Polymer films and uses thereof

Abstract

To provide a polymer film for producing laminated glass which simultaneously satisfies safety, optical properties and sound insulation performance.SOLUTION: There is provided a polymer film comprising a first part and a second part laminated on the first part, wherein the first part and the second part are each independently composed of one or more layers. Each layer of the first part has a melt index in the range of 3.5 g / 10 min to 10.0 g / 10 min and each layer of the second part has a melt index lower than 3.5 g / 10 min. Each layer of the first part has a product of its melt index and the thickness ratio of its thickness to the total thickness of the first part and the second part and the sum of the products of each layer of the first part is in the range 0.39 g / 10 min to 2.50 g / 10 min. Each layer of the second part has the product of its melt index and the thickness ratio of its thickness to the total thickness of the first part and the second part and the sum of the products of each layer of the second part is in the range of 1.10 g / 10 min to 2.95 g / 10 min.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polymer film, specifically to a multilayer polymer film characterized by the product of melt index (MI) and thickness ratio, and to a laminated glass manufactured using the polymer film. [Background technology]

[0002] Laminated glass is a composite glass material made by sandwiching a polymer film between two glass sheets and bonding the glass sheets and polymer film together using a heat press. Laminated glass is widely used in the automotive and construction industries because of its excellent impact resistance and safety.

[0003] The use of a multilayer polymer film as an interlayer in laminated glass can improve the sound insulation of the glass. The polymer film has two outer layers and one inner layer disposed between the two outer layers. By increasing the thickness of the inner layer and adjusting the viscoelastic properties of the inner layer, the sound vibration attenuation is increased, thereby achieving sound insulation. However, conventional laminated glass has not been able to simultaneously satisfy the requirements for safety, optical properties, and sound insulation. Summary of the Invention [Means for solving the problem]

[0004] In view of the above, the present invention relates to a polymer film consisting of a first part and a second part. According to this research, by controlling the melt index of each layer of the first part and the second part, and the product of the melt index and the thickness ratio of each layer of the first part and the second part, it is possible to impart good structural uniformity to the polymer film, and it has been found that laminated glass provided using this polymer film has excellent sound insulation, excellent optical properties, and excellent safety (high mechanical strength). Therefore, the polymer film of the present invention is particularly suitable for producing sound-insulating laminated glass.

[0005] Accordingly, it is an object of the present invention to provide a polymeric film, the polymeric film comprising a first portion and a second portion laminated to the first portion, the first portion and the second portion independently comprising one or more layers. wherein each layer of the first portion independently has a melt index in the range of 3.5 g / 10 min to 10.0 g / 10 min, and each layer of the second portion independently has a melt index less than 3.5 g / 10 min; each layer of the first portion independently has a thickness ratio of its thickness to the total thickness of the first portion and the second portion, and a product of its melt index and thickness ratio, wherein the sum of the products for each layer of the first portion is in the range of 0.39 g / 10 min to 2.50 g / 10 min; Further, each layer of the second portion independently has a thickness ratio of its thickness to the total thickness of the first portion and the second portion, and a product of its melt index and the thickness ratio, wherein the sum of the products of each layer of the second portion is in the range of 1.10 g / 10 min to 2.95 g / 10 min.

[0006] In some embodiments of the present invention, the melt index of each layer of the second portion is independently from 1.5 g / 10 min to 3.3 g / 10 min.

[0007] In some embodiments of the present invention, the melt index of each layer of the first portion and the melt index of each layer of the second portion are measured according to ASTM D1238 at 190° C. and under a load of 2.16 kg.

[0008] In some embodiments of the present invention, each layer of the first portion and each layer of the second portion independently comprises polyvinyl acetal, which may be selected from the group consisting of poly(vinyl formal), poly(vinyl acetal), poly(vinyl butyral), poly(vinyl pentanal), poly(vinyl hexanal), and combinations thereof. In a preferred embodiment of the present invention, each layer of the first portion and each layer of the second portion independently comprises poly(vinyl butyral).

[0009] In some embodiments of the present invention, each layer of the first part independently comprises a polyvinyl acetal having the following properties: a degree of acetalization of 56 mol% to 74 mol%, a degree of acetylation of 5 mol% to 15 mol%, and a hydroxyl group content of 20 mol% to 30 mol%, based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups of the polyvinyl acetal contained in each layer of the first part.

[0010] In some embodiments of the present invention, each layer of the second part independently contains a polyvinyl acetal having the following properties: a degree of acetalization of 60 mol% to 75 mol%, a degree of acetylation of 0.1 mol% to 5 mol%, and a hydroxyl group content of 20 mol% to 35 mol%, based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups in the polyvinyl acetal contained in each layer of the second part.

[0011] In some embodiments of the present invention, the polyvinyl acetal contained in each layer of the first portion independently has a number average molecular weight (Mn) in the range of 100,000 to 240,000.

[0012] In some embodiments of the present invention, the polyvinyl acetal contained in each layer of the second part independently has a number average molecular weight (Mn) in the range of 90,000 to 120,000.

[0013] In some embodiments of the present invention, each layer of the first portion and each layer of the second portion independently further comprises a plasticizer.

[0014] In some embodiments of the present invention, each layer of the first portion and each layer of the second portion independently further comprise a plasticizer, wherein each layer of the first portion independently comprises the plasticizer in an amount ranging from 55 parts by weight to 85 parts by weight based on 100 parts by weight of the polyvinyl acetal contained therein, and each layer of the second portion independently comprises the plasticizer in an amount ranging from 30 parts by weight to 50 parts by weight based on 100 parts by weight of the polyvinyl acetal contained therein.

[0015] In some embodiments of the invention, one or more layers of the first portion constitute first subportions, one or more layers of the second portion constitute second subportions, the first subportions and the second subportions are arranged alternately, the number of first subportions is M, the number of second subportions is N, and M and N are independently positive integers.

[0016] In some embodiments of the invention, N is M+1.

[0017] Another object of the present invention is to provide a laminated glass, which comprises, in order, a first glass sheet, an intermediate film, and a second glass sheet, the intermediate film being provided by the aforementioned polymer film.

[0018] In order to make the above objectives, technical features and advantages of the present invention more apparent, the present invention will be described in detail below with reference to several embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to several embodiments, however, the present invention may be embodied in various different embodiments and should not be limited to the embodiments set forth in the specification.

[0020] Unless otherwise specified, the terms "a," "the," and the like in the specification and claims are intended to include both the singular and the plural.

[0021] Unless otherwise specified, the terms "first," "second," etc. in the specification and claims are used merely to distinguish between exemplified elements or components without any special meaning, and are not used to indicate priority.

[0022] In this specification and claims, "melt index (MI)" is measured according to ASTM D1238 at 190°C under a load of 2.16 kg.

[0023] In this specification and claims, the unit of number average molecular weight (Mn) is "Daltons."

[0024] In this specification and claims, the term "thickness ratio" refers to the ratio of the thickness of a single layer to the total thickness of the polymer film. For example, if a polymer film has a five-layer structure with a thickness of 2 mm, and the first part of the polymer film includes three layers with a thickness of 0.5 mm, and the second part includes two layers with a thickness of 0.25 mm, the thickness ratio of each layer in the first part is 0.25, and the thickness ratio of each layer in the second part is 0.125.

[0025] In this specification and claims, the sum of the products of the thickness ratio and the melt index means the sum of the products of the thickness ratio and the melt index of each layer. For example, if a first part of a polymer film has three layers, the thickness ratios of the three layers are 0.1, 0.2, and 0.3, respectively, and the melt indexes of the three layers are 3.5 g / 10 min, 4 g / 10 min, and 4.5 g / 10 min, respectively, the sum of the products of the layers of the first part is (0.1 x 3.5) + (0.2 x 4) + (0.3 x 4.5) = 2.5.

[0026] The present invention provides a polymer film that can be used to produce laminated glass that has excellent sound insulation, excellent optical properties, and excellent safety (high mechanical strength). The polymer film of the present invention and its uses are described in detail below.

[0027] 1. Polymer film

[0028] 1.1.Characteristics of polymer films

[0029] The polymer film of the present invention comprises a first portion and a second portion, each of which is independently composed of one or more layers and has the following properties:

[0030] Each layer of the first portion independently has a melt index in the range of 3.5 g / 10 min to 10.0 g / 10 min. For example, the melt index of each layer of the first portion may be 3.5 g / 10 min, 3.6 g / 10 min, 3.7 g / 10 min, 3.8 g / 10 min, 3.9 g / 10 min, 4.0 g / 10 min, 4.1 g / 10 min, 4.2 g / 10 min, 4.3 g / 10 min, 4.4 g / 10 min, 4.5 g / 10 min, 4.6 g / 10 min, 4.7 g / 10 min, 4.8 g / 10 min, 4.9 g / 10 min, 5.0 g / 10 min, 6.0 g / 10 min, 7.0 g / 10 min, 8.0 g / 10 min, 9.0 g / 10 min, 10.0 g / 10 min, 11.0 g / 10 min, 12.0 g / 10 min, 13.0 g / 10 min, 14.0 g / 10 min, 15.0 g / 10 min, 16.0 g / 10 min, 17.0 g / 10 min, 18.0 g / 10 min, 19.0 g / 10 min, 20.0 g / 10 min, 21.0 g / 10 min, 22.0 g / 10 min, 23.0 g / 10 min, 24.0 g / 10 min, 25.0 g / 10 min, 26.0 g / 10 min, 27.0 g / 10 min, 28.0 g / 10 min, 29.0 g / 10 min, 30.0 g / 10 min, 31.0 g / 10 min, 32.0 g / 10 min, 33.0 g / / 10 minutes, 5.1g / 10 minutes, 5.2g / 10 minutes, 5.3g / 10 minutes, 5.4g / 10 minutes, 5.5g / 10 minutes, 5.6g / 10 minutes, 5.7g / 10 minutes, 5.8g / 10 minutes, 5.9g / 10 minutes, 6.0g / 10 minutes, 6.1g / 10 minutes, 6.2g / 10 minutes, 6.3g / 10 minutes, 6.4g / 10 minutes, 6.5g / 10 minutes, 6.6g / 10 minutes, 6.7g / 10 minutes, 6.8g / 1 0 min, 6.9g / 10 min, 7.0g / 10 min, 7.1g / 10 min, 7.2g / 10 min, 7.3g / 10 min, 7.4g / 10 min, 7.5g / 10 min, 7.6g / 10 min, 7.7g / 10 min, 7.8g / 10min, 7.9g / 10min, 8.0g / 10min, 8.1g / 10min, 8.2g / 10min, 8.3g / 10min, 8.4g / 10min, 8.5g / 10min, 8.6g / 10min , 8.7 g / 10 min, 8.8 g / 10 min, 8.9 g / 10 min, 9.0 g / 10 min, 9.1 g / 10 min, 9.2 g / 10 min, 9.3 g / 10 min, 9.4 g / 10 min, 9.5 g / 10 min, 9.6 g / 10 min, 9.7 g / 10 min, 9.8 g / 10 min, 9.9 g / 10 min, or 10.0 g / 10 min, or within a range between any two values ​​listed herein. The first portion having a predetermined melt index can attenuate sound vibrations, thereby optimizing the sound insulation effect.

[0031] Each layer of the second portion independently has a melt index less than 3.5 g / 10 min. Preferably, each layer of the second portion independently has a melt index in the range of 1.5 g / 10 min to 3.3 g / 10 min. For example, the melt index of each layer of the second portion can be 1.5 g / 10 min, 1.6 g / 10 min, 1.7 g / 10 min, 1.8 g / 10 min, 1.9 g / 10 min, 2.0 g / 10 min, 2.1 g / 10 min, 2.2 g / 10 min, 2.3 g / 10 min, 2.4 g / 10 min, 2.5 g / 10 min, 2.6 g / 10 min, 2.7 g / 10 min, 2.8 g / 10 min, 2.9 g / 10 min, 3.0 g / 10 min, 3.1 g / 10 min, 3.2 g / 10 min, 3.3 g / 10 min, or 3.4 g / 10 min, or within a range between any two values ​​recited herein.

[0032] Each layer of the first portion independently has a thickness ratio of its thickness to the total thickness of the first portion and the second portion, and a melt index multiplied by the thickness ratio (i.e., melt index multiplied by thickness ratio), the sum of the products of each layer of the first portion ranging from 0.39 g / 10 min to 2.50 g / 10 min. For example, the sum of the products of each layer in the first portion is 0.39g / 10min, 0.40g / 10min, 0.45g / 10min, 0.50g / 10min, 0.55g / 10min, 0.60g / 10min, 0.65g / 10min, 0.70g / 10min, 0.75g / 10min, 0.80g / 10min, 0.85g / 10min, 0.90g / 10min, 0.95g / 10min, 1.00g / 10min, 1.05g / 10min, 1.10g / 10min, 1.15g / 10min, 1.20g / 10min, 1.25g / 10min, 1.30g / 10min, 1.35g / 10min, 1.40g / 10min, 1.45g / 10min , 1.50g / 10min, 1.55g / 10min, 1.60g / 10min, 1.65g / 10min, 1.70g / 10min, 1.75g / 10min, 1.80g / 10min, 1.85g / 10min, 1.90g / 10min, 1.95g / 10min, 2.00g / 10min, 2.05g / 10min, 2.10g / 10min, 2.15g / 10min, 2.20g / 10min, 2.25g / 10min, 2.30g / 10min, 2.35g / 10min, 2.40g / 10min, 2.45g / 10min, or 2.50g / 10min, or a range between any two values ​​recited herein.

[0033] Each layer of the second portion independently has a thickness ratio of its thickness to the total thickness of the first portion and the second portion, and a melt index multiplied by the thickness ratio (i.e., melt index x thickness ratio), the sum of the products of each layer of the second portion ranging from 1.10 g / 10 min to 2.95 g / 10 min. For example, the sum of the products of each layer in the second portion is 1.10g / 10min, 1.15g / 10min, 1.20g / 10min, 1.25g / 10min, 1.30g / 10min, 1.35g / 10min, 1.40g / 10min, 1.45g / 10min, 1.50g / 10min, 1.55g / 10min, 1.60g / 10min, 1.65g / 10min, 1.70g / 10min, 1.75g / 10min, 1.80g / 10min, 1.85g / 10min, 1.90g / 10min, 1.95g / 10min, 2.00g / 10min, 2.05g / 10min , 2.10g / 10min, 2.15g / 10min, 2.20g / 10min, 2.25g / 10min, 2.30g / 10min, 2.35g / 10min, 2.40g / 10min, 2.45g / 10min, 2.50g / 10min, 2.55g / 10min, 2.60g / 10min, 2.65g / 10min, 2.70g / 10min, 2.75g / 10min, 2.80g / 10min, 2.85g / 10min, 2.90g / 10min, or 2.95g / 10min, or a range between any two values ​​recited herein.

[0034] As a result of research, it was found that only when the melt index of each layer of the first part and the second part is within the above range and the sum of the products of the melt index and thickness ratio of each layer of the first part and the second part is within the above range, can laminated glass using the polymer film of the present invention exhibit excellent sound insulation effect, excellent optical properties, and excellent safety (high mechanical strength).

[0035] 1.2. Polymer Film Structure

[0036] The polymeric films of the present invention include a first portion and a second portion, each of which is independently composed of one or more layers, or alternatively, the polymeric films of the present invention consist essentially of the first portion and the second portion, or alternatively, the polymeric films of the present invention consist of the first portion and the second portion.

[0037] In the polymer film of the present invention, the phrase "the first part and the second part are laminated together" means that the layers of the first part and the layers of the second part are laminated in any order. For example, if the first part is composed of two A layers and the second part is composed of three B layers, the lamination order can be, but is not limited to, AABBB, ABABB, ABBBA, BABAB, or BBAAB.

[0038] In some embodiments of the present invention, one or more layers of the first portion constitute a first subportion, and one or more layers of the second portion constitute a second subportion, each of which can independently comprise one or more layers. The number of first subportions is M, and the number of second subportions is N, where M and N are independently positive integers, e.g., integers from 1 to 5. The first and second subportions are arranged alternately. For example, when M is 2 and N is 2, the polymer film is arranged in the order of first subportion, second subportion, first subportion, and second subportion. When M is 2 and N is 3, the polymer film is arranged in the order of second subportion, first subportion, second subportion, first subportion, and second subportion. When M is 3 and N is 2, the polymer film is arranged in the order of first subportion, second subportion, first subportion, second subportion, and first subportion. In a preferred embodiment of the invention, N is M+1. In a more preferred embodiment of the invention, M is 1 or 2 and N is M+1.

[0039] 1.3. Polymer Film Components

[0040] In the polymer film of the present invention, each layer of the first portion and each layer of the second portion independently contain polyvinyl acetal as an essential component, and each layer of the first portion and each layer of the second portion independently may further contain other optional components, such as plasticizers or other common additives, as needed. As used herein, the phrase "each layer of the first portion and each layer of the second portion independently contain polyvinyl acetal" means that each layer of the first portion and each layer of the second portion contain polyvinyl acetal, and the polyvinyl acetal contained in each layer of the first portion or the second portion may be the same or different. In some embodiments of the present invention, each layer of the first portion and each layer of the second portion independently contain polyvinyl acetal and plasticizer, and the polyvinyl acetal and plasticizer contained in each layer may be the same or different. Alternatively, each layer of the first portion and each layer of the second portion may each independently consist essentially of or consist of polyvinyl acetal and a plasticizer, and the polyvinyl acetal and plasticizer contained in each layer may be the same or different.

[0041] 1.3.1. Polyvinyl acetal

[0042] Examples of polyvinyl acetals include, but are not limited to, poly(vinyl formal), poly(vinyl acetal), poly(vinyl butyral), poly(vinyl pentanal), and poly(vinyl hexanal). The polyvinyl acetals may be used alone or in combination. In a preferred embodiment of the present invention, the polyvinyl acetal is poly(vinyl butyral).

[0043] 1.3.1.1. Polyvinyl acetal contained in the first part

[0044] In some embodiments of the present invention, the number average molecular weight (Mn) of the polyvinyl acetal contained in each layer of the first portion is independently in the range of 100,000 to 240,000. For example, the Mn of the polyvinyl acetal contained in each layer of the first portion is independently in the range of 100,000, 105,000, 110,000, 115,000, 120,000, 125,000, 130,000, 135,000, 140,000, 145,000, 150,000, 155,000, 160,000, 165,000, 170,000, 175,000, 176,000, 177,000, 178,000, 179,000, 180,000, 181,000, 182,000, 183,000, 184,000, 185,000, 186,000, 187,000, 188,000, 189,000, 190,000, 191,000, 192,000, 193,000, 194,000, 195,000, 196,000, 197,000, 198,000, 199,000, 200,000, 201,000, 202,000, 203,000, 204,000, 205,000, 206,000, 20 The number average molecular weight of a polymer may be 0,000, 175,000, 180,000, 185,000, 190,000, 195,000, 200,000, 205,000, 210,000, 215,000, 220,000, 225,000, 230,000, 235,000, or 240,000, or within a range between any two values ​​described herein. A higher number average molecular weight of a polymer indicates a higher degree of polymerization of the polymer and therefore a lower polymer flowability and melt index. A lower number average molecular weight of a polymer indicates a higher melt index of the polymer.

[0045] In some embodiments of the present invention, the acetal content (i.e., degree of acetalization) of the polyvinyl acetal contained in each layer of the first portion can be independently in the range of 56 mol% to 74 mol% based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups in the polyvinyl acetal contained in each layer of the first portion. For example, the acetalization degree of the polyvinyl acetal contained in each layer of the first portion can be independently in the range of 56 mol%, 56.5 mol%, 57 mol%, 57.5 mol%, 58 mol%, 58.5 mol%, 59 mol%, 59.5 mol%, 60 mol%, 60.5 mol%, 61 mol%, 61.5 mol%, 62 mol%, 62.5 mol%, 63 mol%, 64 mol%, 65 mol%, 66 mol%, 67 mol%, 68 mol%, 69 mol%, 70 mol%, 71 mol%, 72 mol%, 73 mol%, 74 mol%, 75 mol%, 76 mol%, 77 mol%, 78 mol%, 79 mol%, 80 mol%, 81 mol%, 82 mol%, 83 mol%, 84 mol%, 85 mol%, 86 mol%, 87 mol%, 88 mol%, 89 mol%, 90 mol%, 91 mol%, 92 mol%, 93 mol%, 94 mol%, 95 mol%, 96 mol%, 97 mol%, 98 mol%, 99 mol%, 100 mol%, 101 mol%, 102 mol%, 103 mol%, 104 mol%, 105 mol%, 106 mol%, 107 mol%, mol%, 63.5 mol%, 64 mol%, 64.5 mol%, 65 mol%, 65.5 mol%, 66 mol%, 66.5 mol%, 67 mol%, 67.5 mol%, 68 mol%, 68.5 mol%, 69 mol%, 69.5 mol%, 70 mol%, 70.5 mol%, 71 mol%, 71.5 mol%, 72 mol%, 72.5 mol%, 73 mol%, 73.5 mol%, or 74 mol%, or within a range between any two values ​​recited herein. In a preferred embodiment of the present invention, the degree of acetalization of the polyvinyl acetal contained in each layer of the first portion can independently be in the range of 60 mol% to 71 mol%, based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups of the polyvinyl acetal contained in each layer of the first portion.

[0046] In some embodiments of the present invention, the content of acetyl groups (i.e., the degree of acetylation) of the polyvinyl acetal contained in each layer of the first part may independently be in the range of 5 mol% to 15 mol% based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups of the polyvinyl acetal contained in each layer of the first part. For example, based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups in the polyvinyl acetal contained in each layer of the first portion, the degree of acetylation of the polyvinyl acetal contained in each layer of the first portion can independently be 5 mol%, 5.5 mol%, 6 mol%, 6.5 mol%, 7 mol%, 7.5 mol%, 8 mol%, 8.5 mol%, 9 mol%, 9.5 mol%, 10 mol%, 10.5 mol%, 11 mol%, 11.5 mol%, 12 mol%, 12.5 mol%, 13 mol%, 13.5 mol%, 14 mol%, 14.5 mol%, or 15 mol%, or within a range between any two values ​​described herein. In a preferred embodiment of the present invention, based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups in the polyvinyl acetal contained in each layer of the first portion, the degree of acetylation of the polyvinyl acetal contained in each layer of the first portion independently ranges from 7 mol% to 12 mol%.

[0047] In some embodiments of the present invention, the content of hydroxyl groups in the polyvinyl acetal contained in each layer of the first part may independently be in the range of 20 mol% to 30 mol% based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups in the polyvinyl acetal contained in each layer of the first part. For example, based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups in the polyvinyl acetal contained in each layer of the first portion, the hydroxyl group content of the polyvinyl acetal contained in each layer of the first portion can independently be 20 mol%, 20.5 mol%, 21 mol%, 21.5 mol%, 22 mol%, 22.5 mol%, 23 mol%, 23.5 mol%, 24 mol%, 24.5 mol%, 25 mol%, 25.5 mol%, 26 mol%, 26.5 mol%, 27 mol%, 27.5 mol%, 28 mol%, 28.5 mol%, 29 mol%, 29.5 mol%, or 30 mol%, or within a range between any two values ​​described herein. In a preferred embodiment of the present invention, the hydroxyl group content of the polyvinyl acetal contained in each layer of the first part is independently in the range of 22 mol% to 28 mol% based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups of the polyvinyl acetal contained in each layer of the first part. The lower the hydroxyl group content of the polyvinyl acetal, the greater the amount of plasticizer that the polyvinyl acetal can absorb.

[0048] 1.3.1.2. Polyvinyl acetal contained in the second part

[0049] In some embodiments of the present invention, the number average molecular weight (Mn) of the polyvinyl acetal contained in each layer of the second part is independently in the range of 90,000 to 120,000. For example, the Mn of the polyvinyl acetal contained in each layer of the second part is independently 90,000, 91,000, 92,000, 93,000, 94,000, 95,000, 96,000, 97,000, 98,000, 99,000, 100,000, 101,000, 102,000, 103,000, 104,000, 105,000, 106,000, 107,000, 108,000, 109,000, 110,000, 111,000, 112,000, 113,000, 114,000, 115,000, 116,000, 117,000, 118,000, 119,000, or 120,000, or within a range between any two values ​​recited herein.

[0050] In some embodiments of the present invention, the content of acetal groups in the polyvinyl acetal contained in each layer of the second part (i.e., the degree of acetalization) may independently be in the range of 60 mol% to 75 mol% based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups in the polyvinyl acetal contained in each layer of the second part. For example, based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups in the polyvinyl acetal contained in each layer of the second portion, the degree of acetalization of the polyvinyl acetal contained in each layer of the second portion can independently be 60 mol%, 60.5 mol%, 61 mol%, 61.5 mol%, 62 mol%, 62.5 mol%, 63 mol%, 63.5 mol%, 64 mol%, 64.5 mol%, 65 mol%, 65.5 mol%, 66 mol%, 66.5 mol%, 67 mol%, 67.5 mol%, 68 mol%, 68.5 mol%, 69 mol%, 69.5 mol%, 70 mol%, 70.5 mol%, 71 mol%, 71.5 mol%, 72 mol%, 72.5 mol%, 73 mol%, 73.5 mol%, 74 mol%, 74.5 mol%, or 75 mol%, or within a range between any two values ​​recited herein. In a preferred embodiment of the present invention, the degree of acetalization of the polyvinyl acetal contained in each layer of the second part is independently in the range of 70 mol % to 72 mol %, based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups of the polyvinyl acetal contained in each layer of the second part.

[0051] In some embodiments of the present invention, the acetyl group content (i.e., degree of acetylation) of the polyvinyl acetal contained in each layer of the second part can be independently in the range of 0.1 mol% to 5 mol% based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups of the polyvinyl acetal contained in each layer of the second part. For example, the acetylation degree of the polyvinyl acetal contained in each layer of the second part can be independently 0.1 mol%, 0.5 mol%, 1 mol%, 1.5 mol%, 2 mol%, 2.5 mol%, 3 mol%, 3.5 mol%, 4 mol%, 4.5 mol%, or 5 mol%, or within a range between any two values ​​described herein, based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups of the polyvinyl acetal contained in each layer of the second part. In a preferred embodiment of the present invention, the polyvinyl acetal contained in each layer of the second part independently has a degree of acetylation in the range of 0.5 mol % to 1.5 mol %, based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups of the polyvinyl acetal contained in each layer of the second part.

[0052] In some embodiments of the present invention, the hydroxyl group content of the polyvinyl acetal contained in each layer of the second part can be independently in the range of 20 mol% to 35 mol% based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups of the polyvinyl acetal contained in each layer of the second part. For example, the hydroxyl group content of the polyvinyl acetal constituted in each layer of the second part can be independently in the range of 20 mol%, 20.5 mol%, 21 mol%, 21.5 mol%, 22 mol%, 22.5 mol%, 23 mol%, 23.5 mol%, 24 mol%, 24.5 mol%, 2 ... The polyvinyl acetal content may be 0.5 mol%, 26 mol%, 26.5 mol%, 27 mol%, 27.5 mol%, 28 mol%, 28.5 mol%, 29 mol%, 29.5 mol%, 30 mol%, 30.5 mol%, 31 mol%, 31.5 mol%, 32 mol%, 32.5 mol%, 33 mol%, 33.5 mol%, 34 mol%, 34.5 mol%, or 35 mol%, or within a range between any two of the values ​​recited herein. In a preferred embodiment of the present invention, the hydroxyl group content of the polyvinyl acetal contained in each layer of the second part is independently in the range of 27 mol% to 29 mol%, based on the total number of moles of hydroxyl groups, acetal groups, and acetyl groups of the polyvinyl acetal constituted in each layer of the second part.

[0053] Plasticizers

[0054] As used herein, a plasticizer, also known as a plasticizer, is a chemical substance that can modify the plasticity of a thermoplastic resin. Generally, the greater the amount of plasticizer added, the higher the melt index of the polymer film. The type of plasticizer is not particularly limited, and the plasticizers contained in each layer of the first part and each layer of the second part may be the same or different. Examples of plasticizers include triethylene glycol bis(2-ethylhexanoate), tetraethylene glycol bis(2-ethylhexanoate), triethylene glycol bis(2-ethylbutyrate), tetraethylene glycol bis(2-ethylbutyrate), triethylene glycol diheptanoate, tetraethylene glycol diheptanoate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, dibutyl sebacate, bis[2-(2-butanoic acid)-2-methylpropional]propanol ... Examples of suitable plasticizers include, but are not limited to, esters of polybasic acids or polyhydric alcohols such as [(2-ethoxy)ethyl]adipate, polymeric adipate, dipropylene glycol dibenzoate, tripropylene glycol dibenzoate, polypropylene glycol dibenzoate, isodecyl benzoate, 2-ethylhexyl benzoate, propylene glycol dibenzoate, diisononyl phthalate, dibutoxyethyl terephthalate, castor oil, methyl ricinoleate, soybean oil, epoxidized soybean oil, and combinations thereof. In the accompanying examples, triethylene glycol bis(2-ethylhexanoate) is used as the plasticizer.

[0055] In some embodiments of the present invention, each layer of the first portion independently contains a plasticizer in an amount ranging from 55 parts by weight to 85 parts by weight based on 100 parts by weight of the polyvinyl acetal contained therein. For example, based on 100 parts by weight of polyvinyl acetal in each layer of the first portion, the amount of plasticizer in each layer of the first portion can be 55 parts by weight, 56 parts by weight, 57 parts by weight, 58 parts by weight, 59 parts by weight, 60 parts by weight, 61 parts by weight, 62 parts by weight, 63 parts by weight, 64 parts by weight, 65 parts by weight, 66 parts by weight, 67 parts by weight, 68 parts by weight, 69 parts by weight, 70 parts by weight, 71 parts by weight, 72 parts by weight, 73 parts by weight, 74 parts by weight, 75 parts by weight, 76 parts by weight, 77 parts by weight, 78 parts by weight, 79 parts by weight, 80 parts by weight, 81 parts by weight, 82 parts by weight, 83 parts by weight, 84 parts by weight, or 85 parts by weight, or within a range between any two of the values ​​recited herein. In a preferred embodiment of the present invention, each layer of the first part independently contains a plasticizer in an amount ranging from 60 parts by weight to 80 parts by weight based on 100 parts by weight of the polyvinyl acetal contained therein.

[0056] In some embodiments of the present invention, each layer of the second portion independently contains 30 to 50 parts by weight of plasticizer, based on 100 parts by weight of polyvinyl acetal contained therein. For example, based on 100 parts by weight of polyvinyl acetal contained in each layer of the second portion, the amount of plasticizer contained in each layer of the second portion can be 30 parts by weight, 31 parts by weight, 32 parts by weight, 33 parts by weight, 34 parts by weight, 35 parts by weight, 36 parts by weight, 37 parts by weight, 38 parts by weight, 39 parts by weight, 40 parts by weight, 41 parts by weight, 42 parts by weight, 43 parts by weight, 44 parts by weight, 45 parts by weight, 46 parts by weight, 47 parts by weight, 48 parts by weight, 49 parts by weight, or 50 parts by weight, or within a range between any two of the values ​​recited herein. In a preferred embodiment of the present invention, each layer of the second portion independently contains a plasticizer in an amount ranging from 38 parts by weight to 44 parts by weight based on 100 parts by weight of the polyvinyl acetal contained therein.

[0057] 1.3.3. Other common additives

[0058] Conventional additives include any substance that can appropriately improve the processability of a polymer film during its production or that can impart specific functions to the polymer film, including, but not limited to, one or more of heat insulation, reflection, anti-reflection, refraction, anti-refraction, light division, and light control.

[0059] Examples of common additives include, but are not limited to, dyes, pigments, stabilizers, antioxidants, flame retardants, infrared absorbers, infrared blocking agents, UV absorbers, UV stabilizers, lubricants, dispersants, surfactants, chelating agents, coupling agents, binders, and adhesion control agents. For example, the polymer film may contain dyes or pigments to form a colored polymer film. The polymer film may also contain UV absorbers or infrared absorbers to form a polymer film with UV or infrared protection functions. The above additives may be used alone or in combination. The above additives may be added to one or more layers of the first portion of the polymer film, one or more layers of the second portion of the polymer film, or one or more layers of the first and second portions of the polymer film.

[0060] 1.4. Other properties of polymer films

[0061] In a preferred embodiment of the present invention, the thickness ratio of the first portion (i.e., the ratio of the thickness of the first portion to the total thickness of the first portion and the second portion) based on the total thickness of the first portion and the second portion is 0.05 to 0.4, e.g., 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, or 0.4, or within a range between any two values ​​described herein. The thickness ratio of the second portion (i.e., the ratio of the thickness of the second portion to the total thickness of the first portion and the second portion) based on the total thickness of the first portion and the second portion is 0.6 to 0.95, e.g., 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, or 0.95, or within a range between any two values ​​described herein.

[0062] As a condition that the polymer film satisfies a predetermined melt index and the sum of the product of the melt index and the thickness ratio, the total thickness of the polymer film of the present invention, the thickness of each layer of the first part, and the thickness of each layer of the second part can be adjusted as necessary. Generally, the total thickness of the polymer film of the present invention can be 0.1 mm to 2.5 mm, for example, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1.0 mm, 1.05 mm, 1.1 mm, 1.15 mm, 1.2 mm, 1.25 mm The thickness of the polymer film may be 1.3 mm, 1.35 mm, 1.4 mm, 1.45 mm, 1.5 mm, 1.55 mm, 1.6 mm, 1.65 mm, 1.7 mm, 1.75 mm, 1.8 mm, 1.85 mm, 1.9 mm, 1.95 mm, 2.0 mm, 2.05 mm, 2.1 mm, 2.15 mm, 2.2 mm, 2.25 mm, 2.3 mm, 2.35 mm, 2.4 mm, 2.45 mm, or 2.5 mm, or within a range between any two values ​​listed herein. In the accompanying examples, the polymer film has a thickness of 0.76 mm to 0.85 mm.

[0063] In some embodiments of the present invention, the thickness of each layer of the first portion can independently be from 50 μm to 250 μm, e.g., 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 210 μm, 220 μm, 230 μm, 240 μm, or 250 μm, or within a range between any two values ​​recited herein.

[0064] In some embodiments of the present invention, the thickness of each layer of the second portion can independently be from 250 μm to 450 μm, e.g., 250 μm, 260 μm, 270 μm, 280 μm, 290 μm, 300 μm, 310 μm, 320 μm, 330 μm, 340 μm, 350 μm, 360 μm, 370 μm, 380 μm, 390 μm, 400 μm, 410 μm, 420 μm, 430 μm, 440 μm, or 450 μm, or within a range between any two values ​​described herein.

[0065] 1.5. Polymer Film Production

[0066] The method for producing the polymer film of the present invention is not particularly limited. For example, the polymer film of the present invention may be produced by mixing polyvinyl acetal and optional components (e.g., plasticizers), dry stirring, and kneading to obtain a polymer composition, using the polymer composition to obtain a polymer film by a conventional film forming method, and then mechanically embossing the surface of the polymer film. Examples of conventional film forming methods include, but are not limited to, a calendar method, a casting method, an extrusion stretching method, a direct extrusion method, and an extrusion blow method.

[0067] In some embodiments of the present invention, the polymer film is produced as follows, although the present invention is not limited thereto: A first polymer film composition for producing each layer of the first part and a second polymer film composition for producing each layer of the second part are prepared, and the first polymer film composition and the second polymer film composition are placed in a co-extruder to form the polymer film of the present invention by co-extrusion.

[0068] The first and second polymer film compositions can be prepared independently as follows, but the present invention is not limited thereto: A selected polyvinyl acetal resin is preheated in an oven, the preheated polyvinyl acetal and a plasticizer are dry-mixed to obtain a dry-mixed mixture, and the dry-mixed mixture is then kneaded using a twin-screw kneader to obtain the desired first or second polymer film composition.

[0069] Without being limited by any theory, it is believed that the melt index of a polymer film can be adjusted by controlling the amount of functional groups in the polymer, the amount of plasticizer in the polymer film, and the uniformity of plasticizer absorption in the polymer. The uniformity of plasticizer absorption in the polymer can be adjusted by controlling the preheating temperature, dry mixing temperature, dry mixing time, kneading temperature, and kneading time during polymer film production. Generally, preheating expands the pores between the polymer materials, slightly increasing the resin's fluidity and facilitating subsequent mixing with the plasticizer. Increasing the dry mixing temperature promotes pore expansion and plasticizer absorption. Increasing the dry mixing time results in more uniform mixing of the resin and plasticizer. Increasing the kneading temperature improves the fluidity of the plasticizer, thereby improving the compatibility between the resin and plasticizer. Increasing the kneading time results in more uniform mixing of the resin and plasticizer. Furthermore, the amount of functional groups in the polymer also affects the uniformity of plasticizer absorption into the polymer. Based on the above, in the attached examples, in addition to adjusting the compositions of the first polymer film composition and the second polymer film composition, a polymer film having the melt index characteristics required by the present invention can also be provided under the conditions of a preheating temperature of 30°C to 45°C, a dry stirring temperature of 30°C to 45°C, a dry stirring time of 2 to 3 minutes, a kneading temperature of 180°C to 210°C, and a kneading time of 8 to 12 minutes.

[0070] The uneven structure is formed on the surface of the coextruded polymer film by preheating and mechanical embossing, promoting degassing. Mechanical embossing refers to a process of forming a texture on the surface of a polymer film using a roller. Examples of mechanical embossing methods include, but are not limited to, an embossing roller method or a calendar roller method. The embossing roller method is preferred. The type of texture formed by mechanical embossing is not particularly limited, and examples include a diamond-shaped texture, a linear texture, a sawtooth texture, a square texture, a tapered texture, a circular texture, a subcircle texture, and an irregular texture. The above texture types may be used alone or in combination of two or more. The conditions for preheating and mechanical embossing can be appropriately adjusted depending on the composition of the polymer film.

[0071] 2.Laminated glass

[0072] The polymer film of the present invention can be used to manufacture laminated glass. Accordingly, the present invention also provides a laminated glass comprising, in order, a first glass sheet, an intermediate film, and a second glass sheet, wherein the intermediate film is the above-mentioned polymer film.

[0073] The first glass sheet and the second glass sheet may be the same or different. The first glass sheet and the second glass sheet may each independently be any glass sheet used for conventional laminated glass manufacturing. Examples of conventional glass sheets used for laminated glass manufacturing include float glass sheets, tempered glass sheets, wired glass sheets, and plain plate glass sheets, but the present invention is not limited to these. In the attached examples, float glass sheets are used as the first glass sheet and the second glass sheet.

[0074] The laminated glass of the present invention can be produced by any laminated glass production method known in the art. Generally, the production method of laminated glass can be roughly divided into a pre-pressing process and an autoclave pressing process. The pre-pressing process is as follows: First, a polymer film is sandwiched between two glass sheets to obtain a laminate. Next, the conveying speed of the belt conveyor of the roller press is set to 2 m / min to 8 m / min, the oven temperature is set to 160°C to 190°C, and the roller pressure is set to 3 kg / cm. 2 ~10kg / cm 2 The laminate is placed on a belt conveyor and passes through an oven and rollers, the distance between which is set to 4.5 mm to 6.5 mm. The laminate pressed by the rollers is then cooled to room temperature, completing the pre-pressing. Next, the pre-pressed laminate is placed in an autoclave for the autoclave pressing process. The autoclave pressing process involves hot pressing the pre-pressed laminate under high-pressure and high-temperature conditions for 100 to 150 minutes to obtain laminated glass. Generally, high-pressure and high-temperature conditions refer to a pressure in the range of 10 bar to 15 bar and a temperature in the range of 100°C to 150°C.

[0075] 3. Working Example

[0076] 3.1. Test Method

[0077] The present invention will be further described below with reference to the following embodiments. The test device and test method are as follows.

[0078] [Measurement of acetalization degree, acetylation degree, and hydroxyl group content of polyvinyl acetal]

[0079] The degree of acetalization, degree of acetylation and hydroxyl group content of polyvinyl acetal are measured in accordance with JIS K6728:1977.

[0080] [Measurement of molecular weight distribution of polyvinyl acetal]

[0081] The molecular weight distribution of polyvinyl acetal is measured by gel permeation chromatography (GPC). GPC analysis is performed by dissolving polyvinyl acetal in tetrahydrofuran (THF) under the following conditions. The molecular weight (Mn) of polyvinyl acetal is calculated based on the ratio equivalent to the area of ​​standard polystyrene (Water PS STD). Apparatus: Waters 1515 PUMP system Detector: Waters 2414 RI Elution conditions: 1.0mL / min, THF Column: Waters Styragel HR5 THF, Waters Styragel HR4 THF, Waters Styragel HR3 THF, Waters Styragel HR1 THF

[0082] [Melt index measurement]

[0083] The melt index of polymer films is measured in accordance with ASTM D1238 using a melt index tester (Model: D4002HV, available from Dynisco). The spilled weight is calculated using the manual operation method (Method A). The measurement conditions are 190°C, a load of 2.16 kg, and a polymer film sample weight of 6 g. The detailed measurement steps are as follows: First, the polymer film sample is placed in a constant temperature and humidity chamber at 23°C and 25% relative humidity for 2 hours. Next, the melt index tester is turned on and heated to 190°C, and the sample is added and packed into a cylindrical barrel. A standard load is applied to the sample in the cylindrical barrel via a piston and weight (total weight 2.16 kg). Samples that spill within 120 seconds are excluded from the calculation. The official test begins after 120 seconds. The amount of spilled sample is weighed three times every 200 seconds. The melt index is calculated using the following formula: Melt index = g / 10 min. MI = (total weight of outflow (unit: g)) / (outflow collection time (10 min))

[0084] [Evaluation of continuous layer structure]

[0085] The polymer film is observed using an optical microscope (model: BX51, manufactured by Olympus) to confirm whether the structure of each layer is continuous. The polymer film is cut into a sample of 100 cm x 5 cm (100 cm horizontal length, 5 cm vertical length). Using a clamping jig, the two short sides of the sample are clamped so that the long side of the polymer film (i.e., the cut surface) faces the objective lens. The optical microscope is set as follows, with the objective lens magnification set to 5x. The evaluation criteria are as follows: If the structure of each layer of the polymer film is continuous and no discontinuities are observed, the structural uniformity is good and the result is recorded as "○". If discontinuities are observed in any layer of the polymer film, the structural uniformity is poor and the result is recorded as "×".

[0086] [Layer thickness evaluation]

[0087] The thickness of each layer in the first and second parts of the polymer film was measured using an optical microscope (model: BX51, Olympus) and calculated using the microscope's built-in software (Motic Image Plus 2.0). The polymer film was cut into 100 cm x 5 cm samples. Here, 100 cm is the horizontal length and 5 cm is the vertical length. The two short edges of the sample were clamped using a clamping jig so that the long edge (i.e., the cut surface) of the polymer film faced the objective lens. The optical microscope settings were as follows: the objective lens magnification was 5x. The measurement method for each layer in the first and second parts was as follows: The thickness of each layer was measured at positions 1 cm, 25 cm, 50 cm, 75 cm, and 100 cm from the left border, respectively, to obtain five thickness values. The thickness of each layer in the first and second parts was calculated by averaging the five values.

[0088] [Loss factor evaluation]

[0089] The loss factor of laminated glass is evaluated in accordance with ISO 16940:2008, Mechanical Impedance Measurement (MIM). Samples are prepared as follows: First, a 300mm long, 25mm wide polymer film is sandwiched between two sheets of float glass (300mm long, 25mm wide, 2mm thick) to obtain a laminate. This laminate is then subjected to a pre-pressing process and an autoclave pressing process to obtain a laminated glass. The pre-pressing and autoclave pressing processes are as described above. Next, this laminated glass is placed in a constant temperature and humidity chamber at 23°C and 55% relative humidity for two hours. The loss factor is then tested as follows: First, the center of the laminated glass is fixed to a vibration exciter and vibrated at an ambient temperature of 20°C. Next, the force and frequency of the vibration of the laminated glass are measured using an impedance head, and the obtained values ​​are converted to a damping loss factor using an analysis system. Calculations are performed using the first vibration mode using the half-power method. If the attenuation loss coefficient of the laminated glass at 20°C is 0.25 or more, good sound insulation performance can be obtained.

[0090] [Dropping ball test]

[0091] The drop ball test is conducted at 23°C in accordance with the penetration resistance test described in JIS R 3212:1998 (hereinafter referred to as "Standard 3212"). First, five 30 cm x 30 cm sheets of laminated glass are prepared as test samples. Next, these test samples are placed on a steel support frame conforming to Standard 3212. A steel ball weighing 2260 g and measuring 82 mm in diameter is placed 5 m above the test sample. The steel ball is then allowed to fall freely onto the test sample to confirm whether it penetrates the test sample. The test is conducted five times. If the steel ball does not penetrate the test sample all five times, the drop ball test is considered a pass, and the result is recorded as "○." If the steel ball penetrates the test sample in any of the five tests, the drop ball test is considered a fail, and the result is recorded as "×."

[0092] [Snowflake defect test]

[0093] As used herein, a "snowflake defect" refers to a defect that resembles a snowflake and occurs between a first portion and a second portion of a polymer film. Snowflake defects typically form during the manufacturing of laminated glass and adversely affect the optical performance of the laminated glass. The test for snowflake defects is as follows:

[0094] A 15cm x 15cm piece of laminated glass is prepared as a test sample. This test sample is placed in an oven at 120°C for two hours. After removing it from the oven, the appearance of the test sample (laminated glass) is observed with the naked eye. If no snowflake defects are observed, the snowflake defect test is passed and the result is recorded as "○". If snowflake defects are observed, the snowflake defect test is failed and the result is recorded as "×".

[0095] [Light transmittance measurement]

[0096] The light transmittance of laminated glass is measured in accordance with ASTM D1003. First, two flat glass sheets, each 6 cm long, 6 cm wide, and 3 mm thick, are washed with water and dried. Next, a polymer film is sandwiched between the two glass sheets to obtain a laminate. Using a hot press, the glass is heated at 150°C and 3 kg / cm. 2 This laminate is hot-pressed for 3 minutes under the above conditions to obtain laminated glass. The glass surface is then washed with alcohol. The light transmittance of the laminated glass is then measured using a haze meter (Model: NDH2000 Haze Meter, manufactured by Nippon Denshoku Industries Co., Ltd.). Generally, the light transmittance of suitable laminated glass is considered to be 87.5% or higher.

[0097] 3.2. Polymer Film Production and Property Measurement

[0098] 3.2.1. First Portion of Polymer Film

[0099] 100 parts by weight of poly(vinyl butyral) (PVB, manufactured by Chang Chun Petrochemical Co., Ltd.) was preheated in an oven at 30°C to 45°C for 1 minute. The preheated PVB and plasticizer were then dry-mixed at a first dry-mixing temperature for a first dry-mixing time to obtain a first dry-mixing mixture. The first dry-mixing mixture was then kneaded using a twin-screw kneader at a first kneading temperature for a first kneading time to obtain first polymer film compositions for Examples 1 to 11 and Comparative Examples 1 to 11, respectively. The amount of plasticizer blended is shown in Tables 1-1 and 2-1, and the first dry-mixing temperature, first dry-mixing time, first kneading temperature, and first kneading time are shown in Tables 1-2 and 2-2. The physical properties of the PVB (Mn, degree of acetalization, degree of acetylation, and hydroxyl group content) were measured according to the aforementioned test methods, and the results are shown in Tables 1-1 and 2-1. The units for the degree of acetalization, the degree of acetylation, and the hydroxyl group content are all mol%.

[0100] The first polymer film compositions of Examples 1 to 11 and Comparative Examples 1 to 11 were each placed in an extruder to obtain monolayer polymer films (hereinafter referred to as "first monolayer polymer films"). The melt index of each first monolayer polymer film was measured according to the test method described above, and the results are shown in Tables 1-6 and 2-6, i.e., "Melt index of Layer I." Note that each first polymer film composition was used as the material for each layer of the first portion of the polymer films of Examples 1 to 11 and Comparative Examples 1 to 11 described below, and the melt index of each first monolayer polymer film represents the melt index of each layer of the first portion.

[0101] 3.2.2. Second Part of Polymer Film

[0102] 100 parts by weight of poly(vinyl butyral) (PVB, manufactured by Chang Chun Petrochemical Co., Ltd.) was preheated in an oven at 30°C to 45°C for 1 minute. The preheated PVB and plasticizer were then dry-mixed at a second dry-mixing temperature for a second dry-mixing time to obtain a second dry-mixing mixture. The second dry-mixing mixture was then kneaded using a twin-screw kneader at a second kneading temperature for a second kneading time to obtain second polymer film compositions for Examples 1 to 11 and Comparative Examples 1 to 11, respectively. The amount of plasticizer blended is shown in Tables 1-3 and 2-3, and the second dry-mixing temperature, second dry-mixing time, second kneading temperature, and second kneading time are shown in Tables 1-4 and 2-4. The physical properties of the PVB (Mn, degree of acetalization, degree of acetylation, and hydroxyl group content) were measured according to the aforementioned test methods, and the results are shown in Tables 1-3 and 2-3. The units for the degree of acetalization, the degree of acetylation, and the hydroxyl group content are all mol%.

[0103] The second polymer film compositions of Examples 1 to 11 and Comparative Examples 1 to 11 were each placed in an extruder to obtain monolayer polymer films (hereinafter referred to as "second monolayer polymer films"). The melt index of each second monolayer polymer film was measured according to the test method described above, and the results are shown in Tables 1-7 and 2-7, i.e., "Melt index of Layer II." Note that each second polymer film composition was used as the material for each layer of the second part of the polymer films of Examples 1 to 11 and Comparative Examples 1 to 11 described below, and the melt index of each second monolayer polymer film represents the melt index of each layer of the second part.

[0104] 3.2.3. Polymer film production

[0105] The first polymer film compositions of Examples 1 to 11 and Comparative Examples 1 to 11, and the second polymer film compositions of Examples 1 to 11 and Comparative Examples 1 to 11, were each placed in a coextruder and coextruded to form polymer films. The polymer films had a total thickness of 0.8 mm. Their constructions are shown in Tables 1-5 and 2-5, with "Layer I" representing the first layer of the polymer film formed from the first polymer film composition and "Layer II" representing the second layer of the polymer film formed from the second polymer film composition. The total thickness of Layer I constituting the first portion of the polymer film and the thickness ratio of Layer I to the total thickness of the first and second portions are shown in Tables 1-6 and 2-6. The total thickness of Layer II constituting the second portion of the polymer film and the thickness ratio of Layer II to the total thickness of the first and second portions are shown in Tables 1-7 and 2-7. In embodiments where the polymer film includes two or more Layers I or II, each Layer I has the same thickness, and each Layer II has the same thickness. Therefore, the thickness ratio of each layer can be calculated from the total thickness ratio listed in the table, and the product and sum of the products of the melt index and thickness ratio of each layer can be calculated accordingly.

[0106] Thereafter, the two surfaces of the polymer film were preheated and subjected to mechanical embossing to form a texture, thereby obtaining polymer films of Examples 1 to 11 and Comparative Examples 1 to 11.

[0107] [Table 1-1]

[0108] [Table 1-2]

[0109] [Table 1-3]

[0110] [Table 1-4]

[0111]

Table 1-5

[0112]

Table 1-6

[0113]

Table 1-7

[0114]

Table 2-1

[0115]

Table 2-2

[0116]

Table 2-3

[0117]

Table 2-4

[0118]

Table 2-5

[0119]

Table 2-6

[0120]

Table 2-7

[0121] 3.3. Manufacturing of laminated glass and evaluation of its physical properties

[0122] Laminated glass was produced using each of the polymer films of Examples 1 to 11 and Comparative Examples 1 to 11. First, the polymer film was cut to a size of 300 mm x 300 mm. Next, two clean, transparent float glass sheets (length: 300 mm, width: 300 mm, thickness: 2 mm) were prepared for each polymer film. The cut polymer film of Examples 1 to 11 and Comparative Examples 1 to 11 was sandwiched between two transparent float glass sheets to obtain a laminate. This laminate was pre-pressed by vacuuming using nip rollers. Pre-pressing with nip rollers was carried out as follows: the conveying speed of the belt conveyor of the roller press was 4.5 m / min, the oven temperature was 180°C, and the roller pressure was 3 kg / cm. 2 The laminate was placed on a belt conveyor and passed through an oven and rollers in that order. The distance between the rollers was 5 mm. The pre-pressed laminate was then placed in an autoclave and hot-pressed at a pressure of 13 bar and a temperature of 135°C for 120 minutes, after which it was cooled to room temperature to obtain a laminated glass.

[0123] The polymer films and laminated glasses of Examples 1 to 11 and Comparative Examples 1 to 11 were subjected to evaluation of the continuous layer structure, evaluation of the loss factor, ball drop test, snowflake defect test, and measurement of light transmittance according to the test methods described above. The results are shown in Tables 3-1 and 3-2.

[0124] [Table 3-1]

[0125] [Table 3-2]

[0126] As shown in Table 3-1, Examples 1 to 11 demonstrate that the polymer film of the present invention has a continuous layer structure and good structural uniformity. The laminated glass produced from the polymer film of the present invention all has a loss factor greater than 0.25, i.e., good sound insulation. Furthermore, the laminated glass produced from the polymer film of the present invention can pass the ball drop test and snowflake defect test, and has a suitable light transmittance (i.e., 87.5% or more).

[0127] In contrast, as shown in Table 3-2, laminated glass manufactured from polymer films other than those according to the present invention cannot simultaneously achieve excellent sound insulation, excellent optical properties, and excellent safety. In particular, Comparative Examples 1 and 11 show that when the melt index of each layer in the first portion and the sum of the products of the melt index and the thickness ratio of each layer in the first portion are lower than a predetermined range, the structural uniformity of the polymer film is poor, and the sound insulation of the manufactured laminated glass is poor (loss factor is less than 0.25), even if the melt index of each layer in the second portion and the sum of the products of the melt index and the thickness ratio of each layer in the second portion are within the predetermined range. According to Comparative Example 2, when the melt index of each layer of the first portion and the sum of the products of the melt index and the thickness ratio of each layer of the first portion are higher than the predetermined range, the manufactured laminated glass does not have excellent safety (fails the drop ball test) and has poor optical properties (fails the snowflake defect test and has a light transmittance of less than 87.5%), even if the melt index of each layer of the second portion and the sum of the products of the melt index and the thickness ratio of each layer of the second portion are within the predetermined range. According to Comparative Examples 3 and 4, when the sum of the products of the melt index and the thickness ratio of each layer of the first portion is outside the predetermined range, the manufactured laminated glass has low sound insulation (loss factor less than 0.25) or poor optical properties (light transmittance less than 87.5%), even if the melt index of each layer of the second portion and the sum of the products of the melt index and the thickness ratio of each layer of the second portion are within the predetermined range and the melt index of each layer of the first portion is within the predetermined range. According to Comparative Example 5, when the melt index of each layer of the second part and the sum of the products of the melt index and thickness ratio of each layer of the second part are higher than the specified range, even if the sum of the products of the melt index and thickness ratio of each layer of the first part is within the specified range, the safety of the manufactured laminated glass is inferior (failed the drop ball test) and the optical properties are also inferior (failed the snowflake defect test, light transmittance 87.5%).According to Comparative Example 6, when the melt index of each layer of the second portion and the sum of the products of the melt index and the thickness ratio of each layer of the second portion were lower than a predetermined range, the optical properties of the manufactured laminated glass were poor (failed the snowflake defect test) even if the melt index of each layer of the first portion and the sum of the products of the melt index and the thickness ratio of each layer of the first portion were within a predetermined range. According to Comparative Example 7, when the melt index of each layer of the first and second portions and the sum of the products of the melt index and the thickness ratio of each layer of the first and second portions were higher than the predetermined range, the manufactured laminated glass had poor safety (failed the drop ball test) and poor optical properties (failed the snowflake defect test, light transmittance less than 87.5%). According to Comparative Example 8, when the melt index of each layer of the first and second portions and the sum of the products of the melt index and the thickness ratio of each layer of the first and second portions are lower than a predetermined range, the uniformity of the polymer film structure is poor, and the sound insulation effect of the manufactured laminated glass is poor (loss factor less than 0.25). According to Comparative Example 9, when the sum of the products of the melt index and the thickness ratio of each layer of the first portion, the melt index of each layer of the second portion and the sum of the products of the melt index and the thickness ratio of each layer of the second portion are outside the predetermined range, the manufactured laminated glass has poor safety (failed the drop ball test) and poor optical properties (failed the snowflake defect test, light transmittance less than 87.5%). According to Comparative Example 10, when the melt index of each layer of the first portion and the sum of the products of the melt index and thickness ratio of each layer of the first portion were higher than a predetermined range, the safety of the manufactured laminated glass was poor. On the other hand, when the melt index of each layer of the second portion and the sum of the products of the melt index and thickness ratio of each layer of the second portion were lower than a predetermined range, the manufactured laminated glass was not excellent in safety (failed the drop ball test) and also had poor optical properties (failed the snowflake defect test, light transmittance 87.5%).

[0128] The above examples are used to explain the principle and effectiveness of the present invention and to demonstrate its inventive features, but are not used to limit the scope of the present invention. Those skilled in the art can make various modifications and substitutions based on the disclosure and suggestions of the present invention described. Therefore, the protection scope of the present invention is as defined in the appended claims.

[0129] (Addendum) (Appendix 1) A polymer film comprising a first portion and a second portion laminated to the first portion, wherein the first portion and the second portion are independently composed of one or more layers, each layer of the first portion independently has a melt index in the range of 3.5 g / 10 min to 10.0 g / 10 min, and each layer of the second portion independently has a melt index less than 3.5 g / 10 min; each layer of the first portion independently has a thickness ratio of its thickness to a total thickness of the first portion and the second portion, and a melt index multiplied by the thickness ratio, wherein the sum of the products for each layer of the first portion is in the range of 0.39 g / 10 min to 2.50 g / 10 min; each layer of the second portion independently has a thickness ratio of its thickness to the total thickness of the first portion and the second portion, and a melt index multiplied by the thickness ratio, wherein the sum of the products of the layers of the second portion is in the range of 1.10 g / 10 min to 2.95 g / 10 min; A polymer film characterized by:

[0130] (Appendix 2) The melt index of each layer of the second portion is independently 1.5 g / 10 min to 3.3 g / 10 min. 2. The polymer film according to claim 1,

[0131] (Appendix 3) The melt index of each layer of the first portion and the melt index of each layer of the second portion are measured in accordance with ASTM D1238 at 190°C and under a load of 2.16 kg; 2. The polymer film according to claim 1,

[0132] (Appendix 4) each layer of the first portion and each layer of the second portion independently comprises polyvinyl acetal; 4. The polymer film according to claim 1, wherein the polymer film is a polymer film having a molecular weight of 100 or more.

[0133] (Appendix 5) each layer of the first portion and each layer of the second portion independently comprises poly(vinyl butyral); 5. The polymer film according to claim 4.

[0134] (Appendix 6) each layer of the first portion independently contains polyvinyl acetal having an acetalization degree of 56 mol% to 74 mol%, an acetylation degree of 5 mol% to 15 mol%, and a hydroxyl group content of 20 mol% to 30 mol%; 5. The polymer film according to claim 4.

[0135] (Appendix 7) each layer of the second portion independently contains polyvinyl acetal having an acetalization degree of 60 mol% to 75 mol%, an acetylation degree of 0.1 mol% to 5 mol%, and a hydroxyl group content of 20 mol% to 35 mol%; 5. The polymer film according to claim 4.

[0136] (Appendix 8) the number average molecular weight (Mn) of the polyvinyl acetal contained in each layer of the first portion is independently 100,000 to 240,000; 5. The polymer film according to claim 4.

[0137] (Appendix 9) 5. The polymer film according to claim 4, wherein the polyvinyl acetal contained in each layer of the second portion independently has a number average molecular weight (Mn) of 90,000 to 120,000.

[0138] (Appendix 10) each layer of the first portion and each layer of the second portion each independently further comprises a plasticizer; 5. The polymer film according to claim 4.

[0139] (Appendix 11) Each layer of the first portion independently contains a plasticizer in an amount ranging from 55 parts by weight to 85 parts by weight based on 100 parts by weight of the polyvinyl acetal contained therein, and each layer of the second portion independently contains a plasticizer in an amount ranging from 30 parts by weight to 50 parts by weight based on 100 parts by weight of the polyvinyl acetal contained therein. 11. The polymer film according to claim 10.

[0140] (Appendix 12) one or more layers of the first portion constitute first subportions, one or more layers of the second portion constitute second subportions, the first subportions and the second subportions are arranged alternately, the number of the first subportions is M, the number of the second subportions is N, and M and N are independently positive integers; 4. The polymer film according to claim 1, wherein the polymer film is a polymer film having a molecular weight of 100 or more.

[0141] (Appendix 13) N is M+1, 13. The polymer film according to claim 12.

[0142] (Appendix 14) A laminated glass comprising, in order, a first glass sheet, an intermediate film, and a second glass sheet, The intermediate film is a polymer film according to any one of claims 1 to 3. The laminated glass is characterized by:

Claims

1. A polymer film comprising a first portion and a second portion laminated to the first portion, wherein the first portion and the second portion are independently composed of one or more layers, each layer of the first portion independently has a melt index in the range of 3.5 g / 10 min to 10.0 g / 10 min, and each layer of the second portion independently has a melt index in the range of 1.5 g / 10 min to 3.3 g / 10 min; each layer of the first portion independently has a thickness ratio of its thickness to a total thickness of the first portion and the second portion, and a melt index times the thickness ratio, wherein the sum of the products for each layer of the first portion is in the range of 0.39 g / 10 min to 2.50 g / 10 min; each layer of the second portion independently has a thickness ratio of its thickness to the total thickness of the first portion and the second portion, and a melt index times the thickness ratio, wherein the sum of the products for each layer of the second portion is in the range of 1.10 g / 10 min to 2.95 g / 10 min; each layer of the first portion and each layer of the second portion independently comprises poly(vinyl butyral) and a plasticizer; each layer of the first portion independently contains a plasticizer in an amount ranging from 55 parts by weight to 85 parts by weight based on 100 parts by weight of poly(vinyl butyral) contained therein; and each layer of the second portion independently contains a plasticizer in an amount ranging from 30 parts by weight to 50 parts by weight based on 100 parts by weight of poly(vinyl butyral) contained therein; the thickness of each layer of the first portion is independently 50 μm to 250 μm, and the thickness of each layer of the second portion is independently 250 μm to 450 μm; a melt index of each layer of the first portion and a melt index of each layer of the second portion are measured in accordance with ASTM D1238 at 190°C and a load of 2.16 kg; one or more layers of the first portion constitute first subportions, one or more layers of the second portion constitute second subportions, the first subportions and the second subportions are arranged alternately, the number of the first subportions is M, the number of the second subportions is N, M and N are independently positive integers, and N is M+1; A polymer film characterized by:

2. each layer of the first portion independently comprises poly(vinyl butyral) having an acetalization degree of 56 mol% to 74 mol%, an acetylation degree of 5 mol% to 15 mol%, and a hydroxyl group content of 20 mol% to 30 mol%; 2. The polymer film of claim 1.

3. each layer of the second portion independently comprises poly(vinyl butyral) having an acetalization degree of 60 mol% to 75 mol%, an acetylation degree of 0.1 mol% to 5 mol%, and a hydroxyl group content of 20 mol% to 35 mol%; 3. The polymer film according to claim 1 or 2.

4. the number average molecular weight (Mn) of the poly(vinyl butyral) contained in each layer of the first portion is independently 100,000 to 240,000; 3. The polymer film according to claim 1 or 2.

5. 3. The polymer film according to claim 1, wherein the number average molecular weight (Mn) of the poly(vinyl butyral) contained in each layer of the second portion is independently 90,000 to 120,000.

6. A laminated glass comprising, in order, a first glass sheet, an intermediate film, and a second glass sheet, The intermediate film is the polymer film according to claim 1 or 2. The laminated glass is characterized by:

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