JP2001220184A - Interlayer for laminated glass and laminated glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interlayer for laminated glass and laminated glass which is excellent in basic performance necessary for laminated glass such as transparency, weather resistance, shock energy absorbency and adhesion with glass, prevents the degradation of TL value due to the coincidence effect and exhibits excellent sound insulation in a wide temperature range stably for a long time without impairing the moldability and handling property as the interlayer for laminated glass. SOLUTION: This interlayer for laminated glass consisting of plasticized polyvinylacetal resin film containing polyvinyl acetal resin and plasticizer is featured in that the gel fraction of a surface layer is higher than that of an intermediate layer and the difference between both is >=30% when the region up to 15% of the total thickness in the thickness direction from both surfaces is defined as the surface layer and the part besides the same is defined as the intermediate layer.

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 and a laminated glass using the interlayer film.

[0002]

2. Description of the Related Art Conventionally, an interlayer film for laminated glass, such as a polyvinyl butyral resin film plasticized by a plasticizer, is interposed between a pair of glass plates, and the laminated glass obtained by integration is broken when broken. Since the fragments are not scattered and are excellent in safety and also excellent in sound insulation, they are widely used, for example, for window glasses of traffic vehicles such as automobiles and window glasses of buildings.

[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 A 4708, as shown by the solid line in FIG.
In the case of Hz or more, each is defined as a constant value according to the sound insulation class. However, as shown by the dashed line in FIG. 1, the sound insulation of the glass plate is significantly reduced due to the coincidence effect in a frequency region around 2000 Hz. Corresponding to not maintaining the predetermined sound insulation performance). Here, the coincidence effect means that when a sound wave enters 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. As a result, sound transmission A phenomenon that occurs. In the above-mentioned conventional laminated glass, a decrease in sound insulation performance due to such a coincidence effect is unavoidable in a frequency region centered at 2000 Hz, and improvement in this point 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.

As described above, in order to improve the sound insulation performance of the laminated glass, the above-mentioned coincidence effect is reduced,
FIG. 1 shows a minimum portion of the transmission loss caused by the coincidence effect (hereinafter, the transmission loss of the minimum portion is referred to as a TL value.
It is necessary to prevent lowering of Conventionally, various measures have been proposed as means for preventing a decrease in the TL value, such as an increase in the mass of laminated glass, multi-layering of glass, subdivision of the glass area, and improvement of means for supporting laminated glass plates. However, none of these have sufficiently satisfactory effects, and the cost is not practically reasonable.

[0006] Recently, the demand for sound insulation performance has been increasing more and more, for example, for architectural glazing, excellent sound insulation properties are required near room temperature. That is, the temperature at which the sound insulation performance is the most excellent (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 =
The TLmax value itself is required to be large. The same thing is observed in window glasses for automobiles, and there are increasing places where sound insulation is required, such as wind noise during high-speed running and vibration from an engine unit. Further, in practice, these laminated glasses are exposed to a wide range of environmental temperature changes from a low temperature range to a high temperature range, so that 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 polyvinyl butyral 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.

To cope with the above problem, for example, Japanese Patent Application Laid-Open No. 2-229742 discloses a glass transition temperature of 15 ° C.
The following polymer films, for example, a sound insulating laminated glass comprising a laminate of a vinyl chloride-ethylene-glycidyl methacrylate copolymer film and a plasticized polyvinyl acetal film are disclosed. However, such laminated glass is not available on JI
The sound insulation grade according to SA4706 does not show the sound insulation property exceeding Ts-35 grade, and the temperature range showing the sound insulation property is limited, so that good sound insulation performance in a wide temperature range cannot be exhibited.

Furthermore, Japanese Patent Application Laid-Open No. 51-106190 proposes that a structure having vibration damping properties in a wide temperature range is obtained by laminating two or more resins having different glass transition temperatures. I have. Although such a structure is recognized to have improved vibration damping properties over a wide temperature range,
There is no description about sound insulation, transparency, etc. required for laminated glass, and this structure does not satisfy requirements such as high impact energy absorption required for safety glass and scattering prevention upon glass breakage.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention is excellent in basic performance required for laminated glass such as transparency, weather resistance, impact energy absorption, and adhesion to glass. An interlayer film for laminated glass which can prevent a decrease in TL value due to a coincidence effect and exhibit stable sound insulation performance over a wide temperature range for a long period of time without impairing the moldability and handleability as an interlayer film for laminated glass; The purpose is to provide laminated glass.

[0011]

An interlayer for laminated glass according to the invention of claim 1 (hereinafter referred to as invention 1) is a laminated glass comprising a plasticized polyvinyl acetal resin film containing a polyvinyl acetal resin and a plasticizer. The intermediate layer for laminated glass, the region from both surfaces of the laminated glass intermediate film in the thickness direction up to 15% of the total film thickness is the surface layer, and the other part is the intermediate layer. Is characterized in that the gel fraction of the surface layer is higher and the difference is 30% or more.

[0012] The interlayer film for laminated glass according to the invention of claim 2 (hereinafter referred to as invention 2) is the interlayer film for laminated glass according to the above invention 1, wherein the polyvinyl acetal resin is a polyvinyl butyral resin and a plasticizer. Is triethylene glycol di-2-ethyl butyrate,
It is at least one selected from the group consisting of triethylene glycol di-2-ethylhexanoate and triethylene glycol di-n-heptanoate.

The laminated glass according to the invention described in claim 3 (hereinafter referred to as invention 3) is characterized in that an interlayer film for laminated glass according to the invention 1 or 2 is interposed between at least a pair of glasses and integrated. Features. Hereinafter, the present invention will be described in detail.

The present inventors believe that the sound insulation performance of a laminated glass depends on the dynamic viscoelastic properties of an interlayer film for a laminated glass (hereinafter simply referred to as an interlayer film). It was found that the loss tangent was most affected by the loss tangent, and from this, the inventor made an intensive study to control the loss tangent of the interlayer film so that the sound insulation performance of the laminated glass could be favorably maintained over a wide temperature range. The loss tangent of the intermediate film is affected by the glass transition temperature (hereinafter, referred to as Tg) of the intermediate film. In particular, the temperature range showing the maximum value of the loss tangent corresponds to the vicinity of Tg of the intermediate film. Therefore, for example, in order to improve the sound insulation performance in a lower temperature range than room temperature, it is desirable that the Tg of the interlayer be located near room temperature, and specifically, a method of increasing the content of the plasticizer in the interlayer. Is often used. However, in this case, the Tg of the intermediate film becomes lower than room temperature, so that the intermediate film becomes very soft and sticky, so that the handleability of the intermediate film is impaired.

Therefore, as a result of further intensive studies, an interlayer film having improved sound insulation near or below room temperature after producing a laminated glass without impairing the handleability of the interlayer film was found. The present invention has been completed.

The method for producing the polyvinyl acetal resin used for the plasticized polyvinyl acetal resin film (hereinafter simply referred to as a resin film) of the present invention is not particularly limited.
For example, polyvinyl alcohol (hereinafter referred to as PVA)
Is dissolved in hot water, and while maintaining the obtained aqueous solution at a predetermined temperature, an aldehyde and a catalyst are added thereto to complete the acetalization reaction, followed by neutralization, washing and drying to obtain a powder of polyvinyl acetal resin. There is a way to get

In the above method for producing a polyvinyl acetal resin, the PVA is not particularly limited, but preferably has an average degree of polymerization of 500 to 5,000, and has an average degree of polymerization of 10 to 5000.
Those having a size of from 00 to 3000 are more preferred. When the average degree of polymerization of PVA is less than 500, the penetration resistance and impact energy absorption as a laminated glass may be insufficient. Conversely, when the average degree of polymerization of PVA exceeds 5,000, the resin film is formed. In some cases, the strength of the resin film and the intermediate film is too strong, and the resulting laminated glass may have insufficient penetration resistance and impact energy absorption.

The aldehyde used to obtain the polyvinyl acetal resin includes, for example, formaldehyde, acetaldehyde, propionaldehyde, n-
Examples thereof include butyraldehyde, isobutyraldehyde, valeraldehyde, n-hexylaldehyde, 2-ethylbutyraldehyde, benzaldehyde, and cinnamaldehyde. These may be used alone or two or more of them may be used in combination.

The various polyvinyl acetal resins thus obtained are not particularly limited, but polyvinyl butyral resin (hereinafter referred to as PVB) obtained by acetalization with n-butyraldehyde is used for the transparency and weather resistance of the resin layer and the intermediate film. It is preferable because the adhesiveness to glass and the like become more excellent.

The resin film used in the present invention is plasticized with a plasticizer. The plasticizer is not particularly limited. For example, a monobasic acid ester, a polybasic acid ester or the like may be used. Organic ester plasticizers and phosphoric acid plasticizers such as organic phosphoric acid and organic phosphorous acid may be used. These may be used alone or in combination of two or more.

Specifically, examples of the monobasic acid ester-based plasticizer include glycols such as triethylene glycol, tripropylene glycol and tetraethylene glycol, butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, and the like. Glycol esters obtained by reaction with organic acids such as heptanoic acid and 2-ethylhexylic acid are exemplified.

The polybasic acid ester-based plasticizer is obtained, for example, by reacting a linear or branched alcohol having 4 to 8 carbon atoms with an organic acid such as adipic acid, sebacic acid or azelaic acid. And the like. Examples of the phosphate plasticizer include tributoxyethyl phosphate, isodecylphenyl phosphate and the like.

Among the above various plasticizers, triethylene glycol di-2-ethylbutyrate (3GH) and triethylene glycol di-2-ethylhexanoate (3G)
O), triethylene glycol di-n-heptanoate (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.
At least one plasticizer selected from the group consisting of GH, 3GO, and 3G7 is particularly preferably used.

The content of the plasticizer is not particularly limited, but may be a polyvinyl acetal resin 100.
It is preferably 30 to 70 parts by weight based on parts by weight. 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 and the adhesive strength to glass of the obtained intermediate film may be insufficient. There is.

In the intermediate film of the present invention, when the region from both surfaces of the intermediate film in the thickness direction up to 15% of the total film thickness is the surface layer and the other portion is the intermediate layer, the surface layer and the intermediate layer The gel fraction is higher in the surface layer and the difference is 30%
That is all. By limiting the content to the above range, the intermediate layer is soft and exhibits sound insulation performance, and the surface layer is harder than the intermediate layer, so that the handleability and mechanical strength of the entire intermediate film are improved.

If the difference between the gel fractions is less than 30%, the difference between the hardness of the intermediate layer and the hardness of the surface layer is so small that it is not possible to achieve both sound insulation performance and handleability. If the surface area exceeds 15% of the total film thickness in the thickness direction from the surface of the intermediate film, a high-hardness region in the intermediate film increases, so that good sound insulation performance cannot be obtained.

The means for increasing the gel fraction of the surface layer of the intermediate film is not particularly limited. For example, a method of crosslinking the surface layer by electron beam irradiation or UV irradiation, or a surface treatment by low-temperature plasma, etc. No.

The total thickness of the intermediate film according to the present invention is preferably 0.3 to 1.6 mm, which is a commonly used thickness. The larger the thickness, the better the sound insulation performance, but in consideration of the penetration resistance required as a laminated glass,
Practically, the above-mentioned thickness range is preferable.

The method for producing an intermediate film according to the present invention includes:
For example, a method of forming each layer of the resin film separately, and then laminating them between glass plates,
Various molding methods such as a method of integrally molding these layers using a multilayer molding machine can be applied.

Next, the laminated glass according to Invention 3 is formed by interposing the interlayer film for laminated glass according to Invention 1 or 2 above between at least a pair of glasses.

As a method for producing the above laminated glass, a method used for producing ordinary laminated glass is employed.
For example, there is a method in which an interlayer film is sandwiched between glass plates from both sides thereof, and a laminated glass is manufactured by hot pressing.

Further, as the above-mentioned glass, not only ordinary inorganic transparent glass but also a transparent body having higher rigidity than the above-mentioned plasticized polyvinyl acetal resin film such as a polycarbonate plate or a polymethyl methacrylate plate may be used. Can also.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 (1) Preparation of Intermediate Film 100 parts by weight of PVB (butyralization degree: 60.2 mol%, acetyl group content: 11.9 mol%), 3 parts of plasticizer
The mixture obtained by adding 50 parts by weight of GH was sufficiently kneaded with a mixing roll. Next, a predetermined amount of the kneaded material was held at 150 ° C. for 30 minutes using a press molding machine, to produce a resin film having a thickness of 0.7 mm. The obtained resin film was attached to the inner surface of a cylindrical reaction tube having a length of 170 mm and an inner diameter of 50 mm.
A 30 Watt low-pressure mercury lamp having an outer diameter of 15 mm was installed, and irradiated with ultraviolet rays mainly composed of light beams having wavelengths of 2537 Å and 1849 Å for 5 minutes to obtain an intermediate film.

(2) Preparation of Laminated Glass The interlayer film obtained in the above (1) is sandwiched from both sides by two pieces of float glass having a square of 300 mm on a side and a thickness of 3 mm, and this laminate is put into a rubber bag. Then, after deaeration was performed at a degree of vacuum of 2.7 kPa for 20 minutes, the substrate was transferred to an oven in a deaerated state, kept at 90 ° C. for 30 minutes, and vacuum-pressed.
The thus preliminarily bonded laminated glass was fully pressed in an autoclave under the conditions of a pressure of 1.2 MPa and a temperature of 135 ° C. to obtain a transparent laminated glass.

(3) Evaluation The performance of the interlayer film and the laminated glass obtained in the above (1) and (2) was evaluated by the following method. The results were as shown in Table 1.

1) Gel fraction An intermediate film of 3 cm square was placed on a microtome, and 0.1 mm thick portions were cut from both surfaces of the intermediate film. After measuring the weight (Xg) of the cut film piece and the remaining film piece, the film piece was put in a 1: 1 mixed solvent of methyl alcohol and butyl alcohol, and left at room temperature for 24 hours with stirring. After 24 hours, the insolubles were taken out and left in a vacuum oven at 50 ° C. for 5 hours to completely remove the solvent in the insolubles. The weight (Yg) of the insoluble matter thus dried is measured,
The gel fraction was calculated and evaluated according to the formula of (Y / X) × 100.

2) Handleability of Intermediate Film The feel of touching the intermediate film by hand was examined, and the handleability was evaluated by dividing it into a case having no stickiness and no problem and a case having stickiness.

3) Sound insulation performance At a predetermined temperature, the laminated glass is subjected to a vibration generator for a dumping test (vibrator “G21-005D” manufactured by Shinken Co., Ltd.).
Vibration characteristics obtained are amplified by a mechanical impedance amplifier (manufactured by Rion, "XG-81"), and the vibration spectrum is analyzed by an FFT analyzer (manufactured by Yokogawa Hewlett Packer, "FFT spectrum analyzer, HP-3582AA "). The transmission loss was calculated from the loss coefficient obtained here and the ratio of the resonance frequency to glass. This transmission loss has a frequency of 200
The minimum value around 0 Hz was evaluated as the TL value. The measurement was performed at 10 ° C. intervals between 0 and + 30 ° C.

Example 2 In the production of an intermediate film, PV
An intermediate film and a laminated glass were obtained in the same manner as in Example 1 except that butyralization degree of B was 63.6 mol%, acetyl group content was 13.0 mol%, and 3GO was used as a plasticizer at 60 parts by weight. .

Example 3 A resin film obtained in the same manner as in Example 2 was supplied to a reaction vessel of a low-temperature plasma apparatus, and the pressure in the vessel was reduced to 0.665 Pa or less by a vacuum pump.
Thereafter, oxygen was injected up to 1.33 kPa as a reaction gas, and a voltage of 13.56 MHz and an output of 200 W was applied to the electrodes for 0.03 minutes. A laminated glass was obtained in the same manner as in Example 1 using the intermediate film obtained by the above treatment.

(Example 4) A resin film obtained in the same manner as in Example 2 except that 60 parts by weight of 3G7 was used as a plasticizer in the preparation of the intermediate film, was treated with an electron beam accelerator to obtain 3 Mrads of electron. The line was irradiated. Using the intermediate film thus obtained, a laminated glass was obtained in the same manner as in Example 1.

Example 5 An intermediate film and a laminated glass were produced in the same manner as in Example 1 except that the resin film obtained in Example 2 was irradiated with ultraviolet rays for 5 minutes. I got

(Comparative Example 1) An intermediate film and a laminated glass were obtained in the same manner as in Example 1 except that no ultraviolet irradiation was performed in the production of the intermediate film.

(Comparative Example 2) An intermediate film and a laminated glass were obtained in the same manner as in Example 2 except that no ultraviolet irradiation was performed in the production of the intermediate film.

Comparative Example 3 An intermediate film and a laminated glass were obtained in the same manner as in Example 1, except that ultraviolet rays were irradiated for 15 minutes in the production of the intermediate film.

The performance of the interlayer films and laminated glass obtained in Examples 2 to 4 and Comparative Examples 1 to 3 was evaluated in the same manner as in Example 1. The results were as shown in Table 1.

[0048]

[Table 1]

As is clear from Table 1, the interlayer film and the laminated glass of the examples according to the present invention have no problem in handleability of the interlayer film, have no decrease in TL value, and are excellent in a wide temperature range. It can exhibit sound insulation performance.

[0050]

As described above, the interlayer film for a laminated glass according to the present invention and the laminated glass using the same have a TL value due to the coincidence effect without impairing the moldability and handleability as an interlayer film for a laminated glass. , And excellent sound insulation performance over a wide temperature range can be exhibited stably for a long period of time. Therefore, it is suitably used for vehicles such as automobiles and window glasses for buildings.

[0051]

[Brief description of the drawings]

FIG. 1 is a diagram showing a change in transmission loss depending on a frequency in evaluation of sound insulation performance according to the present invention.

Continued on the front page F-term (reference) 4F071 AA30 AC10 AE04 AF30 AF50 AF57 AF58 AG05 AG15 AH19 BA02 BB03 BC01 4F100 AG00B AG00C AH02A AH02H AK23A BA01 BA03 BA06 BA10B BA10C BA13 BA42 CA04A EJ17 EJ53A01 J01AJK11 EJ53A EJ54A01 JL09 JN01 4G061 AA11 BA01 BA02 CB05 CB18 CB19 CD02 CD12 CD18 4J002 BE061 EH056 FD026

Claims (3)

[Claims] 1. An interlayer film for laminated glass comprising a plasticized polyvinyl acetal resin film containing a polyvinyl acetal resin and a plasticizer, wherein the interlayer film has a total thickness in the thickness direction from both surfaces of the interlayer film for laminated glass. When the region up to 15% is the surface layer and the other part is the intermediate layer, the gel fraction between the surface layer and the intermediate layer is higher in the surface layer and the difference is 30% or more. Interlayer film for laminated glass. 2. The polyvinyl acetal resin is a polyvinyl butyral resin, and the plasticizer is formed from triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate and triethylene glycol di-n-heptanoate. The interlayer for laminated glass according to claim 1, wherein the interlayer is at least one selected from the group consisting of: 3. The method according to claim 1, wherein at least between the pair of glasses.
Or a laminated glass characterized by being integrated with the interlayer film for laminated glass according to 2 above interposed therebetween.