INTERMEDIATE FILM MADE OF PLASTIC AND LAMINATE WITH THIS FILM

Abstract

One plastic intermediate film (100) comprising: a sound-insulating layer (200), wherein the sound-insulating layer (200) comprises a polyvinyl acetal resin, a plasticizer and a refractive index regulator (250), wherein the refractive index regulator (250) consists of particles with an average diameter (D 50 ) of 100 nm or less and has an absolute refractive index of 2.0 or more, wherein the refractive index regulator (250) is contained in an amount of more than 0 wt.% and 1 wt.% or less, based on the total sound-insulating layer and the plasticizer is contained in an amount of 33 to 41 wt.%, based on the total sound-insulating layer, the plastic intermediate film (100) further comprising a first layer (300, 320, 820) arranged on a surface of the sound-insulating layer (200), wherein the plastic intermediate film (100) has an Rsc value of 0 to 1 according to equation 1 below: Rsc = 1 − ( Refractive index of the first layer − Refractive index of the sound-insulating layer ) * 100.

Description

TECHNICAL FIELD [CROSS-REFERENCE TO RELATED APPLICATIONS]

[0001] This application claims the priority of KR patent application No. 10-2019-0144755, filed on 13 November 2019, and all the advantages arising therefrom in respect of the priority, the contents of which are incorporated herein by reference in their entirety.

[0002] The embodiments relate to a plastic intermediate film, a laminate containing it, a vehicle containing it, and the like. BACKGROUND

[0003] Polyvinyl acetal is used as an interlayer (film for laminated glass) in laminated glass (safety glass) or translucent laminates. Laminated glass is primarily used for windows in buildings, cladding, and car windows. Due to its properties, such as preventing shattering upon breakage and its resistance to impacts of a certain magnitude, it can provide stability to minimize damage or injury to objects or people within it.

[0004] The main functions of laminated glass are to prevent penetration (penetration resistance) and to absorb impact energy to minimize damage or injury to objects or people within the transparent walls (impact resistance). Furthermore, laminated glass can be designed to have excellent optical properties, similar to clear glass, to prevent double vision or optical distortion, and to be robust and resistant to environmental damage, such as moisture (optical properties and moisture resistance). Additionally, an interlayer applied to laminated glass can provide further functionality, such as reducing sound levels and transmitting UV and / or IR radiation. [Related state of the art] Korean patent application no. KR 10-1354439 B1 Korean Patent Publication No. KR 10-2017-0063431 A US 2012 162752 A1

[0005] US 2012 162752 A1 describes an interlayer film for laminated glass that imparts thermal insulation properties to the laminated glass and can maintain these thermal insulation properties of the laminated glass over a long period of time. Laminated glass containing the interlayer film is also provided. An interlayer film 1 for laminated glass according to the present invention comprises a thermal insulation layer 2 and a UV protection layer 3. The thermal insulation layer 2 comprises a thermoplastic resin, thermal insulation particles, and at least one component selected from a phthalocyanine compound, a naphthalocyanine compound, and an anthocyanine compound. The UV protection layer 3 comprises a thermoplastic resin and a UV protectant.The laminated glass according to the present invention comprises: a first laminated glass component and a second laminated glass component; and an interlayer film arranged between the first and the second laminated glass component. The interlayer film is the interlayer film for a laminated glass according to the present invention.

[0006] KR 10 2018 0 061 189 A describes an interlayer for laminated glass which, when used in the manufacture of laminated glass, is capable of preventing air bubbles from remaining between the laminated glass elements and the interlayer. The interlayer comprises a thermoplastic resin and has one end and another end located on the opposite side of the first end, which is thicker than the first end. Each of the three values—namely, the ten-point average surface roughness Rz at a position 50 mm from one end to the other, the ten-point average surface roughness Rz at a position midway between the first and second ends, and the ten-point average surface roughness Rz at a position 50 mm from the other end to the first end—is at least 20 µm.The value obtained by subtracting the smallest of the three values ​​from the largest of the three values ​​is at least 3 µm but not more than 9 µm. Detailed description of a technical task

[0007] One objective of the embodiment is to provide a plastic intermediate film, a laminate containing it, a vehicle containing it, and the like. TECHNICAL SOLUTION

[0008] The invention is defined by the claims. To achieve the above objective, a plastic intermediate film comprises a sound-absorbing layer, wherein the sound-insulating layer comprises a polyvinyl acetal resin, a plasticizer and a refractive index regulator, wherein the refractive index regulator consists of particles with an average diameter (D50) of 100 nm or less and has an absolute refractive index of 2.0 or more, and wherein the refractive index regulator is contained in an amount of more than 0 wt.% and 1 wt.% or less, based on the total sound-insulating layer, and the plasticizer is contained in an amount of 33 to 41 wt.%, based on the total sound-insulating layer, the plastic intermediate film further comprising a first layer arranged on a surface of the sound-insulating layer (200), where the plastic interlayer film has an Rsc value of 0 to 1 according to equation 1 below: Rsc=1−(refractive index of the first layer−refractive index of the sound-absorbing layer)*100

[0009] The surface of the sound-absorbing layer can have a surface roughness Sz value of 20 µm or less.

[0010] The plastic interlayer film can have an optical distortion index (A) of 30 µm or less, expressed by equation 2 below. A=Sz / Rsc

[0011] In equation 2, Sz is the surface roughness (µm) of a surface of a sound-absorbing layer, and Rsc is a value according to equation 1.

[0012] The plastic interlayer film can have a turbidity value of 3% or less.

[0013] The plastic interlayer film can have an L / F (loss factor) of 0.34 or more.

[0014] The plastic interlayer film can have a long-term resistance (YH) value of 1.2 or less according to Equation 3 below. YH=dY.I.*dH

[0015] In equation 3, YH is a value for assessing long-term stability, dY.I. is a value obtained by subtracting a yellow index value before an EMMAQUA test, in which an irradiation energy of 500 K Langley is applied, from a yellow index after passing the above test, and dH is a value obtained by subtracting a turbidity value before an EMMAQUA test, in which an irradiation energy of 500 K Langley is applied, from a turbidity value after passing the above test.

[0016] The plastic interlayer can have a value of 3.5 or less, which is obtained by subtracting the value of the yellow index before an EMMAQUA test using an exposure energy of 500 K Langley from the value of the yellow index after passing the aforementioned test.

[0017] The refractive index regulator can account for a particle diameter difference between D 10 and D 90within 1.5 times D 50 exhibit.

[0018] A laminate according to another embodiment comprises a first translucent layer; a sound-insulating layer (200), wherein the sound-insulating layer (200) comprises a polyvinyl acetal resin, a plasticizer and a refractive index regulator (250), wherein the refractive index regulator (250) consists of particles with an average diameter (D50) of 100 nm or less and has an absolute refractive index of 2.0 or more, and wherein the refractive index regulator (250) is contained in an amount of more than 0 wt.% and 1 wt.% or less, based on the total sound-insulating layer and the plasticizer is contained in an amount of 33 to 41 wt.%, based on the total sound-insulating layer, the plastic intermediate film (100) further comprising a first layer (300, 320, 820) arranged on a surface of the sound-insulating layer (200), wherein the plastic intermediate film (100) has an Rsc value of 0 to 1 according to equation 1 below: Rsc=1−(refractive index of the first layer−refractive index of the sound-absorbing layer)*100. BENEFICIAL EFFECTS

[0019] A plastic interlayer and a laminate containing it can have sound-insulating properties and improved optical properties, durability, and the like. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a conceptual view illustrating a plastic intermediate film as one embodiment using a section thereof. Fig. Figure 2 is a conceptual view to illustrate a laminate according to another embodiment using a section thereof. Fig. Figure 3 is a conceptual view to illustrate a vehicle according to another embodiment. DETAILED DESCRIPTION

[0020] Exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings, so that they can be easily implemented by those skilled in the art in the field to which the present invention relates. However, these exemplary embodiments can be implemented in many different forms and are not to be understood as being limited to the embodiments presented here. The same reference numerals denote the same elements throughout the entire description.

[0021] In this description, terms such as "approximately," "essentially," etc., are used to denote values ​​that approximate the value when a tolerance is specified that is significant for the manufacturing process and the substance. Additionally, these terms are used for degree to facilitate understanding of examples and to prevent unauthorized use of the presented content, which refers to an exact or absolute number.

[0022] Throughout the description, the phrase “combination(s) thereof” contained in a Markush expression refers to one or more mixtures or combinations selected from the group consisting of the constituents named in the Markush expression; that is, it contains one or more constituents selected from the group consisting of the constituents.

[0023] In this description, the term “A and / or B” means “A, B or A and B”.

[0024] In this description, terms such as "first", "second", "A" or "B" are used to distinguish the same terms from one another, unless explicitly stated otherwise.

[0025] In this specification, “B placed on A” means that B is placed in direct contact with or above A, with another layer or structure in between, and should therefore not be interpreted as meaning that B is only placed in direct contact with A.

[0026] In this description, a singular form is interpreted contextually to include both a plural form and a singular form, unless explicitly stated otherwise.

[0027] In this description, the size of individual components in a drawing may be exaggerated and differ from the actual size to be used.

[0028] In the present description, the amount of the hydroxyl group was determined by measuring the amount of the ethylene group in combination with the hydroxyl group of the polyvinyl acetal resin according to a method according to JIS K6728.

[0029] Fig. Figure 1 is a conceptual view illustrating a plastic intermediate film as one embodiment using a section thereof, Fig. Figure 2 is a conceptual view to illustrate a laminate according to another embodiment using a section thereof, and Fig. Figure 3 is a conceptual view illustrating a vehicle according to another embodiment. Exemplary embodiments are described below with reference to Fig. 1 to Fig. 3 described in more detail.

[0030] A plastic intermediate film 100 comprises a sound-insulating layer 200, wherein the sound-insulating layer 200 comprises a polyvinyl acetal resin, a plasticizer and a refractive index regulator 250, wherein the refractive index regulator 250 comprises particles with an average diameter (D 50 ) of 100 nm or less.

[0031] In many cases, a larger quantity of plasticizer is used in a sound-insulating layer 200 of a plastic intermediate film 100 than in a layer without sound-insulating properties. Such a sound-insulating layer can easily develop a melt fracture on its surface during the production of the intermediate film, which can lead to optical distortion in the form of a faint image visible to the naked eye, either alone or in conjunction with a difference in refractive index between other layers arranged on the sound-insulating layer. The inventors have demonstrated that such a phenomenon can be remedied by applying a refractive index regulator 250 to the sound-insulating layer 200, and they have disclosed exemplary embodiments.

[0032] The refractive index regulator 250 can contain particles with a higher refractive index than the plasticizer. The refractive index regulator 250 is incorporated into a plastic interlayer film and, in addition to maximizing property variations such as sound-absorbing properties, also improves optical properties.

[0033] The refractive index regulator 250 can have a higher refractive index than the refractive index of the plasticizer.

[0034] The refractive index regulator 250 can have an average diameter (D 50 ) of 100 nm or less. The refractive index regulator 250 can have an average diameter (D 50 ) of 80 nm or less. The refractive index regulator 250 can have an average diameter (D 50 ) of 60 nm or less. The refractive index regulator 250 can have an average diameter (D 50) of 50 nm or less. The refractive index regulator 250 can have an average diameter (D 50 ) of 40 nm or less. The refractive index regulator 250 can have an average diameter (D 50 ) of 5 nm or more. When a refractive index regulator with such an average diameter is used, it is possible to significantly reduce the occurrence of optical distortions in an interlayer and minimize the deterioration of other properties of the interlayer.

[0035] The refractive index regulator 250 can have an average diameter (D 90 ) of 100 nm or less. The refractive index regulator 250 can have an average diameter (D 90 ) of 80 nm or less. The refractive index regulator 250 can have an average diameter (D 90 ) of 60 nm or less. The refractive index regulator 250 can have an average diameter (D90 ) of 40 nm or less. The refractive index regulator 250 can have an average diameter (D 90 ) of 10 nm or more. By applying such a refractive index regulator, it is possible to produce an intermediate layer with improved optical and sound-insulating properties.

[0036] The refractive index controller can satisfy a condition where the difference in particle diameter between D 10 and D 90 within 1.5 times D 50 The refractive index controller can satisfy a condition where the difference in particle diameter between D 10 and D 90 within 1.2 times D 50lies. If a refractive index regulator is used that meets such a condition, the optical properties can be further improved due to the refractive index regulating effect, while the sound-insulating property is essentially retained.

[0037] The refractive index regulator 250 can have an absolute refractive index of 1.4 or more, or 1.5 or more. The refractive index regulator can have an absolute refractive index of 2.0 or more. The refractive index regulator can have an absolute refractive index of 3.0 or less. The refractive index regulator can have an absolute refractive index of 2.4 or less. When a refractive index regulator with an absolute refractive index within such a range is applied to the sound-insulating layer, the refractive index of the sound-insulating layer can be regulated more effectively.

[0038] As described above, the sound-insulating layer 200 can form surface roughness on a surface in a manufacturing process.

[0039] A surface of the sound-absorbing layer 200 can have a surface roughness Sz value of 20 µm or less. A surface of the sound-absorbing layer 200 can have a surface roughness Sz value of 18 µm or less. A surface of the sound-absorbing layer 200 can have a surface roughness Sz value greater than 0 µm. A surface of the sound-absorbing layer 200 can have a surface roughness Sz value greater than 1 µm. If the surface roughness of a surface of the sound-absorbing layer has the values ​​mentioned above, optical distortions can easily occur, but the occurrence of optical distortions can be substantially prevented according to the exemplary embodiments.

[0040] The surface roughness of a sound-absorbing layer can be measured by peeling off a first layer of a section of a sample by hand, storing it in an oven at 50 °C and 20% relative humidity for one week to allow it to shrink naturally, and then creating a contour using the GT-X non-contact optical microscope, which allows the Sz value to be measured among the surface roughness values.

[0041] The refractive index regulator 250 can be present in amounts greater than 0% by weight and 1% by weight or less, based on the total sound-insulating layer. The sound-insulating layer itself can be present in amounts ranging from 0.1% to 0.9% by weight, based on the total sound-insulating layer. When the refractive index regulator is used in such a quantity range, it is possible to obtain an intermediate film with excellent optical properties, such as a yellow index, and to achieve a more stable effect in regulating the refractive index.

[0042] The sound-absorbing layer 200 can include a polyvinyl acetal resin and a plasticizer.

[0043] The polyvinyl acetal resin can be obtained by acetalizing a polyvinyl alcohol with a degree of polymerization of 1,600 to 3,000 with aldehyde. Alternatively, it can be obtained by acetalizing a polyvinyl alcohol with a degree of polymerization of 1,700 to 2,500 with aldehyde. Using such a polyvinyl acetal can significantly improve mechanical properties such as penetration resistance.

[0044] Polyvinyl acetal resin can be synthesized from polyvinyl alcohol and an aldehyde, the type of aldehyde being unrestricted. Specifically, the aldehyde can be selected from the group consisting of n-butylaldehyde, isobutylaldehyde, n-valer aldehyde, 2-ethylbutylaldehyde, n-hexylaldehyde, and their mixtures. When n-butylaldehyde is used as the aldehyde, the resulting polyvinyl acetal resin can have a refractive index only slightly different from that of glass and exhibit excellent adhesion to glass and similar materials.

[0045] The plasticizer can be one of the following: triethylene glycol bis-2-ethylhexanoate (3G8), tetraethylene glycol diheptanoate (4G7), triethylene glycol bis-2-ethylbutyrate (3GH), triethylene glycol bis-2-heptanoate (3G7), dibutoxyethoxyethyl adipate (DBEA), butylcarbitol adipate (DBEEA), dibutyl sebacate (DBS), bis-2-hexyl adipate (DHA), and combinations thereof. In particular, any product from the group consisting of triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol di-n-heptanoate, and combinations thereof can be used as the first plasticizer, and in particular, triethylene glycol bis-2-ethylhexanoate (3G8) can be used.

[0046] The polyvinyl acetal resin applied to the sound-insulating layer 200 can contain a butyral group in an amount of 60 mol% or more, or 60 to 72 mol%. The polyvinyl acetal resin can also contain a hydroxyl group in an amount of 20 mol% or less, 18 mol% or less, or more than 5 mol%. When a polyvinyl acetal resin with such properties is applied to the sound-insulating layer, the sound-insulating layer can have improved optical properties and impart excellent sound-insulating properties to the intermediate film.

[0047] The sound-insulating layer 200 can contain a polyvinyl acetal resin in an amount of 58 to 66 wt.%. The sound-insulating layer 200 can contain a polyvinyl acetal resin in an amount of 60 to 64 wt.%, based on the total sound-insulating layer. If the polyvinyl acetal resin is present in such a range, it is possible to give an intermediate film 100 adequate mechanical strength and at the same time a comparatively excellent sound-insulating property.

[0048] The sound-insulating layer 200 may contain a plasticizer in an amount of 33 to 41% by weight. The sound-insulating layer 200 may contain a plasticizer in an amount of 35 to 39% by weight, based on the total sound-insulating layer.

[0049] The plastic intermediate film 100 can further comprise a first layer 300 which is arranged on a surface of the sound-insulating layer.

[0050] The plastic intermediate film 100 can further comprise a first layer 320 which is arranged on the other surface of the sound-insulating layer.

[0051] The first layers 300 and 320 can each independently contain a first polyvinyl acetal resin and a first plasticizer, as described below.

[0052] The first polyvinyl acetal resin can contain a butyral group in an amount of 50 mol% or more. The first polyvinyl acetal resin can contain a butyral group in an amount of 50 to 60 mol%. The first polyvinyl acetal resin can contain a hydroxyl group in an amount of 35 mol% or more. The first polyvinyl acetal resin can contain a hydroxyl group in an amount of 40 mol% or more. The first polyvinyl acetal resin can contain a hydroxyl group in an amount of less than 49.5 mol%. When the first polyvinyl acetal resin with such properties is applied to the first layer 300, the first layer can exhibit suitable mechanical properties while bonding excellently to a material such as glass, and it can exhibit excellent sound-insulating properties with a sound-insulating layer.

[0053] The first polyvinyl acetal resin can be obtained by acetalizing a polyvinyl alcohol with a degree of polymerization of 1,600 to 3,000 with aldehyde, or by acetalizing a polyvinyl alcohol with a degree of polymerization of 1,700 to 2,500 with aldehyde. Using such a polyvinyl acetal can significantly improve mechanical properties such as puncture resistance.

[0054] The first polyvinyl acetal resin can be synthesized from polyvinyl alcohol and an aldehyde, the type of aldehyde being unrestricted. Specifically, the aldehyde can be selected from the group consisting of n-butylaldehyde, isobutylaldehyde, n-valer aldehyde, 2-ethylbutylaldehyde, n-hexylaldehyde, and their mixed resins. If n-butylaldehyde is used as the aldehyde, the resulting polyvinyl acetal resin can have a refractive index that differs only slightly from that of glass and exhibit excellent adhesion to glass and similar materials.

[0055] The first plasticizer can be any one selected from the group consisting of triethylene glycol bis-2-ethylhexanoate (3G8), tetraethylene glycol diheptanoate (4G7), triethylene glycol bis-2-ethylbutyrate (3GH), triethylene glycol bis-2-heptanoate (3G7), dibutoxyethoxyethyl adipate (DBEA), butylcarbitol adipate (DBEEA), dibutyl sebacate (DBS), bis-2-hexyl adipate (DHA), and combinations thereof. In particular, any product from the group consisting of triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol di-n-heptanoate, and combinations thereof can be used as the first plasticizer, and in particular, triethylene glycol bis-2-ethylhexanoate (3G8) can be used.

[0056] The first layer 300 can contain the first polyvinyl acetal resin in an amount of 60 to 76 wt%. The first layer 300 can contain the first polyvinyl acetal resin in an amount of 70 to 76 wt%. The first layer 300 can contain the first polyvinyl acetal resin in an amount of 71 to 74 wt%. If the polyvinyl acetal resin is present in such a range, an intermediate film 100 can achieve comparatively excellent mechanical properties.

[0057] The first layer 300 can contain the first plasticizer in an amount of 24 to 40 wt.%. The first layer 300 can contain the first plasticizer in an amount of 24 to 40 wt.%. The first layer 300 can contain the first plasticizer in an amount of 26 to 29 wt.%. If the first layer contains the plasticizer in such a range, it is advantageous that a plastic intermediate film can achieve adequate adhesion and impact resistance.

[0058] The first polyvinyl acetal resin and a second polyvinyl acetal resin, which is applied to the sound-absorbing layer, have a difference in the amount of hydroxyl groups of 20 mol% or more. The difference in the amount of hydroxyl groups can be 24 mol% or more. The difference in the amount of hydroxyl groups can be 26 mol% or more. The difference in the amount of hydroxyl groups can also be 32 mol% or less. If the first polyvinyl acetal resin and the second polyvinyl acetal resin are each applied to a first layer 300 and a sound-absorbing layer 200, respectively, to achieve such a difference in the amount of hydroxyl groups, an intermediate film with excellent sound-absorbing properties and moisture resistance is formed, without any significant migration of plasticizers.

[0059] The first layers 300 and 320 and / or a sound insulation layer 200 may also contain an additive described below. This additive may be a heat stabilizer (which may be limited to the first layer), a UV absorber, a UV stabilizer, an IR absorber, a glass adhesion regulator, or combinations thereof.

[0060] A phosphite-based heat stabilizer can be used. For example, IRGAFOS 168, available from BASF SE, is suitable, but not limited to this.

[0061] In particular, Chemisorb 12, Chemisorb 79, Chemisorb 74, or Chemisorb 102, available from CHEMIPRO KASEI KAISHA, LTD, or Tinuvin 328, Tinuvin 329, or Tinuvin 326, available from BASF SE, can be used as UV absorbers. Tinuvin, available from BASF SE, can be used as a UV stabilizer. ITO, ATO, or AZO can be used as an IR absorber, and a metal salt such as magnesium (Mg), potassium (K), sodium (Na), modified silicon (Si) epoxy oil, or a mixture thereof can be used as a glass adhesion regulator, but this is not the only possible application.

[0062] ITO, ATO or AZO can be used as an IR absorber, and a metal salt such as magnesium (Mg), potassium (K), sodium (Na), modified silicon (Si) epoxy-based oil or a mixture thereof can be used as a glass adhesion regulator applied to a first layer, but the present application is not limited to these.

[0063] The intermediate film 100 can comprise a first layer 300 and a sound-insulating layer 200, and it can comprise a sound-insulating layer 200 that is arranged between two first layers 300 and 320.

[0064] The intermediate film 100 can have a three-layer structure or a four- or five-layer structure, which additionally contains a functional layer (e.g. a color layer, a color ribbon, an IR blocker / reflective layer, etc.).

[0065] The interlayer 100 can have a total thickness of 400 µm or more. The interlayer 100 can have a total thickness of 400 to 1600 µm. The interlayer 100 can have a total thickness of 500 to 1200 µm. The interlayer 100 can have a total thickness of 600 to 900 µm. The interlayer can be improved in terms of mechanical strength, sound insulation properties, and other characteristics with a thicker thickness, as it is used for the production of a translucent laminate, such as laminated glass. However, considering the legally required minimum performance, cost, weight reduction, and other factors, the thickness range mentioned above allows for the production of a film that meets various requirements.

[0066] The first layers 300 and 320 can each have a thickness of 20 to 600 µm independently of each other. The first layers 300 and 320 can each have a thickness of 200 to 400 µm independently of each other.

[0067] The sound-insulating layer 200 can have a thickness of 60 to 600 µm. The sound-insulating layer 200 can have a thickness of 70 to 300 µm. The sound-insulating layer 200 can have a thickness of 70 to 200 µm.

[0068] An intermediate film comprising appropriate layers with such a thickness range can provide a translucent laminate with excellent optical and sound-insulating properties in addition to the right mechanical properties.

[0069] The plastic interlayer film can have an Rsc value of 0 to 1 according to equation 1 below. Rsc=1−(refractive index of the first layer−refractive index of the sound-absorbing layer)*100

[0070] The plastic interlayer 100 can have an optical distortion index (A) of 30 µm or less, or 20 µm or less, as expressed by equation 2 below. The optical distortion index (A) can be 0.3 µm or more. The optical distortion index (A) can be 5 µm or more. A=Sz / Rsc

[0071] In equation 2, Sz is the surface roughness (µm) of a surface of a sound-absorbing layer, and Rsc is a value according to equation 1.

[0072] A plastic intermediate film with such a property can have the characteristic of producing essentially no optical distortion and possessing excellent optical properties.

[0073] The plastic intermediate film 100 of the embodiment can have a turbidity value of 3% or less. The plastic intermediate film 100 of the embodiment can have a turbidity value of 2% or less. The plastic intermediate film 100 of the embodiment can have a turbidity value of 1.5% or less.

[0074] The plastic intermediate film 100 of the embodiment can have an L / F value (loss factor at 20 °C) of 0.34 or more.

[0075] The plastic intermediate film 100 of the embodiment can have a transmittance for visible light of 85% or more.

[0076] The plastic intermediate film 100 of the embodiment can exhibit a difference in the yellow index of 3.5 or less between before and after an EMMAQUA test in which an exposure energy of about 500 K Langley is applied.

[0077] The plastic intermediate film 100 of the embodiment can exhibit a difference in the yellow index of 3.5 or less before and after an EMMAQUA test in which an exposure energy of about 500 K Langley is applied.

[0078] The plastic intermediate film 100 of the embodiment can have a value for the assessment of long-term resistance (YH) of 1.2 or less according to equation 3 below. YH=dY.I.*dH

[0079] In equation 3, YH is a value for assessing long-term stability, dY.I. is a difference in the yellow index value before and after an EMMAQUA test applying an irradiation energy of about 500 K Langley, and dH is a difference in the turbidity value before and after an EMMAQUA test applying an irradiation energy of about 500 K Langley.

[0080] The test standard for the YH is ASTM G90 Cycle 3, and the YH is a calculated value obtained by exposing an energy (Night Time Wetting) of a total of 500 K Langley and measuring under two values. dY.I.(difference of YI)=YI after EMMAQUA−test−YI before EMMAQUA−test dH (difference of haze) = Hz after the EMMAQUA test - Hz before the EMMAQUA test

[0081] The dY.I. and the dH are each measured using three or more samples, and the average value of these is used.

[0082] The plastic interlayer 100 can have a long-term stability (YH) value of 0.82 or less according to Equation 3 below. The plastic interlayer 100 can have a long-term stability (YH) value of 0.50 or less according to Equation 3 below. The plastic interlayer 100 can have a long-term stability (YH) value of 0.30 or less, or greater than 0, according to Equation 3 below. The plastic interlayer 100 with such properties can have excellent optical properties that are maintained over a relatively long period.

[0083] A plastic intermediate film 100 may further comprise a second layer 200 comprising a polyvinyl acetal resin and a plasticizer, and a first layer 300 arranged on a surface of the second layer and exhibiting a long-term durability rating test value (YH) of 1.2 or less according to Equation 3 below. YH=dY.I.*dH

[0084] In equation 3, YH is a test value for evaluating long-term stability, dY.I. is a difference in the yellow index value before and after an EMMAQUA test applying an irradiation energy of about 500 K Langley, and dH is a difference in the turbidity value before and after an EMMAQUA test applying an irradiation energy of about 500 K Langley.

[0085] The first layer (300) and the second layer (200) can have a difference in refractive index ranging from 0 to 0.0068. This difference in refractive index refers to the difference between the refractive index of the first layer and the refractive index of the second layer and is expressed as an absolute value. For example, the difference in refractive index could be a value obtained by subtracting the refractive index of the second layer from the refractive index of the first layer.

[0086] The plastic interlayer 100 can have an optical distortion index (A) of 30 µm or less. The plastic interlayer 100 can have an optical distortion index (A) of 20 µm or less. The optical distortion index (A) can be 0.3 µm or more. The optical distortion index (A) can be 5 µm or more. A=Sz / Rsc

[0087] In equation 2, Sz is the surface roughness (µm) of a surface of the second layer, and Rsc is a value according to equation 1-1. Rsc=1−(refractive index of the first layer−refractive index of the second layer)*100

[0088] The description of the second layer overlaps with the above description of the sound-insulating layer, so a further detailed description is omitted.

[0089] The description of the first layer and the description of the plastic intermediate film overlap with the description above, so further detailed description is omitted.

[0090] A translucent laminate 800 can comprise a first translucent layer 820; a plastic interlayer 100 arranged on a surface of the first translucent layer as described above; and a second translucent layer 840 arranged on the plastic interlayer.

[0091] The first translucent layer 820 and the second translucent layer 840 can each consist independently of a translucent glass or a translucent plastic.

[0092] A detailed description of the plastic intermediate film 100 overlaps with the description above, so a further description is omitted.

[0093] The translucent laminate 800 allows translucent layers of both sides to be joined by the plastic interlayer 100 and can exhibit properties required in safety glass and the like, such as impact resistance and penetration resistance, while the translucency property of the first translucent layer 820 and the second translucent layer 840 remains almost identical.

[0094] The translucent laminate 800 can meet an impact strength characteristic according to KS L 2007:2008.

[0095] The translucent laminate 800 can meet a penetration strength characteristic according to KS L 2007.

[0096] The translucent laminate 800 offers excellent functionality when used as automotive glass (including windshields), as cladding in buildings, and similar applications. Specifically, when used as a car windshield, a 100 mm plastic interlayer containing the translucent laminate 800 can be provided, resulting in a relatively thin structure that offers all necessary properties such as impact resistance, sound insulation, and double-image protection.

[0097] A vehicle 900 disclosed in the present description comprises the above-described translucent laminate 800 as a windshield.

[0098] The vehicle 900 can be any vehicle to which a windshield is attached; a representative example of the vehicle can be an automobile; and the body part, driver part, drive wheel, connecting piece, and the like can be attached without restriction if the component is normally attached to an automobile.

[0099] The vehicle 900 comprises a body part forming a main body of the vehicle, a drive part (engine, etc.) attached to the body, a drive wheel rotatably mounted on the body, a connecting piece linking the drive wheel and the drive part, and a windshield attached to part of the body part, which is a translucent laminate for blocking wind from the outside.

[0100] The embodiments are described in more detail below with reference to the specific examples. Production of resin compositions and additives; Manufacturing process for polyvinyl butyral resin (PVB_A):

[0101] A polyvinyl alcohol resin with an average degree of polymerization of 1700 and a degree of saponification of 99 was synthesized with n-butylaldehyde, giving a polyvinyl butyral resin (A) with a butyral group of 56.2 mol% and a hydroxyl group of 42.9 mol%. Manufacturing process for polyvinyl butyral resin (PVB_B):

[0102] A polyvinyl alcohol resin with an average degree of polymerization of 2400 and a degree of saponification of 88 was synthesized with n-butylaldehyde, giving a polyvinyl butyral resin (B) with a butyral group of 68.0 mol% and a hydroxyl group of 16.5 mol%. Production of additive for the first layer:

[0103] Tinuvin-328 as a UV additive of 0.3 parts by weight, a mixture of Irganox 1010 and Irgafos 168 in a 1:1 ratio as an antioxidant of 0.1 parts by weight, a mixture of MgAc (magnesium acetate) of 0.03 parts by weight and KAc (potassium acetate) of 0.02 parts by weight as an adhesion promoter were mixed and an additive for a first layer of 0.45 parts by weight was prepared. Manufacturing a refractive index regulator:

[0104] ZrO2 (absolute refractive index of 2.21), ZnCl2 (absolute refractive index of 1.68), and BaTiO3 (absolute refractive index of 2.41) are each produced as refractive index regulators. The absolute refractive indices of the respective refractive index regulators are the same as shown in Table 1 below. ZrO2 as a refractive index regulator has D 50 in a range of 22 to 32 nm and D 90in a range of 60 nm or less in all cases. Furthermore, ZrO2 was a material used that fulfills the condition that the difference between D 10 and D 90 within 1.5 times D 50 lies. Production of plastic intermediate films

[0105] A mixture with the same composition as in Table 1 was fed as the first layer into a twin-screw extruder a for extrusion. A composition corresponding to the examples listed below was fed as the second layer, or as a sound-dampening layer, into a twin-screw extruder b. This mixture was divided into three layers with the structure a / b / a by a feed block and stretched through a T-nozzle to form a film shape, thus producing a plastic intermediate film pattern. During this process, the temperature of a die lip cooler was set the same for all samples except Example 4. Example 4 was produced to achieve a higher surface roughness value by adjusting the temperature of a die lip cooler. The plastic intermediate films were produced with a total thickness of 780 µm. [Table 1] Production example Composition of the first layer (parts by weight) Refractive index of the first layer Composition of the second layer / sound insulation layer (parts by weight) Refractive index of the second layer / sound insulation layer PVB_A resin 3G8 as a plasticizer Additive for the first layer PVB_B resin 3G8 as a plasticizer Type of refractive index regulator Added quantity (weight percentage) 1 72,58 27 0,45 1,4842 63 37 - - 1,4766 2 72,58 27 0,45 1,4842 70 30 - - 1,4802 3 72,58 27 0,45 1,4842 62,4 37 ZrO2 0,6 1,4809 4 72,58 27 0,45 1,4842 62,4 37 ZrO2 0,6 1,4809 5 72,58 27 0,45 1,4842 61,93 37 ZrO2 1,07 1,4842 6 72,58 27 0,45 1,4842 61,9 37 ZrO2 0,1 1,4773 7 72,58 27 0,45 1,4842 60,7 37 ZnCl2 2,3 1,4808 8 72,58 27 0,45 1,4842 62,5 37 BaTiO3 0,5 1,4811 Evaluation of properties (1) Evaluation of surface roughness

[0106] A first layer of a section of a three-layer plastic interlayer film was peeled off by hand and stored in an oven at 50°C and 20% relative humidity for one week to shrink naturally. Subsequently, the BRUKER Kontur GT-X, a non-contact optical microscope, was used to measure the Sz value among the surface roughness values. (2) Evaluation of optical distortion (preparation and evaluation of the sample for the distortion test)

[0107] The manufactured interlayer sheets were each cut to a size of 10 cm in length and width, inserted between two sheets of clear glass (10 cm long, 10 cm wide and 2.1 mm thick), and vacuum laminated for 30 seconds in a laminator at 110 °C and 1 atmosphere pressure to pre-press the laminated glass. The pre-pressed laminated glass was then pressurized for 20 minutes in an autoclave at a temperature of 140 °C and a pressure of 1.2 MPa, resulting in laminated glass.

[0108] The sample was placed at a distance of 10 cm from a wall, then illuminated with an LED lamp at an angle of 20 degrees and a distance of 30 cm, and it was checked whether an optical distortion could be observed due to a shadow on the wall. (3) Measurement methods for sound insulation performance (L / F)

[0109] The individual interlayer films were cut to a size of 30 cm in length and 2.5 cm in width, placed between two sheets of clear glass (30 cm in length, 2.5 cm in width, and 2.1 mm thick), and vacuum laminated for 30 seconds in a laminator at 110 °C and 1 atmosphere pressure to pre-press the laminated glass. The pre-pressed laminated glass was then pressurized for 20 minutes at a temperature of 140 °C and a pressure of 1.2 MPa in an autoclave, resulting in a laminated glass sample for measuring sound insulation performance.

[0110] The laminated glass samples were stored for two weeks in a chamber with a constant temperature and humidity of 20 °C and 20 RH% (relative humidity %) for stabilization, and their sound insulation performance was then measured.

[0111] The sound insulation performance was measured as follows.

[0112] For the DAMP test, vibration was applied to the laminated glass using a vibration generator, the resulting vibration characteristic was amplified with a mechanical impedance measuring device, and the vibration spectrum was analyzed with an FFT spectrum analyzer in order to calculate the L / F values ​​(loss factor) using a 1dB method.

[0113] If the sound insulation was 0.34 or higher, it was rated as "pass," and if the sound insulation was less than 0.34, it was rated as "fail." The results are shown in Table 2 below. (4) Methods for measuring the refractive index of films

[0114] The refractive indices of the manufactured films were measured using a prism coupler (model 2010M) from METRICON (USA) in offset mode. All measurements were taken using the relative refractive index at 24 °C and a wavelength of 532 nm and are listed in Table 1 above. (5) Measurement of turbidity and YI

[0115] The turbidity was measured using the NDH 5000W model available from NIPPON DENSHOKU in accordance with the JIS K 7105 standard.

[0116] YI was measured in accordance with ASTM E313. Specifically, a sample was prepared by laminating a laminated release-sheet-release-release structure (silicone-coated PET) in a laminator at 150 °C for 15 minutes by heating and pressurizing. The sample was then measured at 400 to 800 nm using a meter available from HUNTERLAB after the release sheets had been removed. A YI of 3.0 or less was considered a pass, and a YI greater than 3.0 was considered a fail, with the results shown in Table 2 below. (6) Assessment of long-term durability

[0117] For each example, three identical samples were produced by a process for manufacturing laminated glass in which an intermediate film is inserted between two glass panes measuring 6 * 15 cm and 2.1 T (T = mm), pre-laminated and then laminated.

[0118] The manufactured sample was tested using the EMMAQUA test, which is a stress test under harsh conditions in Arizona.

[0119] The test standard was ASTM G90 Cycle 3, and the following two values ​​were measured after a total exposure of 500 K Langley (Night Time Wetting). dY.I.(difference of YI)=YI after EMMAQUA−test−YI before EMMAQUA−test dH (difference in turbidity) = Hz after the EMMAQUA test - Hz before the EMMAQUA test

[0120] The dY.I. and dH were measured on three or more samples each, and the average value was used. Additionally, a value resulting from the multiplication of dY.I. and dH was assessed as long-term stability (YH) and is shown in Table 2. Table 2] Production example Difference in refractive index* The result of the assessment Long-term durability EMMAQUA* Sz (µm) distortion A (µm)* Sound insulation performance Turbidity (%) YI Result of the examination YH 1 0,0077 12 Failed 52,17 Passed 1,04 Passed unavailable - 2 0,0007 12 Passed 12,90 Failed 1,00 Passed unavailable - 3 0,0034 12 Passed 18,18 Passed 1,15 Passed Passed 0.25 4 0,0034 25 Failed 37,88 Passed 1,13 Passed Passed 0.24 5 0 12 Passed 12,00 Passed 2 Failed Passed 0.36 6 0,0069 12 Failed 38,71 Passed 1,04 Passed Passed 0.16 7 0,0034 12 Passed 18,18 Passed 6,8 Failed Failed 1.52 8 0,0031 12 Passed 17,39 Passed 4,4 Failed unavailable - * The refractive index difference is a value that results from subtracting the refractive index of a second layer or sound-insulating layer from the refractive index of a first layer. * A is an optical distortion index and a value calculated according to equation 2. A=Sz / Rsc

[0121] In equation 2, Sz is the surface roughness (µm) of a surface of a sound-insulating layer, and Rsc is a value according to equation 1 or equation 1-1. Rsc=1−(refractive index of the first layer−refractive index of the sound-insulating layer)*100 Rsc=1−(refractive index of the first layer−refractive index of the second layer)*100 * YH is dY.I. * dH, and the corresponding values ​​were determined by the following equations. dY.I.(difference of YI)=YI after EMMAQUA−test−YI before EMMAQUA−test dH (difference in turbidity) = Hz after the EMMAQUA test - Hz before the EMMAQUA test

[0122] Referring to the compositions and the results of the property measurements of Production Example 1 and Production Example 2, it was observed that when the amount of a plasticizer in a second layer or a sound-absorbing layer was increased to achieve a sound-absorbing effect, an optical distortion phenomenon occurred that depended on the surface roughness. This was assumed to be due to a difference in the surface roughness and the refractive index of a second layer (or sound-absorbing layer) surface, and it was also identified as a value that was evaluated by the optical distortion test index.

[0123] Sound insulation was rated higher in all cases when a sufficient amount of plasticizer was applied. However, turbidity and yellow index (YI), as optical properties, yielded varying results depending on the type and amount of refractive index regulator used. In particular, high turbidity was observed with ZnCl₂ and BaTiO₃, indicating the need for improvement through a method to increase compatibility with a plasticizer, such as the use of a dispersant.

[0124] As found in manufacturing examples 3 to 6, the result of the long-term stability assessment, taking into account the turbidity and the yellow index, was confirmed to show that the manufacturing examples using zirconium dioxide as a refractive index regulator achieved comparatively good results. DESCRIPTION OF REFERENCE MARKS 100 plastic interlayer sheets and interlayer sheets 250 refractive index regulators 800 laminate 840 Second translucent layer 200 sound-insulating layer and second layer 300 and 320 First shift 820 First translucent layer 900 vehicles

Claims

[1] A plastic intermediate film comprising (100): a sound-insulating layer (200), wherein the sound-insulating layer (200) comprises a polyvinyl acetal resin, a plasticizer and a refractive index regulator (250), wherein the refractive index regulator (250) consists of particles with an average diameter (D 50 ) of 100 nm or less and has an absolute refractive index of 2.0 or more, wherein the refractive index regulator (250) is contained in an amount of more than 0 wt.% and 1 wt.% or less, based on the total sound-insulating layer and the plasticizer is contained in an amount of 33 to 41 wt.%, based on the total sound-insulating layer, the plastic intermediate film (100) further comprising a first layer (300, 320, 820) arranged on a surface of the sound-insulating layer (200), wherein the plastic intermediate film (100) has an Rsc value of 0 to 1 according to equation 1 below: Rsc=1−(refractive index of the first layer−refractive index of the sound-insulating layer)*100. [2] The plastic intermediate film (100) according to claim 1, wherein a surface of the sound-insulating layer (200) has an Sz value of 20 µm or less as surface roughness. [3] Plastic interlayer film (100) according to claim 2 having an optical distortion index (A) of 30 µm or less, expressed by the following equation 2: A=Sz / Rsc In equation 2, Sz is the surface roughness (µm) of a surface of a sound-absorbing layer (200), and Rsc is a value according to equation 1. [4] The plastic intermediate film (100) according to claim 1, which has a turbidity value of 3% or less. [5] The plastic interlayer film (100) according to claim 1, which has an L / F (loss factor) of 0.34 or more. [6] Plastic interlayer film (100) according to claim 1 having a long-term durability (YH) value of 1.2 or less according to equation 3 below: YH=dY.I.*dH In equation 3, YH is a value for assessing long-term stability, dY.I. is a value obtained by subtracting a yellow index value before an EMMAQUA test, in which an irradiation energy of 500 K Langley is applied, from a yellow index value after passing the above test, and dH is a value obtained by subtracting a turbidity value before an EMMAQUA test, in which an irradiation energy of 500 K Langley is applied, from a turbidity value after passing the above test. [7] Plastic interlayer film (100) according to claim 1 having a value of 3.5 or less, obtained by subtracting a yellow index value before an EMMAQUA test in which an exposure energy of 500 K Langley is applied from a yellow index value after passing the above test. [8] A laminate (800, 840), comprising: a first translucent layer; a plastic intermediate film (100) arranged on the first translucent layer; and a second translucent layer arranged on the plastic intermediate film (100), wherein the plastic intermediate film (100) contains a sound-insulating layer (200), wherein the sound-insulating layer (200) comprises a polyvinyl acetal resin, a plasticizer and a refractive index regulator (250), wherein the refractive index regulator (250) consists of particles with an average diameter (D 50) of 100 nm or less and has an absolute refractive index of 2.0 or more, wherein the refractive index regulator (250) is contained in an amount of more than 0 wt.% and 1 wt.% or less, based on the total sound-insulating layer and the plasticizer is contained in an amount of 33 to 41 wt.%, based on the total sound-insulating layer, the plastic intermediate film (100) further comprising a first layer (300, 320, 820) arranged on a surface of the sound-insulating layer (200), wherein the plastic intermediate film (100) has an Rsc value of 0 to 1 according to equation 1 below: Rsc=1−(refractive index of the first layer−refractive index of the sound-insulating layer)*100.

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