Fireproof flame-retardant synthetic resin tile and preparation method thereof

Abstract

The invention discloses a fireproof flame-retardant synthetic resin tile and a preparation method thereof, and relates to the technical field of synthetic resin tiles. The synthetic resin tile comprises a surface layer, a first tough layer, a flame-retardant framework layer and a second tough layer which are sequentially arranged, and the flame-retardant framework layer comprises flame-retardant chopped fibers and a composite smoke suppressant. Through cooperation of the flame-retardant chopped fibers and the composite smoke suppressant, the flame-retardant performance of the flame-retardant framework layer can be improved, the mechanical strength of the flame-retardant framework layer can be improved through the fiber reinforcement effect, and then the flame-retardant framework layer is matched with the first tough layer and the second tough layer to form a multi-layer composite structure; and the prepared synthetic resin tile not only has good flame-retardant and smoke-suppressing effects, but also has high mechanical strength.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of synthetic resin tiles, in particular to a fireproof flame-retardant synthetic resin tile and a preparation method thereof. BACKGROUND

[0002] The synthetic resin tile is a light-weight roofing material made of polyvinyl chloride (PVC), acrylonitrile-styrene-acrylate copolymer (ASA) or polycarbonate (PC) as the main material through co-extrusion or lamination process. Compared with traditional ceramic tiles, metal tiles and colored tiles, the synthetic resin tile has the advantages of light weight, corrosion resistance, impact resistance, good color stability and convenient installation, and has been widely used in roofing fields such as new rural construction, flat-to-pitched roof conversion, scenic decoration and rural old house renovation.

[0003] At present, the common synthetic resin tile on the market is mainly made of PVC. Although the PVC molecule contains chlorine elements that can absorb part of the heat in the burning process and have self-extinguishing effect, the flame retardancy of ordinary PVC is still insufficient, and it belongs to flammable material. Moreover, a large amount of black smoke and harmful gas will be released during the burning process, which has poor environmental performance and is difficult to meet the increasingly stringent building fire safety requirements.

[0004] In order to improve the flame retardancy of the synthetic resin tile mainly made of PVC, the commonly used technical means is to add flame retardants, such as inorganic combustion-supporting agents or halogen flame retardants. However, the traditional inorganic flame retardants have low flame retardant efficiency, such as aluminum hydroxide and magnesium hydroxide, which need high addition amount to make the synthetic resin tile meet the building fire safety requirements. Not only the material cost is greatly increased, but also the flexibility of the resin tile is decreased and the brittleness is increased, which is easy to cause brittle fracture under the load of wind and snow or hail impact. In addition, excessive filling will also affect the processing fluidity of the synthetic resin tile, making it difficult to process and produce. While adding high-efficiency halogen flame retardants can achieve good flame-retardant effect with less addition amount, but halogen flame retardants not only cannot reduce the smoke amount of PVC resin tile during burning, but also release a large amount of hydrogen halide smoke, which has certain environmental and health risks. Therefore, how to synergistically improve the flame-retardant grade of the synthetic resin tile, maintain high mechanical strength and flexibility and reduce the smoke release amount under the limited addition amount of flame retardants has become a technical bottleneck that needs to be broken through in the industry. SUMMARY

[0005] In order to improve the flame retardancy of the synthetic resin tile, balance the flame-retardant effect and mechanical strength, and reduce the smoke amount generated by the resin tile during burning, the present application provides a fireproof flame-retardant synthetic resin tile and a preparation method thereof.

[0006] In a first aspect, the synthetic resin tile provided by the present application adopts the following technical scheme: The synthetic resin tile comprises a surface layer, a first toughness layer, a fire-retardant framework layer and a second toughness layer which are sequentially stacked, wherein the surface layer is arranged on the surface of the first toughness layer by a hot-pressing compounding process of ASA film, and the first toughness layer, the fire-retardant framework layer and the second toughness layer are extruded together by a multi-layer co-extrusion process. The first toughness layer and the second toughness layer are both formed by melt extrusion of a toughness master batch, and the toughness master batch comprises the following raw materials in parts by weight: 100 parts of PVC resin powder, 4.5-6 parts of calcium-zinc stabilizer, 2-4 parts of ACR impact resistance agent, 3-5 parts of CPE, 0.8-1.2 parts of stearic acid, 0.3-0.48 parts of antioxidant, 2-3 parts of titanium white and 10-15 parts of heavy calcium carbonate; The fire-retardant framework layer is formed by melt extrusion of a fire-retardant master batch, and the fire-retardant master batch comprises the following raw materials in parts by weight: 100 parts of PVC resin powder, 5-6.5 parts of calcium-zinc stabilizer, 6-8 parts of CPE, 1-1.2 parts of stearic acid, 0.8-1 part of PE wax, 10-16 parts of fire-retardant short-cut fiber, 6-8 parts of composite smoke suppressant and 30-40 parts of heavy calcium carbonate; The fire-retardant short-cut fiber is specifically prepared by coating the surface of alkali-free glass fiber with zinc hydroxystannate sol and then cutting the dried and solidified alkali-free glass fiber; and the composite smoke suppressant is a mixture of at least one of antimony trioxide, molybdenum trioxide or ammonium molybdate and zinc borate.

[0007] By using the above technical solution, the fire-retardant short-cut fiber is prepared by coating the surface of alkali-free glass fiber with zinc hydroxystannate sol, the zinc hydroxystannate coated on the surface of the alkali-free glass fiber can be fully dispersed in PVC along with the fire-retardant short-cut fiber, and in combination with the uniformly dispersed composite smoke suppressant, the fire-retardant performance of the synthetic resin tile can be obviously improved, and the mechanical strength of the fire-retardant framework layer can be improved through the fiber reinforcement of the fire-retardant short-cut fiber. In addition, the synthetic resin tile with a multi-layer composite structure formed by sequentially stacking the fire-retardant framework layer and the first and second toughness layers can effectively improve the toughness and low-temperature impact resistance of the synthetic resin tile, and thus the relationship between the fire-retardant performance and the mechanical strength of the synthetic resin tile can be balanced, and the synthetic resin tile can have good fire-retardant and smoke-suppressing effects and high mechanical strength, and the comprehensive performance is better.

[0008] Optionally, the preparation method of the fire-retardant short-cut fiber comprises the following steps: A1, first, the alkali-free glass fiber is soaked and cleaned with anhydrous ethanol, and then the alkali-free glass fiber is immersed in an acid solution, heated and continuously stirred to react, taken out, soaked and cleaned with deionized water for multiple times until the cleaning liquid is neutral, and then dried to obtain acid-etched glass fiber; A2, respectively, take zinc chloride and tin tetrachloride, after mixing well, add to deionized water, stirring until completely dissolved, then continue to stir and slowly add sodium hydroxide solution, control the pH value in the range of 8.0-8.5, continue to stir for 2-3h, to obtain zinc hydroxystannate sol; A3, heat the zinc hydroxystannate sol to 60-70℃, then the acid etched glass fiber prepared in step A1 is introduced and immersed in the zinc hydroxystannate sol, continue to soak for 3-5min, then pull out at a uniform speed, dry by hot air, then repeat soaking and drying for not less than 3 times, finally pull into the oven and heat to 150-160℃ and dry and cure for 2-3h, take out and cool, cut short, to obtain the flame-retardant chopped fiber.

[0009] Optionally, in step A2 of the flame-retardant chopped fiber preparation method, the molar ratio of the zinc chloride to the tin tetrachloride is 1:(0.75-0.9), and the zinc chloride is added to the deionized water at an addition concentration of 1-1.5mol / L.

[0010] Optionally, in step A3 of the flame-retardant chopped fiber preparation method, the mass ratio of the zinc hydroxystannate sol to the acid etched glass fiber is 1:(0.5-0.8).

[0011] By adopting the above technical scheme, a flame-retardant chopped fiber with good flame-retardant effect and fiber reinforcement effect can be prepared, which is beneficial to improving the flame-retardant performance of the synthetic resin tile while improving its mechanical strength, and achieving the balance between the flame-retardant performance and the mechanical strength of the synthetic resin tile.

[0012] Optionally, the length of the flame-retardant chopped fiber is 4-6mm.

[0013] By adopting the above technical scheme, the flame-retardant chopped fiber can be prevented from winding, overlapping and forming local aggregation area due to too long fiber under the premise of having certain fiber reinforcement effect, which is beneficial to reducing the stress concentration points in the flame-retardant skeleton layer, and further beneficial to improving the toughness and impact resistance of the synthetic resin tile.

[0014] Optionally, the composite smoke suppressant is a mixture of zinc borate, antimony trioxide and molybdenum trioxide.

[0015] By adopting the above technical scheme, a good smoke suppression system can be formed with the flame-retardant chopped fiber, which is beneficial to improving the flame-retardant and smoke suppression performance of the synthetic resin tile.

[0016] Optionally, the heavy calcium carbonate in the toughness masterbatch and the flame-retardant masterbatch needs to be surface modified before being mixed and added, and the surface modification of the heavy calcium carbonate includes the following steps: The heavy calcium carbonate is added to the ethanol aqueous solution at 20wt%, ultrasonic dispersion is performed, heating is performed to 75-80℃, then the titanate coupling agent and the ammonium polyphosphate are added, the reaction is continuously stirred for 2-3h, vacuum filtration is performed and vacuum drying is performed, to obtain the heavy calcium carbonate after surface modification treatment.

[0017] Optionally, the mass ratio of the heavy calcium carbonate, the titanate coupling agent and the ammonium polyphosphate is 100:(2-3):(12-18).

[0018] By adopting the technical scheme, the surface performance of the heavy calcium carbonate is improved, the heavy calcium carbonate can be fully dispersed and combined in the PVC, and the mechanical properties of the synthetic resin tile are further improved; the ammonium polyphosphate with the flame-retardant effect is introduced on the surface of the heavy calcium carbonate, and then the ammonium polyphosphate is uniformly dispersed in the synthetic resin tile along with the full dispersion of the heavy calcium carbonate, and the comprehensive flame-retardant performance of the synthetic resin tile is further improved.

[0019] In the second aspect, the application provides a preparation method of a synthetic resin tile, which adopts the following technical scheme: A preparation method of a synthetic resin tile, comprising the following steps: S1, the toughness PVC masterbatch and the flame-retardant PVC masterbatch are respectively weighed and fully dried, and are respectively sent to the first extruder, the second extruder and the third extruder, are respectively extruded and mixed, and then are sent to the layer distributor through the respective flow channels, are collected to the main flow channel and are extruded into the die, to form a three-layer tile body arranged in the first toughness layer, the flame-retardant skeleton layer and the second toughness layer; S2, the ASA film is hot-pressed and combined on the surface of the three-layer tile body prepared in step S1 through the hot-pressing roller, and then is sent to the shaping mold for wave-shaped pressing and molding, and after natural cooling, is subjected to traction, edge cutting and fixed-length cutting, to obtain the synthetic resin tile.

[0020] By adopting the technical scheme, the preparation method is simple, the first toughness layer, the flame-retardant skeleton layer and the second toughness layer can be fully combined through the multi-layer co-extrusion process, the ASA film with high weather resistance can be covered on the surface of the first toughness layer through the hot-pressing combination process, and the weather resistance and the service life of the synthetic resin tile are improved. In addition, the required equipment investment is less, and the subsequent mass production of the synthetic resin tile in the factory is facilitated.

[0021] Optionally, the overall thickness of the first toughness layer, the flame-retardant skeleton layer and the second toughness layer co-extruded is 2-3.5mm, and the thickness ratio of the first toughness layer, the flame-retardant skeleton layer and the second toughness layer is 1:(2.5-3): (1-1.5).

[0022] By adopting the technical scheme, the flame-retardant performance and mechanical performance of the synthetic resin tile can be effectively balanced, and the overall weight of the synthetic resin tile is appropriate under this thickness, so as not to be too heavy or too light, and the synthetic resin tile can be applied to the roofing construction of various bearing structures, and has high universality.

[0023] To sum up, the technical scheme of the present application has at least one of the following beneficial effects: 1. The flame-retardant short-cut fiber is prepared by coating the alkali-free glass fiber with zinc hydroxystannate sol, and the uniformly dispersed composite smoke suppressant, which can not only significantly improve the flame-retardant performance of the synthetic resin tile, but also improve the mechanical strength of the flame-retardant skeleton layer through the fiber reinforcement of the flame-retardant short-cut fiber.

[0024] 2. The synthetic resin tile with a multi-layer composite structure is formed by sequentially stacking the flame-retardant skeleton layer, the first toughness layer and the second toughness layer, which can effectively improve the toughness and low-temperature impact resistance of the synthetic resin tile.

[0025] 3. By controlling the length of the flame-retardant short-cut fiber within the range of 4-6 mm, the fiber entanglement, lap joint and local agglomeration area caused by the overlong fiber can be prevented, which is beneficial to reducing the stress concentration points in the flame-retardant skeleton layer, and further beneficial to improving the toughness and impact resistance of the synthetic resin tile.

[0026] 4. By surface modifying the heavy calcium carbonate with titanium ester coupling agent and ammonium polyphosphate, the surface properties of the heavy calcium carbonate can be improved, so that it can be fully dispersed and combined in the PVC, which is beneficial to further improving the mechanical properties of the synthetic resin tile, and the ammonium polyphosphate with flame-retardant effect can be introduced to the surface of the heavy calcium carbonate, and then with the full dispersion of the heavy calcium carbonate, the ammonium polyphosphate can be uniformly dispersed in the synthetic resin tile, which is beneficial to further improving the comprehensive flame-retardant performance of the synthetic resin tile. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a cross-sectional view of a synthetic resin tile in Example 1 of the present application.

[0028] Figure 2 is a cross-sectional view of a synthetic resin tile in Comparative Example 4 of the present application.

[0029] BRIEF DESCRIPTION OF REFERENCE NUMERALS 1. surface layer; 2. first toughness layer; 3. flame-retardant skeleton layer; 4. second toughness layer. DETAILED DESCRIPTION

[0030] The present application will be further described in detail below in combination with the drawings, preparation examples, examples and comparative examples.

[0031] ASA film is specifically selected from PVC special super weather-resistant ASA film of Shanghai Hongjing Printing Industry Co., Ltd., and specifically selected ASA film with a thickness of 0.08 mm.

[0032] PVC resin powder is specifically selected from SG-5 PVC resin powder of Ordos.

[0033] ACR impact modifier is specifically selected from impact modifier ACR of Japan Zhongyuan, and specifically selected with a model number of PA-20.

[0034] Heavy calcium carbonate is selected from heavy calcium carbonate with a mesh size of 1000 of Dongguan Wugen New Material.

[0035] Titanium dioxide is selected from rutile titanium dioxide with a model number of R-248 of Panzhihua Iron and Steel Group Co., Ltd.

[0036] Titanate coupling agent is selected from new alkoxy type titanate with a model number of TCA-L38 of Nengxin New Material.

[0037] Glass fiber is selected from 100g alkali-free glass fiber with a model number of 2116 of Jiujiang Lianfeng Glass Fiber Co., Ltd.

[0038] Preparation example Preparation example 1-1 A kind of flame-retardant short cut fiber, by the following preparation method is prepared: A1, first using anhydrous ethanol is sufficiently soaked and cleaned to alkali-free glass fiber, after drying, then immerse alkali-free glass fiber in acidic solution, wherein the acidic solution is 5% hydrochloric acid aqueous solution, heated to 82 ℃ and continuously stirred for 30 min after taking out, using deionized water is immersed and cleaned for many times, until the cleaning liquid is neutral, dry to obtain etched glass fiber; A2, respectively, 10 mol zinc chloride and 7.5 mol tin tetrachloride are weighed, after being fully stirred and mixed, added to 10L deionized water, stirred until completely dissolved, then continuously stirred and slowly added sodium hydroxide solution, control pH value in the range of 8.0-8.5, continuously stirred for 2h, to obtain zinc hydroxystannate sol; A3, heat zinc hydroxystannate sol to 60 ℃, then take 5kg etched glass fiber prepared in step A1 and immerse in 10kg zinc hydroxystannate sol, continuously soak for 5min, then pull out at a uniform speed, and dry by 75 ℃ hot air, then repeat soaking and drying for 3 times, finally, pull to the oven and heat to 150 ℃ and dry and cure for 3h, after taking out, cool, cut to 4-6mm range, to obtain the flame-retardant short cut fiber.

[0039] Preparation example 1-2 A kind of flame-retardant short cut fiber, by the following preparation method is prepared: A1, first, the alkali-free glass fiber is immersed in deionized water for cleaning, and then the alkali-free glass fiber is immersed in an acidic solution, wherein the acidic solution is a 5% hydrochloric acid aqueous solution, heated to 85°C and continuously stirred for 20 min, then immersed in deionized water for cleaning, until the cleaning solution is neutral, dried to obtain etched glass fiber; A2, 15 mol of zinc chloride and 9 mol of tin tetrachloride are weighed respectively, mixed and added to 10 L of deionized water, stirred until completely dissolved, then continuously stirred and slowly added with sodium hydroxide solution, controlling the pH value in the range of 8.0-8.5, continuously stirring for 2 h, to obtain zinc hydroxystannate sol; A3, heat the zinc hydroxystannate sol to 70°C, then take 8 kg of etched glass fiber prepared in step A1 and introduce and immerse in 10 kg of zinc hydroxystannate sol, continuously immerse for 3 min, then pull out at a uniform speed, and dry by hot air at 80°C, then repeat the immersion and drying for 3 times, finally pull into the oven and heat to 160°C and dry for 2 h, then cool, cut to 4-6 mm, to obtain the flame-retardant short-cut fiber.

[0040]

Preparation Example 1-3

Preparation Example 1

[0041] In this preparation example, in step S3, the etched glass fiber is only immersed in zinc hydroxystannate sol and dried once.

[0042]

Preparation Example 1-4

Preparation Example 1

[0043] In this preparation example, the length of the flame-retardant short-cut fiber is cut to 10-12 mm.

[0044]

Preparation Example 2-1

[0045]

Preparation Example 2-2

[0046] Example 1 A synthetic resin tile, with reference to Figure 1 , comprises a surface layer 1, a first toughness layer 2, a flame-retardant framework layer 3 and a second toughness layer 4 arranged in sequence. The surface layer 1 is formed by hot pressing the ASA film onto the surface of the first toughness layer 2, and the first toughness layer 2, the flame-retardant framework layer 3 and the second toughness layer 4 are formed by multi-layer co-extrusion.

[0047] The first toughness layer 2 and the second toughness layer 4 are both formed by melt extrusion of a toughness masterbatch. In this embodiment, the toughness masterbatch comprises the following raw materials: 100kg of PVC resin powder, 4.5kg of calcium-zinc stabilizer, 2kg of ACR impact modifier, 5kg of CPE, 0.8 parts of stearic acid, 0.3kg of antioxidant, 3kg of titanium white and 10kg of heavy calcium carbonate.

[0048] The antioxidant is specifically a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:2, i.e., the antioxidant comprises 0.1kg of antioxidant 1010 and 0.2kg of antioxidant 168.

[0049] The flame-retardant framework layer 3 is formed by melt extrusion of a flame-retardant masterbatch. In this embodiment, the flame-retardant masterbatch comprises the following raw materials: 100 parts of PVC resin powder, 5kg of calcium-zinc stabilizer, 6kg of CPE, 1kg of stearic acid, 0.8kg of PE wax, 16kg of flame-retardant short fibers, 8kg of composite smoke suppressant and 30kg of heavy calcium carbonate.

[0050] The flame-retardant short fibers are specifically prepared by

Preparation Example 1-1

[0051] A method for preparing a synthetic resin tile, comprising the following steps: S1, the toughness masterbatch and the flame-retardant masterbatch are weighed and mixed according to the mass fraction, then dried, and then sent to the first extruder, the second extruder and the third extruder respectively, extruded and mixed, then collected by a layer distributor into the main flow channel and into the die for co-extrusion to form a three-layer tile body arranged in the first toughness layer 2, the flame-retardant framework layer 3 and the second toughness layer 4.

[0052] S2, hot-pressing the ASA film to the surface of the three-layer tile body prepared in step S1 by a hot-pressing roller, then sending into a setting mold to perform wave-form pressing forming, after natural cooling, performing traction, edge cutting, fixed-length cutting, to obtain the synthetic resin tile.

[0053] In the embodiment, the three-layer tile body of step S1 is extruded according to the overall thickness of 3 mm, wherein the thickness of the first toughness layer 2 is 0.6 mm, the thickness of the fire-retardant framework layer 3 is 1.5 mm, and the thickness of the second toughness layer 4 is 0.9 mm.

[0054]

Embodiment 2

Embodiment 1

[0055] The first toughness layer 2 and the second toughness layer 4 are both formed by melt extrusion of toughness masterbatch, and in the embodiment, the toughness masterbatch comprises the following raw materials: 100 parts of PVC resin powder, 6 parts of calcium-zinc stabilizer, 4 parts of ACR impact modifier, 3 parts of CPE, 1.2 parts of stearic acid, 0.48 parts of antioxidant, 2 parts of titanium white and 15 parts of heavy calcium carbonate.

[0056] Specifically, the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 mixed according to a mass ratio of 1:3, i.e., the antioxidant comprises 0.12 kg of antioxidant 1010 and 0.36 kg of antioxidant 168.

[0057] The fire-retardant framework layer 3 is formed by melt extrusion of fire-retardant masterbatch, and in the embodiment, the fire-retardant masterbatch comprises the following raw materials: 100 parts of PVC resin powder, 6.5 parts of calcium-zinc stabilizer, 8 parts of CPE, 1.2 parts of stearic acid, 1 part of PE wax, 10 parts of fire-retardant short-cut fiber, 6 parts of composite smoke suppressant and 40 parts of light calcium carbonate. Specifically, the fire-retardant short-cut fiber is prepared by

Preparation Example 1-2

[0058] Specifically, in the embodiment, the surface-modified heavy calcium carbonate is prepared by

Preparation Example 2-1

[0059] In the embodiment, the three-layer tile body of step S1 is extruded according to the overall thickness of 3 mm, wherein the thickness of the first toughness layer 2 is 0.6 mm, the thickness of the fire-retardant framework layer 3 is 1.8 mm, and the thickness of the second toughness layer 4 is 0.6 mm.

[0060]

Embodiment 3

Example 1

[0061] In this example, the flame-retardant short-cut fibers used in the flame-retardant masterbatch are specifically prepared by

Preparation Example 1-3

[0062]

Example 4

Example 1

[0063] In this example, the composite smoke suppressant used in the flame-retardant masterbatch is specifically a mixture of zinc borate and diantimony trioxide, wherein the mass ratio of zinc borate to diantimony trioxide is 3:1, i.e. the composite smoke suppressant includes 6 kg of zinc borate and 2 kg of diantimony trioxide.

[0064]

Example 5

Example 1

[0065] In this example, the composite smoke suppressant used in the flame-retardant masterbatch is specifically a mixture of zinc borate, diantimony trioxide and molybdenum trioxide, wherein the mass ratio of zinc borate, diantimony trioxide and molybdenum trioxide is 12:3:1, i.e. the composite smoke suppressant includes 6 kg of zinc borate, 1.5 kg of diantimony trioxide and 0.5 kg of molybdenum trioxide.

[0066]

Example 6

Example 1

[0067] In this example, the composite smoke suppressant used in the flame-retardant masterbatch is specifically a mixture of zinc borate, diantimony trioxide and molybdenum trioxide, wherein the mass ratio of zinc borate, diantimony trioxide and molybdenum trioxide is 12:3:1, i.e. the composite smoke suppressant includes 6 kg of zinc borate, 1.5 kg of diantimony trioxide and 0.5 kg of molybdenum trioxide.

[0068]

Example 7

Example 6

[0069] In this example, the heavy calcium carbonate used in the tenacity masterbatch and the flame-retardant masterbatch is specifically surface-modified heavy calcium carbonate, which is prepared by

Preparation Example 2-2

[0070] Comparative Example

Comparative Example 1

Example 1

[0071] In this comparative example, no flame-retardant short-cut fibers are added in the flame-retardant masterbatch.

[0072]

Comparative Example 2

Example 1

[0073] In this comparative example, the equal length of the alkali-free glass fiber is used to replace the short-cut flame-retardant fiber in the flame-retardant masterbatch.

[0074]

Comparative Example 3

Example 1

[0075] In this comparative example, the composite smoke suppressant is not added in the flame-retardant masterbatch.

[0076]

Comparative Example 4

Example 1

[0077] In this comparative example, referring to Figure 2 , the synthetic resin tile only includes the surface layer 1 and the fire-retardant skeleton layer 3 which are sequentially stacked. Among them, the preparation of the surface layer 1 and the fire-retardant skeleton layer 3 is the same as

Example 1

[0078] Performance test data 1. Limiting oxygen index: According to the 6.1 section of 《TCBMCA 007-2019 Synthetic resin tile》 and 《GB / T 2406.2 2009 Determination of flammability of plastics-Part 2: burning behavior of plastics using a 13 mm thick specimen-Test method B: vertical flame test》, the limiting oxygen index of the synthetic resin tile prepared in each example and comparative example is tested and recorded.

[0079] 2. Smoke density: According to 《GB / T 8323.1-2008 Determination of the smoke density of plastics-Part 1: Test method for smoke density》 and 《GB / T 8323.2-2008 Determination of the smoke density of plastics-Part 2: Test method for determination of smoke density by the single chamber method》, the flame test is carried out, and the smoke density grade (SDR) of the synthetic resin tile prepared in each example and comparative example is recorded.

[0080] 3. Tensile strength: According to the 6.13 section of 《TCBMCA 007-2019 Synthetic resin tile》 and 《GB / T 1040.2-2022 Determination of the tensile properties of plastics-Part 2: test conditions for moulded and extruded plastics》, the tensile strength (MPa) and elongation at break (%) of the synthetic resin tile prepared in each example and comparative example are tested and recorded.

[0081] 4. Impact strength: According to the 6.8 section of 《TCBMCA 007-2019 Synthetic resin tile》, the low temperature falling hammer impact test is carried out, and the breaking condition of the synthetic resin tile prepared in each example and comparative example is recorded.

[0082] Table 1 Partial performance test of synthetic resin tile Combining Example 1 and Comparative Examples 1-3 and combining the data in Table 1, it can be seen that the flame-retardant short-cut fiber prepared by coating the alkali-free glass fiber with zinc hydroxystannate sol, and then cooperating with the composite smoke suppressant, can significantly improve the flame-retardant performance of the synthetic resin tile. Moreover, since the flame-retardant short-cut fiber has a certain fiber reinforcing effect, it can also make the synthetic resin tile maintain a relatively high mechanical strength, which is conducive to balancing the flame-retardant effect and mechanical strength of the synthetic resin tile. In addition, combining Example 1 and Comparative Example 4 and combining the data in Table 1, it can be seen that when the overall structure of the synthetic resin tile is only composed of the surface layer 1 and the flame-retardant skeleton layer 3, although the overall combustion oxygen index of the synthetic resin tile is improved, the smoke density is reduced, and the tensile strength is also significantly improved, the overall toughness is obviously decreased, not only the elongation at break is significantly reduced, but also the number of breakage in the low-temperature impact test is significantly increased. That is, it shows that the first toughness layer 2 and the second toughness layer 4 play an important role in balancing the toughness of the synthetic resin tile.

[0083] Combining Example 1 and Example 3 and combining the data in Table 1, it can be seen that when the alkali-free glass fiber is soaked in the zinc hydroxystannate sol for less times and then dried, the oxygen index of the subsequently prepared synthetic resin tile is significantly reduced, and the smoke density is also increased, that is, the flame-retardant performance of the synthetic resin tile is decreased. This may be because repeatedly soaking the alkali-free glass fiber in the zinc hydroxystannate sol is beneficial to the attachment of zinc hydroxystannate on the alkali-free glass fiber, and thus can effectively improve the coating rate of zinc hydroxystannate on the surface of the alkali-free glass fiber. The higher the coating rate of zinc hydroxystannate on the surface of the flame-retardant short-cut fiber, that is, the higher the proportion of zinc hydroxystannate, the more beneficial to the uniform dispersion of the alkali-free glass fiber and the improvement of the flame-retardant performance of the synthetic resin tile.

[0084] Combining Example 1 and Example 4 and combining the data in Table 1, it can be seen that when the length of the flame-retardant short-cut fiber is in the range of 10-12 mm, the elongation at break and the low-temperature impact performance of the prepared synthetic resin tile are significantly decreased compared to when the length of the flame-retardant short-cut fiber is in the range of 4-6 mm, that is, the toughness of the synthetic resin tile is decreased. This may be because when the length of the flame-retardant short-cut fiber is increased to 10-12 mm, in the process of extruding the flame-retardant skeleton layer 3 with a thickness of 1.5 mm, the longer flame-retardant short-cut fiber is more likely to produce entanglement, lap and form local aggregation zones between fibers. These aggregation zones not only cannot effectively transfer stress, but also become stress concentration points in the material, and thus when the synthetic resin tile is subjected to tensile or impact load, stress will preferentially gather in the matrix around the aggregation, and the brittle fracture of this part will occur more easily, thereby showing the decrease of the elongation at break and the increase of the breakage rate in the low-temperature impact test.

[0085] From the combination of Example 1 and Examples 5-6 and the data in Table 1, it can be seen that when the composite smoke suppressant in the flame-retardant skeleton layer 3 is a mixture of zinc borate, diantimony trioxide and molybdenum trioxide, the flame retardancy of the synthetic resin tile prepared is better than when only one of diantimony trioxide and molybdenum trioxide is mixed with zinc borate. This is probably because the flame-retardant and smoke-suppressing principles of diantimony trioxide and molybdenum trioxide are not the same, and in the smoke-suppressing system of a mixture of zinc borate, diantimony trioxide and molybdenum trioxide, the gas-phase free radical capture of diantimony trioxide and the condensed-phase physical barrier of zinc borate are complementary, and the catalytic carbonization of molybdenum trioxide can both strengthen the carbonization effect of zinc borate and assist diantimony trioxide in reducing the concentration of gas-phase combustible substances, thereby forming a synergistic cycle of a gas-phase blocking-condensed-phase protection-carbon layer strengthening smoke-suppressing system in the flame-retardant skeleton layer 3, and thus the flame-retardant properties of the synthetic resin tile are further improved.

[0086] From the combination of Examples 6-7 and the data in Table 1, it can be seen that using surface-modified heavy calcium carbonate as a filler can not only improve the flame-retardant and smoke-suppressing properties of the synthetic resin tile, but also further improve the tensile strength and breaking properties of the synthetic resin tile, and the comprehensive properties of the synthetic resin tile are better. This is probably because the surface modification of heavy calcium carbonate with a titanate coupling agent and ammonium polyphosphate can not only improve the surface properties of heavy calcium carbonate so that it can be fully dispersed and combined in PVC, but also introduce ammonium polyphosphate with flame-retardant effects onto the surface of heavy calcium carbonate, and then with the full dispersion of heavy calcium carbonate, ammonium polyphosphate can improve the flame-retardant and smoke-suppressing properties of the synthetic resin tile through its own flame-retardant and smoke-suppressing effects, and thus the comprehensive properties of the synthetic resin tile are better.

[0087] The specific embodiments are merely illustrative of the present application, and are not intended to limit the present application, and those skilled in the art can make modifications to the specific embodiments without creative contribution after reading the present specification, and as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A synthetic resin tile, characterized in that: It includes a surface layer (1), a first toughness layer (2), a flame-retardant skeleton layer (3) and a second toughness layer (4) stacked in sequence. The surface layer (1) is formed by hot-pressing composite of ASA film onto the surface of the first toughness layer (2). The first toughness layer (2), the flame-retardant skeleton layer (3) and the second toughness layer (4) are extruded together by multi-layer co-extrusion process. Both the first toughness layer (2) and the second toughness layer (4) are formed by melt extrusion of toughness masterbatch, which comprises the following raw materials in parts by weight: 100 parts PVC resin powder, 4.5-6 parts calcium-zinc stabilizer, 2-4 parts ACR impact modifier, 3-5 parts CPE, 0.8-1.2 parts stearic acid, 0.3-0.48 parts antioxidant, 2-3 parts titanium dioxide, and 10-15 parts heavy calcium carbonate; The flame-retardant skeleton layer (3) is formed by melt extrusion of flame-retardant masterbatch, which includes the following parts by weight of raw materials: 100 parts PVC resin powder, 5-6.5 parts calcium-zinc stabilizer, 6-8 parts CPE, 1-1.2 parts stearic acid, 0.8-1 part PE wax, 10-16 parts flame-retardant chopped fiber, 6-8 parts composite smoke suppressant, and 30-40 parts heavy calcium carbonate; Specifically, the flame-retardant chopped fiber is prepared by coating the surface of alkali-free glass fiber with zinc hydroxystannate sol, and then cutting it short after drying and curing; the composite smoke suppressant is a mixture of at least one of antimony trioxide, molybdenum trioxide or ammonium molybdate and zinc borate.

2. The synthetic resin tile according to claim 1, characterized in that: The method for preparing the flame-retardant chopped fiber includes the following steps: A1. First, soak and clean the alkali-free glass fiber with anhydrous ethanol, dry it, then immerse the alkali-free glass fiber in an acidic solution, heat and continuously stir the reaction, take it out, soak and clean it multiple times with deionized water until the cleaning solution is neutral, and dry it to obtain acid-etched glass fiber. A2. Weigh out zinc chloride and tin tetrachloride separately, mix them thoroughly, add them to deionized water, stir until completely dissolved, then continue stirring and slowly add sodium hydroxide solution, controlling the pH value within the range of 8.0-8.5, and continue stirring for 2-3 hours to obtain zinc hydroxystannate sol. A3. Heat the zinc hydroxystannate sol to 60-70℃, then introduce and immerse the acid-etched glass fiber obtained in step A1 into the zinc hydroxystannate sol. After soaking for 3-5 minutes, pull it out at a uniform speed and air dry it with hot air. Repeat the soaking and air drying at least 3 times. Finally, pull it into an oven and heat it to 150-160℃ and dry and cure it for 2-3 hours. After taking it out, cool it and cut it into shorter pieces to obtain the flame-retardant short-cut fiber.

3. The synthetic resin tile according to claim 2, characterized in that: In step A2 of the method for preparing flame-retardant chopped fibers, the molar ratio of zinc chloride to tin tetrachloride is 1:(0.75-0.9), and the zinc chloride is added to deionized water at a concentration of 1-1.5 mol / L.

4. A synthetic resin tile according to claim 3, characterized in that: In step A3 of the method for preparing flame-retardant chopped fibers, the mass ratio of the zinc hydroxystannate sol to the acid-etched glass fiber is 1:(0.5-0.8).

5. A synthetic resin tile according to claim 2, characterized in that: The flame-retardant chopped fibers have a length of 4-6 mm.

6. A synthetic resin tile according to claim 1, characterized in that: The composite smoke suppressant is a mixture of zinc borate, antimony trioxide, and molybdenum trioxide.

7. A synthetic resin tile according to claim 1, characterized in that: The heavy calcium carbonate in both the toughening masterbatch and the flame retardant masterbatch needs to undergo surface modification treatment before being added together. The surface modification treatment of the heavy calcium carbonate includes the following steps: Heavy calcium carbonate was added to an ethanol aqueous solution at a rate of 20 wt%, and then ultrasonically dispersed. The solution was heated to 75-80°C, and then titanate coupling agent and ammonium polyphosphate were added. The mixture was stirred continuously for 2-3 hours, filtered under reduced pressure, and dried under vacuum to obtain surface-modified heavy calcium carbonate.

8. A synthetic resin tile according to claim 7, characterized in that: The mass ratio of the heavy calcium carbonate, the titanate coupling agent, and the ammonium polyphosphate is 100:(2-3):(12-18).

9. A method for preparing synthetic resin tiles, used to prepare synthetic resin tiles as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Weigh the tough PVC masterbatch and the flame retardant PVC masterbatch respectively and dry them thoroughly. Send them to the first extruder, the second extruder and the third extruder respectively. They are extruded and mixed respectively, and then sent to the layer distributor through their respective flow channels. They are gathered into the main flow channel and enter the die head for co-extrusion to form a three-layer tile body arranged in the first tough layer (2), the flame retardant skeleton layer (3) and the second tough layer (4). S2. The ASA film is hot-pressed onto the surface of the three-layer tile body obtained in step S1 using a hot press roller. Then, it is sent into a shaping mold for wave pressing and molding. After natural cooling, it is pulled, trimmed, and cut to a fixed length to obtain the synthetic resin tile.

10. A synthetic resin tile according to claim 9, characterized in that: In step S1, the overall thickness of the three-layer tile body is 2-3.5mm, and the thickness ratio of the first toughness layer (2), the flame-retardant skeleton layer (3) and the second toughness layer (4) is 1:(2.5-3):(1-1.5).

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