PVC (polyvinyl chloride) film, preparation method thereof, flame-retardant stable lamp box fabric and preparation method thereof

Abstract

The invention discloses a PVC (polyvinyl chloride) film, a preparation method of the PVC film, flame-retardant and stable lamp-box fabric and a preparation method of the flame-retardant and stable lamp-box fabric. The lamp-box fabric comprises the following components in parts by mass: 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. The flame retardant is a mixture of antimony trioxide and a compound flame retardant containing silicon, zinc and boron elements. According to the PVC film, the preparation method of the PVC film, the flame-retardant and stable lamp box fabric and the preparation method of the flame-retardant and stable lamp box fabric, the thermal stability and the molten drop resistance of a product can be improved, and the preparation cost is reduced.

Description

Technical Field

[0001] The 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. It is the third largest type of plastic in the world, second only to polyethylene and polypropylene. PVC has good chemical resistance, weather resistance, electrical insulation and mechanical strength. These characteristics make PVC widely used in the construction industry, packaging industry, furniture industry, automobile industry, electronic and electrical industry, and medical industry. Light box cloth, which consists of two layers of PVC film and a layer of high-strength mesh, is often used in billboards. With the continuous improvement of material flame retardancy awareness, ordinary light box cloth can no longer meet current needs. Now a light box cloth product with high flame retardancy, anti-melting droplet and good heat resistance is needed. At present, the flame retardant antimony trioxide, as a better synergist of the halogen system, has shown good effects in flame retardant PVC. However, in recent years, China's antimony production has declined year by year, resulting in a shortage of antimony trioxide resources and large price fluctuations. In addition, antimony, as a heavy metal element, is harmful to both the human body and the environment. Therefore, it is necessary to find alternative flame retardants to antimony trioxide to control costs and protect the environment without affecting product performance.

[0003] The Chinese invention patent CN115895140A discloses the preparation of a plasticized polyvinyl chloride (PVC) material with high flame retardancy, low smoke and low brittle temperature, which can be used for the preparation of thin films in light box cloth. By constructing a compound flame retardant system and a compound plasticizer system, sepiolite is used to match metal oxides (the metal oxides are one or more of antimony trioxide, tin dioxide and magnesium oxide), metal hydroxides (magnesium hydroxide and / or aluminum hydroxide) and plasticizing flame retardants to improve the flame retardancy of the composite material as a whole, so that the film can achieve the purpose of high flame retardancy, low smoke and low brittle temperature. The experimental method of plasticized PVC film with high flame retardancy, low smoke and low brittle temperature, although the formula involved has high flame retardancy and physical properties, the raw material cost of the system is high, and the product preparation of the method is in intermittent process production, which is in the laboratory stage of exploration. And the hydroxide used in the PVC film is magnesium hydroxide, and excessive use will make the material heat resistance worse, produce yellowing, which is not conducive to the use of light box cloth.

[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 prohibited.

[0005] Chinese utility model patent CN 211467737 U discloses a fireproof 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 contacting 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 aluminum hydroxide particles are dispersible and hygroscopic, which 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 existing flame retardants and light box cloths on the market cannot meet the current demand. 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 part of the above-mentioned defects of the existing light box cloth. Summary of the invention

[0008] The 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 property of the products and reduce the preparation cost.

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

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

[0011] The flame retardant is a mixture of antimony trioxide and a composite flame retardant containing silicon, zinc and boron elements; the mass ratio of the antimony trioxide to the composite 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 superfine 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 cloth and a PVC base film; the PVC mask and the PVC base film are PVC films, and the mesh cloth is a polyester fiber mesh cloth.

[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 cloth is arranged between the PVC surface film and the PVC base film, and a light box cloth product is obtained through a bonding and spraying process.

[0022] As an embodiment of the present invention, in the laminating step, a flat 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 vulcanizer 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 plate 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 scheme is adopted: a PVC film, the PVC film comprising the following components in parts by weight: 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;

[0026] The flame retardant is a mixture of antimony trioxide and a composite flame retardant containing silicon, zinc and boron elements; the mass ratio of the antimony trioxide to the composite 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 superfine 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 scheme is adopted: a method for preparing a PVC film, the preparation method comprising: 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 obtaining a PVC film by calendering.

[0033] The beneficial effects of the present invention are as follows: the PVC film and its preparation method, the flame-retardant and stable light box cloth and its preparation method proposed by the present invention, by adding a compound flame retardant into the light box cloth, the elements therein produce a synergistic effect, promote the combustion of the product into carbon, and improve the thermal stability and anti-melting droplet property. With the global trend of higher requirements for flame retardancy, it has a very good development prospect.

[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 in 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 temperature, 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 mass 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 the light box cloth product 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 are 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. The same or similar prior art means and some technical features in the embodiments are mutually replaced within the scope 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 the present application is not limited by the order of implementation of the steps.

[0040] The 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 composite flame retardant containing silicon, zinc and boron elements; the mass ratio of the antimony trioxide to the composite 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 cloth and a PVC bottom film; the PVC mask and the PVC bottom film are PVC films, and the mesh cloth is a polyester fiber mesh cloth.

[0042] In one embodiment of the present invention, the mixture of silicon, zinc and boron-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 epoxidized 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, talcum powder, 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 an embodiment of the present invention; please refer to 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; steps S1 and S2 are not in particular order and can be performed simultaneously, 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 cloth is arranged between the PVC surface mask and the PVC base film, and a light box cloth product is obtained through a bonding and spraying process.

[0050] In one embodiment of the present invention, in the laminating step, a flat 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. In one embodiment, the hot pressing process parameters of the flat vulcanizing machine are: pre-pressing pressure 1-2MPa, pre-pressing time 1-5 minutes, exhaust times 3-10 times, pressurizing pressure 5-15MPa, pressurizing time 1-5 minutes; the cooling process parameters of the flat vulcanizing machine are: no pre-pressing stage, pre-pressing time 0 minutes, exhaust times 0 times, pressurizing pressure 5-15MPa, pressurizing time 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 composite flame retardant containing silicon, zinc and boron elements; the mass ratio of the antimony trioxide to the composite 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 composite flame retardant includes at least one of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate and zinc borate. In one embodiment, the material containing boron, zinc and silicon is poured into a high-speed mixer, and the parameters are set to a speed of 500-800 rpm, mixing for 10-20 minutes, and discharging for 5-10 minutes to obtain a silicon, zinc and boron composite flame retardant.

[0053] The plasticizer includes at least one of epoxidized 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 calcium zinc stabilizer, organic tin stabilizer, rare earth stabilizer, light stabilizer, metal soap stabilizer, and ultraviolet absorber. The calcium powder includes at least one of ultrafine heavy calcium carbonate, talcum powder, 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 the PVC film.

[0056]

[0057] Table 1 Flame retardant formula data of PVC facial mask in various embodiments

[0058]

[0059]

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

[0061] Example 1

[0062] Preparation of 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 obtain compound flame retardant. The blending ratio of compound flame retardant and antimony trioxide is 5:7.

[0063] The formula of the composite flame retardant 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 bottom film is 0.1-0.15mm; the film ratio of the light box cloth (100% - mesh cloth 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 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 obtain compound flame retardant. The blending ratio of compound flame retardant and antimony trioxide is 5:7.

[0066] The formula of the composite flame retardant 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 bottom film is 0.1-0.15mm. The film proportion of the light box cloth (100% - mesh cloth 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 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 obtain compound flame retardant. The blending ratio of compound flame retardant and antimony trioxide is 5:9.

[0069] The formula of the composite flame retardant 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 bottom film is 0.1-0.15mm. The film proportion of the light box cloth (100% - mesh cloth 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 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 obtain compound flame retardant. The blending ratio of compound flame retardant and antimony trioxide is 5:9.

[0072] The formula of the composite flame retardant 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 bottom film is 0.1-0.15mm. The film proportion of the light box cloth (100% - mesh cloth 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 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 obtain compound flame retardant. The mixing ratio of compound flame retardant and antimony trioxide is 6:7.

[0075] The formula of the composite flame retardant 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 bottom film is 0.1-0.15mm. The film proportion of the light box cloth (100% - mesh cloth 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 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 obtain compound flame retardant. The mixing ratio of compound flame retardant and antimony trioxide is 6:7.

[0078] The formula of the composite flame retardant 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 bottom film is 0.1-0.15mm. The film proportion of the light box cloth (100% - mesh cloth 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 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 obtain compound flame retardant. The mixing ratio of compound flame retardant and antimony trioxide is 6:9.

[0081] The formula of the composite flame retardant 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 bottom film is 0.1-0.15mm. The film proportion of the light box cloth (100% - mesh cloth 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 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 obtain compound flame retardant. The mixing ratio of compound flame retardant and antimony trioxide is 6:9.

[0084] The formula of the composite flame retardant 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 bottom film is 0.1-0.15mm. The film proportion of the light box cloth (100% - mesh cloth 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 table of pure antimony comparative example and compound light box cloth example

[0089] It can be seen from Table 2 that the oxygen index of the light box cloth sample with the addition of compound flame retardant is not significantly different from that of the light box cloth with pure antimony formula, which means 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 and added compound flame retardant mask 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 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 shading rate and 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 color difference, thermal stability, shading rate and transmittance test results 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 light box cloth with added compound flame retardant

[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 light box cloth with added compound flame retardant

[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 and continuing to burn. The thermal stability and anti-melting droplet resistance are not good. However, the light box cloth with added compound flame retardant can stably pass the NFPA701 method 1 flame retardant test without dripping and continuing to burn. It 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 mass loss rate of light box cloth in various embodiments

[0107] It can be seen from Table 7 that the mass loss rate of the light box cloth of each embodiment is lower than that of the pure antimony light box cloth. According to TGA data, the lower the mass loss rate, the higher the residual carbon amount, and the better the carbonization performance. It can be seen that the carbonization performance is better when the compound flame retardant is added.

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

[0109] In summary, the flame-retardant and stable light box cloth and its preparation method proposed by the present invention, by adding a compound flame retardant into the light box cloth, make the elements therein produce a synergistic effect, promote the combustion of the product into carbon, and improve the thermal stability and anti-melting droplet performance. It has a very good development prospect under the global trend of higher requirements for flame retardancy.

[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 in 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 temperature, 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 mass 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 the light box cloth product while increasing the profit of the product.

[0111] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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 it is not intended to limit the scope of the present invention to the above-mentioned 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. The deformation and change of the embodiments disclosed here are possible, and the replacement of the embodiments and the various equivalent parts 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 features of the present invention. Other deformations 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 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 composite flame retardant containing silicon, zinc and boron elements; the mass ratio of the antimony trioxide to the composite flame retardant containing silicon, zinc and boron elements is 1: (0.5-3).

2. The flame-retardant and stable light box cloth according to claim 1, characterized in that: The mixture of silicon, zinc and boron-containing composite flame retardants includes at least one of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate and zinc borate.

3. 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 superfine heavy calcium carbonate, talcum powder, 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.

4. 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 cloth and a PVC base film; the PVC mask and the PVC base film are PVC films, and the mesh cloth is a polyester fiber mesh cloth.

5. A method for preparing a flame-retardant and stable light box cloth, 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 cloth is arranged between the PVC surface film and the PVC base film, and a light box cloth product is obtained through a bonding and spraying process.

6. The preparation method according to claim 5, 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° C. to obtain a PVC light box cloth product.

7. The preparation method according to claim 6, characterized in that: The hot pressing process parameters of the flat vulcanizer 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 plate 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.

8. A PVC film, characterized in that: The PVC film comprises the following components in parts by weight: 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 composite flame retardant containing silicon, zinc and boron elements; the mass ratio of the antimony trioxide to the composite flame retardant containing silicon, zinc and boron elements is 1: (0.5-3).

9. The PVC film according to claim 8, characterized in that: The mixture of silicon, zinc and boron-containing composite flame retardants includes at least one of zinc oxide, zinc sulfide, zinc phthalocyanine, wollastonite, sepiolite, silicate and zinc borate; 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 superfine heavy calcium carbonate, talcum powder, 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.

10. A method for preparing a PVC film, characterized in that: The preparation method 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.

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