CN114933793B - High-transparency high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of functional wood-plastic composite materials, specifically relates to a high-transparency, high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric, and further discloses its preparation method and application. The high transparency and high temperature resistant surface layer flame retardant co-extruded wood-plastic fabric of the present invention adopts 2,3-dibromo-1,4-butanediol, bisphenol F, tetrabromobisphenol A, trimethylolpropane, Diphenyl carbonate, tetrabutyl titanate, polyester chip pellets, antioxidants, ultraviolet absorbers, etc. are used as raw materials for polymerization. The fabric is combined with wood-plastic core material to produce high transparency, high temperature resistance, Co-extruded wood-plastic composite material with excellent flame retardancy has good decorative and practical properties.

Description

A high-transparency, high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric and its preparation method

Technical field

The invention belongs to the technical field of functional wood-plastic composite materials, and specifically relates to a high-transparency, high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric, and further discloses its preparation method and application.

Background technique

Wood-plastic composite material is a new type of environmentally friendly composite material prepared by melt extrusion, injection molding or hot pressing compounding process using a certain proportion of wood fiber material, thermoplastic polymer resin and various additives. It has the dual advantages of wood and plastic. It has a wood-like appearance and the water resistance, corrosion resistance and insect resistance of thermoplastics. Its dimensional stability is better than that of wood, and its hardness and modulus are higher than that of wood. Thermoplastics have flexible production processes and can be processed and recycled for secondary use. They have outstanding environmental protection and unique decorative effects. At the same time, they effectively alleviate the shortage of wood resources and solve the problem of plastic pollution. At present, WPC products have been widely used in automotive interior decoration materials, building decoration, freight pallets, outdoor tables and chairs, packaging materials, sleepers and indoor furniture, especially with the improvement of wood-plastic composite material production technology, the expansion of industrial scale and Due to its outstanding environmental protection characteristics and unique decorative effects, its application in indoor fields (such as doors, windows, floors, furniture, etc.) is gradually expanding.

The traditional first-generation wood-plastic material is directly mixed with wood powder and plastic. Because part of the wood powder is exposed on the surface, it is prone to moisture absorption, mildew and other damage during outdoor use; the second-generation wood-plastic material is Polyethylene is co-extruded as a fabric on the surface of wood-plastics using a co-extrusion method. Since the surface of the material is entirely plastic, it is not easy to absorb water and deteriorate, effectively extending the life span, and is growing rapidly in the development of the wood-plastic industry.

As the application of wood plastic becomes more and more widespread, the decorative requirements for wood plastic materials in high-end wall panels, lofts, countertops and other fields are also getting higher and higher. Not only do the co-extruded fabrics need to have excellent transparency and can be penetrated The appearance of the core material can be seen on the surface layer; at the same time, when the wood-plastic material is used as a countertop, due to the need to place heat source materials such as boiling water cups, the material is also required to have certain high-temperature resistance to avoid co-extruded wood due to the fabric being not heat-resistant. Traces of damage appear on the surface of the plastic. Furthermore, because general decorative second-generation wood-plastic materials are mainly used for indoor installations, they also have higher requirements for flame retardant performance. However, the current ordinary second-generation co-extruded wood-plastic fabrics cannot meet the above requirements at the same time. There is an urgent need to develop a flame-retardant co-extruded wood-plastic fabric with high transparency and high temperature resistance surface layer to meet the decorative, high temperature resistance and Flame retardant performance requirements.

Contents of the invention

To this end, the technical problem to be solved by the present invention is to provide a flame-retardant co-extruded wood-plastic fabric with a high-transparency, high-temperature-resistant surface layer to meet the decorative, high-temperature resistance and flame-retardant performance requirements of wood-plastic materials;

The second technical problem to be solved by the present invention is to provide a preparation method for the above-mentioned co-extruded wood plastic fabric;

The third technical problem to be solved by the present invention is to provide a wood-plastic composite material with high transparency, high temperature resistance and surface flame retardancy.

In order to solve the above technical problems, the present invention provides a high-transparency, high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric, and its raw materials include the following components by weight:

50-70 parts by weight of 2,3-dibromo-1,4-butanediol;

Bisphenol F 30-60 parts by weight;

Tetrabromobisphenol A 120-150 parts by weight;

Trimethylolpropane 15-25 parts by weight;

Diphenyl carbonate 180-300 parts by weight;

Catalyst 0.5-1 parts by weight;

Polyester chip pellets 220-260 parts by weight;

Antioxidant 0.5-1.2 parts by weight;

0.8-1.5 parts by weight of ultraviolet absorber.

Specifically, the high-transparency, high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric:

The polyester chip pellets are mineral water bottle grade polyester chip pellets;

The catalyst includes tetrabutyl titanate;

The ultraviolet absorber includes ultraviolet absorber UV-531;

The antioxidants include antioxidant 1010.

The invention also discloses a method for preparing the high-transparency, high-temperature-resistant surface layer flame-retardant co-extruded wood-plastic fabric, which includes the following steps:

(1) Mix the 2,3-dibromo-1,4-butanediol, bisphenol F, tetrabromobisphenol A, diphenyl carbonate and catalyst in the above formula amounts, and gradually heat up to 170-175℃, and keep it warm to carry out full transesterification polymerization reaction, and collect the by-product phenol;

(2) When the collected amount of phenol reaches 60% of the theoretical amount, add the formula amount of trimethylolpropane, gradually raise the temperature to 230-235°C, start the vacuum at the same time, and perform a secondary polycondensation reaction at 20±2mmHg ;

(3) When the amount of collected phenol reaches 85%, add the polyester chip pellets in the formula amount, raise the temperature to 275-280°C, start the high vacuum system, perform a high vacuum polycondensation reaction at <1 mmHg, and distill at the same time Remove residual phenol and diphenyl carbonate;

(4) After no obvious fractions are evaporated, release the vacuum system, add the prescribed amount of antioxidants and ultraviolet absorbers, mix thoroughly, press in nitrogen, and open the reactor for high-temperature discharge. The materials will be cooled, crushed, and processed. Sieve to obtain the required co-extruded fabric particles.

Specifically, in the step (2), the temperature raising step is to raise the temperature to 230-235°C at a rate of 8-10°C/h.

The invention also discloses the use of the high-transparency, high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric for preparing co-extruded wood-plastic composite materials.

The invention also discloses a high-transparency, high-temperature-resistant surface layer flame-retardant co-extruded wood-plastic composite material, which includes a wood-plastic core material and a surface layer. The surface layer is made of the high-transparency, high-temperature-resistant surface layer flame-retardant co-extruded wood-plastic fabric. Formed by co-extrusion.

Specifically, for the co-extruded wood-plastic composite material, the raw materials for preparing the wood-plastic core material include the following components by weight:

High density polyethylene 40-50 parts by weight;

30-40 parts by weight of wood flour;

Calcium carbonate 12-18 parts by weight;

Lubricant 0.5-2 parts by weight;

5-8 parts by weight of compatibilizer;

Silane coupling agent 0.2-1 parts by weight.

More preferably, the raw materials for preparing the wood-plastic core material include the following components by weight: 45 parts by weight of high-density polyethylene, 35 parts by weight of wood powder, 15 parts by weight of calcium carbonate, and 1 part by weight of lubricant (stearic acid). 6 parts by weight of compatibilizer (SZ11, Huangshan Beno Technology Co., Ltd.) and 0.5 parts by weight of KH-792 silane coupling agent.

Specifically, for the co-extruded wood-plastic composite material, the mass ratio of the co-extruded fabric forming the surface layer to the raw material forming the wood-plastic core material is 0.05-0.08:1.

The invention also discloses a method for preparing the high-transparency, high-temperature-resistant surface layer flame-retardant co-extruded wood-plastic composite material, which includes the following steps:

(A) According to the selected raw materials and proportions, take the raw materials for preparing the wood-plastic core material and mix them thoroughly at 100-120°C, cool down and discharge the material to obtain a special premix for the core material; add it to the parallel twin-screw extruder Perform extrusion granulation in the machine to obtain core material particles for later use;

(B) Prepare co-extruded fabric particles according to the method and set aside;

(C) The core material particles and the co-extruded fabric particles are respectively melted through an extruder and then entered into the core material cavity and the fabric cavity. They are shaped by a shaping mold, cooled and formed, and cut to a fixed length to obtain.

Specifically, the preparation method of the co-extruded wood-plastic composite material:

In the step (A), in the extrusion granulation step, the barrel temperature is controlled to 180-200°C and the screw speed is 200-300 rpm;

In the step (C), in the melting step of the co-extruded fabric particles, the barrel temperature of the extruder is controlled to be 245-250°C;

In the step (C), in the melting step of the core material particles, the barrel temperature of the extruder is controlled to be 190-200°C.

The high transparency and high temperature resistant surface layer flame retardant co-extruded wood-plastic fabric of the present invention adopts 2,3-dibromo-1,4-butanediol, bisphenol F, tetrabromobisphenol A, trimethylolpropane, It is obtained by polymerizing diphenyl carbonate, tetrabutyl titanate, polyester chip pellets, antioxidants, ultraviolet absorbers, etc. as raw materials. Among them, 2,3-dibromo-1,4-butanediol, bisphenol F, tetrabromobisphenol A, trimethylolpropane, diphenyl carbonate, and tetrabutyl titanate undergo copolymerization to obtain flame retardant and Transparent polycarbonate resin is then added to the polyester chip pellets at the later stage of the reaction for melting and mixing, and then antioxidants and ultraviolet absorbers are added and mixed to obtain a fabric with high transparency, high temperature resistance, and body flame retardancy. This co-extruded fabric not only has good transparency and can withstand high temperatures of 120°C for a long time, but also contains a high content of bromine in the chain segments. It has excellent flame retardant properties, an oxygen index of over 33%, moderate flexibility, and resistance to stress cracking. Very good, with very good overall performance.

The high-transparency, high-temperature-resistant surface layer flame-retardant co-extruded wood-plastic composite material of the present invention is obtained by forming the surface layer with the co-extruded fabric and then co-extruding it with core material raw materials. The wood-plastic composite material has a high It has excellent transparency, high temperature resistance and flame retardancy, and has good decorative and practical properties.

Detailed ways

In the following examples of the present invention, the polyester chip pellets used are mineral water bottle grade polyester chip pellets, high transparency, model CR-8816, purchased from China Resources Chemical Materials Technology Co., Ltd.

Example 1

The raw materials for preparing the high-transparency, high-temperature-resistant surface layer flame-retardant co-extruded wood-plastic fabric described in this embodiment include the following components by weight:

The preparation method of the high-transparency, high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric described in this embodiment includes the following steps:

(1) Add the above formula amounts of 2,3-dibromo-1,4-butanediol, bisphenol F, tetrabromobisphenol A, diphenyl carbonate and catalyst tetrabutyl titanate gradually under nitrogen protection. Raise the temperature to 170°C, then maintain the temperature to perform a full transesterification polymerization reaction, and collect the by-product phenol;

(2) When the collected amount of phenol reaches 60% of the theoretical amount, add the formula amount of trimethylolpropane, gradually raise the temperature to 230°C at a heating rate of 8°C, start the vacuum at the same time, and perform a secondary polycondensation reaction at 20mmHg ;

(3) When the amount of collected phenol reaches 85%, add the formula amount of polyester chip pellets, raise the temperature to 275°C, start the high vacuum system, perform a high vacuum polycondensation reaction at <1mmHg, and distill out the remaining phenol at the same time and diphenyl carbonate;

(4) After no obvious fractions are evaporated, release the vacuum system, add the formula amount of antioxidant 1010 and ultraviolet absorber, mix thoroughly, press in nitrogen, and at the same time open the reactor for high-temperature discharge, and the material passes through the steel belt After cooling, crushing with a crusher and sieving, the co-extruded fabric particles described in this embodiment are obtained. Their appearance is colorless and transparent particles with a particle size of 1-3 mm.

Example 2

The raw materials for preparing the high-transparency, high-temperature-resistant surface layer flame-retardant co-extruded wood-plastic fabric described in this embodiment include the following components by weight:

The preparation method of the high-transparency, high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric described in this embodiment includes the following steps:

(1) Add the above formula amounts of 2,3-dibromo-1,4-butanediol, bisphenol F, tetrabromobisphenol A, diphenyl carbonate and catalyst tetrabutyl titanate gradually under nitrogen protection. Raise the temperature to 175°C, then maintain the temperature to perform a full transesterification polymerization reaction, and collect the by-product phenol;

(2) When the collected amount of phenol reaches 60% of the theoretical amount, add the formula amount of trimethylolpropane, gradually raise the temperature to 235°C at a heating rate of 10°C, start the vacuum at the same time, and perform a secondary polycondensation reaction at 20mmHg ;

(3) When the amount of collected phenol reaches 85%, add the formula amount of polyester chip pellets, raise the temperature to 280°C, start the high vacuum system, perform a high vacuum polycondensation reaction at <1mmHg, and distill out the remaining phenol at the same time and diphenyl carbonate;

(4) After no obvious fractions are evaporated, release the vacuum system, add the formula amount of antioxidant 1010 and ultraviolet absorber, mix thoroughly, press in nitrogen, and at the same time open the reactor for high-temperature discharge, and the material passes through the steel belt After cooling, crushing with a crusher and sieving, the co-extruded fabric particles described in this embodiment are obtained. Their appearance is colorless and transparent particles with a particle size of 1-3 mm.

Example 3

The raw materials for preparing the high-transparency, high-temperature-resistant surface layer flame-retardant co-extruded wood-plastic fabric described in this embodiment include the following components by weight:

The preparation method of the high-transparency, high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric described in this embodiment includes the following steps:

(1) Add the above formula amounts of 2,3-dibromo-1,4-butanediol, bisphenol F, tetrabromobisphenol A, diphenyl carbonate and catalyst tetrabutyl titanate gradually under nitrogen protection. Raise the temperature to 170°C, then maintain the temperature to perform a full transesterification polymerization reaction, and collect the by-product phenol;

(2) When the collected amount of phenol reaches 60% of the theoretical amount, add the formula amount of trimethylolpropane, gradually raise the temperature to 230°C at a heating rate of 9°C, start the vacuum at the same time, and perform a secondary polycondensation reaction at 20mmHg ;

(3) When the amount of collected phenol reaches 85%, add the formula amount of polyester chip pellets, raise the temperature to 275°C, start the high vacuum system, perform a high vacuum polycondensation reaction at <1mmHg, and distill out the remaining phenol at the same time and diphenyl carbonate;

(4) After no obvious fractions are evaporated, release the vacuum system, add the formula amount of antioxidant 1010 and ultraviolet absorber, mix thoroughly, press in nitrogen, and at the same time open the reactor for high-temperature discharge, and the material passes through the steel belt After cooling, crushing with a crusher and sieving, the co-extruded fabric particles described in this embodiment are obtained. Their appearance is colorless and transparent particles with a particle size of 1-3 mm.

Example 4

The raw materials for preparing the high-transparency, high-temperature-resistant surface layer flame-retardant co-extruded wood-plastic fabric described in this embodiment include the following components by weight:

The preparation method of the high-transparency, high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric described in this embodiment includes the following steps:

(1) Add the above formula amounts of 2,3-dibromo-1,4-butanediol, bisphenol F, tetrabromobisphenol A, diphenyl carbonate and catalyst tetrabutyl titanate gradually under nitrogen protection. Raise the temperature to 175°C, then maintain the temperature to perform a full transesterification polymerization reaction, and collect the by-product phenol;

(2) When the collected amount of phenol reaches 60% of the theoretical amount, add the formula amount of trimethylolpropane, gradually raise the temperature to 235°C at a heating rate of 9°C, start the vacuum at the same time, and perform a secondary polycondensation reaction at 20mmHg ;

(3) When the amount of collected phenol reaches 85%, add the formula amount of polyester chip pellets, raise the temperature to 280°C, start the high vacuum system, perform a high vacuum polycondensation reaction at <1mmHg, and distill out the remaining phenol at the same time and diphenyl carbonate;

(4) After no obvious fractions are evaporated, release the vacuum system, add the formula amount of antioxidant 1010 and ultraviolet absorber, mix thoroughly, press in nitrogen, and at the same time open the reactor for high-temperature discharge, and the material passes through the steel belt After cooling, crushing with a crusher and sieving, the co-extruded fabric particles described in this embodiment are obtained. Their appearance is colorless and transparent particles with a particle size of 1-3 mm.

Experimental example

This experimental example prepares a high-transparency, high-temperature-resistant surface layer flame-retardant co-extruded wood-plastic material. The wood-plastic material consists of a wood-plastic core material and a co-extruded surface layer, where,

The co-extruded surface layer is made of the co-extruded fabrics in the above-mentioned embodiments 1-4, and ordinary high-density polyethylene is used as the co-extruded fabric as Comparative Example 1. Common polycarbonate standard materials currently on the market (model 1609, Luxi Group Co., Ltd.) as co-extruded fabric as Comparative Example 2;

The raw materials for preparing the wood-plastic core material include: 45 parts by weight of high-density polyethylene, 35 parts by weight of wood powder, 15 parts by weight of calcium carbonate, 1 part by weight of lubricant (stearic acid), compatibilizer (SZ11, Huangshan shellfish) Nuo Technology Co., Ltd.) 6 parts by weight, KH-792 silane coupling agent 0.5 parts by weight;

In the co-extruded wood-plastic composite material described in this experimental example, the mass ratio of the co-extruded fabric forming the surface layer to the raw material forming the wood-plastic core material is 0.06:1.

The preparation method of co-extruded wood-plastic composite materials described in this experimental example includes the following steps:

(A) Mix the above-selected materials for preparing the wood-plastic core material thoroughly at 110°C according to the formula amount, discharge the material into a cold mix, cool it to 70°C and discharge the material to make a special premix; Add the above-mentioned core material special premix to the parallel twin-screw extruder, control the barrel temperature to 190°C, and the screw speed to 250 rpm for extrusion granulation to obtain core material particles for later use;

(B) Prepare the required co-extruded fabric particles according to the above-mentioned embodiments 1-4 respectively, and use ordinary high-density polyethylene as the co-extruded fabric as Comparative Example 1, and use the currently commercially available ordinary polycarbonate standard materials (Model 1609, Luxi Group Co., Ltd.) as co-extruded fabric as Comparative Example 2;

(C) Melt the core material particles prepared above through an extruder (control the extruder barrel temperature to 200°C) and enter the core material cavity of the co-extrusion die; add the above Examples 1-4 and The fabric pellets used as comparative examples were melted through an extruder (controlling the extruder barrel temperature to 250°C) and entered the fabric cavity of the co-extrusion mold; they were obtained by shaping the mold, cooling molding and cutting to length. The finished product is the required co-extruded wood composite material.

The properties of the wood-plastic composite materials produced in the above experimental examples were tested respectively. The test indicators and standards include:

24h water absorption, boiling water resistance, static bending strength testing: in accordance with the standards of GB17657-2013;

Oxygen index test: Prepare the fabric powder according to Type I according to the standard of GB/T 2406.2-2009 "Determination of Combustion Behavior of Plastics by Oxygen Index Method", and then detect the oxygen index;

High temperature resistance test: conduct high temperature resistance performance test at 120℃ for 10 hours to see changes in the surface layer of co-extruded wood plastic fabric;

Transparency test of fabric: melt the fabric powder and apply it on a clean and transparent standard glass plate that has been heated by residual heat. Use a scraper to spread it flat. Control the film thickness to about 5mm. Cool to room temperature to obtain a transparent coating. Test the fabric after coating. The light transmittance of the standard glass plate, compare the light transmittance of the standard glass plate after coating with the light transmittance of the pure standard glass plate, the light transmittance of the fabric coating = the light transmittance of the test plate / the light transmittance of the standard glass plate * 100%.

Anti-stress cracking performance of the surface layer: According to the experimental condition B in GB/T 1842-2008 "Test Method for Environmental Stress Cracking of Plastic Polyethylene", 10% volume fraction of OP-10 was used as the solvent, 20 samples were tested, and the samples were observed after 24 hours Destruction percentage.

The test results are shown in Table 1 below.

Table 1 Performance test results of wood-plastic composite materials

It can be seen from the above data that the co-extruded fabric product of the present invention is prepared from selected raw materials, and the obtained co-extruded wood-plastic composite material has moderate static bending strength and excellent resistance to boiling water; moreover, the fabric is made of special polycarbonate A composite material of ester and polyester resin. The polycarbonate uses linear 2,3-dibromo-1,4-butanediol and bisphenol F to adjust the flexibility of the polycarbonate, and then matches the three functionalities of the polycarbonate. Methylolpropane participates in the reaction and is finally melted and compounded with bottle-grade polyester resin. It not only reduces stress cracking, but also has a lower cost and excellent flame retardant properties. The oxygen index reaches more than 33%, making it flame retardant. grade product, and the surface has outstanding high temperature resistance. There is no change in the surface of the layer after 120℃/10h. At the same time, the transparency of the surface layer is high, with a light transmittance of more than 83%. The core layer of wood can be clearly seen through the surface layer. In powder state, it has excellent decorative properties.

However, in Comparative Example 1, ordinary high-density polyethylene was used as the fabric, and the product's flame retardant performance, light transmittance, and high temperature resistance were poor; in Comparative Example 2, ordinary commercially available polycarbonate standard material was used as the fabric, and its flame retardant performance, light transmittance, and high temperature resistance were poor. It is prepared from bisphenol A and phosgene (or diphenyl carbonate). The product has high light transmittance, but its flame retardant performance is seriously insufficient, the cost is high, and the molecular structure is too rigid, resulting in poor stress crack resistance. , unable to meet the surface application requirements of wood plastic.

Obviously, the above-mentioned embodiments are only examples for clear explanation and are not intended to limit the implementation. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. An exhaustive list of all implementations is neither necessary nor possible. The obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims (10)

1. The high-transparency high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric is characterized by comprising the following raw materials in parts by weight:

50-70 parts by weight of 2, 3-dibromo-1, 4-butanediol;

30-60 parts by weight of bisphenol F;

120-150 parts by weight of tetrabromobisphenol A;

15-25 parts by weight of trimethylolpropane;

180-300 parts by weight of diphenyl carbonate;

0.5-1 part by weight of a catalyst;

220-260 parts by weight of polyester chip granules;

0.5-1.2 parts by weight of an antioxidant;

0.8-1.5 parts by weight of an ultraviolet absorber;

the preparation method of the high-transparency high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric comprises the following steps of:

(1) Mixing the 2, 3-dibromo-1, 4-butanediol, bisphenol F, tetrabromobisphenol A, diphenyl carbonate and a catalyst according to the formula, gradually heating to 170-175 ℃ under a protective atmosphere, preserving heat for full transesterification polymerization, and collecting byproduct phenol;

(2) When the collection amount of phenol reaches 60% of the theoretical amount, adding the trimethylolpropane in the formula amount, gradually heating to 230-235 ℃, starting vacuum, and performing secondary polycondensation reaction under 20+/-2 mmHg;

(3) When the collected phenol amount reaches 85%, adding the polyester chip granules with the formula amount, heating to 275-280 ℃, starting a high vacuum system, performing high vacuum polycondensation reaction under the condition of less than 1mmHg, and distilling out residual phenol and diphenyl carbonate;

(4) And after no obvious fraction is distilled out, removing the vacuum system, adding antioxidant and ultraviolet absorbent in the formula amount, fully and uniformly mixing, pressing nitrogen, simultaneously opening the reaction kettle to carry out high Wen Fang material, and cooling, crushing and sieving the material to obtain the required co-extruded fabric particles.

2. The high transparency, high temperature resistant skin flame retardant co-extruded wood plastic composite according to claim 1, wherein:

the polyester chip granules are mineral water bottle grade polyester chip granules;

the catalyst comprises tetrabutyl titanate;

the ultraviolet absorber comprises an ultraviolet absorber UV-531;

the antioxidant includes antioxidant 1010.

3. A method for preparing the high-transparency high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric according to claim 1 or 2, which is characterized by comprising the following steps:

(1) Mixing the 2, 3-dibromo-1, 4-butanediol, bisphenol F, tetrabromobisphenol A, diphenyl carbonate and a catalyst according to the formula, gradually heating to 170-175 ℃ under a protective atmosphere, preserving heat for full transesterification polymerization, and collecting byproduct phenol;

(2) When the collection amount of phenol reaches 60% of the theoretical amount, adding the trimethylolpropane in the formula amount, gradually heating to 230-235 ℃, starting vacuum, and performing secondary polycondensation reaction under 20+/-2 mmHg;

(3) When the collected phenol amount reaches 85%, adding the polyester chip granules with the formula amount, heating to 275-280 ℃, starting a high vacuum system, performing high vacuum polycondensation reaction under the condition of less than 1mmHg, and distilling out residual phenol and diphenyl carbonate;

(4) And after no obvious fraction is distilled out, removing the vacuum system, adding antioxidant and ultraviolet absorbent in the formula amount, fully and uniformly mixing, pressing nitrogen, simultaneously opening the reaction kettle to carry out high Wen Fang material, and cooling, crushing and sieving the material to obtain the required co-extruded fabric particles.

4. The method for preparing the high-transparency high-temperature-resistant surface flame-retardant co-extruded wood-plastic fabric according to claim 3, wherein in the step (2), the heating step is performed at a rate of 8-10 ℃/h to 230-235 ℃.

5. Use of the high transparency high temperature resistant surface flame retardant co-extruded wood plastic composite material according to claim 1 or 2 for the preparation of co-extruded wood plastic composite material.

6. The high-transparency high-temperature-resistant surface flame-retardant co-extrusion wood-plastic composite material comprises a wood-plastic core material and a surface layer, and is characterized in that the surface layer is formed by co-extrusion of the high-transparency high-temperature-resistant surface flame-retardant co-extrusion wood-plastic fabric according to claim 1 or 2.

7. The co-extruded wood-plastic composite according to claim 6, wherein the wood-plastic core material comprises the following components in parts by weight:

40-50 parts by weight of high-density polyethylene;

30-40 parts of wood powder;

12-18 parts by weight of calcium carbonate;

0.5-2 parts by weight of a lubricant;

5-8 parts of compatilizer;

0.2-1 part by weight of a silane coupling agent.

8. The co-extruded wood-plastic composite according to claim 6 or 7, wherein the mass ratio of co-extruded face material forming the skin layer to raw material forming the wood-plastic core material is 0.05-0.07:1.

9. a method for preparing the high-transparency high-temperature-resistant surface flame-retardant co-extruded wood-plastic composite material according to any one of claims 6 to 8, which is characterized by comprising the following steps:

(A) Taking the preparation raw materials of the wood-plastic core material according to the selected raw materials and the mixture ratio, fully and uniformly mixing the raw materials at 100-120 ℃, and cooling and discharging to obtain a special premix for the core material; adding the mixture into a parallel double-screw extruder for extrusion granulation to obtain core material particles for later use;

(B) Preparing co-extruded fabric particles for later use according to the method of claim 3 or 4;

(C) And respectively melting the core material particles and the co-extrusion surface material particles through an extruder, then entering a core material cavity and a surface material cavity, shaping through a shaping die, cooling, shaping, and cutting to a fixed length to obtain the composite material.

10. The method for preparing the co-extruded wood-plastic composite according to claim 9, wherein:

in the step (A), in the extrusion granulating step, the temperature of a machine barrel is controlled to be 180-200 ℃, and the rotating speed of a screw is controlled to be 200-300rpm;

in the step (C), in the melting step of the co-extrusion fabric particles, the barrel temperature of an extruder is controlled to be 245-250 ℃;

in the step (C), in the step of melting the core particles, the barrel temperature of the extruder is controlled to be 190-200 ℃.