Epoxy modified polyester resin and preparation method and application thereof
阅读说明：本技术 一种环氧改性聚酯树脂及其制备方法和应用 (Epoxy modified polyester resin and preparation method and application thereof ) 是由 雷雨 杜卫东 沈雪峰 宫原贵宏 于 2019-12-13 设计创作，主要内容包括：本发明公开了一种环氧改性聚酯树脂,按重量百分比计,其原料中包含以下组分：新戊二醇20-40％；2-甲基-1,3-丙二醇2-10％；三羟甲基丙烷0-5％；对苯二甲酸5-25％；间苯二甲酸5-25％；癸二酸5-15％；环氧树脂2-8％；有机锡催化剂0.1-0.5％；溶剂35-45％。该树脂适用于卷钢家电底漆,尤其是能配套高平滑表面镀锌板的卷钢家电底漆,且得到的底漆与高平滑表面镀锌板间具有优异的附着力,同时具有好的物理机械性能以及耐水、耐化学性能。本发明还公开了该环氧改性聚酯树脂的制备方法和应用。(The invention discloses an epoxy modified polyester resin, which comprises the following components in percentage by weight: 20-40% of neopentyl glycol; 2-10% of 2-methyl-1, 3-propanediol; 0-5% of trimethylolpropane; 5-25% of terephthalic acid; 5-25% of isophthalic acid; 5-15% of sebacic acid; 2-8% of epoxy resin; 0.1 to 0.5 percent of organic tin catalyst; 35-45% of solvent. The resin is suitable for the priming paint of coil steel household appliances, in particular to the priming paint of coil steel household appliances which can be matched with a galvanized plate with a high smooth surface, and the obtained priming paint has excellent adhesive force with the galvanized plate with the high smooth surface, and simultaneously has good physical and mechanical properties, water resistance and chemical resistance. The invention also discloses a preparation method and application of the epoxy modified polyester resin.)
1. The epoxy modified polyester resin is characterized by comprising the following raw materials in percentage by weight:
2. the epoxy-modified polyester resin as claimed in claim 1, wherein the epoxy-modified polyester resin has a solid content of 55-65%, a hydroxyl value of 60-80mgKOH/g, an acid value of 5mgKOH/g or less, a weight average molecular weight of 25000-45000, and a glass transition temperature TgIs 35-55 ℃;
preferably, the epoxy-modified polyester resin has a Gardner viscosity of Z-Z3 at 25 ℃;
preferably, the epoxy value of the epoxy resin is 0.05 to 0.25mol/100 g;
preferably, the organotin catalyst is selected from one or more of dibutyltin bis (acetylacetonate), dibutyltin dilaurate, dibutyltin dioctoate and dibutyltin diacetate.
3. The epoxy-modified polyester resin according to claim 1, wherein the solvent comprises one or more of S150 aromatic solvent oil, cyclohexanone, propylene glycol methyl ether acetate; preferably, in the solvent, the mass ratio of the S150 aromatic hydrocarbon solvent oil, the cyclohexanone and the propylene glycol monomethyl ether acetate is 40-60:40-60: 0-10.
4. The process for producing an epoxy-modified polyester resin according to any one of claims 1 to 3, comprising the steps of:
polymerizing a mixture of neopentyl glycol, 2-methyl-1, 3-propanediol, trimethylolpropane, terephthalic acid, isophthalic acid and sebacic acid under the action of an organic tin catalyst, adding epoxy resin, continuing to react, and diluting with a solvent to obtain the epoxy modified polyester resin.
5. The preparation method according to claim 4, which specifically comprises the steps of:
heating a mixture of neopentyl glycol, 2-methyl-1, 3-propanediol, trimethylolpropane, terephthalic acid, isophthalic acid and sebacic acid to 160 ℃ under the protection of inert gas, stirring after the mixture is molten, adding an organic tin catalyst, continuously heating to 240 ℃ under 220 ℃ and reacting until the acid value reaches 10-20 mgKOH/g; cooling to 150 ℃ and 160 ℃, adding the epoxy resin, continuing to react until the acid value is less than or equal to 5mgKOH/g, vacuumizing, cooling to 80 ℃, and adding the solvent for dilution to obtain the epoxy modified polyester resin.
6. A coil steel home appliance primer composition, comprising the epoxy-modified polyester resin according to any one of claims 1 to 3.
7. The primer composition according to claim 6, comprising the following components in percentage by weight:
8. the primer composition of claim 7, wherein the amino resin is one or more of melamine formaldehyde resin, methylated melamine resin, butylated melamine resin, methylated urea formaldehyde resin, butylated urea formaldehyde resin, and benzoguanamine formaldehyde resin;
preferably, the isocyanate resin is a blocked aliphatic polyisocyanate resin;
preferably, the auxiliary agent is selected from one or more of wetting dispersant, adhesion promoter, anti-settling agent, leveling agent and defoaming agent.
9. A steel coil home appliance primer prepared from the primer composition according to any one of claims 6 to 8.
10. A method of forming a coating on a substrate, comprising the steps of:
applying the primer composition of any one of claims 6-8 to a surface of a substrate and curing to form a coating;
preferably, the substrate is a high-smoothness surface galvanized sheet.
Technical Field
The invention relates to the technical field of coil steel coating. More particularly, relates to an epoxy modified polyester resin and a preparation method and application thereof.
Background
In recent years, with the continuous and high-speed increase of economic construction in China, the application field of the precoated metal coil is continuously expanded, and the market demand is continuously increased. The home appliance industry adopts precoated metal coiled materials to produce finished product shells, and the adhesive force of the primer coating has great influence on the service life of home appliance products. The service life of the household appliance product is prolonged, the replacement frequency of the household appliance product can be reduced, and resource saving and environmental protection are facilitated.
At present, the existing coil steel household appliance primer in the market mainly comprises two systems, one is polyester, and the other is epoxy. Polyester-based primers have excellent flexibility, but general corrosion resistance and adhesion. Epoxy primers have high hardness, good corrosion resistance, and excellent adhesion to metal substrates, but have the disadvantage of poor flexibility. Because precoated metal coils used in the household appliance industry require excellent surface flatness and processability, in order to meet the requirements for surface flatness, the household appliance industry has gradually begun to use precoated high-smoothness surface galvanized sheets for finished product assembly. The scheme improves the surface flatness of the household appliance and simultaneously inevitably puts higher demands on the adhesive force of the coating.
However, the existing primer cannot be well matched with a high-smooth surface galvanized plate, and the defects of processability and durability are obvious due to insufficient adhesive force of the primer, so that the development of the primer with high adhesive force is urgently needed to be matched with the popularization of the high-smooth surface galvanized plate in the household appliance industry, and the influence on the long-term service performance and the service life of household appliances due to the unsynchronized improvement of the coating technology due to the optimization of the appearance flatness is avoided.
Disclosure of Invention
Based on the facts, an object of the present invention is to provide an epoxy modified polyester resin, which is suitable for a primer for coil steel household appliances, especially for a primer for coil steel household appliances capable of matching with a galvanized plate with a high smooth surface, and the obtained primer has excellent adhesion with the galvanized plate with the high smooth surface, and simultaneously has good physical and mechanical properties, as well as water resistance and chemical resistance.
The second purpose of the invention is to provide a preparation method of the epoxy modified polyester resin.
The third purpose of the invention is to provide a coil steel household appliance primer composition. The primer composition is particularly suitable for high-smoothness surface galvanized plates.
The fourth purpose of the invention is to provide a coil steel household appliance primer. The primer is suitable for high-smooth surface galvanized plates, and has good adhesive force with household appliance substrates, especially high-smooth surface galvanized plates.
A fifth object of the present invention is to provide a method of forming a coating on a substrate.
In order to achieve the first purpose, the invention adopts the following technical scheme:
the epoxy modified polyester resin is characterized by comprising the following raw materials in percentage by weight:
further, the solid content of the epoxy modified polyester resin is 55-65%, the hydroxyl value is 60-80mgKOH/g, the acid value is less than or equal to 5mgKOH/g, the weight average molecular weight is 25000-45000, and the glass transition temperature T is 45000gIs 35-55 ℃.
Further, the epoxy-modified polyester resin has a Gardner viscosity of Z-Z3 at 25 ℃.
Further, the epoxy value of the epoxy resin is 0.05 to 0.25mol/100 g.
Further, the organic tin catalyst is selected from one or more of dibutyltin bis (acetylacetonate), dibutyltin dilaurate, dibutyltin dioctoate and dibutyltin diacetate.
Further, the solvent is selected from one or more of S150 aromatic hydrocarbon solvent oil, cyclohexanone and propylene glycol methyl ether acetate.
Furthermore, in the solvent, the mass ratio of S150 aromatic solvent oil, cyclohexanone to propylene glycol monomethyl ether acetate is 40-60:40-60: 0-10.
In order to achieve the second purpose, the invention adopts the following technical scheme:
a preparation method of epoxy modified polyester resin comprises the following steps:
polymerizing a mixture of neopentyl glycol, 2-methyl-1, 3-propanediol, trimethylolpropane, terephthalic acid, isophthalic acid and sebacic acid under the action of an organic tin catalyst, adding epoxy resin, continuing to react, and diluting with a solvent to obtain the epoxy modified polyester resin.
Further, the preparation method specifically comprises the following steps:
heating a mixture of neopentyl glycol, 2-methyl-1, 3-propanediol, trimethylolpropane, terephthalic acid, isophthalic acid and sebacic acid to 160 ℃ under the protection of inert gas, stirring after the mixture is molten, adding an organic tin catalyst, continuously heating to 240 ℃ under 220 ℃ and reacting until the acid value reaches 10-20 mgKOH/g; cooling to 150 ℃ and 160 ℃, adding the epoxy resin, continuing to react until the acid value is less than or equal to 5mgKOH/g, vacuumizing, cooling to 80 ℃, and adding the solvent for dilution to obtain the epoxy modified polyester resin.
In order to achieve the third purpose, the invention adopts the following technical scheme:
a coil steel home appliance primer composition comprising the epoxy modified polyester resin according to the first object.
Further, the primer composition comprises the following components in percentage by weight:
further, the amino resin is one or more of melamine formaldehyde resin, methylated melamine resin, butylated melamine resin, methylated urea formaldehyde resin, butylated urea formaldehyde resin and benzoguanamine formaldehyde resin.
Further, the isocyanate resin is a blocked aliphatic polyisocyanate resin.
Further, the isocyanate resin is selected from one or more of 2, 4-toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, polymethylene-polyphenyl diisocyanate and methylene diphenyl diisocyanate.
Further, the auxiliary agent is selected from one or more of wetting dispersant, adhesion promoter, anti-settling agent, leveling agent and defoaming agent.
Further, the solvent is selected from one or more of S150 aromatic solvent oil, cyclohexanone, propylene glycol methyl ether acetate, xylene, butyl acetate and 2-butanone.
In order to achieve the fourth object, the invention provides a coil steel household appliance primer prepared from the primer composition of the third object.
To achieve the fifth object, the present invention provides a method of forming a coating layer on a substrate, the method comprising the steps of:
the primer composition is applied to a substrate surface and cured to form a coating.
Further, the substrate is a high-smooth surface galvanized sheet.
The invention has the following beneficial effects:
the epoxy modified polyester resin for the primer for coil steel household appliances provided by the invention organically combines the advantages of the polyester resin and the epoxy resin together, is suitable for the primer for coil steel household appliances which can be matched with a galvanized plate with a high smooth surface, adopts the main resin with the flexibility of long-chain macromolecular polyester resin, introduces the epoxy resin into the molecule, and cross-links with the closed isocyanate resin, so that the comprehensive performance of the primer provided by the invention can reach the balance between high adhesive force and excellent flexibility, and the problem of insufficient adhesive force of the current primer for coil steel household appliances on the galvanized plate with the high smooth surface is effectively solved.
Detailed Description
In order to more clearly illustrate the invention, the invention is further described below in connection with preferred embodiments. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention.
One specific embodiment of the invention provides an epoxy modified polyester resin, which comprises the following components in percentage by weight:
in the process of synthesizing the epoxy modified polyester resin, the polyol, the polyacid and the epoxy resin are different, and the types and the characteristics of the obtained epoxy modified polyester resin are also different. In the present embodiment, the epoxy-modified polyester resin having a specific structure and performance is obtained by selecting a polybasic acid, a polyhydric alcohol, and an epoxy resin having specific contents and compositions as raw materials. The long-chain polyester main chain ensures the processing performance and introduces an epoxy group to improve the adhesive force of the resin. The primer containing the epoxy modified polyester resin has excellent adhesive force with a high-smooth surface galvanized plate for coil steel household appliances, and the problem that the adhesive force of the existing primer product to the high-smooth surface galvanized plate is insufficient is well solved.
In the raw materials of the epoxy modified polyester resin, the addition amount of the trihydroxypropane is 0-5 wt%, namely, the addition amount of the trihydroxypropane can be 0 or not, and when the addition amount of the trihydroxypropane is not 0, the addition amount of the trihydroxypropane can be 0.2-5 wt%.
In a preferred example, the epoxy-modified polyester resin has a solid content of 55 to 65%, a hydroxyl value of 60 to 80mgKOH/g, an acid value of 5mgKOH/g or less, a weight-average molecular weight of 25000-45000, and a glass transition temperature TgIs 35-55 ℃. Illustratively, the hydroxyl value of the epoxy-modified polyester resin includes, but is not limited to, 65 to 80mgKOH/g, 60 to 75mgKOH/g, 65 to 70mgKOH/g, 68 to 75mgKOH/g, 68 to 74mgKOH/g, 65 to 68mgKOH/g, 65mgKOH/g, 68mgKOH/g, 74mgKOH/g, and the like. Illustratively, the acid value of the epoxy-modified polyester resin includes, but is not limited to, 1 to 5mgKOH/g, 1.5 to 4mgKOH/g, 1.5 to 3mgKOH/g, 1.5 to 2.5mgKOH/g, 2 to 3mgKOH/g, 2.4 to 2.8mgKOH/g, 1.6mgKOH/g, 2.4mgKOH/g, 2.8mgKOH/g, and the like. Illustratively, the weight average molecular weight of the epoxy-modified polyester resin includes, but is not limited to, 25000-28000, 31000, 36000, and the like.
In a preferred example, the epoxy value of the epoxy resin is 0.05 to 0.25mol/100 g. Specific models include EPIKOTE 828EL, NPSN-901 × 75, etc., and other similar commercially available epoxies.
In one preferred example, the organotin catalyst includes, but is not limited to, one or more selected from the group consisting of dibutyltin bis (acetylacetonate), dibutyltin dilaurate, dibutyltin dioctoate and dibutyltin diacetate.
In a preferred example, the solvent comprises one or more of S150 aromatic solvent oil, cyclohexanone, propylene glycol methyl ether acetate and toluene.
In a preferred example, the solvent comprises one or more of S150 aromatic solvent oil, cyclohexanone and propylene glycol methyl ether acetate. Furthermore, in the solvent, the mass ratio of S150 aromatic solvent oil, cyclohexanone to propylene glycol monomethyl ether acetate is 40-60:40-60: 0-10.
Yet another embodiment of the present invention provides a method for preparing the epoxy-modified polyester resin as described above, comprising the steps of:
polymerizing a mixture of neopentyl glycol, 2-methyl-1, 3-propanediol, trimethylolpropane, terephthalic acid, isophthalic acid and sebacic acid under the action of an organic tin catalyst, adding epoxy resin, continuing to react, and diluting with a solvent to obtain the epoxy modified polyester resin.
In a preferred example, the preparation method comprises the steps of:
heating a mixture of neopentyl glycol, 2-methyl-1, 3-propanediol, trimethylolpropane, terephthalic acid, isophthalic acid and sebacic acid to 160 ℃ under the protection of inert gas, stirring after the mixture is molten, adding an organic tin catalyst, continuously heating to 240 ℃ under 220 ℃ and reacting until the acid value reaches 10-20 mgKOH/g; cooling to 150 ℃ and 160 ℃, adding the epoxy resin, continuing to react until the acid value is less than or equal to 5mgKOH/g, vacuumizing, cooling to 80 ℃, and adding the solvent for dilution to obtain the epoxy modified polyester resin.
In yet another embodiment, a primer composition for coil steel electrical appliances is provided, the primer composition comprising the epoxy-modified polyester resin as described above.
The primer composition has high adhesive force to a high-smooth surface galvanized plate, and the generated paint film has excellent flexibility and high adhesive force, so that the problem of insufficient adhesive force of the current coil steel household appliance primer to the high-smooth surface galvanized plate base material can be effectively solved.
In a preferred example, the primer composition comprises the following components in weight percent:
in a preferred example, the amino resin includes, but is not limited to, one or more of melamine formaldehyde resin, methylated melamine resin, butylated melamine resin, methylated urea formaldehyde resin, butylated urea formaldehyde resin, and benzoguanamine formaldehyde resin.
In a preferred example, the isocyanate resin is a blocked aliphatic polyisocyanate resin. The isocyanate resin is selected from one or more of 2, 4-toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, polymethylene-polyphenyl diisocyanate and methylene diphenyl diisocyanate.
In a preferred example, the auxiliary agent includes, but is not limited to, one or more selected from wetting and dispersing agents, adhesion promoters, anti-settling agents, leveling agents, and defoaming agents.
In a preferred example, the solvent is selected from one or more of S150 aromatic hydrocarbon solvent oil, cyclohexanone, propylene glycol methyl ether acetate, xylene, butyl acetate, and 2-butanone. Furthermore, in the solvent, the mass ratio of S150 aromatic solvent oil, cyclohexanone to propylene glycol monomethyl ether acetate is 40-60:40-60: 0-10. Under the preferred conditions, the solvent not only has good dissolving effect, but also has the volatilization speed during the baking process to be compatible with the temperature change of the substrate and the curing process of the paint film. The solvents with different boiling points and volatilization speeds are mixed according to a certain proportion, so that shrinkage cavities and poor leveling of a paint film caused by the escape of a large amount of solvents in the initial stage of curing can be prevented, and bubbles and holes can be prevented from being caused by the escape of more solvents when the paint film is nearly completely cured.
In yet another embodiment of the present invention, there is provided a steel coil home appliance primer prepared from the primer composition as described above.
The primer well overcomes the defects that the existing primer cannot be well matched with a high-smooth surface galvanized plate, and the primer has poor processability and durability due to insufficient adhesive force, can be matched with the popularization of the high-smooth surface galvanized plate in the household appliance industry, avoids the influence on the long-term service performance and the service life of household appliances due to the unsynchronized improvement of the coating technology due to the optimization of the appearance flatness, and is favorable for resource conservation and environmental protection.
In yet another embodiment of the present invention, there is provided a method of forming a coating on a substrate, the method comprising the steps of:
the primer composition is applied to a substrate surface and cured to form a coating.
Among them, the substrate is preferably a high-smooth surface galvanized sheet.
The manner of application is preferably coating.
The technical solution of the present invention is described below with reference to some specific examples:
the main raw material information given in the examples is shown in table 1.
Table 1 main raw material information
Name of raw materials
Properties of
Suppliers of goods
YP5627B
High imino carbinol etherified melamine formaldehyde resin
Yuanbang chemical industry
YP5603
Methylated melamine formaldehyde resin
Yuanbang chemical industry
DESMODUR BL3175A
Blocked polyisocyanates
Scientific wound
BIR-1110
Blocked polyisocyanates
From Nippon point of labor
SHIELDEX C303
Calcium ion exchange silica gel nontoxic antirust pigment with calcium ion content of 1 ‰
Grace
SHIELDEX CS311
Calcium ion exchange silica gel nontoxic antirust pigment with calcium ion content of 1 ‰
Grace
TEGO DISPERS 710
Alkali polyurethane copolymer solution, wetting dispersant
Digao (high)
SN-7063 adhesion promoter
Polyethylene oxide phosphate
Deep bamboo
MPA1078X
Anti-settling agent
Haimingsidee modest board
VERSAFLOW BASE
Acrylic resin leveling agent
Three-leaf technology
DISPARLON L-1984-50S
Defoaming agent
Disibalong