Low-atomization polyester polyol as well as preparation method and application thereof

Abstract

The invention provides low-atomization polyester polyol as well as a preparation method and application thereof. The polyester polyol provided by the invention is prepared from the following raw materials: A) at least one of terephthalic acid and derivatives thereof, isophthalic acid and derivatives thereof, and furandicarboxylic acid and derivatives thereof; b) a polyol; c) other polyacids or derivatives thereof other than component A), and / or other polyols other than component B); wherein the mole number of each component meets the condition that (A + B) / (A + B + C) = 0.80-0.99; and the main chain carbon number of the polyol of the component B) is less than or equal to 3. The content of mobility compounds in the low-atomization polyester polyol is low, polyurethane prepared from the low-atomization polyester polyol has a low atomization level, and the low-atomization polyester polyol can be prepared through a conventional polyester polyol preparation process and is easy to industrialize.

Description

Technical Field

[0001] The present invention belongs to the technical field of polyester polyol preparation, and in particular relates to a low-atomization polyester polyol and a preparation method and application thereof. Background Art

[0002] Polyester polyols are important raw materials for the preparation of polyurethane adhesives, including one-component adhesives, two-component adhesives, solvent adhesives and water-based adhesives. End-use applications include home furnishings, automotive transportation, mobile phones and other electronic products, baby / women's hygiene products, etc.

[0003] The preparation process of polyester polyols is accompanied by side reactions such as dehydration of polyols to ethers and esterification of carboxylic acids and alcohol molecules to form cyclic esters. These by-products do not contain active functional groups that can undergo urethane reactions. Therefore, they are mobile after the polyurethane is synthesized, which manifests as an odor in the product. By-products with melting points higher than room temperature may also manifest as migration and the appearance of solid matter. The application scenarios of polyurethane adhesives are closely related to people's food, clothing, housing and transportation. Therefore, the above phenomena are generally unacceptable. For example, one of the important uses of polyester polyols is as an adhesive for automotive interiors. In the field of automotive interiors, high fogging values ​​will limit its application. Migrants may migrate under light and high temperature conditions and adhere to the surface of the car glass panel, resulting in a "fogging effect", affecting the visual effect and even driving safety during driving.

[0004] Patent EP1481998 uses thin film evaporation as a post-treatment to reduce the volatile content of polyester polyols, thereby reducing the atomization value of polyester polyols. However, when polyester is melted or undergoes a urethane reaction under high temperature conditions, volatile byproducts will be formed again.

[0005] In summary, the development of a polyester polyol with an atomization level has important practical application significance. Summary of the Invention

[0006] In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides a low-fogging polyester polyol, which can be used to produce a polyurethane product with a low fogging level by limiting the carbon number of the main chain of the polyol raw material (≤3).

[0007] The present invention also provides a method for preparing the above-mentioned polyester polyol, which is prepared using the raw materials of the present invention and a conventional polyester polyol preparation process, such as a melt polycondensation method. The polyester polyol of the present invention can avoid the generation of migratory compounds during the preparation process, so the content of migratory compounds in the product is low, which can solve the problem of atomization of subsequent polyurethane products.

[0008] In order to achieve the purpose of the present invention, the present invention adopts the following technical solutions:

[0009] The first aspect of the present invention provides a low-fogging polyester polyol prepared from raw materials comprising the following components:

[0010] A) at least one of terephthalic acid and its derivatives, isophthalic acid and its derivatives, and furandicarboxylic acid and its derivatives;

[0011] B) polyols;

[0012] C) other polyacids or their derivatives other than component A), and / or other polyols other than component B);

[0013] Wherein, the molar number of each component meets (A+B) / (A+B+C)=0.80~0.99;

[0014] Furthermore, the carbon number of the main chain of the polyol in component B) is ≤3.

[0015] In one embodiment of the present invention, the main chain carbon number of the polyol in component B) is ≤3, that is, component B) is a polyol with a main chain carbon number ≤3, its structure contains at least two hydroxyl groups, and the main chain is a carbon chain between any two hydroxyl groups, and the number of carbon atoms on the main chain is ≤3;

[0016] Furthermore, in a preferred embodiment, component B) can be specifically selected from one or more of ethylene glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 1,2-pentanediol, 1,2-hexanediol, neopentyl glycol, 1,3-butanediol, 2-ethyl-1,3-hexanediol, glycerol, trimethylolpropane, pentaerythritol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, etc., more preferably one or more of ethylene glycol, 1,2-propylene glycol, neopentyl glycol, and 1,3-butanediol.

[0017] In one embodiment of the present invention, component A) is one or more of terephthalic acid and its derivatives, isophthalic acid and its derivatives, furandicarboxylic acid and its derivatives, wherein the derivatives include one or more of carboxylic acid esters (such as monoesters, diesters), acid anhydrides, acid chlorides, etc.

[0018] Furthermore, in a preferred embodiment, component A) can be selected from one or more of terephthalic acid, isophthalic acid, 2,5-furandicarboxylic acid, dimethyl terephthalate, dimethyl isophthalate, etc., more preferably one or more of terephthalic acid and isophthalic acid.

[0019] In one embodiment of the present invention, component C) is another polyacid or a derivative thereof other than component A), and / or another polyol other than component B);

[0020] Wherein, the other polyacids or derivatives thereof include one or more of C2-C24 aliphatic carboxylic acids or derivatives thereof, C2-C24 aromatic carboxylic acids or derivatives thereof, and the derivatives are selected from carboxylic acid esters, acid anhydrides, acid chlorides, etc.;

[0021] The other polyols include one or more of C2-C24 aliphatic polyols, C2-C24 alicyclic polyols, and C2-C24 aromatic polyols.

[0022] Furthermore, in a preferred embodiment, the other polyacid or its derivative can be specifically selected from one or more of phthalic anhydride, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and undecanedioic acid, preferably one or more of succinic acid and adipic acid;

[0023] Furthermore, in a preferred embodiment, the other polyols can be specifically selected from one or more of cyclohexanedimethanol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, and undecanediol to tetracosanediol, preferably one or more of butanediol, hexanediol, and cyclohexanedimethanol.

[0024] In one embodiment of the present invention, in the raw materials of the low-fogging polyester polyol, the ratio of the total molar number of -OH (hydroxyl) and -COOH (carboxyl) contained in components A) to C) is ≥1.05, preferably 1.05 to 1.50, wherein -COOH includes carboxyl groups and the molar number of carboxyl groups corresponding to the formation of carboxyl derivative groups (such as ester groups, acid anhydrides, etc.).

[0025] In the present invention, the low-atomization polyester polyol has a hydroxyl value of 10 to 500 mg KOH / g and an acid value of 0 to 5 mg KOH / g; preferably, the hydroxyl value is 21 to 56 mg KOH / g and the acid value is 0 to 2 mg KOH / g.

[0026] In the present invention, the low-fogging polyester polyol is tested for polyurethane products using the VDA278 method, and the fogging value can be reduced to below 250 ug / g.

[0027] The second aspect of the present invention provides a method for preparing the low-fogging polyester polyol, which is prepared by a melt polycondensation method. Under nitrogen protection, component A), component B) and component C) are mixed, and then the temperature is increased to carry out a melt polycondensation reaction to obtain the low-fogging polyester polyol.

[0028] In one embodiment of the present invention, the method for preparing the low-atomization polyester polyol comprises the following steps:

[0029] S1: Under nitrogen protection, add component A), component B) and component C) to the reaction kettle, raise the temperature to 150-210°C, and react at this temperature for 1-3 hours, then continue to raise the temperature to 220-240°C and react at this temperature until the acid value reaches 5-30 mg KOH / g;

[0030] S2: Reduce the vacuum pressure of the system to -0.095~-0.098MPa until the acid value and hydroxyl value reach the designed value, then restore the pressure to normal, cool down and discharge the material.

[0031] The third aspect of the present invention provides the use of the low-fogging polyester polyol.

[0032] The low-atomization polyester polyol of the present invention can be used to prepare polyurethane rigid foam, coatings, elastomers, and adhesives;

[0033] In one embodiment of the present invention, the low-atomization polyester polyol is used to prepare a polyurethane adhesive, including a one-component adhesive, a two-component adhesive, a solvent-based adhesive, a water-based adhesive, etc.;

[0034] Furthermore, in a preferred embodiment, the low-atomizing polyester polyol is used to prepare a one-component adhesive, including a one-component moisture-curing polyurethane hot melt adhesive.

[0035] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0036] The low-atomizing polyester polyol provided by the present invention has a low content of migratory compounds, and the polyurethane prepared therefrom has a low atomization level. The polyurethane can be prepared through a conventional polyester polyol preparation process and is easy to industrialize.

[0037] In addition, the polyurethane prepared therefrom can also help shorten the positioning time when used in the adhesive field. Positioning time is an important time parameter in adhesive applications, usually referring to the time it takes for the substrate to be fixed by the adhesive. A shorter positioning time means improved construction efficiency. DETAILED DESCRIPTION

[0038] Below, the content of the present invention is described in detail. It should be noted that the endpoints and any values ​​of the ranges disclosed in this specification are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this article.

[0039] In the present invention, a low-atomization polyester polyol is prepared from raw materials including the following components:

[0040] A) at least one of terephthalic acid and its derivatives, isophthalic acid and its derivatives, and furandicarboxylic acid and its derivatives;

[0041] B) polyols;

[0042] C) other polyacids or their derivatives other than component A), and / or other polyols other than component B);

[0043] The molar ratio of each component is (A+B) / (A+B+C)=0.80-0.99, including but not limited to 0.80, 0.83, 0.85, 0.88, 0.90, 0.93, 0.95, 0.97, 0.99 or any range between any two thereof;

[0044] Furthermore, the carbon number of the main chain of the polyol in component B) is ≤3, such as 1, 2, 3, etc.

[0045] In some specific examples of the present invention, the carbon number of the main chain of the polyol of component B) is ≤3, that is, component B) is a polyol having a carbon number of ≤3 in the main chain, wherein the main chain refers to the carbon chain between any two hydroxyl groups; specifically, the polyol of component B) refers to a polyol having at least two hydroxyl groups in its structure, and the carbon chain between any two hydroxyl groups is the main chain, and the number of carbon atoms in the main chain is ≤3;

[0046] Preferably, component B) can be selected from one or more of ethylene glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 1,2-pentanediol, 1,2-hexanediol, neopentyl glycol, 1,3-butanediol, 2-ethyl-1,3-hexanediol, glycerol, trimethylolpropane, pentaerythritol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, etc., more preferably one or more of ethylene glycol, 1,2-propylene glycol, neopentyl glycol, 1,3-butanediol.

[0047] In some specific examples of the present invention, component A) is one or more of terephthalic acid and its derivatives, isophthalic acid and its derivatives, furandicarboxylic acid and its derivatives, wherein the derivatives include one or more of carboxylic acid esters (such as carboxylic acid monoesters, carboxylic acid diesters, etc.), acid anhydrides, acid chlorides, etc.

[0048] Preferably, component A) can be selected from one or more of terephthalic acid, isophthalic acid, 2,5-furandicarboxylic acid, dimethyl terephthalate, dimethyl isophthalate, etc., more preferably one or more of terephthalic acid and isophthalic acid.

[0049] In some specific examples of the present invention, component C) is another polyacid or its derivative other than component A);

[0050] Specifically, the other polyacids or their derivatives include one or more of C2-C24 aliphatic carboxylic acids or their derivatives, C2-C24 aromatic carboxylic acids or their derivatives, wherein the derivatives are selected from carboxylic acid esters, acid anhydrides, acid chlorides, etc.;

[0051] Preferably, the other polyacid or its derivative can be selected from one or more of phthalic anhydride, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and undecanedioic acid, more preferably one or more of succinic acid and adipic acid.

[0052] In some specific examples of the present invention, component C) is a polyol other than component B);

[0053] Specifically, the other polyols include one or more of C2-C24 aliphatic polyols, C2-C24 alicyclic polyols, and C2-C24 aromatic polyols.

[0054] Preferably, the other polyols can be selected from one or more of cyclohexanedimethanol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, and undecanediol, preferably one or more of butanediol, hexanediol, and cyclohexanedimethanol.

[0055] The addition of component C) to the polyester polyol composition of the present invention can, on the one hand, impart additional functional properties to the polyester polyol itself, such as high-temperature resistance, low-temperature compliance, and differentiated crystallization rates. Furthermore, it can also regulate the application performance of polyurethane products, thereby adapting the products to the needs of various end-use applications. Because different types of component C) have different functions, the present invention does not particularly limit the specific types and selections thereof. In practical applications, skilled artisans can select and combine them as needed.

[0056] Among them, taking polyurethane adhesive products as an example, when component C) is an aliphatic carboxylic acid such as adipic acid and sebacic acid, the glass transition temperature of the polyester polyol can be reduced, which is beneficial to improving the bonding strength of the polyurethane adhesive at low temperatures; when component C) is an aliphatic diol such as pentanediol and nonanediol, the viscosity of the polyester polyol can be reduced, and the polyurethane adhesive prepared with it as raw material has better fluidity and a wider window of construction process conditions.

[0057] In some specific examples of the present invention, in the raw materials of the low-fogging polyester polyol, the ratio of -OH (hydroxyl) and -COOH (carboxyl) contained in components A) to C) is ≥ 1.05, including but not limited to 1.05, 1.10, 1.15, 1.20, 1.30, 1.40, 1.50, 1.55, 1.60, 1.70, 1.80, 1.90, 2.00, etc., or a range between any two thereof, preferably 1.05 to 1.50;

[0058] It should be noted that -COOH includes carboxyl groups and the molar number of carboxyl groups corresponding to the carboxyl derivative groups, for example, ester groups are calculated as 1 mole of carboxyl groups and acid anhydrides are calculated as 2 moles of carboxyl groups.

[0059] In the present invention, the hydroxyl value of the low-atomization polyester polyol is 10 to 500 mg KOH / g, and the acid value is 0 to 5 mg KOH / g; specifically, the hydroxyl value includes but is not limited to 10 mg KOH / g, 50 mg KOH / g, 100 mg KOH / g, 150 mg KOH / g, 200 mg KOH / g, 250 mg KOH / g, 300 mg KOH / g, 350 mg KOH / g, 400 mg KOH / g, 450 mg KOH / g, 500 mg KOH / g, or a range consisting of any two thereof, and the acid value includes but is not limited to 0 mg KOH / g, 1 mg KOH / g, 2 mg KOH / g, 3 mg KOH / g, 4 mg KOH / g, 5 mg KOH / g, or a range consisting of any two thereof; preferably, the hydroxyl value is 21 to 56 mg KOH / g, and the acid value is 0 to 2 mg KOH / g.

[0060] The low-atomizing polyester polyols of the present invention have no specific requirements for the preparation method and can be prepared using conventional polyester polyol preparation methods in the art, or modified methods based on conventional preparation methods in the art, such as the melt polycondensation method. In specific applications, they can be prepared by referring to the methods disclosed in patents such as CN112745492B, CN114316225B, CN110698659B, and CN111518266B. The relevant operating and process conditions, as well as the equipment used in specific applications, can all be selected according to conventional methods in the art and are not particularly required by the present invention.

[0061] The present invention provides a method for preparing low-fogging polyester polyol, which is prepared by a melt polycondensation method. Under nitrogen protection, component A), component B) and component C) are mixed, and then the temperature is increased to carry out a melt polycondensation reaction to obtain the low-fogging polyester polyol.

[0062] In some specific examples of the present invention, the preparation method of the low-atomization polyester polyol is a vacuum melt polycondensation method, comprising the following steps:

[0063] S1: Under nitrogen protection, add component A), component B) and component C) to the reaction kettle, raise the temperature to 150-210°C, and react at this temperature for 1-3 hours, then continue to raise the temperature to 220-240°C and react at this temperature until the acid value reaches 5-30 mg KOH / g;

[0064] S2: Reduce the vacuum pressure of the system to -0.095~-0.098MPa until the hydroxyl value and acid value reach the designed value, then restore the pressure to normal, cool down and discharge the material.

[0065] In specific applications, no catalyst may be used in the reaction process of step S1; alternatively, the reaction process of step S1 may also be carried out under catalyst conditions; preferably, the catalyst is selected from one or more of titanium-based catalysts, tin-based catalysts, bismuth-based catalysts, antimony-based catalysts, germanium-based catalysts, etc., more preferably one or more of tetrabutyl titanate, tetraisopropyl titanate, stannous octoate, stannous chloride, butyl tin oxide, bismuth isooctanoate, etc.;

[0066] Preferably, the amount of the catalyst added is 1 to 2000 ppm of the total mass of the reaction system, including but not limited to 1 ppm, 50 ppm, 100 ppm, 300 ppm, 500 ppm, 800 ppm, 1000 ppm, 1200 ppm, 1500 ppm, 1800 ppm, 2000 ppm or a range between any two of them.

[0067] In the present invention, the designed values ​​of hydroxyl value and acid value to be achieved in step S2, that is, the hydroxyl value of the low-atomization polyester polyol is 10-500 mg KOH / g, preferably 21-56 mg KOH / g, and the acid value is 0-5 mg KOH / g; preferably 0-2 mg KOH / g.

[0068] Specifically, the preparation method is to add components A), B) and C) to a reactor under nitrogen protection, raise the temperature to 150-210°C, including but not limited to 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C, 200°C, 205°C, 210°C or a range between any two thereof, and react at this temperature for 1-3 hours, including but not limited to 1.0h, 1.5h, 2.0h, 2.5h, 3.0h or a range between any two thereof; continue to raise the temperature to 220-240°C, including but not limited to 220°C, 225°C, 230°C, 235°C, 240°C or a range between any two thereof, and react at this temperature. When the acid value reaches 10-30 mg KOH / g, for example, 10 mg KOH / g, 15 mg KOH / g, 20 mg KOH / g, 25 mg When the hydroxyl value and acid value reach the designed values, add an optional catalyst and continue the reaction until the acid value reaches 5-10 mg KOH / g, for example, 5 mg KOH / g, 7 mg KOH / g, 9 mg KOH / g, 10 mg KOH / g or the range between them, start the vacuum system with a pressure of -0.095 to -0.098 MPa, including but not limited to -0.095 MPa, -0.096 MPa, -0.097 MPa, -0.098 MPa or the range between them, and when the hydroxyl value and acid value reach the designed values, restore the pressure, cool the material, discharge the material and package it.

[0069] According to conventional preparation methods of polyester polyols in the art, some specific applications of the present invention may further include a post-treatment step such as vacuum devolatilization. Specifically, after the reactants of the transesterification reaction reach the designed hydroxyl value and acid value, the materials are transported to an evaporation device (e.g., a scraped film evaporator) and subjected to vacuum devolatilization within a certain vacuum range.

[0070] According to conventional preparation methods of polyester polyols in the art, in some specific applications of the present invention, a filtering and packaging step may also be included. Specifically, the polyester polyol after devolatilization is cooled to room temperature, filtered through a filter (e.g., a 200-300 mesh nylon mesh bag), and then packaged.

[0071] The low-atomization polyester polyol of the present invention is tested by the VDA278 method, and the atomization value of the polyurethane product thereof is lower than 250 ug / g.

[0072] The low-atomization polyester polyol of the present invention can be used in the preparation of polyurethane rigid foams, coatings, elastomers, adhesives, etc.

[0073] Among them, it involves the preparation of polyurethane adhesives, including single-component adhesives, two-component adhesives, solvent-based adhesives, and water-based adhesives;

[0074] Among them, it involves the preparation of single-component adhesives, including single-component moisture-curing polyurethane hot melt adhesives.

[0075] One-component moisture-curing polyurethane hot melt adhesives are known in the prior art and can be prepared by reacting polyester polyols and isocyanates. In a specific application of the present invention, a method for preparing a one-component moisture-curing polyurethane hot melt adhesive is as follows: under nitrogen protection conditions, low-atomizing polyester polyols and isocyanates (such as MDI, TDI, HDI, etc.) are added to a reactor in a molar ratio of 1:2.0 to 2.5, and reacted at 80 to 150°C until the NCO% content reaches the theoretical value.

[0076] In some specific examples of the present invention, the terminal applications of the low-fogging polyester polyol of the present invention include woodworking flat adhesive, woodworking edge banding adhesive, woodworking covering adhesive, textile adhesive, automotive interior adhesive, automotive exterior adhesive, mobile phones / Bluetooth headsets / VR glasses and other electronic adhesive fields.

[0077] In order to better understand the technical solutions of the present invention, the present invention is further described below with reference to the following embodiments, but the present invention is not limited to the following embodiments.

[0078] The main sources of raw materials used in the following examples are as follows:

[0079] Terephthalic acid, isophthalic acid, cyclohexanedimethanol: Eastman Chemical Company;

[0080] Phthalic anhydride: Aekyung Chemical Co., Ltd.;

[0081] Adipic acid: Henan Shenma Nylon Chemical Co., Ltd.

[0082] Ethylene glycol, 1,2-propylene glycol, 1,3-butanediol, neopentyl glycol: Wanhua Chemical Group Co., Ltd.

[0083] 1,2-Pentanediol, 1,5-pentanediol, 1,2,6-hexanetriol: Sigma-Aldrich Company;

[0084] MDI: Wanhua Chemical Group Co., Ltd.

[0085] Unless otherwise specified, other raw materials and reagents were obtained through common commercial channels.

[0086] The main analytical methods used in the following examples are as follows:

[0087] Acid value determination: Reference standard HG / T 2708-1995;

[0088] Determination of hydroxyl value: Reference standard HG / T 2709-1995;

[0089] Determination of fogging value: Reference standard VDA278, 120℃ / 30min;

[0090] Positioning time determination: Apply 150℃ glue on a 10*10cm wooden board, glue two wooden blocks together and apply a 3kg weight. This time is taken as time zero, and the positioning time is recorded when the two wooden blocks cannot be twisted by hand.

[0091] Examples 1-9

[0092] Preparation of low-atomization polyester polyols (POL A-I):

[0093] Under nitrogen, raw materials A), B), and C) were added to a reaction kettle in the order specified in the formula in Table 1 below. The system temperature was raised to 210°C and maintained at this temperature for 1 hour. The temperature was then raised to 230°C and the reaction continued at this temperature. When the acid value reached ≤20 mg KOH / g, 30 ppm of the catalyst, tetraisopropyl titanate (TIPT), was added and the reaction continued until the acid value reached ≤10 mg KOH / g. The vacuum was then applied until the acid value and hydroxyl value reached the target values ​​listed in Table 1. The pressure was then restored to normal, and the reaction was cooled and discharged. The resulting low-atomizing polyester polyols are designated POLs A to I.

[0094] Table 1 Raw material formula and indexes of Examples and Comparative Examples

[0095]

[0096]

[0097] In Table 1, the abbreviations of the raw materials are: TPA, terephthalic acid, IPA, isophthalic acid, DMT, dimethyl terephthalate, EG, ethylene glycol, 1,2-PG, 1,2-propylene glycol, 1,2-PDO, 1,2-pentanediol, 1,3-BDO, 1,3-butanediol, NPG, neopentyl glycol, PA, phthalic anhydride, AA, adipic acid, CHDM, cyclohexanedimethanol.

[0098] Comparative Examples 1-3

[0099] Preparation of polyester polyols (POL U~W):

[0100] Polyester polyol (POL U): The raw material formula is the same as that of Example 1, except that the B component (1 mol EG + 0.7 mol 1,2-PG + 1 mol NPG) is replaced by 1,2,6-hexanetriol (1,2,6-HTO) with an equal molar hydroxyl (-OH) content, and other operating conditions remain unchanged.

[0101] Polyester polyol (POL V): The raw material formula is the same as that of Example 1, except that component B (1 mol EG + 0.7 mol 1,2-PG + 1 mol NPG) is replaced by 1,5-pentanediol (1,5-PDO) with an equal molar hydroxyl (-OH) content, while keeping other operating conditions unchanged.

[0102] Polyester polyol (POL W): The raw materials were the same as those in Example 1, except that the ratios were adjusted. Component A consisted of 0.5 mol TPA + 0.5 mol IPA, component B consisted of 1 mol EG + 0.7 mol 1,2-PG + 1 mol NPG, and component C consisted of 1 mol AA. After the adjustment, (A + B) / (A + B + C) = 0.57. Other operating conditions remained unchanged.

[0103] According to the same preparation method as in Example 1, polyester polyols POL U-W were prepared using the above raw material formula.

[0104] Application Examples

[0105] The low-atomizing polyester polyols (POL A-I) prepared in Examples 1-9 and the polyester polyols (POL U-W) prepared in Comparative Examples 1-3 were respectively used to prepare moisture-curable polyurethane hot melt adhesives. The preparation methods are as follows:

[0106] Under nitrogen, polyester polyol and MDI were added to the reactor in a molar ratio of 1:2. The reaction was continued at 130°C until the NCO content reached the theoretical value. The product was then discharged and stored sealed under nitrogen. The atomization value and positioning time were tested, and the results are shown in Table 2.

[0107] Table 2 Performance test results of moisture-curing polyurethane hot melt adhesive

[0108] PUR Number Atomization value, ug / g Positioning time, s Example 1 PUR A 5 10 Example 2 PUR B 5 20 Example 3 PUR C 25 ＜5 Example 4 PUR D 5 ＜5 Example 5 PUR E 5 24 Example 6 PUR F 20 16 Example 7 PUR G 33 25 Example 8 PUR H 50 18 Example 9 PURI 25 30 Comparative Example 1 PUR U 2250 220 Comparative Example 2 PUR V 1852 350 Comparative Example 3 PUR W 1600 145

[0109] As can be seen from the data of the Examples and Comparative Examples, the polyurethane products prepared using the polyester polyols of the present invention have lower atomization values ​​and shorter open times. Specifically, compared to Example 1, Comparative Example 1 replaces component B with a polyol having multiple main chains, but one main chain has a carbon number ≤ 3 and the other main chains have a carbon number > 3, Comparative Example 2 replaces component B with a diol having a single main chain and a carbon number > 3, and Comparative Example 3 leaves the components unchanged and adjusts (A+B) / (A+B+C) to < 80%. The polyurethane products prepared from the resulting polyester polyols have significantly increased atomization values ​​and a longer open time than those in the Examples.

[0110] Those skilled in the art will appreciate that, based on the teachings of this specification, some modifications or adjustments may be made to the present invention, and such modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A low-atomization polyester polyol, characterized in that: It is prepared from raw materials including the following components: A) at least one of terephthalic acid and its derivatives, isophthalic acid and its derivatives, and furandicarboxylic acid and its derivatives; B) polyols; C) other polyacids or their derivatives other than component A), and / or other polyols other than component B); Wherein, the molar number of each component meets (A+B) / (A+B+C)=0.80~0.99; Furthermore, the carbon number of the main chain of the polyol in component B) is ≤3.

2. The low-atomization polyester polyol according to claim 1, characterized in that Component B) is selected from one or more of ethylene glycol, 1,2-propylene glycol, 2-methyl-1,3-propylene glycol, 1,2-pentanediol, 1,2-hexanediol, neopentyl glycol, 1,3-butanediol, 2-ethyl-1,3-hexanediol, glycerol, trimethylolpropane, pentaerythritol, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol, preferably one or more of ethylene glycol, 1,2-propylene glycol, neopentyl glycol, and 1,3-butanediol.

3. The low-atomization polyester polyol according to claim 1, characterized in that Component A) is selected from one or more of terephthalic acid, isophthalic acid, 2,5-furandicarboxylic acid, dimethyl terephthalate, and dimethyl isophthalate, preferably one or more of terephthalic acid and isophthalic acid.

4. The low-atomization polyester polyol according to claim 1, characterized in that In component C), the other polyacid or its derivative is selected from one or more of a C4-C24 aliphatic carboxylic acid or its derivative, a C4-C24 aromatic carboxylic acid or its derivative, and the derivative is selected from one or more of a carboxylic acid ester, anhydride, and acid chloride; and / or In component C), the other polyols are selected from one or more of C4-C24 aliphatic polyols, C4-C24 alicyclic polyols, and C4-C24 aromatic polyols.

5. The low-atomization polyester polyol according to claim 4, characterized in that The other polyacids or their derivatives are selected from one or more of phthalic anhydride, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and undecanedioic acid, preferably one or more of succinic acid and adipic acid; and / or The other polyols are selected from one or more of cyclohexanedimethanol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, and undecanediol to tetracosanediol, preferably one or more of butanediol, hexanediol, and cyclohexanedimethanol.

6. The low-atomization polyester polyol according to any one of claims 1 to 5, characterized in that In the raw materials of the low-fogging polyester polyol, the ratio of -OH and -COOH, calculated based on the total molar number of -OH and -COOH contained in components A) to C), is ≥1.05, preferably 1.05 to 1.

50.

7. The low-atomization polyester polyol according to any one of claims 1 to 6, characterized in that The low-atomization polyester polyol has a hydroxyl value of 10 to 500 mg KOH / g and an acid value of 0 to 5 mg KOH / g; preferably, the hydroxyl value is 21 to 56 mg KOH / g and the acid value is 0 to 2 mg KOH / g.

8. A method for preparing the low-fogging polyester polyol according to any one of claims 1 to 7, comprising preparing the low-fogging polyester polyol by a melt polycondensation method, comprising mixing component A), component B), and component C) under nitrogen protection, and then heating the mixture to carry out a melt polycondensation reaction to obtain the low-fogging polyester polyol.

9. The preparation method according to claim 8, characterized in that The steps include: S1: Under nitrogen protection, add component A), component B) and component C) to the reaction kettle, raise the temperature to 150-210°C, and react at this temperature for 1-3 hours, then continue to raise the temperature to 220-240°C and react at this temperature until the acid value reaches 5-30 mg KOH / g; S2: Reduce the vacuum pressure of the system to -0.095~-0.098MPa until the acid value and hydroxyl value reach the designed value, then restore the pressure to normal, cool down and discharge the material.

10. Use of the low-fogging polyester polyol according to any one of claims 1 to 7 or the low-fogging polyester polyol prepared by the method according to claim 8 or 9 in the preparation of polyurethane rigid foams, coatings, elastomers, and adhesives; Preferably, the low-atomization polyester polyol is used to prepare polyurethane adhesives, including one-component adhesives, two-component adhesives, solvent-based adhesives, and water-based adhesives.

Images