A kind of building exterior wall thermal insulation material and preparation method thereof

Abstract

The invention discloses a building exterior wall thermal insulation material and a preparation method thereof, and relates to the technical field of building materials. The preparation method of the building exterior wall thermal insulation material of the present invention: the modified phenolic resin, the surfactant, and the foaming agent are uniformly dispersed, the curing agent is added and dispersed uniformly, the mold is injected for foaming and curing, and the building exterior wall thermal insulation material is obtained; the modified phenolic resin is ethyl orthosilicate, γ-aminopropyltriethoxysilane prepared by silane-modified silica and octamethylcyclotetrasiloxane, 1,3-bis(3-glycidylpropyl)-1,1,3,3-tetramethyldisiloxane prepared under the catalysis of tetramethylammonium hydroxide, and the organic silicon and phenolic resin are mixed and cross-linked to obtain. The modified phenolic prepared in the present application is added in the phenolic foam as a matrix to prepare the building exterior wall thermal insulation material, which has the advantages of good mechanical properties, low water absorption, good foaming effect, and low thermal conductivity.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, and in particular to a building exterior wall thermal insulation material and a preparation method thereof. Background Art

[0002] Building energy conservation has become one of the important signs of progress in building technology. The basic way to save energy in buildings is to improve the thermal functionality of buildings and the energy efficiency of heating and air-conditioning equipment, that is, to reduce the heat transfer through the enclosure structure. Insulation and energy-saving walls generally refer to building walls constructed with building materials with low thermal conductivity. Due to the low thermal conductivity of the material itself, the heat transfer coefficient of the entire wall is very low, which can play a good role in thermal insulation. At present, the insulation materials used for energy conservation in urban building walls include organic materials such as expanded polystyrene foam, extruded polystyrene foam clinker, polyurethane foam, and inorganic insulation materials such as rock wool, glass wool and insulation mortar. Inorganic fiber insulation materials have fine fibers and dust. During use, they are not only easy to breed bacteria but also pollute the air, which is very harmful to humans. Nowadays, they are basically no longer used; mortar insulation materials have the worst effect and cannot meet the requirements of energy conservation. Organic insulation materials have the advantages of low thermal conductivity and good thermal insulation performance. They can play a good role in thermal insulation and energy saving when applied to building exterior walls. However, these organic thermal insulation materials also have problems such as poor bonding performance, low dimensional stability, easy aging, and easy burning.

[0003] Phenolic resin foam has the advantages of low thermal conductivity, good flame retardancy and heat resistance, and is widely used in office buildings, shopping malls, hospitals, high-clean workshops and subways. However, phenolic resin has problems such as low surface strength, high brittleness and high water absorption, and is not suitable for external wall insulation materials. In order to apply phenolic foam with both fire safety and thermal insulation and energy saving characteristics to the building exterior wall insulation thin plaster system, it is necessary to toughen it without reducing its fire resistance to improve its mechanical properties and meet the requirements of building exterior wall insulation. The general modification methods include the following: (1) using non-reactive external toughening agents to achieve the purpose of toughening by blending, but with the addition of external toughening agents, the viscosity of the blend increases and the foaming process is difficult to control; (2) chemically reacting reactive toughening agents with resol phenolic resin to achieve the toughening effect, but this method reduces the flame retardancy of phenolic foam; (3) using modified phenol with some toughening chains to replace phenol synthetic resin, but this method increases the smoke density and smoke toxicity of phenolic foam. Summary of the invention

[0004] The object of the present invention is to provide a building exterior wall thermal insulation material and a preparation method thereof, to solve the following technical problems:

[0005] The flame retardant property and foaming ratio of the modified phenolic resin prepared by adding the existing toughening agent to the phenolic resin are reduced.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for preparing a building exterior wall thermal insulation material comprises dispersing a modified phenolic resin, a surfactant, and a foaming agent uniformly, adding a curing agent and dispersing the mixture uniformly, injecting the mixture into a mold for foaming and curing, and obtaining the building exterior wall thermal insulation material;

[0008] The preparation method of the modified phenolic resin comprises the following steps:

[0009] S1: add anhydrous ethanol, deionized water and tetraethyl orthosilicate into a reaction bottle, disperse evenly, control the temperature at 45-55°C, add ammonia water to adjust the pH to 8-9, keep warm for 9-18h, add γ-aminopropyltriethoxysilane, keep warm for 9-18h, centrifuge, wash and dry to obtain component 1;

[0010] S2: octamethylcyclotetrasiloxane, 1,3-bis(3-glycidylpropyl)-1,1,3,3-tetramethyldisiloxane and N,N-dimethylacetamide are added to a reaction bottle, dispersed evenly, the temperature is controlled at 70-80°C, tetramethylammonium hydroxide is added, the temperature is controlled at 105-115°C, the temperature is kept at 3-6h, and vacuum is drawn to obtain component 2;

[0011] S3: Add phenol and 37wt% formaldehyde solution into the reaction kettle, control the temperature at 35-45°C, adjust the pH at 9-10, control the temperature at 60-65°C, and keep warm for 0.5-1h; add component 1 and component 2, control the temperature at 85-95°C, keep warm for 1-3h, cool, adjust the pH at 6-7.5, and distill under reduced pressure to obtain modified phenolic resin.

[0012] As a further solution of the present invention: the foaming and curing temperature is 70-80°C.

[0013] As a further solution of the present invention: the reduced pressure distillation in S3 is performed to a viscosity of 5000-9000 mPa˙s.

[0014] As a further solution of the present invention: the ammonia water in S1 is 20-35wt% ammonia water; the addition ratio of anhydrous ethanol, deionized water, ethyl orthosilicate, and γ-aminopropyltriethoxysilane is 40-100mL: 10-20mL: 1-2g: 0.1-0.2g.

[0015] As a further embodiment of the present invention, the addition ratio of octamethylcyclotetrasiloxane, 1,3-bis(3-glycidylpropyl)-1,1,3,3-tetramethyldisiloxane, N,N-dimethylacetamide and tetramethylammonium hydroxide in S2 is 10 g: 0.5-0.8 g: 50-100 mL: 0.003-0.007 g.

[0016] As a further solution of the present invention: the addition ratio of phenol, 37 wt% formaldehyde solution, component one and component two in S3 is 10 g: 10-18 mL: 2-4 g: 1-2 g.

[0017] As a further solution of the present invention: the building exterior wall thermal insulation material comprises the following raw materials in parts by weight: 100 parts by weight of modified phenolic resin, 2-10 parts by weight of surfactant, 5-15 parts by weight of foaming agent, and 5-12 parts by weight of curing agent.

[0018] As a further embodiment of the present invention: the surfactant is any one of Tween 80, polyoxyl castor oil and DC-193 silicone oil or a mixture of several of them in any ratio.

[0019] As a further embodiment of the present invention, any one or more of the foaming agents cyclopentane, n-pentane, n-hexane, dichloromethane, carbonates, bicarbonates, and azo compounds are mixed in any ratio to obtain the foaming agent.

[0020] As a further embodiment of the present invention: the curing agent is one or more of p-toluenesulfonic acid, benzenesulfonic acid, adipic acid, oxalic acid, phosphoric acid, hydrochloric acid and sulfuric acid mixed in any ratio.

[0021] A method for preparing a building exterior wall thermal insulation material, which is prepared by any one of the above-mentioned preparation methods.

[0022] Beneficial effects of the present invention:

[0023] (1) The building exterior wall thermal insulation material prepared in the present application includes a modified phenolic resin, a foaming agent, a surfactant and a curing agent; the present application first uses a sol-gel method to prepare silica microspheres using tetraethyl orthosilicate as a raw material under alkali catalysis, and adds an aminosilane coupling agent during the preparation process to prepare component one; component one prepared in the present application is silica microspheres with amino groups connected to the surface; the present application also uses octamethylcyclotetrasiloxane as a raw material, 1,3-di(3-glycidylpropyl)-1,1,3,3-tetramethyldisiloxane as a capping agent, and tetramethylammonium hydroxide as a catalyst to prepare component two, and component two prepared in the present application is an epoxy-capped organic silicon segment; finally, component one and component two are added during the preparation process of phenolic resin foam, and the phenolic resin foam raw material is grafted and modified using component one and component two to obtain a modified phenolic resin.

[0024] The component one prepared in the present application is added to the modified phenolic resin to improve the strength, heat resistance and flame resistance of the phenolic foam. The component two prepared in the present application has a Si-O bond on the main chain, and the side chain is various organic groups connected to Si atoms and component one. The Si-O bond is long and has a high bond energy, so that the molecular chain connected between component two and the phenolic resin is stable and easy to rotate, giving the material excellent flexibility and extremely low glass transition temperature and good processability, which can significantly improve the low-temperature toughness of the phenolic resin, and at the same time improve the heat resistance and aging resistance of the material. The present application successfully connects heteroatom silicon in the phenolic resin macromolecular chain by grafting component one and component two on the phenolic resin molecular chain, reduces the relative content of phenolic hydroxyl groups in the phenolic resin macromolecule, and achieves the purpose of improving the thermal stability and oxidation resistance of the phenolic resin. With the addition of component one and component two, the epoxy ring of component two opens to generate active groups such as terminal hydroxyl groups. When the hydroxyl groups undergo polymerization reaction with the dimer or trimer, they replace part of the methylene groups to link the two prepolymers, and the long flexible chains with ether bonds and alkyl chains are introduced into the three-dimensional network macromolecules by polycondensation, so that the methylene rigid groups in the phenolic resin are relatively reduced and the flexible groups are increased. The ratio of rigid groups to flexible matrix is ​​moderate, which changes the rigid structure of the phenolic resin and increases the compression strength of the phenolic resin, thereby increasing the toughness of the phenolic foam in the foaming and curing process in terms of chemical structure. Moreover, with the addition of component one and component two, the alkoxy groups in the phenolic resin increase and the viscosity decreases, which solves the problem in the prior art that the addition of modifiers increases the degree of crosslinking in the system and makes the foaming process difficult.

[0025] (2) Components 1 and 2 added in the present application are cross-linked with the phenolic resin, and also give the material excellent water resistance; the phenolic foam prepared in the present application has excellent flame penetration resistance, and has carbonization, no dripping, no curling, and no melting under the direct action of the flame, effectively protecting its internal foam structure. The foam structure prepared by the modified phenolic resin prepared in the present application is an independent closed-cell micro-foam body, which isolates the gases from each other, reduces the convective heat transfer in the gas, and helps to improve the thermal insulation capacity of the foam plastic. DETAILED DESCRIPTION

[0026] The following will be described clearly and completely in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Embodiment 1 The preparation method of modified phenolic resin comprises the following steps:

[0028] S1: 1600 mL of anhydrous ethanol, 400 mL of deionized water, and 40 g of tetraethyl orthosilicate were added to a reaction bottle, dispersed evenly, the temperature was controlled at 45°C, 20 wt% of ammonia water was added to adjust the pH to 8, the mixture was kept warm for 9 h, 4 g of γ-aminopropyltriethoxysilane was added, the mixture was kept warm for 9 h, centrifuged, washed, and dried to obtain component 1;

[0029] S2: 50 g of octamethylcyclotetrasiloxane, 2.5 g of 1,3-bis(3-glycidylpropyl)-1,1,3,3-tetramethyldisiloxane and 250 mL of N,N-dimethylacetamide were added to a reaction bottle and dispersed evenly. The temperature was controlled at 70° C., 0.015 g of tetramethylammonium hydroxide was added, the temperature was controlled at 105° C., the mixture was kept warm for 3 h, and vacuum was applied to obtain component 2.

[0030] S3: Add 100g phenol and 100mL 37wt% formaldehyde solution into a reactor, control the temperature at 35℃, add 20wt% sodium hydroxide aqueous solution to adjust the pH to 9 under stirring, control the temperature at 60℃, and keep warm for 0.5h; add 20g component 1 and 10g component 2, control the temperature at 85℃, keep warm for 1h, cool, add 6mol / L hydrochloric acid solution to adjust the pH to 6 under stirring, and distill under reduced pressure to a viscosity of 7000mPa˙s to obtain a modified phenolic resin.

[0031] Embodiment 2 The preparation method of modified phenolic resin comprises the following steps:

[0032] S1: 2500 mL of anhydrous ethanol, 600 mL of deionized water, and 60 g of tetraethyl orthosilicate were added to a reaction bottle, dispersed evenly, the temperature was controlled at 50°C, 20 wt% of ammonia water was added to adjust the pH to 8, the mixture was kept warm for 12 h, 6 g of γ-aminopropyltriethoxysilane was added, the mixture was kept warm for 15 h, centrifuged, washed, and dried to obtain component 1;

[0033] S2: 50 g of octamethylcyclotetrasiloxane, 3 g of 1,3-bis(3-glycidylpropyl)-1,1,3,3-tetramethyldisiloxane and 350 mL of N,N-dimethylacetamide were added to a reaction bottle and dispersed evenly. The temperature was controlled at 75° C., 0.025 g of tetramethylammonium hydroxide was added, the temperature was controlled at 110° C., the mixture was kept warm for 3 h, and vacuum was applied to obtain component 2.

[0034] S3: Add 100g phenol and 150mL 37wt% formaldehyde solution into a reactor, control the temperature at 40℃, add 20wt% sodium hydroxide aqueous solution to adjust the pH to 9 under stirring, control the temperature at 60℃, and keep warm for 0.5h; add 20g component 1 and 10g component 2, control the temperature at 90℃, keep warm for 2h, cool, add 6mol / L hydrochloric acid solution to adjust the pH to 7 under stirring, and distill under reduced pressure to a viscosity of 7000mPa˙s to obtain a modified phenolic resin.

[0035] Embodiment 3 The preparation method of modified phenolic resin comprises the following steps:

[0036] S1: 4000 mL of anhydrous ethanol, 800 mL of deionized water, and 80 g of tetraethyl orthosilicate were added to a reaction bottle, dispersed evenly, the temperature was controlled at 55°C, 35 wt% of ammonia water was added to adjust the pH to 8, the mixture was kept warm for 18 h, 8 g of γ-aminopropyltriethoxysilane was added, the mixture was kept warm for 18 h, centrifuged, washed, and dried to obtain component 1;

[0037] S2: 50 g of octamethylcyclotetrasiloxane, 4 g of 1,3-bis(3-glycidylpropyl)-1,1,3,3-tetramethyldisiloxane and 500 mL of N,N-dimethylacetamide were added to a reaction bottle and dispersed evenly. The temperature was controlled at 80° C., 0.035 g of tetramethylammonium hydroxide was added, the temperature was controlled at 115° C., the mixture was kept warm for 6 h, and vacuum was applied to obtain component 2.

[0038] S3: Add 100g phenol and 180mL 37wt% formaldehyde solution into a reactor, control the temperature at 45℃, add 20wt% sodium hydroxide aqueous solution to adjust the pH to 9 under stirring, control the temperature at 65℃, and keep warm for 1h; add 20g component 1 and 10g component 2, control the temperature at 95℃, keep warm for 3h, cool, add 6mol / L hydrochloric acid solution to adjust the pH to 7.5 under stirring, and distill under reduced pressure to a viscosity of 7000mPa˙s to obtain a modified phenolic resin.

[0039] Example 4 A method for preparing a building exterior wall insulation material, comprising: adding 100 parts by weight of the modified phenolic resin prepared in Example 1, 5 parts by weight of Tween 80, and 10 parts by weight of n-pentane, controlling the temperature at 40°C, and dispersing them evenly, adding 6 parts by weight of phosphoric acid and 3 parts by weight of p-toluenesulfonic acid, controlling the temperature at 40°C, and dispersing them evenly, injecting them into a mold for foaming, and curing them at 70°C to obtain the building exterior wall insulation material.

[0040] Example 5 A method for preparing a building exterior wall insulation material, comprising: adding 100 parts by weight of the modified phenolic resin prepared in Example 2, 5 parts by weight of Tween 80, and 10 parts by weight of n-pentane, controlling the temperature at 40°C, and dispersing them evenly, adding 6 parts by weight of phosphoric acid and 3 parts by weight of p-toluenesulfonic acid, controlling the temperature at 40°C, and dispersing them evenly, injecting them into a mold for foaming, and curing them at 70°C to obtain the building exterior wall insulation material.

[0041] Example 6 A method for preparing a building exterior wall insulation material, comprising: adding 100 parts by weight of the modified phenolic resin prepared in Example 3, 5 parts by weight of Tween 80 and 10 parts by weight of n-pentane, controlling the temperature at 40°C, and dispersing them evenly, adding 6 parts by weight of phosphoric acid and 3 parts by weight of p-toluenesulfonic acid, controlling the temperature at 40°C, and dispersing them evenly, injecting them into a mold for foaming, and curing them at 70°C to obtain the building exterior wall insulation material.

[0042] Comparative Example 1 The preparation method of the modified phenolic resin comprises the following steps:

[0043] S1: 1600 mL of anhydrous ethanol, 400 mL of deionized water, and 40 g of tetraethyl orthosilicate were added to a reaction bottle, dispersed evenly, the temperature was controlled at 45°C, 20 wt% of ammonia water was added to adjust the pH to 8, the mixture was centrifuged for 9 hours, washed, and dried to obtain component 1;

[0044] S2: 50 g of octamethylcyclotetrasiloxane, 2.5 g of 1,3-bis(3-glycidylpropyl)-1,1,3,3-tetramethyldisiloxane and 250 mL of N,N-dimethylacetamide were added to a reaction bottle and dispersed evenly. The temperature was controlled at 70° C., 0.015 g of tetramethylammonium hydroxide was added, the temperature was controlled at 105° C., the mixture was kept warm for 3-6 h, and vacuum was applied to obtain component 2.

[0045] S3: Add 100g phenol and 100mL 37wt% formaldehyde solution into a reactor, control the temperature at 35℃, add 20wt% sodium hydroxide aqueous solution to adjust the pH to 9 under stirring, control the temperature at 60℃, and keep warm for 0.5h; add 20g component 1 and 10g component 2, control the temperature at 85℃, keep warm for 1h, cool, add 6mol / L hydrochloric acid solution to adjust the pH to 6 under stirring, and distill under reduced pressure to a viscosity of 7000mPa˙s to obtain a modified phenolic resin.

[0046] Comparative Example 2 The preparation method of the modified phenolic resin comprises the following steps:

[0047] S1: 1600 mL of anhydrous ethanol, 400 mL of deionized water, and 40 g of tetraethyl orthosilicate were added to a reaction bottle, dispersed evenly, the temperature was controlled at 45°C, 20 wt% of ammonia water was added to adjust the pH to 8, the mixture was kept warm for 9 h, 4 g of γ-aminopropyltriethoxysilane was added, the mixture was kept warm for 9 h, centrifuged, washed, and dried to obtain component 1;

[0048] S2: Add 100g of phenol and 100mL of 37wt% formaldehyde solution into a reactor, control the temperature at 35℃, add 20wt% sodium hydroxide aqueous solution to adjust the pH to 9 under stirring, control the temperature at 60℃, and keep warm for 0.5h; add 20g of component 1, control the temperature at 85℃, keep warm for 1h, cool, add 6mol / L hydrochloric acid solution to adjust the pH to 6 under stirring, and distill under reduced pressure to a viscosity of 7000mPa˙s to obtain a modified phenolic resin.

[0049] Comparative Example 3 The preparation method of the modified phenolic resin comprises the following steps:

[0050] S1: 1600 mL of anhydrous ethanol, 400 mL of deionized water, and 40 g of tetraethyl orthosilicate were added to a reaction bottle, dispersed evenly, the temperature was controlled at 45°C, 20 wt% of ammonia water was added to adjust the pH to 8, the mixture was centrifuged for 9 hours, washed, and dried to obtain component 1;

[0051] S2: 50 g of octamethylcyclotetrasiloxane, 2.5 g of 1,1,3,3-tetramethyldihydrodisiloxane, and 250 mL of N,N-dimethylacetamide were added to a reaction bottle, dispersed evenly, the temperature was controlled at 70°C, 3 mL of concentrated sulfuric acid was added, the temperature was controlled at 35°C, the temperature was kept at 35°C for 6 h, and vacuum was applied to obtain component 2;

[0052] S3: Add 100g phenol and 100mL 37wt% formaldehyde solution into a reactor, control the temperature at 35℃, add 20wt% sodium hydroxide aqueous solution to adjust the pH to 9 under stirring, control the temperature at 60℃, and keep warm for 0.5h; add 20g component 1 and 10g component 2, control the temperature at 85℃, keep warm for 1h, cool, add 6mol / L hydrochloric acid solution to adjust the pH to 6 under stirring, and distill under reduced pressure to a viscosity of 7000mPa˙s to obtain a modified phenolic resin.

[0053] Comparative Example 4 Compared with Example 4, Comparative Example 4 only replaces the modified phenolic resin prepared in Example 1 added in Example 4 with an equal amount of the modified phenolic resin prepared in Comparative Example 1, and the remaining components and preparation method are exactly the same as those in Example 4.

[0054] Comparative Example 5 Compared with Example 4, Comparative Example 5 is characterized by replacing an equal amount of the modified phenolic resin prepared in Example 1 added in Example 4 with the modified phenolic resin prepared in Comparative Example 2, and the remaining components and preparation method are completely consistent with Example 4.

[0055] Comparative Example 6 Compared with Example 4, Example 6 only replaces the modified phenolic resin prepared in Example 1 added in Example 4 with an equal amount of the modified phenolic resin prepared in Comparative Example 3, and the remaining components and preparation method are exactly the same as those in Example 4.

[0056] Performance Testing

[0057] (1) Compression strength: tested according to GB / T 8813-2020 “Compression test method for rigid foam plastics”. The test results are shown in Table 1.

[0058] (2) Foam pull-out strength: According to JGJ 144-2004 Technical Code for External Wall Thermal Insulation Engineering, the sample size is 100 mm × 100 mm × 50 mm. The sample is placed in an environment of 25°C and relative humidity (65 ± 5)% for more than 4 hours, and the testing machine speed is 5 mm / min. The test results are shown in Table 1.

[0059] (3) Thermal conductivity: According to GB / T 10294-2008 "Determination of Steady-State Thermal Resistance and Related Properties of Insulating Materials - Guarded Hot Plate Method", the sample size is 300mm×300mm×40mm. Use a heat flow thermal conductivity meter, clamp the sample between the hot plate and the cold plate. The sample should be in close contact with the hot and cold plates, cover with a glass cover, keep the hot and cold plates at a constant temperature, and maintain the selected temperature difference. After one hour, read the thermal conductivity value of the sample every 10 minutes until the thermal conductivity does not change within 10 minutes. The test results are shown in Table 1;

[0060] (4) Dimensional stability: According to GB / T 8811-2008 “Test method for dimensional stability of rigid foam plastics”, test at 70±2℃ for 48h. The test results are shown in Table 1.

[0061] (5) Oxygen index: tested according to GB / T 2406.1-2008 “Plastics combustion performance test method oxygen index method”, sample size 12.5mm×12.5mm×120mm, test results are shown in Table 1;

[0062] (6) Water absorption rate: The test was conducted in accordance with GB / T 8810-2005 “Determination of water absorption rate of rigid foam plastics”. The sample size was 100 mm × 100 mm × 20 mm. The sample was completely immersed in distilled water at (23 ± 2) °C for 96 h. After immersion, the sample was weighed and the water absorption rate was calculated.

[0063] δ=[(G1-G0) / G0]×100%

[0064] In the formula, δ-water absorption, %; G0-initial mass of the sample, g; G1-mass after water absorption, g; the test results are shown in Table 1;

[0065] (7) Powdering rate: Place a 200 g weight on the surface of a 50 mm × 50 mm × 50 mm sample and repeat 40 times on 300-mesh sandpaper at a constant force, each time at a distance of 300 mm. Blow away the surface powder, weigh the residual mass, and calculate the powdering rate η:

[0066] η=[(m0-m1) / m0]×100%

[0067] Wherein, η-pulverization rate, %; m0-initial mass of the sample, g; m1-mass after friction, g; the test results are shown in Table 1;

[0068] (8) Closed cell ratio: The closed cell ratio of the sample was calculated according to GB / T 10799-2008 “Rigid foam plastics. Determination of open and closed cell volume percentage”; the test results are shown in Table 1;

[0069] (9) Resin activity: Example 4-6 and Comparative Example 4-6 were subjected to the same material temperature and stirring time, and the rise time and curing time were recorded, the foaming speed was observed, and the foaming ratio was calculated. The test results are shown in Table 1;

[0070] Table 1: Statistical table of performance test data of Examples 4-6 and Comparative Examples 4-6

[0071]

[0072]

[0073] As can be seen from Table 1, the building exterior wall insulation material prepared by adding the modified phenolic formaldehyde prepared in the present application into phenolic formaldehyde foam as a matrix has the advantages of good mechanical properties, low water absorption, good foaming effect and low thermal conductivity.

[0074] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for preparing a building exterior wall thermal insulation material, characterized in that: The modified phenolic resin, surfactant and foaming agent are dispersed evenly, a curing agent is added and dispersed evenly, and the mixture is injected into a mold for foaming and curing to obtain a building exterior wall thermal insulation material; The preparation method of the modified phenolic resin comprises the following steps: S1: add anhydrous ethanol, deionized water and tetraethyl orthosilicate into a reaction bottle, disperse evenly, control the temperature at 45-55°C, add ammonia water to adjust the pH to 8-9, keep warm for 9-18h, add γ-aminopropyltriethoxysilane, keep warm for 9-18h, centrifuge, wash and dry to obtain component 1; S2: add octamethylcyclotetrasiloxane, 1,3-bis(3-glycidylpropyl)-1,1,3,3-tetramethyldisiloxane and N,N-dimethylacetamide to a reaction bottle, disperse evenly, control the temperature at 70-80°C, add tetramethylammonium hydroxide, control the temperature at 105-115°C, keep warm for 3-6 hours, evacuate, and obtain component 2; S3: Add phenol and 37wt% formaldehyde solution into the reaction kettle, control the temperature at 35-45°C, adjust the pH at 9-10, control the temperature at 60-65°C, and keep warm for 0.5-1h; add component 1 and component 2, control the temperature at 85-95°C, keep warm for 1-3h, cool, adjust the pH at 6-7.5, and perform vacuum distillation to obtain modified phenolic resin; The addition ratio of phenol, 37 wt% formaldehyde solution, component one, and component two in S3 is 10 g: 10-18 mL: 2-4 g: 1-2 g.

2. The method for preparing a building exterior wall thermal insulation material according to claim 1, characterized in that: The ammonia water in S1 is 20-35wt% ammonia water; the addition ratio of anhydrous ethanol, deionized water, ethyl orthosilicate, and γ-aminopropyltriethoxysilane is 40-100mL: 10-20mL: 1-2g: 0.1-0.2g.

3. The method for preparing a building exterior wall thermal insulation material according to claim 1, characterized in that: The addition ratio of octamethylcyclotetrasiloxane, 1,3-bis(3-glycidylpropyl)-1,1,3,3-tetramethyldisiloxane, N,N-dimethylacetamide, and tetramethylammonium hydroxide in S2 is 10 g: 0.5-0.8 g: 50-100 mL: 0.003-0.007 g.

4. The method for preparing a building exterior wall thermal insulation material according to claim 1, characterized in that: The building exterior wall thermal insulation material comprises the following raw materials in parts by weight: 100 parts by weight of modified phenolic resin, 2-10 parts by weight of surfactant, 5-15 parts by weight of foaming agent and 5-12 parts by weight of curing agent.

5. The method for preparing a building exterior wall thermal insulation material according to claim 1, characterized in that: The surfactant is any one of Tween 80, polyoxyl castor oil and DC-193 silicone oil or a mixture of several of them in any ratio.

6. The method for preparing a building exterior wall thermal insulation material according to claim 1, characterized in that: The foaming agent is any one of cyclopentane, n-pentane, n-hexane, dichloromethane, carbonate, bicarbonate, and azo compounds, or a mixture of several of them in any ratio.

7. The method for preparing a building exterior wall thermal insulation material according to claim 1, characterized in that: The curing agent is one or more of p-toluenesulfonic acid, benzenesulfonic acid, adipic acid, oxalic acid, phosphoric acid, hydrochloric acid and sulfuric acid mixed in any ratio.

8. A building exterior wall thermal insulation material, characterized in that: Prepared by the preparation method described in any one of claims 1 to 7.

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