Regenerated PVB film layer and preparation method thereof

Abstract

The invention relates to the technical field of PVB membranes, and particularly discloses a regenerated PVB membrane layer and a preparation method thereof. The regenerated PVB film layer is prepared from the following raw materials in parts by weight: 80 to 100 parts of PVB waste films, 10 to 15 parts of nano particles, 10 to 20 parts of plasticizers, 1 to 5 parts of cross-linking agents, 0.5 to 0.8 part of swelling agents and 1 to 3 parts of antioxidants, according to the regenerated PVB film layer prepared by the invention, the waste PVB film sheet is used as a raw material and is compounded with components such as the plasticizer, the cross-linking agent and the nano particles, so that the prepared regenerated PVB film layer has relatively good strength and flexibility.

Description

Technical Field

[0001] The present application relates to the technical field of PVB film sheets, and in particular to a regenerated PVB film layer and a preparation method thereof. Background Art

[0002] Polyvinyl butyral (PVB) is a polymer formed by the condensation reaction of high molecular weight polyvinyl alcohol (PVA) and butyraldehyde. PVB not only has high transparency, good light resistance, cold resistance, water resistance, film-forming and impact resistance, but also has good bonding properties to glass, metal, wood, ceramics, leather and other materials.

[0003] With the increasing application of PVB film, the amount of waste PVB generated is gradually increasing. Currently, the utilization rate of waste PVB film is low, mainly because waste PVB film is used as filler, resulting in a large amount of resource waste. Summary of the invention

[0004] In order to improve the utilization rate of waste PVB film sheets, the present application provides a regenerated PVB film layer and a preparation method thereof.

[0005] In a first aspect, the present application provides a regenerated PVB film layer, using the following technical solution: A regenerated PVB film layer comprises the following raw materials in parts by weight: 80-100 parts of PVB waste film sheets, 10-15 parts of nanoparticles, 10-20 parts of plasticizers, 1-5 parts of crosslinking agents, 0.5-0.8 parts of swelling agents, and 1-3 parts of antioxidants.

[0006] By adopting the above technical scheme, waste PVB film is used as raw material, and then melted with other materials to make regenerated PVB film, the bioavailability of PVB film is improved, and the use of swelling agent in the regenerated PVB film can promote the regenerated PVB film to produce porous results, improve the air permeability and moisture permeability of the regenerated PVB film. Use plasticizer molecules to insert between PVB molecular chains, weaken the intermolecular forces, and improve the toughness and elasticity of the regenerated PVB film. The cross-linking agent can form chemical bonds between PVB molecular chains, so that different waste PVB film molecular chains can form cross-links, thereby improving the thermal stability and strength durability of the regenerated PVB film. Nanoparticles are used to enhance the strength, wear resistance and impact resistance of the regenerated PVB film. The high specific surface area and small size effect of the nanoparticles can be filled in the tiny gaps between the waste PVB matrix to form a denser structure, thereby improving the strength and impact resistance of the regenerated PVB film layer. Antioxidants can capture free radicals, reduce the breakage of PVB molecular chains, and thus increase the service life of the regenerated PVB film.

[0007] Preferably, the plasticizer is one of tributyl phosphate, triacetin, and dioctyl phthalate.

[0008] By adopting the above technical scheme, triacetin as a plasticizer is derived from renewable resources, has good biodegradability, and is environmentally friendly. The glycerol group of triacetin and the long-chain alkyl of dioctyl phthalate can form hydrogen bonds with the PVB molecular chain, be incorporated into the PVB molecular chain, enhance the interaction between molecules, and improve the strength, glossiness and chemical resistance of the PVB film. Tributyl phosphate can reduce the glass transition temperature of the PVB film, improve the flexibility and strength of the regenerated PVB film, and the phosphorus element of tributyl phosphate can form a protective phosphide layer at high temperature to prevent further contact with oxygen, thereby improving the thermal stability and aging resistance of the regenerated PVB film.

[0009] Preferably, the cross-linking agent is an isocyanate cross-linking agent.

[0010] By adopting the above technical solution, isocyanate crosslinking agents have better environmental performance compared with other types of crosslinking agents. Isocyanate crosslinking agents can react with hydroxyl groups in the PVB molecular chain to form stable carbamate bonds. The formation of such chemical bonds enhances the chemical stability of the regenerated PVB film, making it less likely for the regenerated PVB film to degrade when it encounters acid, alkali or solvent, thereby improving the durability of the regenerated PVB film.

[0011] Preferably, the nanoparticles are at least one of nano-titanium dioxide and nano-rare earth boride.

[0012] By adopting the above technical scheme, nano titanium dioxide and nano rare earth boride can improve the strength, wear resistance and impact resistance of the PVB film layer, and promote the regenerated PVB film layer to maintain good transparency. Nano titanium dioxide has good ultraviolet absorption and shielding properties, effectively blocking the direct exposure of ultraviolet rays to the PVB film, reducing the breakage of the PVB molecular chain caused by ultraviolet rays, and can decompose organic pollutants under light, promote the surface of the regenerated PVB film layer to maintain hydroxyl groups, reduce the growth of microorganisms, and improve the weather resistance, antibacterial and self-cleaning effects of the film. Nano rare earth boride has high hardness and thermal stability, and can be filled into the pores between PVB waste film and other components to form a denser structure, thereby improving the thermal stability, wear resistance and impact resistance of the regenerated PVB film layer.

[0013] Preferably, the nanoparticles are prepared into a nanoparticle dispersion in advance, comprising the following specific steps: The nano rare earth boride, solvent and surfactant are mixed evenly, and then nano titanium dioxide is added and high-speed ball milling is performed to form a nano particle dispersion.

[0014] By adopting the above technical solution, nano rare earth boride is compounded with nano titanium dioxide to form a nano particle dispersion, titanium dioxide and nano rare earth boride form chemical bonds, and internal cross-linking forms a network structure, thereby improving the toughness of the regenerated PVB film layer. Pre-forming a nano particle dispersion can reduce the agglomeration of nano particles, promote the uniform distribution of nano particles on the surface of the PVB film layer, and improve the uniformity of the PVB film layer.

[0015] Preferably, the surfactant is polyvinyl pyrrolidone.

[0016] In a second aspect, the present application provides a method for preparing a regenerated PVB film layer, using the following technical solution: A method for preparing a regenerated PVB film layer comprises the following specific steps: The PVB waste film sheets are mixed with a decolorizing agent in advance to form a mixed liquid. After the decolorization reaction, decolorized PVB waste film sheets are obtained. The decolorized PVB waste film sheets are crushed and melted with nanoparticles, a cross-linking agent, an antioxidant, and a plasticizer. Then, a swelling agent is added to heat and expand, and bidirectionally stretched into a mesh shape. After solidification, a regenerated PVB film layer is formed.

[0017] By adopting the above technical solution, the PVB waste film is first decolorized, which can reduce the influence of the color of various PVB waste film sheets and improve the reuse efficiency of PVB film sheets. Finally, the expansion agent is used for expansion, which can increase the back blockage of the PVB film, form a porous structure, and improve the air permeability of the PVB film.

[0018] Preferably, the puffing temperature is 80-120°C.

[0019] Preferably, the decolorization reaction uses a NaClO aqueous solution as a decolorizing agent, and the content of available chlorine in the NaClO aqueous solution is 13-15%.

[0020] By adopting the above technical solution, the hypochlorite ion of NaClO has strong oxidizing property and can oxidize and decompose the organic dyes and pigments in the PVB waste film, thereby achieving the effect of decolorization. Controlling the content of effective chlorine in the NaClO aqueous solution within the range of 13-15% can increase sufficient oxidizing capacity, while avoiding excessive oxidation of the PVB molecular chain, and maintaining the strength and structural stability of the PVB film.

[0021] In summary, this application has the following beneficial effects: 1. Since the present application uses waste PVB film as raw material, the regenerated PVB film prepared by using a bulking agent has good air permeability and moisture permeability. The use of a plasticizer, a cross-linking agent and nanoparticles can promote the cross-linking of different waste PVB film molecular chains, thereby improving the strength, thermal stability and impact resistance of the regenerated PVB film.

[0022] 2. In this application, nano titanium dioxide and nano rare earth boride are used as nanoparticles, and the good ultraviolet absorption and shielding properties of nano titanium dioxide are used to effectively block the direct irradiation of ultraviolet rays on the PVB film, so as to maintain the regenerated PVB film layer with good transparency, antibacterial and self-cleaning properties. Titanium dioxide and nano rare earth boride can also form chemical bonds, internal cross-linking to form a network structure, thereby improving the toughness of the regenerated PVB film layer. DETAILED DESCRIPTION

[0023] The present application is further described in detail below with reference to the embodiments.

[0024] All raw materials in the examples are commercially available. Example

[0025] Example 1 This embodiment provides a regenerated PVB film layer, comprising the following raw materials in parts by weight: 90 kg of PVB waste film, 13 kg of nanoparticles, 15 kg of plasticizer, 2 kg of crosslinking agent, 0.7 kg of swelling agent, and 2 kg of antioxidant. The nanoparticles are nanosilicon dioxide, the average particle size of the nanoparticles is 50-100 nm, the plasticizer is dioctyl phthalate, the crosslinking agent is Houding isocyanate crosslinking agent HD-8035, the swelling agent is Jusheng swelling agent, and the antioxidant is antioxidant 1010.

[0026] The preparation method of the regenerated PVB film layer comprises the following specific steps: The PVB waste film sheet is mixed with a decolorizing agent at a mass ratio of 1:30, wherein the decolorizing agent is a NaClO aqueous solution, and the content of effective chlorine in the NaClO aqueous solution is 14%. The film is vacuum decolorized at 200°C for 30 minutes, and evaporated under reduced pressure to obtain a decolorized PVB waste film sheet. The decolorized PVB waste film sheet is crushed and mixed with nanoparticles, a cross-linking agent, an antioxidant, and a plasticizer, melt-extruded at 170°C, and then a swelling agent is added to swell at 100°C, and then bidirectionally stretched in a mesh shape, and solidified to form a regenerated PVB film layer.

[0027] Example 2 The difference between Example 2 and Example 1 is that the amount of PVB waste film sheets used in the regenerated PVB film layer raw material is 80 kg, the amount of nanoparticles used is 10 kg, the amount of plasticizer used is 10 kg, the amount of cross-linking agent used is 1 kg, the amount of swelling agent used is 0.8 kg, and the amount of antioxidant used is 1 kg.

[0028] Example 3 The difference between Example 3 and Example 1 is that the amount of PVB waste film sheets used in the regenerated PVB film layer raw material is 100 kg, the amount of nanoparticles used is 15 kg, the amount of plasticizer used is 20 kg, the amount of cross-linking agent used is 5 kg, the amount of swelling agent used is 0.5 kg, and the amount of antioxidant used is 3 kg.

[0029] Example 4 The difference between Example 4 and Example 1 is that the plasticizer in the regenerated PVB film layer raw material is tributyl phosphate.

[0030] Example 5 The difference between Example 5 and Example 1 is that the plasticizer in the regenerated PVB film layer raw material is triacetin.

[0031] Example 6 The difference between Example 6 and Example 1 is that the nanoparticles in the raw material of the regenerated PVB film layer are nano-titanium dioxide.

[0032] Example 7 The difference between Example 7 and Example 1 is that the nanoparticles in the raw material of the regenerated PVB film layer are nano rare earth boride, wherein the nano rare earth boride is lanthanum hexaboride powder.

[0033] Example 8 The difference between Example 8 and Example 1 is that the nanoparticles in the raw material of the regenerated PVB film layer are a mixture of nano rare earth boride and nano titanium dioxide, wherein the mass ratio of the nano rare earth boride to the nano titanium dioxide is 1:1.

[0034] The preparation method of the regenerated PVB film layer comprises the following specific steps: The nano rare earth boride and nano titanium dioxide are mixed and ground in advance to obtain nano particles; then the PVB waste film sheet is mixed with a decolorant in a mass ratio of 1:30, the decolorant is a NaClO aqueous solution, the content of effective chlorine in the NaClO aqueous solution is 14%, vacuum decolorization is performed at 200°C for 30 minutes, and reduced pressure evaporation is performed to obtain decolorized PVB waste film sheets; the decolorized PVB waste film sheets are crushed and mixed with nano particles, a cross-linking agent, an antioxidant and a plasticizer, melt extruded at 170°C, and then a swelling agent is added to swell at 100°C, and then bidirectionally stretched in a mesh shape, and solidified to form a regenerated PVB film layer.

[0035] Example 9 The difference between Example 9 and Example 8 is that the nanoparticles are prepared in advance in the regenerated PVB film layer raw material into a nanoparticle dispersion.

[0036] The preparation method of the regenerated PVB film layer comprises the following specific steps: S1: Mix nano rare earth boride, anhydrous ethanol and surfactant evenly, the mass ratio of nano rare earth boride, anhydrous ethanol and surfactant is 1:1:1, and the surfactant is polyvinyl pyrrolidone K-30. Then add nano titanium dioxide and ball mill at a speed of 1000r / min for 10 minutes to form a nanoparticle dispersion.

[0037] S2: PVB waste film sheets are mixed with a decolorizing agent at a mass ratio of 1:30, wherein the decolorizing agent is a NaClO aqueous solution, and the content of effective chlorine in the NaClO aqueous solution is 14%. The mixture is vacuum decolorized at 200°C for 30 minutes, and evaporated under reduced pressure to obtain decolorized PVB waste film sheets. The decolorized PVB waste film sheets are crushed and mixed with a nanoparticle dispersion, a cross-linking agent, an antioxidant, and a plasticizer, melt-extruded at 170°C, and then expanded at 100°C by adding a swelling agent, and then bidirectionally stretched in a mesh shape, and solidified to form a regenerated PVB film layer.

[0038] Example 10 The difference between Example 10 and Example 9 is that no surfactant is used in the preparation of the nanoparticle dispersion.

[0039] The preparation method of the regenerated PVB film layer comprises the following specific steps: S1: Mix nano rare earth boride and anhydrous ethanol evenly, the mass ratio of nano rare earth boride and anhydrous ethanol is 1:1, then add nano titanium dioxide, and ball mill at a speed of 1000 r / min for 10 minutes to form a nanoparticle dispersion.

[0040] S2: PVB waste film sheets are mixed with a decolorizing agent at a mass ratio of 1:30, wherein the decolorizing agent is a NaClO aqueous solution, and the content of effective chlorine in the NaClO aqueous solution is 14%. The mixture is vacuum decolorized at 200°C for 30 minutes, and evaporated under reduced pressure to obtain decolorized PVB waste film sheets. The decolorized PVB waste film sheets are crushed and mixed with a nanoparticle dispersion, a cross-linking agent, an antioxidant, and a plasticizer, melt-extruded at 170°C, and then expanded at 100°C by adding a swelling agent, and then bidirectionally stretched in a mesh shape, and solidified to form a regenerated PVB film layer.

[0041] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that no plasticizer is used in the recycled PVB film layer raw material.

[0042] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that no plasticizer and cross-linking agent are used in the recycled PVB film layer raw material.

[0043] Performance testing The following performance tests were performed on the regenerated PVB film layers provided in Examples 1-10 and Comparative Examples 1-2 of the present application, and the specific test results are shown in Table 1.

[0044] Detection Methods 1. Tensile strength Referring to the standard of ASTM D638 "Tensile Properties of Plastics", the tensile strength and elongation at break of the regenerated PVB film layer prepared in the present application were tested. The regenerated PVB film layer was placed at 80° C. for 30 minutes, and then the tensile strength of the regenerated PVB film layer was tested.

[0045] 2. Haze The haze of the regenerated PVB film layer prepared in the present application was tested with reference to the standard of GB / T2410-2008 "Determination of light transmittance and haze of transparent plastics".

[0046] Table 1: Performance test results data table It can be seen from the performance test results that the regenerated PVB film layer prepared in the present application has good strength and toughness, and at the same time maintains a low haze after decolorization treatment.

[0047] By comparing Examples 4 and 5 with Example 1, it can be seen that the plasticizer in Example 4 is tributyl phosphate, and the plasticizer in Example 5 is triacetin. From the performance test results, it can be seen that the comprehensive performance of the plasticizers used in Examples 4 and 1 is better, but the environmental performance of triacetin used in Example 5 is better.

[0048] By comparing Examples 6, 7, and 8 with Example 1, it can be seen that the nanoparticles in Example 6 are nano-titanium dioxide, and the nanoparticles in Example 7 are nano-rare earth boride. From the performance test results, it can be seen that the nanoparticles used in Example 8 are a mixture of nano-rare earth boride and nano-titanium dioxide, which is more excellent. It further shows that titanium dioxide can form a chemical bond with nano-rare earth boride to form a network structure, further improving the tensile strength and elongation at break of the regenerated PVB film layer.

[0049] It can be seen from Examples 9-10 that the nanoparticles are made into a nanoparticle dispersion in advance, and the comprehensive performance of Example 9 is better, which further illustrates that making the nanoparticles into a dispersion in advance helps to improve the dispersibility of the nanoparticles, enables the nanoparticles to be evenly dispersed on the surface of the PVB film, and improves the uniformity of the PVB film.

[0050] By comparing Comparative Examples 1-2 with Example 1, it can be seen that changing any component in the raw material of the regenerated PVB film prepared in the present application will affect the prepared regenerated PVB film, resulting in a decrease in the performance of the PVB film.

[0051] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A regenerated PVB film layer, characterized in that: The invention comprises the following raw materials in parts by weight: 80-100 parts of PVB waste film sheets, 10-15 parts of nano particles, 10-20 parts of plasticizer, 1-5 parts of cross-linking agent, 0.5-0.8 parts of swelling agent and 1-3 parts of antioxidant.

2. The regenerated PVB film layer according to claim 1, characterized in that: The plasticizer is one of tributyl phosphate, triacetin, and dioctyl phthalate.

3. The regenerated PVB film layer according to claim 1, characterized in that: The cross-linking agent is an isocyanate cross-linking agent.

4. The regenerated PVB film layer according to claim 1, characterized in that: The nanoparticles are at least one of nano titanium dioxide and nano rare earth boride.

5. The regenerated PVB film layer according to claim 4, characterized in that: The nanoparticles are prepared into a nanoparticle dispersion in advance, including the following specific steps: The nano rare earth boride, solvent and surfactant are mixed evenly, and then nano titanium dioxide is added and high-speed ball milling is performed to form a nano particle dispersion.

6. The regenerated PVB film layer according to claim 5, characterized in that: The surfactant is polyvinyl pyrrolidone.

7. A method for preparing a regenerated PVB film layer as claimed in claims 1 to 6, characterized in that: The specific steps include: The PVB waste film sheets are mixed with a decolorizing agent in advance to form a mixed liquid. After the decolorization reaction, decolorized PVB waste film sheets are obtained. The decolorized PVB waste film sheets are crushed and melted with nanoparticles, a cross-linking agent, an antioxidant, and a plasticizer. Then, a swelling agent is added to heat and expand, and bidirectionally stretched into a mesh shape. After solidification, a regenerated PVB film layer is formed.

8. The method for preparing a regenerated PVB film layer according to claim 7, characterized in that: The puffing temperature is 80-120°C.

9. The method for preparing a regenerated PVB film layer according to claim 7, characterized in that: The decolorization reaction uses a NaClO aqueous solution as a decolorizing agent, and the content of effective chlorine in the NaClO aqueous solution is 13-15%.

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