JPH06926A - Intermediate film for laminated glass - Google Patents

Abstract

PURPOSE:To enhance the sound insulating properties without imparing transparency, weatherability and impact energy absorbability by sandwiching two kinds of polyvinyl acetal films consisting of polyvinyl acetal resins having specific acetyl group amounts and plasticizers between two glass plates. CONSTITUTION:A layer consisting of a polyvinyl acetal resin having a 4-6C acetal group and characterized by that the mol ratio of the average value of the amount of ethylene groups to which an acetyl group is bonded to the total amount of the ethylene groups of a main chain is 8-30mol.% and a plasticizer is used. A layer consisting of a polyvinyl acetal resin having a 3-4C acetal group and characterized by that the mol ratio of the average value of the amount of ethylene groups to which an acetyl group is bonded to the total amount of ethylene groups of a main chain is 4mol.% or less and a plasticizer is laminated to said 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.

[0002]

BACKGROUND OF THE INVENTION In general, a laminated glass formed by sandwiching a resin film between a pair of glass plates is excellent in safety because fragments are not scattered when it is broken, and therefore, for example, window glass for transportation vehicles such as automobiles. It is widely used for window glass of buildings.

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

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

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

On the other hand, it is known that human hearing has an extremely high sensitivity in the range of 1000 to 6000 Hz from the equal loudness curve as compared with other frequency regions, and it is necessary to eliminate the deterioration of the sound insulation performance due to the coincidence effect. Turns out to be extremely important for soundproofing.

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

[0008] Conventionally, various measures have been proposed as means for preventing a decrease in the TL value, such as increasing the mass of laminated glass, making glass into multiple layers, subdividing the glass area, and improving the glass plate supporting means. However, none of them bring a sufficiently satisfactory effect, and the cost is not reasonable enough for practical use.

The demand for sound insulation performance has been increasing recently,
For example, architectural window glass requires excellent sound insulation at around room temperature. That is, the transmission loss (TL value) with respect to temperature
The temperature with the best sound insulation performance (maximum sound insulation performance temperature = TLmax temperature) obtained by plotting is around room temperature, and the maximum value of sound insulation performance (maximum sound insulation performance = TLma).
Excellent sound insulation is required, which means that the x value itself is large.

However, the conventional laminated glass for a windshield of a vehicle using a 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 room temperature.

[0011]

2. Description of the Related Art As a prior art of an interlayer film intended to improve the sound insulation performance of laminated glass, for example, Japanese Patent Publication No. 46-5830 discloses a fluidity which is about three times higher than the fluidity of an ordinary interlayer film. An interlayer film made of a resin having a certain degree, for example, polyvinyl butyral is described. However, this has the serious problem that the absolute sound insulation of the laminated glass is low.

Japanese Patent Laid-Open No. 2-229742 discloses a polymer film having a glass transition temperature of 15 ° C. or lower, such as vinyl chloride.
An intermediate film composed of a laminate of an ethylene-glycidyl methacrylate copolymer film and a plasticized polyvinyl acetal film is described. However, this is JIS A470
The sound insulation class according to 6 does not show sound insulation exceeding Ts-35 class, and the temperature range showing sound insulation is limited,
It cannot exhibit good sound insulation over a wide temperature range.

Japanese Laid-Open Patent Publication No. 62-37148 discloses a laminate composed of two or more kinds of viscoelastic materials having different acoustic resistances for the purpose of preventing deterioration of sound insulation performance in the coincidence region of a rigid plate (glass plate). For example, an intermediate film composed of a laminate of a polymethylmethacrylate film and a vinyl chloride-ethylene-glycidyl methacrylate copolymer film has been proposed. However, this has a drawback in that the sound insulation is not satisfactory in the initial performance and the performance is deteriorated in the long-term durability. The cause is that these resins cause mass transfer due to the diffusion action at the interface, and the effect of the constraining layer at the interface is weakened.

Japanese Patent Laid-Open Publication No. 60-27630 proposes an interlayer film containing a polyvinyl chloride resin containing a plasticizer as a measure for improving the sound insulation in the initial stage. In this interlayer film, the initial sound-insulating property is slightly improved, but it was necessary to change the processing condition from the condition of the polyvinyl butyral type interlayer film in the matching processing. At present, polyvinyl butyral-based interlayer films are still the mainstream of materials for laminated glass interlayer films, and the pre-bonding conditions in the bonding processing step are currently set to the conditions for polyvinyl butyral-based interlayer films.

JP-A-62-278148 proposes an interlayer film for a low self-adhesive laminated glass which comprises a polyvinyl acetal resin having an acetal group having 6 to 10 carbon atoms and a plasticizer. However, the sound insulation of this interlayer film is still insufficient.

Japanese Unexamined Patent Publication (Kokai) No. 51-106190 proposes to obtain a structure having a vibration damping property in a wide temperature range by laminating two or more kinds of resins having different glass transition temperatures. It is recognized that this structure has improved damping properties over a wide temperature range. However, in this publication, there is no description about sound insulation, transparency, etc. required as a laminated glass, and this structure has requirements for high impact energy absorption required for safety glass, shatterproof property at the time of glass breakage, etc. It does not meet.

Japanese Unexamined Patent Publication (Kokai) No. 62-10106 proposes polyvinyl butyral lightly crosslinked by intermolecular bonding. However, a laminated glass using an interlayer film formed by adding a plasticizer to this resin can only obtain a sound insulation performance of about 30 dB near room temperature.

Japanese Unexamined Patent Publication (Kokai) No. 3-124441 describes an intermediate film comprising a laminate of two or more layers of polyvinyl butyral containing a plasticizer and having different degrees of polymerization. However, the desired sound insulation performance cannot be obtained by simply laminating two or more layers of polyvinyl butyral having different degrees of polymerization.

Japanese Unexamined Patent Publication (Kokai) No. 62-9928 discloses an extruded sheet comprising a polyvinyl butyral resin lightly crosslinked by a stable intermolecular bond and a plasticizer.
However, this cannot clear JIS30 grade even at around room temperature, and the sound insulation performance is too low.

Japanese Patent Laid-Open No. 4-254444 discloses a film comprising a polyvinyl acetal having an acetal group having 6 to 10 carbon atoms and a plasticizer, and an acetal group having 1 to 10 carbon atoms.
An intermediate film in which a film made of polyvinyl acetal and a film made of a plasticizer is laminated is proposed. With this interlayer film, the effect of improving the sound insulation performance is certainly recognized, and the sound insulation performance due to the temperature change does not largely change, but these effects are not yet sufficient.

Among the intermediate films of JP-A-4-254444, a film made of polyvinyl butyral and a plasticizer is laminated on both surfaces of a film made of a polyvinyl acetal having an acetal group having 6 to 8 carbon atoms and a plasticizer. The intermediate film is JI
The effect of improving the sound insulation performance is recognized in that it is S35 grade. However, this does not have good sound insulation in a wide temperature range, which is an important requirement for a sound insulation interlayer film.

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

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

[0024]

Means for Solving the Problems The present inventors have found that a film made of polyvinyl acetal plasticized with a plasticizer, which is used as an interlayer film for laminated glass, has a transparency,
Weather resistance, impact energy absorption, adhesion to glass, etc.
Focusing on the fact that various properties are well balanced, in order to improve the sound insulation properties without impairing such preferable properties, the inventors have earnestly studied to improve an interlayer film containing polyvinyl acetal as a resin component.

As a result, at least one each of two kinds of polyvinyl acetal films, which are obtained by acetalizing polyvinyl alcohol with an aldehyde, and each of which comprises a polyvinyl acetal resin having a specific amount of acetyl groups and a plasticizer, are laminated, The present invention has been completed by finding that the coincidence effect is alleviated near room temperature by sandwiching this laminated body with two glass plates.

That is, in the first interlayer film for laminated glass according to the present invention, the acetal group has 4 to 6 carbon atoms,
A polyvinyl acetal resin (A) in which the average value of the amount of ethylene groups having acetyl groups bonded to the total amount of ethylene groups in the main chain (that is, the amount of residual acetyl groups) is 8 to 30 mol% And at least one layer (A) comprising a plasticizer, and an acetal group having 3 to 4 carbon atoms, and an average value of the amount of ethylene groups to which acetyl groups are bonded, all ethylene groups in the main chain It is formed by laminating at least one layer (B) comprising a polyvinyl acetal resin (B) having a mole fraction of 4 mol% or less with respect to the amount and a plasticizer.

The second interlayer film for laminated glass according to the present invention is the polyvinyl acetal resin in the first interlayer film.
(A) is a resin having a standard deviation σ of the amount of ethylene groups to which acetyl groups are bonded is 0.8 or less.

The third interlayer film for laminated glass according to the present invention is the polyvinyl acetal resin in the first interlayer film.
(A) is one in which the standard deviation σ of the amount of ethylene groups having acetyl groups bonded is 2.5 to 8.

The fourth interlayer film for laminated glass according to the present invention is the same as the first interlayer film, except that the polyvinyl acetal resin is used.
The molecular weight distribution ratio (weight average molecular weight Mw / number average molecular weight Mn) of (A) is 1.01 to 1.50.

The fifth interlayer film for laminated glass according to the present invention is the same as the first interlayer film, except that the polyvinyl acetal resin is used.
The molecular weight distribution ratio (weight average molecular weight Mw / number average molecular weight Mn) of (A) is 3.5 to 20.

In the sixth interlayer film for laminated glass according to the present invention, in the first interlayer film, at least the outermost layer on the side where weather resistance is required among the laminated layers has an effective ultraviolet absorption wavelength of 300 to 300. A layer containing an ultraviolet absorber having a wavelength of 340 nm so that the ultraviolet absorption coefficient X is 0.01 or more.
It is composed of (B).

The seventh interlayer film for laminated glass according to the present invention is the same as the first interlayer film, except that the polyvinyl acetal resin is used.
The degree of blocking Y of the ethylene group to which the acetyl group is bonded in (A) is 0.15 to 0.40 as defined below.

The eighth interlayer film for laminated glass according to the present invention is the same as the first interlayer film, except that the polyvinyl acetal resin is used.
The degree of blocking Y of the ethylene group to which the acetyl group is bonded in (A) is 0.55 to 0.90 as defined below.

Blocking Degree Y = 0.5 × S / (T × U) Here, S, T, and U in the formula are respectively —CH (OH) −.
CH ₂ — (OCOCH ₃ ) CH—the amount of methylene groups in the structure (S),
It represents the amount of hydroxyl groups (T) and the amount of acetyl groups (U).

The polyvinyl acetal resin is obtained by acetalizing polyvinyl alcohol with an aldehyde, and usually has an acetal group, an acetyl group and a hydroxyl group in the ethylene group of the main chain.

The average degree of polymerization of polyvinyl alcohol, which is a raw material for producing the polyvinyl acetal resin, is preferably 5
It is from 00 to 3000. This is because if the degree of polymerization is less than 500, the penetration resistance of the laminated glass will be poor, and if it exceeds 3,000, the strength will be too large to be normally used as a safety glass. More preferable degree of polymerization is 1000 to 250.
It is 0.

As the aldehyde having 4 to 6 carbon atoms, which is used for obtaining the polyvinyl acetal resin (A) having 4 to 6 carbon atoms in the acetal group, n-butyraldehyde,
Isobutyraldehyde, valeraldehyde, n-hexylaldehyde, 2-ethylbutyraldehyde and the like are used alone or in appropriate combination. When the carbon number of the aldehyde is less than 4, sufficient sound insulation performance cannot be obtained. Aldehydes having more than 6 carbon atoms have extremely poor reactivity for acetalization, and the resulting interlayer film does not exhibit sufficient sound insulation performance near room temperature. As more preferable aldehydes, n-butyraldehyde, isobutyraldehyde, and n-hexylaldehyde are used alone or in combination.

The aldehyde having 3 to 4 carbon atoms used for obtaining the polyvinyl acetal resin (B) having 3 to 4 carbon atoms in the acetal group includes propionaldehyde, n-butyraldehyde, isobutyraldehyde and the like. Used alone or in combination of two or more.

In the polyvinyl acetal resin (A),
The average value of the amount of residual acetyl groups is limited to 8 to 30 mol%. The reason is that if this amount is 8 mol% or less, the sound insulation performance is not sufficiently exhibited, and if it is 30 mol% or more, the reaction rate of the aldehyde is significantly reduced. In the polyvinyl acetal resin (A), the more preferable average value of the amount of acetyl groups is 10 to 24 mol%.

In the polyvinyl acetal resin (B),
The average value of the amount of residual acetyl groups is limited to 4 mol% or less. The reason is that when this amount is 4 mol% or more, the difference from the average value of the residual acetyl groups of the polyvinyl acetal resin (A) is small, and good sound insulation performance cannot be exhibited.
In the polyvinyl acetal resin (B), the more preferable average value of the amount of acetyl groups is 0 to 2 mol%.

Polyvinyl acetal resins (A) and (B)
In particular, it is preferable to use n-butyraldehyde. By using n-butyraldehyde, the adhesive strength between the layers constituting the laminated film is further increased, and the polyvinyl acetal resin can be obtained in the same manner as in the conventional synthesis method of butyral resin.

Polyvinyl acetal resins (A) and (B)
As a mixture of two or more kinds of polyvinyl acetal resins obtained by acetalizing polyvinyl alcohol with the above aldehydes, the above-mentioned aldehydes other than the above aldehydes may be used within a range not exceeding 30% by weight based on the total acetal portion. It does not depart from the scope of the present invention to use the polyvinyl acetal resin obtained by acetalizing the above aldehyde in combination.

The degree of acetalization of the polyvinyl acetal resin (A) is preferably 40 mol% or more. If the degree of acetalization is less than 40 mol%, the compatibility with the plasticizer is poor and it is difficult to add the plasticizer in an amount necessary for exhibiting the sound insulation performance. A more preferable degree of acetalization is 50 mol% or more.

The degree of acetalization of the polyvinyl acetal resin (B) is preferably 50 mol% or more. If the degree of acetalization is less than 50 mol%, the compatibility with the plasticizer is poor and it is difficult to add the plasticizer in an amount necessary to secure penetration resistance.

In the present invention, as a method for obtaining the polyvinyl acetal resins (A) and (B), for example, polyvinyl alcohol is dissolved in hot water, the obtained aqueous solution of polyvinyl alcohol is kept at a predetermined temperature, and then this is added. There is a method in which the above-mentioned aldehyde and a catalyst are added, an acetalization reaction is allowed to proceed, and then the reaction liquid is kept at a predetermined temperature at a high temperature, followed by various steps of neutralization, water washing and drying to obtain a resin powder.

In the second interlayer film, the polyvinyl acetal resin (A) has a molar fraction of the average amount of acetyl groups with respect to the total amount of ethylene groups of the main chain, that is, the average amount of residual acetyl groups is 8 ~ 30 mol%. When the average value of the amount of residual acetyl groups is less than 8 mol%, the sound insulation performance is good in a temperature range higher than room temperature, but the good sound insulation performance may not be obtained near room temperature. On the contrary, if the average value of the residual acetyl groups exceeds 30 mol%,
Sound insulation is good at low temperatures, but it is difficult to obtain good sound insulation at around room temperature. The average value of the amount of residual acetyl groups is particularly preferably 12 to 24 mol%.

In the polyvinyl acetal resin (A), the standard deviation σ of the component fraction of the ethylene group to which the acetyl group is bonded is 0.8 or less. If this standard deviation σ exceeds 0.8, the maximum sound insulation performance may decrease. A particularly preferable range of the standard deviation σ of the component fraction of the ethylene group to which the acetyl group is bonded is 0.5 or less.

In the third interlayer film, the average value of the residual acetyl groups in the polyvinyl acetal resin (A) is also 8 to 30 mol%. Polyvinyl acetal resin (A)
The particularly preferable range of the above-mentioned mole fraction of
Is.

In the polyvinyl acetal resin (A), the standard deviation σ of the component fraction of the ethylene group to which the acetyl group is bonded is 2.5-8. If this standard deviation σ is less than 2.5, good sound insulation may not be obtained in a wide temperature range. On the contrary, when the standard deviation σ exceeds 8, the maximum sound insulation performance may decrease. A particularly preferred range of the standard deviation σ of the component fraction of the ethylene group to which the acetyl group is bonded is 3 to 6.

The polyvinyl acetal resin having a standard deviation σ of 2.5 to 8 is obtained by, for example, saponifying polyvinyl acetate in several steps and acetalizing the obtained polyvinyl alcohol, and the saponification degree. It is obtained by a method of acetalizing a blended product of a plurality of polyvinyl alcohols having different acetyl groups, or a method of blending a plurality of polyvinyl acetals having different acetyl groups. The most economically preferable method is to adjust the distribution of ethylene groups to which acetyl groups are bonded at the stage of polyvinyl alcohol,
It is a method of acetalizing this polyvinyl alcohol.

In the second and third interlayer films, the standard deviation σ of the component fraction of the ethylene group to which the acetyl group is bonded in the polyvinyl acetal resin (B) is particularly limited in order to improve the sound insulation performance. Not done.

In the fourth interlayer film, the molecular weight distribution ratio (M
By using the polyvinyl acetal resin (A) with w / Mn of 1.01 to 1.50, the coincidence effect at room temperature is remarkably alleviated, and the sound insulation according to JIS A4706 is superior to Ts-35. Sex is obtained.

It is difficult to synthesize a resin having a molecular weight distribution ratio (Mw / Mn) of less than 1.01, and if this ratio exceeds 1.50, the TL value decreases.

The polyvinyl acetal resin having such a narrow molecular weight distribution can be obtained, for example, by preparative separation from known polyvinyl acetal using preparative chromatography.

In the fifth interlayer film, the molecular weight distribution ratio (M
By using the polyvinyl acetal resin (A) having a w / Mn of 3.5 to 20, the coincidence effect is remarkably alleviated in a wide temperature range, and good sound insulation is obtained.

If the molecular weight distribution ratio (Mw / Mn) is less than 3.5, the temperature range in which the coincidence effect is alleviated becomes narrow, and good sound insulation may not be obtained in a wide temperature range. When the molecular weight distribution ratio (Mw / Mn) exceeds 20, it is difficult to obtain sound insulation performance exceeding Ts-35 grade.

The polyvinyl acetal resin having such a wide range of molecular weight distribution can be prepared, for example, by a method of blending a plurality of polyvinyl alcohols having different molecular weights followed by an acetal reaction or a method of blending a plurality of polyvinyl acetals having different molecular weights. can get.

In the fourth and fifth interlayer films, the number average molecular weight Mn of the polyvinyl acetal resin is preferably 2
7,000 to 270,000, more preferably 4
It is 5,000 to 235,000. When the Mn of the polyvinyl acetal resin is less than 27,000, the obtained laminated glass is poor in penetration resistance and Mn is 270,000.
If it exceeds, the strength of the obtained laminated glass may be too great to be used as a safety glass.

In the sixth interlayer film, at least the outermost layer of the laminated layers on the side where weather resistance is required contains an ultraviolet absorber having an effective ultraviolet absorption wavelength of 300 to 340 nm and an ultraviolet absorption coefficient X of 0.01. Layers containing as above
It consists of (B).

Here, the ultraviolet absorption coefficient X is {the film pressure t (mm) of the layer (B) used as the outermost layer on the side requiring weather resistance} ×
It is a value defined by {UV absorbent addition number u (weight part)}. In the seventh interlayer film, the degree of blocking of the ethylene group to which the acetyl group is bonded is 0.15 to 0.40.
The polyvinyl acetal resin, which is, has a degree of blocking of an ethylene group to which an acetyl group is bonded is 0.15 to 0.4.
Obtained by acetalization of polyvinyl alcohol which is 0. By using polyvinyl alcohol having such a high blocking property, a polyvinyl acetal resin having a small temperature dependence of the mechanical loss tangent curve in viscoelasticity can be obtained. By using this as the polyvinyl acetal resin (A) in the first interlayer film, an excellent sound insulating interlayer film capable of effectively converting sound energy into heat energy in a wide temperature range can be obtained. A method for synthesizing polyvinyl alcohol having such a high block property is described in, for example, Japanese Patent Publication No. 37-17385.

If the degree of blocking is less than 0.15, the TL value at each temperature may be significantly reduced, and if the degree of blocking is greater than 0.40, good sound insulation is obtained over a wide temperature range. Sometimes you can't get it. The blocking degree is more preferably in the range of 0.20 to 0.35.

In the eighth interlayer film, the degree of blocking of the ethylene group to which the acetyl group is bonded is 0.55 to 0.9.
In the polyvinyl acetal resin having an acetyl group of 0, the degree of blocking of the ethylene group to which the acetyl group is bonded is 0.55 to 0.
It is obtained by acetalization of polyvinyl alcohol which is 90. By using polyvinyl alcohol having such high randomness, a polyvinyl acetal having a low glass transition temperature can be obtained. By using this as the polyvinyl acetal resin (A) in the first interlayer film, an excellent sound insulating interlayer film having good fluidity and capable of more effectively converting sound energy into heat energy can be obtained.
A method for synthesizing polyvinyl alcohol having such high randomness is described in, for example, Japanese Patent Application Laid-Open No. 2-255806.

When the degree of blocking is less than 0.55, excellent sound insulation may not be obtained, and when the degree of blocking is greater than 0.90, the degree of acetalization is lowered, so that an intermediate film is formed. The impact resistance, which is a basic property of, may decrease. The blocking degree is more preferably 0.
It is in the range of 65 to 0.80.

In the definition of the blocking degree of the seventh and eighth interlayers Y = 0.5 × S / (T × U), S, T in the equation
And U were respectively obtained from ¹³ C-NMR measurement-
CH (OH) -CH ₂ - amount of methylene group (OCOCH ₃₎ CH- structure (S), the amount of hydroxyl groups (T), represents the amount of acetyl groups (U).

In the interlayer film of the present invention, as the polyvinyl acetal resin (A), the viscosity of a solution of 10% by weight dissolved in a mixed solvent of ethanol and toluene (weight ratio 1: 1) has a viscosity of 200 by a BM type viscometer. A crosslinked polyvinyl acetal resin having a viscosity of up to 1000 centipoise (cP) is preferably used.

By using the crosslinked polyvinyl acetal resin as described above, the sound insulation performance at room temperature is excellent and
It is possible to obtain an interlayer film for laminated glass which has a wide temperature range effective for converting sound energy into heat energy and has excellent sound insulation performance in a wide temperature range around room temperature.

If the viscosity is less than 200 cP, good sound insulation performance in a wide range may not be obtained, and 100
When it exceeds 0 cP, the change in the sound insulation performance with respect to temperature decreases, but the absolute value of the sound insulation performance becomes low, and it may be difficult to manufacture the resin or form the film. The viscosity range showing a more preferable degree of crosslinking is 300 to 800 cP.

As one of the methods for producing a polyvinyl acetal resin having intermolecular crosslinks as described above, as disclosed in Japanese Patent Publication No. 39-24711, a precipitation method is used together with an intramolecular acetalization reaction. There is a method of causing an acetal reaction between them, that is, intermolecular crosslinking.

On the other hand, the amount of aldehyde used for the acetalization reaction of polyvinyl alcohol is determined to be 10 to 200 depending on the degree of acetalization of the obtained polyvinyl acetal resin.
It is also possible to easily obtain a polyvinyl acetal resin having an intermolecular crosslink by using an excess of mol% or adding an acid catalyst in a larger amount than usual.

When the excess amount of aldehyde is 10 mol% or less, intermolecular crosslinking reaction hardly progresses, and improvement in sound insulation performance in a wide range may not be expected. on the other hand,
When it is 200 mol% or more, gelation may occur at the stage of synthesizing the polyvinyl acetal resin, the reaction rate of the aldehyde may decrease, and treatment of unreacted aldehyde may be difficult, which is not preferable in many cases. More preferably, 15 to 50 mol% of aldehyde is used in excess of the degree of acetalization.

A method of intermolecular crosslinking by adding a small amount of polyfunctional aldehyde is also preferably used. As the polyfunctional aldehyde, glutaraldehyde,
4,4 '-(ethylenedioxy) dibenzaldehyde,
2-Hydroxyhexane dial is preferably used. The addition amount of the polyfunctional aldehyde is 0.001 to 1.0 mol% with respect to the mol% of the hydroxyl group of polyvinyl alcohol.
Is preferable, and more preferably 0.01 to 0.
It is 5 mol%.

In the interlayer film of the present invention, the polyvinyl acetal resin (A) has a narrow acetalization degree distribution, for example, 90% or more of the acetalization degree distribution is -2 of the average acetalization degree. Mol% and +2 mol%
The polyvinyl acetal resin existing in the range of is preferably used.

By using the polyvinyl acetal resin having such a narrow acetalization degree distribution, it is possible to obtain an interlayer film having a far superior sound insulation performance than a conventional sound insulation interlayer film in a certain temperature range. This interlayer film can pass JIS sound insulation grade Ts-40 grade.

The polyvinyl acetal resin having a narrow degree of acetalization distribution as described above has a low temperature when the aldehyde and the catalyst are added to the polyvinyl alcohol aqueous solution,
It is preferably obtained by setting the temperature to 5 ° C or lower. Also,
It is also effective to reduce the initial amount of catalyst used, for example to 60% by weight of the usual amount. In some cases, the remaining catalyst may be added in small portions slowly, for example, over 30 minutes to 3 hours.

In addition, there is a method in which several kinds of solvents having different polarities are used and a synthetic polyvinyl acetal resin having a narrow distribution of acetalization degree is separated and extracted for each certain degree of acetalization degree.

In the interlayer film of the present invention, a polyvinyl acetal resin (A) having a wide distribution of acetalization degree, for example, 10 to 10 of acetalization degree distribution is further used.
A polyvinyl acetal resin having 30% in the range of −10 mol% or less and +10 mol% or more of the average value of the degree of acetalization is preferably used.

An interlayer film made of a polyvinyl acetal resin having such a wide fraction of acetalization is -10.
It can pass JIS sound insulation grade Ts-30 grade in the range of ℃ to 80 ℃.

The polyvinyl acetal resin having a wide degree of acetalization distribution as described above is prepared by dissolving polyvinyl alcohol in hot water and maintaining the aqueous solution at an appropriate temperature, for example, 20 ° C. or higher, and then adding an aldehyde and a catalyst thereto. In addition, it is obtained by proceeding the acetal reaction.
Alternatively, the amount of aldehyde added to the polyvinyl alcohol aqueous solution is initially set to 40% by weight or less of the total amount, and then the reaction liquid is maintained at a required temperature, and then the remaining aldehyde is slowly added little by little, for example, 30 minutes ~
There is also a method of adding it over 3 hours.

Further, a method of mixing two or more kinds of polyvinyl acetal resins having different average acetalization degrees, increasing the amount of the catalyst used, and increasing the temperature rising rate after the addition of the aldehyde and the catalyst is effective. In some cases.

The acetalization degree distribution of the polyvinyl acetal resin can be measured by a method such as liquid chromatography or thin layer chromatography.

Next, the polyvinyl acetal resin (A) (B)
The plasticizer added to is explained.

In the present invention, organic plasticizers such as monobasic acid esters and polybasic acid esters, and phosphoric acid plasticizers such as organic phosphoric acid compounds and organic phosphorous acid compounds are used as the plasticizer.

Among the monobasic acid esters, triethylene glycol, butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptanoic acid, n-octylic acid, 2-ethylhexylic acid, and pelargonic acid (n-nonylic acid) are included. A glycol-based ester obtained by a reaction with an organic acid such as decyl acid is preferred. In addition, esters of tetraethylene glycol and tripropylene glycol with the above organic acids are also used.

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

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

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

The amount of the plasticizer added to the layer (A) is preferably 30 to 70 parts by weight with respect to 100 parts by weight of the polyvinyl acetal resin (A). If the amount of plasticizer added is less than 30 parts by weight, sufficient sound insulation performance cannot be obtained, and if it exceeds 70 parts by weight, the plasticizer bleeds out and the transparency of the laminated glass and the adhesion between the interlayer film and the glass plate are increased. May impair sex. A particularly preferred amount of addition is 35 to 65 parts by weight.

The amount of the plasticizer added to the layer (B) is preferably 25 to 55 parts by weight with respect to 100 parts by weight of the polyvinyl acetal resin (B). If the amount of the plasticizer added is less than 25 parts by weight, the penetration resistance will decrease, and if it exceeds 55 parts by weight, the plasticizer will bleed out and the transparency of the laminated glass and the adhesion between the interlayer film and the glass plate will increase. May be damaged. A particularly preferred amount of addition is 30 to 45 parts by weight.

In the interlayer film according to the present invention, the ultraviolet absorber (i) which is usually used for improving the weather resistance of each polyvinyl acetal resin layer, is usually used for adjusting the adhesive force between the resin film and the glass plate. Additives (ii), stabilizers for preventing the deterioration of polyvinyl acetal (iii), ultraviolet stabilizers for improving the stability of the resin layer against ultraviolet rays (i
v), an antioxidant (v) for improving the thermal stability of the resin layer, and the like are appropriately added when the polyvinyl acetal and the plasticizer are mixed or in the production process of the polyvinyl acetal, if necessary.

In the sixth interlayer film, in order to improve the weather resistance of the polyvinyl acetal resin layer of the layer (A), as described above, at least the side of the layers constituting the laminated film on which the weather resistance is required is the most necessary. The outer layer has an effective ultraviolet absorption wavelength of 300 to 3
The ultraviolet absorption coefficient X of the ultraviolet absorbent having a wavelength of 40 nm is 0.
It is composed of the layer (B) contained so as to be 01 or more.

An ultraviolet absorber having an upper limit of the effective ultraviolet absorption wavelength of 340 nm or less cannot obtain sufficient weather resistance, and therefore such an ultraviolet absorber is not preferable.

(I) The ultraviolet absorber is classified into benzotriazole type, benzophenone type, cyanoacrylate type and the like.

As the benzotriazole type ultraviolet absorber, 2- (2'-hydroxy-5'-methylphenyl) is used.
Benzotriazole, 2- (2'-hydroxy-5'-
t-butylphenyl) benzotriazole, 2- (2 '
-Hydroxy-3 ', 5'-di-t-butylphenyl)
Benzotriazole, 2- (2'-hydroxy-3'-
t-Butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'
-Di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t
-Amylphenyl) benzotriazole, 2- [2'-
Hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5′-methylphenyl]
Examples are benzotriazole and the like.

As the benzophenone type ultraviolet absorber,
2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-
Octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2'-dihydroxy-
4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone and the like are exemplified.

Examples of the cyanoacrylate type ultraviolet absorber include 2-ethylhexyl-2-cyano-3,3'-diphenyl acrylate and ethyl-2-cyano-3,3'-.
Diphenyl acrylate etc. are illustrated.

The addition amount of the ultraviolet absorber is defined by {membrane pressure t (mm) of the layer (B) used for the outermost layer on the side requiring weather resistance} × {number of ultraviolet absorber added u (weight part)} The ultraviolet absorption coefficient X is preferably 0.01 (parts by weight / mm) or more. However, in the sixth interlayer film, the addition amount of the ultraviolet absorber needs to be a value such that the ultraviolet absorption coefficient X defined above is 0.01 (parts by weight · mm) or more.

Ultraviolet absorption coefficient X is 0.01 (mm / part)
If it is less than the above range, sufficient weather resistance may not be obtained. The addition amount of the ultraviolet absorber is more preferably a value such that the ultraviolet absorption coefficient X is 0.02 or more.
Further, the addition amount of the ultraviolet absorber is preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the polyvinyl acetal resin. If the amount added is less than 0.01 parts by weight, sufficient weather resistance may not be obtained, and if the amount added is more than 5 parts by weight, the strength of the interlayer film decreases and the total light transmittance of the laminated glass decreases. As a result, the basic function of the interlayer film for laminated glass may be impaired.

(Ii) As additives, metal salts of carboxylic acids, for example, potassium metal such as octyl acid, hexylic acid, butyric acid, acetic acid and formic acid, alkali metal salts such as sodium, alkaline earth metal such as calcium and magnesium. Salt, zinc,
A cobalt salt or the like is used.

(Iii) As the stabilizer, a surfactant such as sodium lauryl sulfate or alkylbenzene sulfonic acid is used.

(Iv) As the ultraviolet stabilizer, hindered amine type or metal complex salt type ultraviolet stabilizers are preferably used.

In the hindered amine system, bis (2,2,2
6,6-tetramethyl-4-piperidyl) sebacate,
Tetrakis (2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butane tetracarboxylate, Sanol LS-770, Sanol LS-7
65, Sanol LS-2626, Chimasso
b944LD, Thinvin-662, Thinu
vin-622LD, Mark LA-57, Mark
LA-77, Mark LA-62, Mark LA
-67, Mark LA-63, Mark LA-6
8, Mark LA-82, Mark LA-87, G
odrite UV-3404 etc. are illustrated.

As the metal complex salt type ultraviolet stabilizer, nickel [2,2'-thiobis (4-t-octyl) phenolate] -n-butylamine, nickel dibutyldithiocarbamate, nickel bis [o-ethyl-3,5 -(Di-t-butyl-4-hydroxybenzyl)] phosphate, cobalt dicyclohexyldithiophosphate,
[1-Phenyl-3-methyl-4-decanoyl-pyrazolate (5) ₂ ] nickel and the like are exemplified.

The addition amount of the UV stabilizer is preferably 0.01 to 3 parts by weight. If the addition amount is 0.01 parts by weight or less, a sufficient stabilizing effect cannot be obtained, and if the addition amount is 3 parts by weight or more, the total light transmittance of the laminated glass and the physical properties of the interlayer film may deteriorate. A particularly preferred amount of the UV stabilizer added is 0.1 to 1.5 parts by weight.

(V) As antioxidants, phenolic compounds,
Examples thereof include sulfur type and phosphorus type. Especially 2.6-di-t-
Butyl-p-cresol (BHT), butylated hydroxyanisole (BHA), 2,6-di-t-butyl-4
-Ethylphenol, stearyl-β- (3,5-di-
t-Butyl-4-hydroxyphenyl) propionate, 2,2'-methylene-bis- (4-methyl-6-butylphenol), 2,2'-methylene-bis- (4-
Ethyl-6-t-butylphenol), 4,4'-thiobis- (3-methyl-6-t-butylphenol),
4,4'-butylidene-bis- (3-methyl-6-t-
Butylphenol), 1,1,3-tris- (2-methyl-hydroxy-5-t-butylphenyl) butane, tetrakis [methylene-3- (3 ', 5'-butyl-4']
-Hydroxyphenyl) propionate] methane, 1,
1,3-tris- (2-methyl-4-hydroxy-5-
t-butylphenol) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4)
-Hydroxybenzyl) benzene, bis (3,3'-bis- (4'-hydroxy-3'-t-butylphenol) butyric acid) glycol ester and the like are preferably used.

It is preferable to add 0.05 to 3 parts by weight of the antioxidant. When the amount of the antioxidant added is less than 0.05 parts by weight, sufficient antioxidant ability cannot be obtained, and when it is 3 parts by weight or more, the total light transmittance and the physical properties of the interlayer film may deteriorate. The particularly preferable amount of addition of the antioxidant is 0.2 to
It is 1.5 parts by weight.

Next, the laminated structure of the intermediate film according to the present invention will be described.

Examples of the laminated structure are as follows: (1) 2-layer laminated structure of layer (A) / layer (B), (2) layer (A) /
Three-layer laminated structure such as layer (B) / layer (A), layer (B) / layer (A) / layer (B), (3) layer (B) / layer (A) / layer (B) / layer (A) etc. 4 layer laminated structure.

In the multi-layered structure of three or more layers, the laminated structure may be an asymmetrical structure such as / layer (A) / layer (B) / layer (B).

Further, the interlayer film according to the present invention is a layer (C) which does not impair the properties of the interlayer film for laminated glass due to the migration of the plasticizer, for example, a polyethylene terephthalate film having no decoration or decorative printing. May be laminated. Examples of such interlayer stackups include the following: (4) 3-layer stackup such as layer (A) / layer (C) / layer (B), (5)
Layer (B) / Layer (C) / Layer (B) / Layer (A), Layer (B) / Layer (A) /
4-layer laminated structure such as layer (C) / layer (A).

Of the layers constituting the interlayer film for laminated glass, at least the outermost layers on both sides are preferably constituted by layer (B). With this arrangement, the conventional technique can be used as it is when the glass plate and the interlayer film are combined.

Further, when weather resistance from one direction is more desired, for example, in the interlayer film of laminated glass used for automobile windshields, windows of buildings, etc., the outermost layer on the side requiring weather resistance is Effective UV absorption wavelength is 300-340n
It is preferable that the layer (B) contains an ultraviolet absorber having a value of m such that the ultraviolet absorption coefficient X is 0.01 or more.

However, in the sixth interlayer film, the outermost layer on the side requiring weather resistance is a layer containing an ultraviolet absorber having the above-mentioned effective ultraviolet absorption wavelength so that the ultraviolet absorption coefficient X is 0.01 or more ( It must be composed of B).

Regarding the thickness of the layer (A) and the layer (B),
The total thickness of (A) is preferably 0.05 mm or more. If it is less than 0.05 mm, it is not sufficient to exert the sound insulation performance.

The total thickness of the interlayer film is preferably 0.3 to 1.6 mm, which is the thickness of a normal interlayer film for laminated glass.

The larger this thickness is, the more excellent the sound insulating property is, but it is preferable to determine the thickness in consideration of the penetration resistance required for the laminated glass, and the above-mentioned range of thickness is practically preferable.

As the film forming method, various molding methods can be applied, for example, a method of molding each layer separately and then laminating these layers between glass plates, a method of integrally molding each layer using a multi-layer molding machine, and the like.

In order to produce a laminated glass by sandwiching an interlayer film between glass plates, a method used in ordinary production of laminated glass is adopted. For example, a method of producing a laminated glass by sandwiching the film from both sides with glass plates and performing hot pressing is performed.

Further, it does not depart from the scope of the present patent to sandwich the interlayer film of the present invention with a transparent material other than glass, for example, a polycarbonate resin having a rigidity higher than that of the polyvinyl acetal plasticized material such as a polycarbonate resin.

[0119]

EXAMPLES Some examples of the present invention and comparative examples to be compared with the examples will be given below to further show the performance of the laminated glass obtained.

The degree of acetalization of the polyvinyl acetal resin was determined by preparing a 2 wt% heavy water-benzene solution of the resin, adding a small amount of tetramethylsilane [(CH ₃ ) ₄ Si] as a standard substance, and adding polyvinyl chloride at a temperature of 23 ° C. It was measured by taking a proton nuclear magnetic resonance spectrum of the acetal resin.

The average value of the amount of acetyl groups of the polyvinyl acetal resin was measured according to the test method of "vinyl acetal" in the composition analysis section of JIS "Polyvinyl acetal test method" (K-6728-1977).

The distribution of the amount of ethylene groups having acetyl groups bonded was determined by the following method. First, hydroxylamine hydrochloride was allowed to act on the polyvinyl acetal resin to eliminate the acetal group, and the obtained polyvinyl alcohol was fractionated according to its acetyl group amount, and the amount of each fraction was determined by the weight ratio. The above JIS "Polyvinyl acetal test method" (K-6728-1977)
It was measured according to the test method of "vinyl acetal" in the section of composition analysis in.

The weight average molecular weight Mw, the number average molecular weight Mn, and the molecular weight distribution ratio (Mw / Mn) are determined by light scattering gel permeation chromatography GPC (Tosoh "LS-8000 system", column; Showa Denko "Polystyrene gel". KF-802, KF-803, KF-8
04: inner diameter 8 mm, length 300 mm, solvent: hexafluoroisopropanol).

The GPC (LS-8000 system) was used as the preparative chromatography for the preparative separation of the polymer.
It was carried out using Showa Denko HFIP preparative column as a column and hexafluoroisopropanol as a solvent.

The sound insulation of the laminated glass was measured by the following method. That is, at a predetermined temperature, the laminated glass was vibrated by a vibration generator for a damping test (vibration machine manufactured by Shinken Co., Ltd., “G21-005D”), and the vibration characteristic obtained from the vibration was measured as mechanical impedance. Amplifier (Co., Ltd.)
The vibration spectrum is amplified with Rion's "XG-81") and the vibration spectrum is analyzed by an FFT analyzer (Yokogawa Hewlett-Packard's "FFT spectrum analyzer HP 3").
582A ”). The transmission loss was calculated from the loss coefficient thus obtained and the ratio of the resonance frequency with the glass. Based on this result, the TL value was defined as the minimum transmission loss amount around the frequency of 2000 Hz.

The weather resistance of the laminated glass was evaluated using a sunshine weatherometer (according to JIS A1415) at a black panel temperature of 63 ° C. Transmittance (JIS
R3212 (depending on visible light transmittance) and yellowness (JISK
7103) was measured. The yellowness was measured with a reflection type, C light source, and a 2 ° visual field.

For the maximum temperature of sound insulation performance = TLmax temperature and the maximum value of sound insulation performance = TLmax value, the temperature interval is 10
The transmission loss was measured at ℃, and the minimum transmission loss around the frequency of 2000 Hz was plotted against temperature.
The maximum value is TLmax, and the temperature at that time is TLma
x temperature.

Example 1 <Preparation of Resin (A)> Deionized water of 2700 g and polymerization degree of 1700
Polyvinyl alcohol (191 g) was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., and 35 wt% hydrochloric acid 20
Polyvinyl acetal was precipitated by adding 1 g and 130 g of butyraldehyde. After that, the reaction system is heated to 50 ° C.
Hold for 5 hours to complete the reaction. Unreacted aldehyde was washed away by washing with excess water, the hydrochloric acid catalyst was neutralized, the salt was removed, and the product was dried to obtain a white powder of polyvinyl acetal resin (A).

The polyvinyl acetal resin (A) had an acetalization degree of 60.2 mol% and an acetyl group content of 11.9.
It was mol%.

<Preparation of Membrane (A)> 50 g of the above polyvinyl acetal (A) was sampled, and 25 g of triethylene glycol-di-2-ethylbutyrate as a plasticizer and tetrakis [methylene-3-3] as an antioxidant were collected. (3 ', 5'
0.15 g of -butyl-4'-hydroxyphenyl) propionate] methane was added, and the mixture was thoroughly kneaded with a mixing roll, and a predetermined amount of the kneaded product was kept at 150 ° C for 30 minutes on a press molding machine. Thus thickness 0.2
A 0 mm membrane (A) was prepared.

<Preparation of Resin (B)> To 2910 g of pure water, 190 g of polyvinyl alcohol having a degree of polymerization of 1700 was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., 201 g of 35 wt% hydrochloric acid and 124 g of butyraldehyde were added,
Polyvinyl acetal was deposited. Then, the reaction system was kept at a temperature of 50 ° C. for 4 hours to complete the reaction. Unreacted aldehyde was washed away by washing with excess water, the hydrochloric acid catalyst was neutralized, the salt was removed, and the product was dried to obtain a white powder of the polyvinyl acetal resin (B).

The polyvinyl acetal resin (B) had a degree of acetalization of 65.9 mol% and an acetyl group content of 0.9 mol%.

<Preparation of Membrane (B)> 50 g of the polyvinyl acetal resin (B) was sampled, and 20 g of triethylene glycol-di-2-ethylbutyrate as a plasticizer and 2- (2 ' 0.1 g of -hydroxy-5'-methylphenyl) benzotriazole was added, the mixture was thoroughly kneaded with a mixing roll, and a predetermined amount of the kneaded product was kept at 150 ° C for 30 minutes on a press molding machine. Thus, a film having a thickness of 0.20 mm was produced.

<Preparation of Laminated Glass> One film obtained from the polyvinyl acetal resin (A) and two films obtained from the polyvinyl acetal resin (B) were laminated to form a layer (B) / Layer them so that they are layer (A) / layer (B),
A three-layer laminated interlayer film was obtained. Each side of this interlayer film has 3 sides
Sandwich from both sides with two 0 cm square 3 mm thick float glass, put this non-bonded sandwich in a rubber bag, degas for 20 minutes at a vacuum degree of 20 torr, and then in an oven at 90 ° C in the degassed state. And kept at this temperature for 30 minutes. The sandwich thus temporarily adhered by a vacuum press was then thermocompression-bonded at a pressure of 12 kg / cm ² and a temperature of 135 ° C. in an autoclave to produce a transparent laminated glass.

Examples 2 to 7 As shown in Table 1, within the scope of the present invention, polyvinyl acetal resin (A) and polyvinyl acetal resin
An interlayer film was prepared by changing the degree of acetalization and the amount of acetyl groups of (B), the amount of plasticizer added, the layer thickness and the laminated structure, and using this, a laminated glass was produced.

Comparative Examples 1 to 4 <Measurement of Sound Insulation> The above Examples 1 to 7 and Comparative Examples 1 to 4
The sound insulation at a temperature of 20 ° C. was measured for each of the laminated glass of.

The measurement results are summarized in Table 1.

[0138]

[Table 1] As is clear from Table 1, all of the laminated glasses according to the examples of the present invention have excellent sound insulation performance.

Example 8 <Preparation of Resin (A)> In 2890 g of pure water, the average value of the amount of acetyl groups was 12.3 mol%, the standard deviation of the amount of ethylene groups having acetyl groups bonded was σ 0.5, and the degree of polymerization was 180 g of 1700 polyvinyl alcohol (Nippon Gosei Kagaku Co., Ltd.) was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., 200 g of 35 wt% hydrochloric acid and 135 g of butyraldehyde were added,
Polyvinyl acetal was deposited. Then, the reaction system was kept at a temperature of 45 ° C. for 4 hours to complete the reaction. Unreacted aldehyde was washed away by washing with excess water, the hydrochloric acid catalyst was neutralized, the salt was removed, and the product was dried to obtain a white powder of polyvinyl acetal resin (A).

The polyvinyl acetal resin (A) had an acetalization degree of 64.3 mol% and an acetyl group content of 12.3.
The standard deviation σ of the mol% and the amount of ethylene groups bonded with acetyl groups was 0.5.

<Preparation of Membrane (A)> 50 g of the polyvinyl acetal (A) was sampled, and 25 g of triethylene glycol-di-2-ethylbutyrate as a plasticizer and 2- (2'- Hydroxy-5′-methylphenyl) benzotriazole (0.05 g) and BHT (0.05 g as an antioxidant) were added, and the mixture was thoroughly kneaded with a mixing roll, and a predetermined amount of the kneaded product was used in a press molding machine to obtain 150 Hold at 30 ° C for 30 minutes. Thus, a film (A) having a thickness of 0.40 mm was produced.

<Preparation of Resin (B)> By the same procedure as in the preparation of Resin (B) of Example 1, the degree of acetalization was 66.3 mol%, the amount of acetyl groups was 0.9 mol%, and acetyl groups were bonded. A white powder of the polyvinyl acetal resin (B) having a standard deviation σ of the amount of ethylene groups present was 0.3 was obtained.

<Preparation of Membrane (B)> The above polyvinyl acetal (B) was formed into a membrane (B) having a thickness of 0.10 mm by the same operation as in the preparation of the membrane (B) of Example 1.

<Production of Laminated Glass> Transparent laminated glass was produced by the same operation as the production of laminated glass of Example 1.

Examples 9 to 11 As shown in Table 2, within the scope of the present invention, the polyvinyl acetal resin (A) and the polyvinyl acetal resin are included.
An interlayer film was prepared by changing the degree of acetalization and the amount of acetyl groups in (B), the standard deviation σ, the amount of plasticizer added, the layer thickness and the laminated structure, and using this, a laminated glass was prepared.

Comparative Examples 5 to 6 As shown in Table 2, interlayer films not belonging to the scope of the present invention were prepared, and laminated glass was prepared using the interlayer films.

<Measurement of Sound Insulation> The sound insulation of each of the laminated glasses of Examples 8 to 11 and Comparative Examples 5 to 6 was measured at a predetermined temperature.

The measurement results are summarized in Table 2.

[0149]

[Table 2] As is clear from Table 2, all of the laminated glasses according to the examples of the present invention are recognized to have excellent sound insulation performance at around room temperature.

Example 12 <Preparation of Resin (A)> In 2890 g of pure water, the average value of the amount of acetyl groups was 11.8 mol%, the standard deviation of the amount of ethylene groups having acetyl groups bonded was 3.4, and the degree of polymerization was 191 g of 1700 polyvinyl alcohol (Nippon Gosei Kagaku) was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., 201 g of 35 wt% hydrochloric acid and 130 g of butyraldehyde were added,
Polyvinyl acetal was deposited. Then, the reaction system was kept at a temperature of 45 ° C. for 4 hours to complete the reaction. Unreacted aldehyde was washed away by washing with excess water, the hydrochloric acid catalyst was neutralized, the salt was removed, and the product was dried to obtain a white powder of the polyvinyl acetal resin (A).

The polyvinyl acetal resin (A) had an acetalization degree of 61.3 mol% and an acetyl group content of 11.8.
The standard deviation σ of the mol% and the amount of the ethylene group having an acetyl group bonded was 3.4.

<Preparation of Membrane (A)> 50 g of the above polyvinyl acetal (A) was sampled, and 22.5 g of triethylene glycol-di-2-ethylbutyrate as a plasticizer and 2- (2 0.05 g of'-hydroxy-5'-methylphenyl) benzotriazole and 0.05 g of BHT as an antioxidant were added, and this mixture was thoroughly kneaded with a mixing roll, and a predetermined amount of the kneaded product was pressed. And kept at 150 ° C for 30 minutes. Thus, a film (A) having a thickness of 0.15 mm was produced.

<Preparation of Resin (B)> By the same operation as in the preparation of Resin (B) of Example 1, the degree of acetalization was 66.3 mol%, the amount of acetyl groups was 0.9 mol%, and acetyl groups were bonded. A white powder of a polyvinyl acetal resin (B) having a standard deviation of 0.3 of the amount of ethylene groups present was obtained.

<Preparation of Membrane (B)> The above polyvinyl acetal (B) was formed into a membrane (B) having a thickness of 0.10 mm by the same operation as in the preparation of the membrane (B) of Example 1.

<Production of Laminated Glass> A transparent laminated glass was produced by the same operation as the production of the laminated glass of Example 1.

Examples 13 to 16 As shown in Table 3, within the scope of the present invention, the polyvinyl acetal resin (A) and the polyvinyl acetal resin are included.
An interlayer film was prepared by changing the degree of acetalization and the amount of acetyl groups in (B), the standard deviation σ, the amount of plasticizer added, the layer thickness and the laminated structure, and using this, a laminated glass was prepared.

Comparative Examples 7 to 8 As shown in Table 3, interlayer films which do not belong to the scope of the present invention were prepared, and laminated glass was produced using the interlayer films.

<Measurement of Sound Insulation> The sound insulation of each laminated glass of Examples 12 to 16 and Comparative Examples 7 to 8 was measured at a predetermined temperature.

The measurement results are summarized in Table 3.

[0160]

[Table 3] As is clear from Table 3, it is recognized that the laminated glasses according to the examples of the present invention all have excellent sound insulation performance over a wide temperature range.

Example 17 <Preparation of Resin (A)> A polyvinyl acetal resin having an acetalization degree of 60.2 mol% and an acetyl group content of 11.9 mol% was obtained by the same operation as in the preparation of the resin (A) of Example 1. A white powder of (A) was obtained.

This polymer was dissolved in 2 liters of hexafluoroisopropanol and the above GPC (LS-80
00 system), and the number average molecular weight Mn
Of 160,000 and a molecular weight distribution ratio (Mw / Mn) of 1.02 were obtained to obtain a polyvinyl acetal resin (A).

<Preparation of Membrane (A)> The above polyvinyl acetal (A) was formed into a membrane (A) with a thickness of 0.20 mm by the same procedure as in the preparation of the membrane (A) of Example 1.

<Preparation of Resin (B)> Polyvinyl acetal resin (B) having a degree of acetalization of 65.9 mol% and an acetyl group content of 0.9 mol% was obtained by the same operation as in the preparation of the resin (B) of Example 1. Of white powder was obtained.

<Preparation of Membrane (B)> The above polyvinyl acetal (B) was formed into a membrane (B) having a thickness of 0.20 mm by the same operation as the preparation of the membrane (B) of Example 1.

<Production of Laminated Glass> Transparent laminated glass was produced by the same operation as the production of laminated glass of Example 1.

Examples 18 to 23 As shown in Table 4, within the scope of the present invention, the polyvinyl acetal resin (A) and the polyvinyl acetal resin are included.
(B) The degree of acetalization and the amount of acetyl groups, the number average molecular weight Mn and the molecular weight distribution ratio (Mw / Mn), the amount of the plasticizer added, the layer thickness and the layered structure were changed to prepare an interlayer film, which was used. A laminated glass was produced.

Comparative Examples 9 to 11 As shown in Table 4, interlayer films not belonging to the scope of the present invention were prepared, and laminated glass was prepared using the interlayer films.

<Measurement of Sound Insulation> The sound insulation at a predetermined temperature was measured for each of the laminated glasses of Examples 17 to 23 and Comparative Examples 9 to 11.

The measurement results are summarized in Table 4-1 and Table 4-2.

[0171]

[Table 4] As is clear from Table 4, all of the laminated glasses according to the examples of the present invention are recognized to have excellent sound insulation performance at around room temperature.

Example 24 <Preparation of Resin (A)> As a polyvinyl alcohol, a butted product of polyvinyl alcohol having a degree of polymerization of 500 and polyvinyl alcohol having a degree of polymerization of 3000 (blend ratio 1: 1).
A white powder of a polyvinyl acetal resin (A) having an acetalization degree of 59.9 mol% and an acetyl group amount of 12.1 mol% was performed by the same procedure as in the preparation of the resin (A) of Example 1 except that Got

The number average molecular weight Mn of this polymer was 36,
At 400, the molecular weight distribution ratio (Mw / Mn) was 6.71.

<Preparation of Membrane (A)> The polyvinyl acetal (A) was formed into a film by the same operation as in the preparation of the membrane (A) of Example 1 to prepare a membrane (A) having a thickness of 0.20 mm.

<Preparation of Resin (B)> Polyvinyl acetal resin (B) having an acetalization degree of 65.9 mol% and an acetyl group content of 0.9 mol% was obtained by the same procedure as in the preparation of the resin (B) of Example 1. Of white powder was obtained.

<Preparation of Membrane (B)> The polyvinyl acetal (B) was formed into a membrane (B) with a thickness of 0.20 mm by the same procedure as in the preparation of the membrane (B) of Example 1.

<Production of Laminated Glass> Transparent laminated glass was produced by the same operation as in the production of laminated glass of Example 1.

Examples 25 to 30 As shown in Table 5, within the scope of the present invention, the polyvinyl acetal resin (A) and the polyvinyl acetal resin are
(B) The degree of acetalization and the amount of acetyl groups, the number average molecular weight Mn and the molecular weight distribution ratio (Mw / Mn), the amount of the plasticizer added, the layer thickness and the layered structure were changed to prepare an interlayer film, which was used. A laminated glass was produced.

Comparative Examples 12 to 14 As shown in Table 5, interlayer films not belonging to the scope of the present invention were prepared, and laminated glass was prepared using the interlayer films.

<Measurement of Sound Insulation> The sound insulation of each of the laminated glasses of Examples 24 to 30 and Comparative Examples 12 to 14 at a predetermined temperature was measured.

The measurement results are summarized in Table 5.

[0182]

[Table 5] As is clear from Table 5, it is recognized that the laminated glasses according to the examples of the present invention all have excellent sound insulation performance over a wide temperature range.

Example 31 <Preparation of Resin (A)> A polyvinyl acetal resin having a degree of acetalization of 60.2 mol% and an acetyl group amount of 11.9 mol% was obtained by the same operation as in the preparation of the resin (A) of Example 1. A white powder of (A) was obtained.

<Preparation of Membrane (A)> The polyvinyl acetal (A) was formed into a film by the same procedure as the preparation of the membrane (A) of Example 1 to prepare a membrane (A) having a thickness of 0.20 mm.

<Preparation of Resin (B)> The polyvinyl acetal resin (B) having an acetalization degree of 65.9 mol% and an acetyl group content of 0.9 mol% was prepared by the same procedure as in the preparation of the resin (B) of Example 1. Of white powder was obtained.

<Preparation of Membrane (B)> The above polyvinyl acetal (B) was formed into a membrane (B) having a thickness of 0.20 mm by the same operation as in the preparation of the membrane (B) of Example 1.

<Production of laminated glass> By the same operation as in the production of laminated glass of Example 1, the outermost outer layer was the layer (B).
A transparent laminated glass composed of was prepared.

Examples 32 to 33 As shown in Table 6, within the scope of the present invention, the degree of acetalization and the amount of acetyl groups of the polyvinyl acetal resin (A) and the polyvinyl acetal resin (B), the amount of the plasticizer added, An interlayer film was prepared by changing the layer thickness, the laminated constitution and the amount of the ultraviolet absorber, and using this, a laminated glass was produced.

Comparative Examples 15 to 17 As shown in Table 6, interlayer films not belonging to the scope of the present invention were prepared, and laminated glass was prepared using them.

<Measurement of Sound Insulation> With respect to each of the laminated glasses of Examples 31 to 33 and Comparative Examples 15 to 17, the sound insulation at a predetermined temperature was measured and the weather resistance was measured.

The measurement results are summarized in Table 6.

[0192]

[Table 6] As is clear from Table 6, the laminated glasses according to the examples of the present invention all have excellent sound insulation performance at around room temperature,
And it is recognized that it has excellent weather resistance.

Example 34 <Preparation of Resin (A)> Deionized water of 2890 g and polymerization degree of 170
0, 191 g of polyvinyl alcohol having a degree of blocking of an ethylene group bonded with an acetyl group of 0.24 was added and dissolved by heating. Adjust the temperature of the reaction system to 12 ℃, 35% by weight
Hydrochloric acid 201g and butyraldehyde 130g were added to precipitate polyvinyl acetal. Then, the reaction system was kept at a temperature of 50 ° C. for 5 hours to complete the reaction. Unreacted aldehyde was washed away by washing with excess water, the hydrochloric acid catalyst was neutralized, the salt was removed, and the product was dried to obtain a white powder of polyvinyl acetal resin (A).

The polyvinyl acetal resin (A) had an acetalization degree of 60.2 mol% and an acetyl group content of 11.5.
It was mol%.

The definition of the degree of blocking Y = 0.5 × S
/ (T × U), S, T and U in the formula were determined from the ¹³ C-NMR chart of polyvinyl alcohol as follows. Three peaks derived from a methylene group appear at 42.5 ppm. Respectively, from each of the high magnetic field side these three peaks _{-CH (OCOCH 3) -CH 2 -} (OCOCH
₃ ) CH- structure methylene group (methylene 1), -CH (OH)
It is a peak derived from the methylene group (methylene 2) in the —CH ₂ — (OCOCH ₃ ) CH— structure and the methylene group (methylene 3) in the —CH (OH) —CH ₂ — (OH) CH— structure. .

The peak area ratio was calculated from the integral curve, and the amount (S) (mole fraction) of the methylene group in the —CH (OH) —CH ₂ — (OCOCH ₃ ) CH— structure was calculated from it.

The amount (T) (mol fraction) of hydroxyl groups and the amount (U) (mol fraction) of acetyl groups were determined by the following formulas.

T = (amount of methylene 3) + (amount of methylene 2) / 2 U = 1-T <Preparation of membrane (A)> By the same operation as in the preparation of membrane (A) of Example 1, the above polyvinyl The acetal (A) was formed into a film to prepare a film (A) having a thickness of 0.20 mm.

<Preparation of Resin (B)> Polyvinyl acetal resin (B) having an acetalization degree of 65.9 mol% and an acetyl group content of 0.7 mol% was obtained by the same procedure as in the preparation of the resin (B) of Example 1. Of white powder was obtained.

<Preparation of Membrane (B)> The polyvinyl acetal (B) was formed into a membrane (B) with a thickness of 0.240 mm by the same procedure as in the preparation of the membrane (B) of Example 1.

<Production of Laminated Glass> A transparent laminated glass was produced by the same operation as the production of the laminated glass of Example 1.

Examples 35 to 40 As shown in Table 7, within the scope of the present invention, the degree of acetalization and the amount of acetyl groups of the polyvinyl acetal resin (A) and the polyvinyl acetal resin (B), the amount of the plasticizer added, An interlayer film was prepared by changing the layer thickness, the laminated constitution and the amount of the ultraviolet absorber, and using this, a laminated glass was produced.

Comparative Examples 18 to 19 As shown in Table 7, interlayer films not belonging to the scope of the present invention were prepared, and laminated glass was produced using them.

<Measurement of Sound Insulation> The sound insulation of each of the laminated glasses of Examples 34 to 40 and Comparative Examples 18 to 19 was measured at a predetermined temperature.

The measurement results are summarized in Table 7.

[0206]

[Table 7] As is clear from Table 7, it is recognized that the laminated glasses according to the examples of the present invention all have excellent sound insulation performance over a wide temperature range.

Example 41 <Preparation of Resin (A)> Deionized water of 2890 g and polymerization degree of 170
0, 191 g of polyvinyl alcohol having a degree of blocking of an ethylene group bonded with an acetyl group of 0.74 was added and dissolved by heating. Adjust the temperature of the reaction system to 12 ℃, 35% by weight
Hydrochloric acid 201g and butyraldehyde 130g were added to precipitate polyvinyl acetal. Then, the reaction system was kept at a temperature of 50 ° C. for 5 hours to complete the reaction. Unreacted aldehyde was washed away by washing with excess water, the hydrochloric acid catalyst was neutralized, the salt was removed, and the product was dried to obtain a white powder of polyvinyl acetal resin (A).

The polyvinyl acetal resin (A) had an acetalization degree of 60.2 mol% and an acetyl group content of 12.5.
It was mol%.

The definition of blocking degree Y = 0.5 × S
/ (T × U), S, T and U in the formula are obtained in Example 3 from the ¹³ C-NMR chart of polyvinyl alcohol.
The same method as in 4 was used.

<Preparation of Membrane (A)> 50 g of the above polyvinyl acetal (A) was sampled, to which 25 g of triethylene glycol-di-2-ethylbutyrate as a plasticizer and 0.15 g of BHT as an antioxidant were added. The mixture was thoroughly kneaded with a mixing roll, and a predetermined amount of the kneaded product was held at 150 ° C. for 30 minutes with a press molding machine. Thus, a film (A) having a thickness of 0.20 mm was produced.

<Preparation of Resin (B)> The polyvinyl acetal resin (B) having an acetalization degree of 65.9 mol% and an acetyl group content of 0.9 mol% was obtained by the same procedure as in the preparation of the resin (B) of Example 1. Of white powder was obtained.

<Preparation of Membrane (B)> The polyvinyl acetal (B) was formed into a membrane by the same operation as in the preparation of the membrane (B) of Example 1 to prepare a membrane (B) having a thickness of 0.240 mm.

<Preparation of Laminated Glass> Transparent laminated glass was prepared by the same operation as the preparation of laminated glass of Example 1.

Examples 42 to 47 As shown in Table 8, within the scope of the present invention, the degree of acetalization and the amount of acetyl groups of the polyvinyl acetal resin (A) and the polyvinyl acetal resin (B), the amount of the plasticizer added, An interlayer film was prepared by changing the layer thickness, the laminated constitution and the amount of the ultraviolet absorber, and using this, a laminated glass was produced.

Comparative Example 20 As shown in Table 8, interlayer films not belonging to the scope of the present invention were prepared, and laminated glass was produced using them.

<Measurement of Sound Insulation> The sound insulation of each of the laminated glasses of Examples 41 to 47 and Comparative Example 20 at a predetermined temperature was measured.

The measurement results are summarized in Table 8.

[0218]

[Table 8] As is clear from Table 8, all of the laminated glasses according to the examples of the present invention are recognized to have excellent sound insulation performance at around room temperature.

Example 48 <Preparation of Resin (A)> A polymerization degree of 1700 was added to 2890 g of pure water.
Polyvinyl alcohol (190 g) was added and dissolved by heating. The temperature of the reaction system was adjusted to 12 ° C., and 35 wt% hydrochloric acid
Polyvinyl acetal was precipitated by adding 0 g and 170 g of butyraldehyde. After that, the temperature of the reaction system is 45 ° C.
Hold for 6 hours to complete the reaction. Unreacted aldehyde was washed away by washing with excess water, the hydrochloric acid catalyst was neutralized, the salt was removed, and the product was dried to obtain a white powder of polyvinyl acetal resin (A).

The polyvinyl acetal resin (A) had an acetalization degree of 62.3 mol% and an acetyl group content of 12.3.
The mol% and the viscosity were 590 cP.

The viscosity of the polyvinyl acetal resin was measured as follows.

150 ml of a mixed solvent of ethanol / toluene (weight ratio 1: 1) was placed in an Erlenmeyer flask, the sample weighed was added to the Erlenmeyer flask, the resin concentration was adjusted to 10 ± 0.1% by weight, and the temperature was kept in a thermostatic chamber at 20 ° C. And dissolved by shaking for 3 hours or more.
At the same time, this solution was poured into a measuring tube having an inner diameter of 43 ± 2 mm, the temperature was kept at 20 ± 0.2 ° C., and the viscosity was measured using a BM type viscosity system.

<Preparation of Membrane (A)> 50 g of the above polyvinyl acetal (A) was sampled, and 25 g of triethylene glycol-di-2-ethylbutyrate as a plasticizer and 2- (2'- Hydroxy-5'-methylphenyl) benzotriazole (0.05 g) and BHT (0.05 g as an antioxidant) were added, and the mixture was thoroughly kneaded with a mixing roll, and a predetermined amount of the kneaded product was heated to 150 ° C with a press molding machine. Held for 30 minutes. Thus, a film (A) having a thickness of 0.38 mm was produced.

<Preparation of Resin (B)> Polyvinyl acetal resin (B) having an acetalization degree of 66.3 mol% and an acetyl group content of 0.9 mol% was obtained by the same procedure as in the preparation of the resin (B) of Example 1. Of white powder was obtained.

<Preparation of Membrane (B)> The polyvinyl acetal (B) was formed into a membrane by the same procedure as in the preparation of the membrane (B) of Example 1, and the membrane (B) having a thickness of 0.30 mm and 0.40 mm. Was produced.

<Production of Laminated Glass> Transparent laminated glass was produced by the same operation as the production of laminated glass of Example 1.

Examples 49 to 50 As shown in Table 9, within the scope of the present invention, the degree of acetalization and the amount of acetyl groups of the polyvinyl acetal resin (A) and the polyvinyl acetal resin (B), the amount of the plasticizer added, An interlayer film was prepared by changing the layer thickness, the laminated constitution and the amount of the ultraviolet absorber, and using this, a laminated glass was produced.

Comparative Examples 21 to 25 As shown in Table 9, interlayer films not belonging to the scope of the present invention were prepared, and laminated glass was prepared using them.

<Measurement of Sound Insulation> The sound insulation of each laminated glass of Examples 48 to 50 and Comparative Examples 21 to 25 was measured at a predetermined temperature.

The measurement results are summarized in Table 9.

[0231]

[Table 9] As is clear from Table 9, it is recognized that the laminated glasses according to the examples of the present invention all have excellent sound insulation performance over a wide temperature range.

Production Examples Reference Examples 1 and 2 are production examples of polyvinyl acetal resins in which 90% or more of the distribution of the degree of acetalization is within the range of −2 mol% and +2 mol% of the average value of the degree of acetalization. . In addition, Examples of production of polyvinyl acetal resin in which 10 to 30% of the distribution of the degree of acetalization are present in the range of -10 mol% or less and +10 mol% or more of the average value of the degree of acetalization are given as Reference Examples 3 and 4. .

Reference Example 1 To 2900 g of pure water, 193 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 98.9 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 5 ° C., and 35 wt% hydrochloric acid 20
1 g and 192 g of n-hexyl aldehyde were added to precipitate polyvinyl acetal. Then, the reaction system was kept at a temperature of 35 ° C. for 5 hours to complete the reaction. Unreacted aldehyde was washed away by washing with excess water, the hydrochloric acid catalyst was neutralized, the salt was removed, and the product was dried to obtain a white powder of the polyvinyl acetal resin.

The polyvinyl acetal resin had an acetalization degree of 64.0 mol% and a distribution of the acetalization degree of 9%.
4% was within the range of -2 mol% and +2 mol% of the average value of the degree of acetalization.

The distribution of the degree of acetalization of the polyvinyl acetal resin was determined by using liquid chromatography as follows.

First, a polar liquid (eg, water) is used as an eluent.
To the column. Then, the polyvinyl acetal resin was completely dissolved in a solvent such as ethanol and injected into the column, and the resin portion with high polarity (low acetalization degree portion)
Only leaked and detected. After that, gradually decrease the polarity of the eluent (for example, water → ethanol → ethyl acetate →
..), it is possible to sequentially detect and flow a portion having a lower polarity (a portion having a higher acetalization degree). Finally, by flowing a non-polar liquid (for example, toluene), it is possible to detect all outflow even to the less polar resin portion (high acetalization degree portion), and obtain the acetalization degree distribution from these sequentially obtained fractions. You can

Reference Example 2 Polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 87.
8 mol% and changed n-hexyl aldehyde to n-
Instead of butyraldehyde, a white powder of polyvinyl acetal resin was obtained by the same operation as in Reference Example 1.

The polyvinyl acetal resin has an acetalization degree of 57.2 mol% and a distribution of the acetalization degree of 9%.
2% was within the range of -2 mol% and +2 mol% of the average value of the degree of acetalization.

Reference Example 3 To 2900 g of pure water, 193 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 98.9 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 32 ° C., and 35 wt% hydrochloric acid 2
The polyvinyl acetal was deposited by adding 01 g and 192 g of n-hexyl aldehyde. Then, the reaction system was kept at a temperature of 35 ° C. for 5 hours to complete the reaction. Unreacted aldehyde was washed away by washing with excess water, the hydrochloric acid catalyst was neutralized, the salt was removed, and the product was dried to obtain a white powder of the polyvinyl acetal resin.

This polyvinyl acetal resin has an acetalization degree of 62.9 mol% and a distribution of the acetalization degree of 1
9% was -10 mol% or less of the average value of the degree of acetalization, and 12% of the distribution of the degree of acetalization was 10 mol% or more of the average value of the degree of acetalization.

Reference Example 4 Polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 87.
8 mol% and changed n-hexyl aldehyde to n-
By changing to butyraldehyde, the temperature of the reaction system was adjusted to 40 ° C., and a white powder of a polyvinyl acetal resin was obtained by the same operation as in Reference Example 1.

The polyvinyl acetal resin has an acetalization degree of 56.9 mol% and a distribution of the acetalization degree of 2%.
0% was -10 mol% or less of the average value of the degree of acetalization, and 10% of the distribution of the degree of acetalization was 10 mol% or more of the average value of the degree of acetalization.

[0243]

The first interlayer film for laminated glass according to the present invention comprises a plasticized polyvinyl acetal resin (acetal group having 4 to 6 carbon atoms and residual acetyl group content of 8 to 30 mol%). At least one layer (A) consisting of
And at least one layer (B) consisting of a plasticized polyvinyl acetal resin (B) in which the acetal group has 3 to 4 carbon atoms and the residual acetyl group content is 4 mol% or less. Therefore, the sound energy is effectively converted into heat energy and absorbed, and in particular, it is possible to effectively prevent the sound insulation performance from being deteriorated by the coincidence effect in the middle and high range near 2000 Hz. Therefore, the TL value can be increased by relaxing the coincidence effect without impairing the basic performance required for laminated glass such as transparency, weather resistance, impact energy absorption, adhesiveness at the resin layer interface, and contact with the glass plate. Therefore, excellent sound insulation performance can be exhibited.

In the second interlayer film for laminated glass according to the present invention, the polyvinyl acetal resin (A) is a resin having a standard deviation σ of the amount of ethylene groups bonded with acetyl groups of 0.8 or less. It is possible to obtain an interlayer film for a laminated glass which has a maximum temperature of sound insulation performance around room temperature and has a large maximum value of sound insulation performance.

In the third interlayer film for laminated glass according to the present invention, the polyvinyl acetal resin (A) is a resin in which the standard deviation σ of the amount of ethylene groups having acetyl groups bonded is 2.5 to 8. It is possible to obtain an interlayer film for laminated glass which has a maximum sound insulation performance temperature in a wide temperature range and has a large maximum sound insulation performance value.

The fourth interlayer film for laminated glass according to the present invention has a polyvinyl acetal resin (A) having a molecular weight distribution ratio (weight average molecular weight Mw / number average molecular weight Mn) of 1.01 to
Since it is 1.50, it is possible to obtain an interlayer film for laminated glass which exhibits excellent sound insulation properties exceeding the Ts-35 class in the sound insulation class according to JIS A4706.

In the fifth interlayer film for laminated glass according to the present invention, the polyvinyl acetal resin (A) has a molecular weight distribution ratio (weight average molecular weight Mw / number average molecular weight Mn) of 3.5 to 20.
Therefore, it is possible to obtain an interlayer film for laminated glass that exhibits good sound insulation over a wide temperature range.

In the sixth interlayer film according to the present invention, at least the outermost layer of the layers constituting the laminated film, which is required to have weather resistance, absorbs an ultraviolet absorber having an effective ultraviolet absorption wavelength of 300 to 340 nm. Since the interlayer film is composed of the layer (B) contained so that the coefficient X is 0.01 or more, the interlayer film has excellent weather resistance and also has a good processability of the interlayer film for the conventional polyvinyl butyral type interlayer film. Can be equivalent to that of.

In the seventh interlayer film according to the present invention, since the polyvinyl acetal resin (A) is a polyvinyl acetal resin having a high blocking property, it is excellent in that it can effectively convert sound energy into heat energy in a wide temperature range. A sound insulating interlayer film is obtained.

In the eighth interlayer film according to the present invention, since the polyvinyl acetal resin (A) is a polyvinyl acetal resin having high randomness, it has good fluidity and can convert sound energy into heat energy more effectively. An excellent sound insulating interlayer film can be obtained.

[Brief description of drawings]

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

Claims (8)

[Claims] 1. An acetal group having 4 to 6 carbon atoms,
Moreover, the mole fraction of the average value of the amount of ethylene groups having acetyl groups bonded to the total amount of ethylene groups of the main chain is 8 to 30.
At least one layer (A) comprising a polyvinyl acetal resin (A) and a plasticizer in a mol%, and an acetal group having 3 to 4 carbon atoms and an acetyl group-bonded ethylene group amount of Laminated glass obtained by laminating a polyvinyl acetal resin (B) having an average value of 4 mol% or less with respect to the total amount of ethylene groups in the main chain and at least one layer (B) containing a plasticizer. Intermediate film. 2. The polyvinyl acetal resin (A) has a standard deviation σ of the amount of ethylene groups to which an acetyl group is bonded is 0.
The interlayer film for laminated glass according to claim 1, which is a resin having 8 or less. 3. The polyvinyl acetal resin (A) has a standard deviation σ of the amount of ethylene groups having an acetyl group bonded to 2.
The interlayer film for laminated glass according to claim 1, which is 5 to 8. 4. The polyvinyl acetal resin (A) has a molecular weight distribution ratio (weight average molecular weight Mw / number average molecular weight Mn).
The interlayer film for laminated glass according to claim 1, having 1.01 to 1.50. 5. The polyvinyl acetal resin (A) has a molecular weight distribution ratio (weight average molecular weight Mw / number average molecular weight Mn).
The interlayer film for laminated glass according to claim 1, having 3.5 to 20. 6. The effective ultraviolet absorption wavelength of at least the outermost layer on the side requiring weather resistance of the plurality of laminated layers is 30.
The UV absorption coefficient X of 0 to 340 nm
The interlayer film for laminated glass according to claim 1, wherein the interlayer film is composed of a layer (B) contained so as to be 0.01 or more. 7. The interlayer film for laminated glass according to claim 1, wherein the polyvinyl acetal resin (A) has a degree of blocking Y0.15 to 0.40 defined below for an ethylene group to which an acetyl group is bonded: Blocking Degree Y = 0.5 × S / (T × U) Here, S, T, and U in the formula are respectively —CH (OH) −.
CH ₂ — (OCOCH ₃ ) CH—the amount of methylene groups in the structure (S),
It represents the amount of hydroxyl groups (T) and the amount of acetyl groups (U). 8. The interlayer film for laminated glass according to claim 1, wherein the polyvinyl acetal resin (A) has a degree of blocking Y0.55 to 0.90 defined below of an ethylene group to which an acetyl group is bonded: Blocking Degree Y = 0.5 × S / (T × U) Here, S, T, and U in the formula are respectively —CH (OH) −.
CH ₂ — (OCOCH ₃ ) CH—the amount of methylene groups in the structure (S),
It represents the amount of hydroxyl groups (T) and the amount of acetyl groups (U).