JPH08109048A - Intermediate film for safety glass and safety glass - Google Patents

Abstract

PURPOSE: To improve blocking resistance during storage and transportation of a raw material resin without damaging excellent sound insulating characteristics, by blending a resin having such a high glass transition temperature so as to prevent cohesion with a plasticizer to give an intermediate layer for glass. CONSTITUTION: 100 pts.wt. of a resin having >=45 deg.C glass transition temperature is mixed with 30-60 pts.wt. of a plasticizer and optionally a well-known additive and is made into a film having 0.3-1.6mm thickness by an extrusion method to give a resin film having <=15 deg.C glass transition temperature, which is used as an intermediate film for safety glass in production of safety glass. For example, a polyvinyl butyral resin containing 8-30mol% of a vinyl acetate component has about 63 deg.C glass transition temperature and does not show blocking phenomena. A resin film obtained by blending 100 pts.wt. of the resin with 35-60 pts.wt. of a plasticizer has about 10 deg.C glass transition temperature and shows excellent sound insulating characteristics when used for safety glass.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interlayer film for laminated glass having excellent sound insulation and a laminated glass using the same.

[0002]

2. Description of the Related Art Conventionally, laminated glass in which an interlayer film typified by plasticized polyvinyl butyral resin is sandwiched between two transparent glass plates facing each other has been widely used for window glass of automobiles and buildings. in use.

Laminated glass using this type of interlayer film is
It has basic properties required for laminated glass such as good transparency, weather resistance, adhesiveness, and penetration resistance, and glass fragments are difficult to scatter, but it is inferior in sound insulation. Especially the frequency 2000
In the mid-high range near Hz, the amount of sound transmission loss decreases due to the coincidence effect, and the sound insulation decreases.

The coincidence effect means that when a sound wave is incident on the glass, a transverse wave is conducted on the glass surface due to the rigidity and inertia of the glass, the transverse wave and the incident sound resonate, and as a result, the sound is transmitted. This is a phenomenon that occurs.

Recently, the demand for sound insulation has increased,
In particular, laminated glass that exhibits excellent sound insulation in addition to the above-mentioned good basic performance is required for architectural window glass. As such an interlayer film for sound-insulating laminated glass and a laminated glass using the same, a polymer film having a glass transition temperature of 15 ° C. or lower, for example, a vinyl chloride-ethylene-glycidyl methacrylate copolymer film and a plasticized polyvinyl acetal. An intermediate film composed of a laminate with a film (Japanese Patent Laid-Open No. 2-229742) and a glass transition temperature of -20
An intermediate film (Japanese Patent Laid-Open No. 147980/1993) made of a plasticized modified polynorbornene having a temperature of up to 30 ° C. has been proposed.

[0006]

However, in such a conventional interlayer film, since the glass transition temperature is not higher than a predetermined temperature, the glass transition temperature of the polymer material or resin as the raw material is also low. It is shown. Therefore, when the raw material resin is held at high temperature or under high load, for example, in the case of storage in a warehouse or transfer by a truck or the like, the raw material resins are coalesced into a lump, a so-called blocking phenomenon occurs, At the time of film formation of the intermediate film, there was a problem that the raw material could not be supplied to the extruder, or unmelted resin mass was mixed in the formed intermediate film, so-called fisheye phenomenon occurred.

The present invention solves the above problems,
The purpose is that the glass transition temperature does not impair the good sound insulation performance of the resin film having a predetermined temperature or lower,
An object of the present invention is to provide an interlayer film for laminated glass, which has improved blocking resistance during storage and transfer of raw material resins, and a laminated glass using the same.

[0008]

The interlayer film for laminated glass according to claim 1 of the present invention is a resin film having a glass transition temperature of 15 ° C or lower, and the resin film has a glass transition temperature of 45 ° C or higher. And a plasticizer.

The laminated glass according to claim 2 is such that the interlayer film for laminated glass according to claim 1 is sandwiched between glass plates.

As described above, as the resin film in which the glass transition temperature (hereinafter referred to as Tg) of the raw material resin is 45 ° C. or higher and the resin is further plasticized to have Tg of 15 ° C. or lower, for example, a plasticizer and An example of the resin film includes a resin having a very excellent compatibility with and a plasticizer.

Specifically, it is obtained by acetalizing polyvinyl alcohol with butyraldehyde, and is made by adding 35 to 60 parts by weight of a plasticizer to 100 parts by weight of polyvinyl butyral resin containing 8 to 30 mol% of vinyl acetate component. There is a resin film or the like formed from the resin composition.

The polyvinyl butyral resin has a Tg of 6
Despite the high temperature of 3 ° C, the compatibility with the plasticizer is extremely excellent, so that rapid softening progresses when compounded with the plasticizer, and as a result, the Tg of the resin film is lowered to about 10 ° C. To do.

As the resin film used in the present invention, in addition to the above, for example, a resin film comprising a resin having a low Tg and a plasticizer which has been subjected to a modification treatment so as to have improved blocking resistance. To be

Specifically, polyvinyl alcohol is acetalized with an aldehyde having 6 to 10 carbon atoms around a core particle made of a polyvinyl acetal resin,
A plurality of outer shell layers made of a polyvinyl acetal resin obtained by acetalizing polyvinyl alcohol with an aldehyde having 1 to 4 carbon atoms are formed, and the outer shell layers are closer to the surface, the aldehyde having 1 to 4 carbon atoms. There is a resin film formed from a resin composition obtained by mixing 30 to 60 parts by weight of a plasticizer with 100 parts by weight of a resin containing a large amount of the resin component obtained by acetalization.

Although the polyvinyl acetal resin has a Tg of 49 ° C. and excellent blocking resistance by the modification treatment, it has a Tg of low core particles which is emphasized and promoted by blending with a plasticizer, resulting in a resin film. Has a Tg of about 12 ° C.

As the plasticizer used for these resin films, those having excellent compatibility with the resin are used, and examples thereof include fatty acid plasticizers, phthalic acid plasticizers, phosphoric acid plasticizers and the like. Used.

The Tg of the resin film must be 15 ° C. or lower, and a more preferable Tg range is −20 to 15 ° C.
If the Tg of the resin film exceeds 15 ° C, sufficient sound insulation performance cannot be obtained. Further, at a temperature lower than -20 ° C, sufficient sound insulation performance cannot be obtained in a wide temperature range, which is not preferable.

The Tg of the raw material resin must be 45 ° C. or higher, and a more preferable Tg range is 50 ° C. or higher. When the Tg of the raw material resin is lower than 45 ° C., the self-adhesiveness of the resins becomes large, and the resins adhere to each other, causing a so-called blocking phenomenon.

Further, in the resin film, a UV absorber, a light stabilizer, an antioxidant, an adhesiveness adjusting agent, a surfactant, a coloring agent, etc., which are used as an intermediate film for laminated glass, as required, are known. Additives can be added. Further, in forming the resin film, a raw material resin and a plasticizer are mixed and formed into a sheet by a known extrusion method, calender method, pressing method or the like to produce an intermediate film.

The thickness of this resin film is not particularly limited,
It is preferably 0.3 to 1.6 mm, which is the same level as that of a normal interlayer film. The thicker the interlayer film, the better the sound insulation,
The thickness is determined in consideration of the penetration resistance required as a laminated glass, and the above-mentioned thickness range is suitable for practical use.

The resin film used in the present invention has a Tg of 15 ° C. or less as described above,
As long as Tg is composed of a resin having a temperature of 45 ° C. or higher and a plasticizer, other than the above, it is not limited to the above.

To produce a laminated glass using the interlayer film for laminated glass of the present invention, for example, two inorganic glass plates or organic glass plates such as a polycarbonate plate having high rigidity, a polymethylmethacrylate plate, etc. The above-mentioned intermediate film is sandwiched, and this is put in, for example, a rubber bag, and pre-bonded at about 70 to 110 ° C. under vacuum suction,
Then, in the autoclave, the temperature is about 120-150 ° C.
Then, a method of performing main adhesion at a pressure of about 10 to 15 kg / cm ² can be mentioned.

[0023]

The interlayer film for laminated glass according to the present invention has Tg
Is a resin film of 15 ° C. or lower, and the resin film has a Tg of 4
A laminated glass using such an intermediate film is characterized by comprising a resin having a temperature of 5 ° C. or higher and a plasticizer. Due to the peculiar rigidity of the resin film having Tg of 15 ° C. or lower, sound energy is converted into heat energy. Effectively converted and absorbed, especially
In the mid-high range around 2000 Hz, the sound insulation performance is prevented from being deteriorated due to the coincidence effect. Further, the Tg of the raw material resin of the intermediate film is as high as 45 ° C. or higher, so that the self-adhesiveness of the resin is low. As a result, it is possible to prevent the so-called blocking phenomenon, which is a coalescence of the raw material resin during storage and transfer.

[0024]

EXAMPLES Examples and comparative examples of the present invention will be shown below,
The present invention will be described in more detail. The glass transition temperature, sound insulation performance, and blocking resistance were evaluated by the following methods.

(Glass transition temperature) 5 of resin or resin film
cm × 5 cm × 1 mm film was prepared, and the viscoelasticity in a wide temperature range at a frequency of 10 Hz was measured using a viscoelasticity spectrometer, and the ratio G ″ / G of the storage elastic modulus G ′ and the loss elastic modulus G ″ was measured. The temperature at which the loss tangent tan δ, which is ′, has a maximum value is defined as Tg.

(Sound Insulation Performance) A sample was cut out from a laminated glass, and this sample was vibrated by a vibration generator for a damping test (vibration machine “G21-005D” manufactured by Shinken Co., Ltd.), and the vibration obtained from the vibration was obtained. The characteristics are amplified by a mechanical impedance amplifier (“XG-81” manufactured by Rion Co., Ltd.), and the vibration spectrum is analyzed by an FFT analyzer (“FFT spectrum analyzer HP35 manufactured by Yokogawa Hewlett-Packard Co.”).
82A ").

From the ratio of the loss coefficient thus obtained and the resonance frequency of the glass, the sound frequency (Hz) at 20 ° C.
The sound insulation performance of the laminated glass was judged by making a graph showing the relationship between the sound transmission loss (dB) and the minimum sound transmission loss (TL value) near the sound frequency of 2000 Hz.

(Blocking resistance) Resin 25 kg / c
A load of m ² (corresponding to a stack of 5 bags containing 20 kg of resin particles) is applied, and this is applied at 40 ° C. and 50 ° C. for 5 minutes.
The blocking resistance after 00 hours (corresponding to the storage condition in summer) was evaluated.

Example 1 To 2890 g of pure water, 275 g of polyvinyl alcohol having an average degree of polymerization of 1700 and a saponification degree of 87.7 mol% was added and dissolved by heating. The reaction system is 12 ℃
The temperature was adjusted to, 201 g of 35 wt% hydrochloric acid catalyst and 148 g of n-butyraldehyde were added, and the reaction product was precipitated while maintaining this temperature.

After that, the reaction system was kept at 45 ° C. for 3 hours to complete the reaction, washed with excess water to wash off unreacted n-butyraldehyde, neutralize the hydrochloric acid catalyst, washed with water and dried. A white powdery polyvinyl butyral resin was obtained. The Tg of this resin was 70 ° C. As a result of evaluating the blocking resistance, the blocking phenomenon was good at both 40 ° C and 50 ° C.

100 parts by weight of the above resin and triethylene glycol-di-2-ethylbutyrate 40 as a plasticizer
After mixing with 1 part by weight and sufficiently melting and kneading this with a mixing roll, press molding was carried out at 150 ° C. for 30 minutes with a press molding machine to obtain a resin film having a thickness of 0.38 mm. The Tg of this resin film was 13 ° C.

Using the above resin film, it is sandwiched from both sides by transparent float glass (length 30 cm × width 30 cm × thickness 3 mm), placed in a rubber bag, degassed at a vacuum degree of 20 torr for 20 minutes, and then degassed. The mixture was transferred to an oven at 90 ° C. while being kept air, and further vacuum-pressed while holding at 90 ° C. for 30 minutes.

The laminated glass thus pre-bonded in the air type autoclave at a pressure of 12 kg / cm.
² , main bonding was carried out for 20 minutes at a temperature of 135 ° C. to prepare a laminated glass. Moreover, as a result of evaluating the sound insulation performance of the obtained laminated glass, the sound transmission loss (TL value) of the laminated glass was 37 dB, which showed excellent sound insulation.

(Example 2) The procedure of Example 1 was repeated, except that the saponification degree of polyvinyl alcohol was changed from 87.7 mol% to 75.5 mol%. The resin thus obtained had a Tg of 60 ° C. and the resin film had a Tg of 10 ° C. As a result of evaluating the sound insulation performance of the obtained laminated glass, the sound transmission loss (TL value) of the laminated glass was 37.
It showed excellent sound insulation at dB. As a result of evaluating the blocking resistance of this resin, there was no blocking phenomenon at 40 ° C. and 50 ° C., and it was good.

Example 3 Distilled water 286 was placed in a tank reactor.
5g, average degree of polymerization 1700, degree of saponification 98.0 mol%
Put 224 g of polyvinyl alcohol, and add it to 94 ° C.
The polyvinyl alcohol was dissolved with heating to and stirring. This polyvinyl alcohol aqueous solution was cooled to 36 ° C., and 100 g of hydrochloric acid having a concentration of 35% by weight was added as an acid catalyst.
Was added, stirred for 10 minutes, and cooled to 15 ° C. While maintaining this temperature, 96.4 g of n-hexylaldehyde was added dropwise. During this dropping, core particles made of a white resin are deposited. After stirring for 10 minutes as it was, the mixture was slowly cooled to 10 ° C.

Next, 60.9 g of n-butylalaldehyde was added dropwise to the slurry of core particles kept at this temperature and stirred for 30 minutes, and then 100 g of hydrochloric acid having a concentration of 35% by weight was added dropwise as an acid catalyst in 5 minutes. did. 4 while stirring
The temperature was raised to 5 ° C., and the reaction was continued for 3 hours as it was. As a result, an outer shell layer made of a resin acetalized with n-butylalaldehyde is formed on the surface layer portion around the core particles.

Then, it was washed with water and dehydrated, then the dehydrated cake was dispersed in 3000 g of distilled water, and baking soda was added thereto,
The pH was adjusted to 7-8 and neutralized at 45 ° C for 5 hours. Further, it was washed with water, dehydrated, and dried to obtain white granular resin particles. The Tg of the resin particles was 50 ° C. As a result of evaluating the blocking resistance of this resin, 40 ° C, 5
There was no blocking phenomenon at 0 ° C, which was good.

100 parts by weight of the above resin and triethylene glycol-di-2-ethylbutyrate 40 as a plasticizer
After mixing with 1 part by weight and sufficiently melting and kneading this with a mixing roll, press molding was carried out at 150 ° C. for 30 minutes with a press molding machine to obtain a resin film having a thickness of 0.38 mm. The Tg of this resin film was 6 ° C.

Using the above resin film, it was sandwiched with transparent float glass (length 30 cm × width 30 cm × thickness 3 mm) from both sides, placed in a rubber bag, degassed at a vacuum degree of 20 torr for 20 minutes, and then degassed. It was transferred to an air oven at 90 ° C., and vacuum pressed while holding it at 90 ° C. for 30 minutes.

The laminated glass pre-bonded in this manner was placed in an air-type autoclave at a pressure of 12 kg / c.
The main bonding was performed for 20 minutes under the condition of m ² and the temperature of 135 ° C. to manufacture a laminated glass. As a result of evaluating the sound insulation performance of the obtained laminated glass, sound transmission loss (TL value)
Was 38 dB, which showed excellent sound insulation.

Example 4 Example 4 was repeated except that n-hexyl aldehyde was changed to n-octyl aldehyde. The Tg of the obtained resin was 47 ° C. As a result of evaluating the blocking resistance of this resin, there was no blocking phenomenon at both 40 ° C and 50 ° C, and it was good. Further, the Tg of this resin film was 2 ° C., and the sound insulation performance of the obtained laminated glass was evaluated.
The TL value was 38 dB, indicating excellent sound insulation.

Comparative Example 1 The procedure of Example 1 was repeated except that the saponification degree of polyvinyl alcohol was changed from 87.7 mol% to 98.0 mol%. The Tg of the obtained resin was 73 ° C. As a result of evaluating the blocking resistance of this resin, there was no blocking phenomenon at both 40 ° C and 50 ° C, and it was good. However, the T of the resin film
g was 18 ° C. The sound insulation performance of the obtained laminated glass was evaluated. As a result, the TL value was 25 dB, and the sound insulation was insufficient.

(Comparative Example 2) In Example 1, except that the saponification degree of polyvinyl alcohol was changed from 87.7 mol% to 98.0 mol%, and n-butyraldehyde was changed to n-hexylaldehyde. The same procedure as in Example 1 was performed. The Tg of the obtained resin was as low as 42 ° C., and as a result of evaluating the blocking resistance of this resin, a blocking phenomenon occurred at 50 ° C. However, the Tg of the resin film was 5 ° C., and the sound insulation performance of the obtained laminated glass was evaluated. As a result, the TL value was 38 dB, indicating excellent sound insulation.

The results of Examples 1 to 4 and Comparative Examples 1 and 2 described above are summarized in Table 1.

[0045]

[Table 1]

[0046]

As described above, when the Tg of the interlayer film for laminated glass of the present invention is 15 ° C. or lower, sound energy is effectively converted into heat energy and absorbed.
In particular, in the mid-high range near 2000 Hz, deterioration of the sound insulation performance due to the coincidence effect is prevented, and excellent sound insulation performance is exhibited. Moreover, since the Tg of the raw material resin is 45 ° C. or higher, coalescence during storage and transfer, that is, so-called blocking phenomenon is prevented. Therefore, the interlayer film for laminated glass of the present invention and the laminated glass using the same are particularly
It is suitable for building window glass, etc. that requires high sound insulation performance.

Claims (2)

[Claims] 1. An intermediate film for laminated glass, which is a resin film having a glass transition temperature of 15 ° C. or lower, wherein the resin film comprises a resin having a glass transition temperature of 45 ° C. or higher and a plasticizer. 2. A laminated glass comprising the interlayer film for laminated glass according to claim 1 sandwiched between glass plates.