A kind of foamed honeycomb core composite board and preparation method thereof

Abstract

The present invention provides a foamed honeycomb core composite board and a preparation method thereof, and relates to the technical field of composite materials. The composite board comprises an upper skin, a first adhesive film layer, a foamed honeycomb core, a second adhesive film layer, a sound insulation felt, a third adhesive film layer and a lower skin, which are sequentially arranged. The preparation method of the foamed honeycomb core comprises: placing a foamed phenolic resin mixture in a lower mold and an upper mold, placing a honeycomb core body in the lower mold, covering the upper mold on the honeycomb core body, and performing a foaming process. After the foaming is completed, the lower mold and the upper mold are removed to obtain a foamed honeycomb core. The lower mold and the upper mold are both provided with a protrusion adapted to the honeycomb hole of the honeycomb core body, and the outer peripheral surface of the protrusion is fitted with the inner wall of the honeycomb hole to form an unfoamed area at the upper and lower ends of the honeycomb hole. The first adhesive film layer and the second adhesive film layer enter the unfoamed area at the upper and lower ends of the honeycomb hole respectively. The foamed honeycomb core of the composite board has better adhesion to the adhesive film, excellent mechanical properties, and good flame retardant effect.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, and in particular to a foamed honeycomb core composite board and a preparation method thereof. Background Art

[0002] Honeycomb core material is a lightweight, high-strength material with excellent dielectric properties and flame retardant properties. It is widely used in aerospace, electronics, shipbuilding and other fields. However, most of the honeycomb core composite panels on the market are sandwich flat panels with a "skin-film-core material" structure. Most of the honeycomb cores are aramid paper honeycombs, glass cloth honeycombs, aluminum honeycombs, etc. The skins are mostly carbon fiber and glass fiber prepregs. The structure and function are single and cannot meet the application requirements in multiple scenarios. In order to expand the scope of use of honeycomb core materials, foam-filled honeycomb products are gradually appearing on the market. However, the foaming agents currently used are mostly polyurethane, polystyrene, etc., which have relatively poor compatibility with honeycomb cores, resulting in the phenomenon of easy detachment and looseness of the foam. In addition, the traditional foaming process makes the adhesion between the honeycomb core and the film after foam filling worse, resulting in a decrease in product performance when forming a composite structural board. Summary of the invention

[0003] The object of the present invention is to provide a foamed honeycomb core composite board and a preparation method thereof. The foamed honeycomb core composite board has excellent mechanical properties and good flame retardancy.

[0004] The present invention solves the technical problem by adopting the following technical solutions.

[0005] The present invention provides a foamed honeycomb core composite panel, comprising an upper skin, a first adhesive film layer, a foamed honeycomb core, a second adhesive film layer, a sound insulation felt, a third adhesive film layer and a lower skin, and a method for preparing the foamed honeycomb core comprises:

[0006] Putting a foamed phenolic resin mixed liquid into a lower mold and an upper mold, putting a honeycomb core into the lower mold along its axial direction, covering the upper mold on the honeycomb core, and performing foaming treatment. After the foaming is completed, removing the lower mold and the upper mold to obtain the foam honeycomb core, wherein the lower mold and the upper mold are both provided with a protrusion adapted to the honeycomb hole of the honeycomb core, and the outer peripheral surface of the protrusion is in contact with the inner wall of the honeycomb hole to form an unfoamed area at the upper and lower ends of the honeycomb hole;

[0007] The first adhesive film layer and the second adhesive film layer enter the unfoamed areas at the upper end and the lower end of the honeycomb holes respectively.

[0008] Furthermore, in a preferred embodiment of the present invention, the preparation process of the foamed phenolic resin mixed solution includes:

[0009] The epoxy soybean oil, dibutylene glycol and porous filler are mixed and heated to react to obtain a modified filler;

[0010] Dispersing the modified filler in a solvent, adding a surfactant, and mixing to obtain a first solution;

[0011] adding a foamed phenolic resin to the first solution and mixing to obtain a second solution;

[0012] A curing agent and a foaming agent are added to the second solution, and the mixture is mixed to obtain the foamed phenolic resin mixed solution.

[0013] Furthermore, in a preferred embodiment of the present invention, the preparation process of the porous filler includes: reacting silicon nitride with a first monomer, a second monomer and a third monomer to form a coating layer on the silicon nitride; dispersing the silicon nitride with the coating layer in a solvent, adding a pore-forming liquid, stirring the reaction, forming a pore structure on the silicon nitride coating layer, washing and drying to obtain an intermediate product; sintering the intermediate product to obtain a porous filler; wherein the first monomer is selected from one or a mixture of melamine and 1,3,5-tri(4-aminophenyl)benzene, the second monomer is selected from one or two of o-phthalaldehyde and 1,3,5-trialdehydebenzene, and the third monomer is selected from one or two of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and [(6-oxy-6H-dibenzo-(C,E)(1,2)-oxaphosphahexanin-6-one)-methyl]-succinic acid.

[0014] Furthermore, in a preferred embodiment of the present invention, the preparation process of the honeycomb core body includes: obtaining a honeycomb core blank, dipping the honeycomb core blank multiple times in a dipping tank containing a phenolic resin solution, and then heating and curing to obtain the honeycomb core body.

[0015] Furthermore, in a preferred embodiment of the present invention, the upper skin and the lower skin are made of fiber fabric prepreg by hot pressing, and the fiber fabric in the fiber fabric prepreg is carbon fiber fabric or glass fiber fabric.

[0016] Furthermore, in a preferred embodiment of the present invention, the sound insulation felt is pre-impregnated in an interface enhancer, and the interface enhancer includes, by weight: 10 to 20 parts of epoxy resin, 50 to 80 parts of acrylic emulsion, 5 to 10 parts of calcined kaolin, 1 to 5 parts of rutile titanium dioxide, 0.1 to 3 parts of benzoyl peroxide and 5 to 10 parts of curing agent.

[0017] Furthermore, in a preferred embodiment of the present invention, the material of the first adhesive film layer, the second adhesive film layer and the third adhesive film layer is epoxy resin adhesive film or polyimide adhesive film.

[0018] Furthermore, in a preferred embodiment of the present invention, the preparation process of the epoxy resin film includes: mixing 80 to 100 parts of epoxy resin, 20 to 40 parts of phenolic resin, 1 to 6 parts of toughening agent and 10 to 20 parts of curing agent in parts by weight to obtain a mixed slurry, and pressing the mixed slurry into a film at 60 to 70°C to obtain the epoxy resin film.

[0019] Furthermore, in a preferred embodiment of the present invention, the axial height of the unfoamed area is 1-3 mm.

[0020] The present invention provides a method for preparing a foamed honeycomb core composite panel as described in any one of the above, comprising:

[0021] Lay the lower skin, the third adhesive film layer, the sound insulation felt, the second adhesive film layer, the foam honeycomb core, the first adhesive film layer and the upper skin in order from bottom to top to obtain a semi-finished product;

[0022] The semi-finished product is subjected to hot pressing molding, the hot pressing temperature is 100-120°C, the heating rate is 2-5°C / min, and the heat preservation is 70-80min;

[0023] After the hot pressing is completed, the foamed honeycomb core composite board is obtained by cooling.

[0024] The foamed honeycomb core composite board and the preparation method thereof according to the embodiment of the present invention have the following beneficial effects:

[0025] The foamed honeycomb core composite panel of the embodiment of the present invention has an upper skin, a first adhesive film layer, a foamed honeycomb core, a second adhesive film layer, a sound insulation felt, a third adhesive film layer and a lower skin, with a total of seven layers of structure, which greatly expands the application range of the honeycomb core composite panel, and the mechanical properties of the product are easy to control, and it has good flame retardant properties and ablation resistance. Among them, the foamed honeycomb core is foamed with phenolic resin, and the interface bonding force between the honeycomb core and the foaming material is stronger. In addition, a special mold is used for foaming, and a certain unfoamed area is reserved at the upper and lower ends of the honeycomb hole. When compounded with the adhesive film, the adhesive film can enter the honeycomb hole to strengthen the bonding strength between the honeycomb core and the adhesive film. In addition, through the synergistic effect of the foamed honeycomb core and the sound insulation felt, the product can have a good sound insulation and damping effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1It is a schematic diagram of the structure of a foamed honeycomb core composite panel provided in an embodiment of the present invention.

[0028] Figure 2 It is a schematic structural diagram of a lower mold and an upper mold provided in an embodiment of the present invention.

[0029] Figure 3 It is a schematic diagram of the composite structure of the first adhesive film layer, the foam honeycomb core and the second adhesive film layer provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0031] The foamed honeycomb core composite board and the preparation method thereof according to the embodiment of the present invention are described in detail below.

[0032] See also Figure 1 As shown, an embodiment of the present invention provides a foamed honeycomb core composite panel, comprising an upper skin 11, a first adhesive film layer 12, a foam honeycomb core 13, a second adhesive film layer 14, a sound insulation felt 15, a third adhesive film layer 16 and a lower skin 17 arranged in sequence.

[0033] The foamed honeycomb core composite panel of this embodiment is different from the existing "sandwich" structure and adopts a seven-layer composite structure. The product has more superior mechanical properties, good flame retardancy, and sound insulation and damping functions, and can meet application requirements in multiple scenarios.

[0034] In one embodiment, the upper skin 11 and the lower skin 17 are made of fiber fabric prepreg by hot pressing, and the fiber fabric in the fiber fabric prepreg is carbon fiber fabric or glass fiber fabric. The resin matrix in the fiber fabric prepreg can be one or more of epoxy resin, cyanate resin and PET resin. Different fiber fabrics and resin matrices can be selected according to different usage scenarios to meet the needs of different scenarios.

[0035] In one embodiment, the materials of the first adhesive film layer 12 , the second adhesive film layer 14 and the third adhesive film layer 16 are epoxy resin films or polyimide films.

[0036] Further preferably, the materials of the first film layer 12, the second film layer 14 and the third film layer 16 are epoxy resin films, and the preparation process of the epoxy resin film includes: according to weight parts, 80-100 parts of epoxy resin, 20-40 parts of phenolic resin, 1-6 parts of toughening agent and 10-20 parts of curing agent are mixed to obtain a mixed slurry, and the mixed slurry is pressed into a film at 60-70°C to obtain an epoxy resin film. Among them, the toughening agent can be, for example, ethylene propylene rubber, polybutadiene rubber, butyl rubber, etc., and the curing agent can be, for example, polyether amine, isophorone diamine, methyl cyclohexane diamine, etc. The epoxy resin film is modified by adding phenolic resin and toughening agent, so that it can be better composited with other structures and effectively improve the mechanical properties of the product.

[0037] See also Figure 2 In one embodiment, the preparation method of the foam honeycomb core 13 includes: placing a foamed phenolic resin mixture in a lower mold 21 and an upper mold 22, placing a honeycomb core 131 into the lower mold 21 along its axial direction, covering the upper mold 22 on the honeycomb core 131, and performing foaming treatment. After the foaming is completed, the lower mold 21 and the upper mold 22 are removed to obtain the foam honeycomb core 13.

[0038] Specifically, the lower mold 21 and the upper mold 22 are both provided with a protrusion 23 adapted to the honeycomb holes of the honeycomb core 131, and the outer peripheral surface of the protrusion 23 is in contact with the inner wall of the honeycomb hole to form an unfoamed area at the upper and lower ends of the honeycomb hole. Figure 3 The first adhesive film layer 12 and the second adhesive film layer 14 enter the unfoamed areas at the upper and lower ends of the honeycomb holes respectively, thereby effectively improving the bonding strength between the adhesive film and the honeycomb core.

[0039] Furthermore, in one embodiment, the axial height of the unfoamed area is 1-3 mm. Within this range, sufficient foaming is ensured and the adhesive film can enter the inner wall of the honeycomb hole during the hot pressing process to form a good bonding effect with the foam honeycomb core.

[0040] In one embodiment, the preparation process of the honeycomb core 131 includes: obtaining a honeycomb core blank, dipping the honeycomb core blank in a dipping tank containing a phenolic resin solution for multiple times, and then heating and curing to obtain a honeycomb core. The honeycomb core blank can be formed by gluing, laminating, pressing, curing, and stretching a paper or cloth material. The specific preparation process can be carried out according to the prior art and will not be described in detail here. The paper material can be, for example, aramid paper, and the cloth material can be, for example, glass fiber cloth.

[0041] In one embodiment, the preparation process of the foamed phenolic resin mixture includes: mixing 10-20 parts of epoxidized soybean oil, 1-5 parts of diaminobutane and 1-5 parts of porous filler by weight, heating and reacting at 100-150° C. to obtain a modified filler. The modified filler is dispersed in 20 parts of a solvent, 0.1-3 parts of a surfactant are added, and the mixture is stirred and mixed to obtain a first solution. The solvent may be ethanol, isopropanol, etc. The surfactant may be, for example, sodium dodecylbenzene sulfonate, Tween-80, etc.

[0042] Then, 100 parts of foaming phenolic resin are added to the first solution, and the mixture is stirred to obtain a second solution; 5-10 parts of curing agent and 2-7 parts of foaming agent are added to the second solution, and the mixture is stirred to obtain a foaming phenolic resin mixed solution. The curing agent is selected from one or more of toluenesulfonic acid, oxalic acid, acetic acid, sulfuric acid, hydrochloric acid, phosphoric acid and boric acid. The foaming agent is selected from one or more of cyclohexane, sodium carbonate, sodium bicarbonate, ammonium carbonate and ammonium bicarbonate.

[0043] In the preparation process of the above foamed phenolic resin mixture, the epoxy soybean oil has good heat resistance, water resistance and mechanical strength. The epoxy group is introduced into the porous filler through the cross-linking of the epoxy soybean oil and diamine. During the foaming, a stable connection effect is formed in the foamed phenolic resin. The toughness and sound insulation performance of the foamed honeycomb core are effectively improved after foaming.

[0044] Furthermore, the preparation process of the porous filler includes: reacting silicon nitride with a first monomer, a second monomer and a third monomer at 15 to 40° C. for 5 to 15 hours according to weight proportions to form a coating layer on the silicon nitride; dispersing the silicon nitride with the coating layer in a solvent, adding a pore-forming liquid, stirring and reacting for 10 to 20 hours, forming a pore structure on the silicon nitride coating layer, washing and drying to obtain an intermediate product; and sintering the intermediate product to obtain a porous filler. The first monomer is selected from one or a mixture of melamine and 1,3,5-tris(4-aminophenyl)benzene, the second monomer is selected from one or both of o-phthalaldehyde and 1,3,5-trialdehydebenzene, and the third monomer is selected from one or both of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and [(6-oxy-6H-dibenzo-(C,E)(1,2)-oxaphosphahexanin-6-one)-methyl]-succinic acid. The pore-forming fluid is a propylamine solution or an ethylenediamine solution, and the concentration of the pore-forming fluid is 0.02-0.06 mol / L.

[0045] The core of the porous filler is silicon nitride, and the outer shell is a coating layer doped with N and P. The first monomer, the second monomer, and the third monomer undergo an aldehyde-amine condensation polymerization reaction during the reaction to generate a polymer cross-linked network structure, and then the polymer network is etched under the action of a pore-forming agent to form a pore structure. The pore structure can promote the penetration of the foamed phenolic resin, improve the composite strength, and strengthen and toughen the foamed resin. The doped nitrogen and phosphorus elements can give the product better flame retardant properties.

[0046] In one embodiment, the sound insulation felt 15 is pre-impregnated in an interface enhancer, and the interface enhancer includes, by weight, 10-20 parts of epoxy resin, 50-80 parts of acrylic emulsion, 5-10 parts of calcined kaolin, 1-5 parts of rutile titanium dioxide, 0.1-3 parts of benzoyl peroxide, and 5-10 parts of curing agent. By pre-impregnating the sound insulation felt in the interface enhancer, the bonding strength between the sound insulation felt and the adhesive film can be improved, and the sound insulation felt can be given better tensile strength.

[0047] It should be noted that the sound insulation felt can be obtained through commercially available products. The sound insulation felt and the foam honeycomb core work together to exert a better sound insulation and damping effect.

[0048] The embodiment of the present invention also provides a method for preparing the above-mentioned foamed honeycomb core composite board, which comprises: laying the lower skin, the third adhesive film layer, the sound insulation felt, the second adhesive film layer, the foamed honeycomb core, the first adhesive film layer and the upper skin in order from bottom to top to obtain a semi-finished product; hot pressing the semi-finished product, the hot pressing temperature is 100-120°C, the heating rate is 2-5°C / min, and the heat preservation is 70-80min; after the hot pressing is completed, cooling is performed to obtain the foamed honeycomb core composite board. The preparation method is simple and easy to operate.

[0049] The foamed honeycomb core composite board and the preparation method thereof of the present invention are further described in detail below in conjunction with the embodiments.

[0050] Embodiment 1: This embodiment provides a foamed honeycomb core composite board, which is prepared according to the following steps:

[0051] (1) Preparation of skin: 100 parts of epoxy resin, 20 parts of cyanate resin and 10 parts of curing agent (isophorone diamine) were mixed by weight to obtain a resin matrix, and the carbon fiber cloth was mixed with the resin matrix and heated and cured to obtain an upper skin. The lower skin was prepared by the same method.

[0052] (2) Preparation of adhesive film: According to weight proportions, 90 parts of epoxy resin, 20 parts of phenolic resin, 5 parts of polybutadiene rubber and 15 parts of curing agent (polyetheramine) were mixed and stirred, and then pressed into a film at 65° C. to obtain an adhesive film.

[0053] (3) Preparation of foamed phenolic resin mixed solution: 16 parts of epoxy soybean oil, 4 parts of diaminobutane and 5 parts of porous filler were mixed by weight, nitrogen was introduced, and the mixture was heated at 120°C for 2 hours to obtain a modified filler. The modified filler was dispersed in 20 parts of ethanol, 2 parts of sodium dodecylbenzene sulfonate were added, and the mixture was stirred to obtain solution A. 100 parts of foamed phenolic resin were added to solution A, and the mixture was stirred to obtain solution B. 7 parts of toluenesulfonic acid and 3 parts of sodium carbonate were added to solution B, and the mixture was stirred to obtain a foamed phenolic resin mixed solution.

[0054] The preparation process of the porous filler is as follows: according to the weight percentage, 100 parts of silicon nitride are dispersed in 500 parts of ethanol to obtain a matrix liquid. 3.4 parts of melamine, 4.1 parts of o-phthalaldehyde and 2.5 parts of [(6-oxy-6H-dibenzo-(C,E)(1,2)-oxophosphorin-6-one)-methyl]-succinic acid are dispersed in ethanol to obtain liquid a, liquid b and liquid c respectively. Liquid a, liquid b and liquid c are slowly added to the matrix liquid in sequence, and after the addition is completed, the reaction is carried out at 30°C for 14 hours, and after centrifugation, washing and drying, a coating is obtained. The coating is placed in a 0.04 mol / L ethylenediamine solution, stirred at room temperature for 20 hours, and centrifuged, washed and dried to obtain an intermediate product. The intermediate product is sintered at 580°C for 3 hours in a nitrogen atmosphere to obtain a porous filler.

[0055] (4) Preparation of honeycomb core: Use multiple layers of aramid paper to glue and stack to obtain a stacked block, and then heat press, stretch and characterize the stacked block to obtain a honeycomb core blank. The honeycomb core blank is dipped in a dip tank containing a phenolic resin solution for multiple times, and then heated and cured at 160°C for 2 hours to obtain a honeycomb core.

[0056] (5) Preparation of foam honeycomb core: according to Figure 2 As shown, the foamed phenolic resin mixture obtained in step (3) is placed in a lower mold and an upper mold, the honeycomb core is placed in the lower mold, the upper mold is closed, and the mold is placed in an oven for foaming at a foaming temperature of 85°C for 60 minutes. After the foaming is completed, the mold is cooled, and the upper and lower molds are removed to obtain a foamed honeycomb core. A gap of about 2 mm is formed at the upper and lower ends of the honeycomb holes of the foamed honeycomb core.

[0057] (6) Assembly and hot pressing: Cut the upper skin, lower skin, sound insulation felt, adhesive film and foam honeycomb core into corresponding sizes, and lay them in the order of lower skin, adhesive film, sound insulation felt, adhesive film, foam honeycomb core, adhesive film and upper skin to obtain semi-finished products. Place the semi-finished products in a hot press for hot pressing. Set the hot press temperature to 120°C, the heating rate to 3°C / min, and keep warm for 80 minutes to obtain a foamed honeycomb core composite board.

[0058] Example 2: This example provides a foamed honeycomb core composite board, which is different from Example 1 in that the sound insulation felt is pretreated as follows: the sound insulation felt is immersed in an interface enhancer for 20 minutes. In terms of weight, the interface enhancer includes: 12 parts of epoxy resin, 68 parts of acrylic emulsion, 7 parts of calcined kaolin, 2 parts of rutile titanium dioxide, 0.5 parts of benzoyl peroxide and 6 parts of curing agent.

[0059] Example 3. This example provides a foamed honeycomb core composite board, which differs from Example 1 in that: in step (3), the foamed phenolic resin mixed solution is prepared by dispersing 5 parts of porous filler (the same as in Example 1) in 20 parts of ethanol by weight, adding 2 parts of sodium dodecylbenzene sulfonate, and stirring to obtain solution A. 100 parts of foamed phenolic resin are added to solution A, and after stirring to obtain solution B. 7 parts of toluenesulfonic acid and 3 parts of sodium carbonate are added to solution B, and stirred to obtain a foamed phenolic resin mixed solution.

[0060] Embodiment 4, this embodiment provides a foamed honeycomb core composite board, which is different from Embodiment 1 in that: in step (3), the foamed phenolic resin mixed solution is prepared by mixing 16 parts of epoxy soybean oil, 4 parts of diaminobutane and 5 parts of silicon nitride by weight, introducing nitrogen, and heating the mixture at 120°C for 2 hours to obtain a modified filler. The modified filler is dispersed in 20 parts of ethanol, 2 parts of sodium dodecylbenzene sulfonate are added, and the mixture is stirred and mixed to obtain a solution A. 100 parts of foamed phenolic resin are added to solution A, and the mixture is stirred and mixed to obtain a solution B. 7 parts of toluenesulfonic acid and 3 parts of sodium carbonate are added to solution B, and the mixture is stirred and mixed to obtain a foamed phenolic resin mixed solution.

[0061] Comparative Example 1

[0062] This comparative example provides a foamed honeycomb core composite board, which differs from Example 1 in that: in step (5), the upper mold and the lower mold do not have protrusions adapted to the honeycomb holes, and the upper and lower ends of the honeycomb holes are filled with foamed material without any gaps.

[0063] Comparative Example 2

[0064] This comparative example provides a foamed honeycomb core composite board, which is different from comparative example 1 in that: in step (3), the foamed phenolic resin mixed solution is prepared by adding 100 parts of foamed phenolic resin to 20 parts of ethanol by weight, stirring and mixing to obtain solution B. 7 parts of toluenesulfonic acid and 3 parts of sodium carbonate are added to solution B, stirring and mixing to obtain a foamed phenolic resin mixed solution.

[0065] The properties of the samples prepared in Examples 1 to 4 and Comparative Examples 1 to 2 were tested, and the test results are shown in Table 1. The compression strength and peel strength were measured using a universal testing machine CMT6104. The noise reduction coefficient was measured in accordance with GB / T 20247-2006. The thermal conductivity was measured in accordance with GB / T 10294-2008.

[0066] Table 1

[0067] project Compression strength, MPa Peel strength, N / cm Noise Reduction Coefficient Thermal conductivity, W / m·K Example 1 7.71 56 0.82 0.010 Example 2 8.24 61 0.87 0.009 Example 3 7.26 54 0.78 0.013 Example 4 7.05 56 0.70 0.020 Comparative Example 1 6.94 42 0.63 0.018 Comparative Example 2 5.18 37 0.49 0.039

[0068] The embodiments described above are part of the embodiments of the present invention, rather than all of the embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. 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.

Claims

1. A foamed honeycomb core composite panel, characterized in that: The method comprises sequentially arranging an upper skin, a first adhesive film layer, a foam honeycomb core, a second adhesive film layer, a sound insulation felt, a third adhesive film layer and a lower skin, wherein the method for preparing the foam honeycomb core comprises: Putting a foamed phenolic resin mixed liquid into a lower mold and an upper mold, putting a honeycomb core into the lower mold along its axial direction, covering the upper mold on the honeycomb core, and performing foaming treatment. After the foaming is completed, removing the lower mold and the upper mold to obtain the foam honeycomb core, wherein the lower mold and the upper mold are both provided with a protrusion adapted to the honeycomb hole of the honeycomb core, and the outer peripheral surface of the protrusion is in contact with the inner wall of the honeycomb hole to form an unfoamed area at the upper and lower ends of the honeycomb hole; The first adhesive film layer and the second adhesive film layer enter the unfoamed areas at the upper and lower ends of the honeycomb holes respectively; Wherein, the preparation process of the foamed phenolic resin mixed solution comprises: The epoxy soybean oil, dibutylene glycol and porous filler are mixed and heated to react to obtain a modified filler; Dispersing the modified filler in a solvent, adding a surfactant, and mixing to obtain a first solution; adding a foamed phenolic resin to the first solution and mixing to obtain a second solution; Adding a curing agent and a foaming agent into the second solution, and mixing to obtain the foamed phenolic resin mixed solution; The preparation process of the porous filler comprises: reacting silicon nitride with a first monomer, a second monomer and a third monomer to form a coating layer on the silicon nitride; dispersing the silicon nitride with the coating layer in a solvent, adding a pore-forming liquid, stirring and reacting, forming a pore structure on the silicon nitride coating layer, washing and drying to obtain an intermediate product; sintering the intermediate product to obtain a porous filler; wherein the first monomer is selected from one or a mixture of melamine and 1,3,5-tri(4-aminophenyl)benzene, the second monomer is selected from one or two of o-phthalaldehyde and 1,3,5-trialdehydebenzene, and the third monomer is selected from one or two of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and [(6-oxy-6H-dibenzo-(C,E)(1,2)-oxaphosphahexanin-6-one)-methyl]-succinic acid.

2. The foamed honeycomb core composite panel according to claim 1, characterized in that: The preparation process of the honeycomb core body comprises: obtaining a honeycomb core blank, dipping the honeycomb core blank in a dipping tank containing a phenolic resin solution for multiple times, and then heating and curing the honeycomb core body.

3. The foamed honeycomb core composite panel according to claim 1, characterized in that: The upper skin and the lower skin are made of fiber fabric prepreg by hot pressing, and the fiber fabric in the fiber fabric prepreg is carbon fiber fabric or glass fiber fabric.

4. The foamed honeycomb core composite panel according to claim 1, characterized in that: The sound insulation felt is pre-impregnated in an interface enhancer, which includes, by weight, 10 to 20 parts of epoxy resin, 50 to 80 parts of acrylic emulsion, 5 to 10 parts of calcined kaolin, 1 to 5 parts of rutile titanium dioxide, 0.1 to 3 parts of benzoyl peroxide and 5 to 10 parts of a curing agent.

5. The foamed honeycomb core composite panel according to claim 1, characterized in that: The materials of the first adhesive film layer, the second adhesive film layer and the third adhesive film layer are epoxy resin adhesive film or polyimide adhesive film.

6. The foamed honeycomb core composite panel according to claim 5, characterized in that: The preparation process of the epoxy resin film includes: mixing 80-100 parts of epoxy resin, 20-40 parts of phenolic resin, 1-6 parts of toughening agent and 10-20 parts of curing agent by weight to obtain a mixed slurry, and pressing the mixed slurry into a film at 60-70° C. to obtain the epoxy resin film.

7. The foamed honeycomb core composite panel according to claim 1, characterized in that: The axial height of the unfoamed zone is 1 to 3 mm.

8. A method for preparing a foamed honeycomb core composite board according to any one of claims 1 to 7, characterized in that: include: Lay the lower skin, the third adhesive film layer, the sound insulation felt, the second adhesive film layer, the foam honeycomb core, the first adhesive film layer and the upper skin in order from bottom to top to obtain a semi-finished product; The semi-finished product is subjected to hot pressing molding, the hot pressing temperature is 100-120°C, the heating rate is 2-5°C / min, and the heat preservation is 70-80min; After the hot pressing is completed, the foamed honeycomb core composite board is obtained by cooling.

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