Resin compositions, polyurethane materials and polyurethane composites, and methods for their preparation

Abstract

This invention provides a resin composition comprising an isocyanate component, a reactive component, and a free radical initiator. In the reactive component, the sum of the number of acrylate double bonds and active hydrogen atoms per molecule is not less than 2.1. The acrylate double bonds are double bonds on acrylic acid groups or double bonds on methacrylic acid groups, which helps improve product performance and effectively reduces the water sensitivity of the resin composition, minimizing foaming problems during subsequent composite material production and processing. This invention also provides a polyurethane material prepared from the resin composition, a polyurethane composite material comprising the polyurethane material, and methods for preparing the resin composition, the polyurethane material, and the polyurethane composite material.

Description

Technical Field

[0001] This invention relates to the field of polyurethane materials technology, and more particularly to resin compositions, polyurethane materials and polyurethane composites, and methods for their preparation. Background Technology

[0002] Traditional polyurethane resins undergo cross-linking and curing through addition polymerization of isocyanate groups and hydroxyl groups. However, due to their rapid reactivity, short working times and high water sensitivity, they require very strict humidity control during use, making them unsuitable for various composite material preparation processes. In the preparation of novel polyurethane composites, addition polymerization of isocyanate groups and hydroxyl groups occurs simultaneously with free radical polymerization. The resin composition, in its liquid state, is used to wet the reinforcing material, such as fiberglass cloth. The simultaneous addition polymerization and free radical polymerization gradually generate a solid polyurethane matrix, which integrates with the wetted reinforcing material, thus forming a polyurethane composite material.

[0003] The water sensitivity of the resin composition is crucial to the performance of the resulting polyurethane composite. If the water sensitivity is too high, it is prone to foaming with moisture. During resin curing, these newly generated bubbles remain at the resin-composite interface, resulting in numerous pores in the final composite product, leading to product defects. This significantly reduces the material's mechanical properties, makes effective quality control difficult, increases the risk of product quality incidents, and lowers the yield rate of composite products.

[0004] The viscosity of the resin composition is crucial to the performance of the resulting polyurethane composite material. If the viscosity is too low, it will easily flow, causing the resin composition to be unable to be effectively absorbed by the fiberglass cloth, resulting in resin loss and insufficient adhesive in the fiberglass cloth. This lack of adhesive will leave many pores in the fiberglass cloth, and after curing, the final composite product will contain many holes, resulting in product defects and making it unsuitable for processes such as hand lay-up and winding.

[0005] Therefore, it is necessary to develop novel resin compositions to address the aforementioned problems existing in the prior art. Summary of the Invention

[0006] The purpose of this invention is to provide a resin composition, a polyurethane material prepared from the resin composition, a polyurethane composite material containing the polyurethane material, and a method for preparing the resin composition, the polyurethane material, and the polyurethane composite material, so as to effectively reduce the water sensitivity of the resin composition, further improve product performance, and minimize foaming problems during subsequent composite material production and processing.

[0007] To achieve the above objectives, the resin composition of the present invention comprises an isocyanate component, a reactive component, and a free radical initiator; the isocyanate component comprises at least one organic isocyanate; the reactive component comprises: on average, each molecule contains at least one acrylate double bond to undergo free radical polymerization under the action of the free radical initiator, wherein the acrylate double bond is a double bond on an acrylic group or a double bond on a methacrylic group; on average, each molecule contains at least one active hydrogen to undergo addition polymerization with the at least one organic isocyanate; the sum of the number of acrylate double bonds and active hydrogen contained in each molecule is not less than 2.1.

[0008] The beneficial effects of the resin composition of the present invention are as follows: the average number of acrylate double bonds and active hydrogen per molecule in the reactive component is not less than 2.1, wherein the acrylate double bonds are double bonds on acrylic acid groups or double bonds on methacrylic acid groups, which not only helps to improve product performance, but also effectively reduces the water sensitivity of the resin composition, and avoids foaming problems in the subsequent production, preparation and processing of composite materials to the greatest extent.

[0009] Preferably, each molecule of the reactive component contains an average of 1-4 acrylate groups, and each acrylate group contains an acrylate double bond. The beneficial effect is that, in conjunction with the at least one active hydrogen atom, it helps improve product performance and effectively reduces the water sensitivity of the resin composition.

[0010] Preferably, each molecule of the reactive component contains an average of 1.1-4.9 hydroxyl groups, and each hydroxyl group contains the active hydrogen. Its beneficial effects are that, in conjunction with the at least one acrylate double bond, it helps improve product performance and effectively reduces the water sensitivity of the resin composition.

[0011] Preferably, the reactive component comprises an ester product obtained by esterification of at least one organic polyol with an acrylic substance, wherein each molecule of the at least one organic polyol has an average of at least 2.1 active hydrogen atoms. Its beneficial effects include: improving product performance and effectively reducing the water sensitivity of the resin composition.

[0012] More preferably, the at least one organic polyol comprises at least one polyether polyol, and the polyether polyol contains the active hydrogen.

[0013] More preferably, the at least one polyether polyol has an average functionality of 2.1-6 and a hydroxyl value of 25-1100 mg potassium hydroxide / g.

[0014] Preferably, the content of the free radical initiator is 0.01%-7% by mass percentage of the reactive component. Its beneficial effects include: improving product performance and effectively reducing the water sensitivity of the resin composition.

[0015] Preferably, the composition further includes a catalyst to accelerate the crosslinking reaction of the carbamate groups. The catalyst content is greater than 0 and less than or equal to 5% by mass percentage of the reactive component. The carbamate groups are obtained by the addition polymerization reaction of the active hydrogen with at least one organic isocyanate. Its beneficial effects include: improving product performance and effectively reducing the water sensitivity of the resin composition.

[0016] Preferably, it also contains several additives to facilitate the control of the physicochemical properties of the polyurethane material prepared by the resin composition.

[0017] The polyurethane material of the present invention comprises a polyurethane matrix, which is prepared from the resin composition. Since the average number of acrylate double bonds and active hydrogens per molecule in the reactive component of the resin composition is not less than 2.1, and the acrylate double bonds are double bonds on acrylic groups or double bonds on methacrylic groups, it can help improve product performance and effectively reduce the water sensitivity of the resin composition, thereby minimizing foaming problems in the subsequent production and processing of composite materials.

[0018] The method for preparing the polyurethane material of the present invention includes: providing the resin composition, the resin composition comprising a reactive component, a free radical initiator, and at least one organic isocyanate, wherein each molecule of the reactive component comprises at least one acrylate double bond and at least one active hydrogen; initiating a free radical polymerization reaction of the at least one acrylate double bond by the free radical initiator, wherein the at least one active hydrogen undergoes an addition polymerization reaction with the at least one organic isocyanate.

[0019] The polyurethane material preparation method uses the resin composition as a raw material. Since the reactive components of the resin composition contain an average of not less than 2.1 acrylate double bonds and active hydrogen per molecule, and the acrylate double bonds are double bonds on acrylic acid groups or double bonds on methacrylic acid groups, it can help improve product performance and effectively reduce the water sensitivity of the resin composition, thus minimizing the occurrence of glue shortage problems in the subsequent composite material production and processing, which makes the finished product prone to foaming problems.

[0020] Preferably, the resin composition further includes a catalyst, wherein the catalyst accounts for a mass percentage greater than 0 and less than or equal to 5% of the reactive component, to accelerate the crosslinking reaction of the carbamate groups obtained by the addition polymerization reaction of the active hydrogen with the at least one organic isocyanate. Its beneficial effects include: helping to improve product performance and effectively reducing the water sensitivity of the resin composition.

[0021] Preferably, the resin composition further comprises additives to regulate the physicochemical properties of the polyurethane material.

[0022] Preferably, the average functionality of the at least one organic isocyanate is 2.0-3.6. Its beneficial effects include: it helps improve product performance and effectively reduces the water sensitivity of the resin composition.

[0023] Preferably, the viscosity of the at least one organic isocyanate, as determined according to DIN 53019-1-3 at 25°C, is 4-2500 mPa·s. Its beneficial effects include: it helps improve product performance and effectively reduces the water sensitivity of the resin composition.

[0024] The polyurethane composite material of the present invention comprises a reinforcing material and the polyurethane material. Since the polyurethane material is prepared from the resin composition, the average sum of the number of acrylate double bonds and active hydrogen atoms per molecule in the reactive components of the resin composition is not less than 2.1. The acrylate double bonds are double bonds on acrylic groups or double bonds on methacrylic groups, which helps to improve product performance and effectively reduce the water sensitivity of the resin composition, minimizing foaming problems during subsequent composite material production and processing.

[0025] Preferably, the reinforcing material accounts for 1-91% of the mass percentage of the polyurethane composite material. Its advantage lies in allowing for flexible adjustment of the mechanical strength according to usage requirements.

[0026] The polyurethane composite material preparation method of the present invention uses reinforcing materials and the polyurethane material as raw materials, and is prepared by at least one of vacuum induction process, pultrusion process, filament winding process, resin transfer process, hand lay-up process, compression molding process, and spray molding process. Since the polyurethane composite material preparation method uses the polyurethane material as one of the raw materials, the average sum of the number of acrylate double bonds and active hydrogen atoms per molecule in the reactive components of the resin composition is not less than 2.1. The acrylate double bonds are double bonds on acrylic groups or double bonds on methacrylic groups, which helps to improve product performance and effectively reduce the water sensitivity of the resin composition, minimizing foaming problems during subsequent composite material production and processing. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but does not exclude other elements or objects.

[0028] This invention provides a resin composition comprising an isocyanate component, a reactive component, and a free radical initiator.

[0029] In the embodiments of the present invention, for specific descriptions of organic polyisocyanates, polyether polyols, polyester polyols, other types of polyols and oligomers containing active hydrogen, please refer to Chapters 1, 2, 3 and 4 of the reference “Handbook of Polyurethane Raw Materials and Additives, Second Edition, edited by Liu Yijun, 2013, Chemical Industry Press”. All of the above disclosures are incorporated herein by reference.

[0030] In this embodiment of the invention, the isocyanate component comprises at least one organic isocyanate.

[0031] In some embodiments, the at least one organic isocyanate is at least one of any known chain aliphatic isocyanate, alicyclic isocyanate, and aromatic isocyanate used in the preparation of polyurethanes.

[0032] In some specific embodiments, the at least one organic isocyanate is a mixture of 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, monomeric diphenylmethane diisocyanate, and higher homologues of diphenylmethane diisocyanate (abbreviated as polymeric MDI), isophorone diisocyanate (IPDI) or oligomers thereof, 2,4-toluene diisocyanate or 2,6-toluene diisocyanate (TDI) or mixtures thereof; Methyl diisocyanate or oligomers thereof; pentamethylene diisocyanate or oligomers thereof; hexamethylene diisocyanate (HDI) or oligomers thereof; 4,4'-dicyclohexylmethane diisocyanate (HMDI), methylcyclohexyl diisocyanate (HTDI), 1,5-naphthyl diisocyanate (NDI) or mixtures thereof, terephthalic diisocyanate (PPDI), terephthalic diisocyanate (XDI), tetramethyl diisocyanate (TMXDI) and polymers thereof or combinations thereof.

[0033] In some embodiments, at least one of the at least one organic isocyanate exists in the form of a polyisocyanate prepolymer, which is any one of a dimer, trimer, tetramer, or pentamer of the isocyanate.

[0034] In some specific embodiments, the NCO weight percentage of the polyisocyanate prepolymer is 10-48%. In other specific embodiments, the NCO weight percentage of the polyisocyanate prepolymer is either 16-38% or 19-33%.

[0035] In some specific embodiments, the at least one organic isocyanate is diphenylmethane diisocyanate (MDI), polyphenylmethane polyisocyanate (PMDI), and polymers, prepolymers, or combinations thereof.

[0036] In some embodiments, the average functionality of the at least one organic isocyanate is 2.0-3.6. In other embodiments, the average functionality of the at least one organic isocyanate is 2.1-2.8.

[0037] In some embodiments, the viscosity of the at least one organic isocyanate, as determined according to DIN 53019-1-3, is 4-2500 mPa·s at 25°C.

[0038] In some embodiments, the viscosity of the at least one organic isocyanate, as determined according to DIN 53019-1-3 at 25°C, is either 5-800 mPa·s or 10-300 mPa·s.

[0039] In this embodiment of the invention, each molecule of the reactive component contains at least one acrylate double bond and at least one active hydrogen atom on average, and the sum of the number of acrylate double bonds and active hydrogen atoms contained in each molecule on average is not less than 2.1.

[0040] Specifically, the at least one acrylate double bond undergoes a free radical polymerization reaction under the action of the free radical initiator, and the at least one active hydrogen undergoes an addition polymerization reaction with the at least one organic isocyanate.

[0041] In some embodiments, the acrylate double bond is a double bond on an acrylic group or a double bond on a methacrylic group.

[0042] In some embodiments, each molecule of the reactive component contains an average of 1-4 acrylate groups, each of the acrylate groups containing the acrylate double bond.

[0043] In some embodiments, the average number of acrylate groups per molecule of the reactive component is in the range of 1.05-3, 1.1-2.5, 1.15-2.4, and 1.2-2.3.

[0044] In some embodiments, each molecule of the reactive component contains an average of 1.1-4.9 hydroxyl groups, and each hydroxyl group contains the active hydrogen.

[0045] In some embodiments, the average number of hydroxyl groups per molecule of the reactive component is in the range of 1.2-4, 1.25-3.5, 1.3-3, 1.35-2.6, 1.4-2.5, and 1.5-2.4.

[0046] In some embodiments, the reactive component is an ester product obtained by esterification of at least one organic polyol with an acrylic substance, wherein each molecule of the at least one organic polyol has an average of at least 2.1 active hydrogen atoms.

[0047] In some embodiments, the acrylic substance is at least one of acrylic anhydride, methacrylic anhydride, acryloyl chloride, methacryloyl chloride, acryloyl bromide, methacryloyl bromide, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, butyl acrylate, butyl methacrylate, tert-butyl acrylate, and tert-butyl methacrylate.

[0048] In some embodiments, the at least one organic polyol comprises at least one polyether polyol, wherein the polyether polyol contains the active hydrogen.

[0049] In some embodiments, the at least one organic polyol is at least one of polyether polyol, polyether carbonate polyol, polyester polyol, polycarbonate diol, polymer polyol, and vegetable oil-based polyol.

[0050] In some embodiments, the at least one organic polyol is at least one of polypropylene glycol, polyether triol, polyether tetraol, polyether pentaol, polyurea polyol, polytetrahydrofuran diol, adipic acid polyester diol, aromatic polyester polyol, polycaprolactone polyol, polycarbonate diol, polyacrylate polyol, and polyolefin polyol.

[0051] In some embodiments, the at least one polyether polyol has an average functionality of 2.1-6 and a hydroxyl value of 25-1100 mg potassium hydroxide / g.

[0052] In some embodiments, the at least one polyether polyol has an average functionality of 2.5-5 and a hydroxyl value of 35-800 mg potassium hydroxide / g.

[0053] In some embodiments, the at least one polyether polyol has an average functionality of 2.7-4.6 and a hydroxyl value of 50-660 mg potassium hydroxide / g.

[0054] In some embodiments, the at least one polyether polyol has an average functionality of 2.8-4.4 and a hydroxyl value of 80-630 mg potassium hydroxide / g.

[0055] In some embodiments, the at least one polyether polyol has an average functionality of 3.0-4.3 and a hydroxyl value of 100-600 mg potassium hydroxide / g.

[0056] In some embodiments, the at least one polyether polyol has an average functionality of 3.1-4.2 and a hydroxyl value of 110-570 mg potassium hydroxide / g.

[0057] In some embodiments, the reactive component is obtained by esterification of at least one organic polyol with at least one acrylic acid group or methacrylic acid group.

[0058] In some embodiments, the reactive component is obtained by esterification of at least one organic polyol with at least one acrylic anhydride or methacrylic anhydride.

[0059] In some embodiments, the reactive component is obtained by esterification of at least one organic polyol with at least one acryloyl halide or methacryloyl halide.

[0060] Specifically, acryloyl halide is either acryloyl chloride or acryloyl bromide.

[0061] Specifically, methacryloyl halide is either methacryloyl chloride or methacryloyl bromide.

[0062] In some embodiments, the reactive component is obtained by esterification of at least one organic polyol with at least one acrylic acid or methacrylic acid under catalytic conditions.

[0063] In some embodiments, the reactive component is obtained by transesterification of at least one organic polyol with at least one methacrylate or acrylate under catalytic conditions.

[0064] Specifically, the acrylate is any one of methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, and tert-butyl acrylate.

[0065] Specifically, the methacrylate is any one of methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, and tert-butyl methacrylate.

[0066] The specific operating methods of the esterification reactions of at least one of the above-mentioned organic polyols with acrylic anhydride or methacrylic anhydride, with acryloyl halide or methacryloyl halide, with acrylic acid or methacrylic acid, and with acrylate or methacrylate are well known to those skilled in the art. Some esterification methods can be found in CN101983959B or CN101475502B.

[0067] In some embodiments, the content of the free radical initiator is 0.01%-7% by mass percentage of the reactive component.

[0068] In some embodiments, the free radical initiator is a free radical initiator capable of initiating the curing of compounds containing double bonds.

[0069] In some embodiments, the free radical initiator is added to at least one of the at least one organic isocyanate and at least one of the reactive components.

[0070] In some embodiments, the free radical initiator is any one of peroxide, persulfide, peroxycarbonate, peroxyboric acid, and azo compound.

[0071] In some specific embodiments, the free radical initiator is at least one selected from the following: tert-butyl isopropyl carbonate, tert-butyl peroxide-3,5,5-trimethylhexanoate, methyl ethyl ketone peroxide, cumene hydroperoxide, persulfate, azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, benzoyl peroxide, tert-butyl peroxide, and hydroperoxide.

[0072] In some embodiments, the resin composition further comprises a catalyst to accelerate the crosslinking reaction of the carbamate groups, wherein the catalyst content is greater than 0 and less than or equal to 5% by mass percentage of the reactive component, and the carbamate groups are obtained by the addition polymerization reaction of the active hydrogen with the at least one organic isocyanate.

[0073] In some embodiments, the catalyst accounts for 0.001-2% of the mass percentage of the reactive component.

[0074] In some specific embodiments, the catalyst is any one of 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine, triethylamine, tributylamine, triethylenediamine, dimethylbenzylamine, N-methylmorpholine, N-ethylmorpholine, N-cyclohexylmorpholine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylbutyldiamine, N,N,N',N'-tetramethylhexanediamine, pentamethyldiethylenetriamine, tetramethyldiaminoethyl ether, bis(dimethylaminopropyl)urea, dimethylpiperazine, 1,2-dimethylimidazolium, and 1-azabicyclo(3,3,0)octane.

[0075] In some embodiments, the catalyst is any one of 1,4-diazabicyclo(2,2,2)octane, triethanolamine, triisopropanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, and dimethylethanolamine.

[0076] In some embodiments, the catalyst is an organometallic compound. In other embodiments, the catalyst consists of the organometallic compound and a strong basic amine.

[0077] In some specific embodiments, the organometallic compound is any one of tin(II) acetate, tin(II) octanoate, tin(II) ethylhexanoate, tin(II) laurate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate, and dioctyltin diacetate.

[0078] In some specific embodiments, the organometallic compound is bismuth(III) neodecanoate, bismuth 2-ethylhexanoate, and bismuth octanoate, or a mixture thereof.

[0079] In some embodiments, the resin composition further comprises several additives to facilitate the control of the physicochemical properties of the polyurethane material prepared by the resin composition, the physicochemical properties including at least one of viscosity, degree of crosslinking, water resistance, flame retardancy, smoke resistance, stain resistance, antistatic properties, antioxidant properties, UV stability, leveling properties, and adsorption properties.

[0080] In some specific embodiments, the additives are at least one of fillers, internal release agents, flame retardants, smoke inhibitors, dyes, pigments, antistatic agents, antioxidants, UV stabilizers, diluents, defoamers, coupling agents, surface wetting agents, leveling agents, dehydrating agents, catalysts, molecular sieves, thixotropic agents, plasticizers, and free radical reaction inhibitors.

[0081] In some specific embodiments, the filler is at least one of aluminum hydroxide, bentonite, fly ash, wollastonite, perlite powder, cenospheres, calcium carbonate, talc powder, mica powder, kaolin, fumed silica, expandable microspheres, diatomaceous earth, volcanic ash, barium sulfate, calcium sulfate, solid and / or hollow glass microspheres, stone powder, wood powder, sawdust, bamboo powder, bamboo shavings, rice grains, straw fragments, coffee grounds, sorghum stalk fragments, graphite powder, metal powder, recycled thermosetting composite material powder, plastic particles or powder.

[0082] The specific descriptions of catalysts, flame retardants, release agents, anti-aging additives and stabilizers, coupling agents, fillers and reinforcing materials in the embodiments of this invention can also be found in Chapters 6, 7, 8, 9, 11 and 12 of the reference "Handbook of Polyurethane Raw Materials and Additives, 2nd Edition, edited by Liu Yijun, Chemical Industry Press, 2013". All of the above-disclosed contents are incorporated herein by reference.

[0083] This invention also provides a polyurethane material comprising a polyurethane matrix prepared from the resin composition. Since the reactive components of the resin composition contain an average of at least 2.1 acrylate double bonds and active hydrogen atoms per molecule, and these acrylate double bonds are either double bonds on acrylic acid groups or double bonds on methacrylic acid groups, this helps improve product performance and effectively reduces the water sensitivity of the resin composition, minimizing foaming problems during subsequent composite material production and processing.

[0084] The present invention also provides a method for preparing the polyurethane material, comprising: providing the resin composition, the resin composition comprising a reactive component, a free radical initiator and at least one organic isocyanate, wherein each molecule of the reactive component comprises at least one acrylate double bond and at least one active hydrogen; initiating a free radical polymerization reaction of the at least one acrylate double bond by the free radical initiator, wherein the at least one active hydrogen undergoes an addition polymerization reaction with the at least one organic isocyanate.

[0085] The polyurethane material preparation method uses the resin composition as a raw material. Since the reactive components of the resin composition contain an average of not less than 2.1 acrylate double bonds and active hydrogen per molecule, and the acrylate double bonds are double bonds on acrylic acid groups or double bonds on methacrylic acid groups, it can help improve product performance and effectively reduce the water sensitivity of the resin composition, thus minimizing foaming problems in the subsequent production and processing of composite materials.

[0086] In some embodiments, the mass percentage of the catalyst in the reactive component is controlled to be greater than 0 and less than or equal to 5% to accelerate the crosslinking reaction of the urethane groups obtained by the addition polymerization reaction of the active hydrogen with the at least one organic isocyanate.

[0087] In some embodiments, the additives regulate the physicochemical properties of the polyurethane material, including at least one of viscosity, degree of crosslinking, water resistance, flame retardancy, smoke resistance, stain resistance, antistatic properties, antioxidant properties, UV stability, leveling properties, and adsorption properties.

[0088] This invention also provides polyurethane composite materials and their preparation methods.

[0089] The polyurethane composite material of this invention comprises a reinforcing material and the polyurethane material. Since the polyurethane material is prepared from the resin composition, the average sum of the number of acrylate double bonds and active hydrogen atoms per molecule in the reactive components of the resin composition is not less than 2.1. The acrylate double bonds are double bonds on acrylic acid groups or double bonds on methacrylic acid groups, which helps improve product performance and effectively reduces the water sensitivity of the resin composition, minimizing foaming problems during subsequent composite material production and processing.

[0090] In some embodiments, the reinforcing material constitutes any one of the following percentages by mass in the polyurethane composite material: 1-91%, 15-90%, 35-85%, 45-83%, and 50-81%.

[0091] In some embodiments, the reinforcing material includes at least one of glass fiber, carbon fiber, carbon nanotube, polyester fiber, aromatic polyamide fiber, nylon fiber, natural fiber, basalt fiber, silicon carbide fiber, boron fiber, asbestos fiber, whiskers, hard particles, and metal fiber.

[0092] In some embodiments, the polyurethane addition polymerization reaction, i.e., the addition polymerization reaction of isocyanate groups and hydroxyl groups, and the free radical polymerization reaction occur simultaneously. When the resin composition is in a liquid state, it is used to wet the reinforcing material. The simultaneous addition polymerization and free radical polymerization reactions gradually generate a solid polyurethane matrix, which fuses with the already wetted reinforcing material to form the polyurethane composite material.

[0093] The polyurethane composite material preparation method of this invention uses reinforcing materials and the polyurethane material as raw materials, and is prepared by at least one of vacuum induction process, pultrusion process, filament winding process, resin transfer process, hand lay-up process, compression molding process, and spray molding process. Since the polyurethane composite material preparation method uses the polyurethane material as one of the raw materials, the average sum of the number of acrylate double bonds and active hydrogen atoms per molecule in the reactive components of the resin composition is not less than 2.1. The acrylate double bonds are double bonds on acrylic groups or double bonds on methacrylic groups, which helps to improve product performance and effectively reduce the water sensitivity of the resin composition, minimizing foaming problems during subsequent composite material production and processing.

[0094] The aforementioned vacuum induction process, pultrusion process, filament winding process, resin transfer process, hand lay-up process, compression molding process, and spray molding process are all conventional technical means used by those skilled in the art.

[0095] The technical solutions of the embodiments of the present invention will be described in detail below through specific examples.

[0096] The tensile properties of the resin in the specific embodiments were determined according to ISO 527-2.

[0097] The tensile properties of the polyurethane composite material in the specific embodiment were determined according to ISO 527-5.

[0098] The raw materials used in the specific embodiments are as follows:

[0099] Isocyanate components: Isocyanate PM200 and Isocyanate WANNATE MDI-50;

[0100] The raw materials for preparing the reactive component are polyether polyols P1, P2, P3, and P4. Among them:

[0101] Polyether polyol P1 is a trifunctional polyol obtained by using glycerol as an initiator and propylene oxide as the main polymer in the polymerization reaction, with a hydroxyl value of 235 mg KOH / g.

[0102] Polyether polyol P2 is a trifunctional polyol obtained by using glycerol as an initiator and propylene oxide as the main polymer in the polymerization reaction, with a hydroxyl value of 330 mgKOH / g.

[0103] Polyether polyol P3 is a 4-functional polyol obtained by using pentaerythritol as an initiator and propylene oxide as the main polymer. The hydroxyl value is 450 mg KOH / g.

[0104] Polyether polyol P4 is a hexafunctional polyol obtained by using sorbitol as an initiator and propylene oxide as the main polymer in the polymerization reaction, with a hydroxyl value of 430 mgKOH / g.

[0105] Free radical initiators: benzoyl peroxide (PERKADOX CH-50L) and methyl ethyl ketone peroxide (Butanox M-50), purchased from Norinon.

[0106] The additives are 5A molecular sieve activation powder and defoamer BYKA560. The 5A molecular sieve activation powder was purchased from Xintao Technology, and the defoamer was purchased from BYK Chemical.

[0107] In some embodiments, at least one organic polyol and an acrylic acid are esterified in an organic solvent in the presence of a catalyst until no more water is produced during the esterification reaction. The esterification reaction is carried out at a temperature of 60-140 degrees Celsius.

[0108] Specifically, by mass fractions, the at least one organic polyol is 30-100 parts, the acrylic acid substance is 3-35 parts, the solvent is 3-55 parts, the catalyst is 0.05-1 part, and the polymerization inhibitor is 0.03-0.5 parts.

[0109] In some embodiments, the acrylic substance is mixed with at least one organic polyol, solvent and catalyst under ice bath and stirring conditions, and then subjected to esterification reaction for 3-8 hours under ice bath conditions.

[0110] Specifically, by mass parts, the at least one organic polyol is 60-90 parts, the acrylic substance is 20-60 parts, the solvent is 200-500 parts, the additives are 30-150 parts, and the polymerization inhibitor is 0.03-0.45 parts.

[0111] The specific embodiments provide several reactive components, and the reactive components used in different specific embodiments are composed of at least one of the several reactive components.

[0112] In some specific embodiments, each of the reactive components is abbreviated as B-P1-1, B-P1-2, B-P2-1, B-P2-2, B-P3-1 and B-P4-1, respectively.

[0113] Each molecule of B-P1-1 contains two methacrylate esters and one hydroxyl group. The preparation method is as follows: polyether polyol P1 and hydroquinone, with masses of 71.6 g and 0.1 g respectively, hydroquinone as a polymerization inhibitor; methacrylic acid, an acrylic acid, with a mass of 20.7 g; 30 g of cyclohexane as a solvent; p-toluenesulfonic acid as a catalyst, with a mass of 0.8 g; the above mixture is reacted at 80°C until no more water is produced in the water separator, at which point the reaction ends. The solvent is removed by vacuum spin-drying, and the resulting mixture is purified to obtain the product B-P1-1.

[0114] Each molecule of B-P1-2 contains one methacrylate ester and two hydroxyl groups. The preparation method is as follows: 71.6g of polyether polyol P1, 10.3g of methacrylic acid, 15g of cyclohexane, 0.4g of p-toluenesulfonic acid and 0.08g of hydroquinone are mixed and reacted at 80℃ until no more water is produced in the water separator. The solvent is removed by vacuum spin-drying. The resulting mixture is purified to obtain the product B-P1-2.

[0115] Each molecule of B-P2-1 contains two acrylates and one hydroxyl group. The preparation method is as follows: 51g of polyether polyol P2, 17.3g of acrylic acid, 22g of cyclohexane, 0.8g of p-toluenesulfonic acid, and 0.1g of hydroquinone are reacted at 80℃ until no more water is produced in the water separator, at which point the reaction ends. The solvent is removed by vacuum spin-drying, and the resulting mixture is purified to obtain the product B-P2-1.

[0116] Each molecule of B-P2-2 contains one acrylate and two hydroxyl groups. The preparation method is as follows: 51g of polyether polyol P2, 8.7g of acrylic acid, 11g of cyclohexane, 0.4g of p-toluenesulfonic acid, and 0.08g of hydroquinone are reacted at 80℃ until no more water is produced in the water separator, at which point the reaction ends. The solvent is removed by vacuum spin-drying, and the resulting mixture is purified to obtain the product B-P2-2.

[0117] Each molecule of B-P3-1 contains two acrylates and two hydroxyl groups. The preparation method is as follows: 50g of polyether polyol P3, 17.3g of acrylic acid, 22g of cyclohexane, 0.8g of p-toluenesulfonic acid, and 0.1g of hydroquinone are reacted at 80℃ until no more water is produced in the water separator, at which point the reaction ends. The solvent is removed by vacuum spin-drying, and the resulting mixture is purified to obtain the product B-P3-1.

[0118] Each molecule of B-P4-1 contains 5 acrylate esters and 1 hydroxyl group. The preparation method is as follows: Under ice bath (0-4℃) and stirring conditions, 42.5 ml of acryloyl chloride was slowly added dropwise to 350 ml of dichloromethane solution containing 78.3 g of polyether polyol P4, 0.2 g of hydroquinone, and 100 g of triethylamine. The addition was completed over 60 minutes, with triethylamine acting as an auxiliary agent. The reaction was then continued for another 5 hours under ice bath conditions. Stirring was stopped, and the mixture was allowed to stand overnight. After standing overnight, the reaction was terminated. Unreacted products and other impurities were removed by washing with water, 1M hydrochloric acid, and 1M NaOH solution, respectively. The solvent was removed by vacuum rotation, and the resulting mixture was purified to obtain product B-P4-1.

[0119] Test methods in the following examples, unless otherwise specified, are generally performed under standard conditions or as recommended by the manufacturer. Unless otherwise stated, all percentages and parts are by weight.

[0120] Examples 1-5

[0121] First, the casting mold was placed in an oven at 150°C for constant temperature. Then, the components listed in Table 1 were prepared into a resin mixture liquid according to the proportions. After uniform mixing, this resin liquid was quickly poured into the mold and kept at 150°C for 25 minutes. Then, the oven heating was stopped and the temperature was allowed to drop slowly. After cooling to room temperature, the cured sample could be removed to obtain the thermosetting polyurethane resin matrix of Comparative Examples 1-4 and Examples 1-5. Specific test results are shown in Table 1.

[0122] Table 1

[0123]

[0124]

[0125] Analysis of the data from Comparative Examples 1-4 and 1-5 in Table 1 above shows that introducing a reactive component containing both (meth)acrylate and hydroxyl functional groups not only significantly extends the gel time but also further improves the mechanical properties of the cured resin. A longer gel time is beneficial to the needs of the composite materials industry. For example, in pultrusion processes, if equipment malfunctions and requires shutdown for repair, insufficient gel time can lead to blockage of the injection box and mold by the cured resin, resulting in a mold blockage accident. This necessitates disassembling the injection box and mold for cleaning, wasting time, reducing production efficiency, and generating large amounts of glass fiber and resin waste. Similarly, in vacuum induction processes for manufacturing large products such as blades and yachts, a long resin induction time is required. A gel time of less than 150 minutes is far from sufficient. Therefore, Comparative Examples 1-3 based on the traditional polyurethane system are not suitable for the requirements of many composite material production processes. Comparative Example 4 shows that even with the addition of some reactive component (B), the requirements cannot be met. Examples 1-5 show a significantly extended gel time, all exceeding 200 minutes, far surpassing the 150-minute requirement. This allows for better adaptation to the time requirements of various composite material production processes, and significantly improves mechanical properties. Improved mechanical properties help to further reduce the weight of the thermosetting resin-based composite material while meeting practical application requirements, thus achieving even lighter weight. In Example 5, the excessive shrinkage after resin curing caused the resin board sample to become brittle and crack, resulting in unsatisfactory test samples. This was because the acrylate content was too high, leading to an excessively high density of free radical polymerization crosslinking of the active double bonds, resulting in excessive shrinkage and internal cracking of the cured resin. Therefore, while the use of reactive component (B) brings advantages such as long gel time and excellent mechanical properties, there should be an optimal range for the average number of (meth)acrylate functional groups in its molecular structure. If it is too low, it cannot significantly extend the gel time and improve mechanical properties; if it is too high, it will cause adverse effects such as shrinkage and cracking.

[0126] Example 6

[0127] According to the proportions in Table 2, the polyol, isocyanate component (A), reactive component (B), free radical initiator (C), and other additives were mixed to form a resin mixture liquid, which was then stirred and degassed under vacuum for 5 minutes. This resin mixture liquid was then placed in a casting mold that had been kept at a constant temperature of 35°C in an oven, and the temperature was maintained for another 2 hours. The oven temperature was then increased to 80°C and maintained for 4 hours, after which the heating was turned off. After cooling to room temperature, the cured samples could be removed, yielding the thermosetting polyurethane resin matrix of Comparative Example 5 and Example 6. Specific test results are shown in Table 2.

[0128] Table 2

[0129]

[0130] A comparison of the data from Comparative Examples 5 and 6 listed in Table 2 above demonstrates that the introduction of reactive component (B) can significantly improve the gel time and mechanical properties of the resin. A comparison of Comparative Examples 5 and 6 shows that the thermosetting polyurethane resin matrix incorporating reactive component (B) exhibits superior overall performance compared to ordinary polyurethane resins.

[0131] Example 7

[0132] The polyurethane composite material in this embodiment is prepared by laboratory hand lay-up using the polyurethane compositions of Comparative Examples 6, 7 and 7 in Table 3, to compare its processability in actual operation and to observe its cured effect, including the quality of the composite material.

[0133] The operation was carried out on glass plates: Four layers of uniaxial fiberglass cloth (Hengshi, E61200, UD, ~1200g / m2) were placed on the surfaces of three glass plates sprayed with release agent, and placed in an environment of 25℃ and 50% relative humidity for 24 hours to achieve temperature and humidity equilibration. According to the components and proportions in Table 3, the three types of resin were prepared separately and slowly poured onto the surface of their respective fiberglass cloths, allowing the liquid resin to naturally seep into the fiberglass cloth from top to bottom. After waiting 6 minutes for full impregnation, a transparent plastic film was covered on the surface of the fiberglass cloth, and then a hand lay-up roller was used to squeeze out any air from the impregnated fiberglass cloth. (During actual operation, it was found that the resin viscosity of Comparative Example 7 was too low, making it prone to flow. This resulted in the resin not being effectively absorbed by the fiberglass cloth, causing resin loss and resulting in insufficient adhesive on the fiberglass cloth. This lack of adhesive left many pores in the fiberglass cloth, leading to product defects such as numerous voids in the final composite product after curing. In contrast, the resin viscosity of Comparative Examples 6 and 7 was moderate and could be effectively absorbed by the fiberglass cloth, avoiding the problem of insufficient adhesive. If the resin viscosity is too low, it is not suitable for processes such as hand lay-up and winding, as it can cause problems such as dripping and insufficient adhesive. This is a consensus in the composite industry, and Comparative Example 7 also verified this point.) Then, the entire assembly was placed in an 80°C oven and cured for 3 hours. The oven heating was stopped, and the temperature was allowed to slowly drop to room temperature. Then, the three cured composite sheets were removed separately. Observation revealed that the sheet material of resin-impregnated fiberglass cloth from Comparative Example 6 was substandard due to severe foaming, indicating high water sensitivity. The sheet material of resin-impregnated fiberglass cloth from Comparative Example 7 was also substandard, as while the foaming problem was somewhat reduced, it remained significant, indicating that although the composition was adjusted in Comparative Example 7, water-sensitive foaming could not be completely eliminated. In contrast, the sheet material of resin-impregnated fiberglass cloth from Example 7 was of good quality, uniform, and intact, without foaming issues. The experimental results are listed in Table 3. Tensile modulus and tensile strength, measured at 90°, primarily reflect the resin strength and the bonding strength between the resin and fiber interfaces.

[0134] Table 3

[0135]

[0136] A comparison of the data from Comparative Examples 6, 7, and 7 listed in Table 3 above demonstrates that the introduction of reactive component (B) significantly reduces the water sensitivity of the resin, making it suitable even for hand lay-up processes in the preparation of composite products at 50% humidity. Mechanical property testing of the composites also shows that Comparative Examples 6 and 7 exhibit high water sensitivity, resulting in numerous air bubbles in the sheets and significantly reducing their mechanical properties. A comprehensive comparison of Comparative Examples 6, 7, and 7 indicates that the thermosetting polyurethane resin matrix incorporating reactive component (B) exhibits superior composite process operability compared to ordinary polyurethane resins and other modified polyurethanes, making it suitable for preparing hand lay-up products.

[0137] Example 8

[0138] The polyurethane composite materials of this embodiment were prepared using a vacuum infusion process based on the polyurethane resin compositions of Comparative Examples 5 and 6 in Table 2, and their properties were tested. (The composite material of Comparative Example 8 used the resin of Comparative Example 5; the composite material of Example 8 used the resin of Example 6.)

[0139] The operation is performed on a glass plate: Hengshi uniaxial fiberglass cloth (E61200, UD, ~1200g / m2) is placed on the surface of a glass plate sprayed with release agent, followed by the release cloth, flow guide net, and vacuum bag. The front of this device is connected to a vacuum, and the rear is connected to the liquid resin through a flow guide tube. After all these are set up, the flow guide tube is bent and blocked, and the entire device is placed in an oven heated to 60°C. The tube connected to the vacuum is then connected to a vacuum pump, and the device is heated and dehumidified under vacuum conditions for 2 hours to remove as much moisture as possible from the fiberglass and flow guide net. The oven is then turned off, and the entire device is allowed to cool naturally to room temperature while maintaining a vacuum.

[0140] Then, according to the proportions in Table 2, the isocyanate component (A), reactive component (B), free radical initiator (C), and other additives were mixed. After stirring and degassing under vacuum for 6 minutes, the resin mixture was immediately introduced into the fiberglass cloth of the above-mentioned apparatus under vacuum. After the fiberglass cloth was completely impregnated, the guide tube and the tube connecting to the vacuum were bent and blocked, so that the entire system, which was completely impregnated with liquid resin, continued to be under vacuum. Then, the temperature was gradually increased to 80°C within 1 hour, and then maintained at 80°C for 2 hours to promote resin curing through high-temperature heating. Then, the heating was turned off, and the product was allowed to cool naturally to room temperature. The cured product was then demolded to obtain the fiberglass cloth-reinforced polyurethane composite material. The performance parameters of the obtained polyurethane composite material are shown in Table 4.

[0141] The properties of the polyurethane composite material of the present invention are shown in Table 4. The tensile modulus and tensile strength shown in Table 4 are the modulus and strength measured under tensile conditions in the 0° direction.

[0142] Table 4

[0143]

[0144]

[0145] By comparing the mechanical properties of Comparative Example 8 and Example 8 listed in Table 4, it is demonstrated that the composite material prepared from the thermosetting polyurethane resin matrix with the introduction of reactive component (B) exhibits superior mechanical properties compared to composite materials prepared from existing ordinary polyurethane resins. These results indicate that this thermosetting polyurethane resin matrix containing reactive component (B) is suitable for composite processes and can be used to prepare qualified composite products.

[0146] Examples 9 and 10

[0147] To further verify that the introduction of reactive component (B) significantly reduces the water sensitivity of the thermosetting polyurethane resin composition compared to other types of modified polyurethane resins, we made some adjustments to the vacuum induction process. Compared to Example 8, the vacuum heating dehumidification process was skipped to verify the degree of moisture sensitivity of several resins.

[0148] The operation is performed on a glass plate: Hengshi uniaxial fiberglass cloth (E61200, UD, ~1200g / m2) is placed on the surface of the glass plate after being sprayed with release agent, followed by the release cloth, flow guide net, and vacuum bag. The front of this device is connected to a vacuum, and the rear is connected to the liquid resin through a flow guide tube. After all these are set up, the flow guide tube is bent and blocked, and the tube connected to the vacuum pump is then connected to maintain the entire setup under vacuum.

[0149] Next, according to the proportions in Table 5, the isocyanate component (A), reactive component (B), free radical initiator (C), and other additives were mixed and stirred and degassed under vacuum for 6 minutes. This resin mixture was then introduced into the fiberglass cloth of the aforementioned apparatus under vacuum. After the fiberglass cloth was completely impregnated, the guide tube and the tube connecting to the vacuum were bent and blocked, ensuring the entire system, completely impregnated with liquid resin, remained under vacuum. The temperature was then gradually increased to 80°C over 1 hour and maintained at 80°C for 2 hours to promote resin curing. The heating was then turned off. After naturally cooling to room temperature, the cured product was demolded to obtain a fiberglass-reinforced polyurethane composite material. It can be observed that the composite board of Comparative Example 9 still had a small number of bubbles and white fibers in the fiberglass; this is due to the resin's sensitivity to moisture. Examples 9 and 10 did not exhibit these bubbles and white fibers, indicating that the corresponding resins effectively overcame the water sensitivity problem under these conditions. Specific results and test data are shown in Table 5 below. Tensile modulus and tensile strength are the modulus and strength measured in the 90° direction.

[0150] Table 5

[0151]

[0152] By comprehensively comparing the curing effects and mechanical property data of Comparative Example 9 with Examples 9 and 10 listed in Table 5, it is shown that the thermosetting polyurethane resin with the introduction of reactive component (B) has better water sensitivity than polyurethane resins modified by other methods, and its mechanical properties are also superior to composite materials prepared with polyurethane resins modified by other methods. The above results indicate that this thermosetting polyurethane resin matrix containing reactive component (B) is suitable for composite processes and can be used to prepare qualified composite products.

[0153] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A resin composition, characterized in that, It contains isocyanate components, reactive components containing (meth)acrylate and hydroxyl functional groups, and free radical initiators; The isocyanate component comprises at least one organic isocyanate; In the reactive component: Each molecule contains at least one acrylate double bond on average to undergo free radical polymerization under the action of the free radical initiator, wherein the acrylate double bond is a double bond on an acrylic group or a double bond on a methacrylic group; Each molecule contains, on average, at least one active hydrogen atom to undergo an addition polymerization reaction with the at least one organic isocyanate; The sum of the number of acrylate double bonds and active hydrogen atoms in each molecule is not less than 2.1 on average; Each molecule of the reactive component contains an average of 1-4 acrylate groups, and each acrylate group contains an acrylate double bond; Each molecule of the reactive component contains an average of 1.1-4.9 hydroxyl groups, and each hydroxyl group contains the active hydrogen. The reactive component is an ester product obtained by esterification of at least one organic polyol with an acrylic substance, wherein each molecule of the at least one organic polyol has an average of at least 2.1 active hydrogens, and the at least one organic polyol is a polyether polyol containing the active hydrogens.

2. The resin composition according to claim 1, characterized in that, The polyether polyol has an average functionality of 2.1-6 and a hydroxyl value of 25-1100 mg potassium hydroxide / g.

3. The resin composition according to claim 1, characterized in that, The content of the free radical initiator is 0.01%-7% by mass percentage of the reactive component.

4. The resin composition according to claim 1, characterized in that, It also contains a catalyst to accelerate the crosslinking reaction that generates urethane groups, wherein the catalyst content is greater than 0 and less than or equal to 5% by mass percentage of the reactive component, and the urethane groups are obtained by the addition polymerization reaction of the active hydrogen with the at least one organic isocyanate.

5. The resin composition according to claim 1, characterized in that, It also contains several additives to facilitate the regulation of the physicochemical properties of the polyurethane materials prepared by the resin composition.

6. The resin composition according to claim 1, characterized in that, The average functionality of the at least one organic isocyanate is 2.0-3.

6.

7. The resin composition according to claim 1, characterized in that, The viscosity of the at least one organic isocyanate, as determined according to DIN 53019-1-3 at 25ºC, is 4-2500 mPa·s.

8. A polyurethane material, characterized in that, It comprises a polyurethane matrix, said polyurethane matrix being prepared from the resin composition according to any one of claims 1-7.

9. A method for preparing a polyurethane material, characterized in that, include: A resin composition according to any one of claims 1-7 is provided, the resin composition comprising a reactive component, a free radical initiator, and at least one organic isocyanate, wherein each molecule of the reactive component comprises at least one acrylate double bond and at least one active hydrogen atom on average; The free radical polymerization of the at least one acrylate double bond is initiated by the free radical initiator, and the at least one active hydrogen undergoes an addition polymerization reaction with the at least one organic isocyanate.

10. The method for preparing polyurethane material according to claim 9, characterized in that, The resin composition further includes a catalyst, wherein the mass percentage of the catalyst in the reactive component is greater than 0 and less than or equal to 5%, to accelerate the crosslinking reaction of the carbamate groups obtained by the addition polymerization reaction of the active hydrogen with the at least one organic isocyanate.

11. A polyurethane composite material, characterized in that, It includes reinforcing materials and the polyurethane material as described in claim 8.

12. The polyurethane composite material according to claim 11, characterized in that, The reinforcing material accounts for 1-91% of the mass of the polyurethane composite material.

13. A method for preparing a polyurethane composite material, characterized in that, It is prepared using reinforcing materials and the polyurethane material of claim 8 as raw materials through at least one of vacuum induction process, pultrusion process, filament winding process, resin transfer process, hand lay-up process, compression molding process and spray molding process.

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