A modified polyester resin and a method for preparing the same

Abstract

The present application relates to the field of high polymer, and in particular to a modified polyester resin and a preparation method thereof.The modified polyester resin is prepared from the following raw materials: odorless salad oil, castor oil, a first antioxidant, water, mixed acid, polyhydric alcohol, odorless oleic acid, phthalic anhydride, pentaerythritol, a second antioxidant, dimethylbenzene and butyl acetate.The oil is connected to soybean oleic acid, so that the branched chain provides better hardness, dryness, solvent resistance, solvent release and the like, thereby achieving the effects of anti-swelling and anti-collapse, and solving the defects of poor hole entry, easy collapse, easy swelling, strong odor and the like of the traditional PU paint resin.

Description

Technical Field

[0001] This invention relates to the field of polymers, specifically to a modified polyester resin and its preparation method. Background Technology

[0002] Traditional PU paint resins suffer from drawbacks such as poor pore penetration, easy collapse, easy bulging, and strong odor. Especially when applied to deep-veined solid wood, bulging is obvious during surface drying, and the dry film collapses particularly severely, which traditional alkyd resins cannot solve. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the prior art, or at least provide a commercial alternative.

[0004] This invention provides a modified polyester resin and its preparation method. This invention grafts oil onto soybean oleic acid, which provides better hardness, drying properties, solvent resistance, and solvent release properties, thereby achieving the effects of anti-swelling and anti-collapse. This solves the defects of traditional PU paint resins such as poor pore penetration, easy collapse, easy swelling, and strong odor.

[0005] A method for preparing a modified polyester resin, comprising:

[0006] 1) The odor-neutralizing salad oil, castor oil, first antioxidant, first solvent, organic acid and polyol are reacted at 228-232℃ in an environment with CO2 flow;

[0007] 2) Cool the reaction product from step 1) to below 180°C, add odor-neutralizing oleic acid, phthalic anhydride, pentaerythritol, a second antioxidant, a second solvent, and a first aromatic hydrocarbon; carry out the reaction at 178-182°C in an environment with CO2 flow.

[0008] 3) Heat the reaction product from step 2) to 188-192℃; make the acid value of the material less than or equal to 15mgKOH / g and the viscosity (Grünster viscosity) 18-20S / 25℃; cool it down to 170℃ or below, and then mix it evenly with the second aromatic hydrocarbon and butyl acetate.

[0009] According to an embodiment of the present invention, the acid value of the odor-neutralizing salad oil is less than or equal to 1 mgKOH / g. It has a faint oily aroma and no off-odors.

[0010] According to an embodiment of the present invention, the odor-neutralizing salad oil is a high-grade odor-neutralizing salad oil.

[0011] According to an embodiment of the present invention, the castor oil has an acid value of less than or equal to 1 mgKOH / g mg, a hydroxyl value of 160-170 mgKOH / g, and an iodine value of 80-90 gI2 / 100g.

[0012] According to an embodiment of the present invention, the organic acid is adipic acid.

[0013] According to an embodiment of the present invention, the organic acid is a mixed acid; wherein the mixed acid contains C8-C 12 Content 25%, C 18 Content 75%, acid value: 190-210 mgKOH / g.

[0014] In some specific instances, the mixed acid is a mixture of fatty acids, such as C8 acid, lauric acid, etc.

[0015] According to an embodiment of the present invention, the hydroxyl content of the polyol is 49%.

[0016] In some specific examples, the polyol is pentaerythritol, diethylene glycol, glycerol, etc.

[0017] According to an embodiment of the present invention, the C in the odor-neutralizing oleic acid is... 12 Content 10%, C 18 Content 90%, acid value: 190-210mgKOH / g, iodine value: 120-130gI2 / 100g.

[0018] According to embodiments of the present invention, the first antioxidant and the second antioxidant may be the same or different, and may be independently selected from PU01 (hypophosphoric acid) and BHT (2,6-di-tert-butyl-4-methylphenol).

[0019] According to embodiments of the present invention, the first aromatic hydrocarbon and the second aromatic hydrocarbon may be the same or different, and may be independently selected from xylene, toluene, trimethylbenzene, etc.

[0020] According to embodiments of the present invention, the first solvent and the second solvent may be the same or different, and may each be independently selected from water.

[0021] According to an embodiment of the present invention, the reaction temperature in step 1) is 228°C, 230°C or 232°C.

[0022] According to an embodiment of the present invention, the reaction time in step 1) is 1-5 hours.

[0023] According to an embodiment of the present invention, step 1) is carried out under stirring conditions, specifically, stirring can be started in a jogging manner when the temperature is raised to 100°C.

[0024] According to an embodiment of the present invention, the reaction temperature in step 2) is 178°C, 180°C or 182°C.

[0025] According to an embodiment of the present invention, the reaction time in step 2) is 1-5 hours.

[0026] According to an embodiment of the present invention, step 2) is carried out under stirring conditions.

[0027] According to an embodiment of the present invention, the raw materials used, by weight, are as follows:

[0028]

[0029]

[0030] According to an embodiment of the present invention, the raw materials used, by weight, are as follows:

[0031] Raw material number Raw material name weight 1 Pure Salad Oil 9-11 servings 2 castor oil 9 copies 3 First antioxidant 0.1 copies 4 First solvent (pure water) 0.1 copies 5 organic acids 3-8 servings 6 polyols 10-13 servings 7 Pure Oleic Acid 2-7 portions 8 Phthalic anhydride 25-30 servings 9 Pentaerythritol 3.4 copies 10 Second antioxidant (hypophosphoric acid) 0.1 copies 11 Second solvent (pure water) 0.1 copies 12 First aromatic hydrocarbon (xylene) 2.4 copies 13 Second aromatic hydrocarbon (xylene) 13.6 copies 14 Butyl acetate 14 copies

[0032] According to a specific embodiment of the present invention, the modified polyester resin is prepared as follows:

[0033] Raw materials 1 and 2 are drawn into the reactor, and CO2 is introduced for 15 minutes to displace the air inside the reactor. Then, raw material 3 is weighed accurately using a clean plastic bucket and diluted with raw material 4 (the ratio of raw materials 3 and 4 is 1:1), and added to the reactor together. Avoid contact with iron during addition, and rinse the vessels and pipes with water after addition. After adding raw materials 3 and 4, add raw materials 5 and 6. After adding all raw materials, cover the manhole cover, maintain CO2 flow, and simultaneously turn on the horizontal condenser cooling water to start heating. When the temperature inside the reactor reaches 100℃, start stirring in a jogging manner. When the temperature reaches 230℃±2℃ and is held at that temperature for 2 hours, cool down to below 180℃ and add the following raw materials 7-12.

[0034] When adding raw material 10, weigh it accurately using a clean plastic container. Dilute it with raw material 11 (the ratio of raw material 10 to 11 is 1:1) and add it to the reactor together. Avoid contact with iron during addition. After adding the materials, cover the manhole and maintain CO2 flow. Simultaneously, turn on the horizontal condenser cooling water to start heating. When the reactor temperature reaches 100℃, start stirring in a jogging manner. When the temperature reaches 180℃±2℃, hold it at that temperature for 2 hours. After holding at that temperature, heat it uniformly to 190℃ over approximately 3 hours. At this temperature, esterify until the acid value and viscosity are within acceptable limits, then cool and discharge the material. Before discharging, pump raw material 13 into the dilution vessel.

[0035] Once the temperature reaches 190℃, begin testing AV and viscosity. Initially, sample and test every hour. When AV < 15 mg KOH / g / % (60%), sample and test every half hour. The testing time can be shortened depending on the actual situation. Continue testing until the viscosity (Gräger tube viscosity) reaches 60% at 20S / 25℃ and AV < 18 mg KOH / g 60%), then cool down and discharge the material. Add raw material 13 to the dilution vessel beforehand.

[0036] After the acid value and viscosity meet the requirements, the mixture is cooled to 170℃ and transferred to a diluent. After the transfer is complete, the mixture is added to the diluent along with the 14-material-cleaning reactor. The mixture is stirred for 40 minutes, and a sample is taken for AV testing. If the viscosity is within the specified range, it is then filtered and packaged (fineness ≤10µm).

[0037] Finished product specifications: Viscosity (applied viscosity): 6000-12000 CPS / 25℃, Acid value: ≤18KOH mg / g, Solid content: 60% ± 1.5%.

[0038] In some specific examples, the viscosity (application viscosity) of the modified polyester resin is 7500-10000 CPS / 25°C.

[0039] The present invention also includes the modified polyester resin prepared by the above method.

[0040] The modified polyester resin of this invention has the following characteristics: acid value: ≤18KOH mg / g, viscosity: 6000-12000 CPS / 25℃, and solid content: 60% ± 1.5%.

[0041] The fineness of the modified polyester resin of this invention is ≤10μm.

[0042] This invention grafts an oil with a small amount of hydroxyl groups onto a resin and then optimizes the formulation to obtain a polymer with a narrow molecular weight distribution, thereby resulting in a higher hardness, better adhesion, and better solvent release of the paint film. Since the paint film's extensibility is improved after grafting the oil, and the process eliminates the need for staged heat preservation, the reaction time is greatly shortened and energy consumption is reduced. Detailed Implementation

[0043] The following examples are for illustrative purposes only and are not intended to limit the scope of the invention. Where specific techniques or conditions are not specified in the examples, they should be performed according to the techniques or conditions described in the literature in this field, or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased from legitimate channels.

[0044] The following methods are used to determine viscosity:

[0045] Grignard tube viscosity: Pour the sample into the Grignard tube until it is level with the lower graduation line, then stopper it with a rubber stopper until it is level with the upper graduation line. Place it in a constant temperature water bath at 25°C and let it stand for 10 minutes. Remove the Grignard tube and invert it. Simultaneously start a stopwatch. Stop the stopwatch when the air bubbles in the sample reach the top of the Grignard tube. The recorded time is the viscosity unit of the sample. This method is generally used for testing during central control production.

[0046] Viscosity transfer method: Operate according to national standard methods, with units of cps. The viscosity of the final product is tested using this method.

[0047] Example 1

[0048] This embodiment provides a modified polyester resin, prepared by the following method:

[0049] The raw materials, by weight, are as follows:

[0050]

[0051]

[0052] 1) Replace the air in the reactor with CO2, then add raw materials 1-6 (of which, raw materials 3 and 4 should be mixed and dispersed before being added to the reactor; avoid contact with iron during addition). Keep the reactor purging with CO2 and heat to 230℃ for 2 hours.

[0053] 2) Cool the reaction product from step 1) to below 180°C, add raw materials 7-12 (wherein, raw materials 10 and 11 are mixed and dispersed before being added to the reactor; avoid contact with iron when adding); keep CO2 flowing through the reactor, raise the temperature to 180°C and keep it at that temperature for 2 hours.

[0054] 3) Heat the reaction product from step 2) to 190℃ (heat at a constant rate for about 3 hours); when the acid value of the material is 18mgKOH / g and the viscosity (Greek tube viscosity) is 20S / 25℃, cool it down to 170℃ or below, and then mix it evenly with raw material 13-14.

[0055] Finished product specifications: Viscosity (applied viscosity): 7500 CPS / 25℃, Acid value: 18 KO mgKOH / g Hmg / g, Solid content: 60.6%, Fineness ≤10um.

[0056] The modified polyester resin prepared in this embodiment has a low odor, slightly better leveling, slightly better hardness, and good gloss retention.

[0057] Example 2

[0058] This embodiment provides a modified polyester resin, prepared by the following method:

[0059] The raw materials, by weight, are as follows:

[0060]

[0061]

[0062] 1) Replace the air in the reactor with CO2, then add raw materials 1-6 (of which, raw materials 3 and 4 should be mixed and dispersed before being added to the reactor; avoid contact with iron during addition). Keep the reactor purging with CO2 and heat to 228℃ for 3 hours.

[0063] 2) Cool the reaction product from step 1) to below 180°C, add raw materials 7-12 (wherein, raw materials 10 and 11 are mixed and dispersed before being added to the reactor; avoid contact with iron when adding); keep CO2 flowing through the reactor, raise the temperature to 180°C and keep it at that temperature for 2 hours.

[0064] 3) Heat the reaction product from step 2) to 192℃ (heat at a constant rate for about 3 hours); when the acid value of the material is 16mgKOH / g and the viscosity (Greek tube viscosity) is 20S / 25℃, cool it down to 170℃ or below, and then mix it evenly with raw material 13-14.

[0065] Finished product specifications: Viscosity (applied viscosity): 8400 CPS / 25℃, Acid value: 16 mg KOH / g, Solid content: 60.5%.

[0066] The modified polyester resin prepared in this embodiment has a low odor, slightly better leveling, good solvent volatility, high hardness after drying, good fullness, and good gloss retention. The addition of adipic acid in this embodiment increases the hardness after complete drying and also improves fullness and gloss retention.

[0067] Example 3

[0068] This embodiment provides a modified polyester resin, prepared by the following method:

[0069] The raw materials, by weight, are as follows:

[0070] Raw material number Raw material name weight 1 Odorless premium salad oil 11 copies 2 castor oil 9 copies 3 The first antioxidant (i.e., BHT) 0.1 copies 4 First solvent (pure water) 0.1 copies 5 adipic acid 3 copies 6 Polyols (diethylene glycol) 10 copies 7 Pure Oleic Acid 7 copies 8 Phthalic anhydride 25 copies 9 Pentaerythritol 3.4 copies 10 The second antioxidant (i.e., BHT) 0.1 copies 11 Second solvent (pure water) 0.1 copies 12 First aromatic hydrocarbon (i.e., xylene) 2.4 copies 13 Secondary aromatic hydrocarbon (i.e., xylene) 13.6 copies 14 Butyl acetate 14 copies

[0071] 1) Replace the air in the reactor with CO2, and then add raw materials 1-6 (of which, raw materials 3 and 4 should be mixed and dispersed before being added to the reactor; avoid contact with iron when adding).

[0072] Keep CO2 flowing through the reactor and heat it to 232°C for 2 hours.

[0073] 2) Cool the reaction product from step 1) to below 180°C, and add raw materials 7-12 (wherein, raw materials 10 and 11 should be mixed and dispersed before being added to the reaction vessel; avoid contact with iron during addition);

[0074] Keep CO2 flowing through the reactor and heat it to 180°C for 2 hours.

[0075] 3) Heat the reaction product from step 2) to 188℃ (heat at a constant rate for about 3 hours); when the acid value of the material is 15mgKOH / g and the viscosity (Greek tube viscosity) is 20S / 25℃, cool it down to 170℃ or below, and then mix it evenly with raw material 13-14.

[0076] Finished product specifications: Viscosity (applied viscosity): 10000 CPS / 25℃, Acid value: 15 mg KOH / g, Solid content: 60.3%.

[0077] The modified polyester resin prepared in this embodiment has extremely low odor, good leveling properties, and a long activation period. Adding odor-neutralizing high-grade salad oil and odor-neutralizing oleic acid further reduces the odor significantly, while improving leveling and pore penetration.

[0078] Comparative Example 1

[0079] This comparative example provides a modified polyester resin, prepared by the following method:

[0080] The raw materials, by weight, are as follows:

[0081] Raw material number Raw material name weight 1 Odorless premium salad oil 18 copies 2 castor oil 10 copies 3 The first antioxidant (i.e., BHT) 0.1 copies 4 The first solvent (i.e., water) 0.1 copies 5 adipic acid 5 copies 6 polyols 13 copies 7 Pure Oleic Acid 2 copies 8 Phthalic anhydride 32 copies 9 Pentaerythritol 3 copies 10 The second antioxidant (i.e., BHT) 0.1 copies 11 The second solvent (i.e., water) 0.1 copies 12 First aromatic hydrocarbon (i.e., xylene) 2.4 copies 13 Secondary aromatic hydrocarbon (i.e., xylene) 13.6 copies 14 Butyl acetate 14 copies

[0082] 1) Replace the air in the reactor with CO2, then add raw materials 1-6 (of which, raw materials 3 and 4 should be mixed and dispersed before being added to the reactor; avoid contact with iron during addition). Keep the reactor purging with CO2 and heat to 230℃ for 2 hours.

[0083] 2) Cool the reaction product from step 1) to below 180°C, add raw materials 7-12 (wherein, raw materials 10 and 11 are mixed and dispersed before being added to the reactor; avoid contact with iron when adding); keep CO2 flowing through the reactor, raise the temperature to 180°C and keep it at that temperature for 2 hours.

[0084] 3) Heat the reaction product from step 2) to 190℃ (heat at a constant rate for about 3 hours); when the acid value of the material is 15mgKOH / g and the viscosity (Greek tube viscosity) is 20S / 25℃, cool it down to 170℃ or below, and then mix it evenly with raw material 13-14.

[0085] Finished product specifications: Viscosity (applied viscosity): 6000 CPS / 25℃; Acid value: 15 mg KOH / g; Solid content: 60.3%.

[0086] The modified polyester resin film prepared in this embodiment is soft and has a strong odor, but it has good leveling and pore penetration.

[0087] Experimental Example

[0088] The above examples and comparative samples were prepared with PU polyurethane super-clear primer according to the PU super-clear primer: PU polyurethane hardener: PU thinner = 1:0.5:0.7. After standing for 3 minutes, the viscosity of the mixture was tested using a No. 2 coating cup. Color swatches were made on ash wood boards according to the normal process, and the relevant performance indicators were tested after drying for 48 hours. The results are shown in the table below.

[0089] Serial Number Test Project Example 1 Example 2 Example 3 Comparative Example 1 1 Initial viscosity (Ford Cup 2) 15.31s 15.93s 14.74s 15.78s 2 Viscosity after 2 hours 17.92s 23.48s 16.92s 22.45s 3 Viscosity after 4 hours 24.81s 32.12s 18.42s 26.74s 4 Viscosity after 6 hours 36.57s 43.15s 20.35s 32.18s 5 Chinese pencil hardness HB H H HB 6 Adhesion (cross-cut) 1 2 1 2 7 Odor of dried board after 48 hours Low odor Strong odor Almost tasteless The strongest smell 8 Paint film leveling performance good generally excellent better 9 7d gloss retention performance good good excellent good 10 Anti-substituent sagging performance good good excellent good 11 Hot and cold cycles (8 times) No change Slight white No change No change

[0090] As shown in the table above, Example 3 has the best performance, solving an industry problem. The product can maintain excellent anti-biting and anti-sinking performance under extremely low odor conditions, which can meet the product needs of the high-end solid wood bedroom set market.

[0091] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing a modified polyester resin, characterized in that, include: 1) The odor-neutralizing salad oil, castor oil, first antioxidant, first solvent, organic acid and polyol are reacted at 228-232℃ in an environment with CO2 flow; 2) Cool the reaction product from step 1) to below 180°C, add odor-neutralizing oleic acid, phthalic anhydride, pentaerythritol, a second antioxidant, a second solvent, and a first aromatic hydrocarbon; carry out the reaction at 178-182°C in an environment with CO2 flow. 3) Heat the reaction product from step 2) to 188-192℃; make the acid value of the material less than or equal to 15 mgKOH / g and the viscosity 18-20S / 25℃; cool it down to 170℃ or below, and then mix it evenly with the second aromatic hydrocarbon and butyl acetate. The raw materials used, by weight, are as follows: 8-12 parts of clean-flavored salad oil 7-11 parts castor oil First antioxidant 0.05-0.2 parts First solvent: 0.05-0.2 parts 1-10 parts organic acids 8-17 parts of polyols 1-8 parts of clean oleic acid Phthalic anhydride 24-32 parts Pentaerythritol 2.5-5.5 parts Second antioxidant 0.05-0.2 parts Second solvent 0.05-0.2 parts 1-3 parts of the first aromatic hydrocarbon 9-14 parts of secondary aromatic hydrocarbons 9-15 parts of butyl acetate.

2. The method for preparing the modified polyester resin according to claim 1, characterized in that, The acid value of the purified salad oil is less than or equal to 1 mgKOH / g; and / or, The castor oil has an acid value of less than or equal to 1 mg KOH, a hydroxyl value of 160-170 mg KOH / g, and an iodine value of 80-90 g I₂ / 100g; and / or, C in the odor-neutralizing oleic acid 12 Content 10%, C 18 Content 90%, acid value: 190-210 mgKOH / g, iodine value: 120-130 gI2 / 100g.

3. The method for preparing the modified polyester resin according to claim 1, characterized in that, The organic acid is adipic acid or a mixture of acids; and / or... The mixed acid contains C8-C 12 Content 25%, C 18 Content 75%, acid value: 190-210 mgKOH / g; The polyol has a hydroxyl content of 49%.

4. The method for preparing the modified polyester resin according to claim 3, characterized in that, The polyols are pentaerythritol, diethylene glycol, and glycerol.

5. The method for preparing the modified polyester resin according to claim 1, characterized in that, The first antioxidant may be the same as or different from the second antioxidant, and each may be independently selected from hypophosphite or BHT.

6. The method for preparing the modified polyester resin according to claim 1, characterized in that, The first aromatic hydrocarbon may be the same as or different from the second aromatic hydrocarbon.

7. The method for preparing the modified polyester resin according to claim 6, characterized in that, The first aromatic hydrocarbon and the second aromatic hydrocarbon are each independently selected from xylene, toluene, and trimethylbenzene.

8. The method for preparing the modified polyester resin according to claim 1, characterized in that, The first solvent may be the same as or different from the second solvent.

9. The method for preparing the modified polyester resin according to claim 8, characterized in that, The first solvent and the second solvent are both water.

10. The method for preparing the modified polyester resin according to any one of claims 1-7, characterized in that, The raw materials used, by weight, are as follows: 9-11 parts of clean-flavored salad oil 9 parts castor oil First antioxidant 0.1 parts 0.1 parts of the first solvent 3-8 parts organic acids 10-13 parts of polyol 2-7 parts of clean oleic acid 25-30 parts of phthalic anhydride Pentaerythritol 3.4 parts Second antioxidant 0.1 parts 0.1 parts of the second solvent 2.4 parts of the first aromatic hydrocarbon 13.6 parts of the second aromatic hydrocarbon 14 parts of butyl acetate.

11. The modified polyester resin prepared by the method according to any one of claims 1-10.

12. The modified polyester resin according to claim 11, characterized in that, Its acid value is ≤18 mgKOH / g, viscosity is 6000-12000 CPS / 25℃, and solid content is 60%±1.5%.

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