Flame-retardant foaming advertisement board and production process thereof

Abstract

The invention discloses a flame-retardant foaming advertisement board and a production process thereof, and belongs to the technical field of advertisement boards. The foaming advertisement board comprises the following raw materials in parts by weight: 100-105 parts of polyvinyl chloride resin, 3-4.5 parts of a stabilizer, 50-60 parts of polymer modified calcium carbonate, 0.2-0.5 part of a pigment, 10 parts of maleic anhydride grafted polyvinyl chloride, 0.5-1 part of a foaming agent, 6-10 parts of a foaming regulator and 0.5-1.5 parts of a lubricant, and the preparation method comprises the following steps: adding the raw materials into a mixing machine, mixing for 30 minutes at the temperature of 100-115 DEG C, cooling to 40-50 DEG C, and carrying out extrusion molding to obtain the foaming advertisement board. According to the flame-retardant foaming advertisement board provided by the invention, the transverse dimension shrinkage rate is less than or equal to 0.05% and the longitudinal dimension shrinkage rate is less than or equal to 0.45% when being tested at 80 DEG C, so that the flame-retardant foaming advertisement board has relatively high dimensional stability and flame-retardant property, and provides reliable guarantee for outdoor advertisement and decoration.

Description

Technical Field

[0001] The present invention belongs to the technical field of advertising boards, and particularly relates to a flame-retardant foamed advertising board and its production process. Background Art

[0002] Polyvinyl chloride (PVC) foamed board is a green environmental protection material that can replace wood boards. It has the characteristics of light weight, moisture resistance, heat preservation, sound insulation, shock absorption, etc. Printing, laminating or making various colors can be carried out on its surface. Therefore, it is widely popular as a substrate for advertising boards.

[0003] The production process of PVC foaming usually is: PVC resin and additives are obtained through high-speed mixing, low-speed cold mixing, twin-screw extrusion, die shaping, cooling and shaping, multi-roller traction, and cutting. Although polyvinyl chloride itself has good flame retardancy, the fire resistance of the foamed board after foaming treatment decreases, and the smaller the surface density, the worse the flame retardancy. And due to the low degree of polymerization of the linear polyvinyl chloride molecular chain, the PVC chain segments are prone to free curling movement, and the foamed board material shrinks and deforms, especially in areas with large temperature differences, the shrinkage and deformation are more obvious. In this regard, currently, inorganic fillers including calcium carbonate, mica, glass fiber, aluminum hydroxide, etc. are used to enhance the dimensional stability and flame retardancy of PVC foamed boards. However, these inorganic fillers usually have poor compatibility with PVC resin, resulting in poor improvement of the dimensional stability of PVC foamed boards. Therefore, how to provide a flame-retardant foamed advertising board with high dimensional stability is a technical problem that needs to be solved currently. Summary of the Invention

[0004] The purpose of the present invention is to provide a flame-retardant foamed advertising board and its production process to solve the problem of poor dimensional stability of existing PVC foamed advertising boards.

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

[0006] A flame-retardant foamed advertising board, comprising the following raw materials in parts by weight: 100 - 105 parts of polyvinyl chloride resin, 3 - 4.5 parts of stabilizer, 50 - 60 parts of polymer-modified calcium carbonate, 0.2 - 0.5 part of pigment, 10 parts of maleic anhydride grafted polyvinyl chloride, 0.5 - 1 part of foaming agent, 6 - 10 parts of foaming regulator, 0.5 - 1.5 parts of lubricant.

[0007] The polymer-modified calcium carbonate is a copolymerization reaction product of acrylated calcium carbonate, 2-methacryloyloxyethyl phosphorylcholine and unsaturated monomers.

[0008] In some embodiment solutions, the preparation method of the polymer-modified calcium carbonate comprises the following steps:

[0009] Add acrylated calcium carbonate and 2-methacryloyloxyethyl phosphorylcholine into deionized water. After ultrasonic dispersion for 30 min, control the temperature at 60 °C, and simultaneously dropwise add ammonium persulfate solution and unsaturated monomer solution. After the dropping is completed, stir and react at 80 °C for 5 - 10 h. After the reaction is completed, cool to room temperature, centrifuge and wash, and dry the product under vacuum to obtain polymer-modified calcium carbonate.

[0010] Calcium carbonate is an inorganic filler widely used in the plastic industry. However, its interfacial interaction with PVC resin is poor, resulting in a poor reinforcement effect. Based on this, in the present invention, 3-(methacryloyloxy)propyltrimethoxysilane is first used to carry out a coupling reaction on calcium carbonate to obtain acrylated calcium carbonate, and then copolymerization reaction is carried out with 2-methacryloyloxyethyl phosphorylcholine and unsaturated monomers to obtain polymer-modified calcium carbonate. Through the modification treatment, hydroxyl groups or amino groups or carboxyl groups are introduced on the surface of calcium carbonate. These groups can form hydrogen bond interactions with -Cl on the PVC molecular chain, improve the dispersion of calcium carbonate in the PVC foaming matrix, and enable calcium carbonate to construct a skeleton structure on the cell walls of the PVC foaming material, with regular cell structures. When the gas in the foam expands or contracts, the cell structure temperature can be maintained, and macroscopically, the foaming material has better dimensional stability. On the other hand, the polymer formed on the surface of calcium carbonate carries nitrogen, phosphorus, and silicon flame retardant elements. The introduction of these flame retardant elements is beneficial to enhancing the flame retardant performance of the foaming material; in addition, the phosphate group in 2-methacryloyloxyethyl phosphorylcholine can form chelates with metal ions, reduce the catalytic activity of metal ions, slow down the promotion of metal ions on the photoaging of PVC in the foaming matrix, and improve the aging resistance of the product.

[0011] In some embodiment schemes, the mass ratio of acrylated calcium carbonate, 2-methacryloyloxyethyl phosphorylcholine, ammonium persulfate, and unsaturated monomer is 3 - 5: 0.2 - 0.6: 0.5 - 1.0: 0.5.

[0012] In some embodiment schemes, the unsaturated monomer is at least one of an unsaturated monomer with a hydroxyl group, an unsaturated monomer with an amide group, and an unsaturated monomer with a carboxyl group.

[0013] In some embodiment schemes, the unsaturated monomer with a hydroxyl group is at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl acrylate.

[0014] In some embodiment schemes, the unsaturated monomer with an amide group is acrylamide and / or methacrylamide.

[0015] In some embodiment schemes, the unsaturated monomer with a carboxyl group is acrylic acid and / or methacrylic acid.

[0016] In some embodiment schemes, the preparation method of the acrylated calcium carbonate includes the following steps:

[0017] Add glacial acetic acid, calcium carbonate, hydroquinone, and 3-(methacryloyloxy)propyltrimethoxysilane to the ethanol solution. After ultrasonic treatment for 30 min, stir and react at 70 - 80 °C for 24 h. Cool to room temperature, centrifuge, wash the centrifuged product with absolute ethanol, and dry at 50 °C to constant weight to obtain acrylated calcium carbonate.

[0018] In some embodiment schemes, the dosage ratio of the ethanol solution, glacial acetic acid, calcium carbonate, hydroquinone, and 3-(methacryloyloxy)propyltrimethoxysilane is 100 - 500 mL : 1 - 2 mL : 10 g : 0.1 - 1 mg : 0.3 - 1 g.

[0019] In some embodiment schemes, the ethanol solution is composed of absolute ethanol and deionized water in a volume ratio of 7 - 9 : 1 - 3.

[0020] In some embodiment schemes, the calcium carbonate is at least one of light calcium carbonate, nano calcium carbonate, and heavy calcium carbonate, preferably nano calcium carbonate.

[0021] In some embodiment schemes, the preparation method of the maleic anhydride grafted polyvinyl chloride includes the following steps:

[0022] Add polyvinyl chloride, maleic anhydride, diisopropylbenzene peroxide, calcium-zinc composite stabilizer, and magnesium oxide to a high-speed mixer and mix evenly. Then, extrude and pelletize through a twin-screw extruder. The temperature of the feeding section is 120 °C, the temperature of the melting section is 160 °C, the temperature of the homogenizing section and the head is 180 °C, and the screw speed is 25 rpm to obtain maleic anhydride grafted polyvinyl chloride.

[0023] In some embodiment schemes, the mass ratio of polyvinyl chloride, maleic anhydride, diisopropylbenzene peroxide, calcium-zinc composite stabilizer, and magnesium oxide is 100 : 7.5 : 0.2 - 0.4 : 3 - 4.0 : 5 - 7.

[0024] In some embodiment schemes, the stabilizer is a calcium-zinc stabilizer or a lead salt stabilizer.

[0025] In some embodiment schemes, the foaming agent is an NC foaming agent.

[0026] In some embodiment schemes, the foaming regulator is HL-200, HL-901.

[0027] In some embodiment schemes, the lubricant is at least one of polyethylene wax, stearic acid, monoglyceryl stearate, and calcium stearate.

[0028] In some embodiment schemes, the pigment is at least one of iron red and iron yellow.

[0029] The production process of the above-mentioned flame-retardant foamed advertising board includes the following steps:

[0030] Add polyvinyl chloride resin, stabilizer, polymer-modified calcium carbonate, pigment, maleic anhydride grafted polyvinyl chloride, foaming agent, foaming regulator, and lubricant into a mixer, mix at 100 - 115 °C for 30 min, then cool to 40 - 50 °C, and transfer to a twin-screw extruder for melt extrusion to obtain the flame-retardant foamed advertising board.

[0031] In some embodiment solutions, the barrel temperature of the twin-screw extruder is 165 - 180 °C, the main machine speed is 15 - 20 rpm, the temperature of the die heating zone is 160 - 180 °C, and the die lip is 100 °C.

[0032] Advantages of the present invention:

[0033] For the flame-retardant foamed advertising board provided by the present invention, when tested at 80 °C, its transverse dimensional shrinkage rate ≤ 0.05%, and its longitudinal dimensional shrinkage rate ≤ 0.45%. It has high dimensional stability and flame-retardant performance, providing a reliable guarantee for outdoor advertising and decoration.

[0034] For the flame-retardant foamed advertising board provided by the present invention, adding polymer-modified calcium carbonate and maleic anhydride grafted polyvinyl chloride to the formula can enable the raw materials to gradually form a cross-linked network structure during the processing process (the anhydride structure in maleic anhydride grafted polyvinyl chloride reacts with the hydroxyl or amino group of polymer-modified calcium carbonate), increasing the wrapping ability of the polymer to the inorganic filler, enhancing the adhesion and compatibility between the organic matrix and the inorganic filler, realizing the improvement of the hardness and rigidity of the material, and improving the dimensional stability and mechanical properties of the foamed material.

[0035] The present invention uses polymer-modified calcium carbonate as a filler. Compared with unmodified calcium carbonate, it has good dispersion in the base material. Due to the physical and chemical interactions between polymer-modified calcium carbonate and PVC, the movement of PVC molecular segments is restricted, and the dimensional stability of the foamed advertising board is significantly improved. Polymer-modified calcium carbonate also constructs a firm skeleton structure in the pores. When the pores are stressed, they tend to deform as a whole, and the ability to disperse stress is significantly improved, improving the mechanical properties of the foamed advertising board. In addition, the polymer-modified calcium carbonate carried also helps to improve the flame retardancy and aging resistance of the foamed advertising board. Specific embodiments

[0036] In order to make the technical problems, technical solutions, and beneficial effects to be solved by the present application clearer, the following further elaborates on the present application in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0037] In this application, "at least one" means one or more, and "a plurality" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both represent: a, b, c, a~b (i.e., a and b), a~c, b~c, or a~b~c, where a, b, and c can be single or multiple respectively.

[0038] The terms used in the embodiments of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms "a", "the", and "said" used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0039] It should be understood that in various embodiments of this application, the magnitude of the sequence numbers of each process does not mean the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic and should not constitute any limitation to the implementation process of the embodiments of this application.

[0040] The weights of the relevant components mentioned in the specification of the embodiments of this application can not only refer to the specific contents of each component, but also represent the proportional relationship of the weights between each component. Therefore, as long as the contents of the relevant components in the specification of the embodiments of this application are scaled up or down proportionally, they are within the scope disclosed in the specification of the embodiments of this application. Specifically, the mass described in the specification of the embodiments of this application can be mass units well-known in the chemical industry such as μg, mg, g, kg, etc.

[0041] Unless otherwise defined, all the technical terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention.

[0042] In the following examples and comparative examples, the polyvinyl chloride resin is PVC SG5, purchased from Xinjiang Tianye (Group) Co., Ltd., the stabilizer is the calcium-zinc stabilizer BPMC8890KA / 2 of German Xiong Brand, the foaming agent is NC foaming agent, purchased from Qingdao Hruit Chemical Materials Co., Ltd., the foaming regulator is HL-901, purchased from Shandong Rike Chemical Co., Ltd., and other various raw materials, reagents, instruments and equipment used can be obtained through market purchase or can be prepared by existing methods.

[0043] The technical solutions of this application will be described below through specific examples and comparative examples.

[0044] Preparation Example 1

[0045] A polymer-modified calcium carbonate, the preparation method is as follows:

[0046] Add 3 g of acrylated calcium carbonate and 0.2 g of 2-methacryloyloxyethyl phosphorylcholine to 100 mL of deionized water. After ultrasonic dispersion for 30 min, control the temperature at 60 °C. At the same time, dropwise add an ammonium persulfate solution composed of 0.5 g of ammonium persulfate and 10 mL of deionized water and 0.5 g of hydroxyethyl acrylate. After the addition is complete, stir and react at 80 °C for 5 h. After the reaction is completed, cool to room temperature, centrifuge and wash. The product is dried in vacuo to obtain polymer-modified calcium carbonate.

[0047] The preparation method of the acrylated calcium carbonate includes the following steps:

[0048] Add 1 mL of glacial acetic acid, 10 g of nano calcium carbonate, 0.1 mg of hydroquinone and 0.3 g of 3-(methacryloyloxy)propyltrimethoxysilane to 100 mL of 70% by volume ethanol solution. After ultrasonic treatment for 30 min, stir and react at 70 °C for 24 h. Cool to room temperature, centrifuge. The centrifuged product is washed with absolute ethanol and dried to constant weight at 50 °C to obtain acrylated calcium carbonate.

[0049] Preparation Example 2

[0050] A polymer-modified calcium carbonate, the preparation method is as follows:

[0051] Add 4 g of acrylated calcium carbonate and 0.4 g of 2-methacryloyloxyethyl phosphorylcholine to 100 mL of deionized water. After ultrasonic dispersion for 30 min, control the temperature at 60 °C. At the same time, dropwise add an ammonium persulfate solution composed of 0.8 g of ammonium persulfate and 10 mL of deionized water and 0.5 g of hydroxyethyl acrylate. After the addition is complete, stir and react at 80 °C for 8 h. After the reaction is completed, cool to room temperature, centrifuge and wash. The product is dried in vacuo to obtain polymer-modified calcium carbonate.

[0052] The preparation method of the acrylated calcium carbonate includes the following steps:

[0053] Add 1.5 mL of glacial acetic acid, 10 g of nano calcium carbonate, 0.5 mg of hydroquinone and 0.5 g of 3-(methacryloyloxy)propyltrimethoxysilane to 300 mL of 80% by volume ethanol solution. After ultrasonic treatment for 30 min, stir and react at 75 °C for 24 h. Cool to room temperature, centrifuge. The centrifuged product is washed with absolute ethanol and dried to constant weight at 50 °C to obtain acrylated calcium carbonate.

[0054] Preparation Example 3

[0055] A polymer-modified calcium carbonate, the preparation method is as follows:

[0056] 5 g of acrylated calcium carbonate and 0.6 g of 2-methacryloyloxyethyl phosphorylcholine were added to 100 mL of deionized water. After ultrasonic dispersion for 30 min, the temperature was controlled at 60 °C, and an ammonium persulfate solution composed of 1.0 g of ammonium persulfate and 10 mL of deionized water and 0.5 g of 2-hydroxyethyl acrylate were simultaneously added dropwise. After the addition was completed, the mixture was stirred and reacted at 80 °C for 10 h. After the reaction ended, it was cooled to room temperature, centrifuged and washed, and the product was dried in vacuo to obtain polymer-modified calcium carbonate.

[0057] The preparation method of the acrylated calcium carbonate includes the following steps:

[0058] 2 mL of glacial acetic acid, 10 g of nano calcium carbonate, 1 mg of hydroquinone and 1 g of 3-(methacryloyloxy)propyltrimethoxysilane were added to 500 mL of a 90% by volume ethanol solution. After ultrasonic treatment for 30 min, the mixture was stirred and reacted at 80 °C for 24 h. It was cooled to room temperature, centrifuged, and the centrifuged product was washed with absolute ethanol and dried at 50 °C to constant weight to obtain acrylated calcium carbonate.

[0059] Preparation Example 4

[0060] A polymer-modified calcium carbonate, compared with Preparation Example 1, is only different in that the 2-hydroxyethyl acrylate in Preparation Example 1 is replaced by a mixture composed of 0.5 g of acrylamide and 5 mL of deionized water.

[0061] Preparation Example 5

[0062] A polymer-modified calcium carbonate, compared with Preparation Example 1, is only different in that the 2-hydroxyethyl acrylate in Preparation Example 1 is replaced by acrylic acid.

[0063] Control Example 1

[0064] A polymer-modified calcium carbonate, compared with Preparation Example 1, is only different in that the 2-hydroxyethyl acrylate in Preparation Example 1 is replaced by 2-methacryloyloxyethyl phosphorylcholine.

[0065] Control Example 2

[0066] A polymer-modified calcium carbonate, compared with Preparation Example 1, is only different in that the 2-methacryloyloxyethyl phosphorylcholine in Preparation Example 1 is replaced by 2-hydroxyethyl acrylate.

[0067] Control Example 3

[0068] This control example is acrylated calcium carbonate, and the preparation method of acrylated calcium carbonate is the same as that of Preparation Example 1.

[0069] Example 1

[0070] A flame-retardant foamed advertising board, comprising the following raw materials in parts by weight: 100 parts of polyvinyl chloride resin, 3 parts of stabilizer, 50 parts of polymer-modified calcium carbonate of Preparation Example 1, 0.2 part of iron red, 10 parts of maleic anhydride grafted polyvinyl chloride, 0.5 part of foaming agent, 6 parts of foaming regulator, and 0.5 part of stearic acid.

[0071] The preparation method of the maleic anhydride grafted polyvinyl chloride comprises the following steps:

[0072] Add 10 parts by weight of polyvinyl chloride, 7.5 parts by weight of maleic anhydride, 0.2 part by weight of diisopropylbenzene peroxide, 3 parts by weight of calcium-zinc composite stabilizer, and 5 parts by weight of magnesium oxide into a high-speed mixer and mix evenly, then extrude and pelletize through a twin-screw extruder. The temperature of the feeding section is 120°C, the temperature of the melting section is 160°C, the temperature of the homogenizing section and the head is 180°C, and the screw speed is 25 rpm to obtain maleic anhydride grafted polyvinyl chloride.

[0073] The production process of the above-mentioned flame-retardant foamed advertising board comprises the following steps:

[0074] Add polyvinyl chloride resin, stabilizer, polymer-modified calcium carbonate, pigment, maleic anhydride grafted polyvinyl chloride, foaming agent, foaming regulator, and stearic acid into a mixer, mix at 100°C for 30 min, then cool to 40°C, transfer to a twin-screw extruder, and melt and extrude to obtain the flame-retardant foamed advertising board.

[0075] The temperature of the twin-screw extruder is set as follows: zone 1 is 180°C, zone 2 is 178°C, zone 3 is 175°C, zone 4 is 168°C, zone 5 is 165°C, the main machine speed is 15 - 20 rpm, the temperature of the mold heating zone is mold 1 at 178°C, mold 2 at 172°C, mold 3 at 172°C, mold 4 at 172°C, mold 5 at 172°C, mold 6 at 172°C, mold 7 at 178°C, mold 8 at 190°C, mold 9 at 190°C, and the die lip is 100°C.

[0076] Example 2

[0077] A flame-retardant foamed advertising board, comprising the following raw materials in parts by weight: 100 parts of polyvinyl chloride resin, 3.5 parts of stabilizer, 55 parts of polymer-modified calcium carbonate of Preparation Example 1, 0.3 part of iron red, 10 parts of maleic anhydride grafted polyvinyl chloride, 0.8 part of foaming agent, 8 parts of foaming regulator, and 1.0 part of stearic acid.

[0078] The preparation method of the maleic anhydride grafted polyvinyl chloride comprises the following steps:

[0079] Add 10 parts by weight of polyvinyl chloride, 7.5 parts by weight of maleic anhydride, 0.3 parts by weight of diisopropylbenzene peroxide, 3.5 parts by weight of calcium-zinc composite stabilizer, and 6 parts by weight of magnesium oxide into a high-speed mixer and mix evenly. Then, extrude and pelletize through a twin-screw extruder. The temperature of the feeding section is 120 °C, the temperature of the melting section is 160 °C, the temperature of the homogenizing section and the head is 180 °C, and the screw speed is 25 rpm to obtain maleic anhydride grafted polyvinyl chloride.

[0080] The production process of the above flame-retardant foamed advertising board is the same as that in Example 1.

[0081] Example 3

[0082] A flame-retardant foamed advertising board, comprising the following raw materials in parts by weight: 105 parts of polyvinyl chloride resin, 4.5 parts of stabilizer, 60 parts of polymer-modified calcium carbonate prepared in Preparation Example 1, 0.5 part of iron red, 10 parts of maleic anhydride grafted polyvinyl chloride, 1 part of foaming agent, 10 parts of foaming regulator, and 1.5 parts of stearic acid.

[0083] The preparation method of the maleic anhydride grafted polyvinyl chloride comprises the following steps:

[0084] Add 10 parts by weight of polyvinyl chloride, 7.5 parts by weight of maleic anhydride, 0.4 parts by weight of diisopropylbenzene peroxide, 4.0 parts by weight of calcium-zinc composite stabilizer, and 7 parts by weight of magnesium oxide into a high-speed mixer and mix evenly. Then, extrude and pelletize through a twin-screw extruder. The temperature of the feeding section is 120 °C, the temperature of the melting section is 160 °C, the temperature of the homogenizing section and the head is 180 °C, and the screw speed is 25 rpm to obtain maleic anhydride grafted polyvinyl chloride.

[0085] The production process of the above flame-retardant foamed advertising board is the same as that in Example 1.

[0086] Example 4

[0087] A flame-retardant foamed advertising board, compared with Example 1, the difference is only that "polymer-modified calcium carbonate" in Example 1 is replaced with the product obtained in Preparation Example 2.

[0088] Example 5

[0089] A flame-retardant foamed advertising board, compared with Example 1, the difference is only that "polymer-modified calcium carbonate" in Example 1 is replaced with the product obtained in Preparation Example 3.

[0090] Example 6

[0091] A flame-retardant foamed advertising board, compared with Example 1, the difference is only that the polymer-modified calcium carbonate in Example 1 is replaced with the product obtained in Preparation Example 4.

[0092] Example 7

[0093] A flame-retardant foamed advertising board, compared with Example 1, the difference is only that the polymer-modified calcium carbonate in Example 1 is replaced by the product obtained in Preparation Example 5.

[0094] Example 8

[0095] A flame-retardant foamed advertising board, compared with Example 1, the difference is only that the amount of polymer-modified calcium carbonate in Example 1 is adjusted from "50 parts" to "60 parts".

[0096] Comparative Example 1

[0097] A flame-retardant foamed advertising board, compared with Example 1, the difference is only that the polymer-modified calcium carbonate in Example 1 is replaced by the product obtained in Comparative Example 1.

[0098] Comparative Example 2

[0099] A flame-retardant foamed advertising board, compared with Example 1, the difference is only that the polymer-modified calcium carbonate in Example 1 is replaced by the product obtained in Comparative Example 2

[0100] Comparative Example 3

[0101] A flame-retardant foamed advertising board, compared with Example 1, the difference is only that the polymer-modified calcium carbonate in Example 1 is replaced by the product obtained in Comparative Example 3

[0102] Comparative Example 4

[0103] A flame-retardant foamed advertising board, compared with Example 1, the difference is only that the maleic anhydride grafted polyvinyl chloride in Example 1 is replaced by polyvinyl chloride.

[0104] Performance tests were carried out on the flame-retardant foamed advertising boards obtained in Examples 1 - 8 and Comparative Examples 1 - 4. The test process is as follows:

[0105] Tensile strength: Tested in accordance with GB / T1040.3—2006 "Test Method for Tensile Properties of Plastics", the temperature is 23°C, the specimen is dumbbell-shaped, the length is 150 mm, the width is 20 mm, and the tensile rate is 10 mm / min;

[0106] Dimensional stability: Use a 100 mm × 40 mm spline to heat it in a blast drying oven at 80°C for 2 h and then take it out. After the sample cools, use a vernier caliper to measure its length and width, and calculate the transverse dimensional shrinkage rate and the longitudinal dimensional shrinkage rate;

[0107] Oxygen index: Determined in accordance with GB / T 2406-1993 "Test Method for Flammability of Plastics - Oxygen Index Method";

[0108] Aging resistance: The size specification of the specimen is 50mm×120mm×1mm. The specimen is placed in a QUV testing machine for aging. The aging test standard is GB / T 16422.3-2014. The UVA-340 light source is selected, and the test method is 8h drying and 4h condensation exposure cycle. The aging time of the specimen is 7 days, and the tensile strength after aging is tested.

[0109] The results are shown in Table 1:

[0110] Table 1

[0111]

[0112] It can be seen from the data recorded in Table 1 that compared with Comparative Examples 1-4, the comprehensive performance of the advertising boards obtained in Examples 1-8 is higher, with a tensile strength of 17.8-19.2 MPa, a transverse dimensional shrinkage rate ≤0.05%, a longitudinal dimensional shrinkage rate ≤0.45%, and an oxygen index ≥37.2%, showing good aging resistance.

[0113] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprises", "comprising" or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device.

[0114] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A flame-retardant foamed advertising board, characterized in that, It comprises the following raw materials in parts by weight: 100 - 105 parts of polyvinyl chloride resin, 3 - 4.5 parts of stabilizer, 50 - 60 parts of polymer - modified calcium carbonate, 0.2 - 0.5 parts of pigment, 10 parts of maleic anhydride - grafted polyvinyl chloride, 0.5 - 1 part of foaming agent, 6 - 10 parts of foaming regulator, and 0.5 - 1.5 parts of lubricant.

2. The flame-retardant foamed advertising board according to claim 1, wherein The polymer - modified calcium carbonate is a copolymerization product of acrylated calcium carbonate, 2 - methacryloyloxyethyl phosphorylcholine, and an unsaturated monomer.

3. A flame-retardant foamed advertising board according to claim 2, characterized in that, The unsaturated monomer is at least one of an unsaturated monomer with a hydroxyl group, an unsaturated monomer with an amide group, and an unsaturated monomer with a carboxyl group.

4. A flame-retardant foamed advertising board according to claim 2, characterized in that, The preparation method of the polymer - modified calcium carbonate comprises the following steps: Add acrylated calcium carbonate and 2 - methacryloyloxyethyl phosphorylcholine into deionized water. After ultrasonic dispersion for 30 min, control the temperature at 60 °C, and simultaneously dropwise add ammonium persulfate solution and unsaturated monomer solution. After the dropping is completed, stir and react at 80 °C for 5 - 10 h. After the reaction is completed, cool to room temperature, centrifuge and wash, and vacuum - dry the product to obtain polymer - modified calcium carbonate.

5. A flame-retardant foamed advertising board according to claim 4, characterized in that, The mass ratio of acrylated calcium carbonate, 2 - methacryloyloxyethyl phosphorylcholine, ammonium persulfate, and unsaturated monomer is 3 - 5:0.2 - 0.6:0.5 - 1.0:0.

5.

6. A flame-retardant foamed advertising board according to claim 3, characterized in that, The unsaturated monomer with a hydroxyl group is at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl acrylate; the unsaturated monomer with an amide group is acrylamide and / or methacrylamide; the unsaturated monomer with a carboxyl group is acrylic acid and / or methacrylic acid.

7. A flame-retardant foamed advertising board according to claim 2, characterized in that, The preparation method of the acrylated calcium carbonate comprises the following steps: Add glacial acetic acid, calcium carbonate, hydroquinone, and 3 - (methacryloyloxy)propyltrimethoxysilane into an ethanol solution. After ultrasonic treatment for 30 min, stir and react at 70 - 80 °C for 24 h. Cool to room temperature, centrifuge, wash the centrifuged product with absolute ethanol, and dry at 50 °C to constant weight to obtain acrylated calcium carbonate.

8. A flame-retardant foamed advertising board according to claim 7, characterized in that, The dosage ratio of the ethanol solution, glacial acetic acid, calcium carbonate, hydroquinone, and 3 - (methacryloyloxy)propyltrimethoxysilane is 100 - 500 mL:1 - 2 mL:10 g:0.1 - 1 mg:0.3 - 1 g.

9. A flame-retardant foamed advertising board according to claim 7, characterized in that, The calcium carbonate is at least one of light calcium carbonate, nano - calcium carbonate, and heavy calcium carbonate.

10. A production process of a flame-retardant foamed advertising board, characterized in that, The method for preparing the flame - retardant foamed advertising board according to any one of claims 1 - 9 comprises the following steps: Add polyvinyl chloride resin, stabilizer, polymer - modified calcium carbonate, pigment, maleic anhydride - grafted polyvinyl chloride, foaming agent, foaming regulator, and lubricant into a mixer, mix at 100 - 115 °C for 30 min, then cool to 40 - 50 °C, transfer to a twin - screw extruder, and melt - extrude to obtain the flame - retardant foamed advertising board.

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