JP3204890B2 - Interlayer for sound insulating laminated glass and sound insulating laminated glass - 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 sound insulating laminated glass and a sound insulating laminated glass.

[0002]

2. Description of the Related Art A laminated glass in which an intermediate film made of a plasticized polyvinyl butyral resin is bonded between two transparent glass plates has good transparency and weather resistance, has good penetration resistance, and scatters glass fragments. It has the basic performance required for laminated glass, such as being difficult to perform, and is widely used, for example, for window glasses of automobiles and buildings.

[0003] Laminated glass of this kind has good basic performance as described above and is excellent in safety, but is inferior in sound insulation. In particular,
In the middle and high frequency range around the frequency of 2000 Hz, the sound transmission loss is reduced due to the coincidence effect, and the sound insulation is reduced. The coincidence effect is a phenomenon in which when a sound wave is incident on glass, a transverse wave is conducted on the glass surface by the rigidity and inertia of the glass, and the transverse wave and the incident sound resonate, and sound transmission occurs.

[0004] The demand for sound insulating properties has been increasing more and more recently. In particular, architectural glazing has the above-mentioned basic performance and is excellent in safety, has excellent sound insulating performance, and has the opposite side through laminated glass. There is a demand for a so-called small optical distortion in which the image cannot be distorted.

[0005] As such an interlayer film for sound insulating laminated glass and a sound insulating laminated glass, two types of specific plasticized polyvinyl acetal resin films are used, and at least two laminated resin films are formed by laminating these. An interlayer film and a laminated glass for a sound insulating laminated glass have been proposed (for example, see JP-A-7-97240).

[0006]

SUMMARY OF THE INVENTION The interlayer film for sound insulating laminated glass and the sound insulating laminated glass proposed above have considerably improved sound insulation as well as optical distortion. This inventor
In order to further improve the performance such as the sound insulation of the interlayer film for the sound insulation laminated glass and the sound insulation laminated glass, various studies were performed.

[0007] As a result, it has been found that by setting the thickness of the above two specific plasticized polyvinyl acetal resin films in a specific range, a laminated glass having small optical distortion and excellent sound insulation properties can be obtained. I got

[0008] The present invention has been made based on such findings, and is a laminated glass having good transparency, good weather resistance, good adhesion, good penetration resistance, and low scattering of glass shards. It is intended to provide an interlayer film for a sound insulating laminated glass and a sound insulating laminated glass having a small optical distortion and an excellent sound insulating property without impairing the basic performance required for the above.

[0009]

The interlayer film for a sound insulating laminated glass according to the present invention is a laminated resin film of at least two layers composed of two types of plasticized polyvinyl acetal resin films A and B. Is obtained by acetalizing polyvinyl alcohol with an aldehyde having 4 to 6 carbon atoms, the vinyl acetate component is composed of a polyvinyl acetal resin (a) having 8 to 30 mol% and a plasticizer, and the resin film B is formed of polyvinyl alcohol. Is obtained by acetalization with an aldehyde having 3 or 4 carbon atoms, a vinyl acetate component comprising 4 mol% or less of a polyvinyl acetal resin (b) and a plasticizer, wherein the total film thickness of the resin film A is The film thickness is more than 25% and not more than 55% and not less than 0.10 mm.

[0010] Further, the sound insulating laminated glass of the present invention comprises:
The interlayer film for laminated glass is sandwiched between at least two glass plates.

In the present invention, the polyvinyl alcohol used for preparing the polyvinyl acetal resins (a) and (b) preferably has an average degree of polymerization of 500 to 3000, more preferably 1000 to 2500. . If the average degree of polymerization is less than 500, the penetration resistance of the laminated glass decreases. Conversely, if the average degree of polymerization is 3000
If the ratio exceeds the above range, molding of the resin film becomes difficult, and the strength of the resin film becomes too strong, which is not suitable.

The degree of saponification of polyvinyl alcohol is as follows:
In preparing the resin (a), the vinyl acetate component is
Since it must be set to 30 mol%, the degree of saponification is 92 to 7
0 mol% is used. Further, in the preparation of the resin (b), the vinyl acetate component must be set to 4 mol% or less, and therefore, a resin having a saponification degree of 96 mol% or more is used. Here, the average degree of polymerization and the degree of saponification of polyvinyl alcohol can be measured, for example, based on JIS K6726 “Testing method for polyvinyl alcohol”.

In the preparation of the polyvinyl acetal resin (a), as the aldehyde having 4 to 6 carbon atoms, n-butyraldehyde, isobutyraldehyde, valeraldehyde, n-hexylaldehyde, 2-ethylbutyraldehyde and the like can be used alone or in combination. These are used in combination.

In the preparation of the resin (a), if the carbon number of the aldehyde is 3 or less, sufficient sound insulation cannot be obtained.
On the other hand, when the aldehyde has 7 or more carbon atoms, the reactivity of acetalization decreases, and sound insulation near room temperature is not sufficiently exhibited. In particular, n-butyraldehyde, isobutyraldehyde, and n-hexylaldehyde alone or in combination of two or three are preferred.

In the preparation of the polyvinyl acetal resin (b), propionaldehyde, n-butyraldehyde and isobutyraldehyde are used alone or in combination of two or more as the aldehyde having 3 or 4 carbon atoms.

In the preparation of the resin (b), when the number of carbon atoms of the aldehyde is 2 or less, the moldability of the resin film is deteriorated. On the other hand, when the number of carbon atoms of the aldehyde is 5 or more, the reactivity of acetalization is reduced, and at the room temperature. Sound insulation is not sufficiently exhibited. Particularly, n-butyraldehyde and isobutyraldehyde alone or in combination of two kinds are preferable.

Particularly, the resin (a) and the resin (b) are preferably obtained by acetalization with n-butyraldehyde having 4 carbon atoms. By using the resin acetalized with n-butyraldehyde, the adhesive strength of each resin film is increased, the weather resistance is excellent, and the production of the resin is easy.

The polyvinyl acetal resins (a) and (b) can be prepared by any known method. For example, polyvinyl alcohol is dissolved in warm water, the obtained aqueous solution is kept at a predetermined temperature, for example, 0 to 95 ° C., a required acid catalyst and aldehyde are added, and the acetalization reaction is allowed to proceed while stirring, Next, the reaction temperature is raised to ripen the reaction to complete the reaction, and then neutralization, washing and drying are performed to obtain resin (a) and resin (b) powder.

The obtained polyvinyl acetal resins (a) and (b) are composed of a vinyl acetal component, a vinyl alcohol component and a vinyl acetate component. The amounts of these components can be determined by, for example, JIS K 6728 “Testing method for polyvinyl butyral” or nuclear magnetic resonance (NMR).
Can be measured based on

In the case of a polyvinyl acetal resin other than the polyvinyl butyral resin, the amount of the vinyl alcohol component and the amount of the vinyl acetate component are measured, and the amount of the remaining vinyl acetal component is calculated by subtracting the amounts of both components from 100. be able to.

The degree of acetalization can also be measured based on the above-mentioned test method or nuclear magnetic resonance (NMR). Here, the degree of acetalization of the resin (a) is preferably from 40 to 75 mol%. If the acetalization degree is less than 40 mol%, the compatibility with the plasticizer is not good, and it becomes difficult to contain the amount of the plasticizer necessary for exhibiting the sound insulation performance.
Conversely, if the degree of acetalization exceeds 75 mol%, a long reaction time is required to obtain such a resin.

The acetalization degree of the resin (b) is 50 to 50.
75 mol% is preferred. If the acetalization degree is less than 50 mol%, the compatibility with the plasticizer is not good, and it becomes difficult to contain the amount of the plasticizer necessary for securing the penetration resistance. Conversely, if the degree of acetalization exceeds 75 mol%, a long reaction time is required to obtain such a resin.

In the present invention, the content of the vinyl acetate component of the resin (a) must be 8 to 30 mol%. If the content of the vinyl acetate component is less than 8 mol%, the sound insulation performance is not sufficiently exhibited. Conversely, if the content of the vinyl acetate component exceeds 30 mol%, blocking tends to occur during the production of the resin, making production difficult. With In particular, the content of this vinyl acetate component is 10 to
19 mol% is preferred.

The content of the vinyl acetate component of the resin (b) must be 4 mol% or less. When the content of the vinyl acetate component exceeds 4 mol%, the viscoelastic properties of the resin films A and B become similar, and the sound insulation performance in a wide temperature range is not sufficiently exhibited. In particular, the content of the vinyl acetate component is preferably from 0 to 2 mol%.

The polyvinyl acetal resin (a) and the polyvinyl acetal resin (b) thus prepared are each mixed with a predetermined amount of a plasticizer, and this is formed into a sheet by extrusion, calendering, pressing, or the like. The resin film A and the resin film B are formed by film formation. In addition, the above resin (a) and resin
In (b), a predetermined amount of a plasticizer may be mixed, and these may be integrally formed by a multilayer extrusion method.

Examples of the plasticizer include known plasticizers used for this kind of interlayer, for example, organic plasticizers such as monobasic acid esters and polybasic acid esters, and organic phosphoric acid and organic phosphorous acid. A phosphoric acid plasticizer such as an acid plasticizer is used.

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

As the polybasic acid ester, for example, an ester of an organic acid such as adipic acid, sebacic acid or azelaic acid with a linear or branched alcohol having 4 to 8 carbon atoms is preferable. As the phosphoric acid plasticizer, tributoxyethyl phosphate, isodecylphenyl phosphate, triisopropyl phosphite, and the like are preferable.

In particular, triethylene glycol di-2-ethyl butyrate, triethylene glycol di-2-ethylhexoate, triethylene glycol dicaprylate, triethylene glycol di─n-octoate, triethylene glycol di-n -Heptoate, tetraethylene glycol di-n-heptate, other dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate are preferably used.

Then, a polyvinyl acetal resin (a)
Is 35 to 70 parts by weight based on 100 parts by weight of the polyvinyl acetal resin (a). If the amount of the plasticizer is less than 35 parts by weight, sufficient sound insulation may not be obtained. Conversely, if the amount of the plasticizer exceeds 70 parts by weight, sufficient sound insulation may not be obtained. Bleeding increases the optical distortion and reduces the transparency and adhesiveness of the resin film. In particular, the amount of this plasticizer is 40 to 6
0 parts by weight is preferred.

The amount of the plasticizer incorporated in the polyvinyl acetal resin (b) is 25 to 55 parts by weight based on 100 parts by weight of the polyvinyl acetal resin (b). When the amount of the plasticizer is less than 25 parts by weight, the penetration resistance is reduced. On the other hand, when the amount of the plasticizer exceeds 55 parts by weight, the plasticizer bleeds to increase the optical distortion or the transparency of the resin film. And the adhesiveness is reduced. In particular, the amount of this plasticizer is 30 to
45 parts by weight are preferred. Further, in order to suppress the transfer of the plasticizer between the resin films A and B, it is preferable that the amount of the plasticizer with respect to the resin (a) is larger than the amount of the plasticizer with respect to the resin (b).

The resin (a) or the resin (b) contains an ultraviolet absorber, a light stabilizer, an antioxidant, an adhesion regulator, a surfactant, a colorant, etc., which are used for an interlayer film for laminated glass. Some known additives can be blended.

As the ultraviolet absorber, benzotriazole-based ones, for example, Tinuvin P manufactured by Ciba-Geigy, Inc.
(Trade name), Tinuvin 320 (trade name), Tinuvin 32
6 (trade name) and Tinuvin 328 (trade name). As the light stabilizer, a hindered amine-based stabilizer such as ADK STAB LA-57 (trade name) manufactured by Asahi Denka Co., Ltd.
And the like.

Examples of the antioxidant include phenol-based ones such as Sumilizer BHT (trade name) manufactured by Sumitomo Chemical Co., Ltd., and Irganox 1010 (trade name) manufactured by Ciba Geigy Co., Ltd.

Examples of the adhesion modifier include metal salts of carboxylic acids, for example, potassium salts and sodium salts of octylic acid, hexyl acid, butyric acid, acetic acid, formic acid and the like. Also,
Examples of the surfactant include sodium lauryl sulfate and alkylbenzene sulfonic acid.

The interlayer film for a sound insulating laminated glass according to the present invention is obtained by integrally molding the resin films A and B by a multilayer extrusion method as described above, or by heating the resin films A and B which are separately molded. It can be manufactured by a method of integrating by pressing, or a method of laminating resin films A and B between at least two glass plates, integrating by heating and pressing, and molding simultaneously with manufacturing of laminated glass. it can.

In order to produce a sound-insulating laminated glass in which the interlayer film for a laminated glass is sandwiched between at least two glass plates, a normal laminated glass production method is employed. For example, the intermediate film or the resin films A and B are sandwiched between two transparent glass plates, which are put in a rubber bag and pre-adhered at about 70 to 110 ° C. while sucking under reduced pressure,
Using an autoclave or a press, about 12
It is manufactured by performing main bonding at a pressure of about 10 to 15 kg / cm ² at 0 to 150 ° C.

The laminated structure of the resin films A and B is, for example,
The laminated structure is as follows. A two-layer structure of resin film A / resin film B. A three-layer structure of resin film A / resin film B / resin film A or resin film B / resin film A / resin film B. A four-layer structure of resin film A / resin film B / resin film A / resin film B. Note that the resin films A and B may be used by stacking resin films of the same type such as a resin film A / resin film A and a resin film B / resin film B, for example.

In any of the above-mentioned lamination structures, it is preferable to laminate the resin films B so as to be disposed on the outermost layers on both sides. With this arrangement, good workability comparable to that of a polyvinyl butyral-based interlayer can be obtained when the glass plate and the interlayer are combined, and the conventional technology can be used as it is. It is also preferable in terms of adhesion to glass and weather resistance.

As for the overall thickness of the laminated resin film (intermediate film), the larger the thickness, the better the sound insulation. However, in consideration of the minimum penetration resistance and weather resistance required for a laminated glass, practically, a laminated glass is generally used. Generally, the thickness is preferably in the range of 0.3 to 1.6 mm similarly to the thickness of the intermediate film for use. However, the total thickness of the resin film A is 2 times the thickness of the laminated resin film (intermediate film).
It must be more than 5% and not more than 55% and not less than 0.10 mm.

Although the sound insulation is good even when the total thickness of the resin film A is 25% or less of the thickness of the laminated resin film,
If it exceeds 25%, the sound insulation is further improved. But,
If it exceeds 55%, the optical distortion increases, and the basic performance required for laminated glass, such as impact energy absorption, decreases. The total thickness of the resin film A is 0.10 mm.
Although the sound insulation is good even when the thickness is less than 0.10 mm, the sound insulation is further improved when the thickness is 0.10 mm or more.

As the glass plate, not only an inorganic transparent glass plate but also an organic transparent glass plate such as a polycarbonate plate and a polymethyl methacrylate plate can be used.

(Function) The interlayer film for sound insulating laminated glass is
When composed of the above resin films A and B, the resin film A mainly improves sound insulation and optical distortion. That is, when the laminated glass (intermediate film) is bent and deformed by sound waves, sound energy is efficiently converted into heat energy by the internal friction effect (restrained layer effect) at the interface between the resin films A and B having different viscoelastic properties. Conversion is absorbed, and a decrease in sound insulation due to a coincidence effect, particularly in a medium to high temperature region around 2000 Hz, is effectively prevented.

In addition, although there is a difference in the viscoelastic properties of the resin films A and B, the difference is a relatively small difference. At the time of processing, the occurrence of minute disturbance at the interface between the resin films is prevented, the interface becomes uniform, and optical distortion (distortion of an image) is reduced. In addition, the resin film B mainly retains basic properties such as transparency, weather resistance, adhesion, penetration resistance, and scattering of glass fragments.

[0045]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples and comparative examples of the present invention will be described below. Example 1 Preparation of resin (a) and resin film A To 2890 g of pure water, 191 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 88 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., 201 g of a 35% by weight hydrochloric acid catalyst and 130 g of n-butyraldehyde were added, and the temperature was maintained to precipitate a reaction product.

Thereafter, the reaction system was maintained at 50 ° C. for 5 hours to complete the reaction, washed with excess water to wash away unreacted n-butyraldehyde, neutralized the hydrochloric acid catalyst, washed with water and dried. , White powdered polyvinyl acetal resin
(a) was obtained. The acetalization degree of this resin (a) is 60.
2 mol% and the vinyl acetate component was 12 mol%.

100 parts by weight of the resin (a) and triethylene glycol di-2-ethyl butyrate 5 as a plasticizer
After mixing with a mixing roll, the mixture was sufficiently melt-kneaded with a mixing roll, followed by press molding at 150 ° C. for 30 minutes using a press molding machine to obtain a resin film A having a thickness of 0.12 mm.

Preparation of Resin (b) and Resin Film B To 2910 g of pure water, 190 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 99 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., 201 g of a 35% by weight hydrochloric acid catalyst and 124 g of n-butyraldehyde were added, and the temperature was maintained to precipitate a reaction product.

Thereafter, the reaction system was maintained at 50 ° C. for 4 hours to complete the reaction, and washed with excess water to wash away unreacted n-butyraldehyde, neutralized the hydrochloric acid catalyst, washed with water and dried. , White powdered polyvinyl acetal resin
(b) was obtained. The acetalization degree of this resin (b) is 66.3.
Mol%, and the vinyl acetate component was 1 mol%.

100 parts by weight of the resin (b) and triethylene glycol di-2-ethyl butyrate 4 as a plasticizer
After mixing with a mixing roll, the mixture was sufficiently melt-kneaded with a mixing roll, followed by press molding with a press molding machine at 150 ° C. for 30 minutes to obtain a resin film B having a thickness of 0.13 mm.

Preparation of Intermediate Film and Laminated Glass The above resin films A and B were used, and this was
The resin film B was overlaid in this order, sandwiched from both sides with transparent float glass (length 30 cm × width 30 cm × thickness 3 mm), placed in a rubber bag, degassed for 20 minutes at a vacuum of 20 torr, and then degassed. It was transferred to an oven at 80 ° C. as it was, and further vacuum-pressed while being kept at 80 ° C. for 5 minutes.

The laminated glass preliminarily bonded in this manner is placed in an air type autoclave at a pressure of 12 kg / cm ² ,
The main bonding was performed at a temperature of 135 ° C. for 20 minutes, and the intermediate film was formed of B (0.13 mm) / A (0.12 mm) / B (0.13 m).
m) A transparent laminated glass having a laminated structure was obtained.

Example 2 Preparation of Resin (a) and Resin Film A To 2890 g of pure water, 191 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 91 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., and 201 g of a 35% by weight hydrochloric acid catalyst and 130 g of n-hexylaldehyde were added.
The reaction was precipitated while maintaining this temperature.

Thereafter, the reaction system was maintained at 50 ° C. for 5 hours to complete the reaction, washed with excess water to wash away unreacted n-hexyl aldehyde, neutralized the hydrochloric acid catalyst, washed with water and dried. , White powdered polyvinyl acetal resin
(a) was obtained. The degree of acetalization of this resin (a) was 64 mol%, and the vinyl acetate component was 9 mol%.

100 parts by weight of the resin (a) and triethylene glycol di-2-ethylbutyrate 5 as a plasticizer
After mixing with a mixing roll, the mixture was sufficiently melt-kneaded with a mixing roll, and then press-formed at 150 ° C. for 30 minutes using a press-forming machine to obtain a resin film A having a thickness of 0.15 mm.

Preparation of Resin (b) and Resin Film B To 2910 g of pure water, 190 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 98 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., and 201 g of a 35% by weight hydrochloric acid catalyst and 124 g of n-propyl aldehyde were added.
The reaction was precipitated while maintaining this temperature.

Thereafter, the reaction system was maintained at 50 ° C. for 4 hours to complete the reaction, washed with excess water to wash away unreacted n-propyl aldehyde, neutralized the hydrochloric acid catalyst, washed with water and dried. , White powdered polyvinyl acetal resin
(b) was obtained. The degree of acetalization of this resin (b) was 64 mol%, and the vinyl acetate component was 2 mol%.

100 parts by weight of the resin (b) and triethylene glycol di-2-ethylbutyrate 4 as a plasticizer
After mixing with a mixing roll, the mixture was sufficiently melt-kneaded with a mixing roll, and then press-formed at 150 ° C. for 30 minutes using a press-forming machine to obtain a resin film B having a thickness of 0.12 mm.

Otherwise, the procedure was the same as in Example 1, except that the intermediate film was B (0.12 mm) / A (0.15 mm) / B (0.
A laminated glass having a laminated structure of 12 mm) was obtained.

Example 3 Preparation of Resin (a) and Resin Film A To 2890 g of pure water, 191 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 73 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., 201 g of a 35% by weight hydrochloric acid catalyst and 130 g of n-butyraldehyde were added, and the temperature was maintained to precipitate a reaction product.

Thereafter, the reaction system was maintained at 50 ° C. for 5 hours to complete the reaction, washed with excess water to wash away unreacted n-butyraldehyde, neutralized the hydrochloric acid catalyst, washed with water and dried. , White powdered polyvinyl acetal resin
(a) was obtained. The degree of acetalization of this resin (a) was 45 mol%, and the vinyl acetate component was 27 mol%.

100 parts by weight of the resin (a) and triethylene glycol di-2-ethyl butyrate 5 as a plasticizer
After mixing with a mixing roll, the mixture was sufficiently melt-kneaded with a mixing roll, and then press-formed at 150 ° C. for 30 minutes using a press-forming machine to obtain a resin film A having a thickness of 0.20 mm.

Preparation of Resin (b) and Resin Film B To 2910 g of pure water, 190 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 99 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., 201 g of a 35% by weight hydrochloric acid catalyst and 124 g of n-butyraldehyde were added, and the temperature was maintained to precipitate a reaction product.

Thereafter, the reaction system was maintained at 50 ° C. for 4 hours to complete the reaction, washed with excess water to wash off unreacted n-butyraldehyde, neutralized the hydrochloric acid catalyst, washed with water and dried. , White powdered polyvinyl acetal resin
(b) was obtained. The resin (b) had an acetalization degree of 65 mol% and a vinyl acetate component of 1 mol%.

100 parts by weight of the resin (b) and triethylene glycol di-2-ethyl butyrate 4 as a plasticizer
After mixing with a mixing roll, the mixture was sufficiently melt-kneaded with a mixing roll, and then press-formed at 150 ° C. for 30 minutes using a press-forming machine to obtain a resin film B having a thickness of 0.12 mm.

Otherwise, the procedure was the same as in Example 1, except that the intermediate film was B (0.12 mm) / A (0.20 mm) / B (0.
A transparent laminated glass having a laminated structure of 12 mm) / A (0.20 mm) / B (0.12 mm) was obtained.

Comparative Example 1 Preparation of Resin (a) and Resin Film A To 2890 g of pure water, 191 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 88 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., and 201 g of 35% by weight hydrochloric acid catalyst and 130 g of n-propyl aldehyde were added.
The reaction was precipitated while maintaining this temperature.

Thereafter, the reaction system was maintained at 50 ° C. for 5 hours to complete the reaction, washed with excess water to wash away unreacted n-propyl aldehyde, neutralized the hydrochloric acid catalyst, washed with water and dried. , White powdered polyvinyl acetal resin
(a) was obtained. This resin (a) had an acetalization degree of 63 mol% and a vinyl acetate component of 12 mol%.

100 parts by weight of the resin (a) and triethylene glycol di-2-ethylbutyrate 5 as a plasticizer
After mixing with a mixing roll, the mixture was sufficiently melt-kneaded with a mixing roll, followed by press molding at 150 ° C. for 30 minutes using a press molding machine to obtain a resin film A having a thickness of 0.12 mm.

Preparation of Resin (b) and Resin Film B To 2910 g of pure water, 190 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 99 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., 201 g of a 35% by weight hydrochloric acid catalyst and 124 g of n-butyraldehyde were added, and the temperature was maintained to precipitate a reaction product.

Thereafter, the reaction system was maintained at 50 ° C. for 4 hours to complete the reaction, washed with excess water to wash away unreacted n-butyraldehyde, neutralized the hydrochloric acid catalyst, washed with water and dried. , White powdered polyvinyl acetal resin
(b) was obtained. The resin (b) had an acetalization degree of 65 mol% and a vinyl acetate component of 1 mol%.

100 parts by weight of the resin (b) and triethylene glycol di-2-ethyl butyrate 4 as a plasticizer
After mixing with a mixing roll, the mixture was sufficiently melt-kneaded with a mixing roll, followed by press molding with a press molding machine at 150 ° C. for 30 minutes to obtain a resin film B having a thickness of 0.13 mm.

Otherwise, the same procedure as in Example 1 was carried out, and the intermediate film was formed of B (0.13 mm) / A (0.12 mm) / B (0.
A transparent laminated glass having a laminated structure of 13 mm) was obtained.

Comparative Example 2 Preparation of Resin (a) and Resin Film A To 2890 g of pure water, 191 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 94 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., 201 g of a 35% by weight hydrochloric acid catalyst and 130 g of n-butyraldehyde were added, and the temperature was maintained to precipitate a reaction product.

Thereafter, the reaction system was maintained at 50 ° C. for 5 hours to complete the reaction, washed with excess water to wash away unreacted n-butyraldehyde, neutralized the hydrochloric acid catalyst, washed with water and dried. , White powdered polyvinyl acetal resin
(a) was obtained. The degree of acetalization of this resin (a) was 64 mol%, and the vinyl acetate component was 6 mol%.

100 parts by weight of the resin (a) and triethylene glycol di-2-ethylbutyrate 5 as a plasticizer
After mixing with a mixing roll, the mixture was sufficiently melt-kneaded with a mixing roll, followed by press molding at 150 ° C. for 30 minutes using a press molding machine to obtain a resin film A having a thickness of 0.12 mm.

Preparation of Resin (b) and Resin Film B To 2910 g of pure water, 190 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 99 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., 201 g of a 35% by weight hydrochloric acid catalyst and 124 g of n-butyraldehyde were added, and the temperature was maintained to precipitate a reaction product.

Thereafter, the reaction system was maintained at 50 ° C. for 4 hours to complete the reaction, washed with excess water to wash away unreacted n-butyraldehyde, neutralized the hydrochloric acid catalyst, washed with water and dried. , White powdered polyvinyl acetal resin
(b) was obtained. The resin (b) had an acetalization degree of 65 mol% and a vinyl acetate component of 1 mol%.

100 parts by weight of the resin (b) and triethylene glycol di-2-ethyl butyrate 4 as a plasticizer
After mixing with a mixing roll, the mixture was sufficiently melt-kneaded with a mixing roll, followed by press molding with a press molding machine at 150 ° C. for 30 minutes to obtain a resin film B having a thickness of 0.13 mm.

Otherwise, the procedure was the same as in Example 1, except that the intermediate film was B (0.13 mm) / A (0.12 mm) / B (0.
A transparent laminated glass having a laminated structure of 13 mm) was obtained.

Comparative Example 3 Preparation of Resin (a) and Resin Film A To 2890 g of pure water, 191 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 88 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., 201 g of a 35% by weight hydrochloric acid catalyst and 130 g of n-butyraldehyde were added, and the temperature was maintained to precipitate a reaction product.

Thereafter, the reaction system was maintained at 50 ° C. for 5 hours to complete the reaction, washed with excess water to wash away unreacted n-butyraldehyde, neutralized the hydrochloric acid catalyst, washed with water and dried. , White powdered polyvinyl acetal resin
(a) was obtained. The degree of acetalization of this resin (a) was 60 mol%, and the vinyl acetate component was 12 mol%.

100 parts by weight of the resin (a) and triethylene glycol di-2-ethylbutyrate 5 as a plasticizer
After mixing with a mixing roll, the mixture was sufficiently melt-kneaded with a mixing roll, followed by press molding with a press molding machine at 150 ° C. for 30 minutes to obtain a resin film A having a thickness of 0.08 mm.

Preparation of Resin (b) and Resin Film B To 2910 g of pure water, 190 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 99 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., 201 g of a 35% by weight hydrochloric acid catalyst and 124 g of n-butyraldehyde were added, and the temperature was maintained to precipitate a reaction product.

Thereafter, the reaction system was maintained at 50 ° C. for 4 hours to complete the reaction, washed with excess water to wash away unreacted n-butyraldehyde, neutralized the hydrochloric acid catalyst, washed with water and dried. , White powdered polyvinyl acetal resin
(b) was obtained. The resin (b) had an acetalization degree of 65 mol% and a vinyl acetate component of 1 mol%.

100 parts by weight of the resin (b) and triethylene glycol di-2-ethylbutyrate 4 as a plasticizer
After mixing with a mixing roll, the mixture was sufficiently melt-kneaded with a mixing roll, and then press-formed at 150 ° C. for 30 minutes using a press-forming machine to obtain a resin film B having a thickness of 0.15 mm.

Otherwise, the same procedure as in Example 1 was carried out, except that the intermediate film was B (0.15 mm) / A (0.08 mm) / B (0.
A transparent laminated glass having a laminated structure of 15 mm) was obtained.

The sound insulating laminated glasses of Examples 1 to 3 and Comparative Examples 1 to 3 thus obtained were evaluated for sound insulating properties and optical distortion by the following methods. The results are shown in Table 1 (Example) and Table 2 (Comparative Example).

<Evaluation of Sound Insulation Property> A sample was cut out from the laminated glass, and the sample was vibrated by a vibration generator for vibration damping test (vibrator “G21-005D” manufactured by Shinken Co., Ltd.) and obtained therefrom. Vibration characteristics are amplified by a mechanical impedance amplifier (“XG-81” manufactured by Rion),
The vibration spectrum was analyzed with an FFT spectrum analyzer (“FFT Analyzer HP3582A” manufactured by Yokogawa Hewlett-Packard Company).

From the ratio between the thus obtained loss coefficient and the resonance frequency with glass, the sound frequency (H
A graph showing the relationship between z) and the sound transmission loss (dB) was created, and the minimum sound transmission loss (TL value) around a sound frequency of 2000 Hz was obtained. The higher the TL value, the better the sound insulation.

<Optical Distortion> A light source transmitted through a slit with a halogen lamp is applied to the laminated glass, the projection distortion reflected on the screen is passed by a sensor (camera), and data processing is performed by a personal computer. The strain value was used. The higher this value is, the less optical distortion (image distortion) is.

[0092]

[Table 1]

[0093]

[Table 2]

[0094]

As described above, since the interlayer film for sound insulating laminated glass and the sound insulating laminated glass of the present invention use the same polyvinyl acetal resin as in the prior art, they have good transparency and good weather resistance. It has the basic performance required for laminated glass, such as good adhesion, good penetration resistance, and low scattering of glass fragments. Moreover, due to the action of the resin films A and B, optical distortion is small and sound insulation is excellent.

Therefore, the interlayer film for sound-insulating laminated glass and the sound-insulating laminated glass of the present invention are particularly suitable for window glass of buildings requiring high sound insulating performance.

──────────────────────────────────────────────────続 き Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C03C 27/12 B32B 17/10 G10K 11/16 G10K 11/162

Claims (2)

(57) [Claims] 1. A laminated resin film of at least two layers composed of two types of plasticized polyvinyl acetal resin films A and B, wherein the resin film A comprises polyvinyl alcohol having 4 carbon atoms.
And a vinyl acetate component obtained by acetalization with an aldehyde of ~ 6, wherein the vinyl acetate component comprises 8 to 30 mol% of a polyvinyl acetal resin (a) by weight and a plasticizer.
It is obtained by acetalizing polyvinyl alcohol with an aldehyde having 3 or 4 carbon atoms, and comprises a polyvinyl acetal resin (b) having a vinyl acetate component of 4 mol% or less and a plasticizer. An interlayer film for sound insulating laminated glass, characterized in that the thickness is more than 25% and not more than 55% of the thickness of the resin film and not less than 0.10 mm. 2. A sound-insulating laminated glass, wherein the interlayer film for laminated glass according to claim 1 is sandwiched between at least two glass plates.