Glass fiber reinforced polyurethane thermal insulation foam and production method thereof

Abstract

The invention discloses glass fiber reinforced polyurethane thermal insulation foam and a production method thereof, and relates to the technical field of polyurethane foam. The glass fibers are added into the polyurethane heat insulation foam, on one hand, the strength of the polyurethane heat insulation foam is improved, the size stability of a finished product of the polyurethane heat insulation foam is enhanced, on the other hand, the glass fibers can form a framework material during combustion, flame spreading is blocked, foam melting and dripping are reduced, and the flame retardance of the polyurethane heat insulation foam is improved. According to the flame-retardant resin-based polyether polyol, epoxypropane is subjected to a cross-linking reaction with melamine resin and melamino-formaldehyde resin under the catalysis of diethanol amine, so that the flame-retardant resin-based polyether polyol is obtained. And the triethanolamine borate is added, so that the boron element can form a protective layer at high temperature, oxygen and heat are isolated, and the flame retardant property is improved. The silicon dioxide is also added, so that foam holes can be refined, the heat conductivity coefficient is reduced, and the heat insulation performance of the polyurethane foam is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyurethane foam, in particular to a glass fiber reinforced polyurethane foam and a production method thereof. BACKGROUND

[0002] The polyurethane foam is light and elastic, and can be used as sound insulation material, shockproof material, thermal insulation material, decorative material, etc. However, the existing polyurethane foam material still has the following problems, which limit the use of the polyurethane foam: the mechanical strength of the polyurethane foam material is insufficient, and the polyurethane foam material is prone to cracking at low temperature; the flame retardancy is poor; the open porosity is high, and the water vapor permeation aggravates the attenuation of the thermal insulation performance. Although the addition of traditional glass fibers and other fillers can improve the strength, the interface compatibility of the fillers in the polyurethane material is poor, and the thermal insulation effect is reduced instead.

[0003] In order to solve the above problems, the present application provides a glass fiber reinforced polyurethane foam and a production method thereof. SUMMARY

[0004] The present application aims to provide a glass fiber reinforced polyurethane foam and a production method thereof to solve the problems in the prior art.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: A production method of a glass fiber reinforced polyurethane foam, comprising the following steps: Step one: uniformly mix flame-retardant resin-based polyether polyol A, polyether polyol B, hydroxyl-terminated polybutadiene, polysiloxane surfactant, catalyst, dimethyl silicone oil, glass fiber, melamine formaldehyde resin coated nano silicon dioxide, and deionized water to obtain component A; Step two: take polymethylene polyphenyl polyisocyanate as component B; uniformly mix the component B with the component A, and foam to form to obtain the glass fiber reinforced polyurethane foam.

[0006] More preferably, the glass fiber reinforced polyurethane foam comprises the following components, in terms of weight fraction: 20-25 parts of flame-retardant resin-based polyether polyol A, 20-22 parts of polyether polyol B, 10-12 parts of hydroxyl-terminated polybutadiene, 0.5-0.6 parts of polysiloxane surfactant, 1-2 parts of catalyst triethanolamine, 12-17 parts of dimethyl silicone oil, 4-7 parts of glass fiber, 3-5 parts of melamine formaldehyde resin coated nano silicon dioxide, 0.1-0.2 parts of deionized water, and 47-53 parts of polymethylene polyphenyl polyisocyanate.

[0007] More preferably, the polyether polyol B is polyether polyol 220.

[0008] More preferably, the preparation method of the flame-retardant resin-based polyether polyol A is: taking melamine resin, melamine formaldehyde resin, propylene oxide, boric acid triethanolamine ester, diethanolamine, passing nitrogen, increasing the pressure to 1.0 MPa, increasing the temperature to 100 DEG C, then stirring for 6-7 h, stopping stirring, cooling to room temperature, adding ammonium polyphosphate and phosphoric acid, removing small molecules under vacuum, and obtaining the flame-retardant resin-based polyether polyol.

[0009] More preferably, the mass ratio of the melamine resin to the melamine formaldehyde resin is 60: (15-20).

[0010] More preferably, the preparation method of the melamine formaldehyde resin coated nano-silicon dioxide is: taking piperazine pyrophosphate and deionized water, stirring uniformly to obtain a piperazine pyrophosphate aqueous solution, adding pretreated silicon dioxide, stirring for 3-4 h, filtering and drying to obtain silicon dioxide loaded with piperazine pyrophosphate; taking melamine, formaldehyde solution and deionized water, stirring uniformly, increasing the temperature to 85-90 DEG C, reacting for 1-2 h, adding acid and alkali dropwise to keep the pH value of the solution at 8-10, obtaining a melamine formaldehyde solution; adding the silicon dioxide loaded with piperazine pyrophosphate into ethanol, stirring uniformly, adding the melamine formaldehyde solution, then adjusting the pH value to 5-6, increasing the temperature to 80-90 DEG C, reacting for 5-7 h, decreasing to room temperature, filtering, washing and drying to obtain the melamine formaldehyde resin coated silicon dioxide.

[0011] More preferably, the preparation method of the pretreated silicon dioxide is: taking cetyltrimethylammonium bromide, deionized water and triethylamine, increasing the temperature to 80-85 DEG C, stirring uniformly, adding methyl silicate, continuing to stir for 2-3 h, filtering and washing, adding silica sol, stirring at 60-70 DEG C for 1-2 h, adjusting the pH value to 7-8, drying and grinding to obtain the pretreated silicon dioxide.

[0012] More preferably, the solid content of the silica sol is 5.0%-5.5%.

[0013] Compared with the prior art, the application has the beneficial effects that: 1. The application adds glass fibers in the polyurethane heat insulation foam, which improves the strength of the polyurethane heat insulation foam and enhances the dimensional stability of the finished product, and the glass fibers form a skeleton material when burning, block the spread of flames, reduce the melting and dripping of the foam, and improve the flame retardancy of the polyurethane heat insulation foam.

[0014] 2、The application is obtained by cross-linking reaction of epoxy propane, melamine resin and melamine formaldehyde resin under the catalysis of diethanolamine, so as to obtain a flame-retardant resin-based polyether polyol. The addition of boric acid triethanolamine ester can form a protective layer at high temperature to insulate oxygen and heat, thereby improving the flame-retardant property. The application adds melamine resin and melamine formaldehyde resin, and controls the mass ratio to be 60: (15-20). At this time, the melamine resin provides a stable triazine ring skeleton, thereby improving the high-temperature resistance of the carbon layer. The flexible chain segment of the melamine formaldehyde resin can relieve the rigidity of the melamine resin, thereby avoiding excessive brittleness of the product. When the addition amount of the melamine resin is too high, the content of the melamine formaldehyde resin is low, the cross-linking sites are few, the melamine resin is rigid, the polyether chain is flexible, and the compatibility is poor, thereby leading to loose and non-dense carbon layer structure and reduced flame retardancy of the polyurethane thermal insulation foam.

[0015] 3、The application uses cetyltrimethylammonium bromide to prepare silica, thereby improving the dispersibility of the silica. Then, the silica sol is added for further treatment. The hydroxyl groups in the silica sol and the surface hydroxyl groups of the silica undergo condensation reaction, thereby improving the surface hydroxyl group density of the silica, further optimizing the modification effect, improving the loading rate of piperazine pyrophosphate, and enhancing the performance of the polyurethane thermal insulation foam. The addition of the silica can also refine the cells, reduce the thermal conductivity, and improve the thermal insulation performance.

[0016] 4、The silica is coated with melamine formaldehyde, thereby improving the problem of easy agglomeration of the silica in the polyurethane thermal insulation foam matrix, and further improving the performance of the polyurethane thermal insulation foam. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the application will be described below in a clear and complete manner. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0018] The source and model of the substances involved in the application are not specially limited, and exemplarily include: polyether polyol: model 220, which can be purchased from Shanghai Baikuo Chemical; polysiloxane surfactant: model AK8805; hydroxyl-terminated polybutadiene: item number ZS-11116; polymethylene polyphenyl polyisocyanate: which can be purchased from Hubei Shishun Biological Technology Co., Ltd.; melamine resin: CAS number: 3089-11-0, which can be purchased from Nantong Runfeng Petroleum Chemical Co., Ltd.; melamine formaldehyde resin: CAS number: 9003-08-1, which can be purchased from Hubei Hengjingrui Chemical Co., Ltd.; silica sol: model S-830, which can be purchased from Hubei Zhenghe Technology Co., Ltd.; glass fiber: diameter: 9-13 µm, length: 3-10 mm.

[0019] Example 1: A method for producing a glass fiber reinforced polyurethane thermal insulation foam, comprising the following steps: Step one: Preparation of flame-retardant resin-based polyether polyol: Take 60g melamine resin, 17g melamine formaldehyde resin, 120g propylene oxide, 3.5g boric acid triethanolamine ester, 6g diethanolamine, pass nitrogen, pressurize to 1.0MPa, heat to 100℃, then stir for 7h, stop stirring, cool to room temperature, add 6g ammonium polyphosphate, 2g phosphoric acid, then vacuum remove small molecules at 100℃ and -0.10MPa, to obtain flame-retardant resin-based polyether polyol; At this time, the mass ratio of melamine resin to melamine formaldehyde resin is 60:17; Step two: Preparation of melamine formaldehyde resin coated silica: Pretreatment of silica: Add 1g hexadecyl trimethyl ammonium bromide, 200mL deionized water, 0.6mL triethylamine, heat to 82℃, stir uniformly, add 2mL methyl silicate, continue to stir for 2.5h, filter, wash, add 2g silica sol with solid content of 5%, stir at 65℃ for 1.5h, adjust pH to 7, dry, grind through 200 mesh sieve, to obtain pretreated silica; Take 10g piperazine pyrophosphate, 150mL deionized water, stir uniformly, to obtain piperazine pyrophosphate aqueous solution, add pretreated silica, stir for 3.5h, filter, dry, to obtain piperazine pyrophosphate loaded silica; Take 6g melamine, 20g formaldehyde solution with concentration of 37%, 100mL deionized water, stir uniformly, heat to 88℃, react for 1.5h, drop acid and base to keep solution pH value at 9, to obtain melamine formaldehyde solution; Add piperazine pyrophosphate loaded silica to 200mL ethanol, stir uniformly, add melamine formaldehyde solution, then adjust pH value to 5, heat to 85℃ for 6h, cool to room temperature, filter, wash, dry, to obtain melamine formaldehyde resin coated silica; Step three: Mix flame-retardant resin-based polyether polyol A, polyether polyol B, hydroxyl-terminated polybutadiene, polysiloxane surfactant, catalyst triethanolamine, dimethyl silicone oil, glass fiber, melamine formaldehyde resin coated nano silica, deionized water uniformly, to obtain component A; Take poly methylene polyphenyl polyisocyanate to obtain component B; Add component B to component A, mix uniformly, foam and form, to obtain glass fiber reinforced polyurethane thermal insulation foam; The process conditions for foaming and forming are: pressure of 120bar, temperature of 60℃, pressure maintaining time of 110s, heat preservation time of 1h, room temperature standing for 22h; The glass fiber reinforced polyurethane thermal insulation foam comprises the following ingredients, calculated by weight fraction: 20 parts of flame-retardant resin-based polyether polyol A, 20 parts of polyether polyol B, 10 parts of hydroxyl-terminated polybutadiene, 0.5 parts of polysiloxane surfactant, 1.5 parts of catalyst triethanolamine, 15 parts of dimethyl silicone oil, 5 parts of glass fiber, 4 parts of melamine formaldehyde resin-coated nanosilica, 0.15 parts of deionized water, and 50 parts of polymethylene polyphenyl polyisocyanate.

[0020] Example 2: A method for producing a glass fiber reinforced polyurethane thermal insulation foam, comprising the following steps: Step one: Preparation of flame-retardant resin-based polyether polyol: Take 60g melamine resin, 17g melamine formaldehyde resin, 120g propylene oxide, 3.5g boric acid triethanolamine ester, 6g diethanolamine, pass nitrogen, pressurize to 1.0MPa, heat to 100℃, then stir for 6h, stop stirring, cool to room temperature, add 6g ammonium polyphosphate, 2g phosphoric acid, then vacuum remove small molecules at 100℃ and -0.10MPa to obtain flame-retardant resin-based polyether polyol; At this time, the mass ratio of melamine resin to melamine formaldehyde resin is 60:17; Step two: Preparation of melamine formaldehyde resin-coated silica: Pretreatment of silica: Add 1g cetyltrimethylammonium bromide, 200mL deionized water, 0.6mL triethylamine, heat to 80℃, stir uniformly, add 2mL methyl silicate, continue to stir for 2h, filter, wash, add 2g silica sol with a solid content of 5%, stir at 60℃ for 1h, adjust pH to 7, dry, grind through a 200 mesh sieve to obtain pretreated silica; Take 10g piperazine pyrophosphate, 150mL deionized water, stir uniformly to obtain a piperazine pyrophosphate aqueous solution, add the pretreated silica, stir for 3h, filter, dry to obtain piperazine pyrophosphate-loaded silica; take 6g melamine, 20g formaldehyde solution with a concentration of 37%, 100mL deionized water, stir uniformly, heat to 85℃, react for 1h, add acid and base to maintain the solution pH value at 8, to obtain a melamine formaldehyde solution; add the piperazine pyrophosphate-loaded silica to 200mL ethanol, stir uniformly, add the melamine formaldehyde solution, then adjust the pH value to 5, heat to 80℃ and react for 5h, cool to room temperature, filter, wash, dry to obtain melamine formaldehyde resin-coated silica; Step three: Flame-retardant resin-based polyether polyol A, polyether polyol B, hydroxyl-terminated polybutadiene, polysiloxane surfactant, catalyst triethanolamine, dimethyl silicone oil, glass fiber, melamine-formaldehyde resin-coated nano-silica, and deionized water are uniformly mixed to obtain component A. Component B is obtained by taking polymethylene polyphenyl polyisocyanate; Component B is added to component A, mixed evenly, and foamed to obtain glass fiber reinforced polyurethane insulation foam. The foaming molding process conditions are: pressure of 120 bar, temperature of 60℃, pressure holding time of 110s, heat holding time of 1h, and room temperature setting for 22h. The glass fiber reinforced polyurethane insulation foam comprises the following components, calculated by weight fraction: 20 parts flame retardant resin-based polyether polyol A, 20 parts polyether polyol B, 10 parts hydroxyl-terminated polybutadiene, 0.5 parts polysiloxane surfactant, 1 part catalyst triethanolamine, 12 parts dimethyl silicone oil, 4 parts glass fiber, 3 parts melamine-formaldehyde resin-coated nano silica, 0.1 parts deionized water, and 47 parts polymethylene polyphenyl polyisocyanate.

[0021] Example 3: A method for producing glass fiber reinforced polyurethane insulation foam, comprising the following steps: Step 1: Preparation of flame-retardant resin-based polyether polyols: Take 60g of melamine resin, 17g of melamine-formaldehyde resin, 120g of propylene oxide, 3.5g of triethanolamine borate, and 6g of diethanolamine. Purge with nitrogen, pressurize to 1.0MPa, heat to 100℃, stir for 7h, stop stirring, cool to room temperature, add 6g of ammonium polyphosphate and 2g of phosphoric acid, and then remove small molecules under vacuum at 100℃ and -0.10MPa to obtain flame-retardant resin-based polyether polyol. At this point, the mass ratio of melamine resin to melamine-formaldehyde resin is 60:17. Step 2: Preparation of melamine-formaldehyde resin-coated silica: Pretreatment of silica: 1g of hexadecyltrimethylammonium bromide, 200mL of deionized water, and 0.6mL of triethylamine were heated to 85℃ and stirred evenly. 2mL of methyl orthosilicate was added and stirring was continued for 3 hours. The mixture was filtered, washed, and 2g of silica sol with a solid content of 5% was added. The mixture was stirred at 70℃ for 2 hours, the pH was adjusted to 8, dried, and ground through a 200-mesh sieve to obtain pretreated silica. Take 10 g of pyrophosphoric acid piperazine, 150 mL of deionized water, stir evenly to get pyrophosphoric acid piperazine aqueous solution, add pretreated silica, stir for 4 h, filter, dry to get pyrophosphoric acid piperazine loaded silica; Take 6 g of melamine, 20 g of 37% concentration formaldehyde solution, 100 mL of deionized water, stir evenly, heat to 90℃, react for 2 h, add acid and base to keep the solution pH value at 10, get melamine formaldehyde solution; Put the pyrophosphoric acid piperazine loaded silica into 200 mL of ethanol, stir evenly, add melamine formaldehyde solution, then adjust the pH value to 6, heat to 90℃ and react for 7 h, cool to room temperature, filter, wash, dry to get melamine formaldehyde resin coated silica; Step three: Mix flame retardant resin based polyether polyol A, polyether polyol B, hydroxyl terminated polybutadiene, polysiloxane surfactant, catalyst triethanolamine, dimethyl silicone oil, glass fiber, melamine formaldehyde resin coated nano silica, deionized water evenly to get component A; Take poly methylene polyphenyl polyisocyanate to get component B; Add component B to component A, mix evenly, foam molding to get glass fiber reinforced polyurethane thermal insulation foam; The process conditions for foaming molding are: pressure 120 bar, temperature 60℃, pressure maintaining time 110 s, holding time 1 h, room temperature standing 22 h; The glass fiber reinforced polyurethane thermal insulation foam comprises the following components, calculated by weight fraction: 20 parts of flame retardant resin based polyether polyol A, 20 parts of polyether polyol B, 10 parts of hydroxyl terminated polybutadiene, 0.5 parts of polysiloxane surfactant, 2 parts of catalyst triethanolamine, 17 parts of dimethyl silicone oil, 7 parts of glass fiber, 5 parts of melamine formaldehyde resin coated nano silica, 0.2 parts of deionized water, 53 parts of poly methylene polyphenyl polyisocyanate.

[0022] Comparative example 1: no melamine resin is added, the rest is the same as example 1: Step one: preparation of flame retardant resin based polyether polyol: Take 77 g of melamine formaldehyde resin, 120 g of propylene oxide, 3.5 g of boric acid triethanolamine ester, 6 g of diethanolamine, pass nitrogen, increase pressure to 1.0 MPa, heat to 100℃, then stir for 7 h, stop stirring, cool to room temperature, add 6 g of ammonium polyphosphate, 2 g of phosphoric acid, then remove small molecules under the conditions of 100℃ and -0.10 MPa vacuum to get flame retardant resin based polyether polyol.

[0023] Comparative example 2: increase the amount of melamine resin, the rest is the same as example 1: Step one: preparation of flame retardant resin based polyether polyol: Take 65 g melamine resin, 12 g melamine formaldehyde resin, 120 g propylene oxide, 3.5 g boric acid triethanolamine ester, 6 g diethanolamine, nitrogen, pressure to 1.0 MPa, temperature to 100℃, then stirring 7h, stop stirring, cooling to room temperature, add 6 g ammonium polyphosphate, 2 g phosphoric acid, then under the condition of 100℃ and -0.10 MPa vacuum removal of small molecules, get flame retardant resin based polyether polyol; At this time, the mass ratio of melamine resin to melamine formaldehyde resin is 65:12; Comparative Example 3: no silica sol is added, and the rest is the same as Example 1: Step one: preparation of flame retardant resin based polyether polyol: Take 60 g melamine resin, 17 g melamine formaldehyde resin, 120 g propylene oxide, 3.5 g boric acid triethanolamine ester, 6 g diethanolamine, nitrogen, pressure to 1.0 MPa, temperature to 100℃, then stirring 7h, stop stirring, cooling to room temperature, add 6 g ammonium polyphosphate, 2 g phosphoric acid, then under the condition of 100℃ and -0.10 MPa vacuum removal of small molecules, get flame retardant resin based polyether polyol; At this time, the mass ratio of melamine resin to melamine formaldehyde resin is 60:17; Step two: preparation of melamine formaldehyde resin coated silica: Pretreatment of silica: 1 g cetyl trimethyl ammonium bromide, 200 mL deionized water, 0.6 mL triethylamine, temperature to 82℃, stirring uniform, add 2 mL methyl silicate, continue stirring 2.5h, filter, wash, stirring at 65℃ for 1.5h, adjust pH to 7, dry, grinding through 200 mesh screen, get pretreated silica; Take 10 g piperazine pyrophosphate, 150 mL deionized water, stirring uniform, get piperazine pyrophosphate aqueous solution, add pretreated silica, stirring 3.5h, filter, dry, get piperazine pyrophosphate loaded silica; Take 6 g melamine, 20 g concentration 37% formaldehyde solution, 100 mL deionized water, stirring uniform, temperature to 88℃, reaction 1.5h, drop acid and base to keep solution pH value 9, get melamine formaldehyde solution; Add piperazine pyrophosphate loaded silica to 200 mL ethanol, stirring uniform, add melamine formaldehyde solution, then adjust pH value to 5, temperature to 85℃ reaction 6h, drop to room temperature, filter, wash, dry, get melamine formaldehyde resin coated silica; Step three: Mix flame retardant resin based polyether polyol A, polyether polyol B, hydroxyl terminated polybutadiene, polysiloxane surfactant, catalyst triethanolamine, dimethyl silicone oil, glass fiber, melamine formaldehyde resin coated nano silica, deionized water, get component A; Component B is obtained by taking polymethylene polyphenyl polyisocyanate; Component B is added to Component A, uniformly mixed, foamed and molded to obtain the glass fiber reinforced polyurethane thermal insulation foam; The process conditions for foaming and molding are: pressure 120 bar, temperature 60℃, pressure maintaining time 110 s, heat preservation time 1 h, room temperature standing 22 h; The glass fiber reinforced polyurethane thermal insulation foam comprises the following components, calculated by weight fraction: 20 parts of flame-retardant resin-based polyether polyol A, 20 parts of polyether polyol B, 10 parts of hydroxyl-terminated polybutadiene, 0.5 parts of polysiloxane surfactant, 1.5 parts of catalyst triethanolamine, 15 parts of dimethyl silicone oil, 5 parts of glass fiber, 4 parts of melamine formaldehyde resin coated nano silicon dioxide, 0.15 parts of deionized water, 50 parts of polymethylene polyphenyl polyisocyanate.

[0024] Comparative Example 4: Melamine formaldehyde resin is not used to coat the silica, and the rest is the same as Example 1: Step one: preparation of flame-retardant resin-based polyether polyol: Take 60g melamine resin, 17g melamine formaldehyde resin, 120g propylene oxide, 3.5g boric acid triethanolamine ester, 6g diethanolamine, pass nitrogen, increase the pressure to 1.0MPa, increase the temperature to 100℃, then stir for 7h, stop stirring, cool to room temperature, add 6g ammonium polyphosphate, 2g phosphoric acid, then vacuum remove small molecules at 100℃ and-0.10MPa to obtain flame-retardant resin-based polyether polyol; At this time, the mass ratio of melamine resin to melamine formaldehyde resin is 60:17; Step two: preparation of melamine formaldehyde resin coated silica: Pretreatment of silica: Add 1g hexadecyl trimethyl ammonium bromide, 200mL deionized water, 0.6mL triethylamine, increase the temperature to 82℃, stir uniformly, add 2mL methyl silicate, continue to stir for 2.5h, filter, wash, add 2g silica sol with solid content of 5%, stir at 65℃ for 1.5h, adjust pH to 7, dry, grind through 200 mesh sieve to obtain pretreated silica; Take 10g piperazine pyrophosphate, 150mL deionized water, stir uniformly to obtain piperazine pyrophosphate aqueous solution, add pretreated silica, stir for 3.5h, filter, dry to obtain piperazine pyrophosphate loaded silica; Step three: Uniformly mix flame-retardant resin-based polyether polyol A, polyether polyol B, hydroxyl-terminated polybutadiene, polysiloxane surfactant, catalyst triethanolamine, dimethyl silicone oil, glass fiber, piperazine pyrophosphate loaded silica, deionized water to obtain Component A; Component B is obtained from taking polymethylene polyphenyl polyisocyanate; component B is added to component A, uniformly mixed, foamed and molded to obtain the glass fiber reinforced polyurethane thermal insulation foam; The process conditions for foaming and molding are: pressure 120 bar, temperature 60℃, pressure maintaining time 110 s, holding time 1 h, room temperature standing 22 h; The glass fiber reinforced polyurethane thermal insulation foam comprises the following components, calculated by weight fraction: 20 parts of flame-retardant resin-based polyether polyol A, 20 parts of polyether polyol B, 10 parts of hydroxyl-terminated polybutadiene, 0.5 parts of polysiloxane surfactant, 1.5 parts of catalyst triethanolamine, 15 parts of dimethyl silicone oil, 5 parts of glass fiber, 4 parts of silica loaded with piperazine pyrophosphate, 0.15 parts of deionized water, 50 parts of polymethylene polyphenyl polyisocyanate.

[0025] Experiment: The glass fiber reinforced polyurethane thermal insulation foam prepared in Example 1-3, Comparative Example 1-4 is tested for performance, and is prepared into a sample of 100x6.5x3mm 3 ; the LOI value of Example 1-3 and Comparative Example 1-4 is detected using a JF-3 type oxygen index tester, referring to the standard of ASTM D2863; the mechanical properties of the glass fiber reinforced polyurethane thermal insulation foam prepared in Example 1-3 and Comparative Example 1-4 is detected using a mechanical property detector; the obtained data is shown in Table 1 below: the thermal conductivity (mW / m·k) of Example 1 at 20℃ and -163℃ is detected referring to the standard of ASTM C518; the obtained data is shown in Table 2 below: Table 1

[0026] Conclusion: From the data comparison in the table, it can be seen that Comparative Example 1 does not add melamine resin, and the flame retardancy decreases. Comparative Example 2 increases the amount of melamine resin, the content of melamine formaldehyde resin is small, the crosslinking site is less, the rigidity of melamine resin is strong, the flexibility of polyether chain is strong, and the compatibility is poor, which leads to loose and non-dense carbon layer structure, and the flame retardancy of the polyurethane thermal insulation foam decreases. Comparative Example 3 does not add silica sol, the number of hydroxyl groups on the surface of silica decreases, the loading rate of piperazine pyrophosphate decreases, and the performance of the polyurethane thermal insulation foam decreases. Comparative Example 4 does not use melamine formaldehyde resin to coat the silica, and the silica is easy to agglomerate in the polyurethane thermal insulation foam matrix, and the flame retardancy and mechanical properties of the polyurethane thermal insulation foam decrease.

[0027] Table 2

[0028] It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. The embodiments should therefore be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the above description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. A method for producing glass fiber reinforced polyurethane insulation foam, characterized in that: Includes the following steps: Step 1: Mix flame-retardant resin-based polyether polyol A, polyether polyol B, hydroxyl-terminated polybutadiene, polysiloxane surfactant, catalyst, dimethyl silicone oil, glass fiber, melamine-formaldehyde resin-coated nano-silica, and deionized water evenly to obtain component A. Step 2: Take polymethylene polyphenyl polyisocyanate as component B; add component B to component A, mix evenly, and foam to obtain glass fiber reinforced polyurethane insulation foam.

2. The method for producing glass fiber reinforced polyurethane insulation foam according to claim 1, characterized in that: The glass fiber reinforced polyurethane insulation foam comprises the following components, by weight fraction: 20-25 parts flame retardant resin-based polyether polyol A, 20-22 parts polyether polyol B, 10-12 parts hydroxyl-terminated polybutadiene, 0.5-0.6 parts polysiloxane surfactant, 1-2 parts catalyst triethanolamine, 12-17 parts dimethyl silicone oil, 4-7 parts glass fiber, 3-5 parts melamine-formaldehyde resin-coated nano-silica, 0.1-0.2 parts deionized water, and 47-53 parts polymethylene polyphenyl polyisocyanate.

3. The method for producing a glass fiber reinforced polyurethane insulation foam according to claim 1, characterized in that: The polyether polyol B is polyether polyol 220.

4. The method for producing glass fiber reinforced polyurethane insulation foam according to claim 3, characterized in that: The preparation method of the flame-retardant resin-based polyether polyol A is as follows: take melamine resin, melamine-formaldehyde resin, propylene oxide, triethanolamine borate, and diethanolamine, purge with nitrogen, pressurize to 1.0 MPa, heat to 100°C, stir for 6-7 hours, stop stirring, cool to room temperature, add ammonium polyphosphate and phosphoric acid, remove small molecules under vacuum to obtain flame-retardant resin-based polyether polyol.

5. The method for producing glass fiber reinforced polyurethane insulation foam according to claim 4, characterized in that: The mass ratio of melamine resin to melamine-formaldehyde resin is 60:(15-20).

6. The method for producing a glass fiber reinforced polyurethane insulation foam according to claim 1, characterized in that: The preparation method of the melamine-formaldehyde resin-coated nano-silica is as follows: Take piperazine pyrophosphate and deionized water, stir evenly to obtain an aqueous solution of piperazine pyrophosphate, add pretreated silica, stir for 3-4 hours, filter and dry to obtain silica loaded with piperazine pyrophosphate; Take melamine, formaldehyde solution and deionized water, stir evenly, heat to 85-90℃, react for 1-2 hours, add acid and alkali dropwise to maintain the pH of the solution at 8-10 to obtain a melamine-formaldehyde solution; Add the silica loaded with piperazine pyrophosphate to ethanol, stir evenly, add the melamine-formaldehyde solution, then adjust the pH to 5-6, heat to 80-90℃ and react for 5-7 hours, cool to room temperature, filter, wash and dry to obtain silica coated with melamine-formaldehyde resin.

7. The method for producing glass fiber reinforced polyurethane insulation foam according to claim 6, characterized in that: The method for preparing the pretreated silica is as follows: hexadecyltrimethylammonium bromide, deionized water, and triethylamine are heated to 80-85°C, stirred evenly, methyl orthosilicate is added, and stirring is continued for 2-3 hours. After filtration and washing, silica sol is added, and stirring is carried out at 60-70°C for 1-2 hours. The pH is adjusted to 7-8, and the silica is dried and ground to obtain the pretreated silica.

8. The method for producing glass fiber reinforced polyurethane insulation foam according to claim 7, characterized in that: The solid content of the silica sol is 5.0%-5.5%.

9. A glass fiber reinforced polyurethane insulation foam produced by the production method of a glass fiber reinforced polyurethane insulation foam according to any one of claims 1-8.

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