JP3050967B2 - Sound insulating interlayer - Google Patents

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. More specifically, the present invention relates to an interlayer film for laminated glass having excellent sound insulation properties and small optical distortion.

[0002]

2. Description of the Related Art In general, laminated glass in which a resin film is sandwiched between a pair of glass plates is excellent in safety because broken pieces are not scattered at the time of breakage. It is widely used for window glass of buildings and buildings.

[0003] Among such interlayer films for laminated glass,
The resin film of polyvinyl butyral plasticized by the addition of a plasticizer has excellent adhesiveness to glass, strong tensile strength, high transparency, etc. It is suitable as a window glass.

[0004] Generally, sound insulation performance is indicated as a transmission loss according to a change in frequency.
In A4708, as shown by the solid line in FIG.
At a frequency of 0 Hz or more, each is defined as a constant value according to the sound insulation class. By the way, the sound insulation of a glass plate is shown in FIG.
As shown by the broken line therein, in the frequency region centered at 2000 Hz, the noise is significantly reduced due to the coincidence effect (the valley of the broken line in FIG. 1 corresponds to the decrease in the sound insulation performance due to the coincidence effect, and the predetermined sound insulation performance is not maintained. Indicating that). Here, the coincidence effect means that when sound waves enter the glass plate, the rigidity and inertia of the glass plate cause
The transverse wave is conducted on the glass surface, and the transverse wave and the incident sound resonate,
As a result, it refers to the phenomenon that sound transmission occurs.

[0005] The conventional laminated glass is excellent in preventing scattering of fragments, but in terms of sound insulation, it is 2,000 Hz.
In the frequency region centered on, a decrease in sound insulation due to the coincidence effect is inevitable, and an improvement in this respect is required.

[0006] To improve the sound insulation performance of laminated glass,
It is necessary to alleviate the coincidence effect as described above to prevent a reduction in the minimum portion of the transmission loss caused by the coincidence effect (hereinafter, the transmission loss amount of the minimum portion is referred to as a TL value, see FIG. 1).

Conventionally, various measures have been proposed as means for preventing a decrease in the TL value, such as an increase in the mass of a laminated glass and a reduction in the glass area. However, none of these produce a sufficiently satisfactory effect, and the cost is not reasonable for practical use.

[0008] The demand for sound insulation performance has been increasing recently.
For example, there is a growing demand for architectural windowpanes that always exhibit excellent sound insulation performance without being affected by changes in the outside air temperature in each season.

[0009] As a prior art of an interlayer film intended to improve the sound insulation performance of a laminated glass, there are, for example, the following.

Japanese Patent Publication No. 46-5830 describes an interlayer made of a resin having a fluidity about three times higher than that of a normal interlayer, for example, polyvinyl butyral.

Japanese Patent Application Laid-Open No. 60-27630 proposes an intermediate film in which a polyvinyl chloride resin contains a plasticizer as a measure for improving the sound insulation at the initial stage.

Japanese Patent Application Laid-Open No. 51-106190 proposes that a structure having vibration damping properties over a wide temperature range can be obtained by laminating two or more resins having different glass transition temperatures. I have.

[0013]

Among these prior art interlayer films for sound insulating laminated glass, Japanese Patent Publication No. 46-5830.
The sound insulating interlayer described in the above item has a large problem that the absolute value of the sound insulating property of the laminated glass is low.

Although the sound insulating interlayer described in Japanese Patent Application Laid-Open No. 60-27630 has good sound insulating properties, it is necessary to change the processing conditions to those of a polyvinyl butyral-based interlayer in the laminating process. At present, the polyvinyl butyral-based interlayer is still the mainstream of the laminated glass interlayer, and the pre-adhesion conditions in the laminating process are set to the conditions of the polyvinyl butyral-based interlayer.

[0015] In addition, it is recognized that the structure described in JP-A-51-106190 has improved vibration damping properties over a wide temperature range by laminating two or more resins having different glass transition temperatures. . However, requirements such as high impact energy absorption required for safety glass and scattering prevention upon glass breakage have not been satisfied.

[0016] In view of the above, an object of the present invention is to provide, when used as an interlayer film for laminated glass, transparency, weather resistance,
The TL value is increased by relaxing the coincidence effect without impairing the basic performance required for laminated glass such as shock energy absorption and contact with glass, and it has excellent sound insulation performance in a wide temperature range and optical An object of the present invention is to provide an interlayer having a small distortion. Another object of the present invention is to provide an interlayer capable of producing laminated glass with good workability in a laminating process.

[0017]

Means for Solving the Problems The present inventors have found that a resin film composed of polyvinyl acetal and a plasticizer, which is already used as an interlayer film for laminated glass, has transparency, weather resistance, impact energy absorption, and the like. Focusing on the fact that the film has well-balanced properties such as adhesion to glass, the inventors have intensively studied the improvement of the interlayer having the above composition in order to improve the sound insulation without impairing the good characteristics. As a result, by laminating two types of resin layers composed of a specific co-acetalized polyvinyl acetal resin and a plasticizer, the TL value is increased by relaxing the coincidence effect, and excellent sound insulation performance is obtained in a wide temperature range. In addition, the inventors have found that an intermediate film having small optical distortion and good workability in the alignment process can be obtained, and completed the present invention.

That is, the interlayer film for laminated glass according to the present invention comprises a layer (A) having a thickness of 0.05 mm or more comprising a polyvinyl acetal resin and a plasticizer, and a layer (B) comprising a polyvinyl acetal resin and a plasticizer. Layer (B) / Layer (A) / Layer
(B) The polyvinyl acetal resin of the layer (A) is co-acetalized with an aldehyde (a) having 6 to 8 carbon atoms and an aldehyde (b) having 2 to 4 carbon atoms. Aldehyde (a)
The weight ratio of the portion acetalized with aldehyde to the portion acetalized with aldehyde (b) is 60:40 to 100: 0.
In the range, the polyvinyl acetal resin of the layer (B),
Polyvinyl alcohol is an aldehyde having 2 to 4 carbon atoms (b)
And a resin co-acetalized with an aldehyde (a) having 6 to 8 carbon atoms, wherein the weight ratio of the portion acetalized with the aldehyde (b) to the portion acetalized with the aldehyde (a) is 80:20 to 100: 0,
The polyvinyl acetal resin of at least one of the layer (A) and the layer (B) is a co-acetalized resin.

The polyvinyl alcohol which is a raw material of the polyvinyl acetal resin has an average degree of polymerization of 1,000 to 3,
000 is preferred. If the degree of polymerization is less than 1000, the penetration resistance of the laminated glass is inferior, and if it exceeds 3000, the strength is too large and is not usually used as a safety glass. The degree of saponification of polyvinyl alcohol is
Preferably 9 to improve transparency and heat resistance.
5 mol% or more.

In the preparation of the polyvinyl acetal resin, the aldehyde having 6 to 8 carbon atoms includes n-hexylaldehyde, 2-ethylbutyraldehyde, n-heptylaldehyde, n-octylaldehyde, benzaldehyde, phenethylaldehyde and the like. Aromatic or alicyclic aldehydes are used alone or in combination of two or more. If the carbon number of the aldehyde exceeds 8, the laminated system including this resin layer is not preferable because it does not have a broad transmission loss near normal temperature.

On the other hand, the aldehyde (b) having 2 to 4 carbon atoms includes acetaldehyde, propionaldehyde, n-
Butyraldehyde, isolebutyraldehyde, etc. are used alone or in combination of two or more.

In the polyvinyl acetal resin of the layer (A), the weight ratio of the portion acetalized by the aldehyde (a) to the portion acetalized by the aldehyde (b) is 60:40 to 100: 0. Limited to range. If the ratio (a / b) is out of the above range, the obtained laminated glass has a remarkably low sound insulating property and large optical distortion, which is not preferable. A particularly preferred range of the ratio (b / a) is 7
5:25 to 100: 0.

Similarly, in the polyvinyl acetal resin of the layer (B), the weight ratio of the portion acetalized by the aldehyde (b) to the portion acetalized by the aldehyde (a) is 80:20 to 100%. : 0. When this ratio (b / a) is out of the above range,
The resulting laminated glass has an extremely low sound insulating property and a large optical distortion, which is not preferable. A particularly preferred range of the ratio (b / a) is 85:15 to 100: 0.

Aldehydes having 6 to 8 carbon atoms and 2 to 4 carbon atoms
The technical significance of co-acetalization with aldehydes is that the internal friction effect is manifested by the arrangement of the acetal groups at the molecular level where the carbon numbers of the two side chains differ greatly,
This has the advantage that excellent sound insulation properties can be obtained and the difference in refractive index between the layers can be reduced. However, the former internal friction effect, the above-mentioned weight ratio in the polyvinyl acetal resin of the layer (A) (B), that is, the above-mentioned ratio (a
When both (b) and the ratio (b / a) are around 50:50, the high-speed laminar effect as a multilayer system is weakened. Therefore, also from this point, the weight ratios are each limited to the above range.

As a method for preparing polyvinyl acetal, for example, polyvinyl alcohol is dissolved in hot water,
While maintaining the resulting aqueous solution at the required temperature, the required aldehyde and catalyst are added, and the acetalization reaction proceeds,
Then, there is a method in which the reaction temperature is raised and maintained to complete the reaction, followed by neutralization, washing with water and drying to obtain a resin powder.
Here, the degree of acetalization of polyvinyl acetal is 50.
It is preferably at least mol%. Acetalization degree of 50
If the amount is less than 10%, the compatibility with the plasticizer is not good, and it is difficult to add an amount of the plasticizer necessary for securing the penetration resistance.

A conventional polyvinyl acetal resin made of a single aldehyde has a drawback that if the acetalization degree is 60 mol% or less, the compatibility with a plasticizer is poor and it cannot be used. On the other hand, the co-acetalized polyvinyl acetal resin according to the present invention has good compatibility with the plasticizer, so that a polyvinyl acetal resin having a lower degree of acetalization than a polyvinyl acetal resin using a single aldehyde can be tolerated. This is one of the advantages.

As the plasticizer to be mixed with the resin, an organic plasticizer such as a monobasic acid ester or a polybasic acid ester, or a phosphoric acid plasticizer such as an organic phosphoric acid or an organic phosphorous acid is used. .

Among the monobasic acid esters, triethylene glycol and butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptanoic acid, n-octylic acid, 2-ethylhexylic acid, pelargonic acid (n-nonylic acid) And glycol-based esters obtained by reaction with organic acids such as decyl acid. In addition, esters of tetraethylene glycol and tripropylene glycol with the above organic acids are also used.

As the polybasic acid ester, adipic acid,
Esters of organic acids such as sebacic acid and azelaic acid with linear or branched alcohols having 4 to 8 carbon atoms are preferred.

As the phosphoric acid plasticizer, tributoxyethyl phosphate, isodecylphenyl phosphate, triisopropyl phosphite and the like are preferable.

More preferred examples of the monobasic acid ester include triethylene glycol di-2-ethyl butyrate, triethylene glycol di-2-ethylhexoate, triethylene glycol dicapronate, and triethylene glycol. -Di-n-octoate; and dibasic acids include dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate and the like.

The content of the plasticizer is preferably 20 to 60 parts by weight based on 100 parts by weight of polyvinyl acetal. If the content of the plasticizer is less than 20 parts by weight, the penetration resistance is reduced, and if it exceeds 60 parts by weight, the plasticizer bleeds out and the transparency of the laminated glass and the adhesion to the glass plate or the like are reduced. It is because it is damaged. A particularly preferable range of the content of the plasticizer is 3 to 100 parts by weight of polyvinyl acetal.
0 to 55 parts by weight.

The additives usually used for adjusting the adhesive strength between the resin film and the glass plate, a stabilizer for preventing the deterioration of the polyvinyl acetal, an antioxidant, an ultraviolet absorber and the like are used as the polyvinyl acetal. When mixing with and plasticizer, or in the process of producing polyvinyl acetal,
It can be used as needed.

Examples of the additive include metal salts of carboxylic acids, for example, alkali metal salts such as potassium and sodium such as octylic acid, hexylic acid, butyric acid, acetic acid and formic acid; alkaline earth metal salts such as calcium and magnesium; and zinc. , Cobalt salts and the like are used. As a stabilizer, a surfactant,
For example, sodium lauryl sulfate, alkylbenzenesulfonic acid and the like are used. As the antioxidant, tertiary butyl-hydroxytoluene (BHT), “Irganox 1010” manufactured by Ciba Geigy, and the like are used. Examples of ultraviolet absorbers include benzotriazole-based and hindered amine-based ones. In the benzotriazole series, for example, “Tinuvin P”, “Tinuvin 320”, and “Tinuvin 32” manufactured by Ciba Geigy
6 "," Tinuvin 328 "and the like are preferably used. In the hindered amine series, "LA-5" manufactured by Adeka Argus Co., Ltd.
7 "is preferred.

Layers (A) and (B) of the interlayer according to the invention
Is a layer (B) / layer (A) / layer (B). The reason for being limited to this configuration is due to the relative relationship between the glass transition temperatures of layer (A) and layer (B). That is, a laminated structure in which a layer having a high glass transition temperature and a layer having a low glass transition temperature are sandwiched is preferable in order to reduce a change in transmission loss near room temperature due to temperature. This is a finding obtained as a result of a detailed examination of a configuration for stably exhibiting a constrained layer effect in a wider temperature range for two plates having high rigidity such as glass.

Further, another reason why the laminated structure of the present invention is limited to the sandwich type as described above is that the adoption of this laminated structure makes it possible to perform a good work comparable to the case of the polyvinyl butyral-based interlayer in the laminating process. This is because the property can be obtained.

Regarding the thickness of the layers (A) and (B),
(A) requires a thickness of 0.05 mm or more. If the thickness is smaller than this, no good effect of the sound insulation on the temperature is recognized.

Further, the total thickness of the layer (B) does not greatly affect the manifestation of a good effect of sound insulation to temperature, but is preferably 0.2 mm or more. 0.2mm
If it is less than 1, the decrease in penetration resistance is remarkable.

The thickness of the entire film is preferably 0.3 to 1.6 mm, which is the thickness as an ordinary interlayer film for laminated glass.

The greater the thickness, the better the sound insulation. However, in consideration of the penetration resistance required as a laminated glass, the above range is practically preferable.

As a film forming method, there are various forming methods such as a method of forming each film separately and then laminating them between glass plates, a method of integrally forming a plurality of films using a multilayer forming machine, and the like. is there.

In order to manufacture a laminated glass by sandwiching the interlayer film according to the present invention between glass plates, a method used for manufacturing a general laminated glass is employed. For example, a method is used in which a film is sandwiched between glass plates from both sides thereof and laminated glass is manufactured by hot-pressing.

Further, the use of the intermediate film as a rigid body other than glass, for example, a laminated body of a metal or an inorganic material, and used as a laminated rigid body having sound insulation performance is consistent with the gist of the present invention. Excellent sound insulation can be exhibited. Further, sandwiching the intermediate film with a transparent rigid body having high rigidity such as a polycarbonate resin does not depart from the gist of the present invention.

[0044]

EXAMPLES Hereinafter, some examples of the present invention and comparative examples to be compared with the examples will be given, and the sound insulating performance and optical distortion of the obtained laminated glass will be shown.

<Preparation of Membrane (A-1)> i) Preparation of Resin To 2900 g of pure water, 193 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 98.9 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted, and 201 g of 35% hydrochloric acid and n-
200 g of octylaldehyde was added to precipitate polyvinyl acetal. Thereafter, the reaction system was maintained at 30 ° C. for 5 hours to complete the reaction, and neutralized, washed with water and dried to obtain a white resin powder of polyvinyl acetal (acetalization degree: 66.1 mol%).

Ii) Preparation of membrane 50 g of the above polyvinyl octyl acetal was collected, 20 g of triethylene glycol-di-2-ethyl butyrate was added as a plasticizer, and this mixture was sufficiently kneaded with a mixing roll and kneaded. A predetermined amount of the product was kept in a press molding machine at 150 ° C. for 30 minutes. Thus 0.30 thickness
mm (A-1) was prepared.

<Preparation of Membrane (A-2)> In step i), 180 g of n-octyl aldehyde and 22 g of n-butyraldehyde were added as aldehydes to precipitate polyvinyl acetal. A white powder of polyvinyl acetal was obtained in the same manner as in step i) of the preparation of the membrane (A-1) except that the reaction was completed after a certain period of time (acetalization degree: 67.1 mol%). Step ii) was operated in the same manner as in step ii) for preparing the membrane (A-1).

Thus, a film (A-2) having a thickness of 0.30 mm was produced.

<Preparation of Membrane (B-1)> In step i), 190 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 99.2 mol% was added to 2910 g of pure water and heated and dissolved. The temperature of the reaction system was adjusted, and 201 g of 35% hydrochloric acid and 124 g of n-butyraldehyde were added to precipitate polyvinyl acetal. Thereafter, the reaction system was maintained at 50 ° C. for 4 hours to complete the reaction, and a white powder of polyvinyl acetal was obtained. Was obtained (acetalization degree: 66.3 mol%).

Step ii) was operated in the same manner as in step ii) for preparing the membrane (A-1).

Thus, a film (B-1) having a thickness of 0.25 mm was prepared.

<Preparation of Membrane (B-2)> Except that 113 g of n-butyl aldehyde and 25 g of n-hexylaldehyde were used as aldehydes in step i), the same procedure as in step i) of preparing membrane (B-1) was carried out. By operation, a white powder of polyvinyl acetal was obtained (acetalization degree: 67.9 mol%). Step ii) was operated in the same manner as in step ii) of the preparation of the membrane (B-1).

Thus, a film (B-2) having a thickness of 0.25 mm was produced.

<Preparation of Intermediate Film and Preparation of Laminated Glass> The resin film thus prepared was prepared by laminating a layer (B) / layer
In Example 1, layer (B-2) / layer (B) was obtained so that (A) / layer (B).
(A-1) / layer (B-2), and in Example 2, layer (B-1) / layer (A-2) /
Layer (B-1), in Example 3, layer (B-2) / layer (A-2) / layer (B-2)
In Comparative Example 1, layer (B-1) / layer (A-1) / layer (B-1), and in Comparative Example 2, layer (B-1) / layer (A-2) / layer (B-1) In Comparative Example 3, the layers were superposed in the order of layer (B-2) / layer (A-1) / layer (B-2).

This polymer was sandwiched from both sides with a 3 mm-thick float glass having a square shape of 30 cm on each side, and the non-pressed sandwich was put into a rubber bag.
After degassing for 20 minutes at a vacuum of 0 torr, it was transferred to an oven at 90 ° C. while maintaining the degassed state, and this temperature was maintained for 30 minutes. The sandwich body temporarily bonded by degassing in this way,
Then, in an autoclave, pressure 12 kg / cm ² , temperature 13
Thermocompression bonding was performed at 5 ° C. to produce a transparent laminated glass.

<Measurement of Sound Insulation Property> The sound insulation properties of the laminated glasses of the above Examples and Comparative Examples were measured by the following method.

The laminated glass was subjected to a vibration generator (a shaker manufactured by Shinken Co., Ltd., “G21-005”) for a dumping test.
D "), and the vibration characteristics obtained therefrom are converted into a mechanical impedance amplifier (" XG-
81 "), and the vibration spectrum was analyzed by an FFT analyzer (" FFT Spectrum Analyzer HP3582A "manufactured by Yokogawa Hewlett-Packard Company). The transmission loss was calculated from the loss coefficient thus obtained and the ratio of the resonance frequency to the glass (measured temperature: 10).
４０40 ° C.). Based on this result, the TL value was defined as the minimum transmission loss amount near the frequency of 2000 Hz.

<Judgment of Optical Distortion> The optical distortion of the sound-insulating intermediate film is determined by sandwiching the intermediate film between two sheets of glass, applying a strong straight-line light to the glass, and visually observing the projection distortion of the transmitted light. The projection distortion was determined by comparing with the optical distortion of the glass alone.

<Test Results> The measurement results of the sound insulation and the optical distortion are summarized in Table 1.

[0060]

[Table 1]

As is clear from Table 1, it is recognized that the laminated glasses according to the examples of the present invention have excellent sound insulation performance and small optical distortion.

[0062]

The interlayer film for laminated glass of the present invention is obtained by laminating two types of resin layers comprising a specific co-acetalized polyvinyl acetal resin and a plasticizer, so that transparency, weather resistance and impact energy are obtained. Without impairing the basic performance required for laminated glass such as absorption and contact with glass,
A laminated glass having a high TL value by relaxing the coincidence effect, excellent sound insulation performance in a wide temperature range, and small optical distortion can be obtained. Further, a laminated glass can be manufactured with good workability in the laminating process.

[Brief description of the drawings]

FIG. 1 is a graph showing a sound insulation characteristic of a laminated glass as a transmission loss with respect to a frequency.

Claims (1)

(57) [Claims] 1. A layer (A) comprising a polyvinyl acetal resin and a plasticizer and having a thickness of 0.05 mm or more, and a layer (B) comprising a polyvinyl acetal resin and a plasticizer comprise a layer (B) / a layer (A).
/ Polyvinyl acetal resin of the layer (A) is formed of a polyvinyl alcohol having an aldehyde (a) having 6 to 8 carbon atoms and an aldehyde (a) having 2 to 4 carbon atoms.
A resin co-acetalized with the aldehyde (b) of the above, wherein the portion acetalized with the aldehyde (a),
The weight ratio of the portion acetalized with the aldehyde (b) is in the range of 60:40 to 100: 0, and the polyvinyl acetal resin of the layer (B) is obtained by converting the polyvinyl alcohol into an aldehyde (b) having 2 to 4 carbon atoms. And carbon number 6 ~
A resin co-acetalized with the aldehyde (a) of claim 8, wherein the resin is acetalized with the aldehyde (b);
The weight ratio of the portion acetalized with the aldehyde (a) is in the range of 80:20 to 100: 0, and at least one of the polyvinyl acetal resins of the layer (A) and the layer (B) is a co-acetalized resin. A sound insulating interlayer characterized by the following.