Polyurethane prepreg, fiber reinforced polyurethane material and preparation method and application thereof

Abstract

The invention relates to a polyurethane prepreg, a fiber reinforced polyurethane material as well as a preparation method and application of the fiber reinforced polyurethane material. The polyurethane prepreg comprises a component K1 and a component K2, wherein the component K1 and the component K2 exist independently, and the mass ratio of the component K1 to the component K2 is 1: (1.0-1.2); the viscosity of the component K1 and the viscosity of the component K2 are independently 100 to 500 mPa. S. A fiber reinforced composite material prepared from the urethane prepreg is hot-pressed into a fine structure, and the forming effect is good. In addition, the fiber reinforced polyurethane material prepared from the polyurethane prepreg has good mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of polyurethane composite material processing, and more specifically, to a polyurethane prepreg, a fiber-reinforced polyurethane material, and a preparation method and application thereof. Background Art

[0002] With the development of science and technology, various materials have also developed rapidly. Among them, fiber-reinforced composite materials have become a hot research topic due to their price and performance advantages. They are becoming more and more popular in the fields of aerospace transportation, new energy, wind energy and infrastructure. Compared with traditional materials such as metals, non-metals and wood, fiber-reinforced composite materials are light in weight, corrosion-resistant, high in mechanical strength and good in processing performance.

[0003] Fiber-reinforced composite materials are divided into two categories: thermoplastic and thermosetting. Among them, thermosetting fiber-reinforced composite materials are widely concerned due to their high strength, aging resistance, chemical resistance and other characteristics. The preparation process of thermosetting fiber-reinforced composite materials is mainly pre-impregnation, which includes organic solvent pre-impregnation, melt coating and reaction injection molding. The pre-impregnated fiber-reinforced composite materials are cut and hot-pressed to become parts for various application scenarios.

[0004] Commonly used resin materials in thermosetting fiber-reinforced composite materials include epoxy resin materials, unsaturated polyester resin materials, etc. Epoxy resin materials have the problems of high price and insufficient mechanical properties, and their viscosity is usually large, which poses the risk of insufficient pre-impregnation; unsaturated polyester materials have been gradually reduced in use due to their odor (caused by styrene).

[0005] Polyurethane resin is reasonably priced and has good toughness. In recent years, the industry has tried to use thermosetting polyurethane resin to prepare thermosetting fiber-reinforced composite materials, such as a polyurethane prepreg and its preparation method and application. However, this patent uses small molecule acrylic monomers (diluents), and there is still a problem of strong odor. In addition, when pre-impregnating the fibers, the patent can only pre-impregnate the fibers once. As the sheets become thin, the thickness of the sheets is small. The small thickness requires multiple layers to be stacked during the hot pressing process, which consumes time.

[0006] It is also worth noting that although thermosetting fiber-reinforced composite materials have gradually been widely used, they are still limited due to their poor molding effect of fine structures. For example, in the field of new energy and automobiles, many parts (such as power battery trays or car covers) have grooves (size is at the millimeter level). When thermosetting fiber-reinforced composite materials are hot-pressed to prepare these parts, the fine structures often collapse and the molding effect is poor. Summary of the invention

[0007] The primary purpose of the present invention is to overcome the problems existing in the resin materials of the above-mentioned existing thermosetting fiber-reinforced composite materials and provide a polyurethane prepreg.

[0008] A further object of the present invention is to provide a method for preparing the polyurethane prepreg.

[0009] A further object of the present invention is to provide a thermosetting fiber-reinforced polyurethane material.

[0010] A further object of the present invention is to provide a method for preparing the above-mentioned thermosetting fiber-reinforced polyurethane material.

[0011] A further object of the present invention is to provide a production device for realizing the preparation method of the above-mentioned thermosetting fiber-reinforced polyurethane material.

[0012] A further object of the present invention is to provide a composite material article.

[0013] The above-mentioned object of the present invention is achieved by the following technical solutions:

[0014] A polyurethane prepreg, comprising a component K1 and a component K2 which exist independently and have a mass ratio of 1:(1.0-1.2);

[0015] The component K1 comprises the following components in parts by weight:

[0016]

[0017] The component K2 comprises the following components in parts by weight:

[0018] 40-60 parts of polyisocyanate,

[0019] 38-45 parts of blocked polyurethane prepolymer;

[0020] The viscosity of the component K1 and the component K2 is independently 100 to 500 mPa.s;

[0021] The blocked polyurethane prepolymer has reactive NCO after deblocking.

[0022] In the present invention, the viscosities of component K1 and component K2 are measured at 25°C.

[0023] The present invention ensures the basic fluidity of the polyurethane prepreg by regulating the viscosity of the component K1 and the component K2, so that the polyurethane prepreg can be used for pre-impregnating reinforcing fibers. In addition, the present invention does not add acrylic monomer as a diluent, and does not produce the odor problem caused by acrylic monomer.

[0024] The inventors of the present invention have found that by adding primary hydroxyl polyol and secondary hydroxyl polyol to component K1 and adjusting the amounts of the two, and adding polyisocyanate and blocked polyurethane prepolymer to component K2, the fiber-reinforced composite material made of the obtained polyurethane prepreg has good molding effect when hot-pressed into a fine structure.

[0025] The reason is that the reaction activity of primary hydroxyl polyol is higher than that of secondary hydroxyl polyol. By regulating the dosage of the two, the reaction rate of the polyol and the polyisocyanate can be regulated, thereby regulating the viscosity increase rate of the polyurethane prepreg during the prepreg process, which is beneficial to fully prepreg the reinforcing fiber with the polyurethane prepreg and ensure the basic mechanical properties of the fiber-reinforced polyurethane material; when the fiber-reinforced polyurethane material is hot-pressed, the combination of a certain amount of primary hydroxyl polyol and secondary hydroxyl polyol is beneficial to the rapid reaction of the polyol with the NCO after the blocked polyurethane prepolymer is unblocked and cured, and the material after molding is not easy to deform at high temperature and has a good molding effect.

[0026] If component K1 does not contain secondary hydroxyl polyol or contains too little secondary hydroxyl polyol, the viscosity of the prepreg increases too quickly during the prepreg process, the prepreg has a poor prepreg effect on the reinforcing fibers, and the fiber-reinforced polyurethane material has defects in compatibility, which makes it easy for the fine structure to collapse during hot pressing.

[0027] If too little primary hydroxyl polyol is added to component K1 or the amount of primary hydroxyl polyol is less than that of secondary hydroxyl polyol, the fiber-reinforced polyurethane material will cure slowly during hot pressing and will be easily deformed under high temperatures during hot pressing, which is not conducive to the molding of fine structures.

[0028] If component K2 does not contain a blocked polyurethane prepolymer, the fiber-reinforced polyurethane material made from the polyurethane prepreg has poor processability and is difficult to obtain a fine structure with a good molding effect during hot pressing.

[0029] In addition, through the formulation of the components of the polyurethane prepreg of the present invention, the fiber-reinforced polyurethane material prepared from the polyurethane prepreg has good mechanical properties.

[0030] In addition, the polyurethane prepreg of the present invention can continuously prepreg reinforcing fibers of different forms (such as long glass fiber and short glass fiber, or glass fiber cloth and short glass fiber), and the obtained fiber-reinforced polyurethane material has a large thickness, which can reach 1.5 mm, which can reduce the number of superimposed layers of the fiber-reinforced polyurethane material in the hot pressing molding process and save work hours. At the same time, the fiber-reinforced polyurethane material obtained by the polyurethane prepreg of the present invention is easy to store, does not need to be stored in a cold storage, and can be stored at room temperature, which is economical.

[0031] In the present invention, the amount of the primary hydroxyl polyol of component K1 can be 65, 67, 69, 71, 73, 75, 77, 79 or 80 parts by weight; the amount of the secondary hydroxyl polyol can be 20, 22, 24, 26, 28 or 30 parts by weight.

[0032] Preferably, the blocked polyurethane prepolymer is unblocked during the heat curing process. The heat curing time is 140-160°C.

[0033] Preferably, the blocked polyurethane prepolymer is a cardanol-terminated polyurethane prepolymer.

[0034] Preferably, the preparation method of the blocked polyurethane prepolymer is as follows: polyether polyol and liquefied MDI are polymerized at 60-80° C. for 1-2 hours to obtain a polyurethane prepolymer having a large number of NCO groups, and then cardanol is added for end-capping.

[0035] More preferably, the mass ratio of the polyether polyol to the liquefied MDI is 1:(0.5-0.8).

[0036] Preferably, the hydroxyl value of the primary hydroxyl polyol is 150 to 1200 mgKOH / g; and the hydroxyl value of the secondary hydroxyl polyol is 250 to 400 mgKOH / g.

[0037] Preferably, the primary hydroxyl polyol is at least one of BASF Sovermol 805, Stepan BC-180 or triethanolamine; the secondary hydroxyl polyol is at least one of Dow CP450, Covestro Desmophen 1400BT or Bluestar Dongda DL400.

[0038] Preferably, the functionality of the polyisocyanate is ≥3.

[0039] Preferably, the polyisocyanate is at least one of polymeric MDI, liquefied MDI or HDI trimer.

[0040] Preferably, the molar ratio of the sum of the hydroxyl groups of the primary hydroxyl polyol and the secondary hydroxyl polyol to the sum of the NCO groups of the polyisocyanate and the blocked polyurethane prepolymer after deblocking is 1:(1-1.2).

[0041] Preferably, the catalyst is at least one of organic tin (such as stannous octoate) or organic bismuth (such as bismuth neodecanoate).

[0042] Preferably, the component K1 further comprises 5 to 10 parts of a flame retardant; the flame retardant includes but is not limited to a phosphate flame retardant (such as triisopropylphenyl phosphate).

[0043] Preferably, the component K2 further comprises 10 to 20 parts of a flame retardant; the flame retardant includes but is not limited to a phosphate flame retardant (such as triisopropylphenyl phosphate).

[0044] More preferably, the other auxiliary agent in the component K1 is at least one of a silane coupling agent, a phthalate adhesion promoter, a phenolic antioxidant, a UV absorber, and a hindered amine.

[0045] Preferably, within 60 minutes after the components K1 and K2 are mixed, the viscosity is ≤2000 mPa.s, and the temperature rise is ≤10° C. relative to the temperature before mixing. Under such conditions, the obtained fiber-reinforced composite material made of polyurethane prepreg can be hot-pressed into a fine structure with better molding effect.

[0046] The method for preparing the polyurethane prepreg comprises the following steps: mixing the components of component K1; and mixing the components of component K2 to obtain the polyurethane prepreg.

[0047] A thermosetting fiber-reinforced polyurethane material comprises the following components in parts by weight:

[0048] 40-50 parts of the above polyurethane prepreg;

[0049] 50-60 parts of reinforcing fiber.

[0050] Preferably, the reinforcing fibers are glass fibers.

[0051] Preferably, the reinforcing fiber is at least one of fiber cloth, short fiber or long fiber.

[0052] The method for preparing the fiber-reinforced polyurethane material comprises the following steps: pre-impregnating reinforcing fibers with the polyurethane prepreg to obtain the fiber-reinforced polyurethane material.

[0053] Preferably, when the reinforcing fibers include fiber cloth and short fibers, the method for preparing the fiber-reinforced polyurethane material comprises the following steps: firstly pre-impregnating the fiber cloth with the polyurethane prepreg to obtain a pre-impregnated fiber cloth, then spreading short fibers on the pre-impregnated fiber cloth, and then applying the polyurethane prepreg to obtain the fiber-reinforced polyurethane material.

[0054] A production equipment for implementing the above-mentioned preparation method, the production equipment comprises an unwinding module, a first glue mixing module, a first spraying module, a first traction module, a broken glass module, a second traction module, a second glue mixing module, a second spraying module, an extrusion module and a winding module which are arranged in sequence.

[0055] The production equipment of the present invention can pre-impregnate reinforcing fibers of a single form; it can also pre-impregnate reinforcing fibers of different forms continuously. The process of pre-impregnating reinforcing fibers of different forms continuously can be as follows: first, the fiber cloth is sprayed with polyurethane prepreg by the first spraying module; then the chopped glass module spreads the short fibers on the fiber cloth sprayed with polyurethane prepreg, and then the second spraying module sprays the polyurethane prepreg, and then after extrusion and winding, the fiber-reinforced polyurethane material is obtained. The fiber-reinforced polyurethane material obtained in this way has a large thickness, which can reach 1.5 mm, which can reduce the number of superimposed layers of the fiber-reinforced polyurethane material in the hot pressing molding process and save work time.

[0056] A composite material product is obtained by hot pressing the fiber reinforced polyurethane material.

[0057] Preferably, the part is a power battery tray or a car cover.

[0058] Preferably, the product has a microstructure; the size of the microstructure is at the millimeter level.

[0059] More preferably, the fine structure is a groove or a protrusion.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] (1) The fiber-reinforced composite material made of the polyurethane prepreg of the present invention has a good molding effect when hot-pressed into a fine structure.

[0062] (2) Compared with the existing traditional epoxy prepreg, the polyurethane prepreg of the present invention has a low viscosity, and can be used to continuously prepreg reinforcing fibers of different forms (such as long glass fiber and short glass fiber, or glass fiber cloth and short glass fiber). The obtained fiber-reinforced polyurethane material has a large thickness, which can reach 1.5 mm. This can reduce the number of stacked layers of the fiber-reinforced polyurethane material in the hot pressing molding process and save work time.

[0063] (3) The present invention does not add acrylic acid monomer as a diluent, and does not cause the odor problem caused by acrylic acid monomer.

[0064] (4) The fiber-reinforced polyurethane material prepared from the polyurethane prepreg of the present invention has good mechanical properties.

[0065] (5) The fiber-reinforced polyurethane material prepared from the polyurethane prepreg of the present invention is easy to store and can be stored at room temperature without refrigeration, which is economical. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 It is a schematic structural diagram of the prepreg equipment of the present invention.

[0067] Figure 1In the figure, 1 is an unwinding module, 2 is a first glue mixing module, 3 is a first spraying module, 4 is a first traction module, 5 is a broken glass module, 6 is a second traction module, 7 is a second glue mixing module, 8 is a second spraying module, 9 is an extrusion module, and 10 is a winding module. DETAILED DESCRIPTION

[0068] In order to more clearly and completely describe the technical solution of the present invention, the present invention is further described in detail through specific embodiments below. It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention. Various changes can be made within the scope of the rights of the present invention.

[0069] The main reagents are as follows:

[0070] Primary hydroxyl polyol 1#: Sovermol 805, hydroxyl value 170 mgKOH / g, BASF;

[0071] Primary hydroxyl polyol 2#: BC-180, hydroxyl value 180mgKOH / g, Stepan Company,

[0072] Primary hydroxyl polyol 3#: triethanolamine, hydroxyl value 1129 mgKOH / g, commercially available;

[0073] Secondary hydroxy polyol 1#: CP450, Dow Chemical, hydroxyl value 383mgKOH / g;

[0074] Secondary hydroxy polyol 2#: DL400, Bluestar Dongda Chemical, hydroxyl value 280mgKOH / g;

[0075] Flame retardant: triisopropylphenyl phosphate, commercially available;

[0076] Antioxidant: 1010, commercially available; Light stabilizer: 292, commercially available;

[0077] Stannous octoate (T9), bismuth neodecanoate DY-20, Shanghai Deyin;

[0078] Polyisocyanate 1#: Polymeric MDI, PM-200, Yantai Wanhua Chemical,

[0079] Polyisocyanate 2#: Liquid MDI, CDMDI-100LYantai Wanhua Chemical,

[0080] Polyisocyanate 3#: HDI trimer, N3300 Covestro, Germany,

[0081] Cardanol: NX-2026, Carled (Zhuhai) Company, Mn=302.

[0082] The homemade process of the closed polyurethane prepolymer is as follows: 560g of polyether polyol DL-2000 is dehydrated in a vacuum at 105°C for 2h, cooled to 65°C, and then 280g of liquefied MDI is added. The reaction is carried out under nitrogen protection for 1.5h. When the NCO value reaches 7.35%, 417g of cardanol is added and the reaction is carried out until there is no NCO peak in the infrared (IR) test.

[0083] Examples 1 to 4 and Comparative Examples 1 to 3

[0084] Examples 1 to 4 and Comparative Examples 1 to 3 provide a series of polyurethane prepregs, the formulations of which are shown in Table 1.

[0085] Table 1 Formulas of polyurethane compositions provided in Examples 1 to 4 and Comparative Examples 1 to 3 (parts by weight)

[0086]

[0087] The preparation method of the polyurethane prepreg of Examples 1 to 4 and Comparative Examples 1 to 3 is as follows: mixing the components of component K1; mixing the components of component K2 to obtain the polyurethane prepreg.

[0088] Embodiments 5 to 8

[0089] Examples 5 to 8 and Comparative Examples 4 to 6 provide a series of thermosetting fiber-reinforced polyurethane materials, each of which includes 45 parts by weight of polyurethane prepreg, 23 parts by weight of glass fiber cloth, and 32 parts by weight of short glass fiber. Among them, the thermosetting fiber-reinforced polyurethane materials of Examples 5 to 8 are respectively selected from the polyurethane prepregs of Examples 1 to 4, and the thermosetting fiber-reinforced polyurethane materials of Comparative Examples 4 to 6 are respectively selected from the polyurethane prepregs of Comparative Examples 1 to 3.

[0090] The preparation method of the fiber-reinforced polyurethane material of Examples 5 to 8 and Comparative Examples 4 to 6 is as follows: Component K1 and component K2 of the polyurethane prepreg are mixed in the first mixing system of the prepreg equipment and the second mixing system of the prepreg equipment, and the glass fiber cloth is first sprayed by the prepreg equipment, and then short glass fibers are spread, and then sprayed, extruded, and rolled. Figure 1 As shown, it includes an unwinding module 1, a first glue mixing module 2, a first spraying module 3, a first traction module 4, a broken glass module 5, a second traction module 6, a second glue mixing module 7, a second spraying module 8, an extrusion module 9 and a winding module 10. The broken glass module 5 breaks the long glass fibers into short glass fibers.

[0091] Example 9

[0092] Example 9 provides a thermosetting fiber-reinforced polyurethane material, which differs from Example 5 in that short glass fibers are not added; the amount of polyurethane prepreg used is 45 parts by weight, and the amount of glass fiber cloth used is 55 parts by weight.

[0093] Accordingly, in the process of preparing the thermosetting fiber-reinforced polyurethane material of Example 9, the step of spreading short glass fibers is not performed.

[0094] Performance Testing

[0095] 1. Mechanical properties

[0096] Sample preparation: Cut into samples of different sizes, cure the fiber-reinforced polyurethane materials of Examples 5 to 9 and Comparative Examples 4 to 6 (150° C., 5 min), and then test the mechanical properties;

[0097] Mechanical test specimens:

[0098] Flexural strength (Mpa): 127*12.7*3mm, ASTM D790-03;

[0099] Compression strength (Mpa): 140*14*4mm, ASTM D6484-01;

[0100] Tensile strength (Mpa): 250*25*2.5mm, ASTM D3039-07;

[0101] Hardness (D): Thickness ≥ 6mm, GB / T 531.1-2008.

[0102] 2. Molding effect

[0103] The fiber-reinforced polyurethane materials of Examples 5 to 9 and Comparative Examples 4 to 6 were hot-pressed by a hot-pressing mold; a semi-cylindrical protrusion (the diameter of the semi-cylinder was about 2 mm) was provided inside the bottom of the hot-pressing mold, so that the fiber-reinforced polyurethane material could present a groove shape at the corresponding position after hot-pressing, and the number of groove collapses was observed: collapses < 3 were qualified, collapses 3 to 5 were unqualified, and collapses > 5 were poor;

[0104] The results are shown in Table 2:

[0105] Table 2

[0106] project Tensile strengthMpa Bending strengthMpa Compression strengthMpa Hardness D Molding effect Example 5 262 360 230 86 qualified Example 6 266 361 229 86 qualified Example 7 250 345 220 84 qualified Example 8 255 350 225 85 qualified Example 9 341 450 300 86 qualified Comparative Example 4 230 330 202 84 Failure Comparative Example 5 220 315 200 82 Failure Comparative Example 6 248 200 260 88 Difference

[0107] From Table 2, we can see that:

[0108] The fiber-reinforced polyurethane materials (Examples 5 to 9) prepared from the polyurethane prepregs of Examples 1 to 4 passed the molding effect test of the fine structure after hot pressing molding, indicating that the fiber-reinforced composite material made of the polyurethane prepreg obtained by the present invention, which adds primary hydroxyl polyol and secondary hydroxyl polyol to component K1 and controls the dosage of the two at the same time, and adds polyisocyanate and blocked polyurethane prepolymer to component K2, has good molding of fine structure after hot pressing.

[0109] In addition, the fiber-reinforced polyurethane materials of Examples 5 to 9 have good mechanical properties after thermal post-forming.

[0110] The mechanical properties and molding effects of Example 1 and Example 9 are good. Among them, the fiber reinforced polyurethane material of Example 1 has a greater thickness, which can reduce the number of stacked layers of the fiber reinforced polyurethane material during the hot pressing molding process and save more work time.

[0111] The fiber-reinforced polyurethane material of Comparative Example 4 failed the molding effect test after hot post-molding because: the polyurethane prepreg of Comparative Example 1 was selected, and the polyurethane prepreg did not add secondary hydroxyl polyol, and the viscosity of the prepreg increased too quickly during the pre-impregnation process, and the prepreg had a poor pre-impregnation effect on the reinforcing fibers, resulting in defects in the compatibility of the fiber-reinforced polyurethane material, which caused the fine structure to collapse easily during hot pressing molding. In addition, the tensile strength, bending strength and compressive strength of the fiber-reinforced polyurethane material of Comparative Example 4 after hot post-molding were not good.

[0112] The fiber-reinforced polyurethane material of Comparative Example 5 failed the molding effect test after hot post-molding because: the polyurethane prepreg of Comparative Example 2 was selected, and the amount of primary hydroxyl polyol used in the polyurethane prepreg was less than that of secondary hydroxyl polyol, so the fiber-reinforced polyurethane material was slow to cure during hot pressing, and it was easy to deform under the high temperature of hot pressing, which was not conducive to the molding of fine structures. In addition, the tensile strength, bending strength and compressive strength of the fiber-reinforced polyurethane material of Comparative Example 5 after hot post-molding were not good.

[0113] The molding effect test result of the fiber-reinforced polyurethane material of Comparative Example 6 after hot post-molding is poor. This is because: it uses the polyurethane prepreg of Comparative Example 3, and the polyurethane prepreg does not add a closed polyurethane prepolymer. The fiber-reinforced polyurethane material made of the polyurethane prepreg has poor processability, and it is difficult to obtain a fine structure with good molding effect during hot pressing.

[0114] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A polyurethane prepreg, characterized in that: It includes component K1 and component K2 which exist independently and have a mass ratio of 1:(1.0-1.2); The component K1 comprises the following components in parts by weight: The component K2 comprises the following components in parts by weight: 40-60 parts of polyisocyanate, 38-45 parts of blocked polyurethane prepolymer; The viscosity of the component K1 and the component K2 is independently 100 to 500 mPa.s; The blocked polyurethane prepolymer has reactive NCO after deblocking.

2. The polyurethane prepreg according to claim 1, characterized in that: The blocked polyurethane prepolymer is a cardanol-terminated polyurethane prepolymer.

3. The polyurethane prepreg according to claim 1, characterized in that: The polyisocyanate is at least one of polymeric MDI, liquefied MDI or HDI trimer.

4. The method for preparing the polyurethane prepreg according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: mixing the components of component K1; and mixing the components of component K2 to obtain the polyurethane prepreg.

5. A thermosetting fiber-reinforced polyurethane material, characterized in that: The composition comprises the following components in parts by weight: 40 to 50 parts of the polyurethane prepreg according to any one of claims 1 to 3; 50-60 parts of reinforcing fiber.

6. The fiber-reinforced polyurethane material according to claim 5, characterized in that: The reinforcing fiber is at least one of fiber cloth, short fiber or long fiber.

7. The method for preparing the fiber-reinforced polyurethane material according to any one of claims 5 to 6, characterized in that: The method comprises the following steps: pre-impregnating reinforcing fibers with the polyurethane prepreg to obtain the fiber-reinforced polyurethane material.

8. The preparation method according to claim 7, characterized in that: When the reinforcing fibers include fiber cloth and short fibers, the preparation method of the fiber-reinforced polyurethane material includes the following steps: firstly, pre-impregnating the fiber cloth with the polyurethane prepreg to obtain a pre-impregnated fiber cloth, then spreading short fibers on the pre-impregnated fiber cloth, and then applying the polyurethane prepreg to obtain the fiber-reinforced polyurethane material.

9. A production equipment for implementing the preparation method according to claim 8, characterized in that: The production equipment comprises an unwinding module (1), a first glue mixing module (2), a first spraying module (3), a first traction module (4), a broken glass module (5), a second traction module (6), a second glue mixing module (7), a second spraying module (8), an extrusion module (9) and a winding module (10) which are arranged in sequence.

10. A composite material product, characterized in that: The fiber-reinforced polyurethane material is prepared by hot pressing the fiber-reinforced polyurethane material according to any one of claims 5 to 6.

Images