A2 grade halogen-free flame retardant fireproof aluminum-plastic composite panel and preparation method thereof

Abstract

The invention discloses an A2-level halogen-free flame-retardant and fireproof aluminum-plastic composite board and a preparation method thereof, and belongs to the technical field of special composite material preparation. The aluminum-plastic composite board comprises an aluminum panel and a core material. The core material is prepared by using 3-amino-4-hydroxybenzoic acid and trimellitic anhydride as raw materials to prepare a modified polyester monomer having a phenolic benzimide group, and then using hydroxylated norbornene benzimide as an initiator to copolymerize with phthalic anhydride, styrene oxide and the modified polyester monomer to prepare an intermediate product, and finally the intermediate product is copolymerized with ethylene under the action of a catalyst to prepare the intermediate product. The invention provides an A2-level halogen-free flame-retardant and fireproof aluminum-plastic composite board and a preparation method thereof by modifying components on the basis of polyethylene, and improves the flame retardancy of the aluminum-plastic board on the basis of keeping the organic core material light.

Description

Technical Field

[0001] The invention relates to the technical field of special composite material preparation, and in particular to an A2-grade halogen-free flame-retardant fireproof aluminum-plastic composite board and a preparation method thereof. Background Art

[0002] Aluminum Composite Panel (ACP) is a composite panel made of two layers of aluminum plates and a polyethylene (PE) plastic core layer in the middle, which are continuously compounded at high temperature through a polymer adhesive film; the unique properties of the aluminum composite panel itself determine its wide range of uses: it can be used for building exterior walls, curtain wall panels, renovation of old buildings, interior wall and ceiling decoration, advertising signs, display stands, purification and dust prevention projects, and is a new type of building decoration material. Once ordinary aluminum-plastic panels are caught in fire, the spread speed is very rapid, and it is difficult for the fire department to take emergency response. Ordinary aluminum-plastic panels will produce a large amount of thick smoke after being caught in fire, accompanied by a large amount of toxic asphyxiating gas, and a large amount of dripping will be produced, which will cause great harm and safety hazards to national property and personal safety. In view of the shortcomings and deficiencies of ordinary aluminum-plastic panels, such as easy combustion and non-fireproof. Many experts and factories in the industry have done a lot of exploration, research and efforts in fire resistance, and have improved the fire resistance of aluminum-plastic panels by adding some flame retardants (such as magnesium hydroxide, etc.) in the middle plastic core layer. To delay the burning time, thus creating conditions for the escape of personnel and the fire fighting time of the fire department, we call this kind of aluminum-plastic panel with fireproof function fireproof aluminum-plastic panel. At present, the main fireproof aluminum-plastic panel on the market is the fireproof grade B. However, no matter how the aluminum-plastic panel is improved, the B-grade fireproof aluminum-plastic panel still has the fire hazard of burning because the middle core material contains a certain proportion of low-density polyethylene plastic components. When burning, it will produce a lot of smoke and dripping, which only has a certain effect of preventing and delaying the burning.

[0003] The mainstream aluminum-plastic panels in the market can meet the Class B fire protection standard, but with the improvement of fire protection requirements in various countries around the world, Class B aluminum-plastic panels can no longer meet the regulations and market requirements, especially in some high-rise buildings, Class B fireproof aluminum-plastic panels have obvious safety hazards. Class A2 fireproof aluminum-plastic panels are significantly better than Class B fireproof aluminum-plastic panels in terms of fire protection indicators such as flame retardancy, smoke release, and heat release. Therefore, whether from an industrial or policy level, Class A2 fireproof aluminum-plastic panels are a key development direction in the field of aluminum-plastic panels in the future. A2ACP not only has the advantages of ordinary ACP, but also makes up for the shortcomings of ordinary ACP in terms of fire protection level, environmental protection and board strength; but the existing A2ACP mostly uses non-combustible inorganic materials as core materials, and its flame retardant effect is excellent, but its own specific gravity is large, which greatly limits its application. Summary of the invention

[0004] In view of the above problems, the present invention provides an A2-grade halogen-free flame-retardant and fireproof aluminum-plastic composite panel and a preparation method thereof.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] An A2-grade halogen-free flame-retardant aluminum-plastic composite panel comprises an aluminum panel and a core material, wherein a method for preparing the core material comprises the following steps:

[0007] S1. Weigh 3-amino-4-hydroxybenzoic acid and dissolve it in methylpyrrolidone solvent, add trimellitic anhydride, heat to 70-80° C. under protective atmosphere and keep warm, stir and reflux for 1-2 hours, add deionized water to the reaction system after the reaction is completed, stir well and separate the precipitate, wash the precipitate and dissolve it in methanol, add sulfuric acid solution and stir and reflux for 12-20 hours, add deionized water to the reaction system after the reaction is completed, stir well and separate the precipitate, wash and dry the precipitate to obtain a modified monomer;

[0008] S2, respectively adding cis-5-borneol-2,3-dicarboxylic anhydride, ethanolamine and triethylamine to the solvent, fully mixing and stirring to reflux for 6-10h, adding dichloromethane to extract after cooling, washing with hydrochloric acid solution and evaporating the solvent under reduced pressure to obtain an imine product; adding the imine product, phthalic anhydride and the modified monomer to tetrahydrofuran solvent, stirring and mixing, then adding styrene oxide and phosphazene base catalyst, stirring and reacting at 60-70°C for 1-3d, and evaporating the solvent under reduced pressure to obtain an intermediate product;

[0009] S3, copolymerizing the intermediate product with ethylene in the presence of a catalyst to obtain the product; wherein the catalyst comprises a main catalyst and a co-catalyst.

[0010] In some preferred embodiments, the mass ratio of the 3-amino-4-hydroxybenzoic acid to the trimellitic anhydride in step S1 is 1:(1.2-1.4).

[0011] In some preferred embodiments, the mass ratio of the cis-5-norborneol-2,3-dicarboxylic anhydride to the ethanolamine and the triethylamine in step S2 is 1:(0.28-0.35):(0.08-0.1).

[0012] In some preferred embodiments, the mass ratio of the imine product to the phthalic anhydride, the modified monomer, the styrene oxide, and the phosphazene base catalyst in step S2 is (0.5-0.6):(6-7):(1.6-2):10:(0.05-0.08).

[0013] In some preferred embodiments, the phosphazene base catalyst is tert-butylimino-tris(dimethylamino)phosphorane, tert-octylimino-tris(dimethylamino)phosphorane, tert-butylimino-tris(pyrrolidine)phosphine or 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphine.

[0014] In some preferred embodiments, in step S3, the ratio of the intermediate product to the ethylene is 60-300 g / 1 atm; the mass ratio of the intermediate product to the main catalyst is (1000-10000):1; the mass ratio of the main catalyst to the co-catalyst is 1:(100-1000).

[0015] In some preferred embodiments, the main catalyst is a metallocene catalyst, and the co-catalyst is an alkylaluminoxane or an alkylaluminum.

[0016] In some preferred embodiments, the metallocene catalyst is (2,6-diisopropylphenol)indenyl dimethyl zirconium, (2,6-di-tert-butylphenol)indenyl dimethyl zirconium, (2,6-difluorophenol)indenyl dimethyl zirconium, (2,4,6-trichlorophenol)indenyl dimethyl zirconium, (2-dibenzhydryl-4,6-dimethylphenol)indenyl dimethyl zirconium, (2,6-bis(dibenzhydryl)-4-methylphenol)indenyl dimethyl zirconium, (2,6-diisopropylphenol)indenyl dibenzyl zirconium or (2,6-di-tert-butylphenol)indenyl dibenzyl zirconium.

[0017] In some preferred embodiments, the alkylaluminoxane is methylaluminoxane, and the alkylaluminum is triisobutylaluminum.

[0018] In some preferred embodiments, in order to further improve the flame retardant performance, a certain amount of inorganic flame retardant material, such as magnesium hydroxide, etc., may be added to the core material.

[0019] Another aspect of the present invention is to provide a method for preparing the A2-grade halogen-free flame-retardant aluminum-plastic composite panel, comprising the following steps:

[0020] (1) Core material preparation

[0021] The core material is extruded and hot-cut into granules by an extruder, plasticized into sheets by an open mill, and the required composite board core material is obtained after cooling for standby use;

[0022] (2) Plate preparation

[0023] The core material of the composite board is sequentially subjected to upper and lower adhesive films and upper and lower aluminum panels. After preheating, it is heat-bonded and hot-pressed so that the core material is located between the two aluminum panels. It is cold-pressed and shaped. After cooling to room temperature, it is cut to obtain finished products that meet size standards.

[0024] The beneficial effects of the present invention are:

[0025] Aiming at the problem that the flame retardancy of aluminum-plastic composite panels based on ethylene core materials in the prior art is not high and the specific gravity of composite panels with inorganic core materials is too large, the present invention provides an A2-grade halogen-free flame retardant and fireproof aluminum-plastic composite panel and a preparation method thereof by modifying components on the basis of polyethylene, thereby improving the flame retardancy of the aluminum-plastic panel while maintaining the lightness of the organic core material. Specifically, the present invention uses 3-amino-4-hydroxybenzoic acid and trimellitic anhydride as raw materials to prepare a modified polyester monomer having a phenolic benzimide group, and then uses hydroxylated norbornene benzimide as an initiator to copolymerize with phthalic anhydride, styrene oxide and the modified polyester monomer to obtain an intermediate product, and finally The intermediate product is prepared by copolymerization with ethylene under the action of a catalyst. The present invention introduces the modified monomer containing the phenolic benzimide group into the polymer side chain of the core material resin material through a secondary copolymerization reaction. On the one hand, branching helps to improve the crosslinking degree of the resin and improve the mechanical properties of the core material. On the other hand, based on the phenolic benzimide group introduced into the core material resin, it is converted into benzoxazole under high temperature conditions and releases non-flammable carbon dioxide gas and water vapor. At the same time, the generated benzoxazole can also react with the carboxyl group of the polyester end group cracked at high temperature to reduce the high temperature resistance of the resin, thereby improving the flame retardant properties of the core material. DETAILED DESCRIPTION

[0026] The present invention is further described in conjunction with the following examples.

[0027] Embodiment 1, an A2-grade halogen-free flame-retardant aluminum-plastic composite panel, comprising an aluminum panel and a core material, wherein the preparation method of the core material comprises the following steps:

[0028] S1. Weigh 3-amino-4-hydroxybenzoic acid and dissolve it in methylpyrrolidone solvent, add trimellitic anhydride, heat to 76°C under nitrogen atmosphere and keep warm, stir and reflux for 1.5h, add deionized water to the reaction system after the reaction is completed, stir well and separate the precipitate, wash the precipitate and dissolve it in methanol (10g / L), add an equal volume of sulfuric acid solution (3.0mol / L) and stir and reflux for 16h, add deionized water to the reaction system after the reaction is completed to precipitate the product, stir well and separate the precipitate, wash and dry the precipitate to obtain a modified monomer; wherein, the mass ratio of the 3-amino-4-hydroxybenzoic acid to the trimellitic anhydride is 1:1.25;

[0029] S2. Add cis-5-borneol-2,3-dicarboxylic anhydride, ethanolamine and triethylamine to toluene solvent respectively, mix thoroughly and stir to reflux for reaction for 8 hours, add dichloromethane to extract after cooling, wash with hydrochloric acid solution (1.0 mol / L) and evaporate the solvent under reduced pressure to obtain an imine product; add the imine product, phthalic anhydride and the modified monomer to tetrahydrofuran solvent, stir thoroughly and then add styrene oxide and phosphazene base catalyst, keep warm and stir at 70°C for reaction for 60 hours, reduce The solvent is removed by pressure evaporation to obtain an intermediate product; wherein the mass ratio of the cis-5-borneol-2,3-dicarboxylic anhydride to the ethanolamine and the triethylamine is 1:0.32:0.08, the phosphazene base catalyst is tert-butylimino-tris(dimethylamino)phosphorane, and the mass ratio of the imine product to the phthalic anhydride, the modified monomer, the styrene oxide, and the tert-butylimino-tris(dimethylamino)phosphorane is 0.54:6.3:1.72:10:0.06;

[0030] S3, the intermediate product and ethylene are copolymerized under the action of a main catalyst and a co-catalyst to obtain the product. Specifically, the intermediate product is added to a polymerization container, the container is evacuated and then filled with nitrogen, the evacuation and filling are repeated 3 times, and then evacuated, and 1 atm ethylene is filled into the container under the control of a solenoid valve, a toluene solution of the co-catalyst is added, the temperature is raised to 70°C, a toluene solution of the main catalyst is added, and timing is started. When ethylene is consumed, the solenoid valve automatically replenishes and maintains at 1 atm. After reacting for 2 hours, ethylene is turned off, and a mixed solution of concentrated hydrochloric acid and anhydrous ethanol (v / v) is added. =1 / 30), stirred for 6 hours, separated and precipitated, washed and dried to obtain; wherein the main catalyst is (2,6-diisopropylphenol) indenyl dimethyl zirconium, the co-catalyst is methylaluminoxane; the ratio of the intermediate product to the ethylene is 100g / 1atm; the mass ratio of the intermediate product to the main catalyst is 10000:1; the mass ratio of the main catalyst to the co-catalyst is 1:1000; the ratio of the intermediate product to the mixed solution of concentrated hydrochloric acid and anhydrous ethanol is 1g / 50mL;

[0031] The preparation method of the A2 grade halogen-free flame retardant and fireproof aluminum-plastic composite panel comprises the following steps:

[0032] (1) Preparation of core material: the core material is extruded by an extruder, hot-cut and granulated, plasticized by an open mill into sheets, and cooled to obtain the required composite board core material for standby use;

[0033] (2) Plate preparation: The core material of the composite plate is subjected to upper and lower adhesive films and upper and lower aluminum panels in turn. After preheating, it is hot-bonded and hot-pressed so that the core material is located between the two aluminum panels. It is cold-pressed and shaped. After cooling to room temperature, it is cut to obtain finished products that meet size standards.

[0034] Embodiment 2, a fireproof aluminum-plastic composite panel, comprising an aluminum panel and a core material, wherein the preparation method of the core material comprises the following steps:

[0035] S1. Add cis-5-borneol-2,3-dicarboxylic anhydride, ethanolamine and triethylamine to toluene solvent respectively, mix thoroughly and stir to reflux for reaction for 8 hours, add dichloromethane to extract after cooling, wash with hydrochloric acid solution (1.0 mol / L) and evaporate the solvent under reduced pressure to obtain an imine product; add the imine product and phthalic anhydride to tetrahydrofuran solvent, stir thoroughly and then add styrene oxide and phosphazene base catalyst, and stir and react at 70°C for 60 hours. , the solvent is evaporated under reduced pressure to obtain an intermediate product; wherein the mass ratio of the cis-5-borneol-2,3-dicarboxylic anhydride to the ethanolamine and the triethylamine is 1:0.32:0.08, the phosphazene base catalyst is tert-butylimino-tri(dimethylamino)phosphorane, and the mass ratio of the imine product to the phthalic anhydride, the styrene oxide and the tert-butylimino-tri(dimethylamino)phosphorane is 0.54:6.3:10:0.06;

[0036] S2. The intermediate product is copolymerized with ethylene under the action of a main catalyst and a co-catalyst to obtain the product. Specifically, the intermediate product is added to a polymerization container, the container is evacuated and then filled with nitrogen, the evacuation and filling are repeated 3 times, and then evacuated, and 1 atm ethylene is filled into the container under the control of a solenoid valve, a toluene solution of the co-catalyst is added, the temperature is raised to 70° C., a toluene solution of the main catalyst is added, and timing is started. When ethylene is consumed, the solenoid valve automatically replenishes and maintains at 1 atm. After reacting for 2 hours, ethylene is turned off, and a mixed solution of concentrated hydrochloric acid and anhydrous ethanol (v / v) is added. =1 / 30), stirred for 6 hours, separated and precipitated, washed and dried to obtain; wherein the main catalyst is (2,6-diisopropylphenol) indenyl dimethyl zirconium, the co-catalyst is methylaluminoxane; the ratio of the intermediate product to the ethylene is 100g / 1atm; the mass ratio of the intermediate product to the main catalyst is 10000:1; the mass ratio of the main catalyst to the co-catalyst is 1:1000; the ratio of the intermediate product to the mixed solution of concentrated hydrochloric acid and anhydrous ethanol is 1g / 50mL;

[0037] The preparation method of the fireproof aluminum-plastic composite panel is the same as that of Example 1.

[0038] In contrast, a fireproof aluminum-plastic composite panel comprises an aluminum panel and a core material, wherein the core material is low-density polyethylene.

[0039] Experimental example: The fireproof performance of the aluminum-plastic composite panels described in Example 1, Example 2 and the comparative example was tested and compared, and the comparison results are as follows:

[0040] Inspection items unit Performance Indicators Detection Methods Example 1 Example 2 Comparative Example Oxygen Index % ≥32 GB / T2406-2009 37.2 24.6 17.4 Combustion heat value MJ / Kg ≤3.0 GB / T14402-2016 2.7 19.8 43.6 Burning Growth Rate Index W / s ≤120 GB / T20284-2006 102 159 197 Total heat release within 600sTHR600s MJ ≤ 7.5 GB / T20284-2006 4.9 9.0 11.6 Flame lateral spread length m ≤ Sample edge GB / T20284-2006 qualified qualified Failure Burning time s ≤ 20 GB / T5464-2010 10 22 30 Breaking strength MPa ≥20 GB / T1040-2018 26.8 18.9 15.4 Elongation % ≥30 GB / T1040-2018 64.2 67.5 75.4 Roller peel strength N / cm ≥120 GB / T17748-2016 143 147 136 Saturated water absorption % ≤ 0.5 GB / T1034-2008 0.22 0.25 0.22

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. An A2 grade halogen-free flame retardant aluminum-plastic composite panel, comprising an aluminum panel and a core material, characterized in that: The method for preparing the core material comprises the following steps: S1. Weigh 3-amino-4-hydroxybenzoic acid and dissolve it in methylpyrrolidone solvent, add trimellitic anhydride, heat to 70-80° C. under protective atmosphere and keep warm, stir and reflux for 1-2 hours, add deionized water to the reaction system after the reaction is completed, stir well and separate the precipitate, wash the precipitate and dissolve it in methanol, add sulfuric acid solution and stir and reflux for 12-20 hours, add deionized water to the reaction system after the reaction is completed, stir well and separate the precipitate, wash and dry the precipitate to obtain a modified monomer; S2, respectively adding cis-5-borneol-2,3-dicarboxylic anhydride, ethanolamine and triethylamine to the solvent, fully mixing and stirring to reflux for 6-10h, adding dichloromethane to extract after cooling, washing with hydrochloric acid solution and evaporating the solvent under reduced pressure to obtain an imine product; adding the imine product, phthalic anhydride and the modified monomer to tetrahydrofuran solvent, stirring and mixing, then adding styrene oxide and phosphazene base catalyst, stirring and reacting at 60-70°C for 1-3d, and evaporating the solvent under reduced pressure to obtain an intermediate product; S3, copolymerizing the intermediate product with ethylene under the action of a catalyst to obtain a catalyst; wherein the catalyst comprises a main catalyst and a co-catalyst; The mass ratio of the 3-amino-4-hydroxybenzoic acid to the trimellitic anhydride in step S1 is 1:(1.2-1.4); The mass ratio of the cis-5-norborneol-2,3-dicarboxylic anhydride to the ethanolamine and the triethylamine in step S2 is 1:(0.28-0.35):(0.08-0.1); The mass ratio of the imine product to the phthalic anhydride, the modified monomer, the styrene oxide, and the phosphazene base catalyst in step S2 is (0.5-0.6): (6-7): (1.6-2): 10: (0.05-0.08); In step S3, the ratio of the intermediate product to the ethylene is 60-300 g / 1 atm; the mass ratio of the intermediate product to the main catalyst is (1000-10000):1; the mass ratio of the main catalyst to the co-catalyst is 1:(100-1000).

2. The A2-grade halogen-free flame-retardant aluminum-plastic composite panel according to claim 1, characterized in that: The phosphazene base catalyst is tert-butylimino-tris(dimethylamino)phosphorane, tert-octylimino-tris(dimethylamino)phosphorane, tert-butylimino-tris(pyrrolidine)phosphine or 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphine.

3. The A2-grade halogen-free flame-retardant aluminum-plastic composite panel according to claim 1, characterized in that: The main catalyst is a metallocene catalyst, and the co-catalyst is an alkylaluminoxane or an alkylaluminum.

4. The A2-grade halogen-free flame-retardant aluminum-plastic composite panel according to claim 3, characterized in that: The metallocene catalyst is (2,6-diisopropylphenol)indenyl dimethyl zirconium, (2,6-di-tert-butylphenol)indenyl dimethyl zirconium, (2,6-difluorophenol)indenyl dimethyl zirconium, (2,4,6-trichlorophenol)indenyl dimethyl zirconium, (2-dibenzhydryl-4,6-dimethylphenol)indenyl dimethyl zirconium, (2,6-bis(dibenzhydryl)-4-methylphenol)indenyl dimethyl zirconium, (2,6-diisopropylphenol)indenyl dibenzyl zirconium or (2,6-di-tert-butylphenol)indenyl dibenzyl zirconium.

5. The A2-grade halogen-free flame-retardant aluminum-plastic composite panel according to claim 3, characterized in that: The alkylaluminoxane is methylaluminoxane, and the alkylaluminum is triisobutylaluminum.

6. The method for preparing an A2-grade halogen-free flame-retardant and fireproof aluminum-plastic composite panel according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) Core material preparation The core material is extruded and hot-cut into granules by an extruder, plasticized into sheets by an open mill, and the required composite board core material is obtained after cooling for standby use; (2) Plate preparation The core material of the composite board is sequentially subjected to upper and lower adhesive films and upper and lower aluminum panels. After preheating, it is heat-bonded and hot-pressed so that the core material is located between the two aluminum panels. It is then cold-pressed and shaped. After cooling to room temperature, it is cut to obtain finished products that meet size standards.