Stabilizer and method for preparing grafted polyester polyol by using stabilizer

Abstract

The invention provides a stabilizer and application of the stabilizer to preparation of grafted polyester polyol. The stabilizer is obtained by carrying out esterification reaction on polyester polybasic acid and metacrylic acid ester with reaction activity on acid, and the number-average molecular weight of the stabilizer is 1000-3800; the polyester polybasic acid is obtained by reacting small molecule polyhydric alcohol and small molecule polybasic acid, the number-average molecular weight of the polyester polybasic acid is 700-3500, and the preferable acid value is 32-160 mgKOH / g; the metacrylic acid ester with reaction activity on acid contains an epoxy structure, and is preferably glycidyl methacrylate. The stabilizer is low in viscosity and good in operability, no side reaction occurs in the synthesis process, the uniform dispersity of a vinyl monomer can be effectively improved in the grafted polyester polyol preparation process, and the obtained grafted polyester polyol is low in viscosity, good in chromaticity and good in storage stability compared with conventional grafted polyester polyol and can better meet the downstream use requirement.

Description

Technical Field

[0001] The invention relates to the field of chemistry and chemical engineering, in particular to a stabilizer and to a grafted polyester polyol obtained by using the stabilizer. Background Art

[0002] Grafted polyester polyols are widely used in polyurethane foam products. They can effectively increase the open porosity, prevent product shrinkage, increase hardness, and improve mechanical properties. At the same time, they also improve the solvent resistance and spray paint resistance of the products. Grafted polyester polyols are mainly prepared by polymerizing monomers containing unsaturated groups in basic polyester polyols to form a stable emulsion system. They usually need to be prepared in the presence of stabilizers. Currently, there are two main types of conventional stabilizers: (1) stabilizers containing vinyl structures, which are obtained by dehydrating vinyl-containing polyester polyols after esterification and polycondensation of vinyl-containing dibasic acids or diols (such as maleic anhydride, etc.) with adipic acid and diols; (2) stabilizers containing acrylate / methacrylate structures, which are obtained by reacting acrylates (such as hydroxyethyl acrylate, hydroxyethyl methacrylate, etc.) with isocyanates and polymer polyols to obtain acrylate / methacrylate modified polyester polyols. For (1) stabilizers containing vinyl structures, vinyl is unstable at high temperatures, and the temperature required for the synthesis of grafted polyester polyols using such stabilizers is very high. Vinyl will undergo side reactions at high temperatures, causing the product to turn yellow or cross-link, resulting in poor color and high viscosity of the prepared grafted polyester polyols. When using stabilizers containing acrylate / methacrylate structures to synthesize grafted polyester polyols, the reaction temperature requirement is much lower, and there will be no problems with product color and viscosity. However, due to the introduction of carbamate bonds, such stabilizers have a large viscosity, and their molecular weight, structure and functionality are also limited due to viscosity considerations (too low molecular weight or too high functionality will result in too high a carbamate bond content in the molecule and too high a viscosity). In addition, the reaction of acrylates and isocyanates is significantly exothermic, poor controllability, and poor operability in the actual production process. Therefore, it is particularly important to provide a stabilizer with good adjustability of molecular weight and molecular structure, good reaction controllability, and good operability. Summary of the invention

[0003] Technical problem: In order to overcome the shortcomings of the prior art, the present invention provides a stabilizer and the use of the stabilizer for the preparation of grafted polyester polyols; the stabilizer has low viscosity, good operability, and no side reactions occur during the synthesis process. In the process of preparing grafted polyester polyols, the uniform dispersion of vinyl monomers can be effectively improved. The obtained grafted polyester polyols have lower viscosity than conventional grafted polyester polyols, better chroma, and good storage stability, which can better meet downstream usage needs.

[0004] Technical solution: The present invention provides a stabilizer, which is obtained by esterification reaction of polyester polyacid and methacrylate reactive to acid, and the number average molecular weight of the stabilizer is 1000-3800.

[0005] The polyester polyacid is obtained by reacting a small molecule polyol and a small molecule polyacid. The number average molecular weight of the polyester polyacid is 700 to 3500, and the preferred acid value is 32 to 160 mgKOH / g.

[0006] The acid-reactive methacrylate contains an epoxy structure, and is preferably glycidyl methacrylate.

[0007] The small molecule polyols include small molecule polyols of C2 to C10, and the small molecule polyacids include small molecule dibasic acids of C4 to C20.

[0008] The C2-C10 small molecule polyol is selected from one or more of ethylene glycol, diethylene glycol, propylene glycol, trimethylolpropane, butanediol, pentaerythritol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, and decanediol; the C4-C20 small molecule dibasic acid is selected from one or more of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, decanediol, and phthalic acid.

[0009] The polyester polyacid and methacrylate react in the presence of a catalyst to obtain the stabilizer; the catalyst comprises a Lewis base catalyst.

[0010] The present invention also provides a method for preparing a grafted polyester polyol using the stabilizer, which is obtained by reacting a base polyester polyol with a vinyl monomer in the presence of the stabilizer and an initiator;

[0011] The content of the stabilizer is 2-4% based on the mass of the grafted polyester polyol;

[0012] The content of the vinyl monomer is 15-50% based on the mass of the grafted polyester polyol.

[0013] The vinyl monomers include one or more of styrene, acrylonitrile, methacrylate monomers, acrylate monomers, acrylamide, 4-acryloylmorpholine, N-vinyl pyrrolidone, butadiene, and isoprene.

[0014] The methacrylate monomers include one or more of methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, butyl methacrylate, benzyl methacrylate, hydroxyethyl methacrylate, isobornyl methacrylate and lauryl methacrylate.

[0015] The basic polyester polyol is obtained by reacting a small molecule polyol and a small molecule polyacid, wherein the basic polyester polyol has a hydroxyl value of 28-112 mgKOH / g and a number average molecular weight of 1000-4000;

[0016] The small molecule polyol includes a C2-C10 small molecule polyol selected from one or more of ethylene glycol, diethylene glycol, propylene glycol, trimethylolpropane, butanediol, pentaerythritol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, and hempanediol;

[0017] The small molecule polyacid includes a small molecule dibasic acid of C4 to C10, which is selected from one or more of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and phthalic acid.

[0018] Beneficial effects: The stabilizer of the present invention has low viscosity, good operability, and no side reactions occur during the synthesis process. It can effectively improve the uniform dispersion of vinyl monomers in the process of preparing grafted polyester polyols. The obtained grafted polyester polyols have lower viscosity than conventional grafted polyester polyols, better chromaticity, and good storage stability, which can better meet downstream usage requirements. DETAILED DESCRIPTION

[0019] The stabilizer is obtained by reacting polyester polyacid and methacrylate reactive to acid; the methacrylate reactive to acid contains epoxy structure, preferably glycidyl methacrylate.

[0020] The number average molecular weight of the stabilizer is 1000-3800, preferably 2000-3300; the preferred acid value is 32-160 mgKOH / g.

[0021] The polyester polyacid is obtained by reacting a small molecule polyol and a small molecule polyacid, and the polyester polyacid has a number average molecular weight of 700 to 3500, preferably 1700 to 3000;

[0022] In some embodiments of the present invention, the acid value of the polyester polyacid is 32 to 160 mgKOH / g, preferably 37 to 66 mgKOH / g.

[0023] The small molecule polyols include C2-C10 small molecule polyols, selected from one or more of ethylene glycol, diethylene glycol, propylene glycol, trimethylolpropane, butanediol, pentaerythritol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, and hempanediol;

[0024] The small molecule polyacid includes a C4-C20 small molecule dibasic acid selected from one or more of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and phthalic acid;

[0025] The methacrylate contains an epoxy structure;

[0026] Further, the acid-reactive methacrylate comprises the following structure:

[0027]

[0028] The acid-reactive methacrylate includes glycidyl methacrylate;

[0029] In some embodiments of the present invention, the mass content of glycidyl methacrylate reactive to acid in the stabilizer ranges from 8% to 30%;

[0030] Furthermore, the polyester polyacid and methacrylate reactive to acid are reacted in the presence of a catalyst to obtain;

[0031] The catalyst comprises a Lewis base catalyst;

[0032] Preferably, the Lewis base catalyst is selected from triphenylphosphine, triethylenediamine, triethylamine, N,N-dimethylbenzylamine, N,N-dimethylaniline, N,N-dimethyl (hexadecyl) amine, bis (dimethylaminoethyl) ether, cyclohexylmethyl tertiary amine, pentamethyldialkylenetriamine, tetramethylalkylenediamine, trimethylbenzyl ammonium chloride, 1,3,5-tris (dimethylaminopropyl) hexahydrotriazine, 2,4,6-tris (dimethylaminomethyl) phenol, tris (dimethylaminopropyl) amine, dimethylethanolamine, dimethylaminoethoxyethanol, trimethylhydroxy One or more of ethylpropylenediamine, trimethylhydroxyethylethylenediamine, tetramethyldipropylenetriamine, 1,4-dimethylpiperazine, 1-dimethylaminoethyl-4-piperazine, N-methyl-N'-hydroxyethylpiperazine, N,N-dimethyl(4-methyl-1-piperazinyl)ethylamine, N-methylmorpholine, N-ethylmorpholine, bismorpholinyldiethyl ether, N-cocomorpholine, dimorpholinetriethyl ether, N-(dimethylaminoethyl)morpholine, N-methylimidazole, 1,2-dimethylimidazole, DBU, triphenylantimony, chromium acetylacetonate, and tetraethylammonium bromide;

[0033] In some embodiments of the present invention, a polyester polyacid and an acid-reactive methacrylate are reacted in the presence of a catalyst and an inhibitor to obtain;

[0034] The polymerization inhibitor includes one or more of hydroquinone, p-benzoquinone, methyl hydroquinone, p-hydroxyanisole, 2-tert-butylhydroquinone, phenothiazine, and 4-hydroxypiperidinol oxygen free radical;

[0035] Among them, the addition of inhibitors can inhibit the polymerization reaction of unsaturated groups at high temperatures;

[0036] As an example, the stabilizer reaction is as follows:

[0037]

[0038] The R1 is a polyester polyacid residue, and the R2 is a methacrylate residue.

[0039] As an example, the preparation method of the stabilizer comprises the following steps:

[0040] Step a: adding small molecule polyol and small molecule polyacid into a reactor, adding catalyst a, fully reacting at a temperature of 100-250° C. under the protection of inert gas, the acid value reaches 37-66 mgKOH / g, cooling and discharging to obtain polyester polyacid;

[0041] Step b: adding polyester polyacid and glycidyl methacrylate reactive to acid into a reactor, adding a catalyst, reacting fully at a temperature of 50 to 120° C. under the protection of an inert gas, cooling and discharging to obtain a stabilizer;

[0042] The catalyst a in step a includes one or more of tetrabutyl titanate, tetraisopropyl titanate, hydrolysis-resistant titanium, catalyst titanium glycolate, antimony trioxide, antimony acetate, antimony glycolate, germanium dioxide, dibutyltin laurate, and phosphotungstic acid;

[0043] The catalyst in step b comprises a Lewis base catalyst selected from triphenylphosphine, triethylenediamine, triethylamine, N,N-dimethylbenzylamine, N,N-dimethylaniline, N,N-dimethyl (hexadecyl) amine, bis (dimethylaminoethyl) ether, cyclohexylmethyl tertiary amine, pentamethyldialkylenetriamine, tetramethylalkylenediamine, trimethylbenzyl ammonium chloride, 1,3,5-tris (dimethylaminopropyl) hexahydrotriazine, 2,4,6-tris (dimethylaminomethyl) phenol, tris (dimethylaminopropyl) amine, dimethylethanolamine, dimethylaminoethoxyethanol, trimethyl one or more of 1,4-dimethylpiperazine, 1-dimethylaminoethyl-4-piperazine, N-methyl-N'-hydroxyethylpiperazine, N,N-dimethyl(4-methyl-1-piperazinyl)ethylamine, N-methylmorpholine, N-ethylmorpholine, bismorpholinyldiethyl ether, N-cocomorpholine, dimorpholinetriethyl ether, N-(dimethylaminoethyl)morpholine, N-methylimidazole, 1,2-dimethylimidazole, DBU, triphenylantimony, chromium acetylacetonate, and tetraethylammonium bromide;

[0044] Preferably, a polymerization inhibitor may be added in step b to hinder and inhibit the polymerization reaction of glycidyl methacrylate at high temperature;

[0045] According to the requirements, a small molecule polyol with a functionality of 2 or more can be added in step a to increase the total functionality of the polyester polyacid, wherein the small molecule polyol with a functionality of 2 or more includes trimethylolpropane, pentaerythritol, etc.;

[0046] The polyester polyacid has a number average molecular weight of 700 to 3500, preferably 1700 to 3000;

[0047] The number average molecular weight of the stabilizer is 1000 to 3800, preferably 2000 to 3300;

[0048] In the preparation of the stabilizer, there is no special requirement for the acid value of the stabilizer. It is ensured that each component can react fully. The number average molecular weight of the stabilizer is controlled to be 1000-3800, preferably 2000-3300.

[0049] In some embodiments of the present invention, the acid value of the stabilizer is 1 to 5 mgKOH / g, preferably 2 to 4 mgKOH / g.

[0050] The present invention provides a grafted polyester polyol, which is obtained by reacting a base polyester polyol and a vinyl monomer in the presence of a stabilizer and an optional initiator;

[0051] The stabilizer content is 2-4%, calculated based on the mass of the basic polyester polyol;

[0052] The basic polyester polyol is obtained by reacting a small molecule polyol and a small molecule polyacid, wherein the basic polyester polyol has a hydroxyl value of 28 to 112 mgKOH / g and a number average molecular weight of 1000 to 4000;

[0053] The small molecule polyols include C2-C10 small molecule polyols, selected from one or more of ethylene glycol, diethylene glycol, propylene glycol, trimethylolpropane, butanediol, pentaerythritol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, and hempanediol;

[0054] The small molecule polyacid includes a C4-C10 small molecule dibasic acid selected from one or more of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and phthalic acid;

[0055] As an example, the base polyester polyol includes one or more of polyethylene adipate polyol, diethylene adipate polyol, diethylene adipate polyol, polybutylene adipate polyol, polyethylene adipate polyol, and polyethylene terephthalate polyol.

[0056] The vinyl monomer includes one or more of styrene, acrylonitrile, methacrylate monomer, acrylate monomer, acrylamide, 4-acryloylmorpholine, N-vinyl pyrrolidone, butadiene, and isoprene;

[0057] As an example, the vinyl monomer includes one or more of styrene, acrylonitrile, methacrylate monomer, and acrylate monomer;

[0058] The methacrylate monomers include one or more of methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, butyl methacrylate, benzyl methacrylate, hydroxyethyl methacrylate, isobornyl methacrylate, and lauryl methacrylate;

[0059] As an example, the preparation method of the grafted polyester polyol comprises the following steps:

[0060] Add the base polyester polyol and stabilizer into the reactor, fully mix the initiator and vinyl monomer and add them into the drop storage tank, slowly add the mixture of vinyl monomer and initiator into the reactor at a certain rate at a temperature of 70-150° C. under the protection of inert gas to fully react with the polyester polyol and stabilizer, and the hydroxyl value reaches 35-70 mgKOH / g, and cool and discharge to obtain the stabilizer;

[0061] Wherein, the content of the stabilizer is 2-4%, calculated based on the mass of the grafted polyester polyol;

[0062] The content of the vinyl monomer is 15-50% based on the mass of the grafted polyester polyol.

[0063] The initiator includes one or more of azobisisobutyronitrile, azobisisoheptanenitrile, dibenzoyl peroxide, and cyclohexanone peroxide;

[0064] The grafted polyester polyol can be applied to the field of polyurethane foaming, including polyurethane soft foam, polyurethane rigid foam, polyurethane microporous elastomer and the like.

[0065] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0066] Example 1

[0067] The stabilizer 1 having a number average molecular weight of 2800 and an acid value of 2.24 mgKOH / g is obtained by reacting polyethylene glycol adipate polyacid and glycidyl methacrylate, wherein the number average molecular weight of the polyester polyacid is 2500 and the acid value is 45 mgKOH / g. After testing, the viscosity of the stabilizer 1 at 40°C is 4230 cps.

[0068] Example 2

[0069] The stabilizer 2 having a number average molecular weight of 3300 and an acid value of 2.78 mgKOH / g is obtained by reacting polybutylene adipate polyacid and glycidyl methacrylate, wherein the number average molecular weight of the polyester polyacid is 3000 and the acid value is 37 mgKOH / g. After testing, the viscosity of the stabilizer 2 at 40°C is 4520 cps.

[0070] Example 3

[0071] The stabilizer 3 having a number average molecular weight of 2300 and an acid value of 2.04 mgKOH / g is obtained by reacting polyethylene glycol diglycol polyacid and glycidyl methacrylate, wherein the number average molecular weight of the polyester polyacid is 2000 and the acid value is 56 mgKOH / g. After testing, the viscosity of the stabilizer 3 at 40°C is 3950 cps.

[0072] Example 4

[0073] The stabilizer 4 with a number average molecular weight of 2000 and an acid value of 2.36 mgKOH / g is obtained by reacting polyethylene terephthalate polyacid and glycidyl methacrylate, wherein the number average molecular weight of the polyester polyacid is 1700 and the acid value is 66 mgKOH / g. After testing, the viscosity of the stabilizer 4 at 40°C is 3930ps.

[0074] Example 5

[0075] The stabilizer 5 having a number average molecular weight of 3800 and an acid value of 3.16 mgKOH / g is obtained by reacting polyethylene glycol adipate polyacid and glycidyl methacrylate, wherein the number average molecular weight of the polyester polyacid is 3500 and the acid value is 32 mgKOH / g. After testing, the viscosity of the stabilizer 5 at 40°C is 4780 cps.

[0076] Example 6

[0077] The stabilizer 6 having a number average molecular weight of 1000 and an acid value of 2.08 mgKOH / g is obtained by reacting polyethylene glycol adipate polyacid and glycidyl methacrylate, wherein the number average molecular weight of the polyester polyacid is 700 and the acid value is 160 mgKOH / g. After testing, the viscosity of the stabilizer 6 at 40°C is 3210 cps.

[0078] Example 7

[0079] The stabilizer 7 having a number average molecular weight of 2800 and an acid value of 3.57 mgKOH / g is obtained by reacting polyethylene glycol adipate polyacid and hydroxyethyl methacrylate, wherein the number average molecular weight of the polyester polyacid is 2500 and the acid value is 45 mgKOH / g. After testing, the viscosity of the stabilizer 7 at 40°C is 3870 cps.

[0080] Comparative Example 1

[0081] The difference from Example 1 is that a stabilizer containing a vinyl structure is used, and maleic anhydride is added during the preparation of polyethylene adipate polyol to directly obtain a modified polyester polyol containing a stabilizer, and the other parts remain unchanged.

[0082] Comparative Example 2

[0083] The difference from Example 1 is that a stabilizer with an acrylate structure is used, which is obtained by reacting diphenylmethane diisocyanate with polyethylene adipate polyol and hydroxyethyl acrylate, and the other parameters remain unchanged; after testing, the viscosity of the comparative stabilizer 2 at 40°C is 5320cps, which is relatively high, and the operability is not improved.

[0084] Comparative Example 3

[0085] The difference from Example 1 is that a stabilizer with a methacrylate structure is used, which is obtained by reacting diphenylmethane diisocyanate with polyethylene adipate polyol and hydroxyethyl methacrylate, and the other parameters remain unchanged; after testing, the viscosity of the comparative stabilizer 3 at 40°C is 6480cps, which is relatively high, and the operability is not improved.

[0086] Comparative Example 4

[0087] The difference from Example 1 is that the polyethylene glycol polyacid is replaced with polyethylene glycol polyol. It is found through experiments that the stabilizer cannot be obtained by reaction.

[0088] Comparative Example 5

[0089] The difference from Example 1 is that glycidyl methacrylate is replaced by hydroxyethyl acrylate, and the other conditions remain unchanged; after testing, the viscosity of the comparative stabilizer 5 at 40° C. is 3720 cps.

[0090] Application Example 1

[0091] In the presence of stabilizer 1 and azobisisobutyronitrile initiator, a basic polyethylene adipate polyol and styrene are reacted to obtain a grafted polyester polyol 1, wherein the stabilizer content is 3.5%, calculated based on the mass of the grafted polyester polyol; the grafted polyester polyol 1 has a milky white appearance, a viscosity of 1900 cps at 60°C, and good stability without solid precipitation after baking at 130°C for 24 hours.

[0092] Application Example 2

[0093] In the presence of stabilizer 2 and azobisisobutyronitrile initiator, a basic polyethylene adipate polyol and styrene are reacted to obtain a grafted polyester polyol 2, wherein the stabilizer content is 3.75%, calculated based on the mass of the grafted polyester polyol; the grafted polyester polyol 2 has a milky white appearance, a viscosity of 2200 cps at 60°C, and good stability without solid precipitation after baking at 130°C for 24 hours.

[0094] Application Example 3

[0095] In the presence of stabilizer 3 and azobisisobutyronitrile initiator, a basic polyethylene glycol adipate polyol and a vinyl monomer (95wt% styrene and 5wt% hydroxyethyl acrylate) are reacted to obtain a grafted polyester polyol 3, wherein the stabilizer content is 2.5%, calculated based on the mass of the grafted polyester polyol; the grafted polyester polyol 3 has a milky white appearance, a viscosity of 2150cps at 60°C, and good stability without solid precipitation after baking at 130°C for 24h.

[0096] Application Example 4

[0097] In the presence of stabilizer 4 and azobisisobutyronitrile initiator, a basic polyethylene terephthalate adipate polyol and styrene are reacted to obtain a grafted polyester polyol 4, wherein the stabilizer content is 2%, calculated based on the mass of the grafted polyester polyol; the grafted polyester polyol 4 has a milky white appearance, a viscosity of 2260 cps at 60°C, and good stability without solid precipitation after baking at 130°C for 24 hours.

[0098] Application Example 5

[0099] In the presence of stabilizer 5 and azobisisobutyronitrile initiator, base polyethylene adipate polyol and styrene are reacted to obtain grafted polyester polyol 5, wherein the stabilizer content is 3.5%, calculated based on the mass of the grafted polyester polyol; the grafted polyester polyol 5 has a milky white appearance, a viscosity of 2750 cps at 60°C, and solid precipitation after baking at 130°C for 24 hours.

[0100] Application Example 6

[0101] In the presence of stabilizer 6 and azobisisobutyronitrile initiator, base polyethylene adipate polyol and styrene are reacted to obtain grafted polyester polyol 6, wherein the stabilizer content is 3.5%, calculated based on the mass of the grafted polyester polyol; the grafted polyester polyol 6 has a milky white appearance, a viscosity of 2160 cps at 60°C, and solid precipitation after baking at 130°C for 24 hours.

[0102] Application Example 7

[0103] In the presence of stabilizer 7 and azobisisobutyronitrile initiator, base polyethylene adipate polyol and styrene are reacted to obtain grafted polyester polyol 7, wherein the stabilizer content is 3.5%, calculated based on the mass of the grafted polyester polyol; the grafted polyester polyol 7 has a milky white appearance, a viscosity of 2580 cps at 60°C, and solid precipitation after baking at 130°C for 24 hours.

[0104] Application Example 8

[0105] In the presence of stabilizer 1 and azobisisobutyronitrile initiator, base polyethylene adipate polyol and styrene are reacted to obtain grafted polyester polyol 8, wherein the stabilizer content is 1.5%, calculated based on the mass of the grafted polyester polyol; the grafted polyester polyol 8 has a milky white appearance, a viscosity of 1580 cps at 60°C, and solid precipitation after baking at 130°C for 24 hours.

[0106] Application Example 9

[0107] In the presence of stabilizer 1 and azobisisobutyronitrile initiator, a basic polyethylene adipate polyol and styrene are reacted to obtain a grafted polyester polyol 9, wherein the stabilizer content is 6%, calculated based on the mass of the grafted polyester polyol; the grafted polyester polyol 9 has a milky white appearance, a viscosity of 3270 cps at 60°C, and good stability without solid precipitation after baking at 130°C for 24 hours.

[0108] Comparative application example 1

[0109] The difference from Application Example 1 is that stabilizer 1 is removed, and the basic polyethylene glycol adipate polyol is replaced by the modified polyester polyol containing stabilizer prepared in Comparative Example 1, while the other components remain unchanged; the grafted polyester polyol 1 has a milky yellow appearance, a viscosity of 2650 cps at 60°C, and good stability after baking at 130°C for 24 hours.

[0110] Comparative Application Example 2

[0111] The difference from Application Example 1 is that stabilizer 1 is replaced by comparative stabilizer 2, and the other conditions remain unchanged; comparative grafted polyester polyol 2 has a milky white appearance, a viscosity of 2450 cps at 60°C, and good stability after baking at 130°C for 24 hours. However, due to the high viscosity of comparative stabilizer 2, its operability in actual production is significantly worse than that of the embodiment.

[0112] Comparative Application Example 3

[0113] The difference from Application Example 1 is that stabilizer 1 is replaced by comparative stabilizer 3, and the other conditions remain unchanged; comparative grafted polyester polyol 3 has a milky white appearance, a viscosity of 2860 cps at 60°C, and good stability after baking at 130°C for 24 hours. However, due to the high viscosity of comparative stabilizer 3, its operability in actual production is significantly worse than that of the embodiment.

[0114] Comparative Application Example 4

[0115] The difference from Application Example 1 is that the stabilizer 1 is replaced by the comparative stabilizer 4, and the other parts remain unchanged; since the comparative stabilizer 4 cannot be reacted, the grafted polyester polyol cannot be prepared.

[0116] Comparative Application Example 5

[0117] The difference from Application Example 1 is that stabilizer 1 is replaced by comparative stabilizer 5, and the other conditions remain unchanged; comparative grafted polyester polyol 5 has a milky white appearance, a viscosity of 2430 cps at 60°C, and solid precipitation after baking at 130°C for 24 hours.

Claims

1. A stabilizer, characterized in that: The stabilizer is obtained by esterification reaction of polyester polyacid and methyl acrylate reactive to acid, and the number average molecular weight of the stabilizer is 1000-3800.

2. The stabilizer according to claim 1, characterized in that The polyester polyacid is obtained by reacting a small molecule polyol and a small molecule polyacid. The number average molecular weight of the polyester polyacid is 700 to 3500, and the preferred acid value is 32 to 160 mgKOH / g.

3. The stabilizer according to claim 1, characterized in that The acid-reactive methacrylate contains an epoxy structure, and is preferably glycidyl methacrylate.

4. A stabilizer according to claim 1, characterized in that: The small molecule polyols include small molecule polyols of C2 to C10, and the small molecule polyacids include small molecule dibasic acids of C4 to C20.

5. A stabilizer according to claim 4, characterized in that: The C2-C10 small molecule polyol is selected from one or more of ethylene glycol, diethylene glycol, propylene glycol, trimethylolpropane, butanediol, pentaerythritol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, and decanediol; the C4-C20 small molecule dibasic acid is selected from one or more of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, decanediol, and phthalic acid.

6. A stabilizer according to claim 1, characterized in that: The polyester polyacid and methacrylate react in the presence of a catalyst to obtain the stabilizer; the catalyst comprises a Lewis base catalyst.

7. A method for preparing a grafted polyester polyol using the stabilizer according to claim 1, characterized in that: In the presence of the stabilizer and the initiator, a base polyester polyol and a vinyl monomer are reacted to obtain the product; The content of the stabilizer is 2-4% based on the mass of the grafted polyester polyol; The vinyl monomer content is 15-50% based on the mass of the grafted polyester polyol.

8. The preparation of grafted polyester polyol according to claim 7, characterized in that: The vinyl monomers include one or more of styrene, acrylonitrile, methacrylate monomers, acrylate monomers, acrylamide, 4-acryloylmorpholine, N-vinyl pyrrolidone, butadiene, and isoprene.

9. The preparation of grafted polyester polyol according to claim 8, characterized in that: The methacrylate monomers include one or more of methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, butyl methacrylate, benzyl methacrylate, hydroxyethyl methacrylate, isobornyl methacrylate and lauryl methacrylate.

10. The preparation of grafted polyester polyol according to claim 7, characterized in that: The basic polyester polyol is obtained by reacting a small molecule polyol and a small molecule polyacid, wherein the basic polyester polyol has a hydroxyl value of 28-112 mgKOH / g and a number average molecular weight of 1000-4000; The small molecule polyols include C2-C10 small molecule polyols, selected from one or more of ethylene glycol, diethylene glycol, propylene glycol, trimethylolpropane, butanediol, pentaerythritol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, and hempanediol; The small molecule polyacid includes a small molecule dibasic acid of C4 to C10, which is selected from one or more of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and phthalic acid.

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