A transparent pvc film and a method for producing the same

Abstract

The present application provides a kind of transparent PVB film and its preparation method, its characteristics are: by first layer PVB film, second layer PVB film and third layer PVB film sequentially stacked sandwich structure.The first, third layer PVB film includes the following weight parts of components: PVB resin powder: 50-80;Plasticizer: 15-35;Antioxidant: 0.1-3;Ultraviolet absorber: 0.1-3;Second layer PVB film includes the following weight parts of components: PVB resin powder: 50-80;Plasticizer: 15-35;Antioxidant: 0.1-3;Ultraviolet absorber: 0.1-3;Silica gel mixed solution: 0.1-20.The transparent PVB film has the characteristics of simple structure, high tensile strength, high transparency and low haze, place it between two pieces of glass, and get high transparency, low haze laminated glass under the treatment of specific temperature, specific pressure, specific time using flat vulcanizing machine.

Description

Technical Field

[0001] This invention belongs to the field of chemical production technology and relates to the improvement of PVB production technology, specifically a transparent PVB film and its preparation method. Background Technology

[0002] PVB membranes are thermoformed by mixing polyvinyl butyral resin with a certain plasticizer under high temperature conditions. The hydroxyl groups on the polymer in these membranes can react with the silanol on the glass, thus tightly bonding the glass sheet to the interlayer material. This glass-membrane-glass structure is called safety glass. This interlayer material greatly improves the performance of the glass after breakage, especially by transferring the energy of the breakage to the interior of the PVB membrane. The interior of the PVB membrane effectively disperses energy, and its surface adhesion helps to bind the broken glass to the surface, reducing damage caused by direct contact between the broken glass and the outside. Currently, safety glass using PVB as the interlayer is widely used.

[0003] Currently, thanks to the widespread application of safety glass with PVB interlayer, various industries have put forward new and different requirements for this type of safety glass, and PVB film has also undergone extensive new developments. Adding other materials to PVB film can effectively improve its overall performance.

[0004] Chinese patent CN102417682A obtained a high tensile strength PVB film by adding silane coupling agent, ultraviolet absorber nano-inorganic powder and nanocellulose, mixing them evenly in a mixer and then directly extruding them through a twin-screw extruder.

[0005] Chinese patent CN103044827A describes a process where polyethylene glycol, plasticizer, antioxidant, and ultraviolet absorber are mixed and then added to PVB resin powder. The mixture is then stirred and mixed using a twin-screw extruder and plasticized at high temperature to obtain a PVB film with sound insulation properties.

[0006] Chinese patent CN103044828B disperses ITO nanoparticles into a PVB organic solution, then grinds them using a ball mill to form a nanoemulsion. This nanoemulsion is then mixed with a plasticizer in a certain proportion into the PVB resin, and finally thermoplasticized to obtain a PVB film with sound insulation properties.

[0007] Chinese patent CN103214977A obtains a PVB resin with intelligent dimming properties by dispersing vanadium dioxide nanoparticles into an organic solvent system, mixing the dispersion with PVB resin powder, and then coating or extruding the mixture.

[0008] Chinese patent CN103531328A obtained a magnetic PVB film by mixing magnetic powder, coupling agent, plasticizer and PVB resin in a high-speed mixer, and then plasticizing it at high temperature using a twin-screw extruder.

[0009] Chinese patent CN112724689B utilizes bentonite treated in a rare earth medium, grafted onto PVB resin, and then sequentially adds the grafted PVB resin, weather-resistant agent, and active dispersant into a high-speed mixer for mixing. The mixture is then extruded through a twin-screw extruder to obtain a PVB film with good weather resistance.

[0010] Chinese patents CN106003922A, CN105835497B, and CN108032579B obtain special PVB films by preparing intermediate films with different properties and mixing and pressing the intermediate films with normal PVB films.

[0011] While improving the strength of PVB films, the influence of reinforcing materials on the optical properties of the PVB films themselves cannot be ignored. To improve the overall performance of PVB by adding other modifying materials, it is often necessary to modify the PVB materials to improve the compatibility of the modifying materials in PVB, thereby improving the overall performance of the film. Currently, high-strength films with high transparency and low haze are still relatively rare.

[0012] Therefore, how to design a transparent PVB film and its preparation method, with optical performance (haze, transparency) as an important reference indicator, aims to prepare a PVB film with excellent mechanical properties, and at the same time, to make preventive improvement measures for possible poor optical performance indicators, so as to obtain a PVB film with excellent comprehensive performance. This is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0013] To address the aforementioned problems in the prior art, this invention provides a transparent PVB film and its preparation method. The PVB film features a simple structure, high tensile strength, high transparency, and low haze.

[0014] The objective of this invention is achieved through the following technical solution:

[0015] A transparent PVB film, characterized in that the transparent PVB film is a sandwich structure formed by sequentially stacking a first layer of PVB film, a second layer of PVB film, and a third layer of PVB film.

[0016] Improvement to the above technical solution: Both the first PVB film layer and the third PVB film layer comprise the following components in parts by weight:

[0017] PVB resin powder: 50-80

[0018] Plasticizer: 15-35

[0019] Antioxidant: 0.1-3

[0020] Ultraviolet absorber: 0.1-3

[0021] The second PVB film comprises the following components in parts by weight:

[0022] PVB resin powder: 50-80

[0023] Plasticizer: 15-35

[0024] Antioxidant: 0.1-3

[0025] Ultraviolet absorber: 0.1-3

[0026] Silica gel mixture: 0.1-20.

[0027] Improvement to the above technical solution: The components and weight parts of the silica gel mixture include:

[0028] Tetraethyl orthosilicate: 1-30

[0029] Ethanol: 0-300

[0030] Water: 10-70

[0031] Hydrolysis catalyst: 0.01–30

[0032] Silane coupling agent: 0.01-10.

[0033] The present invention provides a method for preparing the above-mentioned transparent PVB film, characterized by comprising the following steps:

[0034] Preparation of the first and third PVB film layers: Antioxidant, ultraviolet absorber and plasticizer are mixed evenly in a certain proportion to obtain plasticizer mixed dispersion; PVB resin and plasticizer mixed dispersion are mixed and kneaded in a certain proportion, and then fed into a twin-screw extruder for mixing, extrusion and molding into film, and then cooled for later use.

[0035] Preparation of the second PVB film: Tetraethyl silicate and ethanol were prepared into a solution in a certain proportion. A certain amount of water was added and mixed. A certain amount of hydrolysis catalyst was added dropwise. After stirring for a period of time, the mixture was allowed to stand. Then, a silane coupling agent was added, and stirring was continued for a period of time to obtain a hydrolyzed mixture. After standing and aging for a period of time, a silica gel was obtained. PVB resin and ethanol were heated in a certain proportion to prepare an organic solution. A certain amount of plasticizer mixture was added. While keeping the temperature constant, a certain amount of silica gel was added to obtain a silica-PVB mixture. The silica-PVB mixture was coated using a coating technique. The resulting film was subjected to a specific air-drying treatment. After demolding, a smooth, uniform, bubble-free film was obtained.

[0036] Improvement to the above technical solution: Stack the first, second, and third PVB films together in sequence, place them between two identical glass sheets, and use a flat vulcanizing machine to process them under specific temperature, pressure, and time conditions to obtain high-transparency, low-haze laminated glass. The specific temperature range is 100-180℃, the specific pressure range is 1000psi-20000psi, and the specific time range is 5-120min.

[0037] Further improvement to the above technical solution: The plasticizer is one or a combination of 3GO, DBS, and DBP.

[0038] Further improvements to the above technical solution: The antioxidant is one or more of the following: TNPP, antioxidant 1076, antioxidant 2246, and dual antioxidant 626.

[0039] Further improvement to the above technical solution: The ultraviolet absorber is one or more of UV-326, UV-327, and UV-328.

[0040] Further improvement to the above technical solution: The hydrolysis catalyst is one or more of the following: hydrochloric acid, sulfuric acid, ammonia, and sodium hydroxide.

[0041] Further improvement to the above technical solution: The hydrolysis catalyst is one or more of KH550, KH560, and KH570.

[0042] The advantages and positive effects of this invention are:

[0043] 1. In order to improve the overall optical performance of the film, the transparent PVB film is a sandwich structure formed by stacking a first layer of PVB film, a second layer of PVB film and a third layer of PVB film in sequence. It adopts a method different from the conventional direct mixing and die casting molding. The prepared PVB film has the characteristics of simple structure, high tensile strength, high transparency and low haze.

[0044] 2. In preparing the composite PVB membrane, this invention does not directly use traditional nanoparticles, but instead uses an organic salt hydrolysis method, namely the sol-gel method, to mix the nanoparticles into the PVB membrane. The heat source during the heat treatment process of the PVB membrane is used to form nanoparticles in the PVB membrane, thereby improving the compatibility between inorganic particles and the PVB membrane. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the layer structure of a transparent PVB film according to the present invention;

[0046] Figure 2 This is a stress-strain curve diagram of Example 5-13 of the transparent PVB film of the present invention.

[0047] The diagram is numbered as follows: 1. First PVB film; 2. Second PVB film; 3. Third PVB film. Detailed Implementation

[0048] The present invention will be further described in detail below with reference to the accompanying drawings:

[0049] See Figure 1 , Figure 2 An embodiment of the present invention is a transparent PVB film, wherein the transparent PVB film is a sandwich structure formed by stacking a first layer of PVB film 1, a second layer of PVB film 2 and a third layer of PVB film 3 in sequence.

[0050] Furthermore, both the first PVB film 1 and the third PVB film 3 described above comprise the following components in parts by weight:

[0051] PVB resin powder: 50-80

[0052] Plasticizer: 15-35

[0053] Antioxidant: 0.1-3

[0054] Ultraviolet absorber: 0.1-3

[0055] The second PVB film 2 described above comprises the following components in parts by weight:

[0056] PVB resin powder: 50-80

[0057] Plasticizer: 15-35

[0058] Antioxidant: 0.1-3

[0059] Ultraviolet absorber: 0.1-3

[0060] Silica gel mixture: 0.1-20.

[0061] Furthermore, the components and weight proportions of the above-mentioned silica gel mixture include:

[0062] Tetraethyl orthosilicate: 1-30

[0063] Ethanol: 0-300

[0064] Water: 10-70

[0065] Hydrolysis catalyst: 0.01–30

[0066] Silane coupling agent: 0.01-10.

[0067] A specific embodiment of the method for preparing the above-mentioned transparent PVB film according to the present invention includes the following steps:

[0068] Preparation of the first PVB film 1 and the third PVB film 3: Antioxidant, ultraviolet absorber and plasticizer are mixed evenly in a certain proportion to obtain plasticizer mixed dispersion; PVB resin and plasticizer mixed dispersion are mixed and kneaded in a certain proportion, and then fed into a twin-screw extruder for mixing, extrusion and molding into film, and then cooled for later use.

[0069] Preparation of the second PVB film 2: Tetraethyl silicate and ethanol were prepared into a solution in a certain proportion. A certain amount of water was added and mixed. A certain amount of hydrolysis catalyst was added dropwise. After stirring for a period of time, the mixture was allowed to stand. Then, a silane coupling agent was added and stirring was continued for a period of time to obtain a hydrolyzed mixture. After standing and aging for a period of time, a silica gel was obtained. PVB resin and ethanol were heated in a certain proportion to prepare an organic solution. A certain amount of plasticizer mixture was added. While keeping the temperature constant, a certain amount of silica gel was added to obtain a silica-PVB mixture. The silica-PVB mixture was coated using a coating technique. The obtained film was subjected to a specific air-drying treatment. After demolding, a smooth, uniform, bubble-free film was obtained.

[0070] Furthermore, the first PVB film 1, the second PVB film 2, and the third PVB film 3 are stacked together in sequence and placed between two identical glass sheets. High-transparency, low-haze laminated glass is obtained by using a flat vulcanizing machine under specific temperature, pressure, and time conditions. The specific temperature range is 100-180℃, the specific pressure range is 1000psi-20000psi, and the specific time range is 5-120min.

[0071] Specifically, the plasticizers mentioned above are one or more of the following: triethylene glycol diisooctanoate (3GO), dibutyl sebacate (DBS), and dibutyl phthalate (DBP).

[0072] The antioxidants mentioned above are one or more of the following: trinonyl phosphite (TNPP), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol (antioxidant 1076), 2,2'-methylene bis(4-ethyl-6-tert-butylphenol) (antioxidant 2246), and pentaerythritol diphosphite bis(2,4-di-tert-butylphenol) (antioxidant 626).

[0073] The aforementioned ultraviolet absorber is one or a combination of 2'-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole (UV-326), 2-(2H-3,5-di-tert-butyl-2-hydroxyphenyl)benzotriazole (UV-327), and 2-(2'-hydroxy-3',5'-di-tert-pentylphenyl)benzotriazole (UV-328).

[0074] One option for the above-mentioned hydrolysis catalyst is one or a combination of hydrochloric acid, sulfuric acid, ammonia, and sodium hydroxide.

[0075] Another option for the above-mentioned hydrolysis catalyst is one or a combination of γ-aminopropyltriethoxysilane (KH550), γ-glycidoxypropyltrimethoxysilane (KH560), and γ-methacryloyloxypropyltrimethoxysilane (KH570).

[0076] The present invention will be further described in detail below with reference to specific embodiments. First, the raw materials and their weight proportions are listed in Table 1 according to five embodiments.

[0077] Table 1

[0078]

[0079] Example 1 (Refer to Table 1 for the raw materials and weight ratio of Example 1): Add 30 parts of ethyl silicate to 250 parts of ethanol and mix evenly. Then add 24 parts of ammonia water and stir evenly at room temperature. Let it stand at room temperature for a period of time. Then add 7 parts of KH570 and continue stirring for a period of time. Let it stand for more than 2 days before use.

[0080] The remaining examples 2-4 were prepared into silica sols using the same method as in example 1, according to the raw materials and their weight ratios in Table 1. Considering the overall performance of the sol, example 4 is preferred.

[0081] The weight ratios of the silica sol and other raw materials from Examples 1-4 are listed in Table 2 according to ten examples.

[0082] Table 2

[0083]

[0084] Example 6 (compare with Table 2 for the raw materials and weight ratio of Example 6): Mix 20 parts of 3GO, 0.5 parts of antioxidant 1076 and 0.10 parts of UV-326 evenly, add 2 parts of silica sol from Example 4, mix well and then add to 50 parts of PVB, and obtain a high-strength tensile PVB film of about 0.5 mm by solvent casting or by mixing and extrusion molding.

[0085] The remaining examples 5 and 7-13 were prepared into films according to the raw materials and their weight ratios in the corresponding examples in Table 2, using the same method as in Example 7. Example 5 served as a blank control group, while Examples 6 and 8 were preferred.

[0086] The properties of the membranes prepared according to Examples 5-13 are first described in Table 3.

[0087] Table 3

[0088]

[0089] Stress-strain curves of Examples 5-13 above Figure 2 .

[0090] In Examples 6, 8, 10, and 12, areas with low transparency and high haze appeared during the high-temperature vulcanization process for preparing safety glass. Examples 8 and blank Example 5 were used as comparative examples to prepare new films by sandwich-like stacking.

[0091] Example 14: Select the films of Example 5 (0.38mm) and Example 8 (0.30mm), and stack them in sequence according to the order of 0.2mm (glass) + 0.38mm (Example 5) + 0.30mm (Example 8) + 0.38mm (Example 5) + 0.2mm (glass), and perform high-temperature vulcanization at 150°C to obtain high-transparency safety glass.

[0092] The following table is a comparison table of results.

[0093] Table 4

[0094]

[0095] The above description is not intended to limit the present invention, nor is the present invention limited to the examples given above. Any changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A transparent PVB film, characterized in that, The transparent PVB film is a sandwich structure formed by sequentially stacking a first PVB film, a second PVB film, and a third PVB film; the first and third PVB films each comprise the following components in parts by weight: PVB resin powder: 50-80 Plasticizer: 15-35 Antioxidant: 0.1-3 Ultraviolet absorber: 0.1-3 The second PVB film comprises the following components in parts by weight: PVB resin powder: 50-80 Plasticizer: 15-35 Antioxidant: 0.1-3 Ultraviolet absorber: 0.1-3 Silica gel mixture: 0.1–20; The components and weight proportions of the silica gel mixture include: Tetraethyl orthosilicate: 1-30 Ethanol: 0-300 Water: 10-70 Hydrolysis catalyst: 0.01–30 Silane coupling agent: 0.01–10; The method for preparing the transparent PVB film includes the following steps: Preparation of the first and third PVB film layers: Antioxidant, ultraviolet absorber and plasticizer are mixed evenly in a certain proportion to obtain plasticizer mixed dispersion; PVB resin and plasticizer mixed dispersion are mixed and kneaded in a certain proportion, and then fed into a twin-screw extruder for mixing, extrusion and molding into film, and then cooled for later use. Preparation of the second PVB film: Tetraethyl silicate and ethanol were prepared into a solution in a certain proportion. A certain amount of water was added and mixed. A certain amount of hydrolysis catalyst was added dropwise. After stirring for a period of time, the mixture was allowed to stand. Then, a silane coupling agent was added and stirring was continued for a period of time to obtain a hydrolyzed mixture. After standing and aging for a period of time, a silica gel was obtained. PVB resin and ethanol were heated in a certain proportion to prepare an organic solution. A certain amount of plasticizer mixture was added. While keeping the temperature constant, a certain amount of silica gel was added to obtain a silica-PVB mixture. The silica-PVB mixture was coated using a coating technique. The resulting film was subjected to a specific air-drying treatment. After demolding, a smooth, uniform, bubble-free film was obtained. The first, second, and third PVB films are stacked together in sequence and placed between two identical glass sheets. High-transparency, low-haze laminated glass is obtained by using a flat vulcanizing machine under specific temperature, pressure, and time conditions. The specific temperature range is 100-180℃, the specific pressure range is 1000psi-20000psi, and the specific time range is 5-120min.

2. A method for preparing a transparent PVB film as described in claim 1, characterized in that, Includes the following steps: Preparation of the first and third PVB film layers: Antioxidant, ultraviolet absorber and plasticizer are mixed evenly in a certain proportion to obtain plasticizer mixed dispersion; PVB resin and plasticizer mixed dispersion are mixed and kneaded in a certain proportion, and then fed into a twin-screw extruder for mixing, extrusion and molding into film, and then cooled for later use. Preparation of the second PVB film: Tetraethyl silicate and ethanol were prepared into a solution in a certain proportion. A certain amount of water was added and mixed. A certain amount of hydrolysis catalyst was added dropwise. After stirring for a period of time, the mixture was allowed to stand. Then, a silane coupling agent was added and stirring was continued for a period of time to obtain a hydrolyzed mixture. After standing and aging for a period of time, a silica gel was obtained. PVB resin and ethanol were heated in a certain proportion to prepare an organic solution. A certain amount of plasticizer mixture was added. While keeping the temperature constant, a certain amount of silica gel was added to obtain a silica-PVB mixture. The silica-PVB mixture was coated using a coating technique. The resulting film was subjected to a specific air-drying treatment. After demolding, a smooth, uniform, bubble-free film was obtained. The first, second, and third PVB films are stacked together in sequence and placed between two identical glass sheets. High-transparency, low-haze laminated glass is obtained by using a flat vulcanizing machine under specific temperature, pressure, and time conditions. The specific temperature range is 100-180℃, the specific pressure range is 1000psi-20000psi, and the specific time range is 5-120min.

3. The method for preparing the transparent PVB film according to claim 2, characterized in that, The plasticizer is one or a combination of 3GO, DBS, and DBP.

4. The method for preparing the transparent PVB film according to claim 2 or 3, characterized in that, The antioxidant is one or more of the following: TNPP, antioxidant 1076, antioxidant 2246, and dual antioxidant 626.

5. The method for preparing the transparent PVB film according to claim 2 or 3, characterized in that, The ultraviolet absorber is one or more of UV-326, UV-327, and UV-328, or a combination thereof.

6. The method for preparing the transparent PVB film according to claim 2 or 3, characterized in that, The hydrolysis catalyst is one or more of the following: hydrochloric acid, sulfuric acid, ammonia, and sodium hydroxide.

7. The method for preparing the transparent PVB film according to claim 2 or 3, characterized in that, The hydrolysis catalyst is one or more of KH550, KH560, and KH570, or a combination thereof.

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