JP2562237B2 - Sound insulating interlayer film for 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 forming a laminated glass which exhibits excellent sound insulation performance over a wide temperature range for a long period of time.

[0002]

2. Description of the Related Art Generally, a laminated glass formed by sandwiching a resin film between a pair of glass plates is excellent in safety because fragments are not scattered when it is broken. It is widely used for window glass of buildings.

Of these interlayer films for laminated glass,
The resin film of polyvinyl butyral plasticized by the addition of a plasticizer has excellent adhesion to glass, tough tensile strength, high transparency, etc., and laminated glass made using this film is especially suitable for vehicles. It is suitable as a window glass for automobiles.

On the other hand, as a window glass for a building, not only is it desired to have a good property of preventing scattering of broken pieces at the time of breakage, but also to be excellent in sound insulation.

Generally, sound insulation performance is shown as a transmission loss amount according to a change in frequency, and the transmission loss amount is JIS.
In A4708, as indicated by the solid line in FIG.
It is regulated at a constant value depending on the sound insulation grade above 0 Hz. By the way, the sound insulation of the glass plate is shown in FIG.
As indicated by a broken line in the figure, in the frequency region around 2000 Hz, the coincidence effect significantly reduces (valley portion of the broken line in FIG. 1 corresponds to a decrease in sound insulation performance due to the coincidence effect and does not maintain a predetermined sound insulation performance). Indicate that). Here, the coincidence effect is defined by the rigidity and inertia of the glass plate when a sound wave is incident on the glass plate.
Transverse waves are conducted on the glass surface and the transverse waves resonate with the incident sound,
As a result, the phenomenon of sound transmission occurs.

Conventional laminated glass is excellent in terms of preventing scattering of fragments, but is 2000 Hz in terms of sound insulation.
In the frequency region centered on, the decrease in sound insulation due to the coincidence effect is unavoidable, and improvement of this point is required.

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

Conventionally, various measures such as increasing the mass of laminated glass and subdividing the glass area have been proposed as means for preventing a decrease in TL value. However, none of them bring a sufficiently satisfactory effect, and the cost is not reasonable enough for practical use.

The demand for sound insulation performance has been increasing recently,
For example, as a window glass for a building, it is required to always exhibit excellent sound insulation performance without being affected by the change in the outside air temperature every season.

Prior art of the interlayer film intended to improve the sound insulation performance of the laminated glass is, for example, as follows.

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

Japanese Unexamined Patent Publication (Kokai) No. 62-37148 discloses a laminate comprising two or more kinds of viscoelastic materials having different acoustic resistances,
For example, an intermediate film composed of a laminate of a polymethylmethacrylate film and a vinyl chloride-ethylene-glycidyl methacrylate copolymer film has been proposed.

Japanese Patent Laid-Open No. 60-276630 proposes an interlayer film containing a polyvinyl chloride resin containing a plasticizer as a measure for improving the sound insulation in the initial stage.

Japanese Unexamined Patent Publication (Kokai) No. 62-278148 proposes a low self-adhesive interlayer film for laminated glass, which comprises a polyacetal resin obtained by acetalizing polyvinyl alcohol with an aldehyde having 6 to 10 carbon atoms and a plasticizer. ing.

JP-A-2-229742 discloses a polymer film having a glass transition temperature of 15 ° C. or lower, for example, a vinyl chloride-ethylene-glycidyl methacrylate copolymer film,
An intermediate film comprising a laminate with a plasticized polyvinyl acetal film is described.

[0016]

Of these prior art interlayer films for sound-insulating laminated glass, Japanese Patent Publication No. 46-5830.
The interlayer film of No. 3 has a big problem that the absolute value of the sound insulating property of the laminated glass is low.

The interlayer film disclosed in JP-A-62-37748 has the drawback that the sound insulation of the laminated glass is not satisfactory in the initial performance and the performance is deteriorated in the long-term durability. The cause is that these resins cause mass transfer due to the diffusion action at the interface, and the effect of the constraining layer at the interface is weakened.

In the intermediate film of JP-A-60-27630,
Although the initial sound insulation is slightly improved, the addition of the plasticizer further promotes the mass transfer of the plasticizer as described above, and there is no improvement effect in terms of long-term durability.

JP 62-278148 A and JP 2
In each of the interlayer films of No. 229742, the sound insulation of the laminated glass is still insufficient.

As described above, the above-mentioned interlayer film of the prior art cannot be used to form a laminated glass which exhibits excellent sound insulation performance in a particularly wide temperature range for a long period of time.

In view of the above points, the present invention provides a TL value by relaxing the coincidence effect without impairing the basic properties required for laminated glass such as transparency, weather resistance, impact energy absorption, and adhesion to glass. It is an object of the present invention to provide an interlayer film for a sound-insulating laminated glass, which is capable of preventing deterioration of temperature and exhibiting excellent sound-insulating performance stably over a wide temperature range for a long period of time.

[0022]

Means for Solving the Problems The present inventors have found that a resin film composed of polyvinyl acetal and a plasticizer, which has already been used as an interlayer film for laminated glass, has transparency, weather resistance, impact energy absorption, Focusing on the fact that it has well-balanced properties such as adhesiveness with glass, the inventors have earnestly studied to improve the interlayer film having the above composition in order to improve the sound insulation without impairing the good properties. As a result, by using a specific combination of two kinds of polyvinyl acetal resins as the constituent material of the interlayer film, the TL value can be increased by mitigating the coincidence effect, and the sound insulation performance can be prevented from lowering due to the coincidence effect, and further, the temperature range can be wide. The inventors have completed the present invention by discovering that an intermediate film can be obtained that exhibits excellent sound insulation over a long period of time.

The interlayer film for laminated glass according to the present invention is
It is a laminated film composed of two kinds of resin films (A) and (B), and the number of each of the resin films (A) and (B) may be plural. ) And a plasticizer, the resin film (B) comprises a resin (b) and a plasticizer, and the resin (a) is a polyvinyl acetal obtained by acetalizing polyvinyl alcohol with an aldehyde having 6 to 10 carbon atoms. The resin (b) is a polyvinyl acetal obtained by acetalizing polyvinyl alcohol with an aldehyde having 1 to 4 carbon atoms (hereinafter referred to as "lamination type").

Particularly preferable as the laminated type intermediate film is the above-mentioned intermediate film, wherein the laminated film is composed of the resin film (A) and the resin films (B) on both surfaces thereof, and the resin (a) is polyvinyl alcohol containing carbon. It is a polyvinyl acetal obtained by acetalizing with an aldehyde of several 6 to 8, and the resin (b) is a polyvinyl acetal obtained by acetalizing polyvinyl alcohol with butyraldehyde.

Another sound-insulating interlayer according to the present invention is
A resin film (C) comprising a mixture of two kinds of resins (a) and (b) and a plasticizer, wherein the resin (a) is a polyvinyl film obtained by acetalizing polyvinyl alcohol with an aldehyde having 6 to 10 carbon atoms. The resin (b) is an acetal, and is characterized by being a polyvinyl acetal obtained by acetalizing polyvinyl alcohol with an aldehyde having 1 to 4 carbon atoms (hereinafter referred to as "resin mixed type").

The mixing ratio of the resin (a) and the resin (b) is preferably in the range of 2:98 to 90:10 by weight. If it is out of this range, the internal friction effect between the resins is not sufficient and the improvement of the sound insulation performance cannot be expected sufficiently. A particularly suitable range of the mixing ratio is 45:50 to 80:20.

Particularly preferable as the resin mixture type interlayer film is the above-mentioned interlayer film, wherein the resin (a) is a polyvinyl acetal obtained by acetalizing polyvinyl alcohol with an aldehyde having 6 to 8 carbon atoms. ) Is polyvinyl acetal obtained by acetalizing polyvinyl alcohol with butyraldehyde, and resin (a) and resin (b)
The mixing ratio by weight is in the range of 45:50 to 80:20.

The polyvinyl alcohol preferably has an average degree of polymerization of 1000 to 3000. Degree of polymerization is 10
When it is less than 00, the penetration resistance of the laminated glass is poor and 30
This is because if it exceeds 00, the strength is too large to be normally used as a safety glass. Further, the saponification degree of polyvinyl alcohol is preferably 95 mol% or more in order to improve transparency and heat resistance.

In the preparation of resin (a), the number of carbon atoms is 6-10.
Examples of the aldehyde include n-hexyl aldehyde and 2-
Ethyl butyraldehyde, n-heptyl aldehyde, n
Aliphatic, aromatic or alicyclic aldehydes such as octyl aldehyde, n-nonyl aldehyde, n-decyl aldehyde, benzaldehyde and cinnamaldehyde are used alone or in combination of two or more. If the aldehyde has more than 10 carbon atoms, the resulting polyvinyl acetal has low rigidity and poor sound insulation, which is not preferable.

On the other hand, in the preparation of the resin (b), the number of carbon atoms is 1
As the aldehydes (4) to (4), formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde and the like can be used alone or in combination of two or more.

As a method for preparing polyvinyl acetal, for example, polyvinyl alcohol is dissolved in hot water, the obtained aqueous solution is kept at a required temperature, a required aldehyde and a catalyst are added, and an acetalization reaction is allowed to proceed. Then, 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 preferably 50 mol% or more. Degree of acetalization is 50%
If it is less than the above range, the compatibility with the plasticizer is not good, and it is difficult to add the plasticizer in an amount necessary for ensuring penetration resistance.

As the plasticizer to be added to the resin, organic plasticizers such as monobasic acid esters and polybasic acid esters, and phosphoric acid plasticizers such as organic phosphoric acid compounds and organic phosphorous acid compounds are 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). A glycol-based ester obtained by a reaction with an organic acid such as decyl acid is preferred. In addition, esters of tetraethylene glycol and tripropylene glycol with the above organic acids are also used.

As the polybasic acid ester, adipic acid,
An ester of an organic acid such as sebacic acid or azelaic acid and a linear or branched alcohol having 4 to 8 carbon atoms is preferable.

As the phosphoric acid type plasticizer, tributoxyethyl phosphate, isodecyl phenyl phosphate, triisopropyl phosphite and the like are preferable.

More preferred examples of the monobasic acid ester include triethylene glycol-di-2-ethylbutyrate, triethylene glycol-di-2-ethylhexoate, triethylene glycol-dicapronate and triethylene glycol. Examples of the dibasic acid include dibutyl sebacate, dioctyl azelate, and dibutyl carbitol adipate.

The content of the plasticizer is preferably 20 to 60 parts by weight with respect to 100 parts by weight of polyvinyl acetal. If the content of the plasticizer is less than 20% by weight, the penetration resistance is lowered. On the contrary, if it exceeds 60% by weight, the plasticizer bleeds out and the transparency of the laminated glass and the adhesiveness to the glass plate etc. Because it damages. A particularly suitable range of the content of the plasticizer is 30 to 55 parts by weight based on 100 parts by weight of the polyvinyl acetal.

Additives usually used for adjusting the adhesive force between the resin film and the glass plate, stabilizers for preventing the deterioration of polyvinyl acetal, antioxidants, ultraviolet absorbers, etc. are polyvinyl acetals. It can be appropriately used when necessary when mixing with a plasticizer or in the production process of polyvinyl acetal.

As the additives, metal salts of carboxylic acids, for example, potassium metal such as octyl acid, hexylic acid, butyric acid, acetic acid and formic acid, alkali metal salts such as sodium, alkaline earth metal salts such as calcium and magnesium, zinc. , Cobalt salts, etc. are used. As the stabilizer, a surfactant,
For example, sodium lauryl sulfate, alkylbenzene sulfonic acid, etc. are used. As the antioxidant, tertiary butyl-hydroxytoluene (BHT), “Irganox 1010” manufactured by Ciba-Geigy Co., etc. are used. Examples of the ultraviolet absorber include benzotriazole type and hindered amine type. In the benzotriazole type, for example, “Tinuvin P”, “Tinuvin 320”, and “Tinuvin 32” manufactured by Ciba-Geigy Co., Ltd.
6 ”,“ Tinuvin 328 ”and the like are preferably used. In the hindered amine system, "LA-5" manufactured by ADEKA ARGUS CORPORATION is used.
7 "is preferable.

The laminated type intermediate film comprises a resin film (A) obtained by forming a resin (a) plasticized by adding a plasticizer,
Similarly, two or more sheets are laminated with the resin film (B) obtained by forming a resin (b) plasticized by adding a plasticizer.
This laminated structure includes the following.

(1) Two-layer laminated structure of resin film (A) / resin film (B).

(2) Resin film (A) / Resin film (B) / Resin film
(A), resin film (B) / resin film (A) / resin film (B), etc., three-layer laminated structure.

(3) Resin film (A) / Resin film (B) / Resin film
(A) / resin film (B) and other multi-layered structure of 4 layers or more.

The above multi-layered structure of three or more layers is a resin film.
(A) / resin film (B) / resin film (B) may have a multi-layered structure including a laminated structure of resin layers of the same kind.

The sound insulation of the laminated glass according to the present invention is
Since it is due to the reflection and absorption of sound at the interface between the resin films, the multilayered interlayer film is superior in sound insulation. In addition, this sound insulation is based on the resin film (A) and the resin film (B).
Since the laminated film of (1) absorbs sound energy by the constrained laminating effect, the laminated structure is not limited to the above, and more various laminated structures also belong to the embodiments of the present invention. An example of such a case is that the resin film (A) has 6 to 1 carbon atoms.
The resin film (A ′) and the resin film (A ″) are respectively obtained from polyvinyl acetal acetalized with two different aldehydes of 0. ) And a combination thereof (for example, resin film (A ′) / resin film (B) / resin film (A ″) / resin film (B))
/ 5-layer laminate of resin film (A ')) and the like.

Each thickness of the resin films constituting the laminated film is usually required to be 1 μm or more from the viewpoint of ensuring sound insulation in a wide temperature range, and is preferably 5 μm or more for practical use.

The thickness of the intermediate film is preferably in the range of 0.2 to 1.6 mm for both the laminated type resin and the mixed type, similar to the thickness of an ordinary intermediate film for laminated glass. As described above, the larger the thickness, the better the sound insulating property is, but in consideration of the strength for securing the impact resistance as the laminated glass and the performance of the penetration resistance, the thickness is practically within the above range. Has a good thickness. A particularly preferable range of the thickness of the interlayer film is 0.3 to 1.2 mm.

As a resin film-forming method, for example, polyvinyl acetal plasticized by adding a plasticizer is dissolved in a solvent, and the solution is applied by a suitable coater to form a film, and then the film is formed. There is a method of obtaining a film by drying.
Not limited to this method, the membrane may be manufactured by extrusion molding, calender molding or the like.

In order to produce a laminated glass by sandwiching an interlayer film between glass plates, a method generally used for producing a laminated glass is adopted. For example, in the case of the laminated type, a laminated film obtained by appropriately stacking each resin film (A) and the resin film (B), and in the case of the resin mixed type, the resin film (C)
Is sandwiched from both sides with glass plates, and the unpressed sandwich body is degassed and hot pressed to produce laminated glass. In the case of a laminated type, a solution of a composition comprising a resin (a) and a plasticizer is applied to a resin film (B) or glass, and the coating film is dried, or a resin film (A) is formed by a multilayer extrusion molding method. A method of obtaining a laminated film with the resin film (B) and laminating and adhering the laminated film between the glass plates is appropriately adopted. Also in the case of the resin mixed type, the coating film forming method as described above can be adopted.

The sound insulating intermediate film of the present invention may be laminated with a rigid body other than glass, for example, a metal or an inorganic material, or may be laminated with a transparent rigid resin plate such as a polycarbonate plate, that is, an organic glass plate. .

The sandwich type laminated glass thus obtained is further laminated with a special glass plate on at least one surface thereof with or without an intermediate film having a sound insulating property or another function, to obtain a multilayer type laminated glass. Glass can also be constructed. In addition, if necessary, a special glass plate may be laminated on at least one surface of the multilayer laminated glass with or without an intermediate film having a sound insulating property or other function to further advance the multilayering. . Here, as the intermediate film having other functions, one having heat resistance,
Those having flame retardancy, those imparting impact resistance, those imparting penetration resistance and the like are appropriately used. Examples of the special glass include organic glass such as a polycarbonate plate and inorganic glass having a special function such as heat ray reflectivity and fire resistance.

Examples of such multi-layer laminated glass include glass plate / sound-insulating interlayer film / glass plate / flame-retardant interlayer film / glass plate, glass plate / sound-insulating interlayer film / glass plate / fireproof inorganic glass plate. / A polycarbonate plate etc. are mentioned.

[0053]

EXAMPLES Some examples of the present invention and comparative examples to be compared with the examples will be given below, and the sound insulation performance of the obtained laminated glass will be shown.

Example 1 i) Preparation of Resin (a) 2900 g of pure water had a polymerization degree of 1700 and a saponification degree of 98.9.
193 g of mol% polyvinyl alcohol was added and dissolved by heating. The temperature of this solution was adjusted to 28 ° C., 201 g of 35% hydrochloric acid and 192 g of n-octyl aldehyde were added, respectively, and then the liquid temperature was lowered to 2 ° C. to maintain this temperature to precipitate polyvinyl acetal. Then, the liquid temperature was maintained at 30 ° C. for 5 hours to complete the reaction, and the mixture was neutralized, washed with water and dried to obtain a polyvinyl octyl acetal white resin powder (acetalization degree: 64.6 mol%).

Ii) Preparation of resin film (A) 50 g of the above polyvinyl octyl acetal was sampled, 20 g of triethylene glycol-di-2-ethylbutyrate as a plasticizer was added thereto, and this mixture was thoroughly mixed with a mixing roll. After kneading, a predetermined amount of the kneaded product was held at 150 ° C. for 30 minutes with a press molding machine. 0.20 thickness
A resin film (A) having a size of mm was obtained.

Iii) Preparation of resin (b) In 2900 g of pure water, the degree of polymerization was 1700 and the degree of saponification was 99.2.
190 g of mol% polyvinyl alcohol was added and dissolved by heating. The temperature of this solution was adjusted to 20 ° C., and 201 g of 35% hydrochloric acid and 124 g of n-butyraldehyde were added to this solution.
Were added respectively, and then the liquid temperature was lowered to 8 ° C. and maintained at this temperature to precipitate polyvinyl acetal. Then, the liquid temperature was maintained at 50 ° C. for 4 hours to complete the reaction, and the mixture was neutralized, washed with water and dried to obtain a polyvinyl butyral white powder resin (degree of acetalization: 66.3 mol%).

Iv) Preparation of resin film (B) 50 g of the above polyvinyl butyral was sampled, 20 g of triethylene glycol-di-2-ethylbutyrate as a plasticizer was added thereto, and this mixture was thoroughly kneaded with a mixing roll. Then, to this kneaded product, 0.05 g of potassium acetate as an additive and 0.08 g of BHT as an antioxidant,
Then, 0.08 g of "Tinuvin P" manufactured by Ciba-Geigy Co., Ltd. was added as an ultraviolet absorber, and a predetermined amount thereof was kept at 150 ° C. for 30 minutes by a press molding machine. Thus, a resin film (B) having a thickness of 0.76 mm was obtained.

V) Preparation of laminated glass The resin film prepared in this manner was used as resin film (A) / resin film (B) /
By laminating the resin film (A), a laminated type intermediate film was manufactured. This interlayer film is sandwiched from both sides with a float glass having a thickness of 3 mm and a square of 30 cm on each side. This non-bonded sandwich body is put into a rubber bag, and after deaeration at a vacuum degree of 20 torr for 20 minutes, it is left in a deaerated state. It was transferred to an oven at 90 ° C. and kept at this temperature for 30 minutes. The sandwich thus temporarily adhered by degassing was then thermocompression-bonded in an autoclave at a pressure of 12 kg / cm ² and a temperature of 135 ° C. to prepare a transparent laminated glass.

Examples 2 to 8 Resins (a) and (b) were obtained using the aldehydes shown in Table 1 in the same manner as in Steps i) and iii) of Example 1. Steps (ii) and iv) of Example 1 using these resins
The resin film (A) and resin film having the thickness shown in Table 1 in the same manner as
I got (B). Then, in the same manner as in step v) of Example 1, these resin films were laminated in the constitution shown in Table 1 to produce a laminated type intermediate film, and a laminated glass was produced using this intermediate film.

Example 9 5 g of the polyvinyl acetal resin (a) obtained in the same manner as in step i) of Example 1 was added to a mixed solvent of methyl alcohol and butyl alcohol in a ratio of 1/1 (weight ratio), and the mixture was heated and stirred. Then
A solution having a concentration of 5% by weight was obtained. Triethylene glycol-di-2-ethylbutyrate was added to this solution as a plasticizer.
g and stirred well.

This solution is added to the steps iii) and iv) of Example 1.
The resin film (B) obtained in the same manner as above was coated on one side so that the final thickness was 20 μm, and the coating film was dried in a Gar oven. Next, the back surface of the resin film (B) was similarly coated and dried to form a resin film (A) having a final thickness of 25 μm.

Film (A) / resin film (B) / resin film thus obtained
A laminated glass was produced in the same manner as in step v) of Example 1 using the laminated film of (A) as an intermediate film.

Comparative Examples 1 to 6 In Comparative Examples 1 to 3, one kind of resin film shown in Table 1 was used as an intermediate film, and in Comparative Examples 4 to 6, as shown in Table 2, acetalization with an aldehyde which does not conform to the present invention. Using the polyvinyl acetal thus obtained, a laminated type interlayer film shown in Table 1 was manufactured by the same operation as in Example 1, and a laminated glass was manufactured using this interlayer film.

Examples 10 to 17 Resins (a) obtained by using the aldehydes shown in Table 2
And the resin (b) were mixed at a ratio shown in Table 2 for 10 minutes with a crusher.

This mixture is then added to step iv) of Example 1.
The resin film (C) shown in Table 2 was produced by the same operation as in step iv), adding the same plasticizer, additives, antioxidant and ultraviolet absorber as in the above case.

Using the resin mixed type intermediate film thus obtained, a laminated glass was produced in the same manner as in step v) of Example 1.

Comparative Examples 7 to 8 In Comparative Example 7, an interlayer film made of one of the resins shown in Table 2 was used, and in Comparative Example 8, a polyvinyl acetal obtained by acetalizing as resin (b) with n-propylene aldehyde. Other than that, the resin-mixed type interlayer film shown in Table 2 was manufactured by the same operation as in Example 10, and a laminated glass was manufactured using this interlayer film.

Measurement of Sound Insulation The sound insulation of the laminated glass of the above Examples and Comparative Examples was measured by the following method. Vibration generator for damping test of laminated glass (vibrator manufactured by Shinken Co., Ltd., "G21-"
005D ”), and the vibration characteristics obtained from the vibration are amplified by a mechanical impedance amplifier (“ XG-81 ”manufactured by Rion Co., Ltd.), and the vibration spectrum is FFT.
Analyzer (Yokogawa Hewlett-Packard "F
FT spectrum analyzer HP 3582A ")
Was analyzed. The transmission loss was calculated from the loss coefficient thus obtained and the ratio of the resonance frequency with the glass (measurement temperature: 10 to 40 ° C.). Based on this result, the frequency 200
The minimum transmission loss amount around 0 Hz was defined as the TL value. Further, after being stored at a constant temperature of 5 ° C. for 30 days, the TL value was obtained by the same operation as above.

The measurement results of the laminated type Examples 1 to 9 are shown in Table 1, the measurement results of Comparative Examples 1 to 6 are shown in Table 2, and the measurement results of the resin mixed type Examples 10 to 17 and Comparative Examples 7 to 8 are shown. Are collectively shown in Table 3.

Further, Examples 1 and 10 and Comparative Example 1
The relationship between the frequency and the transmission loss of the laminated glass of No. 2 is shown in FIG. 2 (measurement temperature: 22 ° C.).

[0071]

[Table 1]

[0072]

[Table 2]

In Tables 1 and 2, mol% in the column of resin indicates the degree of acetalization. The laminated glass of Comparative Example 6 is disclosed in JP-A-2
It is based on Example 1 of JP-A-229742,
It showed poor transparency.

[0074]

[Table 3]

In Table 3, "ratio" means a comparative example. The mol% in the resin column indicates the degree of acetalization.

As can be seen from Table 1, Table 2 and Table 3 and FIG. 2, each laminated glass of the Examples showed a high TL value both in the initial stage and after 30 days. On the other hand, each laminated glass of the comparative example showed a low initial TL value or a decrease in TL value with time.

[0077]

As described above, the sound insulating interlayer film of the present invention comprises a polyvinyl acetal acetalized with two aldehydes having 6 to 10 carbon atoms and 1 to 4 carbon atoms. Seed resin film
Since it is composed of a laminated film of (A) and (B) or a resin (C) composed of a mixture of the above two kinds of polyvinyl acetal resins,
Sound energy due to the constrained layer effect is effectively absorbed,
In particular, it is possible to prevent the sound insulation performance from deteriorating due to the coincidence effect in the mid-high range near 2000 Hz. As a result, excellent sound insulation performance is exhibited for a long period of time in a wide temperature range without impairing various properties required as an interlayer film for laminated glass.

[Brief description of drawings]

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

FIG. 2 is a graph showing the relationship between frequency and transmission loss for the laminated glasses of Examples 1 and 10 and Comparative Example 1.

Claims (4)

(57) [Claims] 1. A laminated film comprising two kinds of resin films (A) and (B), wherein the number of each of the resin films (A) and (B) may be plural. ) Consists of resin (a) and a plasticizer,
The resin film (B) consists of the resin (b) and a plasticizer, the resin (a) is polyvinyl acetal obtained by acetalizing polyvinyl alcohol with an aldehyde having 6 to 10 carbon atoms, and the resin (b) is polyvinyl alcohol. An interlayer film for a sound-insulating laminated glass, which is a polyvinyl acetal obtained by acetalizing C with an aldehyde having 1 to 4 carbon atoms. 2. A laminated film comprising a resin film (A) and resin films on both sides thereof.
(B) and a resin (a) is a polyvinyl acetal obtained by acetalizing polyvinyl alcohol with an aldehyde having 6 to 8 carbon atoms, and a resin (b) is a polyvinyl acetal obtained by acetalizing polyvinyl alcohol with butyraldehyde. The interlayer film according to claim 1, which is acetal. 3. A resin film (C) comprising a mixture of two resins (a) and (b) and a plasticizer, wherein the resin (a) is polyvinyl alcohol containing an aldehyde having 6 to 10 carbon atoms and acetal. An interlayer film for a sound-insulating laminated glass, which is a polyvinyl acetal obtained by converting the polyvinyl alcohol to a resin, and the resin (b) is a polyvinyl acetal obtained by acetalizing polyvinyl alcohol with an aldehyde having 1 to 4 carbon atoms. 4. The resin (a) is a polyvinyl acetal obtained by acetalizing polyvinyl alcohol with an aldehyde having 6 to 8 carbon atoms, and the resin (b) is a polyvinyl acetal obtained by acetalizing polyvinyl alcohol with butyraldehyde. The intermediate film according to claim 3.