A polyvinyl butyral film and a method for producing the same

Abstract

The application relates to the field of C08L29 / 14, in particular to a polyvinyl butyral film and a preparation method thereof. Raw materials of the polyvinyl butyral film include 100 parts of PVB resin and 10-50 parts of plasticizer, the PVB resin is selected from at least one of PVB resins with a hydroxyl value of 15-20%, 20-25%, 25-30%, 30-35% and 35-40%, and the PVB resin has a polymerization degree of 1000-6000; the type and amount of the plasticizer are further optimized, so that the raw material system of the application has excellent compatibility, the amount of the plasticizer can be effectively increased and precipitation of the plasticizer is avoided, and the film has excellent tensile strength and elongation at break, processing performance, transparency and extremely low haze.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyvinyl butyral film, C08L29 / 14, and in particular to a polyvinyl butyral film and a preparation method thereof. BACKGROUND

[0002] Laminated glass composed of at least two glass sheets and an interlayer film is widely used in building glass and automotive window glass. In the prior art, the interlayer film usually uses polyvinyl butyral resin with plasticizer to enable the glass to be firmly bonded to the surface of the film even if it is broken by external force impact, thereby avoiding injury to surrounding personnel.

[0003] High-quality resin is relatively expensive. On the premise of meeting the performance requirements of the product, the higher the content of the plasticizer, the lower the formulation cost. However, the problem of plasticizer precipitation is serious, which is not conducive to the light transmittance and haze of the laminated glass, and also not conducive to the bonding stability between the laminated glasses.

[0004] Chinese patent CN116396579A discloses an anti-adhesion PVB film, a preparation method and application thereof. The film includes the following raw materials by mass fraction: PVB resin 100 parts, plasticizer 30-40 parts, adhesion regulator 0.05-0.15 parts, isooctyl palmitate 2-6 parts, and silicone release agent 0.1-0.7 parts. The isooctyl palmitate (internal plasticizer) and the silicone release agent improve the processing performance of the PVB film without affecting the short-term light transmittance and haze of the laminated glass. However, the patent does not solve the problem of migration and precipitation of the plasticizer after long-term storage.

[0005] Therefore, it is of great significance to prepare a PVB film system with excellent compatibility, inhibit the precipitation of the plasticizer, and improve the mechanical properties of the PVB film. SUMMARY

[0006] To solve the above technical problems, the present application first provides a polyvinyl butyral film (PVB film). The raw materials of the polyvinyl butyral film include 100 parts of PVB resin and 10-50 parts of plasticizer by mass fraction.

[0007] Further, the mass ratio of the PVB resin to the plasticizer is 100:(20-40), preferably 100:(25-35), and can be 100:25, 100:26, 100:27, 100:28, 100:29, 100:30, 100:31, 100:32, 100:33, 100:34, 100:35, 100:36, etc.

[0008] In a preferred embodiment, the mass ratio of the PVB resin and the plasticizer is 100: (29-32).

[0009] Further, the PVB resin has a hydroxyl value ≥ 15% and a polymerization degree ≥ 1000.

[0010] Preferably, the PVB resin has a hydroxyl value of 15-40%.

[0011] Further, the PVB resin is selected from at least one of PVB resins with a hydroxyl value of 15-20%, 20-25%, 25-30%, 30-35%, and 35-40%.

[0012] Preferably, the PVB resin is a combination of PVB resin-A with a hydroxyl value of 15-20% and PVB resin-B with a hydroxyl value of 20-25%, and the mass ratio of the two is 1: (0.2-5).

[0013] Further, the PVB resin has a polymerization degree of 1000-6000, preferably 1000-3000, and more preferably 1000-2000.

[0014] Further, the PVB resin-A has a polymerization degree of 1300-2000, preferably 1500-1800.

[0015] Further, the PVB resin-B has a polymerization degree of 1000-1600, preferably 1100-1500.

[0016] The hydroxyl value of the PVB resin can adjust the polarity and interaction force of the PVB resin, and the polymerization degree directly reflects the size of the molecular weight. When a single PVB resin-B is used, the molecular weight of the PVB resin-A is high, and the too strong intermolecular force will result in a system with high cohesion, which not only leads to the decrease of the elongation at break, but also reduces the compatibility of the plasticizer in the system, causing the latter to precipitate. The use of PVB resin-A with longer molecular chains and the fixed relative amount of the two can solve the problems of plasticizer precipitation and system film forming performance by using the volume effect.

[0017] Further, the mass ratio of the PVB resin-A and the PVB resin-B is 1: (1-4), preferably 1: (1-2).

[0018] In a preferred embodiment, the mass ratio of the PVB resin-A and the PVB resin-B is 1:1.5.

[0019] Further, the plasticizer includes plasticizer A and plasticizer B, the plasticizer A includes at least one of phenyl n-butyl phthalate (BBP), triethylene glycol diisooctylate (3GO), dihexyl adipate (DHA), but the plasticizer B includes at least one of polyethylene glycol (PEG), dipropylene glycol dibenzoate (DPGDB), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), di(butoxyethyl) phthalate (DBEP), di(methoxyethyl) phthalate (DMEP).

[0020] Further, the plasticizer A includes triethylene glycol diisooctylate and / or dihexyl adipate.

[0021] Further, the plasticizer B includes polyethylene glycol.

[0022] Further, the average molecular weight of the polyethylene glycol is 200-1500, preferably 400-1000, more preferably 600.

[0023] Further, the mass ratio of the plasticizer A and the plasticizer B is 1:(0.1-2), preferably 1:(0.3-1.5), more preferably 1:(0.5-1.2).

[0024] In the preferred embodiment of the present application, triethylene glycol diisooctylate and PVB resin-A, PVB resin-B produce intermolecular forces through polar bonds, thereby weakening the interaction of PVB resin-A and PVB resin-B themselves and each other, producing plasticizing effect; polyethylene glycol increases the flexibility of the molecular chain by inserting into the molecular chain of the resin to increase the intermolecular distance, and the use of the two can produce excellent plasticizing effect on the resin. Although triethylene glycol diisooctylate has good plasticizing effect, its solubility in the system is poor, and polyethylene glycol can make up for the defect of poor solubility of triethylene glycol diisooctylate, and the use amount of the two is limited to 1:(0.3-1.5), so that the two can produce excellent compatibility in the system composed of specific resin A and resin B, and avoid the precipitation of plasticizer.

[0025] In a preferred embodiment, the mass ratio of the plasticizer A and the plasticizer B is 1:(0.7-1).

[0026] Further, the raw material of the polyvinyl butyral film further includes an auxiliary agent, and the auxiliary agent includes at least one of ultraviolet absorber, light shielding agent, quenching agent, free radical trapping agent, antioxidant, viscosity regulator, thermal stabilizer.

[0027] Further, the auxiliary agent includes ultraviolet absorber, and the amount of ultraviolet absorber is 0.5-8 parts, preferably 1-6 parts, more preferably 2-4 parts.

[0028] Further, the ultraviolet absorber includes, but is not limited to, at least one of UV-326, UV-P, UV-9, UV-329, UV-531; preferably includes UV-326.

[0029] Further, the auxiliary agent includes an antioxidant, and the amount of the antioxidant is 1-10 parts, preferably 1-8 parts, more preferably 2-5 parts.

[0030] Further, the antioxidant includes, but is not limited to, at least one of hindered phenol, hindered amine, phosphine, and lipid antioxidant.

[0031] Further, the antioxidant includes, but is not limited to, at least one of antioxidant 1010, antioxidant B215, antioxidant 1076, and antioxidant CA; preferably includes antioxidant 1010.

[0032] Further, the auxiliary agent includes a viscosity regulator, and the amount of the viscosity regulator is 0.001-2 parts, preferably 0.01-1 parts, more preferably 0.01-0.3 parts.

[0033] Further, the viscosity regulator includes, but is not limited to, at least one of potassium acetate, magnesium acetate, sodium hydroxide, and potassium hydroxide.

[0034] Secondly, the application further provides a preparation method of the polyvinyl butyral film, specifically: adding raw materials into a double-screw extruder and stirring and extruding at 40-200°C.

[0035] Preferably, the process of adding raw materials is as follows: PVB resin-A and PVB resin-B are respectively added from a main feeding port and a side feeding port, the ultraviolet absorber, the antioxidant, and the viscosity regulator are dissolved in plasticizer A and / or plasticizer B, and then plasticizer A and plasticizer B are simultaneously added into the double-screw extruder from different feeding ports.

[0036] Further, the screw rotation speed of the main feeding port and the side feeding port is 10-250 rpm.

[0037] Further, the screw rotation speed of the main feeding port is 10-100 rpm, preferably 10-50 rpm, more preferably 10-30 rpm.

[0038] Further, the screw rotation speed of the side feeding port is 15-150 rpm, preferably 15-80 rpm, more preferably 20-50 rpm.

[0039] The application changes the traditional preparation method: resin high-speed stirring premixing mode to two resin feeding in two feeding ports of the extruder, and flexibly changes the mixing quality of the two resins by adjusting the feeding screw speed, and changes the two plasticizers to be added through two liquid feeding ports; the feeding in the method is uniform speed and small amount feeding, which can ensure the uniform mixing of the two feeding streams at the screw convergence point, reduces the process step of early premixing, and improves the film preparation efficiency.

[0040] Further, the temperature of the body of the twin-screw extruder is 50-190 DEG C, preferably 80-180 DEG C, and more preferably 90-180 DEG C.

[0041] Further, the temperature of the die of the twin-screw extruder is 150-200 DEG C, preferably 150-180 DEG C, and more preferably 150-170 DEG C.

[0042] Advantages

[0043] 1. The application optimizes the hydroxyl value and polymerization degree of PVB resin, and optimizes the compounding scheme, so that the tensile strength and elongation at break of the PVB film can be improved, and the difficulty of subsequent processing can be reduced;

[0044] 2. The application optimizes the type and relative amount of plasticizer, ensures that the compounded plasticizer can have good solubility and excellent plasticizing effect, increases the overall amount of plasticizer under the condition of ensuring the quality of PVB film, and in addition, the compatibility between the compounded plasticizer and the specific PVB resin is excellent, so that the precipitation problem of the plasticizer can be effectively avoided;

[0045] 3. The application flexibly changes the mass ratio of the two resins by adjusting the rotation speed of the two feeding screws, further changes the plasticizer to be added through two liquid feeding ports, ensures the uniform mixing of the materials by uniform speed and small amount feeding, reduces the complex process step of early premixing, and improves the film preparation efficiency;

[0046] 4. The preparation method of the application is simple and efficient, and the prepared PVB film not only has excellent processability, but also has good light transmittance and extremely low haze. DETAILED DESCRIPTION

[0047] EMBODIMENT

[0048] EMBODIMENT 1

[0049] The embodiment provides a polyvinyl butyral film (PVB film); according to mass parts, raw materials of the polyvinyl butyral film include 100 parts of PVB resin, 30 parts of plasticizer, 0.2 parts of ultraviolet absorber, 0.2 parts of antioxidant, and 0.002 parts of viscosity regulator.

[0050] The PVB resin is a combination of PVB resin-A and PVB resin-B; the hydroxyl value of the PVB resin-A is 17.5%, the polymerization degree is 1799, and the volatile matter is ≤1.5%; the hydroxyl value of the PVB resin-B is 23%, the polymerization degree is 1299, and the volatile matter is ≤1.5%; the mass ratio of the PVB resin-A to the PVB resin-B is 1:1.5.

[0051] The plasticizer is triethylene glycol diisooctylate and polyethylene glycol, and the mass ratio of the two is 1:1; the average molecular weight of the polyethylene glycol is 600.

[0052] The ultraviolet absorber is UV-326, the antioxidant is antioxidant 1010, and the viscosity regulator is potassium acetate.

[0053] The preparation method of the polyvinyl butyral film sheet is as follows: the PVB resin-A is fed into the double-screw extruder through the main feeding port, the main feeding screw rotates at a speed of 20 rmp; the PVB resin-B is fed through the side feeding port, and the side feeding screw rotates at a speed of 30 rmp; the antioxidant 1010, the potassium acetate, and the UV-326 are dissolved in the triethylene glycol diisooctylate, and the mixture and the polyethylene glycol are fed into the extruder through two liquid feeding ports; all the raw materials are fed into the double-screw extruder for melt plasticization (the melt pump rotates at a speed of 40 rmp, and the main screw rotates at a speed of 80 rmp), and then a PVB film sheet with a thickness of 0.76 mm is obtained through extrusion casting.

[0054] The temperature of the body section of the double-screw extruder is 90-180℃, and the temperature of the die head is 160℃.

[0055] Example 2

[0056] The present embodiment provides a polyvinyl butyral film sheet (PVB film sheet); according to mass parts, the raw materials of the polyvinyl butyral film sheet include 100 parts of PVB resin, 30 parts of plasticizer, 0.2 parts of ultraviolet absorber, 0.2 parts of antioxidant, and 0.002 parts of viscosity regulator.

[0057] The PVB resin is a combination of PVB resin-A and PVB resin-B; the hydroxyl value of the PVB resin-A is 17.5%, the polymerization degree is 1799, and the volatile matter is ≤1.5%; the hydroxyl value of the PVB resin-B is 23%, the polymerization degree is 1299, and the volatile matter is ≤1.5%; the mass ratio of the PVB resin-A to the PVB resin-B is 1:1.78.

[0058] The plasticizer is triethylene glycol diisooctylate and polyethylene glycol, and the mass ratio of the two is 1:1; the average molecular weight of the polyethylene glycol is 600.

[0059] The ultraviolet absorber is UV-326, the antioxidant is antioxidant 1010, and the viscosity regulator is potassium acetate.

[0060] The preparation method of the polyvinyl butyral film sheet is as follows: PVB resin-A is fed into the double-screw extruder through the main feeding port, and the main feeding screw rotates at 20 rmp; PVB resin-B is fed through the side feeding port, and the side feeding screw rotates at 30 rmp; antioxidant 1010, potassium acetate, and UV-326 are dissolved in triethylene glycol diisooctanoate, and the mixture and polyethylene glycol are respectively fed into the extruder through two liquid feeding ports; all raw materials are fed into the double-screw extruder for melt plasticization (the melt pump rotates at 40 rmp, and the main screw rotates at 80 rmp), and a PVB film sheet with a thickness of 0.76 mm is obtained through extrusion casting.

[0061] The temperature of the body section of the double-screw extruder is 90-180℃, and the temperature of the die head is 165℃.

[0062] Example 3

[0063] The embodiment provides a polyvinyl butyral film sheet (PVB film sheet); the raw materials of the polyvinyl butyral film sheet include 100 parts of PVB resin, 35 parts of plasticizer, 0.2 parts of ultraviolet absorber, 0.2 parts of antioxidant, and 0.002 parts of viscosity regulator in terms of mass fraction.

[0064] The PVB resin is a combination of PVB resin-A and PVB resin-B; the PVB resin-A has a hydroxyl value of 17.5%, a polymerization degree of 1799, and volatile matter ≤1.5%; the PVB resin-B has a hydroxyl value of 23%, a polymerization degree of 1299, and volatile matter ≤1.5%; and the mass ratio of the PVB resin-A to the PVB resin-B is 1:1.5.

[0065] The plasticizer is triethylene glycol diisooctanoate and polyethylene glycol, and the mass ratio of the two is 1:0.75; and the average molecular weight of the polyethylene glycol is 600.

[0066] The ultraviolet absorber is UV-326, the antioxidant is antioxidant 1010, and the viscosity regulator is potassium acetate.

[0067] The preparation method of the polyvinyl butyral film sheet is as follows: PVB resin-A is introduced into the double screw extruder through the main feeding port, and the main feeding screw rotates at 20 rmp; PVB resin-B is introduced through the side feeding port, and the side feeding screw rotates at 30 rmp; antioxidant 1010, potassium acetate, and UV-326 are dissolved in triethylene glycol diisooctanoate, and the mixture and polyethylene glycol are introduced into the extruder through two liquid feeding ports; all raw materials are introduced into the double screw extruder for melting plasticization (the melt pump rotates at 40 rmp, and the main screw rotates at 80 rmp), and a PVB film sheet with a thickness of 0.76 mm is obtained through extrusion casting.

[0068] The temperature of the body section of the double screw extruder is 90-180°C, and the temperature of the die head is 155°C.

[0069] Example 4

[0070] The polyvinyl butyral film sheet (PVB film sheet) provided in the embodiment comprises 100 parts of PVB resin, 35 parts of plasticizer, 0.2 parts of ultraviolet absorber, 0.18 parts of antioxidant, and 0.003 parts of viscosity regulator.

[0071] The PVB resin is a combination of PVB resin-A and PVB resin-B; the hydroxyl value of the PVB resin-A is 17.5%, the polymerization degree is 1799, and the volatile matter is ≤1.5%; the hydroxyl value of the PVB resin-B is 23%, the polymerization degree is 1299, and the volatile matter is ≤1.5%; and the mass ratio of the PVB resin-A to the PVB resin-B is 1:1.5.

[0072] The plasticizer is triethylene glycol diisooctanoate and polyethylene glycol, and the mass ratio of the two is 1:1.5.

[0073] The ultraviolet absorber is UV-326, the antioxidant is antioxidant 1010, and the viscosity regulator is potassium acetate.

[0074] The preparation method of the polyvinyl butyral film sheet is as follows: PVB resin-A is introduced into the double screw extruder through the main feeding port, and the main feeding screw rotates at 20 rmp; PVB resin-B is introduced through the side feeding port, and the side feeding screw rotates at 30 rmp; antioxidant 1010, potassium acetate, and UV-326 are dissolved in triethylene glycol diisooctanoate, and the mixture and polyethylene glycol are introduced into the extruder through two liquid feeding ports; all raw materials are introduced into the double screw extruder for melting plasticization (the melt pump rotates at 40 rmp, and the main screw rotates at 80 rmp), and a PVB film sheet with a thickness of 0.76 mm is obtained through extrusion casting.

[0075] The temperature of the body section of the double screw extruder is 90-180°C, and the temperature of the die head is 155°C.

[0076] Comparative Example 1

[0077] The polyvinyl butyral film (PVB film) provided by the embodiment includes, by mass fraction, 100 parts of PVB resin, 35 parts of plasticizer, 0.2 parts of ultraviolet absorber, 0.2 parts of antioxidant, and 0.001 parts of viscosity regulator.

[0078] The PVB resin is PVB resin-A, the hydroxyl value of the PVB resin-A is 17.5%, the polymerization degree is 1799, and the volatile fraction is ≤1.5%.

[0079] The plasticizer is triethylene glycol diisooctylate.

[0080] The ultraviolet absorber is UV-326, the antioxidant is antioxidant 1010, and the viscosity regulator is potassium acetate.

[0081] The preparation method of the polyvinyl butyral film includes the following steps: feeding the PVB resin-A into a double-screw extruder through a main feeding port, rotating the main feeding screw at a speed of 20 rmp; dissolving the antioxidant 1010, potassium acetate, and UV-326 in triethylene glycol diisooctylate, feeding the mixture into the extruder through a liquid feeding port; and melting and plasticizing all the raw materials in the double-screw extruder (rotating the melt pump at a speed of 40 rmp and rotating the main screw at a speed of 80 rmp), to obtain a PVB film with a thickness of 0.76 mm.

[0082] The temperature of the body of the double-screw extruder is 90-180°C, and the temperature of the die head is 160°C.

[0083] Comparative Example 2

[0084] The polyvinyl butyral film (PVB film) provided by the embodiment includes, by mass fraction, 100 parts of PVB resin, 35 parts of plasticizer, 0.2 parts of ultraviolet absorber, 0.2 parts of antioxidant, and 0.001 parts of viscosity regulator.

[0085] The PVB resin is PVB resin-A, the hydroxyl value of the PVB resin-A is 17.5%, the polymerization degree is 1799, and the volatile fraction is ≤1.5%.

[0086] The plasticizer is triethylene glycol diisooctylate and polyethylene glycol, and the mass ratio of the two is 1:0.94; the average molecular weight of the polyethylene glycol is 600.

[0087] The ultraviolet absorber is UV-326, the antioxidant is antioxidant 1010, and the viscosity regulator is potassium acetate.

[0088] The preparation method of the polyvinyl butyral film sheet is as follows: the PVB resin-A is introduced into the double screw extruder through the main feeding port, and the main feeding screw rotates at 20 rmp; the antioxidant 1010, potassium acetate and UV-326 are dissolved in triethylene glycol diisooctylate, and the mixture and polyethylene glycol are introduced into the extruder through two liquid feeding ports; all the raw materials are introduced into the double screw extruder for melt plasticization (the melt pump rotates at 40 rmp, and the main screw rotates at 80 rmp), and then the PVB film sheet with a thickness of 0.76 mm is obtained through extrusion casting.

[0089] The body temperature of the double screw extruder is 90-180℃, and the die temperature is 160℃.

[0090] Comparative Example 3

[0091] The polyvinyl butyral film sheet (PVB film sheet) provided by the embodiment includes 100 parts of PVB resin, 30 parts of plasticizer, 0.2 parts of ultraviolet absorber, 0.2 parts of antioxidant, and 0.002 parts of viscosity regulator.

[0092] The PVB resin is a combination of PVB resin-A and PVB resin-B; the hydroxyl value of the PVB resin-A is 17.5%, the polymerization degree is 1799, and the volatile matter is ≤1.5%; the hydroxyl value of the PVB resin-B is 23%, the polymerization degree is 1299, and the volatile matter is ≤1.5%; and the mass ratio of the PVB resin-A to the PVB resin-B is 1:1.5.

[0093] The plasticizer is triethylene glycol diisooctylate.

[0094] The ultraviolet absorber is UV-326, the antioxidant is antioxidant 1010, and the viscosity regulator is potassium acetate.

[0095] The preparation method of the polyvinyl butyral film sheet is as follows: the PVB resin-A is introduced into the double screw extruder through the main feeding port, and the main feeding screw rotates at 20 rmp; the PVB resin-B is introduced into the double screw extruder through the side feeding port, and the side feeding screw rotates at 30 rmp; the antioxidant 1010, potassium acetate and UV-326 are dissolved in triethylene glycol diisooctylate, and the mixture and polyethylene glycol are introduced into the extruder through two liquid feeding ports; all the raw materials are introduced into the double screw extruder for melt plasticization (the melt pump rotates at 40 rmp, and the main screw rotates at 80 rmp), and then the PVB film sheet with a thickness of 0.76 mm is obtained through extrusion casting.

[0096] The body temperature of the double screw extruder is 90-180℃, and the die temperature is 160℃.

[0097] Comparative Example 4

[0098] The embodiment provides a polyvinyl butyral film (PVB film); according to mass parts, raw materials of the polyvinyl butyral film include 100 parts of PVB resin, 40 parts of plasticizer, 0.2 parts of ultraviolet absorber, 0.2 parts of antioxidant, and 0.002 parts of viscosity regulator.

[0099] The PVB resin is a combination of PVB resin-A and PVB resin-B; the PVB resin-A has a hydroxyl value of 17.5%, a polymerization degree of 1799, and volatile matter of less than or equal to 1.5%; the PVB resin-B has a hydroxyl value of 23%, a polymerization degree of 1299, and volatile matter of less than or equal to 1.5%; and the mass ratio of the PVB resin-A to the PVB resin-B is 1:1.5.

[0100] The plasticizer is triethylene glycol diisooctylate.

[0101] The ultraviolet absorber is UV-326, the antioxidant is antioxidant 1010, and the viscosity regulator is potassium acetate.

[0102] The preparation method of the polyvinyl butyral film is as follows: the PVB resin-A is fed into a double-screw extruder through a main feeding port, the main feeding screw rotates at a speed of 20 rmp; the PVB resin-B is fed through a side feeding port, and the side feeding screw rotates at a speed of 30 rmp; the antioxidant 1010, the potassium acetate and the UV-326 are dissolved in the triethylene glycol diisooctylate, and the mixture and polyethylene glycol are fed into the extruder through two liquid feeding ports; and all the raw materials are fed into the double-screw extruder to be melt plasticized (the melt pump rotates at a speed of 40 rmp, and the main screw rotates at a speed of 80 rmp), so that the PVB film with a thickness of 0.76 mm is obtained through extrusion casting.

[0103] The body temperature of the double-screw extruder is 90-180 DEG C, and the die temperature is 160 DEG C.

[0104] Comparative example 5

[0105] The embodiment provides a polyvinyl butyral film (PVB film); according to mass parts, raw materials of the polyvinyl butyral film include 100 parts of PVB resin, 40 parts of plasticizer, 0.2 parts of ultraviolet absorber, 0.2 parts of antioxidant, and 0.002 parts of viscosity regulator.

[0106] The PVB resin is PVB resin-B; the PVB resin-B has a hydroxyl value of 23%, a polymerization degree of 1299, and volatile matter of less than or equal to 1.5%.

[0107] The plasticizer is polyethylene glycol, and the average molecular weight of the polyethylene glycol is 600.

[0108] The ultraviolet absorber is UV-326, the antioxidant is antioxidant 1010, and the viscosity regulator is potassium acetate.

[0109] The preparation method of the polyvinyl butyral film is as follows: PVB resin-A is introduced into the double screw extruder through the main feeding port, and the main feeding screw rotates at 20 rmp; PVB resin-B is introduced through the side feeding port, and the side feeding screw rotates at 30 rmp; antioxidant 1010, potassium acetate and UV-326 are dissolved in triethylene glycol diisooctanoate, and the mixture and polyethylene glycol are introduced into the extruder through two liquid feeding ports; all raw materials are introduced into the double screw extruder for melting and plasticizing (the melt pump rotates at 40 rmp, and the main screw rotates at 80 rmp), and then a PVB film with a thickness of 0.76 mm is obtained through extrusion casting.

[0110] The temperature of the body of the double screw extruder is 90-180℃, and the temperature of the die is 160℃.

[0111] In the above examples and comparative examples, PVB resin-A is purchased from Hukui Yimin Plastic Co., Ltd., and the model number is 2023015-F; PVB resin-B is purchased from Jiangxi Tiancheng New Material Co., Ltd., and the model number is 2303-37B.

[0112] Performance test method:

[0113] 1. PVB film surface plasticizer precipitation test:

[0114] Test device: electronic analytical balance, sulfuric acid dryer, tablet press.

[0115] The PVB film is placed in the dryer containing sulfuric acid in turn, and after 5 days, the mass m1 is measured. Then the dried sample (after weighing) is placed in the dryer containing water in turn, and after 7 days, the water on the surface of the sample is absorbed with filter paper, and then the sample is placed in the sulfuric acid dryer for drying for 5 days, and then the mass m2 is measured. The amount of plasticizer precipitation = (m1-m2) / m1;

[0116] 2. PVB film tensile strength and elongation at break test: according to the provisions of GB / T1040.3-2006, type 5 sample is used, the sample is taken along the longitudinal direction, the test speed is (100±10) mm / min, and the gauge length is (25±0.25) mm.

[0117] The test results are shown in Table 1.

[0118] Table 1

[0119]

[0120] Summary: Comparing the results of the above examples and comparative examples, it can be seen that only when the hydroxyl value and the degree of polymerization of the PVB resin are optimized and a specific plasticizer is further compounded, the PVB film system has excellent compatibility and can avoid the migration of the plasticizer.

Claims

1. A polyvinyl butyral film, characterized in that, The raw materials of the polyvinyl butyral film, by weight, include 100 parts of PVB resin and 10-50 parts of plasticizer. The PVB resin is a combination of PVB resin-A with a hydroxyl value of 17.5-20% and PVB resin-B with a hydroxyl value of 23-25%, with a mass ratio of 1:(1.5-1.78). The degree of polymerization of PVB resin-A is 1500-1799, and the degree of polymerization of PVB resin-B is 1100-1299. The plasticizer includes plasticizer A and plasticizer B; The plasticizer A includes triethylene glycol diisooctanoate; The plasticizer B includes polyethylene glycol, which has an average molecular weight of 400-1000. The mass ratio of plasticizer A to plasticizer B is 1:(0.75-1.5).

2. A method for preparing a polyvinyl butyral film according to claim 1, characterized in that, Simply add the raw material to a twin-screw extruder and extrude it at 40-200℃ while stirring.

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