Phenolic aldehyde vacuum insulation panel core material and preparation method thereof

Abstract

The invention relates to the technical field of vacuum insulation panels, in particular to a phenolic aldehyde vacuum insulation panel core material and a preparation method thereof. The phenolic aldehyde vacuum insulation panel core material provided by the invention is prepared from the following raw material components in parts by mass: 100 parts of phenolic resin, 2-5 parts of an emulsifier, 1-3 parts of a surfactant, 1-3 parts of a defoaming agent, 5-10 parts of a foaming agent, 15-20 parts of a curing agent and 5-7 parts of filler, wherein the filler comprises wollastonite powder and glass fibers; the mass ratio of the wollastonite powder to the glass fiber is 1: 4; the phenolic resin is thermosetting resin, and the viscosity of the phenolic resin is 10000 to 16000 mPa. S. The phenolic aldehyde vacuum insulation panel core material is light in weight, low in heat conductivity coefficient and high in compression strength, has the performance of low density, good compression strength and the like, meanwhile has good heat insulation performance, can effectively prevent fibers from damaging an inner film of a barrier bag in the using process, and is good in heat insulation performance. Therefore, the quality of a vacuum insulated panel prepared from the phenolic aldehyde vacuum insulated panel core material can be obviously improved.

Description

Technical Field

[0001] The present application relates to the technical field of vacuum insulation panels, and in particular to a phenolic vacuum insulation panel core material. Background Art

[0002] Vacuum insulation panel (VIP) is a new type of super-insulating material, which is composed of VIP core material, adsorbent and packaging bag. It adopts the principle of vacuum insulation, puts the core material with good thermal insulation performance into the air barrier structure (barrier bag), evacuates the air and then seals it to form a board.

[0003] The core material is the main material of heat insulation. It can be said that the core material of VIP determines the quality and price of VIP. At present, the core material of VIP is mainly glass fiber wool and other materials, with a density of 300kg / m 3 , mainly used in refrigerators, cold chain systems, etc., and its thermal conductivity can reach 0.003~0.005w / mk.

[0004] Almost all existing glass fiber wool core materials produced domestically are wet core materials, which have a high density, resulting in heavy product quality, thus seriously affecting energy consumption such as transportation.

[0005] Moreover, the above-mentioned wet glass fiber wool core material is prone to problems: the fiber arrangement in the core material is disordered and the thermal conductivity is high. When in use, the vertically arranged glass fibers inside the VIP core material will penetrate and pierce the inner film of the barrier bag, which can easily cause perforation of the barrier bag, resulting in product expansion and bulging, affecting the quality of the vacuum insulation board of this type of core material.

[0006] Therefore, it is imperative to improve the material of VIP core material and provide a VIP core material that is lightweight, has low thermal conductivity and does not damage the inner film of the barrier bag during use to overcome the above-mentioned defects, which has great development prospects in the market. Summary of the invention

[0007] In order to solve the problems of the prior art mentioned in the above technical background, the present application provides a phenolic vacuum insulation board core material, and its technical solution is as follows: The phenolic vacuum insulation board core material provided by the present application: its raw material components include 100 parts of phenolic resin, 2-5 parts of emulsifier, 1-3 parts of surfactant, 1-3 parts of defoamer, 5-10 parts of foaming agent, 15-20 parts of curing agent, and 5-7 parts of filler, by mass; wherein the filler includes wollastonite powder and glass fiber; the mass ratio of the wollastonite powder to the glass fiber is 1:4; the surfactant includes sodium dodecyl sulfate and fatty acid glyceride; the mass ratio of the sodium dodecyl sulfate to the fatty acid glyceride is 12:1.6; the defoamer includes polydimethylsiloxane and polyether defoamer; the mass ratio of the polydimethylsiloxane to the polyether defoamer is 10:1; the phenolic resin is a thermosetting resin, and its viscosity is 10000-16000mPa.s; The preparation process of phenolic vacuum insulation board core material is as follows: According to the formula, the phenolic resin, emulsifier, surfactant, defoamer, foaming agent and filler are uniformly mixed to obtain liquid A; Weigh the curing agent according to the formula to obtain liquid B; The material liquid A and the material liquid B are mixed and poured into a bubble box, the mixed material liquid is solidified and formed in the bubble box, and the plate is cut to obtain a plate; The board is subjected to microwave drying treatment in a vacuum environment to obtain a phenolic vacuum insulation board core material.

[0008] In some embodiments, the microwave drying process under a vacuum environment is as follows: placing a microwave generator under a vacuum environment; placing the plate in the chamber of the microwave generator, and arranging temperature sensing components and weight sensing components to sense the temperature and mass change values ​​of the plate in real time; then starting the microwave generator for microwave drying, and stopping drying after the drying end point; wherein the entire microwave drying process is carried out under a vacuum environment, and the microwave power is 4.5 to 7.8 kw.

[0009] In some embodiments, during the microwave drying process under the vacuum environment, the weight sensing component measures and records the mass value of the plate every 1 second; the drying endpoint is determined as follows: when the weight loss of the plate at an interval of 1 second within a time period of 30 to 120 seconds is less than or equal to 10 mg, it is determined that the drying endpoint has been reached.

[0010] In some embodiments, the length of the glass fiber is 1 to 3 cm.

[0011] In some embodiments, the mesh size of the wollastonite powder is between 800 and 1000 meshes.

[0012] In some embodiments, the filler is composed of wollastonite powder and glass fiber in a mass ratio of 1:4; the surfactant is composed of sodium dodecyl sulfate and fatty acid glyceride in a mass ratio of 12:1.6; the defoamer is composed of polydimethylsiloxane and polyether defoamer in a mass ratio of 10:1.

[0013] In some embodiments, the emulsifier is one or more combinations of EL30, silicone oil, EL80, and Tween 60; the foaming agent is one or more combinations of n-pentane, cyclopentane, and isopentane; the curing agent is one or more combinations of p-toluenesulfonic acid, methanesulfonic acid, phenolsulfonic acid, and phosphoric acid.

[0014] The present application also provides a method for preparing the phenolic vacuum insulation panel core material as described above, which comprises the following steps: According to the formula, the phenolic resin, emulsifier, surfactant, defoamer, foaming agent and filler are uniformly mixed to obtain liquid A; Weigh the curing agent according to the formula to obtain liquid B; After mixing liquid A and liquid B in the pouring head, pour them into the bubble box through the pouring hole; The bubble box is sealed and placed at room temperature to allow the mixed liquid in the bubble box to ferment and solidify; then, after being cooled at room temperature for 1 to 2 days, the liquid in the bubble box is fully reacted and solidified to obtain a foam body; The foam body is cut into boards of required specifications, and the boards are subjected to microwave drying treatment in a vacuum environment to obtain the core material of the phenolic vacuum insulation board.

[0015] In some embodiments, the microwave drying process under a vacuum environment is as follows: placing a microwave generator under a vacuum environment; placing the plate in the chamber of the microwave generator, and arranging temperature sensing components and weight sensing components to sense the temperature and mass change values ​​of the plate in real time; then starting the microwave generator for microwave drying, and stopping the drying after the drying end point; wherein the microwave drying process is carried out entirely under a vacuum environment, and the microwave power is 4.5 to 7.8 kw.

[0016] Based on the above, compared with the prior art, this application has the following beneficial effects: The present application provides a lightweight, low thermal conductivity, high compressive strength phenolic vacuum insulation board core material, which has properties such as low density and good compressive strength, and at the same time has good thermal insulation performance. When used, it can effectively avoid fiber damage to the internal film of the barrier bag, thereby significantly improving the quality of the vacuum insulation board made of the phenolic vacuum insulation board core material.

[0017] Other features and beneficial effects of the present application will be described in the subsequent description, and partly become apparent from the description, or understood by practicing the present application. The purpose and other beneficial effects of the present application can be achieved and obtained by the structures and / or components indicated in the description and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0019] Figure 1 This is an electron microscope image of the core material sample prepared in Example 1; Figure 2 This is an electron microscope image of the core material sample prepared in Comparative Example 1. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments; the technical features designed in different implementation modes of the present application described below can be combined with each other as long as they do not conflict with each other; based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0021] In the description of this application, it should be noted that all terms (including technical terms and scientific terms) used in this application have the same meanings as those generally understood by ordinary technicians in the field to which this application belongs, and cannot be understood as limitations on this application; it should be further understood that the terms used in this application should be understood to have meanings consistent with the meanings of these terms in the context of this specification and in the relevant fields, and should not be understood in an idealized or overly formal sense, unless explicitly defined in this application.

[0022] The present application provides a phenolic vacuum insulation board core material, the formula and preparation method of which are as follows: The core material formula of phenolic vacuum insulation board is: Calculated by weight, the raw material components include 100 parts of phenolic resin, 2-5 parts of emulsifier, 1-3 parts of surfactant, 1-3 parts of defoamer, 5-10 parts of foaming agent, 15-20 parts of curing agent and 5-7 parts of filler.

[0023] The filler is composed of wollastonite powder and glass fiber in a mass ratio of 1:4; the length of the glass fiber is 1 to 3 cm; the mesh number of the wollastonite powder is 800 to 1000 meshes. The surfactant is composed of sodium dodecyl sulfate and fatty acid glyceride in a mass ratio of 12:1.6. The defoamer is composed of polydimethylsiloxane and polyether defoamer in a mass ratio of 10:1. The phenolic resin is a thermosetting resin with a viscosity of 10000 to 16000 mPa.s; the emulsifier is one or more combinations of EL30, silicone oil, EL80, and Tween 60; the foaming agent is one or more combinations of n-pentane, cyclopentane, and isopentane; the curing agent is one or more combinations of p-toluenesulfonic acid, methanesulfonic acid, phenolsulfonic acid, and phosphoric acid.

[0024] The method for preparing the phenolic vacuum insulation board core material comprises the following steps: (1) Place the foam box in a drying room and heat it to 60-75°C for 1-2 hours. The foam box specifications are 2030×1050×85mm or 1050×1050×85mm.

[0025] The specifications of the bubble box can be made according to production requirements, and the four sides and the upper cover of the bubble box are all movably fixed.

[0026] (2) Add phenolic resin, emulsifier, surfactant, defoamer, foaming agent and filler into material tank A and stir evenly to obtain material A; (3) Pour the curing agent into the material tank B; (4) The liquid A and liquid B in the A and B material tanks are pumped to the pouring head for rapid mixing, and then poured into the bubble box through the pouring hole on the top of the bubble box; (5) Cover the casting hole with a lid and place it at room temperature until the mixed liquid in the foam box starts to ferment, so that the mixed liquid begins to solidify and take shape; (6) After cooling at room temperature for 1 to 2 days, the liquid in the bubble box is fully reacted and solidified, and then the bubble box is opened to obtain a complete bubble body.

[0027] (7) Cut the foam into sheets of required specifications.

[0028] (8) Microwave drying treatment: placing the microwave generator in a vacuum environment; Placing the plate in the chamber of a microwave generator, and arranging a temperature sensing component and a weight sensing component to sense the temperature and mass change value of the plate in real time; Then, the microwave generator is started to carry out microwave drying, and the drying is stopped after the drying end point; The microwave drying process is carried out in a vacuum environment, and the microwave power is 4.5-7.8kw. During the microwave drying process in the vacuum environment, the weight sensing component measures and records the mass value of the plate every 1s; the drying endpoint is determined as follows: when the weight loss of the plate at every second interval is less than or equal to 10mg within a time period of 30-120s, the drying endpoint is determined to be reached.

[0029] It should be noted that: according to the need for water removal, those skilled in the art can adaptively adjust the method for determining the endpoint of microwave drying.

[0030] The effects achieved by the phenolic vacuum insulation board core material provided in this application are: (1) The opening rate reaches more than 96%, or even 98-99%; (2) The thermal conductivity is reduced to 0.003w / m·k, and can even be reduced to 0.002w / mk; Note: The thermal conductivity of most wet-process glass fiber VIP core boards on the market is between 0.003 and 0.005 w / mk, and only a few can reach 0.002 w / mk.

[0031] (3) The compressive strength is increased to 0.2 MPa.

[0032] (4) During use, the barrier bag will not be damaged and the VIP product will not expand or bulge.

[0033] The design concept and innovation of the phenolic vacuum insulation board core material provided in this application to achieve the desired effect are: (1) The filler in the traditional VIP core material is glass fiber for strengthening and toughening, and the resin is a resin with a viscosity of about 2000mPa.s. However, the present application adopts a filler system in which wollastonite powder and glass fiber are compounded in a certain proportion, and is used in combination with a phenolic resin with a viscosity of 10000-16000mPa.s. Among them, wollastonite powder and glass fiber have the effect of toughening and strengthening, and the filler can be dispersed in the phenolic resin system during the pouring process, and there will be no problem of agglomeration and clogging the pouring head (the existing technology uses corn protein fiber to replace glass fiber to reduce the risk of glass fiber puncture, but there is a problem of agglomeration and clogging the pouring head during pouring); in addition, wollastonite powder is used to replace part of the glass fiber, and a specific high-viscosity phenolic resin is used. Wollastonite powder and glass fiber (especially glass fiber) can be fully dispersed in the resin, while ensuring the mechanical properties of the VIP core board, it can reduce the risk of puncturing the internal membrane of the barrier bag, thereby improving the quality and safety of the product.

[0034] Among them, the phenolic resin of this application adopts a specific high viscosity range design, changing the foaming process of the original 2000mPa.s viscosity resin, which can effectively improve the compression strength of the core board. By adding fillers such as glass fiber to improve toughness and strength, the glass fiber will not penetrate and damage the barrier bag; if the viscosity of the phenolic resin is less than the specified range, the strength of the VIP core material is insufficient, and it is difficult to significantly reduce the risk of glass fiber puncture. If the viscosity is greater than the specified range, the fluidity of the slurry is poor, which is not convenient for pouring operations and affects product quality.

[0035] (2) In the phenolic formula system of the present application, a surfactant composed of specific raw materials (composed of sodium dodecyl sulfate and fatty acid glyceride in a mass ratio of 12:1.6) is used. Compared with a single type of surfactant or other combinations, this combination has the best effect on improving the open porosity in the formula system of the present application.

[0036] (3) In the phenolic formula system of the present application, a defoamer composed of specific raw materials (composed of polydimethylsiloxane and polyether defoamer in a mass ratio of 10:1) is used. Compared with a single type of defoamer or other combinations, this combination has the best effect on improving the open porosity in the formula system of the present application.

[0037] (4) The open porosity of existing phenolic vacuum insulation panels is low, and the tiny micropores on the foam skeleton are numerous and basically not connected. Therefore, when the foam is heated, small molecules such as water are adsorbed and are not easy to dissipate, thereby affecting the thermal conductivity (increasing the thermal conductivity coefficient) and also reducing the strength. This application sets a certain proportion of foaming agent, surfactant and defoaming agent to be added to make the VIP core material have a high open porosity and suitable density. Since the foam is composed of a skeleton, pores and foam membrane, the reason for the high open porosity of this application is that the original pores in the foam are basically closed, and then due to the effect of the surfactant and other additives added in this application, the membrane of the pores is broken so that the pores are connected to each other. The skeleton of the foam is dense and smooth without micropores. The structural design of the foam with interconnected pores, no micropores and high open porosity is conducive to subsequent vacuuming and vacuum heat radiation, thereby significantly improving the strength of the VIP core material and reducing the VIP thermal conductivity.

[0038] The foaming agent is designed with a specific dosage range in the system. If the dosage is less than the specified range, the gas cannot be expanded, affecting the open porosity, the density of the VIP core material is too high, and the pores are not well connected, resulting in an increase in thermal conductivity. If the amount of the foaming agent is greater than the specified range, the following defects will occur: Waste of foaming agent, because the foaming agent will eventually volatilize, and the excess amount added increases the cost of raw materials. Excluding overflow, if the amount of foaming agent is too large, the density of the entire foam may be uneven, for example, the density of the upper and lower parts of the foam will be very different, affecting the quality of the VIP core material. If the amount of foaming agent is too large, it may also cause defects such as uneven size of the internal pore structure, affecting the quality of the VIP core material.

[0039] (5) This application uses a specific microwave drying process under a vacuum environment to dry the VIP core material: Those skilled in the art know that if the moisture in the VIP core material cannot be removed, the vacuum degree of the VIP will increase after a period of use, and the thermal insulation performance will deteriorate. Therefore, it is very important to dry the VIP core material before sealing.

[0040] However, the inventors of this application have discovered that if conventional drying methods are used to remove moisture from the core material, the heat is transferred very slowly in the filler (glass fiber, etc.) due to the low thermal conductivity of the core material, and the long drying cycle leads to low efficiency. If the drying temperature is increased in order to reduce the drying cycle, excessively high drying temperatures may increase the risk of glass fiber solidification, and simply increasing the drying temperature to improve drying efficiency is not feasible. During the preparation process, long drying cycles lead to too long a production cycle, and in order to reduce production time, the VIP core material is not dried sufficiently, which affects product quality.

[0041] This application uses a specific microwave drying process under a vacuum environment, which can fully dry in a relatively short time to improve the long-term thermal insulation performance of the product: The lower the saturation temperature of the water or wet medium contained in the wet material, that is, the lower the boiling point, the easier it is to vaporize and escape to dry the material. The vacuum environment drying adopted in this application utilizes this thermophysical property. The VIP core material is placed in a closed drying chamber. The drying chamber is evacuated by a vacuum pump while the dried material is continuously heated, so that the moisture inside the material diffuses to the surface of the VIP core material through pressure difference or concentration difference. The water molecules obtain enough kinetic energy on the surface of the VIP core material to overcome the mutual attraction between molecules and escape to the low-pressure space of the vacuum chamber to form non-condensable gas. The non-condensable gas is removed by suction of the vacuum pump, thereby achieving the purpose of sufficient drying.

[0042] As for the heating method under vacuum environment, this application chooses to use microwaves for heating. Microwaves are penetrating as electromagnetic radiation waves. Microwaves are radiated onto the VIP core material through a microwave generator. When microwaves are injected into the interior, polar molecules such as water rotate synchronously at high speed with the frequency of the microwaves, causing the material to instantly generate friction heat. The surface and interior of the VIP core material heat up at the same time. Under the action of the microwaves, water molecules are more likely to escape from the VIP core material, thereby quickly drying the VIP core material, so that the VIP core material can be fully dried in a shorter drying time.

[0043] In order to verify the effect of this application, the following examples and comparative examples are proposed: The embodiment provides a phenolic vacuum insulation board core material formula, see Table 1: Table 1 Example formula (unit, weight parts) raw material Example 1 Example 2 Phenolic resin 100 100 Emulsifier 2.3 4.6 Surfactants 2.5 1.2 Defoaming agent 1.5 1.5 Foaming agent 5.8 8.5 Curing agent 16 16 filler 5 7 In Table 1, the phenolic resin used is a thermosetting resin with a viscosity of 10000-16000 mPa.s; the emulsifier used is EL30; the foaming agent used is cyclopentane; the surfactant used is composed of sodium dodecyl sulfate and fatty acid glyceride in a mass ratio of 12:1.6. The defoamer used is composed of polydimethylsiloxane and polyether defoamer in a mass ratio of 10:1. The curing agent used is p-toluenesulfonic acid. The filler used is composed of wollastonite powder and glass fiber in a mass ratio of 1:4; the length of the glass fiber is 1-3 cm; the mesh number of wollastonite powder is 800-1000 mesh.

[0044] It should be noted that the high-viscosity phenolic resin is obtained by dehydrating the phenolic resin during the heating preparation process in a reactor. The specific dehydration process is an existing process means and will not be described again here.

[0045] The preparation process of Example 1-2 is specifically as follows: Step (1) Place the bubble box in a drying room and heat it to 70°C for 1.5 hours. The bubble box has a size of 1050×1050×85mm. The four sides and the top cover of the bubble box are all movable and fixed.

[0046] Step (2) Add phenolic resin, emulsifier, surfactant, defoamer, foaming agent and filler into material tank A and stir evenly to obtain material A; Step (3) Pour the curing agent into the B material tank; Step (4) The liquid A and liquid B in the A material tank and the B material tank are pumped to the pouring head for rapid mixing, and then poured into the bubble box through the pouring hole on the top of the bubble box; Step (5) Cover the pouring hole with a lid and place it at room temperature until the mixed liquid in the foam box starts to ferment, so that the mixed liquid begins to solidify and take shape; Step (6) After standing and cooling at room temperature for 1.5 days, the liquid in the bubble box is fully reacted and solidified, and then the bubble box is opened to obtain a complete bubble body.

[0047] Step (7) Cut the foam into sheets of required specifications Step (8) vacuum microwave drying: Prepare a box and place a vacuum device (vacuum pump, air inlet valve and pressure regulating components, etc.) on the box so that the inside of the box can maintain a vacuum environment during the entire drying process.

[0048] The plate is placed in the cavity of a microwave generator, and the microwave generator (microwave oven body) is placed inside a box, wherein a temperature sensing component and a weight sensing component are arranged in the cavity of the microwave generator to sense the temperature and mass change value of the plate in real time.

[0049] The vacuum device is used to form a vacuum state in the box body and the cavity of the microwave generator. When a certain vacuum value is reached, the microwave generator is turned on for microwave heating, wherein the microwave power is 6kw.

[0050] During the drying process, the weight sensor component measures and records the mass value of the board every 1 second; when the weight loss of the board every second within the 100-second period is less than or equal to 10 mg, it is determined that the drying end point has been reached, and the microwave generator is stopped to obtain the phenolic vacuum insulation board core material.

[0051] Step (9) Preparation of phenolic vacuum insulation board A groove was dug in the core material of the phenolic vacuum insulation board, a getter was placed in it, and the board was quickly placed in a barrier bag with aluminum on both sides; then vacuuming was performed for 1.5 hours and the vacuum degree was 10 -2 The bag mouth is then sealed to obtain a phenolic vacuum insulation board.

[0052] The present application also provides the following comparative examples: Comparative Example 1 Phenolic vacuum insulation panels currently available on the market.

[0053] Comparative Example 2 The open-cell polyurethane phenolic vacuum insulation panels currently available on the market.

[0054] Comparative Example 3 (Phenolic resin has low viscosity, low compression strength, and a risk of glass fiber puncture) Compared with Example 1, the difference between this comparative example and Example 1 is that the viscosity of the phenolic resin is less than 10000 mPa.s, which is about 2000 mPa.s. Other formulas and preparation processes are consistent with those of Example 1.

[0055] Comparative Example 4 (small amount of foaming agent, increased thermal conductivity) Compared with Example 1, the difference between this comparative example and Example 1 is that the amount of the foaming agent added is less than the limited range (3 parts). Other formulas and preparation processes are consistent with Example 1.

[0056] Comparative Example 5 (no vacuum drying, increased thermal conductivity) Compared with Example 1, the difference between this comparative example and Example 1 is that: vacuum microwave drying is not performed, but the core material is placed in an oven, the temperature is raised to 120° C., and the baking is continued for 40 minutes. Other formulas and preparation processes are consistent with Example 1.

[0057] Comparative Example 6 (no wollastonite, only glass fiber, reduced compressive strength) Compared with Example 1, the difference between this comparative example and Example 1 is that the filler is simply glass fiber. The other formulas and preparation processes are the same as those of Example 1.

[0058] Comparative Example 7 (too much wollastonite, reduced compression strength) Compared with Example 1, the difference between this comparative example and Example 1 is that the filler is composed of wollastonite and glass fiber in a mass ratio of 4:1. Other formulas and preparation processes are consistent with those of Example 1.

[0059] Comparative Example 8 (without adding surfactant, the open porosity is reduced and the thermal conductivity is increased) Compared with Example 1, the difference between this comparative example and Example 1 is that no surfactant is added. Other formulas and preparation processes are consistent with those of Example 1.

[0060] Comparative Example 9 (Different surfactant formula, reduced open porosity and increased thermal conductivity) Compared with Example 1, the difference between this comparative example and Example 1 is that the surfactant is simply sodium dodecyl sulfate. The other formulas and preparation processes are the same as those of Example 1.

[0061] Comparative Example 10 (without adding defoamer, the open porosity is reduced and the thermal conductivity is increased) Compared with Example 1, the difference between this comparative example and Example 1 is that no defoaming agent is added. Other formulas and preparation processes are consistent with those of Example 1.

[0062] Comparative Example 11 (different defoamer formula, reduced open porosity and increased thermal conductivity) Compared with Example 1, the difference between this comparative example and Example 1 is that the defoaming agent is simply polydimethylsiloxane. The other formulas and preparation processes are the same as those of Example 1.

[0063] The products obtained in the above examples and comparative examples were subjected to the following performance tests. The results are shown in Tables 2-4. Table 2 Core material properties project Example 1 Example 2 Comparative Example 1 Comparative Example 8 Sample opening rate, % 99.2 97.1 About 85% 85.7 Electron microscope observation phenomenon like Figure 1 As shown, the slices were placed in an electron microscope for observation. When the magnification was adjusted to 1000 times, the foam skeleton was smooth and had no micropores. The slices were placed in an electron microscope for observation. When the magnification was adjusted to 1000 times, the foam skeleton was smooth and had no micropores. like Figure 2 As shown, at 1000 times, it can be seen that the skeleton is full of micropores / project Comparative Example 9 Comparative Example 10 Comparative Example 11 Sample opening rate, % 92.3 87.3 93.1 Electron microscope observation phenomenon / / / It should be noted that the high open porosity in Table 1 does not mean that there are more micropores. The foam body is composed of a skeleton, pores and a bubble membrane. The high open porosity of the embodiment of the present application is due to the fact that the original pores in the foam body are basically closed, and then due to the action of surfactants, the membrane of the pores is broken so that the pores are interconnected, and the skeleton of the foam body is still dense, smooth and has no obvious micropores. In Comparative Example 1, the micropores refer to the tiny holes on the foam body skeleton. There are many micropores and they are basically not connected. Therefore, when the foam body is heated, small molecules such as water are adsorbed and are not easy to dissipate, which affects the thermal conductivity and also reduces the strength.

[0064] Table 3 Core material properties

[0065] Table 4 Properties of phenolic vacuum insulation panels

[0066] “ / ” in the table means not detected.

[0067] It should be noted that: In this article, “~” is used to indicate a numerical range, and the range indicated by this expression includes two endpoint values.

[0068] In addition to the actual selections embodied in the above specific embodiments, the above formulation ranges may be used in the specific implementation of the present application, including but not limited to the above embodiment schemes.

[0069] The specific parameters or some commonly used reagents or raw materials in the above embodiments are specific embodiments or preferred embodiments of the present application, but are not intended to limit the present application. Those skilled in the art may make adaptive adjustments within the scope of the present application.

[0070] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the present application can be improved in only one or several aspects, without having to solve all the technical problems listed in the prior art or background technology at the same time. Those skilled in the art should understand that the content not mentioned in a claim should not be used as a limitation on the claim.

[0071] Although the terms such as VIP core material, phenolic resin, emulsifier, etc. are used more frequently in this article, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of this application; interpreting them as any additional restrictions is contrary to the spirit of this application; the terms "first", "second", etc. (if any) in the description and claims of the embodiments of this application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A phenolic vacuum insulation board core material, characterized in that: The raw material components include 100 parts of phenolic resin, 2 to 5 parts of emulsifier, 1 to 3 parts of surfactant, 1 to 3 parts of defoamer, 5 to 10 parts of foaming agent, 15 to 20 parts of curing agent and 5 to 7 parts of filler by weight. Wherein, the filler comprises wollastonite powder and glass fiber; the mass ratio of the wollastonite powder to the glass fiber is 1:4; The phenolic resin is a thermosetting resin with a viscosity of 10000 to 16000 mPa.s; The surfactant includes sodium lauryl sulfate and fatty acid glyceride; the mass ratio of the sodium lauryl sulfate to the fatty acid glyceride is 12:1.6; The defoaming agent comprises polydimethylsiloxane and a polyether defoaming agent; the mass ratio of the polydimethylsiloxane to the polyether defoaming agent is 10:1; The preparation process of phenolic vacuum insulation board core material is as follows: According to the formula, the phenolic resin, emulsifier, surfactant, defoamer, foaming agent and filler are uniformly mixed to obtain liquid A; Weigh the curing agent according to the formula to obtain liquid B; The material liquid A and the material liquid B are mixed and poured into a bubble box, the mixed material liquid is solidified and formed in the bubble box, and the plate is cut to obtain a plate; The board is subjected to microwave drying treatment in a vacuum environment to obtain a phenolic vacuum insulation board core material.

2. The phenolic vacuum insulation panel core material according to claim 1, characterized in that: The microwave drying process under the vacuum environment is as follows: placing the microwave generator in a vacuum environment; Placing the plate in the chamber of a microwave generator, and arranging a temperature sensing component and a weight sensing component to sense the temperature and mass change value of the plate in real time; Then, the microwave generator is started to carry out microwave drying, and the drying is stopped after the drying end point; The microwave drying process is carried out in a vacuum environment, and the microwave power is 4.5-7.8 kw.

3. The phenolic vacuum insulation panel core material according to claim 2, characterized in that: During the microwave drying process under the vacuum environment, the weight sensing component measures and records the mass value of the plate every 1 second; The drying endpoint is determined as follows: when the weight loss of the board at intervals of 1 second is less than or equal to 10 mg within a time period of 30 to 120 seconds, the drying endpoint is determined to be reached.

4. The phenolic vacuum insulation panel core material according to claim 1, characterized in that: The length of the glass fiber is 1 to 3 cm.

5. The phenolic vacuum insulation panel core material according to claim 1, characterized in that: The mesh number of the wollastonite powder is between 800 and 1000 meshes.

6. The phenolic vacuum insulation panel core material according to claim 1, characterized in that: The filler is composed of wollastonite powder and glass fiber in a mass ratio of 1:4; The surfactant is composed of sodium lauryl sulfate and fatty acid glycerides in a mass ratio of 12:1.6; The defoaming agent is composed of polydimethylsiloxane and polyether defoaming agent in a mass ratio of 10:

1.

7. The phenolic vacuum insulation panel core material according to claim 1, characterized in that: The emulsifier is one or more of EL30, silicone oil, EL80 and Tween 60; The foaming agent is one or more combinations of n-pentane, cyclopentane and isopentane; The curing agent is one or more combinations of p-toluenesulfonic acid, methanesulfonic acid, phenolsulfonic acid and phosphoric acid.

8. A method for preparing a phenolic vacuum insulation panel core material as claimed in claims 1 to 7, characterized in that: The following steps are involved: According to the formula, the phenolic resin, emulsifier, surfactant, defoamer, foaming agent and filler are uniformly mixed to obtain liquid A; Weigh the curing agent according to the formula to obtain liquid B; After mixing liquid A and liquid B in the pouring head, pour them into the bubble box through the pouring hole; The bubble box is sealed and placed at room temperature to allow the mixed liquid in the bubble box to ferment and solidify; then, after being cooled at room temperature for 1 to 2 days, the liquid in the bubble box is fully reacted and solidified to obtain a foam body; The foam body is cut into boards of required specifications, and the boards are subjected to microwave drying treatment in a vacuum environment to obtain the core material of the phenolic vacuum insulation board.

9. The method for preparing a phenolic vacuum insulation panel core material according to claim 8, characterized in that: The microwave drying process under the vacuum environment is as follows: placing the microwave generator in a vacuum environment; Placing the plate in the chamber of a microwave generator, and arranging a temperature sensing component and a weight sensing component to sense the temperature and mass change value of the plate in real time; Then, the microwave generator is started to carry out microwave drying, and the drying is stopped after the drying end point; The microwave drying process is carried out in a vacuum environment, and the microwave power is 4.5-7.8 kw.

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