An aqueous environmentally friendly high-temperature resistant polyester resin and its preparation method

Abstract

The present invention discloses an aqueous environmentally friendly high-temperature resistant polyester resin and a preparation method thereof. It is made from raw materials such as neopentyl glycol, methylpropanediol, pentaerythritol, trimethylolethane, trimethylolpropane, glycidyl versatate, phthalic anhydride, trimellitic anhydride, hexahydrophthalic anhydride, benzoic acid, 1,4-cyclohexanedicarboxylic acid, isophthalic acid, 2,2-dimethylolpropionic acid, dibutyltin dilaurate, monobutyltin oxide, γ-butyrolactone, ethylene glycol monobutyl ether, methylpropanediol monobutyl ether, ethylene glycol monomethyl ether, propylene glycol methyl ether acetate, deionized water, ammonia water, dimethylethanolamine, etc. Through a large number of experimental screenings, the present invention adopts a positive pressure high-temperature melt polymerization process to preferably adjust a system with an optimal hydroxyl and carboxyl ratio, and the conversion rate of the present invention is as high as 96.86%. The prepared polyester resin has comprehensive properties such as high temperature resistance, high weather resistance, high chemical resistance, high adhesion, high gloss, and good impact performance.

Description

Technical Field

[0001] The present invention relates to an environmentally friendly waterborne high-temperature resistant polyester resin, belonging to the technical field of polymer resins. Background Art

[0002] Waterborne polyester resin is a high molecular compound formed by polycondensation of polyols and polyacids, and its main solvent is water. It has the advantages of good weather resistance, chemical resistance, high adhesion, high gloss, and good impact performance of oil-based polyester resin. The present invention improves the high-temperature resistance of this resin by optimizing raw materials and synthesis ratios without adding silicone resin. Waterborne polyester resin greatly reduces organic solvents and protects the environment.

[0003] Water is widely sourced and easy to purify. Using water instead of solvents saves a large amount of resources. Water can be used during construction, and construction tools can also be cleaned with water. There is no fire hazard during the processing, and there are no toxic gases such as benzene-based organic solvents. The construction is non-toxic, odorless, meeting environmental protection requirements, harmless to the health of construction workers, and can be constructed in relatively enclosed places where use and construction are carried out simultaneously. Construction tools can be washed with water and reused. Waterborne polyester resin is a non-hazardous chemical, does not catch fire, and has a relatively high safety factor. Since the present invention improves high-temperature resistance, its application effect can reach a surface hardness of more than 4H, with strong scratch resistance, wear resistance, and high hardness characteristics.

[0004] Through a large number of experimental screenings, the present invention optimizes different raw materials and selects synthesis conditions to develop a waterborne, high-temperature resistant, good adhesion, high hardness, good impact performance, and medium viscosity waterborne environmentally friendly high-temperature resistant polyester resin with a solid content of about 70%. Summary of the Invention

[0005] Object of the Invention: The invention aims to preferably obtain a waterborne environmentally friendly high-temperature resistant polyester resin with high conversion rate, as well as high high-temperature resistance, weather resistance, chemical resistance, adhesion, glossiness, and good impact performance.

[0006] Technical Solution: To achieve the above object, the technical solution adopted by the present invention is:

[0007] A waterborne environmentally friendly high-temperature resistant polyester resin, characterized in that it is made from the following raw materials:

[0008] Component A: One or a combination of neopentyl glycol, methylpropanediol, and pentaerythritol;

[0009] Component B: One or a combination of trimethylolpropane and trimethylolethane;

[0010] Component C: One or a combination of glycidyl versatate, phthalic anhydride, trimellitic anhydride, and hexahydrophthalic anhydride;

[0011] Component D: one of benzoic acid, 1,4-cyclohexanedicarboxylic acid, isophthalic acid, 2,2-bis(hydroxymethyl)propionic acid, or a combination thereof;

[0012] Catalyst: one of dibutyltin dilaurate and monobutyltin oxide, or a combination thereof;

[0013] Co-solvent: one of γ-butyrolactone, ethylene glycol monobutyl ether, methylpropanediol monobutyl ether, ethylene glycol monomethyl ether, and propylene glycol monomethyl acetate, or a combination thereof.

[0014] As a preferred embodiment, the waterborne environmentally friendly high-temperature resistant polyester resin described above is made from the following raw materials by weight percentage:

[0015] Component A 5-20%, Component B 23-32%, Component C 2-8%, Component D 25-40%, catalyst 0.001-0.005%, co-solvent 25-40%.

[0016] As a preferred embodiment, the waterborne environmentally friendly high-temperature resistant polyester resin described above is made from the following raw materials by weight percentage: 16.7 g of methylpropanediol, 19.3 g of trimethylolethane, 3.6 g of glycidyl versatate, 25.6 g of 1,4-cyclohexanedicarboxylic acid, 5.4 g of 2,2-bis(hydroxymethyl)propionic acid, 0.02 g of monobutyltin oxide, and 29.06 g of co-solvent γ-butyrolactone.

[0017] As a preferred embodiment, the waterborne environmentally friendly high-temperature resistant polyester resin described above is made from the following raw materials by weight percentage: 12.8 of methylpropanediol, 8.5 g of pentaerythritol, 16.5 g of trimethylolethane, 3.6 g of glycidyl versatate, 28.6 g of 1,4-cyclohexanedicarboxylic acid, 0.02 g of monobutyltin oxide, and 28.64 g of co-solvent γ-butyrolactone.

[0018] The preparation method of the waterborne environmentally friendly high-temperature resistant polyester resin described in the present invention includes the following steps:

[0019] (1) First, add a certain amount of Component A, Component B, Component C, Component D, and catalyst to a four-necked flask, protect with nitrogen, and slowly raise the temperature;

[0020] (2) When the temperature in the four-necked flask reaches 80-100 °C, start stirring, continue to slowly raise the temperature, and pay attention to the distillation temperature;

[0021] (3) When the temperature in the four-necked flask is maintained at 160-180 °C, control the distillation temperature not to exceed 101 °C, and maintain for 5-8 hours;

[0022] (4) When the maintenance is completed, continue to raise the temperature. When the temperature in the four-neck flask reaches 190 - 210 °C and the solid acid value reaches 36 - 57 mg KOH / g (the liquid acid value reaches 25 - 40 mg KOH / g), lower the temperature and add a certain amount of cosolvent to obtain the product.

[0023] As a preferred embodiment, in the preparation method of the waterborne environmentally friendly high-temperature resistant polyester resin described above, it is characterized in that in steps (2), (3), and (4), after the materials in step (1) are added completely, nitrogen is passed through for protection throughout the process, the temperature is raised slowly, and care is taken to prevent material overflow; when the temperature in the four-neck flask in step (2) reaches 80 - 100 °C, start stirring, continue to raise the temperature slowly, and observe the column distillation temperature; when the temperature in the four-neck flask in step (3) is maintained at 160 - 180 °C for 5 - 8 hours, the distillation temperature is controlled not to exceed 101 °C; when the temperature in the four-neck flask in step (4) reaches 190 - 210 °C and the solid acid value reaches 36 - 57 mg KOH / g (the liquid acid value reaches 25 - 40 mg KOH / g), lower the temperature and add cosolvent to obtain the product.

[0024] As a preference, the preparation method of the waterborne environmentally friendly high-temperature resistant polyester resin of the present invention includes the following steps:

[0025] (1) First, add a certain amount of component A, component B, component C, component D, and catalyst to a four-neck flask, fill with nitrogen for protection, and raise the temperature slowly;

[0026] (2) When the temperature in the four-neck flask reaches 80 °C, start stirring, continue to raise the temperature slowly, and pay attention to the distillation temperature;

[0027] (3) When the temperature in the four-neck flask is maintained at 165 °C, the distillation temperature is controlled not to exceed 101 °C, and maintain for 5 - 6 hours;

[0028] (4) When the maintenance is completed, continue to raise the temperature. When the temperature in the four-neck flask reaches 190 - 200 °C and the solid acid value reaches 45 - 57 mg KOH / g or the liquid acid value reaches 30 - 40 mg KOH / g, lower the temperature and add a certain amount of cosolvent to obtain the product.

[0029] The present invention adopts a positive-pressure high-temperature melting polymerization process to preferably adjust the system with the best ratio of hydroxyl groups and carboxyl groups, and screens the composition of each raw material through a large number of experiments. Among the raw materials used in the present invention, trimethylolethane has a neopentane structure, which can improve hydrophilicity and high-temperature resistance; the carboxyl group of glycidyl versatate is a short chain, which can reduce the cosolvent and improve the gloss; the carboxyl group of 2,2-dimethylolpropionic acid plays a chain-extending role and can improve hydrophilicity; the cosolvents are all hydrophilic, low-toxic, and friendly solvents.

[0030] Beneficial effects: The present invention has the following advantages:

[0031] Through a large number of experimental screenings, the present invention adopts a high-temperature melting polymerization process, and simultaneously optimizes and adjusts the system with the best hydroxyl and carboxyl ratios. The waterborne polyester resin is formed by esterification polymerization of polyols and polyacids. The conversion rate of the present invention is as high as 96.86%, and the resin solid content can reach more than 70%. Moreover, the waterborne polyester resin of the present invention has comprehensive properties such as a large amount of added water, high temperature resistance, high adhesion, high hardness, and good impact resistance, and has a relatively low viscosity and a relatively reasonable cost. It has strong practicability. Detailed implementation mode

[0032] Example 1

[0033] 1. A preparation method of a waterborne environmentally friendly high-temperature resistant polyester resin, which comprises the following steps:

[0034] (1) First, add 16.7 g of methylpropanediol, 19.3 g of trimethylolethane, 3.6 g of glycidyl versatate, 25.6 g of 1,4-cyclohexanedicarboxylic acid, 5.4 g of 2,2-dimethylolpropionic acid, and 0.02 g of monobutyltin oxide into a four-necked flask, protect with nitrogen, and slowly raise the temperature;

[0035] (2) When the temperature in the four-necked flask reaches 80 °C, start stirring and continue to slowly raise the temperature, paying attention to the distillation temperature;

[0036] (3) When the temperature in the four-necked flask is maintained at 165 °C and the distillation temperature is controlled not to exceed 101 °C, maintain for 5.5 hours;

[0037] (4) When the maintenance ends, continue to raise the temperature. When the temperature in the four-necked flask reaches 200 °C and the solid acid value reaches 55 mg KOH / g (the liquid acid value reaches 38.5 mg KOH / g), cool down and add 29.06 g of co-solvent γ-butyrolactone to obtain the resin. The conversion rate of the final reaction is 96.86%, and the resin solid content is 70%.

[0038] 2. Put the resin prepared in Example 1 and various fillers in Table 1 below into a preparation tank in proportion, stir in a sand mill (2000 revolutions per minute), filter to make a resin white paint slurry, then dilute with 30% ionized water, spray on a board to make the paint thickness reach 23 μm; after the white paint board is made, bake it in an oven at 140 °C for 20 minutes and measure its performance. The test results of its performance are shown in Table 2.

[0039] Table 1 Composition of the industrial coating formula of waterborne polyester resin

[0040] Raw material name Weight (g) Polyester resin prepared in Example 1 100 Dimethylethanolamine 5.85 g, PH = 7 Dispersant BYK190 1 Defoamer BYK022 0.4 Leveling agent BYK307 0.5 Titanium dioxide 50 Ionized water 15 Ethylene glycol monobutyl ether 18 Propylene glycol monomethyl ether acetate 12

[0041] Table 2 Test results of the paint film performance

[0042] Appearance Smooth and particle-free Visual inspection Gloss About 96 GB / T1743-1989 Hardness (pencil scratch) 3H GB / T6739-2006 Impact (recoil) (kg.cm) 50 GB / T1732-2020 Flexibility 1 mm GB / T1731-2020 Adhesion (cross-cut method) Grade 1 GB / T1720-2020 Heat resistance (oven baking) 250 °C / 10 minutes GB / T1735-2009 。

[0043] Example 2

[0044] A preparation method of a waterborne environmentally friendly high-temperature resistant polyester resin, which comprises the following steps:

[0045] (1) First, add 12.8 of methylpropanediol, 8.5 g of pentaerythritol, 16.5 g of trimethylolethane, 3.6 g of glycidyl versatate, 28.6 g of 1,4-cyclohexanedicarboxylic acid, and 0.02 g of monobutyltin oxide into a four-necked flask, protect with nitrogen, and slowly raise the temperature;

[0046] (2) When the temperature in the four-necked flask reaches 80 °C, start stirring, continue to slowly raise the temperature, and pay attention to the distillation temperature;

[0047] (3) When the temperature in the four-necked flask is maintained at 165 °C, control the distillation temperature not to exceed 101 °C, and maintain for 5.5 hours;

[0048] (4) When the maintenance is completed, continue to raise the temperature. When the temperature in the four-necked flask reaches 200 °C and the solid acid value reaches 54 mg KOH / g (the liquid acid value reaches 37.8 mg KOH / g), cool down, and add 28.64 g of co-solvent γ-butyrolactone to obtain the resin. The conversion rate of the final reaction is 95.46%, and the resin solid content is 70%.

[0049] 2. Prepare a paint film according to the same paint formula composition as in Example 1, and the performance test is as shown in Table 3 below.

[0050] Table 3 Test Results of Paint Film Performance

[0051] Appearance Smooth and particle-free Visual inspection Gloss About 90 GB / T1743-1989 Hardness (pencil scratch) 3H GB / T6739-2006 Impact (recoil) (kg.cm) 30 GB / T1732-2020 Flexibility 2 mm GB / T1731-2020 Adhesion (cross-cut method) Grade 1 GB / T1720-2020 Heat resistance (oven baking) 220 °C / 10 minutes GB / T1735-2009 。

[0052] Example 3

[0053] A preparation method of a waterborne environmentally friendly high-temperature resistant polyester resin, which comprises the following steps:

[0054] (1) First, add 5.5 g of neopentyl glycol, 8.5 g of pentaerythritol, 18.3 g of trimethylolethane, 4.5 g of trimellitic anhydride, 3.6 g of benzoic acid, 29.6 g of isophthalic acid, and 0.02 g of monobutyltin oxide into a four-necked flask, protect with nitrogen, and slowly raise the temperature;

[0055] (2) When the temperature in the four-necked flask reaches 90 °C, start stirring, continue to slowly raise the temperature, and pay attention to the distillation temperature;

[0056] (3) When the temperature in the four-necked flask is maintained at 165 °C, control the distillation temperature not to exceed 101 °C, and maintain for 5.5 hours;

[0057] (4) When the maintenance is completed, continue to raise the temperature. When the temperature in the four-neck flask reaches 200 °C and the solid acid value reaches 57 mg KOH / g (the liquid acid value reaches 40 mg KOH / g), lower the temperature and add 27.99 g of the co-solvent ethylene glycol monobutyl ether to obtain the resin. The conversion rate of the final reaction is 93.33%, and the resin solid content is 70%.

[0058] 2. Prepare a paint film according to the same paint formulation composition as in Example 1, and the performance test results are shown in Table 4 below.

[0059] Table 4 Performance test results of the paint film:

[0060] Appearance Smooth and particle-free Visual inspection Gloss About 86 GB / T1743-1989 Hardness (pencil scratch) 3H GB / T6739-2006 Impact (recoil) (kg.cm) 40 GB / T1732-2020 Flexibility 2 mm GB / T1731-2020 Adhesion (cross-cut method) Grade 1 GB / T1720-2020 Heat resistance (oven baking) 200 °C / 10 minutes GB / T1735-2009 。

[0061] Example 4

[0062] A preparation method of a waterborne environmentally friendly high-temperature resistant polyester resin, which comprises the following steps:

[0063] (1) First, add 5.5 g of neopentyl glycol, 8.5 g of pentaerythritol, 16.5 g of trimethylolpropane, 3.6 g of phthalic anhydride, 6.5 g of hexahydrophthalic anhydride, 3.6 g of benzoic acid, 25.8 g of isophthalic acid, and 0.02 g of dibutyltin dilaurate into a four-neck flask, protect with nitrogen, and slowly raise the temperature;

[0064] (2) When the temperature in the four-neck flask reaches 90 °C, start stirring and continue to slowly raise the temperature, paying attention to the distillation temperature;

[0065] (3) When the temperature in the four-neck flask is maintained at 165 °C, control the distillation temperature not to exceed 101 °C and maintain for 5.5 hours;

[0066] (4) When the maintenance is completed, continue to raise the temperature. When the temperature in the four-neck flask reaches 200 °C and the solid acid value reaches 56 mg KOH / g (the liquid acid value reaches 39 mg KOH / g), lower the temperature and add 28.23 g of the co-solvent ethylene glycol monomethyl ether to obtain the resin. The conversion rate of the final reaction is 94.1%, and the resin solid content is 70%.

[0067] 2. Prepare a paint film according to the same paint formulation composition as in Example 1, and the performance test results are shown in Table 5 below.

[0068] Table 5 Performance test results of the paint film:

[0069]

[0070]

[0071] Table 6 Water addition performance test results of Examples 1-4:

[0072] Name Resin weight (g) Dimethylethanolamine (g) Ionized water (g) Appearance, visual inspection Example 1 100 5.92 250 Clear Example 2 100 5.81 100 Clear Example 3 100 6.15 80 Clear Example 4 100 6 70 Clear

[0073] By comparing Example 3 with Example 4, when trimethylolethane is used instead of trimethylolpropane, the gloss is significantly improved, and the high temperature resistance is increased from 180 °C to 200 °C; when Example 2 is compared with Example 3, when 1,4-cyclohexanedicarboxylic acid is used instead of isophthalic acid, the water addition amount of the resin is significantly increased, and when glycidyl versatate is used instead of trimellitic anhydride, the resin viscosity is significantly decreased, which is beneficial to construction applications and improves the solid content of the paint film. By comparing Example 1 with Example 2, when 2,2-dimethylolpropionic acid is added, both the water addition amount and the temperature resistance are improved. Finally, the viscosity of the resin in Example 1 is moderate. The water addition amount can be twice the amount of the resin, and the high temperature resistance can reach 250 °C for 10 minutes, indicating the scientificity of the component ratios and achieving very good and unexpected technical effects.

[0074] And the comparison results of the above examples show that due to the different raw materials of each component and the different dosages of the raw materials, the final performance has a large change, and the performance of Example 1 of the present invention is significantly better than that of other examples.

[0075] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and retouches can be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of a water-based environmentally friendly high-temperature resistant polyester resin, characterized in that, It includes the following steps: (1) First, add 16.7 g of methyl propylene glycol, 19.3 g of trimethylolethane, 3.6 g of glycidyl versatate, 25.6 g of 1,4-cyclohexanedicarboxylic acid, 5.4 g of 2,2-dimethylolpropionic acid, and 0.02 g of monobutyltin oxide into a four-necked flask, protect with nitrogen, and slowly raise the temperature; (2) When the temperature in the four-necked flask reaches 80 °C, start stirring, continue to slowly raise the temperature, and pay attention to the distillation temperature; (3) When the temperature in the four-necked flask is maintained at 165 °C and the distillation temperature is controlled not to exceed 101 °C, maintain for 5.5 hours; (4) When the maintenance ends, continue to raise the temperature. When the temperature in the four-necked flask reaches 200 °C and the solid acid value reaches 55 mg KOH / g or the liquid acid value reaches 38.5 mg KOH / g, cool down and add 29.06 g of co-solvent γ-butyrolactone to obtain the resin.

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