JP7065143B2 - Polymer films and their uses - Google Patents

Description

The present invention provides a polymer film, in particular a polymer film having a specific void volume (Vv) value at a specific material ratio. Polymer films are suitable for use as an intermediate layer in laminated glass for buildings.

Laminated glass is a glass substance having a composite structure formed by interposing a polymer film between two glass sheets and performing hot pressing to join the glass sheet and the polymer film. Laminated glass is widely used in the automobile industry and the construction industry because it has excellent impact resistance and soundproofing.

In general, laminated glass has a step of obtaining a laminate by interposing a polymer film between two glass sheets and a step of pre-pressing the laminate so as to remove air between the glass sheets and the polymer film. , The prepressed laminate is placed in an autoclave under high temperature and high pressure for a certain period of time to obtain a laminated glass. When preparing a flat laminated glass, the preliminary pressing step is usually performed by pressing the laminate with a roller and baking it at an increased temperature.

Since the laminated glass manufacturing process includes a hot pressing process of the glass sheet and the polymer film, it is important to avoid leaving air between the laminated glass sheet and the polymer film in order to improve the yield. .. A known technique for removing air between a glass sheet of laminated glass and a polymer film is to form a concavo-convex structure on the surface of the polymer film to facilitate degassing during hot pressing. However, the existing polymer film still has insufficient degassing performance and usually has a defect of edge peeling (ie, separation of the polymer film and the glass sheet at the edge of the laminated glass). As a result, the yield of laminated glass is still insufficient.

It is an object of the present invention to provide a polymer film, in particular to provide a polymer film having a specific void volume (Vv) value at a specific load area ratio. The polymer film exhibits excellent performance in the production of laminated glass, which is prepressed by rollers. In addition, the polymer film is firmly and completely bonded to the glass. The laminated glass produced shows excellent or good results in the bubbling test and has no edge peeling defects. Therefore, the polymer film of the present invention is particularly suitable for the production of laminated glass for buildings.

Therefore, an object of the present invention is a polymer film containing polyvinyl acetal, wherein at least one surface of the polymer film has voids in the range of ² μm ³ / μm ^{2 to 18 μm 3 / μm 2 with} a loading area ratio of 10%. It is to provide a polymer film having a volume (Vv) value and having a void volume (Vv) and a load area ratio defined in accordance with ISO 25178-2: 2012.

In some embodiments of the invention, the void volume (Vv) values of the two surfaces of the polymer film are independently 2 μm ³ / μm ^2-18 μm ³ / μm with a 10% loading area ratio. It is in the range of ² .

In some embodiments of the present invention, the polyvinyl acetal contained in the polymer film is poly (vinyl formal), poly (vinyl acetal), poly (vinyl butyral), poly (vinyl pentanal), poly (vinyl hexanal), And selected from the group consisting of these combinations.

In some embodiments of the invention, the surface roughness Rz of at least one surface of the polymer film is in the range of 15 μm to 40 μm.

In some embodiments of the invention, the surface roughness Rz of each of the two surfaces of the polymer film is independently in the range of 15 μm to 40 μm.

In some embodiments of the invention, the glass transition temperature (Tg) of the polymer film is in the range of 10 ° C to 22 ° C.

In some embodiments of the invention, the weight average molecular weight (Mw) of polyvinyl acetal contained in the polymer film ranges from 150,000 daltons to 250,000 daltons.

In some embodiments of the invention, the polymer film further comprises a plasticizer, the amount of which can be in the range of 30 to 60 parts by weight per 100 parts by weight of polyvinyl acetal.

In some embodiments of the invention, the thickness of the polymer film ranges from 0.2 mm to 2 mm.

In some embodiments of the invention, the polymer film is a multilayer film.

In some embodiments of the invention, the polymer film is a dye, pigment, stabilizer, antioxidant, flame retardant, infrared absorber, infrared blocker, UV absorber, UV stabilizer, lubricant, dispersant, It further comprises an additive selected from the group consisting of surfactants, chelating agents, coupling agents, adhesives, adhesion control agents, and combinations thereof.

Another object of the present invention is a laminated glass including a first glass sheet, a second glass sheet, and the above-mentioned polymer film arranged between the first glass sheet and the second glass sheet. To provide.

In order to further clarify the above object, technical features and advantages of the present invention, the present invention will be described in detail with reference to some of the following embodiments.

Hereinafter, some embodiments of the present invention will be described in detail. However, without departing from the spirit of the invention, the invention can be embodied in various embodiments and should not be limited to the embodiments described herein.

Unless additionally described, the expressions "one", "relevant", etc. described herein and in the claims should include both the singular and the plural.

Unless additionally described, the expressions "first", "second", etc. described herein and in the claims have no special meaning and are the elements or components shown. Used only to distinguish. These expressions are not used to represent priority.

Unless additionally described, the term "load area ratio" as used herein and in the claims is defined in accordance with ISO 25178-2: 2012. The load area ratio curve means a function curve graph showing the surface height with respect to the local area surrounded by it, and the load area ratio means the enclosed local area above the specified height.

Unless additionally described, the "void volume (Vv)" described herein and in the claims is defined in accordance with ISO 25178-2: 2012. Void volume means the volume of voids per unit area at a particular load area ratio.

Unless additionally described, "surface roughness Rz" as used herein and in the claims means the ten-point average roughness of a surface and is measured in accordance with JIS B 0601 (1994). It is a thing.

The present invention provides a polymer film having a specific void volume (Vv) value at a specific load area ratio and a laminated glass manufactured using the same. Laminated glass produced using the polymer film (particularly laminated glass for buildings) shows excellent or good results in the bubbling test and has no edge peeling defect. Hereinafter, the polymer film of the present invention and its use will be described in detail.

1. 1. Polymer film

1.1. Polymer film composition

The polymer film of the present invention contains polyvinyl acetal as an essential component, and may further contain any other component such as a plasticizer or other standard additive, if desired. In some embodiments of the invention, the polymer film comprises or consists of a polyvinyl acetal and a plasticizer.

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 acetal can be used alone or as a mixture of two or more. In the attached examples, poly (vinyl butyral) is used.

As described herein, a plasticizer, also called a plasticizer, is a chemical that can modify the plasticity of a thermoplastic resin. Examples of plasticizers include triethylene glycol bis (2-ethylhexanoate), tetraethylene glycol bis (2-ethylhexanoate), triethylene glycol bis (2-ethylbutyrate), and tetraethylene glycol bis (2-ethylbutylate). 2-Ethylene Butyrate), Triethylene Glycol Diheptanoate, Tetraethylene Glycol Diheptanoate, Dihexyl Adipate, Dioctyl Adipate, Hexyl Cyclohexyl Adipate, Diisononyl Adipate, Heptyl Nonyl Adipate, Dibutyl Sevacate, Bis [2- (2) -Butoxyethoxy) ethyl] adipate, polymer adipate, dipropylene glycol dibenzoate, tripropylene glycol dibenzoate, polypropylene glycol dibenzoate, isodecylbenzoate, 2-ethylhexylbenzoate, propylene glycol dibenzoate, diisononylphthalate, dibutoxyethyl terephthalate, Esters of polybasic acids or polyhydric alcohols such as, but not limited to, castor oil, methyl lysinolate, soybean oil, epylene glycol soybean oil, and combinations thereof.

A standard additive is any substance that can adaptively improve the processability of a polymer film during the manufacturing process or can impart a particular function to the polymer film. Examples of standard additives include dyes, pigments, stabilizers, antioxidants, flame retardants, infrared absorbers, infrared blockers, UV absorbers, UV stabilizers, lubricants, dispersants, surfactants, etc. Examples include, but are not limited to, chelating agents, coupling agents, adhesives, and adhesion control agents. The above additives can be used alone or in combination thereof. For example, the polymer film can contain dyes or pigments to form a colored polymer film. Further, the polymer film may contain an ultraviolet absorber or an infrared absorber in order to form a polymer film having an anti-ultraviolet function or a polymer film having an anti-infrared function.

The thickness of the polymer film of the present invention can be adjusted according to practical needs as long as the polymer film has a specified void volume (Vv) value. In general, the thickness of the polymer film can be in the range of 0.2 mm to 2 mm, more specifically in the range of 0.5 mm to 1.5 mm, for example 0.51 mm, 0. .52 mm, 0.53 mm, 0.54 mm, 0.55 mm, 0.56 mm, 0.57 mm, 0.58 mm, 0.59 mm, 0.6 mm, 0.61 mm, 0.62 mm, 0.63 mm, 0.64 mm , 0.65mm, 0.66mm, 0.67mm, 0.68mm, 0.69mm, 0.7mm, 0.71mm, 0.72mm, 0.73mm, 0.74mm, 0.75mm, 0.76mm, 0 .77mm, 0.78mm, 0.79mm, 0.8mm, 0.81mm, 0.82mm, 0.83mm, 0.84mm, 0.85mm, 0.86mm, 0.87mm, 0.88mm, 0.89mm , 0.9mm, 0.91mm, 0.92mm, 0.93mm, 0.94mm, 0.95mm, 0.96mm, 0.97mm, 0.98mm, 0.99mm, 1.0mm, 1.01mm, 1 .02 mm, 1.03 mm, 1.04 mm, 1.05 mm, 1.06 mm, 1.07 mm, 1.08 mm, 1.09 mm, 1.1 mm, 1.11 mm, 1.12 mm, 1.13 mm, 1.14 mm , 1.15 mm, 1.16 mm, 1.17 mm, 1.18 mm, 1.19 mm, 1.2 mm, 1.21 mm, 1.22 mm, 1.23 mm, 1.24 mm, 1.25 mm, 1.26 mm, 1 .27mm, 1.28mm, 1.29mm, 1.3mm, 1.31mm, 1.32mm, 1.33mm, 1.34mm, 1.35mm, 1.36mm, 1.37mm, 1.38mm, 1.39mm , 1.4 mm, 1.41 mm, 1.42 mm, 1.43 mm, 1.44 mm, 1.45 mm, 1.46 mm, 1.47 mm, 1.48 mm, or 1.49 mm. Not limited.

The polymer film of the present invention may be a single-layer film composed of a single layer or a multilayer film composed of multiple layers as long as it has a specified void volume (Vv) value as a whole. There may be. When the polymer film is a multilayer film, the plurality of layers of the polymer film are made of the same or different raw materials and can therefore be the same or different functional layers. The functional layer may be, for example, a layer having one or more of a soundproofing function, a heat insulating function, a reflection function, an antireflection function, a refraction function, an antirefraction function, a light division function, and a dimming function. good.

1.2. Characteristics of polymer film

The uneven structure of the surface of the polymer film can be identified by a three-dimensional image of the surface morphology. ISO 25178-2: 2012 is a metric for assessing surface morphology, i.e., discloses void volume (Vv) as a parameter associated with surface morphology. Void volume (Vv) is defined as the volume of voids per unit area at a particular material ratio and can be calculated from the area load area ratio curve graph. In the area load area ratio curve graph, the Y-axis indicates the surface height, and the X-axis indicates the load area ratio. When the load area ratio of the X axis is 0%, the surface height of the Y axis is maximum, and when the load area ratio of the X axis is 100%, the surface height of the Y axis is 0. For example, the void volume (Vv) at a load area ratio of 10% is surrounded below a horizontal cutting plane set at the surface height of the Y axis corresponding to the load area ratio of 10% on the X axis. Represents the volume of the void. Therefore, when the load area ratio is 0%, the value of the void volume (Vv) becomes maximum. When the load area ratio is 100%, the value of the void volume (Vv) is 0. A related description of the parameters of void volume (Vv) can be referred to in ISO 25178-2: 2012, the subject matter of which is incorporated herein by reference in its entirety.

The present inventor surprisingly showed excellent or good results in bubbling tests by controlling the value of the void volume (Vv) of the polymer film used for laminated glass at a specific load area ratio, edge. We have found that it is possible to provide laminated glass (particularly laminated glass for buildings) that does not have peeling defects. Specifically, the value of the void volume (Vv) on at least one surface of the polymer film of the present invention is in the range of ² μm ^{3 / μm 2-18 μm 3 /} μm ² with a load area ratio of 10%, eg, 2 .5 μm ³ / μm ² , 3 μm ³ / μm ² , 3.5 μm ³ / μm ² , 4 μm ³ / μm ² , 4.5 μm ³ / μm ² , 5 μm ³ / μm ² , 5.5 μm ³ / μm ² , 6 μm ³ / μm ² , 6.5 μm ³ / μm ² , 7 μm ³ / μm ² , 7.5 μm ³ / μm ² , 8 μm ³ / μm ² , 8.5 μm ³ / μm ² , 9 μm ³ / μm ² , 9.5 μm ³ / μm ² , 10 μm ³ / μm ² , 10.5 μm ³ / μm ² , 11 μm ³ / μm ² , 11.5 μm ³ / μm ² , 12 μm ³ / μm ² , 12.5 μm ³ / μm ² , 13 μm ³ / μm ² , 13.5 μm ³ / μm ² , 14 μm ³ / μm ² , 14.5 μm ³ / μm ² , 15 μm ³ / μm ² , 15.5 μm ³ / μm ² , 16 μm ³ / μm ² , 16.5 μm ³ / μm ² , 17 μm ³ / μm ² , or 17.5 μm ³ / μm ² . Here, the load area ratio and the void volume (Vv) are defined according to ISO 25178-2: 2012. In a preferred embodiment of the invention, the void volume (Vv) of each of the two surfaces of the polymer film of the invention is independently ² μm ^{3 / μm 2-18 μm 3 /} μm ² with a 10% loading area ratio. Is the range of.

In some embodiments of the invention, the surface roughness Rz of at least one surface of the polymer film of the invention is in the range of 15 μm to 40 μm. The surface roughness Rz of each of the two surfaces of the polymer film is independently in the range of 15 μm to 40 μm, for example, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm. , 28 μm, 29 μm, 30 μm, 31 μm, 32 μm, 33 μm, 34 μm, 35 μm, 36 μm, 37 μm, 38 μm, or 39 μm. The above Rz is measured according to JIS B 0601 (1994).

The method for providing the desired void volume (Vv) value and surface roughness Rz on the surface of the polymer film of the present invention can be any standard method. For example, the surface of the polymer film is mechanically embossed to form an uneven structure on the surface of the polymer film, and the composition of the polymer film or the conditions of the mechanical embossing are adjusted to obtain a specified void volume (Vv) value. And surface roughness Rz is provided. As described herein, mechanical embossing is the formation of a texture on the surface of the polymer film by rollers after the polymer film has been formed. Examples of the method for mechanical embossing include, but are not limited to, the embossing roller method or the calendar roller method. The embossed roller method is preferable. Texture types provided using mechanical embossing methods include diamonds, lines, serrations, squares, tapers, circles, sub-circular shapes, and irregular shapes. Not limited to. The texture types described above can be used alone or in combination thereof. For example, one or more of the following techniques can be used to adjust the properties of the polymer film or the conditions of mechanical embossing to obtain a specified void volume (Vv) value and surface roughness Rz. ..
(I) The weight average molecular weight (Mw) of polyvinyl acetals ranges from 150,000 daltons to 250,000 daltons, eg, 155,000 daltons, 160,000 daltons, 165,000 daltons, 170,000 daltons, 175,000 Dalton, 180,000 Dalton, 185,000 Dalton, 190,000 Dalton, 195,000 Dalton, 200,000 Dalton, 205,000 Dalton, 210,000 Dalton, 215,000 Dalton, 220,000 Dalton, It may be 225,000 daltons, 230,000 daltons, 235,000 daltons, 240,000 daltons, or 245,000 daltons. In some embodiments of the invention, the weight average molecular weight (Mw) of polyvinyl acetals ranges from 180,000 daltons to 205,000 daltons.
(Ii) The glass transition temperature (Tg) of the polymer film is in the range of 10 ° C. to 22 ° C., for example, 10.5 ° C., 11 ° C., 11.5 ° C., 12 ° C., 12.5 ° C., 13 ° C., 13.5 ° C, 14 ° C, 14.5 ° C, 15 ° C, 15.5 ° C, 16 ° C, 16.5 ° C, 17 ° C, 17.5 ° C, 18 ° C, 18.5 ° C, 19 ° C, 19. It may be 5 ° C, 20 ° C, 20.5 ° C, 21 ° C, or 21.5 ° C.
(Iii) The amount of the plasticizer in the polymer film is 30 to 60 parts by weight per 100 parts by weight of polyvinyl acetal, for example, 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, 50 parts by weight, 51 parts by weight, 52 parts by weight, 53 parts by weight, 54 parts by weight, 55 parts by weight, 56 parts by weight, 57 parts by weight, 58 parts by weight or 59 parts by weight. May be good.
(Iv) The pressure of the embossing roller may be in the range of 1 kg / cm ² to 15 kg / cm ² , preferably in the range of 3 kg / cm ² to 13 kg / cm ² , and more specifically in the range of 5 kg. It ranges from / cm ² to 10 kg / cm ² , and may be, for example, 6 kg / cm ² , 7 kg / cm ² , 8 kg / cm ² , 9 kg / cm ² , or 10 kg / cm ² .
(V) The temperature of the emboss roller may be in the range of 80 ° C to 130 ° C, preferably in the range of 85 ° C to 125 ° C, and more specifically in the range of 90 ° C to 120 ° C. For example, 91 ° C, 92 ° C, 93 ° C, 94 ° C, 95 ° C, 96 ° C, 97 ° C, 98 ° C, 99 ° C, 100 ° C, 101 ° C, 102 ° C, 103 ° C, 104 ° C, 105 ° C, 106 ° C. , 107 ° C, 108 ° C, 109 ° C, 110 ° C, 111 ° C, 112 ° C, 113 ° C, 114 ° C, 115 ° C, 116 ° C, 117 ° C, 118 ° C, or 119 ° C. If the temperature of the embossed rollers is not within the specified range, the polymer film may not have the desired void volume (Vv) value.

1.3. Manufacture of polymer films

The method for producing the polymer film of the present invention is not particularly limited. For example, polyvinyl acetal and an arbitrary component (eg, a plasticizer) are mixed and kneaded to obtain a polymer composition so as to provide a desired void volume (Vv) value and surface roughness Rz on the surface of the polymer film. The polymer film of the present invention can be produced by using this polymer composition to provide a polymer film by a standard method and optionally performing a mechanical embossing step. Examples of standard methods for providing a polymer film 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.

In some embodiments of the invention, the polymer film is manufactured as follows. First, the polyvinyl acetal resin and the plasticizer are mixed and kneaded using a mixer at a rotation speed in the range of 10 rpm to 50 rpm and a temperature in the range of 100 ° C. to 150 ° C. for 5 minutes to 30 minutes to form a polymer composition. Get things. The polymer composition is then cooled to room temperature, placed in a hot presser and hot pressed for 1 to 10 minutes at a pressure in the range of 2 kg to 5 kg and at a temperature in the range of 100 ° C to 200 ° C. , Form a film. Optionally, the above film forming step is repeated to adjust the composition of the polymer composition to provide a plurality of films having different functions, and the films are laminated to form a polymer film having a multilayer structure. Further, a mechanical embossing step is optionally performed on the polymer film so as to provide a desired void volume (Vv) value and surface roughness Rz. The conditions for mechanical embossing are that the pressure of the embossing roller is in the range of 5 kg / cm ² to 8 kg / cm ² , and the temperature of the embossed roller is in the range of 90 ° C. to 120 ° C.

2. 2. Laminated glass

The polymer film of the present invention is suitable for use as an intermediate layer of laminated glass. Accordingly, the present invention also provides laminated glass comprising a first glass sheet, a second glass sheet, and the aforementioned polymer film disposed between the first glass sheet and the second glass sheet.

The first glass sheet and the second glass sheet may be the same as or different from each other. The first glass sheet and the second glass sheet can each be any standard glass sheet for producing laminated glass. Standard glass sheets for making laminated glass include, but are not limited to, float glass, tempered glass, wired glass, or flat glass. In the attached examples, float glass is used as the first glass sheet and the second glass sheet.

The laminated glass of the present invention can be produced by any method known in the art. The laminated glass of the present invention can be produced, for example, as follows. First, a polymer film is interposed between two glass sheets to obtain a laminate. The roller presser and the oven are set so that the transport speed of the conveyor belt of the roller presser is 2 m / min to 8 m / min and the oven temperature is 150 ° C. to 200 ° C., respectively. The laminate is placed on the conveyor belt such that the laminate passes through the oven and then between a pair of rollers spaced 5.5 mm to 6.5 mm apart. Then, the roller-pressed laminate is cooled to room temperature to complete the preliminary press. Next, the pre-pressed laminate is placed in an autoclave and hot-pressed under high-pressure and high-temperature conditions for 100 to 150 minutes to obtain a laminated glass. The high pressure and high temperature conditions described above refer to pressures in the range of 10 bar to 15 bar and temperatures in the range of 100 ° C to 150 ° C.

3. 3. Example

3.1. Test method

The present invention is further exemplified by the following embodiments. Here, the test equipment and the test method are as follows.

[Measurement of molecular weight distribution of polyvinyl acetal]

The molecular weight distribution of polyvinyl acetals is measured by gel permeation chromatography (GPC). Here, polyvinyl acetal is dissolved in tetrahydrofuran (THF), and GPC analysis is performed under the following conditions. The molecular weight of polyvinyl acetal is calculated based on the ratio corresponding to the area of standard polystyrene (Water PS STD).
Equipment: Waters 1515 PUMP system
Detector: Waters 2414 RI
Elution conditions: 1.0 mL / min, THF
Columns: Waters Stylel HR5 THF, Waters Stylel HR4 THF, Waters Stylel HR3 THF, Waters Stylel HR1 THF

[Measurement of void volume (Vv)]

Void volume (Vv) values at 10% load area ratio on the surface of the polymer film are lasers at a temperature of 24 ± 3 ° C and a relative humidity of 63 ± 3%, according to ISO 25178-2: 2012. It is measured by using a confocal microscope (model number: LEXT OLS5000-SAF, purchased from Olympus). The measurement conditions are as follows. The light source wavelength is 405 nm, the objective lens is 100 times (MPLAPON-100xLEXT), the optical zoom is 50 times, the observation area is 1500 μm × 1500 μm, and the resolution is 1024 pixels × 1024 pixels. , The operating condition is set to auto tilt remote and the filter is not used. In the obtained load area ratio curve graph, the core void volume (Vvc) value and the Dale void volume (Vvv) value can be obtained. The void volume (Vv) value is the sum of the core void volume (Vvc) value and the Dale void volume (Vvv) value. The unit of void volume (Vv) is μm ³ / μm ² .

[Measurement of surface roughness Rz]

The surface roughness Rz is measured using a roughness tester (model name: SE 300, purchased from KOSAKA Laboratory Ltd.) in accordance with JIS B 0601 (1994). First, the polymer film is cut into a test sample of 8 cm × 30 cm. The measurement conditions are as follows. The vertical magnification is set to automatic, the horizontal dimension is set to 25 mm / λ _c , and the cut off distance is calculated once every 2.5 mm (ie, every 2.5 mm). ), The evaluation length is set to 7 times the cutoff distance, the baseline length is set to 17.5 mm, and the measurement direction is the flow direction (machine direction).

[Measurement of glass transition temperature (Tg)]

The Tg of the polymer film is measured in a nitrogen atmosphere using a differential scanning calorimeter (model number: TA DSC 25, purchased from TA Instruments). First, 7 mg of a polymer film as a sample is placed on a sample table of a differential scanning calorimeter, heated to 150 ° C. at a heating rate of 10 ° C./min, and held at that temperature for 5 minutes. The sample is then balanced at −50 ° C. and held at that temperature for 5 minutes. Then, the sample is heated to 100 ° C. at a heating rate of 10 ° C./min to obtain a curve graph of the temperature with respect to the heat flow (X-axis is temperature, Y-axis is heat flow). The temperature corresponding to the midpoint of the glass transition is recorded as Tg.

[Bubbling test]

The laminated glass is cut to obtain a test sample having a width of 30 cm and a length of 30 cm. The test sample is placed vertically in an oven at 120 ° C. for 14 days. Next, visually observe the test sample to see if bubbling was found. Here, bubbling means that air bubbles that are not exposed to the outside air are present between the glass sheet and the polymer film. The criteria for the bubbling test are as follows. If there are no bubbles in the test sample, the bubbling test result is excellent and is recorded as "◎". If there is only one bubble in the test sample and the diameter of the bubble is less than 0.5 mm, the bubbling test result is good and is recorded as "◯". If there are two or more bubbles with a diameter of less than 0.5 mm or one bubble with a diameter larger than 0.5 mm in the test sample, the bubbling test result is bad and is recorded as "x". To.

[Edge peeling test]

The laminated glass is cut into a test sample having a width of 30 cm and a length of 30 cm. The test sample is placed vertically in an oven at 50 ° C. and 95% relative humidity for 14 days. Next, visually observe the test sample to see if edge peeling is found. The criteria for the edge peeling test are as follows. If the test sample does not have edge peeling (ie, the polymer film is tightly bonded to the glass sheet), the result of the edge peeling test is acceptable and is recorded as "⊚". On the other hand, if the test sample has edge peeling (ie, the polymer film is not tightly bonded to the glass sheet), the result of the edge peeling test fails and is recorded as an "x".

3.2. List of raw materials used in Examples and Comparative Examples

Table 1: Raw material list

3.3. Polymer film manufacturing and properties

The polymer films of Examples 1 to 10 and Comparative Examples 1 to 5 were produced as follows. First, 100 parts by weight of PVB and 38.5 parts by weight of 3GO were mixed to obtain a mixture. This mixture was kneaded using a mixer at 120 ° C. and a rotation speed of 35 rpm for 15 minutes, and then cooled to room temperature to obtain a polymer film composition. Next, the polymer film composition was placed in a hot presser and hot pressed at 150 ° C. at a pressure of 3 kg for 3 minutes to obtain a polymer film.

Then, the two surfaces of the polymer film were optionally mechanically embossed. The conditions for mechanical embossing are shown in Tables 2-1 and 2-2, and the linear velocity of the polymer film passing through the pair of embossing rollers was in the range of 10 m / min to 18 m / min.

The molecular weight of PVB of the polymer films of Examples 1 to 10 and Comparative Examples 1 to 5, and the thickness, Tg, surface roughness Rz, and load area ratio 10 of the polymer films of Examples 1 to 10 and Comparative Examples 1 to 5. Void volume (Vv) in% was measured according to the test method described above. The results are shown in Table 2-1 and Table 2-2.

Table 2-1: Mechanical embossing conditions of Examples 1 to 10 and characteristics of PVB and polymer film

Table 2-2: Mechanical embossing conditions of Comparative Examples 1 to 5 and characteristics of PVB and polymer film.

3.4. Manufacture and properties of laminated glass

Laminated glass was produced using the polymer films of Examples 1 to 10 and Comparative Examples 1 to 5, respectively. First, two clean transparent float glass sheets (length 300 mm, width 150 mm, thickness 2 mm to 4 mm) were prepared. The polymer films of Examples 1 to 10 and Comparative Examples 1 to 5 were interposed between the two transparent float glass sheets, respectively, to obtain a laminate. This laminate was pre-pressed by a roller press using a roller presser and an oven. The roller press went as follows. The transport speed of the conveyor belt of the roller presser was 3.5 m / min, and the oven temperature was 180 ° C. The laminate was placed on the conveyor belt and the roller-pressed laminate was cooled to room temperature so that the laminate passed through the oven and between a pair of rollers at 6.3 mm intervals. Next, the pre-pressed laminate was placed in an autoclave, hot-pressed at a pressure of 13 bar and a temperature of 135 ° C. for 120 minutes, and then cooled to room temperature to obtain a laminated glass.

The bubbling test and the edge peeling test on the laminated glass of Examples 1 to 10 and Comparative Examples 1 to 5 were evaluated according to the above test method. The results are shown in Table 3-1 and Table 3-2.

Table 3-1: Characteristics of laminated glass of Examples 1-10

Table 3-2: Characteristics of laminated glass of Comparative Examples 1 to 5

As shown in Table 3-1 the laminated glass produced from the polymer film of the present invention passed the bubbling test and the edge peeling test, showed excellent or good results in the bubbling test, and had no edge peeling defects. rice field. In particular, as shown in Examples 1 to 10, even if the molecular weight, Tg and embossing conditions of PVB change, each of the laminated glasses has a void volume (Vv) value at a load area ratio of 10% of the polymer film. Within the specified range, the requirement to show good or good results in the bubbling test and the requirement to have no edge peeling can be met.

On the other hand, as shown in Table 3-2, laminated glass produced from a polymer film not belonging to the present invention satisfies the requirement of showing excellent or good results in the bubbling test and the requirement of having no edge peeling. I can't. In particular, as shown in Comparative Examples 2 to 4, when the value of the void volume (Vv) of the polymer film is less than the specified range regardless of the molecular weight of PVB, Tg, and the embossing conditions, any of the above. Laminated glass also cannot pass the bubbling test and cannot be without edge peeling. Further, as shown in Comparative Examples 1 and 5, when the value of the void volume (Vv) of the polymer film is larger than the specified range, the laminated glass shows good results in the bubbling test, but has edge peeling. ..

The above examples are used to illustrate the principles and effectiveness of the invention and show the features of the invention, but are not used to limit the scope of the invention. One of ordinary skill in the art can make various modifications and substitutions based on the disclosed disclosures and suggestions of the invention described without departing from the principles and spirit of the invention. Therefore, the scope of protection of the present invention is defined in the appended claims.

Claims (10)

A polymer film containing polyvinyl acetal and a plasticizer , wherein the value of void volume (Vv) on at least one surface of the polymer film is 2 μm ^{3 / μm 2 to 18 μm 3 / μm 2} at a load area ratio of 10%. The void volume (Vv) and the load area ratio are defined in accordance with ISO 25178-2: 2012.
The surface roughness Rz of at least one surface of the polymer film is in the range of 15 μm to 40 μm.
The polymer film has a glass transition temperature (Tg) in the range of 10 ° C to 20 ° C.
A polymer film characterized by that. According to claim 1, the value of the void volume (Vv) of each of the two surfaces of the polymer film is independently in the range of ² μm ³ / μm ^{2 to 18 μm 3 / μm 2 at} a load area ratio of 10%. The polymer film described. 2. 2. The polymer film according to 2. The polymer film according to claim 2, wherein the surface roughness Rz of each of the two surfaces of the polymer film is independently in the range of 15 μm to 40 μm. The polymer film according to any one of claims 1 to 4, wherein the polyvinyl acetal has a weight average molecular weight (Mw) in the range of 150,000 daltons to 250,000 daltons. The polymer film according to claim 1 , wherein the amount of the plasticizer is in the range of 30 parts by weight to 60 parts by weight per 100 parts by weight of the polyvinyl acetal. The polymer film according to any one of claims 1 to 6 , which has a thickness in the range of 0.2 mm to 2 mm. The polymer film according to any one of claims 1 to 7 , which is a multilayer film. Dyes, pigments, stabilizers, antioxidants, flame retardants, infrared absorbers, infrared blockers, UV absorbers, UV stabilizers, lubricants, dispersants, surfactants, chelating agents, coupling agents, binders, adhesives The polymer film according to any one of claims 1 to 8 , further comprising a control agent and an additive selected from the group consisting of a combination thereof. The polymer film according to any one of claims 1 to 9 , which is arranged between the first glass sheet, the second glass sheet, and the first glass sheet and the second glass sheet. , Including laminated glass.