JP2002326844A - Interlayer for laminated glass and laminated glass - Google Patents

Abstract

(57) [Summary] (Modified) [Problem] Without impairing the basic performance required for laminated glass such as transparency, weather resistance, impact energy absorption, and adhesion to glass, and the mechanical strength of an interlayer film. An interlayer film for sound insulating laminated glass that can reduce the TL value by relaxing the coincidence effect without deteriorating the moldability and handleability, and can exhibit excellent sound insulating performance in a wide temperature range for a long period of time. The purpose is to provide. SOLUTION: This is a resin film comprising a polyvinyl acetal resin (c) in which a polyvinyl acetal resin (a) and a polyvinyl acetal resin (b) are mixed and a plasticizer, wherein the polyvinyl acetal resin (a) and the plasticizer The cloud point (Ta) of the mixed solution is less than 50 ° C., and the cloud point (Tb) of the mixed solution of the polyvinyl acetal resin (b) and the plasticizer.
Is not less than 50 ° C. and Tb−Ta ≧ 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In general, laminated glass formed by laminating a resin film between a pair of glass plates is excellent in safety because fragments are not scattered at the time of breakage. Widely used for window glass of buildings. Among such interlayer films for laminated glass, a polyvinyl butyral (hereinafter abbreviated as PVB) resin film plasticized by the addition of a plasticizer has adhesiveness to glass, strong tensile strength, and high transparency. A laminated glass formed using this film is particularly suitable as a window glass for vehicles.

[0003] In general, the sound insulation performance is indicated as a transmission loss amount corresponding to a change in frequency, and the transmission loss amount is defined by JIS.
In A4708, as shown by the solid line in FIG.
At a frequency of 00 Hz or more, each is defined as a constant value according to the sound insulation class. On the other hand, the sound insulation of the glass plate is remarkably reduced due to the coincidence effect in a frequency region centered at 2000 Hz, as shown by the wavy line in FIG. 1 (the valley of the wavy line in FIG. And does not maintain the predetermined sound insulation performance). Here, 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, and as a result, sound transmission occurs A phenomenon. Although the conventional laminated glass is excellent in the prevention of shattering of shards, in terms of sound insulation, in the frequency range centered on 2000Hz, the sound insulation performance is still inevitably reduced due to the coincidence effect. Is required.

[0004] On the other hand, it is known that human hearing has a very high sensitivity in the range of 1000 to 6000 Hz as compared with other frequency regions based on an equal loudness curve, and a drop in sound insulation performance due to a coincidence effect is eliminated. This is extremely important for soundproofing. In order to improve the sound insulation performance of the laminated glass, the above-described coincidence effect is alleviated to minimize the transmission loss caused by the coincidence effect (hereinafter, the transmission loss of this minimum portion is referred to as a TL value; see FIG. 1). Need to be prevented. Conventionally, various measures have been proposed as means for preventing a decrease in TL value, such as an increase in the mass of laminated glass, multi-layering of glass, subdivision of glass area, improvement of glass plate support means, and the like. None of them have sufficiently satisfactory effects, and are not cost-effective enough to be practically employed.

[0005] The demand for sound insulation performance has been increasing more and more recently. For example, window glass for construction is required to have excellent sound insulation at around room temperature. That is, transmission loss (TL
When the values are plotted, the temperature at which the sound insulation performance is the highest (the maximum temperature of the sound insulation performance = TLmax temperature) is around room temperature, and the maximum value of the sound insulation performance (the maximum value of the sound insulation performance = TLma).
Excellent x-value) itself, that is, excellent sound insulation. The same is required for automobiles, and the number of places where sound insulation is required, such as wind noise during high-speed running and vibration from an engine, is increasing. Further, considering the case where the laminated glass is actually used, 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, good sound insulation performance is required not only near room temperature but also in a wide temperature range. However, for example, a laminated glass using a conventional plasticized PVB resin film has a problem that the maximum temperature of sound insulation performance is higher than room temperature and the sound insulation performance is not good near normal temperature.

In order to improve the sound insulation performance of laminated glass, for example, Japanese Patent Application Laid-Open No. 2-229742 discloses a polymer film having a glass transition temperature of 15 ° C. or less, such as vinyl chloride.
An intermediate film comprising a laminate of an ethylene-glycidyl methacrylate copolymer film and a plasticized PVB film is disclosed. However, the laminated glass is JIS A4706.
In addition to exhibiting a sound insulation rating exceeding Ts-35 in the sound insulation class of the present invention, the temperature range in which the sound insulation is exhibited is limited, and good sound insulation performance cannot be exhibited in a wide temperature range. JP-A-51-106190 proposes to obtain a structure having vibration damping properties in a wide temperature range by laminating two or more resins having different glass transition temperatures. It is observed that the structure has improved damping over a wide temperature range. However, this publication does not describe the sound insulation, transparency, etc. required for laminated glass, and this structure also has requirements for high impact energy absorption required for safety glass, scattering prevention in the event of glass breakage, etc. Not satisfying.

Further, JP-A-4-254444 discloses a film comprising a polyvinyl acetal having 6 to 10 carbon atoms in an acetal group and a plasticizer, and a polyvinyl acetal having 1 to 4 carbon atoms in an acetal group. An intermediate film in which a film made of a plasticizer is laminated has been proposed. With this interlayer film, the effect of improving the sound insulation performance is certainly recognized, and the sound insulation performance does not fluctuate greatly due to the temperature change, but these effects are not yet sufficient.

[0008]

SUMMARY OF THE INVENTION In view of the above, the present invention has been made without impairing the basic performance required for laminated glass such as transparency, weather resistance, impact energy absorption, and adhesion to glass. Sound insulation that does not impair the mechanical strength, moldability, and handleability of the interlayer, reduces the TL value by relaxing the coincidence effect, and can exhibit excellent sound insulation performance in a wide temperature range over a long period of time. An object of the present invention is to provide an interlayer film for laminated glass.

Heretofore, in order to improve the sound insulation performance over a wide temperature range, two layers having different sound insulation performances (for example, a layer having a good sound insulation performance at a low temperature and a layer having a good sound insulation performance at a high temperature) have been used.
Have been practiced. In this case, specifically, the temperature range has been adjusted by changing the amount of the plasticizer added to the two layers. However, depending on the type of the laminated structure, the layer with a large amount of the plasticizer added may
Since the plasticizer migrated to the other layer, it was difficult to improve the sound insulation performance over a wide temperature range.

[0010]

Heretofore, in order to improve the sound insulation performance over a wide temperature range, two layers having different sound insulation performances (for example, a layer having a good sound insulation performance at a low temperature and a sound insulation performance at a high temperature) have been used. Have been carried out. In this case, specifically, the temperature range has been adjusted by changing the amount of the plasticizer added to the two layers. However, depending on the type of the lamination structure, the plasticizer is transferred from a layer having a large amount of the plasticizer to the other layer, and it is difficult to improve the sound insulation performance in a wide temperature range.

In the present invention, the present inventors have found that the above problems can be solved by controlling the compatibility between the resin forming the layer and the plasticizer, and have completed the present invention. That is, the interlayer film for laminated glass according to the invention of claim 1 comprises a polyvinyl acetal resin (a) and a polyvinyl acetal resin.
(b) a resin film comprising a polyvinyl acetal resin (c) and a plasticizer, wherein the mixed solution of the polyvinyl acetal resin (a) and the plasticizer has a cloud point (Ta) of less than 50 ° C. And a cloudy sky (Tb) of the mixed solution of the polyvinyl acetal resin (b) and the plasticizer is 50 ° C. or more,
And an interlayer film for laminated glass in which Tb−Ta ≧ 50.

In the interlayer film for laminated glass according to the second aspect of the present invention, the polyvinyl acetal resin (c) comprises 100 parts by weight of the polyvinyl acetal resin (a) and 5 to 50 parts by weight of the polyvinyl acetal resin (b). Item 4. An interlayer film for laminated glass according to item 1.

In the interlayer film for laminated glass according to the third aspect of the present invention, at least one of the polyvinyl acetal resins (a) and (b) has an acetalization degree of 60 to 85 mol%,
The amount of an acetyl group is 8 to 30 mol%, and the total of the degree of acetalization and the amount of an acetyl group is 75 mol% or more.
2. The interlayer film for laminated glass according to 2. In the interlayer film for laminated glass according to the invention of claim 4, the polyvinyl acetal resins (a) and (b) are polyvinyl butyral resins, and the plasticizers are triethylene glycol-di-2-ethylhexanoate and triethylene. Glycolide-n
-Heptanoate tetraethylene glycol-di-2-
The interlayer film for laminated glass according to any one of claims 1 to 3, wherein the interlayer film is at least one selected from the group consisting of ethyl hexanoate and tetraethylene glycol di-n-heptanoate. A laminated glass according to a fifth aspect of the present invention is a laminated glass obtained by interposing the interlayer film for a laminated glass according to any one of the first to fourth aspects between at least a pair of glasses and integrating them.

The cloud point in the present invention is defined by JIS K-2
269 is a cloud point measured in accordance with “Pour point of crude oil and petroleum products and cloud point test method of petroleum products”. Specifically, a solution obtained by dissolving 8 parts by weight of a polyvinyl acetal resin with respect to 100 parts by weight of a plasticizer was heated to 150 ° C. or more, and then left in an atmosphere of 10 to 30 ° C. to lower the temperature. Sometimes, it means the temperature at which clouding begins to occur in a part of the solution. Here, the lower the cloud point, the better the compatibility between the resin and the plasticizer.

Temperature at which fogging occurs in a part of the above solution
As a method of measuring the (cloud point), for example, a method of visually observing the appearance of the solution, a method of measuring the haze of the solution with a haze meter, and preparing a multi-stage limit sample for cloudiness in advance, and setting the limit sample And a method of determining fogging in contrast to the above.

In the present invention (claim 1), a film obtained by plasticizing a resin obtained by mixing two polyvinyl acetal resins having different compatibility with a plasticizer is used. In the plasticized film,
It is expected that the resin film phase having good compatibility with the plasticizer (phase A) and the resin film phase having poor compatibility with the plasticizer (phase B) take a form as if they were phase-separated. Ideally, the phase (A) is a sea and the phase (B) is an island. The phase (A) exhibits sound insulation performance near room temperature or lower, and the phase (B) exhibits sound insulation performance in a temperature range higher than room temperature. Also,
Since (B) is an island, the entire film is not too soft, the mechanical strength is secured, and the handleability is good without any problem.

Therefore, the above polyvinyl acetal resin
The cloud point (Ta) of the mixed solution of (a) and the plasticizer must be less than 50 ° C, and the cloud point (Tb) of the mixed solution of the polyvinyl acetal resin (b) and the plasticizer must be 50 ° C or more. is there. 50
The reason why the temperature is defined as a boundary is that the temperature is the upper limit for improving the sound insulation performance of the film near room temperature. Further, in the plasticized film, it is necessary that the phase (A) and the phase (B) undergo phase separation. Therefore, Tb-Ta needs to be 50 ° C. or higher. If the temperature is lower than 50 ° C., the phases (A) and (B) in the plasticized film
Does not cause phase separation. For example, since the phase (B) does not take the form of islands in the phase (A), even if the film exhibits sound insulation performance, its mechanical strength is not sufficient.

Preferably, the polyvinyl acetal resin (c) is composed of 100 parts by weight of the polyvinyl acetal resin (a) and 5 to 50 parts by weight of the polyvinyl acetal resin (b). When the amount of the polyvinyl acetal resin (b) is less than 5 parts by weight, there is almost no effect of mixing the resin, and the film does not exhibit excellent sound insulation performance. Conversely, if it exceeds 50 parts by weight, the film becomes cloudy and the transparency is significantly impaired. A more preferred range is from 10 to 30 parts by weight.

The acetal resin is not particularly limited. For example, polyvinyl alcohol (hereinafter abbreviated as PVA) is dissolved in hot water, the obtained aqueous PVA solution is kept at a predetermined temperature, and then the aldehyde is added thereto. , A catalyst is added, the acetalization reaction is allowed to proceed, and thereafter, the reaction solution is kept at a predetermined temperature at a high temperature, and then subjected to various steps of neutralization, washing, and drying to obtain a resin powder.

The PVA used for preparing the polyvinyl acetal resin is not particularly limited, but preferably has an average degree of polymerization of 500 to 5,000, more preferably 1,000 to 3,000. When the average degree of polymerization of PVA is less than 500, the strength of the resin layer and the interlayer is too weak, and the penetration resistance and impact energy absorption when the laminated glass is formed may be insufficient. PV
If the average degree of polymerization of A exceeds 5,000, molding of the resin layer may be difficult, and the strength of the resin layer and the interlayer may be too strong, resulting in penetration resistance and impact energy absorption when a laminated glass is formed. 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 various polyvinyl acetal resins thus obtained may be used alone or in combination of two or more. Among them, polyvinyl butyral resins obtained by acetalization with n-butyraldehyde are preferred. By using a polyvinyl butyral resin, the transparency, weather resistance, adhesiveness to glass, and the like of the resin layer and the interlayer are further improved.

The polyvinyl acetal resin (c) may be a mixture of a polyvinyl acetal resin (a) and a polyvinyl acetal resin (b).
It is preferable that it is composed of 100 parts by weight of the polyvinyl acetal resin (a) and 5 to 50 parts by weight of the polyvinyl acetal resin (b). When the amount of the polyvinyl acetal resin (b) is less than 5 parts by weight, there is almost no effect of mixing the resin, and the film does not exhibit excellent sound insulation performance. Conversely, if it exceeds 50 parts by weight, the film becomes cloudy and the transparency is significantly impaired. A more preferred range is from 10 to 30 parts by weight.

As the polyvinyl acetal resin (c), at least one of the polyvinyl acetal resin (a) and the polyvinyl acetal resin (b) has an acetalization degree of 60 to 85 mol% and an acetyl group amount of 8 to 30 mol.
1%, and the sum of the degree of acetalization and the amount of acetyl groups is 7
It is preferably a polyvinyl acetal resin of 5 mol% or more. When at least one acetal resin satisfies the above condition, the sound insulation performance of the low-temperature portion is significantly improved. When the degree of acetalization is lower than 60 mol%, the compatibility with the plasticizer is reduced, the glass transition temperature of the layer is hardly lowered, and the sound insulation performance in a low temperature region becomes insufficient. Further, the degree of acetalization does not become higher than 85 mol% due to the reaction mechanism.
More preferably, it is 63 mol% to 70 mol%. When the amount of the acetyl group is lower than 8 mol%, the compatibility with the plasticizer is reduced, and the sound insulating performance of the layer is not sufficiently exhibited. On the other hand, if it is higher than 30 mol%, the reaction rate of the aldehyde is remarkably reduced, which is not preferable. More preferably, it is 10 to 24 mol%. As described above, both the degree of acetalization and the amount of acetyl groups of the resin affect the compatibility with the plasticizer. If the total of these is less than 75 mol%, the compatibility with the plasticizer will be reduced, and it will be difficult to improve the sound insulation performance in the low temperature part.

The plasticizer is not particularly restricted but includes, for example, organic ester plasticizers such as monobasic acid ester and polybasic acid ester, and phosphoric acid such as organic phosphoric acid and organic phosphorous acid. A plasticizer is used. Specifically, among monobasic ester plasticizers, triethylene glycol,
Glycols such as tripropylene glycol and tetraethylene glycol, butyric acid, isobutyric acid, caproic acid, 2-
Glycol esters obtained by reaction with organic acids such as 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 carbon atoms with an organic acid such as adipic acid, sebacic acid, and azelaic acid. Examples of the phosphate plasticizer include tributoxyethyl phosphate, isodecylphenyl phosphate and the like.

Among the above various plasticizers, for example, triethylene glycol di-2-ethyl butyrate (3GH),
Triethylene glycol di-2-ethylhexanoate
(3GO), triethylene glycol di-n-heptanoate (3G7), triethylene glycol dicaprylate,
Triethylene glycol di-n-octoate, tetraethylene glycol di-2-ethyl butyrate, tetraethylene glycol di 2-ethylhexanoate (4GO),
Tetraethylene glycol di-n-heptanoate (4G
7), dihexyl adipate, dibenzyl phthalate and the like are preferably used, and particularly preferably used are 3GH, 3GO, 3G7, 4GO, 4G7 and the like. The above plasticizers may be used alone or in combination of two or more.

The amount of the plasticizer is not particularly limited, but is preferably 30 to 70 parts by weight based on 100 parts by weight of the polyvinyl acetal resin. When the amount is less than 30 parts by weight, the plasticization of the polyvinyl acetal resin may be insufficient. On the other hand, when the amount exceeds 70 parts by weight, the mechanical properties of the resin layer and the interlayer and the adhesive strength to glass become insufficient. Sometimes. Among the combinations of the polyvinyl acetal resin and the plasticizer, a polyvinyl butyral resin is used as the polyvinyl acetal resin, and 3GO, 3G7, and 4G are used as the plasticizer.
O, and at least one selected from the group consisting of 4G7
Combinations using seeds are particularly preferred.

Examples of the glass used for the laminated glass include inorganic glass, polycarbonate, and organic glass with polymethyl methacrylate.

The thickness of the above-mentioned interlayer film for laminated glass may be any thickness as long as that of an ordinary interlayer film for laminated glass.
0.3 to 1.6 mm is preferred. The larger the thickness is, the more excellent the sound insulation performance is, but the thickness is determined in consideration of the penetration resistance and the like required for the laminated glass.

As a method for manufacturing a laminated glass by laminating the interlayer film for a laminated glass between glass plates, a method used for manufacturing a general laminated glass is employed. For example, a method of sandwiching a film between glass plates from both sides thereof and manufacturing a laminated glass by hot pressing is performed.

[0031]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Examples 1 to 3 and Comparative Examples 1 to 4 (Preparation of resin film) PVB resin (a) having the composition shown in Table 1
And PVB resin (b) were mixed to prepare PVB (c).
Next, the PVB (c) and the (3GH) mixing roll were sufficiently mixed with the composition shown in Table 1 and a predetermined amount of the kneaded material was maintained at 150 ° C. for 30 minutes by a press molding machine to form a resin film having a thickness of 3 mm. did. (Preparation of laminated glass) The resin film obtained above was laminated from both sides with two float glasses each having a side of 300 mm, and this uncompressed laminated body was placed in a rubber bag at 2.7 kPa.
After degassing for 0 minutes, the sample was transferred to an oven at 90 ° C. while maintaining the degassed state, and the temperature was maintained for 30 minutes. The laminate preliminarily pressure-bonded by the vacuum press was thermocompression-bonded in an autoclave at a pressure of 118 MPa and a temperature of 135 ° C. to obtain a transparent laminated glass.

[0032]

[Table 1]

[Evaluation] The following evaluation was performed using the obtained laminated glass. The results are shown in Table 1. For sound insulation, a strip having a width of 3 cm was cut out into a test piece, and laminated glass having a penetration resistance, haze and heat resistance of 300 mm was used. (Sound insulation performance) At a predetermined temperature, the laminated glass was vibrated by a vibration generator ("G21-005D type vibrator", manufactured by Shinken Co., Ltd.) for a dumping test, and the obtained vibration characteristics were measured by a mechanical Impedance amplifier ("XG-81", Inc.
The vibration spectrum is amplified by an FFT analyzer (“FFT Spectrum Analyzer HP-
3582AA ", manufactured by Yokogawa Hewlett-Packer Company). From the obtained loss coefficient and the ratio of the resonance frequency to the glass, the transmission loss was calculated. Based on the obtained result, the TL value was defined as the minimum transmission loss near the frequency of 2000 Hz. Measurement is between 0 and 30 ° C and 10 ° C
Performed at intervals. (Penetration resistance) According to JIS R 3212, a specimen of laminated glass is horizontally held by a support frame of 30 cm × 30 cm, and a steel ball weighing 2.26 kg from above the laminated glass at a temperature of 23 ° C. Was allowed to fall freely to the center of the specimen. The test was repeated while gradually increasing the falling height of the steel ball, and the distance from the glass surface of the steel ball when 50% of the number of test pieces of laminated glass could prevent penetration of the steel ball was defined as the falling ball height (m). . The higher the falling ball height, the better the penetration resistance of the laminated glass. (Transparency) The haze value was measured according to JIS R3212. (Heat resistance) The laminated glass was left in a constant temperature layer set at an environmental temperature of 90 ° C. for 4 weeks. Thereafter, peeling and foaming of the film were observed at the end of the laminated glass.

[0034]

As described above, the interlayer film for laminated glass and the laminated glass of the present invention are excellent in basic performance such as transparency, penetration resistance and heat resistance, and furthermore excellent in sound insulation. ing.

[0035]

[Brief description of the drawings]

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

Claims (5)

[Claims] 1. A resin film comprising a polyvinyl acetal resin (c) composed of a polyvinyl acetal resin (a) and a polyvinyl acetal resin (b) and a plasticizer, wherein the resin film is composed of the polyvinyl acetal resin (a) and a plasticizer. The cloud point (Ta) of the mixed solution is less than 50 ° C., and the cloud point (Tb) of the mixed solution of the polyvinyl acetal resin (b) and the plasticizer is 50 ° C.
C. or higher and Tb-Ta ≧ 50, an interlayer film for laminated glass. 2. The laminated glass according to claim 1, wherein the polyvinyl acetal resin (c) comprises 100 parts by weight of the polyvinyl acetal resin (a) and 5 to 50 parts by weight of the polyvinyl acetal resin (b). For intermediate film. 3. At least one of the polyvinyl acetal resins (a) and (b) has an acetalization degree of 60 to 85 mol%, an acetyl group amount of 8 to 30 mol%, and a ratio of the acetalization degree to the acetyl group amount. The interlayer for laminated glass according to claim 1, wherein the total is 75 mol% or more. 4. The polyvinyl acetal resin (a) or (b) is a polyvinyl butyral resin, and the plasticizer is triethylene glycol di-2-ethylhexanoate or triethylene glycol di-n-heptanoate tetra. The interlayer film for laminated glass according to any one of claims 1 to 3, wherein the interlayer film is at least one selected from the group consisting of ethylene glycol-di-2-ethylhexanoate and tetraethylene glycol di-n-heptanoate. . 5. The method according to claim 1, wherein at least a pair of glasses is provided.
Interposed interlayer film for laminated glass according to any of
Laminated glass characterized by being integrated.