Polyurethane foaming material and railway flatcar composite floor comprising same

Abstract

The composition comprises a polyether polyol composition, a composite preservative, a flame-retardant plasticizer, a foaming agent, a catalyst and a foam stabilizer, based on the weight of the composition, the weight percentage of each component is as follows: 60%-90% of the polyether polyol composition, 5%-20% of the composite preservative, 5%-20% of the flame-retardant plasticizer, 0-5% of the foaming agent, 0-2% of the catalyst and 0-1.5% of the foam stabilizer. The invention also provides a polyurethane foaming material containing the composition, a wood particle reinforced polyurethane board and a composite board for a railway flatcar. The invention creatively provides the foaming polyurethane with corrosion resistance, the preparation process of the composite board for the railway flatcar floor in the prior art is simplified, and the manufacturing cost of the composite board is reduced on the premise of ensuring the performance of the composite board.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane and wood anticorrosion, and particularly relates to a polyurethane foam material and a railway flat car composite floor comprising the polyurethane foam material. Background Art

[0002] To address the issues of perishable, flammable, and short lifespan of railway flatcar wood floors, relevant research institutions have developed wood particle-reinforced composite flooring, such as the composite panels for railway flatcars described in Chinese invention patent application CN113910732A (published January 11, 2022). Since May 2022, these composite floorings have been installed on over 70,000 vehicles, achieving excellent results and completely eliminating accidents caused by floor fires, damage, and collapse.

[0003] The main raw materials of the wood particle reinforced composite flooring described in CN113910732A are polyurethane foam materials, antiseptic wood particles, etc. Among them, the antiseptic wood particles are used in the largest amount, accounting for about 70% of the total weight of the composite flooring. In addition, the preparation process of the antiseptic wood particles first requires slicing, crushing, and screening the wood to obtain coarse wood particles; then drying the wood, soaking it in a modifying liquid including an organic environmentally friendly preservative, and drying and curing it for a second time; finally, after a second screening, the antiseptic wood particle fibers are obtained. Each of the above steps cannot be omitted, otherwise the obtained wood particles will not meet the use requirements. Because of the need for secondary drying and multiple screening, not only does the production process of the antiseptic wood particles become complicated, but the output and production efficiency are also low; and the high price of organic environmentally friendly preservatives makes the manufacturing cost high. Summary of the Invention

[0004] To address the aforementioned technical issues, the present invention innovatively proposes a polyurethane foam material with corrosion resistance. Wood particles, without requiring further corrosion treatment, can be directly combined with the polyurethane foam material provided by the present invention to produce a highly corrosion-resistant wood particle reinforced composite floor.

[0005] The first object of the present invention is to provide a composition comprising a polyether polyol composition, a composite preservative, a flame retardant plasticizer, a foaming agent, a catalyst, and a foam stabilizer; based on the weight of the composition, the weight percentages of the components are as follows:

[0006] Polyether polyol composition 60% to 90%,

[0007] Composite preservatives 5% to 20%,

[0008] Flame retardant plasticizer 5% to 20%,

[0009] Foaming agent 0-5%,

[0010] Catalyst 0-2%,

[0011] Foam stabilizer 0~1.5%,

[0012] The polyether polyol composition has an average functionality f of 3 to 4, an average hydroxyl value of 200 to 500 mgKOH / g, and a moisture content of ≤0.1%. The composition comprises at least one low-hydroxyl-value polyether polyol with a hydroxyl value ≤100 mgKOH / g, at least one medium-hydroxyl-value polyether polyol with a hydroxyl value of 100 to 400 mgKOH / g, and at least one high-hydroxyl-value polyether polyol with a hydroxyl value greater than 400 mgKOH / g. Based on the total weight of the polyether polyol composition, the low-hydroxyl-value polyether polyol accounts for 30% to 50%, the medium-hydroxyl-value polyether polyol accounts for 30% to 50%, and the balance is the high-hydroxyl-value polyether polyol.

[0013] Preferably, based on the weight of the composition of the present invention, the weight percentages of the components are as follows:

[0014] Polyether polyol composition 70% to 80%,

[0015] Composite preservatives 10% to 15%,

[0016] Flame retardant plasticizer 10% to 15%,

[0017] Foaming agent 0.5% to 3%,

[0018] Catalyst 0.1% to 0.5%,

[0019] Foam stabilizer 0.2%~1%.

[0020] As a preferred embodiment, in the polyether polyol composition, the weight percentages of the three hydroxyl polyether polyols are: 35% to 45% of the low hydroxyl polyether polyol, 35% to 45% of the medium hydroxyl polyether polyol, and the balance of the high hydroxyl polyether polyol.

[0021] As another preferred embodiment, the polyether polyol composition consists of one low hydroxyl value polyether polyol, one medium hydroxyl value polyether polyol and one high hydroxyl value polyether polyol, and the weight percentages of the low hydroxyl value, medium hydroxyl value and high hydroxyl value polyether polyols are as defined above.

[0022] Preferably, the polyether polyol is selected from polypropylene oxide polyol and / or propylene oxide-ethylene oxide copolymer polyether polyol.

[0023] Preferably, the composite preservative comprises a preservative and at least one selected from an insecticide and a mildewcide, wherein the preservative accounts for at least 60% of the total weight of the composite preservative.

[0024] Preferably, the preservative is selected from at least one of tebuconazole, propiconazole, cyproconazole, thiophanate-methyl, clotrimazole, tetrachloroisophthalonitrile, 8-hydroxyquinolinone, 3-iodo-2-propynyl-butylcarbamate (IPBC) and 4,5-dichloro-2-octylisothiazoline-3-one (DCOI).

[0025] More preferably, the preservative is selected from at least one of tebuconazole, propiconazole, thiophanate-methyl, clotrimazole, 8-hydroxyquinolinone, 3-iodo-2-propynyl-butylcarbamate (IPBC) and 4,5-dichloro-2-octylisothiazoline-3-one (DCOI).

[0026] The preservative of the present invention is an organic preservative, has good compatibility with polyether polyol, and has the advantages of high efficiency, low toxicity, good biodegradability, wide application range, etc.

[0027] Preferably, the insect repellent is selected from at least one of deltamethrin, cypermethrin, permethrin, bifenthrin, cyfluthrin, imidacloprid, fipronil and chlorfenapyr.

[0028] Preferably, the mildew preventer is selected from at least one of chlorothalonil, 8-hydroxyquinolinone, methylene dithiocyanate (MBT), thiophene trichloride (TCMTB), carbendazim, thiabendazim, benomyl, 3-iodo-2-propynyl-butylcarbamate (IPBC), propiconazole and fenpropimorph.

[0029] More preferably, the antifungal agent is at least one selected from thiophanate-methyl, 8-hydroxyquinolinone, 3-iodo-2-propynyl-butylcarbamate (IPBC) and propiconazole.

[0030] From the above definition of preservatives, it can be seen that chlorothalonil, 8-hydroxyquinolinone, 3-iodo-2-propynyl-butylcarbamate (IPBC) and / or propiconazole can be used as both preservatives and mildew inhibitors. Therefore, the above compounds are preferred components of the composite preservative described in the present invention.

[0031] Preferably, the preservative accounts for 100% of the total weight of the composite preservative.

[0032] Preferably, the flame retardant plasticizer is selected from at least one of phosphonate, halogenated phosphate and polyphosphoric acid flame retardant plasticizers.

[0033] The phosphonate flame retardant plasticizer is selected from DMMP, DEEP or TEP.

[0034] The halogenated phosphate flame retardant plasticizer is selected from TCEP, TCPP, TDCP, CR-505, T-101 or V6.

[0035] The polyphosphoric acid flame retardant plasticizer is selected from one or more of ammonium polyphosphate and ammonium polyphosphate coated with aluminum hydroxide, melamine formaldehyde or polysiloxane.

[0036] Preferably, the foaming agent is selected from at least one of water, monofluorodichloroethane, trichlorofluoromethane and cyclopentane or pentane.

[0037] More preferably, the blowing agent is water.

[0038] Preferably, the foam stabilizer is hard foam silicone oil.

[0039] The foam stabilizer can be selected from one or more commercially available hard foam silicone oils, such as hard foam silicone oils CGY-1A, CGYM-1 and / or AK-158.

[0040] Preferably, the catalyst is selected from organoamines or organometallics.

[0041] More preferably, the catalyst is selected from one of triethanolamine (TEA), dimethylethanolamine (DMEA) or dibutyltin laurate (DBTDL).

[0042] The second object of the present invention is to provide a method for preparing the above-mentioned composition, comprising the following steps:

[0043] I. Prepare the components according to the ratio;

[0044] II. Preprocessing

[0045] In separate reaction kettles, polyether polyols with different hydroxyl values ​​are heated to 110° C. to 150° C., vacuum-dehydrated for more than 2 hours or until the moisture content is ≤0.1%, then cooled to ≤50° C., sealed, and set aside; the composite preservative, flame retardant plasticizer, catalyst, and foam stabilizer are dehydrated or removed to control the moisture content to ≤1% and set aside;

[0046] III. In addition to the composite preservative, the pretreated flame retardant plasticizer, catalyst and foam stabilizer are added to the pretreated high hydroxyl value (> 400mgKOH / g) polyether polyol in the reactor, and then the foaming agent is added. Stir for at least 20min in a closed state at a stirring speed of 500 to 2000r / min; then the pretreated other polyether polyols are added to the reactor and stirred at a speed of 500 to 2000r / min for at least 10min; finally, the composite preservative is added and stirred at a speed of 500 to 2000r / min for at least 10min to obtain.

[0047] The third object of the present invention is to provide a polyurethane foam material, which is composed of two components A and B that are stored separately during normal use and mixed when used, wherein the component A is the composition described in the present invention and the component B is polymethylene polyphenyl polyisocyanate; the mass ratio of component A to component B is A:B=1:(0.9-1.5).

[0048] Preferably, the mass ratio of the component A to the component B is A:B=1:(1-1.3).

[0049] In addition, a fourth object of the present invention is to provide a use of the above-mentioned polyurethane foam material in the preparation of wood particle reinforced polyurethane boards.

[0050] The present invention also provides a wood particle reinforced polyurethane board, comprising the polyurethane foam material of the present invention and wood particles; wherein, based on the total weight of the polyurethane board, the weight percentage of the polyurethane foam material is 15% to 65%, and the balance is the wood particles.

[0051] Preferably, based on the total weight of the polyurethane board, the weight percentage of the polyurethane foam material is 20% to 35%, and the remainder is the wood particles.

[0052] Preferably, the wood particles have a length of 5 to 35 mm and a particle size of 2 to 5 mm.

[0053] More preferably, the wood particles have a length of 10 to 30 mm and a particle size of 2 to 3 mm.

[0054] The wood particles are selected from recycled old wood, scraps after wood processing and / or wood particles obtained by crushing log branches.

[0055] The present invention also provides a method for preparing the polyurethane sheet, comprising the following steps:

[0056] Prepare raw materials according to the ratio; dry the wood particles to a moisture content of 3% to 10%, mix the components A and B of the polyurethane foam material according to the ratio, add the measured wood particles, mix thoroughly and evenly, introduce into a mold cavity preheated to 50°C to 60°C, flatten, close the mold, pressurize, compress to a specified thickness, keep warm at 50°C to 80°C for 60 minutes to 120 minutes, demold, and leave at room temperature for at least 72 hours to obtain the product.

[0057] Preferably, in the above preparation method, the wood particles are dried to a moisture content of 5% to 8%.

[0058] Preferably, in the above preparation method, after being compressed to a specified thickness, the temperature is kept at 60° C. to 70° C. for 60 min to 120 min.

[0059] Preferably, the A component and the B component are mixed in a high-pressure foaming machine.

[0060] Preferably, after the mold is preheated, a mold release agent is sprayed on the inner surface of the cavity, and then the uniformly mixed polyurethane composition and wood particles are introduced.

[0061] Therefore, the present invention also provides a polyurethane plate directly prepared by the above method.

[0062] The present invention also provides a composite plate for railway flat cars, comprising the polyurethane plate of the present invention and a reinforcing layer arranged on one side of the polyurethane plate, wherein the polyurethane plate and the reinforcing layer are tightly fitted.

[0063] Preferably, the reinforcement layer is a continuous fiber reinforced PE, PP, PVC, PA, PU, ​​PS, ABS, PC, POM or PBT sheet with a thickness of 0.5 to 10 mm.

[0064] Optionally, the width L2 of the reinforcement layer is ≤ the width L1 of the polyurethane plate.

[0065] Optionally, the reinforcement layer has reinforcement ribs.

[0066] The composite plate for railway flat cars of the present invention can be prepared basically according to the method described in CN113910732A.

[0067] As an exemplary embodiment, the present invention provides a method for preparing the composite plate for railway flat cars, comprising:

[0068] S1. Preparation of foaming mixture

[0069] Mixing the components A and B of the polyurethane composition and the wood particles uniformly according to a weight ratio to obtain a foaming mixture;

[0070] S2. Strengthening layer preparation

[0071] The reinforcement layer material is cut into the required size, and the adhesive is applied to the surface of the reinforcement layer that contacts the polyurethane sheet;

[0072] S3. Forming of composite panels

[0073] First, preheat the mold to 50-60°C; then place the reinforcement layer obtained in step S2 at the bottom of the mold cavity, with the adhesive-coated side facing up; then introduce the foaming mixture obtained in step S1 into the mold cavity, flatten it, close the mold, and pressurize it to compress the foaming mixture to a thickness of 70 mm. Keep the temperature and pressure for 120 minutes, demold it, and place it at room temperature for at least 72 hours.

[0074] Preferably, in step S3, after the mold is preheated and before the reinforcement layer is placed, an appropriate amount of release agent is evenly sprayed in the mold cavity.

[0075] The order of the above steps S1 and S2 can be reversed, that is, the reinforcement layer is prepared first, and then the foaming material is prepared.

[0076] The present invention also provides the use of the composite plate for railway flat cars as a floor in railway flat cars.

[0077] In the specification of the present application, the terms "about" and "around" have the meanings reasonably given to them by ordinary technicians in the field when used in conjunction with a specified value or range, that is, indicating slightly higher or slightly lower than the specified value or range: for example, within the range of ±10% of the specified value, ±9% of the specified value, ±8% of the specified value, ±7% of the specified value, ±6% of the specified value, ±5% of the specified value, ±4% of the specified value, ±3% of the specified value, ±2% of the specified value, or ±1% of the specified value.

[0078] Compared with the prior art, the present invention has the following beneficial effects:

[0079] 1. Due to the use of a specific polyether polyol composition, the polyurethane foam material has excellent performance and extends the service life of the composite board.

[0080] 2. The present invention creatively provides a foamed polyurethane with anti-corrosion properties, simplifies the preparation process of the composite board, and reduces the manufacturing cost of the composite board used for railway flat cars.

[0081] 3. Due to the use of specific flame retardant plasticizers, the polyurethane foam material has excellent flame retardant properties, which improves the safety of the composite floor.

[0082] 4. Due to the use of specific foaming agents and foam stabilizers, the polyurethane foam material has a uniform pore structure and good mechanical strength, which improves the stability and durability of the composite floor. DETAILED DESCRIPTION

[0083] The present invention is described below with reference to specific examples. Those skilled in the art will appreciate that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention in any way.

[0084] The experimental methods in the following examples are conventional methods unless otherwise specified. The raw materials, reagents, etc. used in the following examples are commercially available products unless otherwise specified. The sources of some raw materials are as follows:

[0085] 1) Low hydroxyl value polyether polyol

[0086] YD-3050: hydroxyl value 56±2mgKOH / g, Hebei Yadong Chemical Group Co., Ltd.

[0087] MN-3050D: hydroxyl value 56±2mgKOH / g, Shandong Bluestar Dongda Chemical Co., Ltd.

[0088] GMN-3050: hydroxyl value 54.5-57.5 mgKOH / g, Sinopec Shanghai Gaoqiao Petrochemical Co., Ltd.

[0089] 2) Medium hydroxyl value polyether polyol

[0090] TMN-350: hydroxyl value 340-360 mgKOH / g, Sinopec Tianjin Company;

[0091] MN-500: hydroxyl value 330-350 mgKOH / g, Shandong Bluestar Dongda Chemical Co., Ltd.

[0092] R2305: hydroxyl value 335±10mgKOH / g, Wanhua Chemical Group Co., Ltd.

[0093] 3) High hydroxyl value polyether polyol

[0094] TMN-400: hydroxyl value 405-425 mgKOH / g, Sinopec Tianjin Company;

[0095] R2304: hydroxyl value 415±10mgKOH / g, Wanhua Chemical Group Co., Ltd.

[0096] R2303: hydroxyl value 560±15mgKOH / g, Wanhua Chemical Group Co., Ltd.

[0097] 4) Flame retardant plasticizer

[0098] TEP: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0099] DMMP: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0100] TCPP: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0101] 5) Catalyst

[0102] DMEA: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0103] TEA: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0104] 6) Foam stabilizer

[0105] CGYM-1: Yangzhou Chenhua New Materials Co., Ltd.

[0106] AK-158: Shandong Qilu Chemical Technology Co., Ltd.

[0107] 7) Foaming agent

[0108] Dichloromonofluoroethane: Shandong Lubang Chemical Co., Ltd.

[0109] 8) Preservatives

[0110] IPBC: Hefei Bomei Biotechnology Co., Ltd.;

[0111] DCOI: Hefei Bomei Biotechnology Co., Ltd.;

[0112] Tebuconazole: Hefei Bomei Biotechnology Co., Ltd.;

[0113] Propiconazole: Hefei Bomei Biotechnology Co., Ltd.;

[0114] Clotrimazole: Hefei Bomei Biotechnology Co., Ltd.;

[0115] 8-Hydroxyquinolinone: Hefei Bomei Biotechnology Co., Ltd.;

[0116] 9) Polymethylene polyphenyl polyisocyanate

[0117] 44V20L: Covestro Polymers China Co., Ltd.;

[0118] M20S: BASF SE;

[0119] MR200: Japan Tosoh Corporation;

[0120] PM200: Wanhua Chemical Group Co., Ltd.

[0121] Example 1: Composition A-1

[0122] The raw material composition of composition A-1 of this example is shown in Table 1.

[0123] Table 1 Raw material formula of composition A-1

[0124]

[0125] The composition A-1 was prepared by the following method:

[0126] 1. Prepare the raw materials according to the ratio shown in Table 1;

[0127] II. Raw material pretreatment

[0128] YD-3050, TMN-350 and TMN-400 were heated to 110°C in three independent reaction kettles, vacuum-dried for about 2.5h, then cooled to 50°C, ready for use; in addition, the preservatives (IPBC and DCOI, IPBC and DCOI can be treated separately, or mixed together), flame-retardant plasticizer TEP, catalyst TEA and foam stabilizer CGYM-1 were dehydrated or water-removed to make the water content ≤1%, ready for use;

[0129] III. TEP, TEA, CGYM-1 and deionized water were added to the dehydrated TMN-400 polyether polyol in the reaction kettle in turn, and stirred at 1000r / min for about 60min under airtight condition; after fully mixing, the dehydrated YD-3050 and TMN-350 were added to the reaction kettle, and stirred at 1500r / min for 15min; finally, IPBC and DCOI were added, and stirred at 1000r / min for 20min, to obtain the composition.

[0130] Example 2: Composition A-2

[0131] The raw material composition of the composition A-2 of this example is shown in Table 2.

[0132] Table 2 Raw material formula table of composition A-2

[0133]

[0134] The composition A-2 was prepared by the following method:

[0135] I. Prepare each raw material according to the ratio shown in Table 2;

[0136] II. Raw material pretreatment

[0137] MN-3050D, MN-500 and R2304 were heated to about 120°C in three independent reaction kettles, vacuum-dried for about 2h, then cooled to 50°C, ready for use; in addition, the preservatives (tebuconazole and propiconazole; the two preservatives can be treated separately, or mixed together), flame-retardant plasticizer (TEP and DMMP; the two flame-retardant agents can be treated separately, or mixed together), catalyst TEA and foam stabilizer CGYM-1 were dehydrated or water-removed to make the water content ≤1%, ready for use;

[0138] III. TEP, DMMP, TEA, CGY-1A and deionized water were sequentially added to the dehydrated pretreated R2304 polyether polyol in the reactor and stirred in a closed state for about 45 minutes at a stirring speed of 1200 r / min; after thorough mixing, the dehydrated pretreated MN-500 and MN-3050D were added to the reactor and stirred at a speed of 1500 r / min for 15 minutes; finally, tebuconazole and propiconazole were added and stirred at a speed of 1000 r / min for 20 minutes to obtain.

[0139] Example 3: Composition A-3

[0140] The raw material composition of composition A-3 of this example is shown in Table 3, and the composition A-3 was prepared by the following method:

[0141] 1. Prepare the raw materials according to the ratio shown in Table 3;

[0142] II. Raw material pretreatment

[0143] In three separate reaction kettles, GMN-3050, R2305, and R2303 were heated to 110° C. to 115° C., vacuum-dehydrated for approximately 2.5 hours, and then cooled to 50° C. for later use. Furthermore, the preservatives (propiconazole, clotrimazole, and 8-hydroxyquinolinone; the three preservatives can be treated separately or mixed together), the flame retardant plasticizer (TEP and DMMP; the two flame retardants can be treated separately or mixed together), the catalyst DMEA, and the foam stabilizer AK-158 were dehydrated or dewatered to a water content of ≤1% for later use.

[0144] III. TEP, DMMP, DMEA, AK-158 and monofluorodichloroethane were sequentially added to the dehydrated pretreated GMN-3050 polyether polyol in the reactor and stirred in a closed state for about 45 min at a stirring speed of 1500 r / min; after thorough mixing, the dehydrated pretreated R2305 and R2303 were added to the reactor and stirred at a speed of 1200 r / min for 15 min; finally, clotrimazole, 8-hydroxyquinolinone and propiconazole were added and stirred at a speed of 1000 r / min for 20 min to obtain.

[0145] Table 3 Raw material formula of composition A-3

[0146]

[0147] Example 4: Preparation of composite board

[0148] Eucalyptus logs or board scraps are peeled and crushed, dried (temperature ≤ 90°C) to a moisture content of 5% ± 2%, and sieved to obtain wood particles with a length of 12 mm to 30 mm and a particle size of 2 mm to 3 mm.

[0149] The glass fiber reinforced polyurethane fiberglass with reinforcing ribs is cut into a width of 50 mm and a length of 2990 mm to 2998 mm, and polyurethane adhesive is sprayed on the side with the reinforcing ribs.

[0150] Preheat the upper and lower platens and the mold to 50-60°C. Spray an appropriate amount of mold release agent on the inner surface of the mold cavity. Then, place the two cut fiberglass sheets evenly on both sides of the center line of the bottom of the mold cavity, with the side sprayed with polyurethane adhesive facing up.

[0151] Using a polyurethane foaming machine, the composition A-1 (component A) of Example 1 and 44V20L (component B) were uniformly mixed in a ratio of 1:1.2 to obtain a polyurethane composition. The mixture was then uniformly mixed with wood particles in a ratio of 1:3 (polyurethane composition:wood particles = 1:3) to obtain a foamed material. The foamed material was quickly poured into a mold, evenly flattened, and then closed. Finally, the mixture was compressed within the mold to a thickness of 70 mm (at a pressure of approximately 300 tons). The pressure and temperature (50°C to 60°C) were maintained for 60 to 90 minutes, and the mold was demolded, removed, and allowed to stand at room temperature for 72 to 96 hours.

[0152] To prepare a 3000mm x 300mm x 70mm composite board, 4.25kg of composition A-1, 5.1kg of 44V20L, and 28kg of wood particles are required.

[0153] Example 5: Preparation of composite flooring (using component A of 1, different components B)

[0154] Eucalyptus logs or board scraps are peeled and crushed, dried (temperature ≤ 90°C) to a moisture content of 5% ± 2%, and sieved to obtain wood particles with a length of 12 mm to 30 mm and a particle size of 2 mm to 3 mm.

[0155] The glass fiber reinforced polyurethane fiberglass with reinforcing ribs is cut into a width of 50 mm and a length of 2990 mm to 2998 mm, and polyurethane adhesive is sprayed on the side with the reinforcing ribs.

[0156] Preheat the upper and lower platens and the mold to 50-60°C. Spray an appropriate amount of mold release agent on the inner surface of the mold cavity. Then, place the two cut fiberglass sheets evenly on both sides of the center line of the bottom of the mold cavity, with the side sprayed with polyurethane adhesive facing up.

[0157] A polyurethane foaming machine was used to uniformly mix the composition A-2 of Example 2 with PM200 (component B) in a ratio of 1:1.3 to obtain a polyurethane composition. The polyurethane composition was then uniformly mixed with wood particles in a ratio of 1:3 (polyurethane composition:wood particles=1:3) to obtain a foamed material. The foamed material was quickly poured into a mold, evenly flattened, and then molded. Finally, the mixture was compressed in the mold to a thickness of 70 mm (at a pressure of approximately 300 tons), maintained at 60°C to 70°C for 60 to 90 minutes, demolded, removed, and allowed to stand at room temperature for 72 to 96 hours to obtain the product.

[0158] The following materials are required to prepare a 3000 mm × 300 mm × 70 mm composite board: 4.06 kg of composition A-2, 5.28 kg of PM200 and 28 kg of wood particles.

[0159] Example 6: Preparation of composite board

[0160] Eucalyptus logs or board scraps are peeled and crushed, dried (temperature ≤ 90°C) to a moisture content of 5% ± 2%, and sieved to obtain wood particles with a length of 12 mm to 30 mm and a particle size of 2 mm to 3 mm.

[0161] The glass fiber reinforced polyurethane fiberglass with reinforcing ribs is cut into a width of 50 mm and a length of 2990 mm to 2998 mm, and polyurethane adhesive is sprayed on the side with the reinforcing ribs.

[0162] Preheat the upper and lower platens and the mold to 50-60°C. Spray an appropriate amount of mold release agent on the inner surface of the mold cavity. Then, place the two cut fiberglass sheets evenly on both sides of the center line of the bottom of the mold cavity, with the side sprayed with polyurethane adhesive facing up.

[0163] Using a polyurethane foaming machine, the composition A-3 of Example 3 and MR200 (component B) were uniformly mixed in a ratio of 1:1 to obtain a polyurethane composition. The composition was then uniformly mixed with wood particles in a ratio of 1:3 (polyurethane composition:wood particles = 1:3) to obtain a foamed material. The foam was quickly poured into a mold, evenly flattened, and the mold was closed. Finally, the mixture was compressed in the mold to a thickness of 70 mm (approximately 300 tons of pressure), maintained at 70°C to 80°C for 60 to 75 minutes, demolded, removed, and allowed to stand at room temperature for 72 to 96 hours to obtain the product.

[0164] The following materials are required to prepare a 3000 mm x 300 mm x 70 mm composite board: 4.7 kg of composition A-2, 4.7 kg of MR200 and 28 kg of wood particles.

[0165] Test Case

[0166] (1) Properties of polyurethane compositions (foaming of component A and PIPA crude MDI material and its foam properties)

[0167] The compositions A prepared in Examples 1-3 were mixed with the poly-methylene poly-phenyl poly-isocyanate (B component) in a 1:1.1 ratio to obtain polyurethane compositions, and the foaming and the properties of the polyurethane compositions were determined, and the results are shown in Table 4.

[0168] Table 4: Results of the determination of the properties of the polyurethane compositions

[0169]

[0170] (2) Properties of the composite boards of Examples 4-6

[0171] The properties of the composite boards prepared in Examples 4-6 were determined, and the results are shown in Table 5.

[0172] Table 5: Results of the determination of the properties of the composite boards

[0173]

[0174]

[0175] In Table 5, the test items of Nos. 1-13 were determined according to the “Temporary Technical Conditions for Composite Floor of Railway Flat Cars” (TJ / CL577-2022), the item of No. 14 was an internal control test item, and the item of No. 15 was determined according to the provisions of the “Durability of Wood. Part 1: Natural Durability Laboratory Test Methods” (GB / T 13942.1-2009).

[0176] Example 7: Composition A-4

[0177] The raw material composition of the composition A-4 of this example is shown in Table 6, and the composition A-4 was prepared according to the same method and steps as in Example 1.

[0178] Table 6: Raw material formulation table of the composition A-4

[0179]

[0180] Example 8: Composition A-5

[0181] The raw material composition of the composition A-5 of this example is shown in Table 7, and the composition A-5 was prepared according to the same method and steps as in Example 1.

[0182] Table 7: Raw material formulation table of the composition A-5

[0183]

[0184]

[0185] Example 9: Composition A-6

[0186] The raw material composition of composition A-6 of this example is shown in Table 8. Composition A-6 was prepared according to the same method and steps as in Example 1.

[0187] Table 8 Raw material formula of composition A-6

[0188]

[0189] Example 10: Composition A-7

[0190] The raw material composition of composition A-7 of this example is shown in Table 9.

[0191] Table 9 Raw material formula of composition A-7

[0192]

[0193] Composition A-7 was prepared using methods and steps substantially identical to those of Example 1, except that: 1) in step II, only the low-hydroxyl polyether polyol YD-3050 and the medium-hydroxyl polyether polyol TMN-350 were pretreated; and 2) in step III, TEP, TEA, CGYM-1, and deionized water were sequentially added to the dehydrated pretreated TMN-350 polyether polyol in a reactor, and after thorough mixing, the dehydrated pretreated YD-3050 was added, and finally, the dehydrated preservative was added.

[0194] Example 11: Composition A-8

[0195] The raw material composition of composition A-8 of this example is shown in Table 10. Composition A-7 was prepared according to substantially the same method and steps as in Example 1, except that: 1) in step II, only the low-hydroxyl value polyether polyol YD-3050 and the high-hydroxyl value polyether polyol TMN-400 were pretreated; 2) in step III, TEP, TEA, CGYM-1, and deionized water were sequentially added to the dehydrated pretreated TMN-400 polyether polyol in a reactor, and after thorough mixing, the dehydrated pretreated YD-3050 was added, and finally the dehydrated preservative was added.

[0196] Table 10 Raw material formula of composition A-8

[0197]

[0198] Example 12: Composition A-9

[0199] The raw material composition of composition A-9 of this example is shown in Table 11. Composition A-9 was prepared according to the same method and steps as in Example 1.

[0200] Table 11 Raw material formula of composition A-9

[0201]

[0202]

[0203] Example 13: Preparation and performance measurement of composite board

[0204] Composite boards were prepared using the same method and process as in Example 4, with compositions A-4 to A-9 as component A and 44V20L as component B.

[0205] The performance of the composite panels prepared in Example 13 was tested, and the results are shown in Table 12.

[0206] Table 12 Composite plate performance test results

[0207]

[0208] a : This item was not measured.

[0209] In Table 12, the test items No. 1 to 13 are carried out in accordance with the "Interim Technical Conditions for Composite Material Floors of Railway Flat Cars" (TJ / CL577-2022), the item No. 14 is an internal control test item, and the item No. 15 is measured in accordance with the provisions of "Durability of Wood. Part 1: Laboratory Test Method for Natural Corrosion Resistance" (GB / T13942.1-2009).

[0210] The results in Table 12 show that:

[0211] 1) When using compositions A-4, A-6, and A-9 as component A, the resulting composite panels failed the 5 million cycles fatigue test, exhibited a compressive strength less than 5.0 MPa, and exhibited low overall bending load. These three composite panels failed to meet operational requirements and exhibited low reliability.

[0212] 2) The composite panels obtained with compositions A-5 and A-8 as component A had compressive strengths of 5.5 MPa and 5.6 MPa, respectively. Although these met the ≥5 MPa requirement, their performance margin was insufficient, indicating that their strength was low and that long-term use would affect cargo loading.

[0213] In addition, the composite board obtained by using composition A-8 as component A was found to have poor deflection, that is, it was relatively brittle, indicating poor reliability.

[0214] 3) The composite board obtained by using composition A-4, A-6 or A-7 as component A has an oxygen index lower than 26 and its flame retardant performance is unqualified.

Claims

1. A composition comprising a polyether polyol composition, a composite preservative, a flame retardant plasticizer, a foaming agent, a catalyst, and a foam stabilizer; based on the weight of the composition, the weight percentages of the components are: Polyether polyol composition 60% to 90%, preferably 70% to 80%, Composite preservative 5% to 20%, preferably 10% to 15%, Flame retardant plasticizer 5% to 20%, preferably 10% to 15%, Foaming agent 0-5%, preferably 0.5%-3%, Catalyst 0-2%, preferably 0.1%-0.5%, Foam stabilizer 0-1.5%, preferably 0.2%-1%; in, The polyether polyol composition has an average functionality f of 3 to 4, an average hydroxyl value of 200 to 500 mgKOH / g, and a moisture content of ≤0.1%. The composition comprises at least one low-hydroxyl-value polyether polyol with a hydroxyl value of ≤100 mgKOH / g, at least one medium-hydroxyl-value polyether polyol with a hydroxyl value of 100 to 400 mgKOH / g, and at least one high-hydroxyl-value polyether polyol with a hydroxyl value greater than 400 mgKOH / g. Based on the total weight of the polyether polyol composition, the low-hydroxyl-value polyether polyol accounts for 30% to 50%, the medium-hydroxyl-value polyether polyol accounts for 30% to 50%, and the balance is the high-hydroxyl-value polyether polyol.

2. The composition according to claim 1, characterized in that In the polyether polyol composition, the weight percentages of the three hydroxyl polyether polyols are: 35% to 45% of the low hydroxyl polyether polyol, 35% to 45% of the medium hydroxyl polyether polyol, and the balance of the high hydroxyl polyether polyol.

3. The composition according to claim 1 or 2, characterized in that The polyether polyol composition is composed of one low hydroxyl value polyether polyol, one medium hydroxyl value polyether polyol and one high hydroxyl value polyether polyol, and the weight percentages of the low hydroxyl value, medium hydroxyl value and high hydroxyl value polyether polyols are as defined in claim 1 or 2; Preferably, the polyether polyol is selected from polypropylene oxide polyol and / or propylene oxide-ethylene oxide copolymer polyether polyol.

4. The composition according to claim 1, characterized in that The composite preservative comprises a preservative and at least one selected from an insecticide and a mildewcide, wherein the preservative accounts for at least 60% of the total weight of the composite preservative; Preferably, the preservative is selected from at least one of tebuconazole, propiconazole, cyproconazole, thiophanate-methyl, clotrimazole, tetrachloroisophthalonitrile, 8-hydroxyquinolinone, 3-iodo-2-propynyl-butylcarbamate (IPBC) and 4,5-dichloro-2-octylisothiazolin-3-one (DCOI); More preferably, the preservative is selected from at least one of tebuconazole, propiconazole, thiophanate-methyl, clotrimazole, 8-hydroxyquinolinone, 3-iodo-2-propynyl-butylcarbamate (IPBC) and 4,5-dichloro-2-octylisothiazolin-3-one (DCOI); Preferably, the insect repellent is selected from at least one of deltamethrin, cypermethrin, permethrin, bifenthrin, cyfluthrin, imidacloprid, fipronil and chlorfenapyr; Preferably, the mildewcide is selected from at least one of chlorothalonil, 8-hydroxyquinolinone, methylene dithiocyanate (MBT), thiophene thiocarb (TCMTB), carbendazim, thiabendazole, benomyl, 3-iodo-2-propynyl-butylcarbamate (IPBC), propiconazole and fenpropimorph; More preferably, the antifungal agent is at least one selected from chlorothalonil, 8-hydroxyquinolinone, 3-iodo-2-propynyl-butylcarbamate (IPBC) and propiconazole; Also preferably, the preservative accounts for 100% of the total weight of the composite preservative.

5. The composition according to claim 1, characterized in that The flame retardant plasticizer is selected from at least one of phosphonate, halogenated phosphate and polyphosphoric acid flame retardant plasticizers; Preferably, the phosphonate flame retardant plasticizer is selected from DMMP, DEEP or TEP; Preferably, the halogenated phosphate flame retardant plasticizer is selected from TCEP, TCPP, TDCP, CR-505, T-101 or V6; Preferably, the polyphosphoric acid flame retardant plasticizer is selected from one or more of ammonium polyphosphate and ammonium polyphosphate coated with aluminum hydroxide, melamine formaldehyde or polysiloxane.

6. The composition according to claim 1, characterized in that The foaming agent is selected from at least one of water, monofluorodichloroethane, trichlorofluoromethane and cyclopentane or pentane; Preferably, the foaming agent is water; Preferably, the foam stabilizer is hard foam silicone oil; Preferably, the catalyst is selected from organic amines or organic metals; More preferably, the catalyst is selected from one of triethanolamine (TEA), dimethylethanolamine (DMEA) or dibutyltin laurate (DBTDL).

7. A method for preparing the composition according to any one of claims 1 to 6, comprising the steps of: I. Prepare the components according to the ratio; II. Preprocessing In separate reaction kettles, polyether polyols with different hydroxyl values ​​are heated to 110° C. to 150° C., vacuum-dehydrated for more than 2 hours or until the moisture content is ≤0.1%, then cooled to ≤50° C., sealed, and set aside; the composite preservative, flame retardant plasticizer, catalyst, and foam stabilizer are dehydrated or removed to control the moisture content to ≤1% and set aside; III. In addition to the composite preservative, the pretreated flame retardant plasticizer, catalyst and foam stabilizer are added to the pretreated high hydroxyl value (> 400mgKOH / g) polyether polyol in the reactor, and then the foaming agent is added. Stir for at least 20min in a closed state at a stirring speed of 500 to 2000r / min; then the pretreated other polyether polyols are added to the reactor and stirred at a speed of 500 to 2000r / min for at least 10min; finally, the composite preservative is added and stirred at a speed of 500 to 2000r / min for at least 10min to obtain.

8. A polyurethane foam material, comprising two components, A and B, which are stored separately during normal use and mixed upon use, wherein the component A is the composition according to any one of claims 1 to 6 or the composition directly obtained by the preparation method according to claim 7, and the component B is polymethylene polyphenyl polyisocyanate; the mass ratio of component A to component B is A:B = 1:(0.9-1.5); Preferably, the mass ratio of the component A to the component B is A:B=1:(1-1.3).

9. Use of the polyurethane foam material according to claim 8 in the preparation of wood particle reinforced polyurethane boards.

10. A wood particle reinforced polyurethane board comprising the polyurethane foam material according to claim 8 and wood particles; wherein: Based on the total weight of the polyurethane board, the weight percentage of the polyurethane foam material is 15% to 65%, and the balance is the wood particles; Preferably, based on the total weight of the polyurethane board, the weight percentage of the polyurethane foam material is 20% to 35%, and the balance is the wood particles; Preferably, the length of the wood particles is 5 to 35 mm and the particle size is 2 to 5 mm; More preferably, the wood particles have a length of 10 to 30 mm and a particle size of 2 to 3 mm.

11. The method for preparing the polyurethane sheet according to claim 10, comprising the following steps: Prepare raw materials according to the ratio; dry the wood particles to a moisture content of 3% to 10%, mix the components A and B of the polyurethane foam material according to claim 8 according to the ratio, add the measured wood particles, mix thoroughly, introduce into the mold cavity preheated to 50°C to 60°C, flatten, close the mold, pressurize, compress to the specified thickness, keep at 50°C to 80°C for 60 minutes to 120 minutes, demold, and leave at room temperature for at least 72 hours to obtain; Preferably, in the above preparation method, the wood particles are dried to a moisture content of 5% to 8%; Preferably, in the above preparation method, after being compressed to a specified thickness, the material is kept at 60°C to 70°C for 60 minutes to 120 minutes; Preferably, the A component and the B component are mixed in a high-pressure foaming machine; Preferably, after the mold is preheated, a mold release agent is sprayed on the inner surface of the cavity, and then the uniformly mixed polyurethane composition and wood particles are introduced.

12. A polyurethane plate directly prepared by the preparation method according to claim 11.

13. A composite plate for railway flat cars, comprising the polyurethane plate according to claim 12 and a reinforcement layer provided on one side of the polyurethane plate, wherein the polyurethane plate and the reinforcement layer are in close contact with each other.

14. The composite plate for railway flat cars according to claim 13, characterized in that: The reinforcement layer is a continuous fiber reinforced PE, PP, PVC, PA, PU, ​​PS, ABS, PC, POM or PBT sheet with a thickness of 0.5 to 10 mm; Optionally, the width L2 of the reinforcement layer is less than or equal to the width L1 of the polyurethane plate; Optionally, the reinforcement layer has reinforcement ribs.

15. The method for preparing the composite plate for railway flat cars according to claim 13 or 14, comprising: S1. Preparation of foaming mixture Mixing the components A and B of the polyurethane foam material and the wood particles uniformly according to a weight ratio to obtain a foaming mixture; S2. Strengthening layer preparation The reinforcement layer material is cut into the required size, and the adhesive is applied to the surface of the reinforcement layer that contacts the polyurethane sheet; S3. Forming of composite panels First, preheat the mold to 50-60°C; then place the reinforcement layer obtained in step S2 at the bottom of the mold cavity, with the adhesive-coated side facing up; then introduce the foaming mixture obtained in step S1 into the mold cavity, flatten it, close the mold, and pressurize it to compress the foaming mixture to a thickness of 70 mm. Keep the temperature and pressure for 120 minutes, demold it, and place it at room temperature for at least 72 hours.

16. The preparation method according to claim 15, characterized in that In step S3, after the mold is preheated and before the reinforcement layer is placed, an appropriate amount of release agent is evenly sprayed in the mold cavity; Optionally, the order of steps S1 and S2 can be reversed.

17. Use of the composite plate material for railway flat cars according to claim 13 or 14, or the composite plate material for railway flat cars directly obtained by the preparation method according to claim 15 or 16, as flooring in railway flat cars.

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