A bio-based composite decorative film and its preparation method

Abstract

The present invention relates to a bio-based composite decorative film and a preparation method thereof, belonging to the technical field of polymer materials. The decorative film comprises, by weight parts: 80-100 parts of PVC resin, 20-30 parts of linear low density polyethylene, 24-32 parts of bio-based toughening agent, 8-12 parts of active calcium carbonate, 2.5-3.5 parts of heat stabilizer and 1.5-2 parts of lubricant; The bio-based toughening agent uses tung oil as the base material, introduces functional fluorine-containing groups through click reaction of pentafluoropentanethiol, then undergoes alcoholysis with hexahydroxymethylmelamine, and finally is esterified with formic acid. Its end annular branched methyl ester structure plays a guiding and anchoring role, has excellent toughening effect, small addition amount, little influence on the mechanical properties of the matrix, and is not easy to migrate and segregate during long-term service, improving the durability of the film material.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and specifically, relates to a bio-based composite decorative film and a preparation method thereof. Background Art

[0002] A decorative film is a new type of decorative material made from a polymer polymer as a raw material, adding various additives, and obtained by calendering and compounding. It can be compounded with substrates such as wood, plastic plates, aluminum plates, iron plates, etc. to make multi-purpose decorative materials, and is widely used in the surface decoration of household appliances, audio, interior decoration, and the interior decoration of airplanes, ships, and trains. Among them, PVC (polyvinyl chloride) has become the mainstream material of the decorative film due to its comprehensive properties such as wear resistance, good toughness, and high processability.

[0003] However, pure PVC is relatively brittle, and PVC materials generally used for film materials need to be toughened. The most widely used technical means is to dope a certain amount of toughening agent into PVC to weaken the intermolecular force between PVC molecular chains, so as to achieve the toughening effect. Common toughening agents in the prior art include chemically synthesized materials such as dibutyl phthalate, dioctyl phthalate, bis(2-ethylhexyl) phthalate, etc. The effect of this type of toughening agent is good, but the dosage in the film material is large, and problems such as migration and segregation are likely to occur during long-term service, resulting in environmental pollution and deterioration of the mechanical properties of the product; with the improvement of detection technology and people's health awareness, easily permeable chemical plasticizers are gradually replaced by environmentally friendly biomass plasticizers, such as castor oil, linseed oil, soybean oil, etc. This type of plasticizer is not easy to migrate and is environmentally friendly, but this type of plasticizer is not easy to disperse and the plasticization stability is general; therefore, the present application aims to use tung oil as a substrate, make a plasticizer through deep processing, and apply it to PVC decorative films. Summary of the Invention

[0004] In order to solve the technical problems mentioned in the background art, the purpose of the present invention is to provide a bio-based composite decorative film and a preparation method thereof.

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

[0006] A bio-based composite decorative film, comprising the following raw materials by weight:

[0007] 80-100 parts of PVC resin, 20-30 parts of linear low-density polyethylene, 24-32 parts of bio-based toughening agent, 8-12 parts of active calcium carbonate, 2.5-3.5 parts of heat stabilizer, and 1.5-2 parts of lubricant;

[0008] The bio-based toughening agent is prepared by the following method:

[0009] Step A1: Mix tung oil, dimethylphenylphosphine and toluene, protect with nitrogen, heat up to 50 - 60 °C, apply mechanical stirring at 120 - 180 rpm, and supplement with ultraviolet irradiation of 100 - 150 W / m 2 , intermittently add pentafluoropentanethiol, control the total addition reaction time to be 1.5 - 2 h, and remove toluene by rotary evaporation under reduced pressure after the reaction to obtain a fluorinated matrix;

[0010] Furthermore, the dosage ratio of tung oil, pentafluoropentanethiol, dimethylphenylphosphine and toluene is 100 g : 0.65 - 0.75 mol : 0.3 - 0.5 g : 130 - 160 mL. Under the catalysis of dimethylphenylphosphine and the promotion of ultraviolet irradiation, the click reaction occurs between the pentafluoropentanethiol and the unsaturated double bonds in the tung oil molecules, introducing functional fluorine-containing groups onto the long chain of the tung oil molecules, and simultaneously pre-treating the unsaturated long chain to avoid gelation during subsequent processing.

[0011] Step A2: Pre-heat and stir-mix hexamethylolmelamine and dimethylacetamide, then add the fluorinated matrix and mix. Continue to heat up to 80 - 90 °C, apply mechanical stirring at 240 - 360 rpm, slowly add sodium methoxide and reflux for reaction, control the total addition reaction time to be 3 - 4 h, wash with water after the reaction, remove the aqueous phase, and dry to obtain an alcoholysis matrix;

[0012] Furthermore, the dosage ratio of the fluorinated matrix, hexamethylolmelamine, sodium methoxide and dimethylacetamide is 100 g : 0.32 - 0.35 mol : 6 - 8 mL : 220 - 280 mL. Under the strong alkalinity promotion of sodium methoxide, the fluorinated matrix and hexamethylolmelamine undergo alcoholysis to form a compound with a branched hydroxyl group at one end.

[0013] Step A3: Mix the alcoholysis matrix and thionyl chloride, pre-heat to 60 - 70 °C and stir for activation for 15 - 20 min, then add formic acid and anhydrous calcium chloride, continue to heat up to 80 - 90 °C, apply mechanical stirring at 120 - 180 rpm, react for 3 - 3.5 h, remove the excess formic acid by rotary evaporation under reduced pressure, wash the rotary evaporation substrate with water and dry after cooling to obtain a bio-based toughening agent;

[0014] Furthermore, the dosage ratio of the alcoholysis matrix, formic acid, thionyl chloride and anhydrous calcium chloride is 100 g : 240 - 280 mL : 100 - 150 mL : 30 - 40 g. Thionyl chloride activates the terminal hydroxyl group of the alcoholysis matrix, and then esterifies with formic acid to form a terminal branched methyl ester structure modification.

[0015] Furthermore, the PVC resin is SG-5 type resin.

[0016] Furthermore, the heat stabilizer is a calcium-zinc stabilizer.

[0017] Furthermore, the lubricant is a mixture of PE wax and calcium stearate.

[0018] A preparation method of a bio-based composite decorative film specifically includes the following steps:

[0019] Step S1: Add each raw material according to the weight ratio to a mixer for high-speed mixing, and then extrude and granulate the mixture to obtain a composite masterbatch;

[0020] Step S2: Add the composite masterbatch to a calender, control the extrusion temperature at 180 - 190 °C, the die pressure at 0.8 - 1.0 MPa, extrude into a sheet, and roll and shape it into a bio-based composite decorative film.

[0021] Beneficial effects:

[0022] In this invention, tung oil, a biomass raw material, is used as the base material, and through chemical modification treatment, a bio-based toughening agent is made. Applying it in the PVC matrix plays an excellent and stable plasticizing role; this bio-based toughening agent first undergoes a click reaction between pentafluoropentanethiol and the unsaturated double bonds in the tung oil molecules to introduce functional fluorine-containing groups, and pre-treats the unsaturated long chains to avoid the gelation of tung oil. Then, hexamethylolmelamine alcoholyzes the fluorinated matrix under alkaline conditions to form a compound with a cyclic branched hydroxyl structure at one end, and then esterifies and modifies it with formic acid; the end cyclic branched methyl ester structure of the bio-based toughening agent has good compatibility with the PVC matrix and can play a guiding role. During the mixing and plasticizing process, the bio-based toughening agent can be evenly dispersed into the matrix to play a doping plasticizing role. Due to the guiding role, the fluorine structure is also dispersed into the matrix, and its segregation with the matrix greatly reduces the intermolecular force between the matrix molecular chains, playing a strong plasticizing role. Compared with the existing plasticizers, it has a better plasticizing effect, a lower usage amount, and less impact on the strength and toughness of the matrix; in addition, the end cyclic branched methyl ester structure of the bio-based toughening agent is easy to embed in the matrix to form an anchoring effect and is not prone to migration and segregation during long-term service, improving the durability of the decorative film; furthermore, the end branched methyl ester structure contains a large amount of nitrogen elements, which can also improve the flame retardant performance of the decorative film to a certain extent. Specific embodiments

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in combination with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope protected by the present invention.

[0024] To clearly explain the implementation process of the following embodiments, the sources of the raw materials used are disclosed as follows:

[0025] Tung oil, refined native tung oil, provided by Tongyuan Oil Industry Co., Ltd., Xingyi City, Guizhou Province;

[0026] PVC resin, selected from SG-5 type PVC resin powder, provided by Shanghai Jiang's Plastic Co., Ltd.;

[0027] Linear low density polyethylene, model 1C7A, provided by Suzhou Shisheng Plastic Co., Ltd.;

[0028] Activated calcium carbonate, model NC-90, provided by Quanzhou Xufeng Powder Raw Material Co., Ltd.;

[0029] Heat stabilizer, calcium-zinc stabilizer TCS-108A-B, provided by Shandong Jinchang Resin New Material Technology Co., Ltd.;

[0030] Lubricant, composed of PE wax and calcium stearate mixed in a mass ratio of 3:1. The model of PE wax is TS-5218, provided by Nanjing Tianshi New Material Technology Co., Ltd., and the model of calcium stearate is CS-BE, provided by Anhui Ruihua New Material Co., Ltd.

[0031] Example 1

[0032] In this example, a bio-based composite decorative film was prepared, and the specific implementation process is as follows:

[0033] 1) Preparation of bio-based toughening agent

[0034] 1.1. Take tung oil, dimethylphenylphosphine and toluene and feed them into the mixture, introduce nitrogen protection, heat up to 60 °C, apply mechanical stirring at 120 rpm, and supplement with ultraviolet irradiation of 100 W / m 2 Take pentafluoropentanethiol and divide it into two parts, add it to the reaction system intermittently for 30 min, and control the total addition reaction time of pentafluoropentanethiol to be 2 h. During the reaction, the dosage ratio of tung oil, pentafluoropentanethiol, dimethylphenylphosphine and toluene is 100 g: 0.65 mol: 0.3 g: 130 mL. After the reaction, remove toluene by rotary evaporation under reduced pressure to obtain a fluorinated matrix.

[0035] 1.2. Take hexahydroxymethylmelamine and dimethylacetamide and feed them in, apply mechanical stirring at 120 rpm, pre-heat the mixture to 50 °C for mixing, then add the fluorinated matrix for mixing, continue to heat up to 80 °C, increase the stirring rate to 240 rpm, slowly add sodium methoxide for reflux reaction within 3 h, and control the total addition reaction time of sodium methoxide to be 4 h. During the reaction, the dosage ratio of the fluorinated matrix, hexahydroxymethylmelamine, sodium methoxide and dimethylacetamide is 100 g: 0.32 mol: 6 mL: 220 mL. After the reaction, add 2.5 times the mass of the reaction system of water for high-speed stirring and washing, remove the aqueous phase and dry until water analysis shows precipitation to obtain an alcoholysis matrix.

[0036] 1.3. Take the alcoholysis matrix and thionyl chloride, feed and mix them, apply mechanical stirring at 300 rpm and heat up to 60 °C for activation for 20 min. Then add formic acid and anhydrous calcium chloride, continue to heat up to 80 °C, reduce the stirring rate to 120 rpm, and react for 3.5 h. During the reaction, the dosage ratio of the alcoholysis matrix, formic acid, thionyl chloride and anhydrous calcium chloride is 100 g: 240 mL: 100 mL: 30 g. After the reaction, rotary evaporation is used to remove the excessive formic acid. After cooling, add 0.3 times the mass of water to the reaction system for washing, remove the aqueous phase, and dry it under vacuum to obtain the bio-based toughening agent.

[0037] 2) Prepare the bio-based composite decorative film

[0038] 2.1. Take the following raw materials according to weight parts:

[0039] 90 parts of PVC resin, 30 parts of linear low-density polyethylene, 32 parts of bio-based toughening agent (prepared in this example), 12 parts of active calcium carbonate, 3.2 parts of heat stabilizer, and 2 parts of lubricant.

[0040] 2.2. Feed all the raw materials into a mixer and mix them at a high speed of 2000 rpm for 5 min. Then feed the mixed material into a twin-screw extruder, and control the barrel temperature settings as follows: zone 1 at 170 °C, zone 2 at 185 °C, zone 3 at 195 °C, zone 4 at 195 °C, zone 5 at 195 °C, zone 6 at 190 °C, and the die temperature at 200 °C. Extrude the molten material into pellets to obtain the composite masterbatch.

[0041] 2.3. Feed the composite masterbatch into a calender, control the extrusion temperature at 180 °C and the die pressure at 0.8 MPa. Extrude the composite masterbatch into a sheet in a molten state, and then roll and shape it. After cooling, a bio-based composite decorative film is made.

[0042] Example 2

[0043] In this example, the bio-based composite decorative film is prepared, and the specific implementation process is as follows:

[0044] 1) Prepare the bio-based toughening agent

[0045] 1.1. Take tung oil, dimethylphenylphosphine and toluene, feed and mix them, introduce nitrogen for protection, heat up to 60 °C, apply mechanical stirring at 180 rpm, and supplement with ultraviolet irradiation of 150 W / m 2 . Divide pentafluoropentanethiol into two parts and add it to the reaction system intermittently for 30 min, and control the total addition reaction time of pentafluoropentanethiol to be 1.5 h. During the reaction, the dosage ratio of tung oil, pentafluoropentanethiol, dimethylphenylphosphine and toluene is 100 g: 0.75 mol: 0.5 g: 160 mL. After the reaction, rotary evaporation under reduced pressure is used to remove toluene to obtain the fluorinated matrix.

[0046] 1.2. Charge hexamethylol melamine and dimethylacetamide, apply mechanical stirring at 120 rpm, preheat the mixture to 50 °C for mixing, then add the fluorinated matrix for mixing, continue to heat up to 90 °C, increase the stirring rate to 360 rpm, slowly add sodium methoxide for reflux reaction within 2 h, control the total addition reaction time of sodium methoxide to be 3 h. During the reaction, the dosage ratio of the fluorinated matrix, hexamethylol melamine, sodium methoxide and dimethylacetamide is 100 g: 0.35 mol: 8 mL: 280 mL. After the reaction, add water three times the mass of the reaction system for high-speed stirring and washing, remove the aqueous phase and then dry until water analysis shows precipitation, to obtain the alcoholysis matrix.

[0047] 1.3. Charge the alcoholysis matrix and thionyl chloride for mixing, apply mechanical stirring at 300 rpm and heat up to 70 °C for activation for 15 min, then add formic acid and anhydrous calcium chloride, continue to heat up to 90 °C, reduce the stirring rate to 180 rpm, and react for 3 h. During the reaction, the dosage ratio of the alcoholysis matrix, formic acid, thionyl chloride and anhydrous calcium chloride is 100 g: 280 mL: 150 mL: 40 g. After the reaction, rotary evaporate to remove the excess formic acid, cool and then add 0.3 times the mass of water to the reaction system for washing, remove the aqueous phase, and dry under vacuum to obtain the bio-based toughening agent.

[0048] 2) Preparation of bio-based composite decorative film

[0049] 2.1. Take the following raw materials according to parts by weight:

[0050] 80 parts of PVC resin, 20 parts of linear low-density polyethylene, 24 parts of bio-based toughening agent (prepared in this embodiment), 8 parts of active calcium carbonate, 2.5 parts of heat stabilizer, 1.5 parts of lubricant.

[0051] 2.2. Add each raw material to a mixer and mix at a high speed of 2000 rpm for 5 min, then add the mixed material to a twin-screw extruder, control the barrel temperature settings as follows: zone 1 at 170 °C, zone 2 at 180 °C, zone 3 at 190 °C, zone 4 at 200 °C, zone 5 at 200 °C, zone 6 at 190 °C, and the die temperature at 200 °C, and extrude the molten material into pellets to obtain the composite masterbatch.

[0052] 2.3. Add the composite masterbatch to a calender, control the extrusion temperature at 190 °C and the die pressure at 1.0 MPa, melt-extrude the composite masterbatch into sheets, and then roll and shape it, and cool to make the bio-based composite decorative film.

[0053] Example 3

[0054] The bio-based composite decorative film is prepared in this example, and the specific implementation process is as follows:

[0055] 1) Preparation of bio-based toughening agent

[0056] 1.1. Take tung oil, dimethylphenylphosphine and toluene, feed and mix them, introduce nitrogen for protection, heat up to 60 °C, apply mechanical stirring at 180 rpm, and supplement with ultraviolet irradiation of 120 W / m 2 2

[0057]

[0057]

[0058]

[0058]

[0059] 2) Preparation of bio-based composite decorative film

[0060] 2.1. Take the following raw materials by weight parts:

[0061] 100 parts of PVC resin, 28 parts of linear low-density polyethylene, 30 parts of bio-based toughening agent (prepared in this embodiment), 11 parts of active calcium carbonate, 3.5 parts of heat stabilizer, 1.8 parts of lubricant.

[0062] 2.2. Feed each raw material into a mixer, mix at a high speed of 2000 rpm for 5 min, then feed the mixed material into a twin-screw extruder, control the barrel temperature settings as follows: zone 1 at 170 °C, zone 2 at 180 °C, zone 3 at 190 °C, zone 4 at 190 °C, zone 5 at 200 °C, zone 6 at 190 °C, and the die temperature at 200 °C, and extrude and pelletize the molten material to obtain composite masterbatch.

[0063] 2.3. Add the composite masterbatch into the calender, control the extrusion temperature at 180 °C and the die pressure at 0.9 MPa, melt and extrude the composite masterbatch into a sheet, and then roll and shape it. After cooling, a bio-based composite decorative film is made.

[0064] Comparative Example

[0065] This comparative example is a decorative film in production, and its formula is: 80 - 100 parts of PVC resin, 20 - 30 parts of linear low-density polyethylene, 42 parts of toughening agent DEHP (di(2-ethylhexyl) phthalate), 18 parts of activated calcium carbonate, 2.5 - 3.5 parts of heat stabilizer, and 1.5 - 2 parts of lubricant. After melting and extrusion granulation, it is then calendered and formed.

[0066] Take the film materials prepared in Examples 1 - 3 and the film material provided in the comparative example, and test the tensile properties, tear properties, and surface contact angle of the film materials as follows:

[0067] Tensile property test: Refer to the ASTM D638-2014 standard, and dumbbell-shaped specimens are made longitudinally. The test area specification is 40 × 10 mm, and the tensile rate is 200 mm / min.

[0068] Tear property test: Refer to the ASTM D1004-2013 standard, and samples are made transversely and longitudinally respectively. The test area specification is 90° × 15 mm, and the tensile rate is 200 mm / min.

[0069] Contact angle test: Implement according to the GB / T 30447-2013 standard.

[0070] The specific test data are shown in Table 1:

[0071] Table 1

[0072]

[0073] As can be seen from the data in Table 1, the tensile strength and tear strength of the film materials prepared in the examples are higher than those in the comparative example, and the elongation at break is also higher than that in the comparative example. Compared with the existing decorative film materials, the film materials prepared in the present invention have better strength and toughness. At the same time, the surface contact angle of the film materials prepared in the present invention reaches more than 97°, showing certain hydrophobicity and better stain resistance in practical applications.

[0074] To verify the durability of the film material prepared by the present invention, samples were taken from the film materials provided in the examples and comparative examples, and the samples were subjected to a thermal cycling test. The specific test method was as follows: The samples were placed in an oven and left standing for 12 h at a temperature of 50 ± 1 °C, and a 200 W incandescent lamp was turned on for irradiation in the oven. Then, they were placed in a freezer and left standing for 6 h at a temperature of -5 ± 1 °C, and the freezer was closed and dark. After 1800 h of cycling, the samples were taken again for tensile property testing and contact angle testing. The specific test data are shown in Table 2:

[0075] Table 2

[0076]

[0077]

[0078] As can be seen from the data in Table 2, the film materials prepared in the examples had a relatively small decrease in mechanical properties after thermal cycling, and the tensile strength and elongation at break remained above 90%. However, the properties of the comparative examples deteriorated significantly, and the surface became roughened, with a smaller contact angle and being more prone to stain contamination.

[0079] In the description of the specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0080] The above content is only an example and illustration of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the specific embodiments described or use similar ways to substitute them. As long as they do not deviate from the invention or exceed the scope defined by the claims of this patent, they should fall within the protection scope of the present invention.

Claims

1. A bio-based composite decorative film, characterized in that: The composition comprises, by weight: 80-100 parts of PVC resin, 20-30 parts of linear low-density polyethylene, 24-32 parts of bio-based toughening agent, 8-12 parts of activated calcium carbonate, 2.5-3.5 parts of heat stabilizer and 1.5-2 parts of lubricant; The bio-based toughening agent is prepared by the following method: Step A1: Tung oil, dimethylphenylphosphine, and toluene are mixed, protected by nitrogen, and heated to 50-60°C. Stirred and irradiated with ultraviolet light, and pentafluoropentanethiol is added intermittently. The total reaction time is controlled to be 1.5-2 hours. After the reaction is completed, toluene is removed by vacuum rotary evaporation to obtain a fluorinated matrix, wherein the ratio of tung oil, pentafluoropentanethiol, dimethylphenylphosphine, and toluene is 100g:0.65-0.75mol:0.3-0.5g:130-160mL; Step A2: preheating hexahydroxymethylmelamine and dimethylacetamide and stirring to mix, then adding the fluorinated matrix and mixing, continuing to heat to 80-90°C, stirring and slowly adding sodium methoxide to reflux for reaction, controlling the total reaction time to be 3-4 hours. After the reaction is completed, washing with water, removing the aqueous phase, and drying to obtain an alcoholysis matrix, wherein the amount ratio of the fluorinated matrix, hexahydroxymethylmelamine, sodium methoxide, and dimethylacetamide is 100 g: 0.32-0.35 mol: 6-8 mL: 220-280 mL; Step A3: The alcoholysis matrix and thionyl chloride are mixed, preheated to 60-70°C and stirred for activation for 15-20 minutes, then formic acid and anhydrous calcium chloride are added, the temperature is continued to be raised to 80-90°C, and the reaction is stirred for 3-3.5 hours. Excess formic acid is removed by vacuum rotary evaporation, and after cooling, the rotary evaporation substrate is washed with water and dried to obtain a bio-based toughening agent, wherein the usage ratio of the alcoholysis matrix, formic acid, thionyl chloride and anhydrous calcium chloride is 100g:240-280mL:100-150mL:30-40g.

2. The bio-based composite decorative film according to claim 1, characterized in that: The PVC resin is SG-5 type resin.

3. The bio-based composite decorative film according to claim 1, characterized in that: The heat stabilizer is calcium zinc stabilizer.

4. The bio-based composite decorative film according to claim 1, characterized in that: The lubricant is a mixture of PE wax and calcium stearate.

5. The method for preparing a bio-based composite decorative film according to claim 1, characterized in that: The steps include: Step S1: adding the raw materials according to the weight ratio into a mixer and mixing at high speed, and then extruding the mixture into granules to obtain a composite masterbatch; Step S2: adding the composite masterbatch into a calender, controlling the extrusion temperature to be 180-190° C. and the die pressure to be 0.8-1.0 MPa, extruding the sheet, and rolling and shaping the sheet to form a bio-based composite decorative film.

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