PVB film for automobile sunroof, preparation method thereof and automobile sunroof

Abstract

The present invention discloses a PVB film for a car sunroof, which is composed of a reinforced film layer and a weakened film layer. The thickness of the PVB film is 0.30-2.00 mm, and the thickness ratio of the reinforced film layer to the weakened film layer in the PVB film is (1-7): (7-1). The present invention provides a PVB film for a car sunroof, a preparation method thereof, and a car sunroof. A double-layer PVB film is used, and the PVB film is applied between the laminated glass of the car sunroof, thereby improving the overall strength of the laminated glass, and further effectively reducing the risk of passengers in the car being injured by impact objects.

Description

Technical Field

[0001] The invention belongs to the technical field of PVB films, and in particular relates to a PVB film for a car sunroof, a preparation method thereof, and a car sunroof. Background Art

[0002] PVB (Polyvinyl Butyral Resin) film is a plasticized film based on PVB resin. It is widely used in the production of automobile windshields, high-rise building glass, photovoltaic module glass, etc. due to its excellent properties of transparency, light resistance, heat resistance, sound insulation, softness, anti-fog, non-hardening at low temperature and good adhesion to glass.

[0003] At present, car sunroofs are installed on the roof of the car, which can effectively circulate air in the car and increase the intake of fresh air. At the same time, car sunroofs can also broaden the field of vision and meet the needs of mobile photography and video shooting. With the increasing demand of the automobile industry, the loading of car sunroofs has increased dramatically. Car sunroofs occupy a large area of ​​the roof, and their safety is very important. Since the material of car sunroof glass is tempered glass, the glass is generally curved, single-piece glass or double-layer laminated glass. When flying objects (hail, stones, iron products, etc.) hit the sunroof glass, its penetration resistance is poor, and the impact object will directly penetrate the glass and injure the passengers in the car. Summary of the invention

[0004] The purpose of the present invention is to overcome the above problems existing in the prior art and provide a PVB film for a car sunroof, which adopts a double-layer PVB film and is applied between the laminated glass of the car sunroof, thereby improving the overall strength of the laminated glass and effectively reducing the risk of passengers in the car being injured by impact objects.

[0005] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0006] The embodiment of the first aspect of the present invention provides a PVB film for a car sunroof, which is composed of a reinforcing film layer and a weakening film layer. The thickness of the PVB film is 0.30-2.00 mm. In the PVB film, the thickness ratio of the reinforcing film layer to the weakening film layer is (1-7): (7-1);

[0007] The raw materials of the enhanced film layer include, by mass percentage: 65%-77.8% PVB resin, 22%-30% plasticizer, 0.1-0.5% antioxidant, 0.0%-0.5% UV absorber, 0.05-2% chain extender, and 0.05-2% enhanced adhesive;

[0008] The raw materials of the weakened film layer include, by mass percentage, 66%-77.8% of PVB resin, 22%-30% of plasticizer, 0.1%-0.5% of antioxidant, 0.0%-0.5% of ultraviolet absorber, and 0.1%-3% of weakened adhesive.

[0009] Preferably, the hydroxyl content of the PVB resin is 16-22%;

[0010] The viscosity of the PVB resin at 20° C. is 160-300 cp;

[0011] The PVB resin has a melt index of 0.5-2.5 g / 10 min under the test conditions of 120° C. / 2.16 kg.

[0012] Preferably, the plasticizer is any one or more of dibutyl phthalate, dioctyl phthalate, triethylene glycol diisooctanoate, tricresyl phosphate, tetraethylene glycol diheptanoate, dibutyl sebacate, dioctyl sebacate, dioctyl adipate, and dioctyl terephthalate, mixed in any proportion.

[0013] Preferably, the antioxidant is a hindered phenol antioxidant and / or a phosphite antioxidant; the antioxidant is any one or more of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester, 2-methylenebis(4-methyl-6-tert-butylphenol), β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris[2,4-di-tert-butylphenyl]phosphite, dioctadecyl alcohol pentaerythritol diphosphite, bis(3,5-di-tert-butylphenyl)pentaerythritol diphosphite, mixed in any proportion; in some preferred embodiments of the present invention, the antioxidant is tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester;

[0014] Preferably, the ultraviolet absorber is a benzotriazole ultraviolet absorber; the ultraviolet absorber is any one or more of 2-(2'-hydroxy-5'-methyl)-benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methyl)-5-chloro-benzotriazole, 2-(2'-hydroxy-3'5'-di-tert-butyl)-5-chloro-benzotriazole, 2-(2'-hydroxy-3'5'-di-tert-amyl)-benzotriazole, and 2-(2'-hydroxy-5'-tert-octyl)-benzotriazole, mixed in any proportion;

[0015] Preferably, the chain extender is any one or more of phthalic anhydride, dialdehydes, and dibasic acid esters mixed in any proportion; in some preferred embodiments of the present invention, the chain extender is phthalic anhydride.

[0016] Preferably, the reinforcing adhesive is any one or more of silane coupling agent KH-792, silane coupling agent A-150, vinyl trichlorosilane, silane coupling agent A-151, and silane coupling agent KH-550 mixed in any proportion.

[0017] Preferably, the weakened adhesive is a mixture of a solute and a solvent in a mass ratio of (0.01-0.10):1;

[0018] The solute is any one or more of alkali metal salts, alkali metal bases or alkali metal oxides mixed in any proportion;

[0019] The alkali metal salt is any one or more of potassium formate, potassium acetate, magnesium acetate, potassium carbonate, potassium bicarbonate, sodium formate, sodium acetate, sodium carbonate or sodium bicarbonate mixed in any proportion;

[0020] The alkali metal base is potassium hydroxide and / or sodium hydroxide;

[0021] The alkali metal oxide is potassium oxide and / or sodium oxide;

[0022] The solvent is deionized water or an ester solvent; more preferably, the solvent is an ester solvent, and the ester solvent is ethyl acetate.

[0023] The embodiment of the second aspect of the present invention provides a method for preparing a PVB film for a car sunroof, the method comprising the following steps:

[0024] S1: Preparation of film layer

[0025] Taking the raw materials of the enhanced film layer and the raw materials of the weakened film layer, plasticizing them in two extruders respectively, and making enhanced fluid and weakened fluid respectively;

[0026] S2: Preparation of PVB film

[0027] The reinforcing fluid and the weakening fluid prepared in step S1 are respectively introduced into two mold cavities of a double-layer mold to prepare a PVB film.

[0028] An embodiment of a third aspect of the present invention provides a vehicle sunroof, comprising:

[0029] Laminated glass and the PVB film provided by the embodiment of the first aspect of the present invention;

[0030] The laminated glass comprises a sun-facing glass and a sun-backed glass arranged in sequence from top to bottom, and the PVB film is located between the sun-facing glass and the sun-backed glass;

[0031] The enhanced film layer is bonded to the sun-facing glass, and the weakened film layer is bonded to the back-facing glass.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The present invention provides a PVB film for a car sunroof, a preparation method thereof, and a car sunroof. A double-layer PVB film is used, and the PVB film is applied between the laminated glass of the car sunroof, thereby improving the overall strength of the laminated glass, improving the overall anti-penetration performance of the laminated glass of the car sunroof, and thus effectively reducing the risk of passengers in the car being injured by impact objects.

[0034] 2. The PVB film for automobile sunroof provided by the present invention adopts a weakened adhesive, and hydrogen bonds are formed between Si-OH in the glass and C-OH and H2O in the PVB film to form strong bonding force, while the alkali metal ions in the viscosity regulator can combine with Si-OH in the glass to replace hydrogen and prevent the formation of hydrogen bonds, thereby achieving the purpose of controlling the bonding force.

[0035] 3. The PVB film for automobile sunroof provided by the present invention adopts a double-layer structure, namely a reinforcing film layer and a weakening film layer. By adding a chain extender during the preparation of the reinforcing film layer, the tensile strength of the PVB film is enhanced, thereby improving the mechanical properties of the product. Since the bonding strength and tensile strength of the reinforcing film layer and the weakening film layer are different, when the PVB film is used as an automobile sunroof, the overall strength of the laminated glass on the automobile sunroof can be improved.

[0036] 4. The reinforced adhesive added to the PVB film for the automobile sunroof provided by the present invention can increase the bonding strength between the PVB film and the laminated glass on the automobile sunroof, so that the overall rigidity of the PVB film and the laminated glass is relatively strong. When a flying object hits the glass, due to the relatively strong bonding strength between the PVB film and the laminated glass, after the glass breaks, the glass fragments are not easy to fall off, thereby avoiding the risk of glass fragments falling off and injuring people; through this arrangement, the energy brought by the impact object will also be absorbed and weakened through micro-deformation or cracking of the glass and the PVB film.

[0037] 5. The PVB film for the car sunroof provided by the present invention has a weakened film layer with lower viscosity and strength than the enhanced film layer, and the overall bonding strength between the weakened film layer and the back-to-sun glass is weak. Since no chain extender is added, the creep property of the weakened film layer will increase, and thus the bending deformation of the weakened film layer and the back-to-sun glass will further increase. When a flying object hits the sun-facing glass and the enhanced film layer, the energy brought by the flying object will be significantly weakened, and the remaining impact energy brought by the flying object will be completely dissipated through the larger bending deformation of the weakened film layer, and the flying object will not penetrate the laminated glass on the car sunroof.

[0038] 6. The PVB film for automobile sunroof provided by the present invention controls the tensile strength of the enhanced film layer and the weakened film layer by adjusting the addition of chain extender.

[0039] 7. The method for preparing the PVB film for the automobile sunroof provided by the present invention adopts two extruders to extrude the raw materials, and then introduces them into a mold to prepare a double-layer PVB film. The process is simple and suitable for large-scale production.

[0040] 8. The present invention applies the prepared PVB film to the laminated glass on the car sunroof, thereby improving the overall strength of the laminated glass and providing protection for people in the car, providing a basis for the strength improvement mode and method of the laminated glass on the car sunroof. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0042] Figure 1 This is a flow chart of the method for preparing the PVB film for the automobile sunroof provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] The raw materials used in the following examples and comparative examples can all be obtained from conventional commercial sources, and the specific raw materials are as follows:

[0045] PVB resin: hydroxyl content 18.8%, melt index 1.45g / 10min (120°C), product of Anhui Wanwei High-tech Materials Co., Ltd.;

[0046] Plasticizer: Triethylene glycol diethylhexanoate, a product of Chaohu Wanwei Jinquan Company.

[0047] Antioxidant: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0048] UV absorber: 2-(2′-hydroxy-3′-tert-butyl-5′-methyl)-5-chloro-benzotriazole.

[0049] Chain extender: phthalic anhydride;

[0050] Enhanced adhesive: silane coupling agent KH-792;

[0051] Weakened binder: magnesium acetate and potassium acetate are used as solutes, and deionized water is used as solvent, wherein the mass ratio of magnesium acetate, potassium acetate and deionized water is 0.05:0.05:1;

[0052] The extruder is a twin-screw extruder, model 95B extruder;

[0053] The thickness of the enhanced film layer and the weakened film layer is 0.38 mm.

[0054] Example 1

[0055] like Figure 1 As shown, the PVB film for the car sunroof provided in this embodiment is composed of a reinforced film layer and a weakened film layer. The preparation method of the PVB film for the car sunroof is as follows:

[0056] S1: Extrusion and plasticization of film layer raw materials

[0057] Prepare the enhanced film layer: add 71.9 parts by mass of PVB resin, 27 parts by mass of plasticizer, 0.2 parts by mass of antioxidant, 0.2 parts by mass of UV absorber, 0.5 parts by mass of chain extender and 0.2 parts by mass of enhanced adhesive into an extruder for melt plasticization into an enhanced fluid;

[0058] Prepare the weakened film layer: add 71.1 parts by weight of PVB resin, 27 parts by weight of plasticizer, 0.2 parts by weight of antioxidant, 0.2 parts by weight of ultraviolet absorber, and 1.5 parts by weight of weakened adhesive into another extruder for melting and plasticizing to form a weakened fluid;

[0059] S2: Preparation of PVB film

[0060] The reinforcing fluid and the weakening fluid prepared in step S1 are respectively introduced into the two mold cavities of the double-layer mold to prepare the PVB film.

[0061] Example 2

[0062] The PVB film for the car sunroof provided in this embodiment is composed of a reinforced film layer and a weakened film layer. The preparation method of the PVB film for the car sunroof is as follows:

[0063] S1: Extrusion and plasticization of film layer raw materials

[0064] Preparation of a reinforced film layer: adding 70.4 parts by weight of PVB resin, 27 parts by weight of plasticizer, 0.2 parts by weight of antioxidant, 0.2 parts by weight of UV absorber, 2 parts by weight of chain extender, and 0.2 parts by weight of a reinforcing adhesive into an extruder for melt plasticization into a reinforced fluid;

[0065] Prepare the weakened film layer: add 71.1 parts by weight of PVB resin, 27 parts by weight of plasticizer, 0.2 parts by weight of antioxidant, 0.2 parts by weight of ultraviolet absorber, and 1.5 parts by weight of weakened adhesive into another extruder for melting and plasticizing to form a weakened fluid;

[0066] S2: Preparation of PVB film

[0067] The prepared reinforcing fluid and weakening fluid are respectively introduced into two mold cavities of a double-layer mold to prepare a PVB film.

[0068] Example 3

[0069] The PVB film for the car sunroof provided in this embodiment is composed of a reinforced film layer and a weakened film layer. The preparation method of the PVB film for the car sunroof is as follows:

[0070] S1: Extrusion and plasticization of film layer raw materials

[0071] Preparation of enhanced film layer: adding 70.1 parts by weight of PVB resin, 27 parts by weight of plasticizer, 0.2 parts by weight of antioxidant, 0.2 parts by weight of ultraviolet absorber, 0.5 parts by weight of chain extender, and 2 parts by weight of enhanced binder into an extruder for melt plasticization into an enhanced fluid;

[0072] Prepare the weakened film layer: add 71.1 parts by weight of PVB resin, 27 parts by weight of plasticizer, 0.2 parts by weight of antioxidant, 0.2 parts by weight of ultraviolet absorber, and 1.5 parts by weight of weakened adhesive into another extruder for melting and plasticizing to form a weakened fluid;

[0073] S2: Preparation of PVB film

[0074] The prepared reinforcing fluid and weakening fluid are respectively introduced into two mold cavities of a double-layer mold to prepare a PVB film.

[0075] Example 4

[0076] The PVB film for the car sunroof provided in this embodiment is composed of a reinforced film layer and a weakened film layer. The preparation method of the PVB film for the car sunroof is as follows:

[0077] S1: Extrusion and plasticization of film layer raw materials

[0078] Prepare the enhanced film layer: add 71.9 parts by mass of PVB resin, 27 parts by mass of plasticizer, 0.2 parts by mass of antioxidant, 0.2 parts by mass of UV absorber, 0.5 parts by mass of chain extender, and 0.2 parts by mass of enhanced binder into an extruder for melt plasticization into an enhanced fluid;

[0079] Prepare the weakened film layer: add 70.6 parts by weight of PVB resin, 27 parts by weight of plasticizer, 0.2 parts by weight of antioxidant, 0.2 parts by weight of ultraviolet absorber, and 2 parts by weight of weakened adhesive into another extruder for melting and plasticizing to form a weakened fluid;

[0080] S2: Preparation of PVB film

[0081] The prepared reinforcing fluid and weakening fluid are respectively introduced into two mold cavities of a double-layer mold to prepare a PVB film.

[0082] Example 5

[0083] The PVB film for the car sunroof provided in this embodiment is composed of a reinforced film layer and a weakened film layer. The preparation method of the PVB film for the car sunroof is as follows:

[0084] S1: Extrusion and plasticization of film layer raw materials

[0085] Preparation of enhanced film layer: adding 65 parts by weight of PVB resin, 30 parts by weight of plasticizer, 0.5 parts by weight of antioxidant, 0.5 parts by weight of ultraviolet absorber, 2 parts by weight of chain extender, and 2 parts by weight of enhanced adhesive into an extruder for melt plasticization into an enhanced fluid;

[0086] Prepare the weakened film layer: add 77.8 parts by weight of PVB resin, 22 parts by weight of plasticizer, 0.1 parts by weight of antioxidant and 0.1 parts by weight of weakened adhesive into another extruder to melt and plasticize into a weakened fluid;

[0087] S2: Preparation of PVB film

[0088] The prepared reinforcing fluid and weakening fluid are respectively introduced into two mold cavities of a double-layer mold to prepare a PVB film.

[0089] Example 6

[0090] The PVB film for the car sunroof provided in this embodiment is composed of a reinforced film layer and a weakened film layer. The preparation method of the PVB film for the car sunroof is as follows:

[0091] S1: Extrusion and plasticization of film layer raw materials

[0092] Prepare the enhanced film layer: add 77.8 parts by weight of PVB resin, 22 parts by weight of plasticizer, 0.1 parts by weight of antioxidant, 0.05 parts by weight of chain extender, and 0.05 parts by weight of enhanced binder into an extruder for melting and plasticizing to form an enhanced fluid;

[0093] Prepare the weakened film layer: add 66 parts by mass of PVB resin, 30 parts by mass of plasticizer, 0.5 parts by mass of antioxidant, 0.5 parts by mass of ultraviolet absorber and 3 parts by mass of weakened adhesive into another extruder for melting and plasticizing into a weakened fluid;

[0094] S2: Preparation of PVB film

[0095] The prepared reinforcing fluid and weakening fluid are respectively introduced into two mold cavities of a double-layer mold to prepare a PVB film.

[0096] Comparative Example 1

[0097] The PVB film for automobile sunroof provided in this comparative example is composed of a reinforced film layer and a weakened film layer. The preparation method of the PVB film for automobile sunroof is as follows:

[0098] S1: Extrusion and plasticization of film layer raw materials

[0099] Preparation of a reinforced film layer: adding 72.6 parts by weight of PVB resin, 27 parts by weight of plasticizer, 0.2 parts by weight of antioxidant, and 0.2 parts by weight of ultraviolet absorber into an extruder for melt plasticization to form a reinforced fluid;

[0100] Preparation of weakened film layer: adding 72.6 parts by weight of PVB resin, 27 parts by weight of plasticizer, 0.2 parts by weight of antioxidant, and 0.2 parts by weight of ultraviolet absorber into another extruder for melt plasticization into weakened fluid;

[0101] S2: Preparation of PVB film

[0102] The prepared reinforcing fluid and weakening fluid are respectively introduced into two mold cavities of a double-layer mold to prepare a PVB film.

[0103] Comparative Example 2

[0104] The PVB film for automobile sunroof provided in this comparative example is composed of a reinforced film layer and a weakened film layer. The preparation method of the PVB film for automobile sunroof is as follows:

[0105] S1: Extrusion and plasticization of film layer raw materials

[0106] Preparation of a reinforced film layer: adding 72.1 parts by weight of PVB resin, 27 parts by weight of plasticizer, 0.2 parts by weight of antioxidant, 0.2 parts by weight of ultraviolet absorber, and 0.5 parts by weight of chain extender into an extruder for melt plasticization to form a reinforced fluid;

[0107] Prepare the weakened film layer: add 71.1 parts by weight of PVB resin, 27 parts by weight of plasticizer, 0.2 parts by weight of antioxidant, 0.2 parts by weight of ultraviolet absorber, and 1.5 parts by weight of weakened adhesive into another extruder for melting and plasticizing to form a weakened fluid;

[0108] S2: Preparation of PVB film

[0109] The prepared reinforcing fluid and weakening fluid are respectively introduced into two mold cavities of a double-layer mold to prepare a PVB film.

[0110] Comparative Example 3

[0111] The PVB film for automobile sunroof provided in this comparative example is composed of a reinforced film layer and a weakened film layer. The preparation method of the PVB film for automobile sunroof is as follows:

[0112] S1: Extrusion and plasticization of film layer raw materials

[0113] Preparation of a reinforced film layer: adding 72.1 parts by weight of PVB resin, 27 parts by weight of plasticizer, 0.2 parts by weight of antioxidant, 0.2 parts by weight of ultraviolet absorber, and 0.5 parts by weight of chain extender into an extruder for melt plasticization to form a reinforced fluid;

[0114] Preparation of weakened film layer: adding 72.6 parts by weight of PVB resin, 27 parts by weight of plasticizer, 0.2 parts by weight of antioxidant, and 0.2 parts by weight of ultraviolet absorber into another extruder for melt plasticization into weakened fluid;

[0115] S2: Preparation of PVB film

[0116] The prepared reinforcing fluid and weakening fluid are respectively introduced into two mold cavities of a double-layer mold to prepare a PVB film.

[0117] Comparative Example 4

[0118] The PVB film for automobile sunroof provided in this comparative example is composed of a reinforced film layer and a weakened film layer. The preparation method of the PVB film for automobile sunroof is as follows:

[0119] S1: Extrusion and plasticization of film layer raw materials

[0120] Prepare the enhanced film layer: add 72.4 parts by weight of PVB resin, 27 parts by weight of plasticizer, 0.2 parts by weight of antioxidant, 0.2 parts by weight of ultraviolet absorber, and 0.2 parts by weight of enhanced adhesive into an extruder for melting and plasticizing to form an enhanced fluid;

[0121] Prepare the weakened film layer: add 71.1 parts by weight of PVB resin, 27 parts by weight of plasticizer, 0.2 parts by weight of antioxidant, 0.2 parts by weight of ultraviolet absorber, and 1.5 parts by weight of weakened adhesive into another extruder for melting and plasticizing to form a weakened fluid;

[0122] S2: Preparation of PVB film

[0123] The prepared reinforcing fluid and weakening fluid are respectively introduced into two mold cavities of a double-layer mold to prepare a PVB film.

[0124] Comparative Example 5

[0125] This comparative example provides a method for preparing a single-layer PVB film for a car sunroof, and the preparation method is as follows:

[0126] 71.9 parts by mass of PVB resin, 27 parts by mass of plasticizer, 0.2 parts by mass of antioxidant, 0.2 parts by mass of ultraviolet absorber, 0.5 parts by mass of chain extender and 0.2 parts by mass of reinforcing adhesive were added into a twin-screw extruder for melt plasticization, and a PVB film was obtained by extrusion casting.

[0127] Comparative Example 6

[0128] This comparative example provides a method for preparing a single-layer PVB film for a car sunroof, and the preparation method is as follows:

[0129] 71.1 parts by mass of PVB resin, 27 parts by mass of plasticizer, 0.2 parts by mass of antioxidant, 0.2 parts by mass of ultraviolet absorber and 1.5 parts by mass of weakened adhesive were added into a twin-screw extruder for melt plasticization, and a PVB film was obtained by extrusion casting.

[0130] Experimental example

[0131] The PVB films prepared in Examples 1-6 and Comparative Examples 1-6 were subjected to performance tests, and the prepared PVB films were placed between laminated glass of a car sunroof for performance tests;

[0132] The automobile sunroof includes a laminated glass and a PVB film, wherein the laminated glass includes a sun-facing glass and a back-facing glass sequentially arranged from top to bottom, and the PVB film is located between the sun-facing glass and the back-facing glass. Specifically, for the PVB films prepared in Examples 1-6 and Comparative Examples 1-4, the enhanced film layer is bonded to the sun-facing glass, and the weakened film layer is bonded to the back-facing glass;

[0133] Ten PVB films prepared in each embodiment and comparative example were selected for testing. The sizes of the PVB films provided were the same. The specific test contents were as follows:

[0134] PVB film thickness: measured according to GB / T 6672-2001 Plastic film and sheet thickness determination method;

[0135] PVB film haze and light transmittance: measured according to GB / T 2410-2008 Transparent Plastics Light Transmittance and Haze Determination Method;

[0136] PVB film tensile strength: in accordance with the provisions of GB / T 1040.3-2006;

[0137] Plasticizer exudation experiment: PVB film was placed in a sealed container filled with saturated copper sulfate aqueous solution and observed at room temperature for 20 days. The precipitation of plasticizer on the surface of the sample was observed and the precipitation area was calculated. The precipitation area was 6.0 cm 2 Considered as complete precipitation;

[0138] The knock value is tested and determined according to GB / T 32020-2015;

[0139] The penetration resistance and impact resistance tests are carried out according to the test method for laminated glass in GB / T 5137.1.

[0140] The test results are shown in Table 1.

[0141] Table 1

[0142]

[0143]

[0144]

[0145] Note: Among the knock values, A is the knock value obtained based on the surface area of ​​the enhanced film layer exposed after the laminated glass is knocked; B is the knock value obtained based on the surface area of ​​the weakened film layer exposed after the laminated glass is knocked.

[0146] As shown in Table 1, the product performance of the first and second layers of PVB film produced by Example 1 is better. Compared with Example 1, the amount of coupling agent added in Example 2 is increased, the plasticizer precipitation is more obvious, the haze is increased, and the light transmittance is reduced.

[0147] The PVB film for a car sunroof and a preparation method thereof and the car sunroof provided by the present invention adopt a double-layer PVB film, and the PVB film is applied between the laminated glass of the car sunroof, thereby improving the overall strength of the laminated glass, improving the overall anti-penetration performance of the laminated glass of the car sunroof, and further effectively reducing the risk of passengers in the car being injured by impact objects.

[0148] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0149] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A PVB film for automobile sunroof, characterized in that: The PVB film is composed of a reinforcing film layer and a weakening film layer, the thickness of the PVB film is 0.30-2.00 mm, and the thickness ratio of the reinforcing film layer to the weakening film layer in the PVB film is (1-7): (7-1); The raw materials of the enhanced film layer include, by mass percentage: 65%-77.8% PVB resin, 22%-30% plasticizer, 0.1-0.5% antioxidant, 0.0%-0.5% UV absorber, 0.05-2% chain extender, and 0.05-2% enhanced adhesive; The raw materials of the weakened film layer include, by mass percentage: 66%-77.8% PVB resin, 22%-30% plasticizer, 0.1-0.5% antioxidant, 0.0%-0.5% UV absorber, and 0.1-3% weakened adhesive; The enhanced adhesive is any one or more of silane coupling agent KH-792, silane coupling agent A-150, vinyl trichlorosilane, silane coupling agent A-151, and silane coupling agent KH-550 mixed in any proportion; The weakened adhesive is prepared by mixing a solute and a solvent in a mass ratio of (0.01-0.10):1; The solute is any one or more of alkali metal salts, alkali metal bases or alkali metal oxides mixed in any proportion; The alkali metal salt is any one or more of potassium formate, potassium acetate, potassium carbonate, potassium bicarbonate, sodium formate, sodium acetate, sodium carbonate or sodium bicarbonate mixed in any proportion; The alkali metal base is potassium hydroxide and / or sodium hydroxide; The alkali metal oxide is potassium oxide and / or sodium oxide; The solvent is deionized water or an ester solvent.

2. The PVB film for automobile sunroof according to claim 1, characterized in that: The hydroxyl content of the PVB resin is 16-22%; The viscosity of the PVB resin at 20° C. is 160-300 cp; The PVB resin has a melt index of 0.5-2.5 g / 10 min under the test conditions of 120° C. / 2.16 kg.

3. The PVB film for automobile sunroof according to claim 1, characterized in that: The plasticizer is any one or more of dibutyl phthalate, dioctyl phthalate, triethylene glycol diisooctanoate, tricresyl phosphate, tetraethylene glycol diheptanoate, dibutyl sebacate, dioctyl sebacate, dioctyl adipate, and dioctyl terephthalate, mixed in any proportion.

4. The PVB film for automobile sunroof according to claim 1, characterized in that: The antioxidant is a hindered phenol antioxidant and / or a phosphite antioxidant.

5. The PVB film for automobile sunroof according to claim 1, characterized in that: The ultraviolet absorber is a benzotriazole ultraviolet absorber.

6. The PVB film for automobile sunroof according to claim 1, characterized in that: The chain extender is any one or more of phthalic anhydride, dialdehydes, and dibasic acid esters mixed in any proportion.

7. A method for preparing the PVB film for automobile sunroof according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: S1: Extrusion and plasticization of film layer raw materials Taking the raw materials of the enhanced film layer and the raw materials of the weakened film layer, plasticizing them in two extruders respectively, and making enhanced fluid and weakened fluid respectively; S2: Preparation of PVB film The reinforcing fluid and the weakening fluid prepared in step S1 are respectively introduced into two mold cavities of a double-layer mold to prepare a PVB film.

8. A car sunroof, characterized in that: include: Laminated glass and the PVB film according to any one of claims 1 to 6; The laminated glass comprises a sun-facing glass and a sun-backed glass arranged in sequence from top to bottom, and the PVB film is located between the sun-facing glass and the sun-backed glass; The enhanced film layer is bonded to the sun-facing glass, and the weakened film layer is bonded to the back-facing glass.

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