JPH06115981A - Interlayer for laminated glass - Google Patents

Abstract

PURPOSE:To provide an interlayer for a laminated glass, reduced only in adhesive force between the interlayer membrane and the glass without reducing the elemental physical properties of the conventional interlayer for a laminated glass, e.g. fluidity, viscoelastic properties and penetration resistance and stably exhibiting an excellent transparency and moisture resistance for a long period. CONSTITUTION:This interlayer is composed of a multi-ply laminated membrane having a structure of adhesive layer/core layer/adhesive layer. The adhesive layer is composed of a polyvinyl butyral having 80 to 95mol.% acetalization degree and a plasticizer, and the core layer has a single or plural layer structure composed of one or more kinds of resins selected from a methacrylate resin, a cellulose-based resin, a polyurethane and an ethylene-vinyl acetate copolymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated glass used for window glass of transportation vehicles such as automobiles and window glass of buildings. More specifically, it exhibits excellent moisture resistance for a long period of time. The present invention relates to an interlayer film for laminated glass, which has no fear of whitening due to moisture absorption.

[0002]

2. Description of the Related Art Generally, a laminated glass formed by sandwiching a resin film between two sheets of glass is excellent in safety because fragments are not scattered at the time of breakage.
Widely used in window glass for construction. Of these interlayer films for laminated glass, the polyvinyl butyral resin film plasticized by the addition of a plasticizer has excellent adhesiveness with glass, tough tensile strength, and high transparency. The laminated glass constructed is used in particular as safety glass for vehicles.

One of the reasons why plasticized polyvinyl butyral resin films are used in these applications is their excellent adhesion to metals and glass. The excellent adhesiveness is due to the fact that the polyvinyl butyral resin has essentially many hydroxyl groups. However, the hydroxyl group of the polyvinyl butyral resin, on the other hand, causes excessive moisture absorption under high humidity, which also causes deterioration of mechanical strength and deterioration of weather resistance due to water swelling of the resin. In particular, moisture absorption causes the film to whiten, which is extremely dangerous because it significantly reduces the visual field when the vehicle is operating.

The main causative agent of the film whitening due to the moisture absorption is an adhesive force adjusting agent used for reducing the excessive adhesive force between the film and the glass, for example, JP-A-50-12131.
1, JP-A-57-23648, JP-A-60-21055
It is known to be a metal salt as shown in 1 and the like.

[0005]

Conventionally, various adhesive strength control agents have been studied in order to suppress whitening of the polyvinyl butyral resin film due to moisture absorption as much as possible, but a fundamental solution to this problem has not yet been solved. Not done. The reason is that it was not possible to reduce only the adhesive force without changing the physical properties of the film.

As a countermeasure against this, structural measures have been taken to prevent moisture from entering from the outside when the resin is used on the peripheral end surface of the windshield. However, in recent years, in order to simplify the automobile manufacturing process, a flush mount method has been generally adopted in which the end face treatment of the windshield is not performed and the glass is directly adhered to the vehicle with an adhesive. Therefore, whitening of the interlayer film due to moisture absorption has become a serious problem in recent years.

In view of the above-mentioned drawbacks of the prior art, the present invention provides a conventional interlayer film for laminated glass, which does not impair the basic physical properties such as fluidity, viscoelasticity, and resistance to cold frost, and the like. It is an object of the present invention to provide an interlayer film for laminated glass, which has a low adhesive strength and is stable and has long-term transparency and moisture resistance.

[0008]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have used an adhesive layer made of polyvinyl butyral resin having a high degree of acetalization as the outermost layer in contact with the glass surface. This makes it possible to sandwich the core layer, which has the adhesive strength necessary for bonding the interlayer film and glass, and which is highly adhesive with the polyvinyl butyral resin, without using an adhesive modifier for the metal salt that causes whitening. As a result, it has been found that an intermediate film can be obtained which maintains mechanical properties and can stably maintain transparency and moisture resistance for a long period of time, and completed the present invention.

The interlayer film for laminated glass according to the present invention comprises a multilayer laminated film of adhesive layer / core layer / adhesive layer, the adhesive layer comprising polyvinyl butyral having an acetalization degree of 80 to 95 mol% and a plasticizer. The layer is characterized in that it is a single layer or multiple layers made of at least one resin selected from methacrylate resins, cellulose resins, polyurethane and ethylene vinyl acetate copolymer.

In the interlayer film for laminated glass according to the present invention, both outer layers contacting the glass plate are adhesive layers made of plasticized polyvinyl butyral resin.

The polyvinyl butyral resin is obtained by butyralizing polyvinyl alcohol with an aldehyde, and usually has a butyral 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 polyvinyl butyral resin, is preferably 8
It is from 00 to 3000. This is because if the degree of polymerization is less than 800, the laminated glass is poor in penetration resistance, and if it exceeds 3000, the strength is too large to be normally used as a safety glass. More preferable degree of polymerization is 1000 to 250.
It is 0. The saponification degree of polyvinyl alcohol is
In order to have good transparency, heat resistance and weather resistance, 95
It is desirable that the content is mol% or more.

As a method of obtaining a highly acetalized polyvinyl butyral resin having an acetalization degree of about 80 to 95 mol%, for example, a solvent containing DMSO, toluene, xylene, carbon tetrachloride or the like in an amount of 30 wt% or more is used as a reaction solvent. Then, polyvinyl alcohol was dissolved in a solvent, and the obtained polyvinyl alcohol solution was kept at a predetermined temperature, and then an aldehyde and a catalyst were added thereto to proceed an acetalization reaction, and then the reaction solution was kept at a high temperature at a predetermined temperature. After neutralizing, washing with water, through various steps of drying, to obtain a polyvinyl butyral resin powder, or polyvinyl alcohol is dissolved in hot water, and the resulting polyvinyl alcohol aqueous solution is held at a predetermined temperature, and then aldehyde and A catalyst is added to promote the acetalization reaction, and the acetalization degree exceeds 50 mol%. In step, as a reaction solvent, DMS
Using a solvent containing O, toluene, xylene, carbon tetrachloride, etc. in an amount of 30% by weight or more, the reaction is allowed to proceed at a reaction temperature of 55 ° C. or more, and then the reaction solution is kept at a high temperature and then neutralized, washed with water and dried. There is a method of obtaining a polyvinyl butyral resin powder through the above steps.

The degree of acetalization of polyvinyl butyral is 80 mol% to 95%. A polyvinyl butyral film having an acetalization degree of 80 mol% or less cannot usually be used as an intermediate film of safety glass because the adhesion between the film and glass is too strong. If the degree of acetalization exceeds 95 mol%, the required adhesive strength cannot be obtained because the amount of hydroxyl groups that contribute to adhesion is small.

As the plasticizer to be blended with polyvinyl butyral, 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. To be

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). A glycol-based ester obtained by a reaction with an organic acid such as decyl acid is preferred. In addition, esters of tetraethylene glycol and tripropylene glycol with the above organic acids are also used.

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

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

Particularly 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 content of the plasticizer in the polyvinyl butyral resin is preferably 5 to 100 parts by weight of the resin.
80 parts by weight. If the content of the plasticizer is less than 5 parts by weight, the penetration resistance will decrease, and if it exceeds 80 parts by weight, the plasticizer will bleed out and lose the transparency of the laminated glass or the adhesiveness of the glass plate. There is. A particularly suitable range of the content of the plasticizer is 10 to 50 parts by weight with respect to 100 parts by weight of the polyvinyl butyral resin.

In the interlayer film according to the present invention, an ultraviolet absorber (i) usually used for improving the weather resistance of each polyvinyl butyral resin layer, a stabilizer (ii) for preventing the deterioration of polyvinyl butyral, and an ultraviolet ray. UV stabilizer for improving the stability of the resin layer against (iii), antioxidant for improving the thermal stability of the resin layer (iv), etc., when mixing polyvinyl butyral and a plasticizer, or polyvinyl butyral In the manufacturing process, it is added as needed.

(I) As the ultraviolet absorber, an ultraviolet absorber having an effective ultraviolet absorption wavelength of 300 to 340 nm is preferable. Ultraviolet absorbers are 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.

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

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 butyral 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.

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

(Iii) As the UV stabilizer, hindered amine type or metal complex salt type UV 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 and nickel bis [o-ethyl-3,5 are used. -(Di-t-butyl-4-hydroxybenzyl)] phosphate, cobalt dicyclohexyldithiophosphate,
[1-Phenyl-3-methyl-4-decanoyl-pyrazolate (5) ₂ ] nickel and the like are exemplified.

The ultraviolet stabilizer is preferably added in an amount of 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.

(Iv) Phenol-based antioxidants
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.

The resin constituting the interlayer film of the present invention does not contain any adhesive strength adjusting agent usually used for adjusting the adhesive strength between the resin film and the glass plate. The reason is that this kind of additive causes a remarkable whitening phenomenon in the resin film when the resin absorbs moisture. The term "adhesion modifier" as used herein refers to a metal salt of a carboxylic acid, for example, an alkali metal salt such as octylic acid, hexylic acid, butyric acid, acetic acid, or formic acid, such as potassium or sodium; , Zinc, cobalt salts and the like.

The resin constituting the core layer is preferably one having a film refractive index in the range of 1.460 to 1.510 and a light transmittance of 75% or more. If the refractive index is out of this range, optical distortion with the polyvinyl butyral film forming the adhesive layer may occur. Further, the core layer needs to have good adhesiveness to the adhesive layer. The resin having such requirements is selected from a methacrylate resin, a cellulose resin, polyurethane, and ethylene vinyl acetate copolymer.

The methacrylate resin is a homopolymer of methyl methacrylate or a copolymer of methyl methacrylate and another acrylate. The copolymerization ratio is not particularly limited as long as the transparency of the resin is maintained. The molecular weight of the methacrylate resin is 1
0 ³ to 10 ⁵ , tensile breaking strength 300 to 800 (kg
/ Cm ^-2 ) is preferred.

The cellulosic resin is cellulose acetate, ethyl cellulose, methyl cellulose, nitrocellulose, acetylbutyl cellulose, propionyl cellulose or the like. As a cellulosic resin, the molecular weight is 10
^{3-10 5,} tensile break strength 200 to 600 (kg /
Those having a cm ⁻² ) are preferable. As the plasticizer added to the cellulosic resin, for example, camphor, dimethyl phthalate, diethyl phthalate, dibutyl phthalate or the like is used. A particularly suitable range of the content of the plasticizer is
It is 5 to 50 parts by weight with respect to 100 parts by weight of the resin.

The polyol component constituting the polyurethane is, for example, polyether polyol, polyester polyol, polycarbonate polyol, etc., and the isocyanate component is toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, ethylene diisocyanate and their derivatives. Polyurethane has a molecular weight of 10 ³ to 1
0 ⁵ , tensile rupture stress 400 to 700 (kg / c
Those having m ^-2 ) are preferred.

As the ethylene vinyl acetate copolymer,
Molecular weight 10 ³ to 10 ⁵ , tensile breaking strength 50 to 250
Those having (kg / cm ⁻² ) are preferable. The copolymerization ratio is not particularly limited as long as it maintains the transparency of the resin.

The laminated structure of the intermediate film is adhesive layer / core layer / adhesive layer. The core layer may be a single layer or multiple layers. In the former case, the laminated structure is a three-layer laminated structure of adhesive layer / core layer / adhesive layer, and in the latter case, the laminated structure is adhesive layer / core layer /
It is a multilayer laminated structure of a core layer / adhesive layer.

The thickness of each of the adhesive layer and the core layer is usually 1 μm.
m or more, and preferably 5 μm to 2 mm for practical use.

The thickness of the intermediate film is preferably in the range of 0.2 to 1.6 mm, like the thickness of an ordinary intermediate film for laminated glass. This thickness is more preferably 0.3 to 1.2 mm from the practical point of view, considering the strength for securing impact resistance as a laminated glass and performance of penetration resistance.
Is the range.

As a resin film-forming method, for example, polyvinyl butyral plasticized by adding a plasticizer is dissolved in a solvent, the solution is applied by a coater to form a film, and then the film is dried. There is a method to obtain a film. Not limited to this method, the film can be formed by extrusion molding, calender molding, or the like.

As another film forming method, a solution containing polyvinyl butyral and a plasticizer is applied to a core layer or a glass plate, and the obtained coating film is dried to form an adhesive layer, or multi-layer extrusion. A method of obtaining the above-mentioned laminated constitution film of the adhesive layer and the core layer by a molding method, and sandwiching this with a pair of glass plates to adhere the layers to each other is appropriately adopted. Since the adhesive layer of the intermediate film formed by these film forming methods is completely dissolved in the adhesive layer, peeling between resin layers does not occur.

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, the adhesive layer and the core layer are stacked in the above-mentioned laminated structure, the obtained multilayer laminated structure is sandwiched from both sides with glass plates, and the unpressed sandwich is degassed to produce laminated glass by hot pressing. To do.

[0046]

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 method of measuring the degree of acetalization of polyvinyl butyral resin is carried out by the proton nuclear magnetic resonance spectrum (NM
R) was performed by the following method. That is, benzene
A 2 wt% polyvinyl butyral resin solution in dimethylsulfoxide (9: 1) was prepared, a small amount of tetramethylsilane [(CH ₃ ) ₄ Si] was added as a standard substance, and the spectrum was measured at a temperature of 70 ° C.

Example 1 <Preparation of polyvinyl butyral resin> Step i) To 2900 g of pure water, 198 g of polyvinyl alcohol having a polymerization degree of 1700 and a saponification degree of 99.2 mol% was added and dissolved by heating. The temperature of the reaction system was adjusted to 30 ° C., and 196 g of 35 wt% hydrochloric acid and 135 g of n-butyraldehyde were added to precipitate polyvinyl butyral. 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, salts were removed, and after drying,
A white powder of polyvinyl butyral resin was obtained.

Step ii) Next, 60 g of this polyvinyl butyral resin was dissolved in 1768 g of xylene at 25 ° C. Thereafter, 115 g of a 35 wt% hydrochloric acid solution and 95 g of n-butyraldehyde were added as follows. First n-
After adding butyraldehyde to the solution all at once, the mixture was thoroughly mixed by stirring for about 5 minutes, and then hydrochloric acid was added by a dropping funnel over about 15 minutes and mixed. About 30 minutes after mixing these, the whole system was heated to 60 ° C over 60 minutes at a rate of 0.5 to 0.6 ° C / minute. Then, the reaction system was kept at 60 ° C. for 3 hours to complete the reaction.

After completion of the reaction, water / methanol (mixing ratio 1: 1) in which baking soda (60% by weight based on resin solid content) was dissolved was added to the reaction mixture in a large excess to separate the catalyst and neutralize the resin. . Then, this resin was dropped into a large excess of methanol to reprecipitate the resin, and the precipitate was washed with water and dried to obtain a white powder of polyvinyl butyral resin.

The butyralization degree of this polyvinyl butyral resin was 85 mol%.

<Preparation of Resin Film for Adhesive Layer> 50 g of the above polyvinyl butyral was sampled, 15 g of triethylene glycol-di-2-ethylbutyrate as a plasticizer was added thereto, and this mixture was sufficiently kneaded with a mixing roll. did. Next, 0.08 g of BHT as an antioxidant and 0.08 g of Tinuvin Pwo of Ciba-Geigy Co., Ltd. as an ultraviolet absorber were added to the kneaded product, and a predetermined amount of the kneaded product was kept at 150 ° C. for 30 minutes with a press molding machine. did. Thus, a resin film having a thickness of 0.20 mm was obtained.

<Preparation of resin film for core layer> Polyurethane "Peresen 2102-90A" manufactured by MDC Kasei Co., Ltd.
E "(tensile strength at yield point 530 kg / cm ² , elongation at break 500%) at a temperature of 150 ° C for 3 times with a press molding machine.
Hold for 0 minutes. Thus, a polyurethane resin film for the core layer having a refractive index of 1.501 and a thickness of 0.52 mm was obtained.

<Production of laminated glass> Polyvinyl butyra
Two sheets of resin obtained from polyurethane resin
The single layer obtained from
Resin adhesive layer / polyurethane resin core layer / polyvinyl
Overlap so that the butyral resin adhesive layer becomes 3
A laminated interlayer film of layers was obtained. Each side of this intermediate film is 10
2 pieces of float glass with a thickness of 3 mm in a square of cm on both sides
Sandwich from this unbonded sandwich body with rubber
Put in a bag and evacuate for 20 minutes at 20 torr vacuum
Then, transfer it to an oven at 90 ° C in a degassed state, and
Was held for 30 minutes. In this way temporary adhesion by vacuum press
The sandwich is then pressured in an autoclave.
12 kg / cm ², Thermocompression-bonded at a temperature of 135 ℃
A laminated glass was produced.

Example 2 <Preparation of polyvinyl butyral resin> In the step i) of Example 1, the acetalization degree of 8 was obtained by the same procedure as in Example 1 except that the charged amount of n-butyraldehyde was changed.
8 mol% of polyvinyl butyral resin was obtained.

<Preparation of Adhesive Layer Resin Film> The same operation as in the preparation of the film of Example 1 was performed to obtain an adhesive layer resin film having the plasticizer content and film thickness shown in Table 1.

<Preparation of resin film for core layer> Cellulose resin “ACETI 560” manufactured by Art Plus Co., Ltd. (tensile breaking strength 210 kg / cm ² , yield strength 200 kg)
/ Cm ² ) and 10 parts by weight of dimethyl phthalate as a plasticizer was added to 100 parts by weight of the resin.

The operation was performed in the same manner as in the preparation of the film of Example 1 except that the pressing temperature was set in the range of 150 to 200 ° C., and a resin film for core layer having the refractive index and the film thickness shown in Table 1 was obtained. It was

<Production of Laminated Glass> The same operation as in the production of laminated glass of Example 1 was performed.

Example 3 <Preparation of polyvinyl butyral resin> In step i) of Example 1, the acetalization degree of 8 was obtained by the same operation as in Example 1 except that the charged amount of n-butyraldehyde was changed.
9 mol% of polyvinyl butyral resin was obtained.

<Preparation of Adhesive Layer Resin Film> The same operation as in the preparation of the film of Example 1 was carried out to obtain an adhesive layer resin film having the plasticizer content and film thickness shown in Table 1.

<Preparation of resin film for core layer> Methacrylate resin "Delpet SR62" manufactured by Asahi Kasei Corporation
00 "(tensile break strength 450 kg / cm ² , yield strength 520 kg / cm ² were used.

The operation was performed in the same manner as in the preparation of the film of Example 1 except that the pressing temperature was set in the range of 150 to 200 ° C., and a resin film for core layer having the refractive index and the film thickness shown in Table 1 was obtained. It was

<Production of Laminated Glass> The same operation as in the production of laminated glass of Example 1 was performed.

Example 4 <Preparation of polyvinyl butyral resin> In step i) of Example 1, the acetalization degree of 9 was obtained by the same operation as in Example 1 except that the charged amount of n-butyraldehyde was changed.
2 mol% polyvinyl butyral resin was obtained.

<Preparation of Resin Film for Adhesive Layer> The same operation as in the preparation of the film of Example 1 was performed to obtain a resin film for adhesive layer having the plasticizer content and film thickness shown in Table 1.

<Preparation of resin film for core layer> As an ethylene-vinyl acetate copolymer, "SHOREX EVA EM21-1" manufactured by Showa Denko KK (tensile breaking strength 150 kg)
/ Cm ² ) was used.

The operation is performed in the same manner as in the preparation of the film of Example 1 except that the pressing temperature is set in the range of 150 to 200 ° C., and a resin film for core layer having the refractive index and the film thickness shown in Table 1 is obtained. It was

<Production of Laminated Glass> The same operation as in the production of laminated glass of Example 1 was performed.

Comparative Example 1 <Preparation of Polyvinyl Butyral Resin> By the same operation as in Example 1, a polyvinyl butyral resin having an acetalization degree of 85 mol% was obtained.

<Preparation of Adhesive Layer Resin Film> The same operation as in the preparation of the film of Example 1 was carried out to obtain an adhesive layer resin film having the plasticizer content and film thickness shown in Table 1.

<Preparation of resin film for core layer> In step i) of Example 1, the acetalization degree of 6 was obtained by the same operation as in Example 1 except that the charged amount of n-butyraldehyde was changed.
A 5 mol% polyvinyl butyral resin was obtained. Preparation of the film of Example 1 except that 40 parts by weight of a plasticizer triethylene glycol-di-2-ethylbutyrate was added to this resin, and 0.05 g of potassium acetate was added as an adhesiveness modifier in the plasticizer kneading step. By the same operation as above, a resin film for core layer having the refractive index and the film thickness shown in Table 1 was obtained.

<Production of Laminated Glass> The same operation as the production of laminated glass of Example 1 was performed.

Comparative Example 2 <Preparation of polyvinyl butyral resin> In step i) of Example 1, the acetalization degree of 6 was obtained by the same procedure as in Example 1 except that the charged amount of n-butyraldehyde was changed.
A 5 mol% polyvinyl butyral resin was obtained.

<Preparation of Resin Film for Adhesive Layer> This polyvinyl butyral resin was mixed with the plasticizer triethylene glycol-di-
2-ethylbutyrate was added in an amount of 40 parts by weight, and the same operation as in the preparation of the film of Example 1 was performed, except that 0.05 g of potassium acetate was added as an adhesiveness adjusting agent in the plasticizer kneading step,
Resin films for adhesive layers having the plasticizer contents and film thicknesses shown in Table 1 were obtained.

<Preparation of resin film for core layer> By the same operation as in Example 1, a polyurethane resin film for core layer having a refractive index of 1.501 and a thickness of 0.40 mm was obtained.

<Production of Laminated Glass> The same operation as the production of laminated glass of Example 1 was performed.

Comparative Example 3 <Preparation of polyvinyl butyral resin> In step i) of Example 1, the acetalization degree of 6 was obtained by the same procedure as in Example 1 except that the charged amount of n-butyraldehyde was changed.
A 5 mol% polyvinyl butyral resin was obtained.

<Preparation of Resin Film for Adhesive Layer> This polyvinyl butyral resin was mixed with the plasticizer triethylene glycol-di-
Preparation of the membrane of Example 1 except that 40 parts by weight of 2-ethylbutyrate was not added (no addition of the adhesion modifier), the same operation as in the preparation of the membrane of Example 1 was carried out, and the plasticizer content shown in Table 1 was used. A resin film for an adhesive layer having the following thickness was obtained.

<Preparation of resin film for core layer> By the same operation as in Example 1, a polyurethane resin film for core layer having a refractive index of 1.501 and a thickness of 0.40 mm was obtained.

<Production of Laminated Glass> The same operation as the production of laminated glass of Example 1 was performed.

Comparative Example 4 In the production of the laminated glass of Example 1, one film obtained from a polyvinyl butyral resin having a butyralization degree of 85 mol% and obtained in the same manner and two films obtained from a polyurethane resin were used. The same procedure as in Example 1 except that the film and the film were laminated so that the laminated structure was a polyurethane resin adhesive layer / polyvinyl butyral resin core layer / polyurethane resin adhesive layer to obtain a three-layer laminated intermediate film. The operation was performed.

Comparative Example 5 The same operation as in Example 1 was carried out except that a polyvinyl chloride resin having the refractive index and the film thickness shown in Table 1 was used as the resin film for the core layer.

Comparative Example 6 In the production of the laminated glass of Example 1, one film obtained from the polyvinyl butyral resin having a butyralization degree of 85 mol% obtained in the same manner and the methacrylic resin used in Example 3 The two layers obtained from the above are laminated in a methacrylic resin adhesive layer / polyvinyl butyral resin core layer /
Overlap to form a methacrylic resin adhesive layer,
The same operation as in Example 1 was performed except that a three-layer laminated interlayer film was obtained.

Comparative Example 7 A polyvinyl butyral resin having an acetalization degree of 92 mol% obtained in the same manner as in Example 4 was formed into a film, and a laminated glass was prepared using an intermediate film composed of only one film.

Performance Test For each laminated glass obtained in the above Examples and Comparative Examples, the physical properties of the interlayer film were measured by the following methods.

(1) Water resistance Five pieces of laminated glass test pieces (300 mm × 300 mm) were used.
It was kept for 4 weeks under the conditions of 0 ± 3 ° C. and 85 ± 3% relative humidity, then taken out, and the whitening distance from the edge of the laminated glass, the peeling distance of the glass / film, and the adhesion test of the edge were performed.
Three measurements were made for each sample.

[Whitening distance] After holding the laminated glass test piece for 4 weeks under the above conditions, the whitening distance from the end of the test piece was measured with the naked eye.

[Peeling distance] After holding the laminated glass test piece for 4 weeks under the above-mentioned conditions, the presence or absence of peeling between the glass plate and the intermediate film at the edge of the test piece was examined. The maximum distance of peeling from the part was measured as the peeling distance.

[Adhesive Strength of Edge] According to the Pummel test, the adhesive strength of the edge of the laminated glass was measured by the following method. After the laminated glass test piece was cooled to −18 ° C. for 2 hours or more at a constant temperature, it was crushed with a 0.5-pound iron hammer on a supporting iron plate capable of holding an angle of 45 degrees, and the glass adhered state, that is, the glass film. The presence or absence of a portion not attached to the was examined. If there is a non-adhesive part on the glass, the maximum distance of the non-adhesive part on the entire circumference is "distance with no adhesive force"
Was measured as.

(2) Peel strength An interlayer film having a thickness of 0.48 mm and a thickness of 0.05 to 0.1 mm
300mm x 300mm with the polyester film of
The laminated glass was prepared by sandwiching the glass plates with a thickness of 2.5 mm and applying heat and pressure. This laminated glass test piece was heated to a temperature of 2
After conditioning at 0 ° C. for 4 hours or more, a tensile tester (Tensilon) was used to peel the interlayer film from the glass plate at a peeling speed of 500 mm / min, and the peel strength at that time was measured.

(3) Optical characteristics: An interlayer film having a thickness of 0.48 mm is set to 300 mm × 300 mm,
The laminated glass was prepared by sandwiching it with a plate glass having a thickness of 2.5 mm and applying heat and pressure. The light transmittance of the test piece of this laminated glass was measured based on JIS-K7105 "Plastic optical property test method".

(4) Penetration resistance An interlayer film having a thickness of 0.48 mm is 300 mm × 300 mm,
The laminated glass was prepared by sandwiching it with a plate glass having a thickness of 2.5 mm and applying heat and pressure. The edge of the laminated glass test piece was fixed to a supporting frame, which was held horizontally, and then 2.2 from the top.
A 6 kg steel ball was allowed to fall freely in the center of the test piece. The height at which the steel ball was dropped was changed by 0.5 m, and the test was repeated at the same height. Obtain the maximum height at which penetration of the steel ball is obstructed at the number of times equivalent to 50% of the number of test pieces, and use the distance between the steel ball and the glass surface at this time as the "average penetration height".
And Therefore, the larger the average penetration height is,
It shows that the penetration resistance is high. This test was carried out while maintaining the temperature of the test piece at 20 ° C.

(5) Light resistance An interlayer film having a thickness of 0.48 mm is prepared as 300 mm × 300 mm,
The laminated glass was prepared by sandwiching it with a plate glass having a thickness of 2.5 mm and applying heat and pressure. With respect to the test piece of the laminated glass, the light resistance was measured based on JIS-3212 “Testing method for automobile safety glass”. That is, 750 ± 5
After placing a glass test piece at a distance of 230 mm from the light source in a device (high-accelerated light resistance test device, manufactured by Iwasaki Electric Co., Ltd.) held at 45 ± 5 ° C with a 0 w quartz glass mercury lamp as the light source, after 2000 hours have passed. The light transmittance in JIS-
It was measured based on K7105 "Plastic optical property test method".

[0095]

[Table 1] As is clear from Table 1, it is recognized that the laminated glass of the examples shows good results in each test item.

[0096]

According to the present invention, only the adhesive force between the film and the glass is reduced without impairing the basic physical properties such as fluidity, viscoelastic property, and cold resistance of the conventional interlayer film for laminated glass.
It is possible to provide an interlayer film for laminated glass which is stable and has excellent transparency and long-term stability.

Claims (1)

[Claims] 1. A multilayer laminated film comprising an adhesive layer / core layer / adhesive layer, the adhesive layer comprising polyvinyl butyral having an acetalization degree of 80 to 95 mol% and a plasticizer, and the core layer comprising a methacrylate resin or a cellulose resin. Resin, polyurethane,
An interlayer film for laminated glass, which is a single layer or multiple layers made of at least one resin selected from ethylene vinyl acetate copolymer.