Preparation method and application of polyurethane elastomer

Abstract

The invention discloses a preparation method and application of a polyurethane elastomer, and relates to the technical field of polyurethane, the preparation method comprises the following steps: obtaining preset parts by weight of raw materials, mixing and reacting the first group of raw materials to prepare a first component, and mixing and reacting the second group of raw materials to prepare a second component, mixing the first component and the second component, and reacting at a first preset temperature to obtain a reacted mixture; and pouring the reacted mixture into a mold, carrying out heat preservation at a second preset temperature for a first preset time, demolding, taking out a product, cooling the product, and drying to obtain the polyurethane elastomer. By introducing the rigid large-volume structure and the diatomite, the mechanical properties and sound insulation and noise reduction properties of the prepared polyurethane elastomer are improved, and the diatomite has high porosity and mechanical properties and can fill a foamed pore structure, so that the polyurethane microporous elastomer keeps good elasticity and plasticity.

Description

Technical Field

[0001] The present application relates to the technical field of polyurethane materials, and specifically relates to a preparation method and application of a polyurethane elastomer. Background Art

[0002] Polyurethane is a versatile material with unique properties and excellent performance, and is widely used in the automotive manufacturing field, mainly including automotive parts, seats, coatings, etc. Among them, polyurethane microcellular elastomer is a material with properties between elastomers and foam materials, combining the characteristics of light weight, good impact resistance, energy absorption, good buffering performance of foam and high strength and good wear resistance of elastomers. In terms of vibration isolation, the impact energy absorption rate of polyurethane microcellular elastomer can reach 75-95%, with excellent impact absorption performance. Combined with its sound insulation and heat insulation characteristics, it can be used as an excellent buffer and heat insulation material.

[0003] In some related technologies, the mechanical properties of polyurethane foamed elastomer are relatively low, the material is relatively soft after foaming, and the impact resistance is poor, resulting in the mechanical properties and strength of the automotive seat crossmember reinforcement parts manufactured by it not meeting the relevant standards. Summary of the Invention

[0004] In order to solve at least one of the problems mentioned in the above background art, the present application provides a polyurethane elastomer, its preparation method and application. By introducing a rigid large-volume structure and diatomite, the mechanical properties and sound insulation and noise reduction performance of the prepared polyurethane elastomer are improved. Moreover, diatomite can fill the foamed pore structure, has a relatively high porosity and good mechanical properties, enabling the polyurethane elastomer to have good impact resistance while having sound insulation and heat insulation effects.

[0005] The specific technical solutions provided by the embodiments of the present application are as follows:

[0006] In a first aspect, a preparation method of a polyurethane elastomer is provided, and the method includes:

[0007] Mix 280-330 parts by weight of polyether polyol, 1-2 parts by weight of chain extender, 0.5-1.2 parts by weight of crosslinking agent, 5-15 parts by weight of expansion beads, 10-50 parts by weight of diatomite, and 0.5-0.8 parts by weight of foam stabilizer, and heat and react to prepare a first component;

[0008] Mix 110-140 parts by weight of isocyanate, 10-50 parts by weight of hydrogenated castor oil, 83-93 parts by weight of phthalic anhydride polyester polyol, and 0.8-1.5 parts by weight of catalyst, and heat and react to prepare a second component;

[0009] Mix the first component and the second component, and heat to a first preset temperature for reaction to obtain a post-reaction mixture;

[0010] Pour the mixture after the reaction into a mold, keep it warm at a second preset temperature for a first preset time, demold to take out the product, and cool and dry the product to obtain a polyurethane elastomer.

[0011] In a specific embodiment, the polyether polyol includes one or two of polytetrahydrofuran polyol and polyethylene glycol;

[0012] The polyether polyol has a molecular weight of 1200-1400 g / mol and a hydroxyl value of 85-90 mgKOH / g;

[0013] The polyethylene glycol has a molecular weight of 900-1000 g / mol and a hydroxyl group of 105-115 mgKOH / g.

[0014] In a specific embodiment, the chain extender includes one or two of diol and diamine; and / or, the foam stabilizer is a polysiloxane-polyether copolymer.

[0015] In a specific embodiment, the particle size of the diatomite is 1-10 μm, the bulk density is 0.3-0.5 g / cm 3 , and the pore radius is 50-80 nm;

[0016] and / or, the expansion ball is an alkane mixture with a boiling point of 60-70 °C and a particle size of 10-30 μm.

[0017] In a specific embodiment, the phthalic anhydride polyester polyol has a molecular weight of 400-500 g / mol and a hydroxyl value of 300-305 mgKOH / g;

[0018] and / or, the catalyst is a tertiary amine catalyst.

[0019] In a specific embodiment, preparing the first component specifically includes: adding the raw materials in the first component to a reaction kettle for mixing, heating to 35-40 °C, stirring and reacting for 1-2 h to obtain the first component, and storing the first component in a sealed manner.

[0020] In a specific embodiment, preparing the second component specifically includes: adding the raw materials of the second component to a reaction kettle for mixing, heating to 80-85 °C, and keeping the reaction for 3-4 h to obtain the second component.

[0021] In a specific embodiment, the first preset temperature is 40-55 °C;

[0022] The second preset temperature is 80-85 °C, and the first preset time for heat preservation is 3-4 h;

[0023] The drying conditions of the product are vacuum at 60-70 °C for 3-5 h.

[0024] In a second aspect, a seat crossbeam assembly is provided. The seat crossbeam assembly includes a polyurethane elastomer, and the elastomer is prepared by using the preparation method of the polyurethane elastomer described above.

[0025] In a third aspect, a vehicle is provided. The vehicle includes the seat crossbeam assembly described above.

[0026] The embodiments of the present application have the following beneficial effects:

[0027] 1. Adding a rigid bulky substance and diatomaceous earth to the first component provided in the embodiments of the present application can improve the mechanical properties and sound insulation and noise reduction performance after polyurethane foaming. Specifically, bulky bio-based hydrogenated castor oil, phthalic anhydride polyester polyol, and MDI are used for reaction as the polyurethane hard segment, and polytetrahydrofuran polyol is used as the polyurethane soft segment. The hard segment provides a certain strength to the material and improves the impact resistance of the material. The soft segment endows the polyurethane elastomer with elasticity and toughness, so that the prepared polyurethane elastomer has the effect of energy absorption and shock reduction. Adding diatomaceous earth to the microcellular polyurethane can fill the pore structure of the foam. At the same time, diatomaceous earth itself has a high porosity and good mechanical properties, so that the microcellular polyurethane has good impact resistance and at the same time has the effects of sound insulation and heat insulation.

[0028] 2. The rigid bulky substance bio-based castor oil can form a certain network structure and increase the distance between the molecular chain skeletons, forming a microporous structure inside the material. The microporous structure can provide a certain shock absorption and buffering effect, and at the same time, the network structure can also limit the movement and slip of the molecular chains to keep the material in good mechanical properties. When the polyurethane elastomer is applied to the reinforcement of the automotive seat crossbeam, it can reduce the weight and achieve the effects of sound insulation, heat insulation, and lightweight.

[0029] 3. The polyurethane elastomer prepared in this embodiment is used as a composite reinforcement by being installed in a pure sheet metal structure. The outer frame of the reinforcement is a fiber-reinforced polymer composite material, and the inside is filled with polyurethane foam. The main surface of the outer frame bears the internal tensile / compressive force and load-bearing function, and the core layer mainly bears the shear force and buffering function and provides sufficient stiffness. The reinforcement and the sheet metal structure are bonded by structural adhesive. This structure can effectively reduce the impact and improve the safety performance. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0031] Figure 1 Schematic diagram showing the preparation method of the polyurethane elastomer according to the present application;

[0032] Figure 2 Schematic diagram showing the mold according to the present application;

[0033] Figure 3 Schematic diagram showing the outer frame in the mold according to the present application;

[0034] Figure 4 Schematic diagram showing the first positioning plate and the second positioning plate in the mold according to the present application;

[0035] Figure 5 Schematic diagram showing the first injection hole and the second injection hole in the mold according to the present application;

[0036] Figure 6 Schematic diagram showing the pultrusion molding according to the present application;

[0037] Figure 7 Schematic diagram showing the seat crossbeam assembly according to the present application;

[0038] In the figure, 1. Outer frame; 2. Upper plate; 3. Lower plate; 4. Left side plate; 5. Right side plate; 10. First injection hole; 11. Second injection hole; 12. Seat crossbeam; 13. First positioning plate; 14. Second positioning plate. Detailed implementation manners

[0039] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are only a part rather than all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs. The terms used in the description of the present application in this specification are only for the purpose of describing specific implementation manners and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0041] The existing polyurethane elastomer materials have low anti-mechanical properties. The polyurethane material obtained by foaming is relatively soft and has poor impact resistance. Based on the above problems, this embodiment provides a preparation method of polyurethane elastomer. By introducing a rigid large-volume structure and diatomite, the mechanical properties and sound insulation and noise reduction properties of the foamed polyurethane can be greatly improved. In addition, the prepared polyurethane elastomer is applied to the composite reinforcement of the automotive seat crossbeam to ensure that the prepared automotive seat has sound insulation and heat insulation as well as excellent impact absorption properties.

[0042] Example 1

[0043] Provide a preparation method of polyurethane elastomer, as Figure 1 shown, the method includes the following steps:

[0044] Step 101: Mix 280 - 330 parts by weight of polyether polyol, 1 - 2 parts of chain extender, 0.5 - 1.2 parts of crosslinking agent, 5 - 15 parts of expansion beads, 10 - 50 parts of diatomite, and 0.5 - 0.8 parts of foaming stabilizer, and heat and react to prepare the first component.

[0045] Specifically, the polyether polyol in the first component includes one or two of polytetrahydrofuran polyol and polyethylene glycol; wherein, the molecular weight of the polyether polyol is 1200 - 1400 g / mol, and the hydroxyl value is 85 - 90 mgKOH / g; when the first component includes polyethylene glycol, the molecular weight of the polyethylene glycol is 900 - 1000 g / mol, and the hydroxyl group is 105 - 115 mgKOH / g.

[0046] Specifically, the chain extender in the first component includes one or two of diol and diamine; the foaming stabilizer is a polysiloxane-polyether copolymer. The particle size of the diatomite is 1 - 10 um, the bulk density is 0.3 - 0.5 g / cm 3 , and the pore radius is 50 - 80 nm; the expansion beads are an alkane mixture with a boiling point of 60 - 70 °C, and the particle size is 10 - 30 um.

[0047] Preparing the first component includes successively adding the raw materials in the first component: 280 - 330 parts by weight of polyether polyol, 1 - 2 parts of chain extender, 0.5 - 1.2 parts of crosslinking agent, 5 - 15 parts of expansion beads, 10 - 50 parts of diatomite, and 0.5 - 0.8 parts of foaming stabilizer into the reaction kettle for mixing, heating to 35 - 40 °C, stirring and reacting for 1 - 2 h to obtain the first component, and storing the first component sealed.

[0048] By adding diatomaceous earth and a small amount of low-temperature thermally expandable spheres to the raw materials for preparing the first component, a pore structure is formed inside the material. A small amount of diatomaceous earth can fill into the foamed pore structure during the reaction process. At the same time, diatomaceous earth itself has a high porosity and good mechanical properties, enabling the micro-foamed polyurethane to have good impact resistance while having the effects of sound insulation and heat insulation. When applied to the reinforcement of automotive seat cross-members, it can reduce weight and achieve the effects of sound insulation, heat insulation, and lightweighting.

[0049] Step 102: Mix 110 - 140 parts by weight of isocyanate, 10 - 50 parts by weight of hydrogenated castor oil, 83 - 93 parts by weight of phthalic anhydride polyester polyol, and 0.8 - 1.5 parts by weight of a catalyst, and heat and react to prepare the second component;

[0050] Specifically, the molecular weight of the phthalic anhydride polyester polyol in the second component is 400 - 500 g / mol, and the hydroxyl value is 300 - 305 mgKOH / g; the catalyst is a tertiary amine catalyst, including but not limited to dimethylacetamide.

[0051] The preparation of the second component specifically includes: sequentially adding 110 - 140 parts by weight of isocyanate, 10 - 50 parts by weight of hydrogenated castor oil, 83 - 93 parts by weight of phthalic anhydride polyester polyol, and 0.8 - 1.5 parts by weight of a catalyst to a reaction kettle, stirring and mixing evenly, heating to 80 - 85 °C, and holding the reaction for 3 - 4 h to obtain the second component, which is an NCO-terminated isocyanate prepolymer.

[0052] It should be noted that the isocyanate in this embodiment is selected as diphenylmethane diisocyanate.

[0053] Introducing a rigid bulky substance, hydrogenated castor oil, into the second component. The rigid bulky substance, bio-based castor oil, can form a certain network structure and increase the distance between the molecular chain skeletons, forming a microporous structure inside the material. The microporous structure can provide a certain shock absorption and buffering effect, and at the same time, the network structure can also limit the movement and slip of the molecular chains to keep the material having good mechanical properties. And using bulky bio-based hydrogenated castor oil, phthalic anhydride polyester polyol, and MDI reaction as the polyurethane hard segment, and polytetrahydrofuran polyol as the polyurethane soft segment. The hard segment provides a certain strength to the material and improves the impact resistance of the material, while the soft segment endows the material with elasticity and toughness, achieving the effect of energy absorption and shock reduction.

[0054] It should be noted that the cooperation of diatomaceous earth, a small amount of low-temperature thermally expandable spheres, and the rigid bulky structure in this embodiment further enables the material to have a pore structure inside, enabling the micro-foamed polyurethane to have good impact resistance while having the effects of sound insulation and heat insulation.

[0055] Step 103: Mix the first component and the second component, and heat them to a first preset temperature for reaction to obtain a post-reaction mixture.

[0056] Specifically, add the prepared first component and second component into the reaction kettle through the feeding port in sequence, and make them uniformly mixed by mechanical stirring at 40 - 55 °C to obtain a post-reaction mixture.

[0057] Step 104: Pour the post-reaction mixture into a mold, keep it warm at a second preset temperature for a first preset time, demold to take out the product, cool and dry the product to obtain a polyurethane elastomer.

[0058] Pour the post-reaction mixture into a mold, keep it warm at 80 - 85 °C for a first preset time of 3 - 4 h, wait until it cools to room temperature, then demold to take out the product; put the demolded product into an oven and vacuum at 60 - 70 °C for 3 - 5 h to obtain a microcellular foamed polyurethane elastomer.

[0059] In a specific embodiment, the mold in this embodiment is as Figure 2 shown, and includes a hollow outer frame 1, as Figure 3 and Figure 4 shown. The outer frame 1 includes an upper plate 2, a lower plate 3, a left side plate 4 and a right side plate 5. The upper plate 2 and the lower plate 3 are arranged opposite to each other up and down. The left side plate 4 and the right side plate 5 are respectively connected to the two ends of the upper plate 2 and the lower plate 3, and the left side plate 4 is connected to the left end faces of the upper plate 2 and the lower plate 3 through a first locking component, and the right side plate 5 is connected to the right end faces of the upper plate 2 and the lower plate 3 through a second locking component. The outer frame 1 further includes a front plate and a rear plate. The front plate and the rear plate are correspondingly arranged at the front and rear ends of the outer frame 1 to form a seal for the hollow outer frame 1. Specifically, as Figure 4 and Figure 5 shown, the front plate includes two spaced first positioning plates and a first injection hole 10 located between the two first positioning plates. The rear plate includes two spaced second positioning plates and a second injection hole 11 located between the two second positioning plates. The first injection hole 10 and the second injection hole 11 communicate with the middle of the outer frame 1 to realize injecting the post-reaction mixture into the outer frame 1.

[0060] It should be noted that the material of the outer frame 1 in this embodiment includes but is not limited to one or a mixture of glass fiber, carbon fiber, basalt fiber, composite epoxy, PU, unsaturated resin, PA, PP, and PET. The outer frame material can be formed by processes such as pultrusion, vacuum infusion, RTM, or hot pressing.

[0061] Specifically, after the outer frame 1 is pultruded and formed, it is cut according to the dimensional requirements; the outer frame 1 is placed in a forming mold; both ends of the outer frame 1 are fixed by positioning plates, and the positioning plates are provided with polyurethane injection holes; the first component and the second component mixed in proportion are poured into the outer frame cavity in the mold in sequence; the mold and the positioning plates at both ends are pressurized and heated to 80-85 °C and kept warm for reaction for 3-4 hours to complete the polyurethane foaming; after the polyurethane foaming is completed, it is taken out and the excess foamed material is cut off and shaped to form the required polyurethane elastomer.

[0062] Further, as Figure 6 shown, the pultrusion process of the outer frame 1 includes, in the forward direction of the material, a yarn rack, a resin tank, a pultrusion die, a tractor and a cutting machine in sequence.

[0063] In this embodiment, by using the polyurethane elastomer to prepare the seat crossbeam 12 assembly, the overall stiffness and bearing capacity of the components are improved, thereby improving the safety performance of the battery pack; the lightweight effect is good, and the weight can be reduced by 15-20%; the wall thickness dimension of the outer frame of the reinforcement and the density of the internal filling can be designed according to requirements, and this structure can effectively reduce the impact and improve the safety performance.

[0064] Embodiment Two

[0065] Corresponding to the above embodiment, the present application provides a seat crossbeam assembly, and the seat crossbeam 12 assembly includes a polyurethane elastomer, and the polyurethane elastomer is prepared by using the preparation method of the polyurethane elastomer as described above.

[0066] As Figure 7 shown, the seat crossbeam 12 assembly includes a seat crossbeam 12, the seat crossbeam 12 has a specific shape and has grooves, and the outer frame 1 of the mold is installed in the grooves, and the polyurethane elastomer formed by injection molding is inside the outer frame 1. It is used as a composite material reinforcement in a pure sheet metal structure, where the outer frame of the reinforcement is a fiber-reinforced polymer composite material, the inside is filled with polyurethane foam, the main surface of the outer frame bears the internal tensile / compressive force and the load-bearing function, the core layer mainly bears the shear force and the buffering function, and provides sufficient stiffness. The reinforcement and the sheet metal structure are bonded by structural adhesive, and this structure can effectively reduce the impact and improve the safety performance.

[0067] Embodiment Three

[0068] Corresponding to the above embodiment, this embodiment provides a vehicle, and the vehicle includes the seat crossbeam assembly as described above.

[0069] Embodiment Four

[0070] Corresponding to the above embodiments, in this embodiment, polyurethane elastomers are prepared by selecting different raw material components according to the preparation method in this solution. Among them, the isocyanate is selected as diphenylmethane diisocyanate, and the diphenylmethane diisocyanate is selected as an industrial-grade commercially available product. The preparation method is as follows:

[0071] (1) Add 300 parts of polytetrahydrofuran ether glycol (PTMEG-1200), 1.5 parts of chain extender (ethylenediamine), 1 part of crosslinking agent (MDT), 41 parts of diatomite, 12 parts of expandable beads, and 0.8 parts of foaming stabilizer (SY-6193) into a reaction kettle, stir at 35-40 °C for 1 h, mix evenly to form the first component, and store it sealed;

[0072] (2) Put 125 parts of isocyanate (MDI), 86 parts of phthalic anhydride polyester polyol (NGPS-300), 35 parts of castor oil, and 0.8 parts of catalyst (DMEA) into a reaction kettle, and react under mechanical stirring at 85 °C for 3-4 h to obtain an NCO-terminated isocyanate prepolymer, and make it into the second component;

[0073] (3) Add the first component and the second component into a mechanical stirring reaction kettle through the feeding port, stir and mix evenly at room temperature, pour it into a mold, keep it warm at 85 °C for 4 h, cool it to room temperature, and demold to take out the product. Put the demolded product into an oven and keep it at 60 °C under vacuum for 3 h to obtain the polyurethane elastomer.

[0074] Example Five

[0075] Corresponding to the above embodiments, the preparation method of the polyurethane elastomer in this embodiment is as follows:

[0076] (1) Add 150 parts of polytetrahydrofuran ether glycol (PTMEG-1200), 120 parts of polyethylene glycol (PEG-1000), 1.5 parts of chain extender (ethylenediamine), 1.2 parts of crosslinking agent (MDT), 41 parts of diatomite, 12 parts of expandable beads, and 0.8 parts of foaming stabilizer (SY-6193) into a reaction kettle, stir at 35-40 °C for 1 h, mix evenly to form the first component, and store it sealed;

[0077] (2) Put 125 parts of isocyanate (MDI), 86 parts of phthalic anhydride polyester polyol (NGPS-300), 35 parts of castor oil, and 1.2 parts of catalyst (DMEA) into a reaction kettle, and react under mechanical stirring at 85 °C for 3-4 h to obtain an NCO-terminated isocyanate prepolymer, and make it into the second component;

[0078] (3) Add the first component and the second component into a mechanical stirring reactor through the feeding port, mechanically stir and mix evenly at room temperature, pour into a mold, keep at 85 °C for 4 h, cool to room temperature, and demold to take out the product. Put the demolded product into an oven and keep it under vacuum at 60 °C for 3 h to obtain a microporous polyurethane elastomer.

[0079] Example VI

[0080] Corresponding to the above example, the preparation method of the polyurethane elastomer in this example is specifically as follows:

[0081] (1) Add 280 parts of polytetrahydrofuran ether glycol (PTMEG-1200), 1.5 parts of chain extender (ethylenediamine), 0.5 parts of crosslinking agent (MDT), 41 parts of diatomite, 12 parts of expansion beads and 0.6 parts of foaming stabilizer (SY-6193) into the reactor, stir at 35-40 °C for 1 h, mix evenly to prepare the first component, and store it sealed;

[0082] (2) Put 125 parts of isocyanate (MDI), 85 parts of phthalic anhydride polyester polyol (NGPS-300), 47 parts of castor oil and 0.8 parts of catalyst (DMEA) into the reactor, react at 85 °C under mechanical stirring for 3-4 h to obtain an NCO-terminated isocyanate prepolymer, and prepare the second component;

[0083] (3) Add the first component and the second component into a mechanical stirring reactor through the feeding port, mechanically stir and mix evenly at room temperature, pour into a mold, keep at 85 °C for 4 h, cool to room temperature, and demold to take out the product. Put the demolded product into an oven and keep it under vacuum at 60 °C for 3 h to obtain a microporous polyurethane elastomer.

[0084] Example VII

[0085] Corresponding to the above example, the preparation method of the polyurethane elastomer in this example is specifically as follows:

[0086] (1) Add 300 parts of polytetrahydrofuran ether glycol (PTMEG-1200), 1 part of chain extender (ethylenediamine), 1 part of crosslinking agent (MDT), 55 parts of diatomite, 15 parts of expansion beads and 0.8 parts of foaming stabilizer (SY-6193) into the reactor, stir at 35-40 °C for 1 h, mix evenly to prepare the first component, and store it sealed;

[0087] (2) Put 125 parts of isocyanate (MDI), 86 parts of phthalic anhydride polyester polyol (NGPS-300), 35 parts of castor oil and 0.8 parts of catalyst (DMEA) into the reactor, react at 85 °C under mechanical stirring for 3-4 h to obtain an NCO-terminated isocyanate prepolymer, and prepare the second component;

[0088] (3) Add the first component and the second component into a mechanical stirring reactor through the feeding port, mechanically stir and mix evenly at room temperature, pour into a mold, keep at 85 °C for 4 h, cool to room temperature, and demold to obtain the product. Put the demolded product into an oven and keep it under vacuum at 60 °C for 3 h to obtain the microporous polyurethane elastomer.

[0089] Comparative Example 1

[0090] Corresponding to the above-mentioned embodiment, the difference between this comparative example and the fourth embodiment above is that no expansion balls are added to the first component, and the rest is the same as that of the fourth embodiment.

[0091] Comparative Example 2

[0092] Corresponding to the above-mentioned embodiment, the difference between this comparative example and the fourth embodiment above is that no diatomaceous earth is added to the first component, and the rest is the same as that of the fourth embodiment.

[0093] Comparative Example 3

[0094] Corresponding to the above-mentioned embodiment, the difference between this comparative example and the fourth embodiment above is that no hydrogenated castor oil is added to the second component, and the rest is the same as that of the fourth embodiment.

[0095] Comparative Example 4

[0096] Corresponding to the above-mentioned embodiment, the difference between this comparative example and the above-mentioned embodiment is that no diatomaceous earth and expansion balls are added to the first component. The preparation method of the polyurethane elastomer is as follows:

[0097] (1) Add 300 parts of polytetrahydrofuran ether glycol (PTMEG-1200), 1 part of chain extender (ethylenediamine), 0.8 part of crosslinking agent (MDT), and 0.8 part of foaming stabilizer (SY-6193) into the reactor, stir at 35-40 °C for 1 h, mix evenly to prepare the first component, and store it sealed;

[0098] (2) Put 125 parts of isocyanate (MDI), 89 parts of phthalic anhydride polyester polyol (NGPS-300), 12 parts of castor oil, and 0.8 part of catalyst (DMEA) into the reactor, react at 85 °C under mechanical stirring for 3-4 h to obtain an NCO-terminated isocyanate prepolymer, and prepare the second component;

[0099] (3) Add the first component and the second component into a mechanical stirring reactor through the feeding port, mechanically stir and mix evenly at room temperature, pour into a mold, keep at 85 °C for 4 h, cool to room temperature, and demold to obtain the product. Put the demolded product into an oven and keep it under vacuum at 60 °C for 3 h to obtain the microporous polyurethane elastomer.

[0100] Comparative Example 5

[0101] Corresponding to the above embodiments, the difference between this comparative example and the above embodiments is that diatomaceous earth and expansion balls are not added to the first component, and hydrogenated castor oil is not added to the second component. The preparation method of the polyurethane elastomer is as follows:

[0102] (1) Add 330 parts of polytetrahydrofuran ether glycol (PTMEG-1200), 2 parts of chain extender (ethylenediamine), 1 part of crosslinking agent (MDT), and 0.5 part of foam stabilizer (SY-6193) to the reaction kettle, stir at 35-40 °C for 1 h, mix evenly to prepare the first component, and store it sealed;

[0103] (2) Put 125 parts of isocyanate (MDI), 93 parts of phthalic anhydride polyester polyol (NGPS-300), and 1 part of catalyst (DMEA) into the reaction kettle, and react under mechanical stirring at 85 °C for 3-4 h to obtain an NCO-terminated isocyanate prepolymer, and prepare the second component;

[0104] (3) Add the first component and the second component to the mechanical stirring reaction kettle through the feeding port, stir and mix evenly at room temperature, pour into the mold, keep warm at 85 °C for 4 h, cool to room temperature, and demold to take out the product. Put the demolded product into the oven and keep it at 60 °C under vacuum for 3 h to obtain a microcellular polyurethane elastomer.

[0105] The raw materials used in the above Examples 4 to 7 and Comparative Examples 1 to 5 are counted by weight as shown in Table 1.

[0106] Table 1 Raw material dosage table for each example and comparative example

[0107]

[0108] The polyurethane elastomers prepared in the above Examples 4 to 7 and Comparative Examples 1 to 5 were respectively tested for density, tensile strength, elongation at break, impact resistance, compression deformation, and improvement amount of impact sound pressure level according to the corresponding test standards. The test results are shown in Table 2.

[0109] Table 2 Test results for each example and comparative example

[0110]

[0111]

[0112] Combining the raw materials in the examples in Table 1 and the performance test results of the prepared polyurethane elastomers in Table 2, it can be seen that when diatomaceous earth and expanded spheres are added during the preparation of polyurethane elastomers, the density of the prepared polyurethane elastomers is lower than that of the polyurethane elastomers without adding the above components, further indicating that diatomaceous earth, expanded spheres, and the rigid bulky substance bio-based castor oil can increase the distance between molecular chain skeletons and form a microporous structure inside the material. The microporous structure can provide a certain shock absorption and buffering effect while enabling the material to maintain good mechanical properties; and, when diatomaceous earth, expanded spheres, and bulky castor oil are added during the preparation of polyurethane elastomers, the tensile strength of the prepared polyurethane elastomers is somewhat increased compared to the polyurethane elastomers without adding the above components, and the elongation at break is above 500%, proving that the polyurethane elastomers prepared by the preparation method in this solution have good elasticity and plasticity.

[0113] By further analysis of the improvement amounts of compression deformation and impact resistance level in the comparative examples and examples, it can be seen that the improvement amount of the impact sound pressure level of the polyurethane elastomers prepared in this solution basically remains above 20 dB, and the compression deformation is significantly higher than that of the comparative examples, further indicating that the diatomaceous earth in this solution itself has a high porosity and good mechanical properties, enabling the microcellular polyurethane to have good impact resistance performance while having a sound insulation and heat insulation effect.

[0114] Although the preferred embodiments in the embodiments of the present application have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present application.

[0115] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A method for preparing a polyurethane elastomer, characterized in that, The method includes: Mixing 280 - 330 parts by weight of polyether polyol, 1 - 2 parts of chain extender, 0.5 - 1.2 parts of crosslinking agent, 5 - 15 parts of expansion spheres, 10 - 50 parts of diatomite, and 0.5 - 0.8 parts of foaming stabilizer, and heating and reacting to prepare the first component; Mixing 110 - 140 parts by weight of isocyanate, 10 - 50 parts of hydrogenated castor oil, 83 - 93 parts of phthalic anhydride polyester polyol, and 0.8 - 1.5 parts of catalyst, and heating and reacting to prepare the second component; Mixing the first component and the second component, and heating to a first preset temperature for reaction to obtain a post - reaction mixture; Pouring the post - reaction mixture into a mold, insulating at a second preset temperature for a first preset time, demolding to take out the product, and cooling and drying the product to obtain a polyurethane elastomer.

2. The preparation method of the polyurethane elastomer according to claim 1, wherein The polyether polyol includes one or two of polytetrahydrofuran polyol and polyethylene glycol; The molecular weight of the polyether polyol is 1200 - 1400 g / mol, and the hydroxyl value is 85 - 90 mgKOH / g; The molecular weight of the polyethylene glycol is 900 - 1000 g / mol, and the hydroxyl group is 105 - 115 mgKOH / g.

3. The preparation method of the polyurethane elastomer according to claim 1 or 2, characterized in that, The chain extender includes one or two of diol and diamine; And / or, the foaming stabilizer is a polysiloxane - polyether copolymer.

4. The preparation method of the polyurethane elastomer according to claim 1 or 2, characterized in that, The particle size of the diatomaceous earth is 1 to 10 μm, the bulk density is 0.3 to 0.5 g / cm 3 , and the pore radius is 50 to 80 nm; And / or, the expansion spheres are an alkane mixture with a boiling point of 60 - 70 °C and a particle size of 10 - 30 μm.

5. The preparation method of the polyurethane elastomer according to claim 1 or 2, characterized in that, The molecular weight of the phthalic anhydride polyester polyol is 400 - 500 g / mol, and the hydroxyl value is 300 - 305 mgKOH / g; And / or, the catalyst is a tertiary amine catalyst.

6. The preparation method of the polyurethane elastomer according to claim 1 or 2, characterized in that, Preparing the first component specifically includes: Adding the raw materials in the first component to a reaction kettle for mixing, heating to 35 - 40 °C, stirring and reacting for 1 - 2 h to obtain the first component, and storing the first component in a sealed manner.

7. The preparation method of the polyurethane elastomer according to claim 1 or 2, characterized in that, Preparing the second component specifically includes: Adding the raw materials in the second component to a reaction kettle for mixing, heating to 80 - 85 °C, and holding for reaction for 3 - 4 h to obtain the second component.

8. The preparation method of the polyurethane elastomer according to claim 1 or 2, characterized in that, The method further includes: The first preset temperature is 40 - 55 °C; The second preset temperature is 80 - 85 °C, and the first preset insulation time is 3 - 4 h; The drying conditions of the product are vacuum at 60 - 70 °C for 3 - 5 h.

9. A seat crossbeam assembly, characterized in that, The seat cross - beam assembly includes a polyurethane elastomer, and the polyurethane elastomer is prepared by the preparation method of the polyurethane elastomer according to any one of claims 1 - 8.

10. A vehicle, characterized in that, The vehicle includes the seat cross - beam assembly according to claim 9.

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