Polyester ether aliphatic ETPU easy to weld and form as well as preparation and application of polyester ether aliphatic ETPU easy to weld and form

Abstract

The invention discloses a polyester ether aliphatic ETPU easy to weld and form as well as a preparation method and application of the polyester ether aliphatic ETPU easy to weld and form. The preparation method comprises the following steps: mixing and reacting at least one polyester polyol and aliphatic diisocyanate I ester to obtain a prepolymer A; mixing at least one polyether polyol with aliphatic diisocyanate II for reaction to obtain a prepolymer B; putting the prepolymer A, the prepolymer B, a chain extender and a selectively added catalyst into an extruder, reacting, extruding and granulating to obtain aliphatic TPU beads; the preparation method comprises the following steps: adding aliphatic TPU beads, a foaming agent and water into a high-pressure container, stirring to form a suspension, heating to 80-180 DEG C, directly releasing pressure or keeping the pressure at 50-200 bar for a period of time, releasing pressure, and taking out the material to obtain the polyester ether aliphatic ETPU easy to weld and form. The polyester ether aliphatic ETPU foam product prepared by molding has lower compression deformation and higher layering tearing strength.

Description

Technical Field

[0001] The invention relates to the technical field of thermoplastic polyurethane elastomer (TPU) foaming materials, and in particular to polyester ether aliphatic foamed thermoplastic polyurethane elastomer beads (ETPU) that are easy to weld and form, and a preparation method and application thereof. Background Art

[0002] TPU is a semi-crystalline polymer material prepared by combining diisocyanate, long-chain diol and short-chain diol in a certain proportion on a belt system or in a reaction extruder. It has excellent mechanical properties, excellent heat and chemical resistance, and excellent wear resistance. Due to the diversity of its raw material formula, by adjusting the proportion of each raw material, products with a very wide hardness range can be obtained.

[0003] ETPU can be obtained by taking thermoplastic polyurethane elastomer beads as a matrix and filling a large number of bubbles inside the thermoplastic polyurethane elastomer beads through extrusion foaming granulation or high-pressure autoclave foaming.

[0004] The earlier invention patent CN101370861B that disclosed the preparation of ETPU is to impregnate thermoplastic polyurethane elastomer beads with a Shore hardness of 44-84A and a foaming agent under high pressure and high temperature, and then release the pressure to prepare foamed thermoplastic polyurethane elastomer beads. Foamed thermoplastic polyurethane elastic bead molded products have a series of advantages such as low density, heat insulation and sound insulation, high specific strength, high elasticity and cushioning, so they are widely used in the packaging industry, industry, agriculture, transportation industry, military industry, aerospace industry and daily necessities.

[0005] Aliphatic TPU refers to the diisocyanate used to produce TPU, which is an aliphatic diisocyanate, such as hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI), hydrogenated phenylmethane diisocyanate (HDI), etc. 12 MDI), cyclohexyl dimethylene diisocyanate (H6XDI), cyclohexyl diisocyanate, etc.

[0006] Invention patent CN110183843B discloses a yellowing-resistant thermoplastic polyurethane foam material and a preparation method thereof, wherein aliphatic diisocyanate, chain extender, polyol, antioxidant, UV absorber and UV light stabilizer are reacted to obtain a thermoplastic polyurethane elastomer, and then aliphatic ETPU is prepared by autoclave foaming. It is disclosed that aliphatic ETPU has excellent yellowing resistance.

[0007] Invention patent CN112940488B discloses a thermoplastic polyurethane foam product with high flatness, and its preparation method and application. It is prepared by physical gas foaming of aliphatic thermoplastic polyurethane elastomer beads with a melting range of 20-50°C and a melting point of 90-160°C to obtain foamed aliphatic thermoplastic polyurethane elastomer beads, and then welding the foamed aliphatic thermoplastic polyurethane elastomer beads by heating with a heat source. It is disclosed that the prepared aliphatic ETPU product has high flatness and high resilience.

[0008] However, it is found that the current aliphatic ETPU products have either high compression deformation or poor damage resistance during use, so the technical problems of reducing the compression deformation of aliphatic ETPU and improving the delamination tear strength of aliphatic ETPU need to be solved urgently. In addition, it is also necessary to ensure that the obtained aliphatic ETPU can be easily welded and formed so that aliphatic ETPU foam products with high tensile strength and high elongation at break can be further prepared. Summary of the invention

[0009] In view of the above technical problems and the shortcomings in the art, the present invention provides a polyester ether aliphatic ETPU that is easy to weld and mold, and a preparation method and application thereof. The polyester ether aliphatic ETPU of the present invention not only has excellent weld molding (such as steam molding, etc.) capabilities, but also has a more uniform pore size, and the polyester ether aliphatic ETPU foam product prepared by molding has lower compression deformation and higher delamination tear strength.

[0010] In a first aspect, the present invention provides a method for preparing a polyester ether aliphatic ETPU that is easy to weld and form, comprising:

[0011] Mixing and reacting at least one polyester polyol with aliphatic diisocyanate I to obtain a prepolymer A;

[0012] Mixing and reacting at least one polyether polyol and aliphatic diisocyanate II to obtain a prepolymer B;

[0013] Prepolymer A, prepolymer B, chain extender and a catalyst that can be added optionally (i.e., the catalyst can be added or not) are put into an extruder, reacted, extruded, and granulated to obtain aliphatic TPU beads;

[0014] The aliphatic TPU beads, foaming agent and water are put into a high-pressure container, stirred to form a suspension, and then heated to 80-180°C. The pressure is released directly or the pressure is maintained at 50-200 bar for a period of time (for example, not more than 180 minutes), and then the material is released and taken out to obtain the polyester ether aliphatic ETPU that is easy to weld and form.

[0015] The preparation of prepolymer A and prepolymer B can adopt existing technology and can be carried out in an apparatus for preparing prepolymers known to those skilled in the art, such as in a heatable / coolable stirred tank, a reactive extruder, etc., and can be carried out at a temperature known to those skilled in the art, such as at 20°C to 250°C.

[0016] The aliphatic diisocyanate I and the aliphatic diisocyanate II can be independently selected from at least one of hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated phenylmethane diisocyanate, cyclohexyl dimethylene diisocyanate and cyclohexyl diisocyanate, preferably hexamethylene diisocyanate.

[0017] The catalyst may include at least one of stannous octoate, dibutyltin laurate, and an organic bismuth catalyst. When the catalyst is to be added, the amount of the catalyst may be 0.00001 to 0.1 parts by weight per 100 parts by weight of the total raw materials, wherein the total raw materials refer to the polyester polyol, the polyether polyol, the aliphatic diisocyanate I, the aliphatic diisocyanate II, and the chain extender.

[0018] The temperature of the reactive extrusion may be 80-260°C.

[0019] The usage ratio of the prepolymer A to the prepolymer B is 1:0.25-1.5 based on the mass ratio of the polyester polyol to the polyether polyol.

[0020] In the present invention, the polyester polyol and the polyether polyol may not be particularly limited. For example, the number average molecular weight of the polyester polyol may be 600-4000g / mol, and further may be 600-3000g / mol, and may be specifically a polyester diol, which may be prepared from a dicarboxylic acid and a diol having 2 to 12 carbon atoms, preferably 4 to 10 carbon atoms. Examples of usable dicarboxylic acids are: aliphatic dicarboxylic acids, such as at least one of succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, etc.; and / or aromatic dicarboxylic acids, such as at least one of phthalic acid, isophthalic acid, terephthalic acid, etc. The dicarboxylic acids may be used alone or in the form of a mixture, such as in the form of a mixture of succinic acid, sebacic acid and adipic acid. The diol may be a diol having 2 to 10 carbon atoms, preferably 2 to 6 carbon atoms, such as ethylene glycol, diethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 2,2-dimethyl-1,3-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, dipropylene glycol, etc., and the diol may be used alone or in the form of a mixture, such as in the form of a 1,4-butanediol mixture and / or a 1,3-propanediol mixture. The number average molecular weight of the polyether polyol may be 600-2000 g / mol, specifically polytetrahydrofuran diol, etc. The polyester polyol may also include polycaprolactone diol, etc., and the number average molecular weight may be 600-3000 g / mol.

[0021] In the present invention, the chain extender may not be particularly limited. For example, the chain extender may be a small molecule diol, such as a diol having 2 to 6 carbon atoms, such as ethylene glycol, diethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 2,2-dimethyl-1,3-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, dipropylene glycol, etc., or a mixture of several thereof.

[0022] Taking the total mass of the polyester polyol, the polyether polyol, the aliphatic diisocyanate I, the aliphatic diisocyanate II and the chain extender as 100%, the sum of the usage proportions of the aliphatic diisocyanate I, the aliphatic diisocyanate II and the chain extender may be 20%-50%.

[0023] The molar ratio of the polyester polyol to the aliphatic diisocyanate I may be consistent with the molar ratio of the polyether polyol to the aliphatic diisocyanate II.

[0024] The total molar ratio of the NCO group and the hydroxyl group of the polyester polyol, the polyether polyol, the aliphatic diisocyanate I, the aliphatic diisocyanate II and the chain extender may be 0.9-1.1:1.

[0025] The preparation method of the first aspect may adopt supercritical physical foaming. The foaming agent may include at least one of nitrogen and carbon dioxide.

[0026] In a second aspect, the present invention provides a polyester ether aliphatic ETPU that is easy to weld and is prepared by the preparation method described in the first aspect.

[0027] In a third aspect, the present invention provides the use of the polyester ether aliphatic ETPU described in the second aspect in the preparation of polyester ether aliphatic ETPU foam products by fusion molding. Among them, water vapor can be used for fusion molding. Further, the water vapor pressure can be 0.7-1.8 bar, such as 1.2 bar, 1.3 bar, 1.6 bar, etc.

[0028] In a fourth aspect, the present invention provides a polyester ether aliphatic ETPU foam product, which is prepared by welding raw materials including the polyester ether aliphatic ETPU described in the second aspect. Among them, water vapor can be used for welding. Further, the water vapor pressure can be 0.7-1.8 bar, such as 1.2 bar, 1.3 bar, 1.6 bar, etc.

[0029] In a fifth aspect, the present invention provides a method for preparing a polyester ether aliphatic ETPU foam product, comprising:

[0030] The polyester ether aliphatic ETPU described in the second aspect is welded in a mold to obtain the polyester ether aliphatic ETPU foam product.

[0031] In the preparation method of the polyester ether aliphatic ETPU foam product described in the fifth aspect, water vapor can be used for welding molding. Further, the water vapor pressure can be 0.7-1.8 bar, such as 1.2 bar, 1.3 bar, 1.6 bar, etc.

[0032] When the polyester ether aliphatic ETPU of the present invention is used for welding molding, the polyester ether aliphatic ETPU foam product with high elongation at break and high tensile strength can be obtained by good welding molding at a relatively low temperature (such as a relatively low water vapor pressure).

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. The present invention prepares polyester ether aliphatic ETPU through a specific process, which not only makes the pores more uniform, but also solves the problem that the current aliphatic ETPU products either have high compression deformation or poor damage resistance. The obtained foam products have both low compression deformation and high stratified tear strength.

[0035] 2. The present invention prepares aliphatic TPU beads by separate prepolymerization of polyester and polyether and then chain extension, and then prepares polyester ether aliphatic ETPU by foaming. The prepared polyester ether aliphatic ETPU has better weldability (such as steam molding, etc.) compared to polyester ether aliphatic ETPU that does not separate prepolymers but directly reacts, and the physical properties of the molded products (elongation at break, tensile strength, etc.) are better. The polyester ether aliphatic TPU synthesized by separate pre-polymerization of polyester polyether and then chain extension has a more uniform hard segment structure on the one hand, and weakens the difference in the reaction activity of polyester polyether diols on the other hand. The prepared polyester ether aliphatic TPU molecular segment composition is more uniform, and the phase separation of the polyester polyether TPU segment is weakened, thereby reducing the temperature required for the welding molding of the polyester ether aliphatic ETPU after foaming (the steam molding pressure is reduced). In addition, the physical properties of the molded products, such as the elongation at break and the tensile strength, are greatly improved. At the same time, the prepared polyester ether aliphatic TPU has a more uniform hard segment structure. During supercritical physical gas foaming, the crystallization of the hard segment serves as the nucleation point, and the gas nucleation point distribution is more uniform, thereby obtaining a more uniform pore size of the polyester ether aliphatic ETPU. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only intended to illustrate the present invention and are not intended to limit the scope of the present invention. The operating methods in the following examples where no specific conditions are indicated are usually carried out under conventional conditions or under conditions recommended by the manufacturer.

[0037] Note: The amount of foaming agent added during foaming is excessive, and the foaming pressure setting requirement is controlled by exhausting in the middle. Due to the different TPU raw material components or production processes, and in order to achieve the desired bulk density, the foaming temperatures required for preparing aliphatic ETPU in the examples and comparative examples are different.

[0038] Example 1

[0039] The raw material ratio is designed according to the following formula: the mass ratio of the polyester polyol in step (1) to the polyether polyol in step (2) is 1:1, the mass percentage of the added amount of the aliphatic diisocyanate and the chain extender to the total added amount of the raw materials (i.e. the total added amount of the polyester polyol, the polyether polyol, the aliphatic diisocyanate and the chain extender, the same below) is 33%. The molar ratio of the NCO group to the hydroxyl group in the total raw material added of the polyester polyol, the polyether polyol, the aliphatic diisocyanate and the chain extender is 0.99:1.

[0040] More specifically, a method for preparing a polyester ether aliphatic ETPU and a steam molded product thereof comprises the steps of:

[0041] (1) 50 parts by weight of polybutylene glycol adipate diol having a number average molecular weight of 1000 g / mol and 18.9 parts by weight of HDI were mixed and reacted at a reaction temperature of 80° C. to obtain prepolymer A.

[0042] (2) 50 parts by weight of polytetrahydrofuran diol having a number average molecular weight of 1000 g / mol and 18.9 parts by weight of HDI were mixed and reacted at a reaction temperature of 80° C. to obtain prepolymer B.

[0043] (3) Put all the prepolymer A in step (1), all the prepolymer B in step (2), 11.4 parts by weight of 1,4-butanediol, and 0.05 parts by weight of an organic bismuth catalyst into an extruder for reaction extrusion. The extruder temperature is set as follows: 150° C. for zone 1 and zone 2, 220° C. for zone 3, zone 4, and zone 5, 130° C. for zone 6, zone 7, and zone 8, and 100° C. for zone 9 and zone 10. The die temperature is 220° C., the screw speed is 200 rpm, and underwater granulation is performed to obtain aliphatic TPU beads.

[0044] (4) 10 kg of the aliphatic TPU beads prepared in step (3), 4 kg of carbon dioxide and 20 kg of water were added to a 500 L high-pressure reactor to form a suspension. The temperature was then raised to 120°C and the pressure was maintained at 85 bar. The suspension in the pressure vessel was discharged into the atmosphere and dried to obtain polyester ether aliphatic ETPU beads. The performance of the beads was evaluated as shown in Table 1.

[0045] The polyester ether aliphatic ETPU beads obtained above were filled into a mold of 200 mm in length × 100 mm in width × 20 mm in thickness. Water vapor at a pressure of 1.6 bar was used to compress the particles by 10% in the thickness direction of the mold to form a bonding mold, and finally a molded foam product was obtained. The molded foam product was then dried in an oven at 70°C for 6 hours, and then placed at room temperature for 2 hours, and its performance was evaluated, as shown in the data in Table 1.

[0046] Example 2

[0047] The raw material ratio is designed according to the following formula: the mass ratio of the polyester polyol in step (1) to the polyether polyol in step (2) is 1:0.25, the mass percentage of the added amount of the aliphatic diisocyanate and the chain extender to the total added amount of the raw materials is 20%. The molar ratio of the NCO group to the hydroxyl group in the total raw material added of the polyester polyol, the polyether polyol, the aliphatic diisocyanate and the chain extender is 0.95:1.

[0048] More specifically, a method for preparing a polyester ether aliphatic ETPU and a steam molded product thereof comprises the steps of:

[0049] (1) 80 parts by weight of polybutylene glycol adipate diol having a number average molecular weight of 3000 g / mol and 13.1 parts by weight of HDI were mixed and reacted at a reaction temperature of 120° C. to obtain prepolymer A.

[0050] (2) 20 parts by weight of polytetrahydrofuran diol having a number average molecular weight of 2000 g / mol and 4.9 parts by weight of HDI were mixed and reacted at a reaction temperature of 120° C. to obtain prepolymer B.

[0051] (3) Put all the prepolymer A of step (1), all the prepolymer B of step (2), 7.0 parts by weight of 1,4-butanediol, and 0.02 parts by weight of stannous octoate catalyst into an extruder for reaction extrusion. The extruder temperature is set as follows: the first and second zones are both 150° C., the third, fourth and fifth zones are all 200° C., the sixth, seventh and eighth zones are all 130° C., the ninth and tenth zones are both 100° C., the die temperature is 200° C., the screw speed is 200 rpm, and underwater granulation is performed to obtain aliphatic TPU beads.

[0052] (4) 10 kg of the aliphatic TPU beads prepared in step (3), 6 kg of carbon dioxide and 20 kg of water were added to a 500 L high-pressure reactor to form a suspension. The temperature was then raised to 100°C and the pressure was maintained at 150 bar. The suspension in the pressure vessel was discharged into the atmosphere and dried to obtain polyester ether aliphatic ETPU beads. The performance of the beads was evaluated as shown in Table 1.

[0053] The polyester ether aliphatic ETPU beads obtained above were filled into a mold of 200 mm in length × 100 mm in width × 20 mm in thickness. Water vapor with a pressure of 0.7 bar was used to compress the particles by 10% in the thickness direction of the mold to form a bonding mold, and finally a molded foam product was obtained. The molded foam product was then dried in an oven at 70°C for 6 hours, and then placed at room temperature for 2 hours, and its performance was evaluated, as shown in the data in Table 1.

[0054] Example 3

[0055] The raw material ratio is designed according to the following formula: the mass ratio of the polyester polyol in step (1) to the polyether polyol in step (2) is 1:1.5, the mass percentage of the added amount of the aliphatic diisocyanate and the chain extender to the total added amount of the raw materials is 50%. The molar ratio of the NCO group to the hydroxyl group in the total raw material added of the polyester polyol, the polyether polyol, the aliphatic diisocyanate and the chain extender is 1.05:1.

[0056] More specifically, a method for preparing a polyester ether aliphatic ETPU and a steam molded product thereof comprises the steps of:

[0057] (1) 40 parts by weight of polyethylene glycol adipate diol with a number average molecular weight of 600 g / mol and 28.7 parts by weight of HDI were mixed and reacted at a reaction temperature of 70° C. to obtain prepolymer A.

[0058] (2) 60 parts by weight of polytetrahydrofuran diol having a number average molecular weight of 600 g / mol and 43.0 parts by weight of HDI were mixed and reacted at a reaction temperature of 70° C. to obtain prepolymer B.

[0059] (3) Put all the prepolymer A in step (1), all the prepolymer B in step (2), 28.3 parts by weight of 1,6-hexanediol, and 0.01 parts by weight of an organic bismuth catalyst into an extruder for reaction extrusion. The extruder temperature is set as follows: 150° C. for zone 1 and zone 2, 220° C. for zone 3, zone 4, and zone 5, 130° C. for zone 6, zone 7, and zone 8, and 100° C. for zone 9 and zone 10. The die temperature is 230° C., the screw speed is 200 rpm, and underwater granulation is performed to obtain aliphatic TPU beads.

[0060] (4) 10 kg of the aliphatic TPU beads prepared in step (3), 4 kg of carbon dioxide and 20 kg of water were added to a 500 L high-pressure reactor to form a suspension. The temperature was then raised to 125°C and the pressure was maintained at 70 bar. The suspension in the pressure vessel was discharged into the atmosphere and dried to obtain polyester ether aliphatic ETPU beads. The performance of the beads was evaluated as shown in Table 1.

[0061] The polyester ether aliphatic ETPU beads obtained above were filled into a mold of 200 mm in length × 100 mm in width × 20 mm in thickness. Water vapor at a pressure of 1.8 bar was used to compress the particles by 10% in the thickness direction of the mold to bond and form the particles, and finally a molded foam product was obtained. The molded foam product was then dried in an oven at 70°C for 6 hours, and then placed at room temperature for 2 hours, and its performance was evaluated, as shown in the data in Table 1.

[0062] Example 4

[0063] The raw material ratio is designed according to the following formula: the mass ratio of the polyester polyol in step (1) to the polyether polyol in step (2) is 1.5:1, the mass percentage of the added amount of the aliphatic diisocyanate and the chain extender to the total added amount of the raw materials is 30%. The molar ratio of the NCO group to the hydroxyl group in the total raw material added of the polyester polyol, the polyether polyol, the aliphatic diisocyanate and the chain extender is 1.01:1.

[0064] More specifically, a method for preparing a polyester ether aliphatic ETPU and a steam molded product thereof comprises the steps of:

[0065] (1) 60 parts by weight of polycaprolactone diol with a number average molecular weight of 1000 g / mol and 20.6 parts by weight of HDI were mixed and reacted at a reaction temperature of 150° C. to obtain prepolymer A.

[0066] (2) 40 parts by weight of polytetrahydrofuran diol having a number average molecular weight of 1000 g / mol and 13.7 parts by weight of HDI were mixed and reacted at a reaction temperature of 150° C. to obtain prepolymer B.

[0067] (3) Put all the prepolymer A in step (1), all the prepolymer B in step (2), 8.5 parts by weight of 1,4-butanediol, and 0.005 parts by weight of an organic bismuth catalyst into an extruder for reaction extrusion. The extruder temperature is set as follows: 150° C. for zone 1 and zone 2, 200° C. for zone 3, zone 4, and zone 5, 130° C. for zone 6, zone 7, and zone 8, and 100° C. for zone 9 and zone 10. The die temperature is 220° C., the screw speed is 200 rpm, and underwater granulation is performed to obtain aliphatic TPU beads.

[0068] (4) 10 kg of the aliphatic TPU beads prepared in step (3), 4 kg of carbon dioxide and 20 kg of water were added to a 500 L high-pressure reactor to form a suspension. The temperature was then raised to 110° C. while maintaining the pressure at 90 bar. The suspension in the pressure vessel was discharged into the atmosphere and dried to obtain polyester ether aliphatic ETPU beads. The performance of the beads was evaluated as shown in Table 1.

[0069] The polyester ether aliphatic ETPU beads obtained above were filled into a mold of 200 mm in length × 100 mm in width × 20 mm in thickness. Water vapor at a pressure of 1.2 bar was used to compress the particles by 10% in the thickness direction of the mold to form a bonding mold, and finally a molded foam product was obtained. The molded foam product was then dried in an oven at 70°C for 6 hours, and then placed at room temperature for 2 hours, and its performance was evaluated, as shown in the data in Table 1.

[0070] Comparative Example 1

[0071] Without step-by-step prepolymerization, polyester polyol, polyether polyol, aliphatic diisocyanate and chain extender are directly added to the extruder for reaction. The details are as follows:

[0072] The raw material ratio is designed according to the following formula: the mass ratio of polyester polyol to polyether polyol is 1:1, the mass percentage of aliphatic diisocyanate and chain extender to the total raw material addition is 33%. The molar ratio of NCO group to hydroxyl group in the total raw material addition of polyester polyol, polyether polyol, aliphatic diisocyanate and chain extender is 0.99:1.

[0073] More specifically, a method for preparing aliphatic ETPU and steam molded products thereof comprises the steps of:

[0074] (1) 50 parts by weight of polybutylene glycol adipate diol with a number average molecular weight of 1000 g / mol, 50 parts by weight of polytetrahydrofuran diol with a number average molecular weight of 1000 g / mol, 37.8 parts by weight of HDI, 11.4 parts by weight of 1,4-butanediol, and 0.05 parts by weight of an organic bismuth catalyst are put into an extruder for reaction extrusion. The extruder temperature is set as follows: the first and second zones are both 150° C., the third, fourth and fifth zones are all 220° C., the sixth, seventh and eighth zones are all 130° C., the ninth and tenth zones are all 100° C., the die head temperature is 220° C., the screw speed is 200 rpm, and underwater granulation is performed to obtain aliphatic TPU beads;

[0075] (2) 10 kg of the aliphatic TPU beads from step (1), 4 kg of carbon dioxide and 20 kg of water were added to a 500 L high-pressure reactor to form a suspension. The temperature was then raised to 130°C and the pressure was maintained at 85 bar. The suspension in the pressure vessel was discharged into the atmosphere and dried to obtain aliphatic ETPU beads. The performance of the beads was evaluated as shown in Table 1.

[0076] The aliphatic ETPU beads obtained above were filled into a mold of 200 mm in length × 100 mm in width × 20 mm in thickness. Water vapor at a pressure of 2.1 bar was used to compress the particles by 10% in the thickness direction of the mold to form a bond, and finally a molded foam product was obtained. The molded foam product was then dried in an oven at 70°C for 6 hours, and then placed at room temperature for 2 hours, and its performance was evaluated, as shown in the data in Table 1.

[0077] Compared with Example 1, it can be found that in order to obtain higher quality aliphatic ETPU beads and foam products thereof, the foaming process of this comparative example needs to be heated to a higher temperature, and the steam molding process requires a higher steam pressure.

[0078] Comparative Example 2

[0079] Only polyester polyol is added without adding polyether polyol, specifically as follows:

[0080] The raw material ratio is designed according to the following formula: the mass percentage of the added amount of aliphatic diisocyanate and chain extender to the total added amount of raw materials is 33%. The molar ratio of NCO group to hydroxyl group in the total raw material addition of polyester polyol, aliphatic diisocyanate and chain extender is 0.99:1.

[0081] More specifically, a method for preparing aliphatic ETPU and steam molded products thereof comprises the steps of:

[0082] (1) 100 parts by weight of polybutylene glycol adipate diol with a number average molecular weight of 1000 g / mol and 37.8 parts by weight of HDI were mixed and reacted at a reaction temperature of 80° C. to obtain prepolymer A.

[0083] (2) Put all the prepolymer A of step (1), 11.4 parts by weight of 1,4-butanediol, and 0.05 parts by weight of an organic bismuth catalyst into an extruder for reaction extrusion. The extruder temperature is set as follows: 150° C. for zone 1 and zone 2, 220° C. for zone 3, zone 4, and zone 5, 130° C. for zone 6, zone 7, and zone 8, and 100° C. for zone 9 and zone 10. The die temperature is 220° C., the screw speed is 200 rpm, and underwater granulation is performed to obtain aliphatic TPU beads.

[0084] (3) 10 kg of the aliphatic TPU beads from step (2), 4 kg of carbon dioxide and 20 kg of water were added to a 500 L high-pressure reactor to form a suspension. The temperature was then raised to 123°C and the pressure was maintained at 85 bar. The suspension in the pressure vessel was discharged into the atmosphere and dried to obtain aliphatic ETPU beads. The performance of the beads was evaluated as shown in Table 1.

[0085] The aliphatic ETPU beads obtained above were filled into a mold of 200 mm in length × 100 mm in width × 20 mm in thickness. Water vapor at a pressure of 1.7 bar was used to compress the particles by 10% in the thickness direction of the mold to form a bond, and finally a molded foam product was obtained. The molded foam product was then dried in an oven at 70°C for 6 hours, and then placed at room temperature for 2 hours, and its performance was evaluated, as shown in the data in Table 1.

[0086] Comparative Example 3

[0087] Only polyether polyol is added without polyester polyol, specifically as follows:

[0088] The raw material ratio is designed according to the following formula: the mass percentage of the added amount of aliphatic diisocyanate and chain extender to the total added amount of raw materials is 33%. The molar ratio of NCO group to hydroxyl group in the total added amount of polyether polyol, aliphatic diisocyanate and chain extender is 0.99:1.

[0089] More specifically, a method for preparing aliphatic ETPU and steam molded products thereof comprises the steps of:

[0090] (1) 100 parts by weight of polytetrahydrofuran diol having a number average molecular weight of 1000 g / mol and 37.8 parts by weight of HDI were mixed and reacted at a reaction temperature of 80° C. to obtain prepolymer B.

[0091] (2) Put all the prepolymer B in step (1), 11.4 parts by weight of 1,4-butanediol, and 0.05 parts by weight of an organic bismuth catalyst into an extruder for reaction extrusion. The extruder temperature is set as follows: 150° C. for zone 1 and zone 2, 220° C. for zone 3, zone 4, and zone 5, 130° C. for zone 6, zone 7, and zone 8, and 100° C. for zone 9 and zone 10. The die temperature is 220° C., the screw speed is 200 rpm, and underwater granulation is performed to obtain aliphatic TPU beads.

[0092] (3) 10 kg of the aliphatic TPU beads from step (2), 4 kg of carbon dioxide and 20 kg of water were added to a 500 L high-pressure reactor to form a suspension. The temperature was then raised to 112° C. while maintaining the pressure at 85 bar. The suspension in the pressure vessel was discharged into the atmosphere and dried to obtain aliphatic ETPU beads. The performance of the beads was evaluated as shown in Table 1.

[0093] The aliphatic ETPU beads obtained above were filled into a mold of 200 mm in length × 100 mm in width × 20 mm in thickness. Water vapor at a pressure of 1.3 bar was used to compress the particles by 10% in the thickness direction of the mold to form a bond, and finally a molded foam product was obtained. The molded foam product was then dried in an oven at 70°C for 6 hours, and then placed at room temperature for 2 hours, and its performance was evaluated, as shown in the data in Table 1.

[0094] Comparative Example 4

[0095] Only polyester polyol is added, polyether polyol is not added, and prepolymerization is not performed, specifically as follows:

[0096] The raw material ratio is designed according to the following formula: the mass percentage of the added amount of aliphatic diisocyanate and chain extender to the total added amount of raw materials is 33%. The molar ratio of NCO group to hydroxyl group in the total raw material addition of polyester polyol, aliphatic diisocyanate and chain extender is 0.99:1.

[0097] More specifically, a method for preparing aliphatic ETPU and steam molded products thereof comprises the steps of:

[0098] (1) 100 parts by weight of polybutylene glycol adipate diol with a number average molecular weight of 1000 g / mol, 37.8 parts by weight of HDI, 11.4 parts by weight of 1,4-butanediol, and 0.05 parts by weight of an organic bismuth catalyst are put into an extruder for reaction extrusion. The extruder temperature is set as follows: the first and second zones are both 150° C., the third, fourth and fifth zones are all 220° C., the sixth, seventh and eighth zones are all 130° C., the ninth and tenth zones are all 100° C., the die temperature is 220° C., the screw speed is 200 rpm, and underwater granulation is performed to obtain aliphatic TPU beads.

[0099] (2) 10 kg of the aliphatic TPU beads from step (1), 4 kg of carbon dioxide and 20 kg of water were added to a 500 L high-pressure reactor to form a suspension. The temperature was then raised to 126°C and the pressure was maintained at 85 bar. The suspension in the pressure vessel was discharged into the atmosphere and dried to obtain aliphatic ETPU beads. The performance of the beads was evaluated as shown in Table 1.

[0100] The aliphatic ETPU beads obtained above were filled into a mold of 200 mm in length × 100 mm in width × 20 mm in thickness. Water vapor at a pressure of 1.8 bar was used to compress the particles by 10% in the thickness direction of the mold to form a bond, and finally a molded foam product was obtained. The molded foam product was then dried in an oven at 70°C for 6 hours, and then placed at room temperature for 2 hours, and its performance was evaluated, as shown in the data in Table 1.

[0101] Comparative Example 5

[0102] Only polyether polyol is added, polyester polyol is not added, and prepolymerization is not performed, specifically as follows:

[0103] The raw material ratio is designed according to the following formula: the mass percentage of the added amount of aliphatic diisocyanate and chain extender to the total added amount of raw materials is 33%. The molar ratio of NCO group to hydroxyl group in the total added amount of polyether polyol, aliphatic diisocyanate and chain extender is 0.99:1.

[0104] More specifically, a method for preparing aliphatic ETPU and steam molded products thereof comprises the steps of:

[0105] (1) 100 parts by weight of polytetrahydrofuran diol with a number average molecular weight of 1000 g / mol, 37.8 parts by weight of HDI, 11.4 parts by weight of 1,4-butanediol, and 0.05 parts by weight of an organic bismuth catalyst are put into an extruder for reaction extrusion. The extruder temperature is set as follows: the first and second zones are both 150° C., the third, fourth and fifth zones are all 220° C., the sixth, seventh and eighth zones are all 130° C., the ninth and tenth zones are all 100° C., the die head temperature is 220° C., the screw speed is 200 rpm, and underwater granulation is performed to obtain aliphatic TPU beads.

[0106] (2) 10 kg of the aliphatic TPU beads prepared in step (1), 4 kg of carbon dioxide and 20 kg of water were added to a 500 L high-pressure reactor to form a suspension. The temperature was then raised to 115°C and the pressure was maintained at 85 bar. The suspension in the pressure vessel was discharged into the atmosphere and dried to obtain aliphatic ETPU beads having low compression set and high delamination tear strength. The performance of the beads was evaluated, as shown in the data in Table 1.

[0107] The aliphatic ETPU beads obtained above were filled into a mold of 200 mm in length × 100 mm in width × 20 mm in thickness. Water vapor at a pressure of 1.4 bar was used to compress the particles by 10% in the thickness direction of the mold to form a bond, and finally a molded foam product was obtained. The molded foam product was then dried in an oven at 70°C for 6 hours, and then placed at room temperature for 2 hours, and its performance was evaluated, as shown in the data in Table 1.

[0108] Table 1

[0109]

[0110] It can be seen from the data of Examples 1-4 and Examples 1-4 in Table 1 that the polyester ether aliphatic ETPU prepared by the technical scheme of the present invention has a uniform pore size and a low steam molding pressure. The steam molded foam products have lower compression deformation and excellent mechanical strength, which can greatly increase the service life of the foam products.

[0111] Comparing the data of Example 1 and Comparative Example 1, under the condition of the same raw materials, the aliphatic ETPU foam size prepared by the preparation method of the technical solution of the present invention is more uniform, the required water vapor molding pressure is low, and the mechanical properties of the water vapor molded foam product are also better.

[0112] By comparing the data of Example 1 and Comparative Examples 2-5, it can be seen that the performance of the polyether ester aliphatic ETPU prepared by the technical solution of the present invention is more balanced and excellent. The polyether ester aliphatic ETPU steam molded products of the present invention have both lower compression deformation and higher mechanical properties.

[0113] Comparing the data of Comparative Examples 2 and 4, and Comparative Examples 3 and 5, under the same raw materials, the prepolymer method is adopted to synthesize aliphatic TPU, and the pore size of the aliphatic ETPU prepared is more uniform and the performance is also improved.

[0114] In addition, it should be understood that after reading the above description of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A method for preparing a polyester ether aliphatic ETPU that is easy to weld and form, characterized in that: include: Mixing and reacting at least one polyester polyol with aliphatic diisocyanate I to obtain a prepolymer A; Mixing and reacting at least one polyether polyol and aliphatic diisocyanate II to obtain a prepolymer B; Prepolymer A, prepolymer B, chain extender and optionally added catalyst are put into an extruder, reacted, extruded and pelletized to obtain aliphatic TPU beads; The aliphatic TPU beads, foaming agent and water are put into a high-pressure container, stirred to form a suspension, and then heated to 80-180° C., and the pressure is directly released or maintained at 50-200 bar for a period of time, and then the material is released and taken out to obtain the polyester ether aliphatic ETPU that is easy to weld and form.

2. The preparation method according to claim 1, characterized in that: The aliphatic diisocyanate I and the aliphatic diisocyanate II are independently selected from at least one of hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated phenylmethane diisocyanate, cyclohexyl dimethylene diisocyanate and cyclohexyl diisocyanate.

3. The preparation method according to claim 1, characterized in that: The temperature of the reactive extrusion is 80-260°C.

4. The preparation method according to claim 1, characterized in that: The usage ratio of the prepolymer A to the prepolymer B is 1:0.25-1.5 based on the mass ratio of the polyester polyol to the polyether polyol; The number average molecular weight of the polyester polyol is 600-4000 g / mol; The number average molecular weight of the polyether polyol is 600-2000 g / mol.

5. The preparation method according to claim 1, characterized in that: Taking the total mass of the polyester polyol, the polyether polyol, the aliphatic diisocyanate I, the aliphatic diisocyanate II and the chain extender as 100%, the sum of the usage proportions of the aliphatic diisocyanate I, the aliphatic diisocyanate II and the chain extender is 20%-50%.

6. The preparation method according to claim 1, characterized in that: The molar ratio of the polyester polyol to the aliphatic diisocyanate I is consistent with the molar ratio of the polyether polyol to the aliphatic diisocyanate II.

7. The preparation method according to claim 1, characterized in that: The total molar ratio of NCO groups and hydroxyl groups of the polyester polyol, the polyether polyol, the aliphatic diisocyanate I, the aliphatic diisocyanate II and the chain extender is 0.9-1.1:

1.

8. The preparation method according to claim 1, characterized in that: Using supercritical physical foaming; The foaming agent includes at least one of nitrogen and carbon dioxide.

9. The polyester ether aliphatic ETPU that is easy to weld and mold, prepared according to the preparation method according to any one of claims 1 to 8.

10. Use of the polyester ether aliphatic ETPU according to claim 9 in preparing polyester ether aliphatic ETPU foam products by welding molding.

11. A polyester ether aliphatic ETPU foam product, characterized in that: The method is prepared by welding raw materials including the polyester ether aliphatic ETPU described in claim 9.

12. A method for preparing a polyester ether aliphatic ETPU foam product, characterized in that: include: The polyester ether aliphatic ETPU described in claim 9 is welded in a mold to obtain the polyester ether aliphatic ETPU foam product.

13. The method for preparing the polyester ether aliphatic ETPU foam product according to claim 12, characterized in that: Using steam for welding; The water vapor pressure is 0.7-1.8 bar.

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