Double-sided flame-retardant aluminum foil reinforced composite film and preparation method thereof

Abstract

The invention discloses a double-sided flame-retardant aluminum foil reinforced composite film and a preparation method thereof, and relates to the technical field of reinforced aluminum foil veneering. Glass fiber gridding cloth is used as a base material, flame-retardant pressure-sensitive adhesive is coated on two sides of the base material, the glass fiber gridding cloth is covered with an equal-area composite film, and the composite film is formed by coating the flame-retardant pressure-sensitive adhesive on one side of an aluminum foil and compounding an equal-area carbon fiber film. The flame-retardant pressure-sensitive adhesive disclosed by the invention is prepared from the following components in parts by weight: 8 to 12 parts of alkenyl starch, 25 to 35 parts of functional monomer, 10 to 14 parts of hydroxyl silicone oil, 10 to 20 parts of isocyanate ethyl acrylate, 25 to 35 parts of acrylic acid, 0.2 to 1 part of initiator, 3 to 10 parts of hydrotalcite and 3 to 10 parts of magnesium hydroxide. According to the flame-retardant pressure-sensitive adhesive and the preparation method thereof, the flame-retardant pressure-sensitive adhesive with excellent flame retardance, adhesion and holding power can be prepared by properly adjusting the dosage of the pressure-sensitive adhesive, and the flame-retardant pressure-sensitive adhesive can be prepared without any solvent and can be combined with an aluminum foil, glass fiber gridding cloth and a carbon fiber film to further prepare a final product.

Description

Technical Field

[0001] The invention relates to the technical field of reinforced aluminum foil veneer, in particular to a double-sided flame-retardant aluminum foil reinforced composite film and a preparation method thereof. Background Art

[0002] Aluminum foil veneer, also known as barrier film, heat insulation film, heat insulation foil, etc. Aluminum foil veneer has the functions of heat insulation, waterproof, moisture-proof, etc. It is generally widely used in building roof and exterior wall insulation, mainly used as insulation material for cooling and heating equipment pipes and sound insulation materials, rock wool, and outer sheath of ultra-fine glass wool in buildings, playing the role of flame retardant, anti-corrosion, heat insulation, and sound absorption. Aluminum foil veneer is mostly used with pressure-sensitive adhesive to bond different materials.

[0003] In the prior art, pressure-sensitive adhesive is an adhesive that can be firmly bonded to the adherend by applying pressure without the aid of temperature, moisture, ultraviolet light and other means. Because pressure-sensitive adhesive has the characteristics of dry adhesion and peelability, it is widely used in packaging, office labels, protective insulating tapes for electronic appliances and other fields. However, for aluminum foil veneer, it needs to meet multiple effects such as flame retardancy, corrosion resistance, heat insulation, and sound absorption. At the same time, in the use of buildings and pipelines, the multi-layer film contained in the aluminum foil veneer is required to be firmly combined and not easy to fall off. Therefore, it is required to have high peel strength, excellent flame retardancy, and long-lasting adhesion. Stringent performance requirements such as high peel strength, excellent flame retardancy, and continuous adhesion are proposed for pressure-sensitive adhesive. Summary of the invention

[0004] The purpose of the present invention is to provide a double-sided flame-retardant aluminum foil ribbed composite film and a preparation method thereof, so as to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a double-sided flame-retardant aluminum foil sandwich composite film, which uses glass fiber mesh cloth as a substrate, is coated with a flame-retardant pressure-sensitive adhesive on both sides, and covers a composite film of an area equal to that of the glass fiber mesh cloth, wherein the flame-retardant pressure-sensitive adhesive comprises, by weight, 8 to 12 parts of olefinic starch, 25 to 35 parts of functional monomers, 10 to 14 parts of hydroxy silicone oil, 10 to 20 parts of ethyl isocyanate acrylate, 25 to 35 parts of acrylic acid, 0.2 to 1 part of an initiator, 3 to 10 parts of hydrotalcite, and 3 to 10 parts of magnesium hydroxide; The composite film is prepared by coating a flame retardant pressure sensitive adhesive on one side of an aluminum foil and composited with an equal area carbon fiber film.

[0006] The hydroxy silicone oil added in the present invention can enhance the compatibility with acrylic monomers, promote carbonization of acrylic pressure-sensitive adhesive, improve the flame retardant effect of the pressure-sensitive adhesive, and rapidly decompose at high temperature to release a large amount of inert gas to form a protective film, effectively isolate the contact between flame and air to avoid combustion. At the same time, it can participate in the curing of the pressure-sensitive adhesive in the form of hydroxyl-isocyanate with ethyl isocyanate acrylate, improve the curing speed, and cross-link with the original acrylic network to form a double cross-linking structure, thereby improving the cohesive strength of the pressure-sensitive adhesive, thereby improving the adhesion and lasting effect of the pressure-sensitive adhesive. The olefinic starch added in the present invention has a viscosity-increasing effect, improves the adhesion of the pressure-sensitive adhesive, and can also be used as a carbon-forming agent to synergistically act with P and S in the functional monomer to improve the flame retardant effect of the pressure-sensitive adhesive.

[0007] Furthermore, the glass fiber mesh cloth has a thickness of 15-30 μm.

[0008] Furthermore, the single coating amount of the flame retardant pressure sensitive adhesive is 40-50 g / m 2 .

[0009] Furthermore, the thickness of the aluminum foil is 10-15 μm.

[0010] Furthermore, the carbon fiber membrane has a thickness of 10-15 μm.

[0011] Furthermore, the olefinated starch is prepared by using (S)-1,2-epoxy-5-hexene as a modified starch. The specific preparation method is: adding starch and sodium sulfate into water, mixing and stirring evenly to prepare a starch solution; heating the starch solution to 40°C, adding sodium chloride, stirring for 30 minutes, adding hydrogen peroxide with a mass concentration of 30%, stirring for 5 hours, adjusting the pH to 11 with sodium hydroxide solution, and then adding sodium chloride and (S)-1,2-epoxy-5-hexene in turn. After reacting at 40°C for 20 hours, the temperature is reduced to 25°C to 30°C, adding a hydrochloric acid solution with a mass concentration of 20% to adjust the pH to 6.5, and after the reaction is completed, filtering to obtain a solid.

[0012] Furthermore, the functional monomers include 10 to 15 parts of triallyl phosphate, 5 to 15 parts of vinyl sulfonic acid, and 5 to 10 parts of styrene by weight.

[0013] Furthermore, the hydrotalcite and magnesium hydroxide are surface-modified by aminosilane coupling agent, and the specific steps are: adding 0.1 g / mL of hydrotalcite and magnesium hydroxide to 15 vol% KH-550 / ethanol solution, reacting for 5 hours, taking the solid and drying it.

[0014] Furthermore, a preparation method of a double-sided flame-retardant aluminum foil sandwich composite film includes the following preparation steps: uniformly dispersing acrylic acid and hydroxy silicone oil, heating to 70-80°C, adding olefinic starch and functional monomers at 100-200rpm, adding olefinic starch in batches, 2-4 parts each time, adding 1 / 2 of the initiator, stirring and reacting for 30 minutes, adding hydrotalcite, magnesium hydroxide, and the remaining 1 / 2 of the initiator, stirring and reacting for 1 hour, adding isocyanate ethyl acrylate, stirring for 10 minutes to obtain a flame-retardant pressure-sensitive adhesive; coating the flame-retardant pressure-sensitive adhesive on one side of the aluminum foil, and compounding an equal area of ​​carbon fiber film to obtain a composite film; coating the flame-retardant pressure-sensitive adhesive on both sides of the glass fiber mesh cloth, and covering the glass fiber mesh cloth with an equal area of ​​the composite film.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are: (1) The present invention discloses a double-sided flame-retardant aluminum foil sandwich composite film material and a preparation method thereof. The structural design of the scheme is reasonable. The product adopts a pressure-sensitive adhesive with excellent bonding and flame-retardant properties, so the peel strength between the aluminum foil veneers is higher. At the same time, the product has excellent flame-retardant properties and is more practical.

[0016] (2) This method can prepare a flame retardant pressure-sensitive adhesive with excellent flame retardancy, adhesion and lasting adhesion by using appropriate amounts of olefinic starch, monomer, hydroxy silicone oil, ethyl isocyanate acrylate, hydrotalcite and magnesium hydroxide. While undergoing its own curing reaction, it can also achieve dual curing with hydroxy-isocyanate and amino-isocyanate, thereby increasing the curing speed and forming a double cross-linking network to increase the cohesive strength of the pressure-sensitive adhesive. At the same time, the urea group and silane segment generated by the phenyl group and amino-isocyanate in the monomer can be used to improve the adhesion, high peel strength and flame retardancy. The method can also be prepared without any solvent and can be further prepared by combining with aluminum foil, glass fiber mesh cloth and carbon fiber film to obtain the final product. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe 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 making creative work are within the scope of protection of the present invention. Example 1

[0018] A method for preparing a double-sided flame-retardant aluminum foil sandwich composite film comprises the following preparation steps: (1) Add starch and sodium sulfate to water, mix and stir to obtain a starch solution; heat the starch solution to 40°C, add sodium chloride, stir for 30 minutes, add 30% hydrogen peroxide, stir for 5 hours, adjust the pH to 11 with sodium hydroxide solution, then add sodium chloride and (S)-1,2-epoxy-5-hexene in sequence, react at 40°C for 20 hours, then cool to 30°C, add 20% hydrochloric acid solution to adjust the pH to 6.5, and after the reaction is complete, filter to obtain solid olefinated starch; (2) Mix and disperse acrylic acid and hydroxy silicone oil evenly, heat to 75°C, add olefinic starch and functional monomer at 200rpm, add olefinic starch in batches, add 4 parts each time, then add 1 / 2 initiator, stir and react for 30 minutes, add hydrotalcite, magnesium hydroxide, and the remaining 1 / 2 initiator, stir and react for 1 hour, add isocyanate ethyl acrylate, stir for 10 minutes to obtain a flame retardant pressure-sensitive adhesive; apply the flame retardant pressure-sensitive adhesive to one side of a 15μm thick aluminum foil, and composite it with a 15μm thick carbon fiber film of the same area to obtain a composite film; apply the flame retardant pressure-sensitive adhesive on both sides of a 15μm thick glass fiber mesh cloth, and cover the composite film with the same area of ​​the glass fiber mesh cloth; the single coating amount of the flame retardant pressure-sensitive adhesive is 40g / m 2 ; The flame retardant pressure-sensitive adhesive comprises, by weight, 8 parts of olefinic starch, 25 parts of functional monomers, 10 parts of hydroxy silicone oil, 10 parts of ethyl isocyanate acrylate, 25 parts of acrylic acid, 0.2 parts of initiator, 3 parts of hydrotalcite, and 3 parts of magnesium hydroxide; The functional monomers include 10 parts of triallyl phosphate, 5 parts of vinyl sulfonic acid and 5 parts of styrene by weight.

[0019] The hydrotalcite and magnesium hydroxide are also surface-modified with an aminosilane coupling agent, and the specific steps are: adding 0.1 g / mL of hydrotalcite and magnesium hydroxide to a 15 vol% KH-550 / ethanol solution, reacting for 5 hours, taking the solid, and drying it. Example 2

[0020] The difference between Example 2 and Example 1 is that: the flame retardant pressure-sensitive adhesive includes 8 parts of olefinic starch, 28 parts of functional monomers, 10 parts of hydroxy silicone oil, 12 parts of ethyl isocyanate acrylate, 27 parts of acrylic acid, 0.3 parts of initiator, 4 parts of hydrotalcite, and 4 parts of magnesium hydroxide by weight; the functional monomer includes 11 parts of triallyl phosphate, 7 parts of vinyl sulfonic acid, and 6 parts of styrene by weight. The remaining steps are the same as those of Example 1. Example 3

[0021] The difference between Example 3 and Example 1 is that: the flame retardant pressure-sensitive adhesive includes 12 parts of olefinic starch, 30 parts of functional monomers, 12-hydroxy silicone oil, 15 parts of ethyl isocyanate acrylate, 30 parts of acrylic acid, 0.5 parts of initiator, 6 parts of hydrotalcite, and 6 parts of magnesium hydroxide by weight; the functional monomer includes 13 parts of triallyl phosphate, 10 parts of vinyl sulfonic acid, and 7 parts of styrene by weight. The remaining steps are the same as in Example 1. Example 4

[0022] The difference between Example 4 and Example 1 is that: the flame retardant pressure-sensitive adhesive includes 12 parts of olefinic starch, 32 parts of functional monomers, 13 parts of hydroxy silicone oil, 17 parts of ethyl isocyanate acrylate, 32 parts of acrylic acid, 0.6 parts of initiator, 7 parts of hydrotalcite, and 7 parts of magnesium hydroxide by weight; the functional monomer includes 13 parts of triallyl phosphate, 12 parts of vinyl sulfonic acid, and 8 parts of styrene by weight. The remaining steps are the same as those of Example 1. Example 5

[0023] The difference between Example 5 and Example 1 is that: the flame retardant pressure-sensitive adhesive includes 12 parts of olefinic starch, 35 parts of functional monomers, 14-hydroxy silicone oil, 20 parts of ethyl isocyanate acrylate, 35 parts of acrylic acid, 1 part of initiator, 10 parts of hydrotalcite, and 10 parts of magnesium hydroxide by weight; the functional monomer includes 15 parts of triallyl phosphate, 15 parts of vinyl sulfonic acid, and 10 parts of styrene by weight. The remaining steps are the same as those of Example 1.

[0024] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that no olefinated starch is added. The remaining steps are the same as Example 1.

[0025] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that ordinary starch is used instead of olefinated starch. The remaining steps are the same as Example 1.

[0026] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that triallyl phosphate is not added. The remaining steps are the same as Example 1.

[0027] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that vinyl sulfonic acid is not added. The remaining steps are the same as Example 1.

[0028] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that styrene is not added. The remaining steps are the same as Example 1.

[0029] Comparative Example 6 The difference between Comparative Example 6 and Example 1 is that hydroxy silicone oil is not added. The remaining steps are the same as Example 1.

[0030] Comparative Example 7 The difference between Comparative Example 7 and Example 1 is that ethyl isocyanate acrylate is not added. The remaining steps are the same as Example 1.

[0031] Comparative Example 8 The difference between Comparative Example 8 and Example 1 is that the hydrotalcite and magnesium hydroxide are not surface modified. The remaining steps are the same as Example 1.

[0032] Detection experiment: 1. Take the reinforced composite films prepared in Examples 1-5 and Comparative Example 1, and detect their limiting oxygen index according to the method disclosed in JC / T2028-2018 "Composite veneer materials for mineral wool insulation products". Before the test, the sample was placed in deionized water and soaked for 15 minutes at a distance of 20 mm from the water surface. After taking it out, wipe off the floating water on the surface, dry it in an oven at 105°C for 20 minutes, and cool it to room temperature (25°C). The specific data are shown in Table 1.

[0033] 2. According to the pressure-sensitive adhesive prepared in Examples 1-5 and Comparative Example 1, a composite film was prepared. A layer of the composite film was coated with a flame-retardant pressure-sensitive adhesive at the same coating amount. The composite film was attached to the glass surface, rolled with a rubber roller, and left for 30 minutes. The 180° peel strength was tested. The tensile speed during the test was 300 mm / min, and the average value was taken after 5 tests. See Table 1 for details.

[0034] Table 1

[0035] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A double-sided flame-retardant aluminum foil sandwich composite film, with glass fiber mesh as the base material, double-sided coated with flame-retardant pressure-sensitive adhesive, covering the glass fiber mesh with the same area of ​​composite film, characterized in that: The flame retardant pressure-sensitive adhesive comprises, by weight, 8 to 12 parts of olefinic starch, 25 to 35 parts of functional monomers, 10 to 14 parts of hydroxy silicone oil, 10 to 20 parts of ethyl isocyanate acrylate, 25 to 35 parts of acrylic acid, 0.2 to 1 part of initiator, 3 to 10 parts of hydrotalcite, and 3 to 10 parts of magnesium hydroxide; The composite film is prepared by coating a flame retardant pressure sensitive adhesive on one side of an aluminum foil and composited with an equal area carbon fiber film.

2. A double-sided flame-retardant aluminum foil reinforced composite film according to claim 1, characterized in that: The glass fiber mesh cloth has a thickness of 15-30 μm.

3. The double-sided flame-retardant aluminum foil reinforced composite film according to claim 1, characterized in that: The single coating amount of the flame retardant pressure sensitive adhesive is 40-50 g / m 2 .

4. The double-sided flame-retardant aluminum foil reinforced composite film according to claim 1, characterized in that: The thickness of the aluminum foil is 10-15 μm.

5. The double-sided flame-retardant aluminum foil reinforced composite film according to claim 1, characterized in that: The carbon fiber film has a thickness of 10-15 μm.

6. The double-sided flame-retardant aluminum foil reinforced composite film according to claim 1, characterized in that: The olefinated starch is prepared by using (S)-1,2-epoxy-5-hexene as a modified starch.

7. According to the double-sided flame-retardant aluminum foil reinforced composite film according to claim 1, it is characterized in that: The functional monomers include 10 to 15 parts of triallyl phosphate, 5 to 15 parts of vinyl sulfonic acid, and 5 to 10 parts of styrene by weight.

8. According to the double-sided flame-retardant aluminum foil reinforced composite film according to claim 1, it is characterized in that: The hydrotalcite and magnesium hydroxide are also surface-modified by aminosilane coupling agent.

9. The method for preparing a double-sided flame-retardant aluminum foil reinforced composite film according to claim 1, characterized in that: The method comprises the following preparation steps: uniformly dispersing acrylic acid and hydroxy silicone oil, heating to 70-80 DEG C, adding olefinic starch and functional monomer at 100-200 rpm, adding olefinic starch in batches, adding 2-4 parts each time, adding 1 / 2 initiator, stirring and reacting for 30 minutes, adding hydrotalcite, magnesium hydroxide and the remaining 1 / 2 initiator, stirring and reacting for 1 hour, adding ethyl isocyanate acrylate, stirring for 10 minutes to obtain a flame retardant pressure-sensitive adhesive; coating the flame retardant pressure-sensitive adhesive on one side of an aluminum foil, and compounding a carbon fiber film with an equal area to obtain a composite film; coating the flame retardant pressure-sensitive adhesive on both sides of a glass fiber mesh cloth, and covering a composite film with an equal area of ​​the glass fiber mesh cloth.

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