Polyvinyl acetal resin composition, preparation method thereof and intermediate film

Abstract

The invention discloses a polyvinyl acetal resin composition, a preparation method thereof and an intermediate film, and relates to the technical field of polyvinyl alcohol, the polyvinyl acetal resin composition is formed by combining any two or more than two of polyvinyl acetal resin n (n = 1, 2, 3, 4, 5); wherein the average molecular weight Mn1 of the polyvinyl acetal resin 1 is greater than or equal to 140000, the average molecular weight range of the polyvinyl acetal resin 2 is that Mn2 is greater than 100000 and less than or equal to 140000, the average molecular weight range of the polyvinyl acetal resin 3 is that Mn3 is greater than 75000 and less than or equal to 100000, the average molecular weight range of the polyvinyl acetal resin 4 is that Mn4 is greater than 40000 and less than or equal to 75000, and the average molecular weight Mn5 of the polyvinyl acetal resin 5 is less than or equal to 40000; according to the polyvinyl acetal resin composition, under the condition that no additive is added, regulation and control of melt index temperature dependence and mechanical properties can be achieved only by blending polyvinyl acetal resin under different polymerization conditions according to the proportion, the synthesis process is quite simple and efficient, and preparation is convenient.

Description

Technical Field

[0001] The invention relates to the technical field of polyvinyl alcohol, and in particular to a polyvinyl acetal resin composition and a preparation method thereof and an intermediate film. Background Art

[0002] Polyvinyl acetal resin is widely used in construction, automotive safety glass and photovoltaic modules due to its good stability, impact resistance and adhesion.

[0003] Polyvinyl acetal resin is made into a thinner film through processes such as plasticization, heating and pressurization, which is used as the intermediate film of laminated glass. The use of this intermediate interlayer film accounts for 50% of the total amount of polyvinyl acetal resin. The preparation of laminated safety glass includes: glass cutting, lamination of polyvinyl acetal intermediate film and glass, pre-pressing, exhausting and high-pressure molding. In this process, the temperature dependence of the melt index of polyvinyl acetal resin is crucial. If the melt index of polyvinyl acetal resin is too high at low temperature, it may lead to incomplete exhaust and bubbles; if the melt index of polyvinyl acetal resin is low at high temperature, it may lead to loose fitting and failure of lamination. Therefore, in the preparation process of safety glass, polyvinyl acetal resin is required to have excellent melting temperature dependence, that is, the product melt index is low at low temperature and high at high temperature.

[0004] The patent document with publication number CN113861315A adopts a method of first mixing high-polymerization degree and low-polymerization degree polyvinyl alcohol resins and then acetalizing to prepare a polyvinyl alcohol acetal resin. The synthesis process is complicated, and the melt index performance of the corresponding resin product at high temperature is not characterized, and the temperature dependence of the melt index of the product cannot be evaluated; the patent document with publication number CN117362490A starts from the aggregation state of polyvinyl alcohol, and regulates the temperature dependence of the melt index of the polyvinyl alcohol acetal resin by introducing inorganic salts, optimizing the reaction process, etc.; overall, the process parameters of this regulation method are complicated, and a large amount of inorganic salts are introduced, which not only increases the cost, but also the trace residual ions will have an adverse effect on the performance of the product. Summary of the invention

[0005] The object of the present invention is to provide a polyvinyl acetal resin composition and a preparation method thereof and an intermediate film to solve the following technical problems:

[0006] How to simplify the synthesis process of polyvinyl acetal resin and meet the performance requirements of low product melt index at low temperature and high melt index at high temperature.

[0007] The melt index of polyvinyl acetal resin is closely related to its molecular weight. Low molecular weight polyvinyl acetal resin has strong fluidity and good melt index performance, but poor mechanical properties; high molecular weight polyvinyl acetal resin has relatively biased fluidity and relatively biased melt index performance, but has good mechanical properties. Therefore, to a certain extent, from the perspective of low molecular weight resin providing good fluidity and high molecular weight resin providing good mechanical properties, by precisely controlling the blending of polyvinyl acetal resins with different molecular weights, polyvinyl acetal products with good melt index temperature dependence and good mechanical properties can be prepared.

[0008] Based on this, the purpose of the present invention can be achieved through the following technical solutions:

[0009] In a first aspect, the present invention discloses a polyvinyl acetal resin composition, which is composed of any two or more polyvinyl acetal resins n (n=1, 2, 3, 4, 5);

[0010] Among them, the average molecular weight of the polyvinyl acetal resin 1 is Mn1≥140000, the average molecular weight of the polyvinyl acetal resin 2 is in the range of 100000<Mn2≤140000, the average molecular weight of the polyvinyl acetal resin 3 is in the range of 75000<Mn3≤100000, the average molecular weight of the polyvinyl acetal resin 4 is in the range of 40000<Mn4≤75000, and the average molecular weight of the polyvinyl acetal resin 5 is Mn5≤40000.

[0011] Furthermore, among the polyvinyl acetal resins n (n=1, 2, 3, 4, 5) constituting the polyvinyl acetal resin composition, the polyvinyl acetal resins with the highest and lowest average molecular weights satisfy: Mn max -Mn min ≥75000.

[0012] Furthermore, among the polyvinyl acetal resins n (n=1, 2, 3, 4, 5) constituting the polyvinyl acetal resin composition, 8*10 4 <∑Mn n *F n ≤15*10 4 , where F n is the mass fraction of polyvinyl acetal resin n.

[0013] Furthermore, among the polyvinyl acetal resins n (n=1, 2, 3, 4, 5) constituting the polyvinyl acetal resin composition, the average particle size D of the polyvinyl acetal resin n is n =80-300μm, and 0.7≤D n2 / D n1 ≤1.3.

[0014] Furthermore, the hydroxyl value of the polyvinyl acetal resin composition is 16.0-20.0%wt%.

[0015] In a second aspect, the present invention further discloses a method for preparing the polyvinyl acetal resin composition as described above, comprising the following steps:

[0016] S1, placing polyvinyl acetal resins n (n=1, 2, 3, 4, 5) constituting the polyvinyl acetal resin composition in storage tanks respectively;

[0017] S2. Synchronously introduce the polyvinyl acetal resin n (n=1, 2, 3, 4, 5) in the storage tank into a conical mixer and continuously stir and mix them evenly to obtain a polyvinyl acetal resin composition.

[0018] Furthermore, in step S1, the storage tank is provided with a discharge speed control function and a stirring and mixing function.

[0019] In a third aspect, the present invention further discloses an intermediate film, comprising the polyvinyl acetal resin composition as described above.

[0020] Furthermore, the preparation method of the intermediate film is: the polyvinyl acetal resin composition and the plasticizer are uniformly mixed and then plasticized and extruded through an extruder to obtain the intermediate film.

[0021] Furthermore, the usage ratio of the polyvinyl acetal resin composition to the plasticizer is 72.5:27.5.

[0022] Furthermore, the intermediate film has a melt index MI-120°C ≤ 1.60 g / 10 min at 120°C, and a melt index MI-190°C at 190°C satisfies: MI-190°C / MI-120°C ≥ 1.20.

[0023] Furthermore, when the strain degree of the intermediate film reaches 150%, the strain energy is ≥600N / m 2 .

[0024] Beneficial effects of the present invention:

[0025] (1) The polyvinyl acetal resin composition of the present invention can achieve the regulation of the temperature dependence of the melt index and the mechanical properties by simply blending polyvinyl acetal resins of different polymerization conditions in proportion without adding any additives. The synthesis process is very simple and efficient, and it is easy to prepare.

[0026] (2) The MI-120℃, MI-190℃ and strain energy at 150% of the intermediate film prepared by the polyvinyl acetal resin composition of the present invention are more stable and all meet the following conditions: MI-120℃≤1.60g / 10min, MI-190℃ / MI-120℃≥1.20, and when the strain degree reaches 150%, the strain energy is ≥600N / m 2 . BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the accompanying drawings.

[0028] Figure 1 is a product picture of the polyvinyl acetal resin composition prepared in Example 1 of the present invention;

[0029] Figure 2 This is a product picture of the intermediate film prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0030] 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.

[0031] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0032] Example 1

[0033] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0034] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 154,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank A, 500.0 kg of polyvinyl acetal resin with an average molecular weight of 100,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank B, and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 25,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank C; material tank A pumped the polyvinyl acetal resin into a conical mixer at a speed of 88.2 kg / h, material tank B pumped the polyvinyl acetal resin into a conical mixer at a speed of 126.0 kg / h, and material tank C pumped the polyvinyl acetal resin into a conical mixer at a speed of 37.8 kg / h. After the three polyvinyl acetal resins were evenly mixed, the following was obtained: Figure 1 The polyvinyl acetal resin composition shown.

[0035] (2) preparing the intermediate film, as follows:

[0036] Take 50 kg of the polyvinyl acetal resin composition prepared in (1) and 18.97 kg of triethylene glycol di-2-ethyl acetate, and then plasticize and extrude them through an extruder to prepare a Figure 2 The polyvinyl acetal intermediate film shown in the figure; wherein, the screw speed of the extruder is 250r / min; the body temperature of each zone of the extruder is 40℃, 70℃, 150℃, 150℃, 150℃, 150℃, 150℃, 140℃, and 120℃ respectively; the thickness of the obtained polyvinyl acetal intermediate film is 0.76mm.

[0037] Example 2

[0038] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0039] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 126,000 (corresponding to a polyvinyl alcohol resin with a degree of alcoholysis of 99%) was added to material tank A, and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 25,000 (corresponding to a polyvinyl alcohol resin with a degree of alcoholysis of 99%) was added to material tank B. The polyvinyl acetal resin was pumped into a conical mixer from material tank A at a speed of 214.2 kg / h, and the polyvinyl acetal resin was pumped into a conical mixer from material tank B at a speed of 37.8 kg / h. After the three polyvinyl acetal resins were evenly mixed, a polyvinyl acetal resin composition was obtained.

[0040] (2) preparing the intermediate film, as follows:

[0041] Take 50 kg of the polyvinyl acetal resin composition prepared in (1) and 18.97 kg of triethylene glycol di-2-ethyl acetate, and then plasticize and extrude them through an extruder to prepare a polyvinyl acetal intermediate film; wherein the screw speed of the extruder is 250 r / min; the body temperature of each zone of the extruder is 40°C, 70°C, 150°C, 150°C, 150°C, 150°C, 140°C, and 120°C respectively; the thickness of the obtained polyvinyl acetal intermediate film is 0.76 mm.

[0042] Example 3

[0043] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0044] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 140,000 (corresponding to an alcoholysis degree of 99%) was added to material tank A, 500.0 kg of polyvinyl acetal resin with an average molecular weight of 100,000 (corresponding to an alcoholysis degree of 99%) was added to material tank B, and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 25,000 (corresponding to an alcoholysis degree of 99%) was added to material tank C; material tank A pumped the polyvinyl acetal resin into a conical mixer at a speed of 100.8 kg / h, material tank B pumped the polyvinyl acetal resin into the conical mixer at a speed of 113.4 kg / h, and material tank C pumped the polyvinyl acetal resin into the conical mixer at a speed of 37.8 kg / h. After the three polyvinyl acetal resins were evenly mixed, a polyvinyl acetal resin composition was obtained.

[0045] (2) preparing the intermediate film, as follows:

[0046] Take 50 kg of the polyvinyl acetal resin composition prepared in (1) and 18.97 kg of triethylene glycol di-2-ethyl acetate, and then plasticize and extrude them through an extruder to prepare a polyvinyl acetal intermediate film; wherein the screw speed of the extruder is 250 r / min; the body temperature of each zone of the extruder is 40°C, 70°C, 150°C, 150°C, 150°C, 150°C, 140°C, and 120°C respectively; the thickness of the obtained polyvinyl acetal intermediate film is 0.76 mm.

[0047] Example 4

[0048] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0049] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 154,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank A, 500.0 kg of polyvinyl acetal resin with an average molecular weight of 100,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank B, and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 50,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank C; material tank A pumped the polyvinyl acetal resin into a conical mixer at a speed of 88.2 kg / h, material tank B pumped the polyvinyl acetal resin into the conical mixer at a speed of 113.4 kg / h, and material tank C pumped the polyvinyl acetal resin into the conical mixer at a speed of 50.4 kg / h. After the three polyvinyl acetal resins were evenly mixed, a polyvinyl acetal resin composition was obtained.

[0050] (2) preparing the intermediate film, as follows:

[0051] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0052] Example 5

[0053] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0054] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 154,000 (corresponding to an alcoholysis degree of 99%) was added to material tank A, 500.0 kg of polyvinyl acetal resin with an average molecular weight of 86,000 (corresponding to an alcoholysis degree of 99%) was added to material tank B, and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 25,000 (corresponding to an alcoholysis degree of 99%) was added to material tank C; material tank A pumped the polyvinyl acetal resin into a conical mixer at a speed of 100.8 kg / h, material tank B pumped the polyvinyl acetal resin into the conical mixer at a speed of 113.4 kg / h, and material tank C pumped the polyvinyl acetal resin into the conical mixer at a speed of 37.8 kg / h. After the three polyvinyl acetal resins were evenly mixed, a polyvinyl acetal resin composition was obtained.

[0055] (2) preparing the intermediate film, as follows:

[0056] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0057] Example 6

[0058] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0059] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 154,000 (corresponding to an alcoholysis degree of 99%) was added to material tank A, 500.0 kg of polyvinyl acetal resin with an average molecular weight of 100,000 (corresponding to an alcoholysis degree of 99%) was added to material tank B, and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 18,500 (corresponding to an alcoholysis degree of 99%) was added to material tank C; material tank A pumped the polyvinyl acetal resin into a conical mixer at a speed of 88.2 kg / h, material tank B pumped the polyvinyl acetal resin into the conical mixer at a speed of 126.0 kg / h, and material tank C pumped the polyvinyl acetal resin into the conical mixer at a speed of 37.8 kg / h. After the three polyvinyl acetal resins were evenly mixed, a polyvinyl acetal resin composition was obtained.

[0060] (2) preparing the intermediate film, as follows:

[0061] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0062] Example 7

[0063] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0064] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 160,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank A, 500.0 kg of polyvinyl acetal resin with an average molecular weight of 100,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank B, and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 50,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank C; material tank A pumped the polyvinyl acetal resin into a conical mixer at a speed of 75.6 kg / h, material tank B pumped the polyvinyl acetal resin into the conical mixer at a speed of 113.4 kg / h, and material tank C pumped the polyvinyl acetal resin into the conical mixer at a speed of 63.0 kg / h. After the three polyvinyl acetal resins were evenly mixed, a polyvinyl acetal resin composition was obtained.

[0065] (2) preparing the intermediate film, as follows:

[0066] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0067] Example 8

[0068] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0069] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 135,000 (corresponding to an alcoholysis degree of 99%) was added to material tank A, 500.0 kg of polyvinyl acetal resin with an average molecular weight of 100,000 was added to material tank B (corresponding to an alcoholysis degree of 99%), and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 18,500 was added to material tank C (corresponding to an alcoholysis degree of 99%); material tank A pumped the polyvinyl acetal resin into a conical mixer at a speed of 151.2 kg / h, material tank B pumped the polyvinyl acetal resin into the conical mixer at a speed of 63.0 kg / h, and material tank C pumped the polyvinyl acetal resin into the conical mixer at a speed of 37.8 kg / h. After the three polyvinyl acetal resins were evenly mixed, a polyvinyl acetal resin composition was obtained.

[0070] (2) preparing the intermediate film, as follows:

[0071] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0072] Example 9

[0073] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0074] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 160,000 (corresponding to an alcoholysis degree of 99%) was added to material tank A, 500.0 kg of polyvinyl acetal resin with an average molecular weight of 100,000 (corresponding to an alcoholysis degree of 99%) was added to material tank B, and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 18,500 (corresponding to an alcoholysis degree of 99%) was added to material tank C; material tank A pumped the polyvinyl acetal resin into a conical mixer at a speed of 88.2 kg / h, material tank B pumped the polyvinyl acetal resin into the conical mixer at a speed of 126.0 kg / h, and material tank C pumped the polyvinyl acetal resin into the conical mixer at a speed of 37.8 kg / h. After the three polyvinyl acetal resins were evenly mixed, a polyvinyl acetal resin composition was obtained.

[0075] (2) preparing the intermediate film, as follows:

[0076] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0077] Example 10

[0078] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0079] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 160,000 (corresponding to an alcoholysis degree of 99%) was added to material tank A, 500.0 kg of polyvinyl acetal resin with an average molecular weight of 86,000 (corresponding to an alcoholysis degree of 99%) was added to material tank B, and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 18,500 (corresponding to an alcoholysis degree of 99%) was added to material tank C; material tank A pumped the polyvinyl acetal resin into a conical mixer at a speed of 100.8 kg / h, material tank B pumped the polyvinyl acetal resin into the conical mixer at a speed of 113.4 kg / h, and material tank C pumped the polyvinyl acetal resin into the conical mixer at a speed of 37.8 kg / h. After the three polyvinyl acetal resins were evenly mixed, a polyvinyl acetal resin composition was obtained.

[0080] (2) preparing the intermediate film, as follows:

[0081] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0082] Embodiment 11

[0083] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0084] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 154,000 (corresponding to an alcoholysis degree of 99%) was added to material tank A, 500.0 kg of polyvinyl acetal resin with an average molecular weight of 100,000 (corresponding to an alcoholysis degree of 99%) was added to material tank B, 500.0 kg of polyvinyl acetal resin with an average molecular weight of 25,000 (corresponding to an alcoholysis degree of 99%) was added to material tank C; 500.0 kg of polyvinyl acetal resin with an average molecular weight of 75,000 was added to material tank D. Enol acetal resin (the alcoholysis degree of the corresponding polyvinyl alcohol resin is 99%); material tank A injects the polyvinyl alcohol acetal resin into a conical mixer at a speed of 88.2 kg / h, material tank B injects the polyvinyl alcohol acetal resin into a conical mixer at a speed of 75.6 kg / h, material tank C injects the polyvinyl acetal resin into a conical mixer at a speed of 52.4 kg / h, and material tank D injects the polyvinyl acetal resin into a conical mixer at a speed of 37.8 kg / h. After the four polyvinyl alcohol acetal resins are evenly mixed, a polyvinyl alcohol acetal resin composition is obtained.

[0085] (2) preparing the intermediate film, as follows:

[0086] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0087] Example 12

[0088] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0089] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 154,000 (corresponding to the alcoholysis degree of polyvinyl alcohol resin of 99%) was added to material tank A, 500.0 kg of polyvinyl acetal resin with an average molecular weight of 100,000 (corresponding to the alcoholysis degree of polyvinyl alcohol resin of 99%) was added to material tank B, 500.0 kg of polyvinyl acetal resin with an average molecular weight of 25,000 (corresponding to the alcoholysis degree of polyvinyl alcohol resin of 99%) was added to material tank C; 500.0 kg of polyvinyl acetal resin with an average molecular weight of 80,000 (corresponding to the alcoholysis degree of polyvinyl alcohol resin of 99%) was added to material tank D; 500.0 kg of polyvinyl acetal resin with an average molecular weight of 80,000 was added to material tank E; The amount of polyvinyl alcohol acetal resin is 55000 (corresponding to the alcoholysis degree of polyvinyl alcohol resin is 99%); material tank A beats the polyvinyl alcohol acetal resin into the conical mixer at a speed of 100.8kg / h, material tank B beats the polyvinyl alcohol acetal resin into the conical mixer at a speed of 37.8kg / h, material tank C beats the polyvinyl acetal resin into the conical mixer at a speed of 50.4kg / h, material tank D beats the polyvinyl acetal resin into the conical mixer at a speed of 25.2kg / h, and material tank E beats the polyvinyl acetal resin into the conical mixer at a speed of 37.8kg / h. After the five polyvinyl alcohol acetal resins are evenly mixed, a polyvinyl alcohol acetal resin composition is obtained.

[0090] (2) preparing the intermediate film, as follows:

[0091] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0092] Embodiment 13

[0093] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0094] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 115,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank A, and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 25,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank B. The polyvinyl acetal resin was pumped into a conical mixer from material tank A at a rate of 214.2 kg / h, and the polyvinyl acetal resin was pumped into a conical mixer from material tank B at a rate of 37.8 kg / h. After the three polyvinyl acetal resins were evenly mixed, a polyvinyl acetal resin composition was obtained.

[0095] (2) preparing the intermediate film, as follows:

[0096] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0097] Embodiment 14

[0098] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0099] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 135,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank A, and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 25,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank B. The polyvinyl acetal resin was pumped into a conical mixer from material tank A at a rate of 214.2 kg / h, and the polyvinyl acetal resin was pumped into a conical mixer from material tank B at a rate of 37.8 kg / h. After the three polyvinyl acetal resins were evenly mixed, a polyvinyl acetal resin composition was obtained.

[0100] (2) preparing the intermediate film, as follows:

[0101] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0102] Embodiment 15

[0103] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0104] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 126,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank A, and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 50,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank B. The polyvinyl acetal resin was pumped into a conical mixer from material tank A at a speed of 201.6 kg / h, and the polyvinyl acetal resin was pumped into a conical mixer from material tank B at a speed of 50.4 kg / h. After the three polyvinyl acetal resins were evenly mixed, a polyvinyl acetal resin composition was obtained.

[0105] (2) preparing the intermediate film, as follows:

[0106] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0107] Example 16

[0108] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0109] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 126,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank A, and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 18,500 (corresponding to a degree of alcoholysis of 99%) was added to material tank B. The polyvinyl acetal resin was pumped into a conical mixer from material tank A at a rate of 214.2 kg / h, and the polyvinyl acetal resin was pumped into a conical mixer from material tank B at a rate of 37.8 kg / h. After the three polyvinyl acetal resins were evenly mixed, a polyvinyl acetal resin composition was obtained.

[0110] (2) preparing the intermediate film, as follows:

[0111] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0112] Embodiment 17

[0113] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0114] 500.0 kg of polyvinyl acetal resin with an average molecular weight of 135,000 (corresponding to a degree of alcoholysis of 99%) was added to material tank A, and 500.0 kg of polyvinyl acetal resin with an average molecular weight of 18,500 (corresponding to a degree of alcoholysis of 99%) was added to material tank B. The polyvinyl acetal resin was pumped into a conical mixer from material tank A at a rate of 214.2 kg / h, and the polyvinyl acetal resin was pumped into a conical mixer from material tank B at a rate of 37.8 kg / h. After the three polyvinyl acetal resins were evenly mixed, a polyvinyl acetal resin composition was obtained.

[0115] (2) preparing the intermediate film, as follows:

[0116] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0117] Comparative Example 1

[0118] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0119] Compared with Example 1, the only difference is that the polyvinyl alcohol acetal resin in the material tank A and the material tank C are changed to polyvinyl alcohol acetal resin with an average molecular weight of 100,000; the other steps are exactly the same.

[0120] (2) preparing the intermediate film, as follows:

[0121] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0122] Comparative Example 2

[0123] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0124] Compared with Example 1, the only difference is that the polyvinyl alcohol acetal resin in the material tank A and the material tank C are changed to polyvinyl alcohol acetal resin with an average molecular weight of 100,000; the other steps are exactly the same.

[0125] (2) preparing the intermediate film, as follows:

[0126] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0127] Comparative Example 3

[0128] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0129] Compared with Example 1, the only difference is that the polyvinyl alcohol acetal resin in the material tank A and the material tank B are changed to a polyvinyl alcohol acetal resin with an average molecular weight of 25,000; the other steps are exactly the same.

[0130] (2) preparing the intermediate film, as follows:

[0131] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0132] Comparative Example 4

[0133] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0134] Compared with Example 1, the only difference is that the polyvinyl alcohol acetal resin in the material tank A, the material tank B and the material tank C are all replaced with a polyvinyl alcohol acetal resin with an average molecular weight of 110,000; and the other steps are exactly the same.

[0135] (2) preparing the intermediate film, as follows:

[0136] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0137] Comparative Example 5

[0138] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0139] Compared with Example 1, the only difference is that the polyvinyl alcohol acetal resin in the material tank A, the material tank B and the material tank C are all replaced with a polyvinyl alcohol acetal resin with an average molecular weight of 50,000; and the other steps are exactly the same.

[0140] (2) preparing the intermediate film, as follows:

[0141] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0142] Comparative Example 6

[0143] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0144] Compared with Example 1, the only difference is that the polyvinyl alcohol acetal resin with an average molecular weight of 154,000 in material tank A is replaced by a polyvinyl alcohol acetal resin with an average molecular weight of 120,000, and the polyvinyl alcohol acetal resin with an average molecular weight of 100,000 in material tank B is replaced by a polyvinyl alcohol acetal resin with an average molecular weight of 60,000; the rest of the steps are exactly the same.

[0145] (2) preparing the intermediate film, as follows:

[0146] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0147] Comparative Example 7

[0148] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0149] Compared with Example 1, the only difference is that the polyvinyl alcohol acetal resin with an average molecular weight of 154,000 in material tank A is changed to a polyvinyl alcohol acetal resin with an average molecular weight of 210,000, and the polyvinyl alcohol acetal resin with an average molecular weight of 100,000 in material tank B is changed to a polyvinyl alcohol acetal resin with an average molecular weight of 150,000; the rest of the steps are exactly the same.

[0150] (2) preparing the intermediate film, as follows:

[0151] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0152] Comparative Example 8

[0153] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0154] Compared with Example 1, the only difference is that the polyvinyl alcohol acetal resin with an average molecular weight of 100,000 in material tank B is changed to a polyvinyl alcohol acetal resin with an average molecular weight of 140,000, and the polyvinyl alcohol acetal resin with an average molecular weight of 25,000 in material tank C is changed to a polyvinyl alcohol acetal resin with an average molecular weight of 80,000; the rest of the steps are exactly the same.

[0155] (2) preparing the intermediate film, as follows:

[0156] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0157] Comparative Example 9

[0158] (1) preparing a polyvinyl acetal resin composition, specifically as follows:

[0159] Compared with Example 1, the only difference is that the polyvinyl alcohol acetal resin with an average molecular weight of 154,000 in material tank A is changed to a polyvinyl alcohol acetal resin with an average molecular weight of 125,000, the polyvinyl alcohol acetal resin with an average molecular weight of 100,000 in material tank B is changed to a polyvinyl alcohol acetal resin with an average molecular weight of 60,000, and the polyvinyl alcohol acetal resin with an average molecular weight of 25,000 in material tank C is changed to a polyvinyl alcohol acetal resin with an average molecular weight of 15,000; the rest of the steps are exactly the same.

[0160] (2) preparing the intermediate film, as follows:

[0161] The steps for preparing the intermediate film are exactly the same as those in Example 1.

[0162] The hydroxyl value and average particle size of the polyvinyl acetal resin compositions obtained in Examples 1-17 and Comparative Examples 1-9 were tested by the following method:

[0163] Hydroxyl value: Tested by chemical titration, by esterifying the hydroxyl groups in the polyvinyl acetal resin with acetic anhydride in a pyridine solution, then hydrolyzing the excess acetic anhydride, using phenolphthalein as an indicator, and titrating with a NaOH standard solution to calculate the hydroxyl content in the polyvinyl acetal resin;

[0164] Average particle size: refer to national standard GB / T 19077-2016.

[0165] The test results and the particle sizes of resins A, B, C, D, and E in the preparation raw materials are listed in Table 1. Table 1 is as follows:

[0166] Table 1

[0167]

[0168]

[0169] Next, the MI-120°C, MI-190°C, 150% strain energy, fracture energy, light transmittance, and heat resistance of the intermediate films prepared in Examples 1-17 and Comparative Examples 1-9 were tested, and the testing method was as follows;

[0170] MI-120℃ and MI-190℃: respectively at 120℃, load 21.6kg; 190℃, load 2.16kg, use a melt indexer to record the outflow mass after 10 minutes, which is the melt index, unit: g / 10min;

[0171] 150% strain energy: refer to national standard GB / T 32020-2012;

[0172] Light transmittance: Refer to national standard GB / T 32020-2012;

[0173] Heat resistance test: refer to national standard GB / T 5317.3-2002.

[0174] The test results are listed in Table 2. Table 2 is as follows:

[0175] Table 2

[0176]

[0177]

[0178]

[0179] By analyzing the data in Table 2, it can be seen that compared with Comparative Examples 1-9, the MI-120℃, MI-190℃ and strain energy at 150% of the intermediate film prepared in Examples 1-17 are more stable, and all meet the following conditions: MI-120℃≤1.60g / 10min, MI-190℃ / MI-120℃≥1.20, and when the strain degree reaches 150%, the strain energy is ≥600N / m 2 , transmittance>90%.

[0180] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A polyvinyl acetal resin composition, characterized in that Composed of any two or more polyvinyl acetal resins n (n=1, 2, 3, 4, 5); Among them, the average molecular weight of the polyvinyl acetal resin 1 is Mn1≥140000, the average molecular weight of the polyvinyl acetal resin 2 is in the range of 100000<Mn2≤140000, the average molecular weight of the polyvinyl acetal resin 3 is in the range of 75000<Mn3≤100000, the average molecular weight of the polyvinyl acetal resin 4 is in the range of 40000<Mn4≤75000, and the average molecular weight of the polyvinyl acetal resin 5 is Mn5≤40000.

2. The polyvinyl acetal resin composition according to claim 1, characterized in that Among the polyvinyl acetal resins n (n=1, 2, 3, 4, 5) constituting the polyvinyl acetal resin composition, the polyvinyl acetal resins having the highest and lowest average molecular weights satisfy: Mn max -Mn min ≥75000.

3. The polyvinyl acetal resin composition according to claim 1, characterized in that In the polyvinyl acetal resin n (n=1, 2, 3, 4, 5) constituting the polyvinyl acetal resin composition, 8*10 4 <∑Mn n *F n ≤15*10 4 , where F n is the mass fraction of polyvinyl acetal resin n.

4. The polyvinyl acetal resin composition according to claim 1, characterized in that In the polyvinyl acetal resin n (n=1, 2, 3, 4, 5) constituting the polyvinyl acetal resin composition, the average particle size D of the polyvinyl acetal resin n is n =80-300μm, and 0.7≤D n2 / D n1 ≤1.

3.

5. The polyvinyl acetal resin composition according to claim 1, characterized in that The hydroxyl value of the polyvinyl acetal resin composition is 16.0-20.0% by weight.

6. A method for preparing a polyvinyl acetal resin composition according to any one of claims 1 to 5, characterized in that: The steps include: S1, placing polyvinyl acetal resins n (n=1, 2, 3, 4, 5) constituting the polyvinyl acetal resin composition in storage tanks respectively; S2. Synchronously introduce the polyvinyl acetal resin n (n=1, 2, 3, 4, 5) in the storage tank into a conical mixer and continuously stir and mix them evenly to obtain a polyvinyl acetal resin composition.

7. The method for preparing the polyvinyl acetal resin composition according to claim 6, characterized in that: In step S1, the material storage tank is provided with a discharge speed control function and a stirring and mixing function.

8. An intermediate film, characterized in that: The invention comprises the polyvinyl acetal resin composition according to any one of claims 1 to 5.

9. The intermediate film according to claim 8, characterized in that The preparation method of the intermediate film is: the polyvinyl acetal resin composition and the plasticizer are uniformly mixed and then plasticized and extruded through an extruder to obtain the intermediate film.

10. The intermediate film according to claim 9, characterized in that: The usage ratio of the polyvinyl acetal resin composition to the plasticizer is 72.5:27.

5.

11. The intermediate film according to claim 8, characterized in that: The intermediate film has a melt index MI-120°C ≤ 1.60 g / 10 min at 120°C, and a melt index MI-190°C at 190°C satisfies: MI-190°C / MI-120°C ≥ 1.

20.

12. The intermediate film according to claim 9, characterized in that: When the strain degree of the intermediate film reaches 150%, the strain energy is ≥600N / m 2 .

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