial properties. Since the thermos cup will breed some bacteria during use, the antibacterial properties of the coatings prepared by the present invention remain after 500 hours of use. It can be as high as more than 90%, so that the safety of use can be guaranteed, and the coating prepared by the invention is a powder coating, so it hardly contains harmful components, has low VOC content, and does not cause any harm to the environment.

The performance test of table 4 embodiment 2 and comparative example 1-2

As can be seen from the data in the above table 4, changing the mass ratio of curing agent and carboxyl-terminated polyester resin is not within the control scope of the present invention, which will obviously affect the water boiling resistance, chemical resistance and antibacterial properties of the powder coating, so that the coating The life of the thermos cup is shortened.

The performance test of table 5 embodiment 4 and comparative example 3-4

It can be clearly seen from the test data in Table 5 above that changing the mass ratio of curing agent and blocked polyisocyanate is not within the control scope of the present invention, which will obviously affect the chemical resistance and antibacterial performance of the powder coating. The performance test of table 6 embodiment 1 and comparative example 6

From the test data in Table 6 above, it can be clearly seen that changing the softening value of the carboxyl-terminated polyester resin used will affect the impact resistance of the powder coating, and will also have a significant impact on the adhesion.

It can be seen from the test results in Table 4-6 above that changing the content of each component disclosed in the present invention is not within the scope of the disclosure of the present invention, and various properties of the prepared coating will be reduced to a certain extent.

During the implementation process, relevant tests were also carried out for the performance tests of sand grain powder coatings and wrinkle powder coatings, and the test results were basically the same as the above results.

But the above-mentioned ones are only preferred embodiments of the present invention, and should not limit the scope of the present invention, that is, all simple equivalent changes and Modifications still fall within the scope of the claims of the present invention. In addition, the abstract and the title are only used to assist in the search of patent documents, and are not used to limit the scope of rights of the present invention.

Claims (10)

1. a kind of difunctional polyester resin, it is characterized in that：The polyester resin has end carboxyl and terminal hydroxy group Liang Zhong functional groups, Its acid value is 10~56mgKOH/g, and hydroxyl value is 33~53mgKOH/g, and 200 DEG C of viscosity are 2400~6000mPas, and number is divided equally Son amount is 2000~5000, and glass transition temperature is 50~65 DEG C, is mainly melted by the group lease making of following molar content Melt and is polymerized：30~60mol% of dihydric alcohol, 35~50mol% of binary acid, 0.05~3.5mol% of branching agent, acidolysis agent 2~ 20mol%, 0.01~0.20mol% of esterification catalyst.

2. difunctional polyester resin according to claim 1, it is characterized in that：The dihydric alcohol and the branching agent Integral molar quantity and binary acid mole ratio be 1.0~1.25: 1.

3. difunctional polyester resin according to claim 1, it is characterized in that：The binary acid and the acidolysis agent Integral molar quantity and the integral molar quantity ratio of the dihydric alcohol and the branching agent be 0.5~1.2: 1.

4. a kind of powdery paints for thermal insulation cup surface spraying, it is characterised in that：Its component includes by weight percentage：Hold carboxylic Base polyester resin 50-80%, curing agent HAA 1.8-4.2%, NW-51-6%, filler A 0.01-43%, filler B 0.01- 43%, texture agent 0.06-1.0%, pigment 1-25%, auxiliary agent 0.3-8%；

The filler A is wet method sericite in powder；

The filler B be titanium dioxide and silicon powder in-kind or two kinds.

5. powdery paints according to claim 4, it is characterised in that：The terminal carboxyl polyester resin is that acid value is 10- 56mgKOH/g, softness value are the terminal carboxyl polyester resin of 100-120 DEG C and 50-65 DEG C of glass transition temperature.

6. requiring the powdery paints described in 4 according to claim, it is characterised in that：The curing agent HAA is β-hydroxyalkyl acyl Amine curing agent.

7. requiring the powdery paints described in 4 according to claim, it is characterised in that：The texture agent is levelling agent, sand streak agent One or both of with wrinkle agent；

Levelling agent in the powdery paints is by weight percentage 0.7-1.0%；

Sand streak agent in the powdery paints is by weight percentage 0.3-0.8%；

Wrinkle agent in the powdery paints is by weight percentage 0.06-0.1%.

8. requiring the powdery paints described in 4 according to claim, it is characterised in that：The pigment is inorganic pigment, You Jiyan Material or pearlescent pigment.

9. requiring the powdery paints described in 4 according to claim, it is characterised in that：The auxiliary agent is optical brightener, delustering agent, resists One or more of oxygen agent, antiseptic, ultra-violet absorber, degasser and scratching resistant.

10. according to claim 4-9 any one of them powdery paints, it is characterised in that：The terminal carboxyl polyester resin with The mass ratio of curing agent HAA is 12-44: 1；

The mass ratio of the NW-5 and curing agent HAA is 0.25-3.0: 1.