JP2001206741A - Intermediate film for sandwich glass, sandwich glass and method for manufacturing sandwich glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an intermediate film for sandwich glass which is capable of preventing the degradation in a TL value by the relieving of a coincidence effect without the impairment of the basic performance as the intermediate film for sandwich glass and without the impairment of formability and handling quality. SOLUTION: The intermediate film for sandwich glass is formed by laminating plural plasticized polyvinyl acetal resin films Xa, Xb and Y, in which the plasticizer content of the polyvinyl acetal resin film Y contained with the plasticizer at a highest ratio is A pts.wt. per 100 pts.wt. polyvinyl acetal resin and the plasticizer content in the polyvinyl acetal resin film Y contained with the plasticizer at the highest ratio after the sandwich glass is manufactured by mounting the intermediate film for sandwich glass between two planar transparent bodies is B pts.wt. and B-A>=5.

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 used, for example, for window glasses of vehicles and buildings, and more particularly, to an interlayer film for laminated glass exhibiting excellent sound insulation performance, and the laminated glass. TECHNICAL FIELD The present invention relates to a laminated glass using an interlayer film for use and a method for producing the same.

[0002]

2. Description of the Related Art A laminated glass has a structure in which a resin film is sandwiched between a pair of glass plates. Since broken pieces do not scatter at the time of breakage and are excellent in safety, laminated glass is
For example, it is widely used as window glass for traffic vehicles such as automobiles and window glass for buildings.

In the above laminated glass, the resin film sandwiched between the glass plates is called an intermediate film.
As a material constituting the intermediate film, a polyvinyl butyral resin film plasticized by adding a plasticizer is used.

[0004] The plasticized polyvinyl butyral resin film has excellent adhesion to glass, high tensile strength,
Has high transparency. Therefore, a laminated glass using a plasticized polyvinyl butyral resin film as an intermediate film is particularly suitable as a window glass for vehicles.

[0005] Incidentally, the sound insulation performance is represented by a transmission loss amount corresponding to a change in frequency.
In 4708, as shown by the solid line in FIG. 1, the constant is specified at 500 Hz or more according to the sound insulation class. On the other hand, the sound insulation performance of the glass plate is, as shown by the broken line in FIG.
It is significantly reduced due to the coincidence effect. The valley of the characteristic shown by the broken line in FIG. 1 corresponds to a portion where the sound insulation performance is reduced due to the coincidence effect, and it can be seen that a predetermined sound insulation performance is not provided in a frequency region around 2000 Hz.

[0006] The coincidence effect means that when a sound wave is incident on a glass plate, a transverse wave propagates on the glass surface due to the rigidity and inertia of the glass plate, and the transverse wave and the incident sound resonate. Refers to the phenomenon of transmission.

[0007] Although the above laminated glass is excellent in preventing the scattering of fragments, it is inevitable that the sound insulation performance is reduced due to the coincidence effect in a frequency region centered at 2000 Hz, and this point is strongly improved. Was sought.

[0008] On the other hand, it is known from the equal loudness curve that human hearing exhibits a much higher sensitivity in the range of 1000 to 6000 Hz than in other frequency regions. Therefore, it is understood that resolving the drop in the sound insulation performance due to the coincidence effect is extremely important in improving the sound insulation.

Therefore, in order to enhance the sound insulation performance of the laminated glass, the decrease in the sound insulation performance due to the above-described coincidence effect is alleviated, and the minimum transmission loss caused by the coincidence effect (hereinafter, the transmission loss of this minimum portion is referred to as the TL value). .
(See FIG. 1).

Conventionally, as a method of suppressing the decrease in TL value, a method of increasing the mass of a laminated glass, a method of forming a multilayer glass, a method of subdividing a glass area,
Various methods have been proposed, such as a method for improving a glass plate supporting means. However, in any of these methods, a sufficiently satisfactory effect cannot be obtained,
In addition, there is a problem that the cost of the laminated glass is expensive.

[0011] In recent years, demands for sound insulation performance have been increasing more and more. For example, window glasses for construction are required to have excellent sound insulation performance near room temperature. In other words, the temperature at which the sound insulation performance is the best is obtained by plotting the TL value against the temperature (maximum temperature of the sound insulation performance = TL _MAX).
Temperature) is around room temperature, and the maximum value of the sound insulation performance (the maximum value of the sound insulation performance = TL _MAX value) itself is required to be large. Similarly, high sound insulation performance is required for window glass for automobiles, and sound insulation against wind noise during high-speed running, vibration from an engine unit, and the like is strongly required.

Further, in consideration of the actual use, these laminated glasses are exposed to a wide range of environmental temperature changes from a low temperature range to a high temperature range. That is, it is required to have good sound insulation performance not only near room temperature but also over a wide temperature range.

However, for example, a laminated glass using a conventional plasticized polyvinyl butyral resin film has a problem that the maximum temperature of the sound insulation performance is higher than room temperature, and the sound insulation performance is not sufficient near normal temperature.

An example of an interlayer capable of improving the sound insulation performance of the laminated glass as described above is disclosed in, for example, Japanese Patent Laid-Open No. 22974/1990.
No. 2 discloses this. Here, a polymer film having a glass transition temperature of 15 ° C. or lower, for example, vinyl chloride-ethylene-
An intermediate film comprising a laminate of a glycidyl methacrylate copolymer film and a plasticized polyvinyl acetal film is described.

However, the sound insulation grade according to JIS A4706 does not exhibit sufficient sound insulation exceeding Ts-35 grade, and the temperature range showing the sound insulation is limited, so that good sound insulation performance can be exhibited in a wide temperature range. It was not something.

Japanese Patent Application Laid-Open No. 51-106190 discloses a laminated body which exhibits vibration damping properties over a wide temperature range by laminating two or more resin films having different glass transition temperatures on a metal plate. Have been. In this laminate, the vibration damping property is improved in a wide temperature range. However, JP
JP-A-106190 merely discloses the composite metal plate having the above-described vibration damping properties, but does not mention the necessary sound insulation and transparency when used as an interlayer film of laminated glass. Further, the laminated body described in the prior art does not satisfy requirements such as high impact energy absorption required for safety glass and scattering prevention upon glass breakage.

It is an object of the present invention to provide a laminated glass interlayer which does not impair the basic performance required for a laminated glass interlayer, such as transparency, weather resistance, impact energy absorption, and adhesion to glass. An interlayer for laminated glass, an interlayer for laminated glass, capable of preventing a decrease in the TL value by relaxing the coincidence effect and also stably exhibiting excellent sound insulation performance over a wide temperature range for a long period of time without impairing handleability. It is to provide a laminated glass used and a method for producing the laminated glass.

[0018]

Means for Solving the Problems The present inventors have found that the sound insulation performance of a laminated glass is affected by the dynamic viscoelastic properties of the interlayer film, and in particular, the loss tangent which is the ratio between the storage elastic modulus and the loss elastic modulus. Finding that it is most affected, based on the knowledge, if the loss tangent of the interlayer film is controlled, it is thought that the sound insulation performance of the laminated glass may be enhanced over a wide temperature range,
We studied diligently.

The loss tangent of the intermediate film is affected by the glass transition temperature Tg of the intermediate film. In particular, the temperature range indicated by the maximum value of the loss tangent is located near the glass transition temperature Tg of the intermediate film. Therefore, for example, in order to enhance the sound insulation performance in a lower temperature range than room temperature, it is desirable that the glass transition temperature Tg of the intermediate film be located near room temperature. As described above, in order to position the glass transition temperature Tg of the intermediate film near room temperature, for example, in the case of an intermediate film made of polyvinyl acetal, the content ratio of the plasticizer may be increased.

However, when the ratio of the plasticizer contained in the interlayer is simply increased, the glass transition temperature Tg is lower than room temperature, so that the film becomes very soft, and the mechanical properties, handleability, and moldability of the interlayer are increased. Sex is impaired.

The inventors of the present invention have further studied and found that the glass transition temperature Tg of the interlayer film near room temperature or after the production of a laminated glass without impairing the mechanical properties, handleability and moldability of the interlayer film. The present inventors have found a film having a structure located at room temperature or lower and capable of improving the sound insulation performance at or near room temperature or lower, and have accomplished the present invention.

That is, the interlayer film for laminated glass according to the present invention is an interlayer film for laminated glass obtained by laminating a plurality of plasticized polyvinyl acetal resin films, and is a polyvinyl film containing the largest amount of a plasticizer. When the plasticizer content of the acetal resin film is
A weight part with respect to the weight part, the interlayer film for laminated glass is tightly adhered between two plate-shaped transparent bodies to produce a laminated glass, and then the polyvinyl acetal resin containing the largest amount of the plasticizer. The plasticizer content in the film is B parts by weight, and B−A ≧ 5.

In a specific aspect of the interlayer film for a laminated glass according to the present invention, the polyvinyl acetal resin is a polyvinyl butyral resin, and the plasticizer is triethylene glycol-di-2-ethyl butyrate, triethylene glycol- It is at least one selected from the group consisting of di-2-ethylhexanoate and triethylene glycol-di-n-heptanoate.

Further, the laminated glass according to the present invention is characterized in that at least a pair of glass plates is provided with the interlayer film for laminated glass according to the present invention interposed therebetween and these are integrated.

The method for producing a laminated glass according to the present invention comprises:
A laminate in which a plurality of plasticized polyvinyl acetal resin films are laminated, and the plasticizer content in the polyvinyl acetal resin film containing the most plasticizer is A parts by weight with respect to 100 parts by weight of the polyvinyl acetal resin. A step of preparing an interlayer film for glass, sandwiching the interlayer film for laminated glass between two plate-shaped transparent bodies, and hot pressing;
The plasticizer content in the polyvinyl acetal resin film in which the plasticizer content is A parts by weight is defined as B parts by weight (provided that B−A ≧
5).

Hereinafter, the present invention will be described in detail. As a method for obtaining the polyvinyl acetal resin used for the interlayer film for laminated glass according to the present invention, for example, after dissolving polyvinyl alcohol in hot water, maintaining the obtained polyvinyl aqueous solution at a predetermined temperature, and then adding an aldehyde and a catalyst And then the acetalization reaction is allowed to proceed, and thereafter, the reaction solution is maintained at a predetermined temperature, and then a resin powder is obtained through various steps of neutralization, washing and drying.

The polyvinyl alcohol (PVA) used for preparing the polyvinyl acetal resin is not particularly limited, but preferably has an average degree of polymerization in the range of 500 to 5000, more preferably 1000 to 30.
00. If the average degree of polymerization of PVA is less than 500, the strength of the resin layer and the intermediate film becomes too weak, and the penetration resistance and impact energy absorption when a laminated glass is formed may be insufficient. Conversely, if the average degree of polymerization of PVA exceeds 5,000, molding of the resin film may be difficult, and the strength of the resin film and the intermediate film may become too strong, and the penetration resistance when a laminated glass is formed, Impact energy absorption may be insufficient.

Examples of the aldehyde used for preparing the polyvinyl acetal resin include formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, valeraldehyde, n-hexylaldehyde, 2-ethylbutyraldehyde, benzaldehyde and cinnaaldehyde. And aldehyde.

The above-mentioned various polyvinyl acetal resins may be used alone or in combination of two or more. Among them, a polyvinyl butyral resin obtained by acetalization with n-butyraldehyde is preferably used.

By using a polyvinyl butyral resin among the polyvinyl acetal resins, the transparency, weather resistance and adhesion to glass of the polyvinyl butyral resin film and the intermediate film are further improved.

The polyvinyl acetal resin film used in the present invention has been plasticized with a plasticizer. The plasticizer is not particularly limited, and is preferably, for example, an organic ester 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. Used for

Specifically, among the monobasic acid ester-based plasticizers, glycols such as triethylene glycol, tripropylene glycol, and tetraethylene glycol;
Glycol esters obtained by reaction with organic acids such as butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptanoic acid and 2-ethylhexylic acid.

Examples of the polybasic acid ester-based plasticizer include esters obtained by reacting a linear or branched alcohol having 4 to 8 primates with an organic acid such as adipic acid, sebacic acid and azelaic acid. Is mentioned.

Examples of the phosphoric acid plasticizer include tributoxyethyl phosphate, isodecylphenyl phosphate and the like. Among the various plasticizers, for example, triethylene glycol-di-2-ethylbutyrate (3GH), triethylene glycol-di-2-ethylhexanoate (3GO), and triethylene glycol-di-n-heptanoate (3GO) 3G7), triethylene glycol dicaprylate, triethylene glycol di-n-octoate, tetraethylene glycol di-
2-ethyl butyrate, tetraethylene glycol-di-n-heptanoate, dihexyl adipate, dibenzyl phthalate and the like are preferably used, and particularly preferably used are 3GH, 3GO, 3G7 and the like.

The above plasticizers may be used alone or in combination of two or more. The amount of the plasticizer added to the polyvinyl acetal resin is not particularly limited.
It is preferable that the amount of the plasticizer is 30 to 70 parts by weight based on part by weight.

If the amount is less than 30 parts by weight, the plasticization of the polyvinyl acetal resin may be insufficient.
If the amount exceeds 0 parts by weight, the mechanical properties of the resin layer and the interlayer and the adhesive strength to glass may be insufficient.

Among the combinations of the polyvinyl acetal resin and the plasticizer, a combination using a polyvinyl butyral resin as the polyvinyl acetal resin and at least one selected from the group consisting of 3GH, 3GO, and 3G7 as the plasticizer. Is particularly preferred.

In the interlayer film for laminated glass according to the present invention,
A plurality of plasticized polyvinyl acetal resin films are laminated. Then, in this laminate, the plasticizer content in the polyvinyl acetal resin film containing the largest amount of plasticizer is A parts by weight with respect to 100 parts by weight of the polyvinyl acetal resin. When sandwiched between two sheets of glass and integrated to form a laminated glass, the plasticizer content in the polyvinyl butyral resin film in which the plasticizer content is A parts by weight is B parts by weight. In this case, , B−A ≧ 5.

That is, the plasticizer in the interlayer film for laminated glass moves in the laminate after the laminated glass manufacturing process, and the polyvinyl acetal resin film containing the most plasticizer contains another polyvinyl acetal. It means that the plasticizer transfers from the resin film. As described above, the plasticizer is transferred to the polyvinyl acetal resin film having the highest plasticizer content, so that a region containing a larger amount of the plasticizer is formed in the laminate. Therefore, the glass transition temperature Tg of the polyvinyl acetal resin film containing the largest amount of the plasticizer can be set to around room temperature or below room temperature, thereby improving the sound insulation performance around room temperature or around room temperature or below. it can.

Therefore, the B part by weight in the above BA-A ≧ 5 is set such that the glass transition temperature Tg of the polyvinyl acetal resin film containing the most plasticizer is around room temperature or below room temperature. Is preferred.
More specifically, since A parts by weight is 50 to 70 parts by weight, B parts by weight is desirably 55 to 75 parts by weight based on 100 parts by weight of the polyvinyl acetal resin.

When the difference BA between the plasticizer contents before and after the production of the laminated glass is 5 parts by weight or more, both the handleability of the film and the good sound insulation of the laminated glass can be achieved.
If the difference in the content of the plasticizer is less than 5 parts by weight, it is not possible to achieve a balance between the handleability of the film and the sound insulation performance. Conversely, when the sound insulation performance of the laminated glass is emphasized, the handling of the interlayer film is inferior.

An example of a method for giving a difference in the plasticizer content before and after the production of the laminated glass will be described. For example, the following types of resin films (X) and (Y) are prepared.

Resin film (X): A film containing 100 parts by weight of a polyvinyl acetal resin (X ₁ ) and 40 parts by weight of a plasticizer (X ₂ ). Resin film (Y): A film containing 100 parts by weight of a polyvinyl acetal resin (Y ₁ ) and 50 parts by weight of a plasticizer (Y ₂ ).

These are laminated like the resin film (X) / resin film (Y), or the resin film (X) / resin film (Y) / resin film (X) / resin film (X) Thus, a method of forming a four-layered laminate can be mentioned. Further, a three-layer structure of resin film (X) / resin film (Y) / resin film (X) may be adopted.

These lamination methods are optional, and the thicknesses of the resin film (X) and the resin film (Y) may be different. The resin film (X) and the polyvinyl acetal resin (X ₁ ) and the polyvinyl acetal resin (Y ₁ ) constituting the resin film (Y) may be the same or different.
Similarly, regarding the plasticizer (X ₂ ) and the plasticizer (Y ₂ ),
They may be the same or different.

In the laminate exemplified above, the resin film (Y) corresponds to a polyvinyl acetal resin film having the largest plasticizer content in the laminate. Therefore, the content of the plasticizer (Y ₂ ) is A parts by weight. Then, after lamination as described above, after producing a laminated glass, the plasticizer content in the resin film (Y) becomes B parts by weight, and B-A
Is 5 or more.

The thickness of the entire laminated film is preferably in the range of 0.3 to 1.6 mm, which is the thickness as a normal interlayer film for laminated glass. Although the greater the thickness of the interlayer, the higher the sound insulation performance, the thickness is preferably determined in consideration of the necessary penetration resistance as a laminated glass, and the thickness in the above range is practically preferable.

The method for forming the laminate is not particularly limited. For example, after forming each resin film separately,
Any method may be used, such as a method of laminating these between a pair of glass plates and integrating them at the time of producing a laminated glass, a method of integrally forming each layer using a multilayer molding machine to obtain a laminated film, and the like.

In order to manufacture a laminated glass by sandwiching the interlayer film for a laminated glass between glass plates, an ordinary method for producing a laminated glass is used. For example, an interlayer film for laminated glass, or a plurality of the resin films constituting the interlayer film for laminated glass sandwiched between glass plates from both sides,
A method of producing a laminated glass by integrating with a hot press is adopted.

Further, a transparent body other than glass, for example, a plate-like transparent body having higher rigidity than the above-mentioned resin film, such as a polycarbonate resin plate, may be used. Although the method for manufacturing a laminated glass using the interlayer film for a laminated glass according to the present invention is arbitrary as described above, in the method for manufacturing a laminated glass according to the present invention, a plurality of previously plasticized polyvinyl acetal resins are used. The laminated film, the plasticizer content in the polyvinyl acetal resin film containing the largest amount of plasticizer is 100 parts by weight of polyvinyl acetal resin A part by weight for laminated glass intermediate film is prepared, and then The interlayer film for laminated glass is sandwiched between two plate-shaped transparent bodies, integrated by hot pressing, and the plasticizer content in the polyvinyl acetal resin film in which the plasticizer content is A parts by weight is reduced. B parts by weight (B−A ≧ 5).

[0051]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be clarified by giving specific examples and comparative examples of the present invention.
In the following, the sound insulation performance and the plasticizer content of the laminated glass were measured by the following methods.

Sound insulation performance of laminated glass: At a predetermined temperature, the laminated glass is vibrated by a vibration generator for vibration damping test (vibrator manufactured by Shinken Co., product number: G21-005D), and the obtained vibration characteristics are measured by mechanical impedance amplifier. (Rion, product number: XG-81), and the obtained vibration spectrum was analyzed with an FFT analyzer (trade name: FFT spectrum analyzer HP3582AA, manufactured by Yokogawa Hewlett-Packer Company). The transmission loss was calculated from the ratio between the thus obtained loss coefficient and the resonance frequency with glass. Based on this result, the frequency 200
The minimum transmission loss near 0 Hz was defined as the TL value. The measurement was performed at 10 ° C intervals between 0 and + 30 ° C.

Measurement of plasticizer content ratio: JP-A-6-27
A method of calculating a plasticizer based on a film refractive index described in Japanese Patent No. 3327 is adopted. That is, a plasticized resin film whose plasticizer content is apparent in advance (the plasticizer content is
40, 45, 50, 55, and 60 parts by weight of a resin film) with respect to 0 parts by weight. The refractive index of these resin films was measured at a temperature of 25 ° C. using an Abbe refractometer (manufactured by Atago). A calibration curve showing the ratio between the obtained refractive index and the plasticizer content was created, and then the actual refractive index of the resin film was set to 25 ° C.
And the plasticizer content was calculated based on the above calibration curve.

In the present invention, the plasticizer content of the polyvinyl acetal resin film having the largest plasticizer content in the laminated film is determined. Therefore, when measuring the refractive index, cut the laminated film, observe the cross-section along the thickness direction, cut out the center portion of the polyvinyl acetal resin film portion having the highest plasticizer content with a knife, the refractive index evaluation sample Obtained.

In the following Examples and Comparative Examples, the handleability of the interlayer film for laminated glass was evaluated, but the evaluation was performed by sensory evaluation. That is, the intermediate film for laminated glass was touched by hand, and no stickiness was felt, and it was examined whether the handleability was good or whether the handleability was poor due to stickiness.

Example 1 Two types of plasticized polyvinyl acetal resin films Xa and Xb were produced, and a laminated film was produced using these.

(Preparation of Resin Films Xa and Xb) Polyethylene butyral resin (butyralization degree = 65.9 mol%, acetyl group content = 0.9 mol%) was prepared by adding triethylene glycol-di-2-ethyl butyrate as a plasticizer. (3GH) was added in an amount of 40 parts by weight based on 100 parts by weight of the polyvinyl butyral resin, and the mixture was sufficiently kneaded with a mixing roll. A predetermined amount of the kneaded material is 30
The resin film Xa having a thickness of 0.1 mm and a thickness of 0.
A 4 mm resin film Xb was produced.

(Preparation of Resin Film Y) A polyvinyl butyral resin (butyralization degree = 60.2 mol%, acetyl group content = 11.9 mol%) was added with 3GH as a plasticizer at a ratio of 60 to 100 parts by weight of the polyvinyl butyral resin. The mixture was sufficiently kneaded with a mixing roll, and a predetermined amount of the kneaded material was kept at 150 ° C. for 30 minutes by a press molding machine. Thus, a resin film Y having a thickness of 0.2 mm was produced.

(Preparation of Laminated Film and Laminated Glass) As shown in FIG. 1, the resin films Xa, Xb, and Y obtained as described above were laminated with a resin film Xa / resin film Y / resin film X
a / resin film Xb to obtain an interlayer film 1 for laminated glass composed of a four-layer laminate. An area of about 2 cm square was cut out from the interlayer film for laminated glass, and a cross section along the thickness direction was cut out with a knife blade, and the refractive index was measured.
Next, the layer having the highest plasticizer content, that is, the plasticizer content of the resin film Y was calculated from the measured refractive index value according to the method described above, and it was 60.2 parts by weight.

Next, an interlayer film for laminated glass was prepared with a side of 3
3 mm thick float glass 2 of 00 mm square
Sandwiches from both sides with a sheet, put this unpressed sandwich body in a rubber bag, and place it under a vacuum of 2.67 kPa for 20 minutes.
After degassing for a minute, the sample was transferred to an oven at 90 ° C. in a degassed state and held for 30 minutes. Thus, the sandwich body temporarily bonded by the vacuum press was thermocompression-bonded in an autoclave at a pressure of 1170 kPa and a temperature of 135 ° C. to produce a transparent laminated glass.

The obtained laminated glass was allowed to stand at room temperature for 4 days, after which a strip having a width of about 3 cm was cut out from one end of the laminated glass. From this strip-shaped laminated glass, an interlayer film was extracted, and a cross section was cut out in the thickness direction with a knife blade.
The refractive index of the portion corresponding to the resin film Y was measured, and the content of the plasticizer was determined. As a result, the plasticizer content determined from the refractive index of the portion corresponding to the resin film Y was 65.5 parts by weight.

Next, using the remaining laminated glass cut into strips, the sound insulation performance was evaluated according to the method described above. The structure and evaluation results of the interlayer film for laminated glass are shown in Table 1 below.

Example 2 (Preparation of Resin Films Xa and Xb) Polyvinyl butyral resin (butyralization degree = 68.9 mol%, acetyl group content =
0.9 mol%) in 100 parts by weight of triethylene glycol-di-2-ethylhexanoate (3G
O) was added in the same manner as in the resin films Xa and Xb of Example 1 except that a resin obtained by adding 39 parts by weight of O) was used.
Resin films Xa and Xb having a thickness of 1 mm and a thickness of 0.4 mm were prepared.

(Preparation of Resin Film Y) To 100 parts by weight of a polyvinyl butyral resin (butyralization degree = 63.6 mol%, acetyl group content = 13.0 mol%), triethylene glycol-di-2- as a plasticizer was added. Except that 60 parts by weight of ethylhexanoate (3GO) was added, the thickness was 0.2 m in the same manner as in the resin film Y of Example 1.
m of the resin film Y was produced.

Except for the above, an interlayer film for laminated glass composed of four laminated films was produced in the same manner as in Example 1, a laminated glass was produced, and the evaluation was conducted in the same manner as in Example 1.
The evaluation results are shown in Table 1 below.

Example 3 (Preparation of Resin Films Xa and Xb) Polyvinyl butyral resin (butyralization degree = 68.9 mol%, acetyl group content =
0.9 mol%) 100 parts by weight of triethylene glycol-di-n-heptane (3G7) 4 as a plasticizer
A resin film Xa having a thickness of 0.3 mm and a resin film Xb having a thickness of 0.4 mm were prepared in the same manner as in the method of manufacturing the resin film (X) of Example 1 using the resin to which 0 parts by weight was added.

(Preparation of Resin Film Y) 100 parts by weight of polyvinyl butyral resin (butyralization degree = 63.6 mol%, acetyl group content = 13.0 mol%), and 3G as a plasticizer
7, a resin film Y having a thickness of 0.1 mm was prepared in the same manner as in the method of manufacturing the resin film Y of Example 1.

The resin films Xa, X obtained as described above
b and resin film Y, resin film Xa (thickness 0.3 mm)
/ Resin film Y (thickness 0.1 mm) / resin film Xb (thickness 0.1 mm)
An interlayer film for laminated glass having a three-layer structure (4 mm) was produced in the same manner as in Example 1, and a laminated glass was produced and evaluated.

(Comparative Example 1) Resin film X used in Example 1
A laminated glass was obtained in the same manner as in Example 1, except that a resin film Xc having the same composition and a thickness of 0.8 mm was obtained by press molding instead of a and Xb, and only the resin film Xc was used as an intermediate film. Was prepared and evaluated.

(Comparative Example 2) In Example 1, the resin film Y
In producing the laminated glass, a laminated glass was produced in the same manner as in Example 1 except that a resin film was obtained by press molding so as to have a thickness of 0.8 mm, and only this resin film was used as an intermediate film. And evaluated.

Comparative Example 3 (Preparation of Resin Films Xd and Xe) Polyvinyl butyral resin (butyralization degree = 65.9 mol%, acetyl group content =
0.9 mol%) A resin having a thickness of 0.1 mm was formed in the same manner as the resin films Xa and Xb of Example 1 except that 40 parts by weight of 3GO was added as a plasticizer to 100 parts by weight. A film Xd and a resin film Xe having a thickness of 0.4 mm were produced.

(Preparation of Resin Film Y) 100 parts by weight of a polyvinyl butyral resin (butyralization degree = 60.2 mol%, acetyl group content = 11.9 mol%) was mixed with 3G as a plasticizer.
Except for using 60 parts by weight of O,
A resin film Y having a thickness of 0.2 mm was manufactured in the same manner as the resin film Y of Example 1.

Except for the above, in the same manner as in Example 1, an interlayer film for laminated glass was prepared from the four-layer laminated film, and a laminated glass was prepared and evaluated.

[0074]

[Table 1]

As is clear from Table 1, since the interlayer film for laminated glass of Comparative Example 1 is composed of only the resin film (Xc), the plasticizer content hardly changes before and after lamination. For this reason, although the handleability was good, the TL value indicating the sound insulation performance was low.

Further, since the interlayer film for laminated glass of Comparative Example 2 is composed of only the resin film Y, the content of the plasticizer is high.
Therefore, although sufficient sound insulation performance was exhibited at 0 ° C. to 30 ° C., the surface was sticky and the handleability was insufficient because the plasticizer content was high even before the production of laminated glass.

In the interlayer film for laminated glass of Comparative Example 3, although the handleability was good, the difference in the plasticizer content before and after the production of the laminated glass was as small as 62.8-59.9 = 2.9 parts by weight. Or, the sound insulation performance in the temperature range around room temperature and below room temperature was not sufficient.

On the other hand, in the interlayer films for laminated glass of Examples 1 to 3, before the production of the laminated glass, the plasticizer content in the resin film having the highest plasticizer content was 60.2 parts by weight or less. Since it was not so high, it was not sticky during handling and the handleability was good. Moreover, after the production of the laminated glass, the layer having the highest plasticizer content has a plasticizer content of 6%.
It increased to 5.2 parts by weight or more, and exhibited sufficient sound insulation performance over a temperature range of 0 ° C to 30 ° C.

[0079]

According to the interlayer film for laminated glass according to the present invention, the plasticizer of the polyvinyl acetal resin film containing the largest amount of the plasticizer is formed by laminating a plurality of plasticized polyvinyl acetal resin films. Content is
A part by weight (provided that A part by weight is 50 to 70 parts by weight) with respect to 100 parts by weight of the polyvinyl acetal resin, and the interlayer film for a laminated glass is tightly attached between two plate-shaped transparent bodies. After the production of the plasticizer, the plasticizer content in the polyvinyl acetal resin film containing the largest amount of the plasticizer is B parts by weight, and B−A ≧ 5. The agent content is not very high, so it is not sticky and has excellent handleability. In addition, after the laminated glass is manufactured, the plasticizer content in the polyvinyl acetal resin film containing the largest amount of plasticizer is B parts by weight, and the sound insulation is good over a wide temperature range, particularly at room temperature and a temperature range near room temperature or lower. Demonstrate performance.

Accordingly, the TL value can be reduced without impairing the basic performance required for laminated glass such as transparency, weather resistance, impact energy absorption and adhesiveness to glass, and also without impairing moldability and handling. And an interlayer film for laminated glass that can exhibit excellent sound insulation performance over a wide temperature range can be provided.

In particular, a polyvinyl butyral resin is used as the polyvinyl acetal resin, and triethylene glycol di-2-ethyl butyrate, triethylene glycol di-2-ethylhexanoate and triethylene glycol diethanol are used as plasticizers. When at least one selected from the group consisting of -n-heptanoate is used, the transparency, weather resistance and adhesion to glass of the interlayer film for laminated glass can be further enhanced. Further, according to the laminated glass according to the present invention, in which the interlayer film for glass according to the present invention is interposed between at least a pair of plate-shaped transparent bodies, and these are integrated, the transparency of the interlayer film for laminated glass is improved. It not only has good heat resistance, weather resistance, impact energy absorption and glass adhesion, but also has excellent sound insulation performance over a wide temperature range, and particularly has good sound insulation performance near room temperature and below room temperature. Obtainable.

According to the method for manufacturing a laminated glass according to the present invention, after preparing the interlayer film for a laminated glass of the present invention, the interlayer film for a laminated glass is sandwiched between two plate-shaped transparent bodies.
By pressing, the plasticizer content of the polyvinyl butyral resin film having the highest plasticizer content is B parts by weight (however, A = 50 to 70 and BA ≧ 5). A laminated glass exhibiting good sound insulation performance over a wide temperature range can be easily provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a laminated structure of an interlayer film for laminated glass of the present invention.

FIG. 2 is a diagram showing the sound insulation performance of glass.

[Explanation of symbols]

 1: Interlayer film for laminated glass X, Y: Polyvinyl acetal resin film

Claims (4)

[Claims] 1. An interlayer film for laminated glass comprising a plurality of plasticized polyvinyl acetal resin films laminated, wherein the plasticizer content of the polyvinyl acetal resin film containing the largest amount of plasticizer is polyvinyl alcohol. A weight part is based on 100 weight parts of acetal resin, and after the interlayer film for laminated glass is narrowed between two plate-shaped transparent bodies to produce a laminated glass, the plasticizer is most contained. Plasticizer content in the polyvinyl acetal resin film is B
Parts by weight, A = 50 to 70, and B−A ≧ 5
An interlayer film for laminated glass, characterized in that: 2. The polyvinyl acetal resin is a polyvinyl butyral resin, and the plasticizer is triethylene glycol di-2-ethyl butyrate, triethylene glycol di-2-ethylhexanoate and triethylene glycol. Di-n
At least one selected from the group consisting of heptanoates
The interlayer film for laminated glass according to claim 1, which is a seed. 3. A laminated glass, wherein the interlayer film for laminated glass according to claim 1 is interposed between at least a pair of plate-shaped transparent bodies, and these are integrated. 4. A polyvinyl acetal resin film comprising a plurality of plasticized polyvinyl acetal resin films, wherein the plasticizer content in the polyvinyl acetal resin film containing the largest amount of plasticizer is A per 100 parts by weight of the polyvinyl acetal resin. A step of preparing an interlayer film for laminated glass, which is part by weight; and a step of sandwiching the interlayer film for laminated glass between two plate-shaped transparent bodies, hot pressing, and a polyvinyl acetal having a plasticizer content of A part by weight. Making the content of the plasticizer in the resin film B parts by weight (where A = 50 to 70 and BA ≧ 5).