PVC film and preparation method thereof, flame-retardant and stable light box cloth and preparation method thereof

Abstract

The present invention discloses a PVC film and a preparation method thereof, as well as a flame-retardant and stable light box cover and a preparation method thereof. The light box cover comprises the following components by weight: 70-100 parts PVC powder, 25-60 parts plasticizer, 1-8 parts stabilizer, 30-150 parts calcium powder, 5-10 parts titanium dioxide, and 5-30 parts flame retardant; the flame retardant is a mixture of antimony trioxide and a composite flame retardant containing silicon, zinc, and boron. The PVC film and preparation method thereof, as well as the flame-retardant and stable light box cover and a preparation method thereof, can improve the thermal stability and anti-melting properties of the product and reduce production costs.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical materials and relates to a light box cloth, in particular to a PVC film and a preparation method thereof, a flame-retardant and stable light box cloth and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC) is a synthetic plastic that ranks third in the world's plastic market, after polyethylene and polypropylene. PVC's excellent chemical resistance, weather resistance, electrical insulation, and mechanical strength make it widely used in the construction, packaging, furniture, automotive, electronics, and medical industries. Lightbox fabrics, consisting of two layers of PVC film and a high-strength mesh, are commonly used in billboards. With increasing awareness of flame-retardant materials, conventional lightbox fabrics are no longer sufficient. There is a demand for lightbox fabrics with high flame retardancy, anti-drip properties, and excellent heat resistance. Currently, the flame retardant antimony trioxide, a preferred synergist for halogen systems, has demonstrated excellent flame retardancy against PVC. However, China's antimony production has declined annually in recent years, leading to a shortage of antimony trioxide resources and significant price fluctuations. Furthermore, antimony, as a heavy metal, is harmful to both humans and the environment. Therefore, alternative flame retardants to antimony trioxide are needed to control costs and protect the environment without compromising product performance.

[0003] Chinese invention patent CN115895140A discloses the preparation of a highly flame-retardant, low-smoking, and low-brittle-temperature plasticized polyvinyl chloride (PVC) material, which can be used to prepare films for light box fabrics. By constructing a composite flame retardant and plasticizer system, using sepiolite in combination with a metal oxide (one or more of antimony trioxide, tin dioxide, and magnesium oxide), a metal hydroxide (magnesium hydroxide and / or aluminum hydroxide), and a plasticizing flame retardant, the overall flame retardancy of the composite material is improved, thereby achieving the film's high flame retardancy, low smoke generation, and low brittle-temperature properties. While the experimental method for producing highly flame-retardant, low-smoking, and low-brittle-temperature plasticized PVC film involves a formulation with high flame retardancy and physical properties, the system has high raw material costs, and the product preparation method involves batch production, remaining at the laboratory level. Furthermore, the hydroxide used in the PVC film is magnesium hydroxide, and excessive use can impair the material's heat resistance and cause yellowing, making it unsuitable for use in light box fabrics.

[0004] Chinese utility model patent CN207172887U discloses a light box cloth with flame retardant effect. The light box cloth is provided with a PVC surface layer, a flame retardant hot melt layer and an intermediate mesh grid, and the flame retardant hot melt layer is located between the PVC surface layer and the mesh grid, and an asbestos fiber layer and a PVC inner layer are provided on one side of the mesh grid. The flame retardant mechanism is to provide a flame retardant effect on external fire sources by arranging a flame retardant hot melt layer and asbestos fiber inside the light box cloth, and the main component of the flame retardant layer is a phosphorus-containing halogen compound. Although the phosphorus-containing halogen flame retardant has significantly improved the flame retardant effect of the light box cloth, the generation of hydrogen halide gas may cause potential harm to the environment and human health. Therefore, in some countries and regions, especially the European Union, the use of certain types of halogen-containing flame retardants has been restricted or banned.

[0005] Chinese utility model patent CN 211467737 U discloses a fire-resistant light box cloth. The light box cloth consists of an outer PVC layer, a filling layer, and an inner PVC layer. Its flame retardant mechanism is mainly that the filling layer is provided with flame retardant particles made of aluminum hydroxide. After contact with the flame, the aluminum hydroxide particles will oxidize and decompose into a large amount of crystalline water, absorb a large amount of heat, and prevent the spread of the flame. Although the addition of aluminum hydroxide flame retardant can enhance the flame retardant properties of the material, it will reduce the mechanical properties of the material and affect the service life of the light box cloth. The dispersibility and hygroscopicity of aluminum hydroxide particles will affect the expansion degree of the PVC film of the light box cloth, and in order to achieve the ideal flame retardant effect, a large amount of aluminum hydroxide needs to be added. Although the price of aluminum hydroxide is relatively low, adding a large amount will also increase the cost.

[0006] The currently available flame retardants and light box cloths cannot meet current needs. It is necessary to develop compound flame retardants with more ideal flame retardant properties and a simpler preparation process to produce light box cloths. Without reducing other properties of PVC light box cloths, the cost reduction goal can be achieved and the flame retardant stability of light box cloth products can be improved so that they can stably pass the NFPA701 method 1 flame retardant test.

[0007] In view of this, there is an urgent need to design a new light box cloth so as to overcome at least some of the above-mentioned defects of the existing light box cloth. Summary of the Invention

[0008] The present invention provides a PVC film and a preparation method thereof, a flame-retardant and stable light box cloth and a preparation method thereof, which can improve the thermal stability and anti-melting droplet properties of the products and reduce the preparation cost.

[0009] In order to solve the above technical problems, according to one aspect of the present invention, the following technical solution is adopted:

[0010] A flame-retardant and stable light box cloth, comprising a PVC film, wherein the PVC film comprises the following components in parts by weight: 70-100 parts of PVC powder, 25-60 parts of a plasticizer, 1-8 parts of a stabilizer, 30-150 parts of calcium powder, 5-10 parts of titanium dioxide, and 5-30 parts of a flame retardant;

[0011] The flame retardant is a mixture of antimony trioxide and a compound flame retardant containing silicon, zinc and boron elements; the mass ratio of the antimony trioxide to the compound flame retardant containing silicon, zinc and boron elements is 1:(0.5-3).

[0012] As an embodiment of the present invention, the mixture of the composite flame retardant containing silicon, zinc and boron elements includes at least one of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate and zinc borate.

[0013] As an embodiment of the present invention, the plasticizer includes at least one of epoxy soybean oil, di(2-ethylhexyl) adipate (DOA), dioctyl phthalate (DOP), diisononyl phthalate (DINP), and triphenyl phosphate (TPP).

[0014] As an embodiment of the present invention, the stabilizer includes at least one of a calcium zinc stabilizer, an organic tin stabilizer, a rare earth stabilizer, a light stabilizer, a metal soap stabilizer, and an ultraviolet absorber;

[0015] The calcium powder includes at least one of ultrafine heavy calcium carbonate, talcum powder, heavy calcium carbonate, and light calcium carbonate;

[0016] The titanium dioxide includes at least one of anatase titanium dioxide, rutile titanium dioxide, Luanchuan titanium dioxide, and ATR-316.

[0017] As an embodiment of the present invention, the light box cloth includes a PVC mask, a mesh and a PVC base film; the PVC mask and the PVC base film are PVC films, and the mesh is a polyester fiber mesh.

[0018] According to another aspect of the present invention, the following technical solution is adopted: a method for preparing a flame-retardant and stable light box cloth, the preparation method comprising:

[0019] Preparation of PVC facial mask: PVC powder is used as the main raw material, and a set amount of plasticizer, stabilizer, calcium powder, and titanium dioxide flame retardant are added as functional additives, and the PVC facial mask is obtained by calendering;

[0020] Preparation of PVC base film: PVC powder is used as the main raw material, and a set amount of plasticizer, stabilizer, calcium powder, and titanium dioxide flame retardant are added as functional additives, and the PVC base film is obtained by calendering;

[0021] At least one layer of mesh is set between the PVC surface film and the PVC base film, and the light box cloth product is produced through the bonding and spraying processes.

[0022] As an embodiment of the present invention, in the laminating step, a flat-plate vulcanizing machine is used for laminating, and the temperature of the heating plate is 170-220° C. to obtain a PVC light box cloth product.

[0023] As an embodiment of the present invention, the hot pressing process parameters of the flat vulcanizing press are: pre-pressing pressure 1-2 MPa, pre-pressing time 1-5 minutes, exhaust times 3-10 times, pressurizing pressure 5-15 MPa, pressurizing time 1-5 minutes;

[0024] The cooling process parameters of the flat vulcanizer are: no pre-pressing stage, pre-pressing time 0 minutes, exhaust times 0 times, pressurization pressure 5-15 MPa, and pressurization time 5-15 minutes.

[0025] According to another aspect of the present invention, the following technical solution is adopted: a PVC film, the PVC film comprising the following components in parts by mass: 70-100 parts of PVC powder, 25-60 parts of plasticizer, 1-8 parts of stabilizer, 30-150 parts of calcium powder, 5-10 parts of titanium dioxide and 5-30 parts of flame retardant;

[0026] The flame retardant is a mixture of antimony trioxide and a compound flame retardant containing silicon, zinc and boron elements; the mass ratio of the antimony trioxide to the compound flame retardant containing silicon, zinc and boron elements is 1:(0.5-3).

[0027] As an embodiment of the present invention, the mixture of the composite flame retardant containing silicon, zinc and boron elements includes at least one of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate and zinc borate;

[0028] The plasticizer comprises at least one of epoxidized soybean oil, di(2-ethylhexyl) adipate (DOA), dioctyl phthalate (DOP), diisononyl phthalate (DINP), and triphenyl phosphate (TPP);

[0029] The stabilizer includes at least one of a calcium zinc stabilizer, an organic tin stabilizer, a rare earth stabilizer, a light stabilizer, a metal soap stabilizer, and an ultraviolet absorber;

[0030] The calcium powder includes at least one of ultrafine heavy calcium carbonate, talcum powder, heavy calcium carbonate, and light calcium carbonate;

[0031] The titanium dioxide includes at least one of anatase titanium dioxide, rutile titanium dioxide, Luanchuan titanium dioxide, and ATR-316.

[0032] According to another aspect of the present invention, the following technical solution is adopted: a method for preparing a PVC film, the preparation method comprising: using PVC powder as the main raw material, adding a set amount of plasticizer, stabilizer, calcium powder, and titanium dioxide flame retardant as functional additives, and calendering to obtain a PVC film.

[0033] The beneficial effects of the present invention are as follows: the PVC film and its preparation method, as well as the flame-retardant and stable light box cloth and its preparation method, by adding a compound flame retardant to the light box cloth, create a synergistic effect between the elements, promote combustion to charcoal, and improve thermal stability and anti-drip properties. Given the global trend towards higher flame retardancy requirements, these products have excellent development prospects.

[0034] The PVC light box cloth of the present invention not only reduces the cost of flame retardant additives, but also greatly improves the flame retardant properties of the product. The compound flame retardant added to the light box cloth is a substance containing silicon, boron, zinc and calcium elements mixed in a certain proportion. The silicon, boron, zinc and calcium elements contained in the compound flame retardant produce a synergistic effect, which can release water vapor to cool down and form a protective film at high temperatures, and can promote carbonization and improve the thermal stability of the material. This coordinated effect can more effectively inhibit thermal decomposition, slow down or organize the spread of flames, and enhance the flame retardant effect of PVC products. In addition, the production process of the compound flame retardant used in the formula is simple, and large-scale production can be achieved, and the light box cloth products produced can stably pass the NFPA701 method one flame retardant test. Therefore, the compound flame retardant involved in the present invention can be used to ensure the flame retardant stability of light box cloth products while increasing the profit of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The present invention is a flowchart of a method for preparing a flame-retardant and stable light box cloth according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0037] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0038] The description in this section is only for several typical embodiments, and the present invention is not limited to the scope of the embodiments described. The same or similar existing technical means and some technical features of the embodiments are mutually replaced within the scope of the description and protection of the present invention.

[0039] The description of the steps in each embodiment in the specification is only for the convenience of explanation, and the implementation method of this application is not limited by the order of implementation of the steps.

[0040] The present invention discloses a flame-retardant and stable light box cloth, which comprises the following components in parts by mass: 70-100 parts of PVC powder, 25-60 parts of plasticizer, 1-8 parts of stabilizer, 30-150 parts of calcium powder, 5-10 parts of titanium dioxide and 5-30 parts of flame retardant; the flame retardant is a mixture of antimony trioxide and a compound flame retardant containing silicon, zinc and boron elements; the mass ratio of the antimony trioxide to the compound flame retardant containing silicon, zinc and boron elements is 1:(0.5-3).

[0041] The light box cloth may include a PVC mask, a mesh and a PVC base film; the PVC mask and the PVC base film are PVC films, and the mesh is a polyester fiber mesh.

[0042] In one embodiment of the present invention, the mixture of silicon, zinc and boron element-containing composite flame retardants includes at least one of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate and zinc borate.

[0043] The plasticizer may include at least one of epoxy soybean oil, di(2-ethylhexyl) adipate (DOA), dioctyl phthalate (DOP), diisononyl phthalate (DINP), and triphenyl phosphate (TPP).

[0044] The stabilizer may include at least one of a calcium zinc stabilizer, an organic tin stabilizer, a rare earth stabilizer, a light stabilizer, a metal soap stabilizer, and an ultraviolet absorber.

[0045] The calcium powder may include at least one of ultrafine heavy calcium carbonate, talc, heavy calcium carbonate, and light calcium carbonate; the titanium dioxide may include at least one of anatase titanium dioxide, rutile titanium dioxide, Luanchuan titanium dioxide, and ATR-316.

[0046] The present invention also discloses a method for preparing a flame-retardant and stable light box cloth. Figure 1 This is a flow chart of a method for preparing a flame-retardant and stable light box cloth according to one embodiment of the present invention; Figure 1 , the preparation method comprises:

[0047] [Step S1] Preparing a PVC facial mask: Using PVC powder as the main raw material, adding a set amount of plasticizer, stabilizer, calcium powder, and titanium dioxide flame retardant as functional additives, and calendering to obtain a PVC facial mask;

[0048] [Step S2] Preparation of PVC base film: PVC powder is used as the main raw material, and a set amount of plasticizer, stabilizer, calcium powder, and titanium dioxide flame retardant are added as functional additives, and the PVC base film is obtained by calendering; Step S1 and Step S2 are not in particular order and can be performed simultaneously in sequence. Step S1 can be performed first and then Step S2, or Step S2 can be performed first and then Step S1.

[0049] [Step S3] At least one layer of mesh is set between the PVC face mask and the PVC base film, and a light box cloth product is produced through a laminating and spraying process.

[0050] In one embodiment of the present invention, in the laminating step, a flat-plate vulcanizing press is used for laminating, and the temperature of the heating plate is 170-220° C. to obtain a PVC light box cloth product. In one embodiment, the hot pressing process parameters of the flat-plate vulcanizing press are: pre-pressing pressure of 1-2 MPa, pre-pressing time of 1-5 minutes, exhaust times of 3-10 times, pressing pressure of 5-15 MPa, and pressing time of 1-5 minutes; the cooling process parameters of the flat-plate vulcanizing press are: no pre-pressing stage, pre-pressing time of 0 minutes, exhaust times of 0 times, pressing pressure of 5-15 MPa, and pressing time of 5-15 minutes.

[0051] The present invention further discloses a PVC film, which comprises the following components in parts by mass: 70 to 100 parts of PVC powder, 25 to 60 parts of plasticizer, 1 to 8 parts of stabilizer, 30 to 150 parts of calcium powder, 5 to 10 parts of titanium dioxide and 5 to 30 parts of flame retardant; the flame retardant is a mixture of antimony trioxide and a compound flame retardant containing silicon, zinc and boron elements; the mass ratio of the antimony trioxide to the compound flame retardant containing silicon, zinc and boron elements is 1:(0.5 to 3).

[0052] In one embodiment of the present invention, the mixture of the silicon, zinc, and boron-containing composite flame retardant includes at least one of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate, and zinc borate. In one embodiment, the boron, zinc, and silicon-containing material is poured into a high-speed mixer with a speed set to 500-800 rpm, mixing for 10-20 minutes, and discharging for 5-10 minutes to produce the silicon, zinc, and boron-containing composite flame retardant.

[0053] The plasticizer includes at least one of epoxy soybean oil, di(2-ethylhexyl) adipate (DOA), dioctyl phthalate (DOP), diisononyl phthalate (DINP), and triphenyl phosphate (TPP).

[0054] The stabilizer includes at least one of a calcium zinc stabilizer, an organotin stabilizer, a rare earth stabilizer, a light stabilizer, a metal soap stabilizer, and an ultraviolet absorber. The calcium powder includes at least one of ultrafine heavy calcium carbonate, talc, heavy calcium carbonate, and light calcium carbonate. The titanium dioxide includes at least one of anatase titanium dioxide, rutile titanium dioxide, Luanchuan titanium dioxide, and ATR-316.

[0055] The present invention also discloses a method for preparing a PVC film, which comprises: using PVC powder as a main raw material, adding a set amount of plasticizer, stabilizer, calcium powder, and titanium dioxide flame retardant as functional additives, and calendering to obtain a PVC film.

[0056]

[0057] Table 1 Flame retardant formula data of PVC facial mask in each embodiment

[0058]

[0059]

[0060] Table 2 Flame retardant formula data of PVC base film in various examples

[0061] Example 1

[0062] Preparation of the compound flame retardant: One or more of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate, and zinc borate are mixed in a certain proportion to prepare the compound flame retardant. The blending ratio of the compound flame retardant to antimony trioxide is 5:7.

[0063] The formula of the flame retardant compound for the light box cloth is shown in Table 1. The thickness of the double-roll mill proofing film is 0.1-0.2mm, and the thickness of the base film is 0.1-0.15mm. The film ratio of the light box cloth (100% - mesh weight / light box cloth weight * 100%) is 70-80%, and the finished product weight is controlled at 500 (± 50) g / m 2 .

[0064] Example 2

[0065] Preparation of the compound flame retardant: One or more of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate, and zinc borate are mixed in a certain proportion to prepare the compound flame retardant. The blending ratio of the compound flame retardant to antimony trioxide is 5:7.

[0066] The formula of the flame retardant compound for the light box cloth is shown in Table 1. The thickness of the double-roll mill proofing film is 0.1-0.2mm, and the thickness of the base film is 0.1-0.15mm. The film ratio of the light box cloth (100% - mesh weight / light box cloth weight * 100%) is 70-80%, and the finished product weight is controlled at 500 (± 50) g / m 2 .

[0067] Example 3

[0068] Preparation of the compound flame retardant: One or more of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate, and zinc borate are mixed in a certain proportion to prepare the compound flame retardant. The blending ratio of the compound flame retardant to antimony trioxide is 5:9.

[0069] The formula of the flame retardant compound for the light box cloth is shown in Table 1. The thickness of the double-roll mill proofing film is 0.1-0.2mm, and the thickness of the base film is 0.1-0.15mm. The film ratio of the light box cloth (100% - mesh weight / light box cloth weight * 100%) is 70-80%, and the finished product weight is controlled at 500 (± 50) g / m 2 .

[0070] Example 4

[0071] Preparation of the compound flame retardant: One or more of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate, and zinc borate are mixed in a certain proportion to prepare the compound flame retardant. The blending ratio of the compound flame retardant to antimony trioxide is 5:9.

[0072] The formula of the flame retardant compound for the light box cloth is shown in Table 1. The thickness of the double-roll mill proofing film is 0.1-0.2mm, and the thickness of the base film is 0.1-0.15mm. The film ratio of the light box cloth (100% - mesh weight / light box cloth weight * 100%) is 70-80%, and the finished product weight is controlled at 500 (± 50) g / m 2 .

[0073] Example 5

[0074] Preparation of the compound flame retardant: One or more of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate, and zinc borate are mixed in a certain proportion to prepare the compound flame retardant. The blending ratio of the compound flame retardant to antimony trioxide is 6:7.

[0075] The formula of the flame retardant compound for the light box cloth is shown in Table 1. The thickness of the double-roll mill proofing film is 0.1-0.2mm, and the thickness of the base film is 0.1-0.15mm. The film ratio of the light box cloth (100% - mesh weight / light box cloth weight * 100%) is 70-80%, and the finished product weight is controlled at 500 (± 50) g / m 2 .

[0076] Example 6

[0077] Preparation of the compound flame retardant: One or more of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate, and zinc borate are mixed in a certain proportion to prepare the compound flame retardant. The blending ratio of the compound flame retardant to antimony trioxide is 6:7.

[0078] The formula of the flame retardant compound for the light box cloth is shown in Table 1. The thickness of the double-roll mill proofing film is 0.1-0.2mm, and the thickness of the base film is 0.1-0.15mm. The film ratio of the light box cloth (100% - mesh weight / light box cloth weight * 100%) is 70-80%, and the finished product weight is controlled at 500 (± 50) g / m2 .

[0079] Example 7

[0080] Preparation of the compound flame retardant: One or more of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate, and zinc borate are mixed in a certain proportion to prepare the compound flame retardant. The blending ratio of the compound flame retardant to antimony trioxide is 6:9.

[0081] The formula of the flame retardant compound for the light box cloth is shown in Table 1. The thickness of the double-roll mill proofing film is 0.1-0.2mm, and the thickness of the base film is 0.1-0.15mm. The film ratio of the light box cloth (100% - mesh weight / light box cloth weight * 100%) is 70-80%, and the finished product weight is controlled at 500 (± 50) g / m 2 .

[0082] Example 8

[0083] Preparation of the compound flame retardant: One or more of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate, and zinc borate are mixed in a certain proportion to prepare the compound flame retardant. The blending ratio of the compound flame retardant to antimony trioxide is 6:9.

[0084] The formula of the flame retardant compound for the light box cloth is shown in Table 1. The thickness of the double-roll mill proofing film is 0.1-0.2mm, and the thickness of the base film is 0.1-0.15mm. The film ratio of the light box cloth (100% - mesh weight / light box cloth weight * 100%) is 70-80%, and the finished product weight is controlled at 500 (± 50) g / m 2 .

[0085] The oxygen index of the pure antimony comparative example and the compound light box cloth example is shown in Table 2.

[0086]

[0087]

[0088] Table 2 Oxygen index data of pure antimony comparative example and compound light box cloth example

[0089] From Table 2, it can be seen that the oxygen index of the light box cloth sample with compound flame retardant added is not significantly different from that of the light box cloth with pure antimony formula, which shows that the addition of compound flame retardant has little effect on the flame retardant properties of the light box cloth product, and can achieve the goals of reducing costs, increasing efficiency and protecting the environment.

[0090] The color difference between pure antimony mask and mask with compound flame retardant is shown in Table 3.

[0091] Time / min 5 10 15 20 25 ΔE 0.36 0.16 0.2 0.25 0.33

[0092] Table 3 Color difference data of pure antimony and added compound flame retardant mask The shading rate and light transmittance of pure antimony and added compound flame retardant light box cloth are shown in Table 4.

[0093] sample Shading rate Light transmittance Pure antimony 0.56 25.18 Compounding 0.57 24.41

[0094] Table 4 Comparison of light shading rate and light transmittance of pure antimony and light box cloth with compound flame retardant

[0095] From Table 3 and Table 4, it can be seen that the test results of color difference, thermal stability, shading rate and light transmittance of the light box cloth with pure antimony and compound flame retardant are not much different. In fact, the thermal stability of the light box cloth with compound flame retardant is better than that of the light box cloth with pure antimony formula.

[0096] The maximum specific optical density of light box cloth with pure antimony and added compound flame retardant is shown in Table 5.

[0097]

[0098]

[0099] Table 5 Maximum specific optical density data of pure antimony and compound flame retardant light box cloth

[0100] From Table 5, we can see that the smoke density of the light box cloth with compound flame retardant added is lower than that of the pure antimony light box cloth, the amount of smoke generated is smaller, and it is more conducive to environmental protection.

[0101] The fire performance tests of light box cloth with pure antimony and added compound flame retardant are shown in Table 6.

[0102]

[0103] Table 6 Fire performance test data of pure antimony and compound flame retardant light box cloth

[0104] It can be seen from the attached figure and Table 6 that pure antimony light box cloth cannot stably pass the NFPA701 method 1 flame retardant test, and there is a phenomenon of dripping afterburning. The thermal stability and anti-melting droplet resistance are poor. However, the light box cloth with added compound flame retardant can stably pass the NFPA701 method 1 flame retardant test without dripping afterburning, and has good anti-melting droplet performance and good flame retardant stability.

[0105] Group Mass loss rate (TGA) / % Pure antimony light box cloth 34.5 Example 1 33.3 Example 2 32.8 Example 3 33.5 Example 4 33.1 Example 5 32.5 Example 6 31.2 Example 7 33.8 Example 8 32.3

[0106] Table 7 Data table of light box cloth mass loss rate of each embodiment

[0107] Table 7 shows that the mass loss rate of the awning fabrics of each embodiment is lower than that of the pure antimony awning fabric. According to TGA data, the lower the mass loss rate, the higher the residual carbon content and the better the charring performance. Therefore, the charring performance is better when the compound flame retardant is added.

[0108] The above experimental results show that the addition of compound flame retardants to light box cloth can control product costs, reduce the use of antimony trioxide, and improve environmental protection and economic efficiency without affecting other properties (printing, color, thermal stability, etc.). On the other hand, the addition of compound flame retardants can improve the flame retardant stability, anti-melting droplet resistance, and charring properties of light box cloth products, and can stably pass the NFPA701 method 1 flame retardant test. In addition, compared with light box cloth added with pure antimony trioxide, light box cloth added with compound flame retardants has lower costs. Therefore, compound flame retardants can be used as a partial substitute for antimony trioxide, and light box cloth products added with compound flame retardants can improve flame retardant stability.

[0109] In summary, the flame-retardant and stable light box fabric and its preparation method proposed in this invention, by adding a compound flame retardant to the light box fabric, creates a synergistic effect between the elements, promoting combustion to charcoal, and improving thermal stability and anti-drip properties. Given the global trend toward higher flame retardancy requirements, this product holds excellent development prospects.

[0110] The PVC light box cloth of the present invention not only reduces the cost of flame retardant additives, but also greatly improves the flame retardant properties of the product. The compound flame retardant added to the light box cloth is a substance containing silicon, boron, zinc and calcium elements mixed in a certain proportion. The silicon, boron, zinc and calcium elements contained in the compound flame retardant produce a synergistic effect, which can release water vapor to cool down and form a protective film at high temperatures, and can promote carbonization and improve the thermal stability of the material. This coordinated effect can more effectively inhibit thermal decomposition, slow down or organize the spread of flames, and enhance the flame retardant effect of PVC products. In addition, the production process of the compound flame retardant used in the formula is simple, and large-scale production can be achieved, and the light box cloth products produced can stably pass the NFPA701 method one flame retardant test. Therefore, the compound flame retardant involved in the present invention can be used to ensure the flame retardant stability of light box cloth products while increasing the profit of the product.

[0111] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The description and application of the present invention here are illustrative and are not intended to limit the scope of the present invention to the above-described embodiments. The effects or advantages involved in the embodiments may not be embodied in the embodiments due to interference from various factors, and the description of the effects or advantages is not used to limit the embodiments. Variations and changes to the embodiments disclosed here are possible, and the replacement of the embodiments and various equivalent components are well known to those of ordinary skill in the art. It should be clear to those skilled in the art that the present invention can be implemented in other forms, structures, arrangements, proportions, and with other components, materials, and parts without departing from the spirit or essential characteristics of the present invention. Other variations and changes can be made to the embodiments disclosed here without departing from the scope and spirit of the present invention.

Claims

1. A flame retardant and stable light box cloth, characterized in that: The light box cloth includes a PVC film, and the PVC film contains the following components in parts by weight: 70-100 parts of PVC powder, 25-60 parts of plasticizer, 1-8 parts of stabilizer, 30-150 parts of calcium powder, 5-10 parts of titanium dioxide, and 5-30 parts of flame retardant; The flame retardant is a mixture of antimony trioxide and a compound flame retardant containing silicon, zinc and boron elements; the mass ratio of the antimony trioxide to the compound flame retardant containing silicon, zinc and boron elements is 1: (0.5-3); The mixture of composite flame retardants containing silicon, zinc and boron elements includes at least one of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate and zinc borate.

2. The flame-retardant and stable light box cloth according to claim 1, characterized in that: The plasticizer comprises at least one of epoxidized soybean oil, di(2-ethylhexyl) adipate (DOA), dioctyl phthalate (DOP), diisononyl phthalate (DINP), and triphenyl phosphate (TPP); The stabilizer includes at least one of a calcium zinc stabilizer, an organic tin stabilizer, a rare earth stabilizer, a light stabilizer, a metal soap stabilizer, and an ultraviolet absorber; The calcium powder includes at least one of talc, heavy calcium carbonate, and light calcium carbonate; The titanium dioxide includes at least one of anatase titanium dioxide and rutile titanium dioxide.

3. The flame-retardant and stable light box cloth according to claim 1, characterized in that: The light box cloth includes a PVC mask, a mesh and a PVC base film; the PVC mask and the PVC base film are PVC films, and the mesh is a polyester fiber mesh.

4. A method for preparing the flame-retardant and stable light box cloth according to claim 3, characterized in that: The preparation method comprises: Preparation of PVC facial mask: PVC powder is used as the main raw material, and a set amount of plasticizer, stabilizer, calcium powder, and titanium dioxide flame retardant are added as functional additives, and the PVC facial mask is obtained by calendering; Preparation of PVC base film: PVC powder is used as the main raw material, and a set amount of plasticizer, stabilizer, calcium powder, and titanium dioxide flame retardant are added as functional additives, and the PVC base film is obtained by calendering; At least one layer of mesh is set between the PVC surface film and the PVC base film, and the light box cloth product is produced through the bonding and spraying processes.

5. The preparation method according to claim 4, characterized in that: In the laminating step, a flat vulcanizing machine is used for laminating, and the temperature of the heating plate is 170~220℃ to obtain a PVC light box cloth product.

6. The preparation method according to claim 5, characterized in that: The hot pressing process parameters of the flat vulcanizing press are: pre-pressing pressure 1-2 MPa, pre-pressing time 1-5 minutes, exhaust times 3-10 times, pressurizing pressure 5-15 MPa, pressurizing time 1-5 minutes; The cooling process parameters of the flat vulcanizer are: no pre-pressing stage, pre-pressing time 0 minutes, exhaust times 0 times, pressurization pressure 5-15 MPa, and pressurization time 5-15 minutes.

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