KR101354439B1 - Multilayer polyvinyl acetal film having improved sound insulation and preparation method thereof - Google Patents

Abstract

The first resin layer and the second resin layer has a structure alternately stacked, at least one of the resin layer of the first resin layer and the second resin layer comprises a polyvinyl acetal resin, the first resin layer and the second resin The multilayer polyvinyl acetal film having a refractive index difference of 0.08 or less between layers is used as a bonding film for glass of automobiles, buildings, etc., because the sound insulation, water resistance, penetration resistance, and impact resistance are excellently maintained even in a high temperature and high humidity environment. Excellent performance can be exhibited.

Description

Multilayer polyvinyl acetal film excellent in sound insulation and its manufacturing method {MULTILAYER POLYVINYL ACETAL FILM HAVING IMPROVED SOUND INSULATION AND PREPARATION METHOD THEREOF}

The present invention relates to a multilayer polyvinyl acetal film useful as a bonding film for glass used in automobiles, buildings and the like.

Plasticized polyvinyl acetals (particularly polyvinylbutyral) are commonly used in the production of polymer sheets for use as interlayers in light transmitting laminates such as laminated glass (safety glass) or polymer laminates. Laminated glass typically refers to a transparent laminate comprising a polyvinylbutyral sheet sandwiched between two sheets of glass. Laminated glass is mainly used to provide transparent barriers in buildings and automotive openings. Its main function is to minimize the damage or injury to an object or person in the transparent barrier by absorbing energy, such as caused by a blow from the object, without allowing penetration through the opening. Additives for sheet manufacture generally include adhesion modifiers to improve the adhesion of the sheet to the glass, as a result of which an appropriate level of adhesion can be maintained and adequate energy absorption to impact while preventing glass from breaking. To provide. In addition, the interlayer sheet can be improved to impart additional beneficial effects of laminated glass, such as attenuating acoustic noise, reducing UV and / or IR light transmission, or improving the aesthetics of the window opening.

In particular, as a film used for glass of automobiles, buildings, and the like, a film having improved sound insulation function has been developed.

Japanese Laid-Open Patent Publication No. 2007-331964 (Application 2006-164071) is an interlayer film for laminated glass having a protective layer laminated on both surfaces of a soundproof layer containing polyvinyl butyral and a plasticizer. It is disclosed that the butyral degree of butyral is higher than that of the protective layer, and there is little whitening phenomenon even when wet with water, and excellent soundproofing property is achieved.

In addition, Japanese Patent Application Laid-Open No. 08-109048 (Application No. 1994-245102) is an interlayer film for laminated glass made of a resin film having a glass transition temperature of 15 ° C. or less, which is excellent in sound insulation and excellent in blocking resistance during manufacture and transportation. It is starting.

However, these conventional films have a problem in that sound insulation is degraded due to delamination between layers in a high temperature and high humidity environment, and water resistance, penetration resistance, impact resistance, and the like are inferior.

Accordingly, there is a demand for the development of a new polyvinyl acetal film with improved sound insulation and impact resistance than the prior art.

Japanese Laid-Open Patent Publication No. 2007-331964 Japanese Patent Application Laid-Open No. 08-109048

Accordingly, an object of the present invention is to provide a multilayer polyvinyl acetal film excellent in sound insulation, penetration resistance, and the like even in various external environments.

According to the above object, the present invention has a structure in which the first resin layer and the second resin layer are alternately laminated, and the first resin layer and the second resin layer are each independently a polyvinyl acetal resin and a polymethyl methacrylate resin. And a resin selected from blends thereof, wherein at least one resin layer of the first resin layer and the second resin layer includes a polyvinyl acetal resin, and a difference in refractive index between the first resin layer and the second resin layer. A multilayer polyvinyl acetal film having a value of 0.08 or less.

Moreover, this invention provides the laminated glass bonded by the said multilayer polyvinyl acetal film.

As described above, the multilayer polyvinyl acetal film of the present invention is excellent in sound insulation, water resistance, penetration resistance, impact resistance, etc., even in a high temperature and high humidity environment, and thus is used as a bonding film for glass of automobiles and buildings. Performance can be exhibited.

The multilayer polyvinyl acetal film of the present invention has a structure in which the first resin layer and the second resin layer are alternately laminated.

The difference in refractive index between the first resin layer and the second resin layer should be 0.08 or less. If the difference in refractive index is more than 0.08, light scattering of the external light source is amplified when the glass is bonded with the glass to cause optical distortion. This may result in delamination. More preferably, the difference in refractive index between the first resin layer and the second resin layer is 0 to 0.05.

In the multilayer film of the present invention, the resins contained in the first resin layer and the second resin layer are each independently selected from polyvinyl acetal resin, polymethyl methacrylate resin, and blend resins thereof, and In the multilayer film, at least one resin layer of the first resin layer and the second resin layer contains polyvinyl acetal resin. Preferably, the combination of the first resin layer and the second resin layer (polyvinyl acetal resin layer / polymethyl methacrylate resin layer) or (polyvinyl acetal resin layer / polyvinyl acetal resin layer) has a small refractive index difference. Can improve optical ablity or adhesion between layers desirable

In this case, the polyvinyl acetal resin may be a polyvinyl butyral resin, a polyvinyl formal resin, a glutaraldehyde-crosslinked polyvinyl butyral resin, or a blend resin thereof. It is most preferable because it has a small difference in refractive index with glass and excellent bonding strength with glass, and a weight average molecular weight of 50,000 to 250,000 is preferable because of excellent melt flow, mechanical strength, impact resistance, and penetration resistance.

In addition, the use of the polymethyl methacrylate resin in the multilayer film of the present invention is preferable because of the difference in refractive index with the polyvinyl acetal resin because it can improve the optical appearance when manufacturing in a multi-layer, polymethyl methacrylate resin A weight average molecular weight of 5,000 to 250,000 is preferred because it can reduce the difference in viscosity during multi-layer extrusion to improve melt flowability and excellent mechanical strength and impact resistance.

These resins are contained in 30 to 90% by weight, more preferably 50 to 75% by weight based on the weight of each resin layer is good in impact resistance, mechanical properties, heat resistance when bonding with glass.

At least one resin layer comprising a polyvinyl acetal resin in the first resin layer and the second resin layer is triethylene glycol bis 2-ethylhexanoate (3G8), tetraethylene glycol diheptanoate (4G7), tri Ethylene glycol bis 2-ethylbutyrate (3GH), triethylene glycol bis 2-heptanoate (3G7), dibutoxyethoxyethyl adipate (DBEA), dibutyl sebacate (DBS), bis 2-hexyl adipate ( DHA), and mixtures thereof. Such plasticizer is preferably contained in each resin layer at 9 to 69% by weight, more preferably 24.5 to 49.5% by weight, based on the weight of each resin layer, in view of heat resistance, mechanical properties, impact resistance and water resistance of the film.

In addition, at least one resin layer including a polyvinyl acetal resin among the first resin layer and the second resin layer may contain an additive selected from an antioxidant, a UV stabilizer, a UV absorber, a glass adhesion modifier, and a mixture thereof. Can be.

Specifically, as the antioxidant, Irganox, butylhydroxytoluene (BHT) and the like of Basf may be used; As the UV stabilizer, Tinuvin or the like of Basf may be used; As the UV absorber, Chemisorb 12, Chemisorb 79, Chemisorb 74, Chemisorb 102, Tinuvin 328, Tinuvin 329, Tinuvin 326, etc., manufactured by Chemiproplasty, can be used; As the glass adhesion modifier, Mg, K, Na, epoxy-modified Si oil, or a mixture thereof may be used.

Such additives are preferably contained in an amount of 0.01 to 1.0% by weight, more preferably 0.2 to 0.5% by weight based on the weight of the resin layer in view of thermal safety, light resistance, and glass bonding strength.

In the multilayer film of the present invention, it is preferable that the total number of laminated layers is 5 to 500 layers, but if the total number of laminated layers is less than 5 layers, the thickness of the individual layers must be too thick, so that the delamination is likely to occur in a high temperature and high humidity environment. If the number is more than 500 layers, the thickness of the individual layers must be made too thin, so that the film may collapse when the film is formed, and the penetration resistance is poor. More preferably, the total lamination number of the multilayer film is 10 to 250 layers.

In the multilayer film of the present invention, the thickness of the individual layer of the first resin layer or the second resin layer is preferably from 0.01 to 100 ㎛, if less than 0.01 ㎛ may collapse the layer during film forming and the penetration resistance may be inferior If the thickness is greater than 100 μm, the interlayer may be too thick to easily exfoliate under high temperature and high humidity.

Multilayer polyvinyl acetal film of the present invention is preferably a total thickness of 0.2 to 2.0 mm, there is an advantage in the impact resistance and penetration resistance within the above range.

It is preferable that both of the surface roughness Rz of the film of this invention are 20 micrometers or more, for example, it may be 20-70 micrometers. When the surface roughness is in the above range, a blocking phenomenon may occur when the film is loaded during the process, and deairing may be more effectively performed during the glass bonding process.

Such multilayer polyvinyl acetal film of the present invention,

(a) preparing a first resin and a second resin having a refractive index difference of 0.08 or less from the first resin; And

(b) the first resin and the second resin may be manufactured by a method including melting and extruding each of the first and second resins, alternately laminating and cooling to obtain a multilayer film.

In the manufacturing method, the first resin and the second resin each independently include a resin selected from polyvinyl acetal resin, polymethyl methacrylate resin, and blends thereof, wherein the first resin and the second resin At least one of the resins includes a polyvinyl acetal resin.

In addition, at least one resin including the polyvinyl acetal resin among the first resin and the second resin may further include a plasticizer and an additive.

At this time, the first resin, the second resin, the plasticizer, the additives, etc. may be mixed in each component and content range to have the composition of the film of the present invention described above.

Said step (b) after the surface pattern treatment on both sides of the film may further include the step of making the surface roughness (Rz) of both sides to 20㎛ or more, such a surface pattern treatment process, for example Rz 20㎛ It can be carried out through the process of heating and surface compression using the surface-treated matte roll, in this case it can be improved blocking resistance and degassing.

Multi-layer polyvinyl acetal film of the present invention as described above, by minimizing the difference in refractive index between adjacent resin layers to suppress light scattering to the external light source can also suppress the delamination due to the optical distortion (distortion) It is also excellent in durability against high temperature and humidity external environment can be prevented from lowering the glass adhesion force due to the delamination, it is possible to maintain excellent sound insulation, water resistance, penetration resistance, impact resistance and the like. The sound insulation performance of the film of the present invention is excellent in sound insulation performance by reducing the coincidence effect that the sound insulation performance is deteriorated in the high frequency range, especially around 2000 Hz.

Preferably, as an acoustic transmission loss (TL) evaluation for the film of the present invention, a 2.1T glass-multilayer polyvinyl acetal film-2.1T glass laminate was prepared, and the acoustic transmission loss at the time of 2000 Hz acoustic loss test was 30 dB. It is preferable to exceed. When in the above range there is an advantage that can sufficiently block the noise, such as engine or wind noise.

In addition, when a 2.1T glass-multilayer polyvinyl acetal film-2.1T glass laminate was manufactured according to the penetration resistance test procedure of laminated glass according to KS L 2007, and the steel balls dropped 2.26 kg, It can have a penetration resistance of more than 4m. Within the above range there is an excellent advantage in terms of shock absorption, glass protection, safety.

In addition, when dropping 1.20 kg of steel balls onto a 4T glass-multilayer polyvinyl acetal film-4T glass laminate according to the falling ball impact test procedure of laminated glass according to KS L 2004, the impacted laminate was broken and the glass was scattered. Since it may not open, there are advantages of glass scattering prevention, shock absorption, and safety.

In addition, as evaluation of the pummel bonding strength, the amount of glass remaining in the film after producing a 2.1T glass-multilayer polyvinyl acetal film-2.1T glass laminate and cooling it to -18 ° C and successively hammering it was 30 to 80. If it is less than 30%, the bonding strength between the glass and the film is poor, and if it is more than 90%, the bonding strength is too high and the film may be torn, which is undesirable.

In addition, after immersing the 2.1T glass-multilayer polyvinyl acetal film-2.1T glass laminate in water at 100 ° C. for 6 hours as an evaluation of the whitening distance, the whitening distance measured from the edge portion of the laminate may be less than 7 mm. When in the above range is excellent in water resistance, there is an advantage in excellent long-term durability.

In addition, the adhesion between the glass and the film in the laminate of (glass-multi-layer polyvinyl acetal film-backsheet) is very small, the difference between the initial adhesion and the adhesion after boiling in water at 100 ° C. for 6 hours. The probability can be lowered.

In addition, the film of the present invention may exhibit an elastic modulus based on ASTM D882 less than 3.0 kgf / mm 2. Flexibility of the film is exhibited when in the above range, there is an advantage of excellent shock absorption and sound insulation performance.

In addition, the film of the present invention may exhibit a light transmittance of greater than 90% for a wavelength of 550 nm light. When in the above range there is an advantage that the visibility is secured.

Accordingly, the film of the present invention can exhibit excellent performance when used as a bonding film for glass, in particular a bonding film for automotive or building glass.

The present invention thus provides a laminated glass bonded by the multilayer polyvinyl acetal film. The laminated glass according to the present invention may have a laminated structure of glass-multilayer polyvinyl acetal film-glass, and the thickness range of the glass used is preferably 1.0 to 5.0 T.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are illustrative of the present invention, and the present invention is not limited to the following examples.

The components used in the following examples and comparative examples are as follows:

-Polyvinyl butyral (PVB) resin: 70 mol% butylation degree, number average molecular weight 140,000, Tg 72 ℃, GH, Xingwei China

- triethylene glycol bis 2-ethylene hexanoate: purity not less than 97.0%, WVC3800, Celanese, Germany

-Chemisorb 12: Benzophenone series, Chemipro Chemicals, Japan

-Chemisorb 79: Benzotriazole series, Chemiprosseong Co., Japan

Irganox: hindered phenolic, Basf, Germany

Butylhydroxytoluene (BHT): Lanxess, Vulkanox, Germany

Mg, K, and Na: Mg acetate, K acetate, Na acetate, OCI Corporation, Korea

-Epoxy modified Si oil: KCC Silicone, Korea

Example 1

71.78 wt% of polyvinyl butyral (PVB) resin, 28 wt% of triethylene glycol bis 2-ethylenehexanoate as plasticizer, 0.1 wt% of Chemisorb 79 as UV absorber, Irganox as antioxidant based on 100 wt% of the first resin composition 0.1 wt% and 0.02 wt% of Mg + K + Na as a glass adhesion modifier were mixed to prepare a first resin composition having a refractive index of 1.480.

64.7 weight% of polyvinyl butyral (PVB) resin, 35 weight% of triethylene glycol bis 2-ethylenehexanoate as a plasticizer, 0.2 weight% of Chemisorb 79 as a UV absorber, Irganox as antioxidant based on 100 weight% of the second resin composition 0.1% by weight and 0.005% by weight of Mg + K + Na as a glass adhesion modifier were mixed to prepare a second resin composition having a refractive index of 1.475.

The first resin composition and the second resin composition were melt extruded through respective extruders at melt temperatures of 165 ° C. and 150 ° C., respectively, alternately laminated using a multilayer feed block device, and cooled in a casting roll at 20 ° C. for 30 layers. A multilayer film of was obtained. At this time, the thickness of the second resin layer was adjusted to be 20 μm.

The multilayer film cooled by the casting roll was heat-compressed at a temperature of 100 ° C. in a matrol having a Rz 80 μm roughness, thereby finally completing a multilayer film having a surface roughness of Rz 40 μm and a total thickness of 0.76 mm.

Examples 2 and 3 and Comparative Examples 1 and 2

As the first resin composition and the second resin composition, a resin composition having a composition and a refractive index as shown in Table 1 below was used, except that the structure of the multilayer film was configured as shown in Table 1 below, and was the same as in Example 1. The procedure was followed to produce a multilayer film. Especially in the case of the comparative example 2, it did not comprise a 2nd resin layer, but consisted of a single resin layer.

Test Example

The physical properties of the polyvinyl acetal films prepared in Examples and Comparative Examples were evaluated as follows, and the results are shown in Table 1 below.

* Sound transmission loss evaluation

A laminated structure of 2.1T glass-multilayer film-2.1T glass of 600mm x 600mm was laminated in laminator at 150 ℃ for 15 minutes by heating and pressing to make a specimen, and the specimen was excited by the vibration generator for dumping test. By amplifying the obtained vibration characteristics into a mechanical impedance amplifier and analyzing the vibration spectrum by an FFT spectrum analyzer, graphing the relationship between the obtained loss coefficient and the resonance frequency and the frequency and the acoustic transmission loss, the acoustic transmission loss near the frequency of 2000 Hz was obtained. (TL, transmission loss, unit dB) was obtained.

* Elastic modulus evaluation

The elastic modulus of the polyvinyl acetal film was measured according to ASTM D882. Specifically, the specimens were prepared by cutting the film into a width of 15 mm and a length of 100 mm, mounted on a universal testing machine (UTM, Instron, Model No. 4206-001) so as to have a spacing of 50 mm between chucks, and measured at a tensile speed of 200 mm / min. .

* Glass adhesion evaluation (comparison before and after immersion in water)

Laminated structure of glass-multi-layer film-back sheet (PVDF / PET) was laminated by laminating at 150 ℃ temperature for 15 minutes in a laminator to make a specimen, and using a universal testing machine (UTM, QM100, Cumsys) The force applied when the film was dropped from the glass was measured by pulling 180 degrees at a tensile speed of 50 mm / min. Further, after the prepared specimen was boiled in water at 100 ° C. for 6 hours, the glass adhesive force was measured in the same manner with respect to the specimen, and the change in the glass adhesive force of the specimen before and after immersion in water was evaluated.

* Light transmittance evaluation

In order to evaluate the transmittance of sunlight in the visible region, the transmittance of the light at 550 nm was measured.

* Drop height

Based on KS L 2007, the penetration resistance of the glass by which the polyvinyl acetal film was laminated was evaluated. Specifically, the laminated structure of 2.1T glass-multilayer film-2.1T glass of 300mm x 300mm was laminated in a laminator at 150 ° C. for 15 minutes by heating and pressing to prepare a specimen, and then dropped 2.26kg steel balls onto the specimen. The height (MBH) through which the specimen penetrated was measured.

Glass evaluation

Based on KS L 2004, the presence or absence of the glass which the polyvinyl acetal film was laminated was evaluated. Specifically, after laminating the laminated structure of 4T glass-multilayer film-4T glass of 610mm x 610mm by heating and pressing at 150 ° C. for 15 minutes in a laminator, the specimen was fabricated, and then raised the steel ball of 1.20kg. After falling, the shocked specimen was broken and the glass was scattered or opened.

* Fummel Bonding Force Evaluation

The adhesive force between the polyvinyl acetal film and the glass was evaluated through the evaluation of the pummel bonding force. Specifically, the laminated structure of 2.1T glass-multilayer film-2.1T glass of 300mm x 300mm was bonded to the laminator at 150 ° C. for 15 minutes by heating and pressing to prepare a specimen, and the specimen was cooled to -18 ° C. After successive hits with a hammer, measure the amount of glass remaining on the film, and set it as 0 when there is no glass remaining on the film and 10 when all the glass remains on the film. Priced up to ten.

(The numbers in parentheses in the table above represent the weight percentage of each component.)

As shown in Table 1, the multi-layered polyvinyl acetal film of the embodiment according to the present invention has excellent performance compared to the polyvinyl acetal film of the comparative example according to the prior art in terms of sound insulation, penetration resistance, glass bonding force, water resistance, transparency, etc. Exerted.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, It is to be understood that the invention may be practiced within the scope of the appended claims.

Claims (10)

Has a structure in which the first resin layer and the second resin layer are alternately stacked,
The first resin layer comprises a polyvinyl acetal resin, the second resin layer comprises a polymethyl methacrylate resin,
A multilayer poly having a difference in refractive index between the first resin layer and the second resin layer of 0.08 or less, an individual layer thickness of the first resin layer and the second resin layer of 0.01 to 100 μm, and a total stacking number of 5 to 500 layers Vinyl acetal film.
The method of claim 1,
The refractive index difference between the first resin layer and the second resin layer is 0 to 0.05, characterized in that the multilayer polyvinyl acetal film.
delete delete The method of claim 1,
The polyvinyl acetal resin is a polyvinyl butyral resin, polyvinyl formal resin, glutaraldehyde-crosslinked polyvinyl butyral resin, or a blend resin thereof, multilayer polyvinyl acetal film.
The method of claim 1,
The surface roughness Rz of both surfaces of the said multilayer polyvinyl acetal film is 20 micrometers or more, The multilayer polyvinyl acetal film characterized by the above-mentioned.
The method of claim 1,
The first resin layer is triethylene glycol bis 2-ethylhexanoate (3G8), tetraethylene glycol diheptanoate (4G7), triethylene glycol bis 2-ethylbutyrate (3GH), triethylene glycol bis 2-hep 9 to 69 wt% of a plasticizer selected from tanoate (3G7), dibutoxyethoxyethyl adipate (DBEA), dibutyl sebacate (DBS), bis 2-hexyl adipate (DHA), and mixtures thereof It contains, Multilayered polyvinyl acetal film.
The method of claim 1,
The first resin layer is a multilayer polyvinyl acetal film, characterized in that it contains 0.01 to 1% by weight of an additive selected from antioxidants, UV stabilizers, UV absorbers, glass adhesion modifiers and mixtures thereof.
The method of claim 1,
The multi-layer polyvinyl acetal film is a multi-layer polyvinyl acetal, characterized in that the 2.1T glass-multilayer polyvinyl acetal film-2.1T glass laminate was produced, and the acoustic transmission loss at the time of 2000 Hz acoustic transmission loss test was more than 30 dB. film.
The laminated glass bonded by the multilayer polyvinyl acetal film of any one of Claims 1, 2, and 5-9.